HomeMy WebLinkAboutCT 02-29; CASA LA COSTA; STORM WATER MANAGEMENT PLAN; 2004-02-25I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
PLANNING
ENGINEERING
SURVEYING
IRVINE
LOS ANGELES
RIVERSIDE
SAN DIEGO
DAVE HAMMAR
LEX WILLIMAN
ALISA VIALPANDO
HUNSAKER
&ASSOCIATES
S A N D I E G 0, I N C.
STORM WATER
MANAGEMENT PLAN
for
VILLAS DE LA COSTA
City of Carlsbad, California
Prepared for:
Tri-Mark Pacific
Casa La Costa, LLC
613 West Valley Parkway
Suite 200
Escondido, CA 92025
w.o. 2091-37
February 25, 2004
""' ""~"'''"'" Eric,~I~
San Diego, CA 92121 Water Resources Manager
(858)558-4500 PH Hunsaker & Associates San Diego Inc.
(858) 558-1414 FX '
www.HunsakerSD.com
lnfo@HunsakerSD.com
JC:kc h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 12:00 PM
; -
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
STORM WATER
MANAGEMENT PLAN
for
VILLAS DE LA COSTA
City of Carlsbad, California
Prepared for:
Tri-Mark Pacific
Casa La Costa, LLC
613 West Valley Parkway
Suite 200
Escondido, CA 92025
w.o. 2091-37
February 25, 2004
Eric Mosolgo, R.C.E.
Water Resources Manager
Hunsaker & Associates San Diego, Inc.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I·
I
I
I
I
I
I
I
I
I
1·
I
I
I
I
I ..
I
I
I
Villas De La Costa .
Storm Water Management Plan
TABLE OF CONTENTS
CHAPTER 1 -Executive Summary
1.1 Introduction
1.2 Summary of Pre-Developed Conditions
1.3 Summary of Proposed Development
1.4 Results and Recommendations
. CHAPTER 2 -Storm Water Criteria
2.1 Regional Water Quality Control Board Criteria .
2.2 City of Carlsbad SUSMP Criteria · ·
CHAPTER 3 -Identification of Typical Pollutants
3. t Anticipated Pollutants from Project Site
3.2 Sediment
3.3 Nutrients
3.4 Trash & Debris
3.5 Oxygen-Demanding Substances
3.6 Oil & Grease
· CHAPTER 4 -Conditions of Concern
4.1 Receiving Watershed Descriptions
. 4.2 Pollutants of Concern in Receiving Watersheds
CHAPTER 5 -Flow-Based BMPs
5.1 Design Criteria
5.2 Pollutant Removal Efficiency Table
5.3 Maintenance Requirements
CHAPTER 6 -Source Control BMPs
6.1 Landscaping
6.2 Urban Housekeeping
6.3 Automobile Use
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I·
Villa$ De La Costa
Storm Water Management Plan
CHAPTER 7 -Site BMP Design
7.1 BMP Locations
7.2 Determination of Design ireatment Flows
7 .3 Treatment Unit Selection
CHAPf.ER 8 -References
LIST OF TABLES AND FIGURES
Chapter 1 -Vicinity Map
Chapter 1 -Watershed Map
· Chapter 3 -Pollutant Category Table
Chapter 4-Combined 1998 and Draft 2002 Section 303(d) Update
. Chapter 4 ,... Beneficial Uses of Inland Surface Waters
Chapter 4 -Water Quality Objectives
Chapter 5 -Pollutant Removal Efficiency Table (Flow-Based BMPs)
Chapter 7 -Design Flow Determination Spreadsheet
Chapter 7 -CDS Technologies Data and Specifications
ATTACHMENTS
Watershed Map
Developed Site Map.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/0410:58 AM
I
I
I
I
I
I
I
I
I
I
-1
I
I
I
I
I
I
I
I
Villas De La Costa
Storm Water Management Plan
CHAPTER 1 -EXECUTIVE SUMMARY
This "Storm Water Management Plan for Villas de La Costa" addresses the
treatment of 85th percentile runoff from the proposed development. The proposed
storm drain design will utilize one stom'l water treatment unit to treat the a5tli
percentile flow from the proposed development. ·
The 85th percentile de~ign runoff calculations are provided in Chapter 7 of this
report. The proposed storm water treatment unit is a flow-based BMP; the unit has
been specifically-designed based on the runoff calculations.
1.1 -Introduction . -
The Villas· de La Costa site is located in Carlsbad, California. The site is located at
the southwesterly corner of Levante Street and La Costa Avenue, bounded -by
Cantella Street to the west and Rancho Santa Fe Road to the southeast (see vicinity
map below). ·
VICINITY MAP
NTS
Per the City of Carlsbad SUSMP, the Villas de La Costa project is classified as a
priority project and subject to the City's Permanent Storm Water BMP Requirements.
This Storm Water Management Plan (SWMP) has been prepared pursuant to
requirements set forth in the City of San Diego's "Standard Urban Storm Water
Mitigation Plan (SUSMP)." All calculations are consistent with criteria set forth by
the Regional Water Quality Control Board's Order No. 2001-01, and the City of
San Diego Storm Water Standards.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/0410:58 AM
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
1.
I·
I
I
Villas De La Costa
Storm Water Management Plan
This SWMP recommends the location and sizing of site Best Management Practices
(BMPs) which include one treatment unit (see Developed Site Map). Also
incorporated into the site design is a grass lined swale, which is not required to
attain the storm water quality goals for this .project but will provide additional storm
water treatment. ·
Furthermore, this report determines anticipated project pollutants, pollutants of
concern in the receiving watershed, peak flow mitigation, recommended source
control BMPs, and methodology 1.,1sed for the design.of flow-based BMPs.
1.2 -Summary of P·re-Developed Conditions
In pre-developed conditions, the Villas de La Costa site naturally sheet flows to the
west over the curb and down Centella Street to the south into an inlet on the cul-de-
sac that eventually discharges into an unnamed tributary of Encinitas Creek. Prior to
development the site is entirely natural, except for 0.34-acres of which is an existing
fire station (to. be relocated upon development).
The Regional Water Quality Control Board has identified the unnamed tributary of
Encinitas Creek and Encinitas Creek as part of the Carlsbad Watershed, and as
Hydrologic Unit (Basin Number 904.51).as shown in the Watershed Map on the
following page.
1.3 -Summary of Proposed Development
Development of the Villas de L~ Costa will include the construction of 39 single-.
family housing units along with the associated streets, sidewalks and internal storm
drainage systems including an underground detention basin and storm water quality
treatment 6MP (Best Management Practice). The underground detention basin is
proposed to mitigate _the increase in the 10-year runoff due to development of the
site. Runoff from the site will be conveyed in a proposed storm drain system that
drains the site to a storm water quality basin and outlets at the intersection of
proposed Street A-1 and Cantella. Street. The runoff drains down Cantella Street into
ari inlet in the cul-de-sac, eventually disch.arging into an unnamed tributary of
Encinitas Creek.
The "Drainage Study for Villas de La Costa" prepared by Hunsaker & Associates
and dated October 15, 2003, details the storm drain design for the proposed project. '
· One flow-based BMP will be located upstream of the southwesterly discharge
location. The 85th percentile .runoff will be treated in the proposed storm water
treatment system prior to discharging to the south of the site. In addition after being
. discharged from the storm drain system, storm water runoff will be conveyed through
a grass-lined swale that will provide additional storm water treatment.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I·
I
I
I ,,
Villas De La Costa
Storm Water Management Plan
1.4 -Results and Recommendations·
The storm drain system tias been proposed to drain the Villas de La Costa project
site. The ·storm drain system consists of three (3) storm drain segments, two (2)
discharge into the proposed detention basin and one (1) conveys the runoff from the
detention basin and picks up runoff from two (2) grated inlets and discharges at the
southwesterly corner of the site. · This system will also incorporate a stormwater
treatment system to treat the 85th percentile runoff design flow, which will be located
after all collected runoff has entered ·into the storm drain system.
The underground detention basin has been sized to mitigate the increase in the 10-
year runoff. For calculations and further.description of the underground detention
basin, refer to the "Dr~inage Study for Villas De La Costa", Hunsaker & Associates
San Diego,. Inc., January, 2004.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
I
I
I
I
I
I .,
•
'
i
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Villas De La Costa
Storm Water Management Plan· .
CHAPTER 2 -STORM WATER CRITERIA
2.1 -Regional Water Quality Control Board ·Criteria
All runoff conveyed in the proposed storm drain systems will be treated in
compliance with Regional Water Quality Control Board regulations and NPDES
criteria prior to discharging to natural watercourses. California Regional Water
Quality.Control Board Order No. 2001-01, dated February 21, 2001, sets waste
discharge requirements for discharges of. urban runoff from municipal storm
separate drainage systems draining the watersheds of San Diego County.
Per the RWQCB Order, post-development runoff from a site shall not contain
pollutant loads which cause or contribute to an exceedance of receiving water
quality objectives or which have not been reduced to the maximum extent
practicable. Post-construction Best Management Practices (BMPs), which refer to
specific storm water management techniques that are applied to manage
construction and post-construction site runoff and minimize erosion, include source
. control -aimed at reducing·the amount of sediment and other pollutants -and
treatment controls that keep soil and other pollutants onsite once they have been
loosened by storm water erosion.
Post construction pollutants are a result of the urban development of the property
and the effects of automobile use, Runoff from paved surfaces can contain both
sediment (in the form of silt and sand) as well as a variety of pollutants transported
by the sediment. Landscape activities by homeowners are an additional source of
sediment. ·
All structural BMPs shall be located to infiltrate, filter, or treat the required runoff
volume or flow (based on the 85th percentile rainfall) prior to its discharge to any
receiving watercourse supporting. beneficial uses.
2.2 -City of Carlsbad SUSMP Criteria
Per the City of Carlsbad SUSMP, the Villas de La Costa project is classified as a
Priority Project and subject to the City's Permanent Storm Water BMP
Requirements. These requirements required the preparation of this Storm Water
Management Plan.
The Storm Water Applicability Checklist, which must be included along with Grading
Plan applications, is included on _the following pages.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
i
I
i
I
I
I
I
I
I
I
I
I
I
I
' ' ' ' '
Storm Water Standards
4103/03
VI. RESOURCES:.&·REFERENCES·
APPENDIXA
•
-~ .. ....
-SiORM WATER REQUIREMENTS APPLICABILITY CHECKLIST
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 ~ubmitted with your permit application.
Section 1. Pennanent Storm Water BMP R~qufrements:
If any answers to Pait A are answered "Yes,• your project Is subject to the •prfority
Project Permanent Storm Water BMP Requirem~n_ts,• .§!!9. ·standard Permanent Storm
Water_ BMP Requirements• in Section Ill, •perma·nent Storm Water BMP Selection
Procedure• in the Storm Water Standards manual.
If all answers to Part A are ·No,• and mr£ answers to Part Bare -Yes,• your project·is
only subject to the •standard Permanent Storm Water BMP Requirements". If every
question Iii Part A and B · 1s answered ·No,• your project is exempt from permanent
storm water requlrem~n~. · ·
Part A: Determine Priority Prolect Permanent Storm Water BMP Requirements.
Does the prcjact meet the definition of one or mora of the priority project
cataaorles?* Yes No
1. Detached residential develocment of 10 or more units J·
2. Attached residential develecment of 1 o er more-units . -J
3. ·Commercial develocment areater than 100.000 stiuare feet J
4. Automctlve racair shoe J
5. Restaurant _ '1
6. Stee0 hillside develocment areater than 5,000 Muar& feet . 17
7. Prefect dfschamlna to receMna waters within Envlrcnmentallv Sensitive Areas v
8. Parking lots greater than or equal to 5,000 ft' .or with at least 15 pa_rking spa~, and ·
cotentlallv·excosed tc urban runoff _ _ · v
9. · $reets, roads, highways, and freeways which would Q"eate .a new paved surface that Is
. 5,000 sffllare feet er ~ter ./
* -Refer tc the definitions section in the Storm Water Standanis fer expanded definitions of the priority
crolect catanorfes. · . · ·
Limited Exclusion: Trenching and resurfacing work associated ~-utility projects are not considered
priority projects. Parking lots, buildings and ether structures associated with utility proje~ are
priority projects if one er more of the criteria In Part A Is met. If all answers tc Part A are ·No·.
continue to Part B.
30
i
I
I
I
I
I
I
I
I
I
I
I
I
I
---~
I.
l
Storm-Water Standards 4/03/03 . -. .,_ ..
Part B· Det i Sta dard P . ermne n tSt ermanen orm a er eau remen Wt R I ts .
Doe~ the project propose:. Yes No· --
1. New impervious areas,, such as rooftops, reads, parking lots, driveways, paths and ./ sfdewalks?
2. New cervtous landscace areas and lrriaation svstems? ./ 3. Permanent structures within 100 feet of any natural water bodv? ,J'
4. Trash storaae areas? .. v 5. Liquid or solid material loadfna and unloadlna areas? i/
6. Vehicle or eaufoment fueling, washlna. or maintenance areas? v'
7. Require a General NPCES Permit for Storm Water Discharges Associated with I · lndustriaJ-Acttvitles (Except constructfon)r
8. Commerclal or Industrial waste handling or storage, excluding typical office or '/ household waste? . -
9. Anv aradlno or arcund disturbance during construction? ~/
10. Anv new storm drains. or alteration to existing storm drains?· · · v
r-To find out if your project Is required to obtain an lndMdual General NPDES Permit for Storm Water
l;)lscharges· Associated with Industrial Activities, visit the State Water Resources Control Board web site
at www.swrcb.ca.aov/stormwtr/tndustrlal.html
Section 2. Construction Storm Water BMP Requirements:
If the answer to question 1 of Part C Is an$Wered "Yes,• your project is subject to·
Section N, "ConstrtJetlon Storm Water BMP Performance Standards,• and must prepare
a Storm Water PollutiQn Prevention Plan (SwpPP). If the answer to question 1 is "Not
but the answer to any of the remaining questions is ·-ves,• your projeqt 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· 1he construction site
prioritization in Part D, below.·
P rte D t a . e erm ne Constru on ase onn aer eciu remen . • ctl Ph St Wt R I ts ..
Would the proj~ct meet any of these criteria d~ng construction? Yes No ,,
1. Is the project subject to Csllfornia's statewlde General NPDES Permit for Storm Water J Oischaraes Associated With Construction Activities? · ,,
2. Does the Prolect crccose aradlna or soil disturbance? ./
3. ~ould storm water er urban runoff have the poterttfal to contact any portion of the / construction area. fncludlno washlna and staalna areas?
4. Would the prefect use any construction materials that could negatively affect water v quality If discharged frcm the site (such as, paints, solvents, concrete, and
stucco)?
31
i
i
I
I
I.
I
I
I
I
I
I
I
I
I
1: ,. , ..
' '
Stenn Water Standards-
4/03103 .
Part D: Determine Construction Site Priority. ·
In accordance with the Municipal Permit, each construction site with ccmstruction 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 S~PPP or WPCP. Indicate the _project's priority in one of the check boxes using the
crit~~~ below, and existing and surrounding conditiQns 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 rfght 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 fQr more details on construction BMP requirements.] ·
'A) HighP~
1) Projects wtiere the site is 50 acres or ·more and grading will occur during the
rainy season ·
2) Projects 5 acres or more. 3) Projects 5 acres or more within or directly
adjacent to or discharging directly to a coastal lagoon or other receiving water
within an environmentally sensitive area. .
Projects, active or Inactive, adjacent or tributary to sensitive water bodies
Q BJ Medium Priority ·
1) 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-affgnmerits, widening, comfort stations, etc.)
2) 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.
3) Permit p·rojects on private property where grading permits are required,
however, Notice Of Intents (NOls) and SWPPPs are not required.
CJ . CJ Low Priority
1) Capital Projects where minimal to no grading occurs, such as signal light and
loop Installations, street light installatio~s, etc. .
2) Permit projects in the public right-of-way where minimal to no grading occurs,· · ·
such as pedestrian ramps, driveway additions, small retaining walls, etc.
3) Permit projects 011 private property where grading permits are not required,
· such· as · small retaining walls, single-family homes, small tenant
· improvements, etc.
. 32
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Villas De La Cost~
Storm Water Management Plan
CHAPTER 3 -IDENTIFICATION OF TYPICAL POLLUTANTS
3.1 -Anticipated PoUutants from Proiect Site
The following table details typical anticipated and potential pollutants generated by
various land use types. The ViUas de La Costa development will consist of attached
multi-family residences~ Thlis, the Attached Residential Development category has
been highlighted to clearly illustrate which general pollutant categories are
anticipated from the project area.
General Pollutant Cate ories
Priority
Project
. Categories
J!3 C Cl)
E :a Cl) u,
X
J!3 C Cl) :s ::, z
X
Commercial
Development p<1> . p<1>
>100,000 ft2
Automotive
Repair
Sho s
· Restaurants
Hillside -
Development X
>5,000 ft2 . X
Parking Lots • p<1> p<1>
X
X
Streets,
Highways &
Freewa s
X p(1>-X
Retail Gas
Outlets· X
en "CS C
C.) ::,
·-0 C Q. as E e>o OU
X
p<2J X
x<4JCSJ X
X
X
X
x<4> X
x<4> X
X = anticipated
P = potential
<1> A potential pollutant if landscaping exists on-site.
c, en C CD
·-CJ C "Cl C
Cl) cs c, as en
>->< E .c Cl) ::, oc u,
X
p(S)
·x
X
p{1)
p(S)
-0
X
X
X
X
X
X
X
X
oa.
.!! en .. Cl) Sen CJ ::, ~5
X
p(3)
X
<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>1ncluding petroleum hydrocarbons.
<5> Including solvents. .
en Cl)
"Cl ·c::; = II)
Cl)
Q.
X
p(S)
X
p(1)
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/0410:SSAM
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Villc;1s De La Costa
Storm Water Management Plan
3.2 -Sediment
Soils or other surface materials eroded and then transported or deposited by the
action·. of wind, water, ice, or gravity. Sediments cran increase turbidity, clog fish gills,
reduce spawning habitat, smother bottom dwelling organisms, and suppress aquatic
vegetative growth.
3.3 -Nutrients
Inorganic substances, such as nitrogen arid phosphorous, that commonly exist in the
form of mineral salts that are either dissolved or suspended in water. Primary
sources of nutrients fn urban runoff are fertilizers and eroded soils. Excessive
discharge of nutrients to water bodies and streams can cause excessive aquatic
algae and plant growth. Such excessive production, referred to as cultural
eutrophication, may lead to excessive decay of organic matter in the water body,
loss of oxygen in the water, release of toxins in sediment, and the eventual death of
aquatic organisms.
3.4 -Trash & Debris
Examples include paper, plastic, leaves, grass cuttings, and food waste, which may
have a significant impact on the recreational value of a water body and aquatic
habitat. Excess organic matter can create a high biochemical oxygen demand in a
stream and thereby lower its water quality. In areas where stagnant water is present,
the presence of excess organic matter can promote septic conditions resulting in the
growth of undesirable organisms and the release of odorous and hazardous
compounds such as hydrogen sulfide. ·
3.5 -Oxygen-Demanding Substances
Biodegradable organic material as well as chemicals that react with dissolved
. oxygen in water to form other compounds. Compounds such as ammonia and
hydrogen sulfide are examples of oxygen-demanding compounds. The oxygen
demand of a substance can lead to depletion of dissolved oxygen in a water body
and possibly the development of septic conditions.
3.6 --Oil & Grease
Characterized as high high .. molecular weight organic compounds. Primary sources
of oil and grease are petroleum hydrocarbon products, motor products from leaking
vehicles, oils,. waxes, and high-molecular weight fatty acids. Elevated oil and grease
content can decrease the aesthetic value of the water body, as well as the water
quality.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
I
I
1·
I
I
--1 ""----
I
I
I
I
I
I
I
I
·I
I
I
I
Villas De La Costa -
Storm Water Management Plan
CHAPTER 4 -CONDITIONS OF CONCERN
4.1 -Receiving Watershed Descriptions
· As shown in the watershed map on the following page, the pre-developed and
developed condition Villas de La Costa project site drains. to an unnamed tributary of
Encinitas Creek with in the Carlsbad watershed. In developed conditions, runoff from
project site drains through one proposed storm drain systems that discharges along
the southwestern corner of the project site and eventually into the unnamed
tributary of Encinitas Creek, and ultimately into Encinitas Creek.
The Regional Water Quality. Control Board has identified both the unnamed tributary
of the San-Dieguito River and the San Dieguito River as part of the San Dieguito
Hydrologic Unit (basin number 4.51).
4.2 -Pollutants of Concern in Receiving Watersheds
. Neither unnamed tributary of Encinitas Creek nor Encinitas Creek are listed on the
EPA's 303(d) List ofendangeredwaterways (Table 4 included in this Chapter as
evidence that hydrologic unit 904.51 is not listed). Per the "Water Quality Plan for the
San Diego Basin" Table· 2-2 (included at the end of this Chapter), the beneficial uses
for Encinitas Creek include agricultural supply_, contact water recreation, non-contact
recreation, warm freshwater habitat, and wildlife habitat. The water body has been
exempted by the Regional Board from the municipal use designation under the
terms and conditions of the State Board Resolution No: 88-63, Sources of Drinking
Water Policy. · ·
Table 3-2 from the "Water Quality Plan forthe San Diego Basin" (also included at
. the end of this Chapter) lists water quality objectives for a variety of potential
pollutants required to sustain the beneficial uses of the Carlsbad hydrologic unit in
the San Marcos hydrologic area.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
~ Table 4 -Combined 1998A and Draft 2002 Section 303(d} Update
. Hydrologlc · ·. Waterbody Segment i Area·•.· Pollutant/ Extent of Year Descrietor Stressor lmgairment c Usted ~ 21 Loma Alta HA Pacific Ocean Shoreline at Loma Alta. Creek Mouth Bacterial 1 mile (904.10) lndicatorsE. 1998
22 Loma Alta HA L~ma Alta Slough Bacterial ~ (904.10) lndicatorse 8 acres 1998
Eutrcehic
23 Buena Vista Creek at Buena Vista Creek Bacterial a.es miles 1998 I HA(904.20) Pacific Ocean Shoreline Carlsbad City Beach at Carlsbad lndicatorse Village Drive
Carlsbad State Beach, at Pine
I Avenue
24 El Saito HSA Buena Vista Lagoon Bacterial 350 acres (904.21) lndicatorse 1998
I Sedimentation / 350 1998 Siltation acres
Nutrients 150 acres 1998
I 25 Los Monos HSA . Agua Hedlonda Lagoon Bacterial 5 acres 1998 {904.31) lndicatorse
Sedimentation /
Siltation I 26 Los Monos HSA · lower portion Diazinon lower2miles 2002
(904.31) Agua·Hedlonda Creek Total Dissolved 1 8 .1 2002 Solids ower m1 es
I · 21 San Marcos HA Pacific Ocean Shoreline at Moonlight State Beach Bacterial 0.4 miles 1998 (904.50) Indicators!
28 Escondido Creek Pacific Ocean Shoreline at San Elijo Lagoon Baclenal a.a miles 1998
I HA (904.S0l at Solana Beach lndicatorse
29 San Elijo HSA San Elijo Lagoon Bacterial 150 acres 1998 {904.61) lndicatorsE
I Eutroehic 330 acres
S~dlmentation / 150 acres
Siltation
I 30 San Dieguito HU at San Di!9uito Lagoon Mouth Bacterial 0.8 miles 1998
(905.00) Pacific Ocean Shoreline Torrey Pines State_B~ach at Del lndlcatorsE M~r {Anderson ~an~on} ·
I 31 Del Dies HSA Green Valley Creek Sulfate 1 mile 2002 {905.21)
32 Del Dies HSA Hodges Reservoir Entire Reservoir Color Entire 2002
{905.21) Nitrogen Reservoir
' Phosehorus
Total Dissolved
Solids
'
. 33 Felicita HSA Felicita Creek Total Dissolved lower2miles 2002 (905.231 Solids
34 Felicita HSA Total Dissolved 2002 Kit Carson Creek 1 mile
I (905.23} Solids
35 Highland HSA Phosehorus 1 mile 2002
{905.31) Cloverdale Creek Total Dissolved
'
Solids
36 Sutherland HSA Entire Reservoir Color Entire 2002 (905.53) Sutherland Reservoir Reservoir
' last updata1f10/2412003-\
'
S:\WQS\303dllat\SQ Staff Report-200212002 draft 303d Hat\ 38 Tabla 4 • Combined 1998 and 2002 Updale.xfa\Tabl1 4
, ...
· dlll dllllll ... ... .. ·· .. -· --·· 11111 ·... ...,, ·lliai· .... ... llllltir IIIIIIUr ... i
......
Table 2-2. BENEFICI.AL USES ClF. INLAND _SURFACE WATERS
.. BENEFICIAL USE .
1,2 ' M A. l p G F p R R a· w C w
.Inland Surface Waters· .. Hydr~Joglc Unit u G. N R w ·R 0 E E . I A 0 I
Bqsln Number N R D ···o R s w C C b R L l-.. C H 1 2 L ·u D D· . '. . ~
Sii1i"Dlego Coliiity Coastai-Streams -·contldulid . . .
Buena Vista Lagoon 4.21 See Coastal Waters-Tabla 2-3
Buena Vista Creek 4.22 . + • • ·• • • • •
Buena Vista Creek · 4.21 + • • • • • • ..
Agua Hedlonda 4.31 · See Coastal waters--Table 2-3
Agua Hedlonda Cre~k 4.32 • • • • • • •
Buena creek . 4:32 • • • • • • •· .
Agua Hedionda-C~ek 4.31 • • • • • • .. ••
Letterbox canyon .
4:31 • •• . . . . • •· • •
Canyon d~ las Encinas · 4.40. + ·o • • •
San Marcos Creek Watershed
BaUqultos Lagoon 4.51 See Coastal Waters-Table 2-3
San Marcoa Creek 4.52 + • ·• • • •
unnamed Intermittent streams · 4:53 + • • • • •
San Marcos Creak Wat,Hshed .
San Marcos Creek 4.51 + • • • • •
·Encinitas Creek 4.51 + •• • • • •
1 Waterbodlea are Uated mulUple thnea if they cn,1111 hydrologlc area or sub area boundaries. Existing Beneficial Use
O Potential Bef'!eficlal Use 2 . ' .
Beneficial uso dealgnatlona apply to au tributaries to the Indicated waterbody, If not Usted separately.
+ ,Excepted From.MUN (See Text) ·
Table 2.2·
BENEFICIAL USES 2-27
,
R s
A' p
R w
.E N
•
~ ..
, .• ~ ,-.
.·'
·••.--~ r
..
March 12, 1897
i ......... · ...................... · 1111111 11111111 1111111 ........ .
., ...... I"'~'\"
\ .
I
Table 3-2. WATER QUALi-TY-OBJECTIVES
Concentrations not to ba exceeded mqra than 10% of the time during any one one year period.
.
Inland Surface Waters Hydrologic
Unit Basin TDS Cl ~o,. %Na N&P
Number
..
SAN LUIS REV HYDROLOGIC UNIT 903.00 ..
Lower San Lula -HA 3.10 600 260 260 60 •
Monsf:!rat HA 3.20 600 260 250 60 a
Warner Valley HA 3;30 600 260 260 60 a
CARLSBAD HYDROLOGIC UNIT 904.00
Loma Alta HA 4.10 · -----
Buena Vista Creek HA 4.20 600 260 260 60 a
Agua Hedionda HA 4.30 609 260 260 60 a
Encinas .. . HA 4.40 ----. -
San Marcos , · HA 4.60 600 250 260 60 II
Escondido Creak HA 4.80. 600 260 260 60 a
SAN DIEGUITO HVDROLOGIC UNIT 806.00 ..
Solana ·Beach HA ' 6.10 '600 260 260 80 8
Hodges · HA , 6.20 .600 260 250 60 a
San Pasqual · -HA 6.30 600 2~0 260 60 a
Santa Marla Valley HA 6.40 600 260 250 60 r a
Santa Ysabel HA· 6.60 600 260 260 60 .a
PENASpUITOS HYDROLOGIC UNIT 806.00 .
Miramar Reservoir HA 6.1Q 6QQ. 260 260 60 a
Poway HA 8.20 600 .260 260 60 a
HA· Hydroloolo AIH .. . . -
HSA • Hydroloolo Sub Area (Lower cui lsttera Indicate endnow folowlng the tabla,)
Tabla 3~2
WATER QUALITV OBJECTIVES Paaa3-23
Constitiµant
.
Fa ·Mn MBAS
.
0.3 0.06-. 0.6 ·
0.3 0.05 0.6
0.3 _0.05 0.5
---
0.3 0.06 0.6
0.3 o .• os 0.6
---
·o.3 0.06 o~&·
0.3 .0.06 0.6
0.3 0.06 0.6
0.3 0.05 0.6
0.3 0.06 0.6
0.3 0.06 0!6
p.3 0.06 0.6.
0.3 0.06 O.f!
0.3 0.06 ·0.6
(mg/~ or as noted)
B ODOR. Turb
NTU
0.76 none 20
0.76 none 20
0.76 none. 20.
-none 20
0.76 none · 20
0.75 none 20.
-none 20:
0.76 · norio 20
0.76 none 20-
0.76 none 20
0.76 none · 20
0.76 none 20
0.76 none 20
0.76 1)008 20
0.76 nona 20
0.76 none 20
., ......
I '
;
Color
Un!ts
20
20,
20
. 20
20
. 20
20
20
20
..
20.
~o
20 ..
20
20
20
. 20
F
, 1.0
1.0·
··1.0
1.0
1.0
·1.0. ·
1.0
1.0
. 1,0,
' 1.0
1.0
1.0
1.0
· 1.0
1.0
1.0
S1pt1mbar 8, 1984
..
. ,
1
-1
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Villas De La Costa
Storm Water Management Plan
CHAPTER 5 -FLOW-BASED BMPS
5.1 -Design Criteria
Flow-based BMPs shall be designed to mitigate the maximum flowrate of runoff
produced from a rainfall intensity of 0.2 inch per hour. Such BMPs utilize either
mechanical devices (such as vaults that .produce vortex effects) or non-mechanical
devices (based on weir hydraulics and specially designed filters) to promote settling
_and removal of pollutants from the runoff. ·
Per the request of the City of Carlsbad, 85th percentile flow calculations were
performed using the Rational Method. The basic Rational Method runoff procedure
is as follows:
Design flow (Q) = C * I * A
Runoff Coefficient I -In accordance with the County of San Diego standa'rds, the
weighted runoff coefficient for all the areas draining to the treatment unit was
determined using· the areas analyzed i'n the final engineering hydrology report. The
runoff coefficient is based on the following. characteristics of the watershed:
(.,and Use -Single Family Residential in Developed Areas
Soil Type -·· Hydrologic soil group D was assumed for all areas. Group D soils
have very slow infiltration rates when thoroughly wetted. Consisting chiefly of
clay soils with a high swelling potential, soils with a high permanent water
table, soils with clay pan or clay layer at or near the surface, and shallow soils
over nearly impervious materials, Group D soils have a very slow rate of
water transmission.
Rainfall Intensity (I) -Regional Water Quality Control Board regulations and NPDES
criteria have established that flow-based BMPs shall be designed to mitigate a
rainfall intensity of 0.2 inch. per hour.
Watershed Area (A) -Corresponds to total area draining to treatment unit.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
I
I
I
I
I
I
I
I
I
I
I
I
I.
I
:I
I
I
I
· Villas De La Costa
· Storm Water Management Plan
5.2 -Pollutant Removal Efficiency Table ·
The treatment BMP selected to treat the 85th percentile runoff flow from the Villas de
La Costa falls with the Hydrodynamic Separation Device category. As shown in the
table below, hydrodynamic separation device typically exhibit the removal
efficiencies of various pollutants in the ranges illustrated below.
Pollutant Qf Concern BMP Categories
en Demandin · Substances
Bacteria
Oil & Grease
Pesticides
Vortechs
Stormwater
Treatment S stem
H
L-M
L-M
L-M
H
L
L
H
L
(1l The County will periodically assess the performanqe characteristics of these BMPs to
. update this table.
(2l Proprietary $tructural BMPs. Not all serve the same function.
L (Low): Low removal efficiency (roughly 0-25%)
M (Medium): Medium removal efficiency (roughly 25-75%)
· H (High): High removal efficiency (roughly 75-100%)
U: Unknown removal efficiency, applicant must provide evidence supporting use
Sources: Guidance Specifying Management Measures for Sources of Nonpoint Pollution in
Coastal Waters (1993), National Stormwater Best Management Practices Database (2001 ),
and Guide for BMP Selection in Urban Developed Areas (2001 ).
5.3 -Maintenance Requirements
Flow-based storm water treatment devices should be inspected periodically to
assure their condition to treat anticipated runoff. Maintenance of the proposed
stormwater treatment units includes inspection and maintenance 1 to 4 times per
year.
Maintenance of the stormwater treatment units involves the use of a "vactor truck",
which clears the grit chamber of the treatment unit by vacuuming all the grit, oil and
grease, and water from the sump. Typically a 3-man ere"'( is required to perform the
maintenance of the treatment unit.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
I
I
I
I
I
I
I
·I
I
I
I
I
I
I
I
I
I
I
Villas De La Costa
Storm Water Man~gement Plan
Froatables should' be removed and sumps cleaned when the sump storage exceeds
85 percent of capacity. At least once per year, the unit should be p~mped down and
the screen carefully inspected for damage and to ensure that it is properly fastened.
Since the stormwater treatment unit is a confined space, properly trained personnel
equipped with safety gear will be· required to enter the unit to perform the detailed
inspection. For proper maintenance to be performed, the storm water treatment
facility must be accessible to both maintenance personnel and their equipment and
materials.
Proper inspection includes a visual observation to ascertain whether the unit is
. functioning properly and measuring the amount of deposition in the unit. The rate at
which the .system collects pollutants will depend more heavily on site activities than
the size of the unit. ·
Sediment removed during periodic, post-major rainfall event, and annual
maintenance can be placed in a sanitary landfill or used for composting activities,
subject to compliance with Federal, State and local regulations. User is advised that
deferral of basin maintenance for an extended period may allow concentration levels
of captured pollutants to increase where they may be deemed hazardous
and special requirements may apply to disposal activities, requiring, at a minimum,
. testing prior to disposal in a sanitary landfill.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Villas De La Costa
Storm Water Management Plan
CHAPTER6-SOURtECONTROLBMPS
6. ~· --Landscaping
Manufactured slopes shall be landscaped with suitable ground cover or installed with
an erosion control system. Homeowners should be educated as to the proper routine
maintenance to landscaped areas including trimming, pruning, weeding, mowing,
replacement or substitution of vegetation in ornamental-and required landscapes.
Per the RWQCB Order, the following landscaping activities are deemed unlawful
. and are-thus prohibited:
Discharges of sediment · . .
Discharges of pet waste
Discharges of vegetative clippings
· Dischar9es of other landscaping or construction-related wastes.
During landscaping operations both during and after construction, landscape
maintenance should be completed proactively. ·when these operations are in
progress, bare or disturbed areas should be re-seeded/re-vegetated as quickly as
possible to ensure that erosion is minimized. In addition when landscape
maintenance operafions require the stockpiling of materials for longer than a period
of one day, these stockpiles should be covered to minimize the opportunity for
rainfall to·come in contact with the material.
6.2 -Urban Housekeeping
Fertilizer applied by homeowners, in addition to organic matter such as leaves and
lawn clippings, all result in nutrients in storm water runoff. Consumer use of
excessive herbicide or pesticide contributes toxic chemicals to runoff. Homeowners
should be educated as to the proper application of fertilizers and herbicides to lawns
and_gardens. ·
The average household contains a wide variety of toxins such as oil/grease,
antifreeze, paint, household cleaners and solvents. Homeowners should be
educated as to the proper use, storage, and disposal of these potential storm water
runoff contaminants.
Per the RWQCB Order, the following housekeeping activities are deemed unlawful
· and are thus prohibited:
Discharges of wash water from the cleaning or hosing of impervious surfaces
including parking lots, streets, sidewalks, driveways, patios, plazas, and
outdoor eating and drinking areas_ (landscape irrigation and lawn watering, as
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/0410:58 AM
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Villas De La Costa
Storm Water Management Plan
well as non-commercial washing of vehicles in residential zones, is exempt
· from this restriction)'
Discharges of pool or fountain water containing chloride, biocides, or other
chemicals ·
-Discharges or runoff from material storage areas containing chemicals,
fuels, grease, oil, or other hazardous materials
Discharges of food-related wastes (grease, food processing, trash bin
wash_water, etc.). · ·
. .
6.3 -Automobile Use
Urban pollutants resulting from automobile use include oil, grease, antifreeze,
hydraulic fluids, copper from brakes, and various fuels .. Homeowners should be
educated as to the proper use, storage, and disposal of these potential storm water
contaminants. ·
Per the RWQCB Order, the following automobile use activities are deemed unlawful
and are thus prohibited:
Discharges of wash water from the hosing or cleaning of gas stations,
auto repair garages, or other types of automotive service facilities.
Discharges resulting from the cleaning, repair, or maintenance of any type
of equipment, machinery, or facility including motor vehicles, cement-
related equipment,. port-a:-potty servicing, etc ..
Discharges of wash-water from mobile operations such as mobile
· automobile washing, steam cleaning, power washing, and carpet cleaning.
The·Homeown~rs Association should make all homeowners aware of the
aforementioned RWQCB regulations through a homeowners' education program. A
monitoring program should also be implemented to insure compliance.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
·I
I
I
Villas De La Costa
Storm Water Management Plcm
CHAPfER 7 -SITE Bn,IP DESIGN .
TREATMENT UNITS
7 .1 -BMP Locations
The site design includes a storm water treatment unit (shown on the Developed Site
Map included as an Attachm$nt). The treatment.unit is located in the storm drain
system near the discharge point and more critically downstream of the last collection
device (curb inlets in this case) in the.system.
7 .2 -Determination. of Desis:,n Treatment Flows
The 85th percentile design flow rates have been-calculated using the Rational
. Method. Required data for the Rational Method treatment flow determination include
the following:
-Drainage At.ea (A) = 3.7 acres
Rainfall Intensity (I)= 0.2 inches
-Runoff Coefficient (C) = .0.6 ·
Based on this Rational Method calculation, a peak first flush flow rate of 0.44 cfs was
predicted (calculations attached).
7 .3 -Treatment Unit Selection
The proposed storm water treatment unit will be an inline precast treatment unit,
namely a CDS technologies Model PMSU 20-20 (or approved equivalent unit). The
85th percentile design flow rate is will be treated while flows in excess of the design
flow rate by-pass the swirl chamber (treatment) and proceed downstream. The
decision on the selection of stormwater treatment unit was made based on the
stormwater treatment $ystems ability to adequately treat the design runoff flow. All
relevant design information, including the design runoff flow as well as the storm
drain profiles were sent to the proprietary company responsible for designing the
· storm water treatment unit, and based on that data they have selected treatment
units for the storm drain system that are capable of treating the 85th percentile flow.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 11 :23 AM
I I I I I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
85TH PERCENTILE PEAK FLOW AND VOLUMI:: DETERMINATION
Modified. Rational Method -Effective for Watersheds < 1 ~O mi2
Hunsaker & Associates -$an Diego
. .
Note: Only Enter Values in Boxes -Spreadsheet Will Calculate Remaining Values
Project Name Villas De La Costa I
Work Order 2091-37 I
Jurisdiction City of Carlsbad I
BMP Location !CDS Unit Prior to exit of site
85th Percentile Rainfall = 0.67 linches
(from County lsopluvial Map)
Developed Drainage Area = ·3_7 acre~
Natural Drainage Area = 0.0 acres
Total Drainage Area to BMP = 3.7 . acres
Dev. Area Percent impervious = I 45 !%
Overall Percent Impervious =
Dev. Area Runoff Coefficient =
Nat. Area Runoff Coefficient =
Runoff Coefficient.= .
Time of Concentration =
(from Drainage Study)
RATIONAL METHOD RESULTS
Q = CIA where · Q =
C=
I=
A=
V=CPA where Q=
C=
P=
A=
Using the Total Drainage Area:
C=
I=
P=
A=
Q=
V=·
Using Developed Area Only:
C=
I=
P=
A=
Q=
V=
45 %
0.60
0.00
0.60
13.1 !minutes
~5th Percentile P~ak Flow (cfs)
Runoff Coefficient
Rainfall Intensity (0.2 inch/hour per RWQCB mandate)
Drainage Area (acres)
85th Percentile Runoff Volume (acre-feet)
Runoff Coefficient
85th Percentile Rainfall (inches)
Drainage Area (acres
0.60
0.2 inch/hour
0.67 inches
3.7 acres
0.44 cfs
0.12 acre-feet
0.60
0.2 inch/hour
0.67 inches
3 . .7 acres
0.44 cfs
0.12 acre-feet
~··
J>
I
I
• I
I·.
I
I
Ii :'• ...
I, ...... : .: .,
•-t
' ~-
i
CD~ Technologies, Inc.:,
COS TE~HNOLOGY
Continuous Deflective Separation-(CDS9) is an innovative technology that is :revolutio~g
liquids/solids separatiQn in storm water ~ combined sewer overflow indllStry. The technology
accomplishes high efficiency separation of settleable particulate matter and v.irtually 100 percent
capture .of fl~atable material. Its application is ideal to any situation where removal of gross
pollutants is desired.
-The primary f=$lres of the cos• system are:
+ E~CTIVE: c~tming more than 95%.of solidpollutimts
+ NON-BLOCKING: unique design takes advantage of indirect :filtration and properly
proportioned hy~c forces that virtaally :makes the llilit unblockable.
• NON-MECHANICAL: th~ cos• tmit has no ~o:ving p~ and~ no ~ortmg
m~cal package-to affect solid separation from stonnwater :flows .
•
•
•
•·
•
LOW ~.ANCE COSTS: becallSe· the system has no ·moving parts and is
constructed of durable :materlals. .
COMP ACT AND FLEXIBLE: design and size :flexibility enable units em.bodying the ens•·tec1m~logy to be used in a variety of configurations and hi limited spaces.
mGH FLOW EFFECTIVENESS: -the technology remains highly effective across a
broad spectrum of :flow ranges, with hydraulic loadings exceeding 80 gallons per square
foot of plan surface area. ·
. -
ASSURED POLL UT.ANT CAPTOR!: all materials captured are retained during high
:flow COilditions. · ·
SAFE AND EASY POLLlJTANT REMOVAL: ex.traction methods allow safe and
eSS1J removal of pollutants without manual handling.
+ COST EFFECT.IVE: ~tal costs are lower per mass ~·captured comp~ to
existing available alternatives._ _
ens• offers ~-sepatation units to process :flows of 1 ~ic foot per second (cfs) or less. The
smallest unit is ideal-'for small drainage areas such as parking _ lot$. ens• offers a range of·
premanufactured units sized to process typical drainage flows :from new and existing urban
developments.. cos• uo offers design services for larger cast in place units to meet the
treatment requirements of more significant nm.off flows generated by larger drainage areas. Tq
date, ens• can design units capable of processing up to 300 cfs.
ens• units are available in :fiberglass for flows up to 3 cfs and in precast reinforced concrete
modules for all applications processing flows up to 64 cubic feet per second. For applications
requiting larger ±1.ow processing, units are designed complete with construction specifications for
cast in pl~e construction.
. t81os
, .. "'·
CDS Tecbnologies, ~.,
Units can be_ readily adapted to pipelines, ~x culverts; and open channels with varying
geometric shap~.·, . . · .
CDS Tecbnologies9 includes three "Mallhole" units in its Model lineup. These _are lmiquely
designed for in line use on small pipelines to 36" in diameter, where desired process flows are o
cfs or less. The ens• technology including its high flow bypass weir is neatly packaged inside
of 5', 6' and 8' diameter mailhole stacks. 'I:'hese particular units have been specially configm-eq.
~!> allow an effec,tive oil bafile system to be installed increasing ~e capacity to hold greater
quantities_ of free ·oil should~ need arise. For piping larger than 36", CDS Technologies•
recommends using a standard beside line unit with a diversion weir box designed specifically to
accommodate th~ larger pipe~ ..
HYDROLOGIC ANALYSIS
. In storm ~ applications, ·an analysis ·of th~ catchment in terms of its size, topography and
land use will provide information for cktetm:ining the. flow ~ be expected for various mrm
periods. Based_ on the poU,utograph (lfknoWJl), a ens• unit. can be designe4 for the :flow which
mobilizes the gross pollution in the catchment. Since there are variations ~ catchment response
· due to region, land use and topography, CDS Technologies• recommends the selection of a
d~gn flow for t:teatment having_ a~ period between tbree·montbs and one year.
Typically, it is not necessary to &sign CDS* units to process a conveyance system's design :flow
in order to achieve a very high level 9f pollutant removal. .All. effective design recognizes that
the vast ~jority of pollutants are n;iobilized in flows ~ are well below the "design capacity"
for the c:onveyan~e facility. Field eva!Uations to determine pollutant mobilization flows in
combined sewer overflows have determined that the 'pollutants are released and mobilized with
flows having return periods of 3 to 6 months. . : · ·
The majority.of pollutants in storm~ are·mc,bilizecl.ht similar events.
It is well recognfaed t.hat even though the three-month to one-year event is well below the ·
average ~'s capacity, the actaa1 volume tbat is gene.tated in the catcbrnent from events
smaller than these .is about 95% oI the total annual volume gt;le:rated by the catcbrnEm-t.. It is :
worth noting tba;t a-VERY small quantity of solid pollution actaally travels in these highet :flo~,
therefore, from a practical perspective, desisnin:g for the three month to one year event is
virtually designing to treat nearly 100%. of the nmo:fftbat will be transporting p_ollution. · · . '
HYDRAULIC DESIGN .
Every· CDS~ installation requires a detailed hydraulic analysis to ensure the final installation~
. properly perform to effect optimum solids separation without blocking the separation screen.
Proper design requires knowledge of the conveyance-system, and its performance through its
design flow range and the hydraulic performance of the selected CDS® umt through the same
flow range. . '
After the CDS® design :flow is deten:nined, the appropriate standard model can be selected from
TABLE A on Page 6. Each model on Page 6 idep.tifies a reference PAGE on which additional,
. detailed information about the selected model is available.
The design flow is diverted ill.to the CDS® tmit by constructing a diversion weir across the :flow
path of the conveyance facility. The approximate height of the weir can be established by
detemrlning the hydraulic grade line _(HGlctts) in the system immediately downstream of the
~DS
i
I-~·\ . .
I
-I
I
1·
I t I
I~ ..
I ... :: _ _. .
. .
CDS_ Technologies, Inc.,'
CDS® unit and adding the CDS HEAD LOSS ~) i~tified on the PAGE referenced for the
unit selected. The sum of the above represents the HGLu1s required_ at the .entrance to the
diversion weir. ·
. HGLuts= H~s-+ hem· .
The height of the CDS diversion weir can then be determlned to be:
-Wdr Height= HGLw,.:.. Invert.Level
Maxirn1UJ1 Water Surface or HGL Upstream of the CDS ~tallation
The head loss identified in the Tables on Pages 9-13-rci,resents the ideal hydraulic installation.
The head required to _operate a CDSa unit at the. CDSe design flow does not control the
maximum rise in, water surmce upstream of the CDSa uni~ At the CDSa design .flow; the HGL
is at the top of the diversion weir. For most i:nstallations this is w~ll below :finished grade.
The ~um :increase in water surface occurs. tb.e-conv~ce system reaches its design
:flow. When.this flow occurs, the actual·flow through the CDS, may be altered, with the·balance
~fflow pas¢ng over the diversion: weir. Based·on: laboratozy measumnents and analysis, it has·
been established that the actual head loss under system design flow will not exceed 1.3 x V2/2g in a well-designed diversion structo:re, where V is the design flow velocity.in the system when the
pipe is flowing. · ·
To assure passage of system design flow ~ugh the weir area, the. unobstructed area provided
above the weir must be equal to or greater than the cross sectional area for the pipeline entering
the weir box.
In recognition of the potential that the CDSa may fill up with captured. material and lose its
conveyance capacity, · the hydraulic· ·evaluation must include .. analysis u¢er this scenario to
understand the.potential for flooding~
'J;he effects -of the diversion weir primarily influence the rise in the water surface under the
conveyance system design flow. .The actual effect can be ~ontrolled by properly designing the
weir length and cl~ height above the weir to take advantase of th~ potential energy :that can be
developed in the system without inducing :floodmg:upstreani.
CDS Teclmologies recommends that the head l~ss across the weir be limited to no D:tore ~ 1.4
times the CDSa unit headless at its design flow to ensure that it conti]lues to operate properly
during the conveyance system's peak flows.
An example of the hydtaulic design process is proyided under Appendix B.
STRUCTURAL DESIGN
All cnsa units are designed to withstand equivalent fluid pressures that the unit may experience
during its life. The water table at the installation site should be known,· or a conservative
estimate will be made on the maximum expected. U:nits · are analyzed assuming that it is empty
and fb.11 buoyant force is acting on it , ·
The fo1.mdation material needs to be adequate to support the structure's weight without allowing
differential settl~ent
· The materials for · manufacture of precast units are fully described in Appendix D
"Product & Installation Specifications11 of this Manual.
CDS Technologies, Inc.,
Fiberglass units are 'placed in areas with light pedestriaD: traffic areas or . i:nstalled with traffic
bearing covers to protect the unit from vehicular t;affic loads. . . · .
All cast in place c~ desip are based on using structural concrete with rninim,tlll ultimate
strength of 4,000 pounds per square inch (psij, with steel reinforcement having a rninirn1,m ..
ultimate yie14 strength of 600 a3) psi. Concrete mid steel reinforcement are as noted in Appendix
D, unless otherwise specified for site-specific ccmditions. -
.CDS MODEL DESIGNATION
CDS® units are identified by their process· screen diameter. They are also identified by its
application with "SW" designating "S~ Watee, "SU". designating "Storm: -Unit'' ~'CS"
· de~gnating "Combined Sewer".
Model :families are desipated by the letter "F',. "P", PM, or "C", designating "Fiberglass",
"Precast", Precast Manhole, ·or "Cast: bi p~e, along with the application letters and a pair of
~er designations such· as PSWXX_:XX.· The first :XX :represents the separation screen
diameter in .ieet; the second _XX designates-the heighi of the sepamtion screen in feet (see
TABLE A on page 7 for further description of unit designations). General manufacturing details
and weights are included for the various models under .Appendix A.
' I
CDS "f ~LE CQMPONEN):'S · · · .
. The variable components in a CDS® ~t within a model family are the screen height, the screen
aperture (opening), sump diameter and depth,. and typ~ of cover.
. Screen 'Height
The screen height is impo$,D.t within a modelfamily because it controls the desigi;i flow that can
pass tbrough the unit witheut clogging the screen. In general, screen heights can vary between
60 to 150 percent of the screen diameter: .
Screen Aperture
The standard screen for stonn water applications is 4700 miCI011S (.185 inches) for ·coarse
screenm.g. A 2400 micron (0.095) is available where there is a need to separate .finer sediments·
than those tmXlPVcd by the 4700 micron screen.
The screen aperture (opening) is important_b~e it sets-the capture parameter for settleable
pollutants. In general, a ens® unit with a· 4700 micron screen will capture 93~ of all particles
as small as 1/3 the short dimensi0t1 of the screen opening. This has been detemrlned tbrough
extensive pilot work performed by Tony Wong, PhD, Monash University. l'ony Wong's
teclmical paper,. fully descnoing the hydtaulic basis on which ens• achieve effective solid
separation, is readily available.
Sump
The sump_ is another variable . that can be adjusted for site-specific conditions and utility
. preference. Each Model Family is equipped with a.standard sump. However, the diameter and
deptl;L can be adjusted to meet site:-speclfic requirements.
CDS" Covers
Covers can be provided with each CDS~ unit. A pedestrian traffic cover is standard with each
unit. The ~over is _designed with an inspect:ion/cleanout hatch. The entire cover may be removed
to facilitate cleanout
••
i.,'1•,
i
i
I
I
I
I
I
,-~--~ .. ,.
C
' ' ' ' ' I
•• ...
~
~ .
CD~ Technologies, Inc.,
If required, a traffic· bearing cover will be design~ fabricated and furnished. If a traffic bearing
cover is desired, the utility should so advise CDS Technologies~ to include it in the quote. .
ens• SUMP CLEANOlJT -
Sump cleanout is a critical component of a successful ens• operation. The sump is the-
depository for all settleable · pollutants captured by ens•. The methods for maintenance and
cleanout are generally specific, dependent oil the preferences of a given agency. The standard
~odel is pro:vided with a~ sump that ·can be cleaned by methods selected by the utility. .
At·the utility's discretion, a unit can be cleaned using-a vacuum ·truck or a small clamshell
bucket, or a basket can be provided to fit a standani sump. l;f the utility chooses to. use a basket,
it should advise cos• Techno1ogies so it can be included in a 4UC?te.
cns•MAINTENANCE ..
' . .
ens• :maintenance can be site and drainage ~ specific;. The· unit. should be · inspected
periodically· to assure its condition to bandle anticipated runoff: If pollutant ioadings are known, ·
then a preventive rnnntenance schedule can be developed b~ed on runoff voiumes processed.
· Unfortunately, that is seldom the case. , · . · . . '
CDS rechnologies9 recommends the ·following for Storm. Water Applications: .
New Installatiog -Check the condition of the unit after· every runoff event for the :fiist 30 days.
Checking includes a visual i:nspection to ~cert¢n that the unit is functioning properly and
measuring the amount of deposition that has occurred in the unit This can be done with a "dip
stick'' that is· cah'brated so the depth of deposition can be tracked. Based on the behavior of the
unit ~lative to storm events, inspections can be scheduled on projections using storm events vs.
pollutant buildup.-· · · · · · · . .
. Ongoing Otieraticm -During ·the wet season, the unit should be inspected at least once every
thirty days. The floatables should be removed and the sump cleaned when the sump is above
85% full. . At least once a year, the unit should be _pumped. 4own and the. screen carefully
inspected for damage and to ensure ~ it is propedy fastened. Ideally, the screen should be
power washed for the inspection. ·
The cnsc unit is a confined space.. Properly trained people equipped with required safety gear .
will be required to enter the unit to perform the 4etailed inspection.
TABLE -A
MODEL. PERFO·RMANCE · CAPABILITY
MODEL DESIGN FLOW RATE .
·NUMBER CFS · MGO . M3/sec.
FSW20_20· 1.1
FSW30..:.28
PMIU20_15-
PMSU20_15
~MSU20--20 ·
PMSU20--25
PMSU30-20 .
PMSU:30.....28
PMSU40_40
PSWCJ0--28
~ Pswq40_40
PSWCS6_40·
PSWC56_53
PSWC56_68
PSWC56..:j8
PSW30...2B
PSW50_42
PSWS0_SO .
PSN70_70
Psw1.oo_so
PSW100_80
. Psw1 oo_ too·
_CSW150_134 .
·csw200_ 164
· CSW240_ 160
.. -:
3.0
.0.7
p.7.
. 1.1
1..6
2.0
-3.0
6.0
3.0
6.0
9.0
· 14
19
25
3.0
9.0· ~
11
26-. ·
30
50
64
148
. 270
300
. .
0.7
· 1.9
0.5
.0.5.
0.7
1.0 ..
1.3
1.9
· 3.9
· · 1.9 .
: · 3.9
. s.a·
9.0
12
· ·16
· 1.9
·s.a
7.1
17
19
·32
41
95
174
194
.03
.oa.
.02
.02
.03
.05
.06
.08
.17
.08
.17
.25
.40
.54
.• 71
.08
.25 .
.31
.74
.85
1.4
1.8
4.2
7.6
8.5
REFERENCE
PAGE
9
10
1 1
12
13
Conversion: 1cfs ~ 0.0283 cubic meters per second, or 1 M3/sec: S 35.31cfs
1cfs S 0.64512 MGO or 1MGD ~ 1.55 cfs
MODEL DESIGNATIONS
FSW . =·Fiberglass Storm Water
PSW = Precast Storm Weter
PSWC= Precast Storm Weter Concentric
j Screen Diameter .
f . j Screen Height --CSW = Cast in Place Storm Water ---X X _ X X (L or R)*
PMSU=_Precast Manhole Storm Water Unit ------~-l ' Tenths of a Foat · Feet-
Tenths of c Foot . Feet ·
*· L or R designates the location of the CDS when looking downstream.
(L)eft represents being placed on the. Left side of the stormdrain,
(R)ioht is claeed on -t,i,~ ,-inlit !'l:ide. · ·
I
,.
1-
I
I
I·
I
I
I .... :
•. ..,
I -
I
I
J
J
-•
~·
~
HIGH FLOW
. 8YPASS . \
.
. '
CONVEYANCE .· CONDUIT .
SEPARATION ·
. SCREEN .
-.
I •
. .
-PLAN· ·v1 EW
(RIGHT HAND UNIT)
7
OF UNIT
CONVEYANCE
CONDUIT
OUTLET CONTROL WEJR
CDS OUTLET
I
---. GENERAL DESCRIPTION OF UNIT '. . .
.
INLET DIVERSION WEIR
ACCESS·
EXISTING-COVER .•
. qRADE--
•.: .. CDS INLET
I ,
ELEVATION
8
• ii... . I ..
-\
-1 ,.·
I
I
,_.
' ': ··: ,.
' I
' I
' ' I : .
I
' , . .
.PRECAsT·--MA-NH OLE ·M-ODELS
.. PR.OCESSES .FLOWS 0. 75 ··ro 6.5 CFS
VARIES
F'UlV -
A = FOOT PRINT DIAMET'ER I_ . · .. '_A', . I
D = DEPTH BELOW PIPE INVERT, VARIES ~ --i
.-DEPTH .. . BELOW FOOT PR.ECAST .DESIGN -DESIGN SCREEN. . PIPE PRINT
· MODEL FLOW RATE HEAD LOSS DIA./HT. INVERT DIAMETER
NUMBER . "D" "A"
cfs MGD· ml /sec ft. m ft. ft. ft.
PMSU20_15 0.75 0.49 0.021 0.35 0.11 2/1.5 5.3 6.0
PMSU20....;20 , 1.20. 0.78 -0.034 0.48 0.15 2/2.0 5.8 6.0 .
PMSU20-25 1.68 : 1.10 0.048· 0.62 · 0.19 2/25 6.3 6.0
PMSU30-20 2.0 1.29 0.056 0.6,5 0.20 3/2.0 6.25 7.3
PMSU30_28 3.0 '1,94 0.085 o.1p 0.2-1 3/2.8 6.7 7.3
PMSU40_40 . 6.5 4.2 0.18 0.95 0.29 4/4.0 7.8 9.5
*stan.dord -screen opening is 4700 microns (.185 in.). Screens olso
ovailable in 2.400 mJcrons_ (.095 in.).
Maximum head loss: During _high flow condition·s,
if flow exceeds· CDS design capacity, then
average maximum headless is about (1.3 to 2.5) V 3/2g; where V is
determined under full pipe conditions.
' .
I
I ---.
I
I
1· ,.·
1·
I
-1
I,~ ...
I ,,
I
I
!I
ii
I
I
I
. Fiberglass
011 Baffle-~
LEFT-HANDED UNIT SHOWN HERE
. <t_ Separation Screen
I &: Sump ~ccess
j · . ~ M~iser Stack • •• ~ Top Cap
. ~ Approx. Wt. • 3550 #
_...---5'f Manhole Riser Sections
Apprax. wt. •
1950 # (1.5 ft. riser section)
2600 f (2.0 ft. riser section)
3250 # (2.5 ft. riser section)
3900 # (3,0 ft.. riser section)
/Fiberglass Inlet
Separation Chamber Component
/ Approx. wt. • 3900 # . (Typ.)
Inlet Pipe
/
_____ Separation Screen
Separation Chamber Component
Approx. Wt. =
1950 f ( 1.5 ft. riser section)
2600 I (2.0 ft. riser section)
3250 # (2.5 ft. riser section)
3900 II (3.0 ft. riser section)
Separation Slab, ~ Approx. Wt. = 2150 II
Sump, &: Bose ~ Approx. Wt. = 4800 II
SECTION SIZES MAY VARY ACCORDING
TO LOCAL PRECASTERS SPECIFICATIONS.
DATE SCALE
CDS MODEL·PMSU20
TYPICAL ASSEMBLY
DRAWN
APPROV.
01/10/02
J.S.F.
N.T.S.
SHEET
1 R. HOWARD
---·,-·
I
I
I
I
I ,.
I
I ,,
,,. \.
I
I
I
I
I
I
I
I
I
so• 1.0. CONC. .
TYPICAL / GENERIC
INSTALLATION .·
OIL BAFFLE,
MH RISER, s• ----. MODEL A FOR PIPES TO 18"!&
MODEL 8 FOR PIPES TO 30"91 THICK (lYP.)
ELEVATION
VIEW
(SEE SHEET 3) + FLOW )e..,
I L__ j
. XX"91
PIPE INLET
MQIE;
24 "91 MH COVERS c!c
FRAMES (2)-OTHER
HATCHES AVAILABLE
THE INTERNAL COMPONENTS ARE SHOWN IN THE RIGHT-HAND
CONFIGURATION-THESE COMPONENTS MAY BE FURNISHED IN THE
MIRROR IMAGE TO THAT SHOWN (LEFT-HAND CONFIGURATION)
CDS MODEL PMSU20 __ 20, 1.1 CFS CAPACITY.
STORM WATER TREATMENT UNIT
PROJECT NAME
CITY, STATE
DATE
DRAWN
APPROV.
12/3/01
J.S.F.
R. HOWARD
SCALE
1·-2·
SHEET
2
I
1:
I
I
I
I
I
I
·1
·1.
I
I
I
I
I
I
I
I
ii
·. ACCESS RISER~ s·-o· 1.0.
ATTACH SIDE AND BOTTOM.
FLANGES TO WALL OF MH
RISER .USING ANCHOR BOLTS
(6 MIN),·· SUPPLIED BY CDS.
xx·,
PIPE INLET
ATTACH SCREEN
TO SLAB USING 4
ANCHOR BOLTS,
SUPPLIED BY CDS.
TYPICAL· / GENERIC
INSTALLATION
CENTER OF ___ MH RISER
SECTIONS
ROTO-HAMMER OR SAW
CUT OPENINGS FOR
PIPE INLET AND OUTLET
>S NECESSARY
xx·,
PIPE OUTLET
CENTER OF SCREEN,
21 •!D SUMP OPENING
2s•1D SEPARATION SCREEN,
SEE NOTE #2 BELOW ---STAINLESS STEEL
SEPARATION PLATE
NOTES: ..
. 1. THE INTERNAL COMPONENTS ARE SHOWN IN THE RIGHT-HAND
CONFIGURATION-THESE COMPONENTS MAY BE FURNISHED IN THE
MIRROR IMAGE TO THAT SHOWN .(LEFT-HAND CONFIGURATION).
2. FOR ·PROPER INSTALLATION, GREEN FLANGE ON SCREEN FACES UP
FOR RIGHT-HAND INSTALLATION, RED FLANGE FACES UP FOR LEFT-
HAND ORIENTED UNITS.
CDS MODEL PMSU2O __ 2O, 1.1 CFS CAPACirY
STORM WATER TREATMENT UNIT
DATE 12/3/01 SCALE
1·-2· (g P.ROJECT NAME ~»~™ DRAWN SHEET . CITY, STATE J.S.F.
APPROV. R. HOWARD 3 PATENTED
_i :.·
.,
I .,
I ., ,.
I
·1
I , •. ·
I
I
I
I
I
I
I
I
I
TYPICAL. / . GENERIC
INSTALLATION
· 24• ; COVERS & FRAMES (2),
. lYP. -· OTHER HATCH SYSTEMS
READILY AVAILABLE.
RIM EL=XX.X'±
£ SEPARATION I SECTION
,·ct RISER j .. SECTIONS
-----------
,--
1
' DEPTH SECTION VARIES
.CUT
(SEE SHEET ~)
INV EL=XX.X'±
5'-8"
TYPICAL
SUMP EXTERIOR
INV EL=XX.X'±
XX",
XX"¢
CORE
I.
~~--+--'-----+-= ........ -~
10" .
31"
g"·
22"
MIN.
6"
· FIBERGLASS
SEPARATION
CYLINDER &
INLET --------
SEPARATION
SCREEN l
18"
I SEE INSET FOR I PLATE DETAIL
SUMP
72" . I
--7
I
' SECTION
CUT
(SEE SHEET 3)
INTERNAL
SEPARATION
SLAB
l l ~. ST~lh!LESS S:CEEL
SEPARATION PLATE
PLAN VIEW
SCALE: 1 "=2'
CDS MODEL PMSU2O_2O, 1.1 CFS CAPACITY
STORM WATER TREATMENT UNIT
PROJECT NAME
CITY, STATE
DATE
DRAWN
APPROV.
12/3/01
J.S.F.
R. HOWARD
SCALE
1"=2'
SHEET
4
I
I . '•,
I
1,
I'
I
1:
I
I
,.··.
I
I
I
'I
I
;I
1:
I
!I
CONSTRUCT/ON ·NOTES:
,-
i----s·-o·----i
@
18",
SEE NOTE
@
HT. VARIES
5'-8"
DEPTH BELOW
PIPE INVERT
(TYPICAL)
1. APPLY BU1YL MASTIC AND/OR GROUT TO SEAL JOINTS OF MANHOLE STRUCTURE. APPLY LOAD TO MASTIC SEAL IN
JOINTS OF MH SECTIONS TO COMPRESS SEALANT IF NECESSARY. 'UNIT MUST BE WATER TIGHT, HOLDING WATER UP
TO F'LOWLINE INVERT (MINIMUM).
2. IF SEPARATION .SLAB IS NON-INTEGRAL TO THE SEPARATION SECTION OF THE UNIT, SET AND VERIFY TOP ELEVATION
BEFORE PLACING MORE PRECAST COMPONENTS OR BACKFIWNG. ENSURE 31" FROM TOP OF SEPARATION SLAB
TO PIPE INVERT.
3. ROTC-HAMMER OR SAW-CUT OPENINGS FOR PIPE INLET AND OUTLET AS NECESSARY; GROUT PIPE CONNECTIONS TO
SEAL JOINT. .
4. SET BOTTOM OF OIL BAFFLE 18" ABOVE SEPARATION SLAB F'LOOR; DRILL AND INSERT A MINIMUM OF TEN (1.0)
3/8" x 3 3/4" SS EXPANSION BOLTS O 12" O.C. EQUALLY SPACED TO SECURE FIBERGLASS OIL BAFFLE FLANGE
TO RiSER WALL-(HARDWARE SUPPLIED BY CDS TECHNOLOGIES).
5. FASTEN FIBERGLASS CYLINDER/INLET TO SCREEN ASSEMBLY USING FOUR (4) SETS OF 2· x 1 2· SS HEX HEAD
BOLTS W/ NUTS AND WASHERS-(HARDWARE SUPPLIED BY CDS · TECHNOLOGIES). IN THE LEFT-HANDED
CONFIGURATION THE "REO" COLORED FLANGE ON THE SCREEN CYLINDER SHALL FACE UP. IN THE RIGHT-HANDED
CONFIGURATION, THE "GREEN" COLORED FLANGE 'SHALL FACE UP.
6. CENTER SCREEN ASSEMBLY OVER SUMP OPENING AND POSmON FIBERGLASS INLET AGAINST RISER WALL; DRILL AND
INSERT A MINIMUM OF SIX (6) i" x 3 ~-SS EXPANSION BOLTS EQUALLY SPACED TO SECURE FIBERGLASS INLET
FLANGE TO RISER WALL-(HARDWARE SUPPLIED BY CDS TECHNOLOGIES).
7. VERIFY THAT SCREEN ASSEMBLY IS CENTERED OVER SUMP ACCESS HOLE AND ADJUST IF NECESSARY; FASTEN
SCREEN TO SEPARATION SLAB USING. FOUR (4) r x 3 j" SS EXPANSION BOLTS-(HARDWARE SUPPLIED BY CDS
TECHNOLOGIES).
8. BLOCK · AND GROUT SEAL TO MATCH GRADE >.S REQUIRED.
PMSU20_20
CONSTRUCTION
NOTES
DATE
DRAWN
APPROV.
12/3/01 SCALE
N.T.S.
· J.S.F. SHEET
R. HOWARD 5
7
I
I
I
I
I
I
I
I
I
I
1·
I
I
I
I
I
I
I
I
Villas De La Costa
Storm Water Management Plan
CHAPTER 8 -REFERENCES
"Standard Urban· Storm Water Mitigation Plan -Storm Water Standards': ·
City of Carlsbad, April 2003.
"San Diego Municipal Code.Land Development Manual Storm Water Standards':
City of San Diego, California; May 2003.
''Addendum to Hydrology Study for Santaluz Affordable Site",
Hunsaker & Associates San Diego, Inc.; August 9, 2003.
"San Diego County Hydrology Manual': ~ounty of San Diego Department of Public
Works -Flood Control Section;. June 2O0~.
"Order No. 2001-01, NPD~S No. CAS0108758-Waste Discharge Requirements for
Discharges of Urban Runoff from the Municipal Separate Storm Sewer
Systems (MS4s) Draining the Watersheds of the County of San Diego, the
Incorporated Cities of San Diego County, and San Diego Unified Port District':
California Regional Water. Quality Control Board -San Diego Region;
February 21, 2001.
"WaterQuality Plan for the San Diego Basin", California Regional Water Quality
Control Board -San Diego Region, September 8, 1994.
"CDS Technologies Storm Water Pollution Control Technical Manual': CDS
Technologies, Updated April 2003.
"Drainage Study for Villas De La Costa': Hunsaker & Associates San Diego, Inc.,
January, 2004.
JC:de h:\sw quality\2091\37\swmp-03.doc
w.o. 2091-37 2/25/04 10:58 AM
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
'