HomeMy WebLinkAboutCT 05-15; LA COSTA OAKS NEIGHBORHOOD 3.1, 3.3-3.5; STORM WATER MANAGEMENT PLAN; 2007-05-07E1 ZMTAjmmIx S$IVE
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I H*.!HUNSAKER
I \ &ASSOC[ATES
A N D I E C 0,. -1 N C. RECEIVED
PLANNING
I ENGINEERING JUN 22 2001
SURVEYING
STORM WATER ENGINEERING
I LOSANGELES MANAGEMENT PLAN DEPARTMENT
RIVERSIDE
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SAN DIEGO
ARIZONA LA COSTA OAKS NORTH 'l.
NEIGHBORHOOD 3 1 & 3.3- 3.5
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City of Carlsbad, California
WAIM
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Real Estate Collateral Management Company ,
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do Morrow Development
1903 Wright.Piace, Suite 180 U) .
Carlsbad, CA 92008 - (z
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May 07, 2007 .
- . . . Hunsaker& Associates :1 -. Q.OFESSI - • San
LEX WILLIMAN N6. 62891 I .o, ALISAVIALPANDO
R.C.E.
Exp. 06/30/08
DAN SMITH CIV David A.- Blalock,
RAY MARTIN OF C
. 97O7Waptes Street .' ...-..
I San Diego, CA 92121
(858) 558-4500 PH
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
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
1.5 COnclusion
1.6 References
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
3.1 Anticipated Pollutants from Project Site
3.2 Sediment
3.3 Nutrients
3.4 Trash & Debris
3.5 Oxygen-Demanding Substances
3.6 OiI& Grease
3.7 Bacteria and Viruses
3.8 Pesticides
CHAPTER 4— Conditions of Concern
4.1 Receiving Watershed Descriptions
4.2 Pollutants of Concern in Receiving Watersheds
4.3 303(d)Status
4.4 Condition of Concern - Developed Condition Hydrology Summary
4.5 Identification of Primary & Secondary Pollutants of Concern
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
CHAPTER 5— Treatment Control BMP Design
5.1 BMP Locations
5.2 Determination of Treatment Flows
5.3 BMP Unit Sizing
5.4 Vortechs Treatment Units
5.5 Pollutant Removal Efficiency Table
5.6 BMP Unit Discussion
CHAPTER 6— Source Control BMPs
6.1 Landscaping
6.2 Urban Housekeeping
6.3 Automobile Use
,6.4 Integrated Pest Management (IPM) Principles
6.5 Storm Water Conveyance Systems Stenciling and Signage
6.6 Efficient Irrigation Practices
6.7 Trash, Storage Areas
CHAPTER 7— Site Design BMPs
7;1 Site Design BMPs
7.2 Minimize Impervious Footprint
7.3 Conserve Natural Areas
7.4 Permeable Pavements
7.5 Minimize Directly Connected Impervious Areas
7.6' Slopes & Channel Protection I Hillside Landscaping
7.7 Private Roads
CHAPTER 8 - 00erations & Maintenance Plan
8.1 Maintenance Requirements
8.2 Operations and Maintenance Plan
8.3 Annual Operations & Maintenance Costs
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
List of Tables and Flu ures
Chapter 1 -Vicinity Map
Chapter 1 —Watershed Map
Chapter 1 - BMP Location Map
Chapter 2 - Storm Water Requirements Applicability Checklist
Chapter 3 - Pollutant Category Table
Chapter 4 - 2006 CWA Section 303(d) List
Chapter 4 - Beneficial Uses of Inland Surface Waters
Chapter 4 - Water Quality Objectives
Chapter 5— Pollutant Removal Efficiency Table
Chapter 5 - Design Runoff Determination Summary Table
Chapter 5 - BMP Location Map
Chapter 5 - 85th Percentile Rational Method Calculations
Chapter 5 - Vortechs System Data
Li
Attachments
BMP LOCATION EXHIBIT (Pocket)
DRAINAGE EXHIBITS (Pocket)
a
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
CHAPTER 1 - EXECUTIVE SUMMARY'
1.1 - Introduction
The La Costa Oaks North Neighborhoods 3.1 & 3.3 - 3.5 sites are located at the
north eastern corner of the intersection of Poinsettia Lane and Alicante Road in the
City of Carlsbad,' California (see Vicinity Map below).
Per the City of Carlsbad SUSMP, the La Costa Oaks North Neighborhoods 3.1 & 3.3
- 3.5 are classified as Priority Projects and are 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 Carlsbad'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
Carlsbad SUSMP.
This SWMP recommends the location and sizing of four (4) Best Management
Practice (BMP) treatment units, which will treat 85th percentile runoff prior to
discharging from the development site (see BMP Location Map in this chapter)
Furthermore, this report determines anticipated project pollutants, pollutants of
concern in the receiving watershed, recommended source control BMPs, and
methodology used for the design of flow-based BMPs.
'F
ARCOS
11
WJECT
TE
VICINITY MAP
IV TS
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 &.3.5
Storm Water Management Plan
1.2 — Summary of Pre-Develooed Conditions
— The La Costa Oaks North Neighborhoods 3.1, 3.3-3.5 sites are located in the City
I of Carlsbad, California. The site has been mass graded in anticipation for residential
development per the "Mass Graded Hydrology Study for La Costa Oaks North -
Neighborhood 3.1 & 3.3 - 3.5" dated October, 2005 by Hunsaker & Associates.
1 1.2.1 Neighborhood 3.1
I Runoff from the La Costa Oaks North Neighborhood 3.1 site is drained via an
existing 42-inch RCP storm drain to the receiving storm drain located within the
adjacent Rancho Santa Fe Road, ultimately discharging to San Marcos Creek.
1.2.2 Neighborhood 3.3
I Runoff from the La Costa Oaks North Neighborhood 3.3 site drains to four (4)
existing storm drain outlet locations. Three (3) drainage locations (18-inch, 36-inch
and 42-inch RCP's) discharge site runoff to the receiving storm drain located within
I the adjacent Rancho Santa Fe Road, ultimately discharging to San Marcos Creek.
Flow directed to the south of the project site is intercepted via, an existing 48-inch
RCP, discharging to the receiving San Marcos Creek.
1 1.2.3 Neighborhood 3.4 & 3.5
.I Runoff from the La Costa Oaks North Neighborhoods 3.4 & 3.5 site drains to two (2)
existing storm drain outlet locations. Runoff from the mass graded Neighborhood
3.4 site drains north to the receiving 36-inch RCP storm drain within San Elijo Road,
I discharging to the storm drain system within the adjacent Rancho Santa Fe Road.
Runoff from the mass graded Neighborhood 3.5 site drains south to the receiving
I . 48-inch RCP storm drain that discharges directly to San Marcos Creek. All flow from
the La Costa Oaks North project site ultimately drains to San Marcos Creek.
The Regional Water Quality Control Board has identified San Marcos Creek as part
of the Carlsbad Hydrologic Unit, San Marcos Hydrologic Area, and the Batiquitos
Hydrologic Subarea (basin number 904.51).
Table 1 on the following page summarizes pre-developed conditions peak flows for
Neighborhoods 3.1, 3:3 - 3.5.
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
Table I - Summary of Pre-Developed Peak Flows
Drainage 100-Year Peak
Drainage Location Neighborhoods Area Flow
(Ac) (cfs)
48-inch RCP to San Marcos
Creek
3.3 3.4 & 3.5 21.2 53.0
18-inch RCP to Rancho Santa
Fe Road 3.3 3.0 8.7
(Avenida_Soledad)
36-inch RCP to Rancho Santa
Fe Road 3.4 8.9 20.9
(San _Elijo_ Road _at_Node325)
42-inch RCP to Rancho Santa
Fe Road 3.1 3.3 & 3.4 45.7 105.2
TOTAL 78.8 . 187.8
Note: Inclusive of tributary areas from 3.1 & 3.3- 3.5
1.3- Summary of Proposed Development
1.3.1 Neighborhood 3.1
I The proposed La Costa Oaks North Neighborhood 3.1 will consist of 80 single family
residences, roads, sidewalks, curbs and gutters, associated underground utilities
and storm water drainage systems.
Runoff from the residential development will be conveyed via curb and gutter, where
curb inlets will intercept this flow and convey it to the proposed storm drain system.
This storm drain system connects to the existing 42-inch RCP storm drain,
discharging to the existing storm drain system located within the adjacent Rancho
Santa Fe Road.
Based on County of San Diego 2003 Engineering Standards criteria, a runoff
coefficient of 0.52 was assumed for the proposed single-family residential
development.
Prior to discharge from the site, a single flow based BMP is located at the end of the
La Costa Oaks North Neighborhood 3.1 storm drain for storm water treatment. 85th
percentile flow from the site and portions of the neighboring La Costa Oaks North
Neighborhood 3.3 will be treated via this existing Vortechnics flow based treatment
unit.
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
1.3.2 Neighborhood 3.3
The proposed La Costa Oaks North Neighborhood 3.3 will consist of 120 single
family residences, roads, sidewalks, curbs and gutters, associated underground
utilities and storm water drainage systems.
Runoff from the northern portion of the residential development will be conveyed via
curb and gutter, where curb inlets will intercept this flow and convey it to the
proposed storm drain system. This northern storm drain system connects to the
existing 42-inch RCP storm drain, discharging to the existing storm drain system
located within the adjacent Rancho Santa Fe Road.
Runoff from the southern portion of the residential development will be conveyed via
curb and gutter, where curb inlets will intercept this flow and convey it to the
proposed storm drain system. This southern storm drain system connects to the
existing 48-inch RCP storm drain to the south of the project site, discharging to the
receiving San Marcos Creek.
I Runoff from a small portion to the south east of the La Costa Oaks North
Neighborhood 3.3 site discharges to the curb and gutter within Sitio Corazon,
draining to both the storm drain system within Avenida Soledad and San Elijo
I Roads, ultimately discharging to the existing storm drain system within the adjacent
Rancho Santa Fe Road.
Based on County of San Diego 2003 Engineering Standards criteria, a runoff
coefficient of 0.52 was assumed for the proposed single-family residential
development.
Prior to discharge from the site, four (4) flow based BMPs are located at the end of
the four (4) internal La Costa Oaks North storm drain systems for storm water
treatment. 85th percentile flow from the site and portions of the neighboring La
Costa Oaks North Neighborhoods 3.1, 3.4 & 3.5 will be treated via these existing
Vortechnics flow based treatment units.
1.3.3 Neighborhood 3.4 & 3.5
I The proposed La Costa Oaks North Neighborhoods 3.4 & 3.5 will consist of, 83
single family residences, roads, sidewalks, curbs and gutters, associated
I'
underground utilities and storm water drainage systems.
Runoff from the northern Neighborhood 3.4 portion will be conveyed via curb and
gutter, where curb inlets will intercept this flow and convey it to the proposed storm
I drain system. This storm drain system connects to the existing 36-inch RCP storm
drain within San Elijo Road, discharging to the existing storm drain system located
within the adjacent Rancho Santa Fe Road.
I,
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I La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
Runoff from the southern Neighborhood 3.5 will be conveyed via curb and gutter, I where curb inlets will intercept this flow and convey it to the proposed storm drain
system. This storm drain system connects to the existing 48-inch RCP storm drain
I to the south of the project site, discharging to the receiving San Marcos Creek.
Based on County of San Diego 2003 Engineering Standards criteria, a runoff
I: .coefficient of 0.52 was assumed for the proposed single-family residential
development.
I .Prior to discharge from the site, two (2) flow based BMPs area located at the end of
the two (2) internal La Costa Oaks North storm drain systems for storm water
treatment. 851h percentile flow from the site and portions of the neighboring La
I, Costa Oaks North Neighborhood 3.3 will be treated via these existing Vortechnics
flow based treatment units.
I
Per the "Drainage Study for La Costa Oaks North Neighborhoods 3.1 & 3.3 - 3.5",
dated. October 2006 by Hunsaker & Associates, peak flow data from the developed
site is summarized in Table 2 below.
Table 2— Summary of Developed Conditions Peak Flows
Drainage 100-Year Peak
Drainage Location Neighborhoods Area Flow
(Ac) (cfs)
48-inch RCP to San Marcos
Creek . 3.3, 3.4 & 3.5 21.0 * 443
18-inch RCP to Rancho Santa
Fe Road 3.3 2.9 * 7.7
(Avenida_Soledad)
36-inch RCP to Rancho Santa
Fe Road 3.4 8.8 * 20.2
(San _Elijo_Road)
42-inch RCP to Rancho Santa
Fe Road 3.1, 3.3 & 3.4 45.8 * 98.4
TOTAL 78.5 170.6
Note: Inclusive of tributary areas from 3.1 & 3.3-3.5
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
1.4- Results and Recommendations
Table 3 below summarizes rational method 85th percentile calculations for the
proposed water quality treatment unit for the La Costa Oaks North Neighborhood 3.1
& 3.3 - 3.5 developments. The runoff coefficient used for sizing the proposed
treatment units is of 0.52, which was based on 283-dwelling units per 78.5 acres.
Table 3 - Developed Conditions 85th Percentile Calculations
Treatment Drainage Rainfall 85th
Unit Neighborhoods Area Intensity Runoff Percentile
Location (acres) (inches/hour)
,..uci oeent Flow (cfs)
48-inch
RCP to
San 3.3, 3.4 & 3.5 21.0* 0.2 0.52 2.2
Marcos
Creek
18-inch
RCP to
Rancho 3.3 2.9* 0.2 0.52 0.3
Santa Fe
Road
36-inch
RCP to
Rancho 3.4 8.8* 0.2 0.52 0.9
Santa Fe
Road
42-inch
RCP to
Rancho 3.1, 3.3 & 3.4 45.8* 0.2 0.52 4.8
Santa Fe
Road
=inclusive of portions of Neighborhoods 3.1 3.4 & 3.5
Rational Method calculations predicted 85" percentile runoff flows of approximately
2. 2 cfs, 0.3 cfs, 0.9 cfs and 4.8 cfs at the respective four (4) flow based treatment
units.
Vortechs Models 4000, 1000, 2000 & 7000 treatment units with respectiv
treatment flow capacities of 6.0 cfs, 1.6 cfs, 2.8 cfs & 11 cfs are recommended.
The Vortechnics treatment units are offline pre-cast treatment units. The 85th
percentile design flow rate is forced into the treatment area by a diversion weir built
in the upstream junction. Flows in excess of the design flow rate pass over the weir
and proceed downstream.
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CONSTRUCTION NOTES:
SITE DESIGN BMP:
MINIMIZE IMPERVIOUS FOOTPRINT
CONSERVE NATURAL AREAS
- PERMEABLE PAVEMENTS
- MINIMIZE DIRECTLY CONNECTED IMPERVIOUS AREAS
- SLOPE & CHANNEL PROTECTION / HILLSIDE LANDSCAPING
PRIVATE ROADS
SOURCE CONTROL:
- LANDSCAPING
- URBAN HOUSEKEEPING
- AUTOMOBILE USE
- INTEGRATED PEST MANAGEMENT (IMP) PRINCIPLES
- STORM WATER CONVEYANCE SYSTEMS STENCILING AND SIGNAGE
- TRASH STORAGE AREAS
EFFICIENT IRRIGATION PRACTICES
STREETSWEEPING /
/
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42-INCH RrP To RANCHO ROAD
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• c'' - 36-INCH RCP TO RANCHO SANTA FE ROAD -
- - 4 0_ ,o,tm,00u,0
-
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NN"
18-INCH RCP TO RANCHO SANTA FE ROAD
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N.. / o ft '... I - •..;./ 48-INCH RCPTO RANCHO SANTA FE ROAD --••-:.----::::\\4I.:. ::--' • -. \I -
-
LEGEND
.' -
PREPARED BY: BMP LOCATION MAP FOR SHEET
WATERSHED BOUNDARY -
HUNSAKER ASSOCIATES LA COSTA OAKS NORTH&
1
NEIGHBORHOODS 3.1 &3.3-3.5 OF
FLOWLINE _0_•00 ,
000c s C. tot - CITY OF CARLSBAD, CALIFORNIA 1
- ftWflI"Wt,flpot-0fl4 Mfl>,-OZott0tJ2
La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
1.5— Conclusion
The combination of proposed construction and permanent BMP's will reduce, to the
maximum extent practicable, the expected project pollutants and will not adversely
impact the beneficial uses of the receiving waters.
11
S
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
1.6 - References
"Standard Urban Storm Water Mitigation Plan - Storm Water Standards", City of
Carlsbad, April 2003.
"City of Carlsbad Engineering Standards"; Volume I - General Design Standards;
Chapter 5 - Drainage and Storm Drain Standards; Cityof Carlsbad,-
California; June 2004.
"Master Drainage and Storm Water Quality Management Plan", City of Carlsbad,
California; March 1994.
"Mass Graded Hydrology Study for La Costa Oaks North - Neighborhood 3.1 & 3.3
- 3.5", Hunsaker & Associates San Diego, Inc.; October 2005.
"San Diego County Hydrology Manual", County of San Diego Department of Public
Works - Flood Control Section; June 2003.
"Preliminary Hydrology for Villages of La Costa The Ridge& The Oaks", Hunsaker &
Associates, San Diego, Inc. April 25, 2001.
I "Order No. 2001-01, NPDES 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
I of San Diego County, and San Diego Unified Port District", California Regional
Water Quality Control Board - San Diego Region; February 21, 2001.
"Water Quality Plan for the San Diego Basin", California Regional Water Quality
Control Board - San Diego Region, September 8, 1994.
I. "Vortechnics Storm Water Treatment System Manual", Vortechnics; Revised May
2000.
Drawing No. 368-2. "Rancho Santa Fe Road'. Dokken Engineering. July 7, 2002.
Drawing No. 368-2B. "Rancho Santa Fe Road'. Dokken Engineering. August 27,
2003.
"Drainage Study for La Costa Oaks North - Neighborhoods 3.1, 3.3— 3.5", -Iunsaker
& Associates San Diego, Inc.; May, 2007.
I
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
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
I
.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
I . 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
I 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 La Costa Oaks North Neighborhoods 3.1 & 3.3
- 3.5 are classified as Priority Projects and are 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 Precise
Grading Plans applications, is included on the following page.
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Storm Water Standards
4/Ô3103
APPENDIX A
STORM 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 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. 0
Part A: Determine Priority Prnirt PPrmnAnf storm Wifcr RMP Rri,iirrnnfc
Does the project meet the definition of one or more of the priority project categories?* Yes No
Detached residential development of 10 or more units.
Attached residential development of 10 or more units
Commercial development greater than 100,000 square feet
Automotive repair shop ' 1
Restaurant Steep hillside development greater than 5,000 square feet
Project discharging to receiving waters within Environmentally Sensitive Areas
Parking lots greater than or equal to 5,000 fl:2 or with at least 15 parking spaces, and
potentially exposed to urban runoff S
/
- Streets, roads, highways, and freeways which would create a new paved surface that is
5,000 square feet or greater
- * 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 with utility projects are
priority projects if one or more of the criteria in Part A is met. If all answers to Part A are 'No",
continue to Part B.
30
Storm Water Standards
4/03/03
Part B: Determine Standard Permanent Storm Water Reauirmnts
Does the project propose: . Yes No
New impervious areas, such as rooftops, roads, parking lots, driveways, paths and
sidewalks?
-
New pervious landscape areas and irrigation systems? -
3.. Permanent structures within 100 feet of any natural water body?
Trash storage areas? .
Liquid or solid material loading and unloading areas?
Vehicle or equipment fueling, washing, or maintenance areas? - -
Require a General NPDES Permit for Storm Water Discharges Associated with
Industrial Activities (Except construction)?*
-
Commercial or industrial waste handling or storage, excluding typical office or
household waste?
Any grading or ground disturbance during construction? -
Any new storm drains, or alteration to existing storm drains?
*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.gov/storrnwtr/industriaLhtml
Section 2. Construction Storm Water BMP Requirements:
If the answer to question I 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 I is "No,"
but the answer to any of the remaining questions is "Yes," 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
prioritization in Part D, below.
Part C: Determine Construction Phase Storm Water Rnuirmnf
Would the project meet any of these criteria during construction? Yes No
Is the project subject to California's statewide General NPDES Permit for Storm Water T7
Discharges Associated With Construction Activities? -
Does the project propose grading or soil disturbance? - Would storm water or urban runoff have the potential to contact any portion of the
construction area, including washing and staging areas?' - -
Would the project use any construction materials that could negatively affect water
quality if discharged from the site (such as, paints, solvents, concrete, and
stucco)? 0
-
31
Storm Water Standards
4/03/03
Part D: Determine Construction Site Priority
In accordance with the Municipal Permit, 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 conditiohs . of. the project, the type of.
tr ,-rmr,jfg .+h rq,nfruir'firn 6nA n nw r,+hcr vi,,,fir,ri
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-bycase
basis. The construction priority does affect the frequency of inspections that will be
conducted by City staff. See Section lV.1 for more details on construction BMP
requirements.]
Cl' A) High Priority
Projects where the site is 50 acres or more and grading will occur during the
rainy season
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
( B) Medium Priority
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.)
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.
Permit projects on private property where grading permits are required,
however, Notice Of Intents (NOls) and SWPPPs are not required.
IJ C) Low Priority
Capital Projects where minimal to no grading occurs, such as signal light and
loop installations, street light installations, etc.
Permit projects in the public right-of-way where minimal to no grading occurs,
such as pedestrian ramps, driveway additions, small retaining walls,.etc.
Permit projects on I such as small
improvements, etc.
I
private property where grading permits are not required,
retaining walls, single-family homes, small tenant
I 32
La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
CHAPTER 3-IDENTIFICATION OF TYPICAL POLLUTANTS
3.1 - Anticipated Pollutants from Project Site
The following table details typical anticipated and potential pollutants generated by
various land use types. The La Costa Oaks North Neighborhoods 3.1, 3.3, 3.4 & 3.5
developments will consist of detached single-family residence. Thus, the Detached
Residential Development category has been highlighted to clearly illustrate which
general pollutant categories are anticipated from the project area.
General Pollutant Categories
U) Priority m ad U)
Project a Categories .2
am)C , E .
. E 2
Cl) z I 00 i-0
X 00 .- 0 M> CI 0-
UHU 1H Attached
Residential X X X pW p(2) p
Development
Commercial
Development PM p( p(2) x p(5) .. x p(3) p(5
>100,000 ft2
Automotive -
Repair X X X
Shops.
Restaurants X X . X . X
Hillside
Development X X . X X X X
>5,000 ft2
Parking Lots p( p( x x p(
Streets,
Highways & x p( x x -x p(5) x
Freeways
Retail Gas
. Outlets
X = anticipated
P = potential 0
A potential pollutant if landscaping exists on-site.
A potential pollutant if the project includes uncovered parking areas.
A potential pollutant if land use involves food or animal waste products.
Including petroleum hydrocarbons.
Including solvents.
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
I - 3.2 - Sediment
— Soils or other surface materials eroded and then transported or deposited by the
action of wind, water, ice, or gravity. Sediments can increase turbidity, clog fish gills,
reduce spawning habitat, smother bottom dwellihg organisms, and suppress aquatic
vegetative growth. . I
.,
..
3.3—Nutrients
lnbrganic substances, such as nitrogen and phosphorous,that commonly exist in the'
form of mineral salts that are either dissolved or suspended in water. Primary
sources of nutrients in urban runoff are fertilizers and eroded soils: Excessive
discharge of nutrients to water bodies and streams can cause excessive aquatic
algae and plant growth. Such excessive production., referred to as cultural
eutrophication, may lead to excessive decay of organic matter in the water body,
loss of oxygen in the water, release of toxins in sediment, and the eventual death of
aquatic organisms.
3.4 - Trash & Debris
Examples include paper, plastic, leaves, grass cuttings, and food waste, which may
I 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
I . 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
I oxygen in water to form other compounds. Compounds such as ammonia and
I hydrogen sulfide are examples of oxygen-demanding compounds. The oxygen
I demand of a substance can lead to depletion of dissolved oxygen in a water body
and possibly the development of septic conditions. -
1 3.6 - Oil & Grease - - •
•
.•
Characterized as high high-molecular weight organic compounds. Primary sources I • 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 asthe water I quality. •
I
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
3.7 - Bacteria and Viruses
Bacteria and viruses are ubiquitous micro-organisms that thrive under certain
environmental conditions. Their proliferation is typically caused by the transport of
animals or human fecal wastes from the watershed. Water, containing excessive
bacteria and viruses can alter the aquatic habitat and create a harmful environment
for humns and aquatic life. Also; the decomposition of excess organic waste
causes increased growth of undesirable organisms in the water.
3.8 Pesticides
Pesticides (including herbicides) are chemical compounds commonly used to control
nuisance growth or prevalence of organisms. Excessive application of a pesticide
may result in runoff containing toxic levels.of its active component.
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5 I Storm Water Management Plan
CHAPTER 4- CONDITIONS OF CONCERN
4.1 - Receiving Watershed Descriptions
I . As shown in the watershed map on the following page, the pre-developed and post-
developed La Costa Oaks North Neighborhoods 3.1 & 3.3 - 3.5 drain to the San ' Marcos Creek watershed.
The Regional Water Quality Control Board has identified San Marcos Creek as part
of the Carlsbad Hydrologic Unit, San Marcos Hydrologic Area, and the Batiquitos
Hydrologic Subarea (basin number 904.51).
4.2 - Pollutants of Concern in Receiving Watersheds
San Marcos Creek is listed on the EPA's 303(d) List of endangered waterways
I (included in this Chapter).. Per the "Water Quality Plan for the San Diego Basin", the
beneficial uses for San Marcos Creek include agricultural supply, contact water
recreation, non-contact recreation, warm freshwater habitat, and wildlife habitat. In
I . addition, San Marcos Creek is exempted as being designated as a Municipal water
supply.
Table 3-3 from the "Water Quality Plan for the San Diego Basin" (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 San Marcos hydrologic area.
4.3 - 303(d) Status
I
Section 303(d) of the Federal Clean Water Act (CWA) requires the State to identify
surface waters that do not meet applicable water quality standards with certain
technology-based controls. The State Water Resources Control Board has I approved the 2006 303(d) List of Water Quality Limited Segment.
San Marcos Creek (hydrologic unit 904.51) is listed on the EPA's 303(d) List of
I
endangered water bodies (included at the end of this .chapter) as being sensitive to
Bacteria, DDE (d ichiorod iphenylethylene), Phosphorus and Sediment Toxicity.
1
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
4.4 - Condition of Concern- Developed Condition Hydrology Summary
4.4.1 Neighborhood 3.1
The proposed La Costa Oaks North Neighborhood 3.1 will consist of 80 single family
residences, roads, sidewalks, curbs and gutters, associated underground utilities
and stom water drainage systems.
Runoff from the residential development will be conveyed via curb and gutter, where
curb inlets will intercept this flow and convey it to the proposed storm drain system.
This storm drain system connects to the existing 42-inch RCP storm drain,
discharging to the existing storm drain system located within the adjacent Rancho
Santa Fe Road.
Based on County of San Diego 2003 Engineering Standards criteria, a runoff
cQefficient of 0.52 was assumed for the proposed single-family residential
development.
4.4.2 Neighborhood 3.3
The proposed La Costa Oaks North Neighborhood 3.3 will consist of 120 single
I family residences, roads, sidewalks, curbs and gutters, associated underground
utilities and storm water drainage systems.
I Runoff from the northern portion of the residential development will be conveyed via
curb and gutter, where curb inlets will intercept this flow and convey it to the
proposed storm drain system. This northern storm drain system connects to the
I existing 42-inch RCP storm drain, discharging to the existing storm drain system
located within the adjacent Rancho Santa Fe Road.
I Runoff from the southern portion of the residential development will be conveyed via
curb and gutter, where curb inlets will intercept this flow and convey it to the
- proposed storm drain system. This southern storm drain system connects to the
I existing 48-inch RCP storm drain to the south of the project site, discharging to the
receiving San Marcos Creek.
I Runoff from a small portion to the south east of the La Costa Oaks North
Neighborhood 3.3 site discharges to the curb and gutter within Sitio Corazon,
draining to both the storm drain system within Avienda Soledad and San Eljo
I Roads, ultimately discharging to the existing storm drain system within the adjacent
Rancho Santa Fe Road.
I Based on County of San Diego 2003 Engineering Standards criteria, a runoff
coefficient of 0.52 was assumed for the proposed single-family residential
development.
I,
I
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
I Storm Water Management Plan
4.4.3 Neighborhood 3.4 & 3.5
- The proposed La Costa Oaks North Neighborhoods 3.4 & 3.5 will consist of 83
single family residences, roads, sidewalks, curbs and gutters, associated
I underground utilities and storm water drainage systems.
.I
Runoff from the northern Neighborhood 3.4 portion. will be conveyed via curb and
gutter, where curb inlets will intercept this flow and convey it to the proposed storm
drain system. This storm drain system connects to the existing 36-inch RCP storm
drain within San Elijo Road, discharging to the existing storm drain system located I within the adjacent Rancho Santa Fe Road.
I
Runoff from the southern Neighborhood3.5 will be conveyed via curb and gutter,
where curb inlets will intercept this flow and convey it to the proposed storm drain
system. This storm drain system connects to the existing 48-inch RCP storm drain
to the south of the project site, discharging to the receiving San Marcos Creek.
Based on County of San Diego 2003 Engineering Standards criteria, a runoff
I coefficient of 0.52 was assumed for the proposed single-family residential
development.
I Per the "Drainage Study for La Costa Oaks North Neighborhoods 3.1 & 3.3 - 3.5",
dated October 2006 by Hunsaker & Associates, peak flow data from the developed
- site is summarized in Table 3 below.
Table 3- Summary of Developed Conditions Peak Flows
Drainage 100-Year Peak
Drainage Location Neighborhoods Area Flow
(Ac) (cfs)
48-inch RCP to San Marcos
Creek
3.3 3.4 & 3.5 21.0 * 443
18-inch RCP to Rancho Santa
Fe Road 3.3 2.9 * 7.7
(Avenida_Soledad)
36-inch RCP to Rancho Santa
Fe Road 3.4 8.8 * 20.2
(San _Elijo_Road)
42-inch RCP to Rancho Santa 3.1, 3.3 & 3.4 45.8 * 8.4 Fe Road
TOTAL 78.5 170.6
*Note: Inclusive of tributary areas from 3.1 3.3, 3.4 & 3.5
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
Table 4— Summary of Pre Vs Post Developed Peak Flows
Conditions Drainage Area
(Ac)
100-Year Peak Flow
(cfs)
Existing 78.8 * 187.8
Developed 78.5 170.6
Difference -O.3 -17.2
U.,) ,'ures accountea from oan tiijO I-(oao in iviass uraaea
4.5 - Identification of Primary & Secondary Pollutants of Concern
As stated previously in segment 4., the nearest 303(d) listed endangered water body
the La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5 is tributary to is San
Marcos Creek. This water body is listed as being sensitive Bacteria, DDE
(dichiorodiphenylethylene), Phosphorus and Sediment Toxicity.
Thus, primary pollUtants of concern from the proposed single family residential
development include Bacteria, Sediments, Nutrients and Pesticides. Secondary
pollutants generated by the project site include Trash and Debris, Oxygen
Demanding Substances and Oil & Grease.
11
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- - .- ml IM
-' -
-in so : - .- M. — .-
Table 2-2. BENEFICIAL USES OF. INLAND SURFACE WATERS
1,2
Inland Surface Waters HdroloicUnit
Basin Number
BENEFICIAL USE
U
N
MA
G
R
I
N
D
R
0
C
PG
W
R
F
R
S
H
0
W
PR
E
C
1
R
E
C
2
I.
0
L
W•C
A
R
-M
0
L
D
W
I
L
D
R
A
R
E
S
P
W
N
Säñ Diego County Coastal Streams -cOntlhuêd
Buena Vista Lagoon 4.21 See Coastal Waters- Table 2-3
Buena Vista Creek 4.22 •
Buena Vista Creek 4.21 + 0 0 0 • •
Agua Hedlonda 4.31 See Coastal Waters- Table 2-3
Agua Hedionda Creek 432 •
.
Buena Creek 4:32 0 0 0 • 0 0 0
Agua Hédionda Creek 4.31 0 0 • • 0 0
Letterbox canyon 4:31 0 0 - - - - - -
Canyon de las Encinas 440 + a • e
San Marcos Creek Watershed
Batiquitos Lagoon 4.51 See Coastal Waters- Table 2-3
San Marcos Creek 4.52 + 0 0 0 *I I
0
unnamed Intermittent streams 453 + 0 • • S 5 0
San Marcos Creek Watershed
San Marcos Creek 4.51 + 0 0 S 0 5
Encinitas Creek 451 + G
= = =
G 0 0
Existing Beneficial Use 1 Waterbodies are listed multiple times If they cross hydrologic area or subarea boundaries.
O Potential Beneficial Use 2Beneficlal use designations apply to all tributaries to the indicated waterbody, if not listed separately.
+ Excepted From MUN (See Text) 0
Table 2-2 March 12, 1997
BENEFICIAL USES • 2-27
/
Table 3-2.. WATER QUALITY OBJECTIVES
Concentrations not to be exceeded more than 10% of the time during any one one year period.
Inland Surfaàe Waters Hydrologic
Unit Basin
Number
Constitiuent (mg/l, or as noted)
TDS Cl SO 4 %Na N&P Fe Mn MBAS 8 ODOR Turb
NTU
Color
Units F
SAN LUIS REV HYDROLOGIC UNIT 903.00
Lower San Luis HA 3.10 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0
Monsarat HA 3.20 500 250 250 60 a 0.3 0.05 0.6 0.75 none 20 20 1.0
Warner Valley . HA 3.30 500 250 250 60 a 0.3 0.06 0.5 0.75 none 20 20 1.0
CARLSBAD HYDROLOGIC UNIT 904.00
Loma Alta HA 4.10 - - - - - - - - none 20 20 1.0
Buena Vista Creek HA 4.20 500 250 250 80 a 0.3 0.05 0.5 0.75 none 20 20 1.0
Ague Hedionda HA 4.30 509 250 250 CO a 0.3 0.05 0.5 0.75 none 20 20 '1.0
Encinas HA 4.40 - - - - - - - - - none 20 20 1.0
San Marcos HA 1 4.561 500 2501 250 60 a 0.3 10.051 0.5 - 10.751 none 1 20 1 20 1.0
Escondido Creek HA .4.60. 500 12501 250 1 80 a 0.3 10.051 0.5 10.751 none 1 20 1 20 1 1.0
SAN DIEGUITO HYDROLOGIC UNIT 905.00 .
Solana Beach HA 5.10 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0
Hodges HA 5.20 600 260 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0
San Pasqual HA 5.30 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 •, 1.0
Santa Maria Valley HA 5.40 500 260 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0
Santa Ysabet HA : 5.50 500 250 250 60 1 a 1 0.3 10.051 0.5 10.751 lone 1 20 1 20 1.0
PENASQUITOS HYDROLOGIC UNIT 906.00
Miramar Reservoir HA 1 6.101 500 12601 260 160 1 a J 0.3 10.051 0.5 10.751 none J 20 J 20 j 1.0
j Poway . HA . I 6.201 500 12501 250! 60J
.
a 1 0.3 10.051 0.5 10.751 none 1201 20 11.0 II
HA - Hydrologic Area .
.
HSA - Hydrologic Sub Area (Lower ceso letters indicate endnotoa following the table.)
Table 3-2
WATER QUALITY OBJECTIVES .
Page 3-23 . September 8, 1994
Thh 9 RFRFFlflAl IISF OF cnASTAL WATERS
Coastal Waters Hydrologic
Unit Basin
Number
BENEFICIAL USE
I
N
N
A
D
R
E
cc
1
R
E
2
C
.0
MO
ML
B
I
E
S
T
W
I
L
D
R
A
R
E
M
A
R
A
Q
AR
M
I
G
S
- P
NM
W
A
R
S
H
E
L
L
Pacific Ocean 0 0 0 61 0 0 0 0 0 0 a 0
Dana Point Harbor . 0 0. 0 0 0 0 0 0 I) 0 0
Del Mar Boat Basin 0 0 0 0 0 0 0 0 ) 0 0
Mission Bay 0 0 0 0 0 0 0 0 ) •
Oceanside Harbor
San Diego Bay 1 0 0 0 0 0 0 0 Q 0-T-74) 0 0
Coastal Lagoons .
Tijuana River Estuary 11.11 0 0 0 0
Mouth of San Diego River 7.11
Los Penasquitos Lagoon 2 6.10 0 0 0 0 0 0 0 43, 0 0
San Dieguito Lagoon 5.11 0 .0 0 0 0 0 0 0' 0
Batiquitos.Lagoon 4.51 0 0 0 0 0 0 0 0 0
San Elijo Lagoon 5.81 0 0 0 0 0 0 0 0 0
Aqua Hedionda Lagoon "4.31 3
1 Includes the tidal prisms of the Otay and Sweetwater Rivers.
2 Fishing from shore or boat permitted,-but other water contact recreational (nEC-1) uses are prohibited.
0 Existing Beneficial Use
Table 2-3
BENEFICIAL USES - 2-47
March 12, 1997
- - - - - - - - - - - - - - - - - - - PROPOSED 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS
SAN DIEGO REGIONAL BOARD
SWRCB DRAFT 303(d) LIST RELEASE DATE: SEPTEMBER 15, 2006
CALWATER POTENTIAL ESTIMATED PROPOSED TMDL
REGION TYPE NAME . : WATERSHED POLLUTANT/STRESSOR SOURCES . SIZE AFFECTED COMPLETION
9 C Pacific Ocean Shoreline, San Joaquin Hills 90111000
lISA
Indicator bacteria 0.63 Miles 2005
Impairment located at Cameo Cove at Irvine Cove Dr/Riviera Way, Heisler Park-North
Urban Runoff/Storm Sewers
Unknown Nonpoint Source
....................
..- ...
Unknown point source
- . . . .... : .
9
........ . . ...
C Pacific Ocean Shoreline, San Luis Rey HU 90311000
.
Indicator bacteria 0.49 Miles 2005
Impairment located at San Luis Rey River Mouth.
Nonpoint/Point Source
.•: ...........-...., .. . .. . . . . .. . .
9 C Pacific Ocean Shoreline, San Marcos HA 90451000
Indicator bacteria 0.5 Miles 2005
Impairment located at Moonlight State Beach.
Nonpoint/Point Source
's:'.-,'...................... ... •.... 0 . . .
9 C Pacific Ocean Shoreline, Scripps HA 90630000
Indicator bacteria 3.9 Miles 2019
This listing for indicator bacteria onliy applies to the Childrens Pool Beach area of this ocean shoreline segment.
Nonpoint/Point Source
9 C Pacific Ocean Shoreline, Tijuana HU 91111000
Indicator bacteria 3 Miles 2010
Impairment locatedfrom the border, extending north along the shore.
Nonpoint/Point Source
9 R Pine Valley Creek (Upper) 91141000
Enterococcus 2.9 Miles 2010
Grazing-Related Sources
Concentrated Animal Feeding Operations
(permitted, point source)
Transient encampments
Phosphorus 2.9 Miles 2019
Source Unknown
Printout: 9/13/2006 Page 150129
- - - - - - - - - - - - - - - - - - - PROPOSED 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS
SAN DIEGO REGIONAL BOARD
SWRCB DRAFT 303(d) LIST RELEASE DATE: SEPTEMBER 15, 2006
CAL WATER POTENTIAL ESTIMATED PROPOSED TMDL
REGION TYPE,.,.NAME WATERSHED POLLUTANT/STRESSOR SOURCES SIZE AFFECTED COMPLETION
9 R San Juan Creek 90120000
DDE 1 Miles 2019
Source Unknown
Indicator bacteria 1 Miles 2005
Nonpoint/Point Source
9 E San Juan Creek (mouth) 90120000
Indicator bacteria . 6.3 Acres 2008
Nonpoint/Point Source
9 R San Luis Rey River 90311000
Chloride 19 Miles 2019
Impairment located at lower 13 miles.
Urban Runoff/Storm Sewers
Unknown Nonpoint Source
Unknown point source
Total Dissolved Solids 19 Miles 2019
Industrial Point Sources
Agriculture-storm runoff
Urban Runoff/Storm Sewers
Surface Mining
Flow Regulation/Modification
Natural Sources
Golf course activities
Unknown Nonpoint Source
Unknown point source
9 R San Marcos Creek 90451000
DDE 19 Miles 2019
Source Unknown
Phosphorus 19 Miles 2019
Source Unknown
Printout: 9/13/2006 Page 220129
- - - - - - - - - - - - - - - - - - - PROPOSED 2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS
SAN DIEGO REGIONAL BOARD
SWRCB DRAFT 303(d) LIST RELEASE DATE: SEPTEMBER 15. 20(16
CALWATER POTENTIAL ESTIMATED PROPOSED TMDL
REGION TYPE .. NAME . . . WATERSHED POLLUTANT/STRESSOR SOURCES . SIZE AFFECTED COMPLETION
Sediment Toxicity
Source Unknown
... .
9 L San Marcos Lake 90452000
Ammonia as Nitrogen
Source Unknown
Nutrients
Source Unknown
Phosphorus
Source Unknown
9 L San Vicente Reservoir 90721000
Chloride
Source Unknown
Color
Source Unknown
Manganese
Source Unknown
pH (high)
Source Unknown
Sulfates
Source Unknown
Total Dissolved Solids
Source Unknown
9 R Sandia Creek 90222000
Iron
Source Unknown
Printout: 9/1312006 Page 23 of 29
19 Miles 2019
17 Acres 2019
17 Acres 2019
17 Acres 2019
1058 Acres 2019
1058 Acres 2019
1058 Acres 2019
1058 Acres 2019
1058 Acres 2019
1058 Acres 2019
1.5 Miles 2019
I
I La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
CHAPTER 5- TREATMENT CONTROL BMP DESIGN
5.1 - BNIP Locations
I Four (4) Best Management Practice (BMP) treatment units will treat 85th percentile
rufloff prior to discharging from the La Costa Oaks North - Neighborhoods 3.1 & 3.3
I - 3:5.
I
. The map on the following page shows the location of the proposed BMPs.
5.2 - Determination of Treatment Flows
1 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 I 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 (0) = C * I * A
Runoff Coefficient (C) - In accordance with the County of San Diego standards, the
weighted runoff coefficient for all the areas draining to the treatment unit was
I determined using the areas analyzed in the final engineering hydrology report. The
runoff coefficient is based on the following characteristics of the watershed:
I - Land Use - Single Family Residential in Developed Areas
- Soil Type - Hydrologic soil group D was assumed for all areas. Group
I 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
I . the surface, and shallow soils over nearly impervious materials, Group
D soils have a very slOw rate of water transmission.
I . 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.
I Watershed Area (A) - Corresponds to total area draining to treatment unit.
I DG:djg h:'Jeports\2352151 oaks north rough 3.1, 3.3, 3.46 3.5/ilnal 5wm9-03.doc
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CONSRUCTION NOTES:
SITE DESIGN BMP:
- MINIMIZE IMPERVIOUS FOOTPRINT
- CONSERVE NATURAL AREAS
- PERMEABLE PAVEMENTS
- MINIMIZE DIRECTLY CONNECTED IMPERVIOUS AREAS
- SLOPE & CHANNEL PROTECTION / HILLSIDE LANDSCAPING
PRIVATE ROADS
SOURCE CONTROL:
LANDSCAPING
URBAN HOUSEKEEPING
- AUTOMOBILE USE
INTEGRATED PEST MANAGEMENT (IMP) PRINCIPLES
- STORM WATER CONVEYANCE SYSTEMS STENCILING AND SIGNAGE
- TRASH STORAGE AREAS *
- EFFICIENT IRRIGATION PRACTICES
- STBEETSWEEPING
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PREPARED BY: BMP LOCATION MAP FOR SHEET
II
HUNSAKER
& ASSOCIATES - LA COSTA OAKS NORTH 1
NEIGHBORHOODS 3.1 & 33 -35 OF
CITY OF CARLSBAD CALIFORNIA
La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
Table 5 below summarizes rational method 85th percentile calculations for the
proposed water quality treatment unit for the La Costa Oaks North Neighborhood 3.1
& 3.3 - 3.5 developments. The runoff coefficient used for sizing the proposed
treatment units is of 0.52, which was based on 283 dwelling units per 78.5 acres.
Table 5 - Developed Conditions 85th Percentile Calculations
Treatment Drainage Rainfall 8th
Unit Neighborhoods Area Intensity Runoff Percentile
Location (acres) (inches/hour) Coefficient
Flow (cfs)
48-inch
RCP to
San 3.3, 3.4 & 3.5 21.0* 0.2 0.52 2.2
Marcos'
Creek
18-inch
RCP to
Rancho 3.3 2.9* 0.2 0.52 0.3
Santa Fe
Road
36-inch
RCP to
Rancho 3.4 8.8* 0.2 0.52 0.9
Santa Fe
Road
42-inch
RCP to
Rancho 3.1, 3.3 & 3.4 45.8* 0.2 0.52 4.8
Santa Fe
Road
*inclusive of portions of Neighborhoods 3.1, 3.4 & 3.5
Rational Method calculations predicted 85th percentile runoff flows of approximately
2. 2 cfs, 0.3 cfs, 0.9 cfs and 4.8 cfs at the respective four (4) flow based treatment
units.
5.3 - BMP Unit Sizing
The Vortechs unit is an offline precast treatment unit. The 85th percentile dsign
flow rate will be forced into the treatment area by a diversion weir built in the
upstream junction. Flows in excess of the design flow rate pass over the weir and
proceed downstream. The calculations determining the peak flows being forced into
the treatment during a 100-year storm event will govern the sizing requirements
necessary to adequately treat the entire flow passing through the unit during this
significant rainfall event. '
DG:djg h:Veports2352\151 oaks north rough 3.1. 3.3. 3.4 & 3.5'ilnal swmp-03.doc
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
VORTECHS UNIT TREATMENT CAPACITY TABLE
85th Pct. Recommended Treatment Capacity Treatment Unit Design Flow Vortechs (cfs) (cfs) Model
48-inch RCP to San
Marcos Creek 2.2 4000 6.0
18-inch RCP to
Rancho Santa Fe 0.3 1000 1.6
Road
36-inch RCP to
Rancho Santa Fe 0.9 . 2000 2.8
Road
42-inch RCP to
Rancho Santa Fe 4.8 7000 11
Road
5.4 -Vortechs Treatment Units
The Vortechs Storm Water Treatment System is designed to efficiently remove grit,
contaminated sediments, metals, hydrocarbons and floating contaminants from
surface runoff. Combining swirl-concentrator and flow-control technologiesto
eliminate turbulence within the system, the Vortechs System ensures the effective
capture of sediment and oils and prevents resuspension of trapped pollutants for
flows up to 25 cfs.
Other features of the Vortechs Systems include the following:
- Large capacity system provides an 80 percent net annual Total
Suspended Solids (TSS) removal rate.
- Unit is installed below grade.
- •Low pump-out volume and one-point access reduce maintenance costs.
- Design prevents oils and other floatables from escaping the system
during cleanout.
- Enhanced removal efficiencies of nutrients and heavy metals with offline
configuration.
The tangential inlet to the system creates a swirling motion that directs settleable
solids into a pile towards the center of the grit chamber. Sediment is caught in the
swirling flow path and settles back onto the pile after the storm event is over.
Floatable entrapment is achieved by sizing the low flow control to create a rise in the
water level of the vault that is sufficient to just submerge the inlet pipe with the 85th
percentile flow.
DG:djg h:'mports\2352\151 02k5 north rough 3.1, 3.3, 3.4 & 3.5tlrtrat swmp-03.doc
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La Costa Oaks North - Neighborhoods 3.1, 33, 3.4 & 3.5
I Storm Water Management Plan
5.5 - Pollutant Removal Efficiency Table
Pollutant of Concern BMP Categories
Hydrodynamic Vditechs
Separation 'Storñiwa
atméitter• Devices 2 . Tr Sy't':rii -
Sediment M-H . = Nutrients L-M
Heavy Metals L-M LM
Organic Compounds L-M .. "l-'M T . Trash & Debris M-H H - Oxygen Demanding Substances L I:
Bacteria L
Oil & Grease L-H
Pesticides L L
The County will periodically assess the performance characteristics of these BMPs to
update this table.
Proprietary Structural 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).
DG:djg h:Veports2352\151 oaks north rough 3.1, 3.3, 3.4 & 3.511001 swmp-03.doc
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
5.6 - BMP Unit Selection Discussion
5.6.1 Extended Detention Basins
I Extended detention basins collect the first flush runoff volume and retain it in the
basin for. a period, of 24-48 hours.
I 8S' percentile runoff volume, contained below the overflow elevation of the basin
riser, will be slowly discharged from the treatment control basin via low flow orifices
in the basin riser. After passing through the riser, an outlet pipe will dewater the I basin and discharge runoff to the natural drainage course downstream.
I Advantages
Due to the simplicity of design, extended detention basins are relatively
easy and inexpensive to construct and operate.
Extended detentions basins can provide substantial capture of.
sediment and the toxics fraction associated with particulates.
I .
•. Widespread application with sufficient capture volume can provide
significant control of channel erosion and enlargement caused by
changes to flow frequency relationships resulting from the increase of
impervious cover in the watershed.
Limitations
U . • Limitation of the diameter of the orifice may not allow use of extended
detention in watersheds of less than 5 acres (would require an orifice
I with a diameter of less than 0.5 inches that would be prone to
clogging).
Dry extended detention ponds have only moderate pollutant removal
I when compared to some other structural stormwater practices, and
they are relatively ineffective at removing soluble pollutants.
Dry ponds can detract from the value of a home due to the adverse
I ' aesthetics of dry, bare areas and inlet and outlet structures.
Conclusion:
Due to the minimal footprint area available for the BMP treatment units and multiple
points of outlet, construction of extended detention basins is not a feasible option for
the La Costa Oaks North - Neighborhoods 3.1 & 3.3 - 3.5 project site.
11
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
5.6.2 Vegetated Swale
Vegetated swales are open, shallow channels with vegetation covering the side
slopes and bottom that collect and slowly convey runoff through filtering by the
vegetation in the channel, filtering througha 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
velocity of stormwater runoff. Vegetated swales can serve as part of a stormwater
drainage system and can replace curbs, gutters and stormwater systems.
Advantages
If properly designed, vegetated, and operated, swales can serve as an
aesthetic, potentially inexpensive urban development or roadway
drainage conveyance measure with significant collateral water quality
benefits.
Limitations
Can be difficult to avoid channelization.
May not be appropriate for industrial sites or locations where spills may
occur.
Grassed swales cannot treat a very large drainage area. Large areas
may be divided and treated using multiple swales.
A thick vegetative cover is needed for these practices to function
properly.
They are impractical in areas with steep topography.
They are not effective and may even erode when flow velocities are
high, if the grass cover is not properly maintained.
In some places, their use is restricted, by law: many local municipalities
require curb and gutter systems in residential areas.
Swales are more susceptible to failure if not properly maintained than
other treatment BMPs.
Conclusion:
Proposed swales to line the sides of the proposed private roads has potential to
undermine the serviceability of the adjacent roads and sidewalks. Also, due to the
limited footprint available and multiple points of discharge withinthe projectsite for
BMP treatment, master treatment swales are not a feasible treatment option.
DG:djg h:l.rEports\2352151 oaks north rough 3.1. 3.3. 3.4 & 3.5l1Ial swmp-03.doc
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
5.6.3 Infiltration Basins
An infiltration basin is a shallow impoundment that is designed to infiltrate
stormwater. Infiltration basins use the natural filtering ability of the soil to remove
pollutants in stormwater runoff. Infiltration facilities store runoff until it gradually
exfiltrates through the soil and eventually into the water table. This practice has high
pollutant removal efficiency and can also help recharge groundwater, thus helping to
maintain low flows in stream systems. Infiltration basins can be challenging to apply
on many sites, however, because of soils requirements. In addition, some studies
have shown relatively high failure rates compared with other management practices.
Advantages
Provides 100% reduction in the load discharged to surface waters.
The principle benefit of infiltration basins is the approximation of pie-
development hydrology during which a significant portion of the
average rainfall runoff is infiltrated and evaporated rather than flushed
directly to creeks.
If the water quality volume is adequately sized, infiltration basins can
be useful for providing control of channel forming (erosion) and high
frequency (generally less than the 2-year) flood events.
Limitations
I . May not be appropriate for industrial sites or locations where spills may
occur.
Infiltration basins require a minimum soil infiltration rate of 0.5
I inches/hour, not appropriate at sites with Hydrologic Soil Types C and
D.
Infiltration rates exceeding 2.4 inches/hour, the runoff should be
I treated prior to infiltration to protect groundwater quality.
Not suitable on fill sites or steep slopes.
I . Risk of groundwater contamination in very coarse soils.
Upstream drainage area must be completely stabilized before
construction.
I .
• Difficult to restore functioning of infiltration basins once clogged.
Conclusion:
1 . Due to the minimum footprint available within the project site, a filtration basin is not
a viable alternative for the La Costa Oaks North - Neighborhoods 3.1 & 3.3 - 3.5
i developments'.
I DG:dJg h:'tepoits23S2\l5l oaks north rough 3.1,3.3.3.46 3.5/Anal swmp.03.doc
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
5.6.4 Wet Ponds
- Wet ponds are constructed basins that have a permanent pool of water throughout
the year (or at least throughout the wet season) and differ from constructed wetlands I primarily in having a greater average depth. Ponds treat incoming stormwater runoff
by settling and biological uptake. The primary removal mechanism is settling as
stormwater runoff resides in this pool, but pollutant uptake, particularly of nutrients,
also occurs to some degree through biological activity in the pond. Wet ponds are
among the most widely used stormwater practices. While there are several different
I versions of the wet pond design, the most common modification is the extended
detention wet pond, where storage is provided above the permanent pool in order to
detain stormwater runoff and promote settling.
Advantages
.
If properly designed, constructed and maintained, wet basins can
provide substantial aesthetic/recreational value and wildlife and
wetland habitat.
.
Ponds are often viewed as a public amenity when integrated with a
park setting.
Due to the presence of the permanent wet pool, properly designed and
maintained wet basins can provide significant water quality
improvements across a relatively broad spectrum of constituents
including dissolved nutrients.
Widespread application with sufficient capture volume can provide
significant control of channel erosion and enlargement caused by
changes to flow frequency relationships resulting from the increase of
impervious cover in a watershed.
Limitations
Some concern about safety when constructed where there is public
access.
Mosquito and midge breeding is likely to occur in ponds.
Cannot be placed on steep unstable slopes.
Need for base flow or supplemental water if water level is to be
maintained.
Require a relatively large footprint..
Depending on volume and depth, pond designs may require approval
from the State Division of Safety of Dams.
I Conclusion:
Due to the large acreage requirements of a wet pond, proximity to residences
I .(vector issues) and the fact that other BMP's are able to treat pollutants of concern
with equal efficiency, wet ponds are not a feasible option for the La Costa Oaks
North - Neighborhoods 3.1 & 3.3 - 3.5 project site.
OG:djg h:\seports'23521151 oaks flaSh rough 3.1, 3.3, 3.4 & 3.5lilnal swmp.03.doc
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
5.6.5 Media Filters
Stormwater media filters are usually two-chambered including a pre-treatment
settling basin and a filter bed filled with sand or other absorptive filtering media. As
stormwater flows into the first chamber, large particles settle out, and then finer
particles and other pollutants are removed as stormwater flows through the filtering
media in the second chamber.
Advantages
o Relatively high pollutant removal, especially for sediment and
associated pollutants.
Widespread application with sufficient capture volume can provide
significant control of channel erosion and enlargement caused by
changes to flow frequency relationships resulting from the increase of
impervious cover in a watershed.
Limitations
More expensive to construct than many other BMP's.
May require more maintenance than some other BMP's depending.
upon the sizing of the filter bed.
.. Generally require more hydraulic head to operate properly (min 4 feet).
High solids loads will cause the filter to clog.
Work best for relatively small, impervious watersheds.
Filters in residential areas can present aesthetic and safety problems if
constructed with vertical concrete walls.
Certain designs maintain permanent sources of standing water where
mosquito's and midge breeding is likely to occur.
Conclusion:
.I
Due to the minimal foot print area available and its maintenance frequency, media
filters are not a feasible option to treat all developed flows for the La Costa Oaks
North - Neighborhoods 3.1 & 3.3 - 3.5 project site.
I
I . .
I .
DG:djg h:'Ieports2352\151 oaks north rough 3.1. 3.3, 3.4 & 3.55/na) swmp.03.doc
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5 I' Storm Water Management Plan
5.6.6 Drainage Inserts
, Drainage inserts are manufactured filters or fabric placed in a drop inlet to remove
sediment and debris. There are a multitude of inserts of various shapes and
configurations, typically falling to one of three different groups: socks, boxes and
trays. The sock consists of a fabric, usually constructed of polypropylene. The
I fabric may be attached to a frame or the grate of the inlet holds the sock. Socks are
meant for vertical (drop) inlets. Boxes are constructed of plastic or wire mesh.
Typically a polypropylene 'bag" is placed in the wire mesh box. . The bag takes form
I of the box. Most box products are one box; that is, the setting area and filtration
through media occur in the same box. Some products consist of one or more trays
and mesh grates. The trays may hold different types of media. Filtration media vary
by manufacturer. Types include polypropylene, porous polymer, treated cellulose I and activated carbon.
Advantages
Does not require additional space as inserts as the drain inserts are
already a component of the standard drainage systems.
Easy access for inspection and maintenance.
As there is no standing water, there is little concernfor mosquito
breeding.
A relatively inexpensive retrofit option.
Limitations
Performance is likely significantly less than treatment systems that are
located at the end of the drainage system such as ponds and vaults..
Usually not suited for large areas or areas with trash or leaves that can
plug the insert.
Conclusion: -
1 Due to site design constraints and poor levels of treatment effectiveness, curb inlet
filters were deemed to be the less applicable BMP treatment option for the La Costa
Oaks North - Neighborhoods 3.1 & 3.3 - 3.5 developments.
I
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5 I Storm Water Management Plan
I
5.6.7 Hydrodynamic Separator Systems
Hydrodynamic separators are flow-through structures with a settling or separation
I
unit to remove sediments and other pollutants that are widely used in storm water
treatment. No outside power source is required, because the energy of the flowing
water allows the sediments to efficiently separate. Depending on the type of unit,
I
this separation may be by means of swirl action or indirect filtration. Variations of
this unit have been designed to meet specific needs. Hydrodynamic separators are
most effective where the materials to be removed from runoff are heavy particulates
I
- which can be settled - or floatables -which can be captured, rather than solids with
poor settleability or dissolved pollutants. In addition to the standard units, some
vendors offer supplemental features to reduce the velocity of the flow entering the
I . system. This increases the efficiency of the unit by allowing more sediments to
settle out.
I,
Advantages
.• May provide the desired performance in less space and therefore less
I cost.
. May be more cost-effective pre-treatment devices than traditional wet
or dry basins.
I ..
. Mosquito control may be less of an issue than with traditional wet
basins.
Limitations
As some of the systems have standing water that remains between
I storms, there is concern about mosquito breeding.
It is likely that vortex separators are not as effective as wet vaults at
removing fine sediments, on the order 50 to 100 microns in diameter
.I - and less.
The area served is limited by the capacity of the largest models.
As the products come in standard sizes, the facilities will be oversized
I
in many cases relative to the design treatment storm, increasing cost.
The non-steady flows of stormwater decreases the efficiency of vortex
separators from what may be estimated or determined from testing
I, under constant flow.
Do not remove dissolved pollutants.
A loss of dissolved pollutants may occur as accumulated organic
1 matter (e.g., leaves) decomposes in the units.
Conclusion
When compared to other BMP treatment options, Hydro-dynamic separator units
provided a good overall treatment solution due to limited foot print constraints, vector
control, maintenance and treatment effectiveness criteria for the pollutants of
concern generated by the La Costa Oaks North - Neighborhoods 3.1 & 3.3, 3.4 - 3.5
project site.
OG:djg
h:'seports23521 51 oaks north rough 3.1, 3.3, 3.4 & 3.5'ilnul swrnp.03.doc
w.o.2352.151 5(1/2007 9:42 AM
85TH PERCENTILE PEAK FLOW AND VOLUME DETERMINATION
Modified Rational Method - Effective for Watersheds < 1.0 mi2
Hunsaker & Associates - San Diego
Note: Only Enter Values in Boxes - Spreadsheet Will Calculate Remaining Values
Project Name La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5 I
Work Order 2352-151
Jurisdiction lCity of Carlsbad
BMP Location IVortechs Unit - Neighborhood 3.1 (42-inch RCP to Rancho Santa Fe Road
Developed Drainage Area =
F=o-Tlacres
acres
Natural Drainage Area
Total Drainage Area to BMP = 45.8 acres
Dev. Area Runoff Coefficient
Nat. Area Runoff Coefficient =
Runoff Coefficient = 0.52
RATIONAL METHOD RESULTS •
Q = CIA where Q = 85th Percentile Peak Flow (cfs)
C = Runoff Coefficient
I = Rainfall Intensity (0.2 inch/hour per RWQCB mandate)
A = Drainage Area (acres)
Using the Total Drainage Area:
C= 0.52
0.2 inch/hour
A = 45.8 acres
Q = 4.76 cfs
11
H:\EXCEL\2352\15185th.xIsN. 3.1 9/27/2006
85TH PERCENTILE PEAK FLOW AND VOLUME DETERMINATION
Modified Rational Method.- Effective for Watersheds < 1.0 mi2
Hunsaker & Associates - San Diego
Note: Only Enter Values in Boxes - Spreadsheet Will Calculate Remaining Values
Project Name La Costa. Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Work Order 2352-151 I . . .
Jurisdiction City of Carlsbad
BMP Location IVortechs Unit - Neighborhood 3.3 (48-inch RCP to San Marcos Creek) I
Developed Drainage Area . 21.0 acres
Natural Drainage Area = 0.0 acres
Total Drainage Area to BMP = 21.0 acres
Dev. Area Runoff Coefficient = 0.52
Nat. Area Runoff Coefficient =
Runoff Coefficient = . 0.52
RATIONAL METHOD RESULTS
Q = CIA where Q = 85th Percentile Peak Flow (cfs)
C = Runoff Coefficient
= Rainfall Intensity (0.2 inch/hour per RWQCB mandate)
A = Drainage Area (acres)
Using the Total Drainage Area: .
C= 0.52
= 0.2 inch/hour
A= 21.0 acres
Q 2.18 cfs
H:\EXCEL'.2352\151\85th.xlsN. 3.3 - A . 9/27/2006
85TH PERCENTILE PEAK FLOW AND VOLUME DETERMINATION
Modified Rational Method - Effective for Watersheds <1.0 mi2
Hunsaker & Associates - San Diego
Note: Only Enter Values in Boxes - Spreadsheet Will Calculate Remaining Values,
Project Name La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Work Order 2352-151
Jurisdiction City of Carlsbad I
BMP Location Ivortechs Unit- Neighborhood 3.3 (18-inch RCP to Rancho Santa Fe Road) I
Developed Drainage Area 2.9 acres
Natural Drainage Area =' 0.0 acres
Total Drainage Area to BMP = 2.9 acres
Dev. Area Runoff Coefficient = 0.52
Nat. Area Runoff Coefficient =
Runoff Coefficient = 0.52
RATIONAL METHOD RESULTS
Q = CIA where Q = 85th Percentile' Peak Flow (cfs)
C = Runoff Coefficient
I = Rainfall Intensity (0.2 inch/hour per RWQCB mandate)
A = Drainage Area (acres)
Using the Total Drainage Area:
C= 0.52
I = 0.2 inch/hour
A = 2.9 acres
Q 0.30 cfs
H:\EXCEL2352\151\85th.xlsN. 3.3 - B 9/27/2006
85TH PERCENTILE PEAK FLOW AND VOLUME DETERMINATION
Modified Rational Method - Effective for Watersheds < 1.0 mi2
Hunsaker & Associates - San Diego
Note: Only Enter Values in Boxes - Spreadsheet Will Calculate Remaining Values
Project Name La Costa Oaks North Neighborhoods 3.1, 3.3, 3.4 & 3.05
Work Order. 2352-151 .
Jurisdiction City of Carlsbad
BMP Location Ivortechs Unit - Neighborhood 3.3 (36-inch RCP to Rancho Santa Fe Road) I
Developed Drainage Area 8.8 acres
Natural Drainage Area = . 0.0 dacres
Total Drainage Area to BMP = 8.8 acres
Dev. Area Runoff Coefficient = 0.52
Nat. Area Runoff Coefficient =
Runoff Coefficient = 0.52
RATIONAL METHOD RESULTS
Q = CIA where Q = 85th Percentile Peak Flow (cfs)
C = Runoff Coefficient
.1 = Rainfall Intensity (0.2 inch/hour per RWQCB mandate)
A = Drainage Area (acres)
Using the Total Drainage Area:.
0
C= 0.52
= 0.2 inch/hour
A = 8.8 acres
Q= 0.92cfs 0
H:\EXCEL\2352\151\85th.xlsN. 3.3-C 9/27/2006
85TH PERCENTILE PEAK FLOW AND VOLUME DETERMINATION
Modified Rational Method - Effective for Watersheds < 1.0 mi2
Hunsaker & Associates - San Diego -
Note: Only Enter Values in Boxes - Spreadsheet Will Calculate Remaining Values
Project Name La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5 I
Work Order 2352-151 ."
Jurisdiction City of Carlsbad
BMP Location IVoeChs Unit - Neighborhood 3.3 (42-inch RCP to Rancho Santa Fe Road) I
Developed Drainage Area
F
= 45.8 acres
Natural Drainage Area = 0.0 acres
Total Drainage Area to BMP = '45.8 acres
Dev. Area Runoff Coefficient
Nat. Area Runoff Coefficient =
Runoff Coefficient = 0.52
RATIONAL METHOD RESULTS
Q = CIA where Q = 85th Percentile Peak Flow (cfs)
C = Runoff Coefficient
I = , Rainfall Intensity (0.2 inch/hour per RWQCB mandate)
A = Drainage Area (acres)
Using the Total Drainage Area:
C= . 0.52 ,
I = 0.2 inch/hour
A = 45.8 acres
Q= ' 4.76cfs
LI
H:\EXCEL\2352\151\85th.xlsN. 3.3 - D . . 9/27/2006
85TH PERCENTILE PEAK FLOW AND VOLUME DETERMINATION
Modified Rational Method - Effective for Watersheds < 1.0 mi2
Hunsaker & Associates - San Diego
Note: Only Enter Values in Boxes - Spreadsheet Will Calculate Remaining Values
Project Name ILa Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4-&--3.5
Work Order J2352-151 1
Jurisdiction ICity of Carlsbad
BMP Location IVortechs Unit - Neighborhood 3.4 & 3.5 (48-inch RCP to San Marcos Creek) I
Developed Drainage Area = 21.0 acres
Natural Drainage Area = 0.0 acres
Total Drainage Area to BMP = 21.0 acres
Dev. Area Runoff Coefficient
Nat. Area Runoff Coefficient =
Runoff Coefficient = 0.52
RATIONAL METHOD RESULTS
Q = CIA where Q = 85th Percentile Peak Flow (cfs)
C = Runoff Coefficient
= Rainfall Intensity (0.2 inch/hour per RWQCB mandate)
A = Drainage Area (acres)
Using the Total Drainage Area:
0.52
0.2 inch/hour
A= 21.0 acres
Q= 2.18 cfs
I'
H:\EXCEL\2352\151\85th.xlsN. 3.4 & 3.5 - A 9/27/2006
85TH PERCENTILE PEAK FLOW AND VOLUME DETERMINATION
Modified Rational Method - Effective for Watersheds <1.0 mi2
Hunsaker & Associates - San Diego
Note: Only Enter Values in Boxes - Spreadsheet Will Calculate Remaining Values
Project Name La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Work Order 2352-151
Jurisdiction City of Carlsbad -
BMP Location Ivortechs Unit - Neighborhood 3.4 & 3.5 (36-inch RCP to Rancho Santa Fe Road) I
Developed Drainage Area = 8.8 acres
Natural Drainage Area = 0.0 acres 0
Total Drainage Area to BMP = 8.8 acres
Dev. Area Runoff Coefficient
Nat. Area Runoff Coefficient
Runoff Coefficient = 0.52
RATIONAL METHOD RESULTS
0 = CIA where Q = 85th Percentile Peak Flow (cfs)
C = Runoff Coefficient
= Rainfall Intensity (0.2 inch/hour per RWQCB mandate)
A = Drainage Area (acres)
Using the Total Drainage Area:
0.52
= 0.2 inch/hour
0 A= 8.8 acres
Q= 0.92 cfs
H:\EXCEL\2352\151\85thxIsN. 3.4 & 3.5- B 9/27/2006
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I ' Ii D Plus 6' Typical
I Plan View
To begin the design of your
Vortechs System, refer to the
I sizing chart below and com-
plete a Specifier's Worksheet to
provide details about your site I :-- and design flows. Then simply
fax or mail the worksheet to
I Vortechnics with your site plan,,
and we'll produce detailed
I Vortechs System scale draw-
ings free of charge.
I
Elevation View
dime ,-
PPF
Urchs Cbamh g AM Ar, ROOM '-
:::oJ..Oi5Tiefl 5rs9yOil4rnea55UmS.a s tost sump .-.. :'
C) ConsO'ucton details may vary depending an the speaflc epplicaoon Any altcraoons to the szng chart specifi-
-, tabons wifl app ar on Vartochnics dirn,nsionel and ahop drawings Please call Vortechnics for the weight of pa-
ciflo
Vartschs systems it needed
Special Note Cli storage capac.ty when it is needed to meet a specific requirement for spill containment, can- be sized to m et the storage requrement uith the selected model Vortechnics technical staff will opumize system geomeu'y to meet containment requirern_nrs within a correctly sized Vcrtech Sysm -
Chafe available, bydalm,g h,idst(2O7j 87562 - -:-- -
Vortechs System Inlet/Outlet Configurations
Vortechs Systems can be configured to accommo-
date various inlet and outlet pipe orientations.
The inlet pipe can enter the end or side of the
,
End Inlet
- - r Side Inlet
tank at right angles - outlet pipes can exit the end -
Po
TO
lish or the side of system at most angles. I7 I (
I
r6
Pretreatment O
TO
utfall
U __—i .. Th .rhngrnpncreatecIby.the
— I - ngentia1 inlet diätsseeab!i
U r -110ion, Pe
77
M. M. M. M. M. M. M. M.
- - I - solids toWard tle ceter6f this'T -
- - - .J_.. — rhmhir qpdirnni c r'trnht-ir I AM"
I I tCambambe Oi1 "CU dbe&BffWäll&-
- - - - ,- --
Baffle Wail Chamber. -The center baffle afloatbFès ii 1
theoilchambevertduringclee r — -----
i i
1ow Contrl Cham1er
I _Th&Weirand oFilTce floontrols
Raise lever md volume iiithe
I --it•' it - symasflowra sarj
J - 2) gradualfydrain the system a
Elevation View. Dry-Weather flow rate subsides -
i.-r• 1 I-. 11 - _ :w 'E
ZRI
1) Initial Wet Weather Phase -: - - 2) Transition Phase :
During a two-month storm event the water level begins to --As the inflow rate increases above the controlled-outflow. :.
rise above the top of the ir1et pipe. This influent control rates the tank fills and the floating contaminant layer accu-
-. feature reduces turbulence and avàids resuspension mulated from past storms rises. Swirling action increases
of pollutants. . . - .. -
•.. at this stage, while sediment pile remainsstable.
I . •:-..:
_ OL
3) Full Capacity Phase - - .. . 4) Storm Subsidence Phase/Cleaning
I .
•--- When the high-flow outlet àppràaches full diséharge, stori-ri Treated runoff is decanted at a controlled rate, restoring the
drains are lbMng at peak capacity The Vortechs System is
- - water level to a low dry-weather volume and revealing a conical
designed to match ydurdesign storm flow and provide treat- pile of sediment. The low water level facilitates inspection, and
I -ment throughout the range of storm events without bypass- cleaning, and significantly reduces maintenance costs. The =
ing. To accommodate very high flow rates, Vortechnics can system's central baffle prevents trarsfer of floatables to the
assist desianers with conflaurina a peak-flow bypass, outlet during cleaning or during the next storm..;
- .- - -
Tre atm è,nt System
. - The Vortechs Stormwater Treatment System, a major advancement
I in oil and grit separator technology, efficiently removes grit, contami-
nated sediments, metals, hydrocarbons and floating contaminants
-
I from-surface runoff. -
The Vortechs System's innovative design combines
swirl-concentrator and flow-control technologies to
optimize treatment efficiency. These features
ensure effective capture:of sediment and oils, and
I prevent resuspension of trapped pollutants - even
at flow rates of up to 25cfs.
° Large system capacity provides an 80% net
annual TSS removal rate
I . Installs below grade, minimizing land use
°Custom-built of precast concrete near the job site
Low pump-out volume and one-point access
I reduce maintenance costs
: e Unique design prevents oils and other float-
ables from escaping the system during cleanout
1 4,
We have worked with
Vortechnics on at least a
dozen stormwater
management plans for
some of our largest
corporate clients: Their
efficient turnaround on
our, requests far technical
stpport and CADO -
drawings has expedited
the permitting process
fot: our dents. We turn
to Vortechnics when
we need innovative
torm water solutions.
Lawrence Marsiglio, OE.
Senior Civil Engineer,
Barakos-Landino, Inc.
SECTION 02721
STORM WATER TREATMENT SYSTEM
PART 1.00 GENERAL
1.01 DESCRIPTION
A. Work included:
The Contractor, and/or a manufacturer selected by the Contractor and approved
by the Engineer, shall furnish all labor, materials, equipment and incidentals
required and install all precast concrete .storrnwatertreatment systems and..
appurtenances in accordance with the Drawings and these specifications.
B. Related work described elsewhere:
Unit Masonry .
Miscellaneous Metals
Waterproofing
1.02 QUALITY CONTROL INSPECTION
A. The quality of materials, the process of manufacture, and the finished sections
shall be subject to inspection by the Engineer. Such inspection may be made at
the place of manufacture, or on the work site after delivery, or at both places, and,
the sections shall be subject to rejection at any time if material conditions fail to
meet any of the specification requirements, even though sample sections may
have been accepted as satisfactory at the place of manufacture. Sections
rejected after delivery to the site shall be marked for identification and shall be
removed from the site at once. All sections which have been damaged beyond
repair during delivery will be rejected and, if already installed, shall be repaired to
the Engineer's acceptance level, if permitted, or removed and replaced, entirely
at the Contractor's expense.
B: All sections shall be inspected for general appearance, dimensions, soundness,
etc. The surface shall be dense, close textured and free of blisters, cracks,
roughness and exposure of reinforcement.
C. Imperfections may be repaired, subject to the acceptance of the Engineer, after
demonstration by the manufacturer that strong and permanent repairs result.
Repairs shall be carefully inspected before final acceptance. Cement mortar
used for repairs shall have a minimum compressive strength of 4,000 psi at the
end of 7 days and 5,000 psi at the end of 28 days when tested in 3 inch diameter
by 6 inch long cylinders stored in the standard manner. Epoxy mortar may be
utilized for repairs.
1.03 SUBMITTALS
A. Shop Drawings
The Contractor shall be provided with dimensional drawings and, when specified,
utilize these drawings as the basis for preparation of shop drawings showing
details for construction, reinforcing, joints and any cast-in-place appurtenances.
Shop drawings shall be annotated to indicate all materials to be used and all
applicable standards for materials, required tests of materials and design
assumptions for structural analysis Design calculations and shop drawings shall
be certified by a Professional Engineer retained by the system manufacturer or
contractor and licensed in the state where the system is to be installed. Shop
drawings shall be prepared at a scale of not less than 1/4" per foot. Six (6) hard
copies of said shop drawings shall be submitted to the Engineer for review and
approval. V
B. Affidavit on patent infringement
I V The Contractor shall submit to the Engineer, prior to installation of the stormwater
treatment system, an affidavit regarding patent infringement rights stating that
any suit or claim against the Owner due to alleged infringement rights shall be
V defended by the Contractor who will bear all the costs, expenses and attorney's
fees incurred thereof.
V
I PART 2.00 PRODUCTS V V
V
2.01 MATERIALS AND DESIGN
I A. Concrete for precast stormwater treatment systems shall conform to ASTM
C 857 and C 858 and meet the following additional requirements:
The wall thickness shall not be less than 6 inches or as shown on the
dimensional drawings., In all cases the wall thickness shall be no less than
the minimum thickness necessary to sustain HS20-44 loading requirements
as determined by a Licensed Professional Engineer.
Sections shall have tongue and groove or ship-lap joints with a butyl mastic I sealant conforming to ASTM C 990.
V
3. Cement shall be Type Ill Portland cement conforming to ASTM C 150.
1 4. Pipe openings shall be" sized to accept pipes of the specified size(s) and
material(s), and shall be sealed by the Contractor with a hydraulic cement
V V conforming to ASTM C 595M
5. Internal metal components shall be aluminum alloy 5052-H32 in accordance
with ASTM B 209. V
- 6. Brick or masonry used to build the manhole frame to grade shall conform to
ASTM C 32 or ASTM C 139 and the Masonry Section of these Specifications.
I \\MDISYS\DATAWORTECHN\EMAIL\STD5AIL\VORTSPECDOC SECTION 02721 Page 2
Casting for manhole frames and covers shall be in accordance with The
Miscellaneous Metals Section of these Specifications.
All sections shall be cured by an approved method. Sections shall not be
shipped until the concrete has attained a compressive strength of 4,000 psi or
util 5 days after fabrication and/or repair, whichever is the longer.
A butimen sealant in conformance with ASTM C 990 shall be utilized in
affixing the aluminum swiri chamber to the concrete vault.
2.02 PERFORMANCE
Each stormwater treatment system shall adhere to the following performance specifications
at the specified design flows, as listed below:
Table 2.02
Vortechs
Model
Swirl
Chamber
Diameter
(ft)
Design
Treatment
Capacity
(cfs)
Sediment
Storage
(yd 3)
1000 3.67 2.3 1.00
2000 4 2.8 1.25
3000 5 4.5 1.75
4000 6 6.0 2.50
5000 7 8.5 3.25
7000 8 11.0 4.00
9000 9 14.0 4.75
11000 10 17.5 5.50
16000 12 25.0 7.00
Each stormwater treatment system shall include a circular aluminum "swirl chamber" (or "grit
chamber") with a tangential inlet to induce a swirling flow pattern that will accumulate and
store settleable solids in a manner and a location that will prevent re-suspension of previously
captured particulates.. Each swirl chamber diameter shall not be less than the diameter listed
in Table 2.02 (neglecting chamber wall thickness).
Each stormwater treatment system shall be of a hydraulic design that includes flow controls
designed and certified by.a professional engineer using accepted principles of fluid mechanics
that raise the water surface inside the tank to a pre-determined level in order to prevent the
re-entrainment of trapped floating contaminants.
I
. Each stormwater treatment system shall be capable of removing 80% of the net ainual Total
Suspended Solids (TSS). Individual stormwater treatment systems shall have the Design
Treatment Capacity listed in Table 2.02, and shall not resuspend trapped sediments or re-
entrain floating contaminants at flow rates up to and including the specified Design Treatment
Capacity. .
Individual stormwater treatment systems shall have usable sediment storage capacity of not
I
less than the corresponding volume listed in Table 2.02. The systems shall be designed such
I
\\MDI\SYS\DATA\VORTECHMEMAU\STDETAIL\VORTSPEC.DOC SECTION 02721 Page 3
that the pump-out volume is less than 1/z of the total system volume. The systems shall be
designed to not allow surcharge of the upstream piping network during dry weather conditions.
A water-lock feature shall be incorporated into the design of the stormwater treatment system
to prevent the introduction of trapped oil and floatable contaminants to the downstream piping
during routine maintenance and to ensure that no oil escapes the system during the ensuing
rain event. Direct access shall be provided to the sediment and floatable contaminant storage
chambers to facilitate maintenance. There shall be no appurtenances or restrictions within
these chambers.
The stormwater treatment system manufacturer shall furnish documentation which supports
all product performance claims and features, storage capacities and maintenance
requirements.
Stormwater treatment systems shall be completely housed within one rectangular structure.
2.03 MANUFACTURER
Each stormwater treatment system shall be of a type that has been installed and used
successfully for a minimum of 5 years. The manufacturer of said system shall have
been regularly engaged in the engineering design and production of systems for the
physical treatment of stormwater runoff.
TM Each stormwater treatment system shall be a Vortechs System as manufactured by
Vortechnics, Inc., 41 Evergreen Drive, Portland, Maine 04103, phone: 207-878-3662,
fax: 207-878-8507; and as protected under U.S. Patent# 5,759,415.
PART 3.00 EXECUTION
3.01 INSTALLATION
Each Storrnwater Treatment System shall be constructed according to the sizes
shown on the Drawings and as specified herein. Install at elevaons and
locations shown on the Drawings or as otherwise directed by the Engineer.
Place the precast base unit on a granular subbase of minimum thickness of six f inches after compaction or of greater thickness and compaction if specified
elsewhere. The granular subbase shall be checked for level prior to setting and
the precast base section of the trap shall be checked for level at all four corners I after it is set. If the slope from any corner to any other corner exceeds 0.5% the
base section shall be removed and the granular subbase material re-leveled.
Prior to setting subsequent sections place butimen sealant in conformance With ASTM
C990-91 along the construction joint in the section that is already in place.
After setting the base and wall or riser sections install the circular swirl chamber
wall by bolting the swirl chamber to the side walls at the three (3) tangent points
and at the 3-inch wide inlet tab using HILTI brand concrete anchors or equivalent
1/2-inch diameter by 2-314" minimum length at heights of approximately three ' inches (3") off the floor and at the mid-height of the completed trap (at locations
of pre-drilled holes in aluminum components). Seal the bottom edge of the swirl I \\MDI\SYS\DATA\VORTECHN\EMAJL\STDETAIL\VORTSPEC.DOC SECTION 02721 •. Page 4
chamber to the trap floor with the supplied aluminum angle flange. Adhere 1/4
thick by 1" wide neoprene sponge material to the flange with half of its width on
the horizontal leg of the flange and half of it's width on the vertical leg. The
aluminum angle flange shall be affixed to the floor with a minimum 3/8" diameter,
by 2-3/4" drop in wedge anchor at the location of the predrilled holes. Affix the
swirl chamber to the flange with hex head 1/4" x 1-1/2" zinc coated self- tapping
screws at the location of the predrilled holes. Seal the vault sidewalls to the
outside of the swirl chamber from the floor to the same height as the inlet pipe
:
iivert using butyi mastic or approved equal.
Prior to setting tle precast roof section, butimen sealant equal to ASTM C990 shall be
:
placed along the top of the baffle wall, using more than. one layer of mastic if
necessary, to a thickness at least one inch (1") greater than the nominal gap between
the top of the baffle and the roof section.
I The nominal gap shall be determined either by field measurement or the shop
drawings. After placement of the roof section has compressed the butyl mastic sealant
in the gap, finish sealing the gap with an approved non-shrink grout on both sides of
I the gap using the butyl mastic as a backing material to which to apply the grout. Also
apply non-shrink grout to the joints at the side edges of the baffle wall.
After setting the precast roof section of the stormwater treatment system, set
precast concrete manhole riser sections, to the height required to bring the cast
iron manhole covers to grade, so that the sections are vertical and in true
alignment with a 1/4 inch maximum tolerance allowed. Backfill in a careful
manner, bringing the fill up in 6" lifts on all sides. If leaks appear, clean the inside
joints and caulk with lead wool to the satisfaction of the Engineer. Precast
sections shall be set in a manner that will result in a watertight joint. In all
I : instances, installation of Stormwater Treatment Systems shall conform to ASTM
specification C891 "Standard Practice For Installation of Underground Precast
Utility Structures".
11 G. Plug holes in the concrete sections made for handling or other purposes with a
nonshrink grout or by using grout in combination with concrete plugs..
I H. Where holes must be cut in the precast sections to accommodate pipes, do all
cutting before setting the sections in place to prevent any subsequent jarring
which may loosen the mortar joints. The Contractor shall make all pipe
I connections. .
I \\MOI\SYS\DATA\VORTECHN\EMAIL\STDETAIL\VORTSPEC.DOC SECTION 02721 Page 5
vi
La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
CHAPTER 6- SOURCE CONTROL BMPS
6.1 - Landscaping
Manufactured slopes shall be landscaped with suitable ground cover or installed with
an erosion control system. Homeowners will be educated as to the proper routine
mintenance to landscaped areas including trimming, pruning, weeding, mowing, .
replacement or substitution of vegetation in ornamentaF 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
Discharges of other landscaping or construction-related wastes.
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
will 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 will 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 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.).
DG:djg h:seports2352151 oaks north rough 3.1, 3.3, 3.48 3.5vinal swmp.03.doc
w.0.2352-151 5/7/2007 9:42AM
I
La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5 I Storm Water Management Plan
6.3 - Automobile Use
- Urban pollutants resulting from automobile use include oil, grease, antifreeze,
hydraulic fluids, copper from brakes, and various fuels. Homeowners will be
educated as to the proper use, storage, and disposal of these potential storm water
contaminants. .
.
I . 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
I
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
I
. cleaning. .
. . .
The Homeowners Association will make all homeowners aware of the
aforementioned RWQCB regulations through a homeowners' education program,
ii •. samples of which are attached at the end of this chapter.
6.4— Integrated Pest Management (IPM) Principles
Integrated pest management (IPM) is an ecosystem-based pollution prevention
strategy that focuses on long-term prevention of pests or their damage through a.
combination of techniques such as biological control, habitation manipulation,
modification of cultural practices, and use of resistant plant varieties.. Pesticides are
used only after monitoring indicates they are needed according to established
guidelines. Pest control materials are selected and applied in a manner that
minimizes risks to human health, beneficial and non-target organisms, and the
environment. More information may be obtained at the UC .Davis website
(http:/Iwww. ipn. ucdavis.eduIWATERJU/index. html).
IPM is achieved via the following:
Common Areas:
- Eliminate and/or reduce the need for pesticide use in the project design by:
Plant pest resistant or well-adapted plant varieties such as native plants.
Discouraging pests by modifying the site and landscape design.
Home Owners:.
Educate homeowners on applicable pest resistant plants and native species
and also encouraging onsite landscaping design.
DG:djg h:repofls\2352\151 oaks north rough 3.1. 3.3, 3.4 & 3.5rtlnal swmp.03.doc
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La Costa Oaks North - Neighborhoods 3.1 3.3, 3.4 & 3.5
Storm Water Management Plan
Pollution prevention is the primary "first line of defense" because pollutants
that are never used do not have to be controlled or treated (methods which
are inherently less. efficient)..
- Distribute IPM educational materials to future site residents/tenants.
Minimally, educational materials must address the following. topics:*
Keeping pests out of buildings and landscaping using barriers, screens
and caulking. .
S Physical pest elimination techniques, such as, weeding, squashing,
trapping, washing, or pruning out pests.
Relying on natural enerriies to eat pests. (4)5 Proper use of pesticides as a last line of defense.
6.5 - Storm Water Conveyance Systems Stenciling and Signage
The proposed development will incorporate concrete stamping, or equivalent, of all
storm water conveyance system inlets and batch basins within the project area with
prohibitive language (e.g., "No Dumping - I Live in <<name receiving water>>"),
satisfactory to the City Engineer. Stamping may also be required in Spanish.
1 6.6 - Efficient Irrigation Practices .
All Home Owners' Association (HOA) maintained landscaped areas will include rain
I .
shutoff devices to prevent irrigation during and after precipitation.. Flow reducers
and shutoff valves triggered by pressure drop will be used to control water loss from
I .
broken sprinkler, heads or lines. .,• S S
6.7 - Trash Storage Areas .
I . . .
All outdoor trash container areas shall meet the following requirements. A "trash
containment area" refers to an area where a trash receptacle or receptacles are
located for use as a repository for solid wastes. Design for such areas will include:
Paved with an impervious surface, designed not to allow run-on from -
I — . adjoining areas, screened or walled to prevent off-site transport of trash.
- Provide attached lids on all trash containers that exclude rain, roof or
awning to minimize direct precipitation.
LI
OG:djg h:lreports'2352\151 oaks north rough 3.1, 3.3. 3.4 & 3.S01noI swmp-03.doc
w.0.2352.151 SF712007 9:42 AM
4-
2.
In
NOT connected to sanitarsewér,
systems and treatment plants? The
primary"purpose of storm drains, is to
carry rainwater away from developed
'reas to prevent, flooding. Untreated
i'torm water and the pollutants it
carries flow directly into creeks,
lagoons and the ocean
sources of water
pollution like industrial waters torn
factories have been greatly reduced
p 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
J!lthese sources add up to a pollution
problemI But each of us can do our
jjpartto help clean up our water and
that adds up to a pollution solution!
.• Carwashingi
: :coa rte sy 'of
• Quality Cons
cooperative
. •• ; • ' 'between theW;
State Depart
Ecoiogy,Kin
the cities of 3I
Seattle and T.
,,;.••. . .,
Ciof. Ca, rl
,;1635farac
*.•. Carlsbad.c
Storm Wat
760-602-271
k
IN
III? •Y
fl€MJW 1c
no problem with washing your clean environment,
Its just how and where you do it importance for
Ith and economy..
ostsoap contains phosphates and Owls" imeawwaterways provide
her chernicals that harm fish and
lomf IN.
er quality. The soap, together with recreaon, fish habitat and
metal and oil washed from
,
our:car, flows into nearby storm cape YOU can help
gull
drains which run directly into lakes,
..
ocean, creeks and
or marine waters.
..
clean by applying - I
iphosphates from the soap can ti4ollowing tips
,ausojexcess algae to grow Algae . •,.. _________________________
•
ookrad, smelt bad, and harm water the engine or the bottom of your car.
phty.• As algae decay, the process. hose nozzle with a trigger to
'Most car washes reuse wash water
uses..up oxygen in the water that fish sav,ewater. • . . several times before sending it to' the
ne our your bucket of soapy water sewer system for Ireatment
fr("F,sh don't"\ vn'Ahe sink when you're done, not bil
(jIike to swim in 1 r$street
• Hire only moe detail operators
-. that will capture wash water and 11)
0..jo!d.-using engine and wheel '•
chemicals itis unlawful for
0 0
0 0 céaners or degreasers commercial vehicle washing
0 : L. 4'r operators to allow wash water to
iake your car to a commercial car enter the storm drain system
wsh, especially if you plan to clean
- I
— — ---•--: — -- -.--.-.-- — -.-
vic11____
It
l'yqu
ggr
know that storm drains are What's the problem with fertilizers Fertilizer photo Is used courtesy
of the Water Quality Consortium, tOéonnected to sanitary sewer and pesticides?
0
*a cooperative venture beiween
sytems and treatment plants? the Washington State Department
Fertilizer isn't a problem—IF its used of Ecology King County and the l4s' $qIIi% f
mary purpose of storm drains' carefully. it you use too much cities of Bel
r rainWater away from fertilize or apply ry
levue, Seattle and jIiit4i
t at the
$kLid areas t prevent fldng.
u;: time,
Jt(reated storm water and the garden into storm drains and then the P
:ølIiatsit carries, flow directly into flow untreated into lakes or streams t f
grow., In water bodies, extra lbrtilizer.
f1
d the ocean. lag 'ons a '. 'fertilizer in Just like in your garden, C_
all
10,,fecent years, sources of water lagoons and streams makes plants
'Pro(eC' I
0 acces have been greatly reduced. can mean
66like industrial waters from
extra algae and aquatic 0
jever now, the majority of water plant growth Too much algae harms Storm Water HOTline"760-602-2799
itrpg1,1.uU occurs from things like cars water quality and makes boating stormwater@cl carlsbad ca us
eakipg oil fertilizers from farms and fishing and swimming unpleasant As
g,garden%4ailing septic tanks pet ' algae decay,.they use up oxygen in
,wAge:-pnd residential car washing :ocean e into
need.-
that fish and other wildlife
torrn drains and Into
ta d waterways City of Carlsbad
001.tnp~te sou~ces add up.to a pollution., .1635 Faraday Avenue
'/ i •
sm ~
,
M
Carlsbad CA 92008
But each of us can do small A 1
mings.1p. help clean up our water and - MM"
Pndoiuocycledpapor
- - : - —. •• - - •
- -
- * 4
pacean environment is of session into 5 minute intervals - Use pesticides only when absolutely : Gardeners can provide good ifq1mafi
. . .. ?4i
narimportance for our health and allowing water to soak in before the necessary. Use the least toxic about dealing with specific pests
Clean waterways provide next application product intended to target a specific plant You may call the MasterJiJ
'6oniercial opportunities recreation _____________________________ pest such as insecticidal soaps Garth ner Hotline at 858 694 286Oj1
I t boric acid, etc'Always read the label check out their website ta and add beauty to our
sape YOU can help keep our and use only as directed wwwmastergardenerssandie
,41
'si
cjo
lagoons and ocean clean by Use predatory insects to control The hotline is staffed Monday__FçJ
plying the following tips harmful nests when possible.
l 9 am —3 pm by experienced gardnprI r r 1 4 1V I
tffr1bdn t blow or rake leaves and other Keep irrigation systems well who are available to answer speJig
W into the street or gutter maintained and water only when
Properly dispose of unwanted - questions Information from Mast j
needed to save money and prevent
pesticides and fertilizers at Gardeners is free to the public IIq
1ecycle yard-waste or start your own. ... Household Hazardous Waste •. . . over -watering. - . t co p p I
Usd fertilizers and pesticides
"'D60 over irrigate. Use drip -For more information on
Nrp ton, soaker hoses or micro- landscape irrigation, please -
i,s - p - ray system and water early in the Have your soil tested to determine call 760-438-2722;
the nutrients needed to maihtain a
healthy lawn Master Gardeners
you have a spray head sprinkler San Diego County has a
system consider adjusting your Consider using organic fertilizers—
ilWatenng method to 'a cycle and they release nutrients more slowly. Master Gardener program through the University of 4
iLsoak.. Instead of watering for 15 Leave mulched grass clippings on California Cooperative
1.minutes straight, break up the .. . . . . .
-
the lawn to act as a natural fertilizer. Extension Master
-. ..
/ t
1•
.-
I Di
I0 • S• • 00 - 0. . o.e
, 01M
que
lWvIo alcantarilias no estan uso de fertilizantesy pesticidas? La fotografla al frente es cortesIa t1A4}k .d
n el WIR
del Consorcio de Calidad de cofdas al sistema de drenaje .
::5rtas de tratamiento El etz
ai usa con andoo esun
AgUaflCO 0
fertilizante o en la temporada incorrecta Condado de King y las cludades
Lai,rncion principal del desague ôlas resulta en el que el fertilizante se deslave de Bellevue Seattle yTacoma
laqariIias es remover el agua de Iluvia y, con la Iluvia y se vaya por el desagüe ô • • k4
nundaciones El agua que entra alcantarillas a nuestros arroyos lagos y
es desagues va directamente a los el oceano tç thesto
arroyos, lagos y el oceano junto con la
1 '1iciôn depositada en las Los fertilizantes en nuestros lagos y
• :
tnIlas y las calles arroyos h:cen que las plantascrezcan
tos dias la contaminacion del agua el fertilizante causa que las algas y - 'Aç
usada directamente per fabricas e plantas acuaticas sobrecrezcan Y el
hip se ha reducido • exceso de algas marinas pueden ser •
rprotec
gniflcantemente Ahora la mayoria de Ia daninas ala calidad del agua y causar 1M
çrtamInacion del agua ongina de carros que Ia pesca natacion y navegacion Linea de Asistencia 760 602-2799
Jrtzantes para plantas tanques las algas consumen el oxigeno del agua
eJo's danados, suciedad de animales y que los peces y otros animales necesitari
, a1pIe carros en zonas residenciales para sobrevivir.
Tpdósestos contaminantes se acumulan • • • -
Ipdesagues O alcantanllados y son
..,:acreadosdirectamente al oceano • • • • •
Ciudad cle'Carlsbad
contribuimos a un gran
'P l
- - - •
- -- - '-
el medio ambiente Iimpio es Mantener los sistemas de irrigacion En ocasiones se puede dejar el skate Master Gardeners
pqrtante para nuestra salud yla - limpios yen buenas condiciones es reciéncortado sobre el pasto yaque -.
Conservar el agua hmpia importante para reducir el actua como un fertilizante natural
El condado de San Diego y Ia Universdpd
gporciona oportunidades para usos - .desperdicio del agua. Regar
de Calif?rna Extension CooPeratpp - -
ciales, recreativos, habitat para solamente cuando sea necesao --
. El uso de pesticidas debe ocurrir sOlo creaçfo el programa de Master
ayes y agrega belleza a reduce el uso del agua y ahorra como ultimo recurso Es preferible Los expertos de este programa etrI
palsaje Todos podemos ayudar dinero usar productos que sean bajos en disponibles para proporcionar inforiaco
aantener los arroyos, las lagunas, y el _______________________________
toxicos por ejemplo jabones sabre plantas y plagas Usted
I" I sencillamente siguiendo
insecbcidas acido borico etc Seguir Ilamar i la Unea de Master Gardene
11-6, limpios
li
!tosconsejos
las instrucciones en la etiqueta y usar 858-694-2860 de tunes a viernes ept '1
el producto correctamente evita 9am y 1pm para obtener respuestsaAsus U
piP ml adoras no peita que las hojas _________________________________ masteruardenerssandlego orci es
y el césped recién cortado . Para màs inlormaciOn sobre - - Cuando sea posible es prelerible usar recurso con informaciOn sobre estsifr
L Jentren en las alcantarillas o el sistemas de nego flame at insectos predadores para controlar temas Esta informaciOn es totatmd '
deague 760-438-2722.plagas grabs at publico
Es preferible convertir estos Los pesticidas y fertilizantes deben Los pesticidas y lertilizantes
desperdicios del jardln en abono usarse solamente cuando sea vencidos deben desecharse
IN
la nip
'06 isistemas de irrigacion de goteo
absolutamente necesario centros
los
otras tecnicas de conservacion del Para mantener un pasto saludable . substancias toxicas
Rgp $I4
56'-fifeferible regar par Ia manana la tierra para determinar cuales ciudades del condado de
Ls sistemas de riego automatico
fertilizates aplicar y en que...San Diego Llame al 1 SQfl més eticientes si se programan
temporada 760-602-2799 para obtener
ciclos de cinco minutos y mas Es recomendble usar fertitizantes
mas Informaclon
11,
,
cJ4iecuentemente para que el agua organicos en vez de productos
edezca bien Ia tierra - quimicos
/
4
- - - - - * - - - -
- - -, - - - - - - - - •- -. • -
* - - -- - - - -- -
-. •
• Did you know that storm drains are
-
. Moto oil photo is used
courtesy of the Water
• NOT connected to sanitary sewer Quality Consortium, a
• systems and treatment plants? The. - cooperative venture
- between the Washington
primary purpose of storm drains is to State Department of
• carry rainwater away from developed •
Ecology, King County and
-
areas to prevent flooding. Untreated
the cities of Bellevue
. Seattle and Tacoma.
storm water and the pQllutnts it -
carries, flow directly into creeks, - -.
•
• lagons and the ocean.
.• fl
Only Rain in the Storm Drain!
In recent years sources of water,
pollution like industrial waters from
factories have been greatly reduced
However now, the majority of water City of Carlsbad
oIlution occurs from things like cars Storm-Water Protection
- leaking oil, fertilizers from farms, lawns Program
and gardens, failing septic tanks, pet
waste -and residential car washing -into . • • City of Carlsbad
the storm drains and into the ocean Carlsbad -
.163 5 Faraday Avenue
•
• CA-92008
and waterways.
- • - • -
• Storm Water HOTline:
All these sources add up to a pollution 760-602 2799
problem' But each of us can do small
things to help clean up our water and Funded by a grant
that adds up to a pollution solution!
ii
'lntegfated
from the California
Waste
'-
-i' Management Board
-• ;:-. 5t1 - • : - - . • _.
It R- - I
US ED 011. •
---••• •
• .
•
Printed on recycled paper
— — — - — — — - — — — — — — — — — — —
- I : I
Oil does not dissolve in water. It
lasts a long time and sticks to
everything from beach sand to bird
feathers Oil and other petroleum
r products are toxic to people, wildlife
and plants
One pint of oil can make a slick
larger than a football field Oil that
leaks from our cars onto roads and
driveways is washed into storm
drains, and then usually flows
directly to a creek or lagoon and
. finally to the ocean
Used motor oil is the largest single
source of oil pollution in our ocean,
creeks and lagoons Americans spill
180 million gallons of used oil each
year into our waters
This is 16 times the
Z t amount spilled by the
-
Exxon Valdez in JH
............. -
Alaska J1
W
. . ..
Having a clean environment Ril
of primary importance for l, .V
our health and economy. 'c pr
Clean waterways provide
commercial opportunities, f :1
recreation, fish habitat and I
add beauty to our
I
/
landsape YOU can help I
keep our ocean, creeks and I
lagoons clean by applying '
the following tips J/41
Stop drips Check for oil
Ieks regularly and fix them • • • . - V •• • •
promptly Keep your car tuned to dispose of it properly. Never dispose
reduce oil use of oil or other engine fluids down the
storm drain, on the ground or into a
• 1 se ground cloths or drip pans ditc •••- V V
beneath your vehicle if you have leaks
or are doing engine work Recycle used motor oil There
. • . are several locations in Carlsbad that
V
S Clean up spills immediately.
accept used motor oil. For hours and
Collect all used oil in containers with ..
V
.. V - locations, call 7b0434-2980. . V
ightVfitting lids. Do not mix different - • . :
engine fluids Buy recycled ('refined") motor oil
When you change your oil, V
•
to use in your c,r.
.
•
V V V
V
•'
- - - :•
_: -- .-
_______
•0
Did you know that storm drains are of the Water Qua
' NOT connected to sanitary sewer a cooperative venture between 4
. J I the Washington State Department
systems and treatment plants2 The of Ecology King County and the
MN primary purpose of storm drains is to cities of Be vu Seattle and
carry rainwater away from developed lilt
areas to prevent flooding Untreated
storm water and the pollutants it the S 0 4I
carries, flow directly into creeks, I
lagoons and the ocean.-,.' t
-
S
L1I '.• I
In recent years, sources of water
4 pollution like industrial waters from
hfctories, have been greatly red uced.
ro
S
jHoweer now, the majority of water Storm Water HOTline 760-602-2799. -
occurs from things like cars stormwater@cl carlsbad ca us
oil, fertilizers from farms and !IIII ?fI4II1r
;
~,,Jqiling septic tanks, pet waste
tdrtmdrains and into the ocean and
Naterways
bi ~mr: But each of us can if I
do small
1p clean up our water and qjqk
IF tl'bdds up I IM
4 41, I 1J'I' 4111 I
Pnnted on recyc'ed paper
i
MOM
HM
i
eiwsté is a health risk to pets and
j 2 ecjaIly children. It's a
nuisar in our neighborhoods.,Pet
as ti full of bacteria that can make
sick This bacteria gets
affibd!itt6the storm drain and ends
IIiUr creeks, lagoons and ocean
bacthria ends up in shellfish living
bodies People who
may get very sick
studies show that dog and
contribute up to 25% of
J.J.%TYI cteria found in our local.
and clean up after
as easy as 1-2--3'
IN
it U
T; is
-
(t
S, of waste
r ri in toilet or
trash
'tbour
YOU can help
eks, lagoons
,Iëan by
following tips:
'Istic baq when
and be'sure to pick up The best way to dispose of pet waste
. is to flush it down the toilet because'
it gets treated by .p sewage treatment
i pet waste in your yard plant
Other disposal methods for pet
kafter your pets before waste include sealing it in a bag and
atios, driveways and placing in trash or burying small
?ur1aced areas Never quantities in your yard to
iaste into the street or decompose Be sure to keep it away
from vegetable gardens
ean environment
y;importance for
and economy.
rys provide
pportunities,
fiSh habitat and
•, V
V V 7 V : V
•
V
H the St,
V
V t
V V <g V
V etProteC 0 V
V •V VV • V •V •VV
Storm Water Protection Program
s.tormwater®ci.car.lsbad:ca.us
V 7606O22799 -
Vf -
- V -
City of Carlsbad
1635 Faraday Avenue
Carlsbad CA 92008
, V. •
-
Printed onrecyciedpaper V
- : .
V •
V
• -
•
V
V
. :
rAClean
44
Environment Is
Important to All of US!
,
In the City of Carlsbad, storm *
drains flow directly into local OR! gg
creeks lagoons and the ocean eon 1 tiktt i $Wi
1211 IN
without treatment Storm water
pollution is a serious problem for V
our natural environment and for V
people who live near streams or
V wetlands: V
Storm water pollution comes frorn
a variety of sources including oil,
fuel, and fluids, from vehicles and
hetivy equipment,. pesticide runoff
from landscaping, and from V
materials such as concretë,
mortar and soil from construction
V
activities.
The City of Carlsbad is committed
to improving water quality and
reducing the amount of pollutants
Vthat enter our precio.us.
waterways. V
- - - • ••'•••• •- - -
Ifs All Just Water, •. How Do ± Get Rid of Chlorine? '', Pool Filters
Isn't Pool and spa water may be discharged to the Clean filters over a lawn or other landscaped
- stormdr,ain if it has been properly. area where the discharge can be absorbed.
Although we enjoy the fun and relaxing times dechlorinated and doesn't contain other Collect materials on -filter cloth and dispose into
in them the water used in swimming pools chemicals The good news is that chlorine - the trash biatomucEous earth cannot be
and spas can cause problens for our creeks, naturally dissipates over time. Mànitor'nd' dicharged'into.the.;treetor storm drain
lagoons and the . . .• .
ocean if not
disposed of
properly. When
you drain your
swimming
- ,
o
.
.
TOUflTUII' OF :
.
to the street, the high concentrations of 5
. and make sure they dispose of the water and . done in a roper'and safe manner that is not
chlorine and other chemicals found in the
solids properly. For more information about
dischargihg wastewater to the sanitary
harmful to peoplé.or the environment. ft may be
'.discharged into the sanitary sewer through a
water flows directly to our storm drains.
.-'sev,er,,please . legal sewer connection after the pH has been
bid you know that these storm drains are contact the '
adjusted to no lower than 5.5 and no higher
NOT connected to sanitary sewer systems Encina T.! than 11
and treatment plants? The primary purpose Wastewater
of storm drains is to carry rainwater away Authority at
LI b htl 0 , e 0 19
from developed areas to prevent flooding (760) 438-
s
'
Use the water f or irrigation Try draining
,lmproperly, disposing of swimming pool and ' 3941. •. .. I 'de-chlorina'ted pool 'water gradually onto a,,
spa water into storm drains may be harmful •, ' . . - landscaped area. Water discharged to
'to the environment. • .'
- , . ' Before you discharge 'your swimming pool landscape must not èross property lines and
or spa water to the storm drain the must not produce runoff.
Best Management Practices I wQtCI' Do not use copp r-based algaecides
Best Management Practices or BMPs are • Must not contain chlorine hydrogen
Control algae with chlorine or other
alternatives to copper-based pool chemicals
procedures that help to prevent pollutants peroxide acid or any other chemicals Copper is harmful to the aquatic
like chlorine and sediment from entering our.. Can not carry debris or vegetation environment
storm drains Each of us can do our part to
keep storm water clean Using BMPs adds up
* Should have an acceptable pH of 7-8.,
Can not contain algae or harmful bacteria
During pool construction contain ALL
to a pollution solution! (no 'green" present)
materials and dispose of properly
Materials such as cement, Gunite mortar,
' . ..:- :' 4 Flow must be controlled so that 5it does • . and sediment must not be discharged into
- -. not cause erosion problems. . • . - ,
, . .•
the storm drains.
--.--
-
-
- test for chlorine levels in the pool over a systems. Dry IT OUT OS much as possible, bag it
period of 3 to 5 days. brain the water ,.
in plastic and dispose into the trash.
before algae starts to grow. •
•. Acid -Wàshinq -
Consider hiring a professional pool service Acid cleaning wash water is NOT allowed into ;.
company to clean your pool, fountain, or spa the storm drains. Make sure acid washing is
I
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
CHAPTER 7- SITE DESIGN BMPS
7.1 - Site Design BMPs
I Priority projects, such àsthe La -Costa Oaks North Neighborhoods 3.1, 3.3, 3.4 & 3.5
projects, shall be designed to minimize, to the maximum extent practicable the
I .intro'duction of pollutants and conditions of concern that may result in significant
impact, generated from site runoff to the stormwater conveyance system.. Site
design components can significantly reduce the impact of a project on the
I environment.
I
.7.2 - Minimize Impervious Footprint
Methods of accomplishing this goal include:
I - Construct streets, sidewalks, and parking lots to the minimum widths
necessary to be in accordance with standards set forth by the City of
I .
. Carlsbad. .
. 7.3 - Conserve Natural Areas
I The proposed La Costa Oaks North - Neighborhoods 3.1 & 3.3 -3.5 developments
have been mass graded and there is no natural area onsite.
I .
7.4 -Permeable Pavements .
Site design BMP alternatives such as pervious pavements were also considered for I use within the La Costa Oaks North -,Neighborhoods 3.1, 3.3, 3.4 & 3.5 project
sites. However, the use of pervious pavements has several disadvantages such as:
-. Porous pavement has a tendency to become dogged if improperly
installed or maintained..
I - Porous pavement has a high rate of structural failure
Anaerobic conditions may develop in underlying soils if the soil is
unable to dry out between storm events. This may impede
microbiological decomposition. .
I - . Clay soils typically found within the project site are not sufficiently
permeable to convey storm water runoff - leading to possible soil
I swelling and ultimately cracking of the pavement layer.
These factors listed influenced the decision to not include pervious pavements within
I the site design. . . .
.
.
I . OG:dj9 h:zeports\2352\151 oaks north rough 3.1, 3.3, 3.4 & 3.5'iThal swmp-03.doc
- w.o.2352.151 517/2007 9:42 AM
,
La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
7.5 - Minimize Directly Connected Impervious Areas
Methods of accomplishing this goal include:
-Draining rooftops into adjacent landscaping prior to discharging to
the storm drain.
These site design techniques will not be implemented within the La Costa Oaks
North - Neighborhoods 3.1, 3.3, 3.4 & 3.5 project sites.
7.6 - Slope & Channel Protection I Hillside Landscaping
I
Methods of accomplishing this goal include:
- Planting native or drought tolerant vegetation on slopes.
Energy dissipaters, such as riprap, at the outlets of new storm
drains, culverts, conduits, or channels that enter unlined channels.
7.7 - Private Roads
Per Section 3.2.3 of the City of Carlsbad SUSMP, the City of Carlsbad requires the
'
implementation of at least one (1) of the following site design requirements for
private roads: .
I -. Rural swa le system: Street sheet flows to vegetated 'swale or gravel
shoulder, curbs at street corners, culverts under driveways and street
crossings.
Urban curb/swale system: Street slopes to curb, periodic swale
inlets drain to vegetated swale/biofilter.
Dual drainage system: Water quality design storm captured in street
catch basins and discharged to adjacent vegetated swale or gravel
shoulder,. high flows connect directly to storm water conveyance
system.
The proposal of grass lined swales/biofilters lining the proposed private roads within
the La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5 project has been
evaluated and has been deemed infeasible due to the following:
- Grass lined channels would be located beneath the grade level of 1 the adjacent roads and side walks it serves to treat. However, water
drained to these grassy channels would enter the existing clay type
I
soils, causing possible swelling of the clay layers. This swelling will
ultimately undermine the adjacent pervious surfaces (roads and
sidewalks), causing cracking and failure of these surfaces.
I . OG:djg h/aoports\23521151 oaks north rough 3.1, 3.3, 3.4 & 3.5/Sinai swrnp.03.doc
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I La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
CHAPTER 8— OPERATIONS& MAINTENANCE PLAN
8.1 - Maintenance Requirements
I U Maintenance of the site BMPs will be the responsibility of the Homeowners
Association. A maintenance plan will be developed and will include the following
I : information: ..
Specification of routine and non-routine maintenance activities to be
performed
A schedule for maintenance activities
Name, qualifications, and contact information for the parties responsible for
I maintaining the BMPs
For proper maintenance to be performed, the storm water treatment facility must be I accessible to both maintenance personnel and their equipment and materials.
8.1.1 Vortechs Treatment Units
-
. Flow-based storm water treatment devices should be inspected periodically to
assure their condition to treat anticipated runoff. Maintenance of the proposed
I Vortechnics units includes inspection and maintenance 1 to 4 times per year.
. Maintenance of the Vortechs units involves the use of a "vactbr 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 crew is required to perform the
.. maintenance of the treatment unit. Properly maintained Vortechs Systems will only I require evacuation of the grit chamber portion of the system. In some cases, it may
be necessary to pump out all chambers. In the event of cleaning other chambers, it
I .is* imperative that the grit chamber be drained first.
Proper inspection includes a visual observation to ascertain whether the unit is
I functioning properly and measuring the amount of deposition in the unit. Floatables
should be removed and sumps cleaned when the sump storage exceeds 85 percent
of capacity specifically, or when the sediment depth has accumulated within 6 inches.
I . of the dry-weather water level. The rate at which the system collects pollutants will
depend more heavily on site activities than the size of the unit.
I The operational and maintenance needs of a Vortechs unit include:
I Animal
Inspection of structural integrity and screen for damage: . .
and vector control.
I . Periodic sediment removal to optimize performance.
Scheduled trash, debris and sediment removal to prevent obstruction.
I . DG:djg h:reports2352\151 oaks north rough 3.1, 3.3, 3.4 & 3.5'i1nn swmp-03.doc
w.o.2352.15 5/7/2007 9:42 AM
I La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
The facility will be inspected regularly and inspection visits will be completely
documented:
- Preventive maintenance activities for a flow-based treatment unit are:
Trash and Debris Removal.- trash and debris accumulation will bemonitored
:I during both the dry and wet season and after every large stbrrnevent (rainfall
events in excess of 1 inch). Trash and debris will be removed from the
Vortechs unit annually (at the end of the wet. season). Trash and debris 'will
I also be removed when material accumulates to 85% of the unit's sump
capacity, or when the floating debris is 12 inches deep (whichever occurs
first).
I . Sediment Removal - sediment accumulation will be monitored during both the
wet and dry season, and after every large storm (1.0 inch). Sediment will be
I . removed from the Vortechs unit annually (at the end of the wet season).
Sediment will also be removed when material accumulates to 85% of the
unit's sump capacity, or when the floating debris is 12 inches deep (whichever
occurs first). Disposal of sediment will comply with applicable local, county,
state or federal requirements. . S
I . . Corrective maintenance is required on an emergency or non-routine basis to
correct problems and to restore the intended operation and safe function of a
I
. Vortechs unit. Corrective maintenance activities include:
Removal of Debris and Sediment
I
Structural Repairs - Once deemed necessary, repairs to structural
components of a Vortechs unit will be completed within 30 working days.
Qualified individuals (i.e., the manufacturer representatives) will conduct
I . repairs where structural damage has occurred. .
. .
I
I... DG:djg h:repos\2352\151 Oaks north rough 3.1. 3.3. 3.4 & 3.5rttnal swrnp-03.doc
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La Costa Oaks North - Neighborhoods 3.1, 3.3, 3.4 & 3.5
Storm Water Management Plan
I 8.2 - Operations and Maintenance Plan
Target Maintenance Frequency - At a minimum, treatment units should he
cleaned annually.
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Maintenance Activity
- Annual inspection and cleanout
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. Clear grit chamber unit withvactôr truck.. •
Perform visual inspection
Remove floatables
8.3 - Annual Operations & Maintenance Costs .
I .The following costs are intended only to provide a magnitude of the costs involved in
maintaining BMPs. Funding shall be provided by the Master Home Owners
Association for the La Costa Oaks North Neighborhoods 3.1 & 3.3 - 3.5.
Approximate annual maintenance costs for the proposed Vortechs unit are outlined
below., Costs assume a 3 man crew:
Maintenance for Vortechs model 4000:
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Periodic Inspection, Maintenance and Monitoring = $800
Annual Cleanout Cost = $1,250
I Maintenance for Vortechs model 1000:
Periodic Inspection, Maintenance and Monitoring = $800
0 Annual Cleanout Cost = $500
Maintenance for Vortechs model 2000:
Periodic Inspection, Maintenance and Monitoring = $800
Annual Cleanout Cost = $750
Maintenance for Vortechs model 7000:
I 0 Periodic Inspection, Maintenance and Monitoring = $800
Annual Cleanout Cost '= $1,750.
I Subtotal = $2,050-i- $1,300+ $1,550 + $2,550 = $7,450
- Contingency = $745
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Total= $8,195
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I . OG:djg h:lseports\2352151 oaks north rough 3.1. 3.3, 3.4 & 3.541na1 swmp.03.doc
w.o.2352.151 5/7/2007 9:47 AM