HomeMy WebLinkAboutCT 07-04; Bressi Ranch Medical Plaza; Bressi Ranch Medical Plaza; 2008-05-01*
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STORM WATER
MANAGEMENT PLAN
BRESSI RANCH MEDICAL PLAZA
CARLSBAD, CA
AAAY 2008
Prepared For: Bressi Ranch Medical Plaza, LLC.
Prepared By: Fuscoe Engineering, Inc.
JN:2591.02A
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STORM WATER MANAGEMENT PLAN MAY 2008
STORM WATER AAANAGEMENT PLAN
Bressi Ranch Medical Plaza
Town Garden Road and Metropolitan St
Carlsbad, CA 92009
Prepared By
Fuscoe Engineering
6390 Greenwich Dr. Ste 170
San Diego, CA 92122
(858)554-1500
For
Bressi Ranch Medical Plaza LLC
1280 Bison Ave # B9-609
Newport Beach, CA 92660
May 2008
BRESSI RANCH MEDICAL PLAZA TABLE OF CONTENTS
STORM WATER MANAGEMENT PLAN MAY 2008
TABLE OF CONTENTS
1.0 INTRODUCTION 5
1.1 PROJECT DESCRIPTION 5
1.2 PROPOSED LAND USE, BUILDING, AND PARKING SUMMARY 7
1.3 HYDROLOGIC UNIT CONTRIBUTION 8
2.0 WATER QUALITY ENVIRONMENT 9
2.1 BENIFICIAL USES 9
2.1.1 INLAND SURFACE WATERS/COASTAL RECEIVING WATERS 10
+ - excepted from Municipal 10
2.1.2 303(D) STATUS 10
2.2 HYDROLOGY 11
2.2.1 PRE CONSTRUCTION CONDITIONS AND FLOW 12
2.2.2 POST CONSTRUCTION CONDITIONS AND FLOW 12
2.3 POTENTIAL POLLUTANTS 14
2.4 SOIL CHARACTERISTICS 16
3.0 CONSTRUCTION BMPs 17
3.1 CONSTRUCTION PHASE POTENTIAL POLLUTANTS 17
3.2 CONSTRUCTION PHASE BMPS 17
4.0 POST CONSTRUCTION BMPs 19
4.1 POST CONSTRUCTION BMPs 19
4.1.1 SITE DESIGN BMPs 19
LID SITE DESIGN BMPS 20
4.1.2 SOURCE CONTROL BMPs 20
4.1.3 TREATMENT CONTROL BMPs 21
CONTROL 1: BIORETENTION- MODIFIED SAND FILTER TRENCHES 24
5.0 MAINTENANCE 27
5.1 POST CONSTRUCTION BMPs 27
5.2.1 BIORETENTION-MODIFIED SAND FILTER TRENCHES 28
5.3 FISCAL RESOURCES 28
6.0 SUMMARY AND CONCLUSIONS 31
ANNUAL CERTIFICATION OF BMP MAINTENANCE 31
LONG-TERM FUNDING FOR BMP MAINTENANCE 31
ACCESS EASEMENT FOR CITY INSPECTION 31
BRESSI RANCH MEDICAL PLAZA TABLE OF CONTENTS
STORM WATER MANAGEMENT PLAN MAY 2008
7.0 APPENDICES 32
APPENDIX! RUNOFF COEFFICENT REFERENCES
APPENDIX2 NOTICE OF TRANSFER OF RESPONSIBILITY
APPENDIX 3 BMP EDUCATIONAL FACT SHEETS
APPENDIX 4 TREATMENT CONTROL BMP SPECIFCATIONS
APPENDIX 5 PROPOSED HYDROLOGY
APPENDIX 6 BMP MAINTENANCE
BRESSI RANCH MEDICAL PLAZA TABLE OF CONTENTS
STORM WATER MANAGEMENT PLAN MAY 2008
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STREET
PROJECT SITE
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VICINITY MAP
NOT TO SCALE
Figure 1 Vicinity Map
1.0 INTRODUCTION
The Storm Water Management Plan (SWMP) is required per the City of Carlsbad Storm Water
Standards Manual under the Regional Water Quality Control Board Order CAS0108758. The purpose
of this SWMP is to address the water quality impacts from the proposed Bressi Ranch Medical Plaza
project (herein referred to as project). California Stormwater Quality Association (CASQA) BMPs, as
well as those outlined in the Carlsbad Storm Water Standards Manual will be used to provide a long-
term solution to water quality onsite. This SWMP is subject to revisions as needed by the engineer.
1.1 PROJECT DESCRIPTION
This 1.95 acre lot is at the southwest corner of the intersection of Town Garden Road and Metropolitan St. in
Carlsbad, CA. The Bressi Ranch Medical Plaza project will consist of a 9,630 sq ft building containing
medical office condominiums, a surface parking lot, as well as related hardscape, utility, water quality, and
landscape improvements. The existing and proposed zoning of the development consists of planned industrial
(current), and office (proposed).
The project site is Lot 1 of the Bressi Ranch Industrial Area, located in Carlsbad, CA. Bordered by El Camino
Real to the west, open space to the south, Metropolitan St. to the east, and Town Garden Road to the north.
Concurrent to this project, there are mass graded and currently developing areas to the north and east. The
immediate surrounding area is comprised primarily of commercial, industrial, and open space areas. 1-5 is
located approximately 3 miles to the west. Site runoff will enter water quality treatment areas, and
BRESSI RANCH MEDICAL PLAZA INTRODUCTION
STORM WATER MANAGEMENT PLAN MAY 2008
subsequently be routed toward proposed storm drain facilities prior to reaching the existing 24" RCP storm
drain on Town Garden Road. More information concerning storm water flows is located in Section 2.2.
The present condition of the site consists of mass graded land sloping to the northeast at approximately
7.0%. A desilting basin is located in the eastern portion of the site for the purpose of protecting water
quality during the rough grade condition. Flow originating onsite sheet flows to the basin and is
discharged through via a 36" CMP riser or emergency spillway. Flow is conveyed toward a 24" storm
drain stub which ties into the backbone 24" RCP storm drain on Town Garden Road. During
construction, the desilting basin will be removed, and replaced by permanent water quality features.
Flow originating from the vegetated hillside south of the site primarily flows through an existing ditch to
the east. There are no other areas of potential run on surrounding the project site.
PRIORITY PROJECT CATAGORIES
Detached Res. Dev. 10+ Units
Commercial Development + 1 acre
Heavy Industry
Industrial Development + 1 acre
Automotive Repair Shops
Restaurants
Hillside Developments > 5000 sq ft.
Project Discharging to Receiving Waters
within Water Quality Sensitive Areas over
2500 sq ft or increase imperviousness over
1 0% of existing condition.
Parking Lots > 5,000 sq ft or > 15 spaces
Streets, roads, highways, freeways, create
new paved surface > 5000 sq ft.
Retail Gasoline Outlets 5,000 sq ft or more
or project 1 00 or more vehicles per day.
^
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INDIVIDUAL SUSMP PROJECT CATAGORIES
CATAGORY
Parking Areas
BRESSI RANCH MEDICAL PLAZA INTRODUCTION
STORM WATER MANAGEMENT PLAN MAY 2008
EXISTING FACILITIES SUMMARY
FACILITY AREA
Rough Graded Land 1.95 acres
PROPOSED PROJECT SUMMARY
FACILITY PROPOSED AREA
Medical Plaza Development 1.95
1.2 PROPOSED LAND USE, BUILDING, AND PARKING SUMMARY
The proposed project area is comprised of a medical condominium building, parking lot, associated
hardscape, water quality treatment areas, and landscaping.
PROPOSED GENERAL LAND USE SUMMARY
LOCATION
Developed Hardscape
Developed Softscape
ESTIMATED AREA (AC)
66,328
18,154
DEVELOPMENT SUMMARY
BUILDING
Office Building
Water Quality Treatment
Areas
Assorted Landscaping/
Other Softscape*
Parking Lots/Drive Aisles
Assorted Hardscape
SIZE (SF)
9,967
2,448
16,100
35,753
20,708
FEATURES
2 Levels
Water Quality Treatment
Site Landscaping
1 00 Spaces
Sidewalks, Pavement, Entryway
* A majority of the softscape area is located to the west of the building outside the proposed
development area. These areas are not included in the C factor calculation provided in Section 2.2.
BRESSI RANCH MEDICAL PLAZA INTRODUCTION
STORM WATER MANAGEMENT PLAN MAY 2008
1.3 HYDROLOGIC UNIT CONTRIBUTION
The Bressi Ranch Medical Plaza project is located within the Batiquitos Hydraulic Sub-Area, within the
San Marcos Hydraulic Area, within the Carlsbad Hydrologic Unit. The corresponding number
designation is 904.51.
The Carlsbad Hydrologic Unit is approximately 21 0 square miles in area extending from the
headwaters above Lake Wolhford in the east to the Pacific Ocean in the west, and from Vista and
Oceanside in the north to Solana Beach, Escondido, and the community of Rancho Santa Fe to the
south. The cities of Carlsbad, San Marcos, and Encinitas are entirely within this HU. There are
numerous important surface hydrologic features within the Carlsbad HU including four unique coastal
lagoons, three major creeks, and two large water storage reservoirs. The HU contains four major,
roughly parallel hydrologic areas. From north to south they are the Buena Vista (901.2), the Agua
Hedionda (904.3), the Batiquitos (904.5), and the San Elijo (904.6) HAs. Two smaller HAs, the Loma
Alta (904.1) and the Canyon de las Encinas (904.4) are also within the Carlsbad HU.
Flows from the existing project area drains toward existing 24" RCP storm drain heading northeast from
the project site. The storm drain pipe travels in this direction for approximately 300' until reaching a
junction structure and flowing southeast into the open space canyon. The runoff discharges onto an
existing concrete energy dissipater and 5' by 14' rip rap pad prior to its release down the canyon.
Site storm water runoff is conveyed through the canyon, under Carrillo Way, and through the unnamed
tributary transversing the La Costa Resort Golf Course. Flows join San Marcos Creek on the southern
portion of the La Costa property, just north of La Costa Ave. San Marcos Creek empties into the
Batiquitos Lagoon approximately 0.37 miles west of the Resort. The Batiquitos Lagoon is a large, 2.5
mile long lagoon which outlets at the Pacific Ocean north of La Costa Ave, in Carlsbad, CA.
San Marcos Creek has 303(d) listed impairments which are listed in Section 2.1.2. There are no
TMDLs for any of the receiving waters from the proposed project site.
BRESSI RANCH MEDICAL PLAZA 8 INTRODUCTION
STORM WATER MANAGEMENT PLAN MAY 2008
2.0 WATER QUALITY ENVIRONMENT
2.1 BENIFICIAL USES
The beneficial uses for the hydrologic unit are included in Tables 1.1 and 1.2. These tables have been
extracted from the "Water Quality Control Plan for the San Diego Basin (9)," dated September 8,
1994.
MUN- Municipal and Domestic Supply: Includes uses of water for community, military, or individual
water supply systems including, but not limited to, drinking water supply.
AGR-Agricultural Supply: Includes uses of water for farming, horticulture, or ranching including, but
not limited to , irrigation, stock watering, or support of vegetation for range grazing.
WARM— Warm Freshwater Habitat: Includes uses of water that support warm water ecosystems
including, but not limited to, preservation or enhancement of aquatic habitats, vegetation, fish or
wildlife, including invertebrates.
AQUA- Includes the uses of water for aquaculture or mariculture operations including, but not limited
to, propagation, cultivation, maintenance, or harvesting of aquatic plants and animals for human
consumption or bait purposes.
COMM- includes the uses of water for commercial or recreational collection of fish, shellfish, or other
organisms, including, but not limited to, uses involving organisms intended for human consumption or
bait purposes.
BIOL- Includes uses of water that support designated areas or habitats, such as refuges, parks,
sanctuaries, ecological reserves, or Areas of Special Biological Significance (ASBS) where the
preservation or enhancement of natural resources requires special protection.
EST- Includes uses of water that support estuarine ecosystems, including but not limited to, preservation
or enhancement of estuarine habitats, vegetation, fish, shellfish, or wildlife (e.g. estuarine mammals,
waterfowl, or shorebirds.)
RARE- Includes uses of water that support habitats necessary, at least in part, for the survival and
successful maintenance of plant or animal species, established understate or federal law as rare,
threatened or endangered.
SPWN- Includes uses of water that support that support high quality aquatic habitats suitable for
reproduction and early development of fish. This use is applicable for only the protection of
anadromous fish.
SHELL- Includes uses of water that support habitats suitable for the collection of filter feeding shellfish
(e.g. clams, oysters and mussels) for human consumption, commercial, or sport purposes.
MIGR- Includes uses of water that support habitats necessary for migration, acclimatization between
fresh and salt water, or other temporary activities by aquatic organisms such as anadromous fish.
MAR- Includes uses of water that support marine ecosystems including, but not limited to, preservation
or enhancement of marine habitats, vegetation such as kelp, fish, shellfish, or wildlife (e.g. marine
mammals, shorebirds.)
IND - Includes uses of water for industrial activities that do not depend primarily on water quality
including, but not limited to, mining, cooling water supply, hydraulic conveyance, gravel washing, fire
protection, or oil well re-pressurization.
REC1 - Contact Recreation: Includes uses of water for recreational activities involving body contact with
water, where ingestion of water is reasonably possible. These uses include, but are not limited to,
swimming, wading, water-skiing, skin and SCUBA diving, surfing, white water activities, fishing, or use
of natural hot springs.
REC2 - Non-Contact Recreation: Includes the uses of water for recreation involving proximity to water,
but not normally involving body contact with water, where ingestion of water is reasonably possible.
BRESSI RANCH MEDICAL PLAZA 9 WATER QUALITY ENVIRONMENT
STORM WATER MANAGEMENT PLAN MAY 2008
These uses include, but are not limited to, picnicking, sunbathing, hiking, camping, boating, tide pool
and marine life study, hunting, sightseeing, or aesthetic enjoyment in conjunction with the above
activities.
WILD - Wildlife Habitat: Includes uses of water that support terrestrial ecosystems including, but not
limited to, preservation and enhancement of terrestrial habitats, vegetation, wildlife, (e.g., mammals,
birds, reptiles, amphibians, invertebrates), or wildlife water and food sources.
2.1.1 INLAND SURFACE WATERS/COASTAL RECEIVING WATERS
Inland surface waters have the following beneficial uses as shown:
San
Marcos
Creek
Batiquitos
Lagoon
904.51
904.51
+X
X
X
X X X
San
Marcos
Creek
Batiquitos
Lagoon
X X
X X X X X
o - Potential Beneficial Use
x - Existing Beneficial Use
+ - excepted from Municipal
2.1.2 303(D) STATUS
According to the California 2006 303d list published by the State Water Resources Control Board
(SWRCB), San Marcos Creek, is a beneficial impaired water bodies. San Marcos Creek is impaired for
DDE, Phosphorus, and Sediment Toxicity.
The point of discharge into the San Marcos Creek is approximately 2.4 miles downstream of the project
site. The Pacific Ocean Shoreline at the Batiquitos Lagoon outlet is not impaired according to the 2006
303(d) list.
303(d) LISTED WATER QUALITY SEGMENTS 1
RECEIVING WATER
San Marcos Creek
HYDROLOGIC UNIT
CODE
904.51
303(d)
IMPAIRMENT(S)
DDE, Phosphorus,
Sediment Toxicity
DISTANCE FROM
PROJECT (miles)
2.4 miles
BRESSI RANCH MEDICAL PLAZA 10 WATER QUALITY ENVIRONMENT
STORM WATER MANAGEMENT PLAN MAY 2008
The causes of water quality problems are as follows according to the 2006 303(d) list: San Marcos
Creek: Source Unknown.
2.2 HYDROLOGY
City of Carlsbad requirements state that where downstream conditions of concern have been identified,
the drainage study shall establish that pre-project hydrologic conditions that minimize impacts on those
downstream conditions of concern would be either improved or maintained by the proposed project.
The existing project site consists of 1 drainage area sheet flowing into a large desilting basin located in
the northeast corner of the project site. Flows exit the basin via the 36" CMP riser or emergency
spillway, and are conveyed toward the stub 24" RCP which connects to the backbone storm drain on
Town Garden Road.
The proposed site consists of an extremely similar drainage condition as the existing condition. The site
is comprised of drainage areas which discharge to proposed onsite storm drain inlets. These inlets
convey all flow to the northeast corner of the project site; toward the existing 24" RCP on Town Garden
Road. The proposed drainage areas discharge to the storm drain system located on Town Garden Ct.
The proposed project plans very minor alterations to existing site drainage courses. These alterations
are not significant in terms of potential hydrologic impacts offsite, and are present in order to properly
treat and drain the site.
A detailed description of the drainage patterns and flows are discussed in the report titled "Hydrology
Report for Bressi Ranch Medical Plaza" prepared by Fuscoe Engineering.
SITE IMPERVIOUS AREA COMPOSITION
Existing
Proposed
TOTAL
HARDSCAPE
(ACRES)
0.01
1.0
TOTAL
SOFTSCAPE
(ACRES)
1.95
0.83
TOTAL
PLANNING AREA
(ACRES)
1.95
1.83
%
IMPERVIOUS
SURFACES
<1%
54%
RUNOFF
COEFFICIENT
it r*-n
0.35
0.65
BRESSI RANCH MEDICAL PLAZA WATER QUALITY ENVIRONMENT t
STORM WATER MANAGEMENT PLAN MAY 2008
Project Site Drainage and Runoff Characteristics
i nrw1 (Jl)7o ~
3 80% -
g_ 60% -
E
•£ 40% -
0)
£ 20% -
no/(j/o ~i
D Impervious Area ^C-Factor
0.65
- > MJi^/fy^ >^ > *>
( '"*, -*/"p *' >t '^•-1.':; .10.35 """.£•>-:
Existing Proposed
i nn
3 p O O -J *- CN bo c3 O O O CRunoff CoefficientU.Z.U
Figure 1: Changes in site drainage and the coefficient of runoff as a result of the proposed
development.
2.2.1 PRE CONSTRUCTION CONDITIONS AND FLOW
Pre-project features for the existing site include a rough graded pad area sloping to the northeast. A
large desilting basin captures sheet flow, discharging it through the 36" CMP riser, or via the emergency
concrete spillway. The runoff is conveyed toward the existing 24" RCP on Town Garden Rd.
From the hydrology study, the 2, 1 0 and 100 year peak flow rates discharging from the site have been
calculated and are shown in the table below.
EXISTING DRAINAGE FLOWS
DRAINAGE
AREA
A
PIPE SIZE
(INCHES)
24" RCP
DRAINAGE
AREA
(ACRE)
1.95
Q2 (CFS)
1.5
Q,0 (CFS)
2.1
Q,oo (CFS)
3.2
2.2.2 POST CONSTRUCTION CONDITIONS AND FLOW
Post-project conditions include the 2 story medical condominium center, parking lot, water quality
features, landscaping, and associated utilities and hardscape. The proposed site consists of 1 distinct
drainage area with 6 sub drainage areas.
Site development will generally maintain existing drainage patterns. The parking lot will be graded to
sheet flow to the east and drainage will be collected in a private storm drain system, tying in with the
24" existing storm drain at the northeast corner of the site. Biofiltration areas will be used for
conveyance and water quality treatment onsite. The proposed building will convey roof runoff to the
BRESSI RANCH MEDICAL PLAZA 12 WATER QUALITY ENVIRONMENT
STORM WATER MANAGEMENT PLAN MAY 2008
southern side of the building where it will flow to the water quality treatment areas. The parking lot wil
contain two parking landscape islands, both of which are envisioned to be depressed landscaping
areas for water quality purposes with 0" curbs. Both landscaping islands were designed to be
biofiltration swales.
PROPOSED DRAINAGE FLOWS
DRAINAGE
AREA
1
2
3
4
5
6
DRAINAGE
AREA
(ACRE)
0.28
0.72
0.32
0.32
0.27
0.04
Q2 (CFS)
0.3
1.9
0.9
0.83
0.5
0.1
Q,0 (CFS)
0.4
2.7
1.3
1.2
0.7
0.1
Q,oo (CFS)
0.6
4.0
2.0
1.8
1.0
0.1
OVERALL FLOWS COMPARISON
Existing
Site
Proposed
Without
Biofiltration
Proposed
With
Biofiltration
DRAINAGE
AREA
(ACRE)
1.95
1.95
1.95
Q2 (CFS)
1.5
4.0
2.5
Q,o (CFS)
2.1
5.7
4.3
Q,oo (CFS)
3.2
8.6
7.8
As a result of development, peak flows for the proposed site drainage areas will increase due to
increased amounts of impervious surfaces. Site design and treatment control BMPs described in Section
4.1 increase times of concentration, and function to detain, slow down, and treat flows from low to
moderate intensity storm events. Flows through the basins are noted as Post Reduction, in the table
above. Calculation details are included in Appendix 5. These calculations show the site flow and
storm volumes routed through the basins, resulting in an increased time of concentration, as compared
to the proposed pre reduction condition.
The downstream hydrologic impacts have been previously addressed in the master drainage plan for
the Bressi Ranch area. This master plan outlines the flows stemming from the anticipation of
development of the greater project area, and the mitigation measures necessary. Any regional
BRESSI RANCH MEDICAL PLAZA 13 WATER QUALITY ENVIRONMENT
STORM WATER MANAGEMENT PLAN AMY 2008
detention facilities were designed through the master planning process, and are therefore not needed
on the proposed Bressi Ranch Medical Plaza project site.
Per Model SUSMP, interim hydromodification criteria only applies to projects which disturb an area of
50 acres or greater, therefore the proposed project does not apply. As stated in the Drainage Study for
Bressi Lot 1, the previously allowable Q100 value for the project site, referenced in the backbone
drainage studies was 8.8 cfs. The proposed project has a Q100 of 8.6 cfs. The proposed 2 and 10
year flow increase does not conflict with any requirements set forth in the master drainage plan or
previously issued permitted conditions. Calculations are included in Appendix 5.
The Bressi Ranch Medical Plaza project proposes to minimize the increase in peak flows through low
impact site design, utilizing disconnected connected impervious surfaces, and high level filtration based
water quality treatment. In addition, landscaping and curb cuts will be used onsite in order to minimize
the amount curb and gutter flow conditions onsite. These and other techniques outlined in the 2007
San Diego County Low Impact Development (LID) Handbook will be used onsite to minimize impacts
concerning the hydrologic flow regime.
For more detailed information concerning proposed hydrology, reference the report titled "Hydrology
Report for Bressi Ranch Medical Plaza" prepared by Fuscoe Engineering.
2.3 POTENTIAL POLLUTANTS
There is no sampling data available for the existing site condition. The following constituents are
commonly found on similar developments and could affect water quality:
• Sediment discharge due to construction activities and post-construction areas left bare
• Nutrients from fertilizers used in landscaping
• Organic compounds found in pesticides, solvents, and hydrocarbons
• Trash and debris deposited in drain inlets
• Hydrocarbons such as oil and grease from paved areas
ANTICIPATED AND POTENTIAL POLLUTANTS
Detached Residential
Development
Attached Residential
Development
Commercial
Development
Heavy Industrial
Development SEDIMENTX
X
p
Pn,NUTRIENTSX
X
P
P"1 HEAVYMETALSa
ORGANICCOMPOUNpPI
pPi TRASH &DEBRISX
X
X
X
o #OXYGENDEMANDINSUBSTANCEX
Pm
P«
p(5)
Z t/)
=! 0£o o
X
p(2|
X
X BACTERIA &VIRUSESX
p...
p!3|
p(3)PESTICIDESX
X
pa
p(5)
BRESSI RANCH MEDICAL PLAZA 14 WATER QUALITY ENVIRONMENT
STORM WATER MANAGEMENT PLAN MAY 2008
ANTICIPATED AND POTENTIAL POLLUTANTS
Automotive Repair
Shops
Restaurants
Steep Hillside
Development
Parking Lots
Retail Gasoline
Outlets
Streets Highways and
Freeways
LU
5
O
CO
X
pm
X
COi—
LU
(^
f-
z
X
p0)
PP)
co
^ ~j!
"^ i*UJ LLI1 5
x
X
X
X
COQzU ^zo< <o 5z o
OU
x(4)(5)
X
X««
od
X —CO ^
K UJ
i- Q
x
X
X
X
X
X
(,3 to
Z rj
Lu Z <
^ -^ J5$< ,^ iif
O a lo
X
X
pd!
X
p(St
Q LU
^ 55iii_j ^
o o
x
X
X
X
X
X
o£f
"S. *s*O£ ii i
•*^ ^Q
(1 3
b< °^
CO >
X
COLUa
U
1-co
a.
X
Notes:
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
Receiving waters have 303(d) beneficial use impairments consisting of DDE, Phosphorus, and Sediment
Toxicity.
According to the table provided above, which was lifted from the City of Carlsbad SUSMP/ Storm Water
Standards Manual, the designations of Parking Lots, and Streets, Highways and Freeways have
anticipated or potential pollutants for sediment, nutrients, heavy metals, organic compounds, trash and
debris, oxygen demanding substances, oil and grease, and pesticides. Therefore, the following
pollutants are designated as anticipated or potential for the proposed site, as well as have 303(d)
impairments downstream are considered primary pollutants of concern.
PRIMARY POLLUTANTS OF
CONCERN
PESTICIDES
SPECIFIC 303(D) IMPAIRMENT
DDE*
NUTRIENTS PHOSPHOURS
SEDIMENT SEDIMENT TOXICITY
* Dichlorodiphenyldichloroethylene (DDE) is formed through the degradation of DDT, a common
pesticide used widely until its prohibition in 1972. The use of DDT is not anticipated onsite. Although
remnants of DDT and DDE are possible almost anywhere in the United States, the site is not considered
BRESS/ RANCH MEDICAL PLAZA 15 WATER QUALITY ENVIRONMENT t
U
STORM WATER MANAGEMENT PLAN MAY 2008
to be a significant source. The development of the project site is not expected to exacerbate any
beneficial use impairments on downstream waters stemming from the presence of DDE.
2.4 SOIL CHARACTERISTICS
The site is currently comprised of an area which is currently in a mass graded pad condition. The site is
sloped from southwest to northeast, with a large existing desilting basin constructed during the rough
grade. A geotechnical investigation was conducted by Southern California Geotechnical in January
2006, describing the subsurface conditions concerning the proposed development.
The fill materials consist of compacted fill, sandstone, and claystone bedrock. The compacted fill
extends up to 1 2 ft in depth and in combination with the bedrock is of high strength, and of varying
expansion potential. The description of the fill material is one that consists of sands, clayey sands, and
sandy clays with moderate expansive potential. It is expected that overexcavation of approximately 3
feet be conducted on the building pad to ensure the load bearing surface is solid and stable to support
the foundation.
Groundwater was not encountered during geotechnical investigations, however the borings only were
conducted to a depth of 20' bgs. Infiltrating large amounts of surface water through landscaping or
water quality features without sub-drainage is not recommended due to low infiltration rates. According
to the San Diego County Hydrology Manual, the Hydrologic Soil Type is type "D". (Note: Information
regarding soil conditions is also available in the Soil Survey, San Diego Area, California, US
Department of Agriculture, 1 973.) Soil type "D" denotes soils which have substandard infiltration rates,
and are composed of a high percentage of clays.
BRESSI RANCH MED/CAL PLAZA 16 WATER QUALITY ENVIRONMENT
STORM WATER MANAGEMENT PLAN MAY 2008
3.0 CONSTRUCTION BMPs
3.1 CONSTRUCTION PHASE POTENTIAL POLLUTANTS
The main potential pollutants due to construction activity are sediment and construction material waste.
Sediment is possible from grading operations, erosion, and poor stockpile management. Construction
material waste results from improper handling and disposal of waste materials, such as demolished AC
pavement and concrete or empty cans of paint, and not having a designated concrete wash out area. These
wastes can pollute storm water if not handled and disposed of properly. Site activities and potential pollutants
that could potentially be discharged in storm water are summarized below:
Table A - Potential Construction Phase Pollutants
ACTIVITY
Grading
Paving
Construction
Painting
POLLUTANT
Sediment
Asphalt and Concrete
Oil and Grease
Paint
SOURCE
Tracking by vehicles, displacement by wind and equipment
Asphalt and concrete
Vehicles and equipment
Painting of buildings and pavement and curbs
3.2 CONSTRUCTION PHASE BMPS
During construction, Best Management Practices (BMPs) from the California Storm Water Quality Association t
Stormwater Best Management Practice Handbook-Construction (2003) will be used. The project will disturb
approximately 1.95 acres, and is therefore subject to the statewide NPDES program and a SWPPP is required.
The following construction BMPs will be used (the BMP detail is listed next to each BMP): I
• Water Conservation Practices (NS-1)
• Dewatering Operation (NS-2) t
• Paving and Grading Operations (NS-3)
• Illicit Connection/Illicit Discharge (NS-6)
• Vehicle and Equipment Cleaning (NS-8)
• Vehicle and Equipment Fueling (NS-9)
• Vehicle and Equipment Maintenance (NS-10)
• Silt Fence (SE-1)
• Fiber Rolls (SE-5)
• Gravel Bags (SE-6)
• Street Sweeping and Vacuuming (SE-7) I
• Storm Drain Inlet Protection (SE-10)
• Scheduling (EC-1)
• Hydroseeding (EC-4) ',
• Stabilized Construction Entrance/Exit (TR-1)
• Stabilized Construction Roadway (TR-2)
• Entrance/Outlet Tire Wash (TR-3)
• Wind Erosion Control (WE-1)
• Material Delivery and Storage (WM-1)
BRESSI RANCH MEDICAL PLAZA 17 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
• Material Use (WM-2)
• Stockpile Management (WM-3)
• Spill Prevention and Control (WM-4)
• Solid Waste Management (WM-5)
• Hazardous Management (WM-6)
• Concrete Waste Management (WM-8)
• Sanitary/Septic Waste Management (WM-9)
Many of the BMPs listed above are "good housekeeping" that shall be followed in the location of building and
activity areas (e.g. fueling islands, waste container area, wash racks, material storage areas, etc.). The
construction staging area shall be determined by the contractor prior to the start of construction and noted in
the SWPPP. It shall be noted that the SWPPP is a living document and the contractor shall amend the plan as
required during construction.
The potential pollutants listed in section 3.1 will be controlled through the use of the BMPs listed on the
previous page.
Construction materials to be stored and handled at the site include but are not limited to asphalt, concrete,
paint, wood and metal. The typical quantities of these materials and their storage location are not known at
this time. Prior to construction the contractor shall show the designated location for material delivery and
storage on the plan and give a complete list of construction materials and typical quantities that will be stored
and handled on the project site. In addition, on the plan the contractor shall show locations where materials
will be directly exposed to storm water. As stated on the previous page, material delivery and storage and
material use will be conducted in accordance with guidelines set forth in BMP WM-1 and WM-2, respectively.
BRESSI RANCH MEDICAL PLAZA 18 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
4.0 POST CONSTRUCTION BMPs
To address water quality for the project, BMPs will be implemented concerning site planning, activities,
and structural treatment. City of Carlsbad Storm Water Standards Manual guidelines are utilized in the
selection of post construction BMPs. In addition, any features or activities included in the project that
are applicable for the inclusion of CASQA BMPs are included as well. BMP design and education
sheets are included in Appendix 3.
4.1 POST CONSTRUCTION BMPs
4.1.1 SITE DESIGN BMPs
The project is designed to include site design BMPs which reduce runoff, prevent stormwater pollution
associated with the project, and conserve natural areas onsite.
DESIGN CONSIDERED: YES NO DESCRIPTION
MINIMIZE IMPERVIOUS
FOOTPRINT
CONSERVE NATURAL
AREAS/PROVIDE BUFFER
ZONES
MINIMIZE DIRECTLY
CONNECTED IMPERVIOUS
AREAS (DCIAS)
MAXIMIZE CANOPY
INTERCEPTION AND
WATER CONSERVATION
.
13
m
.
a
°
a
"
The project site will include a significant
amount of landscaping. The project site is
small in size and includes landscape planters
as well as surface landscaping and water
quality BMP areas.
Hillsides bordering the project site will remain
in a vegetated condition. The existing project
site consists of rough graded pads, therefore
no natural areas exist onsite. There are no
watercourses bordering the project site.
Runoff from much of the project site will flow
through modified sand filter areas prior to
discharging to storm drain. The use of these
area as well as significant amounts of
landscaping allows for a large portion of site
runoff to have biological contact and
infiltration, rather than direct connection to the
storm drain. The result is increased water
quality, decreased peak flow runoff and
volume, and increased times of concentration
onsite.
The site is currently in a rough graded pad
condition. Site landscaping includes large
numbers of trees and shrubs which are either
native, drought tolerant, or both. Canopy
interception by trees and shrubs will occur
reducing the amount of runoff conveyed by
storm drain offsite. These tress and shrubs are
predominately located in the northern and
western portions of the project site.
BRESSI RANCH MEDICAL PLAZA 19 SUMMARY AND CONCLUSIONS
t
STORM WATER MANAGEMENT PLAN MAY 2008
DESIGN CONSIDERED: YES NO
PROTECT SLOPES AND
CHANNELS
DESCRIPTION
Slopes located to the south of the project site
will be undisturbed by the proposed project.
Onsite 2:1 slopes located north and west of
the proposed office building will be vegetated
and stabilized during and after construction.
Runoff will be routed away from the top of
steep slopes.
LID SITE DESIGN BMPS
Incorporating Low Impact Development (LID) design strategies for priority development projects is
required per R9-2007-0001, the Municipal Storm Water Permit issued to the County of San Diego and
the incorporated cities and districts within. The Bressi Ranch Medical Plaza project proposes to drain
impervious surfaces to pervious areas for storm water treatment.
Only high level filtration style BMPs are chosen for the project site, as noted in the table located in
Section 4.1.3 obtained from the City of Carlsbad SUSMP/ Storm Water Best Management Practices
Manual. These filtration BMPs have a higher treatment effectiveness rating, and lead to positive effects
concerning storm water quality stemming from the project site. Features such as curb cuts are provided
as well to introduce site runoff directly into BMP areas, disconnecting the gutter flow in the parking lot
area. Building downspouts are disconnected as well, feeding into surface water quality treatment areas.
4.1.2 SOURCE CONTROL BMPs
"Source control BMP (both structural and non-structural)" means land use or site planning practices, or
structures that aim to prevent urban runoff pollution by reducing the potential for contamination at the
source of pollution. Source Control BMPs minimize the contact between pollutants and urban runoff.
SOURCE CONTROL BMP
DESIGN OUTDOOR MATERIAL
STORAGE AREAS TO REDUCE
POLLUTION INTRODUCTION
DESCRIPTION
Any hazardous material storage associated with the
building or greater project site will be stored inside,
protected from precipitation as well as run-on from
adjacent areas. Under no circumstances shall
materials with the potential for storm water
contamination be stored outside.
DESIGN TRASH STORAGE
AREAS TO REDUCE
POLLUTION INTRODUCTION
The trash storage area located in the eastern portion of
the project site shall be on impervious ground; as well
as be walled and covered to prevent contact from
precipitation and run-on. Any spills or leaks of trash
will be contained within the trash enclosure.
BRESSI RANCH MEDICAL PLAZA 20 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
SOURCE CONTROL BMP DESCRIPTION
EMPLOY INTEGRATED PEST
MANAGEMENT PRINCIPES
USE EFFICIENT IRRIGATION
SYSTEMS AND LANDSCAPE
DESIGN
PROVIDE STORM WATER
CONVEYANCE SYSTEM
STENCLING AND SIGNAGE
SURFACE PARKING AREAS
The need for pesticide use in the project design will be
eliminated and/or reduced by:
a. Planting pest-resistant or well-adapted plant varietals
such as native plants
b. Discouraging pests by designing the site and landscape
to employ pollution prevention as a first-line of defense.
c. Distributing Integrated Pest Management (IPM)
educational materials to maintenance staff. At a minimum,
educational materials will address the following topics:
i. Keeping pests out of buildings and landscaping
using barriers, screens and caulking
ii. Physical pest elimination techniques, such as
weeding, squashing, trapping, washing or pruning out
pests
iii. Relying on natural enemies to eat pests
iv. Proper use of pesticides as a last line of defense.
Rain shutoff devices will be installed to prevent
irrigation during and after precipitation events. In
addition, flow reducers or shutoff valves will be installed
to control water loss. The overall irrigation system will
be designed taking into account water needs of each
individual area as well as water conservation strategies.
Curb stenciling shall say "No Dumping- I Live
Downstream" or equivalent massage as desired by the
City of Carlsbad.
Surface parking will be routed through vegetated water
quality treatment areas.
4.1.3 TREATMENT CONTROL BMPs
Runoff from the proposed site will flow from impervious and semi-pervious surfaces, picking up
pollutants and other associated debris from the proposed Bressi Ranch Medical Plaza Site. Treatment
of these anticipated pollutants will come from the BMPs listed in this Section. The BMPs were selected
based on new treatment matrices found in the November 2007 San Diego County SUSMP update. The
City of Carlsbad directed Fuscoe Engineering to use these new documents in preparation of this SWMP.
The following shaded areas represent the primary pollutants of concern, and note the nature of those
pollutants as related to treatment removal. Treatment BMPs were chosen based on this as well as other
factors regarding applicability and functionality.
SITE POLLUTANTS OF CONCERN REMOVAL CHARACTERISTICS
SEDIMENT
COURSE
SEDIMENT AND
TRASH
X
POLLUTANTS THAT
TEND TO ASSOCIATE
WITH FINE PARTICLES
DURING TREATMENT
X
POLLUTANTS THAT TEND TO
BE DISSOLVED FOLLOWING
TREATMENT
BRESSI RANCH MEDICAL PLAZA 21 SUMMARY AND CONCLUSIONS t
e
STORM WATER MANAGEMENT PLAN MAY 2008
SITE POLLUTANTS OF CONCERN REMOVAL CHARACTERISTICS
NUTRIENTS
HEAVY METALS
ORGANIC COMPOUNDS
TRASH AND DEBRIS
OXYGEN DEMANDING
SUBSTANCES
BACTERIA
OIL & GREASE
PESTICIDES
COURSE
SEDIMENT AND
TRASH
X
POLLUTANTS THAT
TEND TO ASSOCIATE
WITH FINE PARTICLES
DURING TREATMENT
X
X
X
X
X
X
X
POLLUTANTS THAT TEND TO
BE DISSOLVED FOLLOWING
TREATMENT
X
Certain factors such as site layout, soil feasibility, and treatment capability are taken in to account when
selecting treatment control BMPs. Possible BMP solutions and descriptions concerning feasibility onsite
are described in the table below. The goal in selecting treatment control BMPs is to find the best
solution as to promote water quality treatment, realize project objectives, remain cost efficient, and
utilize low impact design (LID) practices.
TREATMENT CONTROL BMP: YES N/A DESCRIPTION
BIORETENTION FACILITIES
SETTLING BASINS AND
WETLANDS
INFILTRATION FACILITIES OR
PRACTICES
MEDIA FILTERS
m
°
-
°
a
B
•
B
Modified Sand Filter Trenches are
classified as "bioretention" for this
project. The water quality volume will
filter through the treatment area prior
to discharge to the perforated sub-
drainage system.
Adequate room for a dry basin or
wetland is not available onsite.
Alternative modified sand filter trench
areas used for treatment.
Not utilized for this project. Soil
infiltration rates in the area are
substandard for infiltration. In addition
the geotechnical engineer discourages
the infiltration of water due to clay
content in soils and substandard
infiltration rates.
Although similar, the modified sand
filter trenches are classified as
"bioretention" in the criterion for this
project.
BRESSl RANCH MEDICAL PLAZA 22 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
TREATMENT CONTROL BMP: YES N/A DESCRIPTION
HIGH RATE BIOFILTERS
HIGH RATE MEDIA FILTERS
DRAINAGE INSERTS
D
D
.
El
m
-
Another high quality BMP was used on
this project.
A more effective BMP is used for this
project.
An existing offsite PSWC 40_40 CDS
Unit is located downstream of the
proposed project site along Town
Garden Road. The CDS Unit will assist
in the "Treatment Train" approach of
storm water pollutant removal. The
CDS unit is successful in removing
sediments, trash, and oil/grease.
As discussed above, "Bioretention" style treatment control BMPs will be implemented to address water
quality, based on the Primary Pollutants of Concern/303(d) list for the project site.
TREATMENT CONTROL BMP SELECTION MATRIX
COURSE
SEDIMENT AND
TRASH
POLLUTANTS
THAT TEND TO
ASSOCIATE WITH
FINE PARTICLES
DURING
TREATMENT
POLLUTANTS
THAT TEND TO
BE DISSOLVED
FOLLOWING
TREATMENT
ZO «/>p; iu
Z fc 0iu 3 H
ju u ^
0£ .
2 -":
HIGH
HIGH
MEDIUM SETTLING BASINS(DRY PONDS)HIGH
HIGH
LOW WET PONDS ANDWETLANDSHIGH
HIGH
MEDIUM INFILTRATIONFACILITIES ORPRACTICESHIGH
HIGH
HIGH MEDIA FILTERSHIGH
HIGH
LOW HIGH RATEBIOFILTERSHIGH
MEDIUM
LOW HIGH RATE MEDIAFILTERSHIGH
MEDIUM
LOW
ils< O>aos
iSQ
|s
HIGH
LOW
LOW
The Modified Sand Filter Trenches, which are classified as "Bioretention" style BMPs, have a high or
medium removal rating for the three applicable categories concerning the Primary Pollutants of
Concern onsite. The offsite CDS Unit has high removal for course sediments and trash, and functions
as a downstream back up to the onsite treatment BMPs.
BRESS/ RANCH MEDICAL PLAZA 23 SUMMARY AND CONCLUSIONS t
t
STORM WATER MANAGEMENT PLAN MAY 2008
CONTROL 1: BIORETENTION- MODIFIED SAND FILTER TRENCHES
V SUMMARY
Drainage
Area
DRAINAGE
AREA 2:
DRAINAGE
AREA 3:
DRAINAGE
AREA 4:
TOTAL
C
Value
0.85
0.85
0.85
-
ATOTAL M
0.72
0.32
0.32
1.36
24 hr
85%
Storm
(in)
0.70
0.70
0.70
-
Required
Treatment
Volume
(ft3)
1555
691
691
2,918
BMP
Footprint
(ft2)
576
672
621
1,920
BMP Storage
Volume
Surface+
Sub-Surface
(ft3)
742*
865
1,539
3,146
Draw
Down
Time
(days)
0.70
0.40
0.39
-
Notes:
(1) Calculations are based on Carlsbad Storm Water Standards Manual, SUSMP
(2) See Appendix 4 For Calculation Details
(3) * Excess will sheet flow to Sand Filter in Drainage Areas 3 and 4.
Per the City of Carlsbad SUSMP/ Storm Water Standards Manual, volume based treatment control
BMPs on the Bressi Ranch Medical Building site have been designed to treat the volume of runoff
produced by the 85th percentile storm event. This event is shown on the San Diego County 85th
percentile isopluvial map dated 8/7/2003, and is 0.70" for the project location. Modified Sand Filter
Trench areas are the primary treatment control BMP for the parking areas and parking structure.
Modified Sand Filter Trench areas are designed per standard TC-40 in the California Storm Water BMP
Handbook. (4)
The modified sand filter trenches will act as volume-based BMPs and are therefore sized to treat an
amount of runoff calculated by method 1 in the Carlsbad SUSMP/Storm Water Standards Manual.
Water quality volume and BMP sizing calculation details are shown in Appendix 4.
This will allow the first flush storm water runoff to accumulate in the modified sand filter trench, prior to
discharge offsite. The residence time in the basin will be less than 48 hours, for vector control
purposes, allowing time for the settling and filtration of strormwater runoff into the filter medium. This
meets the capacity requirements shown below based on calculations outlined in CASQA TC-40 using
Darcy's Law to size filtration areas and calculate drawdown time. The sizing calculation relates the
velocity of fluids to the hydraulic head and the coefficient of permeability of a medium. The resulting
equation is Af= WQV d/[k t (h + d)]. See Appendix 4 for explanation of the calculations in further detail.
The modified sand filter trenches are limited in size due to the constraints and grades of the proposed
project site. However, the design of the trenches ensures that the 85th percentile storm, which is 0.70
inches at the proposed project site, will be treated over the 24 hour time period.
As shown in the sizing calculations located in Appendix 4, an infiltration rate of 2.1 4 in/day is used.
This is an extremely conservative rate, based on CASQA TC-40. In reality, permeability rates up to and
exceeding 10-15 feet/day are likely considering the uncompacted design of the filter. As proposed, the
filters can store well over the water quality volume, due to both above ground and subsurface storage in
the filter medium. The design storm however is a 24 hour event, in which the filters will function
BRESSI RANCH MEDICAL PLAZA 24 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
throughout. As the storm progresses, storm water will filter down through the layers, reaching the storm
drain through the perforated sub-drainage system. Over the 24 hour period, the drawdown of the filter
trenches will consistently allow storm water to be treated, ensuring that the water quality volume is
stored throughout. Drawdown of a filter can be determined by rearranging the Darcy's law equation,
obtained from CASQA TC-40.
(Basin 2)
t = (WQVxd)/(kxAfx(h + d))
= (1555x3)/(2.14x576x(3 +0.65))
= 1.0 days
The drawdown of the filter trenches can be estimated at 1.0 days maximum, if completely full.
Therefore, during the 24 hour period the filter trenches will be able to simultaneously treat and store the
appropriate water quality volume. The filter trenches in Basins 2 and 3 are not equipped with overflow
risers, therefore overflow storm water will sheet flow to the filter trench in Basin 4, which is oversized for
its respective drainage area.
Side slopes will be vegetated at a slope ratio of 2:1. The primary removal mechanism is the filtration of
particles and pollutants through the filter medium to the perforated sub-drain. The basin bottom will be
vegetated with plants which aid in the filtration of pollutants and can survive in this kind of environment.
The areas are designed so that overflow is conveyed by sheet flow to the east into the designated water
quality areas.
The filter consists of planting soil above hemic or fibric peat, sand, and gravel medium, designed for
the filtration of pollutants from the first flush strormwater runoff. The top layer will consist of 3" of
planting soil, above 8" inches of peat, designed to adsorb pollutants, (particularly nutrients) prior to
further downward filtration. The 1 6" sand layers further treat the storm water through sorption and
filtration processes. The sub-drain is located in the bottom 8" gravel layer which is wrapped in Mirafi
140N (or similar) geotextile fabric. Once the storm water runoff has filtered through the filter medium,
it enters the perforated pipe and is discharged as treated storm water to storm drain leaving the site.
See Appendix 4 for details.
CONTROL 2: PREVIOUSLY SIZED OFFSITE CDS UNIT
Q !
Drainage Area
PROJECT SITE AND
OFFSITE AREAS
Coefficient
0.95
ATOTAL (ac)
23.1
NUMMARY
1
(in/hr)
0.2
Treatment
Flow
4.4 cfs
Unit Spec and
Capacity
PWSC 40 40:
6.0 cfs
Notes:
(1) Calculations are based on Carlsbad Storm Water Standards Manual.
(2) See Appendix 4 For Calculation Details
An existing CDS Unit located downstream of the project site will act as a flow-based BMP and sized to
treat an amount of runoff calculated by the following equation (given in the SUSMP):
QWQ = C x IWQ x A
Where:
QWQ = Flow rate for water quality purposes (cfs)
BRESSI RANCH MEDICAL PLAZA 25 SU/V1MARYAND CONCLUSIONS
t
t
t
STORM WATER MANAGEMENT PLAN MAY 2008
C = Weighted runoff coefficient (greater developed area) = 0.95
IWQ = Rainfall intensity for the treatment design storm (ln/hr) = 0.2 m/hr
A = Area tributary to the treatment control device (AC) = 23.1 ac
The CDS unit was installed underground in the storm drain system to remove pollutants typically
associated with commercial development, including debris, trash, oil and grease, sediment and parking
lot particulates from storm water. Details concerning these treatment BMPs are outlined in Appendix 4.
The capacity for CDS unit PWSC 40_40 is 6.0 cfs. This meets the capacity requirements based on the
contributing watershed area, as shown above.
The CDS Units proposed for the project site are designed to allow for settling of sediment, as well as
removal of oil and grease from the oil baffle located in the unit. The unit is located on Town Garden
Road, and will be maintained by the master plan developer.
BRESSI RANCH MEDICAL PLAZA 26 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
5.0 MAINTENANCE
The operation and maintenance requirements for each type of BMP are contained in the following
sections. If a transfer of responsibility occurs, the property management association will notify the city
using the form included in Appendix 2 as a notice of transfer. If a contractor conducts maintenance
onsite the property management association is still responsible for the correct implementation of this
document. It is up to the property management association to instruct the contractor to maintain the
property in the correct fashion.
ORGANIZATION
ADDRESS
PHONE
To Be Formed Property Management Association:
Interim Contact -Bressi Ranch Medical Plaza LLC
1280 Bison Ave # B9-609
Newport Beach, CA 92660
Fax: 714-292-9007
MAINTENANCE MECHANISM
Project Proponent Agreement to Maintain Storm Water BMPs
Details are provided in this section. Maintenance Agreement is provided in Appendix 6.
5.1 POST CONSTRUCTION BMPs
Post-construction BMPs are to be maintained in perpetuity. Maintenance requirements for source
control BMPs as well as treatment control basin and swale are shown below. It shall be noted that
preventative maintenance such as removal of trash and debris from the site will help ensure proper
function of the BMPs.
SITE DESIGN BMP
MINIMIZE IMPERVIOUS
FOOTPRINT
RESPONSIBLE PARTY
Property Management
Association
MINIMUM MAINTENANCE
FREQUENCY
The site is to be maintained and monitored
to ensure impervious areas are not
expanded or developed at the expense of
pervious areas.
CONSERVE NATURAL
AREAS/PROVIDE BUFFER
ZONES
Property Management
Association
Periodic monitoring of buffer areas along
southeast perimeter to ensure trash and
debris does not accumulate.
MINIMIZE DIRECTLY
CONNECTED IMPERVIOUS
AREAS (DCIAS)
Property Management
Association
Periodic monitoring of landscaped areas to
ensure proper drainage and upkeep.
MAXIMIZE CANOPY
INTERCEPTION AND WATER
CONSERVATION
Property Management
Association
Periodic monitoring of trees to ensure
proper health and upkeep.
BRESSI RANCH MEDICAL PLAZA 27 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
SITE DESIGN BMP
PROTECT SLOPES AND
CHANNELS
RESPONSIBLE PARTY
Property Management
Association
MINIMUM MAINTENANCE
FREQUENCY
Periodic monitoring to ensure slope
stability. Any erosion or rills should be
noted and slope stabilization techniques
employed using jute netting, EC blankets,
or re-vegetation.
DESIGN OUTDOOR MATERIAL
STORAGE AREAS TO REDUCE
POLLUTION INTRODUCTION
Property Management
Association
Loading areas should be inspected and
cleaned on a monthly basis.
DESIGN TRASH STORAGE
AREAS TO REDUCE
POLLUTION INTRODUCTION
Property Management
Association
Periodic normal maintenance to ensure trash
is contained and the area is not a potential
runoff pollution problem area.
USE EFFICIENT IRRIGATION
SYSTEMS AND LANDSCAPE
DESIGN
Property Management
Association
In conjunction with maintenance activities,
verify that landscape design continues to
function properly by adjusting properly to
eliminate overspray to hardscape areas, and
to verify that irrigation timing and cycle
lengths are adjusted in accordance with
water demands, given time of year, weather,
and day or night time temperatures.
PROVIDE STORM WATER
CONVEYANCE SYSTEM
STENCLING AND SIGNAGE
Property Management
Association
Storm drain stencils shall be inspected for
legibility, at minimum, once prior to the
storm season, no later than October 1 each
year. Those determined to be illegible will
be re-stenciled as soon as possible.
EMPLOY INTEGRATED PEST
MANAGEMENT PRINCIPES
Property Management
Association
In conjunction with maintenance activities,
verify that IPM principles are followed.
Includes education of new staff and
residents.
SURFACE PARKING AREAS Property Management
Association
Street sweeping within the internal roads and
parking lot areas shall be conducted at a
minimum frequency of once per year prior to
the rainy season.
Periodic normal maintenance to ensure
parking area is absent of trash and any other
potential contaminants.
TREATMENT CONTROL BMP RESPONSIBLE PARTY MINIMUM MAINTENANCE FREQUENCY
BIORETENTION- MODIFIED
SAND FILTER TRENCH
Property Management
Association
Maintained monthly in conjunction with
regular landscaping activities, including
removal of trash/ debris/sediment, weed
control, and watering during drought
conditions. Damaged or dead plant areas
shall be repaired upon detection. Height of
BRESS/ RANCH MEDICAL PLAZA 28 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
TREATMENT CONTROL BMP RESPONSIBLE PARTY MINIMUM MAINTENANCE FREQUENCY
vegetation on basin floor to be maintained to
12 inches or less. Monitoring for clogging is
crucial for the success of sand filter areas.
See below for details.
5.2.1 BIORETENTION- MODIFIED SAND FILTER TRENCHES
In the modified sand filter trenches, routine maintenance activity consists primarily of debris removal
and vegetation management. Sediment accumulation is possible, and the area needs to be inspected
for possible clogging. If the area is not draining in 72 hours, clogging has occurred and the removal of
the top layer of the filter is required. Clogging of the top layer of the filter is possible and major
maintenance is expected every 2-5 years. The yearly removal sediment/silt material which has
accumulated on the surface is recommended in order to prevent the need for major maintenance of the
filter once it has become totally clogged.
Inspect per CASQA TC-32. Inspections should occur once a month during the rainy season after a
runoff producing event to ensure the area is functioning properly. Plants should be maintained and
kept healthy. If area is not draining within 72 hours, inspect inflow point for excessive sedimentation
and conserved removal of surface material. Excess sediment shall be removed and disposed of
properly. The inlets/outlets shall be inspected frequently for clogging and cleaned out as necessary.
Vegetation shall be trimmed at the beginning and end of the wet season and inspected monthly to
prevent establishment of woody vegetation.
Monitoring will occur on a monthly basis during the first year and quarterly thereafter. Quantitative
data will be collected annually to evaluate frequency of maintenance activities and adjustments to
scheduling will be made accordingly.
5.3 FISCAL RESOURCES
Following the completion of the project, the property management association will be responsible for all
areas within private property as follows: properly disposing of waste material from their assumed areas
within the project site, maintaining landscaping throughout those areas in a manner that will prevent
soil erosion and minimize sediment transport, maintaining drainage facilities in a clean manner and in
good repair, and properly maintaining all post-construction BMPs (both structural and non-structural)
that exist within the private property of the project.
It should be noted that maintenance for any of the above mentioned post-construction BMPs may be
performed through third-party agreements; however, the ultimate responsibility of each facility rests on
the entity denoted above. BMP maintenance costs are listed below.
BRESSI RANCH MEDICAL PLAZA 29 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
BMP OPTION ' CAPITAL0 APPROXIMATE ANNUAL MAINTENANCE
COSTS CUblb
MODIFIED SAND FILTER TRENCH
TRASH STORAGE AREA
CATCH BASIN STENCILING
TOTAL
$5-20/SF =
$17K-$67K
$1,000-
$3,000
$10 per inlet
$18,000 TO
$70,000
$0.50 SF= $1 ,665- Similar to landscaping.
Included in General Site Maintenance
$0 (Re-stencil at $10/inlet when needed)
$ 1,500 -$2,000 /YR
Based on information obtained from CASQA BMP Factsheets, TC-32, and Caltrans Pilot BMP Study
BMP Anticipated Operation and Maintenance Costs.
The developer shall incur the costs for the BMP installation. The responsible party for long term
maintenance and funding is the Property Management Association.
BRESS/ RANCH MEDICAL PLAZA 30 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
6.0 SUMAAARY AND CONCLUSIONS
The use of source control and site design BMPs in practice through the day to day function of the
project will result in a decreased potential for stormwater pollution as opposed to the existing condition.
Treatment control BMPs will function around the clock, providing removal of pollutants from storm
water runoff.
Maintenance will be conducted by the property management association, who will maintain the Site
Design, Source Control, and Treatment Control BMPs throughout the lifetime of the project. In the
event of sale of the site, the new owner will be required to maintain BMPs, ensuring proper function in
perpetuity.
ANNUAL CERTIFICATION OF BMP MAINTENANCE
The maintenance entity shall verify BMP implementation and ongoing maintenance through inspection,
self-certification, survey, or other equally effective measure. The certification shall verify that, at a
minimum, the inspection and maintenance of all structural BMPs including inspection and performance
of any required maintenance in the late summer / early fall, prior to the start of the rainy season. The
enforcement and verification of this task is conducted by The City of Carlsbad Storm Water NPDES
Coordinator, who can be reached at (760) 602-2799.
The city will only verify that the appropriate documentation of maintenance exists. It is the property
management association's sole responsibility to conduct maintenance and provide work orders/receipts
etc, upon request.
LONG-TERM FUNDING FOR BMP MAINTENANCE
Long-term funding for BMP maintenance shall be funded by the property management association.
ACCESS EASEMENT FOR CITY INSPECTION
The property management association assumes responsibility for operation and maintenance of
structural BMPs, however if needed the City of Carlsbad shall be granted able access for inspection
through a formal agreement.
BRESSI RANCH MEDICAL PLAZA 31 SUMMARY AND CONCLUSIONS
STORM WATER MANAGEMENT PLAN MAY 2008
7.0 APPENDICES
Appendix ) Runoff Coefficient References
Appendix 2 Notice of Transfer of Responsibility
Appendix 3 BA/IP Educational Fact Sheets
Appendix 4 Treatment Control BMP Specifications
Appendix 5 Proposed Hydrology
Appendix 6 BMP Maintenance
BRESSI RANCH MEDJCAL PLAZA 32 APPENDICES
Certification
This Storm Water Management Plan has been prepared under the direction of the following Registered Civil
Engineer. The registered Civil Engineer attests to the technical information contained herein and the
engineering data upon which recommendations, conclusions, and decisions are based.
Paul Haaland
RCE #63656
Expires 09/30/08
Date
San Diego County Hydrology Manual Section: 3
Date: June 2003 Page: 4 of 26
» The storm frequency of peak discharges is the same as that of I for the given Tc,
• The fraction of rainfall that becomes runoff (or the runoff coefficient, C) is independent
of I or precipitation zone number (PZN) condition (PZN Condition is discussed in
Section 4.1,2.4),
• The peak rate of runoff is the only information produced by using the RM,
3.1.2 Runoff Coefficient
Table 3-1 lists the estimated runoff coefficients for urban areas. The concepts related to the
runoff coefficient were evaluated in a report entitled Evaluation, Rational Method "C"
Values (Hill, 2002) that was reviewed by the Hydrology Manual Committee. The Report is
available at San Diego County Department of Public Works, Flood Control Section and on
the San Diego County Department of Public Works web page.
The runoff coefficients are based on land use and soil type. Soil type can be determined from
the soil type map provided in Appendix A. An appropriate runoff coefficient (C) for each
type of land use in the subarea should be selected from this table and multiplied by the
percentage of the total area (A) included in that class. The sum of the products for all land
uses is the weighted runoff coefficient (![CA]). Good engineering judgment should be used
when applying the values presented in Table 3-1, as adjustments to these values may be
appropriate based on site-specific characteristics. In any event, the impervious percentage
(% Impervious) as given in the table, for any area, shall govern the selected value for C. The
runoff coefficient can also be calculated for an area based on soil type and impervious
percentage using the following formula:
3-4
San Diego County I lydrology Manual Section: 3
Date: June 2003 Page: 5 of 26
C = 0.90 x (% Impervious) + Cp x (1 - % Impervious)
Where: Cp = Pervious Coefficient Runoff Value for the soil type (shown in
Table 3-1 as Undisturbed Natural Terrain/Permanent Open Space,
0% Impervious). Soil type can be determined from the soil type map
provided in Appendix A.
The values in Table 3-1 are typical for most urban areas. However, if the basin contains rural
or agricultural land use, parks, golf courses, or other types of nonurban land use that are
expected to be permanent, the appropriate value should be selected based upon the soil and
cover and approved by the local agency.
3-5
San Diego County Hydrology Manual
Date: June 2003"
Section:
Page:
3
6 of 26
Table 3-1
RUNOFF COEFFICIENTS FOR URBAN AREAS
Land
NRC'S Elements
Undisturbed Natural Terrain (Natural)
Low Density Residential (LDR)
Low Density Residential (LDR)
Low Density Residential (LDR)
Medium Density Residential (MDR)
Medium Density Residential (MDR)
Medium Density Residential (MDR)
Medium Density Residential (MDR)
High Density Residential (HDR)
High Density* Residential (HDR)
Commercial/Industrial (N. Com)
Commercial/Industrial (G. Corn)
Commercial/Industrial (O.P. Com)
Commercial/Industrial (Limited I.)
Commercial/Industrial (General I.)
Use
County Elements
Permanent Open Space
Residential, 1.0 DU/A or less
Residential, 2.0 DU/A or less
Residential, 2,9 DU/A or less
Residential, 4.3 DU/A or less
Residential, 7.3 DU/A or less
Residential, 10.9 DU/A or less
Residential, 14.5 DU/A or less
Residential, 24.0 DU/A or less
Residential, 43.0 DU/A or less
Neighborhood Commercial
General Commercial
Office Professional/Commercial
Limited Industrial
General Industrial
Runoff Coefficient "C"
% IMPER.
0*
10
20
25
30
40
45
50
65
80
80
85
90
90
95
A
0.20
0.27
0.34
0.38
0.41
0,48
0.52
0.55
0.66
0.76
0.76
0.80
0.83
0.83
0.87
Soil Type
B
0.25
0.32
0.38
0.41
0.45
0.51
0.54
0.58
0.67
0.77
0.77
0.80
0,84
0.84
0.87
C
0.30
0.36
0,42
0.45
0.48
0.54
0.57
0.60
0.69
0.78
0,78
0.81
0.84
0.84
0.87
D
0.35
0.41
0.46
0.49
0.52
0.57
0.60
0,63
0.71
0.79
0.79
0.82
0.85
0.85
0.87
*The values associated with 0% impervious may be used for direct calculation of the runoff coefficient as described in Section 3.1.2 (representing the pervious runoff
coefficient. Cp. for the soil type), or for areas that will remain undisturbed in perpetuity. Justification must be given that the area will remain natural forever (e.g., the area
is located in Cleveland National Forest),
DL'/A = dwelling units per acre
NRC'S ~ National Resources Conservation Service
3-6
Appendix 2
NOTICE OF TRANSFER OF RESPONSIBILITY
STORM WATER MANAGEMENT PLAN
Bressi Ranch Medical Plaza
Submission of this Notice Of Transfer of Responsibility constitutes notice to the City of Carlsbad
that responsibility for the Storm Water Management Plan ("SWMP") for the subject property
identified below, and implementation of that plan, is being transferred from the Previous Owner
(and his/her agent) of the site (or a portion thereof) to the New Owner, as further described
below.
I. Previous Owner/ Previous Responsible Party Information
Company/ Individual Name:
Street Address:
City:State:
Contact Person:
Title:
ZIP:Phone:
Information about Site Transferred
Name of Project (if applicable):
Title of SWMP Applicable to site:
Street Address of Site (if applicable):
Planning Area (PA) and/
or Tract Number(s) for Site:
Lot Numbers (if Site is a portion of a tract):
Date SWMP Prepared (and revised if applicable):
New Owner/ New Responsible Party Information
Company/ Individual Name:
Street Address:
City:State:
Contact Person:
Title:
ZIP:Phone:
IV.Ownership Transfer Information
General Description of Site Transferred to
New Owner:
General Description of Portion of Project/
Parcel Subject to SWMP Retained by Owner
(if any):
Lot/ Tract Numbers of Site Transferred to New Owner:
Remaining Lot/Tract Numbers Subject to SWMP Still Held by Owner (if any):
Date of Ownership Transfer:
Note: When the Previous Owner is transferring a Site that is a portion of a larger project/
parcel addressed by the SWMP, as opposed to the entire project/parcel addressed by the
SWMP, the General Description of the Site transferred and the remainder of the project/
parcel no transferred shall be set forth as maps attached to this notice. These maps shall
show those portions of a project/ parcel addressed by the SWMP that are transferred to the
New Owner (the Transferred Site), those portions retained by the Previous Owner, and those
portions previously transferred by Previous Owner. Those portions retained by Previous
Owner shall be labeled as "Previously Transferred".
V. Purpose of Notice of Transfer
The purposes of this Notice of Transfer of Responsibility are: 1) to track transfer of
responsibility for implementation and amendment of the SWMP when property to which the
SWMP is transferred from the Previous Owner to the New Owner, and 2) to facilitate
notification to a transferee of property subject to a SWMP that such New Order is now the
Responsible Party of record for the SWMP for those portions of the site that it owns.
VI. Certifications
A. Previous Owner
I certify under penalty of law that I am no longer the owner of the Transferred Site as
described in Section II above. I have provided the New Owner with a copy of the
SWMP applicable to the Transferred Site that the New Owner is acquiring from the
Previous Owner.
Printed Name of Previous Owner
Representative:
Signature of Previous Owner
Representative:
Title:
Date:
B. New Owner
I certify under penalty of law that I am the owner of the Transferred Site, as described
in Section II above, that I have been provided a copy of the SWMP, and that I have
informed myself and understand the New Owner's responsibilities related to the
SWMP, its implementation, and Best Management Practices associated with it. I
understand that by signing this notice, the New Owner is accepting all ongoing
responsibilities for implementation and amendment of the SWMP for the Transferred
Site, which the New Owner has acquired from the Previous Owner.
Printed Name of New Owner
Representative:
Signature:
Title:
Date:
Storm Water
Compliance Inspections
The City of Carlsbad has developed an
inventory of all existing commercial and
industrial businesses and has prioritized
them according to the type of business,
proximity to the nearest water body and
potential threat to water quality. Based on
this prioritization, the City will be conducting
storm water compliance inspections of all
industrial and most commercial facilities
within the City. These site inspections will
include a meeting with business
representatives, a walk-through of the
facility, evaluation of current storm water
best management practices and
recommendations for additional measures
that may be required to comply with the new
permit and ordinance. In addition to the
industrial and commercial inspections, the
City is also performing construction site
inspections, conducting a comprehensive
strom drain monitoring program to detect
pollutants, enforcing urban runoff
requirements for new developments and
conducting frequent cleaning of the storm
drain system.
Sanitary Sewer vs. Storm Drain
What's the difference?
The water that drains down a sink or toilet
flows to the sanitary sewer and is treated at
a wastewater treatment plant. The storm
drain, on the other hand, is designed to
carry rainwater away from streets, parking
lots and driveways to prevent flooding. This
water does not receive any treatment and
flows directly into our creeks, lagoons and
ocean.
City of Carlsbad
1635 Faraday Avenue
Carlsbad CA 92008
Storm Water HOTIine: 760-602-2799
stormwater@ci.carlsbadca.us
Printed on recycled paper
Practices For
BUSINESSES
Commercial and Industrial
Ci^rof Carlsbad
Storm Water Protection Program
Storm Water HOTIine
760-602-2799
Pollution Prevention Is Up to US!
Did you know that storm drains are NOT
connected to sanitary sewer systems or
treatment plants? The primary purpose of
storm drains is to carry rainwater away from
developed areas to prevent flooding. As
rainfall flows over the ground, it picks up a
variety of pollutants which flow directly to our
creeks, lagoons and ocean.
Pollutants of concern include:
• Sediments
• Fertilizers
. Metals
• Detergents
• Pesticides
• Organic Compounds
• Trash and Debris
• Oil and Grease
• Bacteria and Viruses
Pollution Prevention Is Up to US!
Best Management Practices (BMPs) are
procedures and practices you can implement
to prevent pollutants and other hazardous
materials from entering our storm drains.
Once potential and existing sources of
pollution have been identified, the next step is
to select proper BMPs to eliminate or reduce
storm water pollution. Program staff is
available to provide information and
assistance in developing BMPs for your
business. Each of us can do our part to keep
storm water clean. Using BMPs adds up to a
pollution solution!
Good Housekeeping
. Instead of using a hose or pressure
washing system, try a dry clean up
method! Use mops, brooms or
wire brushes to clean dumpsters,
sidewalks, buildings,
equipment, pavement,
driveways and other
impervious surfaces. Wash
water should be disposed to the sanitary sewer,
NEVER to the storm drain.
• Minimize the use of cleaning solutions and
agents.
• Keep site free of litter and debris. Place
trash cans and recycling receptacles around the
site to minimize litter.
Preventive Maintenance
• Keep equipment and vehicles in good working
condition. Inspect frequently for leaks and
repair as needed.
• Gutters, storm drains, catch basins and other
storm drainage features should be regularly
inspected and cleaned so that pollutants do not
accumulate.
• Label storm drains to remind employees that
discharge to these drains flows directly to our
waterways.
Materials Storage and Handling
• When possible, store materials indoors or under
covered areas not exposed to rain. If materials
can not be stored under cover, place materials
on pallets and cover with a tarp to avoid contact
with storm water run-on and run-off.
• Store liquids, hazardous waste and other
chemicals in a designated area with secondary
containment. Keep outdoor storage areas in
good condition.
Waste Management
• Sweep up around dumpsters and other areas
frequently to prevent trash from accumulating.
• Place all trash inside dumpsters or containers
until it can be hauled away.
• Dumpsters should always be kept closed to
prevent rainwater from entering. Never place
liquid waste, leaky garbage bags and hazardous
waste in a dumpster or trash bin.
• Recycle cans, bottles, newspaper, office paper
and cardboard. Call 1 -800-CLEANUP for more
information about recycling programs in your
area.
Vehicle Washing and Cleaning
• Wash company vehicles at a commercial car
wash, whenever possible. If vehicles are washed
onsite, wash water must be contained and
disposed of to the sanitary sewer.
Spill Response
• Use brooms and absorbents such as cat litter or
sawdust to clean up small spills. Report
significant spills to the Storm Water Protection
Program and/or the appropriate spill response
agencies immediately.
• Write and keep current a spill response plan.
Ensure that employees are trained on the
elements of the plan.
• Keep rags, damp mops and absorbents readily
accessible. Dispose of waste properly.
Employee Training
• Discuss and distribute information on storm
water pollution prevention during employee
training sessions and at employee meetings.
• Post good housekeeping tips and reminders on
employee bulletin boards.
• Inform subcontractors about the new storm
water requirements and their responsibilities.
For more information or assistance, please call 760-602-2799.
A clean environment is important to all of us!
Did you know that storm drains are
NOT connected to sanitary sewer
systems and treatment plants?
The primary purpose of storm drains
is to carry rainwater away from
developed areas to prevent flooding.
Untreated storm water and the
pollutants it carries, flow directly into
creeks, lagoons and the ocean.
In recent years, sources of water
pollution like industrial waters from
factories have been greatly reduced.
However now, the majority of water
pollution occurs from things like cars
leaking oil, fertilizers from farms and
gardens, failing septic tanks, pet
waste and residential car washing into
the storm drains and into the ocean
and waterways.
All these sources add up to a pollution
problem! But each of us can do small
flings to help clean up our water and
/fiat adds up to a pollution solution!
What's the problem with fertilizers
and pesticides?
Fertilizer isn't a problem—IF it's used
carefully. If you use too much
fertilizer or apply it at the wrong time,
it can easily wash off your lawn or
garden into storm drains and then
flow untreated into lakes or streams.
Just like in your garden, fertilizer in
lagoons and streams makes plants
grow. In water bodies, extra fertilizer
can mean extra algae and aquatic
plant growth. Too much algae harms
water quality and makes boating,
fishing and swimming unpleasant. As
algae decay, they use up oxygen in
the water that fish and other wildlife
need.
Fertilizer photo is used courtesy
of the Water Quality Consortium,
a cooperative venture between
the Washington State Department
of Ecology, King County and the
cities of Bellevue, Seattle and
Tacoma.
Storm Water HOTIine: 760-602-2799
stormwater@ci.carlsbad.ca.us
City of Carlsbad
1635 Faraday Avenue
Carlsbad CA 92008
www.ci.carlsbad.ca.us
£_ ^Printed on recycled paper
How can YOU help keep the environment clean?
Having a clean environment is of
primary importance for our health and
economy. Clean waterways provide
commercial opportunities, recreation,
fish habitat and add beauty to our
landscape. YOU can help keep our
creeks, lagoons and ocean clean by
applying the following tips:
• Don't blow or rake leaves and other
yard waste into the street or gutter.
• Recycle yard waste or start your own
compost pile.
• Don't over irrigate. Use drip
irrigation, soaker hoses or micro-
spray system and water early in the
morning.
• If you have a spray head sprinkler
system, consider adjusting your
watering method to a cycle and
soak. Instead of watering for 15
minutes straight, break up the
session into 5 minute intervals
allowing water to soak in before the
next application.
1 Keep irrigation systems well-
maintained and water only when
needed to save money and prevent
over-watering.
Use fertilizers and pesticides
sparingly.
Have your soil tested to determine
the nutrients needed to maintain a
healthy lawn.
Consider using organic fertilizers—
they release nutrients more slowly.
Leave mulched grass clippings on
the lawn to act as a natural fertilizer.
• Use pesticides only when absolutely
necessary. Use the least toxic
product intended to target a specific
pest, such as insecticidal soaps,
boric acid, etc. Always read the label
and use only as directed.
• Use predatory insects to control
harmful pests when possible.
• Properly dispose of unwanted
pesticides and fertilizers at
Household Hazardous Waste
collection facilities.
For more information on
landscape irrigation, please
call 760-438-2722.
Gardeners can provide good information
about dealing with specific pests and
plants. You may call the Master
Gardener Hotline at 858-694-2860 or
check out their website at
www.mastergardenerssandieqo.org.
The hotline is staffed Monday—Friday,
9 am—3 pm, by experienced gardeners
who are available to answer specific
questions. Information from Master
Gardeners is free to the public.
Master Gardeners
San Diego County has a
Master Gardener program
through the University of
California Cooperative
Extension. Master
3 Environment is
Important
To All of Us!
In the C'iiv o/'Ccirlsluu/.
storm drains /low directly
into Ideal (TcvA.v, lu^oon.^
(iiu/ llie ocean without
treatment. Storm water
pollution can
cause hitman
health nrol
Storm water pollution
comes from a variety of
sources including oil. fj/e
(.nuljlitids, from vehicles
ami hea\'v et/iiinmcni.
landscaping, and front
materials .such as concrete,
mortar and.soil from
3
A
A
The City of Carlshad is
committed to improving
it oj pollutants
our precious
Storm Water Protection Program
Identify and
For more information or to report an illegal
discharge, please call 760-602-2799
Parking/Storage Area Maintenance SC-43
Objectives
Description
Parking lots and storage areas can contribute a number of
substances, such as trash, suspended solids, hydrocarbons, oil
and grease, and heavy metals that can enter receiving waters
through stormwater runoff or non-stormwater discharges. The
protocols in this fact sheet are intended to prevent or reduce the
discharge of pollutants from parking/storage areas and include
using good housekeeping practices, following appropriate
cleaning BMPs, and training employees.
Approach
The goal of this program is to ensure stormwater pollution
prevention practices are considered when conducting activities
on or around parking areas and storage areas to reduce potential
for pollutant discharge to receiving waters. Successful
implementation depends on effective training of employees on
applicable BMPs and general pollution prevention strategies and
objectives.
Pollution Prevention
m Encourage alternative designs and maintenance strategies for
impervious parking lots. (See New Development and
Redevelopment BMP Handbook)
• Keep accurate maintenance logs to evaluate BMP
implementation.
Cover
Contain
Educate
Reduce/Minimize
Product Substitution
Targeted Constituents
Sediment
Nutrients
Trash
Metals
Bacteria
Oil and Grease
Organics
California
Stormwater
Quality
Association
January 2003 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
1 of 4
SC-43 Parking/Storage Area Maintenance
Suggested Protocols
General
• Keep the parking and storage areas clean and orderly. Remove debris in a timely fashion.
• Allow sheet runoff to flow into biofilters (vegetated strip and swale) and/or infiltration
devices.
• Utilize sand filters or oleophilic collectors for oily waste in low quantities.
• Arrange rooftop drains to prevent drainage directly onto paved surfaces.
• Design lot to include semi-permeable hardscape.
• Discharge soapy water remaining in mop or wash buckets to the sanitary sewer through a
sink, toilet, clean-out, or wash area with drain.
Controlling Litter
m Post "No Littering" signs and enforce anti-litter laws.
• Provide an adequate number of litter receptacles.
• Clean out and cover litter receptacles frequently to prevent spillage.
• Provide trash receptacles in parking lots to discourage litter.
• Routinely sweep, shovel, and dispose of litter in the trash.
Surface Cleaning
• Use dry cleaning methods (e.g., sweeping, vacuuming) to prevent the discharge of pollutants
into the stormwater conveyance system if possible.
• Establish frequency of public parking lot sweeping based on usage and field observations of
waste accumulation.
• Sweep all parking lots at least once before the onset of the wet season.
• Follow the procedures below if water is used to clean surfaces:
Block the storm drain or contain runoff.
- Collect and pump wash water to the sanitary sewer or discharge to a pervious surface.
Do not allow wash water to enter storm drains.
Dispose of parking lot sweeping debris and dirt at a landfill.
• Follow the procedures below when cleaning heavy oily deposits:
Clean oily spots with absorbent materials.
Use a screen or filter fabric over inlet, then wash surfaces.
2 of 4 California Stormwater BMP Handbook January 2003
Industrial and Commercial
www.cabmphandbooks.com
Parking/Storage Area Maintenance SC-43
Do not allow discharges to the storm drain.
Vacuum/pump discharges to a tank or discharge to sanitary sewer.
Appropriately dispose of spilled materials and absorbents.
Surface Repair
m Preheat, transfer or load hot bituminous material away from storm drain inlets.
• Apply concrete, asphalt, and seal coat during dry weather to prevent contamination from
contacting stormwater runoff.
• Cover and seal nearby storm drain inlets where applicable (with waterproof material or
mesh) and manholes before applying seal coat, slurry seal, etc. Leave covers in place until
job is complete and all water from emulsified oil sealants has drained or evaporated. Clean
any debris from these covered manholes and drains for proper disposal.
• Use only as much water as necessary for dust control, to avoid runoff.
• Catch drips from paving equipment that is not in use with pans or absorbent material placed
under the machines. Dispose of collected material and absorbents properly.
Inspection
• Have designated personnel conduct inspections of parking facilities and stormwater
conveyance systems associated with parking facilities on a regular basis.
• Inspect cleaning equipment/sweepers for leaks on a regular basis.
Training
• Provide regular training to field employees and/or contractors regarding cleaning of paved
areas and proper operation of equipment.
• Train employees and contractors in proper techniques for spill containment and cleanup.
Spill Response and Prevention
m Keep your Spill Prevention Control and Countermeasure (SPCC) Plan up-to-date.
• Place a stockpile of spill cleanup materials where it will be readily accessible or at a central
location.
• Clean up fluid spills immediately with absorbent rags or material.
• Dispose of spilled material and absorbents properly.
Other Considerations
Limitations related to sweeping activities at large parking facilities may include high equipment
costs, the need for sweeper operator training, and the inability of current sweeper technology to
remove oil and grease.
January 2003 California Stormwater BMP Handbook 3 of 4
Industrial and Commercial
www.cabmphandbooks.com
SC-43 Parking/Storage Area Maintenance
Requirements
Costs
Cleaning/sweeping costs can be quite large. Construction and maintenance of stormwater
structural controls can be quite expensive as well.
Maintenance
m Sweep parking lot regularly to minimize cleaning with water.
• Clean out oil/water/sand separators regularly, especially after heavy storms.
• Clean parking facilities regularly to prevent accumulated wastes and pollutants from being
discharged into conveyance systems during rainy conditions.
Supplemental Information
Further Detail of the BMP
Surface Repair
Apply concrete, asphalt, and seal coat during dry weather to prevent contamination from
contacting stormwater runoff. Where applicable, cover and seal nearby storm drain inlets (with
waterproof material or mesh) and manholes before applying seal coat, slurry seal, etc. Leave
covers in place until job is complete and all water from emulsified oil sealants has drained or
evaporated. Clean any debris from these covered manholes and drains for proper disposal.
Only use only as much water as is necessary for dust control to avoid runoff.
References and Resources
California's Nonpoint Source Program Plan http://www.swrcb.ca.gov/nps/index.html
Clark County Storm Water Pollution Control Manual
http://www.co.clark.wa.us/pubworks/bmpman.pdf
King County Storm Water Pollution Control Manual http://dnr.metrokc.gov/wlr/dss/spcm.htm
Pollution from Surface Cleaning Folder. 1996. Bay Area Stormwater Management Agencies
Association (BASMAA). http://www.basmaa.org/
Oregon Association of Clean Water Agencies. Oregon Municipal Stormwater Toolbox for
Maintenance Practices. June 1998.
Santa Clara Valley Urban Runoff Pollution Prevention Program http: //www.scvurppp.org
The Storm Water Managers Resource Center http://www.stormwatercenter.net/
4 of 4 California Stormwater BMP Handbook January 2003
Industrial and Commercial
www.cabmphandbooks.com
Efficient Irrigation SD-12
Design Objectives
0 Maximize Infiltration
0 Provide Retention
0 Slow Runoff
Minimize Impervious Land
Coverage
Prohibit Dumping of Improper
Materials
Contain Pollutants
Collect and Convey
Description '
Irrigation water provided to landscaped areas may result in excess irrigation water being
conveyed into stormwater drainage systems.
Approach
Project plan designs for development and redevelopment should include application methods of
irrigation water that minimize runoff of excess irrigation water into the stormwater conveyance
system.
Suitable Applications
Appropriate applications include residential, commercial and industrial areas planned for
development or redevelopment. (Detached residential single-family homes are typically
excluded from this requirement.)
Design Considerations
Designing New Installations
The following methods to reduce excessive irrigation runoff should be considered, and
incorporated and implemented where determined applicable and feasible by the Permittee:
• Employ rain-triggered shutoff devices to prevent irrigation after precipitation.
• Design irrigation systems to each landscape area's specific water requirements.
• Include design featuring flow reducers or shutoff valves
triggered by a pressure drop to control water loss in the event
of broken sprinkler heads or lines.
• Implement landscape plans consistent with County or City
water conservation resolutions, which may include provision
of water sensors, programmable irrigation times (for short
cycles), etc.
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
lof 2
SD-12 Efficient Irrigation
• Design timing and application methods of irrigation water to minimize the runoff of excess
irrigation water into the storm water drainage system.
• Group plants with similar water requirements in order to reduce excess irrigation runoff and
promote surface filtration. Choose plants with low irrigation requirements (for example,
native or drought tolerant species). Consider design features such as:
Using mulches (such as wood chips or bar) in planter areas without ground cover to
minimize sediment in runoff
Installing appropriate plant materials for the location, in accordance with amount of
sunlight and climate, and use native plant materials where possible and/or as
recommended by the landscape architect
Leaving a vegetative barrier along the property boundary and interior watercourses, to
act as a pollutant filter, where appropriate and feasible
Choosing plants that minimize or eliminate the use of fertilizer or pesticides to sustain
growth
• Employ other comparable, equally effective methods to reduce irrigation water runoff.
Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.)
define "redevelopment" in terms of amounts of additional impervious area, increases in gross
floor area and/or exterior construction, and land disturbing activities with structural or
impervious surfaces. The definition of" redevelopment" must be consulted to determine
whether or not the requirements for new development apply to areas intended for
redevelopment. If the definition applies, the steps outlined under "designing new installations"
above should be followed.
Other Resources
A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County
Department of Public Works, May 2002.
Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of
San Diego, and Cities in San Diego County, February 14, 2002.
Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood
Control District, and the Incorporated Cities of Orange County, Draft February 2003.
Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures,
July 2002.
2 of 2 California Stormwater BMP Handbook January 2003
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Storm Drain Signage SD-13
Design Objectives
Maximize Infiltration
Provide Retention
Slow Runoff
Minimize Impervious Land
Coverage
,-x Prohibit Dumping of Improper
u Materials
Contain Pollutants
Collect and Convey
Description ~~~—~
Waste materials dumped into storm drain inlets can have severe impacts on receiving and
ground waters. Posting notices regarding discharge prohibitions at storm drain inlets can
prevent waste dumping. Storm drain signs and stencils are highly visible source controls that
are typically placed directly adjacent to storm drain inlets.
Approach
The stencil or affixed sign contains a brief statement that prohibits dumping of improper
materials into the urban runoff conveyance system. Storm drain messages have become a
popular method of alerting the public about the effects of and the prohibitions against waste
disposal.
Suitable Applications
Stencils and signs alert the public to the destination of pollutants discharged to the storm drain.
Signs are appropriate in residential, commercial, and industrial areas, as well as any other area
where contributions or dumping to storm drains is likely.
Design Considerations
Storm drain message markers or placards are recommended at all storm drain inlets within the
boundary of a development project. The marker should be placed in clear sight facing toward
anyone approaching the inlet from either side. All storm drain inlet locations should be
identified on the development site map.
Designing New Installations
The following methods should be considered for inclusion in the
project design and show on project plans:
• Provide stenciling or labeling of all storm drain inlets and
catch basins, constructed or modified, within the project area
with prohibitive language. Examples include "NO DUMPING
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SD-13 Storm Drain Signage
- DRAINS TO OCEAN" and/or other graphical icons to discourage illegal dumping.
• Post signs with prohibitive language and/or graphical icons, which prohibit illegal dumping
at public access points along channels and creeks within the project area.
Note - Some local agencies have approved specific signage and/or storm drain message placards
for use. Consult local agency stormwater staff to determine specific requirements for placard
types and methods of application.
Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.)
define "redevelopment" in terms of amounts of additional impervious area, increases in gross
floor area and/or exterior construction, and land disturbing activities with structural or
impervious surfaces. If the project meets the definition of "redevelopment", then the
requirements stated under" designing new installations" above should be included in all project
design plans.
Additional Information
Maintenance Considerations
m Legibility of markers and signs should be maintained. If required by the agency with
jurisdiction over the project, the owner/operator or homeowner's association should enter
into a maintenance agreement with the agency or record a deed restriction upon the
property title to maintain the legibility of placards or signs.
Placement
• Signage on top of curbs tends to weather and fade.
• Signage on face of curbs tends to be worn by contact with vehicle tires and sweeper brooms.
Supplemental Information
Examples
• Most MS4 programs have storm drain signage programs. Some MS4 programs will provide
stencils, or arrange for volunteers to stencil storm drains as part of their outreach program.
Other Resources
A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County
Department of Public Works, May 2002.
Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of
San Diego, and Cities in San Diego County, February 14, 2002.
Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood
Control District, and the Incorporated Cities of Orange County, Draft February 2003.
Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures,
July 2002.
2 of 2 California Stormwater BMP Handbook January 2003
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Trash Storage Areas SD-32
n . „ Design ObjectivesDescription
Trash storage areas are areas where a trash receptacle (s) are Maximize Infiltration
located for use as a repository for solid wastes. Stormwater Provide Retention
runoff from areas where trash is stored or disposed of can be c. 0 ~11 IT -13- • i IJ-I-T -i Slow Runoffpolluted. In addition, loose trash and debris can be easily
transported by water or wind into nearby storm drain inlets, Minimize Impeivious Land
channels, and/or creeks. Waste handling operations that may be overage
sources of stormwater pollution include dumpsters, litter control, Prohibit Dumping of Improper
and waste piles. Materials
E| Contain Pollutants
Approach Co||ect gnd
This fact sheet contains details on the specific measures required
to prevent or reduce pollutants in stormwater runoff associated
with trash storage and handling. Preventative measures
including enclosures, containment structures, and impervious
pavements to mitigate spills, should be used to reduce the
likelihood of contamination. "~ ~~
Suitable Applications
Appropriate applications include residential, commercial and industrial areas planned for
development or redevelopment. (Detached residential single-family homes are typically
excluded from this requirement.)
Design Considerations
Design requirements for waste handling areas are governed by Building and Fire Codes, and by
current local agency ordinances and zoning requirements. The design criteria described in this
fact sheet are meant to enhance and be consistent with these code and ordinance requirements.
Hazardous waste should be handled in accordance with legal requirements established in Title
22, California Code of Regulation.
Wastes from commercial and industrial sites are typically hauled by either public or commercial
carriers that may have design or access requirements for waste storage areas. The design
criteria in this fact sheet are recommendations and are not intended to be in conflict with
requirements established by the waste hauler. The waste hauler should be contacted prior to the
design of your site trash collection areas. Conflicts or issues should be discussed with the local
agency.
Designing New Installations
Trash storage areas should be designed to consider the following structural or treatment control
BMPs:
• Design trash container areas so that drainage from adjoining
roofs and pavement is diverted around the area(s) to avoid
run-on. This might include berming or grading the waste
handling area to prevent run-on of stormwater.
• Make sure trash container areas are screened or walled to
prevent off-site transport of trash.
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SD-32 Trash Storage Areas
• Use lined bins or dumpsters to reduce leaking of liquid waste.
• Provide roofe, awnings, or attached lids on all trash containers to minimize direct
precipitation and prevent rainfall from entering containers.
• Pave trash storage areas with an impervious surface to mitigate spills.
• Do not locate storm drains in immediate vicinity of the trash storage area.
• Post signs on all dumpsters informing users that hazardous materials are not to be disposed
of the rein.
Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.)
define "redevelopment" in terms of amounts of additional impervious area, increases in gross
floor area and/or exterior construction, and land disturbing activities with structural or
impervious surfaces. The definition of" redevelopment" must be consulted to determine
whether or not the requirements for new development apply to areas intended for
redevelopment. If the definition applies, the steps outlined under "designing new installations"
above should be followed.
Additional Information
Maintenance Considerations
The integrity of structural elements that are subject to damage (i.e., screens, covers, and signs)
must be maintained by the owner/operator. Maintenance agreements between the local agency
and the owner/operator may be required. Some agencies will require maintenance deed
restrictions to be recorded of the property title. If required by the local agency, maintenance
agreements or deed restrictions must be executed by the owner/operator before improvement
plans are approved.
Other Resources
A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County
Department of Public Works, May 2002.
Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of
San Diego, and Cities in San Diego County, February 14, 2002.
Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood
Control District, and the Incorporated Cities of Orange County, Draft February 2003.
Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures,
July 2002.
2 of 2 California Stormwater BMP Handbook January 2003
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Vegetated Swale TC-30
General Description
Vegetated swales are open, shallow channels with vegetation
covering the side slopes and bottom that collect and slowly
convey runoff flow to downstream discharge points. They are
designed to treat runoff through filtering by the vegetation in the
channel, filtering through a subsoil matrix, and/or infiltration
into the underlying soils. Swales can be natural or manmade.
They trap particulate pollutants (suspended solids and trace
metals), promote infiltration, and reduce the flow velocity of
stormwater runoff. Vegetated swales can serve as part of a
stormwater drainage system and can replace curbs, gutters and
storm sewer systems. Therefore, swales are best suited for
residential, industrial, and commercial areas with low flow and
smaller populations.
Inspection/Maintenance Considerations
It is important to consider that a thick vegetative cover is needed
for vegetated swales to function properly. Usually, swales
require little more than normal landscape maintenance activities
such as irrigation and mowing to maintain pollutant removal
efficiency. Swales can become a nuisance due to mosquito
breeding in standing water if obstructions develop (e.g., debris
accumulation, invasive vegetation) and/or if proper drainage
slopes are not implemented and maintained. The application of
fertilizers and pesticides should be minimized.
Maintenance Concerns,
Objectives, and Goals
• Channelization
• Vegetation/Landscape
Maintenance
• Vector Control
• Aesthetics
• Hydraulic and Removal Efficacy
Targeted Constituents
•/ Sediment A
/ Nutrients •
J Trash •
/ Metals A
/ Bacteria •
•/ Oil and Grease A
y Organics A
Legend (Removal Effectiveness)
• Low • High
A Medium
California
Stormwater
Quality
Association
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TC-30 Vegetated Swale
Inspect after seeding and after first major storms for any damages.
Inspect for signs of erosion, damage to vegetation, channelization of flow, debris and
litter, and areas of sediment accumulation. Perform inspections at the beginning and end
of the wet season. Additional inspections after periods of heavy runoff are desirable.
Post construction
Semi-annual
Inspect level spreader for clogging, grass along side slopes for erosion and formation of
rills or gullies, and sand/soil bed for erosion problems.
Annual
Mow grass to maintain a height of 3-4 inches, for safety, aesthetic, or other purposes.
Litter should always be removed prior to mowing. Clippings should be composted.
Irrigate swale during dry season (April through October) or when necessary to maintain
the vegetation.
Provide weed control, if necessary to control invasive species.
Remove litter, branches, rocks blockages, and other debris and dispose of properly.
Maintain inlet flow spreader (if applicable).
Repair any damaged areas within a channel identified during inspections. Erosion rills or
gullies should be corrected as needed. Bare areas should be replanted as necessary.
Declog the pea gravel diaphragm, if necessary.
Correct erosion problems in the sand/soil bed of dry swales.
Plant an alternative grass species if the original grass cover has not been successfully
established. Reseed and apply mulch to damaged areas.
As needed
(frequent,
seasonally)
Semi-annual
Annual (as needed)
Remove all accumulated sediment that may obstruct flow through the swale. Sediment
accumulating near culverts and in channels should be removed when it builds up to 3 in.
at any spot, or covers vegetation, or once it has accumulated to 10% of the original design
volume. Replace the grass areas damaged in the process.
Rototill or cultivate the surface of the sand/soil bed of dry swales if the swale does not
draw down within 48 hours.
As needed
(infrequent)
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Vegetated Swale TC-30
Additional Information
Recent research (Colwell et al., 2000) indicates that grass height and mowing frequency have
little impact on pollutant removal. Consequently, mowing may only be necessary once or twice a
year for safety or aesthetics or to suppress weeds and woody vegetation.
References
Metropolitan Council, Urban Small Sites Best Management Practices Manual. Available at:
http://www.metrocouncil.org/environment/Watershed/BMP/manual.htm
U.S. Environmental Protection Agency, Post-Construction Stormwater Management in New
Development & Redevelopment BMP Factsheets. Available at:
cfpub.epa.gov/npdes/stormwater/menuofbmps/bmp files.cfm
Ventura Countywide Stormwater Quality Management Program, Technical Guidance Manual
for Stormwater Quality Control Measures. July, 2002.
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Bioretention TC-32
Design Considerations
• Soil for Infiltration
• Tributary Area
• Slope
• Aesthetics
• Environmental Side-effects
Description
The bioretention best management practice (BMP) functions as a
soil and plant-based filtration device that removes pollutants
through a variety of physical, biological, and chemical treatment
processes. These facilities normally consist of a grass buffer
strip, sand bed, ponding area, organic layer or mulch layer,
planting soil, and plants. The runoffs velocity is reduced by
passing over or through buffer strip and subsequently distributed
evenly along a ponding area. Exfiltration of the stored water in
the bioretention area planting soil into the underlying soils
occurs over a period of days.
California Experience
None documented. Bioretention has been used as a stormwater
BMP since 1992. In addition to Prince George's County, MD and
Alexandria, VA, bioretention has been used successfully at urban
and suburban areas in Montgomery County, MD; Baltimore
County, MD; Chesterfield County, VA; Prince William County,
VA; Smith Mountain Lake State Park, VA; and Gary, NC.
Advantages
• Bioretention provides stormwater treatment that enhances
the quality of downstream water bodies by temporarily
storing runoff in the BMP and releasing it over a period of
four days to the receiving water (EPA, 1999).
• The vegetation provides shade and wind breaks, absorbs
noise, and improves an area's kndscape.
Limitations
• The bioretention BMP is not recommended for areas with
slopes greater than 20% or where mature tree removal would
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Targeted Constituents
0
0
0
0
0
0
0
Sediment 1
Nutrients A
Trash
Metals
Bacteria
Oil and Grease
Organics
l
L
Legend (RemovalEffectiveness)
• Low • High
A Medium
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be required since clogging may result, particularly if the BMP receives runoff with high
sediment loads (EPA, 1999).
• Bioretention is not a suitable BMP at locations where the water table is within 6 feet of the
ground surface and where the surrounding soil stratum is unstable.
• By design, bioretention BMPs have the potential to create very attractive habitats for
mosquitoes and other vectors because of highly organic, often heavily vegetated areas mixed
with shallow water.
• In cold climates the soil may freeze, preventing runoff from infiltrating into the planting soil.
Design and Sizing Guidelines
• The bioretention area should be sized to capture the design storm runoff.
• In areas where the native soil permeability is less than 0.5 in/hr an underdrain should be
provided.
• Recommended minimum dimensions are 15 feet by 40 feet, although the preferred width is
25 feet. Excavated depth should be 4 feet.
• Area should drain completely within 72 hours.
• Approximately i tree or shrub per 50 ft2 of bioretention area should be included.
• Cover area with about 3 inches of mulch.
Construction/Inspection Considerations
Bioretention area should not be established until contributing watershed is stabilized.
Performance
Bioretention removes stormwater pollutants through physical and biological processes,
including adsorption, filtration, plant uptake, microbial activity, decomposition, sedimentation
and volatilization (EPA, 1999). Adsorption is the process whereby particulate pollutants attach
to soil (e.g., clay) or vegetation surfaces. Adequate contact time between the surface and
pollutant must be provided for in the design of the system for this removal process to occur.
Thus, the infiltration rate of the soils must not exceed those specified in the design criteria or
pollutant removal may decrease. Pollutants removed by adsorption include metals, phosphorus,
and hydrocarbons. Filtration occurs as runoff passes through the bioretention area media, such
as the sand bed, ground cover, and planting soil.
Common particulates removed from stormwater include particulate organic matter,
phosphorus, and suspended solids. Biological processes that occur in wetlands result in
pollutant uptake by plants and microorganisms in the soil. Plant growth is sustained by the
uptake of nutrients from the soils, with woody plants locking up these nutrients through the
seasons. Microbial activity within the soil also contributes to the removal of nitrogen and
organic matter. Nitrogen is removed by nitrifying and denitrifying bacteria, while aerobic
bacteria are responsible for the decomposition of the organic matter. Microbial processes
require oxygen and can result in depleted oxygen levels if the bioretention area is not adequately
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Bioretention TC-32
aerated. Sedimentation occurs in the swale or ponding area as the velocity slows and solids fall
out of suspension.
The removal effectiveness of bioretention has been studied during field and laboratory studies
conducted by the University of Maryland (Davis et al, 1998). During these experiments,
synthetic stormwater runoff was pumped through several laboratory and field bioretention areas
to simulate typical storm events in Prince George's County, MD. Removal rates for heavy metals
and nutrients are shown in Table i.
Table 1 Laboratory and Estimated
Bioretention Davis et al. (1998);
PGDER (1993)
Pollutant
Total Phosphorus
Metals (Cu,Zn,Pb)
TKN
Total Suspended Solids
Organics
Bacteria
Removal Rate
70-83%
93-98%
68-80%
90%
90%
90%
Results for both the laboratory and field experiments were similar for each of the pollutants
analyzed. Doubling or halving the influent pollutant levels had little effect on the effluent
pollutants concentrations (Davis et al, 1998).
The microbial activity and plant uptake occurring in the bioretention area will likely result in
higher removal rates than those determined for infiltration BMPs.
Siting Criteria
Bioretention BMPs are generally used to treat stormwater from impervious surfaces at
commercial, residential, and industrial areas (EPA, 1999). Implementation of bioretention for
stormwater management is ideal for median strips, parking lot islands, and swales. Moreover,
the runoff in these areas can be designed to either divert directly into the bioretention area or
convey into the bioretention area by a curb and gutter collection system.
The best location for bioretention areas is upland from inlets that receive sheet flow from graded
areas and at areas that will be excavated (EPA, 1999). In order to maximize treatment
effectiveness, the site must be graded in such a way that minimizes erosive conditions as sheet
flow is conveyed to the treatment area. Locations where a bioretention area can be readily
incorporated into the site plan without further environmental damage are preferred.
Furthermore, to effectively minimize sediment loading in the treatment area, bioretention only
should be used in stabilized drainage areas.
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Additional Design Guidelines
The kyout of the bioretention area is determined after site constraints such as location of
utilities, underlying soils, existing vegetation, and drainage are considered (EPA, 1999). Sites
with loamy sand soils are especially appropriate for bioretention because the excavated soil can
be backfilled and used as the planting soil, thus eliminating the cost of importing planting soil.
The use of bioretention may not be feasible given an unstable surrounding soil stratum, soils
with clay content greater than 25 percent, a site with slopes greater than 20 percent, and/or a
site with mature trees that would be removed during construction of the BMP.
Bioretention can be designed to be off-line or on-line of the existing drainage system (EPA,
1999). The drainage area for a bioretention area should be between o.i and 0.4 hectares (0.25
and i.o acres). Larger drainage areas may require multiple bioretention areas. Furthermore,
the maximum drainage area for a bioretention area is determined by the expected rainfall
intensity and runoff rate. Stabilized areas may erode when velocities are greater than 5 feet per
second (1.5 meter per second). The designer should determine the potential for erosive
conditions at the site.
The size of the bioretention area, which is a function of the drainage area and the runoff
generated from the area is sized to capture the water quality volume.
The recommended minimum dimensions of the bioretention area are 15 feet (4.6 meters) wide
by 40 feet (12.2 meters) long, where the minimum width allows enough space for a dense,
randomly-distributed area of trees and shrubs to become established. Thus replicating a natural
forest and creating a microclimate, thereby enabling the bioretention area to tolerate the effects
of heat stress, acid rain, runoff pollutants, and insect and disease infestations which landscaped
areas in urban settings typically are unable to tolerate. The preferred width is 25 feet (7.6
meters), with a length of twice the width. Essentially, any facilities wider than 20 feet (6.1
meters) should be twice as long as they are wide, which promotes the distribution of flow and
decreases the chances of concentrated flow.
In order to provide adequate storage and prevent water from standing for excessive periods of
time the ponding depth of the bioretention area should not exceed 6 inches (15 centimeters).
Water should not be left to stand for more than 72 hours. A restriction on the type of plants that
can be used may be necessary due to some plants' water intolerance. Furthermore, if water is
left standing for longer than 72 hours mosquitoes and other insects may start to breed.
The appropriate planting soil should be backfilled into the excavated bioretention area. Planting
soils should be sandy loam, loamy sand, or loam texture with a cky content ranging from 10 to
25 percent.
Generally the soil should have infiltration rates greater than 0.5 inches (1.25 centimeters) per
hour, which is typical of sandy loams, loamy sands, or loams. The pH of the soil should range
between 5.5 and 6.5, where pollutants such as organic nitrogen and phosphorus can be adsorbed
by the soil and microbial activity can flourish. Additional requirements for the planting soil
include a 1.5 to 3 percent organic content and a maximum 500 ppm concentration of soluble
salts.
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Bioretention TC-32
Soil tests should be performed for every 500 cubic yards (382 cubic meters) of planting soil,
with the exception of pH and organic content tests, which are required only once per
bioretention area (EPA, 1999). Planting soil should be 4 inches (10.1 centimeters) deeper than
the bottom of the largest root ball and 4 feet (1.2 meters) altogether. This depth will provide
adequate soil for the plants' root systems to become established, prevent plant damage due to
severe wind, and provide adequate moisture capacity. Most sites will require excavation in
order to obtain the recommended depth.
Planting soil depths of greater than 4 feet (1.2 meters) may require additional construction
practices such as shoring measures (EPA, 1999). Planting soil should be placed in 18 inches or
greater lifts and lightly compacted until the desired depth is reached. Since high canopy trees
may be destroyed during maintenance the bioretention area should be vegetated to resemble a
terrestrial forest community ecosystem that is dominated by understory trees. Three species
each of both trees and shrubs are recommended to be planted at a rate of 2500 trees and shrubs
per hectare (1000 per acre). For instance, a 15 foot (4.6 meter) by 40 foot (12.2 meter)
bioretention area (600 square feet or 55.75 square meters) would require 14 trees and shrubs.
The shrub-to-tree ratio should be 2: i to 3:1.
Trees and shrubs should be planted when conditions are favorable. Vegetation should be
watered at the end of each day for fourteen days following its planting. Plant species tolerant of
pollutant loads and varying wet and dry conditions should be used in the bioretention area.
The designer should assess aesthetics, site layout, and maintenance requirements when
selecting plant species. Adjacent non-native invasive species should be identified and the
designer should take measures, such as providing a soil breach to eliminate the threat of these
species invading the bioretention area. Regional landscaping manuals should be consulted to
ensure that the planting of the bioretention area meets the landscaping requirements
established by the local authorities. The designers should evaluate the best placement of
vegetation within the bioretention area. Plants should be placed at irregular intervals to
replicate a natural forest. Trees should be placed on the perimeter of the area to provide shade
and shelter from the wind. Trees and shrubs can be sheltered from damaging flows if they are
placed away from the path of the incoming runoff. In cold climates, species that are more
tolerant to cold winds, such as evergreens, should be placed in windier areas of the site.
Following placement of the trees and shrubs, the ground cover and/or mulch should be
established. Ground cover such as grasses or legumes can be planted at the beginning of the
growing season. Mulch should be placed immediately after trees and shrubs are planted. Two
to 3 inches (5 to 7.6 cm) of commercially-available fine shredded hardwood mulch or shredded
hardwood chips should be applied to the bioretention area to protect from erosion.
Maintenance
The primary maintenance requirement for bioretention areas is that of inspection and repair or
replacement of the treatment area's components. Generally, this involves no thing mo re than the
routine periodic maintenance that is required of any landscaped area. Plants that are
appropriate for the site, climatic, and watering conditions should be selected for use in the
bioretention cell. Appropriately selected plants will aide in reducing fertilizer, pesticide, water,
and overall maintenance requirements. Bioretention system components should blend over
time through plant and root growth, organic decomposition, and the development of a natural
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TC-32 Bioretention
soil horizon. These biologic and physical processes over time will lengthen the facility's life span
and reduce the need for extensive maintenance.
Routine maintenance should include a biannual health evaluation of the trees and shrubs and
subsequent removal of any dead or diseased vegetation (EPA, 1999). Diseased vegetation
should be treated as needed using preventative and low-toxic measures to the extent possible.
BMPs have the potential to create very attractive habitats for mosquitoes and other vectors
because of highly organic, often heavily vegetated areas mixed with shallow water. Routine
inspections for areas of standing water within the BMP and corrective measures to restore
proper infiltration rates are necessary to prevent creating mosquito and other vector habitat. In
addition, bioretention BMPs are susceptible to invasion by aggressive plant species such as
cattails, which increase the chances of water standing and subsequent vector production if not
routinely maintained.
In order to maintain the treatment area's appearance it may be necessary to prune and weed.
Furthermore, mulch replacement is suggested when erosion is evident or when the site begins to
look unattractive. Specifically, the entire area may require mulch replacement every two to
three years, although spot mulching may be sufficient when there are random void areas. Mulch
replacement should be done prior to the start of the wet season.
New Jersey's Department of Environmental Protection states in their bioretention systems
standards that accumulated sediment and debris removal (especially at the inflow point) will
normally be the primary maintenance function. Other potential tasks include replacement of
dead vegetation, soil pH regulation, erosion repair at inflow points, mulch replenishment,
unclogging the underdrain, and repairing overflow structures. There is also the possibility that
the cation exchange capacity of the soils in the cell will be significantly reduced over time.
Depending on pollutant loads, soils may need to be replaced within 5-10 years of construction
(LID, 2000).
Cost
Construction Cost
Construction cost estimates for a bioretention area are slightly greater than those for the
required landscaping for a new development (EPA, 1999). A general rule of thumb (Coffman,
1999) is that residential bioretention areas average about $3 to $4 per square foot, depending on
soil conditions and the density and types of plants used. Commercial, industrial and
institutional site costs can range between $10 to $40 per square foot, based on the need for
control structures, curbing, storm drains and underdrains.
Retrofitting a site typically costs more, averaging $6,500 per bioretention area. The higher costs
are attributed to the demolition of existing concrete, asphalt, and existing structures and the
replacement of fill material with planting soil. The co sts of retrofitting a commercial site in
Maryland, Kettering Development, with 15 bioretention areas were estimated at $111,600.
In any bioretention area design, the cost of plants varies substantially and can account for a
significant portion of the expenditures. While these cost estimates are slightly greater than
those of typical landscaping treatment (due to the increased number of plantings, additional soil
excavation, backfill material, use of underdrains etc.), those landscaping expenses that would be
required regardless of the bioretention installation should be subtracted when determining the
net cost.
6 of 8 California Stormwater BMP Handbook January 2003
New Development and Redevelopment
www.cabmphandbooks.com
Bioretention TO 3 2
Perhaps of most importance, however, the cost savings compared to the use of traditional
structural stormwater conveyance systems makes bio retention areas quite attractive financially.
For example, the use of bio retention can decrease the cost required for constructing stormwater
conveyance systems at a site. A medical office building in Maryland was able to reduce the
amount of storm drain pipe that was needed from 800 to 230 feet - a cost savings of $24,000
(PGDER, 1993). And a new residential development spent a total of approximately $100,000
using bio retention cells on each lot instead of nearly $400,000 for the traditional stormwater
ponds that were originally planned (Rappahanock, ). Also, in residential areas, stormwater
management controls become a part of each property owner's landscape, reducing the public
burden to maintain large centralized facilities.
Maintenance Cost
The operation and maintenance costs for a bio retention facility will be comparable to those of
typical landscaping required for a site. Costs beyond the normal landscaping fees will include
the cost for testing the soils and may include costs for a sand bed and planting soil.
References and Sources of Additional Information
Coffinan, L.S., R. Goo and R. Frederick, 1999: Low impact development: an innovative
alternative approach to stormwater management. Proceedings of the 26th Annual Water
Resources Planning and Management Conference ASCE, June 6-9, Tempe, Arizona.
Davis, A.P., Shokouhian, M., Sharrna, H. and Minami, C., "Laboratory Study of Biological
Retention (Bioretention) for Urban Stormwater Management," Water Environ. Res., 73(1), 5-14
(2001).
Davis, A.P., Shokouhian, M., Sharma, H., Minami, C., and Winogradoff, D. "Water Quality
Improvement through Bio retention: Lead, Copper, and Zinc," Water Environ. Res., accepted for
publication, August 2002.
Kim, H., Seagren, E.A., and Davis, A.P., "Engineered Bioretention for Removal of Nitrate from
Stormwater Runoff," WEFTEC2OOO Conference Proceedings on CDROM Research
Symposium, Nitrogen Removal, Session 19, Anaheim CA, October 2000.
Hsieh, C.-h. and Davis, A.P. "Engineering Bioretention for Treatment of Urban Stormwater
Runoff," Watersheds 2002, Proceedings on CDROM Research Symposium, Session 15, Ft.
Lauderdale, FL, Feb. 2002.
Prince George's County Department of Environmental Resources (PGDER), 1993. Design
Manual for Use of Bioretention in Stormwater Management. Division of Environmental
Management, Watershed Protection Branch. Landover, MD.
U.S. EPA Office of Water, 1999. Stormwater Technology Fact Sheet: Bioretention. EPA832-F-
99-012.
Weinstein, N. Davis, A.P. and Veeramachaneni, R. "Low Impact Development (LID) Stormwater
Management Approach for the Control of Diffuse Pollution from Urban Roadways," 5th
International Conference Diffuse/Nonpoint Pollution and Watershed Management
Proceedings, C.S. Melchingand Emre Alp, Eds. 2001 International Water Association
January 2003 California Stormwater BMP Handbook 7 of 8
New Development and Redevelopment
www.cabmphandbooks.com
TC-32 Bioretention
CURB STOP5-
OVERFLOW
•CATCH BASIN'
PARKING LOT SHEET FLOW
I 1 I i I
j; y -,#> *? •» t -y * •"£ y - j'J y -ie^-zft •& A-
UNDERDRAIN COLLECTION SYSTEM
- STONE DIAPHRAGM
GRASS FILTER
STRIP
V V V V V V V *» V * * * V V V »
GRAVEL CURTAIN
DRAIN OVERFLOW
PLAN VIEW
6" PONDING
2'-3" MULCH"
4' PLANTING SOIL
8" PERFORATED
PIPE IN 8" GRAVEL
JACKET
TYPICAL SECTION PROFILE
Schematic of a Bioretention Facility (MDE, 2000)
8 of 8 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
January 2003
$• > < ' it » 11. * v " >, v •< tin
ENGINEERING
Modified Sand Filter Trench Sizing Per (CASQATC-40) Using Darcy's Law
AF= (WQVxd)/[kxtx(h+d)]
AF= Area of the filter bed
d= Depth of the Filter Bed
k= coefficient of permeability of the filtering medium (ft/day)
t= time for the WQV to travel through the system
h= average water height above the sand bed (ft) or 1/2 maximum head
Modified Sand Filter Trench: Drainage Area 2
d = 3 feet
t = 1.67 days
h = 0.5ft
k = 2.14 (Sand = 3.5 ft/day; Soil = 1.0 ft/day; Peat = 2.0 ft/day; Gravel = Assume no time)
AF= (1555 x 3) / [2.14x1.67 x (3 + .65]
AF= 357 ft2
The actual size of the filter trench area is 576 ft2 which is greater than the sized area of 357 ft2.
Filter Pore Space
The pore space contained in the 3' deep filter medium relates to the porosity of the materials contained in the
filter. The porosity of the layers is as follows. Soil: 25% porosity; Peat: 80% porosity; Sand: 26% porosity;
Gravel: 23% porosity.
The filter can store 599 ft3 of water as shown in the calculation below, based the 576 ft2 surface area.
Soil: 576 x .08 x 20% = 9 ft3
[ N 6 I N £
Peat: 576 x .66' x 80% = 304 ft3
Sand: 576x1.33x26%= 199ft3
Gravel: 576 x .66 x 23% = 87 ft3
Total = 599 ft3
Modified Sand Filter Trench: Drainage Area 3
d = 3 feet
t = 1.67 days
h = 0.5 ft
k = 2.14 (Sand = 3.5 ft/day; Soil = 1.0 ft/day; Peat = 2.0 ft/day; Gravel = Assume no time)
AF= (691 x3)/[2.14x 1.67x(3 + .65]
AF= 145 ft2
The actual size of the filter trench area is 672 ft2 which is greater than the sized area of 1 45 ft2.
Filter Pore Space
The pore space contained in the 3' deep filter medium relates to the porosity of the materials contained in the
filter. The porosity of the layers is as follows. Soil: 25% porosity; Peat: 80% porosity; Sand: 26% porosity;
Gravel: 23% porosity.
The filter can store 699 ft3 of water as shown in the calculation below, based the 672 ft2 surface area.
Soil: 672 x .08 x 20% = 11 ft3
Peat: 672 x .66' x 80% = 354 ft3
Sand: 672 x 1.33 x 26% = 232 ft3
Gravel: 672 x .66 x 23% = 102 ft3
Total = 699 ft3
Illiii
ENGINEERING
Modified Sand Filter Trench: Drainage Area 4
d = 3 feet
t = 1.67 days
h = 0.5ft
k = 2.14 (Sand = 3.5 ft/day; Soil = 1.0 ft/day; Peat = 2.0 ft/day; Gravel = Assume no time)
AF= (691 x3)/[2.14x 1.67x(3 + 1)
AF= 145ft2
The actual size of the filter trench area is 621 ft2 which is greater than the sized area of 145 ft2.
Filter Pore Space
The pore space contained in the 3' deep filter medium relates to the porosity of the materials contained in the
filter. The porosity of the layers is as follows. Soil: 25% porosity; Peat: 80% porosity; Sand: 26% porosity;
Gravel: 23% porosity.
The filter can store 647 ft3 of water as shown in the calculation below, based the 621 ft2 surface area.
Soil: 621 x.08x20%= 10ft3
Peat: 621 x .66' x 80% = 328 ft3
Sand: 621 x 1.33x26% = 215ft3
Gravel: 621 x .66 x 23% = 94 ft3
Total = 647 ft3
TREATMENT VOLUME QUALITY CONSIDERATION
The treatment capacities for volume-based BMPs are calculated based on the runoff volume produced
from the 85% percentile storm event. The modified sand filter trenches will be provided to treat the runoff
from developed areas of the project site. The 85% percentile storm event is 0.70 for the project site
according to the San Diego County Hydrology Manual. The method used in calculating the treatment
volume is Method 1 outlined in the Carlsbad SUSMP.
Volume based BMPs shall be designed to mitigate (infiltrate, filter, or treat) the volume of runoff produced
from a 24 hour 85th percentile storm event, as determined from isopluvial maps contained in the County
of San Diego Hydrology Manual.
C = .85 (runoff coefficient)
PSS%= -70 (85% percentile storm volume for project site area)
Drainage Area 2
Drainage Area: A= 0.72
0.85x70x0.72 = .43 ac-in
= 0.036 ac-ft
= 1555ft3
= WQV1555ft3
Drainage Area 3
Drainage Area: A= 0.32
0.85x70x0.32 = 0.1 9 ac-in
= 0.01 6 ac-ft
= 691 ft3
= WQV 691 ft3
Drainage Area 4
Drainage Area: A= 0.32
0.85x70x0.32 = 0.19 ac-in
= 0.016 ac-ft
= 691 ft3
= WQV 691 ft3
Appendix 5
SUB-AREA 1
TOTAL AREA: 0.223 Ac
PERVIOUS: 0.223 Ac
IMPERVIOUS: 0.00 Ac
TOTAL AREA: 0.315 Ac.
PERVIOUS: 0.066 Ac.
IMPERVIOUS: 0.249 Ac
SUB-AREAS
TOTAL AREA: 0.318 Ac
PERVIOUS: 0.012 Ac.
IMPERVIOUS: 0.306 Ac.
SUB-AREA 2
TOTAL AREA: 0.715 Ac.
PERVIOUS: 0.152 Ac.
IMPERVIOUS: 0.563 Ac.
SUB-AREAS
TOTAL AREA: 0.333 Ac
PERVIOUS: 0.255 Ac.
IMPERVIOUS: 0.078 Ac
SUB-AREA 6
TOTAL AREA: 0.039 Ac.
PERVIOUS: 0.039 Ac.
IMPERVIOUS: 0.0 Ac.
GRAPHIC SCALE IN FEET
LEGEND
STANDARD DWQ. NO.SYMBOL
POST DEVELOPMENT
DRAINAGE AREA MAP
FINAL DRAINAGE REPORT
BRESSI RANCH MEDICAL PLAZA
TOWN GARDEN ROAD & METROPOLITAN STREET
PROJECT NUMBER: 2591.02A
SCALE: 1--201
DATE: 03/05/08
SHEET 1 OF 1
m FUSCOE
N • I N I I I I N •
6390 Greenwich Drive, Suite 1 70
Son Diego, California 92122
tel 858.554.1500 ° fox 858.597.0335
www.fuscoe.com
Storm Intensity Calculation Sheet
Bressi Ranch Medical Plaza
5/8/2008
Storm Frequency
(yr.)
Frequency 6hr. Storm Frequency 24hr. Storm P6/P24 Adjusted P 6
(in)
Intensity
68%
58%
57%
56%
56%
56%
1.30
1.50
1.85
2.25
2.50
2.80
Sub-Area 1
Sub-Area 2
Sub-Area 3
Sub-Area 4
Sub-Area 5
Sub-Area 6
N/A
3633
1806
1615
N/A
N/A
Total Flow to Existing System (cfs)
Total Bypass Flow (cfs)
8.57
1.00
2 YEAR
Sub-Area 1
Sub-Area 2
Sub-Area 3
Sub-Area 4
Sub-Area 5
Sub-Area 6
0.38
0.76
0.85
0.76
0.50
0.35
0.28
0.72
0.32
0.32
0.27
0.04
7
5
5
5
5
5
Total Flow to Existing System (cfs)
Total Bypass Flow (cfs)
0.29
1.87
0.93
0.83
0.46
0.05
3.98
0.46
N/A
1687
838
750
N/A
N/A
10 YEAR
Sub-Area 1
Sub-Area 2
Sub-Area 3
Sub-Area 4
Sub-Area 5
Sub-Area 6
^ ^•^^•i^^^^^^giJ^^gmffi^^^^M^rg
0.38
0.76
0.85
0.76
0.50
0.35
0.28
0.72
0.32
0.32
0.27
0.04
7
5
5
5
5
5
Total Flow to Existing System (cfs)
Total Bypass Flow (cfs)
0.42
2.67
1.33
1.19
0.66
0.07
5.66
0.66
N/A
2400
1193
1067
N/A
N/A
1:53 PM 5/13/2008
Post Reduction
Basin 2
Basin 3
Basin 4
561
865
1539
100 YEAR
Sub-Area 1
Sub-Area 2
Sub-Area 3
Sub-Area 4
Sub-Area 5
Sub-Area 6
2 YEAR
Sub-Area 1
Sub-Area 2
Sub-Area 3
Sub-Area 4
Sub-Area 5
Sub-Area 6
1 0 YEAR
U, , &li)6HU&tj!.:..~k^
Sub-Area 1
Sub-Area 2
Sub-Area 3
Sub-Area 4
Sub-Area 5
Sub-Area 6
0.38
0.76
0.85
0.76
0.50
0.35
_JSj*f .f ,' ,7
0.38
0.76
0.85
0.76
0.50
0.35
, ^"iflSL^ jLA
0.38
0.76
0.85
0.76
0.50
0.35
0.28
0.72
0.32
0.32
0.27
0.04
ji. jJ^ry^jjJiB
0.28
0.72
0.32
0.32
0.27
0.04
0.28
0.72
0.32
0.32
0.27
0.04
7
7
5
5
5
5
Total Flow to Existing System {cfs}
Total Bypass Flow (cfs)
7
10
10
18
5
5
Total Flow to Existing System (cfs)
Total Bypass Flow (cfs)
7
8
7
10
5
5
Total Flow to Existing System (cfs)
Total Bypass Flow (cfs)
0.63
3.25
2.01
1.79
1.00
0.10
7.79
1.00
0.29
1.20
0.60
0.36
0.46
0.05
2.50
0.46
0.42
1.97
1.07
0.76
0.66
0.07
4.28
0.66
1:53 PM 5/13/2008
Basin Coles
2 Year
Basin 2
Basin Volume = 561 fl3
Time to Fill= 561/1.9= 5 min
QIN = 1.9cfs
Runoff Volume = 1687 ft3
Spillover Volume= 1126ft3
Addl Spillover Flow= 1.25 cfs
10 Year
Basin 2
Basin Volume = 561 ft3
Time to Fill= 561/2.7= 3 min
Q IN=2.7cfs
Runoff Volume = 2400 ft3
Spillover Volume= 1839ft3
Addl Spillover Flow= 2.0 cfs
Travel Time = 3 min
Travel Time=3 min
Basin 3
Travel Time=3 min
Basin Volume = 865 ft3
Time to Fill = 865/2.15= 7 min
QIN = 0.9cfs
Runoff Volume = 838 ft3
Spillover Volume= 1099ft3
Addl Spillover Flow= 1.2 cfs
Basin 3
Basin Volume = 865 ft3
Time to Fill= 865/3.3= 4 mil
Q IN = 1.3cfs
Runoff Volume = 11 93 ft3
Spillover Vo!ume= 2167ft3
Addl Spillover Flow= 2.4 cfs
Travel Time = 3 min
Basin 4
Basin Volume= 1 539 ft3
TimetoFill= 1539/2.0= 13 min
QIN = 0.8cfs
Runoff Volume = 750 ft3
Spillover Volume= 310ft3
Addl Spillover Flow= 0.34 cfs
Basin 4
Basin Volume= 1539 ft3
Time to Fill= 1539/3.6= 7 min
QIN = 1.2cfs
Runoff Volume = 1067ft3
Spillover Volume= 1695ft3
Addl Spillover Flow= 1.9 cfs
100 Year
Basin 2
Basin Volume= 561 ft3
Time to Fill= 561/4.0= 2 min
QIN = 4.0cfs
Runoff Volume = 3633 ft3
Spillover Volume= 3072 ft3
Addl Spillover Flow= 6.8 cfs
Travel Time
T, = -
Travel Time=3 min
VI
D = 59ft
5=4%
C = .72
Ti= 3 min
Basin 3
Basin Volume= 865 ft3
Time to Fill= 865/8.8= 2 min
QlN=2.0cfs
Runoff Volume = 1 806 ft3
Spillover Volume= 4013ft3
Addl Spillover Flow= 8.9 cfs
Travel Time=3 min
Basin 4
Basin Volume= 1539 ft3
TimetoFill= 1539/11 = 2 min
QIN = 1.8cfs
Runoff Volume = 1615ft3
Spillover Volume= 4089 ft3
Addl Spillover Flow= 9 cfs
1:53 PM 5/13/2008
BIORETENTION MAINTENANCE INSPECTION FORM
Facility Number:
Subdivision Name:_
Weather:
Date:Time:
Watershed:
lnspector(s):_
Date of Last Rainfall:_
Mapbook Location:
Amount:Inches Streets:
GPS Coordinates:
Property Classification: Residential Government Commercial Other:
Confined Unconfined Barrel Size As-built Plan Available? Yes No
Is Facility Inspectable? Yes No Why?_Comments Specific Location(s):_
Scoring Breakdown:
N/A = Not Applicable
N/l = Not Investigated
0 = Not a Problem
1 = Monitor (potential for future problem exists)
2 = Routine Maintenance Required
3 = Immediate Repair Necessary
Use open space in each section to further
explain scoring as needed
1. Outfall Channel(s) from Facility
Woody growth within 5' of outfall barrel
Outfall channel functioning
Manholes, frames and covers
Released water undercutting outlet
Erosion
Displaced rip rap
Excessive sediment deposits
Other:
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/l
N/l
N/l
N/l
N/l
N/l
N/l
N/l
0 1
0 1
0 1
0 1
0 1
0 1
0 1
0 1
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
2. Outlet / Overflow Spillway
Woody growth or unauthorized plantings
Erosion or back cutting
Soft or boggy areas
Obstructions / debris
N/A
N/A
N/A
N/A
N/l
N/l
N/l
N/l
0
0
0
0
1 2
1 2
1 2
1 2
3
3
3
3
3. Filter
Existing as required
Sediment accumulation > 1"
Ponding more than 2 days after rain
Vegetation
Depth & material of layers
Sediment accumulation in soil bed
Oil/ chemical accumulation on soil bed
Filter fabric
Other:
N/A
Depth:
N/A
N/A
N/A
N/A
N/l
No
No
No
0
N/l
N/l
N/l
N/l
0
0
0
0
Yes
Yes
Yes
1 2
1 2
1 2
1 2
1 2
3
Material:
3
3
3
3
N/A = Not Applicable
N/l = Not Investigated
0 = Not a Problem
1 = Monitor for Future Repairs
2 = Routine Repairs Needed
3 = Immediate Repair Needed Page 1 of 4
BIORETENTION MAINTENANCE INSPECTION FORM
4. Underdrains
Broken
Daylighted
Clogging
N/A
N/A
N/A
N/l
N/l
N/l
0 1
0 1
0 1
2
2
2
3
3
3
5. Pretreatment
Maintenance access N/A N/l
Pretreatment a practice other than a stone diaphragm and/
or grass filter strip
Stone diaphragm level
Stone diaphragm clogged with sediment/debris
Grass filter strip erosion
N/A
N/A
N/A
N/l
N/l
N/l
Evidence of short circuiting, rails/ gullies in filter strip
Level spreader
Other:
N/A
N/A
N/l
N/l
0 1
No
0 1
0 1
0 1
No
0 1
0 1
2
Yes
2
2
2
Yes
2
2
3
Of so, (code)
3
3
3
3
3
6. Upland Characteristics
Excessive trash / debris
Bare soil present
Sand in parking lot
N/A
N/A
N/A
N/l
N/l
N/l
0 1
0 1
0 1
2
2
2
3
3
3
7. Inflow Points
Number of inflow pipes:Direction:N E W S
Endwalls, headwalls, end sections
Inlet/ outflow pipes
Discharge undercutting outlet or displacing rip-rap
Discharge water is causing outfall to erode
Sediment accumulation
N/A
N/A
N/A
N/A
N/A
N/l
N/l
N/l
N/l
N/l
0 1
0 1
0 1
0 1
0 1
2
2
2
2
2
3
3
3
3
3
8. Special Structures
Manhole access (steps, ladders)
Vehicular access
Concrete/masonry condition
Sediment / trash accumulation
Manhole lockable nuts
N/A
N/A
N/A
N/A
N/A
N/l
N/l
N/l
N/l
N/l
0 1
0 1
0 1
0 1
0 1
2
2
2
2
2
3
3
3
3
3
9. Miscellaneous
Encroachment in facility area and/or easement area by
buildings
Complaints from local residents
Graffiti
Public hazards
N/A
N/A
N/A
N/A
N/l
N/l
N/l
N/l
Were any pad locks cut and replaced
Other:N/A N/l
0
0
0
0
No
0
1 2
1 2
1 2
1 2
Yes
1 2
3
3
3
3
3
How many?
N/A = Not Applicable
N/l = Not Investigated
0 = Not a Problem
1 = Monitor for Future Repairs
2 = Routine Repairs Needed
3 = Immediate Repair Needed Page 2 of 4
c
BIORETENTION MAINTENANCE INSPECTION FORM
Overall Condition of Facility
Total number of concerns receiving a: (1) - Need Monitoring
(2) - Routine Repair
(3) - Immediate Repair Needed
Inspector's Summary
Pictures Clock/Degrees
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
N/A = Not Applicable 1 = Monitor for Future Repairs
N/l = Not Investigated 2 = Routine Repairs Needed
0 = Not a Problem 3 = Immediate Repair Needed Page 3 of 4
BIORETENTION MAINTENANCE INSPECTION FORM
Sketches, If Necessary:
N/A = Not Applicable 1 = Monitor for Future Repairs
N/l = Not Investigated 2 = Routine Repairs Needed
0 = Not a Problem 3 = Immediate Repair Needed Page 4 of 4
RECORDING REQUESTED BY:
City of Carlsbad
Development Services Department
WHEN RECORDED MAIL TO:
City Clerk
City of Carlsbad
1200 Carlsbad Village Dr.
Carlsbad, CA, 92008
SPACE ABOVE THIS LINE FOR RECORDER'S USE
ASSESSOR'S PARCEL NO. 2,/J - 2 60 -.
PROJECT NO.
PERMANENT STORMWATER QUALITY BEST MANAGEMENT PRACTICE MAINTENANCE
AGREEMENT
DATE OF AGREEMENT:
OWNER NAME: &r*fj* /(W4 /lAeA««l ?l^^ LtC
PROJECT NAME: B'tSS' ^W* /tfeet-c*! ?Ul* [B^ess! Lot If
RESOLUTION NUMBER:
CONDITION NUMBER:
DRAWING NUMBER:
STORM WATER MANAGEMENT PLAN (SWMP) NUMBER:
This agreement is made and entered into by and between the City of Carlsbad, California, a
Municipal Corporation of the State of California, hereinafter referred to as "City"; and the Property
Owner named on the current Deed of Trust as referenced above, hereinafter referred to as
"Owner".
RECITALS
WHEREAS, Owner is proceeding to develop a property more particularly described in
Exhibit A, hereinafter referred to as "the Property"; and
WHEREAS, development of the Property has been approved by the City, and is subject to
the requirements of the State of California Regional Water Quality Control Board-San Diego Region
Order No. ORDER NO. 2001-01/NPDES NO. CAS0108758, as promulgated within the City of
1 OF 6 Roy.4" 17/07
Carlsbad Public Works Department, Standard Urban Storm Water Mitigation Plan-Storm Water
Standards, 2003 hereinafter referred to as "storm water regulations" and incorporated herein by this
reference; and
WHEREAS, the Owner is required to comply with all Federal, State and Local storm water
regulations by employing permanent post-construction Best Management Practices (BMP's),
hereinafter referred to as "permanent BMP(s}" to ensure impacts to storm water quality are
mitigated to the maximum extent practicable (MEP) prior to being discharged from the Property;
and
WHEREAS, the City and the Owner, its successors and assigns agree that the health
safety, and welfare of the residents of Carlsbad, California, require that permanent BMP(s) be
established, constructed, inspected, and operated and maintained in perpetuity on the Property;
and
WHEREAS, the storm water regulations require that permanent BMP(s) be established,
constructed and adequately inspected, operated and maintained by the Owner, its successors and
assigns, including any homeowner or property owner association; and
WHEREAS, the Owner has caused to be prepared a Storm Water Management Plan
(SWMP) report and drawing(s) which together detail the objectives, design, construction, inspection
and operation and maintenance responsibility requirements of the permanent BMP(s)
recommended to mitigate impacts to storm water quality due to the development of the Property,
hereinafter collectively referred to as the "Storm Water BMP Plan" and incorporated herein by this
reference; and,
WHEREAS, storm water regulations require that the City ensure the continued
existence and inspection, operation and maintenance of the permanent BMP(s); and
WHEREAS, the City has required the recordation of this agreement as a condition of
approval of the project that secures the construction, inspection, operation and maintenance of on-
site permanent BMP(s) by the Owner, its successors and assigns, including any property owners
association, in perpetuity, and
NOW, THEREFORE, in consideration of the approval of this project, the foregoing
2 OF 8
promises, the mutual covenants contained herein, and the following terms and conditions,
Owner and City agrees as follows:
1. Owner shall comply with all the requirements of said storm water regulations and any
applicable amendments thereto, and with any other provisions of law,
2. The permanent BMP(s) shall be established and constructed by Owner, its successors
and assigns, in accordance with the plans and specifications identified in the Storm Water BMP
Plan and modification to the approved permanent BMP(s) shall not be made without prior approval
of the City Engineer.
3. Owner, its successors and assigns, including any homeowner or property owner
association, shall adequately, inspect, operate and maintain the permanent BMP(s). This includes
all pipes and channels built to convey storm water to the facility, as well as all structures,
improvements, and vegetation provided to control the quantity and quality of the storm water runoff
and any associated practices and programs. Adequate maintenance is herein defined as good
working condition so that the permanent BMP(s) are performing in accordance with their design
objectives and functions.
4. Owner, its successors and assigns, shall inspect applicable permanent BMP(s) as often
as conditions require, or at frequencies recommended in the approved Storm Water BMP Plan, but
in any event at least once each year prior to the rainy season. The purpose of the inspection is to
assure continued safe and proper functioning of the facilities. The inspection shall cover the entire
facilities, berms, outlet structure, pond areas, access roads, etc. Owner shall submit an inspection
report annually to the City in a form as proscribed in the Storm Water BMP Pian or as may be
proscribed by the City. Deficiencies shall be noted in the inspection report. Any deficiencies,
repairs or maintenance obligations shall be noted in a record form and immediately remedied by the
Owner.
5. Owner shall maintain inspection, operation and maintenance records for at least five (5)
years. These records shall be made available to the City for inspection upon request at any time,
6. Owner, its successors and assigns, hereby grant permission to the City, its authorized
agents and employees, to enter upon the Property and to inspect the permanent BMP(s) whenever
3 OF 6 Rev 4)17/0?
the City deems necessary. The purpose of inspection is to follow-up on reported deficiencies to
respond to State and Federal mandated storm water facility inspection requirements and/or to
respond to citizen complaints. The City shall provide Owner, its successors and assigns, copies of
the inspection findings and a directive to commence with the repairs or corrective measures if
necessary.
7. In the event the Owner, its successors and assigns, fails to take corrective action to
maintain the permanent BMP(s) in good working condition acceptable to the City, the City may
enter upon the Property and take whatever steps necessary to correct deficiencies identified in the
inspection report and to charge the costs of such repairs to the Owner, its successors and assigns.
This provision shall not be construed to allow the City to erect any structure of permanent nature on
the land of the Owner outside of the easement for the permanent BMP(s), if an easement is
provided, or outside the limits of the permanent BMP(s) facility footprint described on the Storm
Water BMP Plan, if an easement is not provided, it is expressly understood and agreed that the
City is under no obligation to routinely maintain or repair said facilities, and in no event shall this
Agreement be construed to impose any such obligation on the City.
8. Owner, its successors and assigns, will perform the work necessary to keep the
permanent BMP(s) in good working order as appropriate. In the event a maintenance schedule for
the permanent BMP(s) is outlined in the approved Storm Water BMP Plan, the schedule shall be
followed.
9. In the event the City pursuant to this Agreement, performs work of any nature, or
expends any funds in performance of said work for labor, use of equipment, supplies, materials,
and the like, the Owner, its successors and assigns, shall reimburse the City upon demand, within
thirty (30) days of receipt thereof for all actual costs incurred by the City hereunder. If not paid
within the prescribed time period, the City shall secure a lien against the Property in the amount of
such costs. The actions described in this section are in addition to and not in lieu of any and all
legal remedies available to the City as a result of Owner's failure to maintain the permanent
BMP(s).
4 OF 6
10. Owner agrees that the permanent BMP(s) are privately-owned, operated and
maintained by the Owner and acceptance of the work by the City shall not constitute a responsibility
of the City to maintain them nor a Waiver of Defects by City.
11. Owner agrees that all residual material that is a byproduct of the proper operation and
maintenance of permanent post-construction BMP's (waste) will be disposed of according to all
federal, state and local regulations.
12. The City or any officer or employee thereof shall not be liable for any injury to persons
or property occasioned by reason of the acts or omission of Owner, its agents or employees in the
performance of this agreement. Owner further agrees to protect and hold harmless City, its officials
and employees from any and all claims, demands, causes or action, liability or loss of any sort
because or arising out of acts or omissions of Owner, its agents or employees in the performance
of this agreement, including claims, demands, causes of action, liability, or loss because of or
arising out of the design or construction of the permanent post-construction BMP facilities. Said
indemnification and agreement to hold harmless shall extend to injuries to person and damages or
taking of property resulting from the design or construction of said permanent BMP(s) as provided
herein, and to adjacent property owner as a consequence of the diversion of waters from the
design, construction or maintenance of drainage systems, streets, and other improvements.
13. This Agreement shall be recorded against the Property and shall constitute a covenant
running with the land and shall be binding upon Owner, its successors and assigns, including any
homeowner or property owner association.
14. Invalidation of any one of the provisions of this Agreement shall in no way effect any
other provisions and all other provisions shall remain in full force and effect.
5 OF 6
IN WITNESS WHEREOF, this agreement is executed by the City of Carlsbad, acting by and
through its City Manager, pursuant to Section 20,16.060 of the Carlsbad Municipal Code
authorizing such execution, and by Owner.
APPLICANT:
(Name of Owner)
By:
{sign here)
(print name here)
CITY OF CARLSBAD, a municipal corporation of
the State of California
ROBERT J, JOHNSON, JR., P.E.
Acting City Engineer
By:
David A, Hauser, Deputy City Engineer
RCE 33081 Exp, 06/30/2008
(title and organization of signatory)
By:
(sign here)
(print name here)
(title and organization of signatory)
(Proper notarial acknowledgment of execution by OWNER must be attached)
(Chairman, president or vice-president and secretary, assistant secretary, CFO or assistant
treasurer must sign for corporations. Otherwise, the corporation must attach a resolution certified
by the secretary or assistant secretary under corporate seal empowering the officer(s) signing to
bind the corporation.)
APPROVED AS TO FORM:
RONALD R. BALL
City Attorney
By:.
Deputy City Attorney
6 OF 8
EXHIBIT 'A'
Lot 1 of Carlsbad Tract CT 02-15 Bressi Ranch in the City of Carlsbad, County of San
Diego, State of California, According to Map Thereof, No. 14960 Filed in the Office
of the County Recorder of San Diego County, February 4, 2005.
1 OF1
so
<0
POINSETT1A
LANE
VICNTYMAP
NOT TO SCALE
R '
Project Address Assessors Parcel Number(s): j Project # (city use only);
SE corner Town Garden Road & B Camino Real 213-260-01 j
Complete Sections 1 and 2 of the following checklist to determine your project's permanent and
construction storm water best management practices requirements. This form must be completed
and submitted with your permit application.
Section 1. Permanent Storm Water BMP Requirements;
If any answers to Part A are answered "Yes," your project is subject to the 'Priority Project
Permanent Storm Water BMP Requirements," and "Standard Permanent Storm Water BMP
Requirements" in Section III, "Permanent Storm Water BMP Selection Procedure'* in the Storm
Water Standards manual
If all answers to Part A are "No," and any answers to Part B are "Yes,' your project is only subject
to the "Standard Permanent Storm Water BMP Requirements". If every question in Part A and B
is answered "No," your project is exempt from permanent storm water requirements.
Part A:JDeterrnjne Priority Project Permanent Storm Water BMP Requirements.
Does the project meet the definition of one or more of the priority project categories?*
1, Detached residential development of 10 or more units.
2. Attached residential development of 10 or more units
3, Commercial development greater than 100,000 square feet.
4. Automotive repair shop.
5. Restaurant.
6. Steep hillside development greater than 5.000 square feet. j
7. Project discharging to receiving waters within Environmentally Sensitive Areas. j
""" 28. Parking lots greater than or equal to 5,000 ft or with at least 15 parking spaces, and
potentially exposed to urban runoff.
9. Streets, roads, highways, and freeways which would create a new paved surface that is
5rOOO square feet or greater
Yes
/
/
r~ — "
No
/
/
?':;,,,,;:;:;:.;:;; i
/
/
/
f— — — — -
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• i
* Refer to the definitions section in the Storm Water Standards for expanded definitions of the
priority project categories.
: Limited Exclusion: Trenching and resurfacing work associated with" utility projects are not
' considered priority projects. Parking lots, buildings and other structures associated wiih utility
; projects are priority projects if one or more of the criteria in Pa?1 A is met !f all answe'5 to Pan A
, are '"No", continue to Part B
Part B: Determine Standard Permanent Storm Water Requirements.
Does the project propose; ' « Yes
1, New impervious areas, such as rooftops, roads, parking lots, driveways, paths and
sidewalks?
2. New pervious landscape areas and irrigation systems?
3. Permanent structures within 100 feet of any natural water body?
4, Trash storage areas?
5. Liquid or solid material loading and unloading areas?
6, Vehicle or equipment fueling, washing, or maintenance areas?
7, Require a General NPDES Permit for Storm Water Discharges Associated with Industrial
Activities (Except construction)?*
8, Commercial or industrial waste handling or storage, excluding typical office or household
waste?
9, Any grading or ground disturbance during construction?
10. Any new storm drains, or alteration to existing storm drains?
/
/
/
/
/
No
/
j
/
/
/
*To find out if your project is required to obtain an individual General NPDES Permit for Storm Water
Discharges Associated with Industrial Activities, visit the State Water Resources Control Board web site
at, www.swrcb.ca.3ov/stormwtr/industrial.htmil
Section 2. Construction Storm Water BMP Requirements:
If the answer to question 1 of Part C is answered "Yes," your project is subject to Section IV, "Construction
Storm Water BMP Performance Standards," and must prepare a Storm Water Pollution Prevention Plan
(SWPPP). If the answer to question 1 is "No," but the answer to any of the remaining questions is "Yes,r
your project is subject to Section IV, "Construction Storm Water BMP Performance Standards," and must
prepare a Water Pollution Control Plan (WPCP). If every question in Part C is answered "No," your project
is exempt from any construction storm water BMP requirements. If any of the answers to the questions in
Part C are "Yes/' complete the construction site priorittzation in Part D, betow.
??d ?: ,^?iHIE!I?^?^!H!:iy£(y2.r?^'ll?§f §*2!]01^^^ __,,1 Would the project meet any of these criteria during construction?
i 1. Is the project subject to California's statewide General NPDES Permit for Storm Water
I Discharges Associated With Construction Activities?
; 2. Does the project propose grading or soiTdisturbance?
Yesi No
IT I • J
Part D: Determine Construction Site Priority
In accordance with the Municipal Perrnit, each construction site with construction storm water BMP
requirements must be designated with a priority; high, medium or low. This prioritization must be
completed with this form, noted on the plans, and included in the SWPPP or WPCP, Indicate the project's
priority in one of the check boxes using the criteria below, and existing and surrounding conditions of the
project, the type of activities necessary to complete the construction and any other extenuating
circumstances that may pose a threat to water quality. The City reserves the right to adjust the priority of
the projects both before and during construction, [Note: The construction priority does NOT change
construction BMP requirements that apply to projects; all construction BMP requirements must be
identified on a case-by-case basis. The construction priority does affect the frequency of inspections that
will be conducted by City staff. See Section IV. 1 for more details on construction BMP requirements.)
A) High Priority
1) Projects where the site is 50 acres or more and grading will occur during the rainy season
2) Projects 1 acre or more.
3} Projects 1 acre or more within or directly adjacent to or discharging directly to a coastal lagoon or
other receiving water within an environmentally sensitive area
4} Projects, active or inactive, adjacent or tributary to sensitive water bodies
B) Medium Priority
5) Capital Improvement Projects where grading occurs, however a Storm Water Pollution Prevention
Plan (SWPPP) is not required under the State General Construction Permit (i.e., water and sewer
replacement projects, intersection and street re-alignments, widening, comfort stations, etc.)
6) Permit projects in the public right-of-way where grading occurs, such as installation of sidewalk,
substantial retaining walls, curb and gutter for an entire street frontage, etc. . however SWPPPs are
not required,
7} Permit projects on private property where grading permits are required, however. Notice Of Intents
(NOIs) and SWPPPs are not required.
C) Low Priority
8) Capital Projects where minimal to no grading occurs, such as signal tight and loop installations,
street light installations, etc.
9} Permit projects in the public right-of-way where minimal to no grading occurs, such as pedestrian
ramps, driveway additions, small retaining walls, etc,
10) Perrnit projects on private property where grading permits are not required, such as small retaining
waits, single-family homes, small tenant improvements, etc.
Owner/Agent/Engineer Name (Please Print): ! Title:
- , ' Date:/ s
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