HomeMy WebLinkAboutCT 03-08; CARLSBAD OFFICE PARK; STANDARD URBAN STORMWATER MANAGEMENT PLAN; 2002-07-28e·:
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CARLSBAD OFFICE PARK
BOURESTON DEVELOPMENT
Site Address:
Northwest' corner . of
Camino Vida Roble and
. Corte Del Nogel in
Carlsbad, California
Standard Urban
Stormwater Management
plan (SUSMP)
Prepared for:
Boureston Development
5500 Trabuco Road, Suite 100
Irvine,. Ca 92620
Prepared by:
[[
ANJON
~NG][NlElER1ING, INC.
895 E. Yorba Li.nda Blvd .• Ste 202 Placentia. CA 92870
.(714)572-6800 FAX(714)572-6850
July 28, 2002
02331
RECEiVED
JUL 0 ~ 2nr"
C\TY OF CARLSBAD
PLANN\NG pEPT.
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TABLE OF CONTENTS
INTRODUCTION
1. Project Description
1.1. Topography and Land Use
2. CHARACTERIZATION OF PROJECT RUNOFF
2.1. Existing and Post-Construction Drainage
2.2. Post-Construction Expected Discharges
2.3. Soil Characteristics
3. :MITIGATION MEASURES TO PROTECT WATER QUALITY
3.1. Construction BMPs
3.2. Post-construction BMPs
3.2.1. Site Design BMPs
3.2.2. Source Control BMPs
3.2.3. Treatment Control BMPs
3.2.3.1. Bio-Filters
3.2.3.1.1. Appropriate Applications and Siting Constraints
3.2.3.2.Continuous Deflective Separation@ Units
3.2.3.2.1. Appropriate Applications and Siting Constraints
4. OPERATION AND MAINTENANCE PROGRAM
4.1. Bio-Filters
4.2. Continuous Deflective Separation@ Units
5. FISCAL RESOURCES
6. SUMMARY/CONCLUSIONS
7. LOCATION MAP
8. PROJECT MAP
9. BMPMAP
10. BMP DATASHEETS
11. APPENDIX A: Stormwater Management Program -Business Best Management
Practices .
12. APPENDIX B: Model Standard Urban Storm Water Mitigation Plan For San Diego
County, Port of San Diego, and Cities in San Diego County
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13. APPENDIX C: Storm Drain System Maintenance Activities
14. APPENDIX D: City of Carlsbad Jurisdictional Urban Runoff Management Plan
15. APPENDIX E: Non-Storm Water Discharge Assessment and Failure to Certify
Notification
16. APPENDIX F: Continuous Deflective Separation: Its Mechani~ms and Applications
17. APPENDIX G: Oil and Grease Removal By Floating Sotbent in a CDS D~vice
18. APPENDIX H: Precast Manhole Models
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lNTRODUCTION
The municipal storm water National Pollutant Discharge Elimination System (NPDES) permit (
Order No. NPDES No. CASOI08758, hereinafter referred to as" Municipal Permit") issued to
San Diego County, the Port of San Diego, and 18 cities (Co-permittees) by the San Diego
Regional Water Quality Control Board (Regional Board) on February 21, 2001, requires the
development planning for public and private projects.
This project falls into a priority project category of"Co:Q11llercial developments greater than
1 00, 000 square feet."
1.0 PROJECT DESCRIPTION
The rectangular-shaped parcel is approximately 4.02 acres and is situated within the Palomar
Airport Business Park at the northwest corner of Camino Via Roble and Corte Del Nogal, in the
City of Carlsbad. The undeveloped site was mass graded with topography of the relatively level
parcel descending in a north to .south direction. The site perimeter has graded slopes of2 to 1
(horizontal to vertical) with a maximum height of about 20 feet for anyone slope. ·These slopes .
are covered with landscaping and irrigated. Drainage swales are provided to control surface
runoff.
The graded pad is sparsely covered with natural vegetation (weeds).
Groups of office buildings are proposed on the 4.02-acre subject parcel. The development will
consist of five, two-story structures with conventional slab-on-grade foundation systems."
Supporting parking will consist of conventional asphalt/concrete pavement.
The hardscape construction is set along the perimeter of the buildings with walkways and
landscape between the buildings. The hardscape and walkways are primarily :porthmd cement
concrete, either stamped or broomed. Landscape will meet the city of Carlsbad requirements,
with water conservation being a recommendation. The landscaping isitrigated by a time-
controlled system and should be placed on a multitude of short time intervals ..
The proposed grading for the development will include minor cut and fill on the pad with
retaining walls required along the perimeter slopes to meet the necessary parking requirements
for the project.
1.1 Topography and Land Use
The project is a small portion of a master-planned commercial/industrial community. The sit~ is
a purchased lot in a specifically zoned, designed and graded hillside area for commercial use .
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2. CHARACTERIZATION OF PROJECT RUNOFF
2.1 Existing and Post-Construction Drainage
The proposed project will not alter drainage patterns ofthe master plan development. This site
does not accept water from adjacent project sites, nor does it propose any drainage to or from
adjacent sites.
Standard engineering practices dictate the direction of the flow of storm water runoff and
irrigation away from any buildings. Sheet flow is at areas such as the asphalt concrete parking
surfaces that will then concentrate at a concrete conveyance device such as a ribbon gutters, and
at curb and gutters.
An onsite drainage system with catch basins and underground storm drain is the collection
system of choice for the conditions of this site.
Storm drain, local area drains, and catch basins through the site will carry the drainage. Because
of handicap access requirements, additional basins are required. These are to keep the grades
high enough to allow access via allowable grades by handicap access codes ami regulations, The
storm drain system collects at a CDS facility located at the south end of the site
Approximately 1.1 acres of open ground will be for commercial buildings and p~vement of an
additional 1.5 acres, thus representing a change of65% to the Impervious area. This change in
land use will increase the composite runoff coefficient, of the project, from C=.2 to C=0 .. 64. In
addition, the peak flow rate will increase 18 cfs under the proposed condition.
Post-construction runoffwill be to a storm drain system. This system will not divert waterfroni
its natural outlet points.
The design of this system is included in the HMP map.
Summaries of the post-construction water quality flows are included iti Table '2.1. The flows
were developed using the 85th Percentile Precipitation map developed by the County, which was
obtained from the website http://www.co.san-diego.ca.us/dpw/landlflood.htm.
T bl 2 1 P t C t ct' W t Q r FI a e . os -ons ru Ion a er ua lty ows
Outfall Tributary Area QI00 QWQ
(acres) (cfs) (cfs)
A 4.0 18.0 1.66
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2.2 Post-Construction JI;xpected Discharges
There is no sampling data available for the existing site condition since it is a vacant site. In
addition, because this is an office environment, the project is not expected to generate significant
amounts of non-visible pollutants. However, the following constituents are commonly found on
similar developments and could affect water quality:
o Sediment discharge due to construction activities and post-construction areas left
bare.
o Nutrients from fertilizers
o Trash and debris deposited in drain inlets.
o Hydrocarbons from paved areas.
o Pesticides from landscaping.
o Pesticides from building maintenance use.
2.3 Soil Characteristics
The project area consists of soil group D. The project will not have slopes steeper than 2:1. All
slopes include slope protection for construction and with perm;ment planting for post--
construction. -
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3.0 MITIGATION MEASURES TO PROTECT WATER QUALITY
To address water quality for the project, BMPs are to be implemented during constru~ion by the
contractor and by the owner/operator for post-construction.
3.1 Construction BMPs
Types of temporary BMPs are listed below, with uses:
General Site
BMP description
Preservation of Existing
Vegetation (ESC02)
Dewatering Operations
Vehicle and Equipment
Maintenance (CA032)
WilIBMP be
used?
No
YES
YES
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If yes, Explain
H no. State Reason
s site is upstream of an
environmentally sensitive area.
Contractor shall develop a schedule
for with this
This is part of a rp.aster
community, and ,has nb true native
vegetation because of mass grading
A possibility of ground water during
wet
Primarily needed for grading
operations:
Upstream of an hn'Vlf()ntlneI1ltaltv
sensitive
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WillBMPbe
used?
Material Delivery and Storage YES
Spill Prevention and Control YES
YES
Contaminated Soil YES
Concrete Waste Management YES
Sanitary/Septic Waste YES
Dust Control (ESC21)
Temporary Stream Crossing
Construction Road
Stabilization \.LJ~,'V .... ,J
Temporary Drains and swales
(ESC3!)
Slope Drains (ESC32)
YES
YES
YES
5
No
No
Anticipated for a construction site
For acciqents
In an event ofa nnc!1:!1h
In an evertt of a possible
Anticipated Use
Generally flat site,
is recommended
Multiple uses. Primarily, it is in a
area.
Not applicable to conditions.
Graded and compacted site with
stable
...,~~.n .... .5 basins and temporary
, swales to them needed for interim
conditions
slopes over 5 exist at site. If
slopes are disturbed,due to'
construction flows. Shall be used to
Outlet exists, is in good
condition .
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Check dams (ESC41)
Straw Bale Barrier (ESC51)
WillBMPbe
used?
YES
No
Sand Bag Barrier (ESC52) Yes
Yes
Sediment Trap (ESC55) No
Sediment Basin (ESC56) No
Erosion control during and after
storms, fencing
with winds
Specific gravity of straw allows
Bales to float in high water
conditions and will clog needed
outlets at critical
Site is of size
various locations is thee preferred
method.
Construction BMPs for this project shall be selected, constructed, and maintained so as to
comply with all applicable ordinances and guidance documents.
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3.2 Post-construction BMPs
Pollutants of concern as noted in section 3 will be addressed through three types ofBMPs. These
types ofBMPs are site design, source control and treatment control.
3.2.1 Site Design BMPs
The project is designed to minimize the use of impervious areas. 65% of the project area will be
impervious. Parking lots and drive aisles are designed to meet the minimum widths. -
Landscaping of the slopes and common areas are incorporated into the plans. The landscaping
will consist of both native and non-native plants. The goal is to achieve plant establishment
expeditiously to reduce erosion.
The irrigation system for these landscaped areas must be monitored to reduce over-watering. -
3.2.2 Source Control BMPs
Source control BMPs will consist of measures to prevent polluted runoff. This program will
include an educational component directed at each owner/tenant. The owner/tenants will receive
a set of brochures developed by the County's Environmental Health Department. These will
include the following:
• Stormwater Runoff Pollution Fact Sheet;
• Stormwater Runoff Pollution Prevention Tips
In addition, storm drain inlets shall be stenciled with a messag~ warning citizens not to dump
pollutants into the drains.
3.2.3 Treatment Control BMPs
The following treatment control BMPs will be implemented to address water quality:
• Continuous Deflective Separation@ Units with sorbent material
• Bio-Filters
Placements of the BMPs are noted on the project plan .
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BMP description
Non-storm water discharges to
drains (SCI)
Over-water Activities (SCI3)
Storm Drain System Signs
Vehicle and Equipment
Vehicle and Equipment
Maintenance
Outdoor LoadingfUnloading of
,Outdoor Container Storage of
Outdoor Storage of Raw
Materials, Products, and By-
Products
Waste Handling and Disposal
Building and Grounds
Maintenance Cl
Contaminated or Erodible
Surface Areas
Building Repair, Remodeling,
and Construction (SC 12)
WilIBMPbe
used?
YES
YES
No
No
No
YES
YES
No
YES
YES
YES
YES
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Catch basins exist on the site
the potential oflandscape water and
other .
Irrigation timers and' landscape
Several functional uses for
Not Applicable
Not Applicable
Not
Move in and move out of offices.
Possible use of liquids at site for
Anticipated use
Ongoing operations
Landscape and modificatiOils for
furore use. '
Ongoing operatlons of the site
expect upgrades and chang~s
the life of the site.
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Illegal Dumping Control
(SC50)
Street Cleaning (SC70)
Will be
used?
YES Enforcement isa concern in all
developments, particularly
commercial
YES Use twice a month for parking lots
to reduce pollutants in storm drain
YES To be used in landscape areas prior
to reaching storm drain system.To
settle out pesticides and ferti1i~ers,
along with irrigation waters at the
of . near
OiVwater separators and water YES Filtration system is being installed
in the continuous deflection system.
See manufacturers speci.fications in
quality inlets (TC7)
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3.2.3.1 Bio-Filters
Bio-filtration swales are vegetated channels that receive directed flow and convey storm water.
Bio-filtration strips, also known as vegetated buffer strips, are vegetated sections ofland over
which storm water flows as overland sheet flow. A schematic illustration ofbio-filter is shown in
Figure 3.3.1.
Pollutants are removed by filtration through the grass, sedimentatioI)., adsorption to soil particles,
and infiltration through the soil. Swales and strips are mainly effective at removing debris and
solid particles, although some dissolved constituents are removed by adsorption onto the soil.
3.2.3.1.1 Appropriate Applications and Siting Constraints:
Swales and strips should be considered wherever site conditions and climate allow vegetation to
be established and where flow velocities are not high enough to cause scour. Even where strips
cannot be sited to accept directed sheet flow, vegetated areas provide treatment of rainfall and
reduce the overall impervious surface.
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FACTORS AFFECTING PRELIMINARY DESIGN:
Swales have two design goals: 1) maximize treatment, 2) provide adequate hydraulic function for
flood routing, adequate drainage and scour prevention. Treatment is maximized by designing the
flow of water through the swale to be as shallow and long as site constraints allow: No
minimum dimensions are required for treatment purposes, as this could exclude swales from
consideration at some sites. Swales should also be sized as a conveyam;:e system calculated
according to County procedures for flood routing and scour.
To maximize treatment efficiency, strips should be designed to be as long (in the direction of
flow) and as flat as the site will allow. No minimum lengths or maximum slopes are required for
treatment purposes. The area to be used for the strip should be free of gullies or rills that can
concentrate overland flow and cause erosion.
Vegetation mixes appropriate for various climates and locations will be developed by District
landscape staff. Table 3.3.1 summarizes preliminary design factors for bio-filtration.
Plan View
,,,~ V
1-";' _._-_._-----.-_._-_._-----.-,.
v V V V \!
0::;-
Vegetated Bwale
/J ./
1\ t· /\ f\ /f\ ;\ " ~~. ~~------~----~------~------~----~~
DrainOLtlet !
Cross Section
_ .. 4 ........ _-.. ...... _ ............... -"" ........ :
Drain OuUeI :::::::~~:O ~~~~ve~~~~d~~~e~~~~. ~. ~~::~
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• Figure 3.3.1
Example ofDio-filter Schematic
Table 3.3.1: Summary OfDio-filtration Design Factors (Strips And Swales)
Description Applications/Siting Preliminary Design Factors
Swales are vegetated channels that • Site conditions • Swales sized as a conveyance
receive and convey storm water. and climate allow system (per CoUnty floqd
Strips are vegetated buffer strips vegetation to be routing and scout procedures)
over which storm water flows as established • Swale water depth as shallow,
, sheet flow. as the site will permit
Treatment Mechanisms: Flow velocities • Strips sized as long (~
• Filtration through the grass • direction of flow) and flat as
• Sedimentation not high enough to the site allows
• Adsorption to soil particles cause scour • Strips shotild be free of gullies
• Infiltration or rills
Pollutants removed: • No minimunrdlmensionsor
• Debris and solid particles slope restrictions for treatment
• Some dissolved constituents purposes
• Vegetation mix'appropriate for
climates and location
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3.2.3.2 Continuous Deflective Separation® Units
The CDS Technology was developed as a gross pollutant trap and is a proprietary product
manufactured under patents by CDS Technologies, Inc. The technology captures and retains
floatables, trash and debris greater than 0.05 inch in stormwater runoff, as well as capture offine
sand and larger particles and the pollutants attached to those particles. The addition of the
recommended floating sorbent to the CDS (preferably a high density sorbent) will also coUectoil
and grease. Refer to Appendix Section 17 for additional information .and statistics on use of
sorbents.
The CDS unit is a non-mechanical self-operating system and will function when there is flow in
the storm drainage system. A cross-section of a CDS unit is shown in Appendix Section 16. The
unit is designed to capture pollutants in flows up to the design capacity and during extreme
rainfall events when the designed capacity may be exceeded. Material captured in the CDS
unit's separation chamber and sump is retained even when the unit's design capacity is exceeded.
3.2.3.2.1 Appropriate Applications and Siting Constraints:
CDS should be considered for implementation wherever site conditions allow.
One important siting requirement is that sufficient head is available so that water stored in the
device does not cause a backwater condition in the storm drain system, which would limit its
capacity .
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• 4.0 OPERATION AND MAINTENANCE PROGRAM
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The operation and maintenance requirements for each type ofBMP is as follows:
4.1 Bio-Filters
The operational and maintenance needs of a Swaleare:
• Vegetation management to maintain adequate hydraulic functioning and to limit
habitat for disease-carrying animals.
• Animal and vector control.
• Periodic sediment removal to optimize performance.
• Trash, debris, grass trimmings, tree pruning, and leaf collection and removal to
prevent obstruction of a Swale and monitoring equipment.
• Removal of standing water, which may contribute to the development of aquatic
plant communities or mosquito breeding areas.
• Removal of graffiti.
• Preventive maintenance on sampling, flow measurement, and associated :aMP
equipment and structures.
• Erosion and structural maintenance to prevent the loss of soil and maintain the
performance of the Swale.
Inspection Frequency
The facility will be inspected and inspection visits will be completely documented:
• Once a month at a minimum.
• After every large storm (after every storm monitored or those storms with more
than 0.50 inch of precipitation.)
• On a weekly basis during extended periods of wet weather.
Aesthetic and Functional Maintenance
Aesthetic maintenance is important for public acceptance of stormwater facilities.
Functional maintenance is important for performance and safety reasons.
Both forms of maintenance will be combined into an overall Stortnwater Management
System Maintenance.
Aesthetic Maintenance
The following activities will be included in the aesthetic maintenance program:
• Graffiti Removal. Graffiti will be removed in a timely manner to improve the
appearance of a Swale and to discourage additional graffiti or other acts of
vandalism.
• Grass Trimming. Trimming of grass will be done on the Swale,around fences, at
the inlet and outlet structures, and sampling structures. . .
• Weed Control. Weeds will be removed through mechanical means. Herbicide will
not be used because these chemicals may impact the water quality monitoring.
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Functional Maintenance
Functional maintenance has two components:
Preventive maintenance
Corrective maintenance
Preventive Maintenance
Preventive maintenance activities to be instituted at a Swale are:
• Grass Mowing. Vegetation seed mix within the Swale is designed to be kept short
to maintain adequate hydraulic functioning and to limit the development offaunal
habitats.
• Trash and Debris. During each inspection and maintenance visit to the site, debris
and trash removal will be conducted to reduce the potential fcr inlet and outlet
structures and other components from becoming clogged and inoperable during
storm events.
• Sediment Removal. Sediment accumulation, as part orthe operation and
maintenance program at a Swale, will be monitored once a 'month during the dry
season, after every large storm (0.50 inch), and monthly during the wet season.
Specifically, if sediment reaches a level at or near plant height, or could interfere
with flow or operation, the sediment will be removed. If accumulation of debris or
sediment is determined to be the cause of decline in design performance, prompt
action (i.e., within ten working days) will be taken to restore the Swale to design
performance standards. Actions will include using additional fill and vegetation
and/or removing accumulated sediment to correct channeling or ponding.
Characterization and Appropriate disposal of sediment will comply with applicable
local, county, state, or federal requirements. The swale will be regraded, if the flow
gradient has changed, and then replanted with sod.
• Removal of Standing Water. Standing water must be removed if it contributes to the
development of aquatic plant communities or mosquito breeding areas.
• Mechanical and Electronic Components. Regularly scheduled maintenance will be
performed on fences, gates, locks, and sampling and monitoring equipment in
accordance with the manufacturers' recommendations. Electronic and mechanical
components will be operated during each maintenance inspection to assure
continued performance.
• Fertilization and Irrigation. The vegetation seed mix has been designed so that
fertilization and irrigation is not necessary. Fertilizers and irrigation will not be'
used to maintain the vegetation.
• Elimination of Mosquito Breeding Habitats. The most effective mosquito control
program is one that eliminates potential breeding habitats.
Corrective Maintenance
Corrective maintenance is required on an emergency or non-routine basis to correct
problems and to restore the intended operation and safe function of a Swale. Corrective
maintenance activities include:
• Removal of Debris and Sediment. Sediment, debris, and trash, which impede the
hydraulic functioning of a Swale and prevent vegetative growth, will be removed ,
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and properly disposed. Temporary arrangements will be made for handling the
sediments until a permanent arrangement is made. Vegetation will be re-
established after sediment removal.
• Structural Repairs. Once deemed necessary, repairs to structural components of a
Swale and its inlet and outlet structures will be done within 10 working days.
Qualified individuals (i.e., the designers or contractors) will conduct repairs where
structural damage has occurred.
• Embankment and Slope Repairs. Once deemed nece~sary, damage to the
embankments and slopes of Swales will be repaired within 10 working days).
• Erosion Repair. Where a reseeding program has been ineffective, or where other
factors have created erosive conditions (i.e., pedestrian traffic, concentrated flow,
etc.), corrective steps will be taken to prevent loss of soil and arty subsequent
danger to the performance of a Swale. There are a number of corrective actioQ.s
than can be taken. These include erosion control blankets, riprap, sodding, or
reduced flow through the area. Designers or contractors will be consulted to
address erosion problems if the solution is not evident.
• Fence Repair. Repair offences will be done within 30 days to maintain the security
of the site.
• Elimination of Animal Burrows. Animal burrows will be filled and steps taken to
remove the animals if burrowing problems continue to occur (filling and
compacting). If the problem persists, vector control specialists will be consulted
regarding removal steps. This consulting is necessary as the threat of rabies in some
areas may necessitate the animals being destroyed rather than relocated. If the
BMP performance is affected, abatement will begin. Otherwise, abatement will be
performed annually in September.
• General Facility Maintenance. In addition to the above elements of corrective
maintenance, general corrective maintenance will address the overall facility and its
associated components. If corrective maintenance is being done to one component,
other components will be inspected to see if maintenance is needed.
Maintenance Frequency
The maintenance indicator document, included as Appendix B, lists the schedUle of
maintenance activities to be implemented at a Swale.
Debris and Sediment Disposal
Waste generated at Swales is ultimately the responsibility ofRC Ranch. Disposal of
sediment, debris, and trash will comply with applicable local, county, state, and federal
waste control programs. Table 3.1.2.1 shows a few possible disposal services for waste
material.
Hazardous Waste
Suspected hazardous wastes will be analyzed to determine disposal options. Hazardous
wastes generated onsite will be handled and disposed of according to applicable local,
state, and federal regulations. A solid or liquid waste is considered a hazardous waste if
it exceeds the criteria listed in the CCR, Title 22, Article 1 L
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4.2 Continuous Deflective Separation@ Units
The operational and maintenance needs of a CDS are:
• Inspection of its structural integrity and its screen for damage.
• Animal and vector control.
• Periodic sediment removal to optimize perfonnance.
• Scheduled trash, debris and sediment removal to prevent obstruction.
• Removal of graffiti.
• Preventive maintenance ofBMP equipment and structures.
• Erosion and structural maintenance to maintain the performance of the CDS.
• Addition of sorbent material (12 pounds per year or duty cycle)
Inspection Frequency
The facility will be inspected and inspection visits will be completely d<?cumented:
'. Once a month at a minimum.
• After every large stonn (after every stonn monitored or those stonns with mor~
than 0.50 inch of precipitation.)
• On a weekly basis during extended periods of wet weather.
Aesthetic and Functional Maintenance
Aesthetic maintenance is important for public acceptance of stonnwater facilities .
Functional maintenance is important for perfonnance and safety reasons.
Both fonns of maintenance will be combined into an overall Stonnwater Management
System Maintenance.
Aesthetic Maintenance
The following activities will be included in the aesthetic maintenance program:
Graffiti Removal. Graffiti will be removed in a timely manner to improve the
appearance ofa CDS and to discourage additional graffiti or other acts of vandalism.
Functional Maintenance
Functional maintenance has two components:
Preventive maintenance
Corrective maintenance
Preventive Maintenance
Preventive maintenance activities to be instituted at a CDS are:
• Trash and Debris Removal. Trash and Debris accumulation, as part of the operation
and maintenance program at a CDS, will be monitored once a: month during dty and
wet season and after every large stonn event. Trash and debris will be removed
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from the CDS unit annually (at end of wet season), or when material is at 85% of
CDS' sump capacity, or when the floating debris is 12 inches deep, whichever
occurs first. .
• Sediment Removal. Sediment accumulation, as part of the operation and
maintenance program at a CDS, will be monitored once a month during the dry
season, after every large storm (0.50 inch). Sediment will be removed from the
CDS annually (at end of wet season), or when material is at 85% of CDS' sump
capacity, or when the floating debris is 12 inches deep, whichever occurs ftrst.
Characterization and disposal of sediment will comply with applicable local,
county, state or federal requirements.
• Mechat:rical and Electronic Components. Regularly scheduled maintenance will be
performed on fences, gates, locks, and sampling and monitoring equipment in
accordance with the manufacturers' recommendations. Electronic and mechanical
components will be operated during each maintenance inspection to assure
continued performance.
• Elimination of Mosquito Breeding Habitats. The most effective mosquito control
program is one that eliminates potential breeding habitats.
• Sorbent material. The material may be used until it is saturated with oil and grease.
Monitoring to occur monthly concurrent with Sediment Removal Inspection.
Corrective Maintenance
Corrective maintenance is required on an emergency or non-routine basis to correct
problems and to restore the intended operation and safe function of a CDS. Corrective
maintenance activities include:
• Removal of Debris and Sediment. Sediment, debris, and trash, which impede the
hydraulic functioning of a CDS will be removed and properJy disposed. Temporary
arrangements will be made for handling the sediments until a permanent
arrangement is made.
• Removal of Sorbent. Visual indications of saturated or near saturated sorbent
material include: sorbent appears dark and becomes less buoyant when heavily
saturated with oil, grease, and debris. Heavily saturated -sorbent appears to be coated
with oil, grease and particulates. When determined saturated, the sorbent material is
classified hazardous waste. Contact an authorized CDS Technologies service
company for removal and disposal.
• Structural Repairs. Once deemed necessary, repairs to $tructural components of a
CDS and its inlet and outlet structures will be done within 30 working days.
Qualified individuals (i.e., the manufacturer representatives) will conduct repairs
where structural damage has occurred.
• Erosion Repair. Where factors have created erosive conditions (i.e., pedestrian
traffic, concentrated flow, etc.), corrective steps will be taken to prevent loss of soil
and any subsequent danger to the performance of a CDS. There are a number of
corrective actions than can be taken. These include erosion control blankets, riprap,
or reduced flow through the area. Designers or contractors will be consulted to
address erosion problems if the solution is not evident.
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• Fence Repair. Repair offences will be done within 30 days to maintain the security
of the site.
• Elimination of Animal Burrows. Animal burrows will be filled and steps taken to
remove the animals if burrowing problems continue to occur (filling and
compacting). If the problem persists, vector control specialists will be consulted
regarding removal steps. This consulting is necessary as the threat of rabies in some
areas may necessitate the animals being destroyed rather than relocated. If the
HMP performance is affected, abatement will begin. Otherwise, abatement will be
performed annually in September.
• General Facility Maintenance. In addition to the above elements of corrective
maintenance, general corrective maintenance will address the overall facility
and its associated components. If corrective maintenance is being. done to one
component, other components will be inspected to see if maintenance is needed ..
Maintenance Frequency
The maintenance indicator document, included as Appendix B, lists the schedule of
maintenance activities to be implemented at a CDS.
Debris and Sediment Disposal
Waste generated at a CDS is ultimately the responsibility of the Carlsbad OfticePark
owner. Disposal of sediment, debris, and trash will comply with applicable local,
county, state, and federal waste control programs .
Hazardous Waste
Suspected hazardous wastes will be analyzed to determine disposal options. Hazardous. wastes
generated onsite will be handled and disposed of according to applicable local, state, and federal
regulations. A solid or liquid waste is considered a hazardous waste if it .exceeds the criteria list
in the CCR, Title 22, Article 11 .
18
•
• '
•
5.0 FISCAL RESOURCES
This section is intended to provide information regarding the ability of the owner/developer to
ensure the construction and maintenance of post-construction BMPs [sec. G. 7.2, Stermwater
Standards Manual, Ordinance 9426.}.
Costs of maintenance and site operations shall be included in the association conditions,
covenants and restrictions. The developer shall decide cost allocation amongst tenants/owners for
each portion of the maintenance, and shall include inflation factors for the ongoing maintenance.
At the change of requirements, either by the development or of conditions set down by future
legislation, the association shall revise their costs accordingly .
19
•
•
•
6.0 SUMMARY/CONCLUSIONS'
This SUSMP has been prepared in accordance with the County of San Diego Standard Urban
Stormwater Mitigation Plan, Stormwater Management, and Discharge Control Ordinance .and the
Stormwater Standards Manual. This SUSMP has evaluated and addressed the potential pollutants
associated with this project and their effects on water quality. A summary of the facts and
findings associated with this project and the measures addressed by this SUSMP is as follows:.
• The Carlsbad office park will not significantly alter drainage patterns on the site. The
discharge points will not be changed. Thus preventing downstream e~osion.
• Only 65% of the total project area will be impervious. Open areas and slopes will be .
landscaped to reduce or eliminate sediment discharge.
• The vegetated swales (landscape areas) proposed as part of the project will provide some
mitigation of the increased peak flows by detaining flows, reducing the velocities, and
providing opportunities for infiltration.
• The proposed construction and post-construction HMPs address mitigation measures to
protect water quality and protection of water quality objectives and beneficial uses to the
maximum extent practicable .
20
•
•
•
ATTACHMENT A
LOCATION MAP
•
•
•
PACIFIC
CCEAN
CARLSBAD
CAMINO
VIA ROBLE
LUECADIA
~ q ~ o PALOMAR
AIRPORT RD.
CORTE
DEL NOGAL
LOCATION MAP~
NOT TO SCALE ~ ~
-•• ATTACHMENT B
PROJECT MAP
•
•••
•
•
•
ATTACHMENT C
BMP MAP
(NOTE: INDICATE SITE DESIGN AND SOURCE CONTROL BMPS TO EXTENT
POSSIBLE, IN ADDITION TO TREATMENT CONTROL BMPS)
e-ATTACHMENT D
BMP DATASHEETS
•
• ,
r-----------------------------------------------------~------. ----. ----
ACTIVITY: DEWATERING OPERATIONS
DESCRIPTION
Prevent or reduce the discharge of pollutants to stonn water from dewatering operations
by using sediment' conttols and by testing the groundwater for pollution.
APPROACH
There are two general classes of pollutants that may. result from dewatering operations;
sediment, and taxies and pettoleum products. A high sediment content in dewatering
discharges is common because of the nawre of the operation. On the other haIid. taxies
and pettoleum products ~e not commonly found in dewatering discharges unless, the site
or smrounding area has been used for light or heavy industrial activities, or the area has a
history of groundwater contamination. The following steps will help reduce storm water
pollution from dewatering discharges:
Sediment
\ Use sediment .controls to remove sediment from water generated by dewatering (See
Sediment Trap (ESC 55) and Sediment Basin (ESC 56) in Chapter 5).
• Use flltration to remove sediment from a sediment trap or basin. Filtration can be
achieved with:
Sump pit and a perforated or slit standpipe with boles and wrapped in filter
fabric. The standpipe is smrounded by stones which fJlters the water as it
collects in the pit before being pumped out Wrapping the standpipe in fIlter
fabric may require an increased suction inlet area to avoid clogging and unac-
ceptable pump operation.
Floating suction bose to allow cleaner surface water to be pumped out.
Ioxics and PCtrplCllID 'Products
• In areas suspected of having groundwater pollution, sample the groundwater near the
excavationsi~ andbaye the water tested for known or suspected pollutants at a
certified laboratory. Check: with the Regional Water Quality Conttol Board and the
local wastewater treatment plant for their requirements for dewatering, additional
water quality tests, and disposal options.
• With a pemtit from. the Regional Water Quality Conttol Board, you,may be able to
recycle/reuse pumped groundwater for landscape iIrigation. or discharge to the Stoml
sewer. With a permit from the local agency, you may be able ta treat pumped
groundwater and discharge it to the municipal wastewater treatment plant via the
~~sew~ ,
• For a quick reference on disposal alternatives for specific wastes, see Table 4.2,
CA40, Employee/Subcontractor Trai~g. .
Construction Handbook 4-3
ObjQctives
<:!£US<IkHpif,g Pmc~
Contain Wast.
Minimi;:s Distu/Wd ArMS
Stabi/izs, Distu/Wd AfNS
Targeted Pollutants
• Sttdiment
0 Nutrients
Q Toxic Materials
0 Oil &: Grease
0 Floatable Materials
0 Oth~r Construction
Waste
• Uk_/y to H.v_
Slgnlnc.nt Impect
0 ProbMJ~ Low or
UnkiJO,wn !mp".;:t
Implementation.
Requirements
~ Capital Costs
Q O&:M Costs
Q Maintenance
~ Training
0 Suit~ility for
SJope.s>5"
• High 0 Low
CA1
March, 1993 '
CONTRACTOR ACTIVITY: DEWATERING OPERATIONS (Continue) i
REQUIREMENTS
• Costs (Capital, O&M)
• Sediment cona:ols are low cost measures.
• Treanncnt and/or discharge of polluted groundwater can be quite expensive.
• Maintenance
• Maintain sediment controls and filt:crs in good working order. (See Chapter 5 for details)
• Inspect excavated areas daily for signs of contaminated water as evidenced by discoloration, oily sheen, or
odors.
LIMITATIONS
• The ~ce of conmmin3red water may indicate contaminated soil as well. See CA22 (Cofltami;lated Soil Man-
agement) in this chapter for more infoIIIl3.tion.
REFERENCES "
B"luCprlnt fOr a-cIeari ~ay-Coosiruction-R.Clatcd Industries: Best Mailage'ment "Practices for Scorm Warer "PoIiutio~"
Prevention; Santa aara Valley Nonpoint Source Pollution Control Program. 1992. "" "
Stom W"att:r Management for Construction Activities, Developing Pollution Prevention Plans and Best Management
Practices. EPA 832·R-92005; USEPA. April 1992. "
•
CA1
•
Construction Ha~dbook Mareb,1993
ACTIVITY: PAVING OPERATIONS Objective~
:-lr-apn-jc-:-North--C-ernr-a1-Te-X2S--C-OG-, '-993-------------------; cE§:ek~ping prac~
DESCRIPTION
Prevent or reduce the discharge of pollutants from paving operations, using measures to
prevent ronon and runoff pollution, properly disposing of wastes, and training employees
and subconuactors.
APPROACH
• A void paving during wet weather.
• Store materials away from drainage courses to prevent storm water ronon (see CAlO
Material Delivery and Storage).
• Protect drainage courses, particularly in areas with a grade, by employing BMPs to
divert rpnoff or trap/fIlter sediment (see Chapter 5).
• Leaks and spills from paving equipment can contain toxic levels of heavy metals and
,oil and grease. Place drip pans Ol" absorbent materials under paving equipment when
not in use. Clean up spills with absorbent materials rather than burying. See CA32
(Vehicle and EqUipment Maintenance) and CAl2 (Spill Prevention and Control) in
this chapter.
• C~)Ver catch basins and manholes when applying seal coat, tack coot, slurry seal, fog
seal, etc.
• Shovel or vacuum saw-cut slurry and remove from site. Cover or barricade storm
drains during saw cutting to contain Slurry.
• If paving involves portland cement concrete, see CA23 (Concrete Waste Manage-
ment) in !:his chapter.
• If paving involves asphaltic concrete, follow these steps:
Do not allow sand or gravel placed over new asphalt to wash into storm drains,
streets., or ~ks by sweeping. Properly dispose of this waste by referring to
CA20 (Solid Waste Management) in this chapter.
Old asphalt must be disposed of properly. Collect and ~emove all broken aspbalt
from the site and recycle wbenever possible. ,
If paving involves on-site mixing plant, follow the storm water permitting
requirements for industrial activities.
• Train emplo~ees and subcontractors.
REQUIREMENTS
• Costs (Capital, d&M)
All of !.be above are low cost measures.
• Maintenance
Inspect employees and subconuactors'to ensure that measures are being followed.
Keep ample supplies of drip pans or absorbent materials on-site.
LIMITATIONS
There are no major limitations to this best m.anage~ent practice.
Construction Handbook 4-5
Contain Wasta
Minimize Disturbed Arsas
Stabilize Disturbed Araas
Protect Slopes/Channels
Control Site Perimeter
Control Internal Erosion
Targeted Pollutants
~ Sediment o Nutrients
Q Toxic Materials
~ Oil & Grease o Floatable Materials
o Other Construction
Waste'
• Uktfly to Have
SignifIcant Impact o Probable Lpw or
. , Unknown !mpa,ct
Implementation
Requir~ments
o C~pital Cost:;
o O&MCosts
Q Maintenan<:e
~. Training
o Sl!itability for
SIQpes>5%
Hfgn 0 Low
CA2
March,1993
CONTRACTO'R ACTIVITY: PAVING OPERATIONS (Continue) .' REFERENCES
Blueprint for a Clean Bay-Consttuction-Re1ated Industries: Best Management Practices for Storm Warer Pollution
Prevention; Sama Clara Valley Nonpoint Source pollution Control Program. 1992.
Hot-mix Asphalt Paving Handbook, U.S. Anny Corps of Engineers, AC 15015370-14. Appendix L July 1991.
" . , ..
•
CA2
• Construction Handbook 4-6 March,1993
ACTIVITY:· STRUCTURE CONSTRUCTION AND PAINTING Objectives
:-~------""":':::::::::::::-___ ------------------i ~usekeeping Prac:?' Graphic: North CentraJ Texas COG, 1993 ~ ~
DESCRIPTION
Prevent or reduce the discharge of pollutants to stoIIIl water from structure c>onstruction
aIJ9. painting by enclosing or covering or bemting building material storage areas. usi~g
goodbousekeeping practices. using safer alternative products, and training employees and
subcontractors.
APPROACH
• Keep the worle site clean and orderly. Remove debris in a timely fasbion. Sweep the
area.
• Use soil erosion control techniques ifbare ground is exposed (See Chapter .5).
Buy recycled or less hazardous products to the maximum extent practicable.
• Conduct painting operations consistent with local air quality and OSHA regulations.
• Properly store paints and solvents. See CAlO (Material.Delivery and Storage) in this
chapter. .
Properly store and dispose waste materials generated from the activity. See the waste
management BMPs (CA20 to CA24) in this chapter.
• Reqcle residual paints. solvents. lumber. and other materials to the maximum extenl
praCticable.
• Make sure tbat nearby stOIIIl drains are well marked to minimize the cbance of
inadvertent disposal of residual paints an4 other liquids.
• Clean the storm drain system in the immediate construction area after construction is
completed.
• Educate employees wbo are doing the work.
• InfOIIIl 'subcontractors of company policy on these matters and include appropriate
provisions in their contract to make certain proper housekeeping and disposal
practices are implemented.
• For a quick reference on disposal alternatives for specific wastes. see Table 4.2.
CA40, Employee/Subcontractor Training.
REQUIREMENTS
• Costs (Capital. O&M)
These BMPs are generally of low to moderate cost.
• Maintenance
Maintenance should be minimal.
LIMITATIONS
• Safer alternative products may not be available. suitable, or effective in every case.
• Hazardous waste that ClIlI)ot be re-used or recycled must be disposed of by a licensed
b8zardous waste hauler.
Construction Handbook 4-7
Contain Waste
Control Site Perimeter
Controllntemi'll Erosion
Targeted Pollutants
0 Sediment
0 ·Nutrients-
Q Toxic Mater/als
0 Oil&-Grease • Floatable Materials • Other Construction
Waste
.. • Ukttly_to Have
0
S,ignificant ilPpact
Probable loaw or
Unknown ImpaCt
Implementation
Requirements
0 Capital Costs
0 O&-MCosts
0 Maintenance
~ Training
0 Suitability for
Slopes >5%
• High 0 Low
CA3
March,1993
•
•
••••
ACTIVITY: STRUCTURE CONSTRUCTION AND PAINTING (Continue)
• Be certain that actions to help Stoml water quality are consistent with Cal-and Fed-OSHA and an-quality regula.
tipns.
Construction and painting activities can generate pollutants that can reach storm water if proper care is not taken. The
sources of these contaminants may be solvents, paints, paint and varnish removers, Unishing residues. spent thinners.
soap cleaners, kerosene, asphalt and concrete materials, adhesive residues, and old asbestos insulation. For specific
information on some of these wastes see the following BMPs in this chapter.
CA20 Solid Wasee,
CA21 Hazardous Waste, and
CA23 Concrete Waste.
More specific information on structure construction practices is listed below.
Erosion and Sediment CODtrol
,·If.t1re work involves exposing large areas of soil or if old buildings are being tom down and not replaced in the near
future. employ the appropriate 'soil erosion and cOntrol teCbniques described in Chapter 5.
StQnDlSanirarv Sewer Connections
Carefully install all plumbing and drainage systems. Cross connections between the sanitary and storm drain· systems, as
well as any other connections into the drainage system from inside a building, are fllegal. Color code or flag pipel~es on
the project site to prevent such connections, and train construction personnel. '
P$~e '
Local air pollution regulations may, in many areas of the state, specify painting· procedures which if properly earned out
are usually sufficient to protect Stoml water quality. These regulations may require that.painting operations be properly
enclosed or covered to avoid drift. Use temporary scaffolding [0 hang. drop cloths or draperies to prevent drift Applica-
tion equipment that minimizes overspray also helps. When using sealants on wood, pavement, roofs, etc, quickly dean
up spills. Remove excess liquid with absorbent material or rags.
If painting requires scraping or sand blasting of the existing surface, use a drop cloth to collect most of the chips.
Dispose the residue properly. If !:he paint contains lead or tributyl tin, it is considered a hazardous waste. Refer to the
waste management BMPs in this chapter for more information.
Mix paint indoors, in a containment area.. or in a flat unpaved area not subject to significant erosion. ·DQso even .during
dry weather because cleanup of a spill will never be 100% effective. Dried paint will erode from sloped surfaces and be
washed away by Stomls. If using water based paints, clean the application equipment in a sink that is connected .to the
sanitary sew~ or in a containment area where the dried paint can be readily removed. Properly store leftOver-paints if
they are to be kept for the next job, or dispose of properly.
Roof work
Wben working on roofs. if small particles have accumulated in the gutter. either sweep out the gutter or wash the guuer
and trap the particles at the outlet of-the downspout A sock or geofabric placed over the outletmay effectively trap the
materials. If the downspout is lined tight, place a temporary plug at the nrst convenient point in the 'storm draip and
pump out the water with a vactor truck. and clean the catch basin sump where you placed the plug.
REFERENCES '
Blueprintfor a Clean Bay-Conscruction-Related Industries: Best Manageme~t Practices for Storm Water Pollution
Prevention; Santa Clara Valley Nonpoint Source Pollution Control Program, 1992.
CA3
Construction Handbook 4-8 March, 1993
Acr.VITY: MATERIAL DEUVERY AND STORAGE
DESCRIPTION
Prevent or reduce the discbarge of pollutants to storm water from material delivery and
st,?rage by mipimizing the storage o( hazardpus materials on-site. storing materials in a
desiinated area, instaIii.ng secondary containment, conducting regular inspections, and
training employees and subcontractors.
This best management practice covers only material deli very and storage. For other
information on materials, see CAll (Material Use), or CA12 (Spill Prevention and
Control). For information on wastes, see the waste management BMPs in this chapter.
APPROACH
The following Diaterials are commonly stored on construction sites:
• Soil,
• Pesticides and herbicides,
Fertilizers,
Detergents,
• Plaster or other products,
• Petroleum products such as fuel, oil, and grease, and
• Other hazardous chemicals such as acids, lime, glues, paints, solvents, and curing
compounds.
Storage of these materials on-site can pose the follOwing risks:
Storm water pollution,
Injury to workers or visitors,
• Groundwater pollution, and
• Soil contamination.
Therefore, the following steps should be taken to ~ your risk: .
• De~ignate areas of the construction sire for material delivery and storage.
Place near the construction entrances, away from waterways
Avoid transport near drainage paths or waterways
Surround with earth berms (see ESC30, Earth Dike.)
Place in an area which will be paved
• Storage of reactive, ignitable, or flammable liquids must comply with the tire codes of
yoW" area. Contact the local Fue Marshal to review site materials, quantities, and
proposed storage area to determine specific requirements. See the Flammable and
Combustible Liquid Code, NFPA30.
For a quick reference on disposal alternatives for specific wastes, see Table 42, CA40,
. EmployeeiSubcomracto1 Training.
Keep an accurate, up-to-date inventory of materials delive~d and stored on-site.
Keep your inventory down.
Construction Handbook 4·9
Objectives
c:.JE..usekeeping PractijiP
Ccntain W~te
Minimize Distqri:16d Areas
Stabilize DisturluJd Areas
Protset Slopes/Channels
Control Site Perimeter
Contl'ol Intemal Erosion
Targeted Pollutants
~ Sediment
Q Nutrients .'
Q Toxic Materials
~ 011 & Grease
~ Floatable Materials
0 Other Construction·
Waste
•• Uk,ly to Have
Slgnlficanf ImpM:t
0 Probable Low or
Unknown Impact _
Implementation
Requi~ements
0 Capital Costs
0 O&M Costs
0 Maintenance
~ Training
0 Suitability for
Slopes >5%
• High 0 Low
CA10
March,1993
•
•
.'
ACTIVITY: MATERIAL DELIVERY AND STORAGE (Continue)
• Minimize hazardous materials on-site storage.
• Handle hazardous ma.terials as infrequently as possible.
• During,the rainy season, consider storing materials in a covered area Store marerials in secondary containments
such as an earthen dike, horse trough, or even a children's wading pool for non-reactive materials such as detergents.
oil. grease, and paints. Small amounts of material may be secondarily contained in "bus boy" trays or concrete
mixing trays.
• Do not store chemicals, drums, or bagged materials directly on the group.d. Place wese items on a pallet and, when
poss~ble, in secondary containment.
• If drums must be kept uncovered, store them at a slight angle to ,reduceponding of rnipwater on !.he lidS and to
reduce corrosion.
• Try to keep chemicals in their original containers. and keep them well labeled.
• Train employees and subcontractors.
• Employees trained in emergency spill cleanup procedures should be present when dangerous materials or liquid
" 'chemicals are unloaded. '
• If significant residUal materials remain on the ground after construction is complete, properly remove xnateriafs and
any contaminated soil (See CA22). If we area is to be paved, pave as soon as materials are removed to stabilize the
soil.
REQUJ:REryIENTS
• Cost (Capital, O&M) ,
-All of the above are low cost measures.
• Maintenance
-" Keep the designated storage area clean and well organized.
-Conduct routine weekly inspections and check for external corrosion of material conraineIS.
-Keep an ample supply of spill cleanup materials near !.he storage area
LIMITATIONS'
• Storage sheds often must meet building and fire code requirements.
REFERENCES
Best Management Practices and Erosion Control Manual for Construction Sites; Flood Control'District of Maricopa
Cowuy, AZ, September 1992.
Blueprint for a Clean Bay-Construction-Related Industries: Best Management Practices for Storm Water Pollution
Prevention; Santa Clara Valley Nonpoint Source Pollution Control Program. 1992; Santa Clara Valley Nonpoint Source
Pollution Control Program. 1992.
Cqas~ Nonpoirit Pollution Control Program: Program Development and Approval Guidance, Workin'g droup Working
Paper; USEPA, April 1992.
StOl1Il WaJJ:r Management for ConstrUCtion Activities; Developing Pollution Prevention Plans and Best Management
Practices, EPA 832-R-92005; USEP A, April 1992.
CAto
Construction Handbook 4 -10 March; 1993
ACTIVITY: SCUD WASTE MANAGEMENT
lraphic: North Central Texas COG, 1993
DESCRIPTION
Prevent or reduce the discharge of pollutants to storm water from solid or construction
waste by providing designated waste collection areas and containers, arranging for regulru::
disposal, and training employees and subcontractors.
APPROACH
Solid waste is one of the major pollutants resulting from construction. Construction debris
includes:
Solid waste generated from trees and shrubs removed during 4md clearing, demolition
of existing structures (rubble), and building construction;
• Packaging materials including wood, paper and plastic;
• Scrap or surplus building materials including scrap metals, rubber, plastic, glass
pieces. and masonry productS; and
Domestic wasteS including food containers such as beverage cans', 'coffee cups, paper
bags. and plastic wrappers, and cigarettes.
The following steps will help keep a clean site and reduce storm water pollution:
• Select designated waste collection areas on-site.
• Inform trash hauling contractors that you will accept only water-tight dumpsters for
• on-site use. Inspect dumpsters for leaks and repair any dumpster that is not water
tighL
• Locate containers in a covered area andlor in a secondary containmenL
• Provide an adequate number of containers with lids or covers that can be placed over
the concainer to keep rain out or to prevent loss of wastes when it's windy.
• Plan for additional containers and more frequent pickup during the demolition pbase
of construction.
Collect site trash daily, especially during rainy and windy conditions.
• Erosion and sediment control devices tend to collect litter. Remove this solid waste
promptly.
• Make s~ tbat toxic liquid w~tes (used oils, solventS, and paints) and chemicals
(acids, pesticides, additives, curing compounds) are not disposed of in dumpsters
designated for construction debris.
• Salvage or recycle any useful material. For example, trees and shrubs from land
clearing can be used as a brush barrier (see ESC53), or converted into wood chips,
then uS;ed as mulch on graded areas (see ESCll).
• Do not bose out dumpsters on the conSU1lction site. Leave dumpster cleaning to ~h
hauling contractor. '
Arrange for regular waste collection before containers overflow. ,
Construction Handbook 4 -IS
Objectives
Housek96ping Practic8s
C§ntain Ws~
Minimize Disturbed kess
Stabilize Disturbed Af'9ss.
Protect SlopesiChatmsis
Control Sits Perimeter
Controllntemal Eros!Qn
Targeted Po.1lt,rtants
.~ Sediment
0 Nutrients
0 Toxic Materials
0 Oil & Grease • Floatable Materials • Other "Construction
Waste
• 'Ukely to Have
Significantlinpact
0 Probabl" Low or
Unknown Impact
Implementation
Requirements
0 Capital Costs
0 'O&M Costs
~ Maintenance
~ Training
0 Suitability for
Slopes >5%
• High o Low
CA20
March,1993
•
•
•
ACTIVITY: SCUD WASTE MANAGEMENT (COntinue)
• If a container does spill. clean up immedi.aIely.
• Make sure that construction waste is collected. removed, and disposed of only at authorized disposal areas.
• Train employees and subcontractors in proper solid waste managemenL
• For a.quickreference OIl disposal alt.emaIivesforspecificwasteS.seeTable4.2..CA4Q. Employee/SubcontraCtor
Training.
REQUIREMENTS
• Costs (Capital. O&M)
-All of the above are low cost measures.
• Mamtenance
-Collect site trash daily.
-Inspect constrUCtion waste area regularly.
-Arrange for regular waste collection.
LIMITATIONS
• There are no major limitations to this best management practice.
REFERENCES
B·est Management Practices and Erosion Control Manual for Construction Sites; Flood Control Dlstrict of Maricopa
County, AZ. September 1992.
Processes. Procedures. and Methods t{) Control Pollution Resulting from all Construction Activity; .USEPA. 430/9-73-
007,1973 .
Storm Water Management for ConstruCtion Activities., Developing Pollution Prevention Plans and Best Management
Practices. EPA 832-R-92005; USEPA, April 1992.
CA2Q
Construction Handbook 4 -16 March,1993
ACTIVITY:" HAZARDOUS WASTE MANAGEMENT
Graphic: North Central Texas COG. 1993
DESCRIPTION
Prevent or reduce the discharge of pollutants 'to storm water from hazardous waste through
proper"~ use, w~te disposal. and training of employees and subconttactors.
APPROACH
Many of the cbemicals used on-site can be hazardous materials which become hazardous
waste upon disposal. These wastes may include:
• Paints and solvents;
Petroleum products ·such as oils. fuels, and grease;
• Herbicides and pesticides;
• Acids for cleaning masonry; and
• '. Concrete curing compounds.
Objectives
Housekeeping PtactiC8$
c§ntain Wa~
Minimize DisturjJed Areas
" Stabilize Disturbed Areas
Protect Slopes/Channels
Control Site PeriTrnlter
Contra/Internal Erosion
Targeted Pollutants·
o Sediment
o Nutrients
~ ToxicMateris/s o Oil& Grease
o Floatable Materials
o Other Construction
Waste
• Ukely to Have
Significant Impact o Probable LOw or
.Unknown Impact _
[n addition,. sites with existing strucrures may conrain wastes which must be disposed of in·l.::::=::::=====::::~
accordance with Federal. State, and local regulations .. These wastes include:
• Sandblasting grit mixed with lead-, cadmium-, or chromium-based paints;
• Asbestos; and
• . PCBs (panicularly in older transformers).
The following steps will help reduce storm water pollution from hazardous was.tes:
Material Use
• Use all of the product before disposing of the container.
• Do not remove the original product label. it contains important safety and disposal
informatic;m.
Do not over-apply herbicides and pesticides. Prepare only the amount needed.
Follow the recommended usage instructions. Over-application is expensive and
environmentally harmful. Apply surface dressings in several smaller applications, as
opposed to one large application. to allow time for infiltrntion and to avoid excess
material being carried off-site by runoff. Do not apply these chemicals just before it
rains. People applying pesticides must be certified in accordance with Federal and
State regulations.
Do not clean out brushes or rinse paint containers into the dirt, street, gutter, storm
drain. or stream. "Paint out" brushes as much as possible. Rinse water-based paints
to the sanitary sewer. Filter and re-use thinners and solvcD,ts. Dispose of cxcess oil-
based pamts and sludge as .hazardous waste.
Construction Handbook 4 -17
Implementation
Requirements
o Capital Costs o O&MCost~
Q Maintenl!!nce
~" Training
o Suitability for
Slopes >5%
• High· 0 Low
CA2l
March; 1993
•
•
•
ACTIVITY: HAZARDOUS WASTE MANAGEMENT (Continue)
Waste Recyc!jn~lDjsQOsal
• Select designated hazardous waste collection areas on-site.
• Hazardous materials and wastes should be swred in covered containers and proteCted from vandalism.
• Place hazardous waste containers in secondary containment
• Do'not mix wastes. this can cause chemical reactions, make recycling impossible, and complicate disposal.
• Recycle any useful m.ater:ia.I such as used oil or water-based paint
• Make sure that toxic liquid wastes (used oils, solvents, and paints) and c.bem.icals (acids, pesticides, additives. Curing
compounds) are not disposed of in dumpsters designated for construction debris.
• Arrange for regular waste collection before containers overflow.
• Make sure that hazardous waste (e.g. excess oil-based paint and sludges). is collected, removed, and disposed of only
at authorized dis~sal areas.
• For a quick reference on disposal alternatives for specific wasteS, see Table 4.2, CA40, Employee/Subcontractor
Training.
Training
• Train employees and subcontractors in proper hazardous waste management
• Warning signs should be placed in areas recently treated with chemicals.
• Place a stoekpile of spill cleanup materials where it wiU be readily accessible.
• If a container does spill, clean .up immediately.
REQUIREl'vIENTS
• Costs (Capital. O&M)
-All of the above are low cost measures.
• Maintenance
-Inspect· hazardous waste receptacles and area regularly.
-Arrange for regular hazardous waste collection.
LIMITATIONS
• Ha:zardo~ waste that cannot be reused or recycled must be disposed of by a licensed hazardous waSte ~auler.
REFERENCES
Blueprint for a Clean Bay-Construcnon-Related Industries: Best Management Practices for Storm WlllerPbllution
Prevention; Santa Clara Valley Nonpoint Source Pollution Control Progmm. 1992.
Processes, Procedures, and Methods to Control Pollution Resulting from all Construction Activity; USEP A, 430/9-73-
007.1973.
Storm Water Management for Consttuction Activities, Developing Pollution Prevention Plans and Best Management
Practices, EPA 832-R-92005; USEPA. April 1992.
CA21
Construction Handbook 4 -1.8 Mar~h, 1993
DESCRIPTION
Prevent or reduce th~ discharge of pollutants to storm water from contaminated soil and
highly acidic or alkaline soils by conducting pre-consttuCtion surveys, inspecting excava-
tiops regularly, and rcmediating contaminated soil promptly.
APPROACH
Contaminated soils may occur on your site for several reasons including:
Past site uses and activities;
• Detected or undetected spills and leaks; and
• Acid or alkaline solutions from exposed soil or rock formations high in acid or
alkaline-forming elements.
Most developers conduct pre-construction environmental assessmentS as a matter of
')utine. Recent conn rulings holding cpntractors liable for cleanup costs when they
"'nkn~wingly move contaminated soil, highlight the need for contractors to confirm that a
site assessment is completed ~ earth moving begins.
The following steps will help reduce storm water pollutio~ from contaminated soil:
• . Conduct thor?ugh site planning including pre-construction geologic surveys.
• Look for contaminated soil as evidenced by discoloration, odors, differences in soil
properties, abandoned underground tankS or pipes, or buried debris.
• Prevent le3ks and spills to the maximum extent practicable. Contaminated soil can be
expellliive to IrCat and/or dispose of properly. However, addressing the problem
, befo~ construction is much less expensive than after the strucrures are in place.
• Test suspected soils at a certified laboratory. .
• If the soil is Contaminated, work with the local regulatory agencies to develop options
for treatment and/or disposal.
For a,quick reference on disposal alternatives for specific wastes, see Table 4.2,
CA40, Employee/.Subcontractor Tmining.
REQUIREMENTS
• Costs (Capital, b&M)
Prevention of leaks and spills is inexpensive. Treatment and/or disposal of
contaminated soil can be quite expensive.
• Maintenance
Inspect excavated areas daily for signs of contaminated soiL
Implement CAl2. Spill Prevention and Control, to prevent leaks and spills as
much as possible.
Construction Handbook 4 -19
Objectives
Housekeeping Practi~es
Protect Slopes/Channels
Control Sits Perimeter
Contr.ollntemal erasion
Targeted Pollutants
~ Sediment
0 Nutrients • Toxic' Materials
0 Oil & Grease
0 Floatable. Materials
0 Other Construction
Waste
• Ukely'to Have
Significant Impact
0 Prol;1able Low or
UnknQwn Impact
Implementation'
Requirements
0 Capital Costs
~ O&M Costs
~ Majntenance
~ Training
0 Suitability for
Slopes >50/.
High 0 Low
.CA22
March,1993
•
•
•
.ACTIVITY: CONTAMINATED SOIL MANAGEMENT (Continue)
LIMITATIONS
• CODtamjnate<!. soils that cannot be treated on-site must be disposed of off-site by a licensed hazard0tiS waste hauler.
• The presence of contamjnated soil may indicue contamjnatf"fi water as well 'See CAl (Dewatering Operations) in
this chapter for more informatioa
REFERENCES
Blueprint for a Clean Bay-Construction-Related Industries: Best Management Practices for Storm Water Pollution
Prevention; Santa Clara Valley Nonpoint Source Pollution Control Progrnm. 1992.
Proce~ Procedures, and Methods to Control Pollution Resulting from.all Construction Activity; USEPA. 430/9"73-
007,1973.
Stonn War.er Management for Construction Activities, Developing Pollution Prevention Plans and Best Management
Practices, EPA 832.R-9200?; USEPA, April 1992. .
_--_-""4-.
CA22
Construction Handbook 4 -20 March,1993
ACTIVITY: SANITARY/SEPTIC WASTE MANAGEMENT
Prevent or reduce the discharge of pollutants to storm water from sanitary/septic waste by
providing convenient. well-maintained facilities, and arranging for regular service and
disposal.
APPROACH
Sanitary or septic wastes should be treated or disposed of in accordance with State and
local requirements. Th~ requirements may include:
• Locate sanitary facilities in a convenient location.
• Untreated raw wastewarer should never be discharged or buried.
• Temporary septic systems should treat wastes to appropriate levels before discharging .
• If. using an on-site disposal system (OSDS), such as a septic system, comply with local
health agency requirements.
Temporary sanitary facilities that discharge to the sanitary sewer system should be
properly connected to avoid illicit discharges.
If discharging to the sanitary sewer, contact the local wastewater treatment plant for
their requirements. .
Sanitary/septic facilities should be maintained in good working order by a licensed
service. .
• Arrange for regular waste collection by.a licensed hauler before facilities overflow.
• For a quick reference on disposal alternatives for specifiC wastes, see Table 4.2.
CA40, Employee/SubconuactOr Training.
REQUIREMENTS
• Costs (Capital, O&M)
All of the above are low cost measures.
• Maintenance
Inspect facilities regularly.
Arrange for regular waste collection.
LThfITATIONS
• There are no major limitations to this best management practice.
REFERENCES
Best Management Practices and Erosion Control Manual for Construction Sites; Flood
Control District of Maricopa County, AZ. September 1992.
Storm Wau:r M.anagement for Construction Activities, Developing Pollution Prevention
lans anci Best Management Practices, EPA 832-R-9200S; USEPA, April 1992.
Construction Handbook 4·23
Objectjv~s
Housekeeping Pfacticss
@ntainWa~
Mirfimize DistUrbed Ar6lJ.S
. Stabiliz~ DistUrbed Areas
Protect Slopes/Channels
Control Site Perimeter
Controllntemal Erasion
Targeted Pollutants
0 Sediment
0 Nutrients·
0 Toxic' Materials
0 Oil & Grease
0 Floatable Materials
Q Other Construction
Waste
• Ukttly to Have
Signiflcallt Impact
0 Probabl" LDw or
fJ.nknown Impact
.Implementation
Fiequirements
0 Capital Costs
0 O&MCosts
Q Maintenance
0 Training
0 Suitability far
Slopes >5%
• High 0 Low
CA24
March,1993
ACTIVITY: VEHICLE AND EQUIPMENT CLEANING Objectives ------------------------------i rHc;LlS{IkHping Prac~ Graphic: North Central Texas COO, 1993 ~ ~
Prevent or reduce the discharge of pollutants to storm water from vehicle and equipment
cleaning by using off-site facilities, washing in designated, contained areas only, eliminat-
ing discharges to· the storm drain by infIltrating. or recycling the wash water, andlor
traioiDg employees and subcontractors.
APPROACH
•
•
•
•
•
•
Use off-site <;ammercial washing businesses as much as possible. Washing vehicles
and equipment outdoors or in' areas where wash water flows onto paved surfaces or
into drainage padlways can pollute storm water. If you wash a large number of
vehicles or pieces of equipment, consider conducting this work at an off-site commer-
cial business. These businesses are better equipped to handle and dispose of the wash
waters properly. Performing this work off-site can also be economical by e]jrnjn3ting
the need for a separate washing operation at your site.
If washing must occur on-site, use designated, bermed wash areas· to prevent wash
water contact with storm water, creeks, rivers, and other water bodies. The wash area
can be sloped for wash water collection and subsequent infiltration into the ground.
Use as little water as possible to avoid having to ins~ erosion and sediment controls
for the wash area.
Use phosphate-free, biodegradable soaps.
Educate employees and subcontractors on pollution prevention measure~.
Do not permit steam cleaning on-site. Steam cleaning can generate significant
pollutant concentrations.
For a quick reference 00 disposal alternatives for specific wastes, see Table 4.2,
CA40, Employee/Subcontractor Training. .
REQ"OIREMENTS
• Costs (Capital. O&M)
All of the above are low cost measures.
• Maintenance
Minimal, some berm repair may be nece~.
LIMITATIONS
• Even phosphate-free, biodegradable soaps have been shown to be toxic to fish before
the soap degrades.
• Sending vehicles/equipment off-site should be done in conjtmction with ESC24
(Stabilized CO~trIlction Entrance).
'REFERENCE
Swisher, RD., 1987.
Construction Handbook
Contain Wasta
Minimize DisturbBd ArflllS
Stsbi1ize DisturbBd Araas
Protsct SJopasIChanneis
Targeted Pollutants
o Sediment
. 0 Nutrients
~ Toxic Msterial8
~ Oil & Greae o Floatable Materials
o Other C01l8truction
Wsste
• Uklflyto HIIVIf
SignifiCllnt Im",.ct o ProNbJ. Low or
. Unknown ImpllCt
Implementation
.Requirements
~ Capital Costs o O&MCost8
Q . Maintenance
o Training o Suitability for
SJope$>5%
• High 0 Low
CA3'O
Mar:ch, 1993
ACTIVITY: VEHICLE AND EQUIPMENT FUELING Objectives
------------------------------------------------------------1~usskeepm~P~c~
DESCRIPTION
Prevent fuel. spills and leaks. and reduce their impacts to storm water by using off-site
facilities. fueling in designated areas only, enclosing or covering stored fuel, implementing
spill controls, and craining employ~s and subcontraCtors.
APPROACH
• Use off.-site fueling stations as much as possible. Fueling vehicles and equipment
outdoors orin areas where fuel may spilllleak onto paved surfaces or into drainage
pathways can pollute storm water. If you fuel a large number of vehicles or pieces of
equipment. consider using an off-site fueling station. These businesses are better
equipped to handle fuel and spills properly. Performing this work off-site can also be
economical by eliminating the need for a separate fueling area at your site.
• If fueling must occur on-site; use designated areas, located away from drainage
courses, to prevent the mnon of storm water and the runoff of spills.
Discourage "topping-off' of fuel tanks.
Always use secondary containment. such as a drain pan or drop cloth, when fueling to
catch spillslleaks.
• Place a stoCkpile.of spill cleanup materials where it will be readily accessible.
• Use adso$:nt materials on small spills rather than hosing down or burying !.be spill.
Remove the adsorbent materials promptly and dispose of properly.
• Carry out all Federal and State requirements regarding stationary above ground storage
tanks.
• Avoid mobile fueling of mobile construction equipment around the site; rather,
transport the equipment to designated fueling areas. With !.be exception oI,qacked
equipment such as bulldozers and perbaps -forldifts, most vehicles should be able to
uavel to a designated area with little lost time.
• Train employees and subcontmctors in proper fueling and cle:mup procedures.
• Fo~ a quick reference on disposal alternatives for specific wastes, see Table 4.2, CA40,
Employee/Subcontractor Training.
REQUIREMENTS
• Costs (Capital. O&M)
All of the above measures are low cost. except for !.be capital costs of above
groood tanks that meet all local environmental. zoning, and fue codes.
• Maintenance
Keep ample supplies of spill cleanup materials on-site.
Inspect fueling areas and storage tD.nks on a regular schedule.
LIMITATIONS
Sending vehicleslequipme~t off-site should be done in conjooction with ~SC24
Construction Handbook 4·25
Ccmtain Waste
Minimize Disturbed Areas
Sbbilize Disturbed Areas
Protsct Slopes/Channels
Control Site Perimeter
Control Internal 'Erosion
Targeted Pollutants
0 Sediment
0 Nutrients
Q Toxic Materials
~ Oil !t Grease
0 Floatable Materials
0 Other Construction
Waste
• Uke/y to Have SignifiCant Implf!!t
0 Probab/e-Lew'or U.nkn~wn Impact
Impiementation
Requirements
Q Capital Costs
0 O&M Costs
Q Maintenance
~ Training
0 Suitability for
Slopes >50/.
CA31
March,1993
ACTIVITY: VEHICLE AND EQUIPMENT MAINTENANCE Objectives
--------------------------------------------~---4~~HpfugP~~ Graphic: North Central Texas COG, 1993--
Prevent or reduce the discharge of pollutants to storm water from vehicle and equipment
maintenance by running a "dry site". This involves using off-site facilities, performing
work in designated areas only, providing cover for materials stored outside, checking for
leaks and spills, containing and cleaning up spills immediately, and training employees and
subcontrnctors.
APPROACH
•
•
Keep vehicles and equipment clean, don' t allow excessive build-up of oil and grease.
Use off-site repair shops as much as possible.· Maintaining ve~cles and equipment
outdoors or in areas where vehicle or equipment fluids may spill or leak onto the
ground can pollute Storm water. If you maintain a large number of vehicles or pieces
of equipment, consider using an off-site repair shop. These businesses are better .
equipped to handle vehicle fluids and spills properly. Performing this work off-site
can also be economical by eliminating the need for a separate maintenance area.
• If ~tenance must occur on-site, use designated areas. located away from drainage
courses, to JiRvent tbe runon of storm water and the runoff of spills.
•
•
•
•
•
•
Always use secondary containment, such as a drain pan or drop cloth. to ta.tch spills or
leaks when remOving or changing fluids.
Place a stockpile of spill cleanup materials where it will be readily accessible.
Use adsorbent materials on small spills rather than .hosing do\YD or burYing the spill.
Remove the adsorbent materials promptly and dispose of properly.
Reg~y inspect on-site vehicles and equipment for leaks, and repair immediately ..
Check incoD$g vehicles and equipment (including delivery trucks, and employee and
subcontractor vehicleS) for leaking oil and fluids. Do DOt allow leaking vehicles or
equipment on-site.
Segregate and recycle wastes, such as greases. used oil or oil filters, antifreeze,
cleaning solutions, automotive batteries, hydraulic, and transmission fluids.
Train employees and subcontractors in proper maintenance and spill cleanup proce-
dures.
For a quick reference on dispos3J. alternatives for specific wastes, see Table 4.2, CA40,
Employee/Subcontractor Training.
REQUIREMENTS
• Costs (Capital, O&M)
All of the above are low cost measures.
• Maintenance Keep ample supplies of spill cleanup materials on-site.
U1spcct maintenance areas on a regular schedule.
Construction Handbook
Contain Waste
Minimizs Disturb«! ArMS
Stabilizs Disturb8d AI'NS
Protect Slop6$I'ChanMis
Control Site Perimeter
Contro/lnternsl EroSion
Targeted Pollutants
0 Sediment
0 Nutrients
~ Toxic Materials
~ Oil &: Grease
0 Floatable Materials
0 Other COfJ$truction
Waste
• Uk.1y to Htw.
Significant Impa:t
0 Probllbhl LDw or
Unknown ImplICt
Implementation
Requirements
0 Capital Costs
0 OltMCcsts
0 Maintenance
~ Training
0 Suitability for
Slopes >5%
• High 0 I.,.aw
March,1993
•
•
•
ACTIVITY: VEHICLE AND EQUIPMENT MAINTENANCE (Continue)
LIMIT A nONS
• Sending vehicles/equipment off-site should be done in conjunction wim ESC24 (Stabilized Construction Entrance).
Outdoor vehicle or equipment maintenance is a potentially significant source of storm water pollution. Activities thill
can contaminate storm water include engine repair and service, particularly changing or replacement of fluids, ano
outdoor equipment storage and parking (dripping engines). For further information on v~hicle or equipment servicing.
see CA30, Vehicle and Equipment Cleaning, and E:A3I, Vehicle and Equipment Fueling. .
Listed below is further information if you must penorm vehicle or equipment maintenance on-site.
Waste ReductjQD
Parts are often cleaned using solvents such as,tnchloroethylene, I,l,l-trichloroethane, or methylene Chloride. Many of
these parts cleaners are harmful and must be disposed of as a hazardous waste. Reducing me number of solvents makes
recycling easier and reduces hazardous waste management costs. Often, one solvent can perform a job ~ well as two
... ~e;-ent solvents. ,Also, if possibJ~, eliminate or reduce me amount of ha:z:ardous IIll!-te~ and waste by substitl.i9~g
'non-hazardous or less hazardous marerials. For example, replace chlorinated organic solvents (1,1, 1-trichloroet.llafle,
methylene chloride, etc.) with non-chlorinated solvents. Non-chlorinated solvents like kerosene or mineral spirits are
less toxic and l~s expensive to dispose of properly. Cbeck list of active ingredients to see whether it contains chlori-
nated solvents. The "chlor" term indicates that the solvent is chlorinated. Also, try substiwting a wire brush for soivents
to clean parts.
Recyc1jpoiPjsoosal '
Separating wastes allows for easier recycling and may reduce disposal costs. Keep hazardous and non-hazardous wastes
separate, do not mix used oil and. solvents, and keep chlorinated solvents (like 1,1,t-trichloroethane) separate from non-
chlorinated solvents (like kerosene and mineral spirits). Promptly tranSfer used fluids to me proper waste or recycling
drums. Don't leave full drip pans or other open containers lying around:
Oil mters disposed of in trash cans or dumpsters can leak oil and contaminate storm water. Place the oil mterin a funnel
over a w~te oil recycling drum to drain excess oil before disposal. Oil mters can also be recycled. Ask your oil
supplier or recycler about recycling oil filters.
Do not dispose of extra paints and coatings by dumping liquid onto the ground or throwing it into dllIDPSr.ers. Allow
coatings to.cIry or harden before disposal into covered dumpste~.
Store cracked batteries in a non-leaking secondary container. Do'this with all cracked bauerie:;, even if you think ail me
acid has'drained out. If you drop a bauc:ry, treat it as if it is cracked. Put it into me contairunent area until you are sure it .
is not leaking.
Do Dot bury used tires.
REFERENCES
Best Management Practi~s and Erosion Control Manual for Construction Sites; Flood Control Disaict of Maricopa
COUllty, AZ. September 1992. '
Blueprint for a Clean Bay-Construction-Related Industries: Best Management Practices for StOrIn Water Pollution
Prevention; Santa Clara Valley Nonpoint Source Pollution Control Program, 1992.
Coastal Nonpoint Pollution Control Program: Program Development and Approval Guidance, Working
Group Working Paper: USEP A. April 1992. CA32
Construction Handbook 4 -27 M~t"~h, 1993
ACTIVITY: EMPLOYEEISUBCONTRACTOR TRAINING
DESCRIPTION
Objectives
Cant8in Wasta --
Minimize DisrurtJed Areas
Stabilize Disturbed Arsas
Protect Slop6SiChanneis
Control Site Psrimeter
Control Intemal Erosion
Employee/subcontractor training, like maimenance or a pIece of equipment. is not so much a beSt management practice as
it is a method by which to implement BMPs. This fact sheet higbligbts the importance of training and of integrating the
elements of employee/subcontractor training from the individual source controls into a comprehensive trainiilg program
as part of a company's Storm W":ter Pollution Prevention Plan (SWPPP).
The specific employee/subcontractor training aspects of each of the source controls are highlighted in the individual fact
sheets. The focus of this fact sheet is more general. and includes the overall objectives and approach for asstning
employee/subcontractor training in stOrm water pollution prevention. Accordingly. the organization of this fact sheet
differs somewhat from the other fact sheets in this chapter.
OBJECI'lVES
Employee/subcontractor training should be based on four objectives:
Promote a clear identification and understanding of the problem. including activities with the potential to pollute-
storm water,
• Identify solutions (BMPs);
• Promote employee/subcontraCtor ownership of the problems and the solutions; and
• Integrate employeeJsubcontraCtor feedback into training and BMP implementation.
APPROACH
• Integrate ~ning regarding storm water quality management with existing training, programs that may be req~ired for
your businesS by other-regulations such as: the illness and Injury Prevention Program (IIPP) (SB 1'98) (California.
Code of Regulations TItle 8, Section 3203), the Hazardous Waste Operations and Emergency Response
(HAZWOPER) standard (29 CFR 1910.120). the Spill Prevention Control and Countermeasure (SPCC) Plan (40
CFR 112). and the Hazardous Materials Management Plan (Business Plan) (California Health and Safety Cod~.
Section 6.95).
• Businesses, particularly smaller ones that may not be regUlated by Federal. State, or local regulations, r::n.ay use. the
information in this Handbook to develop a training program to reduce their potential to pollute storm water.
• Use tQe quick reference on disposal alternatives (Table 42) to train employee/subcontractors in Pfoper and consistent
methods fOt: disposal.
CA40
Construction Handbook 4 -28 March,1993
•
•
•
ACTIVITY: EMPLOYEElSUBCONTRAcTOR TRAlNING (Continue)
• Consider posting the quick reference fable around the job site or in the on-site office trailer tP reinforce training,
• Train employee/subcontractors in standard operating procedures and spill cleanup rechniques described in the fact
sheelS. Employee/subcontractors ttained in spill containment and cleanup should· be present during the loading!
unloading and handling of materials.
• Personnel who use pesticides should be trained in their use. The California De~ent oiPesticide Regulation and
county agricultural commissioners license pesticide dealers, certify pesticide applicators, and conduct on-sire
insj:ectiODS.
• Proper education of off-site contractOrs is often overlooked. The conscientious efforts of well trained employee!
subcontIaCtOrs can be lost by unknowing off-site contractors, so make sure they are well informed about what they
are expected to do on-site. .
',',. ',' ..........
CA40,
Construction Handbook 4·29 March. 199.3
BMP:
DESCRIPTION
Sequencing the construction project to reduce the amount and duration of soil exposed to
erosion by wind, rain, runoff, and vehicle tracking.
SUITABLE APPLICATIONS
Proper sequencing of construction activities to reduce erosion potential should be incorpo-
rated into the ~hedule of every construction project. Use of other, more costly yet less
effective, erosion and sedimentation controls. may often be reduced through proper
construction sequencing.
APPROACH
• Project design considerations: Design project to integrate into existing land contours .
Significant regrading. of a site will require more costly erosion and sedimentation
control measures and may require that on-site drainage facilities be installed.
Objectives
Targeted Pollutants
0 Sediment
0 Nufrient5
0 Toxic MaterialS
0 Oil & Grease
0 Floatable Material5
0 Other Construction
Wa5te
• Ukflly to H.v.
Slgn/(1Ctlnt Imp«:t
0 ProWJ.'L,Qwor
• Incorporate existing, natural areas: Inventory and evaluate the existing site terrain and J.,::::;:===:::::::=~==-I
vegetation. Disturbance of highly erosive natural areas (e.g., steep, unstable slope
areas, watercourses) should be minjmjzed, while protecting other areas may enhance
site aesthetics. Construction should not disturb these areas (see ESCZ).
Unknownimp!fCt
• A void rainy periods: Schedule major grading operations during dry months. Allow
enough time before rainfall begins to stabilize the soil with vegetation or physical
means (see ESC 10 to 24) or to install temporary sediment trapping devices (see ESC
50 to 56).
Practice erosion and sediment control year rcimd: Erosion may be caused during dry
seasons by "freak" rainfall, wind and vehicle tracking. Therefore, keep the site
stabilized year-round, and·retain wet season sediment trapping devices.
• Minimize soil exposed at one time: Schedule projects to disturb only small pOrtions
of the site at anyone time. Complete grading as soon as possible. Imniediately
stabilize the disturbed portion before grading the next portion. Practice staged
seeding-revegetate cut and fill slopes as the work progresses.
• Trenching: Oose and stabilize open trenches as soon as possible. Sequence trench-
ing projects so that most open portions of the trench are closed before new trenching
is begun.
REQUIRE1\1ENTS
• Cost
Construction scheduling to reduce erosion may increase other construction costs
due to reduced economics of scale in perfoIlIling site grading. The cost-cffcc-
tiveness. of scheduling techniques should be compared with the other, less
effective erosion and sedimentation controls to achieve a cost-effective balance.
Construction Handbook 5-5
Implementation
Requirements
0 Capital Costs
0 O&MC05ts
0 Maintenance
0 TrainIng
0 Suitibility for
Slope.s>5%
• High 0 Low
ESC1
~brch,1993
•
•
•
BMP: SCHEDUUNG (Continue)
LlMlTATIONS
'Ibcrc arc no significant limitations to the use of this BMP.
REFERENCFS
BestMaDagCIIient Practices and'Erosion Control Manual for ConstruCtion Sites. Flood Control District ,of Maricopa
County, Arizona· 1992.
Erosion and Sediment Control Guidelines for Developing Areas in Texas, U~. Department of Agriculture, SQil Conser-
vation Serviee, Fort Werth. Texas -1976.
Storm Ware;r Management for Construction Activites. Developing Pollution Prevention Plans arid Best Management
Practices, U.S. Environmental Protection Agency, OffIce of Water (EPA 832-R-92-O(5) -September, 1992.
Vugi,nja Erosion and Sediment Control Handbook. Third Edition, Virginia. Department of Conservation and Recreation,
, ,Division of Soil an~ Wau:r Cor;tseryation· 1992. , _, _ " '
Construction Handbook 5·6
ESC1
~
1IeiIt\~
'"'*'-w
Marc;h,1993
• BMP: SEEDING AND PLANTING
GENERAL DESCRIPTION
Seeding of grasses and plantings of trees. shrubs. vines and ground covers provide long-
term stabilization of. soiL 4t some areas. with suitable cl.ima,tes, grasses can.be planted for.
temporary stabilization.
SUITABLE APPLICATIONS
•
•
Appropriate for site stabilization both during construction and post-construction.
Any graded/cleared areas where construction activities have ceased.
• Open space cut and fill areas.
• Steep slopes.
• Spoil piles.
• Vegetated swales.
Landscape corridors.
Stream banks.
INSTALLATION/APPLICATION CRITERIA
Type of vegetation, site and seedbed preparntion. planting time, fertilizatiqn and water
requil'cments should be-considered for each application.
Grasses:
• Ground preparation: fertilize and mechanically stabilize the soil.
• Tolerant of short-term temperature extremes and waterlogged soil conditions.
• Appiopriate soil conditions: shallow soil base, good drainage, slope 2:1 or flatter.
• Develop well· and quickly from seeds.
• Mowing, imgating, and fertilizing are vital for promoting vigorous grass growth.
Trees and Shrubs:
• SeICction Cri~ vigor, species, size, shape & wildlife food source.
• Soil conditions: select species appropriate for soil,drainage & acidity.
• Other Factors: windlexposurc, temperature extremes, and irrigation needs.
Vines and Ground Covers:
• Ground preparation: lime and fertilizer preparation.
• Use proper seeding rates.
• Appropriate soil conditions: drainage, acidity, slopes.
• Generally avoid species requiring irrigation.
Constru~tion Handbook 5·10
Objectives
HousaklH1ping PractiC8S
Contain Wasil
Control SitePerimetflr
Centro/Internal Erosion
Targeted Polhrtants • Sediment
~ Nutrient~'
Q Toxic Mlfteriais
0 Oil & Grease
0 Floatable Materials
0 Other Construction
Waste
• Ukllly to Havtl
SI!J!IIf1C11nt 1m pltCt
0 ProlMble Low or
Unknown Imp.ct
Implementation
Requirements
Q Capital CoSts
Q O&M Cost$
Q Ml;firitenance
~ Training
Q Suitability for
SIQPe8 :>5%
• High 0 Low
ESC10
March, 1993
BMP: SEEDING AND PLANTING (Continue) • REQUIREMENTs
• MainteDa1lce
• Shrubs and trees must be adequately watered and fc:rtilizcd and if needed pruned.
• Grasses may need to be watered and mowed.
• Cost Avcrnge annual cost for installation and maintenance (2 year useiullife, source: EPA., 1992)
• Seeding: $300 per aae. appcopxiate for flat slopes and stable soils.
• Seeding with Mulcbing: $1,100 per acre, appropriate for moderate to steep slopes andlor erosive soils.
• Trees, shrubs, vfues, and ground cover. Cost,·applicability based on species used and terrain feao:u:es.
LIMITATIONS
. • Petmanent and temporary vegetation may not be appropriate in dry periods without i.trigation.
• Fertilizer requirements may have potential to create storm water pollution if improperiy applied.
•
ESC10 ••
Co~truction Handbook 5 • 11 March,199J
•
-
•
Additional Information -Seeding and Planting I
Pennanent seeding of grasses. sodding, and planting of trees, shrubs, vines and ground covers can provide long-tenn
stabilization of soil. Permanent seeding and planting contributes to long-tenn site aesthetics and helps reduce erosion by
reducing the velocity of runoff, allowing infiltration to occur, flltering sediments, and by holding soil partiCles inpl.ace.
-Seeding and planting should be applied as soon as fInal grading is done to all graded and cleared areas of the construc-
tion site where plant cover is ultimately desired. For example, vegetation may be esTablished along landscaped corridors
and buffer zones where they may act as filter strips (see TC6 in Chapter 5 of the Municipal HandbOOk). Additionally,
vegetated swales, steep and/or rocky slopes and stream banks can also serve as appropriate areas for seeding and
plantings.
InstaIlationlAtwUcation Criteria
Application of appropriate vegetation must consider. the seedbed or plantbed, proper seasonal planting times, water
requirements fertilizer requirements and aVailability of the selected vegetation within the project's region. Permanent
plantings during the construction stage of projects require careful coordination betWeen the local agency inspectOrs,
, ' project Iij.aD3gers, construction managers, and landscape contractor. Protocols for coordination '!Ild implementation
: procedures regarding site access, construction staging, and short-and long-teml plantipg areas should be developed prior
to the cOIlSttuction bid process. Where possible, these protocolS should be esTablished by and remain tIie responsibility of
the site owner.
Because of the many available types of plants and ground covers and because site conditions and land use vary so widely
within Qilifornia. a set of general guidelines is included for installation/application of grasses, trees and shrubs, vines
and ground covers. However, your local municipality, Soil Conservation Service, agricultural extention, or other
resources should be consulted on appropriate species, planting requirements, and maintenance needs for your climate and
soils. ' ,
Grasses
Grasses, depending on the type, provide short-teml soil sTabilization during construction or can serve as long-term!
permanent soil stabilization for diswrbed areas. In general; grasses provide low maintenance to areas that have been
cleared, graded and !Dechanically stabilized. .
~election'
The selection of the grass type is determined by the climate, irrigation, mowing frequency, ~tenance effort and soil-
bed conditions. Although grasses provide quick gem:tinalion and rapid growth, they also have a shallow root syS~m an~
are not as effective in stabilizing deep soils, where ~ shrubs and deep rooted grotmd covers may be more appropriate.,
Several grasses are' adapTable to the various California climates. The fIgure at the end of these fact sh,eets shows appro-
priate grasses for regions within California. Blue grass is well adapted throughout California except for in the valley
regions. The blue grass is .found on dry, sandy soils that have good drainage. Bermuda grass, on the other hand is well
adapted in the valley region where soils are dry, coarse and heavier. Specific seed mix andlor varieties for e~h site
should be provided ,by an approved/qualified plant materials speclanst.
. ESCto
Construction Handbook s -12 March,1993
•
•
•• •
Additional Information -Seeding and Planting
Plantjn~:
The following steps should be followed to ensure established growth:
1. Select the proper gmss for the site.
2. Prepare the seedbed; soil should be fertilized and contain good topsoil or soil at least a 2: 1 or flatter slope.
3. Broadcast the seedings in the late fall or early spring. In the late fall, seedings should be planted oy mid-Septem~ .
to have established grass by the October rainy season.
4. Initial irrigation will be required often for most grasses, with follow-up irrigation and fertilization as needed.
Mulching may be required in dry climates or dwing drought years.
Trees & Shrubs
Selection;
Trees and shrubs, when properly selected, are low maintenance plantings that stabilize adjacent soils, moderate the
adjacent temperatures, filter air pollutants. and serve as a banier to wind. Some desirable characteristics to consider in
selecting trees an4 shrubs inclUde: .. vigor, specles,.age, size and shape, and use as a,.wildlife food source and ~i~L
Trees and sbrubs to be saved should be clearly marked so that no con~truction activity will take~place within the driplin~ :
of the plant. The sites for new plantings should be evaluated. Consider the prior use of the land: advc;rse soil conditions
such as poor drainage or acidity; exposure to wind; temperature extremes; location of utilities, paved areas, and security
lighting and traffic problems.
Iransvlandn~:
Tune of Year -Late fail through winter (November to February) is the preferred .time 'fonransplanting in most of
California.
Preparation -Proper digging of a tree/shrub includes the conservation of as much of the toot system as possible. Soil
adhering' to the roots should be damp when the tree is dug, and kept moist until re-planting. The soil ball should be 12
inches in diameter for each inch of diameter of the trunk.
Site preparation -Refer to landscape plans and specifications for site and soil preparation, and for ability to-coordinate
construction strategy with permanent vegetation.
Supporting the trunk·-Many newly planted trecslshrubs need artificial support to prevent excessive swaying.
Watering -Soil around the tree should be thoroughly watered after the tree is set in place. Wben the sOil becomes'dry,
the tree should be watered deeply, but not often. Mulching around the base of the tree is helpful in preventing roots from ..
drying out. -
Vines & Ground Covers
Selectioo;
Vines., ground covers, and low growing plants. that can quickly spread. come in many types. colors, aIJd growth habits.
Some are suitable only as part of a small maintained landscape area, while some can stabilize large areas with little
maintenance. Flowers, which provide little long-term erosion control may be planted to add color and varietal· appear-
ances.
ESC10
Construction Handbook 5 -13 March, 19-93
Additional Information -Seeding and Planting .~------------~~~ Caution should be exercised 41 the non-native vegetation because of .impactS to native vegetation on adjacent lands. For
example, species that may be planted at the construction site can quickly spread and compete with originally undisturbed
vegetation such as the California Poppy and California buckw.beat, both of which complete poorly with introduced .
grasses (e.g., planting wild oa!S is illegal in California). In aOdiIion to stabilizing disturbed soil, viile$ and ground covers
can perform the following functions:
1. Provide attractive cover that does not need mowing.
2. Help to define traffic areas and control pedestrian movement.
Sjte marntiou:
Ground covers are plants that naturally grow very close together. causing severe competition for space nutrients and
-water. Soil for ground covers should be well prepared. The entire area should be spaded, disced. or rototilled to a depth
of six to eight inches. Two to three inches of organic material, such as good topsoil or peat. should· be spread over the
entire area. .
P1antin2:
The following steps will.help ensure good plant growth.
1. Make the plantings following the contours of the land.
2. Dig the holes 113 larger than the plant root ball.
3. Know what depth to place the plants.
4. Use good topsoil or soil mixture with a lot of organic matter.
5. Fill hole 1/3 to 112 full, shake plants to settle soil among roots, then water. • 6. Leave saucer-shaped depression around the plant to hold water .
7. Water thoroughly and regularly.
8. Space plants according to the type of plant and the extent of covering desired.
Materjals:
_ There are many different species of vines and ground covers from which to choose, but care must be taken·in their
selection. It is essential to select planting materials suited to both ~ intended use and specific site characteristics. The
plants discussed in this handbook are those which are known to be adapted to California, and commonly available from
commercial nurseries. Additional information can be obtained from local nurserymen, landscape !lI'Chitects, and-exten-
sion agents. An approved low water use plant list may be obtained from the .State Deparanent of Water Resour~ or the
Soils Conservation Service.
I'
RCQujrementS
Mainterianc:e
General requirements include:
• Grass maintenance should be minimal to none. Irrigation and regular fertilizing may be required for some types of
grasses. Mowing is only required in areas where aesthetics or fIre .hazards are a concern.
• Young trees should receive an inch of water each week for the first two years after planting. The tree should be
watered deeply, but not more often than once per week.
• Transplanted trees should be fertilized on an annual basis.
• Proper pruning, watering, and application of fertilizer is necessary to maintain beal~y and vigorous shrubs. A beaVy
layer of mulch'applied around the shrubs reduces weeds and retains moisture. '
• Trim·old growth as needed to improve the appearance of ground covers. Most covers ,need oDce-a-year ~g to
promote growth. ESC10
Construction Handbook 5 -14 March, 1993
•
•
•
Additional Information -Seeding and Planting
I :imitations
• Cousnu¢on activities are likely to injure or kill trees unless adequaIe protective measures are taken. Direct contact
by equipinent is the most obvious problem, but damage is -also caused by ~t stress from filling, e;cavation, or
ccmpacting too cl~ to-trees.
\ • Temporary seeding can only be viable when adequate time is available for plants to grow and establish.
• Over fertil.iZing of plants may cause pollution of storm water runoff.
• Irrigation source and supply may be limiting.
REFERENCES
Best Management Practices and Erosion Control Manual for ConstruCtion Sites. Flood Control District of Maricopa
County, September 1992.
.. Dtaft· Sedimentation and Erosion Control. An Inventory of Cum:nt Practices", U.S.E.P.A., April., 1990.
Guides foiErosion and Sediment Controls in -California, USDA Soils Conservatio~ Ser.n.re -Jan~ i99C
Kiowa Engineering. Interim Erosion and Sedimentation ContrOl for Construction Activities, Urban Drainage and Flood
C9ntrol District. Denver, Colorado.
Manual of Standar$ of Erosion and Sediment Control Measures, Association of Bay Area Governments. ~Un 1981.
Proposed Guidance Specifying ¥an.agement Measures for Sources of Nonpoint Pollution m Coastal Waters, Wark
Group Working Paper, USEP A, April. 1992 •
Stonnwater Management Wa~ for the Puget Sound Basin, Washington State Department of Ecology, The Technical
-Manual·February 1992, Publication # 91·75.
Wattr Quality Management Plan for the Lake Tahoe Region, Volume-II, Handbook of M:.anagement Practic~, Tahoe
Regional Planning Agency· November 1988.
ESC10
-Construction Handbook 5 -15 March,1993
•
•
•
BMP: MU1.CHING
Mulching
GENERAL DESCRIPTION
Mulching is used to temporarily and permanently stabilize cleared or freshly .seeded areas.
. ,Types.of.mulcbes i;nclude organic materials. straw, wood chips, bark or other wood fiberS,
decomPosed granite. and gravel.
SUITABLE APPLICA.TIONS
• Temporary stabilization of fresb.ly seeded and planted areas.
Temporary stabilization during periods unsuitable for growing vegetation.
Temporary stabilization of areas that cannot be seeded or planted (e.g., insufficient
rain, steep slope). .
• Mulcbes such as gravel and decomposed soils may be used as post-construction
·BMPs, particularly in arid regions.
lNSTALLATION/APPLICATION CRITERIA
Mulch prevents erosion by protecting the soil surface and fostering growth of new
seedings that do not stabilize by themselves.
• May be used with netting to supplement soil stabilization.
• A.pply to ~lanting areas wbere slopes are 2: 1 or greater.
• Binders may be required for steep areas, or if wind and runoff is a problem..
• Type of mulch, binders, and.application rates should be recommended by manufac·
turer/contractor.
REQUiREMENTS
• Maintenance
Must be inspected weekly and after :min for damage or deterioration.
• Cost Average annual cost for installation and maintenance (3-4 month useful life.
source: EPA, 1992)
Straw Muicb: $7,500 per acre. .
Wood Fiber Mulch: 53.500 per acre.
Jute Netting: Sl2.500 per acre.
LlMITATIONS
• Wood fiber mulches should be used only in areas with over 20 inches annUal precipi·
tation.
Organic·mulches are not permanent erosion control measures.
Mulches tend to lower the soil surface t.emper.uure, and may delay germ,inaliOD of
som;seeds •
• Permanent mulcbes for arid regions should include gravel and decomposed soils.
Construction Handbook 5 -16
Objectives
'HOUS4HcHping PracDess
6cntBiti W.!St.'
Minimize Disturbsd ArIllS
Centrol Sits PetimetlH'
Ccmtrollntgmal Erosion
Targeted Pollutants
• sediment
Q Nutrients
o Toxic Materials o Oil &: Grease
o Floatable ~terisls o Other ,Construction
Waste
• Ukely tD Htw.
SlgnlffCllnt Imp«:t o ProbMJJ. LDw or
U/Jknown Imp«:~ .
Implementation
Requirements
Q Capital CoSts
~ O&:M Costs
Q Maintenance o Training
• Suitability for
Slopes >6%
• High . bLow
ESC1'1
March,1993
•
• \
•
Additional Information .-Mulching
Mulching protcC1S the soil from rainfall impact; increases infiltration; conserves moisture around trees. shrubs and
seedings; prevents compaction and cracking of soil; and aids plant growth for seedings andplantiugs by hol~g the
seeds, fertilizers and topSOil in place until growth occurs. Mulches include organic 1IlMeria.ls, straw, wood chipS; bad:: or
other wood fibers, decomposed granite and graveL A variety of nettings or. ma.rs of organic or non,.organ.ic materials and
c.bemica.l soil stabilization are practices that may be used conjunctively with mulching.
Mulching may be applied to all graded and cleared areas of the construction site:
• Areas which ~ve been permanently seeded to assist in retaining moisture. and' to bold seedings;
• Areas which need temporary soil surface protection because seeding cannot occur due to IDe season;
• Areas between t;rees, shrubs and certaip. ground covers;
• Areas where climatic conditions require a soil moisture retention aid to avoid cracking of the soil and associared
compaction. and require soil temperarure modification.
InstalIation/APl'Iicatiop Criteria
Only'a set of general·guidelines is included for application and installation of mulching on diswrbed lands 1x:cause of the"
variousc1imates. soil conditions and land uses in Califomla Installation of mulch consists of furnishing aU materials.
preparing the soil surface and applying the mulch to all soil surface areas designated on the project plans or estahlished ..
by tbe site engineer.
Mau:rjals
Organic mulch materials, such as straw, wood chips, bark and wood fiber, M.ve been found to be most effective where
re-vegetation will be provided by reseeding. The choice of mulch should be based·on the size of the area. site slopes,
surface'conditions such as hardness ·and moisture; weed growth and aVailability of mu1ch materials •
Wood Fiber Mulches: Wood fibe1: mulches consist of specially prepared wood fiber processed to coIitain no growth
germination inhibiting factors. The mulch should be from virgin wood, and be manufactured and pr:ocessed.so the fiberS
will re~ in unifonn suspension in water under agitation to fonn a h~ogenous slurry. The fiber lengths should be as
loog as possiQle to increase the effectiveness for erosion control. Wood fiber mu1cbing should not pc used in areas of
extremely bot summer and late fall seasons because of fire danger. When used as a tacldfier with straw mulch, wood
fiber mulches are good for steep slopes and severe climates. The California Office of the Soils CCioservation Service
recommends a non-toxic mu1ch green dye be used to provide a visual aid in metering applications.
Wood Chips and Bark Chips: Wood and 0axX chips are suitable for application in landscaped area,s that will not be
closely mowed. Wood chips do not require tacking, but do require nitrogen treattnent (14 pounds/ton) to prevent nutrient
deficiency. Barl:: chips do not require additional nitrogen fertilizer. When. the wood source is near the project site, wood .
and tmk chips can be very inexpensive. CautiOD must be used in areas of steep slopes, since both wood ~ bark cbips
tend to wash down slopes exceeding 6 percent.
Straw Mulch: Straw mu1ch is a good short-tcm1. protection most commonly used. with seeding. The mulCh should be
from'tb~ current season's crop. A letter of certification from the supplier should be required to show that the suaw was
baled less than 12 months from the delivery date. Wheat or oat suaw is recommended.
Emulsirled Asphalt: Asphalt is used to adhere the mulch to the ground surface, preventing·the mulch from blowing or
washing off. The type. and quantity of asphalt used should not result in a stOrm water pollution problem.
Binder-: . Binder should be free flowing, nODcorrosive powder produced from nawral plant gum such as those Jilarketed
under M-Bindcr, M14S Binder. or AZ-TAC. Synthetic, spray-on materials are Dot recOmmended since thev tend to
create an impervious sllIface. and may enter the stormwater sewer system via discharge ,nmoff. ESC11
Construction Handbook 5· 17
~ .. .'
s.ot
Pr-='-
Mal'ch,. 1993
•
•
• I
Additional Information -Mulching
Prepara!iop::/MetbO<is and Equipment
Straw Mulch: Should be applied in an even. uniform manner, either by hand or by mulch blowing equipment· Straw
mulches must be anchored to prevent the mulch froni ~ing blown or washed off the site. Anchoring is achieved in twO
ways:
• Crimping: The mulch is anchored by running a heavy disc with flat, dull, serrated, closely-spaced blades over the
mulched soil. Effective crimping embeds the mulch about 2 inches into the soil without completely covering it The
disc should be run once or twice across the soil. About 2 112 tons of straw mulch per acre should be applied if the
mulch is anchored by crimping.
• Tack:ing: Achieved using a emulsified asphalt or binder either independently or followed by crimping. If taCked.
straw mulch may be applied at a rate of 1 3/4 ton per acre, and tacked with emulsified asphalt at a rate of 500 gw,.IOt;ls·
per~.
Wood Fiber Mulch: Typically applied with a hydroseeder at a rare of about 1000 to 1500 pounds per acre, or as a slurry
consisting of at least 150 pounds of binder, 400 pounds of wood fiber mulch, and 200 gallons of water per acre.
Reg1!jrements
Maintenance: Mulched areas require frequent inspection for damage and deterioration. Requirements will vary greatly
based on the type of mulch used and the type of vegetation to be established. Vegetative mulches are usually not
intended to be permanent; but are extended only as a base for re-seeding or re-vegetation. Where a permanent anchor for
vegetation is required, along steep slopes or areas of higher velocity flows, then a geotextile mat or net is recommended
(see ESC20).
REFERENCES
Best Management Practices and Erosion Control Manual for ConstruCtion Sites, Flood Control District of Maricopa
County, September 1992.
Controlling Erosioo of Construction Sites, U.S. Department of Agriculture, Soil Conservation Service, Agriculture
Information # 347.
"Draft -Sedimentation and Erosion Control. An Inventory of ClIJl'Cnt Practices", U.S.E.P.A.. April. 1990.
"Environmental Criteria Manual", City of Austin. Texas.
Guides for Erosion & Sediment Control in California. USDA Soils Conservation Service -JanuarY 1991.
Manual of Standards of Erosion and Sediment Control Measures, Association of Bay Area Governn:lents, June 1981.
Proposed Guidance Specifying Management Measures for Sources of Non point Pollution in Coastal WcitJ!rs, Work Group
Working Paper,.USEPA, April, 1992.
Soil Erosioo by Water, U.S. Department of Agriculture, Soil Conservation District, Agriculture Information Bulletin·
#513.
Stormwatcr Managcqlent Watt:r for the Puget Sound Basin, Washington State Deparonent of Ecology, The Technical
Manual-February 1992, Publication # 91-75.
Water Quality Management Plan for the Lake Tahoe Region, Volume II, Handbook of Management Practices, Tahoe
Regional Planning Agency -November 1988. ESC1 t .
Construction Handbook s -1~ March, 1993
...
BMP: DUST CONTROLS Objectives ~,~----------------------------------------~~cE:~H~~Pmc~
~
~
GENERAL DESCRIPTION
Dust CODuol measures arc used to stabilize soil from wind erosion, and reduce dust
generated by coD$truction activities.
t .,:
'SUIT ABLE APPLICATIONS
• OeariDg and grading, activities.
• Construction vehicle traffic on unpaved roads.
• Drilling and blasting activities.
• Sediment tracking onto paved roads.
• Soil·and debris storage piles.
• Batch drop from froot end loaders.
• Areas with unstabilized soil ..
• Final.grading/site stabilization usually is sufficient to control post-construetion dust
sources.
INSTALLATION/APPLICATION CRITERIA
• Schedule construction activities to minimize exposed area (See ESC 1).
• Quickly stabilize exposed soils using vegetation, mulching, spray-on adhesives,
calcium,ch!oride;sprinkling, and stonelgravellayering (See ESC 10 and 11).
• Identify and stabilize key access points prior to commencement of construction (See
ESC 24).
• Minimizing the impact of dust by anticipating the direction of prevailing winds.
• Direct most construction traffic to stabilized roadways within the project site (See ESC
23).
REQUIREMENTS
• Maintenance
Most dust control measures require frequent. often daily, attention.
• Cost
Contain Wssts'
Protect SlopeSIChanMis
,@roI Site PerimeJE;>
Controllntsmal Erosion
Targeted Pollutants
.' Sediment o Nutrients
Q Toxic Materials
Q Oil & Grease
o Floatable Materials
o Other Construction
Waste
• Likely to HlIVfI
Slgn/Ocant Imf'l'Ct
0 Probllbifl /..Qw or
Unknown implIPt
Implementation
Requirements
0 Capital Costs
Q O&MCosts
Q Maintenance
0 Training
0 Suitability for
Slopu>5%
Installation costs lor water/chemical dust suppression are low, butannual costs • Hiqh O· Low
may be quite high since these measures are effective fot" only a few hours to a few ~====:::::;;;;===:!.I
days.
LIMITATIONS
• Watering prevents dust only for a short period and should be applied daily (or mo~
often) to be effective.
Ovcrwatcring may cause crosion.
~ , Oil shOuld not be used for dust control because the oil may migrate into d.rninageway
and/or'seep into the soil.
• Certain chemi~y-treated subgrades may make soil :water rcpellant. increasin,g runoff.
Construction Handbook . S -2S
ESC21
M~rch, 199~
•
•
••
----
Additional Information -Dust Controls
California's mediterranean climate, with short wet seasons and long hot dry 5eaSOJ:!S, allow the soils to thoroughly dry
out. During these dry seasons, consauction activities are at their peak. and disturbance and exposed areas are increas-
ingly subject to wind erosion, sediment tracking and dust generated by consauction equipment.
Dust control, as a BMP, is a practice that is already in place for many consauction activities. Los Angeles, the Nortb.
Coast and Sacramento, among others have enacted dust control ordinances for constructiOD' activities that cause dust to be
trnnsported beyond the construction project property line. Recently, the State Air Resources. Control Board has, under the
authority of the Clean Air Act, started to address air quality in relation to inhalable particulate matter less than 10 microns
(PM-IO). 90% of these small particles are considered to be dust Existing dust control regulations by local agencies,
municipal departments. public works department. and/or publiC health departmentS are in place in some regions within
California. For jurisdictions that have no formal dust control regulations andlor standards, Sections 10, 17 and 18 of
CalTrans' Standard Specifications provide detailed provisions for dust control practices.
Many local agencies require dust control in order to comply with local nuisance J..aws, opacity laws (visibility impair·
Dient) and the requirements of the Clean Air Act The following are measures that local agencies may 'have already
implemented as requirements for dust control from contractors:
• Constrgction & Gradine PeonHs: Require provisiOns for dust control plans;
• Oj2adty Emission Limjts: Enforce compliance with California air pollution control laws;
• Increase oyerall enforcement actiyjties: Priority given to cases invelving citiZen complaints;
• Majntajn Fjeld AptlUcatiou Records: Require records of dust control measures from contractor,
• StoUDwater Pollution Preyention Plan' (SWPPP): Integrate dust control measures into S'WPPP.
Dust Control Practices
Dust control Bl\.1P's generally stabilize exposed surfaces and minimize activities that suspend or track dliSt particles .
Table ESC21.1 shows which Dust Control BMPs apply to site condi.tions which cause dust For beavily traveled and
distuibed areas, wet suppression (watering), chemical dust suppression, gravel or asphalt surfacing, temporary gravel
construction entrances, equipment wasb-out areas, and haul. truck covers can be employed as dust control applications.
Permanent or temporary vegetation and mulching and sand fences can be employed for areas of occasional or no con-
struction traffic. Preventive measures would include minimizing surface areas·to be disturbed, limiting on-site vehicle
traffic to 15 miles per hour, and controlling the number and activity of vehicles on a site at any given time.
Many of the reasonably available control measures for controlling dust from cons auction sites can also be implemented
as BMPs for StorD:t water pollution prevention. Those BMPs include:
• Pave, vegetate. 01' chemic3l.ly stabilize acCess points where unpaved traffic surfaces adjoin paved roads.
• . Provide covers for l1aul trucks transporting JIl.lU,erials that contribute to dust
• Provide for wet suppression or chemical stabilization of exposed soils.
• Provide for rapid clean-up of sediments deposited on:paved roads. Furnish stabilized construction road eOtrantes
and vehicle wash down areas.
• Stabilize unpaved haul roads, parking and staging areas. Reduce speed and trips on unpaved roads.
• Implement dust control measures for material stockpiles.
• Prevent drainage of sediment laden storm water onto paved surfaces.
• Stabilize abandoned construction sites using vegetation or cbemical stabiliZation methods.
• Lim;.t the amount-of areas disturbed by clearing and earth moving operations by scheduling these activitieS in phases.
For the chemical stabilization, there are many products available for chemically stabilizing gravel roadways and stock-
piles. The types of chemicals available and recommendations for their use are tabulated in Table ESC 21.2, C~only
Used Chemicals for Dust Control.
Construction Handbook 5 -26
ESC2:t
~ .. ,
a..c '
~.'
March, 1993
•
•
•
Additional Information -Dust Controls
In addition, mere are many other BMPs identified in this handbook that provide dust control including:
• Seeding and Plantings (ESC 10)
• Mulching (ESC 11)
• Construction Road Stabi.liz.ation (ESC 23)
• Stabilized Construction Entrances (ESC 24)
Limitations
• Oil treated subgrades should not be used because the oil may migrate into drainageways and/or seep into the soil.
• Qlc:mically ~ subgrades may make the soil water repellant, interfering with long-teml infiltration, and the
vegetationlre-vegetation of the site. Some chemical dust suppressants may be subject to freezing and may cont?iD
solvents and should be handled properly.
• Asphalt, as a mulch tack or chemical mulch, requires a 24 hour curing time to avoid adhere~.e to equipment:, worker
shoes. etc. Application should be limited because asphalt surfacing may eventually migrate. into the .drainage . syStem. .... . .'. '. . " . ,,":
• In compacted areas. watering and other liquid dust control measures may wash Sediment or other.constituents into
the drainage system. '
REFERENCES
Best Management Practices and Erosion Control Manual for Consuuction Sites. Flood Control District of Maricopa
Countr. Arizooa. September 1992.
California Air Pollution Cont:rQl Laws. California Air Resources Board, 1992.
CalTrans. Standard Specifications. Sections 10. "Dust Cootrof"; Section 17, "Watering"; and Sec:tion 18, "Dust Pallia-
tive".
Prospects for Aaaining the State Ambient Air Quality Standards for Suspended Particulate Matter (PMIO), ViSIbility
Reducing Particles .. Sulfates. Lead, 2nd Hydrogen Sulfide. California Air Resources Board, April 1991.
Sacramento County, Wmtcrization Ordinance & Dust Control Ordinance (example).
USDA Soil Conservation Service, "Guides for Erosion and Sediment Control".
ESC21
Construction Handbook s . 27 Mar!=h, 1993
(j a ~ n tr. g
~ &. g
~
til
N 00
:s:,
Cl "I F-
......
\CI ~
•
SITE
CONOITION
Disturbed Areas not
Suhject to Traffic
Disturbed Arens
Subject to Trunjc
Material Stock Pile
StabililJ\lion
Demolition
C.learitlgJExcavatioll
Truck Traffic Oil
Unpaved Roads
MudiDirl Carry-Out
• •
TABLE ESC 21.1 DUST CONTROL UMPs FOR GIVEN SITE CONDITIONS
-----~--~-----.--.-~----------~-.-----------,
UUST CONTROL 1If1-II's I
,
1'empoJ1lry G I1Ivtl Mlllhnlzt
! W~l Chemiclll (:l1Ivl!1 (lr Cllllstrucllun 1111111 ":xlellt
I'~nmlllcl\l SUllpressluIl Dust Asphlllt SlIlId i!:.llr.ulcesfEqullllllcllt Truck uf AnH
Vel:ctlillull Mulchlnc (WlIlt'rlng) SUI'llrrsslull Surfaclllil Fellcl's Wash nU\\11 Cuvl'rs Illslurol'd
X X X X X X
X X X X
X X X X
X X X
X X X
X X X X
X X
•
•
•
8 M P: TEMPORARY CRAINS AND SWALES
GENERAL DESCRIPTION
Temporary drains and swales are used to divert off-site runoff around the construction site,
divert nmoff ~m stabUized areas around disturbed areas,. and direct nmoff into sed~e.nt
basins or traps.
. SUITABLE APPLICATIONS
Temporary drains and swales are appropriate for diverting any upslope runoff around
unstabilized or disturbed areas of the construction site:
• Prevent slope failtm:s.
• Prevent ~ge to adjacent property.
• Prevents erosion and transpon of sediments into water ways.
• '. Increases the potential for infLltration •
• Diverts sediment-laden runoff into sediment basins or traps.
INSTALLATION/APPLICATION CRITERIA
Temporary drainage swales will effectively convey runoff and avoid erosion ifbuilt properly: .
• Size temporary drainage swales using local drainage design criteria.
• A permanent drainage channel must be designed by a professional engineer (see the
local drainage design criteria for proper design).
• Ata miniI;lum, the drainlswale.should conform to.predevelopment·drainage patterns
and capacities.
• Construct the drainlswale with an unintemlpted. positive grade to a stabilized outleL
• Provide erosion protection or energy dissipation measures if the flow out of the drain
or swale can reach an erosive velocity;
REQUIREl\1ENTS
• Maintenance
Inspect weekly and after each min.
Repair any erosion immediately.
Remove sediment which builds up in the swale and restricts its flow capacity.
• Cost
The cost of a drainage swale incrCases with drainage area and slope. Typical.
swales for controlling intcmal erosion are inexpensive.
LlMlTATIONS
• Temporary drains and swales or any other diversion of runoff should not adversely
impact upstream 01' downstream properties.
• Temporary drains and swales must conform to local floodplain management require-
ments.
Construction Handbook 5 -44
Objectives
Housakl18ping Practices
Cont3in waSta
Minimize DisturNd Arw
Stabilize Disturbed Arsas
Cl§9Ct S/OpesiChanEJp
Cf£(1trol Site PflrimsJjp
@[Itrallnternal Erosi'Qjj;>
Targeted Pollutants • Sediment
0 Nutrients
0 Toxic Materials
0 Oil & Grease
0 Floatable Materials
0 Other Construction .
Waste
• Ukll/y to Have
Slgn!flc.nHmplICt
0 Pro~/.Low or
Unknown implICt
Implementation
Requirements
Q Capital COStS
0 O&'M Costs
0 Maintenance
·0 Training
~ Suitability for
Slopes >50/.
• High 0 Low' I
ESC31
e
e-
e--
Additionallnformation--Temporary Drains and Swales
Slopes that are formed during cut and fill-operations should be proteCted from erosion by runoff. A combination of a
temporary drainage swale and an earth dike (see ESC30) at the top of a slope can safely divert runoff to a lQCatioo wbete it
can $afely be brought to the bottom of the slope (see Pipe Slope Drain ESC32). A combinatioo dike and swale is easily
CODStructed by a siDile pass of a bulldozer or grader and compacted by a second pass of the tracks or wheelS over,the ridge .•
DiversiOli structm:es should be installed when the site is initially graded. and remain in place until post~ODStrUctioo BMPs
are installed and/or the slopes are stabilized. ...s.
Diversioo-practices concenttaIe the volume of surface runoff. iriaeasing its velocity and erosive force. Thus, the flow otit
of the drain orswale must be directed ontO astabiliz.edarea orintO a grade stabilization strucoire. A ~wa1e should-be stabilized
using vegeration. chemical treatment, rock rip-rnp, matting, or other physical means of stabilization, if significant erosion
will occur. A1J.y drain or swale which conveys sediment-laden runoff must be diverted into a sediment basin or trtIp before
it is discharged from the site.
InstallationlAPlllicatiou Criteria
PiversiOD drains or swales arc only effective if they are properly installed. S wales -are morc effective than dikes,because they -
tend to be more stahle. The combination of a swale with a dike on the downhill side is the most cost-effective diversion. -
Standard engineering design_ criteria for small open channel and closed conveyance systems should be used-(~ the local
drainage design manual). Unless local drainage design criteria state O(ilcrwlse, drnins or swales shoull,i be designed as
fonows:
• No more than 5 acres may drain to a temporary drain or swale
Place the drain or swale above, not on, a cut and fill slope
Swa1e bottOm width should be at least 2 ft
•
•
•
•
•
•
•
•
•
•
•
Depth of the swale should be at least 18 inches
Side slopes should be 2:1 or flatter
Drain or swale should be layed at a grade of at least 1 percent, but not more than 15 percent
The swale must not be overtopped by the lO-year, 24-hour stonn. irrespective of the design critc:ria Stated above
Remove all trees. srumps, obstructioos, and other objectionable material f:rOm the .swale when it is -built
Compact any fill m.atc:rial aloog -the path of we swale
Stabilize all swales immed.ia.rely. Seed and mulch swales at a-slope ofless than' 5 percent, and ~ rip-rap or sod for
swales with a slope between 5 and 15 percent .
Do not opc:nuc CODSttUction vehicles aaoss a swale unless a stabilized crossing is provided.
The cost of swales and other diversion devices is generally included in the earthwork cost, as a separate item under
thC grading budget of the project construction contract.
REFERENCES
Best Management Practices.and Erosion Control Manual for Construction Sites, Flood Control District of Maricopa
COUllty, Arizona, September 1992. -.
.. Draft -Sedimentation and Erosion Control, An Inventory of Current Practices", U.S.E.P.A.. April, 1990.
Manual of Standards of Erosion and Sediment Control Measures, Association of Bay Area Govenu:nents. June 1981.
Stotmwater Management Water for the Puget Sound Basin. WashingtOn State Department of Ecology, The Technical
Manual-February 1992, Publication # 91-75.
W~ ~tY. Management Plan for the Lake Tahoe Region, Volume II, Handbook ofManagemeot
Practices, Tahoe Regional Planning Agency -November 1988.
Construction Handbook S -4S
ESC31
March, 1993
Additional Information -. Temporary Drains and Swales •. ~--------------------------~~
2' (MIN.) ST ABILlZATION
LEVEL
• CROSS SECTION
0.5% OR STEEPER.
DEFENDENT ON TOPOGRAPHY
'ST ABLE OUTLET REaUIRE
PLAN
TEMPORARY DRAINAGE SW ALE
ESC31 •
Construction Handbook March, 1993 .
•
•
•
BMP: CHECK DAMS
I
GENERAL DFSCRlPTION
Small temporary dams constructed across a swale or drainage ditch. Check dams reduce
_ the velocity of concentrated stormwatcr flows. thereby reducing erosion of the swale or
ditch. and promoting ~entation behind the dam. If properly anchored, brush or rock
filter berms (ESC53) may be used for check dams.
SUITABLE APPLICATIONS
usC<! to prevent erosion by reducing the velocity of channel flow in small intetmittent
channels and temporary swales.
• May also promote sedimentation behind the dam, but should not be considered to be a
primary sediment trapping device because subsequent storms will scour and resus·
pend much of the trapped sediment.
INSTALLATION/APPLICATION CRITERIA
• Check dams should be placed at a distance and height to allow small pools to form
between each one.
• -BackwaterJrom a downstream checi:: dam should reach the toe of the upstream chec)c
dam.
• Major floods (2 year storm or larger) should safely flow over the check dam_ without
an increase in upstream flooding or desttuction of the checkdam.
• Primarily used in small. steep channels where velocities exceed 2 fps.
• Used in steep temIin whex:c velocity reduction is required.
• A deep sump may be provided immediately upstream of the check dam to captlire.
excessive sediment.
• Check dams may be built of rocks or logs. which are secured against d3mage during
significant floods.
REQUIREMENTS
• Maintenance
Inspect for sediment buildup behind the check dam and signs of erosion around
the check dam after each min.
Remove accumulated sediment whenever it reaches one"balf the sump depth.
• Cost
See CalTrans Cost Schedule for regional cost data.
LlMITATIONS
Usc only in small open channels which dxaiD 10 acres ofless.
• Not to be used in live streams .
• Do not install in lined or vegetated channels.
Construction Handbook S· S6 -
ObjectJves
HOUS4klHlping Pf3Ctic.!
Contain Wast.
.J.finimizs DisturiJed Areas
Stabilits Disturbed A/'U4S
~tBCt_Slop9SIchan~
. Control Sits Perimeter
Cantrollntemal Erosioir
Targeted Pollutants
• Sediment
o Nutrients o Toxic Materials
0-ai/ It Grease _
o FlOatable Materials
o Other Construction
Waste
• Uke/y tDHllVtI
Significant Impact
0 ProINtbItl Low or
_ Unknown Imp . .:t
Implementation
Requireinen-ts
-Q Capital Costs
0 OltM. Costs
~ _Maintenance
0 Training
0 Suitability far
SJapes>5%
.. High 0 Low I-
ESC41
March,1993
•
•
•
Additional Information -Check Dams
Check dams crca.tc small poOls in swales and ditc1les whicll drain 10 acres or less. These pools reduce the v!=locity of
SWIDl water flows. thus reducing erosion of the swalelditch. Sedimentation also occurs in these smallp<>ols, but probably
results in little net sediment removal ~se of the small detention time and probable scour during longer stormS. A
sediment trap (ESCS5) may be placed immediately upstream of the check: dam to increase sedin'ient removal efficiency
(but never in a nawral Stream or channel). Check dams should not be placed in swales/ditches with a base flow duriilg
some or all of the year.
In$taUatioolr\pplicatiOQ Criteria
Check dams must be sized and constructed correctly and maintained properly, or they will be either washed out or cause
flooding. Check dams can be coostructed of either rock or logs. Use of other nacufal materials available on .. site that can
witbstand the stormwater flow velocities is acceptable, such as pea-gravel fIlled in S<llld bags. Check dams should IU:ll be
constructed from sttaw bales or silt fences. since concent:rnted flows quickly washout these materials.
A sediment trap (ESCSS) may be installed immediately upstream of the check dam, but may be of limited effectiveness·
if channel flows are large enough to scour the ttap during moderate to large stomis~ Maximum velocity reduction is
achieved if the toe of the upstream dam is at the same elevation as th~ 'top of the downstream dam. The center section of
the dam should be ,lower than the edge sections so that the check dam will act like a weir during major floods.
Rock check dams are usually constructed of appropriately 8"-12" rock. The rock is placed either by band or mechani-
cally, but never just dumped into the channel. The dam must completely span the (!itch or swale to prevent washout. The
rock used must be large enough to Stay in place given the expected design flow through the Channel.
Log check dams are usually conscructed of 4 to 6-incb diameter logs. The logs should be embedded into the soil at l~t
18 inches.
If grass is planted to stabilize the ditch or swale, the check dam should be removed when the grass bas matured (unless
the slope of the swale is greater than 4 percent).
REFERENCES
Best Management Practices and Erosion Control Manual for Construction Sites, Flood Control Disuict of Mariposa
COImty. Arizona, September 1992.
"Dm.ft -Sedimentation and Erosion ConttOl, An Inventory of Cunent Practices", U.S.E.F.A.. April, 1990.
Manual of Standards of Erosion and Sediment Control Measures. Association of Bay Area Governments. June 1981.
StoIDlwatcr Management Water for the Puget Sound Basin. Washington State Department of Ecology, The Techniqil
Manual-February 1992, Publication # 91-75.
Water Quality Management Plan for the Lake Tahoe Region, Volume II, Handbook of Management Practices. Tahoe
Regional Planning Agency -November 1988. .
ESC41
Construction Handbook S -57 March,1993
Additional Information -Check Dams .~. --~--------------~
•
•
4--6'" LOGS--.. \
FLOW
Construction Handbook
\ \ \ ,
w:
I
LOG CHECK DAM
ROCK CHECK DAM
ROCK CHECK DAM CROSS-SECTION
L • THE DISTANCE SUCH THAT POINTS .
A & B ARE OF EQUAL ELEVATION
. SPAClNG BETWEEN CHECK DAMS
5 -58
.... .
ESC41
..~
March,1993
•
•
•
BMP: SAND BAG BARRIER
GENERAL DEFINITION
Stacking sand bags along a level contour creates a barrier which detains sediment-laden
war.c:r, 'po~ding ,water: ups~ of the barrier an4 promoting. sedimentation; . . . -' ,.
SUITABLEA.PPLICATIONS
• Along the perimeter of the site.
• Check dams across streamS and channels.
• Along streams and cbannels.
• Barrier for utility trenches in a channeL
• Across swales with small catchments.
• Division dike or berm.
• Below the toe of a cleared slope.
• Create a ~porary sediment trap.
• Around temporary spoil areas.
• Below other small cleared areas.
INSTALLATION/APPLICATION CRITERIA
• May be used in drainage areas up to 5 aaes.
• Install along a level contour.
• Base .of sand bag barrjer should be at least 48 inches wide.
• Height of ~bag barrier'should be at least 18 inches high.
• 4 inch. PVC PiPe ma.y be installed between the top layer of sand bags to drain large
flood flows.
• ·Provide area behind barrier for runoff to pond aDd sediment to settle, size according to
sediment trap BMP criteria (ESCS5). .
• Place ~ the tee of a slope.
• Use sand bags large enough and sturdy enough to withstand major flooding.
REQUIREMENTS
• Maintenance
lDspect after eacb rain.
Reshape or replace damaged sand bags immediately.
Remove sediment when it reaches six inches in depth.
• Cost
Sand bag barriers are more costly, but typically have a longer useful life than
other barriers.
LIMITATIONS
• . Sand bags arc more expensive·than other barriers, but also more durable.
• . Burlap should not be used for sand bags.
Construction Handbook 5 -71
I
Objectives
HoUS41kseping Practicas
Contain Wasta
Minima. DistlJrb«i AraB!
StabiliZl Disturbed AlNS
c:e€tSct SlopesiChan"i!!!P
c€ntroI SitB Perime];D
<:t:i..titroIlntllmal Eros"tiD
Targeted Pollutants • StKiiment
0 Nutrients
0 Toxic Mllterisis
0 Oil & G/'t!lJ5e
0 Floatable Milterials
0 Other ConstructiOn
Waste
• Uk./y to. Hfti •.
Slgn/~nt ImpllCt
0 ProJJ.b'-Low or
Unknown ImplICt
Implementation
Req ui raments • Capital CO$ts
0 0&:1.1 Costs
'0 Maintenance
0 Training
~ Suitability for
Slope,$>5%
.1 • High 0 Low t
ESC52
March,. 1993
•
•
•
Additional Information -Sand Bag Barrier
Snjtahle Applications
Sand bag berms may be used during construction activities in stream beds and utility construction in chapnels, temporary
cbanncl aossing for construction equipment, etc. Sand bag berms may also be installed parallel [0 roadway constrUc-
tion. Sand bag berms'may also be used to aeate tempOrary sediment trapS, retention basins and in place of straw bales
or silt fences. Examples of applications include:
• Check dams aaOss stream channels.
• Barriers for utility trenches or other construction in a stream channeL
• At temporary cbannel aossings.
• May be used on a slope where straw bales and silt fences are not appropriate.
• N. a diversion ~.
• Embankment' for a temporary sediment basin or retcltion basin.
• Sediment baITicrs'near the toe of slopes.
• At construction perimeter. , .
AdyantafQi
• Provides a semi-permeable baxrier in potentially wet areas.
• More permanent than silt fences or Straw bales.
• Allows for easy relocation on site to meet changing needs during construction.
InsraUarionlAwlicarion
Sand b;lg barriers may be used for sediment trapping in locations where silt fences and straw Dale barrierS are not strong
enough. In addition, sand bag barriers are appropriate to use when construction of ch~k dams Or sumps in a stream is "
undesirable. The sand bag berms can provide the same function as a check dam without.disturbing the stream or
vegetation. The sand bag berm will also allow a small sediment reterition area to be created prior to·construction of final <
detention basins. For installation of a sand bag beIm, the fonowing criteria should be observed:
• Drainage Area -Up to five (5) acres.
• Height of Berm -18 inches minimum height, measured from the top of the existing ground at the upslope tpe to the
top of the barrier.
• Width of Berm -48 inches minimum width measured at the bottom of the barrier, 18 incpes at the top. . '.
• Sand,bag Size -Length 24 to 30 inches, width 16 to 18 inches and thiCkness six (6).toeigbt (8) ipchcs. Weight 90 to
125 pounds.
• Sand bag Material-Polypropylene, polyethylene or polyamide woven fabric, minimum unit we~ght four (4) o~ces
per square yas;d. mullen burst strength exceeding 300 psi and ultraviolet stability exceeding 70 percent. Use of
burlap is discouraged since it rots and deteriorates easily.
• Grade of Sand -Coarse sand, gzavcl.
• Runoff water should be allowed to flow over the tops of the sand bags or throUgh four (4) inch .polyvinyl chloride
pipes embedded below the top layer of bags.
• .Area behind the sand bag baxrier should be established according to sizing criteria for sediment trap B:MP (;ESC55).
REFERENCES
Best Management Practices and Erosion Control Manual for Construction Sites, Flood Control Dismct of :Maricopa
County. Arizooa. September 1992. '
Wav:.r Quality Management Plan for the Lake Tahoe Region. Volume TI. Handbook of Managcment
Practices, Tahoe Regio~ Planning Agency -November 1988 .
Construction Handbook 5 -72
ESC52
March; 1993
Additional Information -Sand Bag Barrier .~------------~----~
4-PVC PIPE
FLOW . ..
•
•
Construction Handbook
18" MIN
I-
I ,-6'" MIN
/ DIAMETER ROCK y
48" MIN 48'" MIN
CROSS-SECTION
WOVEN F A8RIC SAND8AG FILL.ED WITH
COARSE SAND-MIN WEIGHT 40 L8S •
4" PVC PIPE FOR DRAINAGE
DEPENDING ON FIELD CONDITIONS
24 .... MIN
FRONT YIf;-W
SAND BAG BERM.
5 -73
12"
ESC52
March,1993
•
•
BMP: STORM DRAIN INLET PROTECTION
GENERAL DEFINITION
Devices of various designs which detain sediment-laden runoff and allow the sediment it to
settle prior to disc~e into a storm drain inlet or cacch basin.
SUITABLE APPLICATIONS
• Every stoIm drain inlet receiving sediment-laden runoff should be proteCted. either by
covering the inlet or promoting sedimentation upstream of the inlet.
INSTALLATION/APPLICATION
• Five types of ' inlet protection are presented below, howev~, it is recognized that other
effective methods and proprietary device. e:tist and may be selected:
Flltcr Fabric Fence: Appropriate for drainage basins less than one acre with leSs
than. a 5 percent slope. .
Block and Gmvel Fllter: . Appropriate for flows greater than 0.5 cfs.
Gmvel and Wire Mesh Flltcr: Used on curb or drop inlets where coristruction
equipment may drive over the inlet.
Sand bag barrier: Used to create a small sediment trap upstream of inlets on
sloped. paved streets.
Excavated Drop Inlet Sediment Trap: An excavated area around the inlet to trap
sediment (see Sediment Trap ESC 55).
• Select the appxopxia1e type of inlet protection and design as referred to or as desaibed
in this fact sheet. '
• Usc only for drainage areas smaller than one acre unless a sediment !rap flISt intercepts
the runoff.
• Provide area around the inlet for water to pond without flooding structures and
property.
REQUIREMENTS
• Maintenance
Inspect weekly and after each rain.
Replaceclogged filter fabric or stone filters immediately.
Remove sediment when depth exceeds half the height of the filter, or half the
depth of the sediment trap.
Remove as soon as upstream soils arc stabilized and streets are swept.
• Cost-(soma:: EPA. 1992)
Average annual COSt for installation and maintenance (1 year useful life) is $150
per inlet.
Construction Handbook 5·79
Objectives
Housab-eping PtaCticas
ContaiiJ Wssts
Minimize Disturb«! NNS "
Stabllizs Disturb«JArass
Pro~t Slopes/Channels
Targeted Pollutants
• Sediment
'0 Nutrients
."
0 Toxic Materials
0 Oil&-Grease
~ Floatable Materials
0 Other Construction
Waste
• Ubly to HlIVfI
Significant Im".:t
0 PrvbabJ. Lew or
Unknown Imp.:t ""
Implementation
Requjrements
~ Capital Costs
0 OlcM Costs
~ Maintenance
0 Training
0 Suitsbility for
Slopes >5%
• High 6 Low '1"
ESC54
March,1993
• BMP: STORM DRAIN INLET PROTECTJON (Coritinu~)
LRrfiTATIONS
• Drainage area should not exceed 1 acre.
• Runoff will bypass protected inlets on slopes.
• Ponding will occur at a protected inlet. with possible short-term flooding.
• Straw bales are lJ.llt effective for inlet proteetion.
-
..
. '
• ,
.
• ESC54 .
~ .~.
Construction Hand~k 5 -80 March, 1993
•
•
•
Additional Information -Storm Drain Inlet Protection
S toIIIl drain inlet procection consists of a sediment filter or an impounding area around or upStream of a stonndraiJl, drop inlet,.
or curb inlet. This erosion and sedimentation control BM? prevents excessive sediment from entering storm drainage system,s
prior to peIID.aDent stabilization of the disturbed area.
All on-site storm drain inlets should be proteCted. Off-site. inlets should be protected in areas where construction activity
ttacks sediment onto paved areas or where inlets receive runoff from disturbed areas.
InsmIJarionlAp!icatiop Criteria
Planning
Large amounts of sediment may enter the storm drain system when stozm drains are installed before the upslope drainage.area
is stabilized, orwherc construction is adjacent to an existing stoIIll·d.rain. In cases of extreme sediment loading. the storm drain
itself may clog and lose a major portion of its capacity. To avoid these problems, it is necessary to prevent sediment from
entering the system at the inlets. .
. Inlet control measures presented in this handbookshouldnotbe used forinlets draining more than.oneacre·' ·Run0ff·from.)arger '
disturbed areas should be first routed through a Temporary Sediment Trap (see ESC 56). Different types of inlet protection.
are apptopria1e for different applications depending on site conditions and the type of inlet. Inlet protection methods not
presented in this handbook should be approved by the local Stoml water management agency.
General Design and sizing criteria:
• Grates and spaces around all inlets should be sealed to prevent seepage of sediment-laden water.
• Excavate sediment sumps (where needed) 1 to 2 feet with 2: 1 side slopes around the infet.
Installation procedures for filter fabric fence:
a. Place 2 inch by 2 inch wooden stakes around the perimeter of the inlet a maximum of3 feet apart aDd drive.them ~t least
8 inches into the ground. The stakes must be at least 3 feet long.
b. Excavate a trench approximately 8 inches wide and 12 inches deep around the outside perimeter of the stakes.
c. Staple the filter fabric (for materials 3l1d specifications, see Silt Fence ESC 50) to wooden stakes so that 32 inches of the·
fabric extends out and caD be formed into the trench. Use heavy-duty wire staples at least one inch in length.
d. Backfill the trench with 3/4 inch or less washed gravel all the way around.
Installation procedure for block and gravei nIter:
a. Place hardware cloth or comparable wire mesh with ODe-half inch openings over the drop inlet.so that the wire extends
a minimum of 1 foot beyOlld each side of the inlet strUcture. If more than one strip is necessary, overlap the strips. Plaa:
fIlter fabric over the wire mesh.
b. Place concre~ blocks lengthwise on their sides in a single row around the perimeter of the inlet, so that the opeD ends' .
face outward. not upward. The ends of adjacent b10clcs should abut The height of the barrier can be varied. depen9iPg
on design needs. by stacking combinations of blocks that are 4 inches, 8 inches, and 12 inches wide. The row of blockS
should be at least 12 inches but no greater than 24 inches high.
c. Place wire mesh over the outside vertical face (open end) of the concrete blocks to prevent stone from being washed
through the blocks. Use hardware cloth or comparable wire mesh with -one half inch openings.
d. Pile washed stone against the wire mesh to the top of the blocks. Use 3/4 to 3 inch gravel.
Installation procedure for gravel and wire mesh fIlters:
a. Place wire mesh over the drop inlet so that the win: extends a minimum of 1 foot beyond each side of the inlet st;rucrure.
Use hardware cloth or comparable wire mesh with one-half inch openings. If more than one strip of mesh is necessary,
overlap the suips. Place fllter fabric over wire mesh.
ESC54
Construction Handbook March, 1993
•
•
•
Additional Information· -Storm Drain Inlet Protection
b. P~ 3/4 to 3 inch gravel over the filter fabriclwire·meslJ. The depth. of the gravel should be at least 12 inches over the
entire.inletopening (see attached figure).
Installation procedure for sand bag barrier:
a. Use sand bag made of geotextile fubric (DOt bwiap), and fill with 3/4 in. rock or 114.in. pea graveL
b. Construct on gently sloping street.
c. Leave room upstream of banier for water to pond.and sediment to settle.
d. p~.severallayers of sand bags-overlapping the bags and packing them tightly together. .
e. Leave gap of one bag on the top row to serve as a spillway. Flow from a severe storm (e.g., 10-year stoon) should
not overtOp the curb. .
MaintenWlce Rcgpirements
• For filter fabric fences: Inspections should be made on a regular basis, especially after large stDlm events. It the
fabric becomes clogged, it should be replaced. Sediment should be removed when it reaches approximatelyone.h.a1f
t.be height of We fence. If a sump is used, sediment should be removed when it' fills· ·aPPt"oX:ii:narely one-half the-··· .. ":'::
depth of the hole.
• For gravel filters: If the gravel becomes clogged with sediment. it must be carefully removed from ¢Ie inlet, and
either cleaned or replaced. Since cleaning gravel at a construction site may be difficult. use the sediment-laden
StaDe instead as fill and put fresh stone around the inlet.
• The inlet protection should be removed 30 days after the upslope areahas been fully stabilized.. Any sediment
around the inlet must be carefully removed and disposed.
. REFERENCES
Best Management Practices and Erosion Control Mmlual for Construction Sites, Flood Control District of Maricopa
County, ArizOila, September 1992.
"Draft -Sedimentation and Erosion Control. An Inventory of CUlI'Cnt Practices", U.S.E.P.A., April. 1990.
Erosion and Sediment Control Handbook, SJ. GoldIIian, K. Jackson, T.A. 'BursetynSky, P.E., McGraw Hill Book
Company.
Manual of Standards of Erosion aDd Sediment Control Measures, Associatioo of Bay Area·Govemplents, June 1981.
Proposed Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters, Work
Group Wor.ldng Paper, USEPA, April, 1992. '
Stormwater Management Water for the Puget Sound Basin. Wa$ington State Department of Ecology, Th~ Technical
Manual-February i992, Publication # 91-75.
Storm Water Pollution Prevention Handbook, FlISt Edition, State of CalifOrnia. Department of Transportation Division
of New Tecimology, Materials, and Rc;search, October 1992.
ESC54
Construction Handbook 5 -82 March, 1993
Additional Information -Storm Drain Inlet Protection.' .~------------------~ STAKES
• I
••
-DROP INLET WITH GRA TE
'.--
FIL TER FABRIC
ELEVATION
FIL TER FABRIC
SEDIMENT LADEN
~ ~~.,.."",...,....,...~~~
• BURIED FILTER F A8RIC~ e'"
PROFILE
r, WASHED GRAVEL
/ \ DROP INLET
- -
fILTER FABRIC FENCE DROP INLET FIL T..EB.
Construction Handbook S -83
, '. ~ ,j
..
ESC54
March,1993
e
e
e·'
Additional Information -Storm Drain Inlet Protection
GRA VEL FIL TE'~-
(~/4"" TO 3'" GRAVEL)
SEDIMENT
WIRE. MESH WITH
112"" OPENINGS
FIL TERED WA T~
~CUR8 INLET
GRAVEL AND WIRE MESH ElL rEB FOR CURB INLET
ES.C54
Construction Handbook 5·84 March, 1993
Additional Information -Storm Drain Inlet Protection .--~--------------~~
•
•
SEDIMENT-LADEN RUNOFF
RECUIRED
STORM WATER WIT
LARGER PARTICLES
REMOVED
-
~ .~
/ ~ *STORA~E VOLUME-
~ ~ 3600 CU.FT. PER ~ ~ DISTURBED DRAINAGE. I" ~
, DEPTH BEL'QW TOP OF INLET:
MIN I' -MAX 2'
-
DROP INLET--..!ffi;fif"~~~~"'!""':"~
SpECIFIC APPLICATIQN
THIS METHOD OF INLET PROTECTlON IS AF'PUCABLE WHERE HEAVY FLOWS ARE EXPECTED AND WHERE AN OVERFLOW CAPABILITY AND EASE OF
MAINTENANCE ARE DESIRABLE.
EXCAVATED DROP INLET SEDIMENT TRAP
ESCS4
Construction Handl>ook S -8S March,1923
•
•
.'
AdditionaJ Information -Storm Drain Inlet protection' .
, .
WIRE MESH WITH 1/2'" OPENINGS
'-CONCRETE BLOCK
GRA VEL FILTER
(3/4" TO 3" GRAVEL)
DROP INLET WITH GRATE
TERED' wATER
BLOCK AND GRAVEL FILTER AT DROP INLET
RUNOFF WATER
WITH SEDIMENT
3/4" TO 3'" GRAVEL
(12" MIN DEPTH)
,GRAVEL 'ANO WIRE MESH FILTER
FOR OBOP INLET
Construction Handbook 5.86
WIRE MESH (1/2'"
OPENINGS) WITH
FIL TER FABRIC
. ON TOP
ESC54
... f};g) . ~
March. 1993
• '
•
•
.... o •
BMP: PUBLIC EDUCATIONJPARTICIPATION
Graphlc~'Nor!t1 Central \\
Texas COG, 1993 \ \
DESCRIPTION
PtogramElements
Municipal Facilities
~gal Dischafi!j)
Public education/participation, like an ordinance or a piece of equipment, is not so much a best management practice as it
is a method by Y!'hicl1 to implement BMPs. This fact sheet highlights the ~P9~ce.ofinte~g. eleIIl,ents of pub~c.
education and participation into a municipality's over.ill plan for Stoml water quality management Publjc C4ucatiool
participation are vital components of many of the individual sowce control.BMPs that follow in this chapter.
A public education and participation plan provides the municipality with a str.Uegy for educating its employees, the
public. and businesses about the importance of protecting storm water from improperly used, Stored, and disposed' of
. pollutants. Municipal employees must be trained, especially those that work in departments not directly ~lated to storm
water but whose actions affect storm water. Residents must become aware that a variety of hazardous products are used
in the home and that their improper use and disposal can pollute storm water. Increased public awareness also ·facilitates
public sautiny of industrial and municipal·activities and wiIllikely increase public reporting of incidents. Businesses,
particularly smaller ones that may not be regulated by Federal. State, or local regulations, must be informed of ways to
reduce their potential to pollute stoml water.
The specific public education/participation aspects of each of the source controls are highlighted in the individual fact
sheets. The focus of this fact sheet is more general, and includes the overall objectives and approaches for assuring
public involvement in local StoIm water management programs. Accordingly, the organization of this fact sheet differs
somewhat from the other fact sheets in this chap(er.
OBJECTIVES
The public education and participation plan should be based on four objectives:
• Promote a clear identification and understanding of the problem and the solutions,
• Identify responsible parties and efforts to date,
• Promote community ownership of the problems and the solutions, and
• Integmte public feedback into progrnm implementation.
APPROACH
• Pattern a new program after the many established programs from mUnicipatities around the state and COUntry.
Whenever possible, integrate storm water public education/participation into existing progr.uns fronl other depart-
ments at your municipality.
seQ
.'
Municipal Handbook 4-2 March,l993
•
•
•
BMP: PUBUC EDUCATIONJPARTICIPATlON (CONTINUE)
• Implement public educationlparticipation as a coordinated campaign in which each message is related to the last
• Present a clear and consistent message and image to the public regarding how they contribute to storm water
. pollution. and what they can do to reduce it
• Exparid definition of "public" to include small businesses and construction site operators who often possess the same
limited levels of awareness of the problems, regulations, and solutions as the "general" public. As a result, Small
businesses need the same level of technical assistance (education) and participation in the process as· the "ge~e:ra1"
public.
• Utilize multi-media to reach the full range of audiences.
• Translate messages into the foreign.languages of the community to reach the full spectrum of your populace and to
avoid 'misinterpretation of messages.
• Create an awareness and identification with the local watershed.
• Involve focus or advisory groups in the development of a public educationlparticipation plan. This will create a
m~ more effective plan as well as promote ownership of the plan by those involved. • 'Vse everyday language in all public pieces. Use outside reviewers to highlight and reduce the use of techIDqU
terminology. acronyms, and jargon.
• Make sure all statements have a sound, up-tO-date technical basis. Do not COIltribute to the spread of misinforma-
tiOD.
• Break up complicated subjects into smaller more simple concepts. Present these COncepts to· the public in a metered
and ocganized way to avoid "overloading" arid confusing the audience. .
SCO
MuniCipal Handbook 4-3 March,1993
•
•
•
Additional Information -Public EducationlParticipation
Apmrnch
Public education and participation are critical elements of many of these source control BMPs. As each municipality
chooses source controls, and develops and implements its SWMP, it is very important that the public education and
participation aspects of $e chosen source controls be integrated into an overall plan. The presentation of a well Coordi-
nated and comprehensive campaign will be much more effective and efficient at reaching the target audiences thSn a
series of separate actions wbose relation to one another may not be evident.
Threet Audiences
To effectively achieve these objectives, tIle,implementation of a public education and particip3ti.on plan requires that the
full range of target audiences be identified and provide4 with applOpxi.ate infozmation and outreach. The following
audiences should be included;
•
•
Political -Elected officials mid .beads of deparUnents, agencies, and commissions;
Technical (Internal) -Municipal department and agency staffs; · . Technical (External):; State agencieS (Cal-EPA, SWRCB, IWMB, ARB), regional agencies (e.g .. ABAG, SCAG,
AMBAG, water and ttansportation agencies), and neighboring governments;
•
•
•
•
•
•
•
Business -Commercial and industrial, including trade associations;
ConslIUction -Developers and contractors;
Community Groups -Fraternal, ethnic, bobby, horticultural. senior citizen, and service;
Environmental Groups;
General PublicJResidenti.al;
SchoolslY outh Groups;
Media -Print and electronic, and
• Pollutant-defined -Groups of individuals defIned by the specific pollutant(s) they discharge (e.g .. used motor oil,
pesticides).
Suar:gic Actiyities
The public must have a clear understanding of the problem of stonn water pollution in·order to bring about the ~viot3I
changes needed to reduce the discharge of pollutants. Part of this "clear und.etstandiilg" involves inaeasing the public's
realization of their "place" in the watershed. The public should be educated aboqt the ~ w1lere they live in
relation to it. and how their behavior affects the health of the whole watershed. Ultimately, municipal employees,
citizens, and businesses must realize that they contribute to storm water pollution and that by modifying their behavior
they can contribute to the solution. Implementation of the public education and participation 'plan is the meehan,iSm by
which this understanding is attained, and these behavioral changes are brought aboUL
It has been estimated'that some individuals require exposure to the same message tq> to seven ti:n:les. from a varietY of
media. before behavior modification occurs. Therefore, given limited resources,. the key question is not what ~ activity
(e.g., fair) or media (e.g., radio) is best, but what mixture of these elements is most effective for the target audience.
In light of this information, the public education and participation plan should include a varietY of activities to ~ch and
educate the target audiences. These activities may include:
• Program Planning and Tracking -Public surveys and database;
• Program Identity -Program message, logo, and tag line;
• Collateral Material -Newsletter. fact.sheets, brQcbures, J'Osters;
• Coordinating Committees;
• Media Campaign -Press releases, advertising, public service announcements; seo
Municipal Handbook 4-4 March, 1993
• Additional Information -Public Education/Participation
•
•
•
•
• Residential Programs -Storm drain stencilling, home toxics c.JJecklistialtematlves. and specific neighborhood
projects;
•. Presentations -Enviroomental booth, speakers bureau, and special events;
• Business Programs -Workshops. publications, and green business projects;
• Construction Pro~ -Workshops. educational materials, and certification;
• Consumer Programs -Point of purchase displays and printed grocery bags; and
• School Education -Facility tours, contests, and curriculum.
Elements of a·Model· Public EducationLPartidparlon Plan
The following elements of a model plan are based on plans developed in California and elsewhere .. The list of elements
is intended as a guideline or menu only. The list of activities is by no means exhaustive, and new activities are being
develOped 1;>y communities on an ongoing basis. The actual level, priority, and schedule of activities in your agency's
public educationlparticipation plan must be based on your commUnity's needs and resources. Communities have
typically developed 5-year plans to match the length of their NPDES permit There are some activi~es that should OCCUr
before others. These activities are listed as a group first, followed by a genern1 list of other activities.
Start-Up Actiyities
• Program Planning and Tracking (Public survey and dataDase) -A public survey is atr important tool to assess. the use
of toxic materials, perceptions of health risk, disposal pzactices, support and' willingness to pay for new programs, .
and overall environmental awareness. The survey results will educate you as to your CX$munity; s needs and guide
the development and implementation of your public education and participation plan. Surveys are equally important
in establishing a baseline for evaluating the effectiveness of your program. As such, surveys $>uld be conducted
on a regular basis (e.g, biannual) to gauge your prognun's success. Strongly consider the use of a professional
survey firm. Surveys conducted in an unscientific manner often provide poor infoonation at best, and misinfOrma-
tion at worst
A database is another important progrnm assessment tool that should be iriitiated before the program begins. The
database can.maintain infoonation OIl mailing lists,.phone inquiries, material distributions, spill incident data, and
levels of.effort As much as possible, the program's effort should be quantified to track itspiOgress and to provide
feedback to the public and to the regulatory agencies.
Program Identity (Message, logo, and tag line) -The development of a consistent image which appears on all
materials disaibuted by your program will promote an understanding of the program, its mission, and its .
interconnectedness with other issues and programs. The development of a program logo with such high PQblic
exposure should be performed by a professional graphics firm.
Coordinating committees -The work of other agencies within your municipality and other groups outside of the
municiPality often touches on some part of the storm water quality issue as a byproduct of these groups' efforts.
Committees should be established that coordinate the storm water public education/participation progr.;un with other
environmental education efforts within the municipality and at the schools. Likewise, successful implementation of
the storm wati::t management program. cuts across most municipal departments requiring that representatives from
these departments meet regularly to coordinate their efforts •
seo.
~ . ..
.... ,
BiIoIt
~...uc-.
Municipal Handbook 4-5 March, 1993
•
•
•
Additional Information -Public EducationIParticipation
Qther Actiyities
• Media Campaign (Press releases, advertising, and public service announcements) -The med,ia (radio, television, and
_ newspaF.s) offers both widespread coverage and the opportunity to repeat the same message. Cultiwre m-edia
support and involvement by educating media staff on the purpose of the prog:zaza Press rel~s and public Service
announcements (PSAs) may be produced on a regular basis to inform the public about upconili,lg events, household
hazardous-waste collections, and sources of additional information. Billboards and municipal vehicle (buses, street
sweepers) placards are another effective media for transmitting the progr$n logo and tag line.
• Collateral Material (Newsletter, fact sheets, broohure, and posters) -Produce newsletters at reguw,r intervals to
inform program participants, the general public, and businesses about the progr3m.. Fact sheets may1;>e used to
inform the public about specific issues. Brochures provide an overall picture of the program and can be USed to
highlight the progtam.' s comprehensiveness and long term nature. Posters may be displayed at municipal offices ror
both public education and municipal staff training, and distributed to schools and businesses.
-. Residenttii Programs (Storm drain sreuclrung, heme toxies checklisUaltematives, aIid-specific neighborhood-
projects) -Because of its shqrt development time and low maintenance costs, storm drain stencilling is often one of
the first activities implemented by communities. Likewise,-a home toxies checklist/alternatives publication, devel-
oped initially to meet household hazardous waste regulations, may be iiltegrated into the public education effort
about storm water quality. Some larger communities are targeting specific neighborhoods for more concentrated arid
immediate education, because of their geographic position in a watershed,.
• Presentations (Environmental booth. speakers bureau, and special events).· Direct contact between the municipal
staff implementing the stoml water management program. and the public can be a highly effective way of ¢ucaiing
target audiences. Environmental booths can be especially effective because they distribute the messagefu atlu:ee
dimensional, sometimes interactive way. A special event can bring eXtra ~ntion to theprogrnm by highlighting a
milestone, particularly if reporters from the media cover the event.
• Consttuctioo Programs (wOl'ksbops, educational materials and certification) • Contractors and-Qevelopers often need
education on sources, impacts, and control of pollutants from coostruction sites,. Site operators often need ;1SSis.t3nce
in developing erosion and sediment controls. A certification program may be appropt:ia,te for all <;onSttUCtion site
operators, plan reviewers and inspectors. The certification progr.u:n would establish a minimum-competency level
for those-involved in preparing and implementing erosion and sediment control plans, and storm wat.er pollution
preventioo plans.
• Business Programs (Workshops, publications, and "green" business project) • Some businesses are-m~ likely than _
others to contribute to storm water pollution. Municipality's can take advantage of this by defming and focusing
$cation efforts on priority businesses. Small businesses, in particular, need aSsistance with understanding the
problems and being made aware of alternatives and solutions. The use of an educational, positive incentive-baSed
program for small businesses is often much more effective than a traditional command-and-co~trolapproach.
• Consumer Programs (point of purchase displays and printed grocery bags) • Point of purcl:lase displays can be very
effective because they convey the program's message directly to the consumer aUhe time and place tj!e purchase
decision is being made. Grocery bags printed with the program logo and tag line are a quick and effective way to
give brief information to many people .
seQ
Municipal Handbook 4·6 Marcb:, 1993
•
Additional Information -Public EducationIPartiCipation
• School Education (Facility tours, contests, and cmriculum.) -The most effective long term method to modify
behavior is to educate people at an early age. Facility tours of the wastewatet treatment plant. sewer system, .
housebold hazardous waste collection center, and other municipal facilities provides children with a firsthand look at
the processes involved with treating waste and reinforces the aware~ that substances deposited to .thestorm drain
are not treated. Contests to develop posters, calendars, etc. are a fun way to raise children's awareness and the
accuracy of the resulting products can provide feedback as to effectiveness of other educ:ational effOrts. An environ-
mental cmriculum covering recycling, energy use, air and water pollution can be·a highly effective but long term
educational activity. Several groups have recently develope(J.or are developing curricula (see be~ow). .
Examples QfEffectiye ProgramS :
There are a number of communities with effective public educatioDtj>articipation programs. The most ptO-aetive include
Santa Clara County and the City of Palo Alto, Alameda County, the City and COUIlty of San Fnmcisco, the Santa Monica .
Bay.}~estoration Project, City of Los Angeles Clean Water Program, City of Santa Monica, the Muniqpality of Metro-
·poUtan Seattle (Metro), and the Unified Sewerage Agency of Washington County, Oregon. In addition, latge businesses, .
such as PG&E. have used inserts in their bill mailings to educate ·their customers. ·The Callfotnia Coastal·ColIlIllisSiotr .... :
and the Lindsay Museum are both developing a cmricu1um targeted· at nonpoint source pollution, and the San P.raDcisco
Estuary Project has already developed such a CUIriculum for K-I2. ..
REfERENCES
The Global Cities Project, 1992. Offer Residents an Education Program About Water Protection, B.uilding Sustainable
Communities.
Nonpoint Source Pollution: You are the Key to the Qeanup, Water Envirooment Federation, 1992.
Pacific Gas and Electric, 1992. Let's Keep Our Creeks Qean, PG&E Spotlight.
Public InfoonationlParticipation Plan, 1992. Alameda County Urban RUIlOff Clean Water Progrnm..
San Francisco Department of Public W Oti::s, 1992. Best Management Practices Public Education Plan.
Santa Clara Valley Nonpoint Somce Control Program. 1990. Public JnfonnationJParticipaLion Plan .
. Schumacher, l.W. and R.F. Grimes. 1992. A Model Public Education Process for Stormwater ManagemeQt. p. 55-58,
Public Works for September, 1992.
Municipal Handbook 4-7
seQ
~
8Mt\~
.~~
March,1993
•
•
••
ACTIVITY: NON-STORM WATER DISCHARGES TO DRAINS·
D~CRIPTION
E1jminate.noil-s~onn water discharges to the storm water collection system. Non-sto~
. water-dischaiges may'include: process wastewaters, cooling waters, wash waters,' and
. sariitary wastewater.
APPROACH
the following approaches may be used to identify non-storm water discharges:
• Visual Inspection
The easiest method is to inspect each discharge poilu during dry weather.
Keep in mind that drainage from a storm event can continue for three days or
more and groundwater may infiltrate the underground storm water collection
sys~m .
• Piping Scbematic Review
The piping scbematic is a map of pipes and drainage systems used to carry
wastewater; cooling water, sanitary wastes, etc.
A reView of the "as-built" piping schematic is a way to determine if there are any
connections to the storm water collection system. '
Inspect the path of floor drains in older buildings.
• Smoke Testing
Smoke testing of wastewater and storm water collection systems is used to detect
connections 'between the two systems.
During dry weather the storm water collection system is filled with smoke and
then traced to sources. The appearance of smoke at the base of a toilet indicates
that there may be a connection between the sanitary and the storm water system.
• Dye Testing
A dye test can be performed by Simply releasing a dye into either your sanitary
or process wastewater system and examining the discharge points from the storm
water collection system for discoloration.
REQUIREMENTS
Costs (Capital. O&M)
• Can be difficult to locate illicit connections especially if there is groundwater
infiltration.
LIMITATIONS
Many facilities do not have accurnre. up-to-date scbematic drawings.
• TV and visual inspections can identify illicit connections to the storm sewer, but
further testing is sometimes required (e.g. dye, smoke) to identify sources.
Industrial Handbook 4-2
Applications
QanufacturinD
Material Handling
Ci!:hicle MBi~tenBnev
Construction
C§immercial ActivitJii.:;> ,
Roadways
Targeted Constituents
o Sec/iment • Nutrients • Heavy Metal. • Toxic Materials
~ FJostsble Materisls
• Oxygen Demand-
ing Substances
• Oil & Grease
• Bacteria & Viruses • Ukeflf. to. HlIV. Sign flc.nHmptlCt
0 ProbMJ/. Low or
Unknown ImplICt
, '
Implementation
Requirements
~ Capital Costs
0 O&MCosts
0 Maintenance
~ Training
J '. High o Low
SC1
March,1993
•
•
•
Addi~ionallnformation -Non-Storm Water Discharges to Drains
Facilities subjeGt to storm water permit requirements must include a certification lha1 the storm water collection system
bas been tested or evaluated for the presence of non-storm water discharges. The State's General Industrial Storm Water
Permit requires that non-storm water discharges be eliminated prior to implementation of the facility's.SWPPP.
Non-storm water discharges to the storm water collection system may include any water used directly in the manufactiJr-
ing process (process wastewater), air conditioning condensate and coolant. non-contaCt cooling water, cooling·eqtiipm!=Ilt
conden~, outdoor secondary containment water, vclllcle and equipment wash water, sink and drinking fountain
wastewater, sanitary wastes, or other wastewaterS. Table 4.1 presents disposal 0pUQn information for specific types of
wastewaters.
To ensure that the. storm water system discharge contains only storm water, industry should:
• Locate discharges to the municipal storm sewer sys~m or waters of the United States from the industrial
storm sewer system from:
-"as-buUt" pipeline scbematics, and _
.. -visual observation (walk boundary of plant site). : .... ,"~ " ". > •• ,
• Locate and evaluate all discharges to the industrial storm sewer system (including wet weather tIows)froin:
-"as-built" pipeline scbematics,
• visual observation,
-dye tests,
-TV camera,
-chemical field test kits, and
-smoke tests.
• Develop plan to eliminate illicit connections:
-replumb sewer lines,
-isolate problem areas, and
-. plug illicit discharge points.
• Develop disposal options.
• Document that non-storm water discharges have been eliminated by recording tests performed, methods
used, dates of testing, and anyon-site drainage points observ.ed.
REFERENCES
QeneralIndustrial Storm Water Pemlit, SWRCB, 1992.
NPDES General Permit for Discharges of Storm Water Associated with Industrial Activity in Santa Clara County
to South San Francisco Bay or its Tributaries, SFBRWQCB, 1992.
Storm Water Management for Industrial Activities: Developing Pollution Prevention Plans, and Be~t Manage-
mentPractices, EPA 832-R-92-006. USEPA, 1992._ .
SC1
Industrial Handbook 4·3 March, 1993
•
•
•
ACTIVITY: OUTDOOR lOADINGlUNLOADlNG OF MATERiALS
DESCRIPTION
Prevent or reduce the discharge of pollutants to storm water from outdoor loading/
unloading of materials.
APPROACH
• Park tank trucks or delivery vehicles so that spills or leaks ' can be contained.
• Cover the loading/unloading docks to reduce exposure of materials to rain.
• Seal or door skirt between trailer and building can also prevent exposure to rain.
• Design loading/unloading area to prevent storm water runon:
grading or berming, and
position roof downspouts to direct storm water away from loading/unloading
areas .
• Contain leaks during transfer.
• Use drip p~s under hoses.
• Make sure fork lift operators are properly trained.
• Fmploy~ training for spill containment and cleanup.
REQUIREMENTS ,
• Costs (Capital, O&M) -Should be low except when covering a large loading/unload-'
ing area.
• Maintenance
Conduct regular inspections and make repairs as necessary. The frequency of
repairs will depend on'the age of the facility.
-Check IQ~ding aI!d unloading equipment regularly for leaks:
valves, ,
pumps,
flanges, and
connections.
LIMITATIONS
• Space and time limitations may preclude all transfers from being performed indoors or
under cover.
• It may not be possible to conduct transfers only during dry weather.
Industrial Handbook 4 -19
Applications
Manufacturing
Qiaterial Hi1ndli~D
Vehicle Maintenance
Roadways
Waste Containment
~ekeep~gpmct~
Targeted Constituents
0 Sediment • Nutrients • Heavy Metals
• Toxic Materials
• Floatable Materials
• OXygen Demand-
ing Substances,
• Oil & Grease
0 Bacteria & Viruses .' Ub~toHlJve Sign licant ImpiJet
0 Probable Low or
Unkrio~n, Impact
Implementation
Requirements
r.-Capital Costs
'0 O&MCosts
0 Maintenance
~ Tmining
.' High 0 Low
SC5
March,1993
•
•
•
Additional Information -Outdoor LoadinglUnloading of Materials
The loading/unloading of materials usually takes place outside. Loading or unloading of materials occurs in two ways:
materials in containers or direct liquid transfer. Materials spilled, leaked or lost during loading/wlloading may collect in
the soil or on other surfaces and be carried away by runoff or when the area is cleaned. Rainfall may wash pollutants
from machinery used to unload or move materials. The loading or unloading may involve rail or truck transfer.
The most important factors in preventing these constituents from entering storm water is:
• Limit exposure of material to rainfall.
• Prevent storm water runon.
• Check equipment regularly for leaks.
• Contain spills ,during transfer operations.
Loading or unloading of liquids should occur in the manufacturing building so that any spills that are not completely
retained can be discharged to the sanitary sewer, treatment plant, or treated in a manner consistent with local sewer
au$orities, an~ permit requU:ements. Best management practices include: ,
• Use overhangs or door skirts that enclose the trailer.
• Park tank trucks during delivery so that spills or leaks can be contained.
: • Design loading/unloading area to prevent storm water runon which would include grading ,or lxmuing the area, and
positioning roof downspouts so they direct storm water away from the loading/unloading areas.
• Check loading and unloading equipment regularly for leaks, including valves, pumps, tlanges and' connections.
• Look for dust or fumes during loading or unloading operations.
• Usc a written operations plan that describes procedures for loading andlor lIDloading.
• Have an emergency spill cleanup plan readily available.
• Employees trained ill spill containment and cleanup should be present during the loading/unloading .
• Establish depots of cleanup materials next to or. near each loading/unloading area, and train erp.ployees in their use.
• For loading and unloading tank trucks to above and below ground storage tanks, the following procedures should be
used.
-The area where the transfer takes place should be paved. If the liquid is reactive with the asphait, Portland
cement should be used to pave the area.
-Transfer area should be designed to prevent runon of storm water from adjacent areas. Sloping the pad and
using a curb, like a speed bump. around the uphill side of the transfer area shOUld reduce mnon.
-Transfer area should be designed to prevent runoff of spilled' liquids from the area. Sloping the ~ to a drain
should prevent runoff. The drain should be connected to a dead-end sump or to the sanitary sewer. A positive
control valve should be installed on the drain.
• ,For transfer from rail cars to storage tanks that must occur outside, use the following procedures:
-Drip pans should be placed at locations where spillage may occur, such as'hose connections. hose reels, and
filler nozZles. Use drip pans when making and breaking connections.
-Drip pan systems should be installed between the rails to collect spillage from tank cars.
REFERENCES
Best Management Practices for Industrial Storm Water Pollution Control, Santa Clara Valley NonpointSource Pollution
Control Program; 1992 '
Storm Water Management for Industrial Activities: Developing Pollution Prevention Plans. and Bes~ Management
Practices. EPA 832-R-92-006, USEPA. 1992.
Water Quality Best Management Practices Manual, City of Seattle. 1989 .
SC5
Industrial Handbook 4 -20 March. 1993
•
•
•
ACTIVITY: OUTDOOR CONTAINER STORAGE OF LIQUIDS
II , Hr
DESCRIPTION
Prevent or reduce the discharge of pollutants to storm water from outdoor container storage
areas by installing safeguards against accidental releases, installing Secondary containment,
conducting regular inspections, and training employees in standard operating procedures,
and spill cleanup techniques.
APPROACH
• Protect materials from rainfall, runon, runoff, and wind dispersal:
Store materials indoors.
Cover the storage area with a roof.
Miniie storm water runon by enclosing the area or buiding a berm around it
Use "doghouse" for storage of liquid containers .
Use covered dumpsters for waste product containers.
• Storage of oil and hazardous materials must meet specific Federal and State standards
including: '
Spill Prevention Control and Countermeasure Plan (SPCC) Plan,
secondary containment,
integrity and leak detection monitoring, and
emergency preparedness plans.
• Train operator on proper storage.
• Safeguards against accidental releases:
•
•
•
overflow protection devices to warn operator or automatic shut down transfer
pumps,
protection guards (bollards) around tanks and piping to prevent vehicle or forklift
damage, and
clear tagging or labeling, and restricting access to valves to reduce human error.
Berm or surround tank or container with secondary containment system:
dikes, liners, vaults, or double walled tanks.
Some muniCipalities require that secondary containment areas be connected to
the sanitary sewer, prohibiting any bard connections to the storm drain.
Facilities with "spill ponds" designed to intercept, treat,'andJor divert spills
should contact the appropriate regulatory agency regarding envirinmen~
compliance.
REQUIREMENTS
• Cost (Capital, O&M)
Will vary depending on the size of the facility and the necessary controls .
• Maintenance: Conduct reutine weekly inspections.
LIMITATIONS
• Storage sheds often must meet building and fire code requirements.
Industrial Handbook 4 -21
Applications
. Manufacturing
Mat~rial Handling
Vehicle Maintenance
<::§.Qns~ructioD '
<§ii:mer:cial ActiVitJ!j;>
Roadways
Waste Containment
€sekeeping Pract~
Targeted Constituents
'0 Sediment
o Nutrients
'. Heavy Metals
• Toxic Materials
,0 Floatable Materials
• Oxygen Demand-
ing Substances
o Oil & Grease
o Bacteria '& Vir.uses
• Uke/Y to HifVe SignIficant Impact o Probable Low or
Unkno'IJIlJ Impact
Implementation
Requirements
~ Capital Costs
~, O&M' Costs
Q Maintenance
~ Training
I 0 Low ·1 .• High ,
SC6
March,1993
•
•
•
Additional Information -Outdoor Container Storage of Liquids
Accidental releases of materials from aboveground liquid storage tanks, drums, and dumpsters present Ule poten-
tial for conraminating ~torm waters with many different pollutants. Materials spilled, leaked or lost from storage
containers and dumpsters may accumulate in soils or on the surfaces and be carried away by storm water runoff.
These source controls apply to containers located outside of a building used to temporarily-stOre liquid materials.
It should be noted that the storage of reactive, ignitable, or flammable liquids must comply with fIre codes.
Container Mana2ement
To limit the possibility of storm water pollution, containers used to store dangerous waste or other liquids should
be kept inside the building lIDless this is impractical due to site constraints. If the containers are placed outside, the
following procedures should be employed:
• Dumpsters used to store items awaiting transfer to a landflll should be placed in a lean-to structure or other-
wise covered. dumpsters shaIl be kept in good condition without corrosion or leaky seams.
• Garbage dumpsters shall be replaced if they are deteriorating to the point where leakage ~s occutring. It
should ~ kept undercover to prevent the entry of storm water. Employees should bemade aware of the
iinportance of keeping the duInpsters covered and free from leaks. " '.' , . .
• A fillet should be placed on both sides of the curb to facilitate moving the dumpster.
• Waste container drums should be kept in an area such as a service bay. If drums ate kept optside, they must
be stored in a lean-to type structure, shed or walk-in container to keep rainfall from reachiiig the drums.
Storage of reactive, ignitible, or flammable liquids must comply with the fIre codes of your area Practices listed
below should be employed to enhance the fIre code requirements. '
• Containers should be placed in a designated area.
• Designated areas should be paved, free of cracks and gaps, and impervious in order to contain leaks and spills ..
• Liquid waste should be surrounded by a curb or dike to provide the volume to contain 10 percent of the
volume· of all of the containers or 110 percent of the volume of the largest container, whichever is greater.
• The area insiqe the curb should slope to a drain.
-For used oil or dangerous waste, a dead-end sump should be installed in the drain.
-AU other liquids should be drained to the sanitaIy sewer if available. The drain must have a positive-control
such as a lock, valve, or plug to prevent release of contaminated liquids.
• The designated storage area should be coveted.
• Containers used for liquid removal by ~ employees must be placed in. a containment area.
- A drip pan should be used at all times.
• Drums stored in an area where unauthorized persons may gain access mu~t be secured to prevent accidental spillage,
pilferage, or any Wlauthorized use.
• Emp~oyees trained in emergency spill cleanup procedures should be present when dangerous waste, liquid chemicals,
or other wastes are loaded or lIDloaded.
The ·;most common causes of unintentional releases:
• External corrosion and structural failure,
• Installation 'problems,
• Spills and overfills due to operator error,
• Failure of piping systems (pipes. pumps; flanges. couplings. hoses. and valves), and
• LeakS during pumping of liquids or gases from truck or railcar to a storage facility or vice ve~
Qletator TraiDjD2fSafe2uards
Well-trained employees can reduce human errors that lead to accidental releases or spills. Employees should be familiar .
with tlie Spill Prevention Control and Countermeasure Plan. Tbe employee should bave the tools ~d knowledge to .
Industrial Handbook 4 -22
SC6
~ ... . '
a-t
PI:~_
March,1993
'.
•
•
Additional Information -Outdoor Container Storage of Liquids
immediately begin cleaning up a spill if one should occur. Operator errors can be prevented by using engineenng safe
guards and thus reducing accidental releases of pollutant Safeguards include:
• Ovedlow protection devices on tank systems to warn the operator to automatically shutdown transfer pumps when
the tank reaches full capacity,
• Protective guards (bollards) around tanks and piping to prevent vehicle or forklift damage, and
• Clearly tagging or labeling all valves to reduce hUlIUlIl error.
Tank systems should be inspected and tank integrity tested regularly. Problem areas can often be detected by visually
inspecting the tanks frequently. Problems or potential problems 'should be corrected as soon as possible. Registered and
specifically trained professional engineers can identify and correct potential problems such as loose fittings, pq6r w.elding,
and improper or poorly fitted gaskets for newly installed tank systems. The tank foundations, ,connections, coatings, and
tank walls and piping systems also should be inspected. Inspection for corrosion, leaks, cracks~ scratches in protective
coatings, or other physical damage that may weaken the tank system should be a part of regular integrity testing.
SeCQDm Containment ' "':
Tanks should be bermed or surrounded by a secondary containment system. Leaks can be detected more easily and spills
~ be contained when a secondary contairu.D.ent systems are installed. Berms, dikes, liners, vaults, and dOUble-wall tanks
are examples of secondary containment systems.
One of the best protective measures against contamination of storm water is diking. Containment dikeS are 'berms or
retaining walls that are designed to hold spills. Diking is an effective pollution prevention measUre for above ground
storage tauks and railcar or tank truck loading and unloading areas. The dike surrounds the area of concern and' holds the
spill, keeping spill materials separated from the storm water side of the dike area. Diking can be 'used in any industrial
facility, but it is most commonly used for controlling large spills or releases from liquid storage areas and liquid transfer
areaS.
For single-wall tanks, containment dikes should be large enough to hold the contents of the storage tank for t,be facility
plus rain water. For trucks, diked areas should be capable of holding an amount equal to the volume of the tank truck
compartment Diked construction material should be strong enough to safely hold spilled IIUUe1:ials. Dike materials can
consist of earth, concrete, synthetic materials, metal, or other impervious materials. Strong acids or bases may re&ct with ,
metal containers, concrete, and some plastics. Where strong acids or bases or Stored, altemativedUcc<·materials should be
considered. More active organic chemicals may need certain special liners for dikes. Dikes may also-be designed with,
impermeable materials to increase containment capabilities. Dikes should be inspected during or:after significant stOmis
or spills to check for washouts or overflows. Regular checks of containment dikes to insure the dikes,are capable of
holding spills should be conducted. Inability of a structure to retain storm water, dike erosion, soggy areas, or changes in
vegetation indicate problems with dike structures. Damaged ar~ should 'be patched and stabilized immediately. Eartberi
dikes may require special maintenance of vegetation such as mulching and irrigation.
Curbing is a barrier that surrounds an area of concern. Curbing is similar. to containment diking in the way that it preventS
spills and leaks from being released into the environment The curbing is usually small scaled and does not contain large
spills like diking. Curbing is common at many facilities in small areas where handling and transfer liquid materials occur.
Curbjng can redirect contaminated storm water away from the storage area It is useful in areas where liquid materials·are
transferred from one container to another. Asphalt is a common material used for curbing; however, curbing inaterialS
include earth, concrete, synthetic materials, metal, or other impenetrable material~. Spilled materials should be removed
immediately from curbed areas to allow space for future spills. Curbs should have manuaIly-controlled,pump systems
rather than common drainage systems for collection of spilled materials. The curbed area should be inspected ,reguJ.arly to
clear clogging debris. Maintenance should also be conducted frequently to prevent overflow of any spilled ~terials as
curbed areas are designed only for smaller spills. Curbing bas the following advantages:
• Excellent runon control, sea
• Inexpensive,
• Ease of installment,
• Provides option to recycle materials spilled in curb areas, and
• Common industry practice.
Industrial Handbook 4 -23 March,1993
•
• '
•
Addi,ti.onallnformation -Outdoor Container Storage of' Liquids
Majntenance
• WeelOy inspection should be considered and include:
-Check for external corrosion and structural failure,
-Check for spills and overfllls due to operator error,
-Check for failure of piping system (pipes, pumps, flanges, coupling, hoses, and valves),
-Check for leaks or spills during pumping of liquids or gases from truck or rail car to a storage fa~ty or vice
versa,
-Visually inspect new tank or container installation loose fittings, poor welding, and improper or poorly fitted
gaskets, and
-Inspect tank fOlmdations, connections, coatings, and tank walls and ,piping system. Look for corrosion, leaks,
cmcks, scratches, and other physical damage that may weaken the tank or container system.
Examples ofEffectjye ProWWs
The "doghouse" design has been used to store smaIl liquid containers. The roof and flooring design prevent contact with
direcuain or nmo(f. The doghouse h,as ~o solid s~ctural walls and ,tw9 canvas ,CoV~I.:¢ V(~l,s. Th~, floor4tg' js ,wire
mesh about secondary containment The unit has been used successfully at LOckheed MiSsile and Spa¢Company in
Sunnyvale. .
REFERENCES
Best Management Practices for Industrial Storm Water Pollution Control, Santa Clara Valley Nonpoint Source
Pollution Control Program, 1992.
Storm Water Management for Industrial Activities: Developing Pollution Prevention Plans, and Best Management
Practices, EPA 832-R-92-OO6, USEP A, 1992 .
Water Quality Best Management Practices Manual, City of Seattle, 1989.
SCG
Industrial Handbook 4 -24 Marcb.1993
e-
e
e
ACTIVITY: WASTE HANDLING AND DISPOSAL
DESCRIPTION
o
RECYCLABLE
WASTE
ONLY
Prevent or reduce the discharge of pollutants to storm water from waste handling and
-!iisposal by tracking waste generation, storage. and disposal; redlJcing waste geIi~ration, and
disposal through source reduction, re-use, and recycling; and preventing runon and runoff
from waste management areas.
APPROACH
• Maintain usage inventory to limit waste generation.
• Raw material substitution or elimination.
• Process or equipment modification.
• Production planning and sequencing.
• SARA TItle m, Section 313 requires reporting for over 3(XJlisted chemicals and
cheinicaI compounds. This requirement should be used to track these chemicals
although-this is not as accurate a means of tracking as other approaches.
• Track waste generated.
Characterize waste stream.
Evaluate the process generating the waste.
Applications
Manufacturing
Material Handling
Vehicle Maintenance
Targeted Constituents
0 _Sediment
0 Nutrients -Heavy Metals -Toxic Materials
0 -Floatable Materials
0 Oxygen Demand-
Ing Substances -Pi! & Grease
0 Bacteria & Viruses -Uke~toH.ve
Sign f1~ntlmpM:t
0 ProblJb/e LOw or
UlJlcnown Impact Prioritize waste streams using: manifests, biennial reports, permitS, environmen-
tal audits, SARA TItle m reports, emission reports, NPDES monitoring reports. ~=====::::=:::!.I
Inventory reports.
Data on chemical spills.
Emissions.
Shelf life expiration.
• Use design data and review: process flow diagram, materials and applications diagram,
piping and instructions, equipment list, plot plan.
• Use raw material and production data and review: composition sheets, materials safety .
data sheets (MSDS), batch sheets, product or raw material inventory records,produc-
tion schedule. operator data log.
• Use economic data and review:
Implementation
Requirements
o Capital Costs
~ O&MCosts
o Maintenance
~ Training
Waste-treatment and disposal cost.
Product utility-and economic cost
Operation and maintenance labor cost.
_/_ -High 0 Low
• Recycle materials whenever possible.
• Maintain list of and the amounts of materials disposed.
Waste segregation and separation.
• Check industrial waste management areas for spills and leaks.
• Cover, enclose, or berm industrial wastewater management areas whenever possible to
prevent contact with runon or runoff.
• Equip waste transport vehicles with anti-spill equipment.
Industrial Handbook 4 -30 March. 1993
•
•
•
•
•
•
•
•
•
ACTIVITY: WASTE HANDLING AND DISPOSAL (Continue)
Minimize spills and fugitive losses such as dust or mist from loading systems.
Ensure that sediments or wastes are prevented from being tracked off-site.
Training and supervision.
Stencil storm drains on the facility's property with prohibitive message regarding waste disposal.
For a quick reference on disposal alternatives for specific wastes see Table 4.1, SCI.
Consider ordering industry-specific or waste stream-specific guidance from PPIC (see, Appendix G).
REQUIREMENTS
• Costs (Capital, O&M)
-Capital and O&M costs for these programs will vary substantially depending on the size of the facility and the
types of waste handled. Costs should be low if there is an inventory program in place.
• Maintenance
-None except for maintaining equipment for material tracking program.
LIMITATIONS
• Hazardous waste that cannot be re-used .or recycled must be disposed of by a ,licensed hazardous w~te hauler •
SC9
Industrial Handbook 4 -31 March,1993
.... ----------------------------------~~--~~
•
•
I.
Additional Information -Waste Handling and Disposal
Industrial waste management activities occur in areas that can contaminate storm water and include landfills, waste piles, .
wastewater and solid waste treatment and disposal, and land application. Typical operations wbicb affect storm water
pollution may include waste pumping, treatment cbemicals storage, mixing, aeration, clarifieation, and solids dewater-
ing.
Waste Reduction
Waste spilled, leaked, or lost from waste management areas or outside manufacturing activities may build up in soils or
in other surfaces and be carried away by storm water runoff. There is also a potential for liquid waste from lagoons or
surface impoundments to overflow to surface waters or soak the soil where pollutants may' be picked up' by storm water
runoff.
Waste reduction for manufacturing activities is the best way to reduce the potential of storm water cbntami~on from
waste management areas. Reduction in the amount of industrial waste generated can be accomplished using many
different types of source controls sucb as:
• Production planning and sequencing.
• Process or equipment modification.
• Raw material substitution or elimination.
• Loss prevention and housekeeping.
• Waste segregation and separation.
• Close loop recycling.
An approach to reduce storm water pollUtion from waste handling and disposal is to assess process activities at the
facility and reduce waste generation. The assessment is designed to find situations wbere waste can be eliminated or
reduced and emissions and environmental damage can be minimized. The assessment involves collecting pr~SS
specific information, setting pollution prevention targets, and developing, screening and selecting waste feduction
options for further study. Starting a waste reduction program is economically beneficial because of reduced;.raw ipaterial
purchases and lower waste disposal fees. In addition, material tracking systems to increase awareness about materiaJ
usage can reduce spills and minimize contamination, thus reducing the amount of waste prOduced.
SpmlLeak Control ,
Waste can be prevented from contaminating storm water by checking waste management areas for l~g containers or
spills. Corroded or damaged containers can begin to leak at any time. Transfer waste from these damaged containers
into safe containers. Dumpsters should be covered to prevent rain from washing waste out of boles or cracks in the
bottom'of the dumpster. Leaking equipment including valves, lines, seals, or pumps should be repaired promptly.
'Vehicles.transporting waste should bave spill prevention equipment that can prevent spills during transport The spill
. prevention equipment includes:
• Vehicles equipped with baffles for liquid waste.
• Trucks with sealed gates and spill guards for solid waste.
Loading or unloading wastes can contaminate storm water wben the wastes'are lost from the transfer. Loading systems
can also be used to minimize spills and fugitive emission losses sucb as dust ~r mist Vacuum transfer systems can
minimize waste loss.
Ruuon/Rl1noff Preyention .
Storm water runon should be prevented from entering the waste management area. Stonn water pollution from ~non
can be prevented by enclosing the area or building a benn around the area. Other alrer:natJ.ves for reducing storm water
pollution include:
• Preventing the waste materials from directly contacting rain. SC9
Industrial Handbook 4 -32 March, 1993
•
•
•
Additional Information -Waste Handling and Disposal
• Moving the activity indoor after ensming that all safety concerns such as flre hazard and ventilati9n ate addressed.
• Covering the area with a permanent roof.
• .. Covering waste piles with temporary covering material such as reinforced tarpaulin. polyethylene. polyurethane,
polypropylene or hypalon.
To avoid tracking materials off-site, the waste managem.ent area should be. kept clean at an times by sweeping and
cleaning up spills immediately. Vehicles should.never·drive througb spills. If necessary, wash vehicles in designated
areas before they leave the site, and control the wash water.
Minimizing the runoff of polluted storm water from land application of industrial waste on-site can be accomplished by:
• Choosing a site where:
-slopes are under 6 percent
-the soil is permeable
-there is a -low water table
. -... it is located away from.· wetlands or marshes ..
-there is a closed drainage system
• A voiding applying waste to the site:
-when it is raining
-wben the grotmd is frozen
-when the ground is saturated with· water
• Growing vegetation on land disposal areas to stabilize soils and reduce the volume of stlIface water runoff from the
site.
• Maintaining adequate barriers between the land application site and the receiving waters. Planted strips are particu-
larly good.
• Using erosion control techniques
-mulching and matting,
-fllter fences,
-strawbal~
-diversion terracing,
-sediment basins.
• Performing routine maintenance to ensure the erosion control or site stabilization measures. are working.
Examn1es ofEffectiye Pro2rarns
. The port of Long Beach has a state-of-the-art database for identifying potential pollutant sources, documenting facility
management practices, and tracking pollutants.
REFERENCES
Best Management Practices for Industrial Storm Water Pollution Control, Santa Clara Valley Nonpoint Source Pollution
Control Program, 1992.
Publications Than Can Work For You!; California Departm~nt of Toxic Substances Control, SacraIUento, CA., 1991 (A
list and order form for waste minimization publications from the State).
Storm Water Management for Industrial Activities: Developing Pollution Prevention Plans, and Best Management
Practices, EPA 832-R-92-006, US EPA, 1992.
Distribute List, Pollution Prevention Information Clearinghouse, USEPA 1992.
SC9
..~
Industrial Handbook 4·33 March,1993
POOR
QUALITY
ORIGINAL S
.,
.'
•
ACTIVITY: CONTAMINATED OR ERODIBLE SURFACE AREAS
DESCRIPTION
Prevent or reduce the discharge of pollutants to storm water from contaminated or.
erodible suiface areaS by leaving as muCh vegetation on:site as poSsible~ miiihniiing sOil '
e~posure time, stabilizing exposed soils, and preventing storm water runon and runoff.
APPROACH
This BMP addresses soils which are not so contaminated as to exceed criteria (see Title 22
California Code of Regulations for Hazardous Waste Criteria), but the soil is eroding and
carrying pollutants off in the storm water.
Contaminated Or erodible surface areas can be controlled by:
• Preservation of natural vegetation.
• Re-vegetation,
• Chemical stabilization,
• ~e:moval of contaminated soils, or
• Geosynthetics.
• For a quick reference on disposal alternatives for specific wastes see Table 4.1, SCI.
REQUIREMENTS
• Cost (Capital, O&M)
Except for preservation of natural vegetation, each of the above solutions can be
quite expensive depending upon the size of the area.
• Maintenance
Maintenance should be minimhl, except possibly if ilTigation of vegetation is
necessary.
LIMITATIONS
Disadvantages of preserving natural vegetation or re-vegetating include:
• Requires substantial planning to preserve and maintain the exis~g vegetation.
• May notbe cost-effective with bigh land costs.
• Lack of rainfall and/or poor soils may limit the success of re-vegetated areas.
Disadvantages' of chemical stabilization include:
• Creation of impervious surfaces.
• May cause harmful effects on water quality.
Is usually mOle expensive tban vegetative cover .
Industrial Handbook 4·34
Applications
Manufactl)dng
Material Handling
Vehicle Maintenance
<:eE.nstructi;;>'
Commercial Activities
<:Roadwai'i::>
Waste Containment
Housekeeping Practices
Targeted Constituents • Sediment
• Nutrients • Heavy Metals • Toxic Matedals • FloatabJe MElterial$ • Oxygen Demand-
ing Substances
• Oil & Grease
0 Bacteria & Viruses
• lJke% to HlIVe Sign ficant Impact
0 Probable Low Dr
Unlmo~n lirip!lCt
'Implementation
Requirements
~ Capital Costs
~ O&MCosts
0 Maintenance
0 Training
• "High. 0 l.ow
March, 1993
•
•
•
Additional Information -Contaminated or Erodible Surface Areas
Of interest here are.areas within the industrial site that are bare of vegetation and therefore subject to erosion. They may
or may not be contaminated from past or current activities. Activity mayor may not be occurring in the area of interest
According to the State's· General Industrial Activity Storm Water Permit, the SWPPPmust include BMPs iliatdealwith
these situations. If the area is temporarily bare because of construction, see SC12, Building Repair, Remodeling; and
Construction.
Contaminated or erodible surfaces can result from the human activities such as vegetation removal,co~pacting or
disturbing soil, and changing natural drainage patterns. IndusUies must identify the areas of contaminated or erodible
surfaces. The areas may include:
• Heavy activity where plants cannot grow.
• Soil stockpiles.
• Steep slopes.
• CODStruction areas.
• 1;>emolition ·areas.
• Any area where soil is disturbed.
The most effective way to control erosion is to preserve existing vegetation. Preservation of natural vegetation provides
a natural buffer zone and an opportunity for inflluation of storm water and capture of pollutants in the. :soil IIU,UJiX. By
preserving stabilized areas, it minimizes erosion potential, protects water quality, and provides aesthetic benefi4i. This
practice is used as a permanent control measure. Vegetation preservation on~site should be planned before distnrbfug the .
site. Preservation requires.good site management to minimize the impact of construction when construction is underway.
Proper maintenance is important to ensure healthy vegetation that can control erosion. Different species, soil types, and
climatic conditions will require different maintenance activities such as mulching, fertilizing, 14ning, irrigation, pruning
and weed and pest control. Maintenance should be performed regularly especially during eonstruction phases.
Advantages of preservation of natural vegetation are:
• Can handle higher quantities of storm water rimoff than newly seeded areas.
• Increases the flltering capacity because vegetation and root systems are usually dense in preserved natural
vegetation.
• Enhances aesthetics.
• Provides areas for inflltration, thus reducing the quantity and velocity of storin water runoff.
• Allows areas where wildlife can remain undisturbed.
• Provides noise buffers and screens for on-site operation.
• Usually requires less maintenance than planting new vegetation.
The measure of choice is to leave as much native vegetation on-site as possible. thereby reducing or eliminating the
problem. However, assuming the site already has contaminated or erodible surfa~ areas, there are three pos~ible GOUfSeS
of action: .
1. Re-vegetate the area if it is not in use and therefore not subjecno damage from site activities. In as IIluch as
the area is already devoid of vegetation, special measures are likely necessary. Lack of vegetation may be
due to the lack of water andlor poor soils. The later can perhaps be solved with fertilization. Or the ground
may simply be too compacted from prior use. Improving soil conditions may be sufficient to.support
vegetation. If available process wastewater can be used for irrigation, see Construction Best Management
Practice Handbook for procedures to establish vegetation.
seta
Industrial Handbook 4 -35 March, 1993.
•
•
•
Additional Information -Contaminate«(or Erodible Surface Areas
2. ChemiCal stabilization (for example ligno sulfate) can be used as an alternate in areas where temporary
seeding practices cannot be used because of season or climate. It can provide immediate, effective, and
inexpensive erosion control. Application rates and procedures recommended by the manufacturer should be
followed. as closely as possible to prevent the product from forming ponds and creating large areas where
moisture cannot penetrate the soil. The advantages of chemical stabilization include:
• Easily applied to the surface.
• Effective in stabilizing areas.
• Provides immediate protection to soils that are in danger of erosion.
3. Removal of contaminated soils is a last resort and quite expensive. The level ,and extent of the contamination
must be determined. This determination and removal must comply with State and Federal regulation~
permits must be acquired, and fees paid.
,~. , Geosyn~eti9s include those materWs that are deSigned as an impermeabl~ ,baqie~, to contain ~r control ~8.e,.... ',,""
, ' amounts of li'quid or solid matter. Geosynthetics 'have been developed priiilarily for use iIi IaridfiiIs and sunace" !' ..
impoWldments. and the technology is well established. There are two general types of geosynthetics:
geomeinbranes(impermeable) 8nd geotextiles(permeable).
• Geomembranes are composed of one of three types of impermeable materials: elastomers(rubbers).
tbermoplasics(plastics), or a,combination of these two types of materials. The advantages of these materials
include: 1) the variety of compounds available, 2) sheeting is produced in a factory environment, 3) polymeric
membranes are flexible, and 4) simple installation. The disadvantages include: 1) chemical resistance must be
determined for each application. 2) seaming systems may be a weak link in the system. and 3) manymaterials
are subject to attack from biotic. mechanical, or environmentai sourceS .
, • Geotextiles ~ WlCOated synthetic textile products that are not water tight They are composed of a variety of ' ,
materials, most commonly polypropylene and polyester~ Geotextiles serve five basic functions: 1) filtration, 2) ,
drainage"3) separation, 4) reinforcement. and 5) arinoring.
For more information on geosynthetics, see the reference below.
REFERENCES
Covers for Uncontrolled Hazardous Waste Sites, USEP A, EP Al54OI2-85/002, PB87-119483. 1985.
SC10
Industrial Handbook 4 -36 March,1993
••
•
•
ACTIVITY: BUILDING AND GROUNDS MAINTENANCE
1IIIII
III
DESCRIPTION
Prevent or reduce the discharge of pollutants to storm water from buildings and grounds
maintenance by washing and cleaning up with as little water as poSSible, preventing artd
cleaning up spills immediately, keeping debris from entering the storm drains, and
maintaining the storm water collection systein.
APPROACH
•
•
•
•
•
•
•
Leaving or planting native vegetation to reduce water, fertilizer, and pesticide needs,
Careful \lse of pesticides and fertilizers in landscaping.
Integrated pest management where appropriate.
Sweeping of paved surfaces.
Cleaning of the. stomi drainage system at appropriate intervals.
Proper disposal of wash water, sweepings, and sediments.
For a quick reference on disposal alternatives for specific wastes see Table 4.1, SC 1.
REQUIRMENTS
• Costs (Capital, O&M)
Cost will vary depending on the type and size of facility.
Overall costs should be low in comparison to other BMPs.
• Maintenance
The BMPs themselves relate to maintenance and do not require maintenance· as
they do not involve structures.
LIMITATIONS·
• Alternative pest/weed controls may not be available, suitable, or effective in every
case.
Industrial Handbook 4 -37
Applications
Manufacturing
Material Handling
Vehicle Mtfintenance
Construction
~mercial Activit~ .
c:§adwayy
Targeted Constituents • Sediment • . Nutrients
• Heavy Metals
• Toxic MaterialS • FloatsbleMaterisls
• Oxygen DtlmancJ.
ing SubStanCes
• Oi/& Grease
0 Bacteria & Viruses
Uke% to Hav. Sign fiCllnt lropact
0 Pr.obabl.Low Qr
Implementation
Requ~reme!1ts
o Capital Costs
~ O&MCosts
Q Maintenance
Q Training
.1 •. High 0 .Low
March, 1~93,
•
•
• (
Additional Information -Building and Grounds Maintenance
Buildings and grounds maintenance includes taking care of landscaped areas around the facility, cleaning of parking lots
and pavement other than in the area of industrial activity, and the cleaning of the storm drainage system. Painting'and
orner minor or major repairs of buildings is covered in SC12 (Building Repair, Remodeling, and Construction). Certain
normal maintenance activities can generate materials that must be properly disposed. Other'maintenance activities can
enhance water quality if they are carried out more frequently and/or in ,a more deliberate fashion.
PestiddeIFertilizer Mana2ement
Landscape maintenance involves the use of pesticides and fertilizers. Proper use of these materials will reduce the risk
of loss to storm water. In particular, do not apply these materials during the wet season as they may be cairied from the
site by the next storm. When irrigating the landscaped areas, avoid over-watering not only to conserve water but to
avoid the discharge of water which may have become contaminated with nutrients and pesticides.
It is important to properly store pesticides and application equipment, and to dispose the used containers ina responsible
manner, consistent with state regulations. Personnel who use pesticides should De trained in their use. The California
Department of Pesticide Regulation and county agricultural commissioners license pesticide dealers, certify pesticide
applicators, and conduct on-site inspections. , .
Written procedures for the use of pesticides and fertilizers relevant to your facility would help maintenance staff under-
stand the "do's" ;md "don'ts". If you have large vegetated areas, consider the use of integratec;l pest management (!PM)
techniques to reduce the use of pesticides.
Parkjn(ifStonn Sewer Maintenance
A parking area that drains to the same storm drainage system as the industrial activity that is to be permitted must also be
evaluated for suitable BMPs. Storm water from parking lots may contain undesirable concentrations of oil, grease,
suspended particulates, and metals such as copper, lead, cadmium, and zinc, as well as the petroleum byprOducts of
engine combustion. Deposition ,of air particulates, generated by the facility or by adjacent industries, may contribute
significant amounts of pollutants.
The two most appropriate maintenance BMPs are periodic sweeping and cleaning catCh basins if they are part of the
drainage ,system. A vacuum sweeper is the best method of sweeping, rather than mechanical brush sweeping which is
'not as effective at removing the fme particulates.
Catch basins in parking lots generally need to be cleaned every·6·to 12 months, or whenever the sump ishalffull. A
sump that is more than half full is not effective at removing additional particulate pOllutants from the storm water. If the
storm drain lines· have a low gradient, less than about 0.5 feet in elevation drop per 100 feet of line, it is likely (Qat
material is settling in the lines during the small, frequent storms. If you have not cleaned',the storm drain systein for
some time, check the lines as well. If they are not cleaned, the catch basins will likely be filled during, the next-signifi-
cant storm by material that is washed from the lines. Also, install "tum-down" elbows or similar .devices on the outlets
of the catch basins; they serve to retain floatables, oil and grease.
Clearly mark the storm drain inlets, either with a color code (to distinguish from process water inlets if you have them)
or with the painted stencil of "00 NOT DUMP W AS1F'. This will minimi~ inadvertent dumping of liquid waStes.
Sweepings and sediments from these maintenance activities are generally low in metals and other pollutants and there-
fore can be disposed on-site or to a construction debris landfill. Test the material if there is a r~nable doubt whether
metals or other pollutants are present If concentrations of contaminants are high, it indicates that other, BMPS may be
needed to eliminate or reduce emissions from the source. If a vactor truck is used to clean the storm drairiage system,
SC11
Industrial Handbook 4 -38 March,1993
•
•
•
Additional Information -Building and Grounds Maintenance
dirty water will be genefclted. This water should not be discharged to the storm drainage system as it is silt laden and
contains much of the pollutants that were removed by the catch basins. The water should be disposed to the process
wastewa~r system, if you bave one, or to the public sewer if permission is granted by the local sewer authority. Alterna-
tively, the' water can be placed somewhere on the site where it can evaporate.
The cleaning of the paved swfaces and catch basins in the areas of industrial activity has been discuss,ed previou~ly in
SCS (Loading and Unloading of Materials), SC7 (Outdoor Process Equipment Operations ,and Maintenance), and SC8
(Outdoor Storage of Raw Materials, Products, and Byproducts).
If some employees have cars that are leaking abnormal amounts of engine fluids, encourage them to bave the problem
corrected.
Examples of Effectjye Pro2rams
Information on integrated pest management may be obtained from the Bio-Integral Resource Center, P.O. Box. 7414,
Berkeley, CA 94707,510-524-2467.
REFERENCES
Best Management Prnctices for Industrial Storm Water Pollution Control, Santa Clara Valley Nonpoint Source Pollution
Control Program, 1992 .
SC11
Industrial Handbook 4·39 March,1993
•
•
•
ACTIVITY: BUILDING REPAIR, REMODELING AND CONSTRUCTION
Graphic: North Central Texas COG, 1993
DESCRIPTION
,Prevent or reduce the discharge of pollutants to storm water from building repair, ~model
ing, and' construction by using soil erosion controls, enclosing or covering building
material storage areas, using good housekeeping practices, using safer alternative prod-
ucts, and training employees.
APPROACH
• Use soil erosion control techniques if bare ground is temporarily exposed. See the
Construction Activity Best Management Practice Handbook.
• Use permanent soil erosion control techniques if the remodeling clears buildings from
an area that are not to be replaced. See SClO (Contaminted or Erodible Surface
Areas). '
• Encl9se painting operations, consistent with local air quality regulations and OSHA.
• Properly store materials that are normally used in repair and remodeling such as
paints and solvents.
• Properly store and dispose waste materials generated from the activity. See CA20,
Solid Waste Management. Construction Handbook.
• Maintain good housekeeping practices while work is underway.
REQUIREMENTS
• Costs (Capital. O&M)
These BMPs are genernlly of low to modest in cost
LIMITATIONS
• This BMP is for minor construction only. The S~'s General Construction ActiVity
Storm Water Permit bas more requirements for larger projects. The companion
"Construction Activity Best Management Practice Handbook" contains specific
guidance and best management practices for larger-scale projects.
• Hazardous waste that cannot be re-used or recycled must be disposed of by a licensed
hazardous waste hauler.
! Safer alternative products may not be available, suitable, or effective in every case.
• Be certain that actions to help storm water quality are consistent with Cal-and Fed-
OSHA and air quality regulations.
Modifications are a common occurrence particularly at large industrial sites. The activity
Industrial Handbook 4 -40
Applications
, Manufacturing
Mater.ial Handling
Vehicle Maih.tenaflce
~nstructioy
~mercial Acti.Vit~
Roadways
Targeted Constituents:
• Sediment
o Nutrient$
• Heavy'Metals
• Toxic Materials
• Floatable Materials
o Oxygen Demand-
ing Substances
• Oil & Grease,
OSacteria & 'Viruses
• Ukfl/yto,H~. , , SignIficant ImfJllCt o Probab/el.Dwor
Unknown Impact
Implementation
Requirements
o Capital Costs
~ , ,
O&MCosts
~ Maintenance
~ Train,ng
• High 0 Low
SC12
Mat~lJ, 1993
•
•
•
Addifionallnformation -Building Repair, Remodeling, and Construction . .
may vary from minor and normal building repair to major remodeling, or the installation of new facilities on curr~ntly
open space. These activities can generate pollutants that can reach storm water if proper care is not@<en. The sources of '
these contaminants may be solvents, paints, paint and vrunish removers, f"mishing residues, spent thinners, soap c:1eaners,
kerosene, asphalt and concrete materials; adhesive residues, and old asbestos installation.
Good HOusekeeJ)jDI:
Proper care involves a variety of mostly common sense, housekeeping actions such as:
• Keep the work site clean and orderly. Removing debris in a timely fashion. Sweep the area.
• Cover ~s of particular concern that ,must be left out, particularly during the rainy season.
• Educate employees who are doing the work.
• Inform on-site contractors of company policy on these matters and include appropriate provisions in their contract to
make certain proper housekeeping and disposal practices are implemented. .
• Make sure that nearby storm drains are well marked to minimize the chance of inadvertent disposal of residual
paints' and other liquids.
• Do not dump waste liquids down the storm drain.
• Advise concrete truck drivers to not wash their truck over the storm drain. Have a designated area that does not
drain to the storm drain.
• Clean the storm drain system in the immediate vicinity of the construction activity after it is completed.
Proper education of off-site contractors is often overlooked. The conscientious efforts of well trained employees can be
lost by unknowing off-site contractors, so make sure they are well informed about what they are expected to do.
Painting operations should be properly enclosed or covered 10 avoid drift Use temporary scaffolding to hang drop cloths
or draperies to prevent drift Application equipment that minimizes overspray also helps. Local air pollution regulations
may, m many areas of the state, specify painting procedures which if properly carried out are ilsually sufficientto protect
water quality. If painting requires scraping or sand blasting of the existing surface, use a ground doth to collect the
chips. Dispose the residue properly. If the paint contains lead or tributyl tin, it is considered a bazardous waste.
Mix paint indoors before using so that any spill will not be exposed to rain. Do so even during dry weather because
cleanup of a spill will never be 100% effective. Dried paint will erode from a surface and be washed away by ,storms. If
using water based paints, clean the application equipment in a sink that is connected to the'sanitary sewer. Properly store
leftover paints if they are to be kept for the next job, or dispose properly.
When using sealants on wood. pavement, roofs, etc, quickly clean up spills. Remove excess liquid with absorbent
Jrul~ ,or rags. If when repairing roofs, small particleS'have accumulated in the gutter .. ejtber sweep out the gutter or
w3.$b ,the gutter and trap the particles at the outlet of the downspout A sock or geofabric placed over the o!1tle~may
effectively trap the materials. If the'downspout is tight lined, place a temporary plug at theftrst oonvenient;po'int in the
storm drain and pump out the water with a vactor truck, and clean the catch basin, sump where you placed the plug.
SojuErosjOD Control
If the work involves exposing large 'areas of soil employ the appropriate soil erosion and control tecbIliques. See the
Construction Best Management Practice Handbook. If old buildings are being torn down and not replaced in the near
future, stabilize the site using measures described in sew. Contaminated or Erodible Surface AreaS.
If a building is to be placed over an open area with a storm drainage system. make sure the storm inlets within the
SC12
Industrial Handbook 4·41 March,1993
•
•
•
Additional Information -Building Repair, Remodeling, and Constructio'n
building are covered orremoved. or the storm line is connected to the sanitary sewer. If because. Of the remodeling a
new drainage system is to be installed or the existing system is to be modified, consider installing catch basins as they
serve' as effective "in-line" treatment devices. See Te2 (Wet Ponds) in Chapter 5 regarding design criteria. Include in
the catch baSin a "turn-down" elbow or similar device to trap floatables.
Recycle residual paints, solvents, lumber, and other ~s to the maximum extent practical. Buy recycled products
to the maximum extent practical •.
REFERENCES
Best Management Practices for Industrial Stoim Water Pollution ContrOl, Santa Clara Valley Nonpoint Source Pollution
Control Program. 1992 .
SC12
Industrial Handbook 4·42 Marcil, 1993
•
•
•
ACTIVITY: OVER-WATER ACTIVITIES
DESCRIPTION
Prevent or reduce the discharge of pollutants to storm water and receiving waters from
over-water activities by minimizing over-water maintenance, keeping wastes out of the
water, cleaning up spills and wastes immediately, and educating tenants and employees.
APPROACH
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Properly dispose of domestic wastewater and ballast water.
Limit over-water hull surface maintenance to sanding and minor painting.
Use phosphate-free and biodegradable detergents for hull wa$ing.
Use secondary cont$lment on paint cans.
Have available spill containment and cleanup materials.
Use ground cloths when painting boats on land.
Use tarps, plastic sheeting, ~tc. to contain spray paint and blasting sand.
Properly dispose of surface chips, used blasting sand, residual paints,. and other
materials. Use temporary storage containment that is not exposed to min.
Immediately clean up spills on docks or boats ..
Sweep drydoclcs before flooding.
Clean catch basins and the storm drains at regular intervals.
Post signs to indicate proper use and disposal of residual paints, rags, used oil, and
other engine fluids.
Educate tenants and employees on spill prevention and cleanup.
Include appropriate language in tenant con~cts indicating their responsibilities.
Marinas should provide wastewater disposal facilities.
REQUIREMENTS
• Cost (Capital, O&M)
Most of the BMPs are of low and modest cost. Exceptions are· stations for
temporary storage of residual paints and,engine fluids, and wastewater pumpout
facilities.
• Maintenance
Keep ample supply of spill cleanup materials.
LiMITATIONS
Private tenants at marinas may resist restrictions on shipboard painting and maintenance.
Existing contracts with tenants may not allow the owner to require that tenants abide by
new rules that benefit water quality. Even biodegradable cleaning agents have.been found
to be toxic to fish.
Industrial Handbook 4 -43
Applications
Manufacturing
C!l!!terial Hsndlinv
Vehicle Msinte"snce
Construction
. ~merciaIActiViti~
Roadw~ys
aste Containment
Targeted Constituents·
0 Sediment
0 Nutrients • Heavy Metals
• Toxic Materials
• Floatl!ble Materials • Oxygen Detnant!-
ing Substances
• Oil & Grease • Bacteria & Viruses • Ukil~ to Have Sign flt;ltnt IriJplICt
0 Probable Low or
UnkiJown.JmplICt
Implementat!on
Requirements
0 Capital Costs
.~ O&MCosts
Q Maintenance
Q Training
,'., High 0 Low
SC13
March,1993
•
•
•
Additional Information -Over-Water Activities
Over-water activities occur at boat and ship repair yards, marinas, and yacht clubs, although the later' are notrequired (0
obtain a permit Activities of concern inClude chipping and painting of hulls, on board maintenance of engines, and the
diSposal of domestic wastewater and ballast water. With few exceptions, BMPs to protect water quality are common
sense, low cost changes to normal day-to-tlay procedures.
Oyer-water Actiyjty Mjnjmjzp,tjon
Work on boats in the water should be kept to a minimum. Major hull resurfacing should occur on land. ,Surface prepara-
tion oyer water should be limited to sanding. Painting should be limited to spot work. In marinas, tenant maintenance
over water should be such as to not require opening more than a pint size p<)int can. Paint mixing should not occur on
the dock.
Good Housek<:eJ2ine
When conducting on board maintenance, used antifreeze should be stored in a separate, labeled drum and recyCled. Fuel
tank vents should have valves to prevent fuel overflows or spills. Boats with inboard engines shOlild have oil absorption
pads in bilge areas and they should be changed' when no longer useful or at least once a year.' '
Marina owners should provide temporary storage stations for used engine fluids. paint cans, and other maintenance
materials. Signs should be posted at the head of each dock indicating maintenance rules. Marina owners should ~nstaIl a
wastewater disposal system. either dockside lines or a pumpout station., Tenant contracts should include language
indicating their responsibilities.
When ,painting on shore, place paint cans in a tray or comparable device that collects spills and drips. Use groJlIld cloths
when painting., Use spray guns that minimize overspray; also enclose the area with plastic tarps. Identify li'designate(J;
area for washing boats. Vacuum sweep work areas frequently. When doing repairs or painting on a tidal grid or similar
open "dry dock", use ground cloths to retain chips and spilled paint The repair yard owner should install signs so that
boat owners who are doing their own work know their responsibilities.
Large boat repair yards can implement the above BMPs. There are seve~ additional measures. With regard to dry dock
o~tions: sweep the accessible areas of the dry dock before flooding; and pick up other debris that appears arter the
ship is floated. Remove floatable debris such as wood. Shipboard cooling ,and process water discharges ~ould be
directed to minimize contact with spent abrasives, paints, and other debris. Look for and rePair l~g valves, pipes,
hoses, or soil chutes carrying either water or wastewater. Plastic sheeting or other suitable materials should be installed
when sandblasting and spray painting.
Use drip pans or comparable devices when transferring oils, solvents, and paints. Regularly clean the shoreside work
areas of debriS, sandblasting material, etc. Clean catch basins or other parts of the storm drainage system that inight
accumulate these materials.
EshWaste
Fish wastes must also be managed properly. Recycling fish wastes back to the water is encouraged when di~posal will
not result in water quality or public nuisance problems, such as wastes washing up oIishore or causing, odors or bacteria
problems. Fish wastes should not be recycled in any dead end lagoons or other poorly flushed areas. Marina owners,
should provide fish cleaning stations where waste recycling can occur without adversely affecting Vr:ater quality.
Note: San Francisco Bay Area boat repair and maintenance facilities. The San Francisco Bay Regional Warer Quality
Control Board has issued a General Storm Water NPDES Permit to boat yards which work priIfiarily on pleasure vessels
less than 65 feet in length. The General Permit requires maintenance of pressure wash 'containment and recycle or
pretreatment system implementation of a Storm Water Pollution Control Plan (SPCP) and a Mo~itoring Program . .... ----.. SC13
~' . ." ,
Belt '
PrKtIcft '
Industrial Handbook 4·44 March, 1993
•
• -'
•
. Additional Information -Over-Water Activities
REFERENCES
Proposed Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters, USEPA.
1992.
General NPDES Permit for Discharges of Storm Water from Boat Repair Facilities. SFBRWQCB, 1992 .
SC13
..~
Industrial Handbook 4 -4S March,1993
•
•
••
ACTIVITY: EMP.LOYEE TRAINING
DESCRIPTION . .
Applications
~anuf~turing:::>
~terial Handlin
Vehicle Maintenance
PJnployee training, like equipment maintenance, is not so much a best management practice as it is a method by which to .
implement BMPs. Thi.S fact sheet highlights the importance of training and of integrating the elements of eII).ployee
training from the individual source controls into a comprehensive training program as part of a facility's StbrIIi Water
. Pollution Prevention Plan (SWPPP).
The specific employee training aspects of each of the source controls are highlighted in the individual fact sheets. The
focus of this fact sheet is more general, and includes the overnll objectives and approach for assuring employee training
ip storm water pollution preventioo. Accordingly, the organjzation of this fact sheet differs somewhat froDJ. the otherJact
sheets in this chapter .
OBJECI1VES
Employee training should be based on four objectives:
• Promote a clear identification and understanding of the problem, including activities with, the potential to pollute
storm water;
• Identify solutions (B:MPs);
• Promote employee ownership of the problems and the solutions; and
• Integrate employee feedback into training and BMP implementation.
APPROACH
• Integrate training regarding storm water quality management with existing traiQing programs that maybe'~uired
for your business by other regulations such as: the Illness and Injury Prevention Program (IIPP) (SB 198) (OWfornia'
Code of Regulations TItle 8, Section 3203), the Hazardous Waste Operations and Emergency Response .
(HAZWOPER) standard (29 CPR 1910.120), the Spill Prevention Control and Countermeasure (SPCC) Plan (40
CPR 112), and the Hazardous Materials Management Plan (Business Plan) (California Health and Safe~ Code,
Section 6.95).
• Businesses, particularly smaller ones that are not regulated by Federal, State, or local reg~oils, may use the
information in this Handbook to develop a training pro~ to reduce ~eir potential to pollute storm water.
LISTING OF INDUSTRIAL ACfIVITIES
Employee training is a vital component of many of the individual source control BMPs included·in thisc~ter. F()llow-
ing is a compilation of the training aspects of the source control fact sheets.
SC14
Industrial Handbook 4·46 Match, 1993
•
•
•
ACTIVITY -EMPLOYEE TRAINiNG (Continue)
SCt Non-Storm Water Discharges to Drains
• Use the quick reference on disposal alternatives (Table 4.1) to train employees in proper and con~istent methods
for disposal. .
• Consider posting the quick reference table near storm drains to reinforce training.
SO Vehicle and Equipment Fueling
• Train employees in proper fueling and cleanup procedures.
• The SPCC Plan may be an effective program to reduce the number of accidental spills from fueling.
SC3 Vehicle and Equipment Washing and Steam Cleaning
• Train employees in standard operating procedures and spill cleanup techniques described in tQe f~ct sheet.
SC4 Vehicle and Equipment Maintenance and Repair
• Train employees in standard operating procedures and spill cleanup techniques described in the fact sheet.
• Paint stencils to remind employees not to pour waste down storm drains.
SCS Outdoor LoadinglUnloading or Materials
• Use a written operations plan that describes procedures for loading andlor unloading.
• Have an emergency spill cleanup plan readily available.
• Employees trained in spill containment and cleanup should be present during loading/unloading.
• Make sure fork lift operators are also properly trained.
SC6 Outdoor Container Storage or Liquids
• Registered and specifically trained professional engineers can identify and correct potential problems such as
loose fittings, poor welding. and improper or poorly fitted gaskets for newly "installed tank SYSte~S.
• Empl~yees trained in emergency spill cleanup procedures should be present when dangerous waste, liquid
chemicals. or other wastes are handled. -
SC7 Outdoor Process Equipment Operations and Maintenance
• The preferred and' possibly most economical action to reduce storm water pollution is to alter the activity. This
may mean training employees to perform the activity during dry periods only-or substiwting benign materials
for more toxic ones. -
SCS Outdoor Storage or Raw Materials,-Products, and By-Products .
• Train employees in standard operating procedures and spill cleanup techniques described in theJact sheet.
SC9 Waste Handling and Disposal ..
• Train employees in standard operating procedures and spill cleanup techniques described in the fact sheet.
• Paint stencils to remind employees not to pour waste down storm drains.
SC10 Contaminated or Erodible Surface Areas
• Training is not a significant element of this best management practice .
. SC14
Industrial Handbook 4 -47 March, 1993
• ACTJVlty -EMPLOYEE TRAINING (Continue)
•
•
SCll Building'and Grounds Maintenance
• Personnel wbo use pesticides should be trained in their use. The California Department of Pesticide Regulation
and county agricultwal commissioners license pesticide dealers, certify pesticide applicators, and, conduct on-
site. inspections.
• Written procedures for the use of pesticides and fertilizers relevant to your facility would help maintenance staff .
understand the "do's" and "don'ts". If you have large vegetated areas, consider the use of integrated pest.
tnanagement (IPM) tecbniques to reduce the use of pesticides.
SCl2 'Building Repair, Remodeling, and Construction
• Proper education of off-site contractors is often overlooked. The conscientious efforts of well trained employees
can be lost by unknowing off-site contractors, so make sure they are well informed about what they are ex-
pected to do.
SC13 Over-Water Activities
• Post signs,to indicate proper use and disposal of residual paints. rags. used oil, and other engine fluids.
• Educate tenants and employees on spill prevention and cleanup.
• Include appropriate language in tenant contracts indicating· their responsibilities .
SC14
Industrial Handbook 4·48 March, 1993
•
•
•
·BMP: STORM DRAIN SYSTEM SIGNS
DESCRIPTION
Stenciling of the stoml drain system (inlets, catch basins, channels, and creeks) with
prohibitive language/graphic icons discourages the illegal dumping of unwanted materials.
APPROACH
• Create a volunteer work force to stencil storm drain inlets, and use municipal staff to
erect signs near drainage channels and creeks.
• For a quick reference on disposal alternatives for specific wastes, see Table 4.1, SCSO,
illegal Dumping Control.
REQUIREMENTS
• Cost ConsideIations
Volunteer work force serves to lower program cost.
Stenciling kits require procurement of durable/disposable items.
Need for storagelmaintenance of stenciling kits requires planning.
Program. can aid in the cataloging of the storm drain system.
• Regulations
Develop and enforce an ordinance that requires inlets, catch basins, channels, anc;l
creeks to be fitted with anti-dmnping, pollutioo prevention signs.
• Administrative/Staffing
Primary staff demand is for program. setup to provide marketing and training.
~goinglfollow-up staff time is minimal because of volunteer services.
Minimum 2 persons are required for high traffic areas, commercial and industrial
zones.
Staff requirement at program headquarters for emergencies, questions, etc.
• Equlpment
StOIDl drain stenciling kits.
• Trnining
Training sessions of approximately 10-15 minutes will cover stenciling proce-
dures, including bow to stencil. record keeping, problem drain notation, etc.
Proper health and safety protocol (buddy system, traffic, health conce~, etc.).
PUBLIC EDUCATIONlPARTICIPATION
• Promote volunteer services (individual and business) througb radio/television and mail-
out campaigns.
Program Elements
New l)eve/opment
Commercial Activities .
Targeted Con~tituents
• Sediment
• Nutrients
o Heavy Metals • Toxic Msterilll6
• F./otJtable MlIteria/s
• Oxygen Demtlnd-
ing S'!bstancu·
• Oil,& Gl'eB$e
0 Bacteria & Viruses
Implementation .
Requirements
OCapitsl CO$ts
Q O&MCom
O· Regulatory
o Staffing:
~ Tl'lIiiling
o Administrative
• High 0 Low '-
. SCaD
• Public reporting of improper waste disposal by ~ R01LINE number stenciled onto the f----------t
storm. drain inlet.
Municipal Handbook 4 -23 . March, 199~
• BMP: STORM DRAIN SYSTEM SIGNS (Continue)
LIMITATIONS · Private property access limits stenciling to publicly-owned areas.
• Program is highly dependent on volunteer response.
• StoIm drain inlets that are physically'blocked will be missed or require follow-up.
• High ttaffidcommercia1fmdusttiaI zones will be responsibility of city staff.
• Ongoing IIiaintenance to maintain readable signs.
-
•
"
• SC30
~ .. ....
. ~
4 -Z4 MumclpaI Handbook ..
March,1993
•
•
•
Additional Information -Storm Oraln System Signs'
Storm chain system signs act as highly visible source controls that are typically stenciled directly adjacent to stcXm drain
inlets. The signs contain brief statements that discourage the dumping of improper materials into the st~ drain system.
Graphical icons, either illustrating anti-dumping symbols or images of receiving water fat.ma. are effective supplements
to the anti-dumping message. The intent of such a storm drain system stenciling program is to CIihance public awareness
of the pollutant effect on local receiving waters from storm water runoff and also to discOurage individual's habitual
waste disposal actions (e.g. automotive fluids and landscaping wastes).
Awmaclz
AD effectively implemented stenciling program,encourages change in personal behavior and helps minimjz.e non-point
source pollutants from entering the storm drain system. An additional benefit is that waste and catcll basinmainteJ;Umce
isminjmjred through the reduction of disposed materials mtostorm drain inlets. Fmally, some stenciling progratns
include posting of community botline numbers for effective reporting and mOnitoring of improper disposal practices,
plus the encouragement of use of bousehold hazardous waste collection and used·oil recycling programs.
An important aspect of a stenciling program is the'distribution of inform.ational flyers that educate the neighbodlpod
(buSiness or residential) about storm water pollution, the storm drain system, and the watershed, and that provides
information on alternatives such as recycling, household hazardous waste disposal. and safer products.
Stoml drain inlet stenciling programs are generally bandled through community volunteer efforts. ;M;u(licipal staff must
first ocga.nize, market, and provide training for program initialization. However, through an aggressive publiceducati9n
progI'am,·the majority of the labor should be genernted through volunteer serviCC;S. Successful programs have involved
substantial input from business, civic, school, neighborhood, and environmental oxganizations. EtiCourage sChools,
churches, girllboy scout troops, and environmental groups to add storm drain stenciling as a iesson/field trip to existing
activities. This provides a ready-made labor force to.use the stenciling materials developed by the municipality.
The stenciling project can be part of a larger volunteer "watershed· awareness" public eduqttion program. Stenciling
should be the easiest volunteer activity, or the first step in "watershed awareness .... education. ultimately leading to an all:
volunteer water quality monitoring program. Municipal staffmust initially provide'an inventory of curb inlets and
develop the stencil. The stenciled language is most effective if it represents a consistent message ~ted:from. the city's
public education department Communities in California have used messages su.ch as: "No Dumping, Flows to Bay",
"Protect the Bay, Don 't Dump", and "Dump No Waste, Flows to Bay." Program logos and generalized dra~gs of a
fish or a bird may be added to provide a visual aid as well. Once the Stoml inlet'language is.determined, stencil'painting
kits must ~ ordered and training programs/'mstruction sheets may be developed.
The storm drain ste~ciling kits include stencil. paint, paint brush, plastic gloves, catch basin.IllaP,.cllpboard, instructi~
·liability release form. identification form, rags, whisk broom or brush, paper towels, trash bags, safety vests, and a 5-
gallon bucket to bold materials. . .
Readability of stencils is critical to their effectiveness. Wherever possible stencils should be painted on a smooth
surface such as cement, as opposed to asphalt As with any painting, surface preparation is key to paint adhesion and
thus readability and durability. Extra effort expended to clean the surface during the initi,al painting belps reduce the
need for re-painting. Some programs have gone so far as to paint a background color first follOwed by the stencil in a
cootrasting color to increase readability.
Many communities use water-based latex exterior paint from their traffic control ~ents. Brands include; Fuller
O'Brien, Arvoe Stripping Paint. Sherman-Williams Metalex, and All-Kids Traffic Paint Spray paints shou,ld.have a
VOC rating of less than 250 (required by EPA). If there is concern over spray paints, a refillable paint brush ~e4
SC30
Municipal Handbook 4 -25 March,1993
••
•
•
Addi-iionallnformation -Storm Drain System Signs
"Quick-Painter" may be used. It is easier to handle (children can· use it), it is more legible than spray paint. and it also
avoids llle environmental problem of having to properly dispose of spray cans~
Because a stenciling program. involves primarily volunteer services, liability release forms and volunteer identification
notices should also be admjnistered. Training sessions should be restricted to residential or low traffic areas iorsafety .
pmposes. Municipal staff should be responsible for stenciling efforts in mo~t commercial and industrial land' use sectars.
Regan:iless of the manpower, an attempt should be made to accurately log all curb inlets that have been stenciled, which
will also aid the municipality's efforts to catalog the storm sewer system. T13Cking. of stenciled inlets and the overall cost
of the program is necessary to monitor the success of the program. Municipal staff may be accessible during nOll-Work
hours to handle questions, provide instruction, and respond to emergency situations. ProgI'3+Il generated waste materials
should be centrally collected by municipal staff to ensure proper waste disposal.
Olsts.
One municipality from the State of Wa:shington has estimated that stenciling kits cost approximately $50 each. Stencils.
may cost about $8 each including the die cost OIl an order of 1,000. :Re-orders cost about ·SlIstencil. -S tencil deSigns may
be available from other communities. Stencil kits should· be provided on a loan basis to volunteer groups free of charge
with the understanding that kit remnants are to be returned. -
QlannellCreek Si2DS I
Channel and aeek signs are another way of providing a pollution prevention message near the point of discharge. These
signs caD use the same language as the stencil. but are affixed to a metal or wood p1acard and'mounted to a post. Sign
installalioo requires a level of expertise and equipment that most volunteers do not possess, so public w<Xb staff time is
an' additional impleDientation cost.
New Deye1SJDIDent
For the private areas of a new development, the municipality may consider requiring ~veloperS to purchase and paint
stencils near new inlets or catch basins, and to install channe1lcreek signs with a pollution prevention messag~. As an
alternative, the developer could reimburse the municipality's costs to perform the worle. In addition, the municipality cah
develop and enforce an ordinance that requires inlets, catch basins, channels, and aeeks in new developmentS, both
public and private, to be fitted with signs with a pollution prevention message.
Examples of Effective Prornms
The City of Palo Alto has a combined volunteer/contractor progIam which greatly tacilitaIes storm dJ:ain stenciling. The
City retained the Conservation Corps to paint approximately 75% (2,000) ofit's'storm drains; leaving the 25% (700) of-
its drains in more residential areas to be done by volunteers. This strategy speeds up the stenciling, reduces the qty's
liability, supports a worthwhile program. and still allows plenty of stam drains-for volunteers to pamt. '
The Association of Bay Area Governments (ABAG) sponsored a nine-county stenciling effort on Earth Day 1992.
ABAG has up-to-date information on stencil and program development.
The stencil for the City of Huntington Beach includes the municipal code section number for illegal dumping ,to facilitate
incident reporting and enfoo;ement. In Santa Monica, the city provides a packet of IIia1erial regarding storm water
pollution including a catcb basin stencil kit
REFERENCES
Best Management Practices Program for Pollution Prevention, City and County of Sail F):cmcisco, Uribe & Associates,
Oakland. California. 1990 .
SC30
Municipal Handbook -.March; 1993
•
•
•
Additional Information -Stonn Drain System Signs
Municipal Storm Water Discharge Management ~ City of Stockton, California, Camp .Dresser & McKee, Walnut
Creek., 1992. . v
Regional Water Quality Control Plants' News., City of Palo Alto, California, 1991.
Storm W~ Program Guidance Manual for the Puget Sound Basin, (Draft), City of Seattle, Washington; Drainage and
Wastewater Utility, 1992. .
Urban Runoff: A Pollution Abatement Program, Heal the Bay, Santa Monica, CaIlf6inia, 1992 .
Municipal Handbook 4·27
·SC30
s-t~ ES
March, 1~3
•
•
I.
.... ' ..
BMP: ILlEGAL DUMPING CONTROL
Graphic: NoIth Central Texas COG, 1993
DESCRIPTION
Implement measures to detect. correct. and enforce against illegal dumping of pollutants-on
streets and into the storm drain system and creeks. The remedial focus of this best manage-
ment practice contrasts with the preventative focus of the Material Disposal and Recycling
BMPs (SC3O-SC32) in this chapter. megal discharges through physical connections are -
addressed in BMPs SC60-SC62 (illicit Connection Cootrols).
APPROACH
• Public awareness is the key to this BMP. Train municipal employees and educate the
general public to recognize and report illegal dumping.
• Deputize municipal staff with the authority to write environmental tickets.
• Establish system for tracking incidents.
Program ElemQnts
New' Development '
Ruidential
Commercial Actilfitiu
Industrial Activities
Municipal Facilitiu
<:J!&aIDi8ChariE:>
Targeted Constituents
• Sediment
o Nutrient6
• HavyMetal.
• T "xic Materia/$ • Floatable Material.
• Oxygen Demand-
ing Substance.
• Use the quick reference on disposal alternatives at the end of this fact sheet (Table 4.l) • Oil & GfeII6e
to ttai:n ~unicipa1 employees and to educate businesses, cootractors, and the general
public in proper and consistent methods for disposal. • SM:terla & Viruses
REQUIREMENTS
• Cost Considerations
The primary cost is for staff time as noted below. The cost depends on how
aggressively a program is implemented. '
Municipal cost for containment and disposal may be borne by the discharger.
• Regulations
Municipal codes should include sections prohibiting the discharge of soil, debrls,
refuse, hazardous wastes, and other pollutants into the stoIm drain system.
• Administrative I Staffmg ,
Requires technical staff to detect and investigate illegal dumping violations. and to
coordinate public education.
Legal staff is required to pursue prosecution of significant cases.
• Equipment
A database is useful for defining and tracking the magmtude of the problem.
• Training
Training of technical staff in identifying and documenting illegal dumping
incidents is required.
PUBLIC-EDUCATION I PARTICIPATION
• Awareness of the issue accomplishes two things. The receiver of the information
understands the issue and therefore is unlikely to cause a problem. plus thci:r aware-
ness often helps detect other violations.
LIMITATIONS
• The elimination of illegal dumping is dependent OIl the availability, convenien<;:e. and
cost of alternative means of disposal.
Munieipal Handbook 4·44
• 'Ubly to Have -
Slgnifk:ant Im".:t o P",bllble Low or '
-Unknown Imp.¢_
Implementation
Requirements
0 Capn.ICos~
Q O&MCom
0 R,guJatory -. Stilffing
• TrainIng
0 Admini8trstive
• High o Low
seso
March,1993
•
•
•
Additional Information -Illegal Dumping Control
Substances illegally dumped on streets and into the storm drnin system and creekS include paints, used oil and other
automotive fluids, construction debris, chemicals, fresh concrete, leaves. grass clippings, and pet wasteS. All of these
wastes can cause storm water and receiving water quality problems as well as clog·the storm drain system itself.
One of the keys to success is increasing the number of people on the street who' are aware of the problem and who. have the
tools to at least identify the incident, if not correct it. There are a number of ways of accomplishing this:
• Train municipal staff from all departments (public works, utilities. street cleaning, parks and recreation, industrial
waste inspection, hazardous waste inspection, sewer maintenance) to recognize and report the incidents. '
• Deputize municipal staff wbo may come into contact with illegal dumping withfhe authority lD write illegal dwnping
tickets.for offenders caught in the act (see below).
• Educate the public. As many as 3 out of 4 people do not understand that in most con:im.unitiesthe storm drajn does
not go to the wastewater treatment plant. Unfortunately, with the beavy emphasis in recent years OQ, public education
about solid waste management, including recycling .and bousehold hazardous waste, the sewersysrem (both storm
and sanitary) bas been the likely recipient of aoss-media transfers of waste.
• Provide the public with a mechanism for reporting incidents such as a hot line and/or dOor hanger (see-below).
• Help areas where incidents occur more frequently set up enviromnental watcb programs (like crime watcbprograms).
• Another mechanisin for public reporting is volunteer water quality monitOring. Volunteers can be trained to notice
and report the presence and suspected source of an observed pollutant to the appropriate public agency.
The establishment of a system for tracking incidents will belp identify:
• illegal dumping "hot spotS".
• Types and quantities (in some cases) of wastes,
• Patterns in time of occmrence (time of day/night, month, or year),
• Mode of dumping (abandoned cootainers. "midnight dumping" from moving vehicles, direct dumping·of materials,
accidents/spills), and
• Responsible parties.
A tracking system also helps manage the program by indicating trends, and identifying who, what, when; and wbere
efforts should be concentrated.
The Bureau of Street Cleaning and Urban forestI)' in the City and County of San Fnmcisco bas aptborized a' forte of three
E'nviroomental Patrol Officers to issue citations enf~g the mmiicipallitter codes. San Francisco is plamiing on exu;nd-
ing ~ ~thority to other employees including industrial waste inspectors. .
The City of Palo Alto bas developed a public participation program for reporting dwnpipg violations. Wben a concerned
citizen oc public employee encounters evidence of illegal dumping, a door hanger (siinilar in 'format tobo~l "Do Not
Disturb" signs) is placed on the front doors in the neighborhood. The door hanger notes that a violation basoccm:red in
the neighborhood, informs the reader wby illegal dumping is a problem, and notes that illegal dumping ·carries a significant
financial penalty. Infonnation is also provided on what citizens can do as well as contact numbers for more information·or
to report a violation.
The Port of Long Beach has a state of the art database incorporating storm drain infrastructure, potential pollu~t sources,
facility management practices. and a pollutant tracking system.
The State Department ofFISh and Game bas a botline for reporting violations called CalTIP (1-800-9S2~5400). The phone
nwnber may be used to report any violation of a Fish and Game code (illegal dumping, poaching, e~.).
Dc California DeparonCDt of Toxic Substances Control's Waste Alert Hotlin~ 1-g00-69TOXIC. can·be
used to report hazardous waste violations.
REFERENCES
Hazardous Waste Alert; A Citizen's Guide to Enforcemcnt"Californla Department of Toxic Substances
Control, 1990.
scso
~ .....
e,.t
~:
Municipal Handbook 4 -45 Marc,h, 1993
•
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•
8M P: STREET CL.EANING
DESCRIPTlON
Reduce the discharges of pollutants to storm water from street surfaces by conducting stieet,
cleaning on a regular basis. '
, ,
APPROACH
• Prioritize cleaning to use the most sophisticated sweepers. at the highest frequency, and
in areas with the highest pollutant loading.
• Restrict street parlOng prior to and during sweeping.
• Inaease sweeping frequency just before the rainy season.
• Proper maintenance and ope:rati~ of sweepers greatly inaeases·their efficiency.
• Keep accurate operation logs to ttack program.
• Reduce the number of parlred vehicles using regulation.
REQUIREMENTS
• Cost ConsideIations
A street cleaning program requires a significant capital and O&M budgeL
Sweeper capital costs range from S65,OOO to $120,000, with a useful life of about
4 years. A careful review of cleaning efficiency should be performed before
increased cleaning is proposed.
• Regulations
Densely populated areas or heavily used streets may require parking regulations to
clear streets for cleaning.
• Administrative I Staffmg
Sweeper operators, maintenance, superviSory, and administrative persQIlDel are
required.
Traffic control officers may be required to enforce parting restrictions.
Skillful design of cleaning routes is required for program to be productive.
Arrangements must be made for disposal of collected wastes.
• Equipment
Mechanical broom sweepers, vacuum sweepers, combination sweepers, and street
flushers. ' ,
Program Elements
New Devf!/opmeht
Ruidentia/
Commercial Activities
/n,duatrisl Activitiea
Municipal Facilities '
~lega/ Diachsf!!U
Targeted Constituents , • Sediment • NutrieiJ~ • Heavy Metil/a
0 Toxic Mst~riala
• F/ostsb/e MsteriBla • 'Oxygen Demand-
Ing SubatanCN'
0 Oil & Grease
0 Bacteria & Viruses
• Uk:fh to Hw. Sign fIciIi1t I",p«:t
0 ProbllJleLOwor
Unlcno!m ImPllCf
Impleinentation
Requirements
• CapltalCO$U
• O&MCosts"
~ Regalatory
• Staffing
~ Training
~ Adm;hiatrative
• Training
Operators must be trained in proper sweeper operation. ,'/ • High . 0 Low
PUBLIC EDUCATION I PARTICIPATION
The general public should be educated about the need to obey par:i::iilg restrictions and
use litter receptacles to reduce street litter.
LIMITATIONS,
• No currently available conventiooal sweeper is effective at removing oil and grease.
• Mecbanical sweepezs are not effective at removing finer sediments.
Municipal Handbook 4.64
SC70
March,1993
.'
•
•
Additional Information' -Str~t Cleaning
Amnwch
• Parked cars are the major obstacle'to effective medlanical sweeping.
• Effectiveness may'also be limited by street condition, traffic congestion, presence of construction projects, c~c
conditions, and condition of curbs. '
• Sweepers effective at removing smaller particles may generate respirable particulate matter (less than 10 micronS)
(i.e., dust) that would lead to concerns over wOlker and public safety. .
• Number of passes and frequency:
-Increase the sweeping frequency for streets with high pollutant loadings, especially in high ttaffic and industtiaI
areas.
Iilqease the sweeping frequency just before the wet season to remove sediments accumulated during the
summer.
Increase the sweeping frequency for streets in special problem areas such as special events, high litter or erosion
zones.
-To achieve 30% removal of street dirt, the sweeping interval must be no mOre than 2 times the average interval
between storms. To reach SO% removal.' sweeping must-occur In to 1'times the average interval between
stomls.
-Sweeping appears most effective in areas with distinct wet and dry seasons (e.g. California).
• Equipment type and operation:
-' Vacuum oc regenerative air sweepers are more effective at removing the fmer sedin'leilts which often bind a
higher proportion of heavy metals.
-Sweeper operation is aitical to performance. Speeds of 6-8 mph are optimal. In addition, brush adjustment.
rotation rate, and sweeping pattern also affect removal efficiencies.
• Source reduction:
-Enforce construction erosion controls in urban areas.
-I:mprove street conditions to inaease sweeping effectiveness.
-E'nlist the help of citizens to keep yard waste, used oil, and other wastes out of the gutter.
-,Require construction contractors to implement stoml water pollution prevention plans (see Construction
Handbook).
• Maintenance:
-Replace worn parts as necessary.
-Install main and gutter lxooms of the apptopxiate weight.
• Record KeepingfI'rackiog:
-Keep accurate logs of the number of curb-miles swept.
-Record the amount of waste oollected.
-Consider implementing employee deputizatioo and spill tracking measures in IDI, megal Dumping Control, in
conjunction with this BMP to facilitate control of illegal du!iwing.
Eguipment Selection
, There are advantages and disadvantages to the two common types of sweepers. The best choice depends on yqur specific
conditions. Many communities frod it useful to have a compliment of both types in their fleet.
Mechanical Broom Sweepers -More effective at picking up large debris and cleaning wet streets. :Less costly to purchase
and~. Create more airborne dust
Vacuum Sweepers -More effective at removing fine particles and associated heavy metals. Ineffective at cleaning wet
streets. Noisier than mechanical broom sweepers which may restrict areas or times of operation. May require·an advance
vehicle to remove large debris. '
SC70
Municipal Handbook 4 -65 March, 1993
•
•
Additional Information -Street Cleaning
A third piece of equipment used by some muilicipalitles also has its advantages and disadvantages:
Street Rushers -Not affected by biggest interference to cleaning. parked-cars. May remove finer sediments..mQving
them toward the gutter and storm water inlets. For this ~n. flushing fell out of favor and is now used .prima.rUy after
sweeping. Flushing may be effective for canbined sewer systems. Presently street flusbfug is not allowedlinder most
NPDES permits.
Cro&s-Media Transfer of PQUutapts
The California Air Resources Board (ARB) has established state ambient air quality standards-including a standard for
respirable particulate matter (less than or equal to 10 microns in diameter. symbolized as P~O>. In the effort to sweep up
finer sediments to remove attached heavy metals, mtmicipalities should be aware that fine dust, that cannot be captured by
the sweeping equipment and becomes airborne. could lead to issues of worlrer and public safety.
-Examples QfEffectjye ProgramS '
Intbe City and County Qf San Francisco. ninety percent of the streets are swept at least once-Per week, ane!' some -sections -
are swept twQ to three times per week. San Francisco is also cODverting as much of its fleet as possible to vacuum
sweepers.
REFERENCES
Best Management Practices for Street C1eaning (Draft). Maintenance Subcommittee. Alameda CountY Urban Runoff
Clean WatcrProgrnm.I992.
Best Management Practices Program for Pollution Prevention. City and County of San Francisco, 1990 •
Characterizing and Controlling Urban RunoffThmugh Street and Sewenige Cleaning. EP A/60012-85J038. PB85 ... 186500,
USEPA, 1985.
Demonstration of Nonpoint Pollution Abatement Through Improved Street Cleaning Pmctices, EPA-600fl-79-161,
PB80-108988. USE? A, 1979.
Guide to Nonpoint Source Pollution Control. USEP A, 1987.
Mustard, Mll., Ellis, S.R. and Gibbs, J.W .. "RunQff and WashoffLoads from Rainfall-Simulation Exper:inients OIl a
Street SUIface and a Native Pasrure in the Denver MetropOlitan Area, Colaado, USGS, Open-FIle Rqxjrt 84-820, 1985.
Protecting Water Quality in Urban Areas: Best Management Practices for Minnesota, Minnesota Pollution Control
Agency, 1989. .
Stormwater Management Manual for the Puget Sound Basin (The Technical Manual): V olwne IV -Urban Land Use
BMPs, Washington State Department of Ecology, 1992.
Street Qeaning Practice. American Public Works Association, 1978.
Street Sweeping as a Water Pollution Control Measure: Lessons Learned Over the Past Ten Years, The Science of the
Iotal Enyjronment. (33): 171-183. J.D. Sana andD.R. Gaboury. 1984. . ..
SC70
~ ..
Municipal Handbook 4 -66 March, 1993
•
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•
8MP: CATCH BASIN CLEANING
Maintain catch basins and sror.m water inlets on a regular basis to remove pollutants, reduce
high pollutant cooceruratiops during the fIrSt flush of storms, prevent clogging of the
l'dC)ViIlIStn:am cooveyance system, and reston: the ~h basins' sedirilent trapping capacity.
A cai.cb-~ is distingWshed from a storm water inlet by having at its base a sediment
sump designed to catCh and retain sediments below the overflow point. This fact sheet
focuses on the cleaning of accumulated sediments from catch basins.
APPROACH
• Aggressively enforce anti-littering and illegal dumping ordinances.
• Catch basins should be cleaned regularly to reduce the possibility of sedimen~ and
pollutant loading from the flushing effect of stann water inflow .
• Prioritize maintenance to clean catch basins and inlets in .areas with the highest pollut-
ant loading.
• Keep accurate operation logs to track program.
REQUIREMENTS
• Cost Considerations
Program ElGm"nts
New Development
Residential
Commercial Activitiu
Industrial Activit_
Targeted Constituents
• Sediment
b Nutrients ., 1;Ieavy Metals
0 Toxic Milterilt/$ ., Floatable Materials • Oxygeri,Demend-
. ing Subst.ncu
• 01/& Grease
0 Slllcteria &: Virutletl
• Uf::h to HlWe Sign tx:.ntlmpa:t
An aggressive catch basin cleaning program could require a,significant capital and L!::=~~~~~~:!J
O&M budget. A careful study of cleaning effectiveness should be undertaken
0 Prob.pJ..l.Dw 01'
before inc::reased cleaning is implemented.
• Regulations
~ are no regulatory requirements for this BMP. Municipal codes should
include sections prohibiting the disposal of soil, debris. refuse. hazardous waste.
aild other pollutants into the storm drain sys~ and prohibiting littering.
• Adminisiratlve I Staffmg ,
Two-person teams may be required to clean catch basins with vactor trucks.
Anangements must be made for proper disposal of collected wastes.
• Equipment
Except for small communities with relatively few catch basins that maybe ClCCUle(i I
manually, most municipalities will requite m~cal cleaners such as eductors,
vacuums, or bucket loaders.
• Training
Crews must be trained in proper maintenance" including record keeping and
disposal.
PUBLIC EDUCATION / PARTICIPATION
• Educate contractors (cement. masonry, painting) and utility employees (telephone,
cable, gas and electric) about proper waste (solid and liquid) disposal.
LlMITATIONS
• 'Ibere are no major limitations to this best management practice.
Municipal Handbook 4·67
Implementation
'Requirements • ClIpitlll Ccms
• O&:MCQtlts
0 Regl!/atory .' Staffing
~ Training
Q Administrative
• High 0 L.ow
:SC71
March, 1993
••
•
• \
Additional Information -Catch Basin Cleaning
Regular maintenance of public and private catch basins and inlets is necessary to ensure their proper functioning.
Clogged catch basins are not only useless but may act as a source of sediments and pollutants. In general., .the keys to
effective cat.cb basins are:
• At least annual inspections. Municipal staff should inspect public and private facilities to ensure compliance with
the following:
-Immediate repair of any deterioration threatening structural integrity.
-'Cleaning before the sump is 40% full. Catch basins should be cleaned as frequently as needed to meet this
standard.
-Stenciling of catch basins and inlets (see SC30, Storm Drain System Signs).
• Clean catc~ basins in high pollutant load areas just before the wet season to remove sediments and debris 3ccumiI-
lated during the summer.
• Keep accurate logs of the number of catch basins cleaned.
• Record the amount of waste collected.
• C~ider implementing employee deputization and spill tracking measures in SC50, illegal Dumping COQtrol, in
conjunction with this BMP to facilitate control of illegal dumping.
Public education should be implemented in conjunction with the public education effort in SC50, illegal Dilmping
. Control, to I3ise awareness of the problem. Information in the·Construction Handbook regardiIig waste ~ement
(BMPs CA2O-CA24) may be used to develop a program for contractors.
REFERENCES
Best Management Practices for StoIm Drainage Facilities (Draft), Maintenance Subcommittee, Alameda County Urban
Runoff Clean Water Program.. 1992. .
Protecting WatI!r Quality in Urban Areas: Best M.an.agement Practices for Minnesota, Minnesota Pollution Control
Agency, 1989.
Stormwater Management Manual for the Puget Sound Basin (The Technical Manual): Volume IV -Urban Land Use
BMPs, Washington State Department of Ecology, 1992.
Street Qeaning Practice, American Public Works Association, 1978 •
SC71
Municipal Handbook 4·68 March,1993
•
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•
BMP: INFILTRATION
...
DESCR,IPTION
A family of systems in which the majority of the runoff from small storms is infiltrated into
the ground rather than discharged to a surface water body. Infllttation systems jnclude:
ponds, vaults, trenches, dry wells, pOrous pavemen~ and concrete grids. " .
EXPERJENCE IN CALIFORNIA
Inflltration ponds have been used by many local jurisdictions and CalTnms in .the Central
Valley for about three decades.
SELECTION CRITERIA
• Need to achieve high level of particulate and dissolved pollutant removal.
• Suitable site soils and geologic conditions; low potential for long-teml. erosion in the
watershed.
• Multiple management objectives (e.g •• ground water recharge or runoff volume
control).
LIMITATIONS
• Loss of inflltrative capacity and high maintenance cost in fine soils.
• Low removal of dissolved pollutants in very coarse soils.
• Not suitable on fill sites or steep slopes.
• Risk of ground water contamination in very coarse soils. may require ~und water
monitoring.
• Should not use until upstream drainage area is stabilized.
• Inmtration facilities could fall under Chapter 15, TItle 23, of California Code of
Regulations regarding waste disposal to land.
DESIGN AND SIZING CONSIDERATIONS'
• Volume sized to capture a particular fraction of annual runoff.
• Pretreatment in fIne soils.
• Emergency overflow or bypass for larger storms.
Considerations
Wafer Availability· .
A88thetics
HYdraulic Head
Targeted Constituents
• Sediment
~ Nutrients . • Heavy Metal. • Toxic Materials • Flolrtable Materials • Oxygen Demanti-
ing Substances
• Oil &:·GieaSe
• BacteriB &: Viru.&8IJ • Uk~toHIIV. Sign t1cimt Impact
0 ProWS-l.Dwor
Un~~ ImpllCt
ImplernentatiQn
. Requirements
Q Capltlil" Cqsts
.~ O&M Co6tts
~ Maintenance
0 Training
• Observation well in trenches. ·1 • High 0 Low
CONSTRUCI'IONIINSPECIlON CONSIDERA nONS
TC1 • Protect inftltration surface during coostruction.
• Vegetation of pond sides to prevent erosion.
• Frequent inspection for clogging during construction.
Municipal Handbook 5-3 March, 1993
•
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•
"
BMP: INFILTRATION (Continue)
MAINTENANCE REQUIREMENTS
• Remove sediment at frequency appropriate to avoid excessive concentrations of pollutants and loss of inftltrative
" capacity;
• Frequent cleaning of porous pavements.
• Maintenance is diffiaJlt and costly for underground trencbes.
COST CONSIDERATIONS
• Potential for bigh maintenance costs due to clogging .
TC1
Municipal Handbook 5-4 March,1993
•
•
•
Additional Information ~ Infiltration
Genern1 Information
Where conditions are .suitable infiltration systems may be the preferred choice because stocm wal:i!T is placed into the
ground thereby reducing exceSs runoff and providing groundwater recharge.
Inftltration systems include:
• Inftltration basin which is an open surface pond or underground vault (Figure IA)
• Infiltration trench which is an underground chamber filled with rock, also called a rock well (Figure lB).
• Dry well or "vertical" infiltration trench (Figure 1 C)
• Porous pavement both· asphalt and ~ (Figure ID).
• Concrete grid and modular pavement whiCh are lattice grid structures with grassed, perviqus material placed in the
opening~ (Figure IE).
Infiltration basins are generally used for areas less than five·aaes but can handle tributary areas up to 50 ~ if the'soil
is very permeable. The other systems are suitable only for small sites oia fev.: acres. Porous pavement and concrete
grids should only be used in low traffic areas like parldng areas. Studies have shown that porous pavemeIit is strong and
will last as long as conventional pavement (Field, et al,.1982; Gburek and Urban, 1980). Experience in Fiorida and .
MaIyland indicates that concrete porous pavement performs better than porous asphalt
Inflltration systems should be considered where dissolved pollutants ~ of concern. However, sati$factory removal
efficiencies'require soils that contain loam. Coarse soils are not effective at removing dissolved pollutants and fine
particulates before the storm water reaches the ground water aquifer. .
Inftltration basins and trenches may not be feasible if there are pervious areas in the watershed Prone to erosion because
of steepness, thin cover, and/or erosive soils. The·inftltration surface·may clog rnpfdly creating an·unacceptable
maintenance burden. For the same reason, infiltration.systems cannot be used .when construction ~ in progress since
standard soil erosion and sediment control BMPs are ineffective·at controlling siltS. Consequently, infiltration systems
may not be f~ible if the development in the tributary watershed is to occur over several consttuctionseasOllS.
Local jurisdictions may not feel that infiltration systemS are appropriate on industrial sites where spills of hazardous
chemicals can ocazr. However, spill control proreaures may provide .satisfactory control (Chapter 4). Care should be
taken when considering the multiple objectives of using infiltration systems for water qwility treannent, ground water
recharge, and flood control Infiltration basins, trenches, and porous pavement can meet ston;n water detention require-
ments.
Three concerns with inf'tltration systems are clogging, accumulation of metals, and grounq. water contamination.
Infiltration systems have been used successfully on sandy soils in the Central Valley of Califomla and Long Island, New
Yark for many years without operational problems. In both instances the primary objectives are ground water recharge
and ·flood·control, not water quality treatment "
Problems can be expected with inflltration systems placed 41 finer soils. The State of Maryland bas ~DipbasiZed these
systems for about 10 years where they have been installe(lin soils with infiltration rates as low as 027 inches per hQUI'.
A recent survey (Lindsey, et 31., 1991) found that a third of the facilities examined (177) were clogged and another 18%
were experiencing slow infiltration. Dry wells that treat roof IUJioff had the fewest failures (4%) and porous pavement
the most (77%). Dry wells may have the lowest failure rate because they only handle roof runoff. The primary causes
of failure appear to be inadequate pretreatment and lack of soil stabilization in the tributary w3rershed, as well as pOor
Coostruction practices (Shaver, pers. comm.). Erosion of the slopes of ~tltration 'pOnds was a signifiCant problem in
almost half the facilities surveyed. Problems have 0CCUITed in the Central Valley with facilities· placed on finer soils, as
in the case of Modesto. (Tulloch. peTS. comm.).
TC1
Municipal Handbook s-s March,1993
•
•
•
Additional Information -'Infiltration
Based on a review of several SOOdies of infIltration facilities in sandy and loamy soils concluded that "monitoring _,. bas
not demonstrated significant contam.ination .•• although highly soluble pollutants such as nitrate and chloride have been
shown to migrate to ground water" (USEP A, 1991). However, pollution' has ~n found in ground water w)lere
infIltratioo devices are in coarse gravels' (Adopbson, 1989; Miller, 1987).
Site SelectlOO Considerations (infIltration basin)
• Recommended minimum precoostruction inftltration rates have ranged from 0.25 to-4 inches per hour.
• One state (Ecology, 1992) bas specified a maximum clay content (30%) and a minimum cation exchange capacity
(Smeq).
• Not less than three feet separation from seasonal high ground water, much greater distance if ~ils ate very coarse.
• Avoid steep (25%) slopes or other geologic conditions that would be made unstable by the infIltrating water.
• Not less than four feet separation from bedrock.
• Impact on local groundwater including recharg¥ potential, water quality, etc.
Stahre and Urbonas (1988) have JKeSented a site selection procedure, if the site flI'St passes the aoove criteria. ~nted ..
in Table lA is a point system. If the site receives less than 20 points it is considered unsuitable; more than 30 point,s is
considered excellent This procedure is used to enhance infiltnllion performance and minjrnize clogging.
~
The degree of treattnent achieved by infiltration is a function of the amount of storm water that is captured and infil-
trated over time. This relationship for various areas in California is shown in Appendix D. The figures in AppendiX D .
were developed using the hydrological model STORM.
Th¥ procedure to determine the volume of infiltration basin is asJollows: (1) select the appropriate figure iA Appendix:
D; (2) determine for the catchment the percentage of impervious area directly connected to the stOrm drain syStem; (3)
choose a capture goal, and read the required unit basin storage (acre-ft per aae) required for the infilt:raUon basin (19
provide perl'ormance similar to the other treatment control BMPs in Chapter S,·a reasonable captme goal for infiltration.
systems is 80%.); (4) multiply this unit figure times the total acreage of the catchment-and convert to cubiC feet When
using the above approacb to size an infiltration trench, remember to increaSe the volume of the trench to account for the
rock.
To calculate the minimum surface area of the inftltration system obtain the infiltration rate at the site using 3ppropriate
techniques. This value is then used in the following equations:
Am = VIDm (1)
where: Am = minimum area required (ft2)
V = volume of the infIltration basin (ft3)
Dm = maximum allowable basin depth (ft)
The maximum allowable depth is determined from the equation:
Dm = 4OUl2S (2)
where: I = site infiltration rate in inches per hour
S = safety factor
The safety factor accounts for the uncertainty of whether the infiltnllion ~t measureS the reai infIltration rate. Reco~
mendations have ranged from 2 to 10 (consult your local Soil Conservation Servi~ Office). The coefficient of 40
rdcn; to the: RCOlDDlc:nded dcawdoWD time in hours. This is a reasonable draWdOWD time, given. that the average time
Tet
Municipal Handbook 5-6 March. 1993
•
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•
Additional Information -Infiltration
between storms during the wet season in California is on the order of 200· hours, except in Northern California where it
is about 80 hours. A longer drawdown 'time may cause anaerobic conditions in the underlying soil or the production bf
algae during the warmer months that·would clog the soil. A shorter drawdown time reduces the volume of the facility •
. but increases the required surface area. Appendix D contains figures for two drawdown times: 24 and 40 hours. In
most of the State, reducing the drawdown time does not significantly reduce the volume.
Suggested references on the design of porous pavement include Maryland (1984) and Florida (1988).
Additional de.sien considerations
• For basins and trenches, pretreat the storm water to remove the floatables and settleable solids. particularly when
placing these systems in finer soils. Pretreaonent can be accomplished with any of.the oth~ treatment control
BMPs in this handbook.
Communities and CaITrans have used infiltration systems in the Central Valley formore than two decades without
pretreatment. Clogging has not been a problein with well maintained systems disc~ging to sands a;nd courser soils.
suggesting that Pretreatment is of limited value. Pretreatment when infil.trating to fin~soils is suggested by the·
e~rience of Maryland described previously. An infiltration facility sized oniy for treatment is much smaller-thaD one
sized for flood control and therefore may be more susceptible to clogging. COIllDlunities in $e Central Valley ~o. "
. Modesto) require a retention volume that captures the. 1 00 year event, or about 20.000 ft3 per impervious tribUtarY acre.
In com~ above Equation (1) will provide a volume in the range of 2,000 ft3 per impervious acre.
For small systemS t:reati.Iig less than a few acres of pavement, pretreatment can be at;COmpliShed· with a Type 2 catCh
. basin and a submerged outlet. The diameter and depth of tbe sump should be at least four times the diameter of the
outlet pipe to the infiltration system (Lager. et 31 .. 1977). See Figure 1C. The catcb basin Cover should be stenciled
"dump no waste" .
Additional design considerations for ~ include:
• Do not locate on fill sites, or on or near steep slopes
• Energy dissipation at inlet to minimize erosion
• Vegetate the slopes for the same reason
• Vegetate the bottom to reduce tendency to clog with fines
• Freeboard of 1 foot
• Side slopes of at least 3:1 for safety. and for ease of mowing (4:1 slopes are prefered)
• IncotpoIate bypass or overflow for large events
• Provide dedicated access to the basin bottom (minimum 4: 1) for maintenance vehicles
Vegetating the slopes and bottom will be difficult unless the facility can be irrigated during the sumnier. Drou~t
.tolerant ground cover species may be more suitable. See TC4 Biofilte~ for recommended species.
Additional design considerations for trenches include:
• Do not locate on fill sites, or on or near steep slopes
• A 4 inch or 6 inch diameter observation well with locking cap. to check for loss of infiltrative capacity
• 6 inch sand layer or geofabric at the bottom
• Geofabric around trench walls to prevent soils from migrating into the trench rock matrix
• Geofabric 12 inches below ground surface with 3/4 rock placed on top. which serves as filter for coarse solids
• Backfill and filter rock should be clean washed aggregate 1 inch to 3 incbes diameter
• Incorporate bypass or overflow for large events
• Provide dedicated access for maintenance vehicles
TC1
Municipal Handbook 5·7 March,1993
•
•
•
Additional Information -Infiltration
For porous pavement, experience in Maryland suggest that asphalt pavement bas continuous plugging problems and a
limited life. Frequent maintenance is required. For drywells where access for maintenance is difficult if not impossible
pretreatment of the stoml water is highly recommended. Such,pretreaanent may include biofilters, sumps, etc. Consul-
tation with the local jurisdiction regarding the design of drywells is required.
Qmstmctioo
It is very important 10 proteCt the natural infiltration rate by using light equipment and construction procedures that
minimize compactioo. Storm water must not be allowed to enter the facility until all construaionin the,catchtnent area
is completed and the drainage area is stabilized. If this prohibition is not feasible in particular situations, do not excavate
the facility to final grade until after all construction is complete upstream. Leave one foot of native soil In the basin
which can be removed in layers as it clogs. Disking the surface frequently during this period may be beneficial. After
final grading the final surface should also be disked. With trenches, make sure the rock fill does not become dirty while
tem~y staed at,the site.
The local jurisdiction may also specify that the infiltration rate of the facility be Within a certain percentage of the
preconstruction mie be'fore the facility is approved or accepted. ' , " , ' . ":,,' .: . .' ~.,
Maintenance
Inspect the,facility at least annually and after extreme events. If there'is still water in the pond or trench 72,hours after a
stoml it is time to clean the facility. A concern is restrictions on the disposal of the sediment removed from an infiltra-
tion basin due to contamination. Limited studies suggest that this is not a problem, particularly if so~-control BMPs
are effective. The Fresno Metropolitan Flood Control District found noticeable acaunulation of pollutants,in the surface
, layer in infiltration basins that had not been cleaned for about 20 years although the levels were still below toxic tb.resll-
olds. The basins are now cleaned at least once every three years. Limited studjes of the bottom sediments in wet and
extended detention ponds indicate that toxicity limits specified by final disposal regulations are not exceeded (see TC2
Wet Ponds). .
Pretreatment may reduce maintenance costs by capturing gross settleable solids and floatables ina sm3ller ~ that can
be more easily cleaned. Maintenance techniques for basins include rototilling, disking and deep rippillg. .
Porous pavement should be cleaned at least quarterly by vacoum sweeping and high PfCSSure washin~.
See Maryland (1984) and Florida (1988) for additional guidance on the design, construction, and
maintenance of infiltration systems.
REfERENCES
Adolphson Associates, 1991, "Subsurface Storm Water Disposal Facilities", Inte:ri1n Report, for'the Tacoma-Pierce
County Health Department.
Adolphson Associales, 1989, "Storm Water Evaluation, Clover/Chambers Basin Ground Warer ~ement Program" .
for the Tacoma-Pierce County Health Department.
field, R. H. Masters, and M. Singer, 1982, "Status of Porus Pavement Research", Warer Resources Research, 16,849.
Florida (State 00, 1988, 1lle Florida Development Manual", Department of Environmental Regulation.
Goforth, G.F., J.P. Heaney, and w.e. Huber, 1983, "Comparison of Basin Perfo:rmapeeModeling Techniques", Jour. ,
BE, ASCE, 109(5), 1082.
TC1
Municipal Handbook 5-8 March,1993
•
•
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Additional Information -Infiltration
Gburek, W. J, and J.B. Urban, 1980, "Storm Water Detentioo and Ground water Recharge Using Porous Aspbalt -Initial
Results", in Proceedings of Intemational Symposium on Urban Stoxm Water Runoff, Lexington, KentQcky.
King County, 1990, "Surface Water Design Manual", King County Washington.
Lindsey, G., L. Roberts. and W. Page, 1991, "Stormwater Management Inflltration Practices in Maryland: A Secood
Survey", Maryland Department of the Environment.
Maryland (State 01), 1984, "Standards and Specifications for InfIltration Practices", Departmeti~ of Natural Resoun:::es.
MetropOlitan Washington COWlcil of Governments (MWCOG), March, 1992, it A Current Assessment of Urban Best
Management Practices: Techniques for Reducing Nonpoint Source Pollutioo in the Coastal Zone".
Miller. S., 1987, "Urban Runoff Quality and Management in Spokane" in Proceedings of the Northwest Nonpoint Source,
Pollution Conference, March 24-25, Seattle. .' , .
Portland Cement Pervious Pavement Manual. Florida Concrete Products Association, Inc., 649 Vassar Street, Orlando,
Florida, 32804 (no date).
Schueler, T.R., 1987. "Controlling Urban Runoff: A Practical Manual for Plan$lg and Designing Urban BMPs", MetJ;'O-
politan Washington Council of Governments. .
Shaver, E., petS. comm .. Stare of Delaware Deparanent of Natural Resources .
Stahre, P. and Urbonas, B., 1989. "Swedish Approach to infIltration and Percolation Design'.', in Design of Urban Runoff
Quality Control, Americans Society of Civil Engineers.
Tulloch. Alice, pers. comm., City of Modesto Public Works.
United States Environmental Protection Agency (USEPA), 1991, "Detention and Retention Effects on Groundwat.ei",
RegionV.
TC1
Municipal Handbook 5·9 March,1993
, I
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Additional Information -Infiltration
TABLE lA. POINT SYSTEM FOR EV ALUATING INFILTRATION SITES
1. Ratio between tributary connected impervious area (AIMP) and the infiltration area (A1NF):
• ArNF> 2 AIMP
20 points
• .AlMP < AINF < 2 AIMP
10 points
• 0.5 AIMP < .AINF < AIMP
5 points
2. Nature of surface soil layer:
• Course soils with low ratio of organic material
7 points
• _ Normal humus soil
5 points
• Fme grained soils with high ratio of organic material
o points
3. Underlaying soils: • .. If the underlaying soils are courser than surface soil, assign the same number of points as for the
surface soil layer assigned under item 2 above.
• If the underlaying soils are finer grained than the surface soils, use the following points:
• Gravel, sand of glacial till with gravel or sand
7 points
• Silty sand or loam
5 points
• Fme silt or clay
o points
4. Slope (S) of the infiltration surface:
• S < 0.07 filft
5 points
• 0.07 < S < 0.20 ftIft
3 points
• S > 0.20 filft o points
5. Vegetation cover:
• Healthy natural vegetation cover
5 points
• Lawn is well established
3 points
• Lawn is new o points
• No vegetation, bare ground
-5 points
6. Degree of traffic on infiltration surface:
• Little foot traffic
5 points
• Average foot traffic (park. lawn)
3 points
• Much foot ~c (playing fields)
o points
Municipal Handbook 5 -10
TC1
March, 1993
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Top View
Riprap
i
I
Side View
/ I
/
"-
Additional Information -infiltration
--
-------
Back-up Underdraj~
------
------ -------
Exfiltration Storage -
Back-up Underdrain Pipe in Case 01 Slanding Water Problems
NOTE:
1. Backup underdrain is not used in most applications because plugging
occurs in soil ~ the drain. .
,/
\
/
'./"
I
2. An infiltration basin can also be excayated (typically 2 to 6 feet deep)
as long as the bottom of t~ basin is 3 feet above high seasonal water table.
FIGURE lA. INFILTRATION BASIN TC1
Municipal Handbook S -11 March, 1993
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Top View
Additional Information -infiltration
Inflow
Permeable Filter
Fabric One Foot
Below Surface.
Traps Debris
Screened Oyerflow Pipe
Side View-
~ I _ ~ I ' Sides Lined with Permeable Filter Fabric i
Clean wasti~d Stone or Gravel
(1.5.;.3.0 Inch) .,. ~~~~~r6'12 Inch -Sand Filter J: or Permeable Filter
Cloth Lines Bottom
/!!::~~~ ................. ---.
Outflow Source: Sch~ (1987)
BliLDING DRAIN OESlGN
CS Sump with
Sefid Ud -Optionai
Adapted from K'1Iig Cou!'Io/
TC1
FIGURE lB. INFll..TRATION TRENCHES
Municipal Handbook S·12 March,1993
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Additional Information lnfUtration
)'-0"
48" 10 Preca$l Manhole with bottom
Peloroted Manhole filled as shown
with ! 1/2" to ,3" washed Drain ROel<
Manhole has open bottom
Fill oYCt:-uCQ'oIOtcd orea with drain rael<
WITH PRETREATMENT
Side View
, "/
4S" 10 Prcca$t
Concrete uonhole Wanhol. to be per/orated in aree 01 Orain Rock
Top 01 Drain Roel<
'. "
__ 3" PVC collection pipe, dral
3/4" /loin 0 2" etc. lop 01-pope
'-4-
$QUr:ce: Adolphsqn, 1991
Note: See discussion on page 5-6 regarding design consider~tions •
Source: SChueler, 1987
TC1
WITHOUT PRETREATMENT
FIGURE Ie. DRYWELL CONFIGURATIONS , -_.
Municipal Handbook 5·13 March, ·1993
~ = ~.
[ r Q.. [
til • .... ~
~ ~ ~ .... ~
• • •
II"'~ ~ ~ ~ ~ ~ ~ ~ ~ "" ~ POROUS ASPHALT SURFACE COURSE
1/2" to 3/4" Aggregate ..
asphaltic mix
It~:~~~~~~~ " " '" " " 2.5 to 4" thickness typical
~ .... fl[lER COURSE --_ .. --.... -.. _---
1/2" Aggretate » 2" Thickness 0..
0.. _. ,.... _.
~ a RESERVOIR BASE COURSE ::J
1" to 2" Aggregate Q) -Voids volume is designed for -::l ' •. runoff Retention ......
0 -c
\I.JLI~' A V '\f'lA ~ Thickness is based on storage I :3
required Q) ,.... _.
0 -_ .... -............ -:::s ~ 'FIl TER FABRIC _ .... ---_ .. _--I • . EX ISTING SOIL 5"
Minimal compact Ion to retain ~ ;:;
porosity and permeability a c)" ::s
. Source: City of Rockville, Maryland
~Ig FIGURE ID. POROUS ASPHALT PAVING TYPICAL SECTIO·N
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Additional Information -Infiltration
Poured-in-Place Slab Castell a ted Un 1 t :
Lattice Unit
Source: State of Florida
FIGURE 1E. TYPES OF GRID AND MODULAR PAVEMENTS
Municipal Handbook 5 ·15
TC1
. ~r;;;c; =
MatctI, 1993
r---------------------~--__ ~_
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•
BMP: BIOFILTERS
DESCRIPTION
Biofiltcrs are of two typeS: swale and strip. A swale is a vegetated channel that treats
cqocen~ flow. A strip treats sheet flow and is placed parallel to the contrib~,t,ing
'surface.
EXPERIENCE IN CALIFORNIA
No biofilters sPecifically designed to treat storm water have been located However,
instances of "biofilter by happenstance" exist in northern communities (Davis, Sacramento, ,
Turlock, Fresno) where stoml. water is discharged to a grassed area prior to·an inlet ,or an
infiltratioo area.
SELECTION CRITERIA
• Comparable performance to wet ponds and constructed wetlands.
• Limited to treating a few acres.
• Availability of water during dry season.
LIMITATIONS
• Poor performance has occwred but this appears to be due to poor design.
• May be limited to areas wbere summer irrigation is feasible.
• Can be difficult to maintain sheet flow in strips.
• Can be difficult to avoid channelization in swales.
• Cannot be placed OIl steep slope.
• Area required may make infeasible on industrial sites.
• Proper maintenance required to maintain health and density of vegetatioo.
'DEsIGN AND SIZING CONSIDERATIONS
• The surface area is defined by Figure 4A
• The minimum width for a swale is determined by Mannings Equation.
• Minimum length of a strip is 10 feet.
• The longitudinal slope must not exceed 5%.
• Use a flow spreader and energy dissipator at the entrance of a swale.
• Good soils are important to achieve good vegetation COVeI'.
CONSTRUCfIONIINSPECfION CONSIDERATIONS
.M:akc sure soils are suitable for healthy vegetation •
• Level cross-section and even longitudinal slope for swales.
• Achieve sheet flow with strips.
Municipal Handbook 5·32
Considerations
CiijD-
QruReqU/~
~,
~ter AvaiJabiJ~
Authetk:$
Hydraulic Head
Environmental Side
EffecU
Targeted Constituents
• Sediment
g Nutrie(Jf.
Q Heavy Metal. '
Q Toxic Materia/$
Q FloatBble "erisl.
~ oxygen Demand-
Ing $t,lbmtnca
Q 011& GreMe
0 BM:terla & Viruse. ' • ~~foHw. Sign Rt:.nt lmp6/!Ct
0 PtoW~ L.Dw or
UnIrnow!J/mpact
Implementation
Requirements
g, capital Com
Q ,0&Meoat.
Q 'Maiptenance
o Tl'IIin/n~
I,. High 0 Low
TC4
M3I'ch~ 1993
•
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•
Additional Information ~ Biofifters
A biofIlter swale is a' vegetated channel that looks similar to, but is wider than, a ditch that is sized only to transport
flow. The biofllter swale must be wider to maintain low flow velocities and to keep the depth of the water below the
height of the·vegetation up to a particular design event A filter snip is placed along the edge of tbe pavement (its full
length if possible). The pavement grade must be such as to achieve sheet flow to· the maximum ext¢nt practical aiong
the strip.
Vegetated biofilters are suitable only for small catchment-areas of a few acres, for reasons provided ·below. Swales are
particularly suitable for small residential developments. It may be possible to integrate tI"ea;tment l!wales with
greenways within large residential developments but each swale should meet the design guidelines presented in this
handbook. Snips are most suitable for parkiIig lots in commercial and mutifamily developments. Swales may not
function well in residential devel~ents which have open space that remains in ruuive vegetation. Soil er9(led from
these open spaces may clog the biofilter. Placing a Type 2 caleh basin at the upper end of a swale may provide
adequate pretreatment. To be effective, the diameter of the catch basin and the depth of the sump below the inven of
tbe outlet-should each be at least four (4) times the diameter of the outlet (Lager, et al., 1977).
,-.' .. The performance of biofilters is probably somewhat less than wet po~ and constructed wetlands because the latter
provide treatment both during and between storms. Some ~ have observed poor peIfonnance, recommending.
tbeir use QDly in combination with other treatment control BMPs. However, most ~ld research on swale pe:rfoimance
ha$ been cooducted on grassed roadside ditches. A swale must be wider than a tIaditional roadside ditch, to avoid
exceSsive flow velocities which topples tbe grass and causes channelization. It appears that biofIlter& ~remOve
particulale pollutants at Iates similar to wet ponds and constructed. wetlands. The removal of dissolved pollutants may
also be similar to wet ponds but less than constructed wetlands. Some researchers have found effective removal of .
dissolved metals and nutrients whereas others have not.
The swale bottom must be as level as possible; energy. dissipation and a flQw spreader $bould be placed at tbe entrance
to minimize cbannelization. The pavement Iijust be as level as posSible. along its boundary With a biofilttrstrip. The
pavement edge should be left clear, that is, no curbs. Parldng staIrbl~ must be qpen to pass the flow as unhindered
as possible. Use of curb cuts in curbs is not a satisfactory approach. The cuts·chaim~ the water and can-clog with
debris. The pelfonnance of strips may be compromised by the failure to achieve sheet flow at the interface between
the paved area and the strip.
Turf grass is the preferred vegetation. Figure 4B shows recommendations for seven species of turf ps and one
ground cover plant for various areas of California (Y oungner, et al., 1962). More tecent infor.m:ation in this regard il!
also shown in FigUre 4C (CCAE, 1984). Turf grass will require summer irrigation to remain active. Although it bas
not been tried it may be possible to allow the grass to become dormant during the summer since the biof1lter is only in
service during the wet season. The biof1lter could.be iIrigated beginning in October to bring it to ah~thy condition '.
priQr to the ~t: storms. Ground cover species suitable for a non-irrigation situation may worlr.:..but, it ~ bas not ~
tried. The soil must be of a fertility and porosity that allows for healthy vegetation. A porous soil alSo promotes
inf1.ltra1ioo. See the references that follow for Agricultural Extensive publications on efficient water use by tur:t'
grasses.
If erosion of the swale is of concern because of the difficulty of maintaining a gpod grass cover. consider the use of
CODcrete grids (see Infiltration Systems) or similar m.ateri.al. Another concept is to 'usecbeck dams to divide the swale
into a series of tenaces, reducing the longitudinal slope to perhaps 1%, thereby reducing flow velocities.
TC4
Municipal Handbook 5·33 March,1993
•
•
•
Additional Information ....;. Biofitters
I&sim
Several methods have been proposed to size biofilters (Homer, 1988; FHW A, 1989; IEP, 1991; Tollner, et al., 1976).
However, information on the relationship between biofilter area and performance j.s lacking fqr urPan conditions. Figure
4A uses tile method of Horner (1988) with the 2-year storm as the design event, l:l slope of 3%, and a grass height of 4
incbes. A biofilter is sized to tteat all storms up to a particular design event. The design 'event tan be relatively small
because the aggregate of all small events represents the ~ority of pollutant nmoff. Research in western Washington
(Metro. 1992) found that a biofiltcr sized according to this technique removed.80 ~t of the suspendc:(i solids and
attaChed pollutants and 50% of the soluble zinc, It was not able to rem6ve dissolved phosphorus or copper.
Figure 4A 'is. meant for guidance only and should be used with caution in areas wbei'e precipitation varies greatly
because of terrain.
The design engineer must determine the width of a swale using Manning' sEquation and the 2-year rainfall iD,tensity
(California, 1976) appropriate to the site. An "0". of 0.20 is recommen~ (Metro, 1992). The de~gn. engine;er mUst also .
. ca1culate the peak flow of the l00-year event to detemline the depth of a swale. Since a width using $1 "n;' of'0.20 is' .. ;
generally wider than what is required of a grass lined channel. channel stability Should not.be of concern. It is generally
not necessary to have a bypass for the extreme events because the minimmn width specification cOmbined with the
relatively gentle slope avoids excessive velocities. If erosion·at extreme events is of eoDCem, consider the above
concepts to mjnimize erosion.
The design engineer can make the swale wider than detemlined in the above step, with a correspondirig shortening of the
swale length to obtain the same surface area. However, tbere is a practical limitation on how wide the swale can be and'
still be able to spread the flow across the swale width. Splitting the flow into multiple inlets andlQI' placing a flow .
spreader near the Stoml inlet should be incorpaated into the design. A concept that may work is to place a level2"x
12" timber aaoss the width of the swale perhaps 10 feet from. the pipe outlet. Place gravel between the outlet and the
timber, to ~ 2 inches oc so of the top of the timber. Place large rock immediately near the outlet to dissipate the
flow energy; the rock also may help distribute the flow. The timber wiD function like a weir. Flow ~ have seen
limited application and their effect on performance has not been evaluated.
The problem of spreading the flow aaoss the width of tbe·swale may limit its use to tributary catchments of only a few
sacs. The minimum width based on using Manning's Equation results in widths of 3 to 12 feet per aae of impervious
tributary surface, depending on the location and longitudinal slope.
A minimum length of 10 feet is recommended for bi01ilter strips. Length here is defined as tlie measurement in the
direction of flow from the adjoining pavement. Lengths of 20 to 50 feet have been recOmmended by most practitioners
per.baps because of the concern that sheet flow cannot be maintained. Wherever I'()()IQ. permits a length. greater than 1 Q .
feet should be used. The short length is recommended in this handbook because space is at a premimn at most existiJlg
industrial sites: 10 feet should wOIt: satisfactory if good sheet flow is maintained and no obstructions such as curbs are
placed along the pavement edge.
The type of strip discussed here is not to be confused with the natural vegetated buffer strip used in residential develop-
ments to separate the housing from a stream or wetland. As the later type follows the naniraI coo tour flow
channelization is more likely and lengths of 75 to ISO' feet are recommended.
iC4
~ .... ... . ,.,.,..,. ..
Municipal Handbook 5 -34 March,1993
•
•
eo
Additional Information -Biofiiters
The length of pavement prior to the strip should not exceed a few hundred feet to avoid' channeli.z.$on of large aggre-
galeS of runoff along the pavement befOre it reaches the pavement edge. To avoid channelization, Care must be taken
during construction to make sure that the cross-section of the biofllter is level and that its longitudinal slope is evCI;l.
Channelization will reduce the effective area of the biofllter used for treatment and may erode the grass because of
excessive velocities.
Maintenance
The facility should be checked annually for signs of erosion, vegetation loss, and channelization of the flow. The grass
should be mowed when it reaches a height of 6 inches. Allowing the grass to grow taller may callS!! it to thin and
become less effective. The clippings should be removed.
REFERENCES
Califotnia (State 00,1976, "Rainfall Analysis for Drainage Design, Volmne 3, Intensity-Duration-Frequency Curves",
Bulletin No. 195, Department of Water Resources.
California Cooperative Agricultural Extension (CCAE), 1984, "SelectiIig the Best Turf Grass~, Leaflet 2589.
CCAE, 1985, "Turfgrass Water Conservation", Bulletin 21405.
CCAE. 1991, "Effluent Warer for Tmfgrnss Irrigation", Bulletin 21500.
Federal Highway Administration (FHW A), 1989, "Retention, Detention, and Overland Flow for Pollutant Removal of
Highway Stormwater Runoff (DratO", Report No. FHW A/RD-89!.203 •
Homer, R.R., 1988, "Bioftltration Systems for StoIm Runoff Water Quality Control", Washington State Department of
Ecology.
IEP, 1991, "Vegetated Buffer Strip Designation Method Guidance Manuar, Narragansett Bay Project.
Lager, J.A.. W.G. Sm,ith, and G. Tcbobanoglous, 1977, "Catchbasin Tecbnology Overview and
Assessment", USEPA 60012-77-051.
Metropolitan Washington Council of Governments (MWCOG). March, 1992, "A Current Assessment ofl.!rban Best
Management Practices: Techniques for Reducing Nonpoint Source Pollution in the Coastal Zone".
Municipality of Metropolitan Seattle, (Metro), 1992, "Pollutant Removal Effectiveness of a Designed Grassy Swale in "
"Mountlake Terrace. Washington (Drafty'. .
Sacramento County Cooperative Agricultural Extension, UW arer Efficient Landscape Plants" by Pamela,S. Bone,
Environmental Horticultural Notes.
Tollner, E.W .. and BJ. Barfield, 1976, "Suspended Sediment Flltration Capacity of Simulated
Vegetation", Trans. American Society of Agricultural Engineers, 19,678.
Youngner, V.B .. J.H. Madison, M.H. Kimball, and W.B. Davis, 1962, "Climatic Zones forTtnfgrass in California",
California Agriculture, 16 (7), 2.
TC4
Municipal Handbook 5 -35 March,1993
•
•
I.
.
Additional Information -Biofilters
I ~ -1.-
I
. ., -
• ' •• ' •• • ,J • ". ,,.,, .:r
FIGURE 4A. SIZING GUIDELINE F.OR BIOFll..,TERS ...-~TC4~. ---I
(SQ. FTJIMPERVIOUS ACRE) ~
~.
Municipal Handbook S·36 March, 1993
•
•
•
,
Additional Information --Biofittets
l I
!
II W~II ~daPted to area
:l~-:'-:: Adaptable wIth hIgher ma'"tenanc~
":.,;",
;!~l!f.i!~i Better adapted grass available
;---: I i Not adaptable ---.; .
DICHONDRA ZOY~IAGRASS
BENTGRASS RYEGRASS BLUEGRASS
BERMUDA GRASS TALL FESCUE
FIGURE 4B. STATE OF CALIFORNIA SHOWING
MOST SUITABLE -TURF GRASS SPECIES--~:--..
~-
Municipal Handbook 5·37 March, 1993 .
•
•
•
Additional Information -B'iofiHers
COL.D TOL.ERANCE
(winter color persistance)
High Creeping bentgrass
Kentucky bluegrass
Red fescue
COlonial benlgrass
Highland b'.:!ntgrass
Perennial ryegrass
Tall fescue
Weeping alkali grass
Dichondra
Zoysiagrass
HEAT TOLERANCE
High Z':)vslagrass
Hybrid bermudagrass
::;cmmon bermuoagrass
5easnore oaspalum
5<. Augustlnegrass
Kikuyugrass
Tall fescue
Dicnondra
Creeoing benlgrass
Kentucky bluegrass.
Highland bentgrass
Perennial tyegras$
Colonial bentgrass
Common bermudagrass
Hybrid bermudagrass
Kikuyugrass
'Seashore:' paspaium .' weeping"afkaligrass< ":
Low St. Augustinegrass Low Red fescue
MOWING HEIGHT ADAPTATION DROUGHT TOLERANCE
High cut
Low Cut
Tall fescue
Red fescue
Kentucky bluegrass
Perennial ryegrass
Weeping a1kaligrass
St. Augustinegrass
Common bermudagrass
Dichondra
Kikuyugrass
Colonial bentgrass
Highland bentgrass
Zoysiagrass
Seashore paspalum
Hybrid bermudagrass
Creeping bent grass,
MAINTENANCE COST
AND EFFORT
High Creeping bent grass
Dichondra
Hybrid bermudagrass
Kentucky bluegrass
Colonial' bentgrass
Seashore paspalum
Perennial ryegrass
High
L.ow
Sl Augustinegrass
Highland bentgrass
Zoysiagrass
Ta!1 fescue
~mrnon bennudagra:s:5
Low Kikuyugta55
Hybrid bermudagrass
Zoysiagrass
Common bermudagrass
Seashore paspalum
51. Augustinegrass
Kikuyugrass
Tall fescue
Red fescue
Kentucky bluegrass
Perennia,1 ryegrass
Highland bentgras$
Creeping bentgrass
Colonial bentgras~
Weeping alkaligrass
Dichondra
FIGURE 4C •. ADDITIONAL INFORMATION ON THE
SUITABILITY OF TURF GRASS SPECIES
TC4
~'" ... ' ......... ,
Municipal Handbook 5·38 March,1993
•
•
••
BMP: OIUWATER SEPARATORS AND WATER QUALITY INLETS
.................. , •••••••••• 0 .............. ·0 ............... °.1
.' I
.' J
DESCR1PTION
OWwater separators are designed to remove one specific group of coDtaminants: petroleum.
compounds and grease. However, separators will also remove flootable debris and settle-
able solids. Two general types of oilIwater separators are used: conventional gravity
separator and the coalescing plate interceptor (CPl).
EXPERIENCE IN CALIFORNIA
OWwater' separators are in use throughout California at.industrial sites. OilIwater separa-
tors are used at all bulk petroleum storage and refInery faciliti<:$. A few jurisdictions
require new commercial developments to install separators under.certain situations that are
environmentally sensitive.
SELECIlON CRITERIA
Applicable to situations where the concentration of oil and grease related coJ;Dpounds will
be abnormally bigh and source control cannot provide effective control. The genernl typeS
of businesses where this situation is likely are truck, car, and equipment maintenance and
washing businesses, as well as a business.that petfOfDlS maintenance on its own equipDient
and vehicles. Public facilities where separators may be required include marine ports.
airfields. fleet vehicle maintenance and washing, facilities, andmass txansit park-and-ride
lots. Conventional separators are capable' of removing oil droplets with diameters equal to
or greater than 150 microns. A CPI separator should be used if snmller droplets must be
removed.
. LIMITATIONS
., Little data on oil characteristics in StDml water leads to considerable uncertainty about
perfonnance.
• Air quality permit (conditional authorization) permit-by-rule from DTSC may be
required.
DESIGNAND SIZING CONSIDERATIONS
• Sizing related to anticipated influent oil concentration, water temperature and velocity ~
and the effluent goal. To maintain reasonable separator size, it should be designed to
bypass flows in excess of first flush.
CONSTRUCfIONIINSPECTION CONSIDERATIONS
• None identified.
MAINTENANCE REQUIREMENTS
• Clean frequently of accumul.a1ed oil, grease, and floating debris .
COST CONSIDERATIONS
• Coalescing plate material is costly but requires less space than the conventional
or.
Municipal Handbook S· S9
Considerations
Soils
QteaReqUi~
Slope
Water Availability ..
Aesthetics
Hydraulic Head
Environmentsl Side
EffecttJ
Targeted Constituents
~ ·$ediment
.' ~ Nutrjtmt6 . ,. "",
~ Heavy '!etals
~ Toxic "'merlals • Floatable Materials -. Oxygen ·Demand-
ing Substances
• all &: Grease
0 Bacteria & Viruses • ;~::r~v,:pIICt
0 ProWJe·Low 01' Un/qrotim·lmpllCt
ImpI8~ntation'
Requirements
Q capital Costs
~ 0&", Cosis
Q Maintenance
0 Training
• High 0 Low I
Te7
March, 1993
•
•
•
Additional Information -OillWater Separators and Water Quality Inlets
General Information
OilIwater separators will be needed for a few types of industrial sites where activities result in aooormal amounts of
peti'oleum products lost to exposed pavement, either by accidental small spills or normal drippiIig,from the vehicle
undercarriage. This will most likely be relaIed to vehicle and mobile equipment maiptenance activities. Separators ~y
also be advisable where an area is heavily used by mobile equipment such as loading wharfs at IIiarine portS. Limited data
indicates oillwater separators can reduce the oil/grease concentration below 10 mg/l (Lett.enIi;laier, et 21.1985).
Wet ponds, constructed wetlands, and biofilters will remove petroleum products but their reliability 'is uncertain where
high concentrations of petroleum products may occur frequently. Also, BMPs that rely on vegetation may be ~ed or
become unsightly if high concentrations of oil and grease DCalf frequently.
The sizing of separators is based upon the rise rate velocity of oil droplet and rate of runoff. However, with the.exception
of storm water from oil refineries there are no data describing the characteristics of petroleum products in urban storm
wa~ that ate relevant to design: either oil density and droplet size to calculate rise rate or Oirect measurement of rise
raies. Further, it is known (Silverman, 1982) that a significant percentage of the petroieum products are attached to the .
fine suspended solids and therefore are removed by settling not flotation. Consequently, the perfocmance of oillwatf;r
separators is uncertain.
The basic configurations of the two types of separators are illustrated in Figure 7 A,. With small installations, ~,conven
tional gravity separator bas the general appearance of a septic tank, but is· much longer in relationship to ,Us width. Larger
facilities have the appeazance of a municipal wastewater primaIy sedirnentanoo tank. The CPI separ3.tor contains clasc:;ly
spacedp1a,tes which enhances the removal efficiency. In effect, to obtain the same effluent quality a CPI sepcir.uor .
requires considerably less space than a conventional separator. The angle of the plates to the horizontal ranges from ()O
. (horizontal) to 6()0, although 450 to 6()0 is the most common. The perpendicUlar distance between the plates typically
ranges from 0.75 to 1 inch. The storm water will either flow across or down through the plates, depending on the plate
configuration.
A related system is the water quality inlet illustrated in Figure 7B. It is essentially a conventional gravity separator but
without the appropriate geometric configuration (see Design discussion below). Anodler name for this systems is a wet
vault. Water qua1i~ inlets have been found to be generally ineffective (Shepp, et 31., 1992) becaosethe recommended
size (200 to 400 ft3/aae of ttibutary) is too small To be effective, a water quality inlet ~ust have ·the surface area and
volume that is similar to that of conventional separators. They may exhibit odor problems during the summer because of
the lack. of bacterial degradation of accumulated organic matter and the lack of reaeration of the wet pooL Facilities ~
Washington D.C. have been observed to have odor but, it has been noticeable only when the system is opened for
inspection.
DeSign of Conventional Separators
The sizing of a separator is based upon the calculation of the rise rate of the oil droplets using the following equati,on
(modified from API, 1990):
Vp = 1.79 (dp -dc)d2 x 1O-8/n (1)
where: V p = rise rate (ftlsecond)
n = absolute viscosity of the water (POises)
dp = density of the oil (gmIcc)
de = density of the water (gmIcc)
d = diameter of the droplet to be removed (microns)
TC7
Municipal Handbook 5 -60 March, 1993
.----------------------------~~~
•
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Additional Information -Oil/Water Separators and Water Quality Inlets
A water temperature must be assumed to select the appropriate values for water density and viscosity from T~le 7 A. The
engineer should use the expected temperature of the storm water during the Decem~-January periQd. There are no d.ata
on the density"of petroleum products in urban storm water but it can be expected to lie between 0.85 and 0.95. To ~lect
the droplet diameter the engineer must identify an efficiency goal based on an understmding,of the distribution of droplet
sizes in storm water. However. there is no information on the siZe distribution of oil droplets in urban stDrtn Wat.ef.
Figure 7C is a size and volume distribution for storm water from a petroleum products storage facility (Braman. UDdated)~
The engii;leer must also select a design influent concentration. which canies considerable uncertainty'because it will vary
widely within and between StomlS.
To illustta1e Equation 1: if the effiuent goal is:1O mgll and the design influent concentration is 50 mgll, a removal
efficiency of 80% is required. From Figure 7C: this efficiency can be achieved by remOving all droplets with diameters
120 microns or larger. Using a water temperature of lOOC gives a water density of 0.998. Using·ap oil ~ty of 0.898,
the rise rate for a 90 micron droplet is 0.0011 feet per second. '
It is generally believed that conventional separators are not effective at remo:vi:ng droplets. smaller than· of 150 miCO?DS ,
(API, 1990). Theoretically, a conventional separator can be sized to remove a smaller droplet but the facility may be so
large as to :tnake the CPI separatOr more cost-effective.
Sizing conventional separator (modified from API, 1990).
D= (QI2V)0.5
wJ;lere: D = depth, which should be between 3 and 8 feet
Q = design flow rate (cfs)
(2)
V = allowable horizontal velocity which is equal to 15 times the design oil rise i3te bUt not greater than
0.05 feet per second
If the depth exceeds 8 feet, design parallel units dividing the design flow rate by the number of units needed to reach the
maximmn recommended depth of 8 feet. Equation (2) is simplified from equations in API (1990) based on a recom-
mended width to depth ratio of 2. The constmt in Equation-(2) can be changed accordj.ngly if ~d,ifIqeDtratio is as-
sumed. Some engineers may wish to inaease t,be facility size to account for. flow turbulence. See API (1990) for the
desi~ procedure.
Then:
• ·Galculate length. L = VON P ~
• COJIlPute widt,h.· W = Q/(VD). This should be 2 to 3 times the depth, but not to exc;eed 20 feet
• Baffle height to depth ratio of 0.85 for top baffles and 0.15 for bottom baffles
• Locate the distribution baffle at O.lOL from the enttaDCe
• Add one foot for freeboard
• Install a bypass for flows in excess of the design flow
Determining the design flow, Q, requires identification of the design storm.. The ~ isexpeaed to operate effec-
tively at all flow rates equal to or less than the peak runoff rate of the design storm. The.design· storm need not Qe an
extreme event, as is typically used in the sizing of flood control facilities. If sized to handle a' storm frequenCy between
the 3-month to I-year event, the facility will effectively treat the vast majority of storm water that occurs Over time. All
events equal to or less than the 6-month event represents about 90% of the precipitation over time; designing for a2-year
TC7
Municipal Handbook 5·61 Match,1993
•
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•
Additional Information -OILWater separators and Water Quaiity Inlets'
event ooly increases the amount of runoff treated by about 5% (increase from 90% to 95% of rainfall treated). For the
design storm selected, calculate the peak runoff rate using the ratiooal method.
Application of the Conyentional Oil/Water Se;parator
AsSume that a conventional oil/water separator is to be used to treat nmoff from a 112 aae parking lot. Assume further it
is to be sized to treat runoff 'from a rainfall rate of 0.50 incbes/hr (which translates to a runoff rate of 0.50 cfs/acre when
the area is 100 peteent impervious.
Using the example above, the computed Vp is 0.0011 ftlsec. Using Equation 2, V =15 x 0.0011= 0.0165 ftJsec which is
less thaD 0.05 ftlsec; thus. .
D = (Q12V)O.05 = (112 x 0.05/(2 x 0.0165» x 0.05
D= 3.8 ft.
L = VDNp = 0.0165 x 3.8/0.0011
L= 57 ft.
W = Q/(VD) = 0.25/(0.0165 x 3.8)
W = 4.0 it. since W is less than 2 x D, increase width toW = 3.8 x 2 = 7.6 ft.
Thus, a cooventiooaI oillwater separator sized to capture nmofffrom a 0.5 inIbr rainfall on a In. aae parking lotwotild
be:
D = 3.8 ft
W=7.6ft
L = 57 ft
Sizjne CPI Wlarator
Manufacturers can rrovide packaged separator units for flows up to several cubic feet per second. For larger flows, the
engineer most size the plate pack and design the vault. Given the great variability of separatoc redmology among
manufacturers with respect to plate size, spacing, and inclination. 'it is recommended that the design 'engineer consuit
vendors for a plate package that will meet the engineer's criteria. Manufacturer' s typ~cally identify the capacity of
various standaItl units. However. the engineer's design criteria must be comparable to that used by the manufaCtUrer in
rating its units.
~e engineer can size the facility using the follOwing procedure. FJISt identify the expected plate angle, H (as degrees), "
,and calculate the total plate area required, A(fi2.).
A ::;:: QN pCosineH (3)
cpr separators are not 100% hydraulically efficient; ranging from 035 to 0.95 depending on the pl.a1e design (Aquatrend,
undated). If the engineer wishes to incorpornte this factor, divide the result from Equation 3 by the selected efficiency;
•
•
•
Select spacing. S, between the plates, usually 0.75 to 1.5 inch.
Identify ~nable plate width, W, and length, L.
Number of plates. N = AIWL.
Calcul.a1e plate volume. Pv(ft3) •
Municipal Handbook 5 -62
TC7
Mar.ch, 1993"
•
•
•
Additional Information -Oil/Water Separators,and Water,Quality Inlets
Pv = Q:lS. + LCosineH)(WLSineH) (4)
12
• Add a foot beneath the plates foe sediment storage.
• Add 6" to 12" above the plates for water clearance so that the oil accumulates above the plates.
• Add one foot for freeboard.
• Add a forebay for floatables and distribution of flow if more than one plate unit is needed.
• Add after bay for collection of the effluent from the plate pack area.
• For larger units include device to remove and store oil from the water surface.
Horizontal plates require the least plate volume to achieve a particular removal efficiency. However, settleable solids will
accumulate on the plates complicating maintenance procedures. The plates may be damaged by the weight when
removed for cleaning. The plates should be placed at an angle of 450 to 6()0 so that settleable solids slide to the facility
bottom. Experience shows that even with slanted plates some solids will "stick" to the plates because of the oil and
grease. Placing the plates closer together reduces the plate volume. However,_if debris is expected such as twigs, plastiC;S, '
, and paper, select a larger plate separation distance. Or install ahead of the plates a trash rack andlor Screens with a
diameter somewhat smaller than the plate spacing.
Recognizing that an oil/water separator also relIioves settleable solids, it can also be considered a wet vault (TC2). The
engineer can ~ Figure 2B (See TC2) to estimate the efficiency of both the conventional and CPI separators. As Figure
2B does not include the effect of plate technology, a CPI separator should perfonn COIlSiderably better than inclicated in
Figure 2B for the same VrfV r ratio.
See API (1990) for further design concepts for both, the conventional and CPI separatOrS •
Maintenance
Check monthly during the wet season and clean several times a year. Always clean in October before the start of the wet,
season. Properly dispose the oil.
REFERENCES
American Petroleum Institute (AP!), 1990, "Design and Operation of Oil-Water SeparatOrs", Puplicatioo421.
Aquatrend, undated, "Design Manual: Innova Sep Particle Separation System", Shawnee Mission, Kansas.
Branion, R., undated, "Principles for the Separation of Oil Drops from Water in ~vity Type Sepamtors''; Department,of
Chemical Engineering, University of British Columbia. ,
Leuemnaier, D. and 1. Richey, 1985, "Operational Assessment of a Coalescing Plate OilIWater SeparatOr", Municipality
of Metropolitan Seattle.
Metropolitan Washington Council of Governments (MWCOG), March, 1992, "A Current Assessment of Urban Best
Management Practices: Techniques for Reducing Nonpoint Source Pollution in the Coastal Zone".
Silverman, G, 1982, "Wetlands for Oil and Grease Control", Tecb Memo. 87, AsSociation of Bay ~ Governments.
T07
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Municipal Handbook 5 -63 Mar~, 1993
.---------------------.. ~.-
• Additional Information -Oil/Water Separators and Water Quality Inlets
TABLE 7 A. WATER VISCOSITIES & DENSITIES Density of
pure water
Temperature Absolute Viscosity Density in air
'C 'F (Poises) (slugslft.sec.) (gm'cc) ~)
•
0 32.0 0.017921 0.00120424 0.999 (i2351
1 33.8 0.017343 0.00116338 0.999 62355
2 35.6 0.016728 0.00112407 0.999 62358
3 37.4 0.016191 0.00108799 0.999 62.360
4 39.2 0.015674 0.00105324 1.000 62,360
5 41.0 0.015188 0.00102059 0.999 62360
6 42.8 0.014728 0.00098968 0.999 ~2359
'7 44.6 0.014284 0.00095984 '0.999 ' ' 62357
8 ' ',46.4 0.013860 0.00093135 .0.999', " ~2354,
9 48.2 0.013462 0.00090460 'O~999' 62350 :
10 50.0 0.013017 0.00087873 0.999 62345
11 51.8 0.012713 0.00085427 0.999 62339
12 53.6 0.0l2363 0.00084870 0.999 62333
13 55.4 0.012028 0;00080824 0.999 62326
14 57.2 0.011709 0.00078681 0.999 62317
IS 59~0 0.011404 0.00076631 0~999 62.309
16 60.8 0.011111 0.00074662 0.999 62.299
17 62.6 0.010828 0.00072761 0.999 62.289
18 64.4 0.010559 0.00070953 0.999 62.278
19 66.2 0.0l0299 0.00069206 0.999 62.266
20 68.0 0.010050 0.00067533 0.998 62.254
• Te7
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Municipal Handbook 5·64 March, 1993
•
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•
Additional Information -Oil/Water Sepa-ators and Water Quality lnlets
Clear
well \ \ \
Oil retention Oil Oil separation
baffle skimmer compartment
Flow distribution
/baffie
Inspection and
sampling tee
,.'
.I
CONVENTIONAL SEPARATOR
Coalescing
plates
~parator vcutt .
!
/
'\
Grit/sludge
remove I baffle
Adapted from Romano, 1990
Oil
outlet
I
AdaPted from Romano, 1990 .
COALESCING PLATE SEPARATOR
FIGURE 7A .. CONVENTIONAL AND COALESCING
PLATE SEPARATORS
Municipal Handbook 5·65
Te7
.~.
Match,1993
•
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Additional Information -OiVWater Separators and Water Quqlity Inlets
/
Raised Secondary Inlet
r,
p=ri=m=a=ry:::lnII1er:r
t lI\ma:::_IIiII/-==~c::Ja~iIi,~.~s.,e.slc:===:::;::;::=:r~.u.f0.u.r~La~rge ~~=,
Reinforced
"Concrete
Construction
Inverted Elbow
Pipe Regulates
Water
L.evels
.:.:
Adaptec:Urom Schueler; 1987 '
NOTE:
1. Size as conventional separator.
2. Design outlet orifice in elbow to limit outflow
to the design rate for the unit.
FIGURE 7B. WATER Q'U'ALITY INLET
Municipal Handbook 5 -66
Te7
March, 1?93
• Additional Information -OiVWater Separators aod Water Quality Inlets
1~--------------------------------~~----~~~~~
"-BO Q,) -Q,)
Q;E .~.!!;! (1.)0
Q)Q) 15.0.. e e 60
00
5]
11)-E~ ::Ie> (5C/) > G) ».c 40 m-_ r:
_ell c:.c (1)-o ~ ... Q,) G)= Q.eIl E • C/) 20
o 20 40 60 80 100 120 140 1S0 1"80 200
Dro~ Dlameter{mlcron)
SIZE •
VOLUME • Source: Branion (URdata.;f)
FIGURE 7C. SIZE AND VOLUME DISTRIBUTION
TC7
• \
Municipal Handbook S·67 Marc;h,1993
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San Diego County Storrnwater Management Program: Business & Industry
,:;l ~
Stormwater Management Program
BUSINESS BEST MANAGEMENT PRACTICES
Page 1 Qf14
The County Stormwater Ordinance (No. 9424) addresses the management and
discharge of pollutants to the County/s Stormwater Conveyance System (street
gutters, storm drains, drainage ditches, etc.) and Receiving Waters (oceans,
creeks, rivers, estuaries, etc). Simply stated, only rain may legally ent~r storm
drains.
Businesses are encouraged to implement Best Management Practices (BMPs)
to reduce pollutants to stormwater runoff. BMPs are defined as general good
housekeeping practices, schedules of activities, pollution prevention
techniques, educational practices, maintenance procedures, prohibitions of
practices and other management practices. BMPs also include treatment
practices, operating procedures, and practices to control site runoff, spillage or
leaks, sludge or water disposal, or drainage from raw materials storage.
Detailed fact sheets are available in an effort to provide clear guidance. The
BMPs described on these fact sheets are generally inexpensive to implement
and may save you money. The fact sheets cover the following topics:
• Definitions
• Storm Drains and Discharge Points
• Maintenance and Cleaning of Floors and Outside Impervious Surfaces
• Vehicle and Equipment Washing and Cleaning
• Vehicle and Equipment Fueling
• Vehicle and Equipment Operation, Maintenance and Repair
• Materials Loading, Unloading and Storage
• Waste Management and Disposal
• Building and Grounds Maintenance
• Building Repair, Remodeling and Construction
• Waste Recycling & Disposal Reference Guide
If you have questions or would like additional information, call th~ County
Stormwater hotline at (619) 338-2048 or toll-free 1(888) 846-0800.
or email usatswdutyeh@sdcounty.ca.gov
,"
http://www.co.san-diego.ca.us/dehllwq/storrnwateribusiness.html 6/2'1102
•
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San Diego County Stormwater Management Program: Business & Industry Page 20f14
STORM DRAINS AND DISCHARGE POINTS
You are responsible to keep storm drains and other discharge points (draiilage cbannels, '
sheet flow areas, etc.) clear throughout the entire facility (indoors and ,outdoors), including
perimeter areas where surface runoff exits the property.
WHY ARE STORM DRAINS & DISCHARGE POINTS A PROBLEM?
Dirt, oil, grease and litter are washed down the storm drain with each rainfall creating polluted
nmoff. Polluted nmoff from your facility can reach water bodies and other wildlife ha,bitats and
harm fish, birds and human life.
WHAT CAN
IDO?
PREVENT POLLUTED RUNOFF FROM ENTERING STORM DRAINS
AND DISCHARGE POINTS BY:
BEST
MANAGEMENT
PRACTICES
• Implementing Best Management Practices (BMPs) as listed below
• Training employees on BMPs, good housekeeping practices & spill
response
• Prevent spills from entering storm drains and djscharge
points. .
• Eliminate illegal connections to the storm drain.
• Routinely inspect and clean out all storm drains,
discharge point & catch basins.
• Control litter by sweeping and picking up litter regularly.
• Clean mats in a floor-mounted mop sink or use a mat
cleaning service.
• Collect all wash water and discharge to the sanitary
sewer.
• Use "dry" cleaning methods (sweep rather than hose.
down) to clean shop floors, materials processing and
storage areas, access roads and parking lots.
• Use secondary containment measures for waste stotag~
areas.
• Label all storm drain inlets "No DtJInping"
• Practice good housekeeping to minimize liability, reduce
costs and make it easier to detect spills and potential
problems .
• Clean up spills immediately to minimize safety hazards
and deter spreading.
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San Diego COlUlty Storrnwater Management Program: Business & Industry Page 3-of 14
•
• Train all employees. Your success depends on an
effective training program .
If you have questions or want more inforrnatio~ call the
County Stormwater Hotline
(619) 338-2048 or toll-free 1(888) 846-0800.
MAINTENANCE AND CLEANING_ OF FLOORS AND
OUTSIDE IMPERVIOUS SURFACES
You are responsible to keep floors and impervious surfaces free of contaminates that
are generated or accumulated there (process areas, kitchens and rood pr~paration
areas, parking lots, sidewalks, dumpster areas, etc.).
WHY IS PROPER MAINTENANCE & CLEANING SO IMPORTANT?
Contaminants from your facility can contribute to polluted nmoffwhen floors and outside
:impervious areas are not maintained or cleaned properly.
WHAT CAN
IDO?
PREVENT POLLUTED RUNOFF BY:
• Implementing Best Management Practices (BMPs) as listed
below
• Training employees on BMPs"good housekeeping practices &
spill response
BEST • Practicing good housekeeping.
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, San Diego Com:ty Stormwater Management Program: Business & Industry Page4of14
MANAGEMENT
PRACTICES
• Keep outside areas (dumpsters, parking lots, etc.) free of trash
and debris, and regularly clean them to prevent pollutant
buildup.
• Use absorbent for liquid spills and sweeping and mopping to
clean outside areas.
• Regularly inspect and clean out grease traps ..
• Avoid spilling onto floors or other surfaces through good
housekeeping.
• Control litter by sweeping and picking up trash on a regular
basis.
• Never dispose of wash waters to the storm drain .
• Use "dry" cleaning methods (sweeping, vacuuming, etc.) on
sidewalks and parking lots and dispose of waste properly.
• Use a damp mop to clean floors, and contain the wash water for
proper disposal (sewer, on-site tJ:eatmen~ etc.).
• Label all storm drain inlets "No Dumping".
• Clean up spills immediately to minimlze safety hazards and
deter spreading.
• Train all employees. Your success depends on an effective
training program.
If you have questions or want more information, call the
County Stormwater Hotline (619) 338-2048 or toll-free
1(888) 846-0800.
VEHICLE AND EQUIPMENT WASHING AND
CLEANING
You are responsible to wash or clean vehicles and equipment (macl1inery, air fitters,
grease traps, etc.) properly to avoid contributing pollutants to runoff.
WHY IS WASHING AND CLEANING A CONCERN?
Your facility can contribute contaminants to runoff if wash water from equipment and
vehicle cleaning is rinsed onto parking lots or into gutters or storm drains. Irtlproperly
stored rags may also result in an illegal discharge.
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San Diego County Stormwater Management Program: Business & Industry Page 5 of14
WHAT CAN
IDO?
PREVENT POLLUTED RUNOFF BY:
• Implementing Best Management Practices (BMPs) as listed
below
• Training employees on BMPs, good housekeeping practices &
spill response
-BEST
MANAGEMENT
PRACTICES -
• Ifpossible use off-site commercial washing and.steartl
cleaning.
• -Use designated wash areas, preferably covered, to prevent
contact with stormwater. Berm wash areas or use other
measures to contain wash water.
• Use alternative washing and cleaning methods to reduce the
potential for non-stormwater discharges. If possible, use·" drt'
cleaning methods, such as wiping down, rather than hosing
vehicles or equipment.
• Never discharge wash water to the storm drain Discharge it to
the sanitary sewer after contacting your local sewering agency
to find out if pre-treatment is required,-or if possible, filter and
recycle it.
• Properly contain and dispose of cleanup materials (rags, towels,
absorbent materials, etc.).
• Label all storm drain inlets "No Dumping".
• Oean up spills immediately to minimize safety hw;rrds and
deter spreading.
• Educate employees on pollution prevention measures.
If you have questions or want more information, call the
County StormwaterHotline (619) 338-2048 or toll-free
1(888) 846-0800.
VEHICLE AND EQUIPMENT FUELING
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San Diego COlUlty Stonnwater Management Program: Business & Industry Page 60f14
You are responsible to properly fuel vehicles and equipment to avoid contributing
pollutants to runoff. .
WHY IS PROPER FUELING SO Il\1PORTANT?
Spilled fuel can contribute contaminants to fllllofffrom your facility. Ii:pproperly stored
rags used to clean up spilled fuel may also result in an illegal discharge.
WHAT CAN
IDO?
PREVENT POLLUTED RUNOFF BY:
• Implementing Best Management Practices (BMPs) as listed
below
• Training employees on BM;Ps, good hous~keeping ,practices &
spill response
BEST
MANAGEMENT
PRACTICES
• Cover fueling areas.
• Install perimeter drains or slope the surrOlUlding pavement
inward with drainage to a sump or an oil-water separator.
• Pave fueling areas with concrete rather than asphalt, or apply a
sealant to protect asphalt from spilled fuels. .
• Install vapor recovery noziles to control drips.
• Discourage "topping off" fuel tanks.
• Use secondary containment when transferring fuel from tank
trucks to tanks.
• Use absorbent materials or mop up small spills, and for gener~
cleaning rather than hosing down the area. Remove the
absorbent materiais promptly.
• Use a rag cleaning service for contaminated rags used to clean
up spills, which can not be disposed of in trash.
• Transport industrial equipment to a designated ·fuelingarea
rather than using mobile fueling.
• Clean up spills immediately to minimize safety hazards and
deter spreading.
• Train employees on proper fueling and cleanup procedures
If you have questions or want more information, call the
County Stormwater Hotline (619) 338-2048 or toll-free .
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San Diego County Stonnwater Management Program: Business & Industry Page 7 of 14
1(888) 846-0800 .
VEHICLE AND EQUIPMENT OPERATION,
MAINTENANCE AND REPAIR
You are responsible to operate, maintain and repair vehicles and equipment properly
to avoid contributing pollutants to runoff.
WHY IS OPERATING, MAINTENANCE & REPAIR A CONCERN?
Your facility can contribute contaminants to runoff when vehicles and equipment are .
improperly operated, maintained or repaired. Leaky and poorly maintained equipment and
improper maintenance work areas might result in an illegal discharge .
WHAT CAN
IDO?
BEST
MANAGEMENT
PRACTICES
PREVENT POLLUTED RUNOFF BY:
• Implementing Best Management Practices (BMPs) as listed
below
• Training employees on BMPs, good housekeeping practices &
spill response .
• Use benning and drainage routing to rninin'lize stormwater run
on.
• Inspect and clean equipment to prevent leaks and excessive
buildup of contaminants. Keep drip pans and containers under
areas that might drip.
• Move activities indoors, or cover equipment areas with a
permanent roof. Conduct maintenance only in areas designed
to prevent stonnwater pollution
• Never pour materials down stonn drains. Comrect process
equipment areas to the sanitary sewer or a facility wastewater
treatment system.
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San Diego County Stormwater Management Program: Business & Industry Page 8 of 14
• Avoid hosing down work areas. Clean sIIiall spills with rags, .
conduct general clean up with damp mops and clean larger
spills with absorbent material.
• Use non-toxic substitutes for chemicals when possible. Recycle
greases, oil & filters, antifreeze, cleaning solutions, batteries
and hydraulic & transmission fluids. .
• Clean storm drainS regularly, and stencil inlets with "No
Dumping".
• Use catch basin infiltration inserts to capture particulate
pollutants.
• Clean up spills immediately to minimize safety hazards and
deter spreading.
• Train employees on discharge prohibitions.
If you have questions or want more information, call the
County Stormwater Hotline (619) 338-2048 or toll-free
1(888) 846-0800 .
MATERIALS LOADING, UNLOADING AND
STORAGE
You are responsible for preventing runoff from contacting pollutants and avoiding
spills in areas where hazardous and non-hazardous materials are loaded, unloaded
(e.g. delivery or shipping docks) or stored (bUlk storage areas, etc.), especiaDy outside
where they may be exposed to stormwater.
WHY IS LOADING, UNLOADING & STORAGE A CONCERN?
Your facility can contribute contaminants to runoff when loading, unloading and storing
materials. Spills, improper storage and sloppy teclmiques may result in an illegal
discharge .
WHAT CAN PREVENT POLLUTED RUNOFF BY:
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San Diego COlllIty Stormwater Management Program: Business & Industry Pag~ 9 of 14
. IDO? • Implementing Best Management Practices (BMPs) as listed
below
• Training employees on BMPs, good housekeeping practices &
spill response
BEST
MANAGEMENT
.PRACTICES
• Park delivery vehicles so that spills or leaks can be contained.
• Protect materials from rainfall, run-on, run-offand wind
dispersal. For example, cover loading docks to redUce the
exposure of materials to rain.
• Use seals or door skirts between trailers and buildings to
prevent exposure to rain and use grading or bernring to prevent
stormwater run -on.
• Position roof downspouts to direct stormwater away from
loading, unloading and storage areas. .
• Use drip pans under areas that may leak (hose connectionS,
filler nozzles, etc.). .
• Sweep parking lots or other surfaces to remove debris blown or
washed from loading, unloading and storage areas ..
• Store liquids in a designated area on a paved impervious
surface within a secondary containment. Keep outdoor storage
containers in good condition. .
• Clean storm drains regularly, and stencil inlets with "No
Dumping".
• Use catch basin infiltration inserts.
• Clean up spills immediately to minimize safety hazards and
deter spreading. _
• Provide training to employees on spill prevention, c6ntaimnent .
and cleanup.
If you have questions or want more information, call the
County Stormwater Hotline (619) 338-2048 or toll:"free
1(888) 846-0800.
WASTE MANAGEMENT AND DISPOSAL
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San Diego COllllty Stormwater Management Program: Business & Industry Page 10 of14
You are responsible for properly managmg all areas where solid, liqUid or hazardous
wastes are handled, stored or disposed of to prevent pollutants from contaminating
stormwater runoff.
WHY IS WASTE MANAGEMENT & DISPOSAL A CONCERN?
Your facility can contribute contaminants to stormwater runoff if wastes are not managed
and disposed of properly. Poor waste management may result in an illegal dischatge~
WHAT CAN I DO?
PREVENT POLLUTED RUNOFF BY:
• Implementing Best Management Practices (BMPs) as listed below
• Training employees on BMPs, good housekeeping-practices & spill response
BEST
MANAGEMENT
PRACTICES
• Cover and berm waste storage areas.
• Keep outside areas (dumpsters, parking lots, etc.) free or trash
and debris.
• Store wastes indoors when possibl~.
• Keep waste containers covered.
• Regularly inspect and clean grease traps.
• Use non-toxic substitutes for chemicals when'possible.
• Recycle food grease, cleaning solutions, oil, antifreeze,
batteries and fluids.
• Sweep parking lots or other surfaces to remove debris blown or
washed from storage areas.
• Store liquids in a designated area on a paved impervious
surface within a secondary containment, Keep outdoor storage
containers in good condition.
• Regularly inspect and clean storm.drains, and stencil inlets with
"No Dmnping".
• Clean up spills immediately to minimize safety hazar<;ts and
deter spreading.
• Regularly control litter by sweeping· and picking up tr&Sh and .
litter. .
• Educate employees on pollution prevention measures .
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San Diego County Stormwater Management Program: Business & Industry Page 11 of14
If you have questions or want more information, call the
County Stormwater Hotline (619) 338-2048 or toll-free:
1(888) 846-0800.
BUILDING AND GROUNDS MAINTENANCE
You are responsible for preventing contaminants from contributing to polluted
stormwater runoff in areas where building or grounds maintenance is conducted
(landscaping, cleaning activities, etc.).
WHY IS BUILDING & GROUNDS MAINTENANCE A CONCERN?
Areas where building or grounds maintenance is conducted can centribute contaminants to .
runoff when measure have not been taken to prevent discharges. The overuse of pesticides
and fertilizers, over-watering and inadequate erosion control may result in an illegal
discharge .
WHAT CAN
IDO?
BEST
MANAGEMENT
PRACTICES
PREVENT POLLUTED RUNOFF BY:
• Implementing Best Management Practices (BMPs)as listed
below
• Training employees on BMPs, good hOUsekeeping practices
& spill response
• Utilize native vegetation to reduce water, fertilizer or pesticide
needs.
• Use landscaping pesticides and fertilizers only as needed
• Avoid over-watering to prevent excess runoff.
• Use integrated pest management (IPM) where appropriate.
• Sweep paved surfaces, rather than hosing down or using
blowers;. .
• Properly contain and dispose of wash water, sweepings and
sediments.
• Use non-toxic substitutes for chemicals when PQssible.
• Regularly inspect and clean storm drains, also stencil inlets
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San Diego COlmty Storrnwater Management Program: Business & Industry Page 12 of 14.
with "No Dumping".
• Clean up spills immediately to minimize safety haiards and
deter spreading.
• Controllitter by sweeping and picking up trash on a regular
basis.
• Educate employees on pollution prevention measures.
If you have questions or want more information, call the COlmty Storrnwater Hotline (619)
338-2048 or toll-free 1(888) 846-0800.
BUILDING REPAIR, REMODE.LING AND
CONSTRUCTION
You are responsible for preventing contaminants from contributing to polluted
stormwater runoff in areas where building repair, remodeling and construction
activities are conducted.
WHY IS CONSTRUCTION & REPAIR A CONCERN?
Areas where building repair, remodeling and minor construction are conducted can
contribute contaminants to rimoffwhen measure have not been taken to prevent
discharges. .
WHAT CAN
IDO?
PREVENT POLLUTED RUNOFF BY:
• Implementing Best Management Practices (BMPs) as listed
below
• Training employees on BMPs, good housekeeping practices
& spill response
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San Diego County Stormwater Management Program: Business & Industry Page 13 of 14
BEST
MANAGEMENT
PRACTICES
• Use soil erosion control techniques ifbare ground is
temporarily or permanently exposed.
• Enclose painting operations, consistent with local air quality
operations.
• Properly store and dispose of waste materials generated from
the activity.
• Properly store materials that are normally used in repair and
remodeling such as paints and solvents.
• Sweep paved surfaces, rather than hosing down or using
blowers.
• Properly contain and dispose of wash water, sweepings and
sediments. .
• Use non-toxic substitutes for chemicals when-possible.
• Regularly inspect and clean storm drains, also stencil inlets
with "No Dumping".
• Clean up spills immediately to minimize safety hazards and
deter spreading. .
• Control litter by sweeping and picking up trash on a regular
basis.
• Maintain good housekeeping practices while work is tinderway.
• Train all employees. Your success depends on an effective
training program .
If you have questions or want more information, call the
County Stormwater Hotline (619) 338-2048 or toll~free
1(888) 846-0800.
WASTE RECYCLING & DISPOSALREFERENC.E
GUIDE
You are responsible to implement measures to detect, correct and enforce against
illegal dwnping of pollutants on streets, into water and the storm drain ~stem •
WHY IS PROPER DISPOSAL SO IMPORTANT?
Properly dispose of wastes, and recycle when possible, to eliminate illegal discharges.
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San Diego County Storrnwater Management Program: Business & Industry Page 14 of14
Reduce, reuse and recycle hazardous and non-hazardous wastes when possible, to lower
your disposal costs and the amount of waste going into our landfills. Participate in waste
exchange opportunities to decrease the waste you generate and save money.
WHO CAN
I CALL TO GET
INFORMATION?
RECYCLING: NON-HAZARDOUS.W ASTE RECYCLING:
County Recycling Hotline: (619) 467-0903 or (800) 237-2583
HAZARDOUS WASTE RECYCLING: Call the State Department
of Toxic Substances Control to get a copy of the "Directory of
Indus1rial Recyclers and Listing of Ha,zardous Wastes Available for
Recycling": (916) 323-6042 DISPOSAL: NON-HAZARDOUS
WASTE DISPOSAL: County Landfills (Allied Systems, Inc.):
(619) 278-6061 City Landfill (Miramar) Information: (619) 573-
1418 or (619) 573-1420 HAZARDOUS WASTE DISPQSAL:
County Hazardous Materials Duty Specialist: (619) 338-2231
EXCHANGE PROGRAMS: Call the California Integrated
Waste Management Board to get a copy of the "California Materi~s
Exchange (CALMAX) Catalog": (916) 255-2369
If you have questions or want more informatiol\ call the
County StormwaterHotline (619) 338-2048 or toll-free
1(888) 846-0800.
Comments/Suggestions? Email: swdutyeh@sdcounty.ca.gov
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Construction
CONSTRUCTION
BESTMANAGEMENTPRACnCES
CONSTRUCTION SEQUENCING
SURFACE STABILIZATION
RUNOFF CONTROL MEASURES
RUNOFF CONVEYANCE MEASURES
OUTLET PROTECTION
SEDIMENT TRAPS AND BARRIERS
REFERENCES
STORMWA TER PROGRAM
Page 1 of6
The County Stormwater Ordinance (No. 9424) addresses the management and discharge of pollutants to
the County's Stormwater Conveyance System (street gutters, storm drains, drainage ditches, etc.) and
Receiving Waters (oceans, creeks, rivers, estuaries, etc). Simply stated, ,only rain may legally enter
storm drains. Construction site owners and developers are responsible to keep storm drains and other
discharge points (drainage channels, sheet flow areas, etc.) clear throughout the entire construction site, .
including perimeter areas where surface runoff exits the site.
Construction site owners and developers are encouraged to implement Best Management Practices
(BMPs) to reduce pollutants to stormwater runoff. BMPs are defined as general good housekeeping
practices, schedules of activities, pollution prevention techniques, educational practi<::es" maintenance
procedures, prohibitions of practices and other management practices. BMPs also include treatment
practices, operating procedures, and practices to control site runof4 spillage or leaks, sludge or water
disposal, or drainage from raw materials storage. Examples of BMPs for construction sites inclpde .
construction sequencing, surface stabilization, runoff control measures, runoff conveyan<::e measures,
outlet protection, sediment traps and barriers, and stream protection.
It is best to involve a system ofBMPs that targets each stage of the erosion process to ensure sUccess .
from construction activities. The most efficient approach involves minimiziIig the potential :sources of
sediment from the outset. This means limiting the extent and duration ofland disturbance to the
minimum needed, and protecting surfaces once they are exposed. BMPs should also involve controlling
the amount of runoff and its ability to carry sediment by diverting incoming flows and impeding
internally generated flows. And finally, BMPs should also involve retaining sediment that is picked up
on the project site through the use of sediment-capturing devices. On;most sites successful'erosion and
sedimentation control requires a combination of structural and vegetative practices. Above all BMPs are
best performed using advance planning and good scheduling.
Detailed information is attached in an effort to provide you with specific guidance to implement BMPs.
You are encouraged to implement all applicable BMPs to reduce runoffpollutants from your facility .
If you have questions or would like additional information, call the County Stormwater hotline at (619)
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Construction Page 20f6
338-2048 or toll-free 1(888) 846-0800. . ' " "
CONSTRUCTION BEST MANAGEMENT PRACTICES
CONSTRUCTION SEQUENCING
The timing ofland disturbing activities and installation of erosion and sedimentation control measmes
must be coordinated to minimize water quality impacts. In terms of major activities,. the BMP system is
typically installed in reverse order, starting with sediment capturing devices, followed by key runoff
control measmes and nmoff conveyances, and finally involving major land clearing activities after the
minimization and capture elements are in place. Often, construction operations that generate significant
off-site sediment have failed to sequence activities in the proper order.
SURFACE STABILIZATION
Mulching: A protective blanket of straw or other plant residue, gravel, or synthetic material applied to
the soil surface to'minimize raindrop impact energy and nmof£: foster vegetative establishment, reduce
evaporation, insulate the soil, and suppress weed growth. Mulch provides immediate protection, and
straw mulch is also typically used as a matrix for spreading plant seed. Organic mulches such as straw,
wood chips, and shredded bark have been fOlmd to be the most effective. Straw typically requires some·
kind of tacking, such as liquid emulsions or netting. Netting may also be needed to hold mulch in place
on slopes. Mats made from a wide variety of organic and synthetic materials are useful in establishing
grass in charnels and waterways, and they promote seedling growth. Mulching assists in the first, somce
reduction, and second, conveyance, stages of a BMP system. .
Permanent Seeding: Establishment of perermial vegetative cover with seed to minimize nmof£: erosion,
and sediment yield on disturbed areas. Disturbed soils typically reqUire amendment with lime, fertilizer,
and roughening. Seeding should be done together with mulching. Mixtures are typlcally most effective,
and species vary with preferences, site conditions, climate, and season Permanent seeding assists il'\ the
first, somce reduction stage of a BMP system.
Riprap: A layer of stone designed to protect and stabilize areas subject to erosion, slopes SUbject to
seepage, or areas with poor soil structure. Riprap is used on slopes where vegetation cannot be
established, charmel slopes and bottoms, stormwater structure inlets and outlets, slope drains,
streambanks, and shorelines. It should be a well-graded mixture of stone sizes, and should be underlain
by a filter blanket of gravel, sand and gravel, or synthetic material to prevent soil movement into or
through the riprap. Riprap can assist in all stages of a BMP system. '
Sodding: Permanent stabilization of exposed areas by laying a continuous cover of grass sod.. Sod is
useful for providing immediate cover in steep 'critical areas and in areas lUlsuitable for seed, such as
flowways and around inlets. Sod must be rolled over after placement to ensure Qo:htact, and then
watered. Sodded waterways and steep slopes may require netting and pegging or stapling. SQdding
assists in the first, source reduction, and second, conveyance, stages of a BMP system.
Surface Roughening: Roughening a bare, sloped soil smface with horizontal grooves or benches
numing across the slope. Grooves can be large-scale, such as stair-step grading with small benches or
terraces, or small-scale, such as grooving with disks, ti.11ers, or other machinery, Qr with heavy tracked '
machinery which should be reserved for sandy, noncompressible soils. Roughening aids the '
establishment of vegetative cover, improves water infiltration, and decrea~s nmoffvelocity, assisting in
the first, source reduction, and second, pollutant transport, stages of a BMP system.
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Construction Page 3 of6
Temporary Gravel Construction Access: A graveled area or pad located at points where vehicles enter
and leave a construction site, this BMP provides a buffer area where vehicles can drop their moo and
sediment to avoid transporting it onto public roads, to control erosion from surface runofl: and to help
control dust. This measure assists in the third, pollutant capture stage of a BMP system.
Temporary Seeding: Planting rapid-growing annual grasses, small grains, or legumes to provide initial,
temporary stabilization for erosion control on disturbed soils that will not be brought to final grade for
more than approximately one month. Fertilizing and surface roughening facilitates seeding. Raking or
chain dragging must cover broadcast seeds, while hydroseed mixtures are spread in a -mulch matrix.
Temporary seeding assists in the first, source reduction stage of a B MP system.
Topsoiling: Preserving and subsequently re-using the upper, biologically active layer of soil to enhance
final site stabilization with vegetation. T opsoiling should not be conducted on steep slopes. Stockpiled
soil should be contained with sediment barriers, and temporarily seeded for stability. Surfaces, which
will receive topsoil, should be roughened just prior to spreading the soil to improve bonding. Spread
topsoil should be lightly compacted to ensure good contact yvith the subsoil. Topsoil can act as a mulch,
promoting final vegetation establishment, increasing water infiltration, and anchoring more erosive
subsoils, assisting in the first, source reduction, and second, pollutant transport, stages of a BMP system.
RUNOFF CONTROL MEASURES
Runoff Diversion: A structure that channels upslope runoff away from erosion source area&, diverts
sediment-laden runoff to appropriate traps or stable outlets, or captures runoffbefore it leaves fue site,
diverting it to locations where it can be used or released without erosion or flood daIIiage. Diversions
include graded surfaces to redirect sheetflow, diversion dikes or berms which force sheetflow aro~d a
protected area, and stormwater conveyances (swales, channels, gutters, drains, sewers) which intercept,
collect and redirect runoff (USEP A, 1992). Diversions can be either temporary or permanent in nature.
Temporary diversions include excavation of a channel along with placement -of fue spoil in a dike on the
downgradient side of the channel, and placement of gravel in Ii ridge below an exc.avated swale.
Permanent diversions are used to divide a site into specific drainage are~s, should be sized to captt;Jre
and carry a specific magnitude of design storm, and should be constructed of more permanenttnaterials.
A water bar is a specific kind of runoff diversion that is constructed diagonally at intervals across a
linear sloping surface such as a road or right-of-way that is subject to erosion. Water bars are meant to
interrupt the accmnulation of erosive volumes of water through their periodic placement down the slope,
and divert the resulting segments of flow into adjacent undisturbed areas for dissipation. Runoff
diversions assist in the second, conveyance stage of a BMP system.
RUNOFF CONVEYANCE MEASURES
Grass-Lined ChanneL' A swale vegetated with grass, which is dry except following storms -and serves
to convey specified concentrated stormwater runoffvolmnes, without resulting in erosiOn, to disposal
locations. Typical uses include roadside swales, outlets for runoff diversions, site stormwater routing,
and drainage oflow areas. Channels should conform to the natural drainage patte~. Charmels are not
meant to collect sediment, as it will reduce their conveyance capacity. Lining with geoteXtile or other
material is required if design flows are to exceed 2 feet per second Channel veg~tation should-be
allowed to establish before flows are introduced Channels assist in the second, conveyance stage of a
BMPsystem .
Hardened Channel' A channel with erosion-resistant linings of riprap, paving, or other structural
material designed for the conveyance and safe disposal of excess water Without erosion Hardened
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Construction Page 40f6
channels replace grass-lined channels where conditions are llllSuitable for the latter, such as steep slopes,
prolonged flows, potential for traffic damage, erodible soils, or design velocity over 5 feet per second .
Charmels assist in the second, conveyance stage of a BMP system.
Paved Flume: A small concrete-lined charmel to convey water down a relatively steep slope withqut
causing erosion. Flumes serve as stable, permanent elements of a stormwater system receiving drainage
from above a relatively steep slope, typically conveyed by diversions, charmels; or Il&tural
drainageways. Setting the flume well into the ground is important, particularly on fill slopes. Some
means of energy dissipation should be provided at the outlet, and an inlet bypass route should be
available for extreme flows. Flumes assist in the second, conveyance, stage of a BMP system.
Temporary Slope Drain: Flexible tubing or conduit extending temporarily from the top to ,the bottom of
a cut or fill slope for the purpose of conveying concentrated runoff down the slope face without causing
erosion These are generally used in conjunction with diversions to convey runqff down a slope until
permanent water disposal measures can be installed. Temporary slope drains assist:41 the second,
conveyance stage of a BMP system.
OUTLET PROTECTION
Level Spreader: An outlet designed to convert concentrated runoff to sheet flow and disperse it
uniformly across a slope without causing erosion. This structure is particularly well-suited for returrriilg .
natural sheet flows to exiting drainage that has been altered by development, especially for returning
sheet flows to receiving ecosystems such as wetlands where dispersed flow may be import~t for
maintain pre-existing hydrologic regimes. The outlet's receiving area must be uniformly sloped and not
susceptible to erosion Particular care must be taken to construct the outlet lip completely level in a
stable, undisturbed soil to avoid formation of an outlet charmel and subsequent erosion. Erosion-resistant·
matting of some kind may be necessary across the outlet lip depending on expected flows. Alternative
designs to minimize such charmeling include hardened structures, stiff grass hedges, arid segmenting
discharge flows into a number of smaller, adjacent spreaders. The level spreader is often used as ·an
outlet for runoff diversions. Level spreaders assist in the second, conveyance stage of a BMP system.
Outlet Stabilization Structure: A structure designed to control erosion at the outlet of a channel-or
conduit by reducing flow velocity and dissipating flow energy. This should be used wbere the discharge
velocity of a structure exceeds the tolerances of the receiving charme1 or area. Designs will vary based
on discharge specifics and tailwater conditions. A riprap-lined apron is the most commonly used
practice for this purpose because of its relatively low cost and ease of installation Riprap stilling basins
or plunge pools should be considered in lieu of aprons where overfalls exit at the ends of pipes or where
high flows would require excessive apron length. Outlet stabilization structures assist in the second,
conveyance stage of a BMP system.
SEDIMENT TRAPS AND BARRIERS
Block and Gravel Inlet Protection: A temporary sediment control barrier formed around a storm drain
inlet by the use of standard concrete block and gravel, to filter sediment from stormwater entering the
inlet prior to stabilization of the contributing area soils, while allowing Use of the inlet for stormwater
conveyance. The height of the barrier should allow overflow into the inlet and not let ove,rflow bypass
the inlet to unprotected lower areas. An alternative design eliminates the blocks and involves only a
gravel doughnut around the inlet. This practice can be used in combination with other temporary inlet
protection devices, such as excavation and fabric. Inlet protection structures assistin the third, capture,
stage of a EMP system.
http://www.co.san-diego.ca.us/dehllwq/stormwater/construction.html 6121/02
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Construction Page 5 of6
Excavated Drop Inlet Protection: A temporary excavated area arOlmd a storm drain drop inlet ot curb
inlet designed to trap sediment prior to discharge into the inlet. This practice allows use of the
permanent inlet early in the development prior to stabilization of the' contributing area soils. Frequent .
maintenance is required This practice can be used in combination with other temporary inlet protection
devices, such as fabric and block and gravel. Inlet protection structures assist in the third, capture, stage
of a BMP system. '
Fabric Drop Inlet Protection: A temporary fabric barrier placed around,a drop inlet to help prevent
sediment from entering storm drains during construction operations, while allowing use of the 'inlet for
storn.1water conveyance. The height of the barrier should allow overflow into the drop inlet and not let .
overflow bypass the inlet to lll1protected lower areas. This practice can be used in combination with
other temporary inlet protection devices, such as excavation and block and gravel. Inlet protection
structures assist in the third, capture stage of a BMP system.
Sediment BasinIRock Dam: An earthen or rock embankment located to capture sediment from runoff
and retain it on the construction site, for use where other on-site erosion control measur~s ate not
adequate to prevent off-site sedimentation. Sediment basins are more permanent in nature than sediment
traps, and can be designed as permanent features of a development. Basins are most comtnonly used at
the outlets of diversions, channels, slope drains, or other runoff conveyances that discharge sediment-
laden water. Earthen basins should use barrel and riser discharge structures, while rock dru;ns can be
designed to disc~ge over 'the top of the embankment, where a crest should be constructed as the low
point. Smaller gravel should line the inside face of the rock dam. Sediment basins androck dams assist
in the third, capture stage of a BMP system.
Sediment Fence (Silt Fence)/ Straw Bale Barrier: A temporary sediment barrier consisting offilter
fabric buried at the bottom, stretched, and sUpported by posts, or straw bales staked into the ground,
designed to retain sediment from small-disturbed areas by reducing the velocity of sheet flows. B~cause
silt fences and straw bales can cause temporary ponding, sufficient storage area and overflow outlets
should be provided Ends must be well anchored (USEP A, 1993). Sediment fences and straw bale
barriers assist in the third, capture, stage of a BMP system.
Sediment Trap: A small, temporary ponding basin formed by an embankment or excavation to capture
sediment from runoff. Traps are most commonly used at the outlets of diversions, channels, slope drains,
or other runoff conveyances that discharge sediment-laden water. It is important to consider provisions
to protect the embankment from failure from runoff events that exceed the design cap~city. Plan for non-
erosive emergency bypass areas. Make traps readily accessible for periodic maintenance. High length-
to-width ratios minimize the potential for short-circuiting. The pond outlet should be a stone section
designed as the low point. Sediment traps assist in the third, capture, stage of a BMP system.
Sod Drop Inlet Protection: A permanent grass sod sediment filter area around a storm drain drop inlet
for use once the contributing area soils are stabilized. This area is well suited for lawns adjacent to large
buildings. Inlet protection structures assist in the third, capture stage of a BMP system.
Vegetated Filter Strip (VFS): A low-gradient vegetated area that filters solids from overland sheet flow.
VFSs can be natural or planted, should have relatively flat slopes, and should be vegetated with ~-.
culmed, herbaceous, erosion-resistant plant species. The main factors influencing removal efficiency-are
the vegetation type and condition, soil infiltration rate, and flow depth and travel time, which are
affected by size of contributing area, and slope and length of strip. Channelized flows decrease the
effectiveness ofVFSs. VFSs are often used as buffers bordering on construction areas. Level &preaders
are often used to distribute runoff evenly across the VFS (Dill aha, 1989; USEP A, 1993).
http://www.co.san-diego.ca.us/dehllwq/stormwater/construction.html ,61Z1I02
Construction Page 60f6
~. REFERENCES
~
~
"Watersheds, Construction." [WWW document]. Available URL:
http://h2osparc.wg.ncsu.edu/descprob/construc.html (visited 1998, February 20).
Dillaha, T.A.,J.H. Sherrard, and D. Lee, 1989. Long-Term Effectiveness of Vegetative Filter
Strips. Water Environment and Technology, 1:418-421. .
Smolen, M.D., D.W. Miller, L.C. Wyatt, J. Lichthardt, A.L. Lanier, W.W. Woodhouse, and S.W.
Broome, 1988. Erosion and Sediment Control Planning and Design Manual. North Carolina
Sedimentation Control Commission, NC Dept. of Natural Resources and Community
Development, Raleigh, NC.
USEPA, 1992. Storm Water Management For IntiustrialActivities:DevelopingPollutionPrevention
Plans and Best Management Practices. EPA 832-R-92-006. U.S. Environmental Protection Agency,
Office Of Water, Washington, DC. .
USEPA, 1993. Guidance Specifying Management Measures for Sources of Non point Pollution In
Coastal Waters. EPA-840-B-92-002, January 1993. U.S. Environmental Protection Agency,.Office .
of Water, Washington, DC.
Comments/Suggestions? Email: swdutyeh@sdcountv.ca.gov
http://www.co.san-diego.ca.us/deh/lwq/stonnwater/construction.html 6/21/02
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ATTACHMENT F-1 I,
stormwater Management Plan Instructions:
To Accompany All Grading Permit Applications
In order to comply with the federal Clean Water Act, the state Water Code and County Ordinances, the, County 01-
San Diego requires that property owners complete a Stormwater Management Plan prior to issuance of -any
Grading Permit. The purpose of a Stormwater Management. Plan is to document Best Management Practices .
(BMPs) that will be implemented to prevent pollutants (including sediment) from entering stormwater conveyances
and receMng waters. The Stormwater Management Plan becomes a part of the Grading Permit and is subject to
enforcement by County inspectors and others.
Stormwater Management Plans include the elements described in the following sections:
Section 1: Required Information -This section is used to provide the County with basic information necessary to
evaluate and prioritize project activities. Each of the items in this section must be completed, except projects with-
less than 5 acres of disturbed area are not required to have a Waste Discharge Identification Number (WDID).
Grading projects with a disturbed area of 5 acres or greater must also meet additional requirements from. the State
Water Resources Control Board (SWRCB). Those additional requirements include filing a Notice of Intent (NOI)
and preparation of a Stormwater Pollution Pr~vention Plan (SWPPP).
Please note that watercourses and waterbodies include ephemeral drainages (Le., those that are dry during part of
the year).
Section 2: Best Management Practices -Best Management Practices (BMPs) must be selected and
implemented to prevent erosion and construction-related materials, sediment, wastes and spilis from entering
stormwater conveyances and receMng waters .
Note: It is the responsibility of the property owner and the contractor to determin~ the types of BMPs that
will be used, as well as the levels of application necessary to comply with the CountY's Stormwater and
Grading Ordinances. Failure to prevent soil erosion and, discharges of sediment arid other pollutants from
construction sites is subject to enforcement by the County or others. At a minimum, the County requires
that the BMPs listed in Table A (attached) be installed and maintained for all grading prqjects. Additional
BMPs listed in Table B (attached) may also be required in correlation to a project's scope, potential for
discharges and proximity to a watercourse or other receiving waters.
Section 3: Certification -The property owner must sign this section certifying that they understand the County's
minimum requirements for stormwater management of construction actMties and will implement, monitor and
maintain the selected BMPs to ensure their effectiveness.
-.
A County BMP manual can be found at the DPW and DPl.U Permit Counters. The Manual includes all of the
referenced BMPs listed in Tables A and B and from the Caltrans Storm Water Quality HandbOoks and CalifQfnia
Stormwater BMP Handbook for Construction. The entire manuals may also be ordered directly from the following
sources:
Caltrans Manuals
Caltrans Publications unit
(916)445-3520
(916)324-8997 Fax
F-1
County of San Diego
STORMW A1ER MANAGEMENT PLAN
This fonn must be submitted with all Grading Pennit Applications .
. SECTION 1. Required Infonnation
Grading Pennit Application Number: Project Name:
Name of Project Contact Person: Project address or location:
Title: Phone#:
Grading start date: Grading finish date: Project start date:
Estimated amoun~ of disturbed acreage: acres (If equal to or greater than 5 acres, you must
also provide a WDID number from the SWRCB.) WDID
Are there any watercourses or waterbodies within 50 feet of the limits of soil disturbance? YES __ NO_
ATTACHMENT F.:.1
(Continued)
APN#:
Project fmishdate:
Does the soil type have high erosion potential (fme grain soi1like sand, silt, fme disintegrated granite)? YES __ NO __ .
Does the ect site have or than 25 feet or than 1: 1 ? NO
Best Management Practices
The goal of stonnwater management planning is to reduce pollution to the maximum extent practicable by implementing Best Management
Practices (BMPs). There are five categories ofBMPs: 1) Erosion control practices, and; 2) Velocity reduction, and; 3) Sediment control
practices, and; 4) Offsite sediment tracking control, and; 5) General site and materials management. B:MPs from each of the five categories
•
must be used toge~er as a syst~ in. order to prev~ erosi?n, sediment, wastes, spil~s, and: residu:s from leaving t.?e site: ~en ~toperly
'olemented, momtored and mamtamed, BMPs Will function to prevent pollutants (mcludmg sedtment) from leavmg the site. It IS the
,ponsibility of the property owner and the contractor to detennine the types ofBMPs that will be used, as· well as the levels of application
necessary to comply with the County's Stonnwater and Grading Ordinances.
Best Management Practice Tables Tables A and B (attached) must be used to indicate those BMPs that will be used to prevent stormwater
pollution. .At a minimum, the County requires that the BMPs listed in Table A be installed on an grading projects.
However, some BMPs may not be applicable to every project For example, if stonn drain inlets are not present, then Stonn Drain Inlet
Protection (BMP SCI 0) would not be applicable.
Grading Plan Best Management Practice Checklist
The following information shall be shown on the grading plans:
1:1 The project boundaries.
1:1 The footprint of any existing structures and facilities.
1:1 The footprint of all structures and facilities to be constructed.
1:1 The limits of grading.
1:1 The existing and proposed grades of the site, along with any intermediate grades that will significantly aff~t site drainage patterns.
1:1 The location(s) where runoff from the site may enter stonn drain(s), channel(s), and/or receiving waters.
The following certification must be signed before a Grading Permit will be issued
I have read and understand that the County of San Diego has adopted minimum requirements for stonnwater management of construction
activities. I certifY that the BMPs I have selected in Tables A and B will be implemented to effectively minimize the potentially negative
impacts of this project's construction activities on stonnwater quality. I further agree to install, monitor, maintain orrevisethe selected
BMPs to ensure their effectiveness. .
I also understand that non-compliance with the County's Stonnwater and Grading Ordinarices may result in enforcement by the County,
including fmes, citations, stop-work orders, cease and desist orders or other actions . • A loperty owner Date
2 F-2
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2 TABLE A
3 MINISTERIAL and MINOR PERMIT REQUIRED CONSTRUCTION BMPs
Minimum Required
Best Ma·nagement Practices
(BMPs)
CALTRANS
Stormwater
Handbook
Detail
Each selected aMPs
.J must be shown on
BMP Grading .Plan.
Selected If No HM P is
selected! explain Why'
Step 1 Select Erosion Control method for graded Slopes (choose at least (me)
Vege~ation Stabilization SS-2 SS-4
J:l~~l!~JlJ~~~_~_~t~_!l__________________________ ______________ _ __________ _
Hydraulic Stabilization SS-3 SS-4
Hydroseeding (see note 1)
-Bo-nae-d-FTber-~i1rTx-7sE;e-no1E;:2J----------------S:s:4------------------Phy-slcai-Sti-60TzatTon----------------------------------------------------
............ §E9..~.i .. ~.!1 .. ggD.~.~~.!...~!.~~.~.~!f~.~~ ... ~9..~~ ... ?L .................... ~.~.~.~ ................................................................ , .................................................. .
Step 2 Select Erosion Control method for graded Flat Areas (slope < 5%) (choose at least one)
·~~·i·~~r~~::~i:i···s·i·~·~~···c·~~i~~i···~·~~·~·~~·~·~ .. ~.~ ... ~ ... ~.~.~.;~.~.:.~:; .... ~ ........................................................................................................... .
-rvfurch~-sfraw,-wo-oa-chTp-s~-sorri-ppTicatron----ss:irss:s--------------
.~I5~=~~~.~~~~~~~I~~~¥~~~~~~C~~~~~~!i:~~r~=~~~~=~=~ .~===~~~?~~=-=~ ... ~=~===~~~~~~ ................................................................... : .
Step 3 If runoff is concentrated, velocity must be controlled using energy dissipater
.::~~t~~~~~~~~ ;:~t.;;..~~;.~~:::~;.:~;::;~::::::.::::::.::::.:.:: .. :.::::::·::::::[:::::::i.~~·~.·.~.·.·.·.·.··.:· .. I.·.·.::~ ............ :: ....... : ............. J.:.:~ .. :: ........... :: .. .-....... : .............. : . .-....... : ....... ~ ...... ::: ........ : ... : ...... :::::: ...................... :
Step 4 Select Sediment Control method for all disturbed areas .(chooSe at least one) .. sl·it··.·Fe·n·ce ...... ····· .... · .... · ........ · ........ ··· .. · ........ · .. · .. · ...................................... · .. ·· .... sc:·;f .... · .................................................................................................................. ..
-Straw-VVattles--------------------------------------s-c:s-----r------------
-(§ri-vei-siajgs------------------------------------r--sc::6-~:S--------------
-Storrn-Or-iinl-nlef-Prote-ctlCin---------------------sc:~fo----------------
----------~-----------------------------------------------------------------De-silting Basin (sized for 1 O-year flow) SC-2
Step 5 Select method for preventing offsite tracking of sediment (choose at least one)
Stabilized Construction Entrance TC-1 ----------------------------------------------------------------------------Construction Road Stabilization TC-2 -Entri-nce'-ExTflFire-VVas-h--------------------------T-C:3-----------------
-Entri-~ce'~xTfinispe<:fiCin-&-~lea~n-g-----------------------------------
.. E..~;<?!.!.i.!~................... ........................................ .................. ....... .. .. ......... ........ ...... . . ........... ......... .. .................................................................................... " ......... , .... ..
Step 6 select the General Site Management BMPs for each waste that wm be on site
·~:}::::;is~~·~~~~·e~m;t~~:~·:························ ........................ ·······W·M~·1··········· ................................................... : ....................................................... .
-VVas1E;-ftR-an~ge-nn-en1----------------------------------------- --------------------------------------------
Concrete Waste Management WM-8 .
-soira-VV81sfe-~-an~ge-mE!nt--------------~----------~Nf:5----r----------------------~--------------------
-si-nfi~ry-VVas1e--~~na-gerne-nf---------------------vvNf:g----r--------------------------~---------------------------------------------------------------------------------r----------------------------------------~---Hazardous Waste Management WM-6 . . . .
G-1
5
6
7
.~
11
12
13
14
15
16
17
18
Notes
1. When Planting or Hydroseeding are selected for erosion control, the vegetative
cover must be planted by August 15th and established by October 1~t. If in the
opinion of the County Official the vegetative cover is not established by October
1st, additional hydraulic or physical erosion control BMPs will be required.
2. These BMPs are temporary measures only when used without planting or
hydroseeding. All slopes must have established vegetative. cover prior to final
grading approval.
3. Regional Standard Drawing 0-40 -Rip Rap Energy Dissipater is also acceptable for
velocity reduction.
4. Not all grading projects will have every waste identified. The applicant is responsible for identifying
wastes that will be on-site and applying the appropriate BMP. For example, if concrete will be used,
BMP WM-8 should be selected.
19 Table B ADDITIONAL BMPs available for use In conjunction with minimum BMPs
•
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... 1
Erosion Control CALTRANS
Stormwater
: HandbQok
Detail
Site Development Considerations Scheduling SS-1 ======~!=~s~=!~f[~~=~f=~~l~![~i=}C~i~!!![~~====================================== . SS-2 Other (submit description for approval)
---iVege-tiiion-Sia111iia1ioii---------------------------------------------~-----SS-2 Vegetation Buffer Strips
---1?hyslcal-s1~bffizilii()n------------------------------------------------------WE-l Dust Control ------S-oU-Stab11Tzers-----------------------------------------------------------SS-5
Diversion of Runoff
Earthen Dikes SS-9 ---------------------------------------------------------------------------------Ditches and Berms SS-:9 ------Sioj)ei5rafns--------------------------------------------------------------SS-l1
------T-eDiIP~rary-j)-iaii1s-~-svvales----------------------------------------------SS-9
Velocity Reduction
I SS-4 ------~~:i~-J?e~~~fng-------------------------------------------------------~--~I. -
Sediment Control
Brush or Rock Filter -------s-e-JfDi-e-nt1rrap------------------------------------------------------------SC-3 ------S-e-diDi-e-ntl3asifi-----------------------------------------------------------SC~2
General Site Management ______ ~~j_~~~~_~_~~~:_~~~~~£~£~_~~~i~i~~ ______________________________________ -Materials Management WM-4 ______ ~2Jl!_~!~~_~0~_~_~_~~~!~~1 _______________________________________________
Waste Management WM-7 Contaminated Soil Management
---17eilicle-aiid-E-qufpiDeiit~ilnaiieDlent-------------------------------~------NS-8 ______ ~~~i£!:_~_~9~lp~~E.!_~_~e_~~~~~ ___________________________________________
Vehicle & Equipment Fueling N~~9
------"ehTcre-~Efqu1prnen1-~ainten-a-nce---------------------------------------NS-I0 ---c:on-itructioili>ractfces------------------------------~----------------------NS-l Water Conservation
-~----Structu-ie~onstruct1oi1~-PafntTng----------------------------~------------------pjlvfng-6-peratfons--------------------------------------------------------NS-3
------j)e~ater1i1g-6p-eiatio-ns---------------------------------------------------NS-2
Alternatives stormwater protection measures may also be presented for County conslder~tlon
in any category .
G-2
22 ATTACHJYfENT G-1
23 Table 1-Pollutants from the Project Area • I 1 General Pollutant Categories I
I
Priority Trash Oxygen Bacteria.
Project Heavy Organic & Demanding Oil & &
Categories Sediments Nutrients Metals Compounds Debris Substances Grease Viruses Pesticide,s
Detached
Residential X X X X X X x.
Development
Attached
Residential X X X p(l) p(2) P X
Development
Commercial
Development p(l) p(1) p(2) X p(5) X peS) p(5)
>100,000 if
Automotive
Repair X X(4)(5) X X
Shops
Restaurants X X X X
Hillside
Development X X X X ·X X
>5,000 fl:2
Parking Lots p(l) p(l) X X p(l) X p(l)
Streets,
Highways & • X p(l) X X(4) X p(5) X
Freeways
Retail Gas X X(4) X X Outlets
X = anticipated
p = potential
(1) A potential pollutant if landscaping exists on-site.
(2) A potential pollutant if the project includes uncovered parking areas.
(3) A potential pollutant if land use involves food or animal waste products.
(4) Including petroleum hydrocarbons.
(5) Including solvents.
24
•
G-3
24 ATTACHMENT G-2
25 Table 2-Standard Storm Water BMP Selection Matrix
Site Source Treatment • Design Control Control Requirements ApplicabJeto Individual Project
Project Category BMP"$1} BMPs(2} BMPi3} categorlei4}
II)
IU
II) Cl ~ Cl ' m « c c 'a. > .. 'm .c IU « II) ~ .0
1ii e II) II) II)
IU IU "0 II) ~ ..... ~ 11.1 C IU a. c ~ .. !) ~ 11.1 « « .. ~ « 11.1 0 E Cl Cl 11.1 (j o II) ,9-c c' "0 ~ :E "OIU :s2 "0 ''iji Jg 0 ..... 11.1 :::J .. IU 0 11.1 :::J .. C" !IS 0 :::J C > 0« w a. 0::: u. ~
ni .0 d '"0 ID ~ Cl r.
Detached
Residential R R S R
Development
Attached
Residential R R S
Development
Commercial
Development R R S R R R "
>100,000 ff
Automotive R R S R R R R Repair Shop
Restaurants R R S R R • Hillside
Development R R S R
>5,oooff
Parking Lots R R S R
streets, Highways R R S R & Freeways
Retail Gas R R S R R R Outlets
26
27 R = Required
28 S = Select one or more applicable and appropriate treatment control BMPsif needed to meet MEP and
29 performance standards,
30
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G-4
30 ATTACHJv.IENT G-2
31 Table 2-Standard Storm Water B:MP Selection Matrix (cuuiil,l~"d)
Site ~"""''''''''' / I' .... ~-...... ,_ .. _fit
Design Control Control
.'oject ,.. BMPs(1} BMPi2} BMPs(3} t::l"",r" .lI ,I!-.... t -I:·ridua/,...· ,.. 'Y ... o 111 ..... '(, ,~J ......
!!!. la
~ Ul C) ~ C)
~ RI c: « c: Q) 'a' ~C) ... 'iii .c: « Ul RI ';: ,S OJ Q) ~ 0 Ul ii Ul Ul Ul "C O-l!: Q) e RI m "C RI -RI Ul 0 ~ .... Q) c: ~ ,!!! 0-RI c: 0-... Ul RI Q) RI c: « ;;.. « .... Q) ...J as1iS ... as .... en .~ CD « Q) ~m E C) Q)
j "CQ) -(3 ,9-c: .S "C ,-::J ~ c: :E :g "C a; ~ me!) 0 'n; -Q) ::J RI ';: a Q) ::J ... C' RI a ::J 0-C:::~ 0 :E > 0< w 0-c::: u. :c
,-...... ~ -E c: 0 c.. C' s..: iii
Detached
Residential R R S R R R
Dl. '';:~I''IIICm
Attached
Residential R R S R nt!', ~fllt:m
Commercial
Deveiopment R R S R R R R
>100,000 if
Automotive R R S R R R R R Repair Shop
Restaurants R R S R R
Hillside
Development R R S R R
>5,000 if
Parking Lots R R S R ..... ..:;;Ill CCL::',
R R S R Highways & ... : '--"-""J-
Retail Gas R R S R R R Outlets
~ ~ ~:I~~[~~~ or more applicable and appropriate treatment control BMPs if needed to meet MEP and performance
standards.
32
33
•
G-5
•
33 ATTACHMENT G-3
34 Enhanced Treatment Control BMP Selection Matrix
Pollutant of
Concern
L
L
on
Basins
H
M
perlOCllcall~ assess
(2) Including trenches and porous pavement.
Treatment Control BMP Categories
on
Basins(2)
U
U
M
U L
U M
M L
(3) Also known as hydrodynamic devices and baffle boxes.
L (Low): Low removal efficiency
M (Medium): Medium removal efficiency
H (High): High removal efficiency
U: Unknown removal efficiency, applicant must provide evidence supporting use
M L
H M
M L
Sources: Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters (1993),
National Stormwater Best Management Practices Database (2001), and Guide for BMP Selection in Urban Developed
Areas
G-6
•
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Management Guidelines
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1.0 PURPOSE:
Page 1 of3
Affecting Lives in San Diego County Daily
Stormwater
MANAGEMENT GUIDELINES
To provide guidelines for preparation of a Stormwater Management Plan (SWMP)
associated with discretionary project.
2.0 BACKG ROUND:
In order to have effective permanent BMPs, a StormwaterManagement Plan (has to be
developed. This plan will serve as the basis for a long-term solution to water quality
improvements. Early consideration and planning of permanent BMPs ensures that wat~r
quality will be addressed for many years to come. The County Watershed Protection,
Storm Water Management, and Discharge Control Ordinance and the Stormwater
Standards Manual requires the dLong-term protection and improvement of stbrmwater
quality relies in part on permanent post-construction BMPs. eveloptnent and submittal of a
SWMP as part of Project Application. Structural BMPs are difficult to add to the completed
design of a private development project without causing substantial changes to the
project's character or viability. The earlier in the design process storll'l'lVaterfacilities are
considered, the greater the chance a successful and efficient design can be
accomplished.
The SWMP provides the needed information to address both stormwater and non-
stormwater issues. The purpose of the SWMP is to provide all the information needed to
fully and adequately characterize the existing water quality, analyze the drainage, develop
http://www.co.san-diego.ca.us/dpw/stormwater/guidelines.htm 6121/02
•
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•. : ..
Management Guidelines Page 2 of3
effective post-construction stormwater protection, and ensure the ~ffectiveness of the
BMPs through proper maintenance and long-term fiscal responsibility. Information from
the SWMP shall be used in formulating department CEQA responses and proposed
conditions for the project. In addition, the SWMP is a living document and could require
changes if a Stormwater Impact Analysis is needed.
3.0 POLICY:
The County shall require a SWMP at time of initial application which contains all the
minimum project components as identified is section 4.0 of this guideline. The SWMP
shall be prepared by the project proponents and comply with both the County Watershed
Protection, Storm Water Management, and Discharge Control Ordinance and the
Stormwater Standards Manual. .
County staff in the departments of Public Works and Planning & Land Use shall reviewthe
SWMP as part qf the overall project application and for compliance with both the County
Watershed Protection, Storm Water Management, and Dischar.ge Control Ordinance and
the Stormwater Standards Manual. Information from the SWMP shall be used in
formulating CEQA responses and findings, findings of project code compliance, and in
proposing conditions for the project.
4.0 GUIDELINE
4.1 Specific I nformation included in Stormwater Management Plan
SWMP shall include all of the following:
Project Location, Description, and Physical Features
Surrounding Land Use and proposed project land use
Watershed Contribution and potential impacts to State Impaired Waterbodi~s
"303(d) list" which are downstream of proposed project
Beneficial Uses of Surface Waters and Ground Water surrounding the project
Characterization of project runoff both pre-project and post-project, Conditions
of Concern, locations of Storm Water Outfall(s), Tributary Drainage Area to
Outfall (s), changes in downstream erosion potential, and Site Hydrology
Water Quality Pollutants of Concern, Treatment Volume Based on Water
Quality Design Storm, Site Plans and Adjacent Land Use, and Soil
Characteristics. ..
Mitigation Measures to protect water quality, Pollution Prevention SMPs (MEP
Based), Site Design BMPs, Source Control BMPs, Natural BMPs, and
Structural Treatment BMPs .
Mitigation Measures to prevent increases in downstream erosion to MEP, Site
http://www.co.san-mego.ca.us/dpw/stormwater/guidelines.htrn 6/21102
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Management Guidelines Page 3 of3
Design BMPs, Source Control BMPs, Natural BMPs, and Structural Treatment
SMPs,
Any infiltration BMPs proposed for use on project
Agreements, easements, licenses relating to proposed BMP construction,
location, maintenance, or changes in drainage character.
Project Map with Watersheds and Surface Water Bodies Within project Area
Infonnation relating to threat to water quality including (1) soil erosion potential; (2)
site slope; (3) project size and type; (4) sensitivity of receiving water bodies; (5)
proximity to receiving water bodies; and (6)non-stonn water discharges.
A recommended format and guidelines is included as Attachment A. Above items may be
shown on other application documents such as the tentative map, preliminary grading
plan, or preliminary drainage study. If this is done, the Svvrv1P document must identify
where each of these component pieces can be found.
REFERENCE
1) Subdivision Ordinance sectionOrdinance section 81.303 IIGrading Planll and
section 81.605 IIGrading Planll
-
2) County Watershed Protection, Storm Water Management, and Discharge
Control Ordinance
3) Stormwater Standards Manual
SUNSET
EFFECTIVE DATE: February 21, 2002
Page Updated 03/14/02
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[Maintenance Plan] [ Grading Plan Guidelines] [Hydrology-Drainage Study] [:jinpW!t Assessment]
. [ Conditions of Approval] [Findings]
County Home Page Customer Feedback LUEG Hom~ Page
http://www.co.san-diego.ca.us/dpw/stormwater/guidelines.htrn 6121102
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Maintenance Plan
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Stormwater
MAINTENANCE PLAN
Permit No.
One sentence regarding project description. Roadway project, use limits
Prepared By
Prepares Name
For
Proj ect Name
Date (MMfDDIYYYY)
TABLE OF CONTENTS
1. DESCRIPTION OF PROPOSED PROJECT
1.1. Project Location
http://www.co.san-diego.ca.us/dpw/stormwater/plan.htm
Page 1 of3
61211Q2"
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Maintenance Plan
1.2. Project Description
1.3. Project Stormwater Management Plan
1.3.1. Maintenance Responsibility
2. APPLICABLE ORJ)INANCES, REQUIREMENTS
2.1. County Ordinances .
2.2. Other Permit Maintenance Requirements
3. POST CONSTRUCTION BMPs
3.1. Pollution Prevention BMPs (MEP Based)
3.2. Treatment BMPs
4. MAINTENANCE SToRMW ATER MANAGEMENT PROGRAM
4.1. Post Construction BMP
4.1.1. Design Criteria, Routine Action
4.1.2. Maintenance Indicators
4.1.3. Field Measurement
4.1.4. Measurement Frequency
4.1.5. Maintenance Activity
4.1.6. Site-SpecHic Requirements
4.2. (Repeat 4.1 for each BMP)
5. DISPOSAL OF STORMW ATER SEDIMENT
5.1. Monitoring
6. PROGRAM EVALUATION
7. REFERENCES
LIST OF FIGURES
A. Project Map
B. Watersheds and Surface Water Bodies Within project Area
http://www.co.san-diego.ca.us/dpw/stonnwater/plan.htrn
Page 2 of3
6121/02
Maintenance Plan . Page 3 of3
LIST OF TABLES
• Maintenance Indicator Thresholds
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APPENDIX
Appendix A -Maintenance Activities Checklist
Appendix B -Associated Maintenance BMPs (ICIID, Vehicle Maintenance, etc.)
Page Updated 02126/02
[Up] [FLow Chart] [Management Guidelines] [Management Plan] [Mamtenance Guidelines]
[Maintenance Plan] [Grading Plan Guidelines] [Hydrology-Drainage Study] [Impact Assessment]
[ Conditions of Approval] [Findings]
County Home Page Customer Feedback LUEG Home Page
http://www.co.san-diego.ca.us/dpw/storrnwater/plan.h1m 6/21102
•
MODEL STANDARD URBAN STORM WATER MITIGATION PLAN
FOR SAN DIEGO COUNTY, PORT OF SAN DIEGO,
AND CITIES IN SAN DIEGO COUNTY
• FINAL MODEL SUSMP
Jointly Developed by
San Diego Co-Pemlittees 217/02
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TABLE OF CONTENTS
I. BACKGROUND ......................................................................... 3
II. SUMMARy ............................................................................... 3
III. DEFINITIONS ............................................................................ 4
IV. CONFLICTS WITH LOCAL PRACTICES OR MUNICIPAL PERMIT ..... 8
V. IMPLEMENTATION PROCESS .................................................... 8
VI. STORM WATER BMP SELECTION PROCEDURE. .......................... 9
1. Identify .Poll uta nts & Conditions of Concern .............................. 12
a. Identify Pollutants from-the Project Area ................. ~ .......... 14
b. Identify Pollutants of Concern in Receivihg Waters ........•...... 15
c. Identify Conditions of Concern ......................................... !
15
2. Establish Storm Water BMPs ..................................... , ........... 16
a. Site Design BMPs ............................ ! ••••••••••••••••••••••••••••• 19
b. Source Control BMPs .................................................... 22
-c. Treatment Control BMPs ................................................. 26
3. Provide Proof of Ongoing BMP Maintenance ........................... 30
4. Waiver Of Structural Treatment Bmp Requirements .................. 32
VII. RESOURCES & REFERENCES ................................................... 34
Appendix A: Example Best Management Practices ...................... 34
Appendix B: Suggested Resources ........................................... 37
List of Figures
Figure 1: Storm Water BMP Selection Procedure ............................ 11
List of Tables
Table 1: Anticipated and Potential Pollutants Generated
by Land Use Type ............................................... .
14
Table 2: Standard Storm Water BMP Selection Matrix ........... , .......... 18
Table 3: Enhanced Storm Water BMP Selection Matrix ..................... 19
FINAL MODEL SUSMP
Jointly Developed by
Page 20f39
San Diego Co-Pcmlittccs 217102
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MODEL STANDARD URBAN STORM WATER MITIGATION PLAN
The municipal storm water National Pollutant Discharge Elimination System (NPDES)
permit (Order No. 2001-01, NPDES No. CAS0108758, hereinafter referred to as
"Municipal Permit") issued to San Diego County, the Port of San Diego, and 18 cities'
(Copermittees) by the San Diego Regional Water Quality Control Board (Regional
Board) on February 21, 2001, requires the development and illlplementation of a
program addressing urban runoff pollution issues in development planning for public
and private projects.
The requirement to implement a program for development planning is based on federal
and state statutes including: Section 402 (p) of the Clean Water Act, Section 6217 of
the Coastal Zone Act Reauthorization Amendments of 1990 ("CZARA"), and the
California Water Code. The Clean Water Act amendments of 1987 established a
framework for regulating urban runoff discharges from municipal, industrial, and
construction activities under the NPDES program. The Municipal Permit requires,the
implementation of a Jurisdictional Urban Runoff Management Program (URMP). The
primary ,objectives of the Jurisdictional URMP requirements are to:
1. Ensure that discharges from municipal urban runoff conveyance systems do n9t
cause or contribute to a violation of water quality standards;
2. Effectively prohibit non-storm water discharges in urban runoff; and
3. Reduce the discharge of pollutants from urban runoff conveyance systems to the
Maximum Extent Practicable (MEP statutory standard).
The Model Standard Urban Storm Water Mitigation Plan (SUSMP) was developed
collectively by the Copermittees to address post~constructioi1 urban runoff pollution
from new development and redevelopment projects that fall under "priority project"
categories. The goal of the Model SUSMP is to develop and implement practicable
policies to ensure to the maximum extent practicable that development does not
increase pollutant loads from a project site and considers urban runoff flow rates ~nd .
velocities. This goal may be achieved through site-specific controls and/or drainage
FINAL MODEL SUSMP
Jointly Developed ,by
San Diego Co-Permittees 2i7i02
Page 30f39
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area-based or shared structural treatment controls. This Model SUSMP, collectively
developed by the Copermittees, identified appropriate Best Management Practices
(BMPs) for certain designated project types to achieve this goal. This Model SUSMP
will be reviewed and approved by the Regional Board in a public process. The
Copermittees are required to adopt their own Local SUSMP and ordinances consistent
with the Regional Board-approved Model SUSMP within 180 days afierthat approval.
Under the Local SUSMP, each Copermittee will approve the SUSMP project plan(S)' as
part of the development plan approval process for discretionary projects, and .priorto
issuing permits for ministerial projects. To allow flexibility in meeting SUSMP design
standards, structural treatment control BMPs may be located on-or ,off-Site, used singly
or in combination, or shared by multiple developments, provided certain conditions are
m~. -
All new development and significant redevelopment projects that fall into one of the
following "priority projecf' categories are subject to these SUSMP requirements, subject
to the lawful prior approval provisions of the Municipal Permit. In the instance where a
project feature, such as a parking lot, falls into a priority project category, the entire
project footprint is subject to these SUSMP requirements. These categories are:
-Residential development of 100 units or more
-Residential development of 10 to 99 units
-Commercial development greater than 100,000 square feet
-Automotive repair shops
Restaurants
-Hillside development greater than 5,000 square feet
-Projects discharging to receiving waters within Environmentally Sensitive
Areas
-Parking Lots> 5,000 square feet or with> 15 parking spaces and potentially
exposed to urban runoff '
-Streets, roads, highways, and freeways which would create a new paved
surface that is 5,000 square feet or greater.
Limited Exclusion: Trenching and resurfacing work associated with utility projects are
not considered priority projects. Parking lots, buildings and other structures associated
with utility projects are subject to SUSMP requirements if one or more of the criteria for
the a bove categories are met.
"Attached Residential Development" means any development that provides 10 or more
residential units that share an interior/exterior wall. This category includes, but is not
limited to: dormitories, condominiums and apartments .
FINAL MODEL SUSMP
Jointly Developed by
San Diego Co-Pennittees 2i7i02
Page 4of39
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"Automotive Repair Shop" means a facility that is categorized in anyone of the
following Standard Industrial Classification (SI.G) codes: 5013, 5014, 5541, 7532-7534,
or 7536-7539.
"Commercial Development" means any development on private land that is not
exclusively heavy industrial or residential uses. The category includes, but is not limited
to: mini-malls and other business complexes, shopping malls, hotels, office buildings,
public wareh9uses, hospitals, laboratories and other medical facilities, educational
institutions, recreational facilities, plant nurseries, car wash facilities, and other light
industrial complexes.
"Commercial Development greater than 100,000 square feet" means any commercial.
development that with a project footprint of at least 100,000 square feet.
"Detached Residential Developmenf' means any development that provides 10 or mote
freestanding residential units. This category includes, but is not limited to: ·detached
homes, such as single-family homes and detached condominiums.
"Directly Connected Impervious Area (DCIA)" means the area cqvered by a building,
impermeable pavement, and/ or other impervious surfaces, whi.ch drains directly into
the storm drain without first flowing across permeable vegetated land area (e.g., lawns) .
"Environmentally Sensitive Areas" means areas that include, blrtare not limited to, all
Clean Water Act 303(d) impaired water bodies ("303[d] water bodies"); areas
deSignated as an "Area of Special Biological Significance" (ASBS) by the State Water
Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994)
and amendments); water bodies deSignated as having a RARE beneficia! use by the
State Water Resources Control Board (Water Quality Control Plan for the San Diego
Basin (1994) and amendments), or areas deSignated as preser-ves or their equivalent
under the Multiple Species Conservation Program (MSCP) within the Cities and County
of San Diego. The limits of Areas of Special Biological Significance are those defined
in the Water Quality Control Plan for the San Diego Basin (1994 and amendments).
Environmentally sensitive area is defined for the purposes of implementing SUSMP
requirements, and does not replace or supplement other environmental resource-based
terms, such as "Environmentally Sensitive Lands," employed by Copermittees in their
land development review processes. As appropriate, Copermittees should distinguish
between environmentally sensitive area and other similar terms in their Local SUSMPs.
"Hillside" means lands that have a natural gradient of 25 percent (4 feet of horiZontal
distance for every 1 foot of vertical distance) or greater and a minimum elevation
differential of 50 feet, or a natural gradient of 200 percent (1 foot of horizontal distance
for every 2 feet of vertical distance) or greater and a minimum elevation ·differential of
10 feet.
"Hillside development greater than 5,000 square feet" means any development that
. FINAL MODEL SUSMP
Jointly Developed by
San Diego Co-Pemlittees 2i7!()2
Page 50f39
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would create more than 5,000 square feet of impervious surfaces in hillsides with
known erosive soil conditions.
"I nfiltration" means the downward entry of water into the surface of the soil.
"Maximum Extent Practicable (MEP)" means the technology-based standarc:;l
established by Congress in the Clean Water Act 402(p)(3)(B)(iii) that municipal
dischargers of urban runoff must meet. MEP generally emphasizes pollution
prevention and source control BMPs primarily (as the first line of defense) in
combination with treatment methods serving as a backup (aOditionallines of defense).
"New Developmenf' means land disturbing activities; structural development, including
construction or installation of a building or structure, the creation of impervious
surfaces; and land subdivision.
"Parking Lot" means land area or facility for the temporary parking or storage of motor
vehicles used personally, or for business or commerce.
"Projects Discharging to Receiving Waters within Environmentally Sensitive Areas" .
means all development and significant redevelopment that would create 2,.500 square
feet of impervious surfaces or increase the area of imperviousness of a project site to
10% or more of its naturally occurring condition, and either discharge urban runoff to,a
receiving water within an environmentally sensitive area (wher~ any portion of the
project footprint is located within 200 feet of the environmentally sens~ive area), or
discharge to a receiving water within an environmentally sensitive area witl'lout mixing
with flows from adjacent lands (where the project footprint is located more than 200 feet·
from the environmentally sensitive area). .
"Project Footprint" means the limits of all grading and ground disturbance, including
landscaping, associated with a project.
"Receiving Waters" means surface bodies of water, which directly or indirectly receive
discharges from urban runoff conveyance systems, including naturally occurring
wetlands, creeks, rivers, reservoirs, lakes, lagoons, estuari'es, harbors, bays and the
Pacific Ocean. The Copermittee shall determine the definition for wetlands and the
limits thereof for the purposes of this definition. Constructed wetlands are not
considered wetlands under this definition.
"Residential Development" means any development on private land that provides living
accommodations for one or more persons. This category includes, but is not limited to:
single-family homes, multi-family homes, condominiums, and apartments.
"Restauranf' means a stand-alone facility that sells prepared foods and drinks for
consumption, including stationary lunch counters and refreshment stands selling
prepared foods and drinks for immediate consumption (SIC code 5812) .
FINAL MODEL SUSMP
Jointly Developed by
San Diego Co-Pemtittees 2f7i02
Page 6of39
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"Significant Redevelopment" means development that would create or add at least
5,000 square feet of impervious surfaces on an already developed site~ Significant
redevelopment includes, but is not limited to: the expansion of a building footprint;
addition to or replacement of a structure; replacement of an impervious surface that is
not part of a routine maintenance activity; and land disturbing activities related with
structural or impervious surfaces. Replacement of impervious surfaces includes any
activity that is not part of a routine maintenance activity where impervious material(s) .
are removed, exposing underlying soil during construction. Significant redevelopment .
does not include trenching and resurfacing associated with utility work; resu~acing and
reconfiguring surface parking lots; new sidewalk construction, pedestrian ramps, or
bikelane on existing roads; and replacement of damaged pavement. '-
"Site Design BMP" means any project deSign feature that reduces the creation or
severity of potential pollutant sources or reduces the alteration of the project Site's
natural flow regime. Redevelopment projects that are undertaken to remove pollutant
sources (such as existing surface parking lots and other impervious surfaces) or to
reduce the need for new roads and other impervious surfaces (ascompared to-
conventional or low-density new development) by incorporating higher densities and/or
mixed land uses into the project design, are also considered site.design BMPs.
"Source Control BMP (both structural and non-structural)" means land use or site
planning practices, or structures that aim to prevent urban runoff pollutio:n by reducing
the potential for contamination at the source of pollution. Source control BMPs
minimize the contact between pollutants and urban runoff. Examples include roof
structures over trash or material storage areas, and berms around fuel dispensing
areas.
"Storm Water Best Management Practice (BMP)" means any schedL;Jles' of activities,
prohibitions of practices, general good house keeping practices, pollution prevention
and educational practices, maintenance procedures, structural treatment BMPs, and
other management practices to prevent or reduce to the maximum extent practicable
the discharge of pollutants directly or indirectly to receiving waters. Storm Water BMPs
also include treatment requirements, operating procedures and practices to control site
runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material
storage. This SUSMP groups storm water BMPs into the following categories: site
design, source control, and treatment control (pollutant removal) BMPs ..
"Storm Water Conveyance System" means private and public drainage facilities by
which storm water may be conveyed to Receiving Waters, such as: natural drainages,
roads, streets, constructed channels, aqueducts, storm drains, pipes, street gutters, or
catch basins.
"Streets, Roads, Highways, and Freeways" means any project that is not part of a
routine maintenance activity, and would create a new paved surface that is 5,000
FINAL MODEL SUSMP
Jointly Developed by
Sun Diego Co-Pemlittees 217!02
Page 7of39
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square feet or greater used for the transportation of automobiles, trucKs, motorcycles
and other vehicles. For the purposes of SUSMP requirements, Streets, Roads,
Highways and Freeways do not include trenching and resurfacing associated with utility
work; applying asphalt overlay to existing pavement; new sidewalk, pedestrian ramps,
or bikelane construction on existing roads; and replacement of damaged pavement.
"Treatment Control (Structural) BMP" means any engineered system designed' and
constructed to remove pollutants from urban runoff. Pollutant removal is achieved by
simple gravity settling of particulate pollutants, filtration, biological uptake, media
adsorption or any other physical, biological, or chemical process.
Where requirements of the local SUSMP conflict with established local codes, (e.g.,
specific language of signage used on storm drain stenciling), the Co permittee may
continue the local practice and modify the SUSMP to be consistent with the code,.
except that to the extent that the standards in the SUSMP are more string~ntthan
those under local codes, such more stringent standards shall apply .
This model SUSMP is based on the Municipal Permit as it was in force in January
2002, except as that Municipal Permit was directed to be revised -by the State Water:
Resources Control Board. In January 2002 the Municipal Permit was being-challenged
in a court action. Two Copermittees are Petitioners in that action, and all other
Copermittees have been named as Real Parties in Interest in that action. The
submission of this Model SUSMP and of jurisdictional SUSMPs.is not a waiver by any
Copermittee of its legal rights related to that action. If as a result of that court action
any part ofthe Municipal Permit is invalidated, stayed, or required to be revised'.bya
final judgment, Jurisdictional SUSMPs and local ordinances may be appropriately
amended despite the submission of this document.
Copermittees shall identify the department(s) responsible for ensuring SUSMP
requirements are implemented in their Local SUSMP, and the roles and responsibilities
each department possesses. In addition, Copermittees shall describe the point{s) in
the development review process in which project proponents are required to
incorporate SUSMP requirements into the project design. At a minimum, for
discretionary projects, SUSMP requirements shall b~ incorporated into the project
design and shown on the plans prior to decision-maker app.roval of discretibnary
permits. For projects requiring only ministerial permits, SUSMP requirements shall: be
incorporated into the project design and shown on the plans prior to the iS$uance of
FINAL MODEL SUSMP
Jointly Developed by
San Diego Co-Pemlittees 2f7102
Page 8of39
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any ministerial permits. Co permittee departments carrying out public projects that are
not required to obtain permits shall be responsible for ensuring SUSMP requirements
are incorporated into the project design and shown on the plans prior to bidding for
construction contracts, or equivalent. For public projects SUSMP requirements must be
incorporated into the project design and shown on the plans before allowing. the project
to commence.
Ili~"IIIIIIIII~i~~~II~~~~II~~~I~~~~~OOI~~II~~~~OO~~~~1I11111IIIIIIIIIIIIIIt:::~~~~~m1111111111l111l11111111l11l11111l11"1111111111·
Section VI provides a procedure for identifying a project's pollutants and conditions of
concern, and addressing these through site design, source control, and treatment
control storm water BMPs. All priority projects shall implement one or a combination of
storm water BMPs, including, 1) site design BMPs, 2) source control BMPs and, 3)
structural treatment BMPs after the pollutants and conditions of concern have been
identified. Storm water BMPs, from those listed in Appendix.A:"Approved Storm Water
Best Management Practices", shall be considered and implemented where determined
applicable and feasible by the Copermittee. It is recommended that the U.S.
Environmental Protection Agency's "Preliminary Data Summary of Urban Runoff Best
Management Practices" (August 1999, EPA-821 .. R-99-012) be used as a guide. The
storm water BMPs shall adhere to the requirements in SectionVI of this Model SUSMP,
and shall be correctly designed so as to remove pollutants to the maximum eXtent
practicable. A flow chart summarizing the storm water BMP selection procedure is
provided in Figure 1.
Site Design Storm Water Treatment Credits
The Co permittees agree that any Copermittee may develop and submit for Regional
Board review and approval a Site Design Storm Water Treatment Credits program that
allows reductions in the volume or flow of storm water that must be captured ot treated
on a project in retum for the inclusion of specified project design features in the project,
and further agree that any such submittal shall be deemed to be a part of this Model
SUSMP jOintly submitted to the Regional Board for review and approval. Any such
model program shall specify the conditions under which project proponents can be
credited for the use of site design features. and low impact development techniques that
can reduce the volume of storm water runoff, preserve natural areas,. and minimize the
pollutant loads generated and potentially discharged from the site. Provided, however
that if a method for determining site design credits is developed' on atime scbedule
that will permit further Co permittee review prior to submission to the Regional Board,
that proposal shall first be submitted to the ·Copermittees and if agreed to by the
Copermittees will be submitted to the Regional Board as a single regional model. Any
Copermittee may adopt and implement a Storm Water Credit Program consistent with
this model approved by the Regional Board .
FINAL MODEL SUSMP
Jointly Dcvclopcd by
San Dicgo Co-Pcmlittccs 2!7i02
Page 9 of 39 .
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Alternative Methods for Achieving Treatment Reguirements
Copermitlees may propose an alternative method for meeting the BMP requirements in
Section VI.2.c, Step 8, "Design to Treatment Control BMP Standards," for inclusion in
their jurisdictional SUSMP. An alternative method must minimally meetthe following
criteria:
• The alternative treatment area shall be located within the proximity of the project;
• The alternative treatment area shall discharge to the same receiving water as
the project;
• The alternative treatment area shall be equivalent or greater than the project
footprint;
• The alternative treatment area shall have an equiv~lent orgr.eaterimpervious
surface area than the project;
• The alternative treatment area shall have an equivalent or greater pollutant load
than the project;
• Site Design and Source Control BMPs (Sections V1.2.a & b) shall be required in
the project design.
Implementation of an alternative method shall require approval from the Regional
Board .
FINAL MODEL SUSMP
Jointly Developed by
San Diego Co-Pcmlittces 217102
Page 10of39
• •
Figure 1. Storm Water BMP Selection Procedure Flow Chart
1. Identify
Pollutants from
proposed
project
(Section VI. tal
FINAL MODEL SUSMP
Jointly Developed by·
San Diego Co~Pettl1ittees 2l7!02
2. Identify Pollutants
& Conditions of
Concern in
Receiving Waters
(Section VI.1.b)
Page 119f39
NO
YES
Project
Generate
Pollutants or
Conditions of
•
Project required to Implement:
• Site Design
• Source Control
BMPs
• BMPsfor
Individual·
Categories
• Standard
Treatment
Control BMPs
(Table 2)
OR
• Site Design
• Source Control
BMPs
• BMPsfor,
Individual
Categories
• Enhanced
Treatment
Control BMPs
(Table 3)
•
•
1. IDENTIFY POLLUTANTS & CONDITIONS OF CONCERN
Priority project proponents shall use this guidance to identify pollutants and conditions
of concern, for which they need to mitigate or protect against.bnceidentified~
appropriate control measures for these pollutants and conditions are specified in
Section V1.2, "Establish Storm Water BMPs." Standard control, measures are required
based on pollutants commonly associated with the proposed project type (see Table 2,
"Standard Storm Water BMP Selection Matrix"). Priority projects required to implement
structural treatment control BMPs using the standard BMP selection procedure should
use Table 3, "Enhanced Treatment Control BMP Selection Matrix," to aid in selecting
the structural treatment BMP(s) from Appendix A that would have the gre~test pollUtant
removal efficiency for projects. Enhanced control measures are reql!ired for projects·
anticipated to generate pollutants that are also identified as pollutants of con'cemin the
project's downstream receiving water(s) (see Table 3).
Copermittees shall incorporate the requirements listed in Sections VI.1.a-cin the
procedure for identifying pollutants and conditions of concern in the Local SUSMPs ..
For private priority projects, the Copermittee shall require the information to be
provided with the project application prior to being deemed complete~ For public
priority projects, the Copermittee shall approve the information prior to bidding for
construction contracts .
General Categories of Water Pollution
Urban runoff from a developed site has the potential to contribute poliutants, including
oil and grease, suspended solids, metals, gasoline, pesticides, and pathogens to the
storm water conveyance system and receiving waters. For the purposes of identifying
pollutants of concern and associated storm water BMPs, pollutants are grouped in nine
general categories as follows:
1. Sediments -Sediments are soils or other surficial materials eroded and then
transported or deposited by the action of wind, water, ice, orgr~vity. Sediments
can increase turbidity, clog fish gills, reduce spawning, habitat, lower young
aquatic organisms survival rates, smother bottom dwelling organisms, and
suppress aquatic vegetation growth.
2. Nutrients -Nutrients are inorganic substances, such as nitrogen and.
phosphorus. They commonly exist in the form of mineral salts that are either
dissolved or suspended in water. Primary sources of nutrients in urban runoff
are fertilizers and eroded soils. Excessive discharge of nutrients to water bodies
and streams can cause excessive aquatic algae and plant growth. SUCh
excessive production, referred to as cultural eutrophication, may lead to
excessive decay of organic matter in the water body,. loss of oxygen in the water,
release of toxins in sediment, and the eventual death of aquatic organisms.
3. Metals -Metals are raw material components in non-metal' products such as
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fuels, adhesives, paints, and other coatings. Primary source of metal pollution ih
storm water are typically commercially available metals and metal products.
Metals of concern include cadmium, chromium, copper, lead, mercury, and zinc.
Lead and chromium have been used as corrosion inhibitors in primer coatings
and cooling tower systems. At low concentrations naturally occurring in soH,
metals are not toxic. However, at higher concentrations, certain metals can be
toxic to aquatic life. Humans can be impacted from contaminated groundwater
resources, and bioaccumulation of metals in fish and shellfish. Environmental
concerns, regarding the potential for release of metals to the environment, have
already led to restricted metal usage in certain applications.
4. Organic Compounds -Organic compounds are carbon-based. Commercially
available or naturally occurring organic compounds are found in pestiCides,
solvents, and hydrocarbons. Organic compounds can, at certain concentrations,
indirectly or directly constitute a hazard to life or health. When rinsing off
objects, toxic levels of solvents and cleaning compounds can be discharged to
storm drains. Dirt, grease, and grime retained in the cleaning 'fluid or rinse water
may also adsorb levels of organic compounds that are harmful or hazardous to
aquatic life.
5. Trash & Debris -Trash (such as paper, plastic, polystyrene packing foam, and
aluminum materials) and biodegradable organic matter (such as leaves, grass
cuttings, and food waste) are general waste products on the ,landscape. The
presence of trash & debris may have a significant impact on the recreational
value of a water body and aquatic habitat. Excess organic matter can create a
high biochemical oxygen demand in a stream and thereby lower its water quality.
Also, in areas where stagnant water exists, the presence of excess organic
matter can promote septic conditions resulting in the growth of undesirable
organisms and the release of odorous and hazardous compounds such as
hydro'gen sulfide.
6. Oxygen-Demanding Substances -This category includes biodegradable organic
material as well as chemicals that react with dissolved oxygen in water to form
other compounds. Proteins, carbohydrates, and fats are examples of
biodegradable organic compounds. Compounds such as ammonia and hydrogen
sulfide are examples of oxygen-demanding compounds. The Qxygen demand of
a substance can lead to depletion of dissolved oxygen ina water body and
possibly the development of septic conditions.
7. Oil and Grease -Oil and grease are characterized as high,.molecularweight
organic compounds. Primary sources of oil and grease are petroleum
hydrocarbon products, motor products from leaking vehicles, esters, oils, fats,
waxes, and high molecular-weight fatty acids. I ntroduction of these pollutants to
the water bodies are very possible due to the wide ,uses and applications of
some of these products in muniCipal, residential, commercial, industrial, and
construction areas. Elevated oil and grease content can decrease the aesthetic
value of the water body, as well as the water quality .
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8. Bacteria and Viruses -Bacteria and viruses are ubiquitous microorganisms that
thrive under certain environmental conditions. Their proliferation is typicaIly
caused by the transport of animal or human fecal wastes from the watershed.
Water, containing excessive bacteria and viruses can ~Iter the aquatic habitat
and create a harmful environment for humans and aquatic life. Also, the
decomposition of excess organic waste causes increased growth of undesirable
organisms in the water.
9. Pesticides -Pesticides (including herbicides) are chemicarcompounds
commonly used to control nuisance growth or prevalence of organisms.
Excessive application of a pesticide may result in runoff containing toxiC levels of
its active component.
a. Identify Pollutants from the Project Area
Using Table 1, identify pollutants that are anticipated to be generated from the
proposed priority project categories. Pollutants associated with any ,hazardous material
sites that have been remediated or are not threatened by the proposed project are not
considered a pollutant of concern.
T bl 1 Anti· t d d P t f 1 Pit t G a e . clpa e an o en la 01 u an 5 t db L dU T en era e )y an 58 type.
Priority
Project
Categories Sediments
Detached
Residential X
Development
Attached
Residential X
Development
Commercial
Development p(1}
;>100,000 tt2
Automotive
Repair Shops
Restaurants
Hillside
Development X
;>5,000 if
Parking Lots p(1}
Streets,
Highways & X
Freewavs
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X
X
p(1}
X
p(1}
p(1}
San Diego Co-Pcmlittccs 2i7!02
Heavy
Metals
X
X
X
General pOllutant Categories
Trash Oxygen
Organic & Demanding Oil &
Compounds Debris Substances Grease
X X X
, '
X p(1} p(2}
p(2} X p(5} X
X(4}(5} X X
X X X
X X X
X p(1} X
)«4) X p(5} X
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Bacteria
&,
Viruses Pesticides
X X
P X
p(J} p(5}
X
X
p(1}
, -
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General Pollutant Caterzortes
Priority Trash Oxygen
Project Heavy Organic & Demandng
Categories Sediments Nutrients Metals Comoounds Debris Substances
X = anticipated
P = potential
(1) A potential pollutant if landscaping exists on-site.
(2) A potential pollutant if the project indudes uncovered parking areas.
(3) A potential pollutant if land use involves food or animal waste products.
(4) Including petroleum hydrocarbons.
l(5) Including solvents .
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Bacteria
Oil & &
Grease Viruses Pesticides
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b. Identify Pollutants of Concern in Receiving Waters
Pollutants that exhibit one or more of the following characteristics are considered
pollutants of concern in the receiving water:
• Current loadings or historical deposits of the pollutant are impairing the
beneficial uses of a receiving water;
• Elevated levels of the pollutant are found in water or sediments.'of a receiving
water and/or have the potential to be toxic to or bioaccumulate in organisms
therein; and
• Inputs of the pollutant are at a level high enough to be considered potentially
toxic.
To identify pollutants of concern in receiving waters, each priority project shall, at a
minimum, do the following:
c.
1. For each of the proposed projects discharge pOints, identify the receiving
water(s) that each discharge point proposes to discharge to, including hydrologic
unit basin number(s), as identified in the most recent version ofthe Water
Quality Control Plan for the San Diego Basin1, prepared by, the San Diego
Regional Water Quality Control Board .
2. Identify any receiving waters, into which the developed area would discharge to,
listed on the most recent list of Clean Water Act Section 303(d) impaired water
bodies2. List any and all pollutants for which the receiving waters are impaired.
Identify Conditions of Concern
Common impacts to the hydrologic regime resulting from developmeht typically include
increased runoff volume and velocity; reduced infiltration; increased flow frequency,
duration, and peaks; faster time to reach peak flow; and water quality degradation.
These changes have the potential to permanently impact downstream channels and
habitat integrity. A change to a priority project site's hydrologic regime would be
considered a condition of concern if the change would impact downstream channels
and habitat integrity.
Because of these potential impacts, the following steps shall be followed by each
priority project:
1. Evaluate the project's conditions of concern in a drainage study report prepared,
by a registered civil engineer in the State of California, with experience in fluvial
geomorphology and water resources management.'Thereport shall consider
the project area's location (from the larger watershed perspective), topography,
1. http://www.swrcb.ca.gov/-lWqcb9/Programs/Planning_and_ServicesJSD_Basin/sd_basin.html
2. http://www.swrcb.ca.gov/tmdIl303d_lists.html. San Diego is in Region 9
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soil and vegetation conditions, percent impervious area, natural and
infrastructure drainage features, and any other reievant hydrologiC and
environmental factors to be protected specific to the project area's watershed.
2. As part of the drainage study, the civil engineer shall conduct a field
reconnaissance to observe and report on downstream conditiQhs, including
undercutting erosion, slope stability, vegetative stress (due to floodilig~ erosion,
water quality degradation, or loss of water supplies) and the are~'s susceptibility
to erosion or habitat alteration as a result of an altered flow regime.
3. The drainage study shall compute rainfall runoff characteristics from the project
area including, at a minimum, runoff volume, time of concentration, and retention
volume. These characteristics shall be developed for the two-year and 10-year
frequency, Type I storm, of six-hour or 24-hourduration (whichever is the closer
approximation of the site's time of concentration), during critical hydrologiC
conditions for soil and vegetative cove~. The drainage study shall report the
project's conditions of concern based on the hydrologiC and downstream .
conditions discussed above. Where downstream conditions of concern have
been identified, the drainage study shall establish that pre-project hydrologic
conditions affecting downstream conditions of concern 1JVould be maintained by
the proposed project, satisfactory to the Copern1ittee, by incorporatihg thfJ site
deSign, source control, and treatment control requirements identified in Sectioli
V1.2 .
2. ESTABLISH STORM WATER BMPs
Site design BMPs reduce the need for $ource and/or treatment control BMPs, and
source control BMPs may reduce the amount of treatment controlBMPs needed.
Throughout all the following sections, all priority projects shall consider, and
incorporate and implement where determined applicable and feasible by the
Copermittee, storm water BMPs into the project design, in the following progression:
• Site DeSign BMPs
• Source Control BMPs
• Treatment Control BMPs
At a minimum, priority projects must implement source control BMPs, and must
implement treatment control BMPs unless a waiver is granted based 00 the infeasibility
of all treatment control BMPs. BMPs must also achieve certainpeliormance standards
set out in the municipal permit section F.2.(b) (i to xiv). Selection of BMPs from the
3. Design storms can be found at http://www.wrcc.dri.eduJpcpnfreq:html. The Cdpermittees may calCulate
the storm events using local rain data. In addition, isopluvial maps contained in the County of San Diego
Hydrology Manual may be used to extrapolate rainfall data to areas where insuffiCient data exists. if
isopluvial maps are selected, Copermittees shali describe their method for using isopluvial maps in their
Jurisdictional SUSMP .
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menus included in this SUSMP, using the rules $et out in this SUSMP, will in general
fulfill these requirements.
In addition, runoff treated by site design or source control BMPs, such as rooftop runoff
treated in landscaping, may be useful in reducing the quantity of runoff required \0 be
treated in Section V1.2.c, 'Treatment Control BMPs."
To determine whether a priority project is required to select a structural treatment BMP
using the standard or enhanced BMP selection matrices, each priority project shall
compare the list of pollutants for which the downstream receiving waters are impaired
(if any), with the pollutants antiCipated to be generated by the project (as identified in
Table 1). Priority projects that are not anticipated to generate a poll uta ntfo r which the
receiving water is Clean Water Act Section 303(d) impaired shall meet applicable
standard requirements in Section V1.2, and may select any storm water BMPidentified
in Appendix A that would meet the requirements in Section VI.2.c, "Treatment Control
BMPs" (The site design, source control, and standard treatment control BMP
requirements for priority project categories are summarized in Table 2, and described
in detail in Sections VI.2.a-c). Priority projects required to implement structural
treatment control BMPs using the standard BMP selection procedure should use Table
3, "Enhanced Treatment Control BMP Selection Matrix," to aid in selecting the
structural treatment BMP(s) from Appendix A that would have th~ greatest pollutant
removal efficiency for projects. Alternative standard storm water BMPs not identified in
Appendix A may be approved at the discretion of the Copermittee.
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Table 2. Standard Stonn Water BMP Selection Matrix.
Priority Site Source Treatment
Project Design Control Control Requirements Applicable to Individual Priority BMP~1} BMPs(~ BMPsC3J ProjectCategori~.f} Category
«S 8l In >-In II)
! C) .:c In to I:: >-~ 'iii ..c: > ca In In ·c C) III ~ ~ In ii In .Kj 'C ~~ II) to to In t.l ~ 0 II) II) ... .... a ca ... to I:: a. I:: .:c ~ .:c 0::: ; 't\] II) ca II) I:: a. .:c I:: ... ~ ~ 11) .... .l!l II) 0 E C) C)
:-gin 13 a In .9-I:: .5 .:.:: 1::. :c "C to' ::z 'C > In ~ 8 'm '!i~ B-tl! to 11 ·c ~(!) ~ & a. 0 :::E 0« w a. u.
cd .ci d -ci as .....: dl ..c::: .. ....: ......
Detached
Residential R R S R R
Development
Attached
Residential R R S R
Development
Commercial
Development R R S R R R R
>100,000 ft2
Automotive R R S R R R R R Repair Shop
Restaurants R R S R R
Hillside
Development R R S R
>5,000 ~
Parking Lots R R S ' Rllli
Streets,
Highways & R R S R
Freeways
R = Required; select one or more applicable and appropriate BMPs from the applicable steps hi SeCtion VI.2.a &
b, or equivalent as identified in Appendix A.
S = Select one or more applicable and appropriate treatment control BMPs from Appendix A.
(1) Refer to Section VI.2.a.
(2) Refer to Section VI.2.b.
(3) Refer to Section VI.2.c.
(4) Priority project categories must apply specific storm water BMP requirements, where applicabie. Projects are
subject to the requirements of all priority project categories that apply.
(5) Applies if the paved area totals >5,000 square feet or with >15 parking spaces and is potentially exposed to
urban runoff.
Priority projects that are anticipated to generate a pollutant (as identified in Table 1,
"Anticipated Pollutants Generated by Land Use Type) for which the receiving water is
Clean Water Act Section 303(d) impaired, shall meet all applicable requirements in
Section V1.2, and shall select a single or combination of storm water BMPs from Table
3 which maximizes pollutant removal for the particular pollutant(s) of concern. .
Alternative storm water BMPs for enhanced treatment, and specific BMPtypes within
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C)
I:: 'is. to t.l In 'C !ii ..J
II) 'C ;gj'
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the tabulated categories, may be approved at the discretion ofthe Copermittee.
Table 3 Enhanced Treatment Control BMP Selection Matrix(1) • .
Pollutant of Treat,ment Control BMP Categories Concern
Biofilters Detention Infiltration Wet Ponds Drainage Filtratibn Hyarodymimic
Basins Basins(2) or Wetlands Inserts Separator
Systems(3)
Sediment M H H H L H M
Nutrients L M M M l M L
Heavy Metals M M M .H L H L
Organic U U U U L M L Compounds -
Trash & Debris L H U U M H M
Oxygen
Demanding L M M M L M L
Substances
Bacteria U U H U L M L
Oil & Grease M M U U L H [,
Pesticides U U U U L U L
(1) Copermittees are encouraged to periodically assess the performance characteristics of many: of these BMPs to
update this table.
(2) Including trenches and porous pavement.
(3) Also known as hydrodynamic devices and baffle boxes.
L: Low removal efficiency):
M: Medium removal efficiency):
H: High removal efficiency):
U: Unknown removal efficiency
Sources: Guidance Specifying Management Measures for Sources of Nonpoint Ppflution in Coastal Waters (1993),
National Stormwater Best Management Practices Database (2001), and Guide for BMP Selection in Urban
Developed Araas (2001). . " .
a. Site Design BMPs
Priority projects shall be deSigned so as to minimize, to the maximum extent
practicable, the introduction of pollutants and conditions of concern that may result in
significant impacts, generated from site runoff to the storm water conveyance system.
Priority Projects shall also control post-development peak storm water runoff discharge
rates and velocities to maintain or reduce pre-development c;iownstreamerosion and to
protect stream habitat. Although not mandatory, priority projects can address these
objectives through the creation of a hydrologically functional project design that '
attempts to mimic the natural hydrologic regime. Mimicking a site's natural hydrologic
regime can be pursued by: .
• Reducing imperviousness, conserving natural resources and areas, maintaining
and using natural drainage courses in the storm water conveyance system, and
minimizing clearing and grading.
• Providing runoff storage measures dispersed uniformly throughout a site's
landscape with the use of a variety of detention, retention; and runoff practices.
• Implementing on-lot hydrologically functional landscape design 'and
management practices .
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These deSign principles offer an innovative apprqach to urban storm water
management, one that does not rely on the conventional end-of-pipe or in-the-pipe
structural methods but instead uniformly or strategically integrates storm water controls·
throughout the urban landscape. Useful resources for applying these principles,
referenced in the appendix, include Start at the Source (1999), and Low-Impact
Development Design Strategies (1999).
Step 1: Objective: Maintain Pre-Development Rainfall Runoff Characteristics
Priority projects shall control post-development peak storm water runoff discharge rates
and velocities to maintain or reduce pre-development development downstream
erosion. In addition, projects should control runoff discharge volumes and durations to
the maximum extent practicable using the site design, source control, and treatment
control requirements identified in Section V1.2.
Design Concept 1: Minimize Project's ImpeNious Footprint & Conserve Natural Areas
The following site design options shall be considered and, incorporated and
implemented where determined applicable and feasible by the Copermittee, during the
site planning and approval process, consistent with applicable General Plan policies
and other development regulations. .
1. Minimize impervious footprint. This can be achieved in various ways,
including, but not limited to increasing building density (number of stories
above or below ground) and developing land use regulations seeking to limit
impervious surfaces. Decreasing the project's footprint can $ubstantially
reduce the project's impacts to water quality and hydrologic conditions.
Copermittees are encouraged to develop standards for relaxing height and
other zoning restrictions as incentives to achieve this design concept.
2. Conserve natural areas where feasible. This can be achieved by
concentrating or clustering development on the least environmentally
sensitive portions of a site while leaving the remaining land in a natural,
undisturbed condition. The following list provides a guideline for det~rmining
the least sensitive portions of the site, in order of increasing $ensitivity.
Jurisdictions should also refer to their Multiple Species Conservation Plans
or other biological regulations, as appropriate.
a. Areas devoid of vegetation, including previously gradeda'reasand
agricultural fields.
b. Areas of non-native vegetation, disturbed habitats and eucalyptus
woodlands.
c. Areas of chamise or mixed chaparral, and non-native grasslands.
d. Areas containing coastal scrub communities.
e. All other upland communities.
f. Occupied habitat of sensitive species and all wetlands (as both ate
defined by the Co permittee) .
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g. All areas necessary to maintain the viability of wildlife corridors.
Within each of the previous categories, areas containing hillsides (as
defined in this Model SUSMP) should be considered more sensitive than
the same category without hillsides.
3. Construct walkways, trails, patios, overflow parking lots and alleys and other
low-traffic areas with permeable surfaces, such as pervious concrete, porous
asphalt, unit pavers, and granular materials.
4. Construct streets, sidewalks and parking lot aisles to the minimum widths
necessary, provided that public safety and a walkable environment for
pedestrians are not compromised.
5. Maximize canopy interception and water conservation by preserving ,existing
native trees and shrubs, and planting additional native or drought tolerant
trees and large shrubs.
6. Minimize the use of impervious surfaces, such as deGorative concrete, in the
landscape design.
7. Use natural drainage systems to the maximum extent practicable.
8. Other site design options that are comparable, and equally effective.
Design Concept 2: Minimize Directly Connected Impervious Areas (DCIAs) .
Priority projects shall consider, and incorporate and implement the following design
characteristics, where determined applicable and feasible by, the Copermiftee ..
Step 2:
1. Where landscaping is proposed, drain rooftops into adjacent landscaping
prior to discharging to the storm drain. '
2. Where landscaping is proposed, drain impervious sidewalks, walkways,
trails, and patios into adjacent landscaping.
3. Other design characteristics that are comparable and equally effective.
Protect Slopes and Channels
Project plans shall include storm water BMPs to decrease the potential for erosion of
slopes and/or channels, consistent with local' codes and ordinances and with the
approval of all agencies with jurisdiction, e.g., the U.S. Army Corps of Engineers, the
San Diego Regional Water Quality Control Board, and the California Department of
Fish and Game. The following design principles shall be considered~ and incorporated
and implemented where determined applicable and feasible by the Copermittee :
1. Convey runoff safely from the tops of slopes.
2. Vegetate slopes with native. or drought tolerant vegetation.,
3. Control and treat flows in landscaping and/or other controls prior to
reaching existing natural drainage systems.
4. Stabilize permanent channel crossings.
5. Install energy diSSipaters, such as tiprap, at the outlets of new storm
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b.
drains, culverts, conduits, or channels that enter unlined channels in
accordance with applicable specifications to minimize erosion. Energy
dissipaters shall be installed in such a way as to minimize impactsto
receiving waters.
6. Other design principles that are comparable and equally effective.
Source Control BMPs
Step 3: Provide Storm Drain System Stenciling and Sighage
Storm drain stencils are highly visible source control messages, typically placed
directly adjacent to storm drain inlets. The stencils contain a brief stt;ltement that
prohibits the dumping of improper materials into the urban runoff conveyahce system.
Graphical icbns, either illustrating anti-dumping symbols or images of receiving water
fauna, are effective supplements to the anti-dumping message. Priority projects shall
include the following requirements in the project design.
1. Provide stenciling or labeling of all storm drain inlets and catch basins within the
project area with prohibitive language (such as: "NO DUMPiNG .... I LIVE IN
«name receiving water»") and/or graphical icons to discourage illegal
dumping.
2. Post signs and prohibitive language and/or graphical icons, which prohibit illegal
dumping at public access points along channels and creeks within the project
area.
3. Maintain legibility of stencils and signs.
Step 4: Design Outdoor Material Storage Areas to Reduce Pollution Introduction
Improper storage of materials outdoors may increase the potentiaHor toxic compounds,
oil and grease, heavy metals, nutrients, suspended solids, and .other pollutants to enter
the urban runoff conveyance system. Where the priority project plans include outdoor
areas for storage of hazardous materials that may contribute pollutants to the urban
runoff conveyance system, the following storm water BMPs are required:
1. Hazardous materials with the potential to contaminate urban runoff shall either
be: (1) placed in an enclosure such as, but not limited to·, a cabinet, shed, or .
similar structure that prevents contact with runoff or spillage to the storm water
conveyance system; or (2) protected by secondary containment structures such.
as berms, dikes, or curbs.
2. The storage area shall be paved and sufficiently impervious to contain leaks and
spills.
3. The storage area shall have a roof or awning to minimize direct precipitation
within the secondary containment area .
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Step 5: Design Trash Storage Areas to Reduce Pollution Introduction
All trash container areas shall meet the following requirements (limited exclusion:
detached residential homes):
1. Paved with an impervious surface, designed not to allow run-on from adjoining
areas, screened or walled to prevent off-site transport of trash; or,
2. Provide attached lids on all trash containers that exclude rain; or-roof or awning
to minimize direct precipitation.
Step 6: Use Efficient Irrigation Systems & Landscape Design
Priority projects shall design the timing and application methods of.irrigation water to
minimize the runoff of excess irrigation water into the storm water conveyance system.
(Limited exclusion: detached residential homes.) The following methods to reduce
excessive irrigation runoff shall be considered, and incorporated and implemented
where determined applicable and feasible by the Copermittee: .
1. Employing rain shutoff devices to prevent irrigation after precip.itation.
2. Designing irrigation systems to each landscape area's specific water
requirements .
3. Using flow reducers or shutoff valves triggered by a pressure drop to control
water loss in the event of broken sprinkler heads or lines.
4. Employing other comparable, equally effective, methods to reduce irrigation
water runoff.
Step 7: Incorporate Requirements Applicable to Individual Priority Project Categories
Where identified in Table 2, the following requirements shall be incorpo~ted into
applicable priority projects during the storm water BMP selection and design process.
Projects shall adhere to each of the individual priority project category requirements
that apply to the project {e.g., a restaurant with more than 15 parking spaces would be
required to incorporate the requirements for" g. Equipment Wash Areas and "h.
Parking Areas" into the project design}.
a. Private Roads
The design of private roadway drainage shall use at least one of the following (for
further guidance, see Start at the Source [1999]):
1. Rural swale system: street sheet flows to vegetated swale or grav.el shoulder,
curbs at street corners, culverts under driveways and street crossings;
2. Urban curb/swale system: street slopes to curb,. pe"riodic swale inlets drain to
vegetated swale/biofilter;
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3. Dual drainage system: First flush captured in street catch basins and discharged
to adjacent vegetated swale or gravel shoulder, high flows connect directly to
storm water conveyance system.
4. Other methods that are comparable and equally effectiv~ within the project.
Residential Driveways & Guest Parking
The design of driveways and private residential parking areas shall use one at least of
the following features.
1. Design driveways with shared access, flared (single lane at street) or
wheelstrips (paving only under tires); or, drain into landscaping prior to
discharging to the storm water conveyance system.
2. Uncovered temporary or guest parking on private residential lots may oe: paved
with a permeable surface; or, designed to drain into landscaping priQrto
dischargi ng to the storm water conveyance system. .
3. Other features which are comparable and equally effective.
c. Dock Areas
Loading/unloading dock areas shall include the following:
1. Cover loading dock areas, or design drainage to preclude urban run-on and
runoff.
2. Direct connections to storm drains from depressed loading docks (truck wells)
are prohibited. .
3. Other features which are comparable and equally effective.
d. Maintenance Bays
Maintenance bays shall include at least one of the following:
1. Repair/maintenance bays shall be indoors; or, designed to preClude urban ruo-
on and runoff.
2. Design a repair/maintenance bay drainage system to capture all wash water,
leaks and spills. Connect drains to a sump for collection and disposal. Direct
connection of the repair/maintenance bays to the storm drain system is
prohibited~ If required by local jurisdiction, obtain an Industrial Waste Discharge
Permit.
3. Other features which are comparable a'nd equally effective.
e. Vehicle Wash Areas
Priority projects that include areas for washing/steam cl~aning of vehicles ·.shall use at
least one of the following: .
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1. Self-contained; or covered with a roof or overhang;
2. Equipped with a clarifier or other pretreatment facility;
3. Properly connected to a sanitary sewer.
4. Other features which are comparable and equally effective.
f. Outdoor Processing Areas
Outdoor process equipment operations, such as rock grinding or crushing, painting or
coating, grinding or sanding, degreasing or parts cleaning, landfills, was~e piles,and
wastewater and solid waste treatment and disposal, and other operations determined to
be a potential threat to water quality by the Copermittee shall adhere to the following
requirements.
g.
1. Cover or enclose areas that would be the most significant source of pollutants;
or, slope the area toward a dead-end sump; or, discharge to the sanitary sewer
system following appropriate treatment in accordance with conditions
established by the applicable sewer a9sncy. .
2. Grade or berm area to prevent run-on from surrounding are~s.
3. Installation of storm drains in areas of equipment repair ,is prohibited.
4. Other features which are comparable or equally effective.
Equipment Wash Areas
Outdoor equipmentJaccessory washing and steam cleaning activities at priority projects
shall use at least one of the following:
1. Be self-contained; or covered with a roof or overhang;
2. Be equipped with a clarifier, grease trap or other pretreatment facility, as
appropriate;
3. Be properly connected to a sanitary sewer.
4. Other features which are comparable or equally effective.
h. Parking Areas
To minimize the offsite transport of pollutants from-parking areas, the following design
concepts shall be conSidered, and incorporated and implemented where determined
applicable and feasible by the Copermittee:
1. Where landscaping is proposed in parking areas,incOrporate landscape areas
into the drainage deSign.
2. Overflow parking (parking stalls provided in excess of the Copermittee's
minimum parking requirements) may be constructed with permeable paving .
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3. Other design concepts that are comparable and equally effective.
i. Roadways
Priority roadway projects shall select treatment control BMPsfollowing the enhanced
treatment control selection procedure identified in Section VI.2, "Establish Storm Water
BMPs."
j. Fueling Area
Non-retail fuel dispensing areas shall contain the following:
1. Overhanging roof structure or canopy. The cover's minimum dimensions must
be equal to or greater than the area within the grade break. The cover must not
drain onto the fuel dispensing area and the downspouts must be touted to
prevent drainage across the fueling area. The fueling area shall drain to the
project's treatment control BMP(s) prior to discharging to the storm water
conveyance system.
"2. Paved with Portland cement concrete (or equivalent smoothimpervious'surface).
The use of asphalt concrete shall be prohibited.
3. Have an appropriate slope to prevent ponding, and must be separated from the
rest of the site by a grade break that prevents run-on of urban runoff .
4. At a minimum, the concrete fuel dispensing area must extend 6.5 feet (2.0
meters) from the corner of each fuel dispenser, or the length at which the hose
and nozzle assembly may be operated plus 1 foot (0.3 meter), whichever.is less.-
k. Hillside Landscaping
Hillside areas, as defined in this Model SUSMP, that are disturbed by project
development shall be landscaped with deep-rooted, drought tolerant plant species
selected for erosion control, satisfactory to the Copermittee.
c. Treatment Control BMPs
Minimizing a development's detrimeptal effects on water quality can be most effectively
achieved through the use of a comb'ination of site deSign, source and treatment control
storm water BMPs. Where projects have been designed to minimize, to the maximum
extent practicable, the introduction of antiCipated pollutants of concern that may result
in significant impacts to the receiving waters through the implementation Of site design
and source control storm water BMPs, the development would still have "the potential
for pollutants of concern to enter the storm water conveyance system. Therefore,
priority projects shall be designed to remove pollutants of concern from the storm water
conveyance system to the maximum extent practicable through the incorporation and
implementation of treatment control BMPs .
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In meeting the requirements in this section, priority projects shall implement a single or
combination of storm water BMPs that will remove anticipated pollutants of concern, as
identified by the procedure in Section VI.1, in site runoff to the maximum extent
practicable .
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Step 8: Design to Treatment Control BMP Standards
All priority projects shall design, construct and implement structural treatment control
BMPs that meet the design standards of this section, unless specifically exempted by
the limited exclusions listed at the end of Step 8. Structural treatment control BMPs
required by this section shall be operational prior to the use _ of any dependent
development, and shall be located and designed in accordance with the requirements
here in Step 8 and below in Step 9. Copermittees may choose to eliminate one armore
of the numeric sizing methods listed below in the Jurisdictional SUSMPs.
Volume
1. Volume-based BMPs shall be designed to mitigate (infiltrate, filter, or treat) either:
i. The volume of runoff produced from a 24 .. hour 85th percentile storm event, as
determined from the local historical rainfC;l1l record (0.6 inch approxrmate
average for the San Diego County area)4; or
ii. The volume of runoff produced by the 85th percentile 24-hour runoff event,
determined as the maximized capture urban runoff volume for tbe C;lrea, from
the formula recommended in Urban Runoff Quality Management. WEF Manual
of Practice No. 231 ASCE Manual of Practice No. 87, (1998); or
iii. The volume of annual runoff based on unit basin storage volume, to achieve
90 percent or more volume treatment by the method recommended in
California Stormwatet Best Management Practices Handbook -Industn"al/
Commercial, (1993), or
iv. The volume of runOff, as determined from the local historical rainfall record,
that achieves approximately the same reduction in pollutant loads and flows as
achieved by mitigation of the 85th percentile 24-hour runoff event,5
Flow
2. Flow-based BMPs shall be designed to mitigate (infiltrate, filter, or treat) either:
4. This volume is not a Single volume to be applied to all of San Diego County. The s~eof the 85th
percentile storm event is different for various parts of the County. The Copermittees may calCUlate the 85th
percentile storm event using local rain data. In addition, isopluvial maps contained in the County of San
Diego Hydrology Manual may be used to extrapolate rainfall data to areas where insufficient data exists. If
isopluvial maps are selected, Copermittees shall describe their method for using isopluvial maps in their
Jurisdictional SUSMP.
5. Under this volume criterion, hourly rainfall data may be used to c;alculate the 85th percentile stonn
event, where each storm event is identified by its separation from other storm events by at least six
hours of no rain. If hourly rainfall data is selected, the Copermittees shall describe the method using
hourly rainfall data in their Jurisdictional SUSMPs.
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i. The maximum flow rate of runoff produced from a rainfall intensity of 0.2 inch
of rainfall per hour for each hour of a storm event; or
ii. The maximum flow rate of runoff produced by the 85th percentile hourly r~infall
intensity, as determined from the local historical rainfall record, multiplied by a
factor of two; or
iii. The maximum flow rate of runoff, as determined from the local historical rainfall
record, that achieves approximately the same reduction in pollutant loads and
flows as achieved by mitigation of the 85th percentile hourly rainfall intenSity
multiplied by a factor of two.
Limited Exclusions:
1. Proposed restaurants, where the land area for development or redevelopment is
less than 5,000 square feet, are excluded from the numerical sizing criteria
requirements listed in Section VI.2.c, Step 8.
2. Where significant redevelopment results in an increase of less than' 50 percent
of the impervious surfaces of a previously existing development, and the existing
development was not subject to SUSMP requirements, the numeric sizing criteria
discussed in Section VI.2.c, Step 8 apply only to the addition, and not to the
entire development.
Step 9: Locate BMPs Near Pollutant Sources
Structural treatment control storm water BMPs should be implemented close to
pollutant sources to minimize costs and maximize pollutant removal prior to runoff
entering receiving waters. Such BMPs may be located on-or off-site, used singly 01' in
combination, or shared by multiple new developments, pursuant to the following
requirements: '
1. All structural treatment control BMPs shall be located so as to infiltrate, filter,
and/or treat the required runoff volume or flow prior to its discharge to any
receiving water body supporting beneficial uses;
2. Multiple post-construction structural treatment control BMPs for a single priority
development project shall collectively be designed to complywith,the design
standards of Step 8;
3. Shared storm water BMPs shall be operational prior to the use of any dependent
development or phase of development. The shared BMPs shall only be required
to treat the dependent developments or phases of development that are in use;
4. Interim storm water BMPs that provide equivalent or greater treatment than is
required by Section 3.a may 'be implemented by a dependent development until
each shared BMP is operational. If interim BMPs are selected, the BMPs shall
remain in use until permanent BMPs are operational.
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Step 10: Restrictions on Use of Infiltration BMPs
Three factors significantly influence the potential for urban runoff to :contaminate
ground water. They are (i) pollutant mobility, .(ii) pollutant abundance in urban runoff,
(iii) and soluble fraction of pollutant. The risk of contamination of groundwater may be
reduced by pretreatment of urban runoff. A discussion of limitations and guidance fQr
infiltration practices is contained in, Potential Groundwater Contamination trom
Intentional and Non-Intentional Stormwater Infiltration, Report No. !=PAl600/R-94/051,
USEPA (1994).
To protect groundwater quality, each Copermittee shall'apply restrictions to the use of
any BMPs that are designed to primarily function as infiltration devices (such a$
infiltration trenches and infiltration basins). As additional ground water basin data is
obtained, Copermittees may develop additional restrictions on the use of any BMPs
that allow incidental infiltration. At a minimum, use of structural treatment BMPs that
are designed to primarily function as infiltration devices shall meet the following
conditions6:
1. Urban runoff from commercial developments shall undergo pretreatrnentto
remove both physical and chemical contaminants, such as sedimentation or
filtration, prior to infiltration.
2. All dry weather flows shall be diverted from infiltration devices except for those
non-storm water discharges authorized pursuant to 40 CFR
122.26(d)(2)(iv)(B)(1): diverted stream flows, rising ground waters,
uncontaminated ground water infiltration [as defined at 40 CFR 35.2.005(20)] to
storm water conveyance systems, uncontaminated pumped ground water,
foundation drains, springs, water from crawl space pumps, footing drains, air
conditioning condensation, flow from riparian habitats and wetlands, water line
flushing, landscape irrigation, discharges from potable water sources other than
water main breaks, irrigation water, individual residential Car washing, and
dechlorinated swimming pool discharges.
3. Pollution prevention and source control BMPs shall pe implemented at a level
appropriate to protect groundwater quality at sites where infiltratipil structural'
treatment BMPs are to be used.
4. The vertical distance from the base of any infiltration structural treatmeot BMP to
the seasonal high groundwater mark shall be at least 10 feetor as determined
on an individual, site-specific basis by the Copermittee. Where groundwater
does not support beneficial uses, this vertical distance criterion may be reduced,
provided groundwater quality is maintained.
5. The soil through which infiltration is to occur shall have physical and chemical
characteristics (such as appropriate cation exchange capacity, organic content!
clay content, and infiltration rate) that are adequate for proper infiltration
6. These conditions do not apply to structural treatment BMPs which allow inddental infiltration and are
not designed to primarily function as infiltration devices (such as grassy swales, detention basins,
vegetated buffer strips, constructed wetlands, etc.)
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durations and treatment of urban runoff for the protection of groundwater
beneficial uses.
6. Infiltration structural treatment BMPs shall not be used for areas of industrial or
light industrial activity; areas subject to high vehicular traffic (25,000 or greater
average daily traffic on main roadway or 15,000 or more average daily traffic on
any intersecting roadway); automotive repair shops; car washes; fleet storag~
areas (bus, truck, etc.); nurseries; and other high thre.at to water qUc;llity land
uses and activities as deSignated by each Copermitteein their Local SUSMP.
7. The horizontal distance between the base of any infiltration structural BMP and
any water supply wells shall be 100 feet or as determined on an individual, site-
specrric basis by the Copermittee.
Where infiltration BMPs are authorized, their performance shall be evaluated for
impacts on groundwater quality. In developing the Jurisdictional SUSMPs, J
Copermittees may develop additional restrictions on the (;Jse of treatment cOntrol BMPs
-that are designed to primarily function as infiltration devices. Cbpermittees shall
consider the Permit Section D.1.g. requirements to control the contribution of pollutants
from one portion of the watershed to another portion of the watershed thrOl,igh
interagency agreements among the Copermittees. In those instances where a
Copermittee determined that implementation of proposed infiltration BMPs within their
jurisdiction has a potential impact to groundwater quality in another jurisdiction,
Copermittees may include a notification r.equirement be placed 'upon those proposing
such use in addition to the above protection measures.
3. PROVIDE PROOF OF ONGOING STORM WATER BMPMAINTENANCE
Copermittee's shall not consider structural BMPs "effective'" and therefore shall not
accept storm water BMPs as meeting the MEP standard, unless a mechanism is in
place that will ensure ongoing long-term maintenance of all structural. BMPs. This
mechanism can be provided by the Copermittee or by the project proponent. As .partof .
project review, if a project proponent is required to include interim or permanent
structural BMPs in project plans, andrr the Copermittee does not provide a mechanism
for BMP maintenance, the Copermittee shall require that the applicant provide
verification of maintenance requirements through such means as may be appropriate,
at the discretion of the Copermittee, including, but not :Iimited to covenants, legal
agreements, maintenance agreements, and/or conditional use permits.
Maintenance Mechanisms
1. Public entity maintenSnce: The Copermittee may approve a public or acceptable
quasi-public entity (e.g., the County Flood Control District, or annex to an
existing assessment district, an existing utility district, a state orfederar resource
agency, or a conservation conservancy) to assume responsibility for
maintenance, repair and replacement of the BMP. Unless.acceptable to
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individual Copermittees, public !3ntity maintenance agreements shalL ensure
estimated costs are front-funded or reliably guaranteed, (e.g., through atrust
fund, assessment district fees, bond, letter of credit or similar means). In
addition, the Copermittees may seek protection from liability by apprqpriate
releases and indemnities. The Copermittee shall have the authqrity to approve
storm water BMPs proposed for transfer to any other public entity within its
jurisdiction before installation. The Copermittees shall be involved in the
negotiation of maintenance requirements with any other public entities accepting
maintenance responsibilities within their respective jurisdictions; i;lnq irt
negotiations with the resource agencies responsible for issuing permits for the
construction and/or maintenance of the facilities. The Copermittee must be
identified as a third party beneficiary empowered to enforce any such
maintenance agreement within their respective jurisdictions.
2. Project proponent agreement to maintain storm water BMPs; The Copermittee
may enter into a contract with the project proponent obliging the project
proponent to maintain, repair and replace the storm water BMP as necessary
into perpetuity. Security may be required.
3. Assessment districts: The Copermittee may approve an Assessment District or
other funding mechanism created by the project proponent to provide funds for
storm water BMP maintenance, repair and replacement on an ongoing basis.
Any agreement with such a District shall be subject to the Public Entity
Maintenance Provisions above .
4. Lease provisions: In those cases where the Copermittee holds title to the land in
question, and the land is being leased to another party for private or public use,
the Copermittee may assure storm water BMP maintenance, repair and
replacement through conditions in the lease.
5. Conditional use permits: For discretionary projects only, the 'Copermittee may
assure maintenance of storm water BMPs through the inclusion of maintenance
conditions in the conditional use permit. Security may be required.
6. Alternative mechanisms: The Copermittee may accept alternative maintenance
mechanisms if such mechanisms are as protective those listed above.
Verification Mechanisms
For discretionary projects, the Copermittee-approved method of storm water BMP
maintenance shall be incorporated into the project's permit, and shall be consistent with
permits issued by resource agencies, before decision-maker approval of discretionary
permits. For projects requiring only ministerial permits, the Copermittee-approved
method of storm water BMP maintenance shall be incorporated into the permit
conditions before the issuance of any ministerial permits~ In all instances, the project
proponent shall provide proof of execution of a Copermittee-approved method of
maintenance repair and replacement before the issuance of construction approva,ls.
Copermittees carrying out public projects that are not required to obtain permits shall
be responsible for ensuring that a Copermittee-approved method of storm water sMp
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maintenance repair and replacemel1t is executed prior to the commencement of
construction. For all properties, the verification mechanism will include the project
proponent's signed statement, as part of the project application, accepting
responsibility for all structural BMP maintenance, repair and r~placement, until a
Copermittee-approved entity agrees to assume responsibility for structural BMP
maintenance, repair and replacement.
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Maintenance Requirements
4.
1. Operation & Maintenance (O&M) Plan: The Copermittee sball ensure1hat a
copy of an Operation & Maintenance (O&M) plan, prepared by the project
proponent satisfactory to the Copermittee, is attached to the approved
maintenance agreement, which describes the designated responsible party t6
manage the storm water BMP(s), employee's training program and duties,
operating schedule, maintenance frequency, routine service schedule, specific
maintenance activities, copies of resource agency permits, and any other
necessary activities. At a minimum, maintenance agreements shall require the
inspection and servicing of all structural BMPs on an annual basis. The project
proponent or Copermittee-approved maintenance entity shall complete, and
maintain O&M forms to document all maintenance requirements. Parties .
responsible for the O&M plan shall retain records for at least 5 years, These
documents shall be made available to the Copermittee for inspection upon
request at any time. .
2. Access Easement/Agreement: As part of the maintenance mechanism selected
above, the Copermittee shall require the inclusion of a copy of an executed
access easement that shall be binding on the land throughout the life of the
project, until such time that the storm water BMP requiring access is replaced,
satisfactory to the Copermittee .
WAIVER OF STRUCTURAL TREATMENT BMPREQUIREMENTS
Copermittees may provide for a project to be waived from the requirement of
implementing structural treatment BMPs (Section VI.2.c, "DeSign to Treatment Contrdl
BMP Standards") if infeasibility can be established. A Copermittee shall only grant a
waiver of infeasibility when all available structural treatment BMPs have been
considered and rejected as infeasible. Copermittees shall notify the Regional Board
within 5 days of each waiver issued and shall include the name of the person granting
each waiver.
Waivers may only be granted from structural treatment BMP and structural treatment
BMP sizing requirements. Priority development projects, whetber or not granted a
waiver may not cause or contribute to an exceedance of water quality' objectives.
Pollutants in runoff from projects granted a waiver must still be reduced to the maximum
extent practicable.
Each Copermittee that implements a waiver program may at its option also develop a
SUSMP waiver impact fee program, to require project proponents who have received
waivers to transfer the savings in cost, or a proportionate share thereof, as determined
by the Copermittee, to a storm water mitigation fund. Each Copermittee. shall notify the
RWQCB if a SUSMP waiver impact fee program is developed pursuant to this model
SUSMP. Further details for any SUSMP waiver impact fee program may be set out in
jurisdictional SUSMP submiSSions, or in supplemental submissions if multiple
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·' Copermittees establish a joint mitigation fund program for that watershed.
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This model SUSMP does not preclude Copermittees or groups of Copermittees from
imposing any other fees or charges on development projects that are permitted by law,
or from managing or expending the monies received from such non-SUSMP programs
in any manner authorized by law .
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APPENDIX A
STORMWATER BEST MANAGEMENT PRACTICES
The following are a list of BMPs may be used to minimize the introduction of pollutants
of concern that may result in significant impacts to receiving waters. Other BMPs
approved by the Copermittee as being equally or more effective in pollutant reduction
than comparable BMPs identified below are acceptable. See Appendix B: Suggested
Resources for additional sources of information. All BMPs must comply with local
zoning and building codes and other applicable regulations.
Site Design BMPs
Minimizing Impervious Areas
• Reduce sidewalk widths
• I ncorporate landscaped buffer areas between sidewalks and streets.
• Design residential streets for the, minimum required pavement widths
• Minimize the number of residential street cul-de-sacs and incorporate
landscaped areas to reduce their impervious cover.
• Use open space development that incorporates smaller lot sizes,
• Increase building density while decreasing the building footprint
• Reduce overall lot imperviousness by promoting alternative driveway
surfaces and shared driveways that connect two or more homes together
• Reduce overall imperviousness associated with parking lots by providing
compact car spaces, minimizing stall dimensions, incorporating efficient
parking lanes, and using pervious materials in spillover parking areas
Increase Rainfall Infiltration
• Use permeable materials for private sidewalks, driveways, parking lots, and
interior roadway surfaces (examples: hybrid lots, parking: groves, permeable
overflow parking, etc.)
• Direct rooftop runoff to pervious areas $uch as yards, open channels, or
vegetated areas, and avoid routing rooftop runoff tp the: roadway orthe urban
runoff conveyance system
Maximize Rainfall Interception
• Maximizing canopy interception and water conservation ,by preserving
existing native trees and shrubs, and planting additional native or dr.ought
tolerant trees and large shrubs.
Minimize Directly Connected Impervious Areas (DCIAs)
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• Draining rooftops into adjacent landscaping prior to discharging to the storm
drain
• Draining parking lots into landscape areas co-designed as biofiltration areas
• Draining roads, sidewalks, and impervious trails into adjacent landscaping
Slope and Channel Protection
• Use of natural drainage systems to the maximum extent practicable
• Stabilized permanent channel crossings
• Planting native or drought tolerant vegetation on slopes
• Energy dissipaters, such as riprap, at the outlets of Rew storm drains,
culverts, conduits, or channels that enter unlined channels
Maximize Rainfall Interception
• Cisterns
• Foundation planting
I ncrease Rainfall Infiltration
• Drywells
Source Control BMPs
• Storm drain system stenciling and signage
• Outdoor material and trash storage area designed to reduce or control
rainfall runoff
• Efficient irrigation system
Treatment Control BMPs
Biofilters
• Grass swale
• Grass strip
• Wetland vegetation swale
• Bioretention
Detention Basins
• Extended/dry detention basin with grass lining
• Extended/dry detention basin with impervious lining
Infiltration Basins
• Infiltration basin
• I nfiltration trench
• Porous asphalt
• Porous concrete
• Porous modular concrete block
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Wet Ponds and Wetlands
• Wet pond (permanent pool)
• Constructed wetland
Drainage Inserts
• OiVWater separator
• Catch basin insert
• Sto rm drain inserts
• Catch basin screens
Filtration Systems
• Media filtration
• Sand filtration
Hydrodynamic Separation Systems
• Swirl Concentrator
• Cyclone Separator
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APPENDIXB
!1~~~i~m~~I~~~9~~~~~I!!!!!!!!iiiiiiii!!!!!!!!!i!m!!!!!!ll!/!!!!!!!! ! !!~~~!ffi§I~~~!~!~~~II!!!illllll!!!!!!I!!!!!II!!!ill!I!II!!!!!!ll!lll!!!lmmm
Beiter Site Design: A Handbook for Changing Center for Watershed Protection
Development Rules in Your Community (1998) 8391 Main Street
Ellicott City. MD 21043
Presents guidance for different model development 410-461-8323
alternatives. www.cwp.org
California Urban runoff Best Management Los Angeles County Department of Public Works
Practices Handbooks (1993) for Construction Cashiers Office
Activity. Municipal. and Industrial/Commercial 900 S. Fremont Avenue
Alhambra. CA 91803
Presents a description of a large variety of 626-458-6959
StructuralBMPs. Treatment Control. BMPs and
Source ControlBMPs
Caltrans Urban runoff Quality Handbook: Planning Califomia Department of Transportation
and Design Staff Guide (Best Management P.O. Box 942874
Practices Handbooks (1998) Sacramento. GA 94274-0001
916-653-2975
Presents_guidance for desiQn of urban runoff BMPs
Design Manual for Use of Bioretention in Prince George's County
Storm water Management (1993) Watershed Protection Branch
9400 Peppercorn Place. Suite 600
Presents guidance for designing bioretention Landover. MD 20785
facilities .
Design of Stormwater Filtering Systems (1996) by Center for Watershed Protection
Ricflard A. Claytor and Thomas R. Schuler 8391 Main Street
Ellicott City. MD 21043
Presents detailed engineering guidance on ten 41 0-461-83~3
different urban runoff-filtering systems.
Development Planning for Stormwater Los Angeles County
Management, A Manual for the Standard Urban Department of Public Works
Storm water Mitigation Plan (SUSMP), (May 2000) httg:lldgw.co,la.ca.us/egdi or-
httQ:llwww.888deanLA.com
-
Florida Development Manual: A Guide to Sound florida Department of the Environment 2600
Land and Water Management (1988) Blaiffitone Road. Mail Station 3570
Tallahassee. FL 32399
Presents detailed guidance for deSigning BMPs 850-921-9472
Guidance Specifying Management Measures for National Technical Information Service U.S.
Sources of Nonpoint Pollution in Coastal Waters Department of Commerce
(1993) Report No. EPA-840-B-92-002. Springfield. VA 22161
800-553-6847
Provides an overview of. planning and design
considerations. programmatic and regulatory
aspects. maintenance considerations. and costs.
Guide for BMP Selection in Urban Developed ASCE Envir. and Water Res. In!,rt.
Areas (2001) 1801 Alexander Bell Dr.
Reston. VA 20191-44QO
(800) 548-2723
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Low-Impact Development Design Strategies -
An Integrated Design Approach (June 1999)
Maryland St(JlnnllVatl"lr Design Manual (1999)
Presents guidance for designing urban runoff
BMPs
National Storm water Best Management Practices
(BMP) Database, Version 1.0
Provides data on performance and evaluation of
Ps
National Storm water Best
Database (2001)
Operation, Maintenance and Management of
Stormwater Management (1997)
Provides a thorough look at storm water practices
including, planning and design considerations,
programmatic and regulatory aspects,
m~intenance considerations, and costs.
Prince George's County, Maryland
Department of Environmental Resource
Programs and Planning Division
9400 Peppercorn Place
Largo, Maryland 20774
http://www.co.pg.md.us/GovemmentiDERIPPDlpg
I\n",r\fl",r.rI Department of the Environment
2500 Broening Highway
Baltimore, MD 21224
410-631-3000
American Society of Civil Engineers
1801 Alexander Bell Drive.
Reston, VA 20191
703-296-6000
Potential Groundwater Contamination from Report No. EPAl600lR-94/051, (1994).
Intentional and Non-Intentional Stormwater
Infiltration
Preliminary Data of Urban runoff Best
Management Practices (August 1999)
2
Reference Guide for Storm water
Management Practices (July 2000)
Detailed discussion of BMP designs presented to
conserve water, improve water quality, and
Detailed discussion of permeable pavements and
alternative driveway designs presented.
City of Los Angeles
Urban runoff Management Division
650 South Spring Street, th Floor
Los Angeles, California 90014
Tree People
12601 Mullholland Drive
Beverly Hills, CA 90210
(818) 623-4848
Fax (818) 753-4625
Bay Area Management Agencies
Association
2101 Webster Street ,
Suite 500
Oakland, CA
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water Management in Washington State
(1999) Vols. 1-5
Presents detailed guidance on BMP design for new
development and construction.
Stormwater, Grading and Drainage Control Code,
Seattle Municipal Code Section 22.800-22.808, and
Director's Rules, Volumes 1-4. (Ordinance
119965, effective July 5, 2000)
Presents BMP design and guidance information
Department of Printing
State of Washington Department of Ecology
P.O. Box 798
Olympia, WA 98507 .. 0798
360-407-7529
City of Seattle
Department of Design, Construction & Land
Use -
700 5th Avenue, Suite 1900
Seattle, WA 98104·5070
(206) 684-8880
http://www.ci.seattle.wa.usldcluICodes/sgdccode.h
The Practice of Watershed Protection by Thomas for Watershed Protection
R. Shchuler and Heather K. Holland 8391 Main Street
Ellicott City,_ MD 21043
410-461-8323
Urban Iltlnl'Un' -Volume Urban and District
3, Best Management Practices (1999)
Presents
FINAL MODEL SUSMP
Jointly Developed by
San Diego Co-Pemlittees 2/7102
BMPs
2480 West 26th Avenue, Suite 156·8
Denver, CO 80211
303·455-6277
Page 42 of 39
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Table 9 (Page 1 of 8)
Storm Drain System Maintenance Activities
Best Management Practices
Best Management Needed to Reduce or
Practices Currently in Minimize Potential for
Activity Area Priority Pollutants Place Pollutant Discharge
Catchllnlet Basins
Catch basin cleaning Streets and HIGH Sediment, trash, 1. I nspect, "pluck" large 1. Vactor Truck Cleaning; 2. EPA
, Roadways debris debris, clean if needed Storm Water Fact Sheet -Catch
Basin Cleaning; 3. National Menu
of BMPs -Catch Basin Cleaning;
·4. EPA 'Storm Water Fact Sheet-
Hydrodynamic Separators; 5.
Perform Work in Dry Weather
(Section 2.2.6)
Inlet filter pla~ement Streets and HIGH Nutrients, trash, 1. Consider installation ,of drain
Roadways debris filters; 2. Consider Ultra Urban
BMP Inlet Devices -for <5 acre
drainage areas if drain 'filters do
not accomplish goal to reduce
targeted pollutants
Inlet filter cleaning or Streets and HIGH Sediment, trash, ' 1. According to·manufacturer's
replacement Roadways debris instructions; 2. Dispose of
materials or used filters as .solid
waste if appropriate; 3. Documenl
inspections, cleaning, volume of
material, replacement activities;
, 4. Perform Work in Dry Weather
(Section 2.2.6)
_ ___ ___ ~ __ ~_ .. _ __~L--________ ---': __
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Table 9 (Page 2 of 8)
Storm Drain System Maintenance Activities
Best Management Practices
Best Management Needed to Reduce or
Practices Currently in Minimize Potential for
Activity Area Priority Pollutants Place Pollutant Discharge
Vactor equipment Streets and HIGH Sediment, trash, 1. Dry collected materials in
cleaning Roadways debris special designated area(s); 2.
Dispose of dried materials as
solid waste if appropriate; 3.
Perform Work in Dry Weather
(Section 2.2.6)
Disposal of wastes Parks; Streets and HIGH Sediment, 1. Dispose as solid waste 1. Solid Waste Management
. Roadways; nutrients, trash, (Section 4.5.11); 2. Hazardous
Maintenance debris Waste Management (Section
Yards; 4.5.11)
Adm inistration
Buildings
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Table 9 (Page 3 of 8)
Storm Drain System Maintenance Activities
Best Management Practices
Best Management Needed to Reduce or
Practices Currently in Minimize Potential for
Activity Area Priority Pollutants Place Pollutant Discharge
Brow .. V" Ditch
Brow ditch maintenance Parks; Streets and HIGH Sediment, 1. Inspect, repair, clean as 1. Dry Clean Methods; 2. National
Roadways; nutrients, trash, necessary Menu of BMPs -Storm drain
Maintenance debris system cleaning; 3. Perform
Yards; Work in Dry Weather (Section
Administration 2.2.6)
Buildings
Disposal of wastes Parks; Streets and HIGH Sediment, 1. Dispose as solid waste 1. Solid Waste Management
Roadways; nutrients, trash, (Section 4.5.11); 2. Hazardous
Maintenance debris Waste Management (Section
Yards; 4.5.11)
Administration
Buildings
. Disposal of debris Parks; Streets and LOW Organic . 1. Dispose as solid waste 1. Solid Waste Management
Roadways; material,trash, (Section 4.5.11); 2. Hazardous
. Maintenance debris Waste Management (Section
Yards; 4.5.11)
Administration
Buildings
CUlverts
Culvert maintenance Streets,and HIGH Sediment, .1. Inspect, repair, C1el:!n as 1. Dry Clean Methods; 2. Nationa
Roadways nutrients, trash, necessary Menu ofBMPs -Storm drain
debris system cleaoing; 3. Perfor,m
Work'in Dry Weather (Section
,I
!
2.2.6)
• • •
Table 9 (Page 4 of 8)
Storm Drain System Maintenance Activities
I
Best Management Practices
Best Management Needed to Reduce or
Practices Currently in Minimize Potential for
Activity Area Priority Pollutants Place Pollutant Discharge
Culvert replacement Streets and LOW pH 1. Remove and dispose as 1. Solid Waste Management
Roadways solid waste (Section 4.5.11); 2. Hazardous
Waste Management (Section
4.5.11); 3. Perform Work in Dry
Weather (Section 2.2.6)
Disposal of debris Parks; Streets and LOW Organic 1. Dispose as solid waste 1. Solid Waste Management
Roadways; material, trash, (Section 4.5.11); 2. Hazardous
Maintenance debris Waste Management (Section
Yards; 4.5.11)
Administration
Buildings
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Table 9 (Page 5 of 8)
Storm Drain System Maintenance Activities
Capital
Improvements
Needed to Schedule for BMP
Implement BMP Implementation Goal
1. Vactortruck -S140K; 1. September 1, 2002; 50% of Catch Basins
2. Hydrodynamic 2. September 1, 2003 cleaned by September 1 ,
Device -S15Kfcatch 2002
basin (includes 90% of Catch Basins
installation) cleaned by September 1,
2003
1. Install 175 filters in 1. September 1,2002; Complete assessment of
high volume area~ @ 2. September 1, 2003 Inlet Filters by
S2001fj1ter; 2. September 1, 2002
Construction Cost S600 Install at high flow areas
S900 each (clean by September 1,2003
annuallv)
1. September 1,2004
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Table 9 (Page 6 of 8)
Storm Drain System Maintenance Activities
Capital
Improvements
Needed to Schedule for BMP
Implement BMP Implementation Goal
1. September 1, 2002 Purchase Vactor
Equipment by June 1,
2002
1. September 1, 2002
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Table 9 (Page 7 of 8)
Storm Drain System Maintenance Activities
Capital
Improvements
Needed to Schedule for BMP
Implement BMP Implementation Goal
1. September 1,2002 50% of Brow Ditches
cleaned by September 1,
2002
90% of Brow Ditches I
cleaned by September 1,
2003
1.$eptember 1, 2002 ' Inspect 80% of major
~ulverts by September 1,
2002
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Table 9 (Page 8 of 8)
Storm Drain System Maintenance Activities
Capital
Improvements
Needed to Schedule for BMP
Implement BMP Implementation Goal
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Section 4
Commercial Component
Section 4
Commercial Component
4.0 Overview
The City of Carlsbad currently has over 500 high priority commercial facilities operating within its
jurisdiction. Commercial facilities can generate a variety ofpollutants depending on the activities performed.
Automobile maintenance, carpet cleaning, and landscaping activities have the potential.togerterate significant
amounts of pollutant<;, if performed with disregard to the environment. Even in small qu~ntities, these-
pollutants can combine in the storm water conveyance system and cause significant degradation-to receiving
waters. In order to determine specific potential sources, a comprehensive database of commercial facilities
within the City has been compiled and high priority facilities have been selected based on threat t9 water
quality. This prioritization process will determine the appropriate minimum BMPs for the commerci~1 sites
and sources.
This section discusses Permit requirements that apply to the Commercial Component of the Jurisdictional
Urban Runoff Management Plan (JUR~) and actions proposed by the City of Carlsbad to minimiz~ poll:uted
runoff. This section meets or exceeds minimum requirements as specified in Section H ofthe Permit. The
following subsections address storm water nmoff issues from commercial sites and sources and how the City
of Carlsbad will minimize those impacts on receiving water quality:
• Pollution Prevention (Section 4.1)
• Source Identification (Section 4.2)
• Best Management Practices Implementation (Section 4.3)
• Inspections of Commercial Sites and Sources (Section 4.4)
• Enforcement of Commercial Sites and Sources (Section 4.5)
Subsections 4.1 through 4.5 use a table format to briefly summarize the purpose of the subsection, quote the
applicable regulatory requirements from Sections F and H of the Permit (italicized), and li~ the City's action
plans. The rest of the subsection describes the specific actions that have been completed, are in progress, or
are planned for fixture implementation.
The types of information that should be collected for lIse in preparing the Annual Report and
Assessment'Evaluation of the JURMP is outlined in Section 11 of this JURMP, Assessment ofJurisdictional
URMP Effectiveness Component .
Ci{i' oj'CarlshadJurisdiclional Urhan Rultojj'M(lfUlgemem Plait -4-1
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Section 4
Commercial Component
4.1 Pollution Prevention
4.1.1 Purpose and Permit Requirements
Purpose
NPDES Permit
Order No. 2001-01
Requirement(s)
Jurisdictional
URMP
Requirements
City Action Plan
The purpose of this Permit requirement is to evaluate th~ pollution
prevention opportunities applicable to commerCial sites and sources for
preventing or red1.1cing pollutants from entering the storm drain system.
The Permit requirement under the Commercia] Component for
Pollution Prevention is as follows:
Section F.3.c.(l)
Each Copermillee shall imp/emeltl pollution prevemion methods ilt its
Commercia/ (Exisling Developmem) CompoltelU altd s/wll require its u,<;e
by commerce, where appropriate.
The Permit requirement under the Commercia] Component for
Po]]ution Prevention is as fo]]o\\,s:
Section H.l.a.(4)(a)
Which pollution prevemion method~ will he required for implemelUatioll;
(JIui how and wltere tltey will be required.
1) Develop a list of pollution prevention opportunities for commercial
facilities.
2) Encourage commercial facilities to develop and implement Storm
Water Pollution Prevention Plans .
City oj'Car/sbad.Jurisdictiolla/ Urh(JIt RUllofj'M(JIUlgemelU Plait 4-2
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Section 4
Commercial Component
4.1.2 Pollution Prevention Action Plan
Action #1 -Develop a list of po]]ution prevention opportunities for commer.cia] sites ,a:ndsources.
Pollution prevention is defined as practices and processeS that reduce or eliminate the generation of
pollutants. There are four key components to a pollution prevention program and a ·fifth component added for
storm water. Reviewing the following five "Rs" will assist'in identifYing the pollution prevention
opportunities available for commercial sites. The definitions ofthese terms are as follows:
• Reduce -BEFORE generating a waste stream, minimize the quant£ty or toxicity ofthe waste by
substituting nontoxic chemicals.
• Reuse -Material, unwanted in one area, may be used for its intended p1.1rpose in another area.
• Recycle -Take 1.1sed materials, reprocess, and produce a useful product in the same or other form.
• Rebuy -Purchase a product that contains recycled-content materials.
• Redirect '-Divert the flow of storm water to reduce or eliminate contact with potential pollution.
Direct storm water away from contact with known pollutants.
Pollution prevention eliminates or reduces the management ofpolluted stontI water runoff. Commercial
facilities often handle a 'variety of pollutants, both indoors and outdoors, that pose potential environmental
threats if transported by way of urban runoff. In commercial operations, pollutIon prevention strategies enable
the operator to reduce the volume of solid, liquid and hazardous wastes, as well 'as the accompanying costs of
storage, disposal or treatment. The City will recommend the incorporation of such strategies into the standard
operating procedures of all commercial facilities; whether a corporate chain store, a franchise, an independent
shop or a "mom 'n' pop" operation. The City of Carlsbad will enCOl.1rage or require the following pollution
prevention methods, when appropriate: .
• Use smaller quantities oftoxic materials or substitute less-toxic materials.
• Minimize the volume of cleaning water to decrease wastewater or use dry methods.
• Provide signage to remind or instruct employees and customers.
• Implement a spill response plan.
• Segregate and recycle wastes.
• Provide a schedule of preventive maintenance.
• 'Provide on-going training of employees in ~llution prevention methods ..
The City of Carlsbad is implementing a comprehensive Outreach and Educ~tion program, and commercial
owners and operators are one of the target audiences. The 1.1ltima:te goal of the City's storm water program is
to improve water quality and minimize polluted storm water runoff by preventing it at the "source". With
effective pollution prevention measures in place, treatment or other structural controls may be 1.1nnece~ or
minimized. The City will work to achieve this outreach and education goal by implementing a systeJ(l~tic,
approach that increases knowledge and awareness ofpollution prevention measures. Commercial owners and
operators will be educated using a v-ariety of outreach methods to progreSSively achieve the key stages of
awareness and ownership of storm water runoffpollution and prevention practices by using '13est
Management Practices". The City's Outreach and Education program is described in section 9 of this
JURMP. BMPs for commercial sites and sources are further described in section 4.3 of this component.
Action #2 -Encourage commercial facllities to develop and implement Storm Water Pol1ution
Prevention Plans (SWPPPs)
City oj'CarlsbadJurt:<;dicliollal Urban RUllojj'lvkuUJ.gemem Plan 4-3
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Secticm4
Commercial Component
Pollution prevention eliminates or reduces the management of polluted storm water runoff. Commercial
sites/sources are not explicitly required to implement SWPPPs. However, the City of Carlsbad will be
conducting inspections of high priority commercial facilities, as outlined in 'section 4.4 of this component.
The City will encourage all commercial facilities to develop and implement SWPPPs appropriate for their
operation, and will retain authority within the ordinance to require SWPPPs when tbe inspector believes it is
necessary to protect water quality. Guidelines for developing a SWPPP are described in Section A otWater
Quality Order No. 97-03-DWQ, Waler Disclwrge Requirememsjor Disc/wrges oj'Storm Waler Assodaled
with Industrial Activities Excluding Construction Activities, issued by SWRCB ..
Cizv oj'ulr/sbad.Jurisdictiona/ Urban Runojj'Mmulgemem Plan 4-4
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Section 4
Commercial Component
4.2 Source Identification
4.2.1 Purpose and Permit Requirements
Purpose
NPDES Permit
Order No. 2001-01
Requirement(s)
The purpose of this Permit requirement is to generate an inventory of
Commercial Sites/Sources to focus storm water qu~lity "~fforts.
The Permit requirement under the Commercia] Component ft)r Source
Identification is as fo]]ows: "
Section F .3.c.(2)
Each Copermiliee shall develop al1d update alUtual(v (Dt invemory of the
jollowing high priori{v threat to water quali(l' commerci(u sizes/sources listed
below. (ffallY commercial site/source listed below l'> inventoried as (lit
industrial site, as required under section F.3.b.(2) of this Order, il is I10t
Ilecessary to aim invemory it as a commercial.,>ite/source).
(eJ) Automobile meciumic(J/ repair, maimeluJ.ltce,jueling, or cleaning;
(b) Airplane meciumical repair, mainteluJ.ltce,jueling; or cleaning;
(c) Boal meclumica{repair, nWimenance,jueling, or cleaning.:
(iI) Equipmem repair, maimelumce, fueling, or cleaning;
(e) Automobile and other vehicle body repair or paiming;
fj) Mobile aUlomobile or other vehicle w(Jshing,·
(g) Automobile (or mher vehicle) parking lOIS mu/ stomge j(iCilities;
(It) Retail or wholes(J/ejueling,'
(1) Pest coltlrol services,;
0) Eming or drinking establishmems,;
(k) i110bile carpet, drape or jumiture cleaning;
(1) Cement mLringorculling;
(m) Masonry;
(n) Palming mu/ coating;
(0) BOlanic(u or zoological gardens mu/ exhibilS;
(j)) Landscaping;
(q) Nurseries mu/ greenhouses;
(I') Golfcourses, parks and other recre(Jtiona/ (JreaS1(lcilities;
(.~) Cemeteritw;
(i) Pool arul jowtUlin clemting;
(iJ.) Marinas;
(i:) POrl-tl-POIlY servicing;
(it:) Other commercitJ! sites/sources tlu1tthe Copermjllee determinesm(~v
coltlribUle a sigltijicam pollutamlo(ulto the M..W;
(.'r) A1tl' commercial site or source tributary to a Clean' Water Act section
303(iI) impaired wmer bod)~ where tlte site or source generates
pollUlamsjor which the water body is impaired,; and
0:) A1tl' commercial site or source within or direct{l' ai{jacenz'td or
dl'>citarging directb' to a coastal klgoon or miter receiving water withilt
an environmemal(v sel'lsitive area (e1s dejined in F.l.b(2)(a)vii of this
Order).
The use of an (Jutommed database system, such a.,>' Geograpiticallnjorhlmiolt
City of Carlsbad Jurisdictioltal Urban RunoJI Malu1gemem Plan 4 .. 5
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Jurisdictional
URMP
Requirements
City Action Plan
l~~'Stem (Gm) is high{~' recommended, but {'lot required.
$ection4
Commercia/Component
The Permit requirement under the Commercia1 Component for Source
Identification is as follows:
Section H.l.a.(4)(b)
A completed watershed-h(lSed inventory o/hig~z priori(l' commercial sites.
1) Generate an electronic list l.1Sing spreadsheet software and GIS map of
commercial facilities by watershed.
2) Annually update list and map of commercial areas .
City o/Carlsbad.Jurisdictional Urban RunojIM(J/wgemem Plan 4-6
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Section 4
Commercial Component
4.2.2 Source Identification Action Plan
Action #1 -Generate a ]ist and GIS map of commercial areas by watershed.
D-Max Engineering, Inc. (D-M~) was contracted to identifY commercial facilities within the City of
Carlsbad. To accomplish this, D-Max reviewed the following databases and listings:
1. City of Carlsbad husiness license listing;
2. County of San Diego hazardous materials and waste listings; and,
3. Encina Wastewater Authority list of facilities with wastewater discharge permits.
Using this information, commercial sites/sources were analyzed using the criteria de..o;cTfbed b¢low. Currently,
525 high priority commercial facilities have been identified within the City ofCatlsbad·and ate presented in
Appendix C, Table 4-1. An additional 65 facilities were found in the County of San Diego listing that did not
have similar records with the City of Carlsbad. These facilities require further review and have been listed
separately in Appendix C, Table 4-2. Fourteen industrial and commercial facilities \Vere found in the Encina
Wastewater Authority records that did not have similar records with the City or County. These facilities are
presented in Appendix C, Table 3-9 with the Industrial inventory component and require fi.lrther review by the
City. The inventory will be updated and revised annually.
High Priority Criteria
The permit defines the following twenty-two (22) types of commercial sites/sotuces that must be considered a
high priority threat to water quality:
1. Automobile mechanical repair, maintenance, file ling 'or cleaning;
2. Airplane mechanical repair, maintenance, fueling, or cleaning;
3. Boat mechanical repair, maintenance, iileling, or cleaning;
4. Equipment repair, maintenance, fueling, or cleaning;
5. Automobile and other vehicle body repair or painting;
6. Mobile automobile or other vehicle washing;
7. Automobile (or other vehicle) parking lots and storage facilities;
8. Retail or wholesale fueling;
9. Pest control services;
10. Eating or drinking establishment,,;
11. Mobile carpet, drape or furniture cleaning;
12. Cement mixing or cutting;
13. Masonry;
14. Painting and coating;
15. Botanical or zoological gardens and exhibits;
16. landscaping;
17. Nurseries and greenhouses;
18. Golf courses, parks and other recreational areas/facilities.;
19. Cemeteries;
20. Pool and fountain cleaning;
21. Marinas; and
22. Port-a-potty servicing.
In addition to the criteria listed above, the City also considered the following site attributes to evaluate the
potential threat to water quality:
Ci{~' of CiJ.risb(J.d Jurisdictional Urban RUllojj"Malwgemem Pkm 4-7.
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Section'4·
Commerciai' Component
• Proximity and sensitivity to receiving water bodies. The potential for pollutant transportto
sensitive receiving water bodies was evaluated by determining the proximity and sen~itivi1Y of
receiving water bodies. Using the definitions from section F .1.b.(2)(a)viiofthe Permit, it was
determined that the City of Carlsbad contains the following environmentally sensitive areas
(ESA's):
o Buena Vista Lagoon (RARE Beneficial Use, 303(d) impaired)
o Buena Vista Creek (RARE Beneficial Use)
o Agl.1a Hedionda Lagoon (RARE Beneficial Use, 303( d) impaire~)
o Agl.1a Hedionda Creek (proposed 303( d) for 2002)
o Multiple Habitat Conservation Program Biological Core and Linkage Areas
o Sensitive Vegetation Buffers as determined by the City of Carlsbad .
All facilities directly discharging to or within 200 feet of the ES~ listed above were considered high priority.
• Commercial sites/sources contributing significant poUutant loads to the MS4. Dry weather
field screening and analytical monitoring results were evaluated to identify any commercial
sites/sOl.1rces that contribute significant pollutant loads to the MS4. Complaints, "lolatioTIs, and
field investigation reports were also reviewed, where available, to identify such sites.
• Commercia] facilities with Pretreatment Waste Permits. C.ommercial facilities possessing
Pretreatment Wastewater Permits were identified using a listing from· the Encina Wastewater
Authority and are noted with a double-asterisk in the tables at the end of this document.
The City of Carlsbad has generated a watershed-based map using GIS technology, and the commercial
sites/sources identified by D-Max were entered into the GIS map. Figure 4-1 (belmv) provides the ,~sual aid
to indicate the location of each commercial facility by name and type offacility. The complete commercial
inventory is f01md in Appendix C.
Fi lfe 4-1
Characteristic or Criteria
Facility
Location
Watershed
. Type of Commercial Activity
Definition
Commercial Facilities as provided by D-MaxEngineering, Inc. and
identified by regional maps.
Address from City of Carlsbadlrhomas ('1l,1ide or nearest street used as
locator in placing the Facility within a GIS framework.
The hydrologic unit within the Carlsbad watershed.
Narrative description including SIC Codes that best reflect the principal·
products or services provided by the facility .
Ci{v of Carlsbad Jurisdictional Urban Runoff M(JfuJgemelll Platz 4-8
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Generated Wastes
High Priority (Permi~)
Section 4
Commercial Component
As listed in Permit Order No. 2001-01, Finding tt7, Pollutant Types:
Suspended solids
Sediment*
Nutrients (nitrogen and phosphoms fertilizers)*
Pathogens (bacteria*, vimses, protozoa)
Heavy metals (copper, lead, zinc, and. cadmium)
Petroleum products/PARs
Pesticides, Herbicides, PCBs
Oxygen-demanding substances (decaying vegetation, animal wast~)
Trash
*303(d) water bmJies listed poUutants
Commercial Permit Order No. 2001-01, Section F.3.c.(2) defines the 22
types of commercial sites/sources that must be considered a high priority
threat to water quality.
Action #2 -Annua]]y update 1ist and map of commercia1 sites.
The City of Carlsbad plans to inspect commercial sites at the frequencies specified in ·Section 4.4 of this
component. The inspections will provide current commercial information that wUI be used, to annually update
the database and map of high priority commercial sites. These changes will be identified in the Annu~
Report to the San Diego Regional Water Quality Control Board .
CifY oj'Carisbad.JurisdicIioltal Urban RunojfMalUlgemem Plan 4-9
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Section 4
Commercial Component
4.3 Best Management Practices Implementation·
4.3.1 Purpose and Permit Requirements
Purpose
NPDES Permit
Order No. 2001· 01
Requirement(s)
Jurisdictional
URMP
Requirements
City Action Plan
The purpose of this section is to list theBMPs best suited for each priority
category defined in Section 4.2 of this JURMP and how those BMPs will be
implemented.
The Permit requirements under the Commercial Component Best
Management Practices Implementation are a~ fonoWs:
Section F .3.c.(3)( a)
Each Copermillee shall desiglUlte a set 0/ millimUm Blv!Ps jor the high
priority threat to water quality commercitJI sites/sources (listed above in
section F.3.c.(2)). The desigluued minimum BMPsjor the high threat to
water quali{~' commercial sites/sourcf~~ siuJIl be site alldsource specijic (L~
appropriate.
Section F .3.c.(3)(b)
Each Copermillee shall implemeilt, or require the implemeltlation oj; the
dfwigllated minimum BMPs at each high priority threat to water quality
commercial site/source withill itsJurisdictioll. l/panicular millinmm mvlPs
are injeasible jor allY specific site/source, each Copermillee shall. implemelll,
or require the implemeillation oj; other equivaleJll BIv!Ps .. Each Copermillee
shall alm implemelll or require aI~~' additional site specific BMPs as
necessary 10 comp(v with this Order.
Section F.3.c.(3)(c) .
Each Copermillee slUlll implemelll, or require implementation oj; additiO/UlI
cOlllro/sjor commercial sites or sour£~es tribuwry to Clean Water Act section
303(d) impaired water bodies (i11here'asite or sourcegel1erauWpOIlUlalllsjor
which the water body is impaired) as Ilecessary to compb' with this Order.
Each Copermillee sluJll implemelll, or require implementation oj; additl()luJi
comrols jor commercial sile~ or sources within or direct(~' tKljacem 10 or
dl~c/uJrgillg directb' 10 coaswl kJgool1s or Qther receiving waters within
ellvironmeillalb' semitive (veas (as defined in section F.J,b.(2)(a)(vU) o/this
Order) as necess(vy 10 comp(~' with this Order.
The Permit requirements under the Commercia] Component for Best
1Vlanagement Practices Imp1ementation are as fol1ows:
Section H.l.a.(4)(c)
Which BIv!Ps will be implemellled, or required 10 be implemel1led, jor high
priority site~.
Section H.l.a.(4)(d)
How BMPs will be implemellled, or required tf) be implemellled,jor high
priority site~.
1) Develop a list ofBMPs for high priority commercial sites and sources.
2) SpecifY how BMPs will be implemented for each category .
City of Carlsbad Jurisdictional Urban Runojf MalUlgemelll Pkm 4-10
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. Section 4-
Commerc;ial Component
4.3.2 Best Management Practices Implementation Action Plan
Action #1 -Deve]op a list ofB1\IIPs for high priority commercia] sites and sources.
BMPs are crucial to the success of nmoff control in growing urban areas. The use ofBMfs can be an ever-
changing process. In order to be effective, BMPs must be properly implemented and assessed. If the desired
result is not being achieved, the BMPs should be modified or changed. The ch~nge could be anew
technology or it could simply be a creative use of an existing application. BMPsmust be selected that are
appropriate to prevent or mitigate pollution generated from the specific activities at the site, and may be
selected based on the information learned from the facility inspection.
1) "/'Ii on-Structural B1\IIPs
Non-structural BMPs are procedures and practices that prevent pollutants from entering storm ,vater. Because
of their low cost and simplicity, non-stmctural BMPs should be considered first in the development of a
mcility's SWPPP or BMP program. Many of these methods may already exist as part of the standard
operating procedures for a site: .
o Good housekeeping;
o Preventive maintenance;
o Material handling and storage of significant materials;
o Employee training;
o Solid waste (non-hazardous) handling and recycling;
o Record keeping;
o Selfinspectionlquality assurance; and
o Spill response plan.
2) StructuralB1\IIPs
Structural BMPs consist of specialized equipment, structural components, or engineered technologies that can
be used when non-structural BMPs are ineffective. Becau')e structllTal BMPs are .site specific, the mcility
operator needs to evaluate each proposed use. Proper installation and regular maintenance of structllTal BMPs
are imperative to their effectiveness. Following are some examples ofstructutal BMPs:
o Overhead coverage of outdoor work areas or storage;
o Retention ponds, basins, or surface imp01.mdments that confine storm water to .tpe site;
o Berms and concrete swales or channels that divert nm-on and runoff a,vay from pollutant S01.1rces;
o Secondary containment structures; and
o Treatment controls, e.g., infiltration devices and oiL/water separators, to reduce pollutants in
storm water or authorized non-storm water discharges.
3) High Priority Commercia] Sites and Sources
Permit section F .3.c.(2) describes high priority commercial sites, cas designated by the SDRWQCB,
requiring a set of minimum BMPs. The City will consider the following activities when assisting with or
reviewing the BMP plan for a particular facility: .
o Loading/unloading;
Ci~l' of ujrlsbad Jurisdiclional Urban Runof/ M(uUlgemeIU Plan 4-11
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o Fueling;
o Landscaping/grounds keeping;
o Washing equipment and/or vehicles;
o Cleaning and maintaining parking lots.;
o Storing significant materials;
o Storing equipment and/or vehicles;
o Cleaning and maintaining of equipment on rooftops;
o Storing solid wastes;
o Discharging liquid wastes; and
o Controlling pests.
Section 4
Commercial Component
Not all of the aforementioned activities may pertain to a site, so BMPs applicable to the particular site will be
selected after the site inspection. BMP mam1als will be cqnsulted; examples are listed in the source list found
in Section 15.
The City may develop business or activity specific BMP booklets or guidance, ifthe grouping approach
provides the most effective and efficient means of informing and educating a particular commercial facility
type. As part of the inspection program, the City will analyze the feasibility of grouping commercial facilities
for the purpose of developing specific BMP information; this effort will also be reviewed at the Watershed
level with other cities in the North County to identify fi.lrther oppornmities not available at the local level.
4) Hazardous Materials Management
Many commercial facilities handle hazardous materials during different stages of operation. All hazardous
materials and hazardous wastes mtlst be handled, stored, or disposed of as required by all applicable local,
State, and Federal regulations.
For more information, facil ity operators may be directed to contacttheir County HazardotlS Materials
. inspector or the County HazardotlS Materials Division duty specialist at (619) 338-2231.
Operators of plant (flora) production facilities (greenhouses and nurseries) and certain non-plant-production
operations (golf courses, pest control services, botanical or zoological gardens, cemeteries, parks, and
recreational facilities) may also be referred to the County Department of Agriculture, Pesticide Regulatory
Program, at (858) 694-3122 for information regarding the storage and handling of hazardous materials and
wastes.
Action #2 -Specify how B1\tIPs wiD be implemented for each commercial category.
1) Outreach and Education
The City's Storm Water Outreach Team has developed commercial activity BMP booklets for distribution to
target audiences. The "ResUJuram Best ii,1anagemem Praclices" booklet, in both English and Spanish
versions, was the first of the series. The City also held workshops and provided a model SWPPP with BMP
information for Auto Dealers and Auto Repair Shops. In the coming year, the City antici~tes developing
several other BMP booklets. Target commercial audiences or groups under consideration at this time incltide
impervious surface cleaning, mobile vehicle ,\laShing, landscaping, and pool and spa service. This
information will be made available at workshops, training sessions, and meetings organiZed by the City or
with the collaboration of business associations or groups .
Ci{l' ofCarishad.Jurisdiclional Urban RUl1ojj'lvf(J./wgemem Plan
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2) FaciJity inspections
Section 4
Commercial Component
The City of Carlsbad will require commercial sites and sources to implement BMPs and the effectivene.ss of
BMPs will be evaluated during inspections. In response to Section F.3.c.(3)(c), additional controls, if
warranted, will be implemented for commercial sites or sources tributary to Clean Water Act section 303(d)
impaired waters or other receiving waters within Emfironmentally Sensitive Areas.
Commercial business employees must be trained to understand the requirements of the SWPPP or the BMPs
for the activities at each facility. During inspections, City staffwill verii)rthat on-going training is being
conducted as required.
3) S,\YPPP Review
In some cases, commercial busines..<;es may have been required to submit a SWPPP as a condition· for
developing or building the facility. The SWPPP and BMPs will be reviewed during routine inspections to
ensure that they are being implemented effectively .
CiZ~' oj'Carlsbad.Jurisdiclioltal Urban RunojIMmuJgemelU Plan
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Section 4
Commerclai Component
4.4 Inspection of Commercial Sites
4.4.1 Purpose and Permit Requirements
Purpose
NPDES Permit
Order No. 2001-01
Requirement(s)
Jurisdictional
URMP
Requirements
City Action Plan
The purpose ofthis section of the Commercial Component is to developaJi
inspection protocol for sites and sources that have a high potential for
impacting storm water qUality. .
The Permit requirement under the Commercial Component for
Inspections of Commercia] Sites is as follows:
Section F .3.c.( 4)
Each Copermillee shall inspect high priority commercial sites (JIulso'U.rces
as needed. B(J.<;ed upon site inspectionjindiltgs. each Copermillee shall
implemem all jollow-up actions necessary to comp(~' with this Order.
The Permit requirements under tJ1e Commercia] Component for
Inspections of Commercia] Sites are as follows:
Section H.l.a.(4)(e)
Planned inspection ji·equencies jor high priori{~' sites.
Section H.l.a.(4)(t)
Methodsjor inspection
1) Establish inspection frequencies for high priority commercial sites.
2) Develop an inspection procedme for the..<;e high priority sites ahd
sources .
City of Carlsbad Jurisdictional Urban Runojj'M(JIuJgemem Plan 4-14
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Secfjon4
Commercial Component
4.4.2 Inspection of Commercial Sites Action Plan
Action #1 -Determine inspection frequencies for these facUities.
Permit section F.3.c.(4) states that high priority commercial sites and sources arc to be i11spected' a.~
11eeded. An inspection includes, but is not limited to, a review ofBMP implementation plans and an
assessment of their effectiveness. The inspection results will provide additional information for updating the
watershed-based inventory database required by Permit section F.3.b.(2).
The City plans to inspect high priority commercial sites every other year, with approximately half being
inspected during the first year of this JURMP and the remainder inspected ci'tuing the seco,nd year, Due to the
high number of commercial facilities in the City, this inspection frequency may be modified if resources are
limited. To facilitate compliance by commercial facilities, the City may coordinate inspections with planned
workshops and BMP booklet development aimed at specific commerci!ll activities (Le., restaurant BMPs,
mobile washing, landscaping, etc.).
The City will also investigate all complaint'> of illegal discharges from-commercial si~es made by the public or
another agency or those arising from the results of dry-weather field screening and analytical monitoring.
Investigations of illicit discharges will be performed according to the proced1.ireS described in Component 8 of
thisJURMP.
Action #2 -Deve]op an inspection procedure for these commercia1 sites •
1) Goal The City will inspect a commercial site to determine ifthe facilities and operations are in
compliance with the Permit and local ordinances, and to review and asSess the BMP implementation plans
to determine their effectiveness. To accomplish this goal, the City may provide educational materials and
technical or regulatory updates, review SWPPPs (if avail!lble), provide feedback about BMPs appropriate
for a given activity, and identify any illicit discharges and connections to the storm water conveyance
system.
Types ofTnspections.
a. Advisory inspections. The City plans to conduct advisory inspections for most flrsttime faCility
inspections, and to follow these 1.1p with compliance inspections. Advisory inspections will be
announced inspections, so that the inspector can meet with the responsible facifity owner/operator
in order to provide more efficient communication of the storm water req1,1irements and inspection
goals. An advisory inspection will focus on current operations, BMPs in u!!e,.and the
effectiveness of those BMPs.
b. Compliance Inspections. A Compliance Inspection will cover the same information as an
advisory inspection, but will typically be unann01.mced in order to verify compliance and that
BMPs are being effectively implemented.
c. General Procedures. For conducting inspections, the City may use ti1e Alameda Countywide
Clean Water Program's California Industrial/Commercial StormwalerInspectiotl Program
Handbook, M(Jrch 1996, the U.S. EPA (1994) lndustrial User Inspection (md Sampling Manual
for POTW"s, or other City of Carlsbad Storm Water Protection Program procedures .
City o/Car!sbadJurisdictional Urb(JIl RUltofIM(J,fuJgemem Plan 4-15
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Section 4
Cpmmercial Component
3) Pre-inspection Preparation.
a. Purpose. The inspector needs to establish the purpose and scope bfthe in~pection and to review all
pertinent background information. For an advisory inspection, the inspector will' contact the
commercial owner or operator to schedule the inspection. The inspector may also request
that relevant documents be available for on-site review (e.g., SWPPP, site plans, spill
response plan, etc).
b. File review. The inspector will review any existing City files or information for thee business,which
may include past complaints, permits, monitoring data or submitted SWPPPs.
c. Database review. The inspector will also review the inventory database to ic;ientifY the SICc6de and
determine what type of commercial activities and pollutants may be expected. The $tabase
will identifY the sub-watershed and proximity to Clean Water Act (CW A) 303( d) water
bodies or environmentally sensitive areas (ESAs).
4) Approach to the Site
Observations. Before entering the facility grOlmds, the inspector shbuld make note of the following:
a. Nearby conveyances or water bodies;
b. Visible discharge points along the perimeter of the site,;
c. Outdoor areas of intensive commercial activity; and
d. Signs of recent additions or remodels.
5) Entry and Opening Conference
a. General procedures. The inspector will present proper credentials and will request to meet with
the appropriate business owners/operators to discuss the itJ.spection scope and objectives.
b. Denial Ifthe inspector is denied entry into the facility, the inspector will withdtaw"from the
premises and contact the Environmental Programs Manager toc).etermine if court action should be
sought to obtain entry.
c. Opening Conference. After authorized entry, the inspector will fi.lrther discuss the inspection
scope and objectives. The inspector should attempt to verifY and update ~e City's inventory
information, such as:
i. Changes in ownership or operations;
ii. Clarification of observations noted before entering the facility; and
iii. Review of the SWPPP or BMP plans, which can include these elements:
1. Site map;
2. List of activities, types ofpolh.ltants, and existing non-stmctllral and structl1ral BMPs to
reduce these pollutants in storm water discharge;
3. Pollution prevention methods;
4. Description of type and location of non-storm water discharges, both authorized and
unauthorized; and
5. Inventory of materials, including storage and loading/unloading areas .
Cilyoj'Carl"bad.Jurisdiclional Urban Rultojj'McuuJgemem Pilm 4-16
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Section 4
Commercial Component
6) Faci)ity Inspection
a. Outdoor walk through. The inspector and business official( s) should walk througJr all O1;ttdoor
areas and observe activities, wherever it is safe to do so. Typical areas of activity thatmlght
impact storm water quality include:
b.
c.
i. Wash and rinsing areas;
ii. Processing areas;
iii. Material storage area.<;;
iv. L.oading, unloading and transfer areas.;
v. Waste storage/disposal areas;
vi. Vehicle and heavy equipment storage and maintenance areas;
vii. Parking areas and access roads; and
viii. Rooftop equipment areas.
i.
ii.
The inspector should attempt to gain a clear understanding of how runoff lea·v'es the site by
observing all portions of the storm water conveyance system and site grading, where possible and
safe. This includes inlets, open channels, ditches, etc.
The inspector will document the observed conditions, including any BMPs being implemented,
and will assess the facility's impact on storm water quality from the outdoor activities. Impact
includes the facility's pOlemia/ to discharge and the facility's actual discharge,. which are further
described below.
Indoor walk through. Review indoor activities and areas to ensure that pollutants are not
spilled, dumped, or allowed to flow outdoors. The inspector \Vill document the observed
conditions, induding any BMPs being implemented, and will assess the facility's impact on
storm water qtlality from the indoor activities.
Assess impact on storm water quality. The inspector should attemptto determine the facility's
impact on storm water quality at two levelS: the facility's potential to discharge and the facility's
actual discharge. The difference between potential and actual-is determined by whether BMPs
are effectively applied. For example, a facility that stores all of its. machinery and heavy
equipment outdoors has a h\gh potential to impact storm drains from any oil and grease that might
be exposed to nmoff. However, if the equipment is well maintained and always covered by a tarp
when not in use, the level ofpollutant exposure is minimized and the actual impact of the facility
is small. The inspector should note three things on the inspection ·report.
What is the facility's potential to impact storm water quality from :pol\tltant exposure and·
non-storm water discharges? IdentifY areas or activities that require BMPs to be applied-to
reduce or eliminate potential pollutant discharges to storm drains. IfBMPs ate in place,
determine what the impact would be ifBMPs failed or were no longer applied.
Are BMPs effectively applied so that pollutant exposure is minimized and non-storm water
discharges are eliminated? For each ofthe facility's areas of activity, observe whether BMPs
are in place and effective. The inspector may encounter situations where aBMP is in place
but is not effecti·vely applied. For example, an mltdoor drum storage area might be bermed
but the berm leaks or is already full of raimvater so that a spill would overflow the contained
City oj'Car/sbad.Jurl<;dicliona/ Urban RUl1ojj'lvkJlulgemem Pkm 4-17
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Section 4
Commercial Component
area. The inspector will use best professional judgment on the imminent impact ofthe
facility and decide how much time to allow the owner/operator to correct the problem.
iii. What WeIs) of impact does or could the facility have on storm water quality? Clearly
describe on the inspection report whether the impact is from: 1) .pollutant exposure to runoff;
and/or 2) non-storm water intentionally or accidentally discharged to the storm drains (e.g.,
illicit connections, process wastewater, spills, illegal dumping, etc.).
d. Document inspection activities. As the inspector observes the outdoor and indoor activities atthe
facility, she should take notes and photos as appropriate. The inspe~or should document the
locations and types ofBMPs that are currently being implemented, and also assess areas whereBMPs
will need to be implemented. The City will develop an inspection form toa.~ist the inspector with
collecting general information, documenting observations, reviewing SWPPPs,assessing BMPs, and
recommending corrective actions for violations. The inspector may also collect illicit discharge or
storm water samples from the facility as appropriate.
e. Closing Conference. After the walk-through of the facility, the inspector should collect any missing
or additional information, including verifYing the SIC code. The inspector may review other
documentation to look for indications of discharge problems, such as monitoring data records, the
Hazardous Materials Release Response Plan and Inventory, permits, manifests, logs or other records
that may be required of the facility from local, state or federal laws in order to conduct business on
the premises. The inspector should re"view the inspection findings and inform the' owner/operator of
follow-up procedures. .
Inspection report and fo]]ow-up. The inspector will update the inventory and complete the inspection
report upon return to the office. The inspection report should contain. at least the following sections:
a. General information to update the inventory;
b. Review of the SWPPP, ifavailable;
c. Assessment ofBMP implementation;
d. Documentation ofviolations and time frame for correction; and
e. Signatme and confrrmation.
Follow-up inspections will be done as needed to confirm BMP implementation and compliance. Section
4.7 of this component provides more detailed guidelines concerning enfo(cement actions .
CilY oj'Carlsbad.lurisdiclional Urban RUltoj/Alcuulgemem Pkm 4-18
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Section4
Commercial Component
4.5 Enforcement of Commercial Sites and Sources
4.5.1 Purpose and Permit Requirements
Purpose
NPDES Permit
Order No. 2001-01
Requirement(s)
Jurisdictional
URMP
Requirements
City Action Plan
The purpose of this section of the Commercial Component ,is to define the
enforcement actions associated with noncompliance ofthe Permit, City
Ordinance, or .TURMP requirements.
The Permit requirement under the Commercia] Component for
Enforcement of Commercia] Sites is as follo\V~:
Section F.3.c.(5)
Each Copermillee shall enforce ils storm w(Jler ordiluUlce jor all commercial
sites and sources as nece.',sary to mainUlin compliance with tlu: .. Order.'
The Permit requirement under the Commercial Component for
Enforcement of Commercia] Sites is as follows:
Section H.l.a.(4)(g)
A d(~ .. cription ofel1jorceme11l mechanisms mu/ how they will be used.
1) Generate a list of enforcement mechanisms.
2) Develop an Enforcement Respon..'ie Plan to outline how each
enforcement mechanism will be applied .
City of CtJr/sbad Jurisdictional Urban Runoj]' Mmmgemem Plan -4-19
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4.5.2 Enforcement of Commercial Sites and Sources Action Plan
Action #1 -Generate a Ust of enforcement mechanisms.
. Section 4
Commercial Component
City inspectors and staff members with enforcement authority wm iss1.ie enforcement actions to commercial
owners and operators failing to comply with the Carlsbad Municipal Code, storm water pollution prevention
plan or BMP requirements specified by the City. The inspectors, in accordance with the City's existing
procedures, will document each observed violation. Depending on the severity of the violation, ·enforcement
actions can range from a verbal warning to civil or criminal court actions with monetary fines. The inspectors
will have flexibility to recommend appropriate compliance time frames and to escalate enforcement Qn aca~-
by-case basis as needed to ensure compliance. .
If a signijicam and/or immediate threat to water quality is observed. by a City of Carisbad inspector, action
will be taken to require the j(lcility owner (mdior operator to immediateb"c£!.ase the discharge. The
enforcement mechanisms av-ailable to City of Carlsbad inspectors are as follows:
(a.) Verbal and/or written warnings;
(b) Notice of Violation;
(c) Compliance schedule;
(d) Cease and Desist Orders or Stop Work Orders;
(e) Notice to Clean, Test and/or Abate;
(1) Suspension, revocation, or denial of perm its or license;
(g) Administrative penalties and fines;
(~) Declaration of a Public Nuisance; and,
(i) Civil and/or criminal court actions.
While these measures typically escalate in enforcement action, they are not required.to be issued in the-exact
order presented here. City inspectors will apply or recommend any of the enforcement steps as appropriate
according to their best professional judgment and the guidelines of the Enforcement Response Plail. A
discussion ofthese measures is provided below. .
1. Verba1 and/or written Warnines
A common initial method of req1.1esting corrective action and obtaining compliance is a verbal or written
warning from the City of Carlsbad inspector to the commercial facility owner and/or operator. Verbal
warnings are often sufficient to achieve correction of the violation, often while the inspector is present at the
facility. After notifjring the owner or operator of the violation, the inspector should document the violation
and notification in the in~pection file, and note any time frames given for correcting the problem or follow-llP
inspections needed. In judging the degree of severity, the City of Carlsbad inspector may also take into
account any history of similar or repeated violations at the facility.
2. 1\"otice ofVio1ation
A written Notice of Violation is used when verbal or written warnings are not deemed sufficient to correct the
violation or additional documentation is warranted. The written Notice of Violation descrlbes the infraction
that is to be corrected and the required response or time frames for correction. The notice is issued to the
operator and/or owner, and a copy is placed in the active inspection file. If the violation JS corrected ts the
satisfaction ofthe inspector, the inspector will document compliance in the 'inspection file .
Ci{~' of Carl.r;had Jurisdictional Urban RunofI MmulgemelU Plan 4-20
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3. Comp1iance Schedules
Section 4
Commercial Component
A compliance sched1.1le may be issued to ensure that multiple violations or more complex violation~ requiring
capital expenditures or improvements are corrected by specified deadlines.
4. Cease and Desist Orders or Stop Work Order.s
A City inspector may issue an order to cease and desist a discharge, practice or operation that is occurring or
is likely to take place in violation of the City ordinance. The inspector may direct theresPQnsibleparty to
take appropriate remedial or preventive action to prevent the violation from recurring. Whenever any work is
being done contrary to the provisions of the City ordinance, the City inspector may issue a written order that
the work be stopped until Ruther notice.
5. l'iotice to (.1ean, Test and/or Abate
If the enforcement official finds any sediment, waste or pollutants on the sidewalk or a parcel of land that has
potential to enter the City's storm water conveyance system in violation oftbe City ordinance, the inspector
may issue a written notice to remove the material in a reasonable manner. .
6. Suspension, Revocation, or Denial of Permits or Licenses
Violations of the City ordinance may be grounds for local permit or license denia~ suspension, or revCiCation .
7. Administrative Penalties or Fines
Because violations 'vary in threat to water quality, City of Carlsbad inspectors may consider utilizing storm
water field citations for infractions or misdemeanors. Similar to traffic violations, the penalty for a storm
water infraction can be relatively minor for a first offense. Repeated violations could result i"nescalating fines
or misdemeanor charges.
8. Declaration ofa Public l'iuisance
Whenever an existing condition or a discharge into the storm water conveyance system violates the City
ordinance, it is considered a threat to public health, safety, and welfare and may be declared a public
nuisance. The inspector may follow appropriate procedures to recommend a declaration ofa Public Nuisance
by City Council in order to abate the ruisance discharge or cortdition.
9. Civil and/or Criminal Court Actions
As a final resort, the City of Carlsbad may use civil and or criminal court actions under the. State Potter
Cologne Water Quality Act or the Federal Clean Water Act, which may result in significant fines levied upon
the non-compliant responsible parties.
Action #2 -Develop an Enforcement Response Plan to outline how each enforcement mechanism will
be applied
The City will develop an Enforcement Response Plan to outline the procedures to' be followed by City
inspectors to identiiY, document, and respond to storm water violations. The plail will provide guidan~e in
selecting initial and follow-up enforcement actions, identiiYing responsible staff, and speciiYjng appropriate
time frames for actions.
CilY oj'Carlsbad.Jurisdicliollal Urban RUlloj/A1mwgemem Plait 4-21
POOR
QUALITY
ORIGINAL S
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Worksheet 117
NON .. STORM WATER DISCHARGE ASSESSMENT AND Completed: by:
FAILURE TO CERTIFV NOTIFICAnON Title: til 'f
(Source; EPA. 1992) Data:
Direction.: If you clnnot feallbly te.t or evalultl an outfaH due to ana of the rollowlng ra.sons, fill In the table below with the appropriate
'nformatlon Ind .lgn this form to certify the accuracy of the Included Information.
Ust all outfalls not testad or Ivaluated, d.scrlbe any pOllntlal lourcel of non-storm water pollution from listed outfalls, and atate the raasontsl why
cenlflcatlon Is not possible. Usa the kay from your ,lte map to Identify ,ach outfall.
tmportant Nattce: A copy of this notification must be signed lind submitted to the RWQCSwlthln 180 days of the .ffectlve date of this permit.
Identify Outilll Not . Description of Why Certlflcatlon Description of Potenttal Sources of Non-
Tilted/Evaluated ' .' I, Infeasible Storm Water Pollution
t:.) .. . ~
CERTIFICATION
I clrtlfy under, penalty of.llw that. this document and all attachmentl were prepared under my direction or supervision In accordance with a system
dlligned to 1,lur. thl' quatlUedper.oMI' proptrly Dathlr Indevaluate ·the Informallon submitted •. Based on my Inquiry of the parlon or per Ions
who mlnage thl IVltim ar tholl persons directly responsible far gathering the Information, the Information submitted II. to the best of my
knowledge and bt'lef. true, Iccurate, .nd compllte. ., am aWl'. thl' there ar •. significant penaltlel for submitting falle Information, Including the
poll'bUlly of tlnl .nd Imprisonment f~ knowing vlalatlon., and thlt luch notification hal been made to the RWQCB within 180 daYI of'
ldatt permit WI' ...... d), tht.fftctlvlt . dati of thll permlt. . . . .
A. Name !a Offlclal ntle ltvpe or print' B. Area Code and Telephone No.
f .. g, C. Slan.lure .
. O. Date Slgn.d·
..
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NON-STORM WATER DISCHARGE
ASSESSMENT AND CERTIFICATION
(Soutce: EPA. 1992)
Dlte of
Test or
Evalultlon
Oud,,, Directly
Observed During the
Tilt (ld.ntlty •• lndlc.t.d on
thl .11. map'
Method Used to
Telt or Evaluate
Discharge
1.
Workstleet 116
Completed by:
nUe:
Date:
Describe Relults from Test for
the Prasence of Non-Storm
Water Discharge
CERTIFICATION
IdenUfy Potential
Significant Sources
1.
Name of Person Who
Conducted the Test 0
Evaluation
tr.IPonslbi. cQrpotatt offlclan, certify under penalty ,of law that this document and all attachments were
:. !;,.,---..... r.~d~u-n""!'dlf-...... iny ... -~dl:;r.r::.c::':i:Io=n-:or;:;lu::p=ery'slan In .ccordlnce with. system designed to ,assure ~h.t qualified perlonne' ,properly oather and evatuate th
information lulMNtted. Baled on mv inquiry o' the p.rsonor perlonl who manaoe the IVltem or ~hollt personl directly responsible for Oltherll'lO'
the ,nt_mltlon. the Informatton _ubmltted .. , ta the be.tat my knowledge end bellel, truI, I(~cur.te, and completli I am IWlrtthat thera are . sIan'ftc.;"' ~_I tor ,ubmltt1ftQ ,.I.e lnfonnatll)11, fnct~lna' ~e po •• lblll~.y of fin. and Imp'll~nm.nt for ~liowlng. vlol.tlonl. .
A~ N8t!'t It O ..... t nt",'typi ~ print, I B. A~" Code .nd T,lephone No .
C. Slonatun ,0. Data Signed
") ,) )
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Check which of the following describe your facility •
Name of Reviewer: . Date:
Yes No NJA
DOD Are outside areas kept ~ and clean?
[] 0 0 Is the facility orderly and neat?
DOD Is process debris removed regularly?
DOD Is the area clear of excessi~ dust from industrial operations?
'0 D' D Is there no evidence ofleab and drips from equipment and machinery?
D D 0 Are employees regularly informed of tbe importance of good housekeetiDg?
DOD Are cateb basins, storm conveyance pipes. and storin water treatme~t facilities cleaned at the
apJXUprlale intervals (see Chapter 5)'1
DOD Are good housekeeping procedures and reminders posteci'in appropriate locations?
DOD Are vebic1e maintenance activi1ies kept indoOts ud kept ftom "Creeping-oUt tJie .ftont door of . -~ , .
the maintenance sbop? o 0 0 Are containers for chemical substances and:roc «emporary storage of waStes 1abeled?
C1D 0 Is vehicle and equipment wasiiing done in a designated area so that tile ~ water can be
discbarged to the sanitary or process wastewater sewer?
[J [] Cl Are regular housekeeping p:actices carried out?
o 0 0 Is there a spill prevention and response team?
[J 0 CI Are appropriate spill containment and cleanup materials kept on-site and in convenient
locations?
CI 0 0 Are cleanup procedmes~!« spills fuDowed regularly and conectly?
DOD
ODD
ClOD
[J[]O
[JOD
Are used absorbent materials removed and disposed iii a timely ~.
Are personnel regularly trained in the use of spill contrOl materialS?
sed •. and process equipment regularly iDspeCtCd and/or tested to :uncover Is expo pIpIDg • • A: ..... "' ... ...,; ..... of conditions that could cause breakdowns or failures teSQlung In ~.-6-
pollutants to surface waters?
Are drainage ditdJeS or tbe areas arowd tbe outfa11(s) flee 'of erosion?
°nd erosion? Are unpaved outdoor areas protected from water or WI . '
. JJSide[alion in the selection of BMPs. Any items cbeQl:d "No· reqwre co
r-,~l-Nl::A~=~N:O:t~~::·:~::re~·============================aa __ ----.a~~=---~
March, 1993
• ,
It---------------------------r---....... i...-'----------it ... ~.
ACTIVTI1ES -Check each activity present at site
o Nou-stoml water discharges 10 drains. Describe BMPs in place:
o Vehicle and equipment fueling. l)csuibe BMPs in place:
o Vehicle and equipment washing and steam cleaning. Describe BMPs in place:
o Vebick and equipment maintenaocc and JepOir. Describe BMPs in place:
Oucdoors loadingfunJoading of liquid:mareria1s. Describe BMPs in place:
o Outdoor process equipment opem1icos and maintetiaoce.. Describe B.MPs in place:
C10utdoor storage of raw materials. products aod byproduds.. DcIlcribc BMPs in place:
[J Wac baDdIiD& and disposal. Describe BMPs in place:
Cl ~"L-~ in..J-. COJPamjnated or erodible surface ueas..~..... t--
2 -12
"I(_i1 ........ ISll Handbook
mOH MID. LOW
March, 1993
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SPn.,LS INVENTORY
(Adopt from EPA, 1992)
J .• ".
Worksheet No.3
Completed By:
Title:
Date:
Instructions: Record below all significant spills and significant leaks of toxic or hazardous pollutants that have occurred at the facility
in the three years prior to the effective date of the pennit.
Definitions: Significant spills include, but are not limited to, releases of sill or hazardous substances in excess of repQrtable
gugntitie§.
1st Year Prior
Check Bolt Location '1'1' Description
Date (as indicated on
Type of Material Quantity
Response
(month/day/year) Spill Leak site map) Source. If Known Reaion Procedure Preventive MCllIurcs Taken
2nd Year Prior
Check Bolt Location (as Description
Date indicated on aite lte.ponse
(month/day/year) . Spill Leak map) Type of Material Quantity Source. If Known Realon Procedure Preventive Measures Taken
3rd Year Prior
CheckBOl ~oa Description
Date (as indicated Oil typll oUiltttrial
Response
(G\Ol\tfII~1ytti) . Spill Ltak Site map) Quantity Source, If Known Rea.on Procetiure Preventive Measures Taken
:
..
--
1 • J'. T
" ' \ Worksheet No. 1. ~
I . ~ I : ..
MATERIAL INVENTORY Completed By: I , ' ,
Title:
(Adopt from 'EPA, 1991) Date:
Instructions: Based on your material inventory, describe the significant materials that were exposed to stonn water during the past
tbree years and/or are currently exposed. For the definition of "significant materials" see Appendix E of the handbook.
Description of Exposed Period or Quantity Exposed (units) Location <as Indicated on Method of Storage or Disposal . Description of Material Management
Significant Material Bx.posurc the site map) (e.g., pile, drum, tank) Practices (e.g., pUc covered, drum sealed)
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Worksheet No.1
~TERlALINVENTORY Completed By:
'Title: .
(Adopt from SPA, 1992.) Date:
Instructions! List all materials used, storedt or produced onsite. Assess and evaluate these materials for their potential to cont1ibute
Material
• ••
pollutants to storm water runoff. Also complete WOl'ksheet 3 if the material has been exposed during the last three years.
QUlUllity (units)
Purpose/Location Used
,
"
BxpIU801l sepiaIe abr:et if qI8l1tily wa$ UlOR: ...... the ~lnimum?"
BxpIaiD baDs cbeckecJ yes oil a separalesbed.
Produced
Past Significant
Spill or Leak""
Quantity Eltposed Likelihood of contnet
with storm water. Yes No in Last 3 Years'
•
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. ·CO'Nl1Nuo.tJ$'Di:F'k!t~~I~I£~~~~~~i8lJt:;:
.. ITSMeCHA;Nf&M"AfJiD:".PF¥tJc~ji.~: .' .'
. ' . . .. ':,'~' •.•. ' .' •. :"·~~,i:~!!:,';:",.,,:,;; .. ~,~}~;, jf7~~:',f"~~t,',:1.,;.,.'.:,;:',,:;,>:.,~':, .•..••.• ,'.
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•
•
•
CONTINUOUS DEFLECTIVE SEPARATION: ITS MECHANISM AND APPLICAtiONS
ABSTRACT
Tony H F Wong,
Department of Civil Engineering
Monash University
Problems associated with pollution of waterways by floating litter and flow debris are
becoming a focal point for community concerns of environmental management 9f
discharges from stormwater and combined sewer drainage systems: While pollutants
emanating from an urban catchment are wide ranging in their character and hence
require different management measures, each .of these measures require a d~gree of
prfmary separation of th_e gross solids. A new approach in separating ·gross solids from
wet weather flow in stormwater drainage systems has been developed using the
continuous deflective separation mechanism. This new approach overcomes many of
the current problems encountered in conventional gross pollutant traps using trash
racks where significant blockage of the trap can occur leading to a reduction in trapping
efficiency and hydraulic performance of the' drainage system. The continuous'
deflective separation mechanism is also different from the mechanism of typical
hydrodynamic separators used in combined sewer overflow management and is
expected to be more efficient in removing gross solids, especially during rapid flow
conditions. This paper describes the fundamental mechanism behind the continuous
deflective separation technology and outlines the potential application of the technology
in pollution abatement in stormwater systems and other wet weather flow applications.
KEYWORDS
Gross Pollutant Trap, Hydrodynamic Separator, Continuous Deflective Separation
INTRODUCTION
Stormwater pollution, emanating from separate stormwater or combined sewer systems
from urban catchments, is now widely recognized by the community asa pressing
environmental issue requiring urgent attention by catchment managers. The types of
stormwater contaminants can be grouped according to their water quality impacts such
as suspended solids, nutrients, BOD and COD, micro-organism, toxic organics, toxic
trace metals, oils and surfactants and litter. Oil and surfactants and litter are often
identified as of primary concern by the community mainly due to their visual impacts.
Pollution impacts due to suspended solids are probably of most environmental
significance due to the fact that many other contaminants such as nutrients, micro-
organisms and toxic trace metals are sediment bound .
10f15
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The nature of pollutants emanating from differing landus"e are very diverse. As a
consequence treatment techniques to improve the stormwater quality would necessarily
involve a number of measures. There have been a number of significant studies into
developing appropriate treatments for the range of pollutants generated from urban
catchment activities. These, treatment methods are often used iriseries or concurrently
in an integrated approach leading to a sustainable strategy which can overcome site
factors that limit the effectiveness of a single measure.
Gross solids including heavy sediments and litter are usually the first pollutant group to
be removed from stormwater and combined sewer discharges. It is often necessary for
some form of primary gross solid separation to be undertaken in the first instance for
many of the more elaborate measures to be effective. , Nutrients, BOD demanding
organisms and metals may require tr~atment involving the use of' wetlands and
infiltration systems. These treatment facilities could be located immediately
downstream of the gross pollutant trap. '
GROSS POLLUTANT TRAPS -AN OVERVIEW
Current approaches to gross pollutant separation from flows in stormwater systems
center ,around the mechanism of direct filtration. Their application is primarily focused
on litter and debris removal and they are generally placed at outlets of piped drainage
systems. Trash racks are placed across the flow path of the stormwater with the bar
spacings being as fine as 6 mm. Experiences with direct filtration systems have found
them to be susceptible to clogging with the c,onsequential redl,.Jction, in both the
efficiency of the device in water quality improvement and the hydraulic capacity of the
drainage system. It is often for this reason that careful specification of the height .of the
trash rack is necessary to ensure that the discharge capacity of the system is not
significantly reduced by clogging of the trash rack. '
In combined sewer systems, developments of a wide range of hydrodynamic separato'rs
have seen their applications in treating overflows from these system. These devices
utilises the drag due to secondary flow current induced by the creation of a vortex in
separating solids from the incoming fluid. These hydrodynamic separators .have been
shown to exhibit decreasing trapping" efficiencies with increasing discharge through the
separators (Huebner and Geiger, 1996).
A new approach in separating and retaining gross solids under rapid flow c,onditions
has been developed using the mechanism of continuous de~ective separation (CDS).
This system of solid separation overcomes the problems and ineffiCiencies of current
systems, especially under rapid flow conditions. This paper describes the fundamental
mechanism behind the continuous deflective separation technQlogy and outlines the
potential application of the technology in pollution abatement in stormwater and
combined sewer systems .
20f15
•
• \
•
General
The mechanism by which the CDS technology separates and retains gross pollwtant is
by first diverting flow and associated pollutants in a stormwater or combined sewer
drainage system away from the main flow stream of the pipe or channel into a pollutant
separation and containment chamber. The separation and containment chamber
consist of a containment sump in the lower section and an upper separation section.
Gross pollutants are separated within the chamber using a perforated plate allowing the
filtered water to pass through to a volute return system and thence to the ,outlet pipe.
The water and associated pollutant contained within the separatioh :chamber are kept in
continuous motion by the energy generated by the incoming flow. This has the effect of.
preventing the separation plate from being blocked by the gross solids separated from
the inflow. The heavier solids ultimately settle into the containment sump. Figure 1 is. a
schematic representation of the solid separation mechanism of the CDS technology.
The diversion of the stormwater and associated pollutants into· a separation chamber
overcomes problems associated with the direct filtration systems of conventional gross
pollutant traps. The present design of the CDS system utilises a simple solid diVersion
unit to divert flows into the separation chamber. The diversion unit is designed to diVert
all flows into the separation chamber as long as water levelS are below the crest level of
the diversion unit. As water levels exceed the crest of the diversion unit, some flows
would by-pass the CDS system. The crest level of the diversion unit mey be adjusted to .
suit individual installations.
The solid separation system consists of a large expanded stainless steel plate which
acts as a filter screen with an outer volute outlet passage. The perforations in the'
separation screen are typically elongated in shape and are aligned with the longer axis
in the vertical direction. The size of the elliptical holes can be specified according to
performance requirements and typical width of the short axis ranged from 0.6 mm to4;7
mm. The separation screen is installed in the unit such that the leading edge of each
perforation extends into the flow within the containment chamber. .
Figure 1 Schematic Representation of the CDS _""'TroUTl
Plan View
3 of15
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Comparison with Current HydrodynamiG Separators
The CDS unit appears to have similar features to dynamic solids separators whith were
first used in England in 1963 and adapted for use to separate solids in combined sewer
overflow (GSO) systems in the US in the mid-70s. As described by Pisano ,(1988),
these hydrodynamic separators rely entirely on the secondary flow current indu.ced by
the vortex to separate and draw solids downwards to a. gutter. "Clear" 'water was
allowed to overflow at the top of the separation chamber. Figure 2 below illustrates' an
idealised view of a vortex separator (Pisano, 1988). This form of solid s.eparatidn. would
become increaSingly ineffective as the flow rate increases. The uplift pressure on the
solids caused by the high discharge rate would overcome the effect of the 'downward
pressure due to the secondary current.
Figure 2 Idealised View of Vortex Separator during High Flow Operation
Rg,3
Id.allzed View 01 VOMex Sep.rator
Dunng High Row Operation
The CDS system differs from the traditional hydrodynamic separator in that it utilises a
filtration mechanism for solid separation and does not rely -on secondary flow currents
induced by the vortex action. The CDS system notionally involves a single flow path
and has one outlet point while hydrodynamic separators discharges fluids at the top
and bottom of the devices. The flow conditions within the separation chamber are
significantly different from conventional hydrodynamic separators and have an entirely
different velocity profile within this chamber. As indicated in discussions in the following
section, the velocity distribution in the separation chamber of the CDS unit is the
reverse of that normally observed in the conventional vortex separator, i.e .. the surface
velocity increases with increasing distance from the center of the separation chamber in
the CDS unit.
Operating Mechanism
The essential operational function of the CDS unit is to ensure that the separation
screen remains free from blocking by trapped material as the volume of pollutant
trapped increas~s. The screen 'surface area is of the order of 40-45 times the pipe inlet
40f15
•
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area. Measurement of screen perforations indicates that the orifice area in the direction
perpendicular to the plate is approximately 20% of the total plate area. The' maximum
orifice flow area available (looking at an angle against the direction of flow) is
approximately 40% of the plate area. The radial flow velocity through the screen is thus
an order of magnitude less than pipe inlet velocity. Gross solids are prevented from
blocking the separation screen using the significantly higher tangential flow velocity
compared to the radial velocity throughout the surface of the separation screen. The
now direction in the outer volute outlet system is opposite to that of the circular motion
in the separation chamber.
Tangential Velocity Distribution
The CDS mechanism can be explained by examination of the water velocity distribution
within the separation chamber. Flow velocity decreases along the separation screen 't;ls
well as with depth and decreasing distance from the. center of the separation chamber ..
Figure 3 illustrate typical flow velocities measured on the water surface for one of the
units tested. The velocity distribution demonstrates the action of the incoming flow in
maintaining continuous circulation within the separation chamber. This action promotes
a shearing mechanism which keeps the pollutants in continuous circular motion.
Figure· 3 Surface Velocity distribution within the Separation Chamber
Inlet . -----....
/ I
Particles are prevented from being held against the screen by this significantly higher
shearing force along the screen' compared to the low pressure differential across the
screen. Much research has been undertaken to promote high efficiency in the
conversion of the inlet velocity to tangential velocities along the separation 'screen. In
so doing, the relationships between the inlet velocity and tangential velocities can be
maintained as near-linear relationships thus ensuring consistent ratios of tangential to
radial velocities for a wide range of discharges. .
5 of 15 .
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Radial Velocity Distribution
The radial velocity distribution is a direct reflection of the distribution of flow through the
separation screen. With the overall screen ·area being an order of magnittlde larger
than the inlet area, flow velocity through the separation screen is expected to
correspondingly be an order of magnitude lower. The low pressure differential force
acting on any object near the separation screen is primarily due to th.elow radial
velocity through the screen. Different inlet conditions can influence the distribution of
flow through the separation screen and optimization of the CDS unit configurcation has
been conducted to promote a radial velocity distribution which is consistent with the
distribution of tangential velocities along the separation screen. In the case of the unit
exhibiting tangential velocity characteristics as shown in Figure 3, observations from
tracer studies suggest that flow rates through the separation screen vary along the
screen with the highest flow rate near the inlet and the .f1ow'rate decreasing with
increasing distance along the screen from the inlet. This enabled the ratio of tangential
to radial velocities to be maintained at a high level throtlghout the surface of the
separation screen with both variables decreasing with inoreasing distance from the
inlet.
Head Losses
With the installation of a solid separator on an existing pipeline or open channel, the
hydraulic characteristics of the drainage system will be altered by the introduction of
addition energy loss components. The CDS unit diverts all flows in the drainage system
below the level of the diversion unit into the separation chamber and under such
conditions, additional head loss can be significant. The height of the diversion unit is
determined by careful consideration of the physical and hydraulic characteristics of the
drainage system in the vicinity of the CDS installation. During high flow conditions,
some of the flow would by pass the CDS unit by flowing over the diversion ur:lit. The
energy loss attributed to the CDS unit becomes influenced by the hydraulic
characteristics of the crest of the diversion weir under stlch conditions.
In a closed conduit drainage system, flow conditions during· periods when the entire
flow is diverted to the CDS unit is often that of open chc;mnel flow (or referred to as non-
pressurised flow). During by-pass operation, flow conditions in the system are often
that of pressurised closed conduit flow. Head loss measurements under non-
pressurised open channel flow and pressurised closed conduit flow conditions have
been conducted to derive the head loss coefficient for the fufl. range of flow conditions
encountered by the CDS unit. In this particular case, the height of the diversion unit
was set at the soffit level of the inlet pipe. The value of the head loss coefficient was
determined by computing the ratio of the energy loss, to the equjvalent "pipe full"
velocity head at the inlet pipe~
The measurements found the value of the head loss coefficient to be highest at 'low
discharge. This value decreases with increasing discharge and approaches a constant
60f15
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of 1.3 for bypass and pressurised flow conditionS as shown iJ1 Figure 4. This value is
expected to be higher if the height of the diversion weir were to be set nigher (for lower
frequency of bypass operation) and vice versa. The head loss coefficient under full,
diversion conditions was as high as 21 but this should be interpreted with some caution
owing to low flow velocities and pressure differentials, and the fact that absolute
magnitudes of these measurements are small and subject to measurement tolerances.
In interpreting the results for application in design, it should be borne in' mind that the
value of the head loss coefficient in operation conditions close to design conditions of
the pipe conveyance system (ie. under bypass and pressurised flow conditions) is 1.3.
This is thought to be the appropriate value to use in investigating the overall' effect of
the CDS Unit on the discharge capacity of the system.
Figure 4 Head Loss Coefficients derived for the CDS Unit
25~------------+-------~
5 20 -1--;------1-Pressurised Flow
<3 Conditions !: ~ 15 Non-Pressurised Flow -1-----------1 Col '" Conditions 3 10+---~----~~
"0 '" ~ 5+---~~--~--~-----~
ot-~--~~~~~~
o 0.005 0.Q1 0.Q15 0.02 0.025
Discharge (m3/s)
Gross Solids Separation
Solids entering the separation chamber can either be floating or settleable materials
with those solids which are larger than the aperture size of the separation screen being
prevented from passing through the screen. The trapped material is kept .in motion
within the separation chamber by the design of the unit which maintains the ratio of
tangential to radial velocities necessary to, promote the non-blocking mechanism
throughout the surface of the separation screen. The settleable material ultimately
settles into the containment sump. The floating material that enters the CDS unit
(including organic matter which over time absorbs water and eventually 'sinks, ego leaf
litter) remains within the separation chamber and circulates at the water surface until
the water level drops and inflow ceases. The action of the inflow'jet, the shJaping of the
screen and centrifugal effects tend to concentrate this floating material towards tlie
center ot-the chamber away from the screen. Tests were carried ,out with ,a variety of '
materials which included cans, plastic bags, newspaper, Leaf litter, polystyrene beads
and samples of mixed litter col/ected from actual drainage pits .
70f15
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Fine Solids Separation
For solids which are smaller than the aperture size of the separation screen, trapping
efficiency would be affected by the ability of the unit in keeping these solids away from
the separation screen as they progressively settle into the containment chamber. The
trajectory of these fine particles within the separation chamber is defined by the
combined effect of fluid velocity within the chamber and the settling velocity of the
particles. The likelihood for very fine particles to flow through the separation screen is
higher than coarser particles owing to the trajectory of the former being more exposed
to the separation screen. Unlike the mechanism of hydrodynamic separators, both
particle size and its settling velocity have a direct influence on the trapping efficiency of
these particles by the CDS unit. In the case of hydrodynamic separators, trapping
efficiencies of these devices are often related to the ratio of the hydraulic loading
(discharge per unit area) and the settling velocity. In the case of the CDS unit, it is
envisaged that the trapping efficiency is related to the "exposure time" (ie. related to the
trajectory of the particle) and the aperture size of the separation screen~
ApPLICATIONS OF THE CONTINUOUS DEFLECTIVE SEPARATION MECHANISM·
Gross Pollutant Traps (GPT) in Stormwater Drainage System
An obvious application of the CDS unit is in the separation of gross solids in a
stormwater drainage system. The system can be retrofitted to existing pipe system as
described by Allison et al. (1996). The CDS unit is most appropriately used as a form of
first .flush device, set to divert all flows up to a threshold discharge. Selection of the
threshold discharge above which by-pass of the CDS unit would occur is dependent on
a number of factors including the general terrain of the site, available freeboard
between the drainage system and ground level, costs and the nature of pollutants being
generated from the catchment.
Figure 5 Trap Efficien~ies Vs Design Bypass Frequency
100
99 ,..... e 98 ;>,
~--' ,
u c " 97 ·u
IE Ul c 96 0 .§ 1-" 95 ;.
is
94
---30m -*-1 hr .~
'I
-+-3 hrs --6hrs
93
o 2 4 6 8 10
Diversion Weir By-pass Frequency (ARI)
80f15
•
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As part of developing design guidelines for first flush devices, continuous simulation
using 100 years of recorded rainfall data for Melbourne, Australia was carried out to
investigate the diversion efficiencies associated with different d.esign standards for the
height of the diversion weir. Diversion efficiency is defined as the percentage volume of
stormwater which has been diverted into the separation chamber over the 100 year
simulation period. Simulations were carried out for catchments with critical storm
durations of 0.5, 1, 3 and 6 hours and the results for each of these cases were found to
be similar as illustrated in Figure 5. Diversion efficiencies in excess of 93% for design
bypass frequency as high as once in 0.25 years were found, suggesting that the .height
of the diversion weir need not be set excessively high to gain significant belJefits in the
. overall proportion of stormwater diverted to the CDS system. An optimal retrofit of
existing stormwater system based on a 0.25 years or 0.5 years bypass frequency would
facilitate effective gross pollutant entrapment without unduly affecting the discharge
capacity of the drainage system. .
Currently there are 15 installations of CDS stormwater gross pollutant traps Tn Australia,
two in New Zealand and one in the United States of America. Jago (1997) reported
trapped annual quantities of 20 tonnes of litter by such systems in a number of
installations in Australia. Typical composition of solids trapped in these installations
consisted of approximately 60% organic material, 30% silt and sediment and 10% litter
but varys widely with the nature of the catchment.
Pre-screening for Fine Solids Treatment Facilities
Settleable solids are those solids with specific gravities greater than unity and which will
sink to the bottom of the separation chamber into the sump. They will include silts and
sands as well as saturated organic material. CDS units could be utilised. to provide
primary treatment of stormwater and wastewater before their discharge to more
elaborate treatment facilities such as wetlands and ultra-violet disinfection systems.
Solids of sizes less than the aperture size of the separation screen may pas~ through
the screen or may be trapped. Tests were c~rried out by Wong et al.. (1995) to
determine the efficiency of the trap for these types of solids. A range of graded mineral
sands was obtained and further graded by sieving. Six groups of sand grades were
determined with mean diameters ranging from 200 microns to 780 microns. Tests were
carried out with each grade of sand for pipe full inflow velocities ranging from 0.5 mls to
1.4 m/s. The aperture of the separation screen used in the test was 2.4 mm by 7 mm.
The results of the tests are presented in Figure 6 and cleariy show the unit to be very
effective (ie. >90% separation) for solids as small as 900 micron or 38% of the minimum
aperture size of the separation screen. For solids up to 500 micron (ie. 1f5th of:the
screen aperture size), the trapping efficiency was found to be approximately 50%. The
tests suggest that separation efficiencies were largely independent of inflow velocities
for the range tested. .
90f15
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Figure 6 Sand Trapping Efficiency of CDS Unit with Apertur.e Size of 2.4 mm
100
"" 90 <I)
'S 80 '" ..c: ()
d 70 0 .~
'" l;j 60 p..
<I)
CIl 50 .S
"Cl 40 <I) p.. g.
30 t!::
~ 20 '0
CIl
'<t. 10
0
K • Single Outlet; vel = 0.5 rnIs; 2.417.0 (Wonget al.; 1996)
~ ... Single Outlet; vel = 1.0 rnIs; 2.417.0 (Wong et'al., 1996) I--
0 Single Outlet; vel = 1.4 rnIs; 2.417.0 (Wong et aI., 1996) -I Fitted CUlVe
IJ -•••••• Separation Screen Aperture Size
~ , · · tI · · · p · · · t, · · · ~. · · · l/ · · ·
o 500 1000 1500 2000 2500 3000 3500 4000
Solid Size (Microns)
Dual Outlet Syst~m
In industrial applications and in treating csa, it may be necessary to adopt a system
which would allow separate discharge of filtered fluid and concentrated f1u'id, a similar
approach to that adopted in current application of hydrodynamicseparatdrs for GSa
management. Figure 7 shows a schematic representatiol1 of the CDS unit fitted with a
return flow system. Inflow enters the separation chamber at c;l level above the
separation screen. The floating solids and oil would thus be expected to be contained
and kept in a circular motion at a level higher than the screen and consequently
prevented from passing through the screen. Flow exits the separation chamber through
the separation screen and the sump outlet with all settleable particulates larger than the
size of the screen aperture being conveyed alit of the separation chamber via the sump
outlet. A significant proportion of smaller particles will also be trapped and dischc;lrged
through the sump outlet. The proportion of the total inflow discharged via the sump
outlet is dependent on the hydraulic configuration of the system. '
10 of 15
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Figure 7 Schematic Diagram of a Dual Outlet CDS Unit
'rf8]CAl SECTIQN
NOn::
OII.lENSIOHS IN IMPERJAl AND I.IETR/C
A -0--
Laboratory tests have been carried out to define the significance of the second oLitlet on
the performance of the CDS unit in trapping fine solids smaller tban the aperture size of
the separation screen. The tests conducted were similar to tests conducted with the
single outlet·"·system (Wong et aI., 1995) using graded sand as the tracer. Two screen
sizes were used in the tests, one with an aperture size of 2.4 mm by 7.0 mm and the
second of 4.7 mm by 1'8.0 mm. The latter screen size is that normally adopted for
stormwater applications in the field.
In addition to running the test with no discharge from the sump outlet, tests were a'iso
conducted with sump discharges equivalent to 10% and 24% of the total inflow. The
results of the tests conducted are compared with the results for a single outlet system in
Figure 8. Tests with zero discharge from the sump outlet for the screen aperture size of
2.4 mm by 7.0 mm were conducted to provide a basis for comparing the consistency of
the results of previous tests for a single outlet system (presented in Figure 6) to the
present tests. Two runs were conducted using particle size of 260 microns and 750
microns. The results are plotted in Figure 8 and show general consistency with the
results of previous tests with the single outlet system with a separ$tion screen ,aperture
of 2.4 mm and 7.0 mm.
The results of tests with the dual outlet in operation are also plotted irl Figure 8. The
results show the general slopes of the trapping efficiency lines to be significantly flatter
than the corresponding slope for the screen aperture size of 2.4 hlm by 7.0 mm. The
effect of the aperture size of the' separation screen was accounted for by normalising
the particle size according to the screen aperture size. The result of this normalisation
of sediment sizes is shown in Figure 9 with normalised x-axis representing the particle
size expressed as a ratio of the width of the separatiorl screen apertu're .
11 of IS
I
• Figure 8 Sediment Trapping Efficiencies of CDS Units
100
90
80
.~
N1 '" ~
I ~ • Single Oudet; vel s 0.5 mls; 2.4n.0 f-1/ I'-. Dual Outlet with A Single,Oudet; vel a 1.0 mi.; 2.417.0
II VI 2.417.0 screen; -
~ VQr=O C Single Outlet; vel a 1.4 mi.; 2.417.0
~I / / -Fitted CurVe -Singl~ Outlet I-
/ --Dual Outlet System Qr=O; 4.7/18.0
/J;; V ---Dual Oudet; Qr-'IO%; 4.7/1S:0 '-
T --Dual Oudet'System Qr=24%; 4.7/IS.0 ,-
• Dual Outlet Qr=O; 2:417.0
10
o
y.
/
0 500 1000 1500 2000 . ;2500 3000 3500 4000
Solid Size (Microns) • Figure 9 Normalised Sediment Trapping Efficiency Curves
100
90
80
... " .c 70 E '" .c U 60 '" 0 .~
'" 50 c. " en
.5
'" 40 " c. c. ~ 30 :;: "0 en 20 ~
10
l~
! wi \
I / \
V/ AI \ • Single Outlet; vel,· Q.5 mls; 2.417:0 l-I II/ It Dual Outlet
/' with 2.417.0 .t. Single Oudet; vel-l.O mls; 2.4/7.0
~/ / :/ ~ scre~;Qr=O <> Single Oudet; .vel-1.4 mi.; 2.4/7.0
/ /J ~ / -Fitted Curve -Single Outlet
--Dual Outlet System Qt-O; 4.7/is.0 . ., --D""I Outlet; Qr-l0%; 4.7/18.0
iii ~DUaI Outlet; Qr-'24%; 4.7/18.0'
7 • • DIJllI 'Oudet Qr<"O; 2.417.0
/ I I o
o 0.1 0.2 OJ 0.4 0.5 0.6 0.7 0.8 0.9
• Solid Si2!e as proportion of minimum aperture size
12 of 15
•
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•
The normalised curves of trapping efficiencies are not expected to collapse. into a siFlgle
curve due to the fact that screen aperture size is not the only factor influencing the
performance of the CDS unit. Normalising against screen aperture size ,has -
nevertheless established the characteristics of the sediment trapping effiCiency curves
in terms of their general shape and gradient. The experimental results indicate that the
reduction in trapping efficiency of a given size particle due to an increase in the
aperture size of the separation screen in not linear.
When operating under dual outlet, a vortex was observ~d to have developed at the
center of the separation chamber. The development of this vbrtex was found to be
evident even for a small amount of return flow. The region of influence of the. vortex at
the water surface can be significant and has the effect of drawing f10atables towaJds the
middle of the separation chamber but not necessarily of sufficient energy to discharge
these f10atables out of the separation chamber. The extent of thi!? region of influence is
depel'1dent on the proportion of the flow leaving the separation chamber Via the sump
outlet, ie. proportion of return flow.
Velocity measurements within the separation chamber rndicated a Significant alteration
to the velocity profile which can be attributed to the characteristics of the sump outlet.
As expected, the velocities in the vicinity of the center of the separation Chamber are
most affected with near zero velocity fbr a no return system to veloCities up to twice that
at the separation screen for a 24% return flow system. However, it is noteworthy that
the velocities in the vicinity of the separation screen were largely unaffected. This
observation has important implications in that th~ non-blocking fUnction . of the CDS
mechanism, which relies on the dominance of velocity vectors parallel to the separation
screen and validated in earlier laboratory and field studies, is essentially unaffected by
the dual outlet system.
The results of the investigation clearly show improved performance with higher
proportion of return flow. This improvement is attributed to the combined ~ffect of fluid
and solid removal via the sump outlet and the vortex acti'on induced by the second
outlet. An increase in return flow from 0% to 10% led to an average increase in
sediment capture of approximately 23%. A further increase from 10% to 24% return
flow led to an increase in sediment trapping efficiency of approximately 57% over the
case of a single outlet system. The improvement in performance' appears to be
reasonably constant throughout the sediment size range.
CONCLUSION
A new approach has been developed for separating gross solids from stormwater and
wastewater discharges under rapid flow conditions. This technology, based on the
continuous deflective separation mechanism, overcomes many ,of the current problems
encountered in conventional gross pollutant traps using trash racks where significant
blockage of the trap can occur leading to a reduction in trapping efficiency and
hydraulic performance of the drainage system. The innovation in this technology is the
13 of 15
•
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•
prevention of blockage of the separation screen during rapid flow filtrationoperatiofl.
The mechanism by which solid separation occurs involves the .deflection of solids away
from a filter screen with the energy required for solid deflection being derived from the
energy associated with the incoming flow. The fundamental basis for ensuring the non-
blocking function of the technology is the maintenance of a suitably high ratio of
tangential velocity to radial velocity along the surface of the' separation scree.fl. The
configuration of the inlet to the separation chamber, the dimension of the separation
chamber, the form of the separation screen and the form of the outlet volute channel an
have a direct influence on this velocity ratio.
'In addition to being an efficient device for separating gross solids Which are larger than
the aperture size of the separation screen, the device was also found to be Capable of
effectively separating finer solids which would normally pass through the separation
screen under a direct filtration mechanism. Tests have indicated near 100% trapping
efficiency' for solids sizes down to 40% of the minimum aperture size of the sep~ration
screen. The introduction of a second outlet was found to farther improve separation
efficiency of fine solids.
Potential applications of the technology encompass a wide range of operation which
are not necessarily related to stormwater and wastewater management. Many
operation requiring efficient and reliable separation of solids from fluid are expected to
benefit from the technology. The selection of the aperture size of the separation screen
can be matched to the minimum solid size required to be separated. Current
experience with stormwater and csa applications have highlighted the signifiCant
benefit of the technology in environmental management of "public drainage
infrastructure.
ACKNOWLEDGMENT
The author wishes to thank CDS Technologies for permission to publish the paper.
REFERENCES
Allison, R, Wong, T H F and McMahon, T A. (1996), "Field Trials of thePo/lutec Gross
Pollutant Trap", Water, Vol. 23, No.5, pp 29-33.
Huebner, M and Geiger, W.F. (1996), "Influencing Factors oli Hydrodynamic Separator
Performance", proceedings of the 7th International Conferef)ce on Urban Stormwater
Drainage, Hannover, Germany, 9-13 September 1996, pp. 899-904.
Jago, R.A. (1997), "CDS - A New Screening Technology for the Environment", Water,
Vol.24 No.1. May/June 1997. pp. 47-49 .
Pisano, w.e., (1988), "Swirl Concentrators Revisited -The American Experience and
New German Technology", Proceedings of an ASCE Engineering FoundatioA
14 of 15
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•
•
Conference on Current Practice and Design Criteria for Urban Quality Control, Missouri,
USA, 10-15 July, 1988.
Wong, T H F and Wootton, R M. (1995a), "An Innovative Gross Pollutant Trap for·
Stormwater Treatment", Proceedings of the Institution of Engineers, Australia, 2nd
Intemational Symposium on Urban Stormwater Management, Melbourne, Australia, pp.
407-412, July 1995
Wong, T H F and Wootton, R M (1995b), "Investigation of the Hydraulic and Functional
Performance of the Pollutec Continuous Deflective Separation Gross Pollutant Trap -
Stage 1 Report on Functionality", Monash University, April 1995
Wong, T H F, Wootton, R M and Fabian, D. (1996), "A Solid Separator using a
Continuous Deflective System", proceedings of the 7th International Conference ,on
Urban Stormwater Drainage, Hannover, Germany, 9-13 September 1996, pp. 88'1--886 .
150f15
• -',
OIL SORBENT SPECIFICATIONS
Oil Sorbent Material For Use With CDS Units
Material,. Application and Replacement Specifications
Oil & Grease Removal From Stormwater Runoff
Material
If sorbent material is to be added to the CDS unit, it shall be Rubberizer® filter media 8
to 4 Mesh or be Oars® Particulate·for Filtration, HPT4100 or equal. Rubbetizer® 8 to 4
'Mesh is supplied by Haz-Mat Response Technologies, Inc., 4626 Santa Fe Street, San
Diego, CA 92109, (619) 274-4585. Oars® Particulate for Filtration, HPT4100 is
supplied by AbTech Industries, 4110 N. Scottsdale Rd., Suite 235, Scottsdale, AZ 85251,
(602) 874-4000.
Application
Place sorbent material within the CDS unit's separationchamper. Initial application'of
sorbent shall be a minimum of Y4 inch thick layer across 'the entire area of the separatioJ;1
chamber. The annual application of sorbent shall be a minimum of four (4) pounds per
acre of impervious surface subject to oil and grease runoff' This fow(4) pound lacre
application is proposed for runoff from surfaces subject to typical oil arid grease
concentrations of 5 milligrams per liter (mg/l). Higher rates of soi-bent ,application' will
be require4 where oil and grease concentrations exceedS mg/I.
Sorbent Inspection and Replacement
Sorbent may be used until it is saturated with oil and, grease~ VisuC;l.l indications of
saturated or near saturated sorbent material include: sorbent appears dark and becomes
less buoyant when heavily saturated with oil, grease and debris. Heaviiy saturated
sorbent appears to be coated with oil, grease and particulates.
Disposal
Used sorbent material may be categorized as hazardous waste in some states~ consult
local and state requirements.
Consult with CDS Technologies' for additional information ori 'efficiencies· of s~rbent
material, estimating annual sorbent needs, replacement frequency or maintenance needs.
CDS Technologies, Inc
Corporate Headquarters
163.60 South Monterey Road, Suite 250
Morgan Hill, CA 95037
Toll Free: 888 535-7559
Phone: 408 779-6363
Facsimile: 408 782-0721
0-9
Regional Offices -
1255 La Quinta Drive, Suite 218
Orlando, FL 32809,
Toll Free: 800 848-9955
Phone: 407 855-8848
Facsimile: 407 '855-78i8
OIL SORBENT SPECIFICATIONS
Oil Sorbent Material For Use With CDS Units , . .
Material, Application and Replacement Specifications
Oil & Grease Removal ,From Stormwater Runoff
Material . ,
If sorbent material is to be added to the CDS unit, it shall be Rubberizer® filter media 8
to 4 Mesh or be Oars® Particulate·for Filtration, HPT4100 or equal. Rubberizer® 8 to 4
'Mesh is supplied by Haz-Mat Response Technologies, Inc., 4626 Santa Fe Street, San
Diego, CA 92109, (619) 274-4585. 'Oars® Particulate for Filtration, HPT4100 is
supplied by AbTech Industries, 4110 N. Scottsdale Rd., Suite 235, Scottsdale, AZ 85251,
(602) 874-4000.
" .
Application
Place sorbent material within the CDS unit's separation ch~ber. Initial application of
sorbent shall be a minimum of ~ inch thick layer across ~e entire area of the separation
chamber. The annual application of sorbent shall be a. minimum of four (4) pOU1.1ds per
acre of impervious surface subject to oil and grease, runoff. This four (4) pound /acre
applicatiop. is proposed for runoff from surfaces subject to typical oil and grease'
concentrations of 5 milligrams per liter (mg/l). Higher rates of sorbent ,application will
be require4 where oil and grease concentrations exceed 5 mg/I..
,Sorbent Inspection and Replacement
Sorbent may be used until it is saturated with oil and grease. Visual indications of'
saturated or near saturated sorbent material inc1u4e: sor1:>ent appears dark and becomes
less buoyant when heavily saturated with oil, grease and debris. Heaviiy saturated
sorbent appears to be coated with oil, grease and particulates.
Disposal
Used sorbent material may be categorized as hazardous waste in some states; consult
local and state requirements.
Consult with CDS Technologies for additional information ori 'efficiencies of sorbent
material, estimating annual sorbent needs, replacement frequency or maintenance needs.
CDS Technologies, Inc
Corporate Headquarters
163.60 South Monterey Road, Suite 250
Morgan,Hili, CA 95037
Toll Free: 888 535-7559
Phone: 408 779-6363
Facsimile: 408 782-0721
D-9
Regional Offices
1255 La Quinta Drive, Sl.lite 218
Orlando', FL 32809 '
Toll Free: 800 84-8-9955
Phone: 407 855-8848
Facsimile: 407 '855-7818
•
•
•
OIL AND GREASE REMO:V AL BY
FLOATING SORBENT IN A CD'S D'EVICE
by
Michael K. Stenstrom ·
Sim-Lin. Lau
Civil and Environmenta'l Engineering Department
Universi,ty of Californi·a, Los AngeJes
4173 Engineering I '.
Los Angeles., CA 9.009:5-15'93
July 2, 1998
•
•
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Executive Summary
A series of experiments were performed in a small but full-scale CDS device to' detennine its
ability to remove free oil and grease from polluted waters using sorbents. Nine experiments
were performed using five different sorbents. One control experiment was performed without a
sorbent. The sorbents were allowed to float on the .surface of the separation chamber of the CDS
device. The CDS unit was not modified to accept the sorbents. Different amounts of each
sorbent were used because of the varying properties of the ,sorbents (density and surf.:u;:e area).
Tests were performed using a 2400-micron screen over 30 minutes at 125 GPM (approximately
50% of the CDS unit's nominal flow capacity). Used motor oil was introduced into the feed of
the CDS at approximately 25 mg/L, which is generally the upper limit of oil and' grease
concentrations found in storm waters. Oil and grease was measured at various times to determine
the removal efficiency. Background oil and grease was measured as well as oil and grease
released from the sorbents after the influent oil and grease was reduced to zero. Removal
efficiencies for most sorbents varied from 63 to 96% depending ·upon conditions. One sorbent
removed only 18%. Sorbent saturation was not achieved in any of the experiments. Very little
oil and grease (generally less than 1 to 2 mgJL) was releasec:i from sorbents when the influent oil
and grease was reduced to zero.
Without a sorbent, the CDS unit removed 80% of the influent oil and grease, but released it after
the oil and grease in the influent was reduced to zero. This suggests that the CDS unit might be.
effective in capturing a spill, if the unit could be isolated after the spill to' allow oil and grease
recovery .
1
• Introduction
. Woodward-Clyde Consultants, Psomas and UCLA (Civil and EnVironmental Engineering
Department) performed a catch basin insert study for a group of Southern California Cities and
the Santa Monica Bay Restoration Project (the project was lead by the. City of Santa Monica).
As an amendment of this study, a CDS unit (which is not a catch ba$in insert -see references Ito
3) was evaluated. The unit was assembled in a laboratory at UCLA using tap' water to simulate
stonn water, and evaluated for its ability to remove trash and suspended solids. This setup was
used in a further study, not associated with catch basin insert study, to evaluate the unit's ability
to remove oil and grease.
CDS contracted with the Civil and Environmental Engineering Department at UCLA to perform
this work. Professor Michael K. Stenstrom directed the work.
Oil and grease removal by various sorbents was evaluated. Free oil and grease was Introduced at
approximately 25 mgIL into the feed of the CDS unit. The sorbents were allowed to float in the
top of the CDS unit. No modifications were made to the CDS unit to accommodate the sorbents.
'Most experiments were conducted at 125 gallons per minute (125 GPM), which is approximately
50% of the test CDS unit's nominal capacity (for the particular size unit evaluated -CDS units
are produced in a range of sizes). Oil and grease was measured at various times in the effluent to
determine removal efficiency.
• This report describes the research and results .
•
2
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•
•
Experimental Methods
Sorbents. A great deal of research has been performed previously at UCLA on oil and grease in
stormwaters and its removal. Sorbents have been evaluated for this purpose. They have been
proposed for this application for many years, but very few studies by independent investigators
have been performed. This study builds upon earlier work and uses. many of the previously
developed concepts and techniques (Lau and Stenstrom, 1995, 1997).
These materials are called "sorbents" as opposed to "adsorbers" or "absorbers" because both
absorption and adsorption mechanism are present. It is sometimes diffic1,llt to. know which
mechanisms are important.
Five sorbents were evaluated. They were obtained from the manufacturers or from dealers in the
Los Angeles area. Most are marketed for oil spill clean up. Table 1 shows the size analys~s for
all sorbents except the Nanofiber (mesh size is not applicable to this sorbent). The numbers in
the table are percent of the sorbent, by weight, that is retained on an ASTM standard wire screen
for the mesh size or opening size shown. Table 2 shows the bulk sorber density. This was
determined by filling a tarred container of known volume with sorb'entand measuring its weight.
This density is not the particle density, which excludes void spaces.
1. OARS. OARSTM (AbTech Industries, 4110 N. Scottsdale Rd., Suite 235, Scottsdale, AZ
85251) is a "rubber" type of sorbent. It can be manufactured in anY desired size fraction.
The material is sintered into larger particles from smaller particles. The material used in
this study was originally intended for use in catch basin inserts; and is someWhat larger
than optimal for this application. The manufacturer generally believes th.at the removal
mechanism is absorption. Of the sorbentseva1uated in this study, the AbTech sorbent is
most similar to the Rubberizer sorbent. The material is denser than the other sorbent~ and
tends to wet better in the separation chamber of the CDS device.
2. Rubberizer. Rubberizer™ is a sorbent that is marketed by Haz-Mat Response
Technologies, Inc (4626 Santa Fe Street, San Diego, CA 92109) as a clean up sorbent for
various types of solvents, oils and fuels. It is composed of a mixture of hydrocarbon
polymers and and additives. It can be purchased in as a particle (used in this test) or water
gel or assembled into pillows and booms. It is similar to the touch as the OARS sorbent.
3. Aluminum Silicate. Aluminum silicate is a popular material-for oil and grease sorptien. It
is lightweight and hydrophobic. It is also used to add bulk to soil. Two types were used in
this study: the first product is marketed as Xsorb™ (Impact Absorbent Technologies, P.O.
Box 1131, Atascadero, CA 93423) and is sold for stQrmwater applications; 2) .the second
type is Sponge Rok™ type 23 (Paramount Perlite Co., Paramount, CA, 90723) and our
understanding it is that is primarily sold as a soil bulking agent. Xsorb is approximately 8
mesh and the particles have sharp edges, as if they were recently fractured. Sponge Rok is
larger, with a mesh size of 3.5, and has rounded edges. Both matefi.als easily abrade to
create a fine powder .
3
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•
4. Nanofiber. Nanofiber™ (Nanofiber Technology Inc, 205 Artillery Road, NC, 29837) is a
polypropylene fiber adsorbent. It is similar to fibers made by 3M for uses in pillows, pads
and sausage sorbers for oil spill control. Nanofiber and other similar materials were uSe!d
extensively in a previous study by the al.lthors (Lau and Stenstrom, 1995).
The sorbers all have different bulk densities, spe9ific surface areas and costs. It was not possible
to create an equivalent mass of each sorbent on any common basis. Th,erefore the experiments
were conducted with sufficient sorbent to cover the top of the CDS unit. When these sorbents
are used to clean up oil spills they are exposed to either pure oil and very concentrated mixtures
of oil and water. Under these circumstances, they will sorb many times their weight.
Table 1. Sorbent sizes (numbers are percent retained on each screen size)
Screen size Screen Mesh Rubberizer OARS Xsorb'
(mm)
26.7
13.3
5.7
4.7
2.4
<2.4
3.5
4
8
<8
Table 2. Bulk sorbent density.
Sorbent
Rubberizer
OARS
Xsorb
SpongeRok
0.0
0.0
0.4
0.2
99.2
0.2
Density (glrol)
0.26
0.22
0.13
0.10
39.7 0.0
50.0 0.0
9.9 11.1
0.2 12,6
0.2 73.8
0.1 2.4
SpongeRok
0.0
O~O
87.1
5.4
3.8
3.7
For the applications investigated in this report, they sorb much less because they are only
exposed to very dilute mixtures of oil and water.
Oil and Grease Analysis. Oil and grease was measured using a solid phase extraction (SPE)
technique developed earlier by the authors (Lau and Stenstrom, 1997). Tbis technique uses a
known volume of sample (generally 500 ml for this study) which is pumped ,through an SPE
column at a constant but low rate (e.g., 5 mlImin). The oil and grease in the sample is sorbed on
the SPE column. After the sample is pumped through the column, it is eluted With a small
volume of solvent (5 ml): methylene chloride and hexane. The sample bottle is aJ:so washed with
a small volume of solvent (isopropanol). The two solvent volumes are combined and placed in a
tarred container. The solvents are allowed to dry at 50°C using a gentle nitrogen pllfge. The
residue is weighed. The results are reported as mgIL based upon the original sample voh.lm~.
This method is not yet a standard method, but is being developed by the US EPA and others as a
standard method. It has the advantages of higher re~overy, especially for the more volatile
components in oil and grease, and using less solvent (the solvents used for traditional oil and
grease analyses are usually flammable, toxic and either green house gases or ozone depleting
gases). By using different sample volumes is it possible to have low detection limits, !lnd the
4
•
•
•
limit with 500-ml sample volume is typically 0.25 mgIL. This method does not quantitatively
measure oil and grease adsorbed to solids and an alternate technique must be used for particle-
bound oil and grease. However, this is not important for this study because no particlyS were
added to the tap water used for testing. '
CDS Unit. Figure 1 shows the CDS unit. This is a schematic diagram and not. to scale. The
manufacturer should be consulted for manufactured sizes and exact dimensions. The screen was
23.375 inches in internal diameter by 24.5 inches tall. The screen size was 2400 microns (1200
and 600 micron screens were used in the previous study to test solids removal but were not used
in this study). The screen openings are elliptical.
The unit was connected to a high-pressure tap water line in the Engineering I building at UCLA
through a cut off valve (not shown) and a metering valve. Small amounts of air Were introduced
into the pipeline to allow an ultrasonic (Doppler effect) velocity meter to be used. The meter
was used.in a three-inch diameter section of pipe that was flowing full under all test condition$.
Figure 2 is a schematic of the piping. .
Oil was introduced at a reducing tee, which allowed the pipe size to increase from 3 inches to 6
inches ("trade" sizes used for all pipe dimensions). A Masterflex peristaltic pump was used to
deliver the oil to the 6-inch line. Flow rate was "determined by pumping from a graduate cylinder
and noting the reduction in volume over time. The oil flow rate was set to deliver the desired
concentration (25 mgIL) for each flow rate. The oil specific gravity'was measured as 0.86' g/cm3.
The 6-inch pipe was flanged to the CDS unit. The 6-inch pipe did not flow full at all flow rates .
The effluent pipe was also six inches in diameter and discharged into a plywood box that
contained the turbulence and splash. The effluent was then sent to a sanitary sewer.
Influent samples were collected from the surface of the CDS unit by dipping a sample container
below the surface in the influent water jet. Effluent samples werecQllected at the endbf the
discharge pipe (a free waterfall).
Prior to the beginning of each test, the freeboard of the CDS unit was wiped clean and a small
amount of new sorbent was used to remove any oil that remained from the previous test. This
sorbent was removed prior to the beginning of the test. A weighed amount of test sorbent Was
then dumped into the separation chamber of the CDS unit. Sorbents were r:emoved using, a large
fine mesh sieve.
Test Sequence. Tests were begun by collecting a background sample prior to tbe introduction of
any oil to the influent. Next the oil-metering pump was turned op. Effluent samples were
collected approximately every 5 minutes for the test duration, which was usually 30 mihutes. At
the end of the test, the oil-metering pump was turned, off and the -influent Was allowed to
continue for another 30 minutes. Two influent samples were collected at approximately 10 and
20 minutes. At the end of the second 30 minutes (total elapsed time of 60 minutes), a sample
was collected to determine if any oil was desQrbing. After collecting the sample the influent'
water was turned off and the used sorbent was recovered and disposed. ' The CDS unit was then
drained and prepared for the next test. Oil and greases samples were generally analyzed within
16 hours after the tests were completed. Tap water temperature during the test was 15 ± 2°C.
5
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•
Influent (6 in.)
..................
'-..
2in elevation ~ I Difference T
/
/ /
/
Effluent (6 in)
~ .. Screen Inside
Large Cylincer
Nominal screen dimension
23.375 in 10 by 24.5 tall.
Sludge
Outlet (2'in.)
Figure 1. Schematic of the CDS unit (not to scale). Nominal screen dimensions are 23.375 by
24.5 inches. The screen is in the middle section and is installed or removed from the top.
Influent and effluent pipes were six in dianleter with flanges. Unit sits on three legs and is
approximately 60 inches tall .
6
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•
3 in. Tap water line.
Control Valve
Effluent
Sample
Point
Air Injection
Point
~ • Doppl,er Effect
Flow Meter
CDS Unit
Figure 2. Process flow diagram .
7
Metering pump
6'in pipe
D
Oil Reservoir
, Influent
Samp.l.e
Point
•
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•
Results and Discussion \ .
A total of 9 tests were perfonned using various types of sorbents. One test was perfonned
without a sorbent to detennine the efficiency of the CDS unit to remove oil and grease by itself.
Table 3 shows the final, averaged results of all tests.
The tests are sorted by sorbent name, in alphabetical order with the test without sorbent last. The
second column shows the amount of sorbent used during the test. The next two coluITms show
the average influent and effluent oil and grease concentrations. The percent removal column was
calculated based upon the average influent and effluent concentrations. The flow column shows
the flow rate used during the tests. All were conducted at 125 G~M except for two tests with
OARS sorbent, which were conducted at 75 and 190 GPM. These tests were conducted to show
the impact of flow rate on removal rates. Test 5 was conducted for'125 minutes to saturate the
sorbent (unsuccessful-the sorbent was not saturated).
Table 3. Test results
Test Sorbent Type Sorbent Inf. Eff. Percent Flow mass (mg) Q(l11g/g) Residu.al
No. Mass {g} {mg/L} {mg/L}. Removal !gEm} {mg/L}
Nanofiber 570 29.3 3.8 87 125 3.62E+05 635 0.68
2 OARS 2600 19.6 2.7 86 125 2.39 E+05 92 0.5
3 OARS 2600 24.0 4.3 82 190 4.25 E+05 164 .0.84
4 OARS 2600 30.7 1.7 94 75 2.47E+05 95 0,68
5 OARS (125) 2600 21.0 3.5 83 125 1.02 :a+06 392
6 Rubberizer 1030 27.2 3.9 86 125 3.30E+05 321 1.96
7 SpongeRok 660 41.1 7.2 41 125 481 E+04 729 0.74
8 Xsorb 661 13.6 2.9 79 125 1.53 E+05 231 0.74
9 No Sorbent 0 19.7 4.5 77 125 3.35
The more dense sorbents (OARS and Rubberizer) generally have greater efficiencies that the
lighter sorbents such as Xsorb and Sponge Rok. This is because the lighter $orbents float on top
of the water and have less contact with influent water and oil and grease. In some' cases, there
was poor mixing of the sorbents with the influent. The OARS and Rubberizer sorbents floated
just below the fluid surface and had much better circulation patterns. .
The column Q represents the mass of removed oil and grease per unit mass of sorbent. The units
are mg per gram (or gram per kilogram). A sorbertt with a Q of 1,ODO would remove oil and
.. grease equal to its weight. In oil spill control, these same sorbents may remove many tirne~ their·
weight. The reduced Q in these experiments results because of the low 'concentrations of oil and
grease in simulated stonnwater, as compared to oil spill conditions. Since none of the sorbents
in these tests were saturated, higher Q's should be anticipated. Generally sorbents will produce
lower effluent concentrations at lower Q's. As saturation occurs, the Q is maximized but
effluent quality suffers .
8
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•
The sorbents generally retained the sorbed oil and grease. Effluent concentrations were les$ than
1.0 mgIL except for the Rubberizer which as almost 2 mg/L. This may have resulted because of
its high Q.
The test with no sorbent is interesting. The CDS unit by itself removed approximately 77% of
the incoming oil and grease. The effluent concentration after oil and grease injection ended was
still high (4.5 mgIL), and the unit without a sorbent would probably have lost all the retained oil
and grease to the effluent.
This behavior suggests a removal mechanism for the CDS/sorbent combination. The CDS unit is
functioning as a gravity oil/water separator. The free oil and grease rise~ to the surface due to
th~ influence of gravity. Once at the surface the oil is captured by a sorbent which retains it.
The tests conducted at different flow rates show the impact of flow rate or retention time on
removal efficiency. The efficiency at the low flow rate was 94% as compared to 82 and 83'% at
the higher flow rates.
The CDS unit retained the sorbents and released hone into the effluent, with the exception of the
Nanofiber. Fine fibers could be seen in the effluent when using Nanofiber.
Figures 3 to 9 show the results of the various tests. The spikes in concentration are mostly likely
due to poor mixing and are more common with the light sorbents. Figure 10 shows a progression
of oil sorption on the OARS sorbent. Figure 11 shows an electron micrograph of the Nanofiber
sorbent.
9
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•
• \
14~--~----~--~----~---'---~--~
. . . 1~luent J 29.341
8
6
: ~~~=~=]~-~~~:~:'=F=r:~~r=~:
o~~~~~~~~~~~ .... ~ .. ~~~
o 10 20 30 40 50 60 70
Time
Figure 3. Test No.1 using Nanofiber at flow rate of 125 GPM .
14·~--~----~--~--~----~---'---~
.... ~ 4
::l ~ 2
o~~~~~~~~~~~~~~~~~~
30 35 o 5 10 15 20 25
Time
Figure 4. Tests No.2 - 4 using OARS at various flow r:;ttes.
10
•
•
•
~ I I 1
j I
Influ€lnt = 21.(}4 mg/L _,",,_1_---F'towl="1"25"'e'PM .
Sorbent = OARS ,, __ l I -,--,"-1----I -+= -, ___ J ---__ ,i,, __
U " --I
;J~'~--I--i --1--
--F ..
--f i "'0"
I
14
12 -...J -. 10 O'l E -CJ 8 ~ 0
+-' 6 c Q)
:::l ;;:::: -4 UJ
2
I I I 0 o 20 40 60 80 100 140 140
Time (min)
Figure 5. Test No.5 using OARS at flow rate of 125 GPM .
-C ell ::J
5: UJ
.Influent =l27.21 ~9/L __ + ___ l-___ "I ___ Eow-=-1.~5-GBMl4---,
forbent!: Rubbe'izer
14
12 ----
-
10 "'-
8 -I
'---I'--____ D-
6 -J"'\ I -!-----
4 -1-\ V', :--/."e--+--------1--1 .. I, --..r
2 -" i ,,-,----........---0~~~~1~ .. ~~1~~~~~~~~~1~1~, ~~ , I
o 10 20 30 40 50 60 70
Time (min)
Figure 6. Test No.6 using Rubberizer at flow rate of 125 GPM .
11
•
•
•
14
12
-10
...J --OJ E 8 ......
(!J
oi!! 0 6 -c: (])
::J 4 E UJ
2
0
0 10 20
IJfluent = h2.13 milL
'_._I __ '~'_"""~ Qw.:".1,25.c;aF.!.MI"·'T-'-"';"-
, rbe~t=lspong
30 40 50 60
Time (min)
70
Figure 7. Test No.7 using Sponge Rok at flow rate of 125 GPM .
12
-10
...J --OJ
E 8 ......
(!J
oi!! 0 6 -c: (])
::J 4 ~ UJ
2
0
-~ I Influent L 13.64 ~9/L -
-'~~ Sorben = Xsorb!
-___ I,
-.--J __
f. I ---' --1 ~ ..
~ I -~~ ----
-.,;-'·'r-·-
T
I I I
14
o 10 20 30 40 50 60 70
Time (min)
Figure 8. Test No.8 using Xsorb at flow rate of 125 GPM .
12
•
12
::J' 10 ....... Cl E -8 (!) 06 0 6 -c Q)
::l :E 4 LU
2
0
14 ~ l~flU.nt~ 19.72 ~91L .
i ~l~;L I
---l
-
I -
-J-I-. I
I I • I I '---'---T 1--,
! ! . I I T I
o 10 20 30 40 50 60 70
Time (min)
Figure 9. Test No.9 using Xsorb at flow rate of 125 GPM .
••
•
13
•
•
• Figure 10. Oil and Grease sorption as a function of time (OARS sorbent, time series progression
from 0, before oil and grease addition to 4, 7, 10, 13, 17, 19 and 30 minutes)
14
•
• \ -20 microns
Figure 11. Electron microscope photograph of N anofiber .
•
15
•
•
•
Conclusions and Recommendations
The short series of tests prefonned in short project demonstrate that the combination of a CDS
unit with sorbents can remove 80 to 90 of the oil and grease at concentrations typically found in
stonnwaters. The removal efficiencies are in the same range as removals obtained in sorbent
columns evaluated in a recently completed study in our laboratory.
The results suggest that the combination is a promising alternative for stonnwater treatment:
This results in large part because of the CDS unit's previously demonstrated ability to remove
trash, debris and suspended solids. These materials tend to clog column sorbers.
The choice of the best sorber is still an open question. The sorbers which traditionally have-very
high Q's (e.g. polypropylene fibers) may not be best in this application because of their tendency
to float on top of the water and poorly mix with the influent (a large portion of these sorbents
never contacts the oil and grease because it is above the liquid surface). None of the sorbents
evaluated were saturated in these tests. Additionally testing must be perfonned to determine each
sorbent's maximum capacity for this application .
16
•
•
•
References
Lau, S-L. and M. K. Stenstrom (1995), "Application of Oil Sorbents in Oil and Grease Removal
from Stormwater Runoff," Proceedings of the 68th Annual Water Environment Federation
Conference and Exposition, Miami Beach, FL, October 21-25, 1995, # 9572008, Vol. 3, pp.
685-695.
Lau, S-L. and M.K. Stenstrom (1997), "Solid Phase Extraction for Oil and Grease Analysis,"
Water Environment Research, Vol. 69, No.3, pp. 368-374.
Wong, T.R.F, R.M. Wootton and D. Fabian (1996a), "A Solid Separator Using a Continuous
Deflective System," unpublished paper, Dept. of Civil Eng., Monash Dniv., P.O. Box 197,
Caulfield East, Vic 3145, Australia (estimated date).
Wong, T.R.F, D. Fabian and R.M. Wootton (1996b), "Hydraulic Performance and ~ediment
Trapping Efficiencies of a Dual Outlet CDS Device," unpublished 'paper, Dept. of Civil Eng.,
Monash Dniv., P.O. Box 197, Caulfield East, Vic 3145, Australia (estimated date). '
17
• Appendix -Raw Data.
Test No. Sorbent Flow rate Time Sample O&G mass O&G cone. %
(GPM} (min} vol. (ml} (mg} (mg/L} Removal
1 Nanofiber 125 Influent 500 14;67 29.34
0 515 0.02 0.04
3 510 1.34 2.63 91.04
6 510 6.26 12.27 '58.1q
10 515 1.60 3.11 89,41
15 500 1.51 3.02 89.71
20 505 0.68 1..35 95.41'
25 500 ' 1.09 2.18 ,92.57
30 500 1.13 2.26 92.30
60 500 0.04 0.08
2 OARS 125 Influent 510 9.98 19.57
0 500 0.00 0.00
3 520 1.21 2.33 88.11
6 500 1.29 2.58 86.82
9 520 1.51 2.90 85.1'6
12 510 1.37 2.69 86.27
16 510 1.32 2.59 8'6.77 • 18 530 1.31 2.47 87.37
22 520 1.55 2.98 84.77'
29 510 1.63 3.20 83.67
35 510 3.72 7.29 62.73
60 520 0.26 0.50
3 OARS 190 Influent 500 12.02 24.04
0 500 0.36 0,72
3 500 2.80 5.60 76.71
6 500 1.44 2.88 88.02
10 500 2.00 4.00 83.36
15 500 1.88 3.76 84.36
20 500 2.73 5.46 77.29
25 500 . 2.45 4.90 79.62
30 50b 1.84 3.68 84.69
38 500 0.42 0.84 .
4 OARS 75 Influent 1200 36.88 30.73
0 500 0.60 0.12
3 500 1.15 2.$0 92.52
6 .500 1.21 2.42 92.13
• 10 500 1.13 2.26 92.65
15 500 0.77 1.54 94.99
18
••• Test No. Sorbent Flow rate Time Sampl~ O&G mass O&G conq. %
{GPM) {min} vol. {ml} {mg} {mg/L} . Removal
20 500 0.57 1.14 96.29
25 500 0.57 1.14 96.29
30 500 0.67 1.34 95.64
38 500 0.34 0.68
5 OARS 125 Influent 500 10.52 21,04
a 500 0.26 0.52
5 500 1.53 3.06 85.46
15 500 1 .. 38 2.76 86.88
30 500 1.80 3.60' 82.89
45 500 1.76 3.52 83.27
60 500 1.62 3.24 84.60
75 500 1.91 3.82 81.84
90 500 2.01 .4.02 80.89
123 500 2.00 4.00 80.99
6 Rubberizer 125 Influent 1000 27.21 27.21
a 500 0.00 0.00
3 500 2.08 4.16 84.71
6 500 3.10 6.20 77.21
• 10 500 1.5':/ -3.14 88.46
15 500 1.96 3.92 85.59
·20 500 1.56 3.1"2 88.53
25 510 1.39 2.73 89.98 .
30 510 2.06 4.04 85.16
60 505 0.99 1.ge
7 Sponge Rok 125 Influent 1000 12.13 12.13
0 500 0.46 0.92
3 5.00 2.24 . 4.48 63.07
6 500 3.05 6.10 49.71
10 500 3.32 6.64 45 . .26
15 .500 3.36 6.72 44.60
20 500 3.34 6.68 44.93
25 500 .4.60 ·9.20 24.15
30 500 5.11 10.22 15.75
60 500 . 0.37 0.74
8 Xsorb 125 Influent 500 6.82 1·3 .. 64
0 500 0.7 1.40
3 520 1.35 2.60 80.97
6 500 1.95 . 3.90 71.41 • 10 500 1.22 2.44 82.11
19
., Test No. Sorbent Flow rate 'Time Sample O&G mass O&Gconc. %
(GPM} (min} vol. (ml) {mg} {mg/L} Removal
15 500 0.93 1.86 86:36
20 500 1.49 2.98 78.15
25 500 1.27 2.54 81.38-
30 500 1.84 3.68 73.02
60 500 0.37 0.74
9 None 125 Influent 500 9.86 19.72
0 500 0.24 0.48
3 505 ' 2.03 4.02 79.62
6 500 2.11 4.22 78.60
10 500 . 2.33 4.66 76.37
15 500 3.19 6.38 67.65
20 500 2.28 4.56 76.88
25 510 1.97 3.86 . 80.41
30 500 1.79 3.58 81.85
60 520 1.74 3.35
•
•
20
•
• \
•
PRECAST MANHOLE MODELS
PROCESSES FLOWS 0.75 TO 0.5 CFS
1
II .I\, --
r.~ l ,..
VARIES
""\. cr:
F'LIJ\I ,_ .. _--... ~~ _ .. Of"','_ . ---' :
."~
T .. --" -. -. --. .,. ............ -.... _---" -----
h. V-
""'" 'D" r
l ""\ I J ,-l----·'A'----t
A -FOOT PRINT DIAM ETER -
b -DEPTH eEL.OW PIPE INVERT, VARIES
. DtPTH
PRECAST DESIGN BELOW FOOT
DESIGN SCREEN PIPE PRINT
MODEL FLOW RATE HEAD· LOSS DIA./HT. lNVERT DIAMETER
"D" "A u
NUMBER cfs MGD m 3 /sec ft. m ft. ft. ft.·
0.7 2/1.5 ---4.8 PMIU20_15 0.49 0.021 0.+5 0.11 4.2
PMSU20_15 0.7 0.49 0.021 0.35 0.11 2/1.5 ~.J 6.0
PMSU20_20 1.20 0.78 0.034 0,48 0.15 2/2.0 5.8 6.0
PMSU20 25 1.68 1.10 0.048 0.62 0.19 2/2.5 6.3 .6.-')
PMSU30_20 2.0 1.29 0.056 0.65 0.20 3/2.0 6.25 7.3
PMSUJO_28 3.0 1.94 0.085 0.70 0.21 .3/2.8 6.7 7.3
PMSU40_40 6.5 4.2 0.1B 0.95 0.29 . 4/4.0 7.B 9.5
*Stondard screen opening is 4-700 microns (.185 in.). Screens also . available In 2400 mIcrons (.095 In.) .
Maximum heed loss: DUr'lng high flow conditions,
if flow exceeds CDS design capacity. then
overage maximum headlcss is obout (1.3 to 2.5) V 2/29; where V is
determined under full pipe conditibns.
10
•• .-•• _-_ •• _-•• __ • ~-t'!'!:
•
•
EXPLODED VIEW
FI8ERGLASS Oll8AFFLE~
ASSEMBLED VIEW
It SEPARATION SCREEN
/lc SUMP ACCES5
MH RISER STACK TOP CAP
---11---'--___ ~ APPROX. wr.-3.550, (TYP.)
___ 5'~ MANHOLE RISER SECTIONS
~ APPROX. WTS:
1.950# (1.5, FT, SEClioN)
2.600# (2.0 FT. SECTION) ,
3.2.50i¥ (2.5 FT. SEtnON)
3.900# (3.0 FT. SECTION)
__ / FlBERGLASS INLET
SEPARATION CHAMBER COMPONENT '
/ APPROX. wr.= 3.9001 (TYP.)
SEPARATION SCREEN
SEPARATION CHAMBER COMPON~NT
APPROX. WI.s :3,9001 ~ (3 FT. RISER SECTION)
SEPARATION SLAB. ~ APPROX. 'NT.=-2.1506 (rYP.)
suMp & BASE ~ APPROX. wr ... , 4,SOO* eNP ..
, ~ SEE NOTE BELOW)
SECTION SIZES UAY VARY AGCORPING
TO LOCAL PRECASTER SPECIFICATIONS.
DATE 10/19/00
CDS MODE,L PMSU20
TYPICAL ASSEMBLY
CRAWN
APPROV.
J.S.F.
R. HowARD 1
•
•
•
ELEVATION VIEW
(SEE SHEET 3)
~ I L._
FLOW -
XX"9\
PIPE INLET
FIBERGLASS INLET
ANO "CYLINDER
TYPICAL / GENERIC
INSTALLATION
NOTE:
OPTIONAL
OIL BAFfLE
xx" !II
PIP~ OUTLET
24", MH COVERS &
FRAMES (2)-OtHER
HATCHES AVAIlABLE
THE INTERNAL COMPONENTS ARE SHOWN IN THE RIGHT-HAND
CONFIGURATION-THESE COMPONENTS MAY BE FURNISHED IN THE
MIRROR IMAGE TO THAT SHOWN (LEFT-HAND CONfiGURATION).
CDS MODEL PMSU20_15, 0.7 CFS CAPACITY
STORM WATER TREATMENT UNIT
e DATE 4/3/01 SCALE
1M_2'
~Rjr PROJECT NAME DRAWN J.S.F. SHEET
CITY, STATE .APPROV. 2
PATENTED
hI'> ~I":'I~..J Uf'*<t~~C' .e.t...ln, Wlj~ I ell'" Cls;'s;'Q ... 17717_7C(C 717 :ClT 'TClCl7./hClI TT
.' "'
•
•
•
TYPICAL / GENERIC
INSTALLATION
SHOWN IN RIGHT-HAND
CONFIGURATION
CENTER OF
ACCESS RISER.
5'-0" 1.0.
,,--___ MH RISER
SECTIONS
ATTACH SlOe: AND BOTTOM
FLANGES TO WALL OF MH
RISER USING ANCHOR BOLTS
(6 MIN). SUPPUED BY COS.
FLOW
xx"" PIPE INLET
OPENINGS PROVIOED DURING
PRECASTING FOR
PIPE INLET AND OUTLET
-_IE. FLOW -
ATTACH SCREEN TO SLAB
USING 4 ANCHOR BOLTS.
CENTER OF SCREEN,
21"~ SUMP OPENING
SUPPLIED BY CDS.-----J
25"" SEPARATION SCREEN, __ ...J
SEE NOTE #2
NOTES:
STAINLESS STE:EL
. SEPARAiloNP\.ATE
1. THE INTERNAL COMPONENTS ARE SHOWN IN THE: RIGHT-HAND
CONFIGURATION-THESE COMPONENTS MAY BE FURNISHED IN THE
MIRROR IMAGE TO THAT SHOWN (LEFT-HAND CONFiGURATION).
2. FOR PROPER INSTALlATION, GREEN FIMGE -ON SCREEN FACES ·UP
FOR R1GHT-fiANO INSTALLATION, RED FlANGE UP FOR LEFT-HAND
ORIENTED UNITS.
CDS MODEL PMSU20_15, 0.7 CFS CAPACITY
STORM WATER TREATMENT UNIT
t6
OA1E 4/3/01 SCALE
1~=2'
Iljll'M PROJECT NAME DRAWN J.S.F. SHEET
CITY, STATE APPRO\'. 3
f::IATENTED
--__ \...01 I ,,_L..I-',..., _ .. ,"'"-_ I , ...... -, I ,...,., ..... OCCO_h7h_70r. 7h'/:IT n:II':l7 ICIA J T T
•
•
•
SECTION CUT (srt !;lHEEr 2)
SUUP EXTERIOR
INY E1.-XXJ<X'±
TYPICAL / 'GENERIC
INSTALLATION
2"-.. COVERS de FRAMES (2),
Tl'P. -OTHER HATCH S'VSTEMS
READILY AVAILABLf:.
5'-1"±
OEPTH
BElOW
PIPE
INVER
LI'-6WL ___ 22r-_' ----~--------~ Mit
J-l. --S'-O" ----1.1
INTERNAL.
SEPARAll0N
SLAB
PLANVIElr
SCALE: 1"-2'
CDS MODEL PMSU20,.:.15t 0.7 CFSCAPAC1TY
STORM WATER TREATMENT UNIT
DATE 4/3(01 f6' ~~ PROJECT NAME DRAWN J.S.F. CITY, STATE APPRO'{.
PATENTED
~~ _ ..... u I I , ...... """'...,,.., "' .. ,1"")-, I I"'-,! t::'''"!r"\ OC'C'O_t.7t._70C· 7b :ClT
SCAlE
1-=2.5'
SHEET
4
TClCl7. Ir;CI iT T
•
•
•
®
ct SEPARATION
&: R1SER I SECTIONS
I
....... ~~-5·-0 .. -----1 CD ~~I--~
"{ i
__ FlBERGlASS
, SEPARATION I, " CYUIIIDER & [--n -~~---
--":..:"t--"---+--'i-----
I,~'
®
VARIES
5'-1" ±
DEPTH
BELOW
PIPE
INVERT
• (TYPICAL)
L.--__ Q)~l_---'.~
t------6'-0" -----II
CONSTRUCTION NOTES:
1'. APPLY BU'TYL MASTIC TO SEAL RISER JOINTS-APPLY LOAD TO MH SECTIONS TO CO~PR£SSSE'Al.ANl IF NECESSARY.
2. IF SEPARATION SU\B IS NON-INTEGRAL TO THE SEPARATION SECTION OF' THE UNIT. SET AN.D VERIFY TOP ~LEVATlON
BEFORE PLACING MORE PRECAST COMPONENTS OR BACKFlWNG. ENSURE J1-FROM TOP OF SEPARATION SLAB
TO PIPE INVERT.
3. G~OUT PIPE CONNECTIONS TO $e:.\L JOINT.
-4. SI:;T BOTIOM OF OIL BAFFl..E 14-A80VE SEPARATION SlJ.B FLOOR; DRILL AND INSERT A MINIMUM OF tEN (10)
3/8-)( J 3/4" SS EXPANSION BOLTS 0 12" O.C. ECUALLY SPACED TO SECURE' FIBERGlASS' OIL BAFFLE Fl,ANGE:
TO RISER WALL-(HAROWARE SUPPUED BY CDS TECHNo.LOGIES).
5. FASTEN FIBERGLASS CYUNDER/INLET TO SCREEN ASSEMBLY USING mUR (4) SETS OF 1/z")(1i-SS HEX HEAD
BOLiS WI NUTS AND WASHERS-(HAROWARE SlJPPUEO 'sy CDS TECHNOLOGIES). IN THE LEFT-f-fANOED
CONFIGURATION THE -RED-COLORED F1.ANGE ON THE SCREEN CYLINDER SHALL FACE UP. IN THE RIGHT-HANDED
CONFIGURATION, THE -GREEN" COLORED fLANGE SHALL FAC'E UP.
G. Ce:NTER SCRIi:E:N ASSEMBlY OVER SUMP OPENING AND POSITION f'IBERGI,ASS INLET AGAINST RISE~ WALl.; DRILL AND
INSERT A MINIMUM OF SJX (6) 3/8" x .3 3/4-SS EXPANSION BOLTS EQUALLY SPACED TO SECURE FIBERGLASS
INLET' f'l.ANGE TO RISER WALL~(HAROWARE SUPPUED BY COS TECHNOLOGIES).
7. VERIFY THAT SCREEN ASSEMBLY IS CENTERED OVER SUMP ACCESS HOl.E AND ADJUST If' NEC~RY; FASTEN
SCREEN TO SEPARA110N SLAB USINC FOUR (+) r >c 3 i" SS EXPANSION SOLTS-(HARDWARE SUPpliED BY CDS
TECHNOLOGIES).
B. SLOCK AND GROUT SEAL TO MATCH GAAOE !oS REQUIRED •
DAT( 4/3 SCAlE 1 N.T.S.
PROJECT NAME DRAWN J~S.F. SHEET
CITY, STATE J.PPRCN. 5
'I'> ':It:>H..J U'-'I-!':lO t:>~ln" U .... :l1 C:f.I,") qs:-s:'~'-177. n-7.QC 7.0 :ClT TC!!il7./F;!iI/ TT r .-
I
I '-,. .. '
-: .
"-'" ' .. -'.;
I
l··, '
I
1
I, "
I
I
I
1
I
J
I
I
I
I
I '
1
1
1
I
1
I
1
I ,','
, ,
I
, , '
I
. , ..
"
.'.~
,
"." ," '-"'",
. :' -
41
;
. // _':' . . -~~.~'. i;.'-,,," l'i'l =.,:!!!I1t: :": t ~'11 \\~~~ I!~==""",,-="'=='1"'''ll7IH'"''===",==dJi /;i! : ;
\
r - --i#J. ' i I
---.. ". -. " -
. --
:~~:: -= ~ ~ -':' ~-:'~'~:' =:'~-':~~r,i~~ ~~~·.~-~e:.i' Ci'-~'ti' iZ' :i:::s~~~0ir:""'i',:"~:~~~~ci)' z":;' a::-i:: i:~~':-:i~~' c~~~~:a:tE~. "'-~?'+~ilS~"'s:?'~:;.:~ ~i'~&~i:ii4t:1i;:'~:X:i;ii:;;iO'~~~~::i:;g~~~~:ii~g::;~/~ /,);.sJ ./ I!' --"______ --:if)i'f
~~"'.~~-.,.~, .~" -.~ -~ .......... ~~ '-'-=-~~=-"~~"""'""t ...... ....= __ '-'-'0'-=""..-., ..-..,.. .. _"N. • ..,,' ........ " =_ .. ",... _>..-.. ... ~~~-. ' ..... ~........-=""'-.= ~'="~-~~" ...... .........,. -=,., ~ ~. --~-.,.= ~ -, '" ., .~---'"'~-I
i ~
-----______ _ __ , . ____ , --+j-~,'\o."-" 1'\ fI I' ____ ~_, ____ , __ ~ ___ ,.. __ . -61
, -----. --, ~-=-~--=-, ==--'1 1-' -----,-~--CAMliiov-u>'A~OBLE-~=::,-=-:'--:="~-=--",J
.>
" . , ",
, "
. -'"'. ~ --. '
,," ',-
, "0
.,
'" "-'-.' '. "" '. ,
-',.:
.' .-
~'-~ :...:..::-:-"'~ ~.;--:-; -.-. ,,-.'
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i ~. ,
i !
f
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o. -1
i _, ' ,
.{
\
" .
. --; ~ ,<'-.:. -
", .
--,.-,--~~-,-~~'-,--'-,-.-'
,-
AL SYSTEM OF LOW PRECIPITATION SPRINKLER HEADS
PROVIDING 100%
COVERAGE.
2. AREAS SLOPED LESS THAN 6:1 SHALL BE IRRIGATED AS APPROVED BY
THE CITY '
ENGINEER, PRIOR TO HYDROSEEDING, THE DEVELOPER SHALL SUBMIT A
PROPOSED SCHEME TO PROVIDE IRRIGATION TO THE CITY ENGINEER. THE
PROPOSAL SHALL BE SPECIFIC REGARDING THE NUMBERS,TYPES AND
COSTS OF
THE ELEMENTS OF THE PROPOSED SYSTEM. !
3. IRRIGATION SHALl.. MAINTAIN THE MOISTURE LEVEL OF THE SOIL AT THE
opnMUM LEVEL FOR THE GROWTH OF THE HYDROSEEOED GROWTH.
HYOROSEEDING MIX SHALL CONSIST OF ALL OF THE FOLLOWING: C.
f.
1. SEED MIX SHALL CONSIST OF NO LESS THAN: :
Q, 20 Ibs. PER ACRE OF ROSE CLOVER
b. 20 Ibs. PER ACRE OF ZORRO FESCUE !
c. 3 Ibs. PER ACRE OF E SCHOOL CIA CALIFORNIA
d. 4 Ibs. PER ACRE OF ACHILLEA MILLEFOLIA
e. 3 Ibs. PER ACRE OF ALYSSUM (CARPET OF SNOW)
1/2 lb. PER ACRE OF DIMORPHOLECA
g. . ITEMS c,d,e, AND f OF THIS SUBSECTION' MAY BE OMITTED
ON LOCATIONS WHERE THE AREA BEING HYDROSEEDED IS NOT VISIBLE FROM
EITHER A PUBLIC STREET OR RESIDENTIAL STRUCTURES.
h. ITEM a OF THIS SUBSECTION MUST BE INOCULATED WITH A
NITROGEN FIXING BACTERIA AND APPLIED DRY EITHER BY DRILLING OR
BROADCASTING BEFORE HYOROSEEDING.
i. ALL SEED MATERIALS SHALL BE TRANSPORTED TO THE
JOBSITE IN UNOPENED CONTAINERS WITH THE CALIFORNIA DEPARTMENT OF
FOOD AND AGRICULTURE CERTIFICATION TAG ATTACHED TO, OR PRINTED ON SAID
CONTAINERS. •
j. NON-PHYTO-TOXIC WETTING AGENTS MAY BE ADDED TO THE
HYDROSEED SLURRY AT THE DISCRETION OF THE CONTRACTOR.
2. TYPE 1 MULCH APPLIED AT THE RATE OF NO LESS THAN 2000 Ibs PER
ACRE. TYPE 6 MUlCH (STRAW) MAY BE SUBSTITUTED, ALL. O~ PART, FOR.'
HYDRAULICALLY APPLIED FIBER MATERIAL. WHEN STRAW ISUStD IT MUST BE
ANCHORED TO THE SLOPE BY MECHANICALLY PUNCHING NO LESS THAN 50%
OF THE STRAW INTO THE SOIL :
3. FERTILIZER CONSISTING OF AMMONIUM PHOSPHATE SULFATE, 16-20-0,
WITH 15% SULFUR APPLIED AT THE RATE OF 500 Ibs. PER ACRE .
D. AREAS TO BE HYDROSEEDED SHAUL BE PREPARED PRIOR TO HYDROSEEDING
BY:
1. ROUGHENING THE SURFACE TO BE PLANTED BY 'ANY OR A
COMBINATION OF:
a. TRACK WALKING SLOPES STEEPER THAN 6: 1
b. HARROWING AREAS 6:1 OR FLATTER THAT ARE SUFFICIENTLY
FRIABLE. ,
c. RIPPING AREAS THAT WILL NOT BREAK UP, USING ITEMS a
OR b ABOVE.
2. CONDITIONING THE SOILS SO THAT IT IS SUITABLE FOR FLANTING BY:
a. ADJUSTING THE SURFACE SOIL MOISTURE TO PROVIDE A DAMP BUT
NOT SATURATED SEED BED. '
, b. THE ADDITION OF, SOIL AMENDMENTS, PH ADJUSTMENT, LEACHING
OR COVERING SALINE SOILS TO PROVIDED VIABLE CONDITIONS: FOR GROWTH.
E. ' HYDROSEEDED AREAS SHALL BE MAINTAINED TO PROVIDE A VIGOROUS
GROWTH UNTIL THE PROJECT IS PERMANENTLY LANDSCAPED OR, FOR AREAS
WHERE HYDROSEEDING IS THE PERMANENT LANDSCAPING,UNl1L THE PROJECT
IS COMPLETED AND ALL BONOS, RELEASED.
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SOILS ENGINEER
PROJECT NUMBER 9851-02
NORCAL ENGINEERING
10641 HUMBOLT ST
LOS AlAMITOS, CA. 90720
TEL,562-799-9469 FAX 562-799-9459
THIS PLAN HAS BEEN PERUSED AND CONFORMS TO
THE RECOMMENDATIONS OF THE REPORT OF
GEOTECHINICAL ENGINEERING INVESTIGATION
DAnED APRIL 25, 2002
SOILS ENGINEER SIGNATURE DATE
EROSION CONSTRUCTION NOTE
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STAMP
WOVEN FABRIC SANDBAG FILLED
WITH COARSE SAND-MIN.
2 BAG HEIGHT -UNLESS
NOTED OTHERWISE
G CONSTRUCT SANDBAG BARRIER, PER DETAIL 'K' HEREON,
WEIGHT 40 LBS.
@ CONSTRUCT CHECKDAM PER DETAIL 'J' HEREON.
@ CONSTRUCT 6" THICK AGGREGATE BASE IN ENTRANCE.
1., ,111., ,III" ,111-" ,III" ,111" ,III~III, ,
FRONT VIEW
NOTES: ,
"t
1 . SANDBAG MATERIAL TO BE GEOnEXTILE FABRIC.
2. REMOVE SEDIMENT WHEN DEPTH EXCEEDS 1/2 OF
SANDBAG HEIGHT.
DET AIL 'K' -SANDBAG BARRIER
SECTION
2' 8'
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'MAX HEIGHT OF CHECK DAM = 3'
PROVIDE AN EXTRA ROW OF
SANDBAGS FOR EVERY ROW OF
SANDBAGS 3 SANDBAGS HIGH
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t=i:=jP===~==i--'-2'MIN I I \ J I
SEC110N
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DETAIL 'J' CHECKDAM
PLOTTED
JUL 2 82002
OANJON ENGINEERING, INC,
. '
GRAPHIC SCALE
( IN FEET )
1 inch = 30 ft,
PLANNING DEPARTMENT APPROVAL
(SIGNED) DATE: / /
IIICIIAEL J. HOlZVllJRl!, PLINNIIIG DIRECTOR
__ ---..:=.--___ DATE: / /
(SIGNED)
RICOlIIIENDED Bt:-----=="'=..-----'--(PIIINT IWIB)
\ ' ( 't
"AS BUILT"
RCE __ _ EXP. ___ _
REVIEWED BY:
INSPECTOR
DATE
DATE
:',
~-4~_+--------------------~-r4_--~--~~ISH8EETI CITY OF CARLSBAD ISH~TSI ~==~~===E=N=G=IN=EE=R=IN=G==D=EP=A=R=TM=E=N=T====~====~
I--' _ _+--+-------~-------_+-..,..;..+-_I--_+-~ GRADING PLANS FOR: PRECISE GRADING &
PAVING PLAN FOR'
CARLSBAD OFFICE PARK
CARLSBAD, CAUFORNIA
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I--'--+--+--~---,.----------+-+-+--+---+-~ 1:""I~o:-P-:-R::::N.,.,:"":.,.,E::EO:-R--:-,.".P=-E---EX...,P-IR-E-S---'· -D-A-TE-~-.l ""1
EN~~:R ~NI:K ' . REVISION DESCRIPTION o~~ AP~::~ ':~ APP~~:~ 2~ Bi~~E~~R""w""-l XXPRXXT NO. " _I DRA~NGNO~ .':
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PROJECT MAP i
:IN T E CITY OF CARLSBAD: CA.
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31.0'
'TYPiCAL STREET SECriON
GAMINO VIDA. ROBUt
. CORTE DEL N o GAt j
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5.0'
LEGAL DESCRIPTION
PARCEL 4 OF PARCEl MAP 9959 IN THE CITY OF CARLSBAD,
COUNTY OF SAN DIEGO
.
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FF"209.3
//
-BLDG [l
FF=210.0
.,---/ -~ ",
BLDG D
FF"'208.5
GRAPHIC SCALE
( IN FEET )
1 !nch -40 tt.
EXISTING RIGHT OF WAY
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EASEMENT NOTES •
TITLE REPORT
ITEM No.
DESCRIPTION '
® EASEMENT IN FA\()R or SAN DlEOO' GAs &
ELECTRIC flLED JIp' 81-252845 O.R. ON ALE IN
'THE SAN DIEGO ¢OUNTY RE~ 0f11C£, ,.
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NOTES
1. PROJECT NAME: CARLSBAD OFFICE PARK
2. OTHER APPLICATIONS SUBMliTED
c. PLANNED INDUSTRIAL PERMIT
3. PRE-APPLICATION NO. PRE 02-09
4. ASSESSORS PARCEL NUMBER 213-061-25
5. SITE ACREAGE 4.02 ACRES .
6. EXISTING ZONING AND GENERAL PLAN DESIGNATION:
P-M PLANNED INDUSTRIAL ZONE
7. EXISTING LANDUSE: VACANT "
PROPOSED LANDUSE: 5 BUILl~INGS WITH PARKING
8. 6 LOTS PROPOSED <-
9. TOTAL GROSS BUILDING COVERAGE: 48.920 SF·· 28%
10. PERCENT OF SITE LANDSCAPED = . .
11. PARKING SPACES '
12, SQUARE FOOTAGE OF EMPLOYE( EATING AREAS ..
13. AVERAGE DAILY TRAFFIC GENERATED -
14. SEWER AND WATER AGENCY ;
CITY OF CARLSBAD "
15. PERCENT OF SITE USED FOR; LANDSCAPE =
16. PROPOSED INCREASE IN AOT J;;. 978·'
17. TYPE OF SUBDIVISION -INDUSTRIAL·
18. EARTHWORK VOLUMES r
CUT=4320 CY
FILL= 1980 CY
NET=2340 CY EXPORT
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-----LOCATION MAP ,
PACIFIC
CCEAN
CARLSBAD
CAMINO
PALOMAR
AIRPORT RD.
VIA ROBLE --.c..._ ........ ~t"
CORTE
DEL NOGAL
LUECADIA
VICINITY MAP
NOT TO SCALE.
OWNERISUBOIVIDER:
BOURESTONDEVELOPMENT
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PREPARED BY:'