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CT 05-05; LA COSTA GREENS NGBHD 1.16; STORM WATER MANAGEMENT PLAN; 2006-07-12
I I I 'I I ,i I I I I I I I I I II i I I I HUNSAKER &ASSOCLATES ~--.::!!I 5 AND lEG O. INC. PLANNING ENGINEERING SURVEYING IRVINE LOS ANGELES RIVERSIDE SAN DIEGO ARIZONA DAVE HAMMAR LEX WILLIMAN STORM WATER MANAGEMENT PLAN for LA COSTA GREEN,S NEIGHBORHOOD 1.16 CT 05-05 City of Carlsbad, California Prepared for: KB Home, Inc. 12235 EI Camino Real Suite 100 San Diego, CA 92130 W.O. 490-71 July 12, 2006 AMENDED JUNE 23, 2.008 Hunsaker & Associates San Diego, Inc. ALISA VIALPANDO ~ DANSMITH/ ~ RAY MARTIN ~ ~?/. CHUCK CATER R d L M rt' R C E on . a In, ... 9707 Waples Street San Diego. CA 92121 (858) 558-4500 PH (858) 558-1414 FX www.HunsakerSD.com Info@HunsakerSD.com Vice President RECEIVED JUL 112008 ENGINEERING DEPARTMENT DE kc H'\REPORTSI0490171ISWMP·FE·05.doc >- t!:b ~ e",~ ik&!d ~~ ~ ~, C-T(J 'S W:~'7~/200B4'~ .' I I I I I I I I I I I I I I I I I I I La Costa Greens 1.16 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 Oil & Grease 3.7 Pesticides 3.7 Bacteria & Viruses 3.9 Organic Compounds 3.10 Metals CHAPTER 4 -Conditions of Concern 4.1 Receiving Watershed Descriptions 4.2 303(d) Status 4.3 Pollutants of Concern in Receiving Watersheds 4.4 Conditions of Concern -Developed Condition Hydrofogy Summary 4.5 Identification of Primary & Secondary Pollutants of Concern DE:de H:IREPDRTSI0490\71\swMP-FE-04.doc w.o. 490-71 6/4/200~ 7:31 PM I I I I I I I I I I I I I I I I I I II La Costa Greens Neighborhood 1.16 Storm Water Management Plan CHAPTER 5 -Site Design & Low Impact Development (LID) BMPs 5.1 Site Design and LID BMPs 5.2 BMP 1 -Minimize and Disconnect Impervious Surfaces 5.3 BMP 2 -Conserve Natural Areas 5.4 BMP 3 -Minimize Directly Connected Impervious Areas 5.5 BMP 4 -Maximize Canopy Interception & Water Conservation 5.6 BMP 5/6/7/8/9 -Slope & Channel Protection CHAPTER 6 -Source Control BMPs 6.1 BMP 10-Design Outdoor Material Storage Areas 6.2 BMP 11 -Design Trash Storage Areas 6.3 BMP 12/13 -Integrated Pest Management Principles 6.4 BMP 14/15/16 -Efficient Irrigation & Landscaping Design 6.5 BMP 17/18 -Storm Water Conveyance Systems· Stenciling & Signage 6.6 BMP 19 -Private Roads 6.7 BMP 20/21 -Residential Driveways & Guest Parking CHAPTER 7 -Treatment Control BMP Design 7.1 BMP Location 7.2 Determination of Treatment Flow 7.3 BMP Unit Sizing 7.4 Filterra Bio Filtration Units 7.5 Vortechs Treatment Units 7.6 Pollutant Removal Efficiency Table 7.7 BMP Unit Selection Discussion CHAPTER 8 -Operations & Maintenance Plan 8.1 Maintenance Requirements 8.2 Operation and Maintenance Plan 8.3 Annual Operation & Maintenance Costs CHAPTER 9 -Fiscal Resources 9.1 Agreements (Mechanisms to Assure Maintenance) DE:de H:IREPORTSI04901711SWMP-FE-04.dac w.o. 490-71 6/4120087:31 PM I I I I I I I I I I I I I I I I I I I La Costa Greens Neighborhood 1.16 Storm Water Management Plan List of Tables and Figures Chapter 1 -Vicinity Map Chapter 1 -Watershed Map Chapter 1 -BMP Location Exhibit 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 7 -BMP Location Exhibit Chapter 7 -Pollutant Removal Efficiency Table Chapter 7 -Design Runoff Determination Summary Table Chapter 7 -85th Percentile Rational Method Calculations Chapter 7 -Vortechs Product Information Chapter 7 -Filterra Product Information Chapter 7 -CASQA Treatment Control Documentation Exhibits BMP Location Exhibit Developed Conditions Hydrology Exhibit DE:de H:IREPORTSI0490171ISWMP·FE·05.doc w.o. 490-71 6123/200610:15 AM 'I I I I ·1 I "I I I ·1 I I I I I I I I I La Costa Greens Neighborhood 1.16 Storm Water Management Plan CHAPTER 1 -EXECUTIVE SUMMARY 1.1 -Introduction The La Costa Greens Neighborhood 1.16 site is located at the northwest and northeast corners of the Dove Lane-Estrella de Mar Road intersection in the City of Carlsbad, California. The project site is also bounded by the existing La Costa Greens Neighborhood 1.17 development to the north, existing La Costa Greens Neighborhood 1.15 development to the south, and another existing development to the west. The vicinity maps below have been included to illustrate the project site's location. LA COSTA GREENS NEIGHBORHOOD 1. 16 ! r~~'<£ ~ _ MAl' BOUNOARY VICINITY MAP NTS All runoff from the site will drain to an unnamed tributary of San Marcos Creek. Runoff from this tributary discharges into San Marcos Creek and eventually discharges to the Batiquitos Lagoon. Per the City of Carlsbad Standard Urban Storm Water Mitigation Plan (SUSMP) Questionnaire for residential urban runoff, the La Costa Greens 1.16 project is classified as a priority project and subject to the City's Permanent Storm Water Priority BMP Requirements. 05:de H:\R8'ORTS\o490\71\SWMP-F5~04.doc w.o. 490-71' ,61~12008 6:42 PM I I I I I I I I I I I I I I I I I I I La Costa Greens Neighborhood 1.16 Storm Water Management Plan This Storm Water Management Plan (SWMP) has been prepared pursuant to requirements set forth in the City of Carlsbad's Engineering Standards, Volume 4, Section 2, "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. R9-2007-0001 and the City of Carlsbad SUSMP. This SWMP identifies anticipated project pollutants, pollutants of concern in the receiving watershed, conditions of concern, applicable Best Management Practices (BMPs) peak flow mitigation, recommended source control BMPs, and methodology used for the design of flow-based BMPs. . Low Impact Development (LID) design techniques have also been identified and incorporated throughout the project site in order to minimize storm water runoff from the project site in accordance with the RWQCB's 2007 permit. 1.2 -Summary of Pre-Developed Conditions Located in the Carlsbad watershed, the 11.6 acre site has been mass graded per the "Grading and Erosion Control Plans for La Costa Greens Neighborhoods 1.16 & 1.17" DWG. No. 433-7A dated February 2005 by Hunsaker & Associates .. Runoff generated by the northern portion of the site is currently collected on site and discharged to an existing 36-inch RCP storm drain within the adjacent Estrella De Mar Road. Flow within this 36-inch RCP is then conveyed in a northerly direction towards the adjacent La Costa Greens Neighborhood 1.17. Flows from both Neighborhoods' 1.16 and 1.17 are confluenced and then discharged to the receiving detention basin located in the southeast corner of La Costa Greens Neighborhood 1.17. The existing Neighborhood 1.17 detention basin was designed to attenuate ultimate condition peak flows below pre-developed peak flows to the receiving storm drain system within the La Costa Golf Course. A portion of the southern segment of the La Costa Greens 1.16 development discharges to the curb and gutter within the adjacent Estrella De Mar Road. This flow is intercepted via curb inlets to a receiving storm drain and conveyed in a southerly direction towards the existing La Costa Greens Neighborhood 1.15 storm drain system. Runoff from the southern portion of the La Costa Greens 1.16 development confluence with flows from the adjacent La Costa Green 1.15 development prior to draining to the basin located in the western portion of the Neighborhood 1.15 site, bordering the adjacent La Costa Golf Course. The existing Neighborhood 1.15 detention basin was designed to attenuate ultimate condition peak flows below pre-developed peak flows to the receiving storm drain system within the La Costa Golf Course. DE:de H:IREPORTSI0490171ISWMp·FE·04.doc w.o. 49()'71 614120066:42 PM I I I I I I I I I I I I I I I I I I I La Costa Greens Neighborhood 1.16 Storm Water Management Plan Developed site runoff then flows in an easterly direction to an unnamed tributary of San Marcos Creek, which flows in a southerly direction along the site boundary with the La Costa Golf Course, west of the La Costa Greens Phase I development area. All the runoff eventually drains under Alga Road via three 96" RCP culverts, as shown in Drawing No. 397-2, and discharges into San Marcos Creek en route to the Batiquitos Lagoon. The Regional Water Quality Control Board has identified San Marcos Creek as part of the Carlsbad Hydrologic Unit, San Marcos Hydrologic ArE~a, and the Batiquitos Hydrologic Subarea (basin number 904.51). For further information in regards to the sizing of receiving storm drain system within Estrella De Mar Road and existing condition hydrology, refer to the "Drainage Study for La Costa Greens Neighborhood 1.17" dated May 2005 by Hunsaker & Associates and "SWMP for La Costa Greens Neighborhood 1.17" by Hunsaker & Associates dated February 2005. 1.3 -Summary of Proposed Development Development of the 11.6-acre area will consist of 86 multi-family residences, associated roads, foot paths, communal open space, onsite parking and underground utilities. The project has entrances from the adjacent pove Lane to the south and Estrella De Mar Road to the east of the project site. Runoff from the developed Neighborhood 1.16 site area will drain to two (2) points of discharge. The northern portion of the development will-drain northerly via the storm drain within Estrella De Mar Road, converging with the adjacent La Costa Greens Neighborhood 1.17 storm drain system. This confluenced flow will then discharge to the detention basin within Neighborhood 1.17, ultimately flowing eastward into-the La Coast Greens Golf Course. The southern portion of the La Costa Greens 1.16 development discharges to the curb and gutter within the adjacent Estrella De Mar.Road. This flow is intercepted via curb inlets to a receiving storm drain and conveyed in a southerly direction towards the existing La Costa Greens Neighborhood 1.15 storm drain system. Runoff from the southern portion of the La Costa Greens 1.16 development confluence with flows from the adjacent La Costa Green 1.·15 developm~nt prior to draining to the basin located in the western portion of the Neighborhood 1.15.site, bordering the adjacent La Costa Golf Course. Peak flows are mitigated via this detention basin and then discharged in an easterly direction to the La Costa Golf Course and San Marcos Creek. Per the "Drainage Study for La Costa Greens 1.16", dated June 2008 by Hunsaker & Associates, peak flow data from the developed site is summarized in Table 1. DE:de H:IREPORTSI0490171ISWMp·FE·05.doc w.o.490-71 6123/20082:55 PM ----, - --- -- crt~::SBAD" \ .~ . - --- ---- LA COSTA GREENS NEIGHBORHOOD 1.16 CITY OF CARLSBAD, CA.lIFORNIA .- I I I I I I I I I I I I I I I I I I I La Costa Greens Neighborhood 1.16 Storm Water Management Plan TABLE 1 -Summary of Developed Conditions Hydrologic Analysis Runoff Location Node 100* Node 205* Mass-Graded Conditions Devel oped Conditions Drainage 100-Year Drainag e 100-Year Area Peak Flow Area Peak Flow (ac) (cfs) (ac) (cfs) 56.0 110.1 56.2 111.2 0.8 2.9 0.7 2.1 * = refer to attached Developed Condition Hydrology Exhibit Fo'r the Rational Method Analysis, a runoff coefficient of 0.35 was used for undisturbed, natural terrain; a runoff coefficient of 0.90 was used for paved streets, corresponding to areas that are 90% impervious; a runoff coefficient of 0.55 was used for constructed slopes; and a runoff coefficient of 0.63 was used for developed areas, which corresponds to a medium-density residential land use with 14.5 DUlac or less. The mass-graded condition peak flowrate into the northern detention basin, at Node 100, was obtained from the "Hydrology Study for La Costa Greens Neighborhood 1.17' prepared by Hunsaker & Associates San Diego, Inc. on May 2005. The existing condition peak flowrate from the bottom half of the eastern portion of the site, at Node 205, was obtained from the mass-graded hydrology study for Neighborhood 1.16 labeled "Hydrology Study for La Costa Greens Neighborhood 1. 16, CT 99-03" by Hunsaker & Associates, dated January 7 2004. Please refer to the "Drainage Study for La Costa Greens 1.16", dated June 2008 by Hunsaker & Associates for further discussion in regards to site hydrology. To provide maximum water quality treatment for flows generated by the proposed development, Low Impact Development based BMPs are to be employed throughout the multi-family site. Flows generated via the site will drain to multiple Filterra Bio- Retention Filtration Systems located throughout the site to provide high levels of treatment for pollutants generated via the residential development. In order to meet LID requirements of providing treatment near the source of the pollutants, Filterra units are located at every inlet within the project site. The Filterra Bio-Retention Filtration System is a landscaped concrete inlet box which contains a filter media mixture and a selected plant (small shrub or tree). The landscaping, either a tree or shrub, grows out of the box and through a grate at the top. The filter media captures and immobilizes pollutants from the storm water; those pollutants are then decomposed, volatized, and incorporated into the biomass of the Filterra system's micro/macro fauna and flora. Stormwater runoff flows through the media and into an under drain system at the bottom of the container, where the treated water is discharged. Higher flows .bypass the Filterra via a downstream inlet structure. DE:de H:IREPORTSI0490171ISWMP:FE-OS.dOC w.o.490-71 6123120082:54 PM I I I I I I I I I I I I I I I I i I I I La Costa Greens Neighborhood 1.16 Storm Water Management Plan Downstream of the La Costa 1.16 project site, master treatment control BMPs were constructed to treat portions of the overall La Costa Green development. 85th percentile runoff generated by the La Costa 1.16 development is treated prior to discharge to the receiving La Costa Golf Course. Flows tributary to the northern storm drain system (La Costa Greens 1.17) are treated via an existing Vortechnics Model 7000 flow based treatment unit. This unit was constructed as part of the adjacent La Costa Greens 1.17 residential development and has been sized in anticipation of the ultimate development of both the La Costa Greens 1.17and La Costa Greens 1.16 residential developments. . A'small portion of the La Costa Greens 1.16 development (the entrance from Dove Lane) drains to a sump that due to physical constraints was unable to incorporate a Filterra to treat this tributary area. This developed area consists of primarily paved surface -areas from the private entrance. Pollutants associated with this entrance (such as hydrocarbons and trash & debris) are treated via the Master Vortechnics unit located downstream of the project site. 1.4 -Results and Recommendations Based on an 85th percentile rainfall of 0;65 inches (see Isopluvial Map in chapter 5) and 85th percentile intensity of 0.2 in/hr and approximately 65 percent imperviousness in the contributing watershed, Table 2 summarizes 85th percentile rational method flow calculations used to size the LID flow based treatment units within the 1.16 development. Table 2 -Onsite LID Flow Based 85th Percentile Calculations Total BMP Drainage Location Area (acres) Filterra Unit 1 0.59 Filterra Unit 2 0.58 . Filterra Unit 3 0.37 Filterra Unit 4 1.01 Filterra Unit 5 1.08 Filterra Unit 6 0.62 Filterra Unit 7 1.26 Filterra Unit 8 0.59 Filterra Unit 9 0.72 Filterra Unit 10 0.69 Rainfall Intensity (inches/hour) 0.2 0.2 0.2 0.2 0.2' . 0.2 0.2 0.2 0.2 0.2 Runoff ·85th Percentile Coefficient Flow (cfs) 0.63 0.63 0.63 0.63 0.63 0.63 0.63 0.63 0.63 0.63 0.07 0.07 0.05 0.13 0.14 0.08 0.16 .. 0.07 0.09 0.09 DE:de H:IREPORTSI049017,1ISWMP-FE-05.doc W.O. 490-71 6123/200610:16 AM ----- - VICINITY MAP HIS --- LA COSTA GREENS BORHOOD 1.17 4.5 I ,.. ~. 1177.71 I --.~ I ........... I ..................... : " IIIPf/MOUS MfA IJlPERIfOUS ARE'A lANDSCAPING MfA .. ----- -- LA COSTA GREENS NEIGHBORHOOD 1.16 CITY OF CARLSBAD, CALIFORNIA -- OVERLAND WOGETATED CONWOYANCe 1 OF 1 I I I I I I I I' I I· I I I I I I I I I La Costa Greens Neighborhood 1.16 Storm Water Management Plan Table 3 summarizes 85th percentile rational method flow calculations for the existing water quality treatment BMP for the La Costa Greens Neighborhoods 1.1"6 & 1.17 developments. Table 3 -Master Flow Based 85th Percentile Calculations BMP Total Drainage Rainfall Runoff 85 Location Area Intensity Coefficient Pe (acres) (inches/hour) FI Neighborhood 55.7 0.2 0.58* 6.5 1.17 *-weighted C coefficient, see chapter 7. Rational Method calculations predict an 85th percentile runoff flow of 6.5 cfs for the area discharging to the La Costa Greens Neighborhood 1.17 treatment unit. 85th percentile flows will be treated in the proposed treatment unit prior to discharging to the Neighborhood 1.17 detention basin. Further information and product testing on Filterra and Vortechnics Treatment units is provided in Chapter 7 of this report. Many alternate treatment BMPs, including drainage inserts, infiltration. basins, wet ponds, media filters, and grassy swales were explored and evaluated (see Chapter 5 for a full comparison on all treatment BMPs considered). However, due to treatment effectiveness for pollutants of concern, the Filterra Bio-Retention Units and the Master Vortechnics unit were deemed to be the most effective and feasible for the . La Costa Greens 1.16 development. Site design BMPs & Low Impact Design (LID) principles will also be implemented on this site to the maximum extent practicable to ensure water quality treatment is maximized throughout the La Costa Greens 1.16 development. As site design & LID BMPs, Filterra Bio-Retention Units will be located throughout the proposed development to provide site design/LID BMPs. Rooftop runoff from the residential structures will be discharged to vegetated landscaped areas adjacent to the homes, draining overland via the vegetated landscaping to the receiving area drain. The conveyance of treatment flows via the vegetated landscaping provides passive treatment for pollutants such as NLltrients' and Bacteria & Viruses. A full discussion is .provided within Chapter 5 of this report. Grassy swales within the interior of the project site were also evaluated and deemed infeasible. Grassy swales were deemed infeasible due to potential damage to street foundations (for swales running along road sections) and also swale areas often result in standing water that could lead to vector issues (see discussion provided in Chapter 5 for further details). The OperatIons and Maintenance plan for the proposed project has been Included in Section 8 of this report. DE:de H:IREPORTSI0490171ISWMp·FE·05.doc W.o, 49{).71 6123/20083:27 PM r-------------------------------------------------------------------------------- I I I I I I I' I I I I I I I I I I I I La Costa Greens Neighborhood 1.16 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. 1.6 -References "Standard Urban Storm Water Mitigation Plan -Storm Water Standards': City of Carlsbad, March 2008. "City of Carlsbad Engineering Standards, Volumes 1 -4': City of Carlsbad, 2004. "Master Drainage and Storm Water Quality Management Plan': City of Carlsbad, California; November 2007. '7M Drainage Study for La Costa Greens Neighborhood 1.17': Hunsaker & . Associates San Diego, Inc.; November, 2004. "Drainage Study for La Costa Greens Neighborhood 1.16': Hunsaker & Associates San Diego, Inc.; June, 2008. "San Diego County Hydrology Manual': County of San Diego Department of Public Works -Flood Control Section; June 2003. "Order No. R9-2007-0001, NPDES No. CAS01 08758 -Waste Discharge Requirements for Discharges of Urban Runoff from. the MuniCipal Separate Storm Sewer Systems (MS4s) Draining the Watersheds of the County of San Diego, the Incorporated Cities of San Diego County, San Diego Unified Port District and the San Diego County Regional Airport Authority", California Regional Water Quality Control Board -San Diego Region; January 24, 2007. "Water Quality Plan for the San Diego Basin", California Regional Water Quality Control Board -San Diego Region, 2006. 'Vortechnics Storm Water Treatment System Manual': Vortechnics; Revised May 2000. "Improvement Plans for La Costa Greens Phase 1A", dated 4/5/04 by O'day Consultants DE:de H:IREPORTS\0490171ISWMP-FE-05.doc w.o. 49().'·1 6123120082:55 PM I I I I I I I I I I I I I I I I I II i l La Costa Greens 1.16 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. R9-2007-0001, dated January 24 2007, sets waste discharge requirements for discharges of urban runoff from municipal storm separate drainage systems draining the watersheds of San Diego County. Per the RWQCB Order, post-development runoff from a site shall not contain pollutant loads which cause or contribute to an exceedance of receiving w*er quality objectives or which have not been reduced to the maximum extent ! practicable. Post-construction Best Management Practices (BMPs), which refer to specific storm water management techniques that are applied to manage construction and post-construction site runoff and minimize erosion, include source control -aimed at reducing the amount of sediment and other pollutants -and treatment controls that keep soil and other pollutants onsite once they have been loosened by storm water erosion. Post construction pollutants are a result of the urban development of the property and the effects of automobile use. Runoff from paved surfaces can contain both sediment (in the form of silt and sand) as well as a variety of pollutants transported by the sediment. Landscape activities by homeowners are an additional source of sediment. All structural BMPs shall be located to infiltrate, filter, or treat the required runoff volume or flow (based on the 85th percentile rainfall) prior to its discharge to any receiving watercourse supporting beneficial uses. 2.2 -City of Carlsbad SUSMP Criteria Per the City of Carlsbad SUSMP, the La Costa Greens Neighborhood 1.16 project is classified as a Priority Project and subject to the City's Permanent Storm Water BMP Requirements. These requirements required the preparation of this Storm Water Management Plan. The Storm Water Applicability Checklist, which must be included along with Grading Plan applications, is included on the following page. - DE:de H:\REPORTSI0490171\SWMp·FE·04.doc w.o. 491)..71 6/412008 6:42 PM I I I I I I I I I I I I I I I I I I I INSTRUCTIONS: This questionnaire must be completed by applicant in advance of submitting for a development application (subdivision and land use planning approvals and construction permits). The results of the questionnaire determine the level of storm water pollution prevention standards applied to a proposecl development or redevelopment project. Many aspects of project site design are dependent upon the storm water pollution protection standards applied to a project. Applicant responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City staff has responsibility for making the final assessment after submission of the development application. A staff determination that the development application is s.ubject to more stringent storm water standards, than initially assessed by the applicant, will result in the return of the development application as incomplete. If applicants are unsure about the meaning of a question or need help in determining "how to responcl to one or more of the questions, they are advised to seek assistance from EngineeringDepartment Development Services staff. A separate completed and signed questionnaire must be submitted for each new development" application submission. Only one completed and signed questionnaire is required when multiple development applications for the same project are submitted concurrently. In addition to this questionnaire, applicants for construction permits must also complete, sign and submit a Construction Activity Storm Water Standards Questionnaire. To address pollutants that may be generated" from new development, the City requires that new development and significant redevelopment priority projects incorporate Permanent Storm Wat(?r Best Management Practices (BMPs) into the project design, which are described in Section 2 of the City's Storm Water Standards Manual This questionnaire should be used to categorize new development and significant redevelopment projects as priority or non-priority, to determine what level of storm water standards are required or if the project is exempt. I 1. Is your project a significant redevelopment? Definition: Significant redevelopment is defined as the creation or addition of at least 5, 000 square feet of impervious surface on an already developed site. Significant redevelopment includes, but is not limited to: the expansion of a building footprint; addition to or replacement of a structure; structural development including an increase in gross floor area and/or exterior construction remodeling; replacement of an impervious surface that is not part of a routine maintenance activity; and land disturbing activities related with structural or impervious surfaces. Replacement of impervious surfaces includes any activity that is not part of a routine maintenance activity where impervious material(s) are removed, exposing underlying soil during construction. Note: If the Significant Redevelopment results in an increase of less than fifty percent of the impervious surfaces of a previously existing development, and the existing development was not subject to SUSMP requirements, the numeric sizing criteria discussed in Section F.1.b. (2)(c) applies only to the addition, and not to the entire development. 2. If your project IS considered significant redevelopment, then please skip Section 1 and proceed with Section 2. 3. If your project IS NOT considered significant redevelopment, then please proceed to Section 1. I I I I I I I I I I I I I I I I I I I I SECTION 1 NEW DEVELOPMENT PRIORITY PROJECT TYPE YES NO Does you project meet one or more of the following .criteria: 1. Home subdivision of 100 units or more. V Includes SFD, MFD, Condominium and Apartments 2. Residential development of 10 units or more. ,,/' Includes SFD, MFD, Condominium and Apartments 3. Commercial and industrial development greater than 100,000 sguare feet including earking areas. Any development on private land that is not for heavy industrial or residential uses. Example: Hospitals, V'" Hotels, Recreational Facilities, Shopping Malls, etc. 4. Heavv Industrial/Industry greater than 1 acre (NEED SIC CODES FOR PERMIT BUSINESS TYPES) / SIC codes 5013, 5014,5541,7532-7534, and 7536-7539 5. Automotive repair shop. t/" SIC codes 5013, 5014, 5541, 7532-7534, and 7536-7539 6. A New Restaurant where the land area of develoement is 5,000 sguare feet or more inCluding earking areas. //' SIC code 5812 7. Hillside development (1) greater than 5,000 square feet of impervious surface area and (2) development will grade on any V natural slope that is 25% or greater 8. Environmentallv Sensitive Area (ESA). Impervious surface of 2,500 square feet or more located within, "directly adjacent,,2 to (within 200 feet), V- or "discharginQ directly to,,3 receivinQ water within the ESA 1 9. Parking lot. ./ Area of 5,000 square feet or more, or with 15 or more parking spaces, and potentially exposed to urban runoff 10. RetaH Gasoline Outlets -serving more than 100 vehicles per da I::: ,,/" Serving more than 1 00 vehicles per day and greater than 5,000 square feet 11. Streets, roads, highways, and freeways. V Project would create a new paved surface that is 5,000 square feet or greater. 12. Coastal Development Zone. / Within 200 feet of the Pacific Ocean and (1) creates more than 2500 square feet of impermeable surface or (2) increases impermeable surface on property by more than 10%. 1 Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and Count of San Diego; and any other equivalent enVironmentally sensitive areas which have been identified by the Copermittees. 2 "Directly adjacent" means situated within 200 feet of the environmentally sensitive area. 3 "Discharging directly to" means outflow from a drainage conveyance system that is composed entirely of flows from the subject development or redevelopment site, and not commingled with flow from adjacent lands. Section 1 Results: If you answered YES to ANY of the questions above you have a PRIORITY project and PRIORITY project requirements DO apply. A Storm Water Management Plan, prepared in accordance with City Storm Water Stqndards, must be submitted at time of application. Please check the "MEETS PRIORITY REQUIREMENTS" box in Section 3. If you answered NO to ALL of the questions above, then you are a NON-PRIORITY project and STANDARD requirements apply. Please check the "DOES NOT MEET PRIORITY Requirements" box in Section 3. I I I I I I I I I I I I I I I I I I I I SECTION 2 SIGNIFICANT REDEVELOPMENT: YES NO 1. Is the project an addition to an existing priority project type? (Priority projects are defined in Section 1) If you answered YES, please proceed to question 2. If you answered NO, then you ARE NOT a significant redevelopment and you ARE NOT subjE:)ct to PRIORITY project requirements, only STANDARD requirements. Please check the "DOES NOT MEET PRIORITY Requirements" box in Section 3 below. 2. Is the project one of the following: a. Trenching and resurfacing associated with utility work? b. Resurfacing and reconfiguring surface parking lots? c. New sidewalk construction, pedestrian ramps, or bike land on public and/or private existing roads? d. Replacement of damaged pavement? -. If you answered NO to ALL of the questions, then proceed to Question 3. If you answered YES to ONE OR MORE of the questions then you ARE NOT a significant redevelopment and you ARE NOT subject to' PRIORITY project requirements, only STANDARD requirements. Please check the "DOES NOT MEET PRIORITY Requirements" box in Section 3 below. 3. Will the development create or add at least 5,000 square feet of impervious surfaces on an existing development or, be located within 200 feet of the Pacific Ocean and (1 )create more than 2500 square feet of impermeable surface or (2) increases impermeable surface on property by more than 10%? If you answered YES, you ARE a significant redevelopment, and you ARE subject to PRIORITY project requirements. Please check the "MEETS PRIORITY REQUIREMENTS" box in Section 3 below. If you answered NO, you ARE NOT a significant redevelopment, and you ARE NOT subject to PRIORITY project requirements, only STANDARD requirements. Please check the "DOES NOT MEET PRIORITY Rsquirements" box in Section 3 below. I SECTION 3 Questionnaire Results: ~ MY PROJECT MEETS PRIORITY REQUIREMENTS, MUST COMPLY WITH PRIORITY PROJECT STANDARDS AND MUST PREPARE A STORM WATER MANAGEMENT PLAN: FOR SUBMITTAL AT TIME OF APPLICATION. o MY PROJECT DOES NOT MEET PRIORITY REQUIREMENTS AND MUST ONLY COMPLY WITH STANDARD STORM WATER REQUIREMENTS. Applicant Information and Signature Box This Box for City Use Only Address: Assessor Parcel Number(s): City Concurrence: Yess No Applicant Name: Applicant Title: By: Applicant Signature: Date: Date: Project ID: I I I I I I I I I I ·1 I I I I I I I I La Costa Greens 1.16 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 Greens 1.16 development will consist of . attached multi-family residences. Thus, the Attached Residential Development, Parking Lots and Streets, Highways & Freeways categories have been highlighted to clearly illustrate which general pollutant categories are anUcipated from the project area. Priority Project Categories Detached Residential Commercial Development >100 000 ff Heavy Ind/lnd Development Automotive Repair Shops Restaurants X = anticipated p = potential III .... c G) .5 "C G) en X p(1) X X III "C c J!J c.> ::;, ~III C .-0 G) >.111 Co. .c .-'0: >-ca E III .. caS .... E'o ca.c ::;, G) G) ... G) z ::I::lE cu 1-0 X X p(1) p(2) X X X X X X(4)(5) X X X X (1) A potential pollutant if landscaping exists on-site. C)III G) III c G) ca ~ ._ c.> e c"C C .! III G) C ca C!) .. G) C)ca1i) G) III ~ >.E.c .... ::;, g.!:, >< G) ::;, 0 oOt/) Ill> X X X p(5) X p(3) X X X X X X X X (2) A potential pollutant if the project includes uncovered parking areas. (3) A potential pollutant if land use involves food or animal waste products. (4) Including petroleum hydrocarbons. (5) Including solvents. III G) "C . '(3 :;:; III G) a. X p(5) X DE:de H:IREPORTSI0490171ISWMP·FE·04.doc w,o.490·71 6/4/20088:42 PM I I I I I I I I I I I I I I I I I I I La Costa Greens 1.16 Storm Water Management Plan 3.2 -Sediment ,Soils or other surface materials eroded and then transported or deposited by the action of wind, water, ice, or gravity. Sediments can increase turbidity, clog fish gills, reduce spawning habitat, smother bottom dwelling organisms, and suppress aquatic vegetative growth. 3.3 -Nutrient! Inorganic 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 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 ~ stream and thereby lower its water quality. In areas where stagnant water is present, the presence of excess organic matter can promote septic conditions resulting in the growth of undesirable organisms and the release of odorous and hazardous compounds such as hydrogen sulfide. 3.5 -Oxygen-Demanding Substances Biodegradable organic material as well as chemicals that react with dissolved oxygen in water to form other compounds. Compounds such as ammonia and hydrogen sulfide are examples of oxygen-demanding compounds. The oxygen demand of a substance can lead to depletion of dissolved oxygen in a water body and possibly the development of septic conditions. 3.6 -Oil & Grease Characterized as high high-molecular weight organic compounds. Primary sources of oil and grease are petroleum hydrocarbon products, motor products from leaking vehicles, oils, waxes, and high-molecular weight fatty acids. Elevated oil and grease content can decrease the aesthetic value of the water body, as well as the water quality. DE:de H:IREPORTSI0490171ISWMp·FE·04.doc w.o. 490-71 6/4/20086:42'PM I I 'I I I I I I I I I I I I I I I 'I I La Costa Greens 1.16 Storm Water Management Plan 3.7 -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. , 3.8 -Bacteria & Viruses Bacteria and viruses are ubiquitous microorganisms that thrive under c~rtain environmental conditions. Their proliferation is typically caused by the transport of animal or human fecal wastes from the watershed. Water, containing excessive bacteria and viruses can alter the aquatic habitat and create a ,harmful environment for humans and aquatic life. Also, the decomposition of excess organic waste causes increased growth of undesirable or.ganisms in the water. 3.9 -Organic Compounds ' Organic compounds are carbon-based. Commercially available or naturally occurring organic compounds are found in pesticides, solvents and hydrocarbons. Organic compounds can, at certain concentrations, indirectly or directly constitute a hazard to life or health. When rinsing off objects, toxic levels of solvents and cleaning compounds can be discharged to storm drains. Dirt, grease and grime retained in the cleaning fluid or rinse water may also adsorb level of organic compounds that are harmful or hazardous to aquatic life. 3.10 -Metals, Metals are raw material components in non-metal products such as fuels, adhesives, paints and other coatings. Primary sources of metal pollution in storm water are typically commercially available metals and metal products. Metals of concern include cadmium, chromium, copper, lead, mercury and zinc. Lead and chromium have been used as corrosion inhibitors in primer coatings and cooler tower systems. At low concentrations naturally occurring in'soil, metals are not toxic. However, at higher concentrations, certain metals can be toxic to aquatic life. Humans can be impacted from contaminated groundwater resources, and bioaccamulation of metals in fish and shellfish. Environmental concerns, regarding the potential for release of metals to the environment, have already led to restricted metal usage in certain applications. DE:de H:IREPORTSI0490171ISVVMp·FE·04,doc w,o, 49(J..71 6/4120086:42 PM I I I I ,I I I I I I I I I I I I I I I La Costa Greens 1.16 Storm Water Management Plan CHAPTER 4 -CONDITIONS OF CON.CERN 4.1 -Receiving Watershed Descriptions As shown in the watershed map on the following page, the pre-developed La Costa . . Greens Neighborhoods 1.16 site drains to an unnamed tributary of San Marcos Creek which eventually discharges to the Batiquitos Lagoon within the San Marcos Creek watershed. . Development of the site will not cause any diversion to or from the existing watershed. . The Regional Water Quality Control Board has identified the Batiquitos Hydrologic' Subarea (basin number 904:51) as part of the San Marcos Creek Watershed within the Carlsbad Hydrologic Unit. 4.2 -303! d) Status 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 approved the 2006 CWA Section 303(d) List of Water Quality Limited Segments . Requiring TMDLS. San Marcos Creek is listed on the EPA's 303(d) List of endangered waterways as impaired by DOE, Phosphorus ~nd Sediment Toxicity. . 4.3 -Pollutants of Concern in Receiving Watersheds The beneficial uses for the Batiquitos Lagoon and San Marcos Creek (per table 2-2 from the 'Water Quality Plan for the San Diego Basin", included at the end of this Chapter), include Municipal and Domestic Supply, Agricultural Supply, Industrial Service Supply, Contact Water Recreation, Non-Contact Recreation, Warm Freshwater Habitat and Wildlife Habitat. The beneficial uses for the Batiquitos Lagoon (per table 2-3 from the 'Water Quality Plan for the San Diego Basin", included at the end of this Chapter), include Contact Water Recreation, Non-Contact Recreation, Preservation of Biological Habitats of Special Significance, Estuarine Habitat, Wildlife Habitat, Rare, Threatened, or Endangered Species, Marine Habitat, Migration of Aquatic Organisms, and Spawning, Reproduction, and/or Early Development. Table 3-2 from the 'Water Quality Plan for the San Diego Basin" (also included at the end of this Chapter) lists water quality objectives for a variety of potential pollutants required to sustain the beneficial uses of the San Marcos hydrologic area. DE:de H:IREPORTSI0490171ISWMP·FE·04.doc w.o. 490-71 614120087:19 PM r---------------------------------------------------------~---------------- I I I I I I I .1 I I I I I' ,I 'I I I I I La Costa Greens 1.16 Storm Water Management Plan 4.4 -Condition of Concern-Developed Condition Hydrology Summary Onsite and offsite hydrology for the La Costa 1.16 development is analyzed in the' report entitled "Tentative Map Drainage Study for La Costa Greens, Neighborhood' 1.16" by Hunsaker & Associates, Inc. dated January, 2006. This study is available for review in the office of the City Engineer. 4.5 -Identification of Primary & Secondary Pollutants of Concern As stated previously in segment 4.3, San Marcos Creek is listed on the EPA's 303(d) List of endangered waterways as impaired by DOE, Phosphorus and Sediment Toxicity. Thus, primary pollutants of concern from the proposed multi-family residential include Nutrients, Pesticides and Sediments. Secondary pollutants generated by the project site include Bacteria & Viruses, Heavy Metals, Trash and Debris, Oil and Grease, and Oxygen Demanding Substances. 85th percentile flows conveyed via the private storm drain will rec.eive treatment via proposed Filterra Bio-Retention filtration units filtering out trash and debris, sediments, organic compounds oxygen demanding substances, pesticides, oil/hydrocarbons, nutrients and bacterial pollutants to a high level of efficiency .. DE:de H:IREPORTSI0490171ISwMP-FE-04.doc w.o. 490-71 6/4/20086:42 PM ----------------. --2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQUIRING TMDLS 9 C Pacific Ocean Shoreline, San Clemente HA SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD 90130000 Indicator bacteria 3.7 Miles 2005 Impairment located at Poche Beach (large olltlet), Ole Hanson Beach Club Beach at Pico Drain, San Clemente City Beach at El Portal St. Stairs, San Clemente City Beach at Mariposa St., San Clemente City Beach at Linda Lane, San Clemente City Beach at South Linda Lane, San Clemente City Beach at Lifeguard Headquarters, Under San Clemente Municipal Pier, San Clemente City Beach at Trafalgar Canyon (Trafalgar Ln.), San Clemente State Beach at Riviera Beach, San Clemente State Beach at Cypress Shores. Nonpoint/Point Source f>.;:-'~ ~;;"::,:~;:.t· ... ~;'Y':~'~~:':',&~~S:<·~Xi.'S!.!<:£B.f<f.,';: <~\&'~~;'i(.:..rY1;':{:,~f.:~~':;.t\:&::.~;,,:.m:;J.;;'':.}':"'!' ; ....... ::1.::::w~;:.;.;1:-~~;~:1~';.~~-%:~\L.::-: "'~.ff(·)-~f.'-:"t\\.r: '''';~.;'')::,:-:?:;:!.,~~ ;~.:,\:., ;.'11'1 .... \',~,V!,,'»~~<):.";~·;(;,!· ... ~\;'!.;;-:'i'\:" ·:·~ .... ?,¥~,~;S\...,~'~'?·<r1-r .. :::~-'f.~,':;~'· ,,\.i:',:·,~·w:ht .:':f;:X:· ,; "')d\ :,.;:;,:::~ J: .• ~ ,;" ' .. :<,,~: f' i ~ :'-;.., {... :~r <~ .:: ,,,..: .. '''"'';, :,,,::,~;, -." ~,;;-: 9 C Pacific Ocean Shoreline, San Diego HU 90711000 Indicator bacteria 0.37 Miles 2005 Impairment located at Sail Diego River Mouth (aka Dog Beach). Nonpoint/Point Source tt:;:{".-:1>,;~~~\::'-l~:Y.~~\Ui{~"'iw.,-:;~~~,s~:;~gaJ.~r.::t..:s:0'fri.-)'''l:}l~~,\:~~Si:.()'~~:~;;~~~:;.i;{S:<~~'t9.f't:.:;:;'~~-:-i..i~·~v~~2,:~'!t\;~:;.-;~\&\f,.,:-\~-:!:.i;'~;~~::'" "':;',?\?'~1Y .. ;i.;-~r.r.~:·~\~ "";'J:~;:;' .. :iIE ~':,\:~;':,';':' ,;;., ·:;:',!';,·:;':;lWu",t;',';!-,;;\J~:'~'i~,~":"'1' ,~:,~ :;:,~ ';:\\~:'::;,::;'>"~ -. ,,"'(.;:J:::-:, ~:<' :'~'~~;l 'Y ;",>~., :.-;'~",:,:::;?~~..-,~,".' ';:", ( ." '.\ <':(""~'\. "'.~ J.;-I'.:; .. ". " "., \' . , "-'~'''-, ',: .. :., 9 C Pacific Ocean Shoreline, San Diequito HU 90511000 Indicator bacteria 0.86 Miles 2005 Impairmellliocated at San Dieguilo Lagoon Mouth, Solana Beach. Nonpoint/Point Source t';:~;-:'~ ••• ,~.·~:";,J:.o..\{\:.,!'-f,:-;;\-r"'.~:::J;?:;rM';:;M:~~..".0':WYJ,<;) .. ·~"~}:~;~,~~:\$:;t;<,;~'P;;~vl¢WJ~:'!&-i':r~;;_;(...~:;:~,~~"'~,"':;',,~c':'\.'~;).;-';~\<-:'i":"f,,~';:. ~t~>;,~, 'P.,Sf.:!·W;J,-.x/,: T,,;':: ;~:1\\,; ,"""1~.:\q. v -.-,::v:~\:-:::x.if'"~:t-: '-~';;,?l-~\'~ ..... -S-\~ ... ~-:{7"'·"'.!s: • .f:;f,i!o/,;"i':;~1-' ~ ~.~"'J"~ ~'~V""",::;.!;;-,\~:)/, ~~ F ;'{"-,$".7 > ',,~.;::,\,~ ~:~ ""'S,;... ';;'::,\',\"j}'~' •• ' ",,; ;. ..... ,<:"" 't', :i.'·.~::-~ .I-'~' .:~ ',".;;-:,(-\ ,,{y, •••• ;--;--. 9 C Pacific Ocean Shoreline, San Joaquin Hills HSA 90111000 Indicator bacteria 0.63 Miles Impairment located at Cameo Cove at II'I'ine Cove Dr.lRiviera Way, Heisler Park-North Urban Runoff/Storm Sewers Unknown Nonpoint Source Unknown point sour!!e 2005 i~;;;;$.;;.;r.1E'i.~;;;J·':?~~:;f.~':'~R;x:~~.m·:!..,,::,~v.~~~\II~;;:~wt~!.i.~z:~.itfti."0:;';(~W;;:}Si}'i.'V~\·::YN~.M~?J~~\~':'·:~~~..t~~;~'t~~~".:f,:.~~::';W~'f~~t~~~~:P:"\;'\\·~,~~:~·:·:.;;-{,:;:-;'':~.ol\!'\~~*1.;'~~,;."~~~t"~~r;;;,,.-:-*, .. ,;: .. ·..r; ..... ~~:';;:'~.:-~~,;:72.'Y;'·?::;;-:":;N:-'~$':'!.;/<r,~:.;,~.;{,.: ~\~.J.';v;;:~'''~;,'(;·-: f~:\~~~·,~.:.':~::.;~'{:)· ...... ~· ::::'f.:c:'c.\:;'·~\i~·.· ( ~,';::? 9 C Pacific Ocean Shoreline, San Luis Rey HU 90311000 Indicator'bacteria 0.49 Miles 200S Impairme1lt located at San Luis Rey River MOllth. Nonpoint/Point Source ~*"~~';{(\wh~~§y~.q..~~~~,>$'J«,$~IZ;:5~;r:'i1p;:;~v:J.'",,,7.'$1'1?;;S::~:S';"~~'rf.'::~~~~\~~:{$~-:;.~~~¢.~~g»,~w~';.l},.~~~.@.~f.'!'~~r;;-.i~:\r::'~:~AA;'J~ )%~l}:""<I\\\.~~'.%~.z:.;:t.~,~~,:·';Y~}\\:~:;'~~:'.;:\::('\~;;;2:r--:;r·m:;~!'">:M-,""}t.r.t::';;'~~;-:~'<;(';:A'\" ~iv.~\~ ~J: ~ ~~::':'.i..~,1.' :;-~;(.':,;:;:~:}::, (,. .. -?:t.:; ::''j,;' ·~"'-:\:~,;::·~:::'Y~':;':,,'~ .', r :;. ~/ ....... ,..:,: '~:', ", .... : :";~ ";~'<:' •• ?'\:'-;~ 9 C Pacific Ocean Shoreline, San Marcos HA 90451000 Indicator bacteria O.S Miles 2005 Impairment located at Moonlight State Beach. . Nonpoint/Point Source \~\~f~~ill:.t;;~~;U~~':;~11~~~W>.~~:$73'?'%~~\-i\~~f;I:tE<ltr'~~~\%iMf~~~::U;:::;;n~\~.:un::!\:"\~%«.~~.s;::.51hlli.fl~~:s.~e;,;~X~\t.~~;;~,:;;;~.~~~~;,t:J~~~;:-f,6~)3i1.~~J5,~:(:;,~:t:1£-;:%,~~t~\t~};~~~.G~y'}')Z."4:S:1:;'~~~~ ~~i\.~~rJ;\:,;t~,~.;.;',;··~'K:',.;;:';';··:-~~\ :Yn~~.\::z:~~ '1~0\~:\r..;~;r,:·;,'M~~r. ~~~~\")~1.;<;', (r·':!'"!, ·~;:~~:i.:;-:P!, ~:':t:r..;~:;:~?';?'-;17,~ 9 C Pacific Ocean· Shoreline, Scripps HA 90630000 Indicator bacteria 3.9 Miles 2019 This listingfor indica/or bacteria ollliy applies to the Childrens Pool Beach area of this ocean shoreline segment. Nonpoint/Point Source ~;~~":(~';'~Sd.~:«:.:':~;:S'k:.\\i.~;,w.~{~~~ ~:~~.!:'f..~:"y :1'1r'{flJ/i!.~:;:J~;{~\~~~.G~e:f~';!::.i:,%.~~:~\~~!r-~iE\~;~::"ti):~nl:;r:11~*;.0~?:~~::0:X·~~:~~ ~~"!:ws:> ... ,\l.,:\n:~'\~W~';i'\f.!~~~~:~1.:(t,~':?~:·:;',,,,:, =-:-4t,:;;;~~r:'";;;'i',?'G',:;.f{,,:,1t*.:~<i·~;:d':~/( ".'~'.t~~~~.r.f·:$i~"::Yi:'r"";,\"'~~~~;f't:·f,;~{::-v:-;~r~~ ·~,!::::~,:, ... ,~i~» ~.t';f,.,...f, ~:';'':-:4;~':,'~ J.SI:;':(~:,*,~"'1: Page 13 of27 - ------ ---------- --2006 CWA SECTION 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS REQIDRING TMDLS SAN DIEGO REGIONAL WATER QUALITY CONTROL BOARD. Total Dissolved Solids 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 USEPA APPROVAL DATE: JUNE 28, 2007 --,' '" ~'.' ','. ~:-J!" .... ..-:i":.-.~_ ~. I!! Miles 2019 t:::d:Jr~}_ ;::·-:k,·x>£~~;.;\~~'&:;~::rJ~«<-r.~·';;.'\\~:,~~~-r-j!,t;1:'-1~V\·NcK';;1.5;::: ... '1.:.::::;::n'?'I~{.r~.~ji>~:}::.f..::'1l;k;\;;,:~~f!..;~{\'.:n-:~z;.:::;:~W~J-;f\:!7h'i-~~;;W\{{t.,;.,~~Jt~Si~::';"~ ;'J',---t\ .\~!:.'\\, ~ I, ")~lf:r,.:.':'{:;:~':\\' ":'~'<::;~-. ·.,.Yd.".~t.~~:·, .,?",,~ ·r,;:.\::!"",,~, ~'~":'"9;.':::' ·;;:':\<:::·:*:E;::0):'~/·0::~' <':.;'~::.~/' .-;~ .. ;,,":,,~. :\":j:~:. ,?'~ .:.. '.' ,~'f " ~~"'< 'I~1-'" :.:;~ ,'~~';.: '.' . :::!' ", ., ... .;: 9 R San Marcos Creek 90451000 DDE 19 Miles 2019 Source Unknown Phosphorus 19 Miles 2019 Source Unknown Sediment Toxicity 19 Miles 2019 Source Unknown U-g0:':·~.11i ~~~.~:w.; ... ~~~~~~;.::::'t!".;,::;;,;~~~~;::.~r.;~.~;."1Z:~i&ili.%\:\*~;;32::';~~v~~z3: Z~1¥*:,ti©4R~1);:i;t:::i1tI..:'~;2T<.:.~:i:(~~1Ur,'?t~"'lt':f:~,::~::~~\.~.;1":.\i;r~';;.;'$:i,::',;;,,'{t::::;;:,):rs:::::.'J.,; ~f\=.~$'%,':::?f.~~ ... ~..%c:'::C~5Y,~~},A:·:.rt~~;~·~~\:~:.t.?;~;:~&~:r~~;; :~:-::~~'i:\::i~;:·'~:~",~}.~':;<\'{~~' ~;; \;';!.::.~' ~.,.".;,~~\,* 7,;' :.:--:',i}"';;' ,;;,-\~. K.,.~i"; :":;;':"::.(:: ;~. ::;.. 'r'~"::.;"::o, 9 L San Marcos Lake 90452000 Ammonia as Nitrogen 17 Acres 2019 Source Unknown Nutrients 17 ACloes 2019 Source Unknown Phosphorus 17 Acres 2019 Source Unknown 1~",~~:.it.·~.Z$;;';;I~~:-:~~~1.~~t:~7~i~~:~as*~:~~~~,.~:.w~(~'f::;:;$~});''?'i}-~\}:~::~tJ~~~;'~M~"1!H~~&·.r,~~:-,~~m:1:i.f .?~~~(?;;\,~~~:~~{;;\~f:..\()1< }~:~~~~~~~(..}~~~,:;~1..!\~~}:i.:?,~&1"$~~!:~':l.'X{,'{::\7~,·~":...,&1~.~~~*-";4:t";.:..~ .. v-:i~1i:;';';:! ~:~!..~~~;&':';~~~):"J;.~'T:~.,*f,\;',\"Y'!\~!~·Y''::i.':--;':~:, 'r.;-~;?'::':;~*;"'~~t(.~?, .... :~ .. ! ;S'i? ;t':',;:;;:~""Cf',~,,~~':,1;': 9 L San Vi~ente Reserv:oir 90721000 Chloride 1058 Acres 2019 Source Un!mown Page 21 0/27 - ----- -,-'------ -- Tabfe 2-2. BENEFICIAL USES 0·[-= INL.A{\I\lD SURFj~CE WATERS 1,2 IlI1l~aJlld Surface VVaters , ~'-.-.-. Sarfpiegn GOI,lhly 9Mstal 13trE)ams • co ntirtLlecl rt, ,t, " : ,I •• : to' Of .,' '0 Ejuena Vista Lagoon . ---J . . I. -T-. , '13u,enfl Y!sta. cr~ek . B4eha \(i~taqr~~I{ • '-I~ ___ -,--'-----__ , ____ .' j--;'-----,-------;--., -'.-.--,-, )\gua /'/edlonda HydrologIc Unit Basin Number 4.2" 4.72 4.21 4.31 Agua Hedionda Creek 4.32 rvr U N . + + A G R (ii) (J.;) I N o &1 Gl li'll I f) I COl P R o C G W R BENEFICIAL USE F P R R ROE E S W C C H 1 2 B I "0 L W A R M See Coastal Waters-Table 2-3 e) I ® I I ® ® I <II I I g See Coastal Wa{ers-Table 2-3 $ Ill) s ~ o L o - W I L o Cl!l f.ll III - R A R E ,j) s p W N - 6ll (/J (J,)" I /1.! I (!! Buena Creek 4.32 1--1 . I 1 __ . __ . __ • __ ID r» ~ (ll ® o ~ ~I Cl ® III r; LeUerbox canyon 4.31 Agua Iiedionda Creek 4.31 ® I GI a? I ® Canyon de las Encinas 4.40 + o I Ell \I) Gill Sa:i1lVlarcos Creek Watershed Elallquilos Uigooll 4.51 See Coaslal Waters-Table 2-3 San Marcos Creel< 4.52 -I< I I~ 'lD I (b !!P \I) unnamed IntermIttent streams 4.53 -I-I G'J @ I $ e ('jl San Marcos Greel{ Vlfat~rshud . San Marcos Creele 4.51 + I 0 fill I @ ,® t;J> Encinitas Creel~ 4.51 + I (!iJ ® I ® '~ G!l 1 Walerbodias are listed rnulliple-Umes if they cross hydrologic area or sub area boundaries. ·VI Ex/sting Beneficial Use I) Potential Bef!efidal Use 2 Benefic/al use designations apply til all tributaries 10 Ihe Indicated wa,lerbodY. If not listed separalely. -I-EJecepted From rvrUN (See Text) T"lJlo 7.-2 fjE~jcFICl"L U!iEG 2-27 March 12, 1997 - - - - - - - - - - - - --.----- - Ta~'~e t!'·"3"cBIE~Jl!EPI!CiAI\L USES or= COASTt\L VVj!\~TERS 2 Goas;tal VVaters Pac:lfic Ocelln Hydrologic Unit Basin Number N R N A E D V C 1 BENEFICIAL USE R C Ii E W R M E.O S J A A C iVI 0 T·L R R 2 M L D E A Q U A M S W S I P ~. H G W R E R N M L L (["1il1~1~~I~I~f:})I$ ·----------------1---- Dana Poinl Harbor Ql1 $1~J®I®It®, ~~ t~(il II&I~ ~~) tIiJ~ ~ ~~ @.~ ®.~ (~nl Del Mar Boat Basin @1@}I({fpI~I~ o ~J17I~I®I~ @ I ~j) ~ OCHanside Harbor !ll\ll ~ I ~~ !® I ~~'\) ,. @) ft'iiJ 6.lil @l ~ ~l Safl Diego Bay ~I@I~I~I~I~I~I~I~I® l@) 1 @l tru~ Coasial Lagoons Tijuana River EstuClrY 11.11 .... \ (~~ I lID 1 ~ I 11) I ~ I @~ I $ I ~ :. e I ~ <ifii Mouth of Sun Dingo River Olf& I $ I ® 7.11 11/)J I ~ ~i:l I '-1-1-1 ~ I Q'j ® @I@ flJb Los Penasquitos Lagoon . .. . 1--1-- San Diegulto Lagoon 5.11 iii) @ ~ @; @ f.?p ~~ @ @l 2 <®1t1!l! 6.10 @ I ~) I I @i'O '-----------1-----' . I--/--Batiquitos Lagoon 4.51 @ (hiP @} ~' ~ ~ ~ $ @l , r--~ __ _ San Elijo Laooon . 5.61 ®I I~ Ii} ® (j) ~~ @i . ~@ @) Aquo' Hedionda ,Lanoon L. @til Includes the tidal prisms of the Otay and Sweetwater Rivers. Fishing :trom shore or bout permitted, but other water contact rOGro.£1lional IREC-1) uses 'ure prohibited. @ Existing Beneficial Use TlIblu 2-3 BENEFICIAL USES 2-47 March 12, 1997 ----------------.---..-"" ...... Table 3 .. 2. WATER QUALITY OBJECTIVES Concentrations not to be exceeded more than 1 0% of the time during anyone one year ·period. _.----.- Constitiuerit (mg/L or as noted) Inland Surface Waters Hydrologic Unit Basin TDS CI S04 %Na N&P Fe Mn MBAS B ODQR Turb Color F Number NTU Units SAN LUIS REY HYDROLOGIC UNIT 903.00 Lower San Luis HA 3.10 600 250 250 60 a 0.3 0.06 0.5 0.75 none 20 20 1.0 Monserat HA 3.20 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 Warner Valley HA 3.30 500 250 250 60 a 0.3 '0.05 0.5 0.75 none 20 20 1.0 CARLSBAD HYDROLOGIC UNIT 904.00 Lorna Alta HA 4.10 ---------none 20 20 1.0 Buena Vista Creek HA 4.20 500 260 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 Agua Hedionda HA 4.30 500 250 250 60 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 4.50 500 250 ·260 60 a 0.3 0.05 0.5 . 0.75 none 20 20 1.0 Escondido Creek HA 4.60 600 250 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 SAN DIEGUITO HYDROLOGIC UNIT 905.00 . Solana Beach HA 5.10 500 250 250 60 a 0.3 0.05 0.5 0.76 none 20 20 1.0 Hodges HA .. 5.20 500 260 250 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 San Pasqual HA 5.30 500 260 260 60 a 0.3 0.05 0.5 0.75 none 20 20 1.0 Santa Maria Valley HA 5.40 500 250 2!;i0 60 a 0.3 0.05 ·0.5 0.75 none 20 20 1.0 ! Sant;l Ysabel HA . 5.50 500 250 250 60 a 0.3 0.05 0.5 0.75 none 20 ·2:0 1.0 i PENAS9,UliOS HYDRQLOGIC UNIT 906.00 " Miramar l1eservoir HA 6.10 5QO 250 260 60 a· 0.3 0.05 0.5 0.75 nona 20 20 1.0 Poway HA 6.20 500 .250 250 60 a 0.3 '0.05 0.5 0.75 none 20 20 ' 1.0 HA -Hydrologic Area . HSA -Hydrologic Sub Area (Lower case letters indicate endnotes'following the teble.) Table 3-2 WATER QUALITY OBJECTIVES Paga 3-23 S!lptainber 8. 1994 . ------- - -----------.-- - - -- --.. ' ,,,, ... '. j'" TabJe.3-::tv\fATER QUALITY OB~JECTIVIES COIlCEllltr.ations not to bo 6)(ceedea /lIore than 10% of the time during anyone year period. IGround W:~er -----~ ------------------------- C;:oristituent {mg/L or' 85 noted} Hydrologio Turb Color Basin Unit TDS CI SO'I %Na N03 Fe Mn MOAS 8 ODOR NTU Units F -Number Buella Vista Cmek HA 4.20 EI Saito HSA a 4.21 3500 BOO 500 GO 45 0.3 0.05 0.5 2.0 none 5 15 1.0 I Vista HSA a 4.22 1000 b 400 b 500 b 60 . 10 b 0.3 b 0.05 b 0.5 0.75 b nona 5 .11; 1.0 AglJ:! Hodionda HA a 4.30 1200 500 500 60 10 0.3 0.05 a.!) 0.75 none Ii Hi 1.0 --Le·s Monos I-ISA aj 4.31 3500 800 500 60 45 0.3 0.05 0.5 2.0 nona (j 15 1.0 Encinas· I-IA a 4.40 3500 b 800 b 500 b 60 45 b 0.3 b 0.05 b 0.5 2.0 b none 5 15 1.0 San Marcon HA ae . 4.50 1000 400 500 60 10 0.3 0.05 0.6 .0.75 none 5 16 1.0 . -'-- BlilIquitos HSA ook 4.51 3500 . BOO 500 60 45 0.3 0.05 0.5 2.0 none 5 15 1.0 Escondido Creek i I-IA n 4.60 750 300 300 GO 10 0.3 -0.05 0.5 0.75 none 5 15 '1.0 ----. Son Ellio HSA n 4.61 2800 700 600 60 45 . 0.3 0.05 0.5 1.0 none {j 15 1.0 Escondido HSA 4.62 1000 300 ~ 400 60 10 0.3 I-0.05. 0.5 0.75 nono 5 15 1.0 SAN DIEGUITO HYDROLOGIC Ul\lIT 905.00 Sol111la Bepch .. HA a 5.10 1500 b 500 b 500-b 60 45 h 0.85 b 0.15 b 0.5 0.75 b nono 5 'I!; 1.0 Hod;]os -HA 5.20 1000 b 400 b 500 b 60 10 b 0.3 b 0.05_ b 0.5 0.76 b nona 5 15 1.~ San Pasqual riA ri.30 1000 b 400 b 500 b 60 10 b 0.3 b 0.05 b 0.5 0.76 b none 5 15 1.0 ----8mr:'1 Muria Valley HA 5.40 1000 40~ . 500 60 10 .0.3 0.05 0.5 0.75 Ilone 5 15 1.0 --Snma Ysabel HA 5.50 500 250 250 _ • 60 5 0.3 0.05 0.5 0.75 none 5 15 1.0 PENJ.\SQUIT.OS HYDROLOGIC UNIT 906.00 Miromnr Resolvoir HA af 6.10 1200 500 500 60 10 0.:3" 0.05 0.5 0.75 none 5 15 '1.0 Poway' I-IA 6.20 750 q 300 300 60 10 '0.3 0.05 0.5 0.75 nano 5 15 1.0 Scripps I-IA 6.30 - --- -----------Miramllr I-IA 9 6.40 750 300 300 . 60 10 0.3 0.05 0.5 0.75 none [) 15 1.0 ~)lote HA 6.60 -------------~---.---'------------- IIA • lIydrologlc Am .. liSA· lIydroloUlc Sub Araa ILowDr cn60 loiters Indlcote ondnotuu raliowinU the table.] 'fublp 3-3 WATI!ll QUALITY ODJECTIVES Pugo 3-29 Ontch;,,. 13, 1 [l(H I I I I I I I I I I I I I I I I II , I I La Costa Greens 1.16 Storm Water Management Plan CHAPTER 5 -SITE DESIGN &.LOW IMPACT DEVELOPMENT (LID) BMPs 5.1 -Site Design & LID BMPs Priority projects, such as the La Costa Green 1.16 development, shall be designed to minimize, to the maximum extent practicable, the introduction of pol.lutants generated from site runoff and address conditions of concern that may impa9t the receiving watershed and/or downstream water conveyance systems. Site design & LID components can significantly reduce the impact of a project on the environment. Low Impact Development is an innovative stormvyater management approach with the basic principle that is modeled after nature: manage rainfall runoff at the source using uniformly distributed decentralized micro-scale controls. . LID's goal is to mimic a site's predevelopment hydrology by using design practices and techniques that effectively capture, filter, store, evaporate, detain and infiltrate' runoff close to its source. . 5.2 -BMP-1 -Minimize Directly Connected Impervious Areas Methods of accomplishing this goal include: Increase building density (number of stories above or below ground); Construct walkways, trails, patios, overflow parking lots and alleys and· other low-traffic areas with permeable surfaces, such as pervious concrete, porous asphalt, unit pavers, and granular materials; Construct streets, sidewalks and parking lot aisles to the minimum widths necessary, provided that public safety and a walkable environment for pedestrians are not compromised; Minimize the use of impervious surfaces, such as decorative concrete, in the landscape design. In order to achieve this site design BMP, all streets, sidewalks, and parking lots tb· the minimum widths necessary to be in acco(dance with standards set forth by the City of Carlsbad. 5.3 -BMP-2 -Conserve Natural Areas The current La Costa 1.16 project site is mass graded and awaiting ultimate development, hence there is no existing natural area to preserve. DE:de H:IREPORTSI0490171ISWMP-FE·04.doc w.o. 49Q. 71 6/4/2006 6:42 PM I I I I I I I I I I I I I ·1 I I I I I La Costa Greens 1.16 Storm Water Management Plan . 5.4 -BMP-3 -Minimize Directly Connected Impervious Areas Methods of accomplishing this goal include: Draining rooftops into adjacent landscaping prior to discharging to the storm drain. Draining roads, sidewalks and impervious trails into adjac'ent landscaping. These site design techniques will be implemented within the La' Costa Greens 1.16 development. Rooftop runoff will be discharged to vegetated landscaped areas on each resiqence, draining overland via the vegetated landscaping to the 'receiving area drain system. This conveyance through the natural landscaping provides passive treatment for these flows and also allows for partial infiltration via the on-lot vegetated areas, targeting the potential bacterial and nutrient pollutants of concern generated via each family residence. The Filterra Bio-Retention Filtration System is a landscaped concrete inlet box which contains a filter media mixture and a selected plant (small shrub or tree). The landscaping, either a tree or shrub, grows out of the box and through a grate at the top. The filter media captures and immobilizes pollutants from the storm water; those . pollutants are then decomposed, volatized, and incorporated into the biomass of the Filterra system's micro/macro fauna and flora. Stormwater runoff flows through the media and into an under drain system at the bottom of the cOl1tainer, where the treated water is discharged. Higher flows bypass the Filterra via a downstream inlet structure. 5.5 -BMP-4 -Maximize Canopy Interception & Water Conservation In order to maximize canopy interception and water conservation: Preserve existing native trees and shrubs; Plant additional native or drought tolerant trees and large shrubs in place of non-drought tolerant exotics. Landscaping on site will incorporate the planting of native, drought tolerant vegetation to meet this requirement. DE:de H:IREPORTSI0490171ISWMP-FE-OS.doc w.o.490-71 6123/200810:19 AM I I I I I I I I I I I ·1 I I I I I I I La Costa Greens 1.16 Storm Water Management Plan 5.6 ~ BMP 5/6/7/8/9 -Protect Slopes & Channels Methods of accomplishing this goal include: Use of natural drainage systems to the maximum extent practicable. Stabilize permanent channel crossings. 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. Minimize disturbances to n~tural drainages. All slopes will be stabilized by erosion control measures. All outfalls will be equipped with an energy dissipation device and/or a riprap pad to prevent erosion. . I DE:de H:IREPORTS\0490\71\SWMP·~E,04.doc w.o.490.71 6/4/200B 6:42 PM I I I' I '1' I, I- I I I· I I I I I II ,I I I La Costa Greens 1.16 Storm Wat~r Management Plan CHAPTER 6 -SOURCE CONTROL 6~ 1 -BMP 1 0 ~ Design Outdoor Material Storage Areas to Reduce Pollution This is not applicable,to the project site as no.hazardous materials will be stored outdoors. 6.2 -BMP 1 t -Design Trash Storage Areas to Reduce Pollution .Introduction '. . , ,It should be rioted that no trash storage areas will be located on the La Costa Greens 1.16 project site. Each individual residentis to store trash in their respective. garag$\mtil weekly collection. . 6.3 -BMP 12/13 -I'ntegrated Pest Management (lPM) Principles Integrated' p'est 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 cultur~1: 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://www.ipn.ucdavis.eduIWATERlUlindex.html). 6.3.1 -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 --Discourage pests by modifying the site and landscaping design. In order'to achieve this source ,control BMP objective, native vegetation will be used throughout the project site in accordance with the landscape architects plans. 6.3.2 -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; . -Physical pest elimination techniques, such as, weeding, squashing, trapping, washing, or pruning out pests; . -Relying on natural enemies to eat pests; -Proper use of pesticides as a last line of defense. The Homeowners Association will make all homeowners aware of the aforementioned RWQCB regulations through a homeowners' education program. Homeowners should be notified via HOA newsletter prior to the rainy season (o.ct. 15t) of storm water requirements. ,.' . ..... DE:de H:IREPORTS\0490\71ISWMP.FE·04,doc w,o,490-71' 6/4/20088:42 PM I I I I I I I I I ,I' I' I I I II I I I I La Costa Greens 1,16 Storm Water Management Plan 6.4 -BMP 14/15/16 -Efficient Irrigation Systems & Landscaping Oesign In compliance with the Water Conservation in, Landscaping Act, the following methods to reduce excessive irrigation runoff shall be implemented: ' ,. ,. Employ rain shutoff devices to prevent irrigation during and after precipitation. Design irrigation systems to each landscape area's specific water requirements. 'Use flow reducers or shutoff valves triggered by a pressure drop to control water loss in the event of broken sprinkler heads or lines. All Home Owners' Association (HOA) maintained landscaped areas will include rain shutoff devices to prevent irrigation d~ring and after precipitation. Flow reducers and shutoff valves triggered by pressUre drop will be 'used to control water loss from broken sprinkler heads or lines. " 6.5 -BMP 17 & 18 -Storm Water Conveyance Systems Stenciling and Signage The proposed development will incorporate concrete stamping, or equivalent, of all storm water conveyance system inlets and catch basins within t~e 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. 6.6 -BMP 19 -Private Roads The design of private roadway drainage shall use at least one of the following: Rural swale system-street sheet flows to vegetated swale or grave,! shoulder, curbs at street corners, cu,lverts under driveways and street crossings; Urban curb/swale system-street slopes to curb, periodic swale inlets drain to vegetated swale/biofilter; Dual drainage system-first flush captured in street catch basins and discharged to adjacent vegetated swale or gravel shoulder. The p~oposal of grass lined swales/biofilters lining the proposed private roads within the La Costa Greens 1.16 project has been evaluated and has been de,emed infeasible due to the following: Grass lined channels would be located beneath the grade level of the adjacent roads and sidewalks it serves to treat. However, water drained to these grassy channels would enter the existing clay type 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. DE:de H:\REPORTSI0490171ISWMp·FE..Q4,doc' w,o,490·71 6/4/20086:42 PM I I I, I I I I I I I I I I I I I.· I I I La Costa Greens 1.16 Storm Water Management Plan The site design proposes parking on the shoulders of the p~oposed private roads. As this is a sizeable multi-family development, extensive use of parking areas could lead to excessive wear and tear upon these proposed natural swales bordering the roads, causing erosion and silt pollutants to enter the storm clrain system. To ensure water quality treatment is maintained, the Filterra treatment units have been selected to ensure maximum treatment for pollutants of concern generated by the multi family development. 6.7 -BMP 20/21 -Residential Driveways & Guest Parking Driveways shall have one of the following: Shared access; Flared entrance (single lane at street); Wheelstrips (paving only under tires); Porous paving; Designed to drain into landscaping prior to discharging to the storm water conveyance system. As this is a multifamily development there is not.cm, allocated driveway, each residences garage borders the servicing private road. Hence this is not applicable to the project site. . Uncovered temporary or guest.parking on private residential lots shall be: Paved with a permeable surface; . Designed to drain into landscaping prior to discharging to the storm water conveyance· system. To ensure water quality treatment is maintained, the Filterra Bio-Retention treatment units have been selected to ensure maximum treatment for pollutants of concern generated by the multi family development, inclusive of external parking lots. DE:de H:IREPORTSI0490171ISWMP-.FE-04.doc w.o. 490-71 6/4120086:42 PM - - - - - - - - - - - - - -.... - - - - In the City of Carlsbad, storm drains flow directly into local creeks, lagoons and the ocean without treatment. Storm water pollution is a serious problem for our natural environment and for people who live near streams or wetlands. Storm water pollution comes from a variety of sources including oil, fuel, and fluids, from vehicles and heavy equipments, pesticide runoff from landscaping, and from materials such as concrete and mortar from construction activities. The City of Carlsbad is committed to improving water quality and reducing the amount ofpollutants that enter our precious waterways. A Cle.aro Environment is Important to 'AU of Us~ City of Carlsbad 1635 Faraday Avenue Carlsbad, CA 92008 Storm Water HOTline: 760-602-2799 stormwater@ci.carlsbad.ca.us March 2003 ------~------------ Pollution Prevention. is up to YOU! Did you know that storm drains are NOT connected to sanitary sewer systems or treatment plants? The primary purpose of storm drains is to carry rainwater away from developed areas to prevent flooding. Untreated pollutants such as concrete and mortar flow directly into creeks, lagoons and the ocean and are toxic to fish, wildlife, and .the aquatic environment. Disposing of these materials into storm drains causes serious ecological problems-and is PROHIBITED by law. Do the Job Right! This brochure was designed for do-it- yourself remodelers, homeowners, masons and bricklayers, contractors, and anyone else who us~s concrete or mortar to complete a construction project. Keep storm water protection in mind whenever you or people yoU' hire work on your house or property. Best Management Practices Best Management Practices or BMPs are procedures and practices that help to prevent pollutants such as chemicals, concrete, mortar, pesticides, waste, paint, and other . hazardous materials from entering our storm drains. All these sources add up to a pollution problem. But each of us can do our part to keep storm water clean. These efforts add up to a pollution solution! What YOU Can Do: • Set up and operate small mixers on tarps or heavy plastic drop cloths. • Don't mix up more fresh concrete or mortar than you will need for a project. . • Protect applications of fresh concrete and mortar from rainfall and runoff until the material has dried. • Always store both dry and wet materials under cover, protected from rainfall and runoff and away from storm drains or waterways. • Protect dry materials from wind. Secure . bags of concrete mix and mortar after they are open. Don't allow dry products to blow. into driveways, sidewalks, streets, gutters, or storm drains. • Keep an construction debris away from the street, gutter and storm drains. .• Never dispose of washout into the street, storm drains, :Iandscape drains, drainage ditches, or streams. Empty mixing 'containers and wash out chutes onto dirt areas that do not flow to s.treets, drains or waterways, or allow material to dry and dispose of properly. . . • Never wash ~xcess material from bricklaying, patio, driveway or sidewalk construction into a street or storm drain. Sweep up and dispose of small amounts of excess dry concrete, grout; and mortar in the trash. • Wash concrete or brick areas only . when the wash water can flow onto a dirt area without further runoff or drain onto a surface which has been bermed so that the water and solids can be pumped off or vacuumed up for proper disposal. . • Do not place fill material, soil or compost piles on the sidewalk or st~eet. • If you or yqur contractor keep a dumpster at your site, be sure it is securely covered with a lid or tarp when not in use. • During cleanup, check·the street and gutters for sediment, refuse, or debris. Look .around the corner or down the street and clean up any materials that may have already traveled away from your property. - - - - - - - - - - - --. - - -.-- - A Clean Environment is Important to· All of. Us! In the City of Carlsbad, storm drains flow directly into local creeks, lagoons and the ocean without' treatment. Storm water pollution is a serious problem for our· natural environment and for people who live near streams or wetlands. Storm water pollution comes from a variety of sources including oil, fuel, and fluids, from vehicles and heavy equipment, pesticide runoff from landscaping, dnd·from .. materials such as concrete, mortar and soil from construction activities. The City of Carlsbad is committed to improving. water quality and reducing the qmount of pollutants that enter our precious waterways. Storm Water Protection Program stormwater@ci.carlsbad.ca.us 760-602-2799 City of Carlsbad 1635 Faraday Avenue .. Carlsbad, CA 92008 l ~ Printed on recycled paper - - - - - - -.-.---.--. -:---, - -.- It's All Just Water,' Isn't It? Although we enjoy the fun and relaxing times in them, the water used in swit:nming pools and spas can cause problems for our creeks, . lagoons and the : ocean if not disposed of properly. When you drain your swimming pool, fountain or spa to the street, the high concentrations of chlorine and other chemicals found in the water flows directly to our storm drains. Did you know that these storm drains are NOT connected to sanitary sewer systems and treatment plants? The primary purpose. of storm drains is to carry rainwater away from developed areas to prevent flooding. . Improperly disposing of swimming pool and spa water into' storm drains may be harmful to the' environment: Best Management. Practices Best Management Practi~es or BMPs are -procedures that help to prevent pollutants like chlorine and sediment from entering our storm drains. Each of us can ~o our part to keep storm water' clean. Using BAAPs adds up to a poUution solution! How Do I Get Rid of Chlorine? Pool and spa water may be discharged to the storm drain if it has been properly dechlorinated and doesn't contain other chemicals. The good news is t.hat chlorine naturaUy dissipates over time. Monitor a~d test for chlorine levels in the pool over a period of 3 to 5 days. Drain the water before algae starts to grow. Consider hiring a professional pool service company to clean your pool, fountain, or spa and make sure they dispose of the water and solids properly. For more information about discharging wastewater to the sanitary . sewer, please contact the Encino Wastewater Authority at (760) 438- 3941. Before you discharge your swimming pool or spa water to the storm drain, the water: + Must not contain chlorine, hydrogen perOXide, acid! o~ any other chemicals .. ' +. Can not carry debris or vegetation. + Should hav~ an acceptabl~ pH of 7-8. + Can not contain algae or ,harmful bacteria (no "green" present); + Flow must be controlled so that it does not cause erosion problems. . Pool Filters Clean fi Iters over a lawn or other landsca'ped area where the' discharge' can be absorbed. ' .. Collect materials on filter cloth and dispose .into the trash. Diatomaceous earth cannot be discharged into the street or storm drain systems. Dry it out as much as possible, bag it in plastic anq dispose into the trash. Acid Washing Acid cleaning. wash water is NOT allowed into the storm drains. Make sure acid washing· is . done in a proper and safe mal'.lner that'is not , harmful to people or the environment. It may be discharged'into the sanitary sewer through a legal sewer connection after the pH has been adjusted to no lower than 5.5 and no higher than 11. Do the Job Rightl . • Use the water' for irrigation. Try draining de-c\1lorinated pool water gradually qnto .a. landscaped area. Water discharged to . landscape must not cross property lines and·. must not produ~e runoff. • Do not use copper-based algaecides. Control algae. with chlorine or other. alternci:tives tb copper-basec;f pool chemicals. Copper is harmful to the aquatic - environ~ent. . • (luring pool (:onstruction, contain ALL materials:and qispose of properly. '. Materials $uch as cement I Gunite,tnortar, . c,mq sedim~nt must not he discharged into .. the storm drains. - - - - - - - - - - - ----- -- - - connected to sanitary sewer and treatment plants? The mary purpose of. storm drains is to rainwater away from developed to prevent flooding. Untreated water and the pollutants it , flow directly into creeks, years, sources of water like industrial waters from e,-"tr.riac. have been greatly reduced. f\IA/allar now, the majority of water occurs from things like cars oil, fertilizers from farms and failing septic tanks, pet waste car washing into the sources add up to a pollution But each of us can do small help clean up ,our water and up to a pollution solution! -Pet waste photo is used courtesy of tlie Water Quality Consortium, a cooperative v~nture between the Washington State Department of Ecology, King County and the cities of Bellevue, Seattle and Tacoma. Storm Water HOTline: 760-602-2799 stormwater@ci.carlsbad.ca.us www.ci.carlsbad.ca.us l ~Prinled on recycled paper ---, - - ---- - - -,---~ - - - - - is a health risk to pets and ;;,t;;;)IJt:vlally children. It's a of bacteria that can make This bacteria gets the storm drain and ends ks, lagoons and ocean. ends up in shellfish living h may get very sick. V'.'HUUIt;;;) show that dog and co~tdbute up to 25% of 'ibh""tnria found in our local and clean up after as easy as 1-2-3! a clean environment " primary importance for health and economy . • 1.~J" • \.,,,,tarlA,,,,I/C provide opportunities, , fish habitat and to our , YOU can help creeks, lagoons clean by and be sure topick up Rafter your pets before 'patios, drive~ays and surfaced areas. Never waste into the street' or The' best way to dispose of pet waste, is to'flush it down the toilet'because , ' ' it' gets treated ,by a sewage treatment plant. , , Other disposal methods for pet " wast~ ,include seali,ng it in a b~g and placing in 'trash Q,f burying'smalL - quantities in you-r yard to" decompose. Be sure to keep it away, 'from'vegetable gardens. -: --' - - - - - - - - -.. - - - - - - .... :.: .... ".-,,', ,',,".;',,-: A clean'e'nvironment is import~nt to all of usl Did you know that storm drains are NOT connected to sanitary sewer systems and treatment plants? The primary purpose of storm drains is to carry rainwater away from developed areas to prevent flooding. Untreated storm water ano the pollutants it carries, flow directly into creeks, lagoons and the ocean. ::' :;,;; , In recent years, sources of water l::~\~' ',: , pollution like industrial waters from i''-;';",', factories have been greatly reduced. However now, the majority of water pollution occurs from things like cars leaking oil, fertilizers from fC}rms, lawns and gardens, failing septic tanks, pet waste and residential car washing into the storm drains and into the ocean and watelWays. ,All these sources add up to a pollution " proble~1 But ~ach of us can do small ", ", ~hln'gs' to help clean up our water and that adds up ~o a pollution solution! "e·---. .' Meter eil phete is used courtesy ef the Water Quality Consortium, a cooperative venture' between the Washington State Department of, Ecelogy, King Ceunty and the cities of Bellevue, Seattle and Tacoma. Only Rain in the'Storm Drain! City of Carlsbad Sterm Water Protection , Program City ef Carlsbad 1635 Faraday Avenue Carlsbad CA 92008 Sterm Water HOTline: 760-602-2799 Funded by a grant from tlJe 'Califernia Integrated Waste It !;eve 1.1'. Manageme,nt Beard l!SIW 011. l. ~ Printeil on recycled paper M oto;r~, 0 ii"',. ,'!\ " Only Rain in the Sterm. Drain!.' ',,: . . ' " -: :::, :",:, :" :. :', ' -... ---- - - - - - --.-.:-.. - -.. - - ': .. :.,' Oil does not dissolve in water. It ,lasts a.long time and stic~s to :',' everything from beach sand to bird feathers. Oil and other petroleum : ',:': .:, 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. 'i.,Used motor oil is the largest single /,~ource of oil pollution in our ocean, and lagoons. Americans spill , .80 million gallons of used oil each ;i'!:':year into our waters. , .::This is1 ~ times the . ! 'amount spnted by the '. Exxon Valdez in .," ... ·Alaska. !.',' l~/:· ' .. ~\ ~':;'.' fJ;':, : ",', f" ; . t~:~":.< .. ;. :.: :' :'''1 •• ::1':" r~\~~: . t/;::,'.~ " " rl{:':::" ':,,' ;::::: ! ... :~~. How can YOU help keep our environment clean? Having a clean environment is of primary importance for our health and economy. Clean waterways provide commercial opportunities, recreatibn, fish habitat and add beauty to our landscape. YOU can help keep our ocean, creeks and lagoons clean by applying the following tips: • Stop drips. Check for oil leaks regularly and fix them . promptly. Keep your car tuned to reduce oil use. • Use ground cloths or drip pans beneath your vehicle if you have leaks or are doing engine work. • Clean up spills immediately . Collect all used oil in containers with tight fitting lids. Do not mix different engine fluids. • When you change your oil, dispose of it properly. Never dispose' of oil or other engine fluids down the 'storm drain, on the ground or into a . ditch .. • Recycle used motor oil. There" . . are several locations 1n Cgrlsba~ that accept used motor oil. For hours a~d locations, call 760-434-29~O. - . • Buy recycled ("refined") motor oil . to use .in your car. --- -- que los desagues de "I""ntarillas no estfm al sistema de drenaje a las plantas de tratamiento negras? principal del desagiie 6 las es remover el agua de lIuvia y ir inundaciol.'!es. EI agua que entra lies va directamente a los y el oceano junlo con la depositada en las y las calles. conlribuimos a un gran contaminaci6n. IPero cada puede hacer algo para y participar en la soluci6n -----,-------:- "Cui II es el problema creado por el' uso de fertilizantes y pesticidas?- EI fertilizante no es un problema SI se usa con cuidado. Usar un exceso de fertilizante 6 en la temporada incorrecta resulla en el que el fertilizante se deslave con la lIuvia y se vaya por el desagiie 6 alcantarillas a nuestros arroyos, lagos y eloceano. Los fertilizantes en nuestros lagos y arroyos hacen que las plantas crezcan, tal como en el jardin. Pero en el oceano el fertilizante causa que las algas y plantas acuilticas sobrecrezcan. Y el exceso de algas marinas pueden ser daninas a la calidad del agua y causar que la pesca, nataci6n y navegaci6n sean desagradables. AI echarse a perder las algas consumen el oxlgeno del agua que los peces y olros animales necesilan para sobrevivir. La fotografia al frente es cortesla del Consorcio de Cali dad de Agua. en cooperacion can el Departamento Ecologico del Estado de Washington. el Condado de King. y las ciudades de Bellevue. Seattle y Tacoma. . \{\ the Slo ~~ \f"'?,o ~ ,0 ~ . ~ ~ ~. o 2- If). E 9. It ~ tt: ~o -~1. . ",<I. fir Prolec\\O Linea de Asistencia: 760-602-2799 stormwater@ci.carlsbad.ca.us Ciudad de-Carlsbad 1635 Far~day Avenue Carlsbad CA 92008 www.cLcarlsbad.ca.us t.~ Pri~lod on recycled papor ---- ---- medio ambiente Iimpio es para nuestra salud y la Conservar el agua lim pia oportunidades para usos recreativos, habitat para y agrega belleza a - T odos po.demos ayudar los arroyos, las lagunas, y el sencillamente siguiendo o usar maquinas no permita que las hojas y el casped recian'cortado en las alcantarillas 0 el de irrigaci6n de goteo tacnicas de conservaci6n del qrl:lferible regar por la manana. !~~., r~ic:t"'mas de.riego automatico eficienles si se programan de cinco mimitos y mas .ntom9nte para que el ag\la bien· lei tierra, --.--.- • Mantener los sistemas de irrigacion limpios y en buenas condiciones es importante para reducir el desperdicio del agua. Regar solamente cuando sea necesario reduce el uso del agua y ahorra dinero. '''' .... ~.;,./ .. "":""·: ... 't·.·:·.il". fl."'.'.'.".:.):".:'.;.'."'.". ;~;i.!l)I:Uj."~.·.·. 'ij.'.'11.· .. ,"'I •. " .. o; .. "H""~~' ~~~"t"IMi,;<." ''''\~';h~'!,''\','ttI :·:{~~t!~.1;. ~c(,~ t~~.:~~.'·.,I.·"::t~i.. \;';i/.~\il~:\j~::I~ ~('" \~i\'.:~:, ~'~ff ~~! :·\~~!:~f\',~lt;~r'~ ,', ~~,:,j,~~~,;}~.I;',1}~ ;~. "· . .'·'·~.l~·~ ... '."'iIl''''' .'fiJ, ,I '·'.;···i'<"j.~~: \v·.:"'''''''. "",\ .'11' .• ! :!.h~;~);'~'-. t>t' ·'~"I~\.'Yr.;\ :1 ) .. ,'J'~" ',1 1~~ I 1'~,ii~;4~~I';\;f,R,.,i!fJ·; I~f:yl!',~~':{ ~f:~~<' I~;_~ ~~.~:"'I',~\ 1~~li~;~I~~\t;I' _~' ~ ~ '! ~.;~;;~. I'~~' Para mas informaci6n sobre sistemas de riego lIame al 760-438-2722. • Los pesticidas y fertilizantes deb en usarse solamente cuando sea absolutamente necesario. • Para mantener un pasto saludable se recomienda, hacer un analisis de la tierra para determinar cuales ferlilizantes aplicar y en que temporada. • Es recomendable usar ferlilizantes organicos en vez de productos quimicos. -.--- En ocasiones se puede dejar el sacate recian cortado sobre el pasto ya que actua como un fertilizante natural. • EI uso de pesticidas debe ocurrir solo como ultimo recurso. Es preferible usar productos que sean bajos en t6xicos, por ejemplo jabones . insecticidas, acido borico, etc: Seguir las instrucciones en la etiqueta y usar el producto correctamente evita contaminar el agua de riego y lIuvia. • Cuando sea posible es preferible usar insectos predadores para controlar plagas. • Los pesticidas y fertilizantes vencidos deben desecharse legalmente lIevandolos a los centros de coleccion de substancias t6xicas localizados en varias ciudades del condado de San Diego. Llame al 760-602-2799 para obtener mas informacion. - -- Master Gard~ner5 EI condado de San Diego y la de California Extension creado el programa de Master Los expertos de este programa disponibles para proporcionar sobre plantas y plagas. Usted lIamar a la linea de Master 858-694-2860 de lunes a 9am y 3pm para obtener preguntas. La pagina Interne~ mastergardenerssandiego.org es recurso con informacl6n sobre temas. Esta informacion es gratis al publico. - - ---- unnelOleu to sanitary sewer and treatment plants? purpose of storm drains rainwater away from areas to prevent flooding. storm water and the and the ocean. years, sources of water industrial waters from have been greatly reduced. . now, the majority of water \ o'ccurs from things like cars fertilizers from farms and . . residential car washing into drains and into the ocean , clean up our water and up to a pollution solutionl --- --.-.--- - What's the problem with fertilizers and pesticides? Fertilizer isn't a problem-IF it's used carefully. If you use too much fertilizer or apply it at the wrong time, it can easily wash llff your lawn or garden into storm drains and then flow untreated into lakes or streams. Just like in your garden, fertilizer in lagoons and streams makes plants grow. In water bodies, extra Ertilizer can mean extra algae and aquatic plant growth. Too much algae harms water quality and makes boating, fishing and SWimming unpleasant. As algae decay, they use Lip oxygen in the water that fish and other wildlife need. Fertilizer photo Is used courtesy of the Water Quality Consortium, a cooperative venture between the Washington State Department of Ecology. King County and the cities of Bellevue, Seattle and Tacoma. \(\ the Sto riP 11"", ~ ·6 ~ • 11\ c: (JY ;i o "._ (J) E: 'C r,) -t;j ~ tv. ( (l~ OJt", "0"" 'or Protec.'~ Storm Water HOTline: 760-602·2799 stormwater@ci.carlsbad.ca.us I ! I ! ! City of Carlsbad 1635 Faraday Avenue Carlsbad CA 92008 www.ci.carlsbad.ca.us 1\ L.jPrlntod on rocycled pap~r ---.. - - -- - opportunities, recreation, and add beauty to our YOU can help keep our into the street or gutter. - yard waste or start your own pile. soaker hoses or micro- and water early in the consi~er adjusting your method to a cycle and . .Instead of watering for 15 . straight, break up the _:--.- session into 5 minute intervals allowing water to soak in befor~ the next application. ~J~l~:~;;l~ ·K~Y.~f:~~~!~tl!.),h~:::.~~~~:;fq~~t:~j:i~W1J'~"'~~'I~4i Ii jt,'~~i :~11 ~.~~l~i!:::~,i,::.;:.~t'.:~I;t ~I;~'.;;j i\~~'I~.\ffi.\t~~il·~'t,rl ~\ J~:~: ,·';,.l~:' . :~'I"\i~,-i;(':"t~~";ri I " /t:',rtl:·f'iY»' .:t,1f~ '.'\ :".l· .. t'.rJ''''~i.,;~ "i""/ ., .. :~'h~·1 iI~ ,·1,''', ii&!., '~~.~~' J ~;,~".:<,:~:,:.t:,'Ii·r)1 ,J,:"s~~r(~I.-'~.&:, '~:!~i,'l:~,ll:' ".~;:.:::_: • .,t ;:'~' ".,~~iljr~!h!'1 !., .. l'(~,;, '.:.'\Ji~'" 'i.I'J~II' I. ~ '?" ,\j!JJ,~""f1tiI~ Il"'-P' .. , ... ~ :r··.\gt\'.:i·-~:'At' IIl'1.t' "'··:fr· "" '·,.'f· '. . .. ', "'''''v''~. r"'''','''I., .~.:"."" h",t( .. .,. t" "." PI"'" ·""""'~.I . 'Jj'~'J. ~II " "!. j ~_ ., .... '" ", .' ra:tMi ",,~, .~-'~ f,.! "r.1 "~I\ -\lj . . _ ... r ~,I,", ,'~'. '/''.''''''~ • Keep irrigation systems well- maintained and water only when needed to save money and prevent over-watering. ~ Use fertilizers and pesticides sp~lringly. • Have your soil tested to determine the nutrients needed to maintain a healthy lawn. • Consider ur;;ing organic ferlilizers- they release nutrients more slowly. • Leave mulched grass clippings cn the lawn to act as a natural fertilizer. -'----.--- - • Use pesticides only when absolutely necessary. Use the least toxic product intended to target a specific pest, such as insecticidal soaps, boric acid, etc. Always read the label and use only as directed. • Use predatory insects to control harmful pests when possible: • Properly dispose of unwanted pesticides and fertilizers at Household Hazardous Waste collection facilities. For more information on landscape irrigation, please call 760-438-2722. Master Gardeners San Diego County has a Master Gardener program through the University of California Cooperative Extension. Master Gardeners can provide good about dealing with specific plants. You may call the Gardener Hotline at 858-694-281 check out their website at - -. -- - ------ ----. -- -- - OT connected to. sanitary sewer and treatment plants? The mary purpose of storm drains is to :carry rainwater away from developed :'areas to prevent flooding. Untreated water and the pollutants it flow directly into creeks, n recent years, sources of water lution like industrial waters from ,.HnlAU::l\//:>r, now the majority of water HJUIlUlIUl1 occurs from things like cars ng oil, fertilizers from farms and n~rtionc, failing septic tanks,. pet yvaste r\rnnloml But each of us can do our to help clean up our water and adds up to a polluUon solutionl ~ ~~ _ ... - - -,-- -.-.. _' - - - - --. -'.-- - - no problem with washing your just how and where you do it. soap contains pnosphates and chemicals that harm fish and quality. The soap, together with metal and oil washed from :car, flows into nearby storm which run directly into lakes, or marine waters. '. osphates from the soap can smell bad, and harm water As algae decay, the process oxygen in the water that fish o 0 o o o <> How can YOU help kee'p the environment clean? Having a clean environment of primary importance for r health and economy. lean waterways provide Imar"i~1 opportunities, rO"I""",tiM, fish habitat and our ocean, creeks and clean by applying tips: soap sparingly. a hose nozzle with a trigger to our your bucket of soapy water the sink when you're done, not using engine and wheel la~nar", or degreasers. your car to a commercial c~r especially if you plan to "Clean the engine or. the bottom of your car. Most Gar washes. reuse wash water . . 'several times before sending ·it to the sewer systell! for treatment. • Hire only mobile' detail oper.ator~ that will capture, wash water and chemicals. It is unlawfl,lI.for: comme~cial vehicle washing· , operators to allow wash water to enter the storm drain system. I I I· I I I I· II. I I I I· I I I I I I II La Costa Greens 1.16 Storm Water Management Plan Chapter 7 -TREATMENT CONTROL BMP DESIGN 7.1-SMP Location To provide maximum water quality treatment for flows generated by the proposed development, Low Impact Development based BMPs are to be employed throughout the multi-family site. Flows generated via the site will drain to multiple Filterra S'io- Retention Filtration Systems located throughout the site to provide high levels of treatment for pollutants generated via the residential deyelopment. In order to"meet LID requirements of providing treatment near the source of the pollutants, Filterra un!ts are located at every inlet within the project site, Downstream of the La Costa 1.16 project site, master treatment control BMPs were constructed to treat portions of the overall La Costa Green development '85th percentile runoff generated by the La Costa 1.16 development is treated prior to discharge to the receiving La Costa Golf Course. Flows tributary to the northern storr:n drain system (La Costa Greens 1.17) are treated via an existing Vortechnics Model 7000 flow based treatment unit. This unit was constructed as part of the . adjacent La Costa Greens 1.17 residential development and has been sized in anticipation of the ultimate development of both the La Costa Greens 1.17 and La Costa Greens 1.16 residential developments. The map on the following page shows the location of the proposed BMPs. 7.2 -Determination of Treatment Flow 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 BMP's utilize either mechanical devices (such as vaults that produce vortex effects) or non-mechanical devices (based on weir hydraulics and specially designed filters) to promote settling and removal of pollutants from the runoff. 85th percentile flow calculations were performed using the Rational Method. The basic Rational Method runoff equation is as follows: Design flow (Q) = C * I * A Runoff Coefficient (C) -The runoff coefficient for the treatment unit was determined using the areas analyzed in the final engineering hydrology report. The runoff· coefficient is based on the following characteristics of the watershed: Land Use -Multi-Family Residential Soil Type -In order to provide a conservative flow estimate, type D soil is assumed as this provides the highest possible runoff coefficient. OE:de H:IREPORTSI0490171ISWMP,FE,04.doc w.o.490,71 614120086:42 PM· --------- 50 100 -------- !, r .,,,,,,,,,,fAnlE IJ _ IAAP 80IJNDARr IIIPEIMOUS AREA ~ WlDSCN'ING AREA h:" : ;:,::1 WETAW COM£fNiCE AREA VICINITY MAP HIS 8 FlLIDIRA BIO-IIf[fEJ{TI( UD 1REI7IIENl' UHI1S --- ---- - LA COSTA GREENS NEIGHBORHOOD 1.16 CITY OF CARLSBAD, CALIFORNIA -- 1 OF 1 07 I I I I ·1 I I I I I I I I I I I' I I '. La Costa Greens 1.16 Storm Water Management Plan . . Rainfall Intensity (I) -Regional Water Quality Control Board regulations and NPDES .criteria have established that flow-based BMPs shall be designed to mitigate a rainfall intensity of 0.2 inch per hour. Watershed Area (A) -Corresponds to total area draining t6 treatment uhit. The 85th percentile flow rate has been calculated using the Rational Method. Required data for the Rational Method Treatment flow determination is as follows: . Table 3 -Onsite LID Flow Based 85th Percentile Calculations Total Rainfall 85th .. BMP' Drainage Intensity -Runoff Percentile .. Location Area Coefficient: (acres) (inches/hour) : Flow (cfs) Filterra Unit 1 . 0.59, 0.2 0.63 0.07' FUterra Unit 2 0.5'8 0.2 0.63 0.07 Filterra Unit 3 ' 0.37 0.2 0.63 0.05 Filterra Unit 4 1.01 0.2 0.63 0.13 Filterra Unit 5 '1.08 0.2· 0,63 0.14 Filterra Unit 6 0.62 0.2 0.63 0.08 Filterra Unit 7 1.26 . 0.2 0.63 0.16 Filterra Unit 8 0.59 0.2. 0.63 0.07 Filterra Unit 9 0.72 0.2 0.63 0.09 Filterra Unit 10 0.69 0.2 0.63 0.09 Table 4 summarizes 85th percentile rational method flOw calculations for the existing water quality treatment BMP for the La Costa Greens Neighborhoods 1.16 & 1.17 developments. Table 4 -Master Flow Based 85th Percentile Calculations BMP Total Drainage Rainfall Runoff 85tn Location Area. Intensity Coefficient Percentile (acres) (inches/hour) Flow (cfs) Neighborhood 55.7 0.2 0.58* 6.5 1.17 * = weighted C coefficient Rational method calculations predict an 85th percentile flow of approximately 6.5 cfs from the La Costa Greens 1.16 and adjacent La Costa Greens 1.17 tributary areas. DE:de H:IREPORTSI0490171ISWMP-FE-04.doc w.o. 490-71 61412006 6:42 PM I' I I I. I· I I I I I I I I I I I I I I La Costa Greens 1.16 Storm Water Management Plan 7.3 -BMP Unit Sizing . 7.3.1 Filterra Unit Sizing Filterra Bio-Retention inlets ate sized in accordance with the ·85th percentile treatment flow generated by the tributary area. The Filterra unit can vary in size from approximately 4-feet x 6.5-feet through to a maximum sizing of 6-feet x·12·:feet. . The Filterra inlets are sized to intercept only the 85th percentile flows, peak flows bypass the unit and are intercepted via a storm drain inlet downstream of the unit. FILTERRA TREATMENT CAPACITY TABLE. 85tn Pct. Recommended Treatment Capacity Treatment Unit Design Flow : Filterra Model (cfs) (cfs) Filterra Unit 1 0.07 4' x8' 0.074 Filterra Unit 2 0.07 4' x8' 0.074 . Filterra Unit 3 0.05 4'x6.5' 0.06 Filterra Unit 4 0.13 6' x 10' 0.14 Filterra Unit 5 0.14 6' x 12' 0.17 Filterra Unit 6 0.08 6' x6' 0.083 Filterra Unit 7 0.16 6' x 12' 0.17 Filterra Unit 8 0.07 4' x8' 0.074 Filterra Unit 9 0.09 6' x 8' 0.11 Filterra Unit 10 0.09 6' x 8~ 0.11 7.3.2 Vortechs Unit Sizing The existing Vortechs unit is an offline precast treatment unit. The 85th percentile design flow rate will be diverted into the treatment area by a diversion weir built in the upstream junction. Flows in excess of the design flow rate passover the weir' and proceed downstream. The calculations determining the peak flows being forced into the treatment during a 1 OO-year storm event will govern the sizing requirements necessary to adequately treat the entire flow passing through the unit during this significant rainfall event. The following table shows the treatment capacity of the Vortechs treatment unit. VORTECHS UNIT TREATMENT CAPACITY TABLE 85tn Pct. Treatment Unit Design Flow (cfsl La Costa Greens 6.5 1.17 Recommended Vortechs Model 7000 Treatment Capacity (cfs) 11.0 DE:de H:IREPORTS\o4901711SWMP-FE-04.doc . w.o. 490-71 6/4/20086:42 PM I I I I I I I I I I I I I I I I I I , I La Costa Greens 1.16 Storm Water Management Plan' The treatment capacity of the Vortechs Model 7000 is greater than the treatment flow provided from the 85th percentile flow. Flow generated by the 100 Year storm however directs increased flow to the unit of approximately 9.8 cfs. As such, a Vortechs Model 7000 has been selected to treat storrn water runoff from the proposed La Costa 1.16 development. 7.4 -Filterra Bio-Filtration Units The Filterra Bio-Retention Filtration .System is a landscaped concrete inlet box which contains a filtet media, mixture and a selected plant (small, shrub or tree). The landscaping, either a tree or shrub, grows out of the box and through a grate at the top. The filter media captures and immobilizes pollutants from the storm water; those, pollutants, are then decomposed, volatized, and incorporated into the biomass of the Filterra system's micro/macro fauna and flora. Stormwater runoff flows through the, media and into an under drain system at the bottom of the container, where the treated water is discharged. Higher flows bypass the Filterra via a downstream inlet structure. 7.5 -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 technologies to 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 a,nd settles back onto the pile after the storm even~ 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. DE:de H:\REPORTSI0490171ISWMP·FE·05,doc W,O. 49Q.71 6123/2006 10:20 AM i I I I I I I I I I, I' I I I II I I I I I La Costa Greens 1.16 Storm Water Management Plan 7.6 -Pollutant Removal Efficiency Table The table below shows the generalized pollutant removal efficiencies for biO- retention facilities. The proposed Filterra Bio-Retention filtration units target trash and debris, sediments, organic compounds oxygen demanding substances', pesticides, oil/hydrocarbons, nutrients and bacterial pollutants to a high level of efficiency. Table 4. Structural Treatment Control BMP Selection Matrix Settling Infiltration Trash Racks & Bioretention Wet Ponds Facilities High-rate Pollutants of Facilities Basins and Media High-rate media' Hydro Concern (Dry or Filters biofilters -dynamic (LID) Wetlands Practices filters Ponds) (LID) Devices Coarse Sediment HIGH HIGH HIGH:, HIGH HIGH HIGH HIGH HIGH and Trash , Pollutants that tend to associate HIGH HIGH HIGH HIGH HIGH MEDIUM MEDIUM LOW with'fine particles during treatment Pollutants' that tend to be MEDIUM LOW MEDIUM HIGH LOW LOW LOW LOW dissolved following treatment Pollutants that tend Pollutants that tend Pollutant Coarse Sediment to associate with to be dissolved and Trash fine particles during following treatment treatment Sediment X X Nutrients X X " Heavy Metals ' X Organic Compounds X Trash & Debris X OXYQen Demanding X Bacteria X Oil & Grease X Pesticides X 7.7 -BMP Unit Selection Discussion 7.7.1 Extended Detention Basins Extended detention basins collect the first flush runoff volume and retain it in the basin for a period of 24-48 hours. DE:de H:IREPORTSI0490171ISWMP-FE-04,doc w,o.490-71 6/4120086:42 PM I I I I I I I I I I I' I I I I I I II I La Costa Greens 1.16 Storm Water Management Plan 85th 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 hasin and discharge runoff to the natural drainage course downstream. 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. • 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. limita~ions • Limitation of the diameter of the orifice may ndt allow use of extended detention in watersheds of less than 5 acres (would require an orifice with a diameter of less than 0.5 inches that would be prone to clogging). • Dry extended detention ponds have only moderate pollutant removal 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 aesthetics of dry, bare areas and inlet and outlet structures. Conclusion: Due to limited treatment efficiency for pollutants of concern, an extended detention basin was not selected as a BMP treatment control for the La Costa 1.1.6 development. 7.7.2 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 through a subsoil matrix, and/or infiltration into the underlying soils. Swales can be natural or manmade. They trap particulate pollutants (suspended solids and trace metals), promote infiltration, and reduce the velocity of stormwater runoff. Vegetated swales 'can serve as part of a stormwater drainage system and can replace curbs, gutters and stormwater systems. , ' DE:de H:IREPORTSI0490171ISWMP-FE-04,doc w,o.49()'71 6/4/20086:42 PM I I I I I .1 I I I I I I I I II I I I I La Costa Greens 1.16 Storm Water Management Plan Advantages • If properly designed, vegetated, and operated, swales can serve as an aesthetic, potentially inexpensive urban development 9r 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 wh~re spills may occur. • Grassed swales cannot treat a very large dra'inage 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 site topography with the project site for BMP treatment, master treatment swales are not a feasible treatment option. 7.7.3 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 belping 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. DE:de H:1REPDRTSI04901711SWMP·FE·04.doc w.o.490-71 6/4/20086:42 PM I 'I I I I I I I I I I I I I I I I I I La Costa Greens 1.16 Storm Water Management Plan Advantages • Provides 100% reduction in the load discharged to surface waters. • The principle benefit of infiltration basins is the approximation of pre- 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 • Ma-y not be appropriate for industrial sites or locations where spills may occur. • Infiltration basins require ~ minimum soil infiltration rate of 0.5 inches/hour, not appropriate at sites with Hydrologic Soil Types .C and D. • Infiltration rates exceeding 2.4 inches/hour, the runoff should be treated prior to infiltration to protect groundwater quality. • Not suitable on fill sites or steep slopes. • Risk of groundwater contamination in very coarse soils. • Upstream drainage area must be completely stabilized before construction. • Difficult to restore functioning of infiltration basins'once clogged. Conclusion: Due to the minimum available storage volume within the detention facility, a filtration. basin is not a viable alternative for the La Costa Greens 1.16 development. 7.7.4 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 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 s$veral different 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. DE:de H:IREPORTSI0490171ISWMP·FE.04,doc w.o,49Q.71 6/4/20086:42 PM I I I I I , I I I I I I I I I I I I I II La Costa Greens 1.16 Storm Water Management Plan 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 cha~ges 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. Conclusion: Due to the large acreage requirements of a wet pond, proximity to residences . (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 Greens 1.16 project site. 7 .. 7.5 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 fUtering 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. DE:de H:IREPORTSI0490171ISWMP·FE·04.doc w.o.490·71 6141200a 6:42 PM I I I I· I . 1 I I I I I· I ! I I' I I I I '1 La Costa Greens 1.16 Storm Water Management Plan Advantages • 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. ..... IMay 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 'Ioads 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: . Due to the pollutants of concern generated by the multi-family development, Bio- Retention based Filterra treatment units were incorporated within the project site. 7.7.6 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 polypropyl~ne. The 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 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 and activated carbon. DE:de H:\REPORTSI0490171\SWMP-FE-04.doc w.o.490-71 6/4/20086:42 PM I I I I I I I I I I I I I I I I I I I La Costa Greens 1.16 Storm Water Management Plan Advantages • Does not require additional space as iliserts 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 concern for 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: Due to lower levels of treatment efficiency for target pollutants of concern, curb-inlet filters were deemed infeasible for the La Costa Greens 1.16 development. . - 7.7.7 Hydrodynamic Separator Systems Hydrodynamic separators are flow-through structures with a settling or separation 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, 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 -which can be settled -or floatables -which can be captured, rather than solids with poor settleability or dissolved pollutan.t~. In addition to the standard units, some . vendors offer supplemental features to reduce the velocity of the flow entering the system. This increases the efficiency of the unit by allowing more sediments to settle out. Advantages· • May provide the desired performance in I.ess space and therefore less cost. • ' May be more cost-effective pre""treatment devic.es than traditional wet or dry basins. • Mosquito control may be less of an issue than with tradit10nal wet basins. DE:de. H:\REPORTSI049,0171ISWMP-FE-04.doc w.o. 490-71 6/4120086:42 PM I I I I I I I I I I I I II I ·1 I I I I La Costa Greens 1.16 Storm Water Management Plan Limitations • As some of the systems have standing water tbat remains between storms, there .is concern about mosquito breeding. • It is likely that vortex separators are not as effective as wet va!llts at removing fin·e sediments, on the order 50 to 100 microns in diameter 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 in many cases relative to the design treatment storm, increasing cost. • The non-steady flows of stormwater decrease$ the efficiency of vortex separators from what may be estimated or determined from testing under constant flow. • Do not remove dissolved pollutants. • A loss of dissolved pollutants may occur as accumulated organic 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 Greens 1.16 & 1.17 project sites. This unit is a master BMP unit and treats an overall tributary area. It should be noted that treatment for the La Costa 1.16 development is addressed via Bio- Retention Based treatment systems. DE:de H:IREPORTSI0490171IS1!VMP-FE-04.doc w.o.490-71 614120086:42 PM - - - - - - - - ---' - ------- , ·.".'(fgiJJ~l? ~ ::!"':':""""'. ,/ I / L-.......... ,.. • • New or Existing BloretentlOn Catch Basin;' Curb Cut Curb and Gutter _J~~~ilf/SoiIJMicrobe,CQmple.x, ' "orO~hpr;iVfea~s of , 'ReriWV~!fPollu~nt~~Js.~::,;"~,~ ::, __ .. • perflOW Rehef Pho~phoro.u~;~!~Q1J~~~ H~avy -" '-:-.. > Metals, ~drifc"i!r~~~sj etc:' ' <" ,'.", >~< :~?' /l,",', ';;::}[: '"'''' Page 6 ftlterra: A Growing Idea in Stormwater Filtration. u.s. Patent 16,217.274 #6,~69,321 I I I 1 .1 I ·1 I I I I 1 I I I ·1 I I I FILTERRA® ADVANCED 810RETENTION SYSTEM PRODUCT OVERVIEW AND PERFORMANCE SUMMARY ':1. , Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 fHterra Toll Free (West Coast) (877) 345-1450 www.filt~rra.com June 2006 A Growing Ideo in 'Stannwntcr Filtmnan Filterra Advanced Bioretention S:ystem' Product Overview and Performance' Summary Performance Summary for the followil'lg,. Pollutant Constituents:' Total Suspended Solids Heavy Metals Phosphorus Nitrogen Oil and Grease Bacteria' Flow Rate Performance Effluent Water Quality Performance Summary provided to ______ _ Manufactured by: .-,l/ifMlIl8RJJC51JJ0fl For ordering and technical information ca1I: 8663493458 I I I I ,I I I I I I I 1 I I I I I I I \, \ , FILTERRA® ADVANCED BIORETENTION SYSTEM PRODUCT OVERVIEW AND PERFORMANCE SUMMARY ~, ~~~, Application: Stand Alone Stormwater Treatment Best Management Practit;)e Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc filterra 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 Toll Free (West Coast) (877) 345·1450 www.filterra.com June 2006 PRODUCT DESCRIPTION Filterra is an advanced high flow rate Bioreten~ion Best MElnagement Practice (!3MP) for treating urban stormwater' runoff. Exceptional pollutant removal effic\enci~s' are, achi~ved by filtering runoff. through a specially' engineered plant I soil I microbe media: that captures, removes, degrades and uptalces pollutants thi'qugh a variety of physical, chemical, and biological proce'sses. Filterra is a self contained system that is delivered to a, site completely assembled and ready for u~e. The system consists of a concrete box, three inches of mulch, two feet of filter media, plant (shrub or tree), observation I cleanout pipe and under-drain system. Runoff drains directly from impervious surfaces through an inlet' stn.-!ctur~· in the conyrete box and flows through the mulch, plant, and soil filter media. Treated water flows out of the system via an under-drain connected to a storm drain pipe, receiving water body or other appropriate outfall. The concrete container and treatment media are below grade with the only features vi$.ible being the concrete top slab, tree grate! plant, anq inlet opening. Filterra® looks very similar to an ordinary tree box except that it is specially designed to treat runoff. This is the only commercially available BMP that can also help to enhance the aesthetic value of the urban setting since it uses typical landscaping plants. ,\ GItl'I\ing lIl<'.:1l11 Slurmw:!lcr ~lllmtinll. 8MP PERFORMANCE. COMPARISON Th~. pE:!rforfuance, dat? o'n tilterra® curr~!1tly available indicates that the; system is capable of providing effective treatment ·for· tss (spUds),. phosphorus, nitrog~ri, metals and bacteria. The table below compares the removal. efficiency of FUterra wtth other BMP' technologies. The, table snows ~hat FUterra performs as well or better than. many other BMP technol()gi~s avaifable. BMP Pollutant Removal Efficiency Comparison • Filterra 3.4.5 85 51 43 57 Th.e Filterra® soil media is' specifically deSigned to achieve relatively high flow-through rates, much greater than thqse ,found"· in typi~al bioretentiori' or filtratio'il practices. Based on available field and l8:b-scale test data' and long4erm continuous simulati.on modeling of the system's hydraulic functfon, Filterra is: deSigned to treat 90% or greater of the annual rainfall. Bioretention Systems 4 81 29 49 51·71 FIL TERRA ADVANTAGES & BENEFiTS Small, Shallow Footprint High Removal Rates & Effluent Quality High Treatmen,t Volume Aesthetically Pleasing Low Maintenance Sustainable Design Well engineered Simple to Design Manufactured hy: ,~~aJf.l!IJ!{[f@!IJ(;9fi Sand Filters 6 81·90 3944 36-53 50·94 [nfiltration Systems 2 95 70 51 98 Propriet~1)' Media Filter~1l 40 17 13 93 Hydrodynamic Devlcesl! 0 15 5 8~17 CONcLUS[ON The Filterra bioretention system has been developed over many years in arder. to prqvide a BMP technology that witl reliably and effectfvely address your water qualtty requirements. Fil'terra has been designed with ease of maintenance in mincf to ensure long temt operation and effectiveness. Fina:lly. we at FHterra are committed' -fo providing. you the highest quality p?rf~rmance and services avaUable. For ordering an4 tecl'mical informati<?p..call: 8663493458 I I I I I I I I I I I I I I I I I I I FILTERRA® ADVANCED BIORETENTiON SYSTEM PRODUCT OVERVIEW AND PERFORMANCE SUMMARY Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 Toll Free lWest Coast) (877) 345-1450 www;filterra.com June 2006 REFERENCES: 1, Scnueler, T. 1996 Design of Stormwater Filterinf:j Systems, Center for Watershed Protection,. Columbia, MD 2. Center for Watershed Protection (undated) Comparative Pollutant Removal Capacity of Stormwater Treatment Practices, Article 64, Practfce of Watershed Protection, Columbia MD 3. Yu, Shaw, 2001 Laboratory Testing of!'! Mix Media Filter System, Department of Civil Engineering. University of Virginia, Chaliottesville, VA. 4. Yu. Shaw, et.al., 2006 Field Evaluation of Filterra@ Storm water Bioreiention Filtration System, Department of Civil Engineering, University of Virginia, Charlottesville. VA. 5. GeQSyntec Consultants, Inc. 200f;) Filterra® Bioretention Treatment System Technical Evaluation Report, Acton, MA. 6. California Department of Transportation. piyision of Environmental Analysis, 2004. BMP Pilot Retrofit Program, REPORT 10 CTSW - RT -01 -050, Sacramento, CA 95814, tables 1~3,~5.2-3,2-4 7: GeoSyntec Consultants, 2000. Determining Urban Stormwater Bel?t Management Practice (BMP) Removal Efficiencies, Urban· Water. Resources Research Council (UWRRC) of ASCE. 8. Davis, A" M. Sho\wuhian. H. Sharma, and C. Henderson. 1998. Optimization of BforetenUion o~slgn for Water Quality and Hydrologic Characteristics. Department of Civil Eng!neering. University of Maryland, CoUege Park ~\\ V~? . fllterra Manufactured by: ~~fJtiJ~fJflfJ@EJ0fl For ordering and technical infonnation call: 8663493458 I I I I I I, I I I I I I I I I I I I I FILTERRA® ADVANCED BIORETENTION SYSTEM TSS REMOVAL PERFORMANCE SUMMARY Application: S~nd Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free.(EastCoast) (866) 349·3458 Toll Free (West Coast) (877) 345·1450 www.filterra.com Julie 2006 TOTAL SUSPENDED SOLIDS (TSS) 8aclcground -·Total Suspended solids (TSS) has been and still remainS' the basic stsf)dard parameter tq measure BMP performance. Because many pollutants of conce·m (P I metals t organic toxins I etc) are att~ched' to sediments in runoff (through weak electro statio forces I adsorption I cation exchahge I etc.),. TSS is often used as a target pollutant and surrogate for many other pollutants. Generally, the smaller the sediment partiGles the higher the surface area and the more reactive pollutants are to clinging ontc; small sediment particles. This means that finer sedtments from erosion of fine silts, clays, glacial tills and atmospheric deposition may carry with tliem higher concentrations of pollutants than sedinient \/'IZith larger partloles. These fine particles are of greater concern than the coarse particles in that phosphorus, heavy metals and other toxins will .readily attach to, and be transported with. fine particles B. • Therefore, in general. to achieve better performance. a BMP. technology must be capable of removing finer sedimEint particles. For example, in areas where aur deposition is one of the dominate sources of pollutant particulate matter, a BMP must be able to remove particte sizes ranging from about 10 microns to 60 microns. To evaluate TSS performance it is important to understand not.011ly the TSS removal efficiency but particle size dIstribution of the technology and sediment sources. STUDY RESULTS ,\ G"""lug Itlt:alll Slonlllwlwr 1'lllrJ!inn. PARTiCLE SIZE REMOVAL In 200a GeoSyntec. Consultants 5 condude~ a lab7scqle particle siz~ treatmen~ aJ1~Iy'si!> of the Filterra® soil- mUlch media. The' test showed that Filterra® could rel"(loye 87%. of·a $iI-Cb-$il mix'with a mean, particle size Qf 1·9. microns. This study was conducted in aCcordance With Washington's Department of Ecology TAPE' protpcol. to ev~luate. particle f?ize dJstributioll. This result is of particular relevance when runoff sedinwnts are dominated by small particles, ,. Table 3.155 dala for lab-$cale trecslment slvdy f.~J!,1?,S1~IJ J)uplica'~ Ro!,ud h.flow Outflow . Pe'Cf!tlt Relative. Removal ""'ceI,1 Differellce 1 41.7 11.S 72.4% 2 4S.7 4.2 9:1AO/, 3 43.6 6.6 84.4% • 28.4 6.5 7()jo/t ... 5 44.0 <2.0 ~5.5% (> 77JJ 6.3 9i.8'10 1 15JJ 27/4.3 95.W. 45.7"1. a-18.0 37 79.4% <I U <20 75.9% 10 ft4JJ 7.S 90.7% H 170/140 1111 92..9% 19.4% 12 11M 18.0 91.4% 13 12M 11.0/3.3 a~.9% 145.7% 1.4 ~W.(J 14.0 94.6"/0 15 100.0 12.0 a&.O'1t Ta~l!I 2. $t(llillk"at wmmol)'llf TSS dllio fllr lob-stole Ireotmeniliudy .. 1 The. TSS performance summary data table below shows. the. findlhgs of both the 20q1 Uhiv.ersity of Virginia laboratory· tests 3. and the 2006 University of Virginia field' monitoring program 4. GeoSyntec C9nsultants also condiJ9ted. an independent evaluation of the UVA field study with their summary evaluation also providec!. TSS field dat~ was analyzed using EPA MethOd 160.2 using a 0.45 miCron pore size with a practical range of the method of 4 mg/L to 20,000 mg/L. 'MAl d ottJttri .. MttllaA(liIgff.I.· 9'.m~af1IiMt.~ mn (mg/L) AmGptO .S!QoiI:~. .~ Perc.nt .~(Ll. SUMMARY OF TSS % REMOVAL. STUOY Min Max Avg, OVA Lab 3 57 98 815 OVA Field Monitoring 4 75. 93 81 GeoSYl1teQ Evalu~tion Study 5 70 95 82 Average % Removal (ALL) 85 I\.1allufactured by: <!,#Jf2!J~fJ&!J@f1Jg)f1. :P.fIfm'*' Offf~ Mfo,'IOt 75.0:1:17.5 8.3 260 SILRt 7.9U.2 NO 16.0 86.f,i \'6S ila.o) aJ ~tl!d II! ,.-u • .n MflidM:fucl_lIf/CfO! rElI',Q'l:i1t. 14 bd QI MCI;IlIfItIIIIrI: =cI~ d tg:€ft"= diff;,-t!!:. (a = O.(lS) btlwttn fnftrnlll eM ,ffiUfnl w!:mr. CONCLUSION Based on these fmdings Filferra® has: demonstrated a TS'$ percel1t removC!f. of 85o/~ for typical urba:n runoff sedimentiif and an· 37% removal rate. for smaller size. partf'Cl~s of a mean $ize of 1 Q microns. . Fat on$ering and technical information call: 8663493458 I I I I I I I I I I I I I I I I I I FILTERRA® ADVANCED BIORETENTION SYSTEM TSS REMOVAL PERFORMANCE SUMMARY Applica~ion: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention J\IIanufactur~d by: Amerlcast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 Toll Free (West Coast) (877)345-1450 www-filterra.cqm June 2006 REFERENCES: 1'7-Schueler, T. 1996 Design of Stormwater Filtering Systems, Center for Watershed Protection, Columbia, MD 2. Cen~er for Watershed Protectipn (undated) . Comparative Pollutant Removal Capacify of Storlnwater· Treatment pr~ctices, Article 64, Practice of Watershed Protection, Coiumbia MD' 3. Yu, Shaw, 2001 Laboratory Testing of a Mix Media Filter System, Department of CiVil Engineering, University of Virginia', Charlottesville, VA. 4. Yu, Shaw, et.al., 2006 Field Evaluation. of FlIterr'a@ Stormwater Bioretention Filtration System. Department of Civil Engineering, University of Virginia, Charlottesville, VA. TablaE8-1 5. GeoSyntec Consultants, Inc. 2006 FJlti'lrra® l;\iorefention Treatment System Technical Evaluation Report, Acton, MA .• Appendices E 8d 6. California. Department of Transporta~ion, Di',(ision of Environme-ntai Arialysis; 2004, BMP Pifot Retrofit Program, REPORT ID CTSW - RT -01 -050, Sacramento, CA 95814 1. GeoSyntec Consultants, 2000, Determining Urban Stormwater Best Management Practice. (BMP) Removal Efficiencies, Urban Water Resources Research Council (UWRRC) of ASCE. 8. URS Greiner Woodward Clyde, 1999. USEPA Issue' Paper, Measurement of TSS in Runoff, 1:\BSFR977001.00\TO ZUss-final.doc, San Diego. CA. 1\ 6lth\'lng IdC:1ln :;loml\\~I!l'r I'lilmlilln. Manufactured by: $, f2:fJmwJ!i@f1JfJJLJJ: For orderin.g and techni,c;:!.l in.formation c~ll: 8:663493458 ~~. '. I I I I I I I I I I I I I I I I I I I FIL TERRA ® ADVANCED BIORETENTION SYSTEM HEAVY METAL REMOVAL PERFORMANCE SUMMARY ~ fjlterra Application: Stand Alone Sformwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11362 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349·3458 Toll Free (West Coast) (877) 345·1450 www.fllterra.com June 20Q6 HEAVY METALS M BACKGROUND The .major anthropogenic sources of heavy metals come ,from intensive automobile use, weatherin!;l of buildi.ng materials, and atmospheric deposition which contribute lead, copper, zinc, and other heavy metals to urb.an and roadway runoff. Metals may be found in natura!' waters in. partictllate form by the formation of precipitates, such as hydrpxides, sulfides, and carbonates, or by adsorption to clay, silica, or 6rganic particulate matter. J Metals have been found to be one of the leading pol,lutants of lakes; reservoirs and ponds in the U.S., ~mcl a leE\ding pollutant of estuaries. Metals do not break down or degrade over time but accumUlate in the environment in the sediments and find their way into the food chain. Metals bio-accumulate in living organisms and are to)cic. Human hearth can be affected if metals enter the drinking water supply or if consumed by eating contaminated fish. Investigations by the University of Marylanc! have shown that bioretentlon facUlties are quite effective in removing metals such as lead, copper, and zinc from stormwater runoff. Removal rates of these metals were excellent: over 95% for all metals, with effluent copper and lead levels mostly less than 5 ugJL and zinc less than 25 ugfL. FILTERRA REMOVAL PROCESSES Fllterra uses several mechanisms to remove heavy metals. First, metals strongly attached to TSS particulate matier are removed through sedimentation an'd filtration. Fllterra has been shown to have a TSS removal' efflClen.cY of 85%; . . Second, dissolved metals react with the organic matter (I.e., carboxyl ions) to form organic qomp'lexes~ Met1::!Is tightly bInd to the mulch and other organic: particles in the soil. In a 2001 bioretentioll lab study· performed by Davis at aI, the surface mulch layer exhibited a high capacity for metal removal with sorption capabtlities two to three times greater than the soit used. Third, metal removal occurs by the microbes and plant uptake. As the organic matte>r decays metals are released and available for-up-take by the plants, FHter.ra blo·accumulates metals within the plant and captureE? metals In the media As the plant grows so dbes Fllterra's ability to store more metals. Manufactured by: JJtJfIJfJflfJ&fIJ0fl ,\ GnlWiltgldt:a11l5Iumfu:tllJr flhr:uinn. STUDy',RESULTS The table below shows the percent removal for the 2001 University. of Vlrg'inla Laboratory qtudy fqr CHI the 2006' field monitoring study also conducted by the' University of Virginia and an independent eValuation of the UVA dE!ta by GeoSyntec. Th~ field sample$ were· analyze.Q1 for' total cac!.mium, copper, lead and zinc. No cadmium or lead was detected in any of the samples. Complicating the fie.lt;l. data is that a significant proportion of the total Cu and tn analyses resulted in concentrations below thi;! limits oJ" detection. fol' both influent and effluent concentrations. SUMMARY OF METALS % REMOVAL STUDY' UVA~ Lab (Cu) UVA Field Mon{tol'ing3 (Cu) UYA Field' Monitoring3 (Zn) AYg.% Remo.val 33 48 64. 51 FOr ordering and :technical information call: 8663493458 I I I I I I I I I I I I I I I I I I I FILTERRA® ADVANCED BIORETENTION SYSTEM HEAVY METAL REMOVAL PERFORMANCE SUMMARY Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 Toll Free (West Coast) (877) 345-1450 www.filtarra;com June 2006 REFERENCES: 1. Davis, A, M., Shokouhian, et., al. 1998 Optimization of Bioretention Design for water Quality and Hydrologic Characteristics, Department of Civil Engineering, University of Marylind, College park, MD . 2. Yu, Shaw, 2001 Laboratory. Testing of a Mix Media Filter System, Department of Civil Engineering, University of Virginia, Charlottesville, VA 3. Yu, Shaw, et.aL, 2006 Field Evaluation of FlIterra® stormwater Bioretention· Filtration System, Department of Civil Engineering, University of Virginia, Charlottesville, VA. Table ES-1 4, GeoSyntec Consultants, Inc. 2006 Filterra® Bioretention Treatment System Technical Evaluation Report, Acton; MA. Appendix E Table 1 6, CH2M HILL, 2004, Technical Memorandum 3: Characterization. of Dry Weather Urban Runoff 6. Water Quality. Urban Runoff Study, W062004002SCO , OCSD UR STUDY FI NAL TM3 10-19-04. DOCr 041530002. t... ~~ .~~ filterra ,\ (iN1I\'jng I,ll", III SIClmlrotlUr l'illMinu. 11allufactured by: }' liiJ&fliiJ@lJJ[;f)fl For ordering and technical information call: 8663493458 I I I I I I' I I I I I I I I I I i I I I FIL TERRA ® ADVANCED BIORETENTION SYSTEM PHOSPHORUS REMOVAL PERFORMANCE SUMMARY ~. nlterra Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11'352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (8S6) 349-3458 Toll Free (West Coast) (87T) 345-1450 www.filterra.com June 2006' TOTALPHOSPHORUS(TP)-BACKGROUND Phosphorus' is often identified as a pollutant of concern where runoff discharges to fresh or brackish lakes and bays., , In these aquatic ecosystems too m(jch, pho~pliorus can contribute to eutrophication and aigae blooms' that can cause harm to, fisheries and restrict, recr~atiqnal uf'les. When phosphorus enters a lake or. a bay, it generally accumulates in the bottom sediments and ,cycles' seasonally between organic and inorganic forms ma~ing' p~osphorus readily available for plant and algae uptake. Urban runoff can contain levels of P that are many (three to five) times' higher than a natural stream or' river. To minimize phosphorus buildup and its adverse elwlronmental impacts it is necessary to prevent it entering urban runoff by reducing non-point inputs such as controlling the use of fertilizers or capturing phosphorus in treatment technologies before it enters the aquatic system. Fllterra works differently from most BMPs in how it, removes phosphorus from runoff. Rlterra works in two stages. tn the first stage phosphorus is captured by the filter media. Organic phosphorus (i.e., parfofthe plants, animal tissues and their waste) is removed by filtration and sedimentation. Inorganic phosphorus (te. from' fertilizers) and soluble ertha-phosphorus (from decaying matter) chemioally react with Fe, Ca and AI silicates in the media's sand components to create phosphate compounds. The second stage of removal is unique to bioretention technology and Filterra. The soluble orthd-pnospnorus from runoff is created by decomposition of organic, matter and Is up-taken and retarned by bo1ih the media rhfcro-organisms and plant -hence the, term "Bibr~t~ntion". FUterra not only captures phospharus\ but consumes it. As Filterra's plant grows so does F(lt~ra's capacity to transform and retain phosphorus. Rlterra's ability to remove phosphorus doesn't degrade over time, but actually increases. Filterra is capable of regeneration of its pollutant removal capacity as long as the plant continues to grow. STUDY RESULTS The TP' performance summary data ta~e below snows the findings of both the 2001 University of Vll"g!nia (UVA) laboratory tests and the 2006 WA field monitoring program. GeoSyntec Conswmrns roooucted an Independent evaluation of, the 'field nnoniroMg fmt is also provided. Mallufacturecl hy: <'. ~ [;(£ffNfJf1JJ@!JJflJ'u: ~..rw ,I GllJ\\'lfiS IIk~ III Sl:mnw:llcr l'lhr:llillll. Total Phosphorus (TP) was determined In the inffuem and effluent samples by' Standard Method 18,4500 P B+E (colorimetric determination of qissolved orthophosphate; persulfate dig~~tion, ascorbic acid determination). . FILTERRA TOTAL PHOSPHORUS % REMOVAL STUDY ! Min Max Ave. UVA6 Lai:l '. 29, 8~ 58 uvA Field Monitoring8 ·3 90 60 GeoSyritec Evaluatiiir? ·50 90, 52 Average % Removal 57 EFFLUENT QUALITY The Filterra system prod!.jced an average effluent T atal Phosphorus con.centratio!,! of 0.1 ~g/,L; the m~a!'l irreducible concentration for filtering systems is O~ 14 mg/L with a lower confidence limit concentration of 0:01 mg/L This shows that Fitterra performs as well as or better than other media filters. Comparisqi1 of F!ltemi PerfQi'm~nce wit!t 'irreducible' Concentrations;!! , , ' , .To~I' TS$: To~'P KjeldahlN All Filtering, 20'-40 0.15-1.2 Systems 0.2 Mean Runoff 22.5 0.209 < 1.46 concentration Mean FlIterra , effluent 4.5 0.10 1.1 concentration , Concentrations In mg/L. For ordering and technical information caH~ 8663493458 I I I I I I I I I I I I I I I I FILTERRA® ADVANCED BIORETENTION SYSTEM PHOSPHORUS REMOVAL PERFORMANCE SUMMARY Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349·3458 Toll Free (West Coast) (877) 345·1450 www.fllterra.com June 2006 REFERENCES: 1.. Schueler, T. 1996 Design of Stormwater Filterhig Systems, Center fpr Watershec;l Protection •. Co!uf!1bia, MD 2. Center for Watershed Protection (undated) Comparative Pollutant Removal Capacity of Stormwater Treatment Practices, Article 64, Practice of Watershed Protection, Columbia MD . 3. Yu, Shaw, 2001 Laboratory Testing of a Mix Media Filter System, Department of Civil Engineering, University of. Virginia, Charlottesville, VA. 4. Yu, Shaw, et.al., 2006 Field Evaluation of Filterra® Stormwater Bioretention Filtration System, Department of Civil Engineering, University of Virginia, Charlottesville, VA. 5. GeoSyntec Consultants, Inc. 2006 Filterra® Bioretention Treatment System Tectmical Evaluation Report, Acton, MA. 6. California Department of Transportatio.n, Division of Environmental Analysis, 2004, BMP Pilot Retrofit Program, REPORT to CTSW - RT -01-050, Sacramento, CA 95814 7. GeoSyntec' Consultants, 2000. Determil'!ing Urban Stonnwater Best Management Practice (BMP) Removal Efficiencies, Urban Water Resources Research Council (UWRRC) of: ASCE. 8. Source: 1) Center for Watershed Protection (undated). Irreducible Pollutant Concentration&: Discharged From Stormwater Pr'acti'cep. Article 65 .In: Practice. of Watershed Protection. ElIlcott City, MD. Also in Schueler, T. 1996. The limits of stormwater Treatment. Technical Note 75. Watershed Protection Techniques 2:2 pp. 376-379. I.~ ~~~ filterra .~ (in/wing Idea III S,.mnwalCr Villr:uillfl. Mallufactured by~ <*-.#J/J5Jwf]J1[J(5!IJfl)fl For ordering and techDicallnformation ca1l~ 866 349 3458' I I I I I I I I I I I I I I I I I FllTERRA® ADVANCED BIORETENTION SYSTEM NITROGEN REMOVAL PERFORMANCE SUMMARY ~ fHterra Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Amerlcast, Inc 11362 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349·3458 Toll Free (West Coast) (877) 345·1450 www.filterra.com June 2006 NITROGEN REMOVAL -BACKGROUND Total Kjeldahl ,nitrogen (rKN) is a parameter that-is sometim~s used as an indicator of pollution. TKN includes' nitrogen from ammonia, amino acids;, polypeptidel>. proteins or ,otlier organic sources. TKN is a measure of the concentration of reduced forms of nitrogen in surface water., principally, ammonium and ,amino forms of organic I')itroger'l. TKN plus N02 and NOa is generally used to derive total nitrogen TN. TKN and TN are not synonymous as they, include different forms of nitrogen. However, TKN and TN are often used interchangeably as TKN usually comprises the major source' of nitrogen in urban runoff. Because nitrogen is so readily converted from one form to another C!E1pending on environmental conditions, identifying sources of nitrogen from analyses of different forms at a single monitoring station is difficult. Filterra's field testing focused on TKN which means the TN would have been siightly higher by adding nitrate and nitrite components. Filterra was designed to support a complete soil ecosystem and thus Filterra cycles nitrogen. As organic nitrogen (detritus materiaQ and ammonia enter the mediai, It is biologically transformed by bacteria into nitrites and then nitrates. Nitrate is the form of nitrogen that plants can up-take and transform in tissue. Nitrogen from fertilizer contains inorganic forms of nitrate that is readily availal:!!e for plant up-take. So Whether nitrogen enters the' Filterra ecosystem in an organic or inorganic from, nitrogenous' compounds are eventually transformed into nitrates ready for plant uptake. Essentially any form of nitrogen ponution b~comes plant food. The result is the piant grows more vigorously. Just as with most of the pollutants of cqncern the plant performs a vital role of retaining nitrogen by up-take into its tissue -i.e. bioretention. A major benefit Of FHterra and bioretention technology i~ ,the ability of the system to captufe and hold' pollutants such as N, P and metals as Icng as the plant is alive al1d thriVing. Vigorous plant growth is the indicafor that nature is transforming pollutants in the runoff into plant food. l\1'anu:factured by: .. tfiJ[/:/J[jJ[j@8@/JJf/1JU A (in1ll'lllg Ilk::llll Slumllv:ucr t'Ulralilll1. STUDY RESULTS TKN ,was determined it:! ~he influ~nt (:IncJ effluent samples by U.S. EPA Method 351.3 (Cblorimetric;, iitrimetric; Potentio'metrlc). Total Kjeldahl· I'litrogen is defined as the sum of fr€?e~t:!llJ.mol1ifl ~nd organic nitrogen compounds which are converted to ammonium sulfate when the sample is heated in the P'JElsenc~ of concentrated sulfuric aCid. potassium: sulfate and mercuric sulfate. The ammonia Is distilled and determined by titration if the' co'neenti-ation of-nitfogen i~ above 1 mg/'L. by calorimetric pro,ceduresif the nitrogen corrcentration is below 1 mg/L. or by a' potentiometric procedure for nitrogen concentrations between 0.05 and 1,400 mglL. The results, shown below are the findings from all Filterra,stu(:lies. SUMMARY OF FILTERRA TN (TKN) % REMOVAl- Study Min Ma~ Avg, UVALa~1 25 '15 45 uV A F!~'d ~o~itoring2 28 53 >42 , Get;)Syntec: Evaluation Study :3 Q' 53 42 Average '/0 Removal' 43 ',-. .-." , : ~. '01\ .. • Fot ordering and technical information call: 8663493458 I I I I I I I I I I I I I I I I I I I FILTERRA® ADVANCED BIORETENTION SYSTEM NITROGEN REMOVAL PERFORMANCE SUMMARY Application: Stand Alone Stormwater Treatment Best Management Practice, Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 Toll Free (West Coast) (S77) 345-1450 www.filterra_com June 2006 REFERENCES: 1. Yu, Snaw, 2001 Laboratoiy Test!ng of a, Mix Media Filter System. Department of Civil ~ngiDeering, University of Virginiar Cliarlot~esvme, VA. 2. YU, Shaw, et.al., 2009 Field Evaluation of Filterra® Stormwater Bioretention Filtration System, Department of Civil Engineering, University of Virginia, Charlottesville, VA. Table2!3 3. GeoSy'nt~ Consultants, Inc. 2006 Filterra® Bloretention Treatment System Technical Evaluation Report, Acton, MA. Appendix: E 4. Richard, Larson et.aL, 2002, Nitrate Management Using Terrestrial and Aquatic Plant Spec,ies, 12th annuallGC Conference Ground Wafer Consortium Proceedings, University of Illinois at Urbana-Champaign .~ (jnr,~lllg IIbllll 51m1l1Walcr l'illralinll. Manufactured by: ",~£l!J£§lfJ!l[]@.aJfl)fl For ordering and technical' ihf01:mation call: 8663493458 '" I I I I I I I I I I I I I I I I I !I I FILTERRA® ADVANCED BIORETENTION SYSTEM OIL AND GREASE REMOVAL SUMMARY ~ filterra Application: Stand Alone Stormwater Treatment Best Management Practi~e Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11852 ·Vlrglnia Precast Road. Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 Toll Free (West Coast) (S77) 345-1450 www.f11terra.com June 2006 OIL AND GREASE -BACKGROUND High concentrations. of oil and grease (O&G) can cause toxicity, in .receiving waters-. thus many jurisdictions §Ire· requiring t~at. O&G discharge be redqced or eliminated" In stormwater discharges. Sources of O&G ·in stormwater are primarily from the operation. use a.nd handling of oil associated with automobile operation and' maintenance. O&G can also be founq in higher concentrations depending on tne land use and types of activities. Generally O&G concentrations are .higher in Industrial and commercial land uses and highway.s and lower in residential uses. Of course O&G can be discharged through accidental spills or illegal dumping from restaurants. individuals and maintenance facilities. Oobe O&G finds its way into stormwater runoff it· car} become emulsified with water to form little droplets; fioat on the surface of the wafer or attach to the surface of trash debris or sediments through absorption or adsorptloA. 08:G that bs'COme attached to trash; debris arid sedIment can be removed by any number of processes commonly used by most 8MP technologies. The difficult portion of ihe O&G to remove is the part that is free flowing on the surface or emulsified within the water column. FILTERRA'S REMOVAL PROCESSES i=ilterra v.ery efficiently captures that portion of the O&G att.a·ched to tra~h, debris and sediments through the. simple filtration process. Essentially. all of the trash and debris. is captured on ilie surface of the filter media, . O&G attached tq sediment are also trapped withfh the filtef media. Studies show that Filterra will capture about 85% of all sediments. The ·emulqifi~c! and ·free floating porti.on of t/1~ O&G is essentiaify captured, absorbed or· soaked up by· the. organ.ic material in the Filterra system, Le. 3" of mulch on thei surface of the media and the peat within the media. Once the emursffied and fliee floating O&G have. been captured it is then degraded and fu"ansfonned by pacteria to smalUer less harmful compounds that can be volatilized or completely consumed to CO2 and water. This biological degradation of O&G occurs over the course of 3 to 10 days with 92% efficienci. In 20q4 the University of Maryland (UM) conducted a series of tests to demonstrate the effectiveness of mulch In capturing and remQvlng O&G from runoff. The UM study showed about 90% (l1f the O&G is captured through sorption by mulch. VVithin 3 to 10 days 92% of "the capture O&G has been degraded through 1Manllfacmred by: O!J@!Y1{](§fIJflJfl microbiological processes. Additipnal findings and recommendations from thEl 2004 UM report the importance of mulctr in-biorE?~entiQn systeins are provided ·below:' "Overall, it can be concluded that thete are several advantag(3s to'-placing a surface· mulch layer on a biqretehtiof! system for O&G ·remoliaL First; it appears th~t high contaminan.t removal effich?ncy ceQ pe. achieved .by tfle· placerpen.t of a thin (-3· em) layer of mulch to treat both dissolved and partiQ:ulate~assoc;ated l1ydrocarbon contaminants. Second •. because it onfy" tak'e$ q. relatively short time (3 tq 4 days with single contaminants, C1I1d.a· maximum 10 days with the Mgher contamination of oil) to degrade the trapped contaminants after the storm event, no acoumulation of hydrooarbons occurs, demonstrating that this is a sustainable process. Third, there is· no need. to inoculate· the mulch with specific microorganisms to degrac!e thf)· O&G contaminants ·because the native microbial popufation in the mulch tested has been found to have anapproprfate biodegradation oapaoity. In addition, afl~r exposure Qf the. mulch microorganisms to the contaminants, an increased popufation of contaminant-deg~~ing mfcrC!bes is available for biodegradation during a subsequentre-exposu~. . Fourth, the moiSture· content of"the -mulch layer: did not deote'aSI1. dfasticrcllfy· a'{ter th~: s(qrm. event u.n.c!er !'In a.ir. s.trf!~rn, which will be beneficial-for microorganisms in the mulch as well as iri·the soil below. . Fifth, the muloh layer has high permeability; therefore, it ~tlOuld noJ cause sign.ffjoa'nC Heart· build-up on the surface· of bloretentlon sysiems. dunng the stOf111 event so that the runoff can readilyihfiltrafe to the ·~o(/. n MONITORING RESULTS, Unfortunately O&G levels at our monitoring 9ite we.r~ below the levels of detection. Since Fllterre is a bioretention system with a: 3 inch layer of mulch it is assumed until further studies -that Fiiterra win perform with the similar efficiency as tests show in the UM study, i.e.. gu-eater that 90% removal through sorption and microbiological degradation in 3 to 10 days. For ordering and technieal. information call: 8663493458 I I I I I I I, I I I I I I I I I I I FIL TERRA ® ADVANCED BIORETENTION SYSTEM OIL AND GREASE REMOVAL SUMMARY Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manl!factured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 Toll Free (West Coast) (877) 345-1450 www.filterra.com June 2006 REFERENCES: 1. Yu, Shaw, eta!., 2006 Field Evaluation of Filterra® Stormwater Bioretention Filtration System, Department of Civil Engineering, University of Virginia, Charlottesville, VA. 2. Hong, EUflYoun9, 2002, Sustainable Oil and" Grease Removal from Stormwater Runoff Hotspots using Bioretention, "MS Dissertation, Department of Civil and Environmental Engineering, A.J. Clark School of Engineering, University of Maryland, College Park, Maryland, 167 pages, 3, California Department of Transportation, Division of Environmental Analysis, 2004, BMP Pilot Retrofit Program, REPORT ID CTSW- RT -01 -050, Sacramento, CA 95614 A (ilt)\\'lug It~;a III :;lo:nW,~<lc[ J-ll1mlinll, :Mallufactured by: ~.lfiJoo@fJ&[f&l1JfJ)fl For ordering' and technical mfor~l1ation call: 86.6 349 3458 . I I I I I I I I I I I I I I I I I I I FILTERRA® ADVANCED BIORETENTION SYSTEM BACTERIA REMOVAL PERFORMANCE SUMMARY Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Milnuf~·ctured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349·3458 Toll Free (West Coast) (877) 345·1450 www.filterra.com June 2006 BACTERIA REMOVAL Filterra: is an innovative stormwater Best Managem.ent Practice that has been shown to be effective in removal of TSS; TP •. TN and metals. The technology uses a variety ·of p.hy~ical, chemical and biological pollutant re·molial mechanisms to achieve high removal efficiencies· to· meet local, state and· national pollutant r~moval requirement~. With the growing concern about bacterial impairment 'of recreational waters associated with stormwater runoff, laboratory tests were Gonducted on the Filterra media to determine its ability to remove fecal coUform. Urban stormwater runoff may have fecal coliform levels of 3,600 6 to 20,000 7 MPN 1100 ml. For safe water contact usages fecal coliform levels should be at or below 400 to 200 MPN 1100ml. The Washingfon Suburban Sanitary Commission (W8SC) in Silver Spring. MD conducted a series of Filterra· colUilln tests in the laboratory. The samples were analyzed for fecal coliform MPN via Method 8M 9221 E2 (MTF Direct Test, A-1 Medium) from the 19th edition of standard Methods for the Examination of Water and. Wastewater. Data were reported in MPN per 100 mL. Over 30 tests were performed during a 6 week period. TtJe average removal over the test period was 70%. However. after 4 weeks of testing the average removal increased to 98%. During the first 4 weeks there was some variability in removal and on two occasions fecal coliform br9Kl;! through the filter media. The lowest MPN (evel· achieved was 170 MPN which is near·the commonly used threshold number of ZOO MPN for water contact activities. The table below shows the influent and effluent MPN counts. FilIana tVPN Fecal CoifQnn Rem:r,ral 1 234 5 6 7 89m T""~ Ma1lufactured by: .. !2{]@[JfiO@L!J[;9'i7. A (jtc1\~llIg l<tc'a In Stcmmm.tcr tlltnuJun. The table below shows how: tne effluent quality improved over time (6· week period). I~ 1~ oelieved that the media goes through a maturation process where it develops a complex microbiological' ecosystem. that enhances predation, capture and destruction of fecal coliform. Clark and Pitt (1999), (late that media ;filters develop a biofilm on and within the media that promotes the ability of the media to remove bacteria. I 1 2. 3 ~ 5 ~ 7 9 9 ~ Tollt-' FIELD TESTING· Preliminary· 2006 site evaluation field tests·· were condlicted on several l!nits for analysis of E. coli to meet 'ocal regulatory requirements. Grab sam·ples were taken of the influent and effluent during a storm event. Initial analysis resulted in low levels of E. coli in both influent and effluent samples. Cold weather and new site development may explain these low results. However. where Influent levels were greater.. results showed levels of E~ coli at 10 and 18 MP.Nf100ml arid both wIth less than 1 MPN/100ml In the effluent samples, although these. conc{3ntratlons are too low for statistical extrapolation. Due· . to low. E. coli levels and the: need to meet n~tionwfde reguiatory· reqUirements, subsequent tes~s will inc1ude fecal coliform analysis. Field testing will contihue tflrough 2008 with penodic Upqates as well as r~search on how to optimize the bacteria removal capabiiities of the Filterra system. CONCLUSION' The be~ available information on FilteiTa demonstrates this technology Is capable of removal of· fecal bacterIa. cumrent data has shown removal rates of up to 90% and ef!olll.leflt quality at or near to that sulta~le for receiving wat6r$ designated for hUman contact·uses. For ordering l:J.nd te<;hnical infonnation call: g66·34934SS I I I I I I I I I I I I I I I I I I I FILTERRA® ADVANCED BIORETENTION SYSTEM BACTERIA REMOVAL PERFORMANCE SUMMARY Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 Toll Free (West Coast) (877) 345·1450 wwwJilferra~com June 2006 REFERENCES: 1. Erickson, J. 2004, Fecal Coliform Removal by FHterra Bioretention Media, WSSC Laboratory Services·Group, Silver Sprin~, MD I 2. Ceriter for Watershed Protection, 1999, Article, "Microbes and Urban Watersheds: "Ways to Kill 'Emil, Watershed Protection Techniques, 3(1): 566·574 3. Center for Watershed Protection, 1999, Article l; "Microbes and Urban Watersheds: I. Introduction: Vol. 3, No.1, Watershed Protection Techniq(Jes. 4. Centerfor Watershed Protection, 1999. Article II; "Microbes and Urban Watersheds! Concentration, Sources~ and Pathways". Vol. 3, No.1, Watershed Protection Techniques. 5. Center for Watershed Protection, 1999, Arti~le. IV. "Microbes and Urban Watersheds: "Implication for Managers"; Vol. 3, No.1, Watershed Protection Techniques. 6. Maryland Dept. of the Environment; 4000 Marylan.d Stormwater Design Manual. 2000, Chapter 1, Table 1.1 ·7. Pif(1. R. 199B. "Epidemiology and Stormwater Management." stoimwarer Quality· Manag~ment. eRC /Lewis publishers. New York. NY. t '. I .~ • ~ ~ fllterra :\ GII/willg Itll::l III Slunnw:!.wr fllllOlUilll. Manufacturect by: ,,;~f}fJ&fEfJ&fl1[Dfl for oxdering and tecImicaI fufOl'mation call; 8663493458 I I I I I I I I I I I I I I I I I I I FIL TERRA ® ADVANCED BIORETENTION SYSTEM FLOW RATE PERFORMANCE SUMMARY ~ filterra Application: Stand Alone stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretentlon Manufactured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349·3458 Toll Free,{West Coast) (877) 345·1450 www.filterra.com June 2006 HIGH FLOW RATE One of the, most innovative and Eldvanced features of Filterra is, its, very high design flow rate. It was the des'ign objective to engineer a media that' had the highest flow rates possible to treat large 'volumes yet $till retained pollutant removal capabilities to meet water quality standards. Generally. media filters (sand I bioretentlon) operate i,n th~ flow r.ange' of 0.25" tQ 4.0" I hp'ur 1. Filterra operates in an effective range of 80" to 115" I hour. Americast, Inc. Filterra's manufacturer working with the Civil Engineering Department at the University of Virginia spent over 2 years in the development of the current media formula. Filterra's. high flow rate is orders of magnitude' higher than cOr)ventional. pr~ctices'. Hig~ flows ?re key to Fflterra's ability to treat high volumes of runoff with' a sman filter surface area. Generally. Filterra is designed to treat >90% of the total annual rainfall events using a fl!ter surface area of only 36 if. Higher volume tre.atment is possible by increasing the filter surface area'to drainage area ratio. HIGH FLOW VERIFICATioN The high flow. rate has been verified with laboratory' column tests, full scale model tests, flow test for a three year old operating unit and actual storm event' testing. The results of these tests are discussed below. LABORATORY TESTS The independent soils testing firm GeoTesting Expre9s( lnc. in Acton, MA 3, performed the laboratory tests. Testing was performed under constant h~ad, condiitions using ASTM D 2434 protocol. The soil media was tested using in a saturated condition using lightly and heavily. compacted media. These test results show the extreme range of flow rates possible under the best or worst conditions. Filterra Media laboratory Hydraulic Function Test Void Bulk Perm'b'ty Permeability Sample 3 Ratio Density cmlsec inlhr Ught , Comoactlon 0.67 123 0.21 297 HlghlHeavy Compaction 0.43 134 0.035 5£1 Averacre 0.55 1ZS: 0.123 173 !vfallufactured by: .:.tfJJlJ£.J~!Jf1 B@££J0fl :\ (j,lJ\\'lng 1,lc:1ln Sl,mllw;ucr flhr:tlillll. FULL"SCALE MODEL TESTS Extensive model testing .v\ta,~ n¢ces$a!'Y, duiing, product d~vE!lopment not only to ve~ifY the ult!~ate desigilflow rate, but also to optimize the' under drain design SG it would :ilot restrict flows ahd to Elns'Ure the consistency betWeen various media. batches. The table: below shoWS it summary of six t~st series;, each with different batches of media. The table' shows each batch had quite consistent f1oWEj: with an average flow (pernie~qi!ify) of 97 inches l h.our. Full·scale Model T~st ,iJ~ilig a, 6'x&J Filt,e,ti'aunit Test Rumr NQ.Te st galll11in cf/min i~~~ Runs, TestA 7 31A 4.2 84" TestS 10 40,2-5A' 107 Teste 10 35.9: 4,8 96 Test,D 10 31.2 4.2 ~3 Test'E I) 37.1 5 '99' TestF 3 43.1 5:B 1W Average 97 LONG-TERM FIELD FLOW TESTS Flow tests have been performed on a three: year ol~; regularly' mail'itain'edW~~' Unit ~re~ting a commercial development. The flow. test was performed just prior to, the scheduled mainfenance to see if the, unit 'was still operating at design floW rates. Water Was deihleredth the Filterra unit at the design, tate of (300 cflh or 100 In Illlr) to see if ,a system due for maintenance still operated at the design flow rate. The', findings were tht:it no bypass occurred at 100 in J hr; Filterra. Fi~ld, FlbwTests Fil~erra. Sy~~m DSi;>i9ti Flow 05selVe~ Field Rate FI,?w Rate :3 yrcil!=l ~stem, 300 cflh > 300 cflh EYx6' size ~ dry a mth old 'system. i02 cf/h >225 cfIh €j'x4' size· dry 6 mttl. old system 202'cflh > 225 cf/h 6"x4's~ ~wet STORM EVEM' F1ElD MONITORING A total of sWeen precipiiaffol'Tl events were monitored dlUmg ~fs$WdY. pe~ from October 2004 -through Niovembef 2005 2, The. popufation of storms that were rUOilillftored includes a rsnge o:f precipitation average ... For' o:t:derfug a:nd te¥hnical information call: 8663493458 I I I I I I I I I I I I I I I I I 'I I FILTERRA® ADVANCED BIORETENTION SYSTEM FLOW RATE PERFORMANCE SUMMARY .~. ~~ Application: Stand Alone Stormwater Treatment Best Management Practi£?e Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Amerlcast, Inc 11352 Virginia Precast Road, Ashland VA 23005 "1'011 Free (East Coast) (866) 349-3458 fllterra Toll Free (\!Vest Coast) (877) 345-1450 www.filterra.com June 2006 STORM EVENT FIELD MONITORING (CONTD) ..• intensities from a maximum of 1.07 inches per. hour (June 29', 2005) to 0.01 inches' per hour (November 28" 2005). DU!1P9 tM study period only three storm events caused the unit to, over flow. During these overflow events the measured effluent of tlie unit was at or. above 116 in! hr. (i.e. at 'the meas'urement c}3p'acity of the weir used for the effluent from the unit) 3., The total rainfall that fell during the events monitored was measured at 14.92". The amount that, was measured through the study Fiiterra unit was 13.84", or 93% of the, total. This provides further confirmation of the 9qo/q treatment performance goals. CONSERVATIVE DESIGN FLOW RATE All data shows that Filterra is capable of operating at over 100 in I hr. However, in sizing Filterra, an engineering safety factor of 1.25 is used. The design rate used for sizing Filterra is 80 in I hr. This conservative flow rate ensures the long term, high flow rate capacity of the system is sustainable' between maintel)ance periods for many years. 11anl.lfactured by: ,";#JOOf1Jfil!JC5£fJ.g)fZ ,\ (illlwing 111\:1110 $ll1nnW:UCr flhmlilm. REFERENCES, -1. Maryland D~pt of thEl EnvIronment, 2000 Maryland Stormwater Design Manual, 2000, Chapter 1, Chapter 3; ~.40 2., Yu, Shaw, etal., 2006 Field Evaluation of Filterra® Stormwater Bioretention Filtration System, Department of Civil Engineering, University of Virginia; Charlottesville, VA. 3. GeoSyntec Consultar.tts, Inc. 2006 Filterra® Bioretention Treatment System Technical Evaluation Report,' Acton, MA. Appendix H, E' ' For ordering and techniyal informa,tioll call: 8663493458. I I I I I I I I, ·1 I I 1 I I I I I I I FILTERRA® ADVANCED BIORETENT10N SYSTEM EFFLUENT WATER QUALITY COMPARISON ~ Application: Stand Alone Stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Ma'nufactured by: Ainericast, Inc ~' filterra 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 'T'?trFree (West Coast) (S77) 345-1450 Www.iilterra.com June 2006 EFFLUENT WATER QUALITY COMPARISON Each BMP technology has a practical limit to the quality' of effluent it can achieve. Effluent quality is a function of various ,design parameters, influent concentranon and the nature, of the poll!Jtant removal me'chanism' (s)' used for a given technology. For exampl~, Filterra has been designed to optim,iz~ the' poflutant removal mechanisms incorporating an array of physical (i.e., filtratioi~ I sedimentation) chemica\. (Le'., catlo,li exchange I adsorption) and biological (i.e., degradation I uptake) pollutant removal processes found 'tn nClture's plant I soil / microbe comple~. Hydrodynamic devices and dry detention basins rely primarily on physical sedimentation processes. qel1erally, tl')6 more pollutant removal mechanisms, the higher the treatment levels tend to be. This is the theory behind treatment trains where several different tephnoiogies are p~aced in a series to impmve water quality. Filterra is designed as a self contained treatrnent trai.n containing aU treatment mechanisms possible in one system. For mec!ia filters in general, any device capable of high removal efficiency with high pqllutaot influent: concentration may show [ow removal efficiency with row influent concentrations. Decreased effic!ency of media and qtber BMPs receiving low influent concentration has: been demonstrated, and it has beeA shown .that ih some cases there' is an 'irreducible" concentration achievable. The foUow1ng extract discUsses this fact 1,2; ')lls treatment occurs and pollutants in stormwater become less concentrated, they become increasingly h~rd to remove. There appears to be a practical limit to the effluent qualify that any 8MP can be observed to achieve for the stormwater it treats. This limit is dictated by the chemical and physical nature of the pollutant of conoem, the treatment mechanisms end processes within the BMP, and the sensftMty of laboratory analysis techniques to measure the pollutant This concept of "irreducible ooncentration" 3 ftas signifICant implications for how BMP efficiency estimates are interpreted" The.refoi'e, in order to understand how to evaluate the relative performance of BMPs by percent removal arone, e'Ven where the results are statistically signifrcant, qften d,,~s not provide a useful mefuod to compare BMP perfOrmance 4. Mallufactured by: -~#8IXJ&mfJ@LfJfJ3fl ,\ Growing ltEt-.lln SI"flIlWotlCl' fllirnlitlll. COMPARISON OF EFFLUENT QUALITY' Filterra's effluent water qualify, as! measured. by TSS1 TP arid TKN has been shown to be Qetter thl;lA oth~r ,media filters as shown in the table below. This' is· particular inter~lst when considering BMP qhoice tq .achieve TMDL targets: Comp~ri,son of Filterra Effluent'Cbncentr;ltions all Filter. Systems 'Irreducible Concentrations'; TSS TotaiP"': TKN Filterra a 4.9 0.10 1.1 All 9ther Filters 20-40 0.15-0.2 1.2 , Mean Influent 22.5 0.209 < 1.46 Concentrations Conoentrations in rTfg/L.: Source: 5 Th,e. 2004' Caltrans '''BMP R~trofrtStudy?' 7 als,G found, that a more valid approach for relative comparison of BMp. perform~nce would be pollutant effluent' concentrations at the same in'fluent concentrations; Caltrans developed a comparison method' that shows thE) rE)lativ'~, expeoted effluent concentrations~f vario,us BMPs at the, same influent concentration. . The 'table below shows the actual Filterra effluent Concentrations from ij~'d' stCldies compared to the expected effluent concentrations shown in the Caltraf)s study. The Filte:r.t~ bo'ncentrations used are at or yery near the same influent concentrations' used in the Caltrans report'; RelatIve Emuent Concentration . Comparison for'BMPs .. Totaltn ~"ffuent TSS TP " 114~g/L o.38mgtL,: 355inglL, FUterra 8.8 12 0.22 , .:::20 Sand Filters 7 8-1p 0,16-0.34 24-50 Proprietary Media Fflters, 7 78 0.3' 333 Hydrodynamic Systems 7 68 0.28' 197 rf can be seen from the table above that based on the best-available Information on the, expected efflue,nt quality that, Filterra effluent water qualiity is as' good EIS or better than sand filters, propriefary meara, f~ters and, hydrodynamic systems. For o'Idering and tech.nLcal in.form~ticncall: 866349345& I I I I I I I I I I I I I I I I I I I FILTERRA® ADVANCED BIORETENTION SYSTEM EFFLUENT WATER QUALITY COMPARISON Application: Stand Alone stormwater Treatment Best Management Practice Type of Treatment: High Flow Rate Media Filtration and Bioretention Manufactured by: Americast, Inc 11352 Virginia Precast Road, Ashland VA 23005 Toll Free (East Coast) (866) 349-3458 Toll Free (West Coast) (877)345-1450 WWW.filterra.com June 2006 REFERENCES: 1. V.S .. EPA report "Stormwater Best Maf'\agelTlent Practice Design Guide: Volume 1 General Considerations", (U.S. EPA,2004). 2. U.S. EPA report "Urban Stormwater BMP P.erfortnance Monitoring" (Strecker et aI., 2002):~ 3. Schueler, T. 1996 Design of Stormwa:ter FIltering Systems,. Center for Watershed p.rotection,. Columbia, MD 4. GeoSyntec Consultants, 2000, Determining Urban Stormwater Best Management Practjc:;e (BMP) Removal Efficiencies, Urban Water R.esourc~s Research Council (UWRRC) of ASCE. 5. Center. for Watershed Protection (undated}. Irreducible Pollutant Concentrations Discharged From Stormwater Practices. Article 65 In: Practice of Watershed Protection. Ellicott City, MD. Also ili1 Schueler, T. 1996. The limits of stormwaterTreatment. TeclInical Note 75. Watershed Protection Techniques 2:2 pp. 376-379. 6. Yu, Shaw, et.al., 200'6 Field Evaiuation of Filterra® Stormwater Bioreterrtion Filtration System, Department of Civi! 'Engineering, University of Virginia, Charlottesville, VA. Table 4, 5', 6 7. California Department of TrG!nsportatlon., Division of Environmental Analysis, 2004, BM? Pilot Retrofit Program, REPORT 10 CTSW'-. RT -01 -050, Sacramel'lto\ CA 9581.4, Table i 8. Ge.oSyntec Consultants, Inc. 2006 Frtte .. a@ Bioretention Treatment System Teclmical Evaluation Report, Acton, MA. Appendix: l .~ Gnr",llIg Jd\:1111 SJelClnw:I.!cr "ll1m!!II". J\.1allufactul'ed by: .,.~Lr;;fJmfRllJ@flJ[;DV: For ordering and teclmical information call: 8663493458 i I I I I I I I I I I I I I I I I I I !I PLANT FILTER SPECIFICATIONS (1) i. GENERAL DESCRIPTION THE FOLLOWING GENERAL SPECIFICATIONS DESCRIBE UlE COMPONENTS AND INSTALLATION REQUIREMENTS FOR A PLANT FILTER FOR BIORETENTION FILTRATION OF STORMWATER THAT UTILIZES PHYSICAL, CHEMICAL AND BIOLOGICAL MECHANISMS OF A SOIL, PLANT AND MICROBE COMPLEX TO REMOVE POLLUTANTS TYPICALLY FOUND IN URBAN STORMWATER RUNOFF. THE TREATMENT SYSTEM SHALL BE A FULLY EQUIPPED, PRE~CONSTRUCTED, DROP~IN-PLAC~ UNIT DESIGNED FOR APPUCATIONS IN THE URBAN LANDSCAPE TO TREAT CONTAMINAtED RUNOFF F~OM IMPERVIOUS SURFACES. II. WORK INCLUDES THE DEALER OR MANUFACTURER, SELECTED BY THE CONTRACTOR.5HALL FURNIS,H ALL !t:E,Q!JIRED ENG1NEERING AS,SISTANCE REQUIRED TO P'RQPERLY SIZE AND INSTALL ALL COMPONENTS OF THE TREATMENT DEVICE IN ACCORDANCE WITH THE APPROVED DRAWINGS- AND 'rHESE SPECIFICATIONS. THE CONtRACTOR WILL BE Rl;SPONSIBLE FOR UNLOADING AND INSTALLATION OF THE DELIVERED PRODUCT. MANUFACTURER SHALL PROVIDE, AT NO ADDmONAL COSJ"; MAINTENANCE OF THE TREATMENT SYSTEM FOR A PERIOD OF ONE YEAR. I Ill. : QUAlITY CONTROL A. THE QUALITY OF PRECAST CONCRETE COMP,ONE~TS, UJIJDERDWN MATERIALS, FILTER MEDIA, LANDSCAPE MATERIALS AND ALL OTHER APPURTENANCES AND THEIR ASSEMBLING PROCESS SHALL BE SUBJECT TO INSPECTION UPON DEUVERY OF THE UNIT AT THE WORK SITE. B. THE UNIT AND ALL COMPONENTS SHALL BE INSPECTED BY THE MANUFACTURER FOR CQMPLETENESS, CONSISTENCY WITH APPROVED DRAWINGS, APPEARANCE, DIMENSIONS, ENGINEERED FILTER MEDIA AND TYPE OF PLANT MATERIALS. C. ALL PLANT MATERIALS SHALL COMPLY WITH THE; TY.pE' AND SIZE REQUIRED BY THE APPROVED DRAWINGS AND SHALL BE AUVE AND FREE OF OBVIOUS SIGNS OF DISEASE. D. FILTER MEDIA SHALL BE ViSUALLY INSPECTED TO ENSURE APPROPRIATE VOLUf\1E, TeXTURE AND CONSISTENCY WITH THE APPROVED DRAWINGS AND MU$1' BE EITHER TESTED, OR HAVE BEEN CERTIFIED USING APPROVED PROCEDURES TO MEET OR EXCEED THE FILTER MEDIA MINIMl,lM FLOW RATES, ANNUAL VOLUME TREATMENT CAPACITY, POLLUTANT REMOVAL EFFICIENCY AND SOIL CONTENT (SAND, SILT, CLAY AND ORGANIC MAtERIAL) OF THE PLANT FILTER. IV. SUBMITTALS A. INSTALLATIONl OPERAttON AND MAINTENAN,CE MANUAL THE CONTRACTOR SHALL SUB...,ITTHE MANUFACTURERS APPltOVED pLANT 'FILTER INSTALLATION1 OPERATION, AND MAINTENANCe MANUAL FOR THE SYSTEM. rr WILL BE'THE RESPONSIBILITY OF THE UNIT OWNER/OPERATOR. OR. THEIR. CONTRACTOR TO ENSURE, THE UNIT IS OPERATED AND MAINTAINED IN ACCORDANCE WITH THe MANUAL. B. DRAWINGS THE, CONTRACTOR SHALL SE PROVIDED DiMIENSIONAL DRAWINGS ANDt WHEN SPECIFIED" UTILIZE THESE DRAWINGS TO SHOW DETAIL,S FOR CO~STRUCTION,. MATERIALS, SPECIFICATIONS,. REINFORCING, PI,PIE JOINTS AND A.NY MAINTENANCES. C. MANUfAcTIJRfRS GUARANTEE THE MANUFACTURER SHALL GUARANTEE ALL COMPPNENTS OF THE UNITS FOR A MINIMUM PERIOD Of. ONE YEAR PROVIDED THE UNIT IS OPERATED AND MAINTAINED IN ACCORDANCE WITH THE MANUAl. IMPROPER. OPERATION,. MAINrENANCE OR ACCIDENTAL OR ILLEGAL ACTlVlTIES (IE. DUMPING OF POLLUTANTS, VANDAUSM, ETC.) WILt. Vf)ID THE GUARANTEE. I I I I I I I I I I I I I I I I I I I V. i (2) MATERIALS AND DESIGN EACH UNIT. SHALL CONSIST OF A PRECAST CONCRETE CONTAiNER TOGETHER WITH AN U~DE!tDRAIN SYSTEM, fILTER MEDIA, PLANT MATERIAL, AND APPROPRIATE' GRATE LANDSCAPE COVER WHERE APPLICABLE. A. CONCRETE FOR PRECAST UNIT SHALL CONFORM" TO THE FOLLOWING: 1.. TH!; WALL THICKNESS SHALL. NOT BE LESS THAN 150MM [5"1 QR AS SHOWN ON THE DIMENSIONAL DRAWINGS. IN ALL CAsES, THE WALL THICKNESS' SHALL BE NO LESS THAN THE MINIMUM THICKNESS REQUIRED TO MEEr LOADING REQUIREMENTS OF THE APPLICATION. 2. THE PRECAST CONCRETE UNIT SHALL BE Cl,IRED BY AN APPROVED. M~THOD. THE UNIT SHALL NOT BE SHIPPED UNTIL THE CONCRETE HAS ATrAINED 85% OF ITS DESIGN COMPRESSIVE STRENGTH. 3~ THE CONNECTIONS SHALL BE PRQVIDED TO ACCEPT PIPES OF THE SPECIFIED SIZE(S) AND MATERIAL(S). 1 \(.1. PERFORMANCE CRITERIA I Y I A. THE MEDIA SHALL ACHIEVE A FLOW RATE EQU~ELANT TO 80-100 INttlE~PER HOUR. B. THE UNIT SHALL REMOVE 80%. TOtAL SUSPENDED SOtIDS AND A TOTAL OF 50% PHOSPHOROUS. C. THE UNIT SHALL BE LOCATED·TO ENSURE THAT HIGH FLOW EVENTS SHALL BYPASS ni'E fiLTER MEDIA PREVENTING ER,?SION AND RESUSPENSION OF POLLUTANTS. D. THE FILTERED EFFLUENT SHALL BE DISCHARGEt;> TO ALL APPROPRIATE STORM DRAINA.GE SYSTEM IN ACCORDANCE WITH THE APPROVEP D~WINGS. VII. CONSTRUCTION A. EACH UNIT SHALL BE CONSTRUCTED AT THE LOCATION~ A~D ELEVATIONS ACCORDING TO THE SIZES SHOWN ON THE APPROVED DRAWINGS. ~y MODIFICATIONS TO THE ELEVATION OR LOCATION SHALL BE AT THE DIRECTION OF AND WITH APPROVAL BY THE ENGINEER. ~. INLIET AND OUTLET CONNECTIONS SHALL BE ALIGNED TO MEET THE APPROVED DRAWINGS WITH MODIfiCATIONS NECESSARVTO MEET SIT·Ii·cONDITIONS. C. ONCE THE UNIT is SET, BACKFILliNG'. SHOULD BE PERFORMED IN A CA~FUL MANNER, BRINGING THE APPROPRIATE FIl,.L MATE~P;LJ~P I(f1S0mm [$"] LIFTS ON ALL ~IDE$ •. IN ALL INSTANCES INSTALLATION OF FILTER UNIT-SHALL CoNFORM TO ASTM . SPECIFICATION C891 "STANDARD PRACTIce FOR. INSTALLATION OF UNDERGROUND PRECAST UTILITY STRUCTUREst'. . V!II~' MAINTENANCE A. EACH CORRECTLY INSTALLED SYSTEM IS TO BE MAINTAINED BYTHE MANUFACTURER fOR A MINIMUM PERIOD OF ONE YEAR. THE COST OF THIS SE~VICE IS TO BE INCLUDED lUll TIllE PRICE OF THE SYSTEM. B. ANNUAL MAlrIM1iIENA[I8CE CONSISTS OF A MAXIMUM Of TWO [2] SCHEDULED W:SITS. C. IEACIHIIMMNTIEINANCIE VISIT CONSISTS Of THE fOLLOWING: 1. SYSTEiM INSPECTION 2. FOREIGN DEBRIS, SILT, PLANT MATERIAL AND TRAsH REMOVAL 3. FILTER.. MEDIA EVAWATION 4.. PLANT HEALTH EVAWAlION AND ~UNING S. REPLACEMENT OF PLANT MATERIAL 6. DISPOSAL OF ALL MAINTENANCE REfUse ll'EMS 7. MAINTENANCE RECORDS UPDATED AND STORED I I I I I I I I I I I I I II I Filterra ® by Americast An Advanced Sustainabl~ Stonnwatet Treatment System. By Larry S. Coffinan1 and Terry Sivitel.2 I. Abstract FiltelTa® is the late~t advancement in Bioretention treatment technology for'WQan stOl'Plwater nmoff. Americast,'8, Division 'Of Valley Blox, Inc.,. worldng with the University .ofVirginia' s Civil Eilgineering Department has optimized the tteatinent capacitY of thi.s·lntiovative best Dianagement practice (BIVrP). FiltelTa® relies on a specially' engineered high f10w rate· ttea;tnlent system to provide exceptional pollutant removal. Monitoring data shows Filterra® can treat over 90% oft4e total annual v01ume of rainfall with maximum pollutant removal rates reaching 95% for total suspended solids, 82% total phosphorus" 76% total nitrogen and 91 % heavy metals (measured as Cu). The high pollutant retnoval efficiency is primarily due the. multiple treatm:ellt systems inherent ill its unique plant I' soil! microbe treatment media. Its unique desi'gn and use of typicallanq,sc.ape plants also provides many added values such as low maintenance costs, enhanced aesthetics, impr~v~d habitat value, and easy I safe inspection. The. "at-the-source" treatment strategy is highly adaptable for any urban setting to achieve multiple stonnwater management water quality and quantity goals includin~ combined sewer overflow control. II. Background Fi1tt:~lTa® is based on Bioretention technology. Bioretention has b~n'defil1ed as filtering stpffi1water runoff through a terrestrial aerobic plant / soil I microbe c0i11pleX' to capture, reJ:!.love, and cycle. pollutants through a variety of physical, chemical, and biolog:ical prO',?esses. The l~lultiple pollutant removal mechanisms of tIns technology make it the most efficient of all HMP's. The word '"Bioretention" was derived from the fact that the biomass of'the plant I m.lcl'obe complex retains, degrades, uptakes, and cydes many of the p'ollut8J1ts I contaminants of conc~m including bacteri~ nitrogen, pl1osphorlfs, heavy metals, and organics su~h as oil I grease a11d polycyclic aromatic hydrocarbons (P AH). Therefore, it is the "bio"-mass that ultimately "retains" and transforms. the pollutants -hence "Bio-reterition". Treatment technologies using soils" sand, organic materials, microbes and plants have been used in both water and wastewater treatment For example, wastewater ef:f{uefit spray in-igation on fields and meadows has been successfully used for centuries tltrougb,outthe world,(Shuval et aI., 1 Mr. Coffman has over 30 years of ell.-perience in the stonnwater f water resources management He bas authored numerous papers and articles Oil stom1water managemellt programs and pioneered the development ofbioretention or "Rairi Qardensn, He is the principal author of Prince George's County's, M3l)'laud national award wining "Low Impact Development Design Mlmual" ~ an alternative feclmologieal !ippl'oacb to stormwaler management He is a member ofAmetican Society of Civil Engineer's Urban Water ResoUfceg Research Catmci[·and!he Water Environment Research Federation StormwarerTetimica! AdvisofY Committee. Mr. Coffinan is collsirJeroo one of the nation's leading experts DIll Low Impact Development technologies for water resources I ecosystem protection. 2 Mr. 'Siviter has been tbe Director of Bus mess Developmeqt for An'!eri'cast for over 10 y~. fIe i~ l1?sp'onsible for the technical development, marketing, and sales of products and services for stormwater treatment I conveyance systems and industrial wastewater and water pollution control technologies. 1 I I I I I I I I I I I I I I I I 1986). these systems have been shown to be both economically and enviromuelltally sustainable (Feigin et al., 1991). Bioretention was first developed by Prince George's County, Maryland's Deparllhent of Environmental Resources (pGCDER) in the early 1990's (Coffinal1 et al.l993}. The PGCDER desigllll1anua1 provides basic Bioretention planning, design and maintenance guidance. The practice, was originally developed to allow use of sites' landscaped and green space to filter and treat ninoff. The origfual design 'Was. essentially an enhanced infiltration teclmique where the fiiteted water was allowed' to infiltrate into the ground. Since the intro-duction ofBioretention, the success of the practice has.b~e~l mixed primarily clue to the lack of det:1.i1ed· specific de~ign and constructio:Q. standards. This lack of Specifi9ity has lead to wide variations in the soil I filter mix, infiltration rates, plant materials; and sizing resulting in costly reconstruction and n1;aintenance repairs. The advanced design ofFiltelTa@has eliininated all of the past problems and ~iabi1ities of conventional Biol'etention designs and greatly improved its performance, reliability, and ease of construction and maintenance. ill •. Filterra® Physical Description The system consists of a concrete container, a 3 inch mulch layer, 1.5 to 3.5 feet of a unique soil filter.media, an observation I c1eanout pipe~ an under-drain system and all appropriate type"of plant Le., flowers, grasses, shrub, or tree (see Figure 1). I Figure 1 StonnWC).ter mnoffdrains directly from impervious surfuceg through an inlet sttt.tctut~· jn th~ concrete box and flows through the mullc~ plant, and soil filter media. Treated wl;!ter·:flows out of the system via an under-drain connected to a stonn drain pipe <;>! other·apprQ.prii:rle outfall. 2 ~I I I I I I I I I I I I I I I FiltelTa@ can also be used to control runoff volumes / flows by adding storage volume beneath the filter box for either infiltration or detention control (e.g; a gravel infiltration trench area ben~ath the box). The concrete container and treatment media are below grade with tIle only features visible being, the top concrete slab, tree grate, plant, and inlet opening. Filterra® looks very similar to an ordhiary tree box except that it is specially desigp.eq: to treat runoff (see Figure 2). This is one of the few commercially available BJ\.1:p' that can also help to enhance the aesthetic value of the urban setting. IV.. Pollutant Removal Processes Poll,vtants are captured, cycled, and removed by a wide variety of complex: physical, chemical, and biological processes as the contaminated nmofffl.OWSi onto and through the. mulch I soil I microbe I plant treatment system. Suspended solids are removed through sedimentation as runoff is allowed to pond above the filter media with filtration of pollutants as the runoff passes through the media. Organic compounds are removed by chemical complexfug with the organic constituents of the media, microbial degradation, :fiI:tration~ and sedimentation. Nitrogen is captured through physical and chemical means and ,removed through nitrification, denitrificatio~ and plant uptake. Phosphorus is removed through adsorption, sedimentation, precipitation and p1~t uptake. Heavy metals are removed through sedimentation, organic complexing, ' p').·ecipitation, adsorpti()n~, and plant uptake. The pollutant removal mechanisms operate in twO' d~stinct time scales. The first time scale ocCUtS during the storm event when pollutants come into. contact with the w.edia and are captured instantaneously through sedimentation, filtration, adSorption, absorption, in;filtratiO'n, and chemical precipitation. The second time scale is between storm events. Pollutant removal and cycling occurs in a matter of hQUfs, qays, and weeks through. biological degradation, biological' uptake, and volatilization. The Filterra® filter media is designed to capture pollutants during tIle smml event while biological processes degrade, metabolize, detoxify, and volatilize the- pollutants during and behveen storms. the difficulty with removing pollutants in ~ban runoff is that they OCC;tit in a wide array ot 3 I I I I I I I I I I I I I I il I I I I organic and inorganic forms and in various particle sizes fl.·om gross solids to dissolved molecules. Each of the various pollutant fonns and ofartic1e sizes can require different processes· and mechanisms for capture and treatment FiltelTa .. complex media structure provides for an array of physical, chemical, and biological treatment processes to haildle a, wide variety of pollutants. Each of these processes is described below~ A. Physical Processes' 1. Sedimentation (Event Time Scale) l':..... The stora,ge area above the mulch layer· is designedto-:allow a quiescent pooling of . lUl10ff witbfu. the filter box that encoura,ges sedimentation. Most'of the larger . p~ticles a,ssociated ,vith. gross. and sUspended souds 'are deposited on th~ surfa,ce ana / or entrained within the 3-djinensionalmriI.ch l~y'~~'; rhe am,ou,nt of sedimentatton is a ~ction of particle' density, size .. ah¢t-water density (Stokes Law). Heavy metals lrre commonly attached to theseiparticles so the: sedimentation process is' effective in reIl10ving a Iiortion of the heavy metals and other pollutants in particulate form.. 2. Filtration ~vent Time Scale) The. mulch and sandy organic media are designed to·filt¢t out many particulate pollutants-. As runoff passes through the mulch layer an4 il1.to. the underlining sandy filter media, many smaller particles are captured in the media. The efficiency of the filtration process is a function of flIter depth, media size, porosity, velocity, and nature of the particles. Studies at the University of Virginia helped to optimize the filter media to. achieve both high flows and pollutant removal. Particles found in runoff range in size from trash anq debris to. less thal1 1 micron all qfwhlch can be captured in. the media. 3. Infiltration (Event Tn,te Scale) When designed as an i.nfUtration device~ where Soils. permit, Filterra.@·removes pollutants from runoff by reducing the total annual rUnoff volume. This iJ.rfiitrated runoff is fi.ni:her treated through additional chen:i.ical·and biolo.gical processes occurring in the soils. B. ·Chemical Processes 1. Adsorption: (Event Time Scale) The mulch and sandy I org~c treatment 1:p.edia is complex and has a tremel}dous surface' area. The process of adsorption is sp.nply the preferential partitioning of a substance onto the surface of a solid substrate. Thls physical adsorption is caused mainly by electrostatic forces and is: a function of surface area and the polarity of the materials. The media co.ntains hydrophilic adsorbents such as aluminosilicates (sand) and hydrophobic adsorbents such as carbonaceous I organic n1atter that allow for wide range ofpollutauts to adhere to the surface of the media's components. 4 I I I I I' I I I I I I I I I I I I I I 2. Absorption (Event Time Scale) Absorption can be physical or chemical where the molecules of one substanc.e ate: taken into the physical structure of another substance. For example~ organic matte.r can act as a sponge to essentially .soak up soluble molecules within. its· physicaJ structure such as occurs with activated Garbon. 3. Volatilization (Between Event. Time Scal~) Volatile orgru:iic cotllpounds (i.e., gasoline) fou!1.d inl'Ul,1<;>ff.and capj;ured in i:1J.e filter media and will, over time, be volatized back into the atmosphere. Gases such as water, CO2, and N2, which are derived from metabolic ptocesse.s, Will also be volatize<d back into the atmosphere. C.' Biological Processes 1. Biological Adsorption'and Capture (Event Tiine Scale) The bacteria growing in the Fiiterra® media are encapsulated with a: slime layer~ TIus layer helps to protect the bacteria and provides a: "sticky" surface to bind with particles containing organic matter and heavy lIi~ta1s, As t1.).e bacteria level increases in the filter media the greater the volutne of sticky surface cell surfaces there are to capture pollutants. 2. Evapotranspiration Plants also transpire: or release gases to the atmosphere through openings .in their leaf tissues. Phytoremediation technology has shown that plants can remove volatile substance from the soil and transpire them back into the 'atmosphere illcludingvolatile organi.c compounds VOC's (Zha1;i.g, et aI., 2(01). - 3. Biological Processes (Between Event time ScaI~) . There are s~yeral biologicalptQcesses: that are iinporfan±" in th~ removing pqll'!1tants from the runqff. These pfocesses are quite complex and vary as a function of moisture, temperatUJ.:e;, pH, salinity, exposure to toxins, and the presence of or absence of oxygen. Basically, these processes transfOlTIl pollutants into other less hannful chemicals and compounds or incorporate the pollutant$ into the microbe! plant biomass to create new cell matter. Some of these processes are listed below and briefly defined. a. NnItll"ffteni Assimilation -Biologically available forms of nitrogen, phosphorus; and. carbon are actively takell into the cells of organisms and used for metabolic processes (energy production and growth). Bactena will use ali types of carbon sources for food lncluding (oil products) breaking them down fot a variety .of metabolic processes and needs. Nitrogen and phosphorus are actively taken up by organisms as nutrients that are vital for a number of cell functions, growth, and en.ergy production. These processes remove metabollites from th~ media during 5 .-----------------------I I I I I I I' I I I I I I I I and be"hxreen stonn events. h. Nitrificatic;m I Denitrification -Through a complex series of processes and reactions that occur with arid ,lilithout oxygen, bacteria transform various forms of nitrogen into cell tissue or nitrogen gas. These processes help to reduce the total nitrogen in the treated discharge. c. Biodegradation -Organisms can brealc down a wide :array of org;:tPic compounds into less toxic forms or completely breaJ.c them dQwp: iJ;I.to CO2 and water. This process is important 1n detoxifying or ~14irillating a numbef of toxic organic compot'!llds of concern. d. Bioremediation -Bacteri~; and plants have a wide array of mechaItisI);l.S to immobilize and detoxify organic compounds and heavymetalsi. For example, \ bacteria can cause· metals to precipitate. out as: salts, bind. them in protems in the. ' cell and ceil ·wall slime, and accumulate metais ill nodules withii:!. the cells. Metals are captured in the bacteria and transformed in ways. that are g~nerally less toxic to them and the plants (Means et al, 1994). e. PhytoremeCiiation -Plants also have the ability to metabolize rqany pollutants such as the uptake and accumulation of metals in the cell tissue to make them less toxic (Re.eves and Baker? 2000). Filterra®"is a living system that metabolizes volatizes, detoxifies, and cycles many pollutants in runoff. Nitrogen and phosphorus are used by the plants and bacteria to grow more cells. Organic matter is used as an en~rgy source and metabolized into water and carbon dioxide. This means that a$ the biomass (plant and microbes) of the system increases in mass; so does the system's capacity to capture and process more pollutants. FilteiTa@USeS all of the natural process of the plant I'soil complexpossibre to treat urban runoff~ These processes can last many 'years as p'oU~ts' are. simply recycled within the system ancl c()nyerted into biomass. ThQ. ~cQumulc~.tion of· debris and sediment can be removed with ~imple annual maintenance Practices. If toxic substances should ever build to levels that may ·cause harm to the receiving water or wildlife, the media and plants can easily be replaced. V. Treatment Capacity The treatment capacity of Filterra® is dependant on the overall pollutallt removal capabilities of the treatmel1t media and the hydraulic properties. oftlle media. Many of the pollutant removal processes were mentioned above. The hydraulic properties of importance are the flow rate through the media and the volume of runoff it can treat. Both the pollutant removal and hydraulic capacity of th.e system have been measmed though monitoring cm'llducted by the University of Virginia. Based on these measured values, a perfonnance curve can be developed for various pollutants (see Figure 3). This curve shows that pollutant removal capabilities vary With the ratio of media's surfuce area to con:trlbuting drainage area. Increasing this ratio will 6 I I I I I I' I I I I I I I I I I I I increase the pollutant removal rat~ up to the maximum removal capacity of the media to captur~ andprocess the pollutants. I· Figure 3 FUterra® Performance Mid-Atlantic U.S. Region ~~~~~ 100% 90% '\:I' SO% UI,s 70% 2m ~t-60% _QI 50% ~ e ~~ 40% ~'\:I 30% fij 200"' 10% 0% 0.0% 0.2.% 0.4% 0.6% 0.8% 1.0% 1.2% 1.4% Ratio -Falter Surfaca Area I Drainage Area .Legend Based on test data and rainfall distribution of the Mid-Atlantic region of the U~S" the optimum media surface to drainage area ratio is about 0.33% or 36 square feet of media / 0.25 acres of contributing drainage area. Using the 0.33% ratio, the system will treat approxiinately 90%. of the alUlUal volume of runoff and can achieve maximum expected pollutaht removals of 95% for total suspended solids, 82% total phosphorus, 76% total nitrogen, and 91 % h~avy metals (measured as Cu). The 0.33% ratio will vary from region to region as rainfall intensities varies. An explanation of the hydrology and hydraulic method for sizing the system is' provided below. VI. Hydrology and Hydraulic Analytical Method Filterra® uses a unique and sound analytical method' to determine 111e appropriate meilia surface area needed to achieve the desired treatment levels .. The l..<:.ey is to approprrately' rilatch the me<;1ia's flow rate to the unique rainfall / runoff characteristics of the drainage area. Tb,is is achieved by matching the volume of runoff treated by the m~dia to the volume of runoff g~nerated by the drainage area based on actual rainfall intensity distributions for ally.given .region. For the Mid--Atlantic region, 50 years of rainfall data was anaiyzed from Re,agan National Ai1:POlt from which the probability and frequencies of all.rainfall i11tel1sities (incheslhour) were determined. Knowing this and the flow characteristics of the Filterra® media (from University of Virginia testing), one can determine the annual volume of runoff that call be treated alld the optimum surface area for any given drainage area. The Filterra® perfonnance chart for the Mid- Atlantic U. S. region (see Figure 4) summarizes the rainfall intensity distributions, ptedicted pollutal1t removal rates, and volumes treated for 36 sq. ft. of media surface area with a Y4: acre drail1age .area. The MS Excel based pel'formancespreadsheet will automatically calculate the filter media surface area needed. to treatment goals of any given drainage area. If other ponutant removals are required or certain annual pollutant load reductions are needed, the spreadsheet can also calculate the surface area needed... 7 I 1 ·1 I 1 1 I I I I 1 I I I I I I Filterra® Performance for Mfd-Atlantic U.S. Region Dralnage Area (OA) = Filterrae Length :: FDterrallI Width = !lVillIab1991z,,!, Td.alConlribIlIJllII OrainaoaAlel 4x6 or 6.4 fi.17 ac 0.25 6.00 6.00 Acrt:1 feet feet DA'" 10,890 if PUtar Sutfaca Area lFSA1" 36.00 It' 4>8 Dr BY.4 0.22'0 Standard 61a 0.25.c .sxa or BxS 0.33.c 6xlli orlOlS 0.42 ac 6x12 or 12)(5 0.50 ac FSA to DARatio = Flow VolUIlJEl F1lt.ered :: TP ~emDval (Max 82%):: TN Removal (Max '!:~%) = TSS Fl-eJ.TI0val (~ax.95%) = Met~! Removal (Max 91%).= 0.331% 90.64% 74.33% 68.89% 86.11% 82.49% .. filterrcf SUe ConditIon = con'sfJ:ler lolal conlrU)ulIng DA as 1 Po% ImpelVlous FHterra6> Flow Volume = 0.01 x lWMIlI4.27Sl( 3600 = 303.09 cu IIIhr Volumetric Runoff Coaniclen!. R, (usa MDE Formula) = 0.95 Runo!!'Volume = P • Rv 112 • DA = 86.2.125 P cu ftlhr lal (b) (e) (,j) (e)' (Ii. !9l RaInfall j~-;;'ft~rL Runoff Treated ;~~ '. :~, i (~).~ ~e~rtu l!J:i<;!r) J1nlhrt (ClJlt!hr) -~ O. 11,2· '.2 .21 O. !4.4~ 6'.28 6 O. )1.1: 5.1 0 30 'B.e' 4. §. 00 16. 0 25 0 50 29.l 172.~ O. :2 215. Q. O· 0 25B.E O. o. ( 1..9918· ..9930 1.9942' 1.995()1 Q. 10 G! )3.1 ( 0.910 15.9' .9911 1 62.1: .9999 2.010 r24.25 ~03.09 .001)0 0.000 o 3 (1.1' 1,0000 Figure 4 Table is based an' precipltalion data obtained [rom NCDC (NationafClimatic Data Center). Calculating the annual pollutant load' removal is detennined by shnp1y multiplying the perc~nt: annual volt.U,ne treated by the maximum pollutant removal pereentage for 'each pollutant. These values can be found in the perfonnance chart above. Example: Annual volume treated = 90.64 % Maximum TSS Removal = 95% Anllual TSS. Removal = (90.64%) (95%) = 86.11 % lOa VII. Unique Decentralized Placement of Filterra®-Systems' Another unique feature of the design, sizing, and placement of FUterra® is that it utilizes a distributed design approach :fundamental to the Innovative Low Impact Development technol:o~ I , I '1 I .1 I I I I I I I I I I I :. I I (LIP) .. This design philosophy promotes at-the:-source controls; off-line configuration of the units, treating relatively small drainag~ areas Oess than Yz acre), and a more unlloIfu distribution of controls throughout the site. This is oppos~d t6 conventional end-of pipe and in-My treatment approach used for mqst J3MP desig~s. The LID approach red\lc~s the effective hydraulic and pollutant load to each unit thereby' increasing performance and reducing maintenance burdens. Controlling runoff as close to the source as possible also eliminates problems common to convelltional BMP's such as concentrated high flows that cause erosion and resuspension·of pollutants or expensIve control strq.crures to store, split, ot divert high flows. Ushig small drainage areas ensures that runoff flows and. velociti~s'are always very low. . VIll. Ea,se of Design Americast"s recommend media surface area to drainage area ratio of 0.33% f9r tbe Mid-Atlantic l'egiOll is· adequate toimeet current state. and Federal NPDES pollutant removal requirements. For your cOiwenience, Americast offers a variety of precast. concrete' Filterra® box sizes to meet 1110st of your site design needs. As long as you follow the LID design pru,1Cipl~s py distributing the units a11d keeping the diain8:ge area to each lJIJit at or below Yz acres, all you have to do is to properlY'place the right size unit to match drainage area (see Figure 5). Available Sizes 4xQ"or 6x4 4x8 or8x4 Standard 6x6 6x8 arSx6 6x10or10X6 6x12 or 12x6 Figure 5 IX. Oft'..Line I Bypass Design Total Conirlbutiilg Drairlag~ p,rea' O.17aG O.2~ ac 0.25 aGo O.33ao O.42.ac O.50ac Another unique design feature ofFilterra® is its off-line d.esign coilfiguratio.ll;, This design strategy improves treatment and avoids the possibility of res us pension ofp~iiculat~ Platter; It is important that the site designer confer with Americast on the proper location of the un~t. to ensure that the site grading and placement are correct (see Figure 6). Example scenarios are available by contacting Americast. I ! I Figure 6 I PAVED. ARCA REQUIRED CROSS UNEAR ( currER F!.DW ~ FRO!!1" or fIl:.'I'EAA'A em'} JLOVI PDI!!1" __ 9 I I I I I I I I I I I I I I I II I I I I The site designer must also plan for the by-pass' of high flows. Although the system will treat about 90% of the total rainfall events tvolume, occasionally the flow capacity oftlle treatment media will be exceeded causing the unit to go into bypass mode. The bypass flows must be safety conveyed to a nearby inlet or other appropriate discharge point. Sump conditions must be avoided. lfthe unit is placed in a sump, bypass mode will result in flooding around the unit and cause re~uspension oftlle debris collected in the unit. X. Construction O~nsider;:ttions Perh~ps the most, critical construction issue is proper lopation of the unit in re~ati9nship to the site grading. Generally, the units are placed in ~he curb'line, of parking lots and roadways. In this configuration, the site grading must direct runoff to the curb first to allow the flow to enter the unIt 11:om the curb in a cross linear malmer aiong the face of the inlet. Filterta® looks very much Uke an inlet stl.1lcture and often cOl;1tractors will grade the site as if the unit is a standard inlet (i.e. placing it in a sump condition). The site engineer must ~nsure that this does not happen. XI. Conclusions Filten'a® is one of the most advallced alld adaptive BMP"s on the market today. It has, been carefully engineered and designed t6 meet all your water quality needs in the most cost effective manner possible. XIL References Coffinan. L. S., Prince George's Cot!nty, MH, lIpesign Manual for the Use ,ofBiq~etention in Stprmwater Management", Prince George's County; Marylan!:l, June 1993. Feigjn~ A., 1. Ravina and J. Shalhevet. 1991. Irrigation. with Treated Sewage Effluent. Management for Environmental Protection. Advanced Series in Agricultural SCiences 17. Springer-Verlag. 224pp Means J., Hinchee R, 1994. Emerging TechnQtogy for-Eiotemt;!diation of Metals, Battelle, Columbus, Ohio,158'pp. ISBN:1-56670-085-X ' Reeves R. D. and AJM Baker. Metal-accumulating pl~ts. fuPhytore;mediation: of Toxic Metals, I" Raskin and B Ensley (Eels.). John Wiley & Sons, New Y qrk, pp. 1.93-230 (2000). Shuval, H. I., A. Adin, B. Fattal, E. Rawitz andP~ Yekutlel.. 1986. Wastewater irrigation in developing countries. Health effects and technical solutions. World Bank Tech. Pap. 51, 325pp. Zhang Q. Davis L. C., Erickson LE. TrailspOli of methyl tert-buty 1 ether through alfaifa plants. Env. Sci. Techno!., 35: 725-731 (2001). 10 I, I I I I I I~ I 1 I I I 'I I fS5TfrPE'RCEflTlLE PEAK FLO,,-{1AND VOLUME DETErR~fINA TION jModified Rational Method· Effective for Watersheds < i.O mt lliunsal<er & Ass£:.iates • San Diego Note: Only Enter Values in Boxes -Spreadsheet Will Calculate Remaining Values IProject Name La Costa Greens Neighborhood 1.17 & 1.16 Work Order 2352-109 I . Jurisdiction City of Carlsbad I 8MP Location IUpstream of Detention Basin 85th Percentile Rainfall ::; (from County Isopluvial Map) 0.65 linches Developed Drainage Area ::; p....,;;.;;~=-lacres -i.:N~a~tu~r~a~1 ;;;.D~ra;;;;in:,;.;a:.=g6:e;,.;A.;;r.;e;;;,a_::;""!",,~_bo~~,..,,..!acres Total Drainage Area to 8MP = acres Dev. Area Percent Impervious::; I Overall Percent Impervious ::; 45 ::]% 45 % Dev. Area Runoff Coefficient::; ro.sal Nat Area Runoff Coefficient::; r--l DRunoff Coefficient = 0.58 - Time of Concentration = 11.0 lminutes ,~(fr~o-m~D~r~a~in-a-ge~S~tu~d~y~)====~~-=~=== ,RATIONAL METHOD RESULTS Q = CIA where 85th Percentile Peak Flow (efs) Runoff Coefficient I Q= C= 1= A= Rainrallintensity (0.2 inch/hour per RWQCB mandata} . Drainage Area (acres) v = CPA where V= C= p= A= 85th Percentile Runoff Volume (acre-feet) Runoff Coefficient 85th Percentile Rainfall (inches) Drainage Area (acres Using the Total Drainage Area: C= 1= P,:, A= Using Developed Area Only: 0.58 0.2 inch/houi 0.65 inches 55.7 acres ==:6.46 as 1.75 acre-feet C = 0.58 I = 0.2 inch/hour P = 0.65 inches A = OO,{ acres 'Q';= ==~ 6,46 cis V = 1.75 acre-feet I I I I I I I. I I I I I I I I I I I I La Costa Greens Neighborhoods 1.16 ~ 1.1i 8MP #1 -Prior to Detention Basin HYDRAULIC ANALYSIS OF LO"" FLOW DIVERSION & VORTECHS UNIT AT CLEANOUT (Node #) LOW FLOW ORIFICE (Q = 6.7 cfs) Weir Formula for Orifices & Short Tubes (free & submerged) Q::: Ca(2gh)o.5 (Eqn. 1) Q::: Ca(64.32ht5; C = 0.56 Q ::: 4.491 a(h)o.5, where a ::: area of orifice opening, h = head (ft) above centerline of orifice Orifice Size, L::: in. , a = 1.07 sq. ft., invert elevation::: 100.00 ft. H::: 14 in. HIGH FLOW (Q 100 = 107.6 cfs) Weir Formula for Bypass Weir & Vortechs Weir Q ::: CLH1.5; C::: 3.3 for Bypass 6.2 for Vortechs Bypass: L::: 8.6 ft. @ elevation 102.50 ft. Vortechs: L::: 1.0 ft. @ elevation 104.00 ft. 105 (Eqn.2) ( 2.50 ft.) Lo Flow (Eq. 1) Weir Flow (E . 2) La Flow (Eq. 1) ELEV. Orifice Vortechs S'/oass TOTAL ELEV. Orifice (feet) h (ft) Q(C1S) H (ftl Q (cis) H 1ft) Q (cfs) Q (cis) (ieer) h (ft) Q (cis) 100.00 0.0 0.0 0.0 0.0 0.0 0.00 0.0 102.58 2.00 6.79 100.17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 102.67 2.08 6.93 100.25 0.00 0.00 0.00 0.00 0.00 0.00 0.00 102.75 2.17 7.07 100.33 -0.25 #NUM! 0.00 0.00 0.00 0.00 #NUM! 102.83 2.25 7.20 100.42 -0.17 #NUM! 0.00 0.00 0.00 0.00 #NUM! 102.92 2.33 7.33 100.50 -0.08 #NUM! 0.00 0.00 0.00 0.00 #NUM! 103,00 2.42 7.46 , 100.58 0.00, 0.00 0.00 0.00 0.00 0.00 0.00 103.08 2.50 7.59 100.67 0.08 1.39 0.00 0.00 0.00 0.00 1.39 • 103.17 2.58 7.72 100.75 0.17 1.96 0.00 0.00 0.00 0.00 1.96 103.25 2.67 7.84 100.83 0.25 2.40 0.00 0.00 0.00 0.00 2.40 103.33 2.75 7.96 100.92 0.33 2.71 0.00 0.00 0.00 0.00 2.77 103.42 2.83 8.08 101.00 0.42 3.10 0.00 0.00 0.00 0.00 3.10 103.50 2.92 8.20 101.08 0.50 3.40 0.00 0.00 0.00 0.00 3.40 103.58 3.00 8.32 101.17 0.58 . 3.67 0.00 0.00 0.00· 0.00 3.67 103.67 3.08 8.43 101.25 0.67 3.92 0.00 0.00 0.00 0.00 3.92 103.75 3.17 8.54 101.33 0.75 4.16 0.00 0.00 0.00 0.00 4.16 103.83 3.25 8.66 101.42 0.83 4.38 O.CO 0.00 0.00 0.00 4.3'8 103.92 3.33 8.71 101.50 0.92 4.60 0.00 0.00 0.00 0.00 4.60 104.00 3.42 8.88 101.58 1.00 4.80 0.00 0.00 0.00 0.00 4.80 104.08 3.50 8.98 101.67 1.08 5.00 0.00 0.00 0.00 0.00 5.00 104.17 3.58 9.09 101.75 1.17 5.19 0.00 0.00 0.00 0.00 5.19 104.25 3.67 9.19 101.83 1.25 5.37 0.00 0.00 0.00 0.00 5.37 104.33 3.75 9.30 101.92 1.33 5.54 0.00 0.00 0.00 0.00 5.54 104.42 3.83 9.40 102.00 1.42 5.72 0.00 0.00 0.00 0.00 5.72 104.50 3.92 9.50 102.08 1.50 5.88 0.00 0.00 0.00 0.00 . 5.88 104.58 4.00 9.60 102.17 1.58 6.04 0.00 0.00 0.00 0.00 6.04 102.25 1.67 6.20 0.00 0.00 0.00 0.00 6.20 104.67 .t 08 970 ~;~~ ~~!~ ~&q80~ ~&':"'2~ .~..:..... .. ~.i:ii 102.33 1.75 6.35 0.00 0.00 0.00 0.00 6.35 104.83 4.25 9.90 102.42 1.83 6.50 0.00 0.00 0.00 0.00 6.50 104.92 4.33 10.00 ~f0T~~~-~ ,~o .ffias~ i~~ ~00i~ r[®r~~ ~~~~arem lli"'6rsS"J'i ~~ 105.00 4.42 10.09 Weir Flow (Eg. 2) Vortechs Bvoass H (ft) Q (cis) H (ft) Q (Cis) 0.00 0.00 0.08 0.7 0.00 0.00 0.17 1.9 0.00 0.00 0,25 3.5 0.00 0.00 0.33 5.5 0.00 0.00 0.42 7.6 0.00 0.00 0.50 10.0 0.00 0.00 0.58 12.5 0.00 0.00 0.67 15.4 0.00 0.00 0.75 18.4 0.00 0.00 0.83 21.6 0.00 0.00 0.92 24.9 0.00 0.00 1.00 ?8.4 0.00 0.00 . 1.0B 32.0 0.00 0.00 1'.17 35.8 '0.00 0.00 1.25 39.7 0;00 0.00 1.33 43.7 0.00 0.00 1.42 47.9 0.00 0.00 1.50 52.1 0.08 0.15 1.58 56.5 0.17 0.42 1.67 61.1 0.25 0.77 1.75 65.7 0.33 1.19 1.83 7004 0.42 1.67 1.92 75.3 0.50 2.19 2.0.0 80.3 0.58 2.76 2.08 85.3 067 337 2.17 905 ~~ ~~66~~ ti~~2~ ;s95t~ -.s-~ ... ~ .. -~ ~ ... ~~ 0.83 4.72 2.33 101.2 0.92 5.44 2.42 106.6 1.00 6.20 ·2.50 112.2 - 1 ,! TOTAL Q (efs) 7.5 B.9 10;6 12.7 15.0 17.5 20.2 23.2 26.3 29.6 33.0 36.6 40.3 44.2 48.2 52.4 56.6 . 61.12. ,65.7 70.6 75.7 80.9 86.4 92.0 97.7 1036 ~1ifgy~ 115.8 122.1 128.5 I. I I I I I· I I: I I ·1 I I II I Rational Method Results at: La Costa Greens Neighborhoods 1.1.6 .& 1.17 c= 0.55 0.70 0.45 0.95 Development Area (ac) 2.90 9.48 2.08 0.17 1.99 1.09 1.64 0.49 1.52 . 2.23 1.20 2.28 2.22 0.88 0.81 I 2.58 10.66 0.84 I 0:38 I 0.86 0.99 1.33 I 4.23 2.81 I I , I > Sum of Areas 55.7 ac. % Impervious 41.6% imper-vious 0.58 I I I I I I: I I: I I II I I I I Vortechs T.\! Stom7water Treatment Systems FLOW CALCULATIONS Vmteclmics ® La Costa Greens Neighborhoods 1.16 and 1.17 Carlsbad, CA :0-!:=. g ~ ill Model 7000 WQS Vortechs Orifice Vortechs Weir 8vpassWeir Cd::: 3.3- Weir Crest Length (ft)= 8.6 Cd::: 0.56 A (ft2) ::: 1.02 Cd::: 3.33 Weir Crest Length (ft) = 0 'Crest Elevaiion = 100.00 = 103.92 = 102.4 105.0 105.0 104.0 103.0 1.02.0 101.0 100.0 99.0 Vortechs TIIi System Stage Discharge Curve 1 , 1 1 1 I 1 1 I ! :. l 1---------r --~I ------1---------f We',,"""· ",'"'=r::".&-, -+,---1 t_ -~ -~ ---------1----------1---'--~ ---~ ---------I Bypass crestl / , I I I.. I 1 II I I I I I ,,~~~~.=,t--!-, 1_-1 1 I Iii i OHIlw _,>Ow r. 0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 Discharge (cis) 7514.A.DSWQS.xls 1/25/2005 I I I I I I I I I I I I I I 'I I I the ,Stornl\Jvater Treatment I f-.o__-----0 Plu5 6' Typical-----_>: J- Plan View To begL11. the design of your Voriechs System, refer to the sizing chart below and com- plete a Specifier's Worksheet to provide detajls about you:; site and design flov"'rs. T'nen simply fcc{ or mail t.he worksheet to Voriechnics with your site plan, and vye'l1 produce detailed VOriechsSystem scale draw- ings free of charge. I ~ I I I I I J. 1 ~~ ~ I I / 1 3'to S 6' to S' '-_ ... _,/ ~: I Typical 1 ! 11\1\1. .,. j r --J,-.. -... ----~ " , ) , I S'ti:J4' I T Elevation View ,,:' ':' " .f··;· ,.' . ".' '",.. . Engineering Notes' .: ."".: '. Ai Fa~in.line·Vo~ts~hs SYstems without a ~ypas5. sizing crit:ria is basa'd co 'providing one 'square rnot'~r g:-it ... . chamber sur:acs area for" each 1CO gpm of peak. dzs:gn s~orm flow rata [e.g., 10-jeer'stc:-m]. Fop mera da::alls about Vortachr:ics si,ing criteria rere!" to Vortachni::~ Technical 8uiletEf1 3.. . . .'" . En Sediment! stOrage VQ!~m2 -ass'umes 'a' :3' foot sum~~ .: :'" '..: .': ' , C) Construc:fon'datails may va;'1 de'pe~ding on ~he ~p;ciiic sppiicaci~n. A..ny =I:arstians::o the siz!r.g"chart~peclft .. 'cations wm appear on 'ICli:acnnics dimsnsioilal and shop cra1o"Jing;. Flease c~lI Vor:!:chnicS fer. the w2ight or s;:e· cine Vcrtaci"s systsms if i:esded. . Specisl Noes: Oil storage cspacicy. when ic is needed to m.es: a sp~c.ific rsquir;men; for spiil ~cntainmen:. csn :,S sizsd to mast::he st::iage raquiraman: ·.~.oji:h the selac:ed medel. Vor:ec~nics tacnnicai scaff "'Jill optirr.i.f:;:!' SYS-~lil gS?msTJ m meet cQntainmsr:c raquir=m=n~ 'Nj~hin ~ ccrrscti'l sized Vcrtachs Sy~~am~ l'vlet:rfc~S.aaci,icarian. Char: E:'Isiiab/e by C3~/~ng Var:tachnfcs ae (2Q7J 878-3552. Vortechs System Inlet/Outlet Configurations Vortechs Systems cw"1 be cOD_figured to accorr.!.!:lO- date various inlet and outlet pipe orienta~ions. The inlet pipe cw"1 enter L'!.e end or side of tb,e . tan.k: at right angles -outiet pipes ccm erit the end or t.h.e side or syste:n at most CL'1g1es. ,If) ~ -I End Inlet L 1- Oil r) I F I t I Side Inlet 10 ~~I~=)=I ~ I tit 7b Pretreatment Cu",,=!! I ~ I 0''''' , I I I' mine I T I ---f)/' ~,_ ! \ (\ I I I I I I I I I I , I I I I I I I I 1) Initial Wet Weather Phase During a two-month storm event the water lev!?1 oegins to rise above the top of the inlet pipe. Tnis influent control' feature reduces l'Jrbulence and avoids resuspension of pollutants. 8) Full Capacity Phase \II/hen the high-aolN outlet approaches full dischsi9a, ",:"";r;n crains ere ilo/IJing et paak capacity. The VcrL8cGs Sys-cam is designad to match your design stcrm flow and provide Cieac- mane throughout the range or storm 8'Jenk3 't'lfthout bypass- ing. To accommodsi:Ei vary hip.h nov·} races, \ion::=chnics ca~ ,., ,:.1"i";;"~"":2·.:'·~ . " .: ~ ___ : .: :.:·~~:~~~~~:·~~~~~:·;~::~;.:£~£~::~i~l; 2) Transition Phase As the infiow rate increases above the controlled outflow- rate, the tank)iIIs arid the floating contamina'ntlayer accu- mulated from past storms rises. Swirling action increases at this stage, while sediment pile remains stable. 4) Storm Subsidence Pha'se/Cleaning lraa1:ad runar.' is decanced at a controllad ra'"'tE.. restoring the water lava! to a low dry-weather volume end r8'Jeaiing a conical piie of sadimenc. The low watar level racilit3tss inspeccion and cieaning, and significantly reduces maintenance costs. The --------------------------~---------------- I .1 I I I I I I I I I I I I I , I I I I -Ireatrnent The Vortechs Stormwater Treaw..dent System, a major advancement i,'1oil and grit separator technology. efficiently removes grit, contCUJ:1i- nated sedL.-nents, metals, hydrocarbons and floating contCUJ:1inants from surface runoff. The Vortechs System's iTh."'1ovative design cor:r.bhles svvirl-concentrator and flow-conrrol techIlologies to optiwize treatment efficiency. These features ensure effective capture or sed1.-nent and oils, and preyent resuspension of trapped pollutcmts -even at flow rates or up to 2S ds. " Large system capacity provides an 80% net annual TSS removal rate '" Installs belmy grade, wipimizi.'T'J.g land use ~ Custom-built or precast concrete near l.h.e job site G LO'iti pump-out yolume and one-poL."1t access reduce maintenance costs c Upique design prevents oils and ot.~er £loat- abIes from es<;:aping t..h.e system during cleanout VOliechs Systems may be used in a wide range of water-quality improvement applications. including: iiVetlandslVVOierlront Protection Retail Dsvelooment Industrial Sites Mu:licipal Lrnprovements Commercial Development T'rar~sportation Facilities I System "We have worked with Vortechnics on at least; a .dozen ston71~vater management plans for some of our largest corporate clients. Their efficient turnaround on our requests for technical support; and GADO drawings has expedited the permitting process for our clients. liVe turn . to Vqrtechnics when we need innovative st;ormwater solutions. " -Lawrence Mersiglia, RE. Senior Civil Engineer, 8arakos-Landino, Inc. ----------------------------------------------------- I. '1 I I I I I I I -I ... ' I I I I I I I I SECTION 02721 STORMWATER 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 stormwater treatment systems and appurtenances in accordance with the Drawings and these specifications. B. Related work described elsewhere: 1. Unit Masonry 2. Miscellaneous Metals I 3. Waterproofing 1.02 QUALITY CONTROL INSPECTION A. The quality of materials, the process of manufacttlre, 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 fan. to meet any of the specification requirements, even though sample sectioncimay 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 wi!! 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, dos'e textured and free of blisters, cracks, roughness and exposure of reinforcement. C. Imperfections may be repaired, subject to the acceptance, of rh'e Eng~neer, after demonstration by the manufacturer that ~trong and permanent repairs 'result. Repairs shall be carefully inspecteq before finaI acceptance. Cement mortar used for repairs shall have a minimum compressive strength of.4,OOO psi at the end of 7 days and 5,000 psi at the end of 28 days when tested in 3 inch diameter by (3 inch long cylinders stored in the standard manner. Epoxy mortar may be utilized for repairs. I I I I I I I I I I I I I I I I I I I '1.03 SU Bilil I-I I ALS A. ~. :10P Drawings B, . The Contractor shall be provided with dimensional drawings and, when specified, utilize these drawings as the basis for preparation of shqp 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 ancj 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. Afildavit on patent infringement The Contractor shall submit to the Engineer, prior to installation of the stormwater treatment system, an affidavit regarding pate'nt infringement rights stating that any suit or claim against the Owner due to alleged infringement rights shall be defended by the Contractor who will bear all the costs, expenses and attorney's fees incurred thereof. I PART 2.00 PRODUCTS '2.01 MATERIALS AND DESIGN A. Concrete for precast stormwater treatment systems shall conform to ASTM C 857 and C 858 and meet the following additional requirements: 1. 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. 2. Sections shall have tongue and groove or ship-lap joints wit~ a butyl mastic sealant conforming to ASTM C 990. 3. Cement shall be Type III Portland cement conforming to ASTM C 150. 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 conforming to ASTM C 595M 5. Internal metal components shall be aluminum alloy 5052-H32 in accordance with ASTM 8 209. . 6. Brick or masonry used to build the manhol~ frame to grade shall confOim to ASTM C 32 or ASTivI C 139 and the Masonry Section o.f these Specifications. :""\ -~ -,... .:," ". ----------------------------------- I I· I I I I I I I I I .... I I I 'I I I I I 7. Casting for manhole frames and covers shall be in accordance with The Miscellaneol:ls Meta!s Section ofthese Specifications. 8. AU sections shall be cured by an approved method. Sections sh~1I not be shipped .untl! the. concrete has attained a compressive strength of 4,000 psi or utrl-5-_days afterrabrication and/or repair, whichever is the longer. 9. A 9utimen sealant in conformance with ASTM'C 990 shall be utilized in affixing. the attJminum.swirl chamber to the concrete vault. 2.02 PERFORMANCE Each stormwa-tec treatment system shall adhere to the fo![owing performance specifications at the sPecified design flows·, as listed below:' Table 202 Swirl Design Sediment VoIiechs Chamber Treatment Model Diameter Capacity Storage ., (ft) (cfs) (yd3) 1000 3.67 I 2.3 I 1.00 2000 I 4 I 2.8 I 1.25 I 3000 1 5 I I 4.5 I 1.75 4000 1 6 I. 6.0 1 2.50 5000 1 7 1 8.5 I 3.25 7000 I 8 11.0 1 4.00 9000 9 I 14.0 I 4.75 ' 11000 I 10 I 17.5 1 5.50 o· 16.000 1 12 1 25.0 1 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 thEit will prel/ent 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 5tormwater treatment system shall be of a hydraulic design that includes flow conImls 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. , . Each stormwater treatment system shall be capable of removing 80% of the net annual 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 usabie Sediment storage capacity of net less than the corresponding volume listed in Tabie 2.02. The systems shall be designed such \\MDI\3YSiDATp-.\VORT;::CHN\E:MAiL \STDSAiL \\j()RT;:;P=(~ nnr. I I I I I I I I I I I I I I I I I that the pump-out volume is less than :Y2 of the tota! system Yo!tIme. The systems shall be designed to not allow surcharge of the upstream piping .11etwor.K.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 'Ojl e$Cdjles the system during the ensuing rain event. Direct access shall be provided to the sedimen.t.and floatable contaminant storage chambers to facilitate maintenance. There shaH be 110 appurtenances or restrictions within these chambers. The stormwater treatment system manufacturer shall' furnish documentatior:l which suooorts all product performance claims and features, storage capacities and maintenance' .. requirements. Stormwater treatment systems shall be completely.!:loused:within one rectangular structure. 2.03 MANUFACTURER Each stormwater treatment system shall be of a '~jpe that lias been installed and used successfully for a minimum of 5 years. The manUt.~ct1:.lrer of safd system shall have been regularly engaged in the engineeiing design and production of systems. for the physical treatment of stormwater runoff. Each stormwater treatment system shall be a Vortechs ™ Sys.tem as manufactured by Vortechnics, Inc., 41 Evergreen Drive, Portland, Maine 04193, 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 A. B. C. Each Stormwater Treatment System shall be constructed according to the sizes shown on the Drawings and as specified herein. Install at elevations and locations shown on the Drawings or as other\vise directed by the Engineer. Place the precast base unit on a granular subbase of minimum thickness of six 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 aU four corners 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 ie-leveled. Prior to setting subsequent sections place butimen sealant in conformance with ASTiVl C990-91 along the construction joint in the section that. is already in place. D. . After setting the base and wall or riser sections instal! the circular sir/irl 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 HIL TI brand concrete anchors or equivalent 1/2-inch diameter by 2-3/4" minimum length at heights of approximately thre~ inches (3") off the floor and at. the mid-height of the completed trap (at locations' of pre-drilled ho;es in aluminum components). Seal the bottom sdge of the swirl \\iv1Di\SYS\C;A. T A\VORT~CHi';\~l\;iA!L\STDE.T AJL\VORTSP:=:r. nnr. i1 ............... ~ ,I. 1 I I I I I I I I I I I E. F. G. H. chamber to the trap floor with the supplied aluminum angle flange. Adhere 'Y-.'" thick by 1" wide neoprene sponge material to the flange wtth half ot it's width .on the horizontal leg of the flange and half of it's width on the verticaUeg. ~l:1e' aluminum angle flange shaH be affixed to the floor with a minimum 3/8" diame.ter by 2-3/4" drop in wedge anchor at the location of the predrilled hores. AFLIX the swirl chamber to the flange with hex head 14" x 1-1/2" zinc coate"d self-·tapp~ng 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 invert using butyl mastic-.or approved -equal. - Prior to setting the precast roof section, butimen sealant equal to ASTNl' C99.0 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 gcrp betwe-en the top of the baffle and the roof section. The nominal gap shall be determined either by field measurement or the snap 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 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 ~ide edges of the baffle \Va-II. 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 veri:ical and in true alignment with a 1/4 inch maximull} toleran'ce allowed. Backfill in a careful manner, bringing the fill up in 6" Iifts,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 vvateri:ightjoint. 1r:J all instances, installation of Stormwater Treatment Systems shall conform to ASTM specification Ca91 "Standard Practice For Installation of Under-ground Precast Utility Structures". 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. 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 ma~e all pipe connections. . \\MDI\SYS\O,; T AWQ?!cCHN\2MA.lL'.STD2TAIL \\fOF:TS?~C: n0.r. ............. -. :: I I, I I' -I' I' I '1 I I I I I I I I I I I HUNSAKER & ASSOCIATES ''''4 OIlCD. .. (e Pl.~~"'IC VIn tUrrd=I 5t:eel ~s.z,I7qa.Clflt!1 SIA\ot'l'N:~.~1n4 " '-PROJF:CT SOUNom>" ~ ~ 40 '<. so SCALE: 1'=.040' .......... 120 ". A LOT 42 .......... '..,' FlfT1)RE ESTRELlA DE MAR ROAD 2"· OP9i~~ FL ,loG Sit'.(!£ TO CPfH.'N!i CF !M.tT ~ L-.-',,'.-'~r -Fl,ON_-_ ,~ .. , 1D+S8..2.f. SD lJ-4t £i.i£RG'i" DlSSIPAJ'tlR !;RAn;' Ga~ ps; jJ-17 (r-6· SP.t.er..~) 24~ OPt.({IM; it ~ Dl1CH Oil EN1THE:H SWIJ.£ TO ~orMEr iO:=I OF _ J.CS'~\ ; " i1 ~l\" :iiC ~'" ] ~~ VI ~ I - ---F!D .. --~ ~--,<,-~ ~~ :s ~!U.'~ PLAN VIEW TYPE B INLET WITH CSP RISER HaT 11J SCIlE SECTION A-A .. ' RC' a'PASS ~RCU vmE:CH:'i1CS UNi (;:t:UVAi":. 1..50 l.F -le~ Re:? 0 11.0::= 99.~7 n. SiCa\i'-c:W:n:SiEUhG ClEA."iCYT 0 99.8-4 Ft Sol-RC? Si'CR\I cru.."f-EjillSG ct£A.",CUT 0 99.97 Fl MODIFIED TYPE B-7 CLEANOUT (DIVERSION BOX) HOT 10 = ~511.'R 1 1 I 1 ~, 1" DETAIL '8' -SLOTTED HOLE q, Sj.lJ .... !.£ss Sit CE11iTERLINE DAT_<\. i S£AFtit."t;/D:!.TA P.,!,DIUS !.£NGrrl I R~.tA.::CKS I I IZ-46'36-I -400.00' I 89.20' I r ;Z T N .J2"05'OO~ 101,08' J 1 fr07'53· 385.00' 61.36' STOR~f DR.4.IN DAT.<\. dT3~nG/!F'J.T~ I RA!).(JS I LEIGTH i R:wMS I jlO'Il9'Zi'-41J.oo' 73.21' 130· ReP IJ5O-O" 2 I H 32"05'00· E .Jl.fU" 1.30* RCP r:SSO-D- J 1 N 5755'00-W 3.38' !-Ia· ReP I=-O- of I H 5755'00· W 29.38' 11S* ReP tlSO~ SIN CW44'IO-e: ...,.'' 1.36-ReP 1=-0- 6 I H 76"16"35" E' 25.50' I lS* RCP TJSO-D- 7 J <5"<8'27" <5.OO';J5.98' ! 18-ReP 1:J5O-D~· a 1 N 5755'00' W 4.33' I 18· ReP 1=-0- 9 J N 6IT<Cl'IO' W 48.#' J 54-ReP 1=-0- lCj N 60".l9'25-If' 4.'75' 154* RCP lJSO-OD III N 6ITJ9'25-W 127.77' ;54-ReP IJSO-O 12i H 29"2C'ZS* E .)'.00' l'S-RCP lJSO-D rJl H 29"20'.,lS-E 3.SO· fB-RCP l.1SO-0 '"I N 83"19'14" W , 54,74' 130-ReP 1350-0 WATER 11GHT JOINTS -SEE PROFILE FOR WATER 11GHT JOMS • WATER nGHl' JOIlflS (FOR ULnlolollC C1lMJIIlONS) • 4' sa:TJONS ~ earn ENDS t;;1..:.~ O:.ilJLS P-:R ~I~ 1/2-!y,,!JI. X 7-~ ~X StOmJ] HO'..£ ::i'~' L '--t~-"'~'t' ~ \ = "'-SO JI!N I ~ 1 ~i. sa~IJ..i.~· """" .' .. I I I , k' IS' CO I T'(?- DETAIL 'A'-SOLT q, ' ........ ;r 0-17 cr-5· sP.ta~) ~::::: roP or £I,.~Tr:£N ~ I 2' Ci~ £Ci/r.nr;.~{Ff1/PUJ/) I 1 L.,L ---, I • I i I ~ ~ . 'r~' I I ~J' DVoU. CSP ntSEi/ I i NOTES FOR DETAIL A': I • .AU. BG!.r5 S1W.L e£ 1/2 INCH IN Dw.k.'7E1l I.Il!J , ~'OT£S I:i f...~ "·It.l.·~ B IN!£j aax 2. .(LT'£im).iT/£ G:."71JlS 8£ suEll!liCD BY T1£ CGNTP.ACTOi? f'C.? 1orril!71JJ.. BY rre E1CN££R. .J. SEE 0-11. 0-16 ANa 0-17 FC.'? .A!JDmDN;.L HOiF:S. ENGINEER OF WORK ~.Z"'~ :lir%s-~~TIN DA~ R.C." NO, oIIl670 EXP, 6/30/06 "AS BUILT" RCC ___ 'Xi'. ___ _ DAn: "...n: ISH~I 4.0' I==E=E==========:i=~~==tf==!~=1'lllliPROVEMENi ~~~~~S I---:::--+----------+--{-; -+, --+1_°-/. NEIGHBORHOOD 1.16 'l .' SECTION A-A DAn: I IKnuJ. REVISION DESCRIPTION CAli. I INmAL DTHtR APPROVAl, .4n: IIHlTlAL CJt'Y APPROVAL ENGUfE£R Of W.O. No. 2352-112 ;; .. Q '" .... Q ~ N Q Q '" I I I I I I I I I I I I I I I I I I I Bioretention Description The bioretention best management practice (BMP) functions as a soil and plant-based filtration device that removes pollutants .. through a variety of physical, biological, and chemical treatment processes. These facilities normally consist of a grass buffer strip, sand bed, ponding area, organic layer or mulch layer, planting soil, and plants. The runoff s velocity is reduced by passing over or through buffer strip and subsequently distributed evenly along a ponding area. Exfiltration of the stored water in the bioretention area planting soil into the underlying soils occurs over a period of days. California Experience None documented. Bioretentionhas been used as a stormwater BMP since 1992. In addition to Prince George's County, MD and Alexandria, VA, bioretention has been used successfully at urban and suburban areas in Montgomery County, MD; Baltimore. County, MD; Chesterfield County, V.A; Prince William County, VA; Smith Mountain Lake State Park, V A:, and caiy, NC. Advantages • Bioretention provides stormwater treatment that enhances the quality of downstream water bodies by temporarily &toring runoff in, the BMP and releasing it over a period of four days to the receiving water (EPA, 1999). • The vegetation provides shade and wind breaks, absorbs noise, and improves an area's landscape. Limitations • The bioretention BMP is not recommended for areas with slopes greater than 20% or where mature tree removal would January 2003 Califomia Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 'TC-32' Design Considerations • Soil for Infiltration • Tributary Area • Slope • Aesthetics • Environmental Side-effects Targeted Constituents liT Sediment .' liT Nutrients .... liT Trash • liT Metals. • liT Bacteria • liT Oil and Grease • liT Organics • Legend (Removal Effectiveness) • Low • High .... Medium ' .. ~ ~. ASQ CAUl'OlU'<lf.$lQRMW.'.:l'l:." y::/l.JAt rr\'" :~SStl\: lA tiel" 1 of8 " I I I I I I I I I I I I I I I I I I I I TC-32 Bioretention be required since clogging may result, particularly if the BMP receives runoff with high sediment loads (EPA, 1999). • Bioretention is not a suitable BMP at locations where the water table is within 6 feet of the grolilld surface and where the surrounding soil stratum is unstable. • By design, bioretention BMPs have the potential to create very attractive habitats for mosquitoes and other vectors because of highly organic, often heavily vegetated areas mixed with shallow water. • In cold climates the soil may freeze, preventing 'runoff from infiltrating into the planting soil. Design and Sizing Guidelines • The bioretention area should be sized to capture the design storm runoff. • In areas where the native soil permeability is less than 0.5 injhr an lillderdrain should be provided. • Recommended minimum di:rnensions are 15 feet by 40 feet, although the preferred width is 25 feet. Excavated depth should be 4 feet. • .Area should drain completely within 72 hours. • Approximately 1 tree or shrub per 50 ft2 of bioretention area should be included. • Cover area with about 3 inches of mulch. Construction/Inspection Considerations Bioretention area should not be established until contributing watershed is stabilized .Performance Bioretention removes stormwater pollutants through physical and biological processes, including adsorption, filtration, plant uptake, microbial activity, decomposition, sedimentation and'volatilization (EPA, 1999). Adsorption is the process whereby particulate pollutants attach to soil (e.g., clay) or vegetation surfaces. Adequate contact time between the surlace and . pollutant must be provided for in the design of the system for this removal process to occur. Thus, the infiltration rate of the soils must not exceed those specified in the design criteria or pollutant removal may decrease. Pollutants removed by adsorption include metals, phosphorus, and hydrocarbons. Filtration occurs as runoff passes through the bioretention area media, such as the sand bed, ground cover, and planting soil. Common particulates removed from stormwater include particulate organic matter, phosphorus,and suspended solids. Biological processes that occur in wetlands-result in pollutant uptake by plants and microorganisms in the soil. Plant growth is sustained by the uptake of nutrients from the soils, with woody plants locking up these nutrients-through the seasons. Microbial activity within the soil also contributes to the removal of nitrogen and organic matter. Nitrogen is removed by nitrifying and denitrifying bacteria, while aerobic bacteria are responsible for the decomposition of the organic matter. Microbial processes require oxygen and can result in depleted oxygen levels if the bioretention area is not adequately 2of8 Califomia stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com January 2003 I I I I I I I I I I I I I I I I I I I Bioretention TC-32 aerated. Sedimentation occurs in the swale or ponding area as the velocity slows and solids fall out of suspension. . The removal effectiveness of bioretention has been studied during field and laboratory studies conducted by the University of Maryland (Davis et al, 1998). During these experiments, synthetic stormwater runoff was pumped through several laboratory and field bioretention areas to simulate typical storm events in Prince George's County, MD. Removal rates for heavy metals and nutrients are shown in Table 1. . Table 1 Laboratory and Estimated Bioretention Davis et at. (1998); PGDER (1993) Pollutant Removal Rate Total Phosphorus 70-83% Metals (Cu, Zn, Ph) 93-98% TKN. 68-80% Total Suspended Solids 90% Organics ·90% Bacteria 90% Results for both the laboratory and field experiments were similar for each of the pollutants analyzed. Doubling or halving the infJ.uentpollutant levels had little effect on the effluent pollutants concentrations (Davis et al, 1998). The microbial activity and plant uptake occurring in the bioretention area will likely result in higher removal rates than those determined for infiltration BMPs. Siting Criteria Bioretention BMPs are generally used to treat stormwater from impervious surfaces at commercial, residential, and industrial areas (EP A, 1999). Implementation of bioretention for stormwater management is ideal for median strips, parking lot islands, and swales. Moreover, the runoff in these areas can be designed to either divert directly into the bioretention area or convey into the bioretention area by a curb and gutter collection system. The best location for bioretention areas is upland from inlets that receive sheet flow from graded areas and at areas that will be excavated (EPA, 1999). In order to maximize treatment effectiveness, the site must be graded in such a way that minimizes erosive ·conditions as sheet ·flow is conveyed to the treatment area. Locations where a bioretention area can be readily incorporated into the site plan without further environmental damage are preferred. Furthermore, to effectively minimize se~ment loading in the treatment area, bioretention only should be used in stabilized drainage areas. . January 2003 California stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 30f8 I I I I I I I I I I I I I I I I I TC-32 Bioretention Additional Design .Guidelines The layout of the bioretention area is determined after site constraints such as location of utilities, underlying soils, existing vegetation, and drainage are considered (EP A, 1999). Sites with loamy sand soils are especially appropriate for bioretention because the excavated soil can be backfilled and used as the planting soil, thus eliminating the cost of importing planting soil. The use ofbioretention may not be feasible given an unstable surrounding soil stratum, soils with clay content greater than 25 percent, a site with slopes greater than 20 percent, and/or a site with mature trees that would be removed during construction of the BMP. Bioretention can be designed to be off-line or on-line of the existing drainage system (EPA, 1999). The drainage area for a bioretention area should be between 0.1 and 0-4 hectares (0.25 and 1.0 acres). Larger drainage areas may require multiple bioretention areas. Furthermore, the maximum drainage area for a bioretention area is determined by the expected rainfall intensity and runoff rate. Stabilize,d areas may erode when velocities are greater than 5 feet per second (1.5 meter per second). The designer should determine the potential for erosive conditions at the site. The size of the bioretention area, which is a function of the drainage area and the runoff generated from the area is sized to capture the water quality volume. The recommended minimum dimensions of the bioretention area are 15 feet (4.6 meters) wide by 40 feet (12.2 meters) long, where the minimum width allows enough space for a dense, randomly-distributed area of trees and shrubs to become established. Thus replicat:iI:lg a natural forest and creating a microclimate, thereby enabling the bioretention area to tolerate the effects of heat stress, acid rain, runoff pollutants, and insect and disease infestations which landscaped areas in urban settings typically are unable to tolerate. The preferred width is 25 feet (7.6 meters), with a length of twice the width. Essentially, any facilities wider than 20 feet (6.1 meters) should be twice as long as they are wide, which promotes the distribution of flow and decreases the chances of concentrated flow. In order to provide adequate storage and prevent water from standing for excessive periods of time the ponding depth of the bioretention area should not exceed 6 inches (15 centimeters). Water should not be left to stand for more than 72 hours. A restriction on the type of plants that can be used may be necessary due to some plants' water intolerance. Furthermore, if w1,l.ter is left standing for longer than 72 hours mosquitoes and other insects may start to breed. The appropriate planting soil should be backfilled into the excavated bioretention area. Planting soils should be sandy loam, loamy sand, or loam texture with a clay content ranging from '10 to 25 percent. Generally the soil should have infiltration rates greater than 0.5 inches (1.25 centimeters) per hour, which is typical of sandy loams, loamy sands, or loams. The pH of the soil should range between 5.5 and 6.5, where pollutants such as organic nitrogen and phosphorus can be adsorbed by the soil and microbial activity can flourish. Additional requirements for the planting soil .. include a 1.5 to 3 percent organic content and a maximum 500 ppm concentration of soluble salts. 4of8 Califomia Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com January 2003 I I I I I I I I I I I I I I I I I I I Bioretention TC-32 Soil tests should be performed for every 500 cubic yards (382 cubic meters) of planting soil, with the exception of pH and organic content tests, which'are required only once per bioretention area (EPA, 1999). Planting soil should be 4 inches (10.1 centimeters) deeper than the bottom of the largest root ball and 4 feet (1.2 meters) altogether. 1his depth will provide adequate soil for the plants' root systems to become established, prevent plant damage due to severe wind, and provide adequate moisture capacity. Most sites will require excavation in order to obtain the recommended depth. Planting soil depths of greater than 4 feet (1.2 meters) may require additional construction practices such as shoring measures (EPA, 1999). Planting soil should be placed in 18 inches or greater lifts-and lightly compacted until the desired depth is reached. Since high canopy trees may be destroyed during maintenance the bioretention area should be vegetated to resemble a terrestrial forest community ecosystem that is dominated by understory trees. Three species each of both trees and shrubs are recommended to be planted at a rate of 2500 trees and shrubs per hectare (lOooper acre). For instance, a 15 foot (4.6 meter) by 40 foot (12.2 meter) bioretention area (600 square feet or 55.75 square meters) would require 14 trees and shrubs. The shrub-to-tree ratio should be 2:1 to 3:1. ' Trees and shrubs should be planted when conditions are favorable. Vegetation should be watered at the end of each day for fourteen days following its planting. Plant species tolerant of pollutant loads and varying wet and dry conditions should be used in the bioretention area. The designer should assess aesthetics, site layout, and maintenance requirements when selecting plant species. Adjacent non-native invasive species should be identified and the designer should take meas~es, such as providing a soil breach to eliminate the threat of these species invading the bioretention area. Regional landscaping manuals should be consulted to ensure that the planting of the bioretention area meets the landscaping requirements established by the local authorities. The designers should evaluate the best placement of vegetation within the bioretention area. Plants should be placed at irregular intervals to replicate a natural forest. Trees should be placed on the perimeter of the area to provide shade and shelter from the wind. Trees and shrubs can be sheltered from damaging flows if-they are placed away from the path of the incoming runoff. In cold climates, species that are more tolerant to cold winds, such as evergreens, should be placed in windier areas of the site. Following placement of the trees and shrubs, the ground cover and/or mulch should be established. Ground cover such as grasses or legumes can be planted at the beginning of the growing season. Mulch should be placed immediately after trees and shrubs are planted. Two to 3 inches (5 to 7.6 cm) of commercially-available fine shredded hardwood mulch or shredded hardwood chips should be applied to the bioretention area to protect from erosion. Maintenance -The primary maintenance requirement for bioretention areas is that of inspection and repair or replacement of the treatment area's components. Generally, this involves nothblg more than the routine periodic maintenance that is required of any landscaped,area. Plants that are appropriate for the site, climatic, and watering conditions should be selected for use in the bioretention cell. Appropriately selected plants will aide in reducing fertilizer, pesticide, water, and overall maintenance requirements. Bioretention system components should blend over time through plant and root growth, organic decomposition, and the development of a natural January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 50f8 I I· I I I I. I I I I I I I I I I I I I TC-32 Bioretentio.n soil horizon. These biologic and physical processes over time will lengthen the facility's life span and reduce the need for extensive maintenance. Routine mailltenance should include a biannual health evaluation of the trees and shrubs and subsequent removal of any dead or diseased vegetation (EPA, 1999). Diseased vegetation should be treated as needed using preventative and low-toxic measures to the extent possible. BMPs have the potential to create very attractive habitats for mosquitoes and other vectors because of highly organic, often heavily vegetated areas mixed with shallow water. Routine inspections for areas of standing water within the BMP and corrective measures to restore proper infiltration rates are necessary to prevent creating mosquito and other vector habitat. In addition, ,bioretention BMPs are susceptible to invasion by aggressive plant species such as cattails, which increase the chances of water standing and subsequent vector production if not routinely maintained In order to mailltaill the treatment area's appearance it may be necessary to prune and weed. Furthermore, mulch replacement is suggested when erosion is evident or when the site begins to look unattractive. Specifically, the entire area may require mulch replacement every two to three years, although spot mulching may be sufficient when there are random void areas. Mulch replacement should be done prior to the start of the wet season. New Jersey's Department of Environmental Protection states in their bioretention systems standards that accumulated sediment and debris removal (especially at the inflow point) will normally be the primary maintenance function. Other potential tasks include replacement of dead vegetation, soil pH regulation, erosion repair at inflow points, mulch replenishment, unclogging the underdraill, and repairing overflow structures. There is also the possibility that the cation exchange capacity of the soils in the cell will be significantly reduced over time. Depending on pollutant loads, soils may need to be replaced within 5-10 years of construction (LID, 2000). CQst Construction Cost Construction cost estimates for a bioretention area are slightly greater than those for the required hindscaping for a new development (EP.A, 1999). A general rule of thumb (Coffman, 1999) is that residential bioretention areas average about $3 to $4 per square foot, depending on soil conditions and the density and types of plants used. Commercial, industrial and institutional site costs can range between $10 to $40 per square foot, based on the need for control structures, curbing, storm drains and underdrains. Retrofitting a site typically costs more, averaging $6,500 per bioretention area. The higher costs are attributed to the demolition of existing concrete, asphalt, and existing structures and the replacement of fill material with planting soil. The costs of retrofitting a commercial site in Maryland, Kettering Development, with 15 bioretention areas were estimated at $111,600. In any bior~tention area design, the cost of plants varies substantially and can account for a significant portion of the expenditures. While these cost estimates are slightly greater than those of typical landscaping treatment (due to the increased number of plantings, additional soil excavation, backfill material, use of underdraills etc.), those lruidscaping expenses that would be required regardless of the bioretention installation should be subtracted when determining the net cost. . . 6of8 Callfomia Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com . January 2003 I I I I I I I I I I I I I I I I I I Bioretention TC-32 ' Perhaps of most importance, however, the cost savings compared to the use of traditional structural stormwater conveyance systems makes bioretention areas quite attractive financially. For example, the use ofbioretention can decrease the cost required for constructing stormwater conveyance systems at a site. A medical office building in Maryland was able to reduce the amount of storm drain pipe that was needed from 800 to 230 feet - a cost savings of $24,000 (PGDER,1993). And a new residential development spent a total of approximately $100,000 using bioretention cells on each lot instead of nearly $400,000 for the traditional stormwater ponds that were originally planned (Rappahanock, ). Also, in residential areas, stormwater management controls become a part of each property owner's landscape, reducing the public burden to maintain large centralized facilities. Maintenance Cost The operation and maintenance costs for a bioretention facility will be comparable to those of 1:ypicallandscaping required for a site. Costs beyond the normal landscaping fees will include the cost for testing the soils and may include costs for a sand bed and planting soil. References and Sources of Additional Information Coffman, 1.S., R. Goo and R. Frederick, 1999: Low impact development an innovative alternative approach to stormwater management. Proceedings of the 26th.Annual Water Resources Planning and Management Conference ASCE, June 6-9, Tempe, Arizona. Davis, AP., Shokoubian, M., Sharma, H. and Minami, C., "Laboratory Study'ofBiological Retention (Bioretention) for Urban Stormwater Management," Water Environ. Res., 73(1), 5-14 (2001). ' Davis, AP., Shokoubian, M., Sharma, H., Minami, C." and Winogradoff, D. "Water Quality Improvement through Bioretention: Lead, Copper, and Zinc," Water Environ. Res., accepted for publication, August'2002. K:iJ:D., H., Seagren, E.A, and Davis, AP., "Engineered Bioretention for Removal of Nitrate frOII;1 Stormwater Runoff," WEFTEC 2000 Conference Proceedings on CDROM Research Symposium, Nitrogen Remova~ Session 19, Anaheim C.A, October 2000. Hsieh, C.-h. and Davis, AP. "Engineering Bioretention for Treatment of Utban Stormwater Runoff," Watersheds 2002, Proceedings on CDROM Research Symposium, Session ;1.5, Ft. Lauderdale, FL, Feb. 2002. ' Prince George's County Department of Environmental Resources (PGDER), 1993. Design Manual for Use of Bioretention in Storm water Management. Division of Environmental Management, Watershed Protection Branch. Landover, MD. U.S. EPA Office of Water, 1999. Stormwater Technology Fact Sheet Bioretention. EPA 832-F- 99-012. ,Weinstein, N. Davis, AP. and Veeramachaneni, R. "Low Impact Development (LID) Stormwater Management Approach for the Control of Diffuse Pollution from Urban Roadways," sth International Conference Difjuse/Nonpoint P0Uution and Watershed Management Proceedings, C.S. Melching and Emre Alp, Eds. 2001 International Water Association JanUary 2003 California StormwaterBMP Handbook' New Development and Redevelopment www.cabmphandbooks.com 7of8 I I I I I I I I I I I I· I I I I I I TC-32 CURB STOPS OVERFLOW "CATCH BASIN" o PIPE IN 8" GRAVEL TYPICAL SECTION Schematic of a Bioretention Facility (MOE, 2000) 8:of8 Califomia Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com Bioretention GRASS FILTER STRIp' OPTIONAL SAND LAYER PLAN VIEW PROFILE January 2003 r--------------------------------------------------------------------------------- I I I I I I I I I I I I I I I Vortex Separator Description Vortex separators: (alternatively, swirl concentrators) are gravity separators, and in principle are essentially wet vaults. The difference from wet vaults, however, is that the vortex separator is round, rather than rectangular, and the water moves in a centrifugal fashion before exiting. By having the water move in a circular fashion, rather than a straight line as is the case with a standard wet vault, it is possible to obtain significant removal of suspended sediments and attached pollutants with less space. Vortex separators were originally developed for combined sewer overflows (CSOs), where it is used primarily to remove coarse inorganic solids. Vortex separation has been adapted to stormwater treatment by several manufacturers. California Experiem:e There are currently about 100 installations in California. Advantages • May provide the desired performance in less space and therefore less cost. • May be more cost-effective pre-treatment devices than traditional wet or dry basins. • 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 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 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 in many cases relative to the design treatment storm, increasing the cost. • The non-steady flows of stormwater decreases the efficiency of vortex separators from what may be estimated or determined from testing under constant flow. • Do not remove dissolved pollutants. • A loss of dissolved pollutants may occur as accumulated organic January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com MP-51 Design Considerations • Service Area • Settling Velocity • Appropriate Sizing • Inlet Pipe. Diameter Targeted Constituents ./ Sediment ... ./ Nutrients • ./ Trash ./ Metals • Bacteria ./ Oil and Grease ./ Organics Legend (Removal Effectiveness) • Low A Medium • High Stormwater Quality Association 1 of 5 I I I I I I I I I I I I I I I I I 'I I MP-51 Vortex Separator matter (e.g., leaves) decomposes in the units. Design and Sizing Guidelines The stormwater enters, typically below the effluent line, tangentially into the basin, thereby imparting a circular motion in the system. Due to centrifugal forces created by the circular motion, the suspended particles move to the center of the device where they settle to the bottom. There are two general types of vortex separation: free vortex and dampened (or impeded) vortex. Free vortex separation becomes dampened vortex separation by the placement of radial baffles on the weir-plate that impede the free vortex-flow pattern It has been stated with respect to CSOs that the practical lower limit of vortex separation is a particle with a settling velocity of 12 to 16.5 feet per hour (0.10 to 0.14 cm/s). As such, the focus for vortex separation in CSOs has been with settleable solids generally 200 microns and larger, given the presence of the lighter organic solids. For inorganic sediment, the above settling velocity range represents a particle diameter of 50 to 100 microns. Head loss is a function of the size of the target particle. At 200' microns it is normally minor but increases significantly if the goal is to remove smaller particles. The commercial separators applied to stormwater treatment vary considerably with respect to geometry, and the inclusion of radial baffles and internal circular chambers. At one extreme is the inclusion of a chamber within the round concentrator. Water flows initially around the perimeter between the inner and outer chambers, and then into the inner chamber, giving rise, to a sudden change in velocity that purportedly enhances removal efficiency. 'The opposite extreme is to introduce the water tangentially into a round manhole with no internal parts of any kind except for an outlet hood. Whether the inclusion of chambers and baffles gives better performance is unknown. Some contend that free vortex, also identified as swirl concentration, creates less turbulence thereby increasing removal efficiency. One product is unique'in that it includes a static separator screen. ' • Sized is based on the peak flow of the design treatment event as specified by local government. • If an in-line facility, the design peak flow is four times the peak of the design treatment event. • If an off-line facility, the design peak flow is equal to the peak of the design treatment event. • Headloss differs with the product and the model but is generally on the order of one foot or less in most cases. Construction/Inspection Considerations No special considerations. Performance Manufacturer's differ with respect to performance claims, but a general statement is that the manufacturer's design and rated capacity (cfs) for each model is based on and believed to achieve an aggregate reduction of 90% of all particles with a specific gravity of 2.65 (glacial sand) down to 150 microns, and to capture the tloatables, and oil and grease. Laborqtory tests of two products support this claim. The stated performance expectation therefore implies, that a ' 2 of 5 . . California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com January 2003 I I I I- I I I I I I I I I I I I I Vortex Separator MP-51 lesser removal efficiency is obtained with particles less than 150 microns, and the lighter, organic settleables. Laboratory tests of one of the products found about 60% removal of 50 micron sand at the expected average operating flow rate Experience with the use of vortex separators for treating combined sewer overflows (CSOs}, the original application of this technology, suggests that the lower practical limit for particle removal are particles with a settling velocity of 12 feet per hour (Sullivan, 1982), which represents a particle diameter of 100 to 200 microns, depending on the specific gravitY of the particle. The CSO experience therefore seems consistent with the limited experience with treating stormwater, summarized above Traditional treatment technologies such as wet ponds and extended detention basins are generally believed to be more effective at removing very small particles, down to the range of 10 to 20 microns. Hence, it is intuitively expected that vortex separators do not perform as well as the traditional wet and dry basins; and filters. Whether this matters depends op the particle size distribution of the sediments in stormwater. If the distribution leans towards small material, there should be a marked difference between vortex separators_ and, say, traditional wet vaults. There are little data to support this conjecture In Gomparison to other treatment technologies, such as wet ponds and grass swales, there are few studies 6f vortex separators. Only two of manufactured products currently available have been field: tested. Two field studies have been conducted. Both achieved in excess of 80% removal of TSS. However, the test was conducted in the Northeast (New York state and Maine) where it is possible the stormwater contained significant quantities of deicing sand. _ Consequently, the influent TSS concentrations and particle size are both likely considerably higher than is found in California stormwater. These data suggest that if the stormwater particles are for the most part fine (Le., less than 50 microns), vortex separators will not be a:s efficient as traditional treatment BMPs such as wet ponds and swales, if the latter are sized according to the recommendations of this handbook. There are no equations that provide a straightforward-determination of efficiency as a function of unit configuration and size. Design specifications of commercial separators are derived from empirical equations that are unique and proprietary to each manufacturer. However, some general relationships between performance and the geometry of a separator have been developed. CSO studies have found that the primary determinants of performance of vortex separators are the diameters of the inlet pipe and chamber with all other geometry proportional to these two. - Sullivan et al. (1982) found that performance is related to the ratios of chamber to inlet diameters, D2/D1, and height between the inlet and outlet and the inlet diameter, H1/Dl, shown in Figure 3. The relationships are: as D2/D1 approaches one, the efficiency decreases; and, as the H1/D1 ratio decreases, the efficiency decreases. These relationships may allow qualitative comparisons of the alternative designs of manufacturers. Engineers who wish to apply these concepts should review relevant pUblications presented in the References. Siting Criteria There are no particularly unique siting criteria. The size of th~ drainage area that can be served by vortex separators is directly related to the capacities of the largest models. January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 3 of 5 - I I I I I· I I I I I I I I I I MP-51 Vort~x Separato'r Additional Design Guidelines Vortex separators have two capacities if positioned as in-line facilities; a treatment capacity and a hydraulic capacity. Failure to recognize the difference betwe.en the two may lead to significant under sizing; i.e., too small a model.is selected. This observation is relevant to three ofthe five products. These three technologies all are designed to experience a unit flow rate of about 24 gallons/square foot of separator footprint at the peak of the design treatment event. This is the horizontal area of the separator zone within the container, not the total footprint of the unit. At this unit flow rate, laboratory tests by these manufacturers have established that the performance will meet the general claims previously described. However, the units are sized to handle 100 gallons/square foot at the peak of the hydraulic event. Hence, in selecting a particular model the design engineer must be certain to match the peak flow of the design event to the stated treatment capacity, not the hydraulic capacity. The foriner is one-fourth the latter. Ifthe unit is positioned as an off-line facility, the model selected is based on the capacity equal to the peak of the design treatment event. Maintenance Maintenance consists of the removal of accumulated material with an eductor truck. It may be necessary to remove and dispose the floatables separately due to the presence of petroleum product. Maintenance Requirements Remove all accumulated sediment, and litter and other floatables, annually, unless experience indicates the need for more or less frequent maintenance. Cost Manufacturers provide costs for the units including delivery. Installation costs are generally on the order of 50 to 100 % of the manufacturer's cost. For most sites the units ate cleaned annually. Cost Considerations The different geometry of the several manufactured separators suggests that when comparing the costs of these systems to each other, that local conditions (e.g., groundwater levels) may affect the relative cost-effectiveness. . References and Sources of Additional Information Field, R, 1972, The swirl concentrator as a combined sewer overflow regulator facility, EPA/R2- 72-008, U.S. Eiivironmental Protection Agency, Washington, D.C. Field, R, D. Averill, T.P. O'Connor, and P. Steel, 1997, Vortex separation technology, Water Qual. Res. J. Canada, 32, 1, 185 Manufacturers technical materials' Sullivan, RH., et al., 1982, Design manual -swirl and helical bend pollution control devices, EPA-600/8-82/013, U.S. Environmental Protection Agency, Washington, D.C. . . Sullivan, RH., M.M. Cohn, J.E. Ure, F.F. Parkinson, and G. Caliana, 1974, Relationship between diameter and height for the design of a swirl concentrator as a combined sewer overflow regulator, EPA 670/2-74-039, U.S. Environmental Protection Agency, Washington, D.C. 4 of 5 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com January 2003 I I I I I I I' I I I I I I I I I Vortex Separator MP-51 Sullivan, R.H., M.M. Cohn, J.E. Ure, F.F. Parkinson, and G. Caliana, 1974, The swirl concentrator as a grit separator device, EPA670/2-74-026, U.S. Environmental Protection Agency, Washington, D.C. . Sullivan, R.H., M.M. Cohn, J.E. Ure, F.F. Parkinson, and G. Caliana, 1978, Swirl primary separator device and pilot demonstration, EPA6oo/2-78-126, U.S. Environmental Protection Agency, Washington, D.C. January 2003 California Storm water BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 5 of 5 I I I I I I I I I I I I I I I I I I I La Costa Greens 1.16 Storm Water Management Plan CHAPTER 8 -OPERATIONS & MAINTENANCE PLAN 8.1 -Maintenance Requirements Maintenance of the site BMPs will be the responsibility of the Master Home Owners Association for La Costa Greens. A maintenance plan will be developed and will include the following 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 maintaining the BMPs For proper maintenance to be performed, the storm water treatment facility must be . accessible to both maintenance personnel and their equipment and materials. 8.1.1 Vor:techs Treatment Unit· Flow-based storm water treatment devices should be inspected periodically to assure their condition to treat anticipated runoff. Maintenance of the proposed Vortechnics unit includes inspection and maintenance throughout the year. Maintenance of the Vortechs units involves the use of a "vactor truck", which clears the grit chamber of the treatment unit by vacuuming all the grit, oil and grease, and water from the sump. Typically a 3-man crew is required to perform the maintenance of the treatment unit. Properly maintained Vortechs Systems will only 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 is imperative that the grit chamber be drained first. Proper inspection includes a visual observation to ascertain whether the unit is functioning properly and measuring the amount of deposition in the unit. Floatable$ 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 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. The operational and maintenance needs of a Vortechs unit include: Inspection of structural integrity and screen for damage. Animal and vector control. Periodic sediment removal to optimize performance. Scheduled trash, debris and sediment removal to prevent obstruction. DE:de H:IREPORTSI0490171ISWMp·FE·OS.doc w.o. 490-71 6123/20082:36 PM I I I I I I I I I I I I I I I I I I I I La Costa Greens 1.16 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 be monitored during both the dry and wet season and after every large storm event (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 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). 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 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. 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 Vortechs unit. Corrective maintenance activities include: Removal of Debris and Sediment Structural Repairs -Once deemed necessary, repairs to structural components of a Vortechs unit will be completed within 30 working days . . Qualified individuals (Le., the manufacturer representatives) will conduct repairs where structural damage has occurred. 8.1.2 Filterra Sio-Retention Filtration System Annual maintenance of the Filterra consists of a maximum of two (2) scheduled visits. Maintenance visits are scheduled seasonally and consist of inspectiflg the Filterra, removing debris, and replacing mulch as necessary. . 8.2 -Operations and Maintenance Plan Vortechs Unit Target Maintenance Date -March 15th Maintenance Activity -Annual inspection and cleanout. Clear grit chamber unit with vactor truck. Perform visual inspection. Remove floatables. Target Maintenance Dates -15th of each month; October through May (Rainy Season Inspections) DE:de H:IREPORTSI0490171ISWMp·FE·04.doc w.o.490-71 6/4120086:42 PM I I I I I I I I I I I I I 'I I I I I !I La Costa Greens 1.16 Storm Water Management Plan Maintenance Activity -Regular inspection to ensure tha,t unit is functioning properly, has not become clogged, and does not need to be cleared out; Filterra Sio-Retention Filtration System Target Maintenance Dates -March 15th, September 15th Maintenance Activity -Inspection and removal of foreign debris', silt, mulch and trash. Evaluate filter media and recharge as necessary. Evaluate health of plant and prune or replace as necessary. Replace mulch. For proper maintenance to be performed, all storm water treatment facilities must be accessible to both maintenance personnel and their equipment and ma~ria~. I \ 8.3 -Annual Operations & Maintenance Costs The following costs are intended only to provide a magnitude of the costs involved in maintaining BMPs. Funding shall be provided by the Master HOA for the La Costa Greens development. Approximate annual maintenance costs for the Filterra and Vortechs unit are outlined below. Costs assume a 3 man crew. Vortechs Unit: Periodic Inspection, Maintenance and Monitoring = $800 Annual Cleanout Cost = $2,000 Vortechs SUbtotal = $2,800 Filterra Bio-Retention Filtration Units: Periodic Inspection, Maintenance and Monitoring = $400/unit (10 units) Filterra Subtotal = $4,000 TOTAL BMP MAINTENANCE = $6,800 TOTAL (inclusive of 10% Contingency) = $7,480 DE:de H:\REPORTSI049017.1ISWMP·FE-04.doc w.o. 490-71 6/4/20086:42 PM · 1 I I I I I I I I I I I I I I I I I I I ;1 I II La Costa Greens 1.16 Storm Water Management Plan Chapter 9 -FISCAL RESOURCES 9.1 -Agreements (Mechanisms to Assure Maintenance) The Filterra Structural Treatment Controls located within the La Costa Greens 1.16 site for storm water quality treatment shall be the responsibility of the Avellino HOA per the CC&R's. Per the CC&R's submitted for Avellino at La Costa Greens (Neighborhood 1.1.6) the . HOA is responsible for all maintenance associated with the Filterra treatment units. The Vortechnics treatment unit only shall be maintained by the Master HOA for the La Costa Greens Development. . The City of Carlsbad Watershed Protection, Stormwater Management, and Discharge Control Ordinance require ongoing maintenance of BMPs to ensure the proper function and operation of these BMPs. Costs for this maintenance will he the responsibility of the Developer at the time of inception and by the contractor during construction of the development. The LID & Treatment Control BMPs will require maintenance activities as outlined in Chapters 8 of this report. DE:de H:IREPORTSl0490171ISWMp·FE·05.doc W.o. 490-71 6123/20082:50 PM , "'....J <(' i- Z W o , -,"-en <..,/ W ;C:C:C~'d)! ::::......... 0::: J-;::i;;;o!i,{ ~ :: -z i-en X~'''\ w i- Z w ::::iE n.. o ....J W > W o -....J ~ 14'."7. « 'n- ",i-' Z W o en w 0::: ~ Z i-en X w 329 I .t p , "-, " , , I I , I I' '0 i {.jj l ! i~ , ! I Co II'''' I \ i ! I I ! I i , , 1;'1'1, , " i { , .t i I ' \ i ' I I i \ ! ill i i I ; I I I , $ l 1 iii , i ~fJll' . i l' I r ,,';:~;;;-\ ;,111" !i'!'} . I ' , I I f l I t r ( ? ! J ' t t \ , \ \ ·315 LEGEND PROJECT BOUNDARY WATERSHED BOUNDARY LOCATION ID NODE DRAINAGE DITCH ID PROPOSED STORM DRAIN EXISTING STORM DRAIN DRAINAGE DITCHES NOTES: --------- --------------- ===(QF=== ===(QF=--= C) C) C) ;> » » ! "., .---, \ \ a ~ '00 ,~ ~ i~_~ SCALE ,"=50' * Denotes Node 10 from Neighborhood 1.16 Mass-Graded Hydrology Study. /\. Denotes Node 10 from Neighborhood -L17 Hydrology Study. \ \ " 111 . fffl14kJ~, , -~-,-,-~ -." ~ --, .-~-l. '-~---... '\ I , " \ , , ; y " \\, PREPARED BY: / HUNSAKER / . / \ & ASSOCIATES SAM DIECo. INC PLANN1NG 10179 Huemekens Street ENQNEEKING San Diego, Ca 92121 SURVEYING PH(858)558-4500 FX(858)558-1414 ,,' \ \ \ \ \ \ \ \ , \ \ \ , 1 ! I r-----.' I I r MAS1[R 1[NrAnl![ '--1 _ MAP BOUNDARY " "" " LA COSTA GREENS NEIGHBORHOOD 1.16 DOl![ LANE...)(\ ESTRELLA DE MAR ROAD ALGA ROAD VICINITY MAP I" / EXISTING DETENTION BASIN NTS OUTFALL: Q fOO = 111.0 cfs. A=56.2ac. Tc=11.Bmin. \ , ,\\1 '\ ',,-r l I ., r OUTFALL: \ 1 I Q 100 =2.3 cfs. A=O.7ac. Tc = 7.9 min. " / / ( , ) \ /ll j I \ / // fL \ \ f .. < '( /1 'I \ , ,( / i ! / , I ' ; , / , ! / I / ! .( ! DEVELOPED CONDITION HYDROLOGY MAP SHEET LA COSTA GREENS 1 NEIGHBORHOOD 1.16 OF 1 , CITY OF CARLSBAD, CALIFORNIA , I 0 m " "" 0 '"