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Home My WebLink AboutCT 00-02; CALAVERA HILLS VILLAGE Y; STORMWATER MANAGEMENT PLAN; 2003-07-07STORMWATER MANAGEMENT PLAN FOR VILLAGE 'Y' FOR CALAVERA HILLS CARLSBAD TRACT 00-02 Carlsba(d, California Water Discharge Identification No. July 7, 2003 PREPARED BY O'Day Consultants, Inc. 2710 Loker Avenue West, Suite 100 Carlsbad, CA 92008 (760)931-7700 981020 Table of Contents Vicinity Map 3 Drainage Study 4 Project Description 4 Pollutants and Conditions of Concem 4 Site Design BMPs 5 Source Control BMPs 5 Structural Treatment BMPs 6 Maintenance 7 Appendices Appendix A - Village ' Y' Post Construction BMP Summary Sheet Appendix B - Selected Source Control BMPs Appendix C - Selected Treatment Control BMPs Appendix D - Bioclean Environmental Services, Inc. Grate Inlet Skimmer Box, Curb Inlet Basket, Nutrient Baffle Box Report & Data Appendix E - Drainage Study for Calavera Hills-Village 'X' Appendix F - Hydrology Study for Calavera Hills Village ' Y' Appendix G - Excerpt of Declaration of Restrictions for Calavera Hills II Planned Development Appendix H - Excerpt of Calavera Hills II Resource Agency Permits-Regional Water Quality Control Board Order No. R98-2002-0014 Waste Discharge Requirements and Section 401 Certification Dated February 13, 2002 Appendix I - Sample Water Quality Pamphlets W:\MSOFFICE\WINWORD\981020\Village Y SWMP Rpt.doc VICINITY MAP NOT TO SCALE PACIFIC OCEAN CITY OF SAN MARCOS CITY OF ENCINITAS VILLAGE r PREPARED BY ODAY CONSULTANTS, INC Gi\SDSK\PRaj\9810aO\BWG\CALAVERA\98eOXVHBVG 7-8-2003 10ieei46 an Drainage Study There appeared to be no drainage concems downstream of the site at the time of investigation. Project Description The proposed condition for Village Y will be a 9.40-acre multi-family residential and community facilities sub-division. 6.94 acres of the project site will be developed. 0.97 acres of the developed area will be mass graded for fiature community facilities development. The remaining 2.46 acres will remain in its existing condition. 6.36 acres of the development will be conveyed southerly through stormwater drainage pipes towards a cul-de-sac on Village "X" and discharged into a stormwater drainage system within the adjacent development. These flows are then combined with a portion of Village "X" stormwater mnoff and ultimately discharged into an extended detention basin located at the northwesterly comer of Village "X". 0.58 acres of the developed 6.36 acres will be a mass-graded pad for future community facilities development while the remaining 5.78 acres will be multi-family residential development. 0.58 acres of Village "Y" development, northerly portion, will be discharged northerly into College Boulevard's stormwater drainage system. Surface mnoff generated from this area will flow southeasterly along College Boulevard. 0.38 acres of this developed area will be a mass-graded pad for the fiiture community facilities development. The remaining 0.20 acres will be a portion of the private road accessing College Boulevard. Pollutants and Conditions of Concern The anticipated and potential pollutants that will be generated by this project was determined using Table 2 of the Storm Water Standards. The following are potential and anticipated pollutants for this project: • Sediments • " • Nutrients • Trash and Debris • Oxygen Demanding Substances • Oil and Grease • Bacteria and Vimses • Pesticides Organic compounds are considered potential pollutants if the community facilities development includes uncovered parking areas, but the extent of the community facilities pad's friture development is undetermined at this point. There are no additional conditions of concems identified at this time. Site Design BMPs The BMPs selected for this project were based on the Regional Water Quality Control Board Order No. R98-2002-0014 Waste Discharge Requirements and Section 401 Certification Dated Febmary 13, 2002 and its exhibit Attachment 1 (See Appendix H for an excerpt of the Calavera Hills II Resource Agency Permit Report). The post constmction BMP's that will be used for this project will be addressed on the following paragraphs. Several Site Design BMPs will be used on this project site. See Appendix B for additional information on the selected Site Design BMPs. The following Site Design BMPs will be implemented in order to minimize impervious areas: • A total of six feet wide landscaped buffer will be incorporated within the general utility and access easements with the site. • A total of eleven feet wide landscaped buffer will be incorporated within some areas of Red Bluff Place general utility and access easement. The developer will install the pavement, sidewalk and landscape buffer. All exposed earth will be hydroseeded or landscaped per the Village Y's landscape plans and will be installed by the developer. The developed site will be irrigated to maintain all vegetation and will be installed by the developer. Source Control BMPs The following Source Control BMPs will be incorporated to the site: • All stormwater curb inlets will be stamped with thermoplastic letterings "No Dumping - I Live Downstream" Curb inlet stamps will be placed on all curb inlets onsite and will be placed by the developer. Water quality educational pamphlets will also be sent to tenants and contractors. The developers will be responsible for ensuring the contractors receive the pamphlets prior to constmction. The homeowner's association will be responsible for sending these educational pamphlets to all new tenants and once a year. See Appendix I for sample pamphlets. Mechanical sweeping shall be used to clean the street. Street sweeping shall be done twice a month and the homeowner's association will provide the service. Trash storage areas will be installed by the contractor and built per City of Carlsbad standard drawings. Structural Treatment BMPs Storm drainage inserts and an extended detention basin will be used for Stmctural Treatment BMPs. The drainage inserts will be Curb Inlet Baskets. The drainage inserts are Suntree Technologies Inc. products. See Appendix D for product information. The extended detention basin will be located at the southwesterly comer of the Village "X" development. This basin will be used to detain and treat portions of Village "X" and Village "Y" developments. The other portions of Village "X" and "Y" will be discharged into the storm drainage system along College Boulevard. The total required volume for the extended detention basin was determined as follows: V = C*P24*(1 ft/12 in)*A*(43560 sf/1 ac) Where, V = Volume in cubic feet C = Runoff coefficient (See Appendix E and F for coefficients used) P24 = 24-hour 85* percentile storm event (0.6 inches) A = Area to be detained in acres (See Appendix E and F for areas used) The required volume for Village 'X' was determined as follows: Required volume for the 2.56-acre open space: V = 0.45*0.6*1/12*2.56*43560 = 2509 cf Required volume for the single-family development area: A V-0.55*0.6*1/12*6.16*43560 = 7379 cf The required volume for Village 'Y' was determined as follows: Required volume for the community facilities area: V = 0.85*0.6*1/12*0.59*43560 = 1092 cf Required volume for the multi-family development area: V = 0.70*0.6*1/12*5.77*43560 = 9889 cf The total required volume for the extended detention basin is approximately 20,869. The extended detention basin will provide approximately 25,200 cubic feet of live storage. The drainage inserts and extended detention basins will reduce the following pollutants from entering downstream: • Oxygen Demanding Substances • Nitrate and Nitrite • Nitrogen • Oil and Grease • Phosphate • Solids Maintenance The post constmction BMP's will be maintained as follows (See Village 'Y' Post Constmction BMP Summary Sheet in Appendix A for BMP maintenance information): Streetsweeping: Homeowner's Association Catch Basin Inserts: Homeowner's Association Extended Detention Basin: Homeowner's Association Inlet Basin Labeling: Homeowner's Association Landscaping: Homeowner's Association Irrigation: Homeowner's Association The maintenance ofthese BMP's is in conformance with Attachment 1 ofthe Regional Water Quality Control Board Order No. R98-2002-0014 Waste Discharge Requirements and Section 401 Certification Dated Febmary 13, 2002 (See Appendix H). Additional maintenance requirements are addressed on Article X Maintenance Responsibilities of the Declaration of Restrictions for Calavera Hills II Planned Development. See Appendix G for j^rticle X. Site Pesign & Landscape Planning SD-10 Design Objectives • • Maximize Infiltration Provide Retention Slow Runoff iVlinimize Impervious Land Coverage Prohibit Dumping of Improper Materials Contain Pollutants Collect and Convey Description Each project site possesses unique topographic, hydrologic, and vegetative features, some of which are more suitable for development than others. Integrating and incorporating appropriate landscape planning methodologies into the project design is the most effective action that can be done to minimize surface and groundwater contamination from stormwater. Approach Landscape planning should couple consideration of land suitability for urban uses with consideration of community goals and projected growth. Project plan designs should conserve natural areas to the extent possible, maximize natural water storage and infiltration opportunities, and protect slopes and channels. Suitable Appiications ' Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment. Design Considerations Design requirements for site design and landscapes planning should conform to applicable standards and specifications of agencies with jurisdiction and be consistent with applicable General Plan and Local Area Plan policies. ,C A S Q A :alifornla Stormwater Quality Association January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 1 of 4 SD-10 Site Design & Landscape Planning Designing Neiv Installations Begin the development of a plan for the landscape unit with attention to the following general principles: • Formulate the plan on the basis of clearly articulated community goals. Carefully identify conflicts and choices between retaining and protecting desired resources and community growth. • Map and assess land suitability for urban uses. Include the following landscape features in the assessment: wooded land, open unwooded land, steep slopes, erosion-prone soils, foundation suitability, soil suitability for waste disposal, aquifers, aquifer recharge areas, wetlands, floodplains, surface waters, agricultural lands, and various categories of urban land use. When appropriate, the assessment can highlight outstanding local or regional resources that the community determines should be protected (e.g., a scenic area, recreational area, threatened species habitat, farmland, fish run). Mapping and assessment should recognize not only these resources but also additional areas needed for their sustenance. Project plan designs should conserve natural areas to the extent possible, maximize natural water storage and infiltration opportunities, and protect slopes and channels. Conserve Natural Areas during Landscape Planning ' If applicable, the following items are required and must be implemented in the site layout during the subdivision design and approval process, consistent with applicable General Flan and Local Area Flan policies: • Cluster development on least-sensitive portions of a site while leaving the remaining land in a natural undisturbed condition. B Limit clearing and grading of native vegetation at a site to the minimum amount needed to build lots, allow access, and provide fire protection. • Maximize trees and other vegetation at each site by planting additional vegetation, clustering tree areas, and promoting the use of native and/or drought tolerant plants. • Promote natural vegetation by using parking lot islands and other landscaped areas. • Preserve riparian areas and wetiands. Maximize Natural Water Storage and Infiltration Opportunities Within the Landscape Unit m Promote the conservation of forest cover. Building on land that is already deforested affects basin hydrology to a lesser extent than converting forested land. Loss of forest cover reduces interception storage, detention in the organic forest floor layer, and water losses by evapotranspiration, resulting in large peak runoff increases and either their negative effects or the expense of countering thern with structural solutions. • Maintain natural storage resei-voirs and drainage corridors, including depressions, areas of permeable soils, swales, and intermittent streams. Develop and implement poiicies and 2 of 4 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Site Design & Landscape Planning SD-10 regulations to discourage the clearing, filling, and channelization of these features. Utilize • them in drainage networks in preference to pipes, culverts, and engineered ditches. • Evaluating infiltration opportunities by referring to the stormwater management manual for the jurisdiction and pay particular attention to the selection criteria for avoiding groundwater contamination, poor soils, and hydrogeological conditions that cause these facilities to fail. If necessary, locate developments with large amounts of impervious surfaces or a potential to produce relatively contaminated runoff away from groundwater recharge areas. Protectionof Slopes and Channels during Landscape Design • Convey runoff safely from the tops of slopes. • Avoid disturbing steep or unstable slopes. ' • Avoid disturbing natural channels. • Stabilize disturbed slopes as quickly as possible. • Vegetate slopes with native or drought tolerant vegetation. • Control and treat flows in landscaping and/or other controls prior to reaching existing natural drainage systems. • Stabihze temporary and permanent channel crossings as quickly as possible, and ensure that increases in run-off velocity and frequency caused by the project do not erode the channel. • Install energy dissipaters, such as riprap, at the outlets of new storm drains, culverts, conduits, or channels that enter unlined channels in accordance with applicable specifications to minimize erosion. Energy dissipaters shall be installed in such a way as to minimize impacts to receiving waters. • Line on-site conveyance channels where appropriate, to reduce erosion caused by increased flow velocity due to increases in tributary impervious area. The first choice for linings should be grass or some other vegetative surface, since these materials not only reduce runoff velocities, but also provide water quality benefits from filtration and inflitration. If velocities in the channel are high enough to erode grass or other vegetative linings, riprap, concrete, soil cement, or geo-grid stabilization are other alternatives. • Consider other design principles that are comparable and equally effective. Redeveloping Existing Installations Variousjurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior constmction, and land disturbing activities with structural or impervious surfaces. The definition of" redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment. Ifthe definition apphes, the steps outhned under "designing new installations" above should be followed. January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 3 of 4 SD-10 Site Design & Landscape Planning Redevelopment may present significant opportunity to add features which had not previously been implemented. Examples include incorporation of depressions, areas of permeable soils, and swales in newly redeveloped areas. While some site constraints may exist due to the status of already existing infrastmcture, opportunities should not be missed to maximize infiltration, slow runoff, reduce impervious areas, disconnect directly connected impervious areas. Other Resources A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of PubUc Works, May 2002. Stormwater Management Manual for Western Washington, Washington State Department of Ecology, August 2001. Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003. Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002. 4 of 4 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Roof Runoff Controls SD-11 Design Objectives yf Maximize Infiltration •/ Provide Retention y Slow Runoff Minimize Impervious Land Coverage Prohibit Dumping of Improper Materials •/ Contain Pollutants Collect and Convey Rain Garden Description ' • ' - ' Various roof runoff controls are available to address stormwater that drains off rooftops. The objective is to reduce the total volume and rate of runoff from individual lots, and retain the pollutants on site that may be picked up from roofing materials and atmospheric deposition. Roof runoff controls consist of directing the roof runoff away from paved areas and mitigating flow to the storm drain system through one of several general approaches: cisterns or rain barrels; dry wells or infiltration trenches; pop-up emitters, and foundation planting. The first three approaches require the roof runoff to be contained in a gutter and downspout system. Foundation planting provides a vegetated strip under the drip line ofthe roof. Approach • ' s- .f. • Design of individual lots for single-family homes as well as lots for higher density residential and commercial structures should consider site design provisions for containing and infiltrating roof runoff or directing roof runoff to vegetative swales or buffer areas. Retained water can be reused for watering gardens, lawns, and trees. Benefits to the environment include reduced demand for potable water used for irrigation, improved stormwater quality, increased groundwater recharge, decreased runoff volume and peak flows, and decreased flooding potential. Suitable Applications Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment. Design Considerations Designing New Installations Cisterns or Rain Barrels One method of addressing roof runoff is to direct roof downspouts to cisterns or rain barrels. A cistern is an above ground storage vessel with either a manually operated valve or a permanently open outlet. Roof runoff is temporarily stored and then released for irrigation or infiltration between storms. The number of rain CA S Q^JA,,^ Caiifornia Stormwater Quaiitf Association January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbook.com 1 of 3 SD-11 Roof Runoff Controls barrels needed is a function of the rooftop area. Some low impact developers recommend that eveiy house have at least 2 rain barrels, with a minimum storage capacity of iooo liters. Roof barrels serve several purposes including mitigating the first flush from the roof which has a high volume, amount of contaminants, and thermal load. Several types of rain barrels are commercially available. Consideration must be given to selecting rain barrels that are vector proof and childproof. In addition, some barrels are designed with a bypass valve that filters out grit and other contaminants and routes overflow to a soak-away pit or rain garden. If the cistern has an operable valve, the valve can be closed to store stormwater for irrigation or infiltration between storms. This system requires continual monitoring by the resident or grounds crews, but provides greater flexibility in water storage and metering. If a cistern is provided with an operable valve and water is stored inside for long periods, the cistern must be covered to prevent mosquitoes from breeding. A cistern system with a permanently open outlet can also provide for metering stormwater runoff. If the cistern outlet is significantly smaller than the size of the dovmspout inlet (say VA to V2 inch diameter), runoff will build up inside the cistern during storms, and will empty out slowly after peak intensities subside. This is a feasible way to mitigate the peak flow increases caused by rooftop impervious land coverage, especially for the frequent, small storms. Dry wells and Infiltration Trenches Roof downspouts can be directed to dry wells or inflitration trenches. A dry well is constructed by excavating a hole in the ground and filling it with an open graded aggregate, and allowing the water to fill the dry well and infiltrate after the storm event. An underground connection from the downspout conveys water into the dry well, allowing it to be stored in the voids. To minimize sedimentation from lateral soil movement, the sides and top of the stone storage matrix can be wrapped in a permeable filter fabric, though the bottom may remain open. A perforated observation pipe can be inserted vertically into the dry well to allow for inspection and maintenance. In practice, dry wells receiving mnoff from single roof downspouts have been successful over long periods because they contain very little sediment. They must be sized according to the amount of rooftop runoff received, but are typically 4 to 5 feet square, and 2 to 3 feet deep, with a minimum of i-foot soil cover over the top (maximum depth of 10 feet). To protect the foundation, dry wells must be set away from the building at least 10 feet. They must be installed in solids that accommodate infiltration. In poorly drained soils, dry wells have very limited feasibility. Infiltration trenches function in a similar manner and would be particularly effective for larger roof areas. An infiltration trench is a long, narrow, rock-filled trench with no outlet that receives stormwater runoff. These are described under Treatment Controls. Pop-up Drainage Emitter Roof downspouts can be directed to an underground pipe that daylights some distance from the building foundation, releasing the roof mnoff through a pop-up emitter. Similar to a pop-up irrigation head, the emitter only opens when there is flow from the roof The emitter remains flush to the ground during dry periods, for ease of lawn or landscape maintenance. 2 of 3 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbook.com Roof Runoff Controls SD-11 Foundation Planting Landscape planting can be provided around the base to allow increased opportunities for stormwater infiltration and protect the soil from erosion caused by concentrated sheet flow coming off the roof Foundation plantings can reduce the physical impact of water on the soil and provide a subsurface matrix of roots that encourage infiltration. Tiiese plantings must be sturdy enough to tolerate the heavy runoff sheet flows, and periodic soil saturation. Redeveloping Existing InstaUations Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impervious surfaces. The definition of " redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment. If the definition applies, the steps outlined under "designing new installations" above should be followed. Syppiemental Information . \ • Examples • City of Ottawa's Water Links Surface -Water Quality Protection Program a City ofToronto Dovmspout Disconnection Program • City of Boston, MA, Rain Barrel Demonstration Program Other Resources Hager, Marty Catherine, Stormwater, "Low-Impact Development", January/February 2003. www.stormh2o.com Low Impact Urban Design Tools, Low Impact Development Design Center, Beltsville, MD. www.lid-stormwater.net Start at the Source, Bay Area Stormwater Management Agencies Association, 1999 Edition January 2003 California Stormwater BMP Handbook 3 of 3 New Development and Redevelopment www.cabmphandbook.com Efficient Irrigation SD-12 Design Objectives •</ Maximize Infiltration yf Provide Retention y Slow Runoff Minimize Impervious Land Coverage Prohibit Dumping of Improper Materials Contain Pollutants Collect and Convey Description Irrigation water provided to landscaped areas may result in excess irrigation water being conveyed into stormwater drainage systems. Approach Project plan designs for development and redevelopment should include application methods of irrigation water that minimize runoff of excess irrigation water into the stormwater conveyance system. \ . - Suitable Applications Appropriate applications include residential, commercial and industrial areas planned for development or redevelopment. (Detached residential single-family homes are typically excluded from this requirement.) Design Considerations v Designing New Installations The following methods to reduce excessive irrigation runoff should be considered, and incoi-porated and implemented where determined applicable and feasible by the Permittee: • Employ rain-triggered shutoff devices to prevent irrigation after precipitation. • Design irrigation systems to each landscape area's specific water requirements. • Include design featuring flow reducers or shutoff valves triggered by a pressure drop to control water loss in the event of broken sprinkler heads or lines. • Implement landscape plans consistent with County or Cit>' water conservation resolutions, which may include provision of water sensors, programmable irrigation times (for short cycles), etc. ^^4C A S O A California Stormwater Quality Association January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 1 of 2 SD-12 Efficient Irrigation m Design timing and application methods of irrigation water to rniriimize the nmoff of excess irrigation water into the storm water drainage system. .. • Group plants with similar water requirements in order to reduce excess irrigation runoff and promote surface filtration. Choose plants wdth iow irrigation requirements (for example, native or drought tolerant species). Consider design Itatiires such as: Using mulches (such as wood chips or bar) in planter areas without ground cover to minimize sediment in runoff Installing appropriate plant materials for the location, in accordance with amount of sunlight and climate, and use native plant materials where possible and/or as recommended by the landscape architect Leaving a vegetative barrier along the propeity boundary and interior watercourses, to act as a pollutant filter, where appropriate and feasible Choosing plants that minimize or eliminate the use of fertilizer or pesticides to sustain growth m Employ other comparable, equally effective methods to reduce irrigation water mnoff. Redeveloping Existing Installations :V Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impervious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impervious surfaces. The definition of " redevelopment" must be consulted to determine whether or not the requirements for new development apply to areas intended for redevelopment. If the definition applies, the steps outlined under "designing new installations" above should be followed. Other Resources A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002. Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003. Ventura Count)wide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002. 2 of 2 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com storni Drain Signage SD-13 Design Objectives Maximize Infiltration Provide Retention Slow Runoff i Minimize Impervious Land Coverage y Prohibit Dumping of Improper Materials Contain Pollutants Collect and Convey Description • ' • Waste materials dumped into storm drain inlets can have severe impacts on receiving and ground waters. Posting notices regarding discharge prohibitions at storm drain inlets can prevent waste dumping. Storm drain signs and stencils are highly visible source controls that are typically placed directly adjacent to storm drain inlets. Approach ... . .. ^ The stencil or affixed sign contains a brief statement that prohibits dumping of improper materials into the urban runoff conveyance system. Storm drain messages have become a popular method of alerting the public about the effects of and the prohibitions against waste disposal. Suitable Applications Stencils and signs alert the public to the destination of pollutants discharged to the storm drain. Signs are appropriate in residential, commercial, and industrial areas, as well as any other area where contributions or dumping to storm drains is likely. Oesign Considerations Storm drain message markers or placards are recommended at all storm drain inlets within the boundary of a development project. The marker should be placed in clear sight facing toward anyone approaching the inlet from either side. All storm drain inlet locations should be identified on the development site map. Designing New Installations The following methods should be considered for inclusion in the project design and show on project plans: Provide stenciling or labeling of all storm drain inlets and catch basins, constructed or modified, within the project area with prohibitive language. Examples include "NO DUMPING -California Stormwater Quality Association January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 1 of 2 SD-13 storm Drain Signage DRAINS TO OCEAN " and/or other graphical icons to discourage illegal dumping. • Post signs with prohibitive language and/or graphical icons, which prohibit illegal dumping at public access points along channels and creeks within the project area. Note - Some local agencies have approved spedfic signage and/or storm drain message placards for use. Consult local agency stormwater staff to determine specific requirements for placard types and methods of apphcation. Redeveloping Existing Installations Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.) define "redevelopment" in terms of amounts of additional impei-vious area, increases in gross floor area and/or exterior construction, and land disturbing activities with structural or impei-vious surfaces. If the project meets the definition of "redevelopment", then the requirements stated under " designing new installations" above should be included in all project design plans. Additional Information Maintenance Considerations •• m Legibility of markers and signs should be maintained. If required by the agency with jurisdiction over the project, the owner/operator or homeowner's association should enter into a maintenance agreement with the agency or record a deed restriction upon the property titie to maintain the legibility of placards or signs. Placement m Signage on top of curbs tends to weather and fade. a Signage on face of curbs tends to be worn by contact with vehicle tires and sweeper brooms. Supplemental Information Examples B Most MS4 programs have storm drain signage programs. Some MS4 programs will provide stencils, or arrange for volunteers to stencil storm drains as part of their outreach program. Other Resources A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County Department of Public Works, May 2002. Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of San Diego, and Cities in San Diego County, February 14, 2002. Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood Control District, and the Incorporated Cities of Orange County, Draft February 2003. Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures, July 2002. 2 of 2 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Drain Inserts Description Drain 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 falhng into one ofthree different groups: socks, boxes, and trays. The sock consists of a fabric, usually constructed of polypropylene. 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 the 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 or 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. California Experience The number of installations is unknown but likely exceeds a thousand. Some users have reported that these systems require considerable maintenance to prevent plugging and bypass. Advantages a Does not require additional space as inserts as the drain inlets are already a component of the standard drainage systems. a Easy access for inspection and maintenance. a As there is no standing water, there is little concern for mosquito breeding. a 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 suitable for large areas or areas with trash or leaves than can plug the insert. Design and Sizing Guidelines Refer to manufacturer's guidelines. Drain inserts come any many configurations but can be placed into three general groups: socks, boxes, and trays. The sock consists of a fabric, usually constructed of polypropylene. 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 the form of the box. Most box products are Design Considerations a Use with other BMPs a Fit and Seal Capacity within Inlet Targeted Constituents V Sediment yY Nutrients yY Trash - yY Metals Bacteria y Oil and Grease yY Organics Removal Effectiveness See New Development and Redevelopment Handbook-Section 5. Caiifomla Stormwater Quality Association January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 1 of 3 MP-52 Drain Inserts one box; that is, the setting area and filtration through media occurs in the same box. One manufacturer has a double-box. Stormwater enters the first box where setting occurs. The stormwater flows into the second box where the filter media is located. Some products consist of one or more trays or mesh grates. The trays can hold different types of media. Filtration media vary with the manufacturer: types include polypropylene, porous polymer, treated cellulose, and activated carbon. Construction/Inspection Considerations Be certain that installation is done in a manner that makes certain that the stormwater enters the unit and does not leak around the perimeter. Leakage between the frame of the insert and the frame of the drain inlet can easily occur with vertical (drop) inlets. ; Performance Few products have performance data collected under field conditions. Siting Criteria It is recommended that inserts be used only for retrofit situations or as pretreatment where other treatment BMPs presented in this section area used. -' Additional Design Guidelines ' Follow guidelines provided by individual manufacturers. Maintenance Likely require frequent maintenance, on the order of several times per year. Cost m The initial cost of individual inserts ranges from less than $100 to about $2,000. The cost of using multiple units in curb inlet drains varies with the size ofthe inlet. B The low cost of inserts may tend to favor the use of these systems over other, more effective treatment BMPs. However, the low cost of each unit may be offset by the number of units that are required, more frequent maintenance, and the shorter structural life (and therefore replacement). ' ' References and Sources of Additional Information Hrachovec, R., and G. Minton, 2001, Field testing of a sock-type catch basin insert, Planet CPR, Seattle, Washington Interagency Catch Basin Insert Committee, Evaluation of Commercially-Available Catch Basin Inserts for the Treatment of Stormwater Runoff from Developed Sites, 1995 Larry Walker Associates, June 1998, NDMP Inlet/In-Line Control Measure Study Report Manufacturers literature - Santa Monica (City), Santa Monica Bay Municipal Stormwater/Urban Runoff Project - Evaluation of Potential Catch basin Retrofits, Woodward Clyde, September 24,1998 2 of 3 California Stormwater BMP Handbook January 2003 New Development and Redevelopment www.cabmphandbooks.com Drain Inserts MP-52 Woodward Clyde, June ii, 1996, Parking Lot Momtoring Report, Santa Clara Valley Nonpoint Source Pollution Control Program. January 2003 California Stormwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 3 of 3 BIO CLEAN ENVIRONMENTAL SERVICES, INC. Grate Inlet Skimmer Box Curb Iniet Basicet Nutrient Separating Baffle Box REPORTS & DATA PoUutant Loading Analysis for Stormwater Retrofitting in Melboume Beach, Florida Pollutant Removal Testing for A Suntree Technologies Grate Inlet SIdmmer Box Site Evaluation of Suntree Technologies, Inc. Grate Inlet Skimmer Boxes for Debris, Sediment And Oil & Grease Removal BIO CLEAN ENVIRONMENTAL SERVICES, INC. P O BOX 869, OCEANSIDE, CA 92049 (760) 433-7640 FAX (760) 433-3176 Pollutant Loading Analysis For Stormwater Retrofitting in Melbourne Beach, Florida By: Gordon England, P.E. Creech Engineers, Inc. 4450 W. Eau Gallie Blvd, #232 Melbourne, FI. 32932 Introduction At Gemini Elementary School in Melbourne Beach, Florida, there has been a history of repeated flooding on the school grounds and in properties adjacent to the school. In 1999 Creech Engineers, Inc. (CEI) was chosen by Brevard County Stonnwater Utihty to design drainage improvements to alleviate these flooding conditions, as well as to provide for stormwater treatment within this 20.06 hectare drainage basin. The project was divided mto two phases. Phase 1 improvements were made in order to accelerate initial flood control measures for homes downstream ofthe schooL Phase 2 involved the design of more extensive flood and water quality control measures along Oak Street for fiirther protection of school property and roadway flooding at nearby church property. This paper highlights the political challenges of retrofitting stormwater systems in developed areas, as well as demonstrates a methodology for performing a nonpoint source pollutant loading analysis. Existing Conditions Gemini Elementary School is located on a 8.02 hectare, triangular shaped property along the south side of Oak Street, a two lane collector road in Melboume Beach, about one half mile from the Atlantic Ocean. See Exhibit 1. Residential properties lie downstream ofthe school, along its southeast and southwest borders. 8.51 hectare Doug Flutie Park is on the north side of Oak Street. A soccer club uses the park and school grounds on a daily basis. There was no stormwater system at the park, along Oak Street, or on the school site. Stormwater flowed southward off Doug Flutie Park, across Oak Street, through the school site, and into the yards and homes south ofthe school. These yards, and the roads downstream of them, are very flat and only a few feet above sea level. Once water stages high enough in the yards, it gradually sheetflows down the adjacent roads a few hundred yards to the Indian River. The affected homeowners naturaUy blamed the school for allowing the school's water to flood them. West ofthe school, a few hundred yards along Oak Street, was a low point in the road where water ponded and flooded the road and an adjacent churchyard. Due to a thin clay lens at 26 cm deep causing a perched water table, water stood in the road for several days after even a nominal rainfall. This drainage basin was ahnost completely built out, with no easy path for developing outMs to relieve flooding. This section of the Indian River is a Class 2 v^rater body, with a Shellfish Harvesting classification bringing intense scrutiny from the St. Johns River Water Management District. Corp of Engineers permitting is required for new outfalls in the area due to seagrasses near the shoreline. The park, the schooL and Oak Street lie in unincorporated Brevard Couniy. The church, and properties west of the school are in Melboume Beach. Being a collector road, all of the utility companies have major transmission lines m the road right-of-way. As can be seen, this challenging project involved Brevard County, Melbourne Beach, the School Board, Brevard County Parks and Recreation Department, Brevard County Road and Bridge Department, Brevard County Stormwater Utility, a church, three different Homeowners Associations, a soccer club, the Water Management District, the Corp of Engineers, and several utility companies. Stakeholder involvement and partnerships were going to be critical to weave a solution through the many players involved. Proposed Improvements The first priority was to alleviate flooding in the homes adjacent to the school. As an interim measure, a berm was designed and constmcted by County personnel along the south property lines of the schooL with a swale behind the berm directing water to the southernmost point of the school property. At that location, an inlet and 18" outfell pipe were constmcted in a utility easement through two heavily landscaped and fenced yards, to Pompano Street, where it was tied into an existing storm drain pipe. A short time later, heavy rains overflowed the berms and swales and flooded homes adjacent to the school again. CEI was engaged at that point to provide more effective drainage improvements. Fortunately, Gemini Elementary School had a significant area of vacant land on their site. The school entered into agreements with Brevard County allowing the constmction of three dry retention ponds totaling 2.95 hectare to reduce flows leaving the school site, as well as provide stormwater treatment where none existed. These dry ponds were wound around several soccer and baseball fields. The soccer field's locations had to remain in place due to previous agreements with the school and Parks and Recreation Dept. The ponds were only 26-40 cm (12"- 18") deep and sodded, allowing the soccer teams to use the pond areas as practice fields when dry. When the ponds were excavated, the confining clay layer was removed to allow for infiltration though the beach sand at the site. Constmction was scheduled during the summer when school was out. A control stmcture was designed at the outfall pipe location to provide protection for a 25 year storm. The temporary connection to the existing downstream pipe had overloaded the downstream system in a heavy rain event, so a new outM to the Indian River was designed through a park adjacent to the River. The park was owned by a Homeowners Association, which reluctantly gave a drainage easement through the park. The County agreed to make several improvements to the park and its boat ramp in exchange for the easement. The Corp of Engineers was concemed that the new outfell pipe discharges would unpact the nearby seagrasses, so the new discharge pipe was not permitted to be constracted in the Indian River. A bubbleup box was designed ten feet back from the shoreline and rock riprap was placed between the bubbleup box and the mean high water line to prevent erosion. As mitigation for disturbing the shoreline, spartina and other plants were planted among the rocks to further buffer the shoreline from the stonnwater discharges. This first phase of improvements was finished in September 2000 at a cost of $124,000. The improvements implemented proved successful in preventing any flooding of adjacent homes in several large ramfalls in 2001. The second phase of the project addressed stormwater quantity and quality concems along 1650 meters of Oak Street, from AIA to Cherry Street. To provide fiirther flood protection at Gemini Elementary School, retention swales were designed along both sides of Oak Street and 625 meters of storm drain pipe was designed to intercept runoff and prevent it from crossing the road onto school property. The piping also provided an outfall for the low spot m the road by the church. This new pipe system discharged into a residential canal system, which was used by many of the adjacent residents for boating to the Indian River Lagoon (Bay). These canals were very pohtically sensitive since they were in need of dredging and the Town of Melboume Beach does not dredge canals. The residents were concemed that the new stormwater system would lead to further sedimentation ofthe canals. The first altemative for treatment was to use land at the church site for a pond for the road runoff. The church was willing to donate the land where their septic tank fields were located ifthe County would provide a sewer connection. This scenario was designed, but when it came time for the church to give easements to the County, they balked and it was back to the drawing board. St. Johns River Water Management District, (District), criteria requires stonnwater treatment for improvements wiiich a) increase discharge rates b) which increase pollutant loadings, or c) which mcrease impervious areas. With this project, no new mcreased impervious areas were proposed, but there would be additional water flowing to the residential canal from the extension of the pipe system to the flood prone areas. These new flows create the potential for increased pollutant loadings to the canal. Normal design methods would have used treatment ponds to offset these potential impacts. Due to lack of available land for ponds, altemative treatment methods were proposed for this project. The District will consider altemative treatment methods if it can be demonstrated that all other possible altematives have been exhausted. It would not be possible pohtically to use more school or paric area for treatment ponds. For this project, CEI showed that the only altematives were to tear down houses for ponds, or use alternate treatment technologies. The treatment strategy involved maximizing treatment methods within the project basin with altemative BMPs, as well as retrofittmg two adjacent watersheds as additional mitigation. A total of 1.67 acre feet of retention storage was provided in Phase 2 in the roadside swales and small ponds. This was equivalent to 0.032 inches of retention from the drainage areas flowing to the retention areas. A treatment train along Oak Street was designed by using 9 Grated Inlet Skimmer Boxes, from Suntree Technologies, Inc., in the new inlets to trap debris entering the inlets, constmcting berms to slow runoff from the ball fields, and installing one baffle box at the downstream end of the new pipe system along Oak Street. Baffle Boxes are in-line stormwater treatment devices which tr^ sediment, trash, and debris. They have been used by Brevard County successfully for the last 9 years. In offsite Basin 4, which only had one existing baffle box to provide sediment removal, 16 Curb Inlet Skimmer Boxes were installed in all of the existing inlets to provide nutrient removal by trapping grass clippings, leaves, and yard debris. Nutrients were a concem in the canals since the nutrients promote algae blooms, which in tum increase muck build up in the canals. In offsite drainage Basin 5, there are 3 existing pipes which discharge direcfly to the canals. Three baffle boxes and 6 curb inlet skimmer boxes were designed to provide sediment and nutrient treatment for this drainage basin. Brevard County Stormwater Utility will implement this project and be responsible for all maintenance of the knprovements. The baffle boxes will be mspected twice a year and cleaned as needed. The inlet traps will be cleaned twice a year. Brevard County has a vacuum tmck dedicated to cleaning stormwater BMPs. Using numerous BMPs used on this project provided a high degree of treatment for the new pipmg system along Oak Street, and provided treatment for two offsite basins where little treatment existed. The retrofitting of the offsite areas was, m effect, mitigation for the new discharges to the canal. See Exhibit 1 for a map ofthe improvements. Calculations In Phase 1 of the project, the dry ponds and outfell pipes were modeled hydrauhcally using the Interconnected Pond Routing program. Since the dry ponds in the Phase 2 project area were too small to provide effective attenuation, the predevelopment and post development runoff calculations were made using Hydraflow and the rational method. The only available storm drain pipe for Phase 2 was a 36" pipe in offsite Basin 4. The new piping along Oak Street was connected to the existing 36" pipe, and the piping downstream ofthe connection was upgraded to a 42" pipe. The pipes were designed for a 25 year storm. Basins 1,2, and 3 were a much longer distance from the outfell than Basin 4. As a result of different times of concentration, the peak flows from Basin 4 passed sooner than Basins 1,2, and 3, givuig only a slight increase in peak discharge, despite adding 12.25 hectares to the area flowing to the existing outfell. The potential for increased poUutant loadings in the canal system was a concem of local residents. These canals had a history of dredging operations every 8-10 years, and the residents did not want to increase the frequency of costly dredging. The main poUutants of concem leading to muck deposition in the canals were Total Suspended Solids (TSS), Total Nitrogen (TN), and Total Phosphoms (TP). Sediment build up at the end of the pipes was common. Nutrient loadings from grass clippings, leaves, and fertilizers leads to algae blooms and low dissolved oxygen in the canals, which in tum leads to muck build up from the eutrophication process. Most ofthe material dredged from residential canals is typically muck. To address this concern, a poUutant loadmg analysis of the existing and proposed stormwater discharges was performed. In the existing conditions, the only stonnwater treatment for the canal system was a baffle box along Cherry Street for offeite Basin 4 of 24.24 hectares. There were a total of 7 outfaU pipes discharging into the canal system. In the first phase of this project stormwater treatment was provided for 8.02 hectares of the school grounds with 3 dry detention ponds. The discharge from these ponds was to the Indian River, rather than the canal system, so these poUutant loads were not included in the pollutant load analysis for the canal outfell. The existing pollutant load to the canal only came from the drainage Basins 4 and 5, totaling 31.2 hectares. The runoff from Oak Street did not drain to the canal in existing conditions, only in the post development conditions. The strategy for the poUutant analysis was to calculate the poUutant toads in the existing conditions, and then calculate the poUutant loads after the new pipes were added to the system and offsite areas retrofitted for stormwater treatment. The poUutants used in this analysis were TSS, TP, and TN. Each drainage basui was categorized by land use. Areal, annuaL mass loading rates from "Stormwater Loading Rate Parameters for Central and South Florida", Harper, 1994, were multiplied by each basin's area to give existing and potential annual pollutant loadings. See Table 1. The next step was to calculate the poUutant removal rates for the different BMPs. Individual BMP removal efficiencies were take from "A Guide for BMP Selection in Urban Developed Areas", EWRI, 2000. What was challenging with this analysis was the use of multiple BMPs in series for the treatment tram. Each BMP receives cleaner and cleaner water as the water moves down the train. At each BMP, the removal efficiency for each constituent was multiplied by the remainmg percentage of the imtial loading to give a weighted, cumulative, removal efBciency for each constituent. See Table 2. These calculated removal efficiencies were then multiplied by the total calculated poUutant loads to give the reduced pollutant loadings after the BMPs were mstalled. See Table 3. Table 4 shows that the total loads to the canal were reduced as a resuh ofthe retrofitting of onsite and offsite basins. The pollutant loading analysis below demonstrates that as a resuh of the numerous BMPs proposed, the total pollutant loadhigs entering the canals after project completion will actually be sigmficantiy reduced from the existing pollutant loadings entering the canals. The key to overall pollutant reduction is to provide additional treatment in offsite drarnage basins. This wUl result in a net benefit of reduced poUutants entering the canals and a reduction of the severe floodmg often seen along Oak Street. Table 1 Existing Pollutant Loading Basin Area (acres) Land Use Loading Rate* (Icg/ac - year) Potential Pollutant Loading (kg-year) Basin Area (acres) Land Use TSS Total Phosphorus Total Nitrogen TSS Total Phosphorus Total Nitrogen 2A 9.23 Recreational 7.6 0.046 1.07 70.15 0.425 9.876 2B 1.15 Recreationai 7.6 0.046 1.07 8.74 0.053 1.231 20 0.77 Recreational 7.6 0.046 1.07 5.85 0.035 0.824 2D 1.45 Recreational 7.6 0.046 1.07 11.02 0.067 1.552 2E 2.63 Recreational 7.6 0.046 1.07 19.99 0.121 2.814 2F 1.97 Recr^ior^ 7.6 0.046 1.07 14.97 0.091 2.108 2G 0.75 Recreationai 7.6 0.046 1.07 5.70 0.035 0.803 2H 1.29 Recreational 7.6 0.046 1.07 9.80 0.059 1.380 21 0.08 Recreational 7.6 0.046 1.07 0.61 0-004 0.086 2J 0.8 Recreatkxial 7.6 0.046 1.07 6.08 0.037 0.856 2K 0.57 Recreational 7.6 0.046 1.07 4.33 0.026 0.610 2L 0.34 Recreational 7.6 0.046 1.07 2.58 0.016 0.364 3A 2.19 Single FamTy 56.1 0.594 4.68 122.86 1.301 10.249 3B 3.02 Single Family 56.1 0.594 4.68 169.42 1.794 14.134 30 4.02 Low Intend Commercial 343 0.65 5.18 1378.86 2.613 20.824 Subtotal 30.26 1830.97 6.68 67.71 4" 59.9 Single Fanvly 56.1 0.594 4.68 672.00 24.910 280.332 5A 5.9 Single FanrHly 56.1 0.594 4.68 330.99 3.505 27.612 5B 8.62 Single Fanily 56.1 0.594 4.68 483.58 5.120 40.342 50 2.68 Single Family 56.1 0.594 4.68 150.35 1.592 12.542 Subtotal 77.1 1636.92 35.13 360.83 Totals 107.36 3467.89 41.80 428.54 * From "Stormwater Loading Rate Parameters for Central and South Florida", 1994. Harper ** Basin 4 has an existing baffle box providing treatment. Basins 4 and 5 are the existing pollutant loadings to the canals. Table 2 BMP Pollutant Removals BMP POLLUTANT REMOVAL TABLE* BMP BMP Removal Efficiency Type (%) TSS TP TN Dry Pond 85 61 91 Swale 80 45 25 Baffle Box 80 30 0 Inlet Trap (grated) 73** 79** 79** Inlet Trap (curb) 11*** 10*** Swale + Inlet Trap (g) + Baffle Box 98.9 91.9 84.2 Dry Pond + Inlet Trap (g) + Baffle Box 99.2 94.3 98.1 Inlet Trap (c)+ Baffle Box 84 37.7 10 Inlet Trap (g)+ Baffle Box 81.1 85.3 79 Multiple BMP Poilutant Removal Calcuiations Swale + Inlet Trap (g) + Baffle Box TSS - 100x0.8 + (100-80)x0.73 + (100-80-14.6)x0.8 = 98.9% Removal TP - 100x0.45 + (10a45)x.79 + (100-45-43.45) = 91.9% Removai TN - 100X.25 + (100-25)x.79 = 84.2% Remmak Dry Pond + Iniet Trap (g) + Baffle Box TSS - 100x0.85 + (100-85)x0.73 + (100-85-10.95)x0.8 = 99.2% Removal TP - 100x0.61 + (10a€1)x0.79 + (100-61-30.8)x.3 = 94.3% Removal TN - IOOx.91 + (100-91)x.79 = 98.1% Removal Iniet Trap (c) + Baffle Box TSS - 100-X0.2 + (100-20)x0.8 = 84% Removal TP - 100x0.11 + (100-11 )x.3= 37.7% Remcwai TN - IOOx.10 = 10% Removal Inlet Trap (g) + Baffie Box TSS - 100x0.73 + (100-73)x0.30 = 81.1% Removai TP - 100x0.79 + (100-79)x0.3 = 85.3% Removal TN - 100X.79 = 79% Removai All removal values are from "Guide For Best Management Praclice ** From Creech Engineers study "Pollutant Removal Testing For a Suntree Teclinologies Grate Inlet SIdmmer Box", 2001 ***From visual observation by Brevard County staff Tables Proposed Pollutant Loading Basin BMP Type BMP Removai Efficiency From New BMPs {%) Pollutant Load Reduction From BMPs (kg/year) Proposed Pollutant Loading (kgAyear) TSS TP TN TSS TP TN TSS TP TN 2A swale -^ inlet trap (g) -^ tjaffle t>ox 98.9 91.9 84.2 69.38 0.39 8.32 0.77 0.03 1.56 2B swale+ iriet trap (g) + t>afne box 98.9 91.9 84.2 8.64 0.05 1.04 0.10 0.00 0.19 2C dry pond + inlet trap (g) + baffle box 99.2 94.3 98.1 5.81 0.03 0.81 0.05 0.00 0.02 2D dry pond + iniet trap (g) -<• baffle box 99.2 94.3 9ai 10.93 0.06 1.52 ao9 0.00 0.03 2E dry pond + inlet trap (g) + baffle box 99.2 94.3 98.1 19.83 0.11 2.76 0.16 0.01 0.05 2F swale -•• inlet trap (g) baffle box 98.9 91.9 84.2 14.81 0.08 1.77 0.16 0.01 0.33 2G dry pond ••- inlet trap (g) + t>afne box 99.2 94.3 98.1 5.65 0.03 0.79 0.05 0.00 0.02 2H dry pond + inlet trap (g) + baffle bm 99.2 94.3 98.1 9.73 0.06 1.35 0.08 0.00 0.03 21 smfalte-*- intet trap (g) + baffle t>ox 96.9 91.9 84.2 0.60 0.00 0.07 0.01 0.00 0.01 2J inlet trap (g) + baffle box 81.1 85.3 79 4.93 0.03 0.68 1.15 0-01 0.18 2K inlet traf) (g) -•- t>afne bm 81.1 85.3 79 3.51 0.02 0.48 0.82 0.00 0.13 2L inlet trap (g) + t>afne box 81.1 85.3 79 ZIO 0.01 0J29 0.49 0.00 0.08 3A ipiei trap (g) -^ t>afRe box 81.1 85.3 79 99.64 1.11 8.10 23.22 0-19 2.15 38 inlet trap (g) baffle box 81.1 85.3 79 137.40 1.53 11.17 32.02 0.26 2.97 3C dry pond -•• inlet trap (g) + baffle box 99.2 94.3 98.1 1367.83 2.46 20.43 11.03 0.15 0.40 4 inlet iiap (g) + baffle box 81.1 85.3 79 544.99 21.25 221.46 127.01 3.66 58.87 5A inlet trap (c) + baffle box 84 37 10 278.03 1.30 276 52.96 2.21 24-85 5B ini^ trap (c) + t>afne t>ox 84 37 10 406.21 1.89 4.03 77.37 3.23 36.31 5C inlet trap (c) + b^e box 84 37 10 126.29 0.59 1.25 24.06 1.00 11.29 Total 2305.77 27.24 281.03 197.19 4.34 67.01 Table 4 Net Pollutant Removals TSS (kg/yr) TP (kg/yr) TN(kg/yr) Predevelopment 3015.78 35.13 380.83 Postdevelopment 630.97 21.95 289.15 Net Reduction 2384.81 (79%) 13.18(37.52%) 91.68(24.07%) Summary The days of solving flooding problems in communities with simple ditch and pipe solutions have disappeared. Environmental concems now dictate that stormwater treatment techniques be integrated into these flood relief projects. By addmg water quality components to water quantity projects, communities can help achieve poUution remediation goals being estabUshed for NPDES, TMDL, and PLRG programs. Retrofitting existing stormwater systems to provide water quahty treatment is more complicated, expensive, and time consuming than traditional stormwater designs for new development. The scarcity of available land and numerous existmg utilities m older built out areas will tax an engmeer's imagination to provide ixmovative BMPs m these locations. An carefiilly planned treatment train was designed consisting of swales, ponds, berms, baffle boxes, and inlet traps to provide overaU stonnwater poUution reduction. In order to address stormwater poUution concerns, treatment mitigation was designed in offsite drarnage basms. The poUutant loadmgs and removals were calculated using a simple but effective spreadsheet analysis incorporating the latest in BMP efficiency studies. WhUe complicated stormwater modeling software can be used for pollutant analysis, this type of modeling is more cost effective on large basin studies than small basins and individual projects. The poUutant removal calculations showed an annual net reduction of 79% for TSS, 37% for Total Phosphorus, and 24% for Total Niti-ogen in the Oak Street basin despite the creation of a new stormdrain system for a landlocked area. As this project demonstrates, there are typically numerous stakeholders that need to be brought into the project early in the process and kept m flie process throughout the life of the project. Many meetii^s were held with city, county, and state officials, homeowners associations, schools, soccer clubs, churches, and utility companies. All it takes is one uncooperative stakeholder to set back or kUl a project, as was demonsti-ated with the church backing out of flie land acquisition process after many verbal indications of approvaL Using creative parhierships with other entities and agencies allowed the development ofa unique sfi-ategy to solve flooding at several locations m the project area. References ASCE - "Guide For Best Management Practice Selection m Urban Developed Areas" 2001 Gordon England, P.E. "PoUutant Removal Testing For a Suntree Technologies Grate Inlet Skimmer Box", 2001 Harvey Harper, Ph. D, P.E., "Stormwater Loading Rate Parameters for Central and South Florida", 1994 POLLUTANT REMOVAL TESTING FOR A SUNTREE TECHNOLOGIES GRATE INLET SKIMMER BOX Prepared for Suntree Technologies, Inc. November 2001 CEI Project #21121.00 Prepared By: 11-I'l'li mmm mQimm, IIMC. c^¥fly^AT(ioM :. • esvi€Bi!i?-^eERiaD 4450 W. Eau GaUie Blvd., Ste. 232 Melboume, FL 32934 (321)255-5434 TABLE OF CONTENTS PAGE Background 1 Methodology 2 Results 2 Table 1 - Sediment Sieve Analysis P Conclusions 3 APPENDIXA > Site Photos APPENDIX B > Universal Engineering Sciences Grate inlet Skimmer Box Evaluation Report Pollutant Removal Testing for a Suntree Technologies Grate Inlet Skimmer Box by Creech Engineers, Inc. November 2001 With special thanks to Joanie Regan ofthe Cocoa Beach Stormwater Utility Background; Over the last several years, a number of BMPs have been developed to provide stormwater treattnent by trapping poUutants and debris in inlets. Inlet trap BMPs are quasi source controls, being ine^qiensive, requiring no roadway constniction or utiUty relocation, and keeping poUutants out of the water bodies, ratha: dian trying to remove the poUutants from the water once it is contaminated. Suntree Technokigies, of C^ Canaveral, Florida commissioned Creech Engineers, Inc. and Universal Ei^ineering to perform testing on a Grate Inlet Skimmer Box (GISB) to detenmne its poUutant removal effectiveness for sediment and grass clq)pings. The testing was perfonned on September 26, 2001. Attached are photogrs^hs from the test and the acconpanying report by Universal Engineering Sciences. The GISB is designed to trap sediment, grass, leaves, orgame debris, floating trash, ai^ Itydrocarbons as they enter a grated infet, thereby preventing these poUutants from entering the stormdrain system where they wouM cause detrimental in^ts on downstream waterbodies. The GISB is a 3/16" thick fiberglass devfce custom made to fit most types of grated inlets. The overflow capacity ofthe GISB is designed to be greater than the curb grate capacity, thereby insuring that there wifl be no toss of hydrauUc capacity due to the devke being inside the inlet. The bottom ofthe GISB is designed to be above any pipes entering or leaving the inlet so that flow thiough the inlet is not blocked. Water flowing through the grate first encounters a I^drocarbon absorbing ceUulose. This boom also serves to trap large debris between the boom and the body ofthe GISB. At the bottom of the trap are a sertos of stainless steel filter screens covering 3.5 inch wide cutouts in the fiberglass body. These screens trap debris whfle aUowing water to pass through the bottom of the body and out to the storm drain system. The screens in the floor and first vertkjal row of the GISB are fine mesh. The second vertfcal row of screens are medium mesh and the highest row are coarse mesL On the outside ofthe cutouts the screens are backed by stainless diamond plate to provide sapport to the screens siiKie heavy loads of debris buiW iq) in the box. Ifthe flow rate through the inlet exceeds the capacity of the fifter screens there is another row of overflow holes cut out with no screens. These overflow holes aUow water to pass through the GISB even if it becomes fiiU of debris. The level of the holes is above the bottom ofthe top tray, enabling the tray to act as a skimmer to prevent floating ttash fiom escaping through the overflow holes. About halfway down the box is a diffuser plate to minimize resuspension of trapped sediment. Inlet traps such as these are generaUy designed to capture hydrocarbons, sediment, and floating debris. There is generaUy a large buUd up of grass, leaves, and yard debris in the GISBs; which represent a source of nutrients, which do not enter the waterbodies. Royal and England, 1999, determined that leaves and grass leach most of their nuttients into the water within 24-72 hours after being submerged in water. GISBs are designed to keep capttired debris in a dry state, off the bottom ofthe inlet, tiius preventing phosphates and nittBtes from leaching into the stormdrain system, vrfiere much more expensive BMPs would be required to remove the dissolved nutrients. Methodology; A test was designed to simulate a rainfeU event and measure the abUity of a GISB to remove sediment and grass leaves from a typical grated inlet at 600 South Brevard Ave., Cocoa Beach, Florida. Joanie Regan of the Cocoa Beach Stormwater UtUity provided this location for the test, as weU as a water ttuck to flush the curbs. Universal Engineering Sciences periformed tiie testing, measurements, and sediment sampUng. Creech Engineering, Inc. observed the testing. The City has instaUed a number of tiiese devices and Joanie indicated tiiis location was typical ofa nonnal instaUatioa The grate, curb, and gutter around and upstteam oftiie inlet were brushed and washed clean. A new, clean GISB was placed inside tiie inlet. A water tiuck witii a pmnp discharged reuse water into tiie gutter upstteam ofthe inlet at a rate of 500 gpm (1.1 cfe). Dry, green St. Augustine grass cUppings from a yard tiiat had been recently fertUized were slowly fed into tiie gutter and flushed into tiie inlet. It was observed tiiat tiie cast iron grate ttapped a significant amount of grass around tiie edges of tiie grate. The grate was removed for aU tests to enable all ofthe grass and sediment to enter tiie box. After aU ofa measured satap]e of grass had been washed into tiie inlet, tiie grass was removed from tiie inlet, dried, and weighed. Samples of grass before and after tiie test were sent to PC&B Laboratories in Oviedo, Ftorida. Laboratory analysis was performed to detennine the Total Phosphorus and TKN content oftiie grass. Next, a sediment sample was washed tiirough tiie GISB using tiie same metiiodotogy. Umversal Engineering ran a sieve size analy^ using ASTM D 422 procedures, before and after tiie test. The sediment was classified as a poorfy graded gravefy sand. The sediment was removed fiom the GISB, dried, and weigted. Results; During both of tiie tests, aU water leaving tiie GISB passed tiirough tiie filter screens. The water levels in tiie box onfy rose a few inches, witii no water passing tiirough tiw overflow holes or coarse screens, even tiiough tiie bottom screens were completety covered witii grass or sediment. There was a smaU amount of grass and sediment tiiat passed between tiie box and tiie concrete waUs oftiie inlet because oftiie uneven edges of the inlet. This situation is feirly common in most inlets due to loose tolerances in constmction techniques. In the grass test, 6.58 lbs. of grass were washed into tiie inlet and 5.22 lbs. were capttired, resulting in 1.36 lbs. of grass passing tiirough the GISB. This represents a removal efBciency of 79.3%. The pretest grass sample had a Total Phosphorus content of 950 mg/kg and a TKN content of 510 mg/kg. The grass sample removed from the GISB had a Total Phosphoms content of2,270 mg/kg and TKN content of905 mg/kg. The sediment test was a Uttle more complex. The initial results ^owed that ofthe 57.87 lbs. of sediment inttoduced to the GISB, 42.41 Ibs. Avere captured, giving a total mass removal efBciency of 73.3%. Umversal Engineering indicates that the Pretest sanpto had 10.7 % gravel, 88.0% sand, and 1.4% clay. The Post test sampfe had 25.9% gravel, 14.7% sand, and 1.7% clay. Gravel is considered to be parttoles No.4 and larger. SUt and clay is defined as particles passing the No. 200 sieve. Table 1 Sediment Sieve Anafysis Sieve Size 3/8" No.4 No.10 No.40 No. 60 No. 100 No. 200 PreTest % Passing 94.3 89.3 81.8 64.8 50.3 25.5 1.4 Post Test % Passmg 88.8 74.1 62.6 44.2 31.8 14.7 1.7 Difference 5.5 15.2 19.2 20.6 18.5 10.8 -0.3 Conclusions; At tiie flow rate tested, tbe GISB removed 79.3% ofthe grass clqjpings washed into it. The abUity of tte GISB to remove grass during large flows yvbea water passes through tiie bypass holes was not tested. In Florida, 90% oftiie storms are low rainfeU events of 1" or less, resulting in low flows simUar to tiie test conditions. This makes tiie GISB a very effective BMP for Low flow events. It is unknown how effectively the GISB works in large storm events. By keeping grass and other trapped organic debris in a dry state, the nuttients in the debris do not leach out and become dissohred nitrates ami phosphates. The GISB is a very effective BMP for preventing nuttients from orgame debris from entering waterbodies. The significant increase in nutrient concentt^on after the test is probably attributed to the use of wastewater reuse water during tiie test. The grass matted several inches thick m the bottom of tiie box. This tiiick layer could have acted as a filter to remove nutrients from the water source. At the flow rate of 1.1 cfe, tiie GISB had a sediment removal efBciency of 73.3%. As would be expected, most of the tr^ped sediment was gravel and sand, witii Uttle fine material coUected. The GISB has sediment removal capabflities rivaUng those found in many sttucttiral BMPs, at a fi:action of the cost, and witiiout disraptive constiuction. UNIVERSAL ENGINEERING SCIENCES Ca«ulbnts In: Gecieciviical Engneering • Efwinx^^ Constmciion Maierials tesling • Thceshold Inspeclion 620 Brevard Avenue • Rockledge, Florida 32955 (321)638-0808 Fax (321) 638-0978 . ' November 2, 2001 Mr. Gordon England, P.E. ^ Creech Engineers, Inc. 4450 West Eau Gallie Boulevard Melbourne, Florida 32934 Reference: Grate Inlet Skimmer Box Evaluation Northwest Comer of South Brevard Avenue and South 8** Street Cocoa Beach, Brevard County, Florida Universal Project No. 33186-002-01 Universal Report No. 51479 Dear Mr. England: Universal Engineering Sciences, Inc. (Universal) has completed an evaluation of a Grate Inlet Skimmer Box (GISB) in accordance with Universal Proposal No. P01-0781. The evaluation was conducted to document the pollutant removal effectiveness at the above-referenced site. A Location Map, Site Map and Site Photographs are presented as Attachments 1. 2 and 3, respectively. Sediment Testing Universal supplied the sediment sample for the GISB evaluation. The sediment sample consisted of fine sands, coarse grain sands with crushed shells, and gravel. A gradation analysis of the sediment sample (S-1) was performed, prior to GISB perfomiance testing. The percentages of soil grains, by weight, retained on each sieve were measured and a grain size distribution curve generated, to detennine the textural nature of the sample and provide a control (baseline) prior to fieldwork. A sediment sample of known weight (57.87 Ibs.) was placed on the pavement upstream of the GISB and washed into the GISB with a portable water source simulating a storm event. The captured sediment was then removed firom the GISB. dried and weighed. The captured sediment weighed 42.41 Ibs. resulting in a loss of 15.46 Ibs. from Uie GISB testing. A gradation analysis of the captured sediment sample (S-2) was performed. Universal completed particle size analyses on the two representative sediment samples (S-1 and S-2). The samples were tested according to the procedures for mechanical sieving of ASTM D 422 (Standard Method for Particle Size Analysis of Soils). In part, ASTM D 422 requires passing each specimen over a standard set of nested sieves (% inch. No. 4. No. 10. No. 40, No. 60, No. 100, No. 200). The percentage of the soil grains retained on each sieve size are detemiined to provide the grain size distribution of the sample. The distribution determines the textural nature of the soil sample and aids in evaluating its engineering characteristics. Mr. Gordon England November 2, 2001 Page 2 Project No. 33186-002-01 Report No. 51479 S-1 consisted of 10.7 percent gravel (grain size larger than 4.75 mm), 88.0 percent sand (grain size between 0.075 mm and 4.75 mm), and 1.4 percent fines (grain size less than 0.075 mm). S-2 consisted of 25.9 percent gravel, 72.4 percent sand, and 1.7 percent fines. The grain size distribution curves are presented as Attachment 4. According to the Unified Soil Classification System (USCS), S-1 and S-2 were classified as pooriy-graded gravely sand [SP]. Based on the gradation analysis, the major portion of the lost sediment was the fine sand component. Grass Clippings Test The grass clippings were supplied by Suntree Technologies. A grab sample of grass (G-1) was collected and submitted for laboratory analysis to detennine the TKN (EPA Method 351.2) and Total Phosphoms (EPA Method 365.3) content A grass sample of known weight (6.58 Ibs.) was placed on the pavement upstream of the GISB. The grass clippings were washed Into the GISB in the same manner as the sediment sample. The capUjred grass clippings were then removed from the GISB. dried and weighed. The captured grass clippings weighed 5.22 Ibs. resulting in a loss of 1.36 Ibs. A second grab sample (G-2) was collected from the captured grass clippings and submitted for laboratory analysis to detemnine the removal efficiency for TKN and Total Phosphoms. The samples were shipped to PC&B Laboratories, Inc. in Oviedo, Rorida. Laboratory analysis documented 950 milligrams per Kilogram (mg/Kg) of Total Phosphoms and 510 mg/Kg of TKN ?.^K?^''' analysis documented 2,270 mg/Kg of Total Phosphorus and 905 mg/Kg of TKN for G-2. Laboratory Analytical Results and Chain-of-Custody Documentation are presented as Attachment 5. Universal appreciates the opportunity to provide environmental services as part of your project team. Should you have any questions, please do not hesitate to contact the undersigned at (321) 638-0808. Respectfully submitted. Universal Engineering Sciences, Inc. James E. Adams^— Staff Scientist II (2) Addressee Attachments Robert Alan Speed Regional Manager Rockledge Branch Office Attachment 1 Attachment 2 Attachment 3 Attachment 4 Attachment 5 Site Location Map Site Map Site Photographs * Soil Gradation Curves Laboratory Analytical Results and Chain-of-Custody Documentation \\uesrock\data\reports\envrpts\env2001\51479 gisb evaluation reportdoc ATTACHMENT 1 SITE LOCATION MAP • % .r-i- ;• , Mil" Grate Inlet Skimmer Box Evaluation South Brevard Boulevard Cocoa Beach, Brevard County, Rorida UNIVERSAL SITE LOCATION MAP J ADAMS SCQX^ " BATE; CMECKEOSY: JAOAIMS 103001 AS SHOWN PHuJbUf ND^ ~ HtMOHINO: 51479 PA6ENIJ: ATTACHMENT 1 ATTACHMENT 2 SITE MAP RESIDENTIAL CONDOMINIUMS CONDOMINIUM DRIVEWAY t LANDSCAPED ^ MEDIUM J RESIDENTIAL CONDOMINIUMS I UJ 9 w UJ 9 to Ul Z UJ i Q CH $ Ui cr: CQ X H o CO RESIDENTIAL CONCRETE DRAINAGE S\NALE SOUTH 8™ STREET RESIDENTIAL Grate Inlet Skimmer Box Evaluation (/M South Brevard Boulevard ^ Cocoa Beach, Brevard County, Florida ^ UNIVERSAL ENG»EER»IG SCIENCES SITE MAP UNIVERSAL ENG»EER»IG SCIENCES J. AOAMS DKTE: 10/30/01 CHECXBIBY: J. ADAMS MTE 10/30/01 SCALE; ^.—fcns- PROJECTNO: 331fl6^X)?-ni REPORT NO: 51479 PAGE NO: _-ArrACHMENT2 ATTACHMENTS SITE PHOTOGRAPHS Grate Inlet at 600 South Brevard Avenue, Cocoa Beach Grate Inlet Skimmer Box Features Rorida Type C Inlet Storm Boom Zip Tie Skimmer Tray Deflection Shield Flange is reinforced with knitted 1808 ±45° biaxial fiberglass ttEECH m^i I'f PoUutant Removal Testing for a Sunttee Technotogies Grate Inlet Skimmer Box SITE PHOTOGRAPHS Sediment Entering GISB Sedhnent Trapped in GISB cm 'I^'l\i37 •ERS. !MC. E?\?G8I^JEERED PoUutant Removal Testing for a Suntree Technologies Grate Inlet Skimmer Box SITE PHOTOGRAPHS GISB Inserted into Inlet WiXSHITi'g Grass Testing PoUutant Removal Testing for a Simttee Technologies Grate Inlet Skimmer Box SITE PHOTOGRAPHS • 1 '^.ra^ Grass CUppings Entering GISB SIP Sediment Testing tHEECH EiiWIERS.. IMC. Pollutant Removal Testing for a Suntree Technologies Grate Met Skimmer Box SITE PHOTOGRAPHS Photo No. 1: (Pre-Test) Installation of new GISB Photo No. 2: Start of the grass clippings test Grate Inlet Skimmer Box Evaluation NWC of South Brevard Avenue and South 8'" Street Cocoa Beach, Brevard County. Florida SITE PHOTOGR/\PHS N/A ISCHTET N/A tWME: loraowi wmiUiHU 33186-024)1 N/A 61479 lorao/oi PAGE1 Photo No. 3: Stonm simulation for the grass dip test Photo No. 4: Completion of grass clippings test. GISB removed for cleaning. sm Grate Inlet Skimmer Box Evaluation NWC of South Brevard Avenue and South B'" Street Cocoa Beach, Brevard County, Ftorida SfTE PHOTOGRAPHS N/A DAIE: N/A lorsiVDi 3CCKa>BY: 33186-02-01 N/A 51479 10/30/01 PAGE 2 Photo No. 5: Start of sediment test. Photo No. 6: Sediment test in progress. Grate Intot Skimmer Box Evaluation NWC of South Brevard Avenue and South 8*" Street Cocoa Beach. Brevard County, Florida SITE PHOTOGRAPHS N/A DATE: N/A 1IV3D/01 3CCKEDBY: WLUkUINU 3318602-01 N/A JAI6: ^TORTTBr 61479 10/30/D1 PAGE 3 Photo No. 7: Completion of sediment test, Photo No. 8: Stomiwater catch basin after testing Grate Intet Skimmer Box Evaluation NWC of South Brevard Avenue and South 8'" Street SITE PHOTOGR/\PHS N/A 10/30/01 31ECKE0BY: N/A JftTE: 10/30/01 N/A 33186-02-01 TPtmm •— 51479 ^IsfcNU ~"—'— PAGE 4 ATTACHMENT 4 SOIL GRADATION CURVES U.S. SIEVE OPENING IN INCHES 6 1 U.S. SIEVE NUMBERS 14* TT HYDROMETER GRAIN SIZE IN MIUIMETERS 0.01 0.001 1 COBBLES GRAVEL 1 SAND SILT OR CLAY 1 COBBLES coarse | fme 1 coarse | medium | tme SILT OR CLAY Specimen Identification Classification MC% LL PL PI Cc Cu SI 0.79 3.7 SEDIMENT 1 Spedmen Identification D100 D60 D30 DIO %Gravel %Sand %Silt %Clay • SI 12.50 0.36 0.164 0.0961 10.7 88.0 1.4 3/4" 3/8" NO.4 NO. 10 NO.40 NO. 60 NO. 100 NO. 200 94.3 89.3 81.8 64.8 50.3 25.5 1.4 Client: CREECH ENGINEERING 4450 W. EAU GALUE BOULEVARD MELBOURNE FLORIDA 32934 Project: GRATE INLET SKIMMER BOX EVALUATION BREVARD COUNTY, FLORIDA Client No: Report No: Date: 33186-002-01 51479 10/9/01 SOIL GRADATION CURVES Universal Engineering Sciences. Inc. 100 95 90 85 80 75 70 65 60 55 50 U.S. SIEVE OPENING IN INCHES 6 rTTi * 3 2 1.5 ^ a/4 M ' 4 U.S. SIEVE hAJMBERS 14* rr « e'" 14*20 » 40 » TO'^I* HYDROMETER 200 rr R 45 B Y 40 IW35 G^ " 25 20 15 10 5 0 10 GRAIN SIZE IN MILLIMETERS SAND 0.1 0.01 0.001 COBBLES GRAVEL Specimen Identification Classification LL PL PI Cc Cu 1 • S2 0.30 13.7 1 SEDIMENT 2 Specimen Identification D100 D60 D30 DIO %Gra\ rel % Sand %Sit I >Clay 1 • S2 12.50 1.61 0.237 0.1169 25.9 72.4 1.7 1 3/4" 3/8" NO.4 NO. 10 NO.40 NO. 60 NO. 100 NO. 200 88.0 74.1 62.6 44.2 31.8 14.7 1.7 Client CREECH ENGINEERING 4450 W. EAU GALUE BOULEVARD MELBOURNE FLORIDA 32934 Project GRATE INLET SKIMMER BOX EVALUATION BREVARD COUNTY, FLORIDA Client No: Report No: Date: 33186-002-01 51479 10/9/01 SOiL GRADATION CURVES Unhrersal Enalneerina Sciences. Inr ATTACHMENTS LABORATORY ANALYTICAL RESULTS AND CHAIN-OF-CUSTODY DOCUMENTATION PC&B Environmental Laboratories, Inc. 210 Park Road, Oviedo, Florida 32765 Phone: 407-359-7194 Fax: 407-359-7197 Client: Universal Engineering Sciences 820 Brevard Avenue Rockledge. FL 32955- Contact: James Adams Phone: (321) 638-0808 Laboratory Reference Number: 201090199 Project Name : Inlet Skimmer Box Evaluation Project Number: Laboratory ID Matrix Client ID 201090199-1 Solid G-1 Chain ofCustody: 24025 Status Date/Time Sampled RUN 09/26/2001 14:20 Number 1 Parameter Description EPA 6010 EPA 9200/351.2 Phosphorus by IC/VP Total Nitrogen PC&B Environmental Laboratories, Inc. 210 Park Road Oviedo, FL 32765-8801 407-359-7194 - (FAX) 407-359-7197 Case Narrative James Adams Universal Engineering Sciences 820 Brevand Avenue Rockledge, FL 32955- CASE NARRATIVE for Wori< Order: 201090199 Project Number: Project Name: Inlet Skimmer Box Evaluation This Case Narrative is a summary of events and/or problems encountered with this Work Ordar Analysis for TKN was perfonned by Environmental Science Corporation (E87487) Definilion of Fbos DL = No surrogate result due to dOubon or matrix interfeience ~ ~ J = Estimated Value, value not accurate. L = Ofr-scaie liigh. Actual vaiue is grealer ttian value given Q = Sample analyzed beyond the accepted hohfing time T = Value reported is less than the laboratory method detection HmR. V = Analyte was bo«h detected in the method blank and sample PC4B Environmental Laboratories Inc Rannrt ..t i. • _ 210 Paric Road ™nes, inc. Reportof Analysis CL'^NT NAME: Universal Engineering Sciences Oviedo. FL 32765-8801 PROJECT NAME: Inlet Skimmer Box Evaluation PHONE: 407-359-7194 PROJECT NUMBER: Lab Reference Number 201090199-1 DATE RECEIVFO nq/?R/?nni CHent Sample ID Q_., Datemme Sampled 09/26C001 Sample Matrix (as Received^ EPA 6010 Phosphorus, Total mg/kg Iso ' • . EPA 9200/351.2 Total Nitrogen mg/kg 510 U ^Undetected. The value preceedlng the Vte the RLfc. the ^ P>>-..|ts reported on a W..W».MK... rutKUompUAPP#900134G - FDOH Cert.I.cat.on # E83239 '' Reviewed by: VjL-TY^ Quality Control Report for Spike Analysis INORGANICS e^iir. Lower Upper . *P"* Sample Spike Percent Control Control ass^^ ^^^..^ .S^'^'^'^"^^'^^-^^^^-^ ^6 0 Park R35CI, Oviedo, FL 32765 7-359-7194 (FAX) 407-359-7197 Chain of Custodv| Work Order Date 01 "^9 Page of WHITE: Ptetmet mim vmi • nu.. ?.rai:^7iy'°^^giT'_JgjTain oftustodv Work Order: ak)li6^>i WHITE noiwtFM* vSTrwEiTC PC&B Environmental Laboratories Inc '210 Pai* Road Oviedo, FL 32765-8801 PHONE: 407-359-7194 Reportof Analysis Lab Reference Number Client Sample ID Date/Time Sampled Sample Matrix fas Received) 201100168-1 G-2 10/10/2001 0:00: Solkt CLIENT NAME: Universal Engineering Sciences PROJECTNAME: PROJECT NUMBER: DATE RECEIVED: 10/180001 EPA 6010 EPA 9200/351.2 Phosphorus, Total Total Nitrogen mg/kg mg/kg 2270 905 U = Undetected. The value preceedinc '^^ Y.^.}^^ ^^^""^ ^ported on a W^t w^ir^hf basis hutK CompQAPP # 900134G - FDOH Certification # E83239 Reviewed by; PC&B Environmental Laboratories, Inc. 210 Park Road, Oviedo. Florida 32765 Phone: 407-359-7194 Fax: 407-359-7197 Client: Universal Engineering Sdences 820 Brevard Avenue Rockledge, FL 32955- Laboratory Reference Number: 201100168 Project Name: Project Number: Latwratory ID Matrix Client ID Contact: Bob Speed Phone: (321) 638-0808 Chain of Custody: 20344 Status Date/Ttme Sampled 201100168-1 Solid G-2 RUN 10/10/2001 Number Parameter Descriptfon EPA 6010 EPA 9200/351.2 Phosphorus by ICAP Total Nitrogen Quality Control Report for Spike Analysis INORGANICS Lower Upper SpBte Sample Spike Percent Control Control f^y^, Rest* ResuK Recovery Limit Limit IMhod: B>A eOlOA QC Balch: 2aj110RC107 gmge»^^ IMe f^: lOnSQOOl An.1: l6na/^1 Analyst GG Phosphorus. Total 20.0 mgfltg 178.0 199.0 105 70 120 SHE EVALUATION OF SUNTREE TECHNOLOGIES, INC. GRATE INLET SKIMMER BOXES FOR DEBRIS, SEDIMENT, AND OIL & GREASE REMOVAL Reedy Creelc ]mpn>Yemeiit District Planning & Engineering Department Eddie Snell, Compliance Specialist StmnwatBT is now recogmzed as the leading source of pdhitioo to our lanainii^ natural wata- bodies in Ae United States. Devdkipoient and udxmizirtion have lonoved mo^ of tiie natural filtratioo and sedimoit tr^jping systems provided by tiie mvircMimOTt Cunent development must address tiiis need through die implemeoitation of stonnwater treatments systraas in tin fHcyect deagn. Most of tiiese systons pofinm reasonaUy weU, if ptapesfy designed, constiiKtBd, and mamtaiaed. Retrofit of oldo" uiban areas laddng tiiese modem stCHmwater systems is a continually expensive challaige. The Downtown Disney complex, fonnerly tiie Lake Buena Vista Shopping Village has sevoal drainage basins witii 1970's stunnwito systraos. These older systems disdunge directfy mto tiie adjacent drarnage canal vntii no pollutant treatment OVCT time tiie accumulation of sediments, nutrients, intraisive development, and recreational/entertainment pressures are c(»itributing to water quality d^radation. Whenevo- new devdopment or redevelqnnent occurs, tiie stormwata- system is brought to currrait code/permit requirements. In flte interim, several areas are in need for r^id, effective, and economical improvonent in tiie quality of its stonnwater discharge. Suntree Tedinologies InccHpcxalBd, located in Cape Canavoal, FL, manu&ctures stonnwater grate inlet skimmer boxes. They are made of a high quality fiberglass tame, witii stainless steel filta- scre^ backed by heavy-duty aluminum grating. Each unit is custom made to accommodate various inlet sizes. A hydrocarbon absorption boom is attached to tiie top of tiie skimmer box for petroleum, oil, and grease removal. These devices fit below tiie grate and catch sediment, debris, and petroleums, oils & greases. Clean-out, maintenance, and performance reporting is provided by Suntree on a scheduled basis. Picture of Grate Inlet Skimmer Box The Reedy Creek Improvement District (RCID) selected six (6) test sites in tiie Lake Buena Vista area to evaluate tiie performance of tiiese units. One unit was placed in a cuii) inlet alcmg Hotel Plaza Boulevard to tr^ landscape leaf litter, sediment, and oil & grease fi-om a high use roadway. Three (3) units were placed in tiie backstage service area of die Rain Forest Cafe. Two (2) units were placed in the backstage service area of tiie McDonald's restaurant and Legos merdiandise shop. After several field meetings, during which Suntree took extensive measurements, photos, and otiier documentation of each stormwater drain, tiie Grate Inlet Skimmer Boxes were manufactured and delivered for installatim. All units were installed witiiout mishap approximately two weeks before tiie 1999 Christmas holiday season. The target time period for particle catchment was one montii. Mr. Hemy and Tom Happel, Suntree Technologies, visited each site several times during tiie montii to ensure tiiat debris would not fill tiie units too soon. On January 25,2000, Suntree serviced flie six units. At each site, the material captured in tiie skimmer boxes was removed, measured, weighed, visually identified, photographed, and recorded. Some units were sligjitiy field modified for optimum performance. All units poformed as expected removii^ on average, 20 poimds of ddxis from eadi of the sbc dtes. The c(»npositi(n of debris varied ccndderably. The Hotd Plaza (roadw^) site was 90% leaf litter and 10% sediment ITie Rain Fwest Cafe sites ran in opposition as you got close to tiie lake. First inlet was about 50% leaf litter and cigarette butts and 50% sediment The middle inlet was 60 %sedim«it and 30 % leaf litter (10% miscellaneous). The inlet closest to tiie lake was 95% sediment and 5% leaf litter. The two sites at tiie McDonalds/Legos area were similar to each otiier. The site closest to tiie lake was 95% sediment and 5% leaf litter. The site closest to tiie entrance gate was 98% litter sediment and 2% leaf litier. This composition is indicative of tiie human activities and drainage flow pattems of tiiat site. Backstage areas in tiie Walt Disn^ Worid Resot receive an artifidal rain event each night during cleaning operations. This washes a continual flow over tiie impervious site, washing all materials into tiie stonnwater system. Municipalities in Brevard, Volusia and Dade counties have successfiilfy used inlet skimmers in Florida. RCID partnraied witii Walt Disney Imagineering (WDI) Research and Development to coonlinate some basic chemical sampling for pollutant removal efBciency detennination. Mr. Craig Duxbury, WDI, provided technical support and guidance for tiiis. An ingenious^ ample device was fabricated by Suntree to allow sampling of tiie First Flush of water going into tiie units and ultimately coming out of tiie skimmer boxes. Collected samples were processed and analyzed by tiie RCID Environmental Services Laboratory. Analysis parameter were: Ammonia, Chemical Oxygen Demand, Fecal Colifomi (MPN), Nitrite and Nitrate, Total Kjeldahl Nitrogen, Oil and Grease, Total Phosphate, Suspended Solids, and Metals. Analysis results are presented in tiie following table: Pollutant ANALYSIS LOCATION LAB NO. VALUE UNITS SAM-DATE Chanoe Ammonia, Salicylate RF-IN 1646 0.38 mg/1 09-FebOO 0.14 Ammonia, Salicylate RFOUT 1646 0.23 mg/1 09-Feb-OO Ammonia, Salicylate RF-OUT-I 1646 0.25 mg/1 09-Feb-OO Chemical Oxygen Demand RF-IN 1646 2670 mg/1 09-Feb-OO 1036 Chemical Oxygen Demand RF-OUT 1646 1780 mg/1 09-Feb-OO Chemical Oxygen Demand RF-OUT-I 1646 1490 mg/1 09-Feb-OO Coliform, Fecal MPN RF-IN 1646 1600 #100 ml 09-Feb^ •93400 Conform, Fecal MPN RFOUT 1646 160,000 #100 ml 09-Feb-OO Conform, Fecal MPN RF-OUT-I 1646 30,000 #100 ml 09-Feb-OO Nitrate and Nitrite RF-IN 1646 0.06 mg/1 09-FebOO 0.035 Nitrate and Nitrite RF-OUT 1646 0.04 IT^ 09-Feb-OO Nitrate and Nitrite RF-OUT-1 1646 0.01 mg/1 09-Feb-OO Nitrogen, Total l^eldahl RF-IN 1646 24.3 mg/1 09-Feb^ 13.55 Nitrogen, Total Kjeldahl RF-OUT 1646 10.4 mg/1 09-Feb^)0 Nitrogen, Total Kjeldahl RF-OUT-l 1646 11.1 mg/1 09-Feb^ Oil and Orease RF-IN 1646 526 mg/1 09-Fel)-00 283 % Chanae 37% Pollutant removal efficiencies averaged about 50% for all parameters tested. The minimal removal was 3?/o for Ammonia and the maximum ranoval was 74% for Suqjended Solids. Colifomi bacteria were not effectively removed by Ae skimmer boxes, althot^ they are not designed to provide water disinfection. Oil and Grease are a food source for bacteria and reduction of this pollutant should provide some effect on bacterial numbers. Pollutant Removal Efficiency 80% 70% 60% c 0 50% 0 ' o 5 40% m ^ 30% 20% 10% 0% % Change Parameter I Ammonia, Salicylate I Chemical Oxygen Demand • NRrale and Nitrite • Nitrogen, Total Kjeldahl • Oil and Grease • Phos|4iate, Total • Solids, Suspender