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HomeMy WebLinkAboutPIP 05-25x1A; HCP Bressi Ranch PA 2; Planned Industrial Permit (PIP) (4)I """"" BRESS/ RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PIAN OWNER'S CERTIFICATION STORM WATER MANAGEMENT PLAN (SWMP) Bressi Ranch Planning Area 2 October 2011 This Storm Water Management Plan has been prepared for the City of Carlsbad for the Bressi Ranch Planning Area 2 project at the southeasterly corner of the intersection of El Camino Real and Gateway Road in Carlsbad, CA, by Fuscoe Engineering, Inc. It is intended to comply with the requirements of the January 14, 2011 City of San Carlsbad's Storm Water Standards Manual and the City of Carlsbad Municipal Code Chapter 1 5.12 which require a Storm Water Management Plan be prepared for all Priority Development Projects. The undersigned, while it owns the subject property, is responsible for the implementation of the provisions of this plan. Once the undersigned transfers its interest in the property, its successors-in-interest shall bear the aforementioned responsibility to implement this SWMP. A signed copy of this document shall be made available by the project's owner for the subject site in perpetuity. Signature Title Name Company Address Phone Date BRESS/ RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PLAN TABLE OF CONTENTS October 201 1 1 .0 INTRODUCTION ...................................................................................................... 1 1 .1 PROJECT DESCRIPTION ........................................................................................... ] 1 .2 PRESENT CONDITION ............................................................................................. 1 1.3 PROPOSED LAND USE, BUILDING, AND PARKING SUMMARY ................................... 2 1 .4 HYDROLOGIC UNIT CONTRIBUTION ...................................................................... 2 2.0 WATER QUALITY ENVIRONMENT .............................................................................. .4 2.1 BENIFICIAL USES ..................................................................................................... 4 2.1.1 INLAND SURFACE WATERS .............................................................................. 5 2.1.2 COASTAL WATERS .......................................................................................... 6 2.1.3 GROUND WATERS .......................................................................................... 6 2.1.4 2010 Section 303(d) List Status ......................................................................... 6 2.2 HYDROLOGY .......................................................................................................... ? 2.3 POTENTIAL POLLUTANTS ....................................................................................... 1 0 2.4 SOIL CHARACTERISTICS ........................................................................................ 13 3.0 CONSTRUCTION PHASE BMPs ................................................................................ 15 4.0 POST CONSTRUCTION BMPs ................................................................................. 16 4.1 LOW-IMPACT DEVELOPMENT DESIGN PRACTICES ................................................. 16 4.2 SOURCE CONTROL BMPs ..................................................................................... 16 4.3 TREATMENT CONTROL BMPS ................................................................................ 20 4.3.1 FLOW THROUGH PLANTERS .......................................................................... 21 4.3.2 PERMEABLE PAVERS ........................................................................................ 22 5.0 MAINTENANCE ...................................................................................................... 24 5.1 PERMEABLE PAVERS ........................................................................................ 25 5.2 FLOW THROUGH PLANTERS .......................................................................... 26 6.0 SUMMARY AND CONCLUSIONS ............................................................................. 28 7.0 APPENDICES .......................................................................................................... 29 Appendix 1 .................................................. Completed City of Carlsbad Form E-34 Appendix 2 .......................................................................................... Project Map Appendix 3 ........................................................................ BMP/Water Quality Plan Appendix 4 .... ... .... . . . . . ................ .... .... .. . ..... . . . .. . . . . . . . . . . . . .. . . ... .. . . Educational Material Appendix 5 ................................................................ Treatment Control BMP Sizing Appendix 6 ........................................................ Treatment Control BMP Fact Sheets Appendix 7 ............................................................... 2010 CWA Section 303(d) List BRESS/ RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PLAN 1 .0 INTRODUCTION October 2011 This Storm Water Management Plan (SWMP) is required per the January 14, 2011 City of San Carlsbad's Storm Water Standards Manual, City of Carlsbad Municipal Code Chapter 15.12, NPDES Order No. 2001-01 and under the Regional Water Quality Control Board Order R9-2007-0001. The purpose of this SWMP is to address the water quality impacts from the Bressi Ranch Planning Area 2 development (herein referred to as the project) and is intended to address potential water quality impacts associated with the project. California Storm Water Quality Association (CASQA} BMPs, as well as those outlined in the Storm Water Standards Manual, will be used to provide a long-term solution to water quality on-site. 1 . 1 PROJECT DESCRIPTION This 23.09± acre project site consists of eight (8) existing, mass-graded, undeveloped lots which will be graded to accommodate the construction of eight (8) new two-story buildings with a parking structure, associated on-grade parking and site improvements. The project site is bordered on the north by Gateway Road, to the east by Alicante Road, to the south by Town Garden Road and west by El Camino Real. The immediate surrounding area is comprised primarily of industrial and commercial uses as well as some single family residential as planned for in the Bressi Ranch master plan. Interstate 5 is approximately 3.5 miles to the west of the project site along Palomar Airport Road. The project site is currently located in the zone designated as P-M, planned industrial. The proposed project is designated as a "Priority Development Project" as described in the City of Carlsbad's Storm Water Standards Questionnaire, Form E-34. The applicable categories of which the project qualifies as "priority" from the Storm Water Standards Questionnaire are listed below: o Commercial -greater than 1-acre. Any development other than heavy industry or residential. Examples: hospitals; laboratories and other medical facilities; educational institutions; recreational facilities; municipal facilities; commercial nurseries; multi-apartment buildings; car wash facilities; mini-malls and other business complexes; shopping malls; hotels; office buildings; public warehouses; automotive dealerships; airfields; and other light industrial foci lities. o Parking lot. Area of 5,000 square feet or more, or with 15 parking spaces, and potentially exposed to urban runoff. o More than 1-acres of disturbance. Project results in the disturbance of 1-acre of land and is considered a Pollutant-generating Development Project. 1 .2 PRESENT CONDITION The site currently does not have any storm drain infrastructure installed on-site, but public storm drain infrastructure is located in the adjacent public rights-of-way along Gateway Road, Town Garden Road and Alicante Road. Storm drain laterals have been installed during the previous mass-grading BRESS/ RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PLAN October 201 1 operation to serve the temporary desilting basins located on site. These storm drain laterals will be used for the new private storm drain systems associated with the project's development. Presently, the site sheet flows to temporary desilting basins located on each lot. The site generally drains to the south and to the east toward the public storm drain infrastructure located in Town Garden Road and Alicante Road. Runoff from the project site enters the public storm drain system through the existing storm drain laterals, and flows to two storm drain outfalls south of the project in an unnamed canyon. The westerly outfall discharges through a concrete energy dissipater and over a rip rap apron. The easterly outfall discharges into a detention basin through a concrete energy dissipater and rip rap apron. The flow continues to the south after the existing detention basin through another concrete energy dissipater and rip rap apron. The two flows confluence at this down gradient point and continue to flow to the south in swales through the future Alga Norte Community Park site. The runoff then crosses under Poinsettia Lane, flows across the La Costa Resort golf course, crosses under Alga Road, continues to flow through the La Costa Resort golf course and enters San Marcos Creek near the intersection of El Camino Real and La Costa Avenue. Near this intersection, San Marcos Creek drains to the west and discharges into Batiquitos Lagoon and ultimately the Pacific Ocean. 1.3 PROPOSED LAND USE, BUILDING, AND PARKING SUMMARY For the proposed project, the construction of eight (8) new two-story buildings with a parking structure, associated on-grade parking and site improvements will occur. ~ 1 .4 HYDROLOGIC UNIT CONTRIBUTION The proposed project is located within the Batiquitos Hydrologic Sub-Area within the San Marcos Hydrologic Area of the Carlsbad Hydrologic Unit. The corresponding number designation is 904.51. According to Project' Clean Water's website, 'The Carlsbad Hydrologic Unit (HU) is approximately 210 square mt1es in area extending from the headwaters above Lake Wolhford in the east to the Pacific Ocean in the west, and from VIsta and Oceanside in the north to Solana Beach, Escondida, and the community of Rancho Santa Fe to the south. The cities of Carlsbad_ San Marcos, and Encinitas are entirely within this HU. There are numerous important surface hydrologic features within the Carlsbad HU including four unique coastal lagoons, three maior creeks, and two large wafer storage reservoirs. The HU contains four maior, roughly parallel hydrologic areas (HAs}. From north to south they are the Buena VIsta (901.2}, the Agua Hedionda (904.3), the Batiquitos (904.5), and the San Eli;o (904.6) HAs. Two smaller HAs, the Lama Alta (904.1) and the Canyon de las Encinas (904.4) are also within the Carlsbad HU. " 'The largest iurisdictions in terms of land area in the Carlsbad HU are the unincorporated San Diego County areas (66 sq. mt1es}, the cities of Carlsbad (39 sq. miles} and San Marcos (24 sq. miles}, and an approximately 2 7 square mile portion of the City of Escondido. The cities of Carlsbad_ San Marcos, and Encinitas are located entirely within the HU. Approximately 48% of the Carlsbad HU is urbanized The dominant land uses are residential (29%/ commercial/industrial (6%}, freeways and - roads (12%), agriculture (12%}, and vacant/undeveloped (32%}." ~- 2 BRESS/ RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PIAN October 201 1 'The Agua Hedionda, Buena Vista, and San Eliia lagoons are experiencing impairments to beneficial uses due to excessive coliform bacteria and sediment loading from upstream sources. These coastal lagoons represent critical regional resources that provide freshwater and estuarine habitats for numerous plant and animal species. Other wafer bodies in the Carlsbad HU have been identified as impaired on the California 303(d) list for elevated coliform bacteria including several locations in the Pacific Ocean near creek and lagoon outlets. 11 'The population of the Carlsbad HU is approximately 500,000 residents making it the third most densely populated in San Diego County behind the Pueblo San Diego and the Penasquitos HUs. A high percentage of the undeveloped land is in private ownership and the population of the Carlsbad HU is proiected to increase to over 700,000 residents by 2015. EHective planning measures w1tl be needed to prevent this rapid development from further degrading water quality in this region of San Diego County. 11 (Source:http://www.projectcleanwater.org/index.php?option=com_content&view=article&id=S&Itemi d=40, accessed October, 2011) San Marcos Creek is listed as a water quality limited segment in the 2010 Integrated Report (Clean Water Action Section 303(d) List I 305(b) Report) list of impaired water bodies which are discussed in more detail in Section 2.14. Currently, there are TMDLs for San Marcos Creek for DOE (Dichlorodiphenyldichloroethylene), phosphorous, sediment toxicity and selenium which all have a Category SA TMDL requirement status, meaning that a TMDL is still required. 3 BRESS/ RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PlAN 2.0 WATER QUALITY ENVIRONMENT 2.1 BENIFICIAL USES October 2011 The beneficial uses for the hydrologic unit are included in tables in sections 2.1 .1, 2.1 .2 AND 2.1.3. These tables have been extracted from the "Water Quality Control Plan for the San Diego Basin (9)," dated September 8, 1994 with amendments effective prior to April 25, 2007. MUN-Municipal and Domestic Supply: Includes uses of water for community, military, or individual water supply systems including, but not limited to, drinking water supply. AGR-Agricultural Supply: Includes uses of water for farming, horticulture, or ranching including, but not limited to, irrigation, stock watering, or support of vegetation for range grazing. WARM--Warm Freshwater Habitat: Includes uses of water that support warm water ecosystems including, but not limited to, preservation or enhancement of aquatic habitats, vegetation, fish or wildlife, including invertebrates. AQUA-Includes the uses of water for aquaculture or mariculture operations including, but not limited to, propagation, cultivation, maintenance, or harvesting of aquatic plants and animals for human consumption or bait purposes. COMM-includes the uses of water for commercial or recreational collection of fish, shellfish, or other organisms, including, but not limited to, uses involving organisms intended for human consumption or bait purposes. BIOl-Includes uses of water that support designated areas or habitats, such as refuges, parks, sanctuaries, ecological reserves, or Areas of Special Biological Significance (ASBS) where the preservation or enhancement of natural resources requires special protection. EST-Includes uses of water that support estuarine ecosystems, including but not limited to, preservation or enhancement of estuarine habitats, vegetation, fish, shellfish, or wildlife (e.g. estuarine mammals, waterfowl, or shorebirds.) RARE-Includes uses of water that support habitats necessary, at least in part, for the survival and successful maintenance of plant or animal species, established under state or federal law as rare, threatened or endangered. SPWN-Includes uses of water that support that support high quality aquatic habitats suitable for reproduction and early development of fish. This use is applicable for only the protection of anadromous fish. SHELL-Includes uses of water that support habitats suitable for the collection of filter feeding shellfish (e.g. clams, oysters and mussels) for human consumption, commercial, or sport purposes. MIGR-Includes uses of water that support habitats necessary for migration, acclimatization between fresh and salt water, or other temporary activities by aquatic organisms such as anadromous fish. MAR-Includes uses of water that support marine ecosystems including, but not limited to, preservation or enhancement of marine habitats, vegetation such as kelp, fish, shellfish, or wildlife (e.g. marine mammals, shorebirds.) 4 BRESS/ RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN October 20 II IND -Includes uses of water for industrial activities that do not depend primarily on water quality including, but not limited to, mining, cooling water supply, hydraulic conveyance, gravel washing, fire protection, or oil well re-pressurizotion. RECl -Contact Recreation: Includes uses of water for recreational activities involving body contact with water, where ingestion of water is reasonably possible. These uses include, but ore not limited to, swimming, wading, water-skiing, skin and SCUBA diving, surfing, white water activities, fishing, or use of natural hot springs. REC2 -Non-Contact Recreation: Includes the uses of water for recreation involving proximity to water, but not normally involving body contact with water, where ingestion of water is reasonably possible. These uses include, but ore not limited to, picnicking, sunbathing, hiking, camping, boating, tide pool and marine life study, hunting, sightseeing, or aesthetic enjoyment in conjunction with the above activities. WILD -Wildlife Habitat: Includes uses of water that support terrestrial ecosystems including, but not limited to, preservation and enhancement of terrestrial habitats, vegetation, wildlife, (e.g., mammals, birds, reptiles, amphibians, invertebrates), or wildlife water and food sources. 2.1.1 INLAND SURFAC E WATERS Inland surface waters hove the following beneficial uses as shown: RECEIVIhiG HYDROLOGIC \'/ATERS u:~IT BA.Sir'-l !~UMBER Son Marcos Creek -904.51 unnamed intermittent streams o -Potential Beneficial Use x-Existing Beneficial Use +-Excepted From MUN 1.\UIJ A.GR REC l + X X 5 REC2 ':.'ARt/1 \"/ILD X X X BRESS/ RANCH PLANNING AREA 2 STORM WATER MANA GEMENT PLAN PROPOSED DRAINAGE FLOWS BASIN DRAINAGE AREA (ACRES) 1 4.2 2 6.0 3 4.6 4 3.4 5 1.4 6 0.6 7 0.2 Proposed Total Flow Rote Q 1oo (CFS) 20.5 23.6 23.9 16.6 7.6 3.5 1.4 97.1 Table 2. Proposed Condition Peak Drainage Flow Rates Odober2011 The table above lists the peak flow roles for the project site for the proposed condition for the 1 00 year rainfall event. PEAK DRAINAGE FLOW COMPARISON RAINFALL EVENT Q 1oo (CFS) PLANNED, ULTIMATE CONDITION 103.5 Table 3 . Proposed Condition Peak Drainage Flow Rates PROPOSED CONDITION 97.1 COMPARISION Less than existin Table 3 shows the comparison between the peak flow rates for the proposed project and the ultimate, cumulative flow rote for the project site for the proposed condition for the 1 00 year rainfa ll event. As shown in Table 3 above, the project does not increase the peak runoff rate for the 100 year ra infall event. This cumulative peak flow rate was reduced when compared to the projected ultimate condition because the proposed project's runoff coefficient used in the project's calculations was 0.85 when compared to the assumed 0 .95 in the original calculations by Project Design Consultants. This lower C value yields a lower peak flow rote for the design storm analyzed than what was origina ll y calculated in the original planning of the storm drain infrastructure provided to serve the project's lots and the surrounding area. Therefore, proposed project is not anticipated to negatively affect any downstream facilities since the overall 1 00 year cumulative flow rote decreased when compared to the previously analyzed, ultimate build-out condition. 9 BRESS/ RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN October 201 1 ANTICIPATED AND POTENTIAL POLLUTANTS GENERATED BY LAND USE TYPE PROBABLE BENTHIC SEDIMENT TOXICITY (IN LOW DISSOLVED POLLUTANTS EUTROPHIC COMMUNITY TOXICITY STORM WATER OXYGEN DEGRADATION RUNOFF) Sediment Nutrients X X Heavy Metals X X O rganic Compounds X X X Trash and Debris X O xygen Demanding X X Substances Oil and Grease Bacteria and Viruses Pesticides X Th e table above was extracted from Table 4-2 of the City of San Diego's Storm Water Standa rds Manual (January 14, 20 l l ). Th erefore, th e followi ng pollutants ore designated as a nticipated or potential for the proposed si te, as well as hove 303(d) impairments downstream ore considered primary polluta nts of concern. PRIMARY POLLUTANTS OF SPECIFIC 303(D) IMPAIRMENT CONCERN NUTRIENTS Phosphorous METALS Sediment Toxicity ORGANIC COMPOUNDS Sediment Toxicity OXYGEN DEMANDING Phosphorous SUBSTANCES PESTICIDES DOE Nutrients -Nutrients ore inorganic substances, such as nitrogen and phosphorus. They commonly exist in the form of minera l salts that ore either dissolved or suspended in water. Primary sources of nutrients in urban runoff ore ferti lizers and eroded soils. Excessive discharge of nutrients to water bodies and streams con cause excessive aquatic algae and plant growth. Such excessive production, l l BRESS/ RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PIAN 2.4 SOIL CHARACTERISTICS October 201 1 A Geotechnical Update Study was completed by Leighton and Associates, Inc. dated April 12, 2011 (Project No. 971 009-065) which details the subsurface conditions for the project. Selected excerpts from the report are as follows: Site Location and As-Graded Description: "The Bressi Ranch Industrial Planning Area 2 site is located south of Palomar Airport Road and east of El Camino Real Road in Carlsbad, California (Figure 7). The mass grading operations for the site were performed between June 2003 and January 2004 (Leighton_ 2004b). The mass grading of the site resulted in three terraced sheet-graded pads separated by south-and west-facing slopes approximately 5 to 8 feet in height and three desi/ting basins along Town Garden Road, the southern boundary of the site. In addition, along Town Garden Road there is a south-to southeast facing 2 to 1 hi/ slope, which ranges from 5 to 7 5 feet in height. In general the mass grading of the site included: 1} the removal of potentially compressible desiccated older hi/ so11s, undocumented fill soils, topsoil colluvium, alluvium, landslide deposits, and weathered formational material· 2) preparation of areas to receive h"ll· 3) the placement of a subdrain system in the canyon bottom; 4) excavation of formational material· 5) the placement of compacted h1/ soils, and 6) excavation of stability fill keys. Up to approximately 15 feet of cut was excavated and a maximum of approximately 90 feet of fill was placed during the mass grading operations within the lim !Is of the site. "The sheet-graded pads of Planning Areas 2 consist of both cut and h1/s. The cut/fill transition conditions on the sheet-graded pads were not mitigated during the mass grading operations. As reported, once the site improvements on the pads of the planning areas are determined, specih"c recommendations concerning the cut/fill transition conditions were to be provided in an update report for the site. In general the cut/hi! transition conditions can be mitigated by the overexcavation of the cut portion of the pad or by designing deep foundations that extend through the fill. " Geologic Setting: "The subject site is located in the coastal section of the Peninsular Range Province, a geomorphic province with a long and active geologic history throughout Southern California. Throughout the last 54 million years, the area known as the "San Diego Embayment" has undergone several episodes of marine inundation and subsequent marine regression, resulting in the deposition of a thick sequence of marine and nonmarine sedimentary rocks on the basement rock of the Southern California batholith. Gradual emergence of the region from the sea occurred in Pleistocene time, and numerous wave-cut platforms, most of which were covered by relatively thin marine and nonmarine terrace deposits, formed as the sea receded from the land Accelerated fluvial erosion during periods of heavy rainfall coupled with the lowering of the base sea level during Quaternary time, resulted in the rolling h11!s, mesas, and deeply incised canyons which characterize the landforms we see in the general site area today. " Geologic Units: "The geologic units encountered during our update study included both recent artificial hi/ and the Tertiary-aged Santiago Formation. The artiheia/ fill (Af} was placed during the mass grading operations and generally consist of sl1ty sands to sandy silts/clays. The approximate limits of the artificial fill soils are presented on the Geotechnical Map (Plate 7). In addition to the fill limits, the 13 BRESS/ RANCH PLANNING AREA 2 October 20 II STORM WATER MANAGEMENT PLAN elevations of the bottom of the h1/ are provided on the geotechnical map so that potential ft11 differentials across the site can be identified " "In accordance with the project geotechnical recommendations, the h1/ soils in the lower portions of the deep ft1/ areas (t".e. fill areas generally deeper than approximately 40 feet below the proposed finish grade elevations of the sheet-graded pads) were compacted to at least 95 percent of the maximum dry density in accordance with ASTM Test Method D 1557. Ft1/ sot1s placed within 40 feet of the ftnish grade surface were compacted to a minimum 90 percent relative compaction (based on with ASTM Test Method D 1557). '' 'The Tertiary-aged Santiago Formation, as encountered dunng the mass gradtng operations, consisted primarily of massively bedded sandstones and claystones/siltstones. The sandstone generally consisted of orange-brown (iron oxide sfaimng} to light brown, damp to moist, dense to very dense, silty very fine to medium gratned sandstone. The siltstones and claystones were generally olive-green to gray (unweathered}, damp to moist stiff to hare£ moderately weathereci and occasionally fractured and moderately sheared Several wei/cemented fosst1iferous sandstone beds were encountered dunng the mass grad1ng operations. It should be noted that high to very high expansive formational claystones and siltstones are present at the exisftng ftnish grade elevation of the sheet-graded pad in the eastern portion of Planning Area 2 (see Geotechnical Map-Plate 1). '' Ground Water.· "Dunng the origtnal site gradtng, perched ground water was encountered tn the alluvial sot1s located ~ tn the lower portions of the main canyon and tn some of the lower tributary canyons on the east side of Planning Area 2. In addition several seepage zones were also encountered along the base of a number of the relatively permeable sandstone units tn the lower portion of the canyon on the southwest side of Planmng Area 2. Canyon subdratns were installed along the canyon bottoms dunng the mass gradtng operations, as shown on the Geotechnical Map (Plate 1)." nBased on the as-graded geotechnical conditions and our geotechnical observations dunng site grading, ground wafer seepage may be encountered dunng site earthwork for the project, and appropriate recommendations for mitigation should be issueci if necessary. In addt"tion, unanticipated seepage or shallow ground wafer conditions may occur after the completion of grading and establishment of site irrigation and landscaping. If these conditions should occur-steps to mitigate the seepage should be made on a case-by-case basis. " Conclusions: 'The site is underlain bv the Rl/ soils and Santiago Fotmation that are known to contain both permeable and impetmeable layers which can transmit and perch ground wafer in unpredictable wavs. Therefore, given the site geotechnical conditions, low Impact Development (LID) measures are not recommended for this proied. " 14 BRESS! RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PIAN 3.0 CONSTRUCTION PHASE BMPs October 20 I I The project will disturb an area greater than one acre during construction and will need to obtain a Waste Discharge Identification (WOlD) Number under the Statewide General Construction Permit prior to the beginning of grading operations. The project will prepare an erosion and sediment control plan and Storm Water Pollution Prevention Plan (SWPPP) to cover the necessary BMPs required during the project's construction operation. 15 BRESS/ RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN 4.0 POST CONSTRUCTION BMPs October 201 1 To address water quality for the project, BMPs will be implemented concerning site planning, activities, and structural treatment. The January 14, 2011, City of Carlsbad Storm Water Standards Manual guidelines have been utilized in the selection of post construction BMPs. In addition, any features or activities included in the project that are applicable for the inclusion of CASQA BMPs are included as well. Treatment control BMP sizing calculations are included in Appendix 5 and educational materials are included in Appendices 4 and 6 of this report. 4.1 LOW-IMPACT DEVELOPMENT DESIGN PRACTICES • Minimize Impervious Surfaces o Several areas of permeable pavers have been located in the project's parking lot to serve as a treatment control BMP o Large areas of decorative hardscape have not been used above the minimum required by code to provide patio and break area space outside • Disconnect Discharges o Numerous flow through planters and permeable paver areas have been integrated into the project site so that there is not a direct connection between impervious surfaces and the project's storm drain system o Runoff from impervious areas is directed toward landscaped areas or pervious surfaces to promote vegetative contact. Roof drains, driveways, walkways, parking areas and patios are designed to drain to landscaped areas prior to being collected in the storm drain system to the maximum extent allowed by the project's site and grading design • Conserve Natural Areas o The project will mmtmtze the grading and disturbance of the existing landscaped slopes and areas surrounding the project site to the extent possible with the project's site and grading design. 4.2 SOURCE CONTROL BMPs The proposed use of the project incorporates the following Source Control BMPs tn the project's design: • Stenciling Inlets and Signage o All storm drain inlets will either be stenciled or stamped with prohibitive language such as "No Dumping -I Live Downstream" or other language approved by the City Engineer. o No dumping signs or graphical icons may be installed throughout the project site to prohibit dumping. 16 BRESS/ RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PLAN • Landscape Design October 201 1 o The project will incorporate some native, drought-tolerant species that do not require excessive irrigation. The design will strive to maximize canopy interception and employ water conservation by preserving native trees and shrubs, if applicable. o The project will consider using pest resistant plants. o To insure successful establishment, the plant palate will aim to be appropriate to the site's soils, slopes, climate, sun, wind, rain, land use, air movement, ecological consistency and plant interactions. • Water Efficient Irrigation o The project's irrigation system design will reduce over-irrigation, employ rain shutoff devices which will prevent irrigation after rainfall events and minimize unnecessary runoff. • Protect Slopes and Channels o Not applicable • Trash Receptacles o Trash storage areas will be constructed to city standard drawing G-16 or an approve equal. Trash storage areas will be located on an impervious surface designed not to allow run-on from adjoining areas. The trash storage area will be screened or walled to prevent the transport of trash. All trash containers shall include lids or covers to prevent contact with rainfall. • Material Storage Areas o Not applicable • Interior floor drains and elevator shaft sump pumps (if applicable) o Interior floor drains and elevator shaft sump pumps will be plumbed to sanitary sewer, if applicable • Interior parking garages o Not applicable • Food service o Not applicable • Industrial processes o Not Applicable • Outdoor Storage Areas o Not Applicable • Vehicle and Equipment Cleaning o Not Applicable • Vehicle and Equipment Repair and Maintenance o Not Applicable 17 BRESS/ RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN • Fuel Dispensing Areas o Not Applicable • Loading Docks o Not Applicable • Miscellaneous Drain or Wash Water October 201 1 o Boiler drain lines shall be directly or indirectly connected to the sanitary sewer system and may not discharge to the storm drain system. o Condensate drain lines may discharge to landscaped areas if the flow is small enough that runoff will not occur. Condensate drain lines may not discharge to the storm drain system. o Rooftop mounted equipment with potential to produce pollutants shall be roofed and/or have secondary containment. o Any drainage sumps on-site shall feature a sediment sump to reduce the quantity of sediment in pumped water. o Avoid roofing, gutters and trim made of copper or other unprotected metals that may leach into runoff. • Plazas, sidewalks and parking lots o Plazas, sidewalks and parking lots shall be swept regularly to prevent the accumulation of litter and debris. Debris from pressure washing shall be collected to prevent entry into the storm drain system. Wash water containing any cleaning agent or degreaser ~ shall be collected and discharged to the sanitary sewer and not discharged to a storm drain. • Employ Integrated Pest Management Principals o Integrated pest management (IPM) is an ecosystem-based pollution prevention strategy that focuses on long-term prevention of pests or their damage through a combination of techniques such as: • Biological control • Habitat manipulation • Use of resistant plant varieties o 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 surrounding environment. More information regarding pesticide application may be obtained at the following University of California-Davis website: http://www.ipm.ucdavis.edu/WATER/U/index.html o To eliminate or reduce the need for pesticide use, the following strategies can be used: • Plant pest-resistant or well-adapted plant varieties • Discourage pests by modifying the site and landscaping design o IPM educational materials should be distributed to future site residents and tenants. These educational materials should address the following: • Use of barriers, screens, and caulking to keep pests out of buildings and landscaping 18 BRESS/ RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN October 2011 • Physical pest elimination techniques, such as weeding, washing , or trapping pests • Relying o n natural enemies to eliminate pests • Proper use of pesticides as o last line of defense 19 BRESS/ RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN 4.3 TREATMENT CONTROL BMPS 0dober2011 Structural treatment facilities are designed to remove pollutants contained in storm water runoff. Runoff from the proposed site will flow from impervious and semi-pervious surfaces, picking up pollutants and other associated debris from the proposed project site. T reotment of the anticipated pollutants will come from the BMPs listed below. The selected BMPs were selected based on the following treatment matrices located in the City of Carlsbad's Storm Water Standards Manual, shown on the following page from Tables 2-2 and 2-3, respectively. Pollutants that tend to Pollutants that tend to Pollutant Coarse Sediment and associate with fine be dissolved followmg Trash particles during treatment treatment Sediment X X Nutrients X X Heavy Metals X Organic Compounds X Trash & Debris X Oxygen Demanding X Bacteria X Oil & Grease X Pesticides X Set~lmg Wet Ponds I nfdtratton Polluton•s Btore•ent:on Basms and Facdtltes Medta Htgher-Htgher Trash Racks & Vege•ated of Focdtttes (Dry Constructed or Fdters rote ra•e medta Hydrodynamtc s .... ales concern (LID) Ponds) Wetlands Proc!tces btofdters ftlters Devtces (LID) Coarse Sediment High High High High High High High High High and Trash Pollutants that tend to associate High High High High High Medium Medium Low Medium with fine particles during treatment Pollutants that tend to be Medium Low Medium High Low Low Low Low Low dissolved following treatment 20 BRESS/ RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PLAN October 201 1 Certain factors such as site layout, soil feasibility, and treatment capability are taken in to account when selecting treatment control BMPs. The goal in selecting treatment control BMPs is to find the best solution as to promote water quality treatment, realize project objectives, remain cost effective, and utilize low impact design (LID) practices. Since the project site is underlain by fill soils and Santiago Formation that are known to primarily be impermeable, as discussed in the project's geotechnical report referenced in Section 2.4. Therefore, treatment control BMPs that rely on infiltration will not be used for the project. The next best efficient treatment control BMP are bioretention facilities (LID) which have high removal efficiency for coarse sediment and trash and pollutants that tend to associate with fine particles during treatment. Bioretention facilities (LID) also have a medium removal efficiency for pollutants that tend to be dissolved following treatment. The following treatment control BMPs will be implemented to address water quality, based on the Primary Pollutants of Concern/303(d) list for the project site. 4.3.1 FLOW THROUGH PLANTERS According to the County of San Diego's LID Appendix, Fact Sheet 7, "Biofiltration systems are essentially a surface and sub-surface water filtration system. In function they are similar to sand filters. Biofiltration systems incorporate both plants and underlying filter soils for removal of contaminants. These facilities normally consist of a treatment train approach: filter strip, sand bed, pending area, organic layer, planting soil, and plants." According to the City of Carlsbad's Storm Water Standards Manual, "Flow-through planters treat and detain runoff without allowing seepage info the underlying sot!. They can be used next to buildings and on slopes where stability might be affected by adding soil moisture. " "Flow-through planters typically receive runoff via downspouts leading from the roofs of adjacent bu1ldings. However, they can also be set in ground and receive sheet flow from adjacent paved " areas. "Pollutants are removed as runoff passes through the so1l layer and is collected in an underlying layer of gravel or drain rock. A perforated-pipe underdrain is typically connected to a storm drain or other discharge point. An overflow inlet conveys flows which exceed the capacity of the planter. " Flow through planter systems are effective at removing sediments and pollutants which are associated with fine particles by filtration through surface vegetation and underlying engineered soil media. These systems can also delay runoff peaks by providing detention and/or retention capacity in the media layer and pending area through the controlled release of treated runoff. The addition of vegetation not only increases the aesthetic value of these areas, but also enhances the filtration component of the system through plant uptake and helps maintain the porosity of the engineered soil layer. Flow through planter systems can be constructed as either large or small scale devices with native or amended soils. Flow through planter systems, like the systems designed for this project, collect storm water from impervious areas (roof areas and other impervious surfaces) through the site's grading design. 21 BRESS/ RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN October 201 1 "Concrete block pavers and brick pavers are designed to set on sand or fine gravel and form an interlocking pavement surface. Modular block pavers are designed to bear heavy loads and are well suited for industrial and commercial parking lots, utility access, residential access roads, driveways, and walkways. " "Solie£ pre-cast concrete unit pavers are available in a wtde variety of colors, shapes, sizes, and textures. They are designed to be set on sand and form an interlocking pavement surface that can bear heavy traffic loads. Their permeabt1ity and performance is sirm1ar to brick-on-sand Some manufacturers are now producing concrete unit pavers with small voids to increase permeability (e.g. "Ecostone J. The cost of concrete umY pavers is generally the lowest of all unit pavers, though if can vary depending on shipping, special colors or finishes. " The proposed permeable paver systems designed for the project will feature permeable pavers located in some the project's parking areas where flow through planter areas could not be placed due to the location of existing fill slopes sloping down from the parking areas. The systems are comprised of a permeable pavers section which will allow low flow storm events (water quality events) to filter through the void space between paver units and into the system's sub-base from the project's parking areas as well as runoff from some of the roofs of the proposed buildings for the project. The systems will store the captured runoff in the gravel storage layer while the water filters through an eighteen inch thick sand filter located at the bottom of the system. The systems will be lined with an impermeable liner and an under drain due to the poor infiltration characteristics of the in situ soil. These areas will also be providing attenuation for the project's hydromodification impacts, which are discussed in a separate report prepared by Fuscoe Engineering. The permeable paver systems will provide water quality treatment for the first 0.2 of an inch of rainfall for a flow based BMP and are sized to be a minimum of 4% of the contributing drainage area based on a minimum infiltration rate of 5 inches per hour for the engineered soil media per the City of Carlsbad's Storm Water Standards Manual (January 14, 2011 ), as well as conveying larger rainfall events due to its integral nature in the project's drainage design. Sizing calculations for the permeable pavers systems are included in Appendix 5 of this report. 23 BRESS/ RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN 5.0 MAINTENANCE Designated Responsible Party: HCP LS Carlsbad, LLC c/o Project Management Advisors 462 Stevens Avenue, Suite 1 06 Solana Beach, CA 92075 (858) 704-1980 October 201 1 A training program will be administered and implemented by HCP LS Carlsbad, LLC and shall occur at a minimum of once annually. The training program shall consist of, at a minimum: the disbursement of the brochures and flyers included in this SWMP and a copy of the maintenance plan to all operation and maintenance staff associated with the project. A training log shall be filled out at each training session and kept for a minimum of five (5) years. HCP LS Carlsbad, LLC will complete and maintain operation and maintenance forms to adequately document all maintenance performed on the project's treatment control BMPs. These records should be kept on file for a minimum of five (5) years and shall be made accessible to the City of Carlsbad, the State Water Resources Control Board or any other authority regulating storm water discharges for inspection upon request at any time. All waste generated from the project site is ultimately the responsibility of HCP LS Carlsbad, LLC. Disposal of sediment, debris, and trash will comply with applicable local, county, state, and federal waste control programs. Suspected hazardous waste will be analyzed to determine proper disposal methods. The following Operation and Maintenance Plan has been developed for each type of treatment control BMP used on this project. These are minimum requirements only. Their frequency and/or scope may be increased, if necessary, to meet and/or maintain the level of storm water quality treatment required of this project. All costs associated with the operation and maintenance of the treatment control BMPs listed below will be funded by HCP LS Carlsbad, LLC in perpetuity or until the project is sold to another entity where the responsibility would transfer with the sale of the property. The project's owner, HCP LS Carlsbad, LLC, will enter into the City of Carlsbad's Storm Water Quality BMP Maintenance Agreement which will be executed prior to grading permit issuance. 24 BRESS/ RANCH PLANNING AREA 2 STORM WATER MANAGEMENT PLAN 5.1 PERMEABLE PAVERS Permeable Paver Inspection Activities Inspect permeable paver system Inspect perforated cleanout pipe to check for standing water on the surface or in the subgrade section. Permeable Paver Maintenance Activities Keep landscaped areas well maintained Prevent soil from bein~ washed onto pavement Vacuum clean the pavement openings and replenish the aggregate joint material after vacuuming as needed. Regular surface vacuuming will maintain the infiltration performance of the system and reduce the risk for dogging. Clean oil and grease deposits Repair pavers more than 1 /4-inch above or below adjacent units Repair ruts in the pavement qreater than 1 /2-inch Replace broken or cracked paver units Replenish a~~re~ate joint material as needed Check observation cleanouts to ensure free flow of water If routine cleaning does not restore infiltration characteristics of the system, then reconstruction of part or the whole permeable paver system may be required. The surface area affected by hydraulic failure should be lifted for inspection of the internal materials to identify the location and extent of the blockage. Sub-surface layers may need cleaning and/or replacement. Note: Removed silts may need to be disposed of as controlled waste. The reconstruction should be per the approved plans for the system unless otherwise directed by the Engineer of Work. October 201 1 Recommended Frequency -Before/after rainy season -Before/after rainy season -After significant rainfalls (greater than 0.5''} Recommended Frequency -Continual -Continual -Annually -As needed -As needed -As necessary -As necessary -As necessa_ry_ -As necessary -Annually -As needed (infrequent) Expected annual operating costs: The expected annual costs of maintaining and operating the project's permeable paver systems are: $3,960/acre of contributing drainage area* x 3.3 acres of tributary area "per SD-20 from CASQA New Development and Redevelopment Handbook (January, 2003) Estimated Annual Operating Costs = $13,070.00 25 BRESS! RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PlAN 5.2 FLOW THROUGH PLANTERS Flow Through Planter System Inspection Activities Inspect flow through planter system Inspect soil and repair eroded areas Inspect for erosion or damage to vegetation, preferably at the end of the wet season to schedule dry season maintenance and before major wet season runoff to be sure the areas are ready for the wet season. However, additional inspection after periods of heavy runoff is recommended. Inspect to ensure grasses, ground covers, vegetation is well established. If not, either prepare soil and reseed or replant with appropriate alternative species. Install erosion control blankets if necessary. Check for debris and litter, areas of sediment accumulation Inspect health of trees and shrubs and vegetation Inspect system cleanouts and outfall structures Inspect for stand in~ water and vectors Flow Through Planter System Maintenance Activities Remove litter and debris in conjunction with regularly scheduled landscape maintenance Irrigate flow through planter area(s) during dry season (April through October) and as necessary to maintain vegetation during the rainy season. Physically remove weeds Remove sediment Apply mulch to areas devoid of mulch, especially prior to the wet season Replace damaged or diseased trees and shrubs Mow turf areas, if any Repair erosion at inflow points Uncloq underdrain system Remove and replace dead and diseased veqetation Replace tree stakes and wires, if any Mulch should be replaced every 2 to 3 years or when bare spots appear Rototill or cultivate the surface if the system does not draw down in 48 hours 26 October 201 1 Recommended Frequency -Before/after rainy season -Bi-weekly during the rainy season -After a rainfall event of 0.5" or more Monthly Prior to rainy season & every other month Every other month Every other month Every other month Every other month Every other month Recommended Frequency As part of routine, regular landscape maintenance Every 2-3 years, or as needed As needed BRESS! RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN October 201 1 Expected annual operating costs: The expected annual costs of maintaining and operating the project's flow through planter areas are: $2,972.42 per unit* x 39 unit *per County of San Diego's Appendix H "Estimated O&M Costs for BMP Project" (January 23, 2003) Estimated Annual Operating Costs = $116,000.00 Total Project's Estimated Annual Operating Costs = $129.070.00 27 - - BRESS! RANCH PlANNING AREA 2 STORM WATER MANAGEMENT PIAN 7.0 APPENDICES Appendix 1 Completed City of Carlsbad Form E-34 Appendix 2 Pro;ed Map Appendix 3 BMP/Water Quality Plan Appendix 4 Educational Material Appendix 5 Treatment Control BMP Sizing Appendix 6 Treatment Control BMP Fad Sheets Appendix 7 2010 CWA Sedion 303(d) List 29 October 201 1 ;;:~---@ ----- 6. 7. 8. 9. «' ~ CITY OF CARLSBAD STORM WATER STANDARDS QUESTIONNAIRE E-34 Development Services Land Development Engineering 1635 Faraday Avenue 760-602-2750 www.carlsbadca.gov Hillside d!velopment. Any development that creates more than 5,000 square feet of impervious surface and Is X located In an area with known erosive soil conditions, where the development will grade on any natural slope that is twenty-five percent (25%) or greater. Envl':f?mtntaiiV Sensitive Area CE$AI . Aft development located within or directly adjacenf to or discharging directl to an ESA (where discharges from the development or redevelopment will enter receMng waters within the X ESA), which either creates 2,500 square feet or more of impervious surface on a proposed project site or increases the area of imperviousness of a proposed proJect site 10% or more of Its naturally occurring condition. Ptrlclna lot Area of 5,000 square feet or more, or with 15 or more parking spaces, and potentially exposed to urban runoff X Struts. COf!d£ hlqhwevs. tad fruWIVJ. Any paved surface that is 5,000 square feet or greater used for the X transportation of automobiles, trucks, motorcycles, and other vehicles 10. B.t1J.Il GIISoi[DJ! Qdltl. Serving more than 100 vehicles per day and greater than 5,000 square feet X 11. Cogt«l Dtyeloqment Zonl· AnY project located within 200 feet of the Pacific Ocean and (1) creates more than X 2500 square feet of impervious surface or (2) Increases impervious surface on property by more than 1 0%. 12. Mont than 1-tcre of disturbance. Project results in the disturbance of 1-acre or more of land and is considered a X Pollutant-generating Development Project4• 1 Environmentally Sensitive ArMs Include but ere not Hmlted to ell Clean Water Ad Section 303(d) nnpaired water bodies. areas designated as Ateas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodiaa daalgnated wl1h the RARE beneflclel use by the State Water R-Control Board (Water Quality Control Plan for the Sen Diego Basin (1994) and amendments); areas designated as pres81V8S or their equivalent under the MuiU Spaclas Conservation Progrem within the Cities and County of Sen Diego; and any other equivalent environmentally sensitive areas which have been ldentlflad by the Copennlttaas. 2 "Directly adjacent" meana litullted Within 200 feet d 1he Environmenmly Senlitive Area. 3 "DiiiCharglng dinlc:tly to• ~Mana outflow from • drelnege conYIIyence ayatem that Is composed entirety ot ftowl from the aubject development or redevelopment site, and not commingled with flow from adjacent lands. 4 Pollutant-generating Daveloprnent Projects are those projada that genarete pollutants at levels greater than background levels. In general. these includa all projects that contribute to an axoaedence to en Impaired water body or which create new impervious surfaces greeter then 5000 square feat and/or Introduce new landscaping araas that raqulra routine uaa of fertilizers and pasticldaa. In most cases linear pathway projects that are for Infrequent vehicle uaa. such as emergency or maintenance acceas, or for padaatrtan or bicycle uaa. are not considered Ponwmt.ganarating Development Projects If they are built with pervious surfacaa or If they sheet ftow to surrounding pervious surfaces. INSTRUCTIONS:. Section 1 Ruultsi If you answered YES to ANY of the questions above, your project is subject to Priority Developmtot Project requirements. Skip Section 2 and please proceed to Section 3. Check the "meets PRIORITY DEVELOPMENT PROJECT requirements" box In Section 3. Additional storm water requirements will apply per the SUSMP. If you answered NO to ALL of the questions above, thto please proceed to Section 2 and follow the instructions. E-34 Page2 of3 REV 1/14/11 SC-10 Non-Stormwater Discharges .......... ''-"' Pollution Prel1ention • Ensure that used oil, used antifreeze, and hazardous chemical recycling programs are being implemented. Encourage litter control. Sugguted Protocou Recommended Complaint Investigation Equipment • Field Screening Analysis pH paper or meter Commercial stormwater pollutant screening kit that can detect for reactive phosphorus, nitrate nitrogen, ammonium nitrogen, specific conductance, and turbidity Sample jars Sample collection pole A tool to remove access hole covers • Laboratory Analysis Sample cooler Ice Sample jars and labels Chain of custody forms • Documentation Camera Notebook Pens Notice ofViolation forms Educational materials General • Develop clear protocols and lines of communication for effectively prohibiting non- stormwater discharges, especially those that are not classified as hazardous. These are often not responded to as effectively as they need to be. • Stencil or demarcate storm drains, where applicable, to prevent illegal disposal of pollutants. Storm drain inlets should have messages such as "Dump No Waste Drains to Stream" stenciled or demarcated next to them to warn against ignorant or intentional dumping of pollutants into the storm drainage system. 2 of6 California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Non-Stormwater Discharges SC-10 • See SC44 Stormwater Drainage System Maintenance for additional information. Illicit Connections • Locate discharges from the industrial storm drainage system to the municipal storm drain system through review of "as-built" piping schematics. • Isolate problem areas and plug illicit discharge points. • Locate and evaluate all discharges to the industrial storm drain system. Vtsual Inspection and Inventory • Inventory and inspect each discharge point during dry weather. • Keep in mind that drainage from a storm event can continue for a day or two following the end of a storm and groundwater may infiltrate the underground stormwater collection system. Also, non-stormwater discharges are often intermittent and may require periodic inspections. Review Infield Piping • A review of the "as-built" piping schematic is a way to determine if there are any connections to the stormwater collection system. • Inspect the path of floor drains in older buildings. Smoke Testing • Smoke testing of wastewater and stormwater collection systems is used to detect connections between the two systems. • During dry weather the stormwater collection system is filled with smoke and then traced to sources. The appearance of smoke at the base of a toilet indicates that there may be a connection between the sanitary and the stormwater system. Dye Testing • A dye test can be performed by simply releasing a dye into either your sanitary or process wastewater system and examining the discharge points from the stormwater collection system for discoloration. 1V Inspection of Drainage System • 1V Cameras can be employed to visually identify illicit connections to the industrial storm drainage system. Illegal Dumping • Regularly inspect and clean up hot spots and other storm drainage areas where illegal dumping and disposal occurs. • On paved surfaces, clean up spills with as little water as possible. Use a rag for small spills, a damp mop for general cleanup, and absorbent material for larger spills. Ifthe spilled material is hazardous, then the used cleanup materials are also hazardous and must be sent to a certified laundry (rags) or disposed of as hazardous waste. January 2003 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 3 of 6 SC-10 Non-Stormwater Discharges ~ '--"' • Never hose down or bury dry material spills. Sweep up the material and dispose of properly. • Use adsorbent materials on small spills rather than hosing down the spill. Remove the adsorbent materials promptly and dispose of properly. • For larger spills, a private spill cleanup company or Hazmat team may be necessary. Once a site has been cleaned: • Post "No Dumping" signs with a phone number for reporting dumping and disposal. • Landscaping and beautification efforts of hot spots may also discourage future dumping, as well as provide open space and increase property values. • lighting or barriers may also be needed to discourage future dumping. • See fact sheet SCu Spill Prevention, Control, and Cleanup. Inspection • Regularly inspect and clean up hot spots and other storm drainage areas where illegal dumping and disposal occurs. • Conduct field investigations of the industrial storm drain system for potential sources of non-stormwater discharges. • Pro-actively conduct investigations of high priority areas. Based on historical data, prioritize specific geographic areas and/or incident type for pro-active investigations. Reporting • A database is useful for defining and tracking the magnitude and location of the problem. • Report prohibited non-stormwater discharges observed during the course of normal daily activities so they can be investigated, contained, and cleaned up or eliminated. • Document that non-stormwater discharges have been eliminated by recording tests performed, methods used, dates of testing, and any on-site drainage points observed. • Document and report annually the results of the program. • Maintain documentation of illicit connection and illegal dumping incidents, including significant conditionally exempt discharges that are not properly managed. Training • Training of technical staff in identifying and documenting illegal dumping incidents is required. • Consider posting the quick reference table near storm drains to reinforce training. • Train employees to identify non-stormwater discharges and report discharges to the appropriate departments. 4 of6 California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Non-Stormwater Discharges SC-10 • Educate employees about spill prevention and cleanup. • Well~trained employees can reduce human errors that lead to accidental releases or spills. The employee should have the tools and knowledge to immediately begin cleaning up a spill should one occur. Employees should be familiar with the Spill Prevention Control and Countermeasure Plan. • Detennine and implement appropriate outreach efforts to reduce non-pennissible non- stormwater discharges. • Conduct spill response drills annually (if no events occurred to evaluate your plan) in cooperation with other industries. • When a responsible party is identified, educate the party on the impacts of his or her actions. Spill Ruponse and .l'rfmention • See SCu Spill Prevention Control and Cleanup. Other Considerations • Many facilities do not have accurate, up-to-date schematic drawings. Requirements Costs (inchuling capital and operation & maintenance) • The primary cost is for staff time and depends on how aggressively a program is implemented. • Cost for containment and disposal is borne by the discharger. • Illicit connections can be difficult to locate especially ifthere is groundwater infiltration. • Indoor floor drains may require re-plumbing if cross-connections to storm drains are detected. Maintenance (including administrati11e and sta[fi.ng) • Illegal dumping and illicit connection violations requires technical staff to detect and investigate them. Supplemental Information Further Detail of the BMP Illegal Dumping • Substances illegally dumped on streets and into the storm drain systems and creeks include paints, used oil and other automotive fluids, construction debris, chemicals, fresh concrete, leaves, grass clippings, and pet wastes. All of these wastes cause stormwater and receiving water quality problems as well as clog the storm drain system itself. • Establish a system for tracking incidents. The system should be designed to identify the following: Illegal dumping hot spots January 2003 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 5 of 6 c SC-10 Non-Stormwater Discharges Types and quantities (in some cases) of wastes Patterns in time of occurrence (time of day/night, month, or year) Mode of dumping (abandoned containers, "midnight dumping" from moving vehicles, direct dumping of materials, accidents/spills) Responsible parties One of the keys to success of reducing or eliminating illegal dumping is increasing the number of people at the facility who are aware of the problem and who have the tools to at least identify the incident, if not correct it. Therefore, train field staff to recognize and report the incidents. What constitutes a "non-stormwater" discharge? • Non-stormwater discharges to the stormwater collection system may include any water used directly in the manufacturing process (process wastewater), air conditioning condensate and coolant, non-contact cooling water, cooling equipment condensate, outdoor secondary containment water, vehicle and equipment wash water, sink and drinking fountain wastewater, sanitary wastes, or other wastewaters. Permit Requirements • Facilities subject to storm water permit requirements must include a certification that the stormwater collection system has been tested or evaluated for the presence of non- stormwater discharges. The State's General Industrial Stormwater Permit requires that non- stormwater discharges be eliminated prior to implementation of the facility's SWPPP. Performance Evaluation • Review annually internal investigation results; assess whether goals were met and what changes or improvements are necessary. • Obtain feedback from personnel assigned to respond to, or inspect for, illicit connections and illegal dumping incidents. References and Resources California's Nonpoint Source Program Plan http://www.SWfcb.ca.iWv/nps/index.html Clark County Storm Water Pollution Control Manual http: //www.co.clark. wa.us/pubworks/bmpman.pdf King County Storm Water Pollution Control Manual hUP://<lnr.metrokc.e;oy/wlr/dss/s,pcm.htm Santa Clara Valley Urban Runoff Pollution Prevention Program http://www .scvurpp,p.or~ The Storm Water Managers Resource Center http://www.stormwatercenter.net/ 6 of6 California Smrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 SC-11 Spill Prevention, Control & Cleanup Description of the facility, owner and address, activities and chemicals present Facility map Notification and evacuation procedures Cleanup instructions Identification of responsible departments Identify key spill response personnel • Recycle, reclaim, or reuse materials whenever possible. This will reduce the amount of process materials that are brought into the facility. Suggated Protocols (including equipment needs) Spill Prevention • Develop procedures to prevent/mitigate spills to storm drain systems. Develop and standardize reporting procedures, containment, storage, and disposal activities, documentation, and follow-up procedures. • If consistent illegal dumping is observed at the facility: Post "No Dumping" signs with a phone number for reporting illegal dumping and disposal. Signs should also indicate fines and penalties applicable for illegal dumping. Landscaping and beautification efforts may also discourage illegal dumping. Bright lighting and/or entrance barriers may also be needed to discourage illegal dumping. • Store and contain liquid materials in such a manner that if the tank is ruptured, the contents will not discharge, flow, or be washed into the storm drainage system, surface waters, or groundwater. • If the liquid is oi~ gas, or other material that separates from and floats on water, install a spill control device (such as a tee section) in the catch basins that collects runoff from the storage tank area. • Routine maintenance: 2 of9 Place drip pans or absorbent materials beneath all mounted taps, and at all potential drip and spill locations during filling and unloading of tanks. Any collected liquids or soiled absorbent materials must be reused/recycled or properly disposed. Store and maintain appropriate spill cleanup materials in a location known to all near the tank storage area; and ensure that employees are familiar with the site's spill control plan and/or proper spill cleanup procedures. Sweep and clean the storage area monthly if it is paved, do not hose down the area to a storm drain. California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Errata 4-06 Spill Prevention, Control & Cleanup SC-11 Check tanks (and any containment sumps) daily for leaks and spills. Replace tanks that are leaking, coiToded, or otherwise deteriorating with tanks in good condition. Collect all spilled liquids and properly dispose of them. • Label all containers according to their contents (e.g., solvent, gasoline). • Label hazardous substances regarding the potential hazard (corrosive, radioactive, flammable, explosive, poisonous). • Prominently display required labels on transported hazardous and toxic materials (per US DOT regulations). • Identify key spill response personnel. Spill Control and Cleanup Activities • Follow the Spill Prevention Control and Countermeasure Plan. • Clean up leaks and spills immediately. • Place a stockpile of spill cleanup materials where it will be readily accessible (e.g., near storage and maintenance areas). • On paved surfaces, clean up spills with as little water as possible. Use a rag for small spills, a damp mop for general cleanup, and absorbent material for larger spills. If the spilled material is hazardous, then the used cleanup materials are also hazardous and must be sent to a certified laundry (rags) or disposed of as hazardous waste. Physical methods for the cleanup of dry chemicals include the use of brooms, shovels, sweepers, or plows. • Never hose down or bury dry material spills. Sweep up the material and dispose of properly. • Chemical cleanups of material can be achieved with the use of adsorbents, gels, and foams. Use adsorbent materials on small spills rather than hosing down the spill. Remove the adsorbent materials promptly and dispose of properly. • For larger spills, a private spill cleanup company or Hazmat team may be necessary. Reporting • Report spills that pose an immediate threat to human health or the environment to the Regional Water Quality Control Board. • Federal regulations require that any oil spill into a water body or onto an adjoining shoreline be reported to the National Response Center (NRC) at 800-424-8802 (24 hour). • Report spills to local agencies, such as the fire department; they can assist in cleanup. • Establish a system for tracking incidents. The system should be designed to identify the following: Types and quantities (in some cases) of wastes Patterns in time of occurrence (time of day /night, month, or year) January 2003 Errata 4-06 California StDrrnwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 3 of 9 -SC-11 Spill Prevention, Control & Cleanup Mode of dumping (abandoned containers, "midnight dumping" from moving vehicles, direct dumping of materials, accidents/spills) Responsible parties Training • Educate employees about spill prevention and cleanup. • Well-trained employees can reduce human errors that lead to accidental releases or spills: The employee should have the tools and knowledge to immediately begin cleaning up a spill should one occur. Employees should be familiar with the Spill Prevention Control and Countermeasure Plan. • Employees should be educated about aboveground storage tank requirements. Employees responsible for aboveground storage tanks and liquid transfers should be thoroughly familiar with the Spill Prevention Control and Countermeasure Plan and the plan should be readily available. • Train employees to recognize and report illegal dumping incidents. Other Considerations (Limitations and Regulations) • A Spill Prevention Control and Countermeasure Plan (SPCC) is required for facilities that are subject to the oil pollution regulations specified in Part 112 of 'Iitle 40 of the Code of Federal Regulations or if they have a storage capacity of to,ooo gallons or more of petroleum. (Health and Safety Code 6.67) • State regulations also exist for storage of hazardous materials (Health & Safety Code Chapter 6.95), including the preparation of area and business plans for emergency response to the releases or threatened releases. • Consider requiring smaller secondary containment areas (less than 200 sq. ft.) to be connected to the sanitary sewer, prohibiting any hard connections to the storm drain. Requirements Costs (including capital and operation & maintenance) • Will vary depending on the size of the facility and the necessary controls. • Prevention ofleaks and spills is inexpensive. Treatment and/or disposal of contaminated soil or water can be quite expensive. Maintenance (including administrative and staJfing) • This BMP has no major administrative or staffing requirements. However, extra time is needed to properly handle and dispose of spills, which results in increased labor costs. 4 of9 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Errata 4-06 Spill Prevention, Control & Cleanup SC-11 Supplemental Information Ftu-ther Detail of the BMP Reporting Record keeping and internal reporting represent good operating practices because they can increase the efficiency of the facility and the effectiveness of BMPs. A good record keeping system helps the facility minimize incident recurrence, correctly respond with appropriate cleanup activities, and comply with legal requirements. A record keeping and reporting system should be set up for documenting spills, leaks, and other discharges, including discharges of hazardous substances in reportable quantities. Incident records describe the quality and quantity of non-stormwater discharges to the storm sewer. These records should contain the following information: • Date and time of the incident • Weather conditions • Duration of the spill/leak/ discharge • Cause of the spill/leak/discharge • Response procedures implemented • Persons notified • Environmental problems associated with the spill/leak/discharge Separate record keeping systems should be established to document housekeeping and preventive maintenance inspections, and training activities. All housekeeping and preventive maintenance inspections should be documented. Inspection documentation should contain the following information: • The date and time the inspection was performed • Name of the inspector • Items inspected • Problems noted • Corrective action required • Date corrective action was taken Other means to document and record inspection results are field notes, timed and dated photographs, videotapes, and drawings and maps. Aboveground Tank Leak and Spill Control Accidental releases of materials from aboveground liquid storage tanks present the potential for contaminating stormwater with many different pollutants. Materials spilled, leaked, or lost from January 2003 Errata 4-06 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 5 of 9 SC-11 Spill Prevention, Control & Cleanup ~ . ......., tanks may accumulate in soils or on impervious surfaces and be carried away by stormwater runoff. The most common causes of unintentional releases are: • Installation problems • Failure of piping systems (pipes, pumps, flanges, couplings, hoses, and valves) • External oorrosion and structural failure • Spills and overfills due to operator error • Leaks during pumping of liquids or gases from truck or rail car to a storage tank or vice versa Storage of reactive, ignitable, or flammable liquids should comply with the Uniform Fire Code and the National Electric Code. Practices listed below should be employed to enhance the code requirements: • Tanks should be placed in a designated area. • Tanks located in areas where firearms are discharged should be encapsulated in concrete or the equivalent. • Designated areas should be impervious and paved with Portland cement concrete, free of cracks and gaps, in order to contain leaks and spills. • Liquid materials should be stored in UL approved double walled tanks or surrounded by a curb or dike to provide the volume to contain 10 percent of the volume of all of the containers or uo percent of the volume of the largest container, whichever is greater. The area inside the curb should slope to a drain. • For used oil or dangerous waste, a dead-end sump should be installed in the drain. • All other liquids should be drained to the sanitary sewer if available. The drain must have a positive oontrol such as a lock, valve, or plug to prevent release of contaminated liquids. • Accumulated stormwater in petroleum storage areas should be passed through an oil/water separator. Maintenance is critical to preventing leaks and spills. Conduct routine inspections and: • Check for external corrosion and structural failure. • Check for spills and overfills due to operator error. • Check for failure of piping system (pipes, pumps, flanger, coupling, hoses, and valves). • Check for leaks or spills during pumping of liquids or gases from truck or rail car to a storage facility or vice versa. 6 of9 California StDrrnwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Errata 4-06 Spill Prevention, Control & Cleanup SC-11 • Visually inspect new tank or container installation for loose fittings, poor welding, and improper or poorly fitted gaskets. • Inspect tank foundations, connections, coatings, and tank walls and piping system. Look for corrosion, leaks, cracks, scratches, and other physical damage that may weaken the tank or container system. • Frequently relocate accumulated stormwater during the wet season. • Periodically conduct integrity testing by a qualified professional. Vehicle Leak and Spill Control Major spills on roadways and other public areas are generally handled by highly trained Hazmat teams from local fire departments or environmental health departments. The measures listed below pertain to leaks and smaller spills at vehicle maintenance shops. In addition to implementing the spill prevention, control, and clean up practices above, use the following measures related to specific activities: Vehicle and Equipment Maintenance • Perform all vehicle fluid removal or changing inside or under cover to prevent the run-on of stormwater and the runoff of spills. • Regularly inspect vehicles and equipment for leaks, and repair immediately. • Check incoming vehicles and equipment (including delivery trucks, and employee and subcontractor vehicles) for leaking oil and fluids. Do not allow leaking vehicles or equipment onsite. • Always use secondary containment, such as a drain pan or drop cloth, to catch spills or leaks when removing or changing fluids. • Immediately drain all fluids from wrecked vehicles. • Store wrecked vehicles or damaged equipment under cover. • Place drip pans or absorbent materials under heavy equipment when not in use. • Use adsorbent materials on small spills rather than hosing down the spill. • Remove the adsorbent materials promptly and dispose of properly. • Promptly transfer used fluids to the proper waste or recycling drums. Don't leave full drip pans or other open containers lying around. • Oil filters disposed of in trashcans or dumpsters can leak oil and contaminate stormwater. Place the oil filter in a funnel over a waste oil recycling drum to drain excess oil before disposal. Oil filters can also be recycled. Ask your oil supplier or recycler about recycling oil filters. January 2003 Errata 4-06 California StDrrnwater BMP Handbook Industrial and Commercial www.cabmphandbooks.com 7 of 9 SC-11 Spill Prevention, Control & Cleanup '-"" • Store cracked batteries in a non-leaking secondary container. Do this with all cracked batteries, even if you think all the acid has drained out. If you drop a battery, treat it as if it is cracked. Put it into the containment area until you are sure it is not leaking. Vehicle and Equipment Fueling • Design the fueling area to prevent the run-on of stormwater and the runoff of spills: Cover fueling area if possible. Use a perimeter drain or slope pavement inward with drainage to a sump. Pave fueling area with concrete rather than asphalt. • If dead-end sump is not used to collect spills, install an oil/water separator. • Install vapor recovery nozzles to help control drips as well as air pollution. • Discourage "topping-off of fuel tanks. • Use secondary containment when transferring fuel from the tank truck to the fuel tank. • Use adsorbent materials on small spills and general cleaning rather than hosing down the area. Remove the adsorbent materials promptly. • Carry out all Federal and State requirements regarding underground storage tanks, or install above ground tanks. • Do not use mobile fueling of mobile industrial equipment around the facility; rather, transport the equipment to designated fueling areas. • Keep your Spill Prevention Control and Countermeasure (SPCC) Plan up-to-date. • Train employees in proper fueling and cleanup procedures. Industrial Spill Prevention Response For the purposes of developing a spill prevention and response program to meet the stormwater regulations, facility managers should use information provided in this fact sheet and the spill prevention/response portions of the fact sheets in this handbook, for specific activities. The program should: • Integrate with existing emergency response/hazardous materials programs (e.g., Fire Department) • Develop procedures to prevent/mitigate spills to storm drain systems • Identify responsible departments • Develop and standardize reporting procedures, containment, storage, and disposal activities, documentation, and follow-up procedures .~ • Address spills at municipal facilities, as well as public areas '-"' 8 of9 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Errata 4-06 Spill Prevention, Control & Cleanup SC-11 • Provide training concerning spill prevention, response and cleanup to all appropriate personnel References and Resources California's Nonpoint Source Program Plan http://www.swrcb.ca.eov/nps/index.html Clark County Storm Water Pollution Control Manual http://www.co.elark.wa.us/pubworks/bmpman.pdf King County Storm Water Pollution Control Manual http://dnr.metrokc.gov/wlr/dss/spcm.htm Santa Clara Valley Urban Runoff Pollution Prevention Program htt,p: //www .scyuwpp.ore The Stormwater Managers Resource Center http:f/www.stormwatercenter.net/ January 2003 Errata 4-06 California Smrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 9 of 9 SC-34 Waste Handling & Disposal "-"' Suggested Protocols General • Cover storage containers with leak proof lids or some other means. If waste is not in containers, cover all waste piles (plastic tarps are acceptable coverage) and prevent stormwater run-on and runoff with a berm. The waste containers or piles must be covered except when in use. • Use drip pans or absorbent materials whenever grease containers are emptied by vacuum trucks or other means. Grease cannot be left on the ground. Collected grease must be properly disposed of as garbage. • Check storage containers weekly for leaks and to ensure that lids are on tightly. Replace any that are leaking, corroded, or otherwise deteriorating. • Sweep and clean the storage area regularly. If it is paved, do not hose down the area to a storm drain. • Dispose of rinse and wash water from cleaning waste containers into a sanitary sewer if allowed by the local sewer authority. Do not discharge wash water to the street or storm drain. • Transfer waste from damaged containers into safe containers. • Take special care when loading or unloading wastes to minimize losses. Loading systems can be used to minimize spills and fugitive emission losses such as dust or mist. Vacuum transfer systems can minimize waste loss. Controlling Litter • Post "No Littering" signs and enforce anti-litter laws. • Provide a sufficient number of litter receptacles for the facility. • Clean out and cover litter receptacles frequently to prevent spillage. Waste Collection • Keep waste collection areas clean. • Inspect solid waste containers for structural damage regularly. Repair or replace damaged containers as necessary. • Secure solid waste containers; containers must be closed tightly when not in use. • Do not fill waste containers with washout water or any other liquid. • Ensure that only appropriate solid wastes are added to the solid waste container. Certain wastes such as hazardous wastes, appliances, fluorescent lamps, pesticides, etc., may not be disposed of in solid waste containers (see chemical/ hazardous waste collection section below). 2 of 5 California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 c Waste Handling & Disposal SC-34 • Do not mix wastes; this can cause chemical reactions, make recycling impossible, and complicate disposal. Good Housekeeping • Use all ofthe product before disposing of the container. • Keep the waste management area clean at all times by sweeping and cleaning up spills immediately. • Use dry methods when possible (e.g., sweeping, use of absorbents) when cleaning around restaurant/food handling dumpster areas. If water must be used after sweeping/using absorbents, collect water and discharge through grease interceptor to the sewer. Chemical/Hazardou.s Wastes • Select designated hazardous waste collection areas on-site. • Store hazardous materials and wastes in covered containers and protect them from vandalism. • Place hazardous waste containers in secondary containment. • Make sure that hazardous waste is collected, removed, and disposed of only at authorized disposal areas. • Stencil or demarcate storm drains on the facility's property with prohibitive message regarding waste disposal. Run-on/Runoff Prevention • Prevent stormwater run-on from entering the waste management area by enclosing the area or building a berm around the area. • Prevent waste materials from directly contacting rain. • Cover waste piles with temporary covering material such as reinforced tarpaulin, polyethylene, polyurethane, polypropyleneor hypalon. • Cover the area with a permanent roof if feasible. • Cover dumpsters to prevent rain from washing waste out of holes or cracks in the bottom of the dumpster. • Move the activity indoor after ensuring all safety concerns such as fire hazard and ventilation are addressed. Inspection • Inspect and replace faulty pumps or hoses regularly to minimize the potential of releases and spills. • Check waste management areas for leaking containers or spills. January 2003 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 3 of 5 SC-34 Waste Handling & Disposal ""'-" • Repair leaking equipment including valves, lines, seals, or pumps promptly. Training • Train staff in pollution prevention measures and proper disposal methods. • Train employees and contractors in proper spill containment and cleanup. The employee should have the tools and knowledge to immediately begin cleaning up a spill should one occur. • Train employees and subcontractors in proper hazardous waste management. Spill Response and Prfmention • Keep your Spill Prevention Control and Countermeasure (SPCC) Plan up-to-date. • Have an emergency plan, equipment and trained personnel ready at all times to deal immediately with major spills • Collect all spilled liquids and properly dispose of them. • Store and maintain appropriate spill cleanup materials in a location known to all near the designated wash area. • Ensure that vehicles transporting waste have spill prevention equipment that can prevent spills during transport. Spill prevention equipment includes: Vehicles equipped with baffles for liquid waste Trucks with sealed gates and spill guards for solid waste Other Considerations (Limitations and Regulations) Hazardous waste cannot be reused or recycled; it must be disposed of by a licensed hazardous waste hauler. Requirements Costs Capital and O&M costs for these programs will vary substantially depending on the size of the facility and the types of waste handled. Costs should be low if there is an inventory program in place. Maintenance • None except for maintaining equipment for material tracking program. Supplemental Information Further Detail of the BMP Land Treatment System Minimize runoff of polluted stormwater from land application by: • Choosing a site where slopes are under 696, the soil is permeable, there is a low water table, !"""-it is located away from wetlands or marshes, and there is a closed drainage system \..... 4 of 5 California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Waste Handling & Disposal SC-34 • Avoiding application of waste to the site when it is raining or when the ground is saturated with water • Growing vegetation on land disposal areas to stabilize soils and reduce the volume of surface water runoff from the site • Maintaining adequate barriers between the land application site and the receiving waters (planted strips are particularly good) • Using erosion control techniques such as mulching and matting, filter fences, straw bales, diversion terracing, and sediment basins • Performing routine maintenance to ensure the erosion control or site stabilization measures are working Examples The port of Long Beach has a state-of-the-art database for identifying potential pollutant sources, documenting facility management practices, and tracking pollutants. References and Resources California's Non point Source Program Plan http:f/www.swrcb.ca.&Qv /nps/index.html Clark County Storm Water Pollution Control Manual http://www.co.elark.wa.us/pubworks/bmpman.pdf Solid Waste Container Best Management Practices-Fact Sheet On-Line Resources- Environmental Health and Safety. Harvard University. 2002. King County Storm Water Pollution Control Manual http://dnr.metrokc.&Qv/wlr/dss/s.pcm.htm Pollution from Surface Cleaning Folder. 1996. Bay Area Stormwater Management Agencies Association (BASMAA). http://www.basmaa.or; Santa Clara Valley Urban Runoff Pollution Prevention Program http://www.scvur.pw.or; The Storm Water Managers Resource Center http;//www.stormwatercenter.net/ January 2003 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 5 of 5 SC-41 Building & Grounds Maintenance ,.._ • Encourage use oflntegrated Pest Management techniques for pest control. • Encourage proper onsite recycling of yard trimmings. • Recycle residual paints, solvents, lumber, and other material as much as possible. Suggested Protocols Pressure Washing of Buildings, Rooftops, and Other Large Objects • In situations where soaps or detergents are used and the suiTounding area is paved, pressure washers must use a water collection device that enables collection of wash water and associated solids. A sump pump, wet vacuum or similarly effective device must be used to collect the runoff and loose materials. The collected runoff and solids must be disposed of properly. • If soaps or detergents are not used, and the surrounding area is paved, wash runoff does not have to be collected but must be screened. Pressure washers must use filter fabric or some other type of screen on the ground and/or in the catch basin to trap the particles in wash water runoff. • If you are pressure washing on a grassed area (with or without soap), runoff must be dispersed as sheet flow as much as possible, rather than as a concentrated stream. The wash runoff must remain on the grass and not drain to pavement. Landsooping Activities • Dispose of grass clippings, leaves, sticks, or other collected vegetation as garbage, or by composting. Do not dispose of collected vegetation into waterways or storm drainage systems. • Use mulch or other erosion control measures on exposed soils. Building Repair, Remodeling, and Construction • Do not dump any toxic substance or liquid waste on the pavement, the ground, or toward a storm drain. • Use ground or drop cloths underneath outdoor painting, scraping, and sandblasting work, and properly dispose of collected material daily. • Use a ground cloth or oversized tub for activities such as paint mixing and tool cleaning. • Clean paintbrushes and tools covered with water-based paints in sinks connected to sanitary sewers or in portable containers that can be dumped into a sanitary sewer drain. Brushes and tools covered with non-water-based paints, finishes, or other materials must be cleaned in a manner that enables collection of used solvents (e.g., paint thinner, turpentine, etc.) for recycling or proper disposal. • Use a storm drain cover, filter fabric, or similarly effective runoff control mechanism if dust, grit, wash water, or other pollutants may escape the work area and enter a catch basin. This is particularly necessary on rainy days. The containment device(s) must be in place at the beginning of the work day, and accumulated dirty runoff and solids must be collected and ~ disposed of before removing the containment device(s) at the end of the work day. '-"' 2 of 5 California StDrrnwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Building & Grounds Maintenance SC-41 • If you need to de-water an excavation site, you may need to filter the water before discharging to a catch basin or off-site. If directed off-site, you should direct the water through hay bales and filter fabric or use other sediment filters or traps. • Store toxic material under cover during precipitation events and when not in use. A cover would include tarps or other temporary cover material. Mowing, Trimming, and Planting • Dispose of leaves, sticks, or other collected vegetation as garbage, by composting or at a permitted landfill. Do not dispose of collected vegetation into waterways or storm drainage systems. • Use mulch or other erosion control measures when soils are exposed. • Place temporarily stockpiled material away from watercourses and drain inlets, and berm or cover stockpiles to prevent material releases to the storm drain system. • Consider an alternative approach when bailing out muddy water: do not put it in the storm drain; pour over landscaped areas. • Use hand weeding where practical. Fertilizer and Pesticide Management • Follow all federal, state, and local laws and regulations governing the use, storage, and disposal of fertilizers and pesticides and training of applicators and pest control advisors. • Use less toxic pesticides that will do the job when applicable. Avoid use of copper-based pesticides if possible. • Do not use pesticides if rain is expected. • Do not mix or prepare pesticides for application near storm drains. • Use the minimum amount needed for the job. • Calibrate fertilizer distributors to avoid excessive application. • Employ techniques to minimize off-target application (e.g., spray drift) of pesticides, including consideration of alternative application techniques. • Apply pesticides only when wind speeds are low. • Fertilizers should be worked into the soil rather than dumped or broadcast onto the surface. • Irrigate slowly to prevent runoff and then only as much as is needed. • Clean pavement and sidewalk if fertilizer is spilled on these surfaces before applying irrigation water. • Dispose of empty pesticide containers according to the instructions on the container label. January 2003 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 3 of 5 SC-41 Building & Grounds Maintenance • Use up the pesticides. Rinse containers, and use rinse water as product. Dispose of unused pesticide as hazardous waste. • Implement storage requirements for pesticide products with guidance from the local fire department and County Agricultural Commissioner. Provide secondary containment for pesticides. Inspection • Inspect irrigation system periodically to ensure that the right amount of water is being applied and that excessive runoff is not occurring. Minimize excess watering and repair leaks in the irrigation system as soon as they are observed. Training • Educate and train employees on pesticide use and in pesticide application techniques to prevent pollution. • Train employees and contractors in proper techniques for spill containment and cleanup. • Be sure the frequency of training takes into account the complexity of the operations and the nature of the staff. Spill Response and .Prcwention • Keep your Spill Prevention Control and Countermeasure (SPCC) Plan up-to-date. • Place a stockpile of spill cleanup materials, such as brooms, dustpans, and vacuum sweepers (if desired) near the storage area where it will be readily accessible. • Have employees trained in spill containment and cleanup present during the loading/unloading of dangerous wastes, liquid chemicals, or other materials. • Familiarize employees with the Spill Prevention Control and Countermeasure Plan. • Clean up spills immediately. Other Considerations Alternative pest/weed controls may not be available, suitable, or effective in many cases. Requirements Costs • Cost will vary depending on the type and size of facility. • Overall costs should be low in comparison to other BMPs. Maintenance Sweep paved areas regularly to collect loose particles. Wipe up spills with rags and other absorbent material immediately, do not hose down the area to a storm drain. 4 of 5 California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Building & Grounds Maintenance SC-41 Supplemental Information Ftuoth.er Detail ofth.e BMP Fire Sprinkler Une Rushing Building fire sprinkler line flushing may be a source of non-stormwater runoff pollution. The water entering the system is usually potable water, though in some areas it may be non-potable reclaimed wastewater. There are subsequent factors that may drastically reduce the quality of the water in such systems. Black iron pipe is usually used since it is cheaper than potable piping, but it is subject to rusting and results in lower quality water. Initially, the black iron pipe has an oil coating to protect it from rusting between manufacture and installation; this will contaminate the water from the first flush but not from subsequent flushes. Nitrates, poly- phosphates and other corrosion inhibitors, as well as fire suppressants and antifreeze may be added to the sprinkler water system. Water generally remains in the sprinkler system a long time (typically a year) and between flushes may accumulate iron, manganese, lead, copper, nickel, and zinc. The water generally becomes anoxic and contains living and dead bacteria and breakdown products from chlorination. This may result in a significant BOD problem and the water often smells. Consequently dispose fire sprinkler line flush water into the sanitary sewer. Do not allow discharge to storm drain or infiltration due to potential high levels of pollutants in fire sprinkler line water. References and Resources California's Nonpoint Source Program Plan http://www.swrcb.ca.~y/nps/index.html Clark County Storm Water Pollution Control Manual http: //www.co.elark.wa.us/pubworks/bmpman.pdf King County Storm Water Pollution Control Manual http;//dnr.metrokc.&<>Yiwlr/cJss/s,pcm.htm Mobile Cleaners Pilot Program: Final Report. 1997. Bay Area Stormwater Management Agencies Association (BASMAA). http: /{www.basmaa.org/ Pollution from Surface Cleaning Folder. 1996. Bay Area Stormwater Management Agencies Association (BASMAA). http://www.basmaa.org/ Santa Clara Valley Urban Runoff Pollution Prevention Program htt.P://www.scvumpp.org The Storm Water Managers Resource Center http://www.stormwatercenter.net/ January 2003 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 5 of 5 SC-42 Building Repair and Construction ,-. ''-"' • Make sure that nearby stonn drains are well marked to minimize the chance of inadvertent disposal of residual paints and other liquids. Suggested Protocols Repair & Remodeling • Follow BMPs identified in Construction BMP Handbook. • Maintain good housekeeping practices while work is underway. • Keep the work site clean and orderly. Remove debris in a timely fashion. Sweep the area. • Cover materials of particular concern that must be left outside, particularly during the rainy season. • Do not dump waste liquids down the storm drain. • Dispose of wash water, sweepings, and sediments properly. • Store materials properly that are normally used in repair and remodeling such as paints and solvents. • Sweep out the gutter or wash the gutter and trap the particles at the outlet of the downspout if when repairing roofs, small particles have accumulated in the gutter. A sock or geofa bric placed over the outlet may effectively trap the materials. If the downspout is tight lined, . ..,.... place a temporary plug at the first convenient point in the storm drain and pump out the '-" water with a vactor truck, and clean the catch basin sump where you placed the plug. • Properly store and dispose waste materials generated from construction activities. See Construction BMP Handbook. • Clean the storm drain system in the immediate vicinity of the construction activity after it is completed. Painting • Enclose painting operations consistent with local air quality regulations and OSHA • Local air pollution regulations may, in many areas of the state, specify painting procedures which if properly carried out are usually sufficient to protect water quality. • Develop paint handling procedures for proper use, storage, and disposal of paints. • Transport paint and materials to and from job sites in containers with secure lids and tied down to the transport vehicle. • Test and inspect spray equipment prior to starting to paint. Tighten all hoses and connections and do not overfill paint containers. • Mix paint indoors before using so that any spill will not be exposed to rain. Do so even during dry weather because cleanup of a spill will never be too% effective. ~ • Transfer and load paint and hot thermoplastic away from storm drain inlets. '-" 2 of 4 California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Building Repair and Construction SC-42 • Do not transfer or load paint near storm drain inlets. • Plug nearby storm drain inlets prior to starting painting and remove plugs when job is complete when there is significant risk of a spill reaching storm drains. • Cover nearby storm drain inlets prior to starting work if sand blasting is used to remove paint. • Use a ground cloth to collect the chips if painting requires scraping or sand blasting of the existing surface. Dispose the residue properly. • Cover or enclose painting operations properly to avoid drift. • Clean the application equipment in a sink that is connected to the sanitary sewer if using water based paints. • Capture all cleanup-water and dispose of properly. • Dispose of paints containing lead or tributyl tin and considered a hazardous waste properly. • Store leftover paints if they are to be kept for the next job properly, or dispose properly. • Recycle paint when possible. Dispose of paint at an appropriate household hazardous waste facility. Training Proper education of off-site contractors is often overlooked. The conscientious efforts of well trained employees can be lost by unknowing off-site contractors, so make sure they are well informed a bout what they are expected to do. Spill Response and Prevention • Keep your Spill Prevention Control and Countermeasure (SPCC) Plan up-to-date. • Place a stockpile of spill cleanup materials where it will be readily accessible. • Clean up spills immediately. • Excavate and remove the contaminated (stained) soil if a spill occurs on dirt. Limitations • This BMP is for minor construction only. The State's General Construction Activity Stormwater Permit has more requirements for larger projects. The companion "Construction Best Management Practice Handbook" contains specific guidance and best management practices for larger-scale projects. • Hazardous waste that cannot be reused or recycled must be disposed of by a licensed hazardous waste hauler. • Be certain that actions to help stormwater quality are consistent with Cal-and Fed-OSHA and air quality regulations. January 2003 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 3 of 4 SC-42 Building Repair and Construction '~ '-"" Requirements Costs These BMPs are generally low to modest in cost. Maintenance N/A Supplemental Information Further Detail of the BMP Soil/Erosion Control If the work involves exposing large areas of soil, employ the appropriate soil erosion and control techniques. See the Construction Best Management Practice Handbook. If old buildings are being tom down and not replaced in the near future, stabilize the site using measures described in SC-40 Contaminated or Erodible Areas. If a building is to be placed over an open area with a storm drainage system, make sure the storm inlets within the building are covered or removed, or the storm line is connected to the sanitary sewer. If because of the remodeling a new drainage system is to be installed or the existing system is to be modified, consider installing catch basins as they serve as effective "in- line" treatment devices. See Treatment Control Fact Sheet TC-20 Wet Pond/Basin in Section 5 of the New Development and Redevelopment Handbook regarding design criteria. Include in the catch basin a "tum-down" elbow or similar device to trap floatables. References and Resources California's Nonpoint Source Program Plan http://www.swrcb.ca.~y/nps/index,html Clark County Storm Water Pollution Control Manual http://www .co. clark. wa.uslpubworks/bmpman.pdf King County Storm Water Pollution Control Manual http://dnr.metrokc.~ov/wlr/dss/s,pcm.htm Santa Clara Valley Urban Runoff Pollution Prevention Program http://www.scvurppp.or~ The Storm Water Managers Resource Center http://www.stormwatercenter.net/ 4 of 4 California Stxmnwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 SC-43 Parking/Storage Area Maintenance ,..,-. ,_,. Suggested Protocols General • Keep the parking and storage areas clean and orderly. Remove debris in a timely fashion. • Allow sheet runoff to flow into biofilters (vegetated strip and swale) and/or infiltration devices. • Utilize sand filters or oleophilic collectors for oily waste in low quantities. • Arrange rooftop drains to prevent drainage directly onto paved surfaces. • Design lot to include semi-permeable hardscape. • Discharge soapy water remaining in mop or wash buckets to the sanitary sewer through a sink, toilet, clean-out, or wash area with drain. Controlling Litter • Post "No Littering" signs and enforce anti-litter laws. • Provide an adequate number of litter receptacles. • Clean out and cover litter receptacles frequently to prevent spillage. • Provide trash receptacles in parking lots to discourage litter. • Routinely sweep, shovel, and dispose of litter in the trash. Surface Cleaning • Use dry cleaning methods (e.g., sweeping, vacuuming) to prevent the discharge of pollutants into the stormwater conveyance system if possible. • Establish frequency of public parking lot sweeping based on usage and field observations of waste accumulation. • Sweep all parking lots at least once before the onset of the wet season. • Follow the procedures below if water is used to clean surfaces: Block the storm drain or contain runoff. Collect and pump wash water to the sanitary sewer or discharge to a pervious surface. Do not allow wash water to enter storm drains. Dispose of parking lot sweeping debris and dirt at a landfill. • Follow the procedures below when cleaning heavy oily deposits: 2 of 4 Clean oily spots with absorbent materials. Use a screen or filter fabric over inlet, then wash surfaces. California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Parking/Storage Area Maintenance SC-43 Do not allow discharges to the storm drain. Vacuum/pump discharges to a tank or discharge to sanitary sewer. Appropriately dispose of spilled materials and absorbents. Surface Repair • Preheat, transfer or load hot bituminous material away from storm drain inlets. • Apply concrete, asphalt, and seal coat during dry weather to prevent contamination from contacting stormwater runoff. • Cover and seal nearby storm drain inlets where applicable (with waterproof material or mesh) and manholes before applying seal coat, slurry seal, etc. Leave covers in place until job is complete and all water from emulsified oil sealants has drained or evaporated. Clean any debris from these covered manholes and drains for proper disposal. • Use only as much water as necessary for dust control, to avoid runoff. • Catch drips from paving equipment that is not in use with pans or absorbent material placed under the machines. Dispose of collected material and absorbents properly. Inspection • Have designated personnel conduct inspections of parking facilities and storm water conveyance systems associated with parking facilities on a regular basis. • Inspect cleaning equipment/sweepers for leaks on a regular basis. Training • Provide regular training to field employees and/ or contractors regarding cleaning of paved areas and proper operation of equipment. • Train employees and contractors in proper techniques for spill containment and cleanup. Spill Response and Prevention • Keep your Spill Prevention Control and Countermeasure (SPCC) Plan up-to-date. • Place a stockpile of spill cleanup materials where it will be readily accessible or at a central location. • Clean up fluid spills immediately with absorbent rags or material. • Dispose of spilled material and absorbents properly. Other Considerations Limitations related to sweeping activities at large parking facilities may include high equipment costs, the need for sweeper operator training, and the inability of current sweeper technology to remove oil and grease. January 2003 California Stxmnwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 3 of 4 SC-43 Parking/Storage Area Maintenance "'-" Requirements Cotlts Cleaning/sweeping costs can be quite large. Construction and maintenance of stormwater structural controls can be quite expensive as well. Maintenance • Sweep parking lot regularly to minimize cleaning with water. • Clean out oil/water/sand separators regularly, especially after heavy storms. • Clean parking facilities regularly to prevent accumulated wastes and pollutants from being discharged into conveyance systems during rainy conditions. Supplemental Information Further Detail of the BMP Surface Repair Apply concrete, asphalt, and seal coat during dry weather to prevent contamination from contacting stormwater runoff. Where applicable, cover and seal nearby storm drain inlets (with waterproof material or mesh) and manholes before applying seal coat, slurry seal, etc. Leave covers in place until job is complete and all water from emulsified oil sealants has drained or evaporated. Clean any debris from these covered manholes and drains for proper disposal. Only use only as much water as is necessary for dust control to avoid runoff. References and Resources California's Nonpoint Source Program Plan http://www.swrcb.ca.~v/nps/index.html Clark County Storm Water Pollution Control Manual btW: //www.co.elark.wa.us/pubworks/bmpman.pdf King County Storm Water Pollution Control Manual http://dnr.metrokc.gov/wlr/dss/spcm.htm Pollution from Surface Cleaning Folder. 1996. Bay Area Stormwater Management Agencies Association (BASMAA). http://www.basmaa.or&/ Oregon Association of Clean Water Agencies. Oregon Municipal Stormwater Toolbox for Maintenance Practices. June 1998. Santa Clara Valley Urban Runoff Pollution Prevention Program http://www.scvurpl!l!·or& The Storm Water Managers Resource Center http://www.stormwatercenter.net/ 4 of 4 California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 SC-44 Drainage System Maintenance • Clean catch basins, storm drain inlets, and other conveyance structures before the wet season to remove sediments and debris accumulated during the summer. • Conduct inspections more frequently during the wet season for problem areas where sediment or trash accumulates more often. Clean and repair as needed. • Keep accurate lo~ of the number of catch basins cleaned. • Store wastes collected from cleaning activities of the drainage system in appropriate containers or temporary storage sites in a manner that prevents discharge to the storm drain. • Dewater the wastes if necessary with outflow into the sanitary sewer if permitted. Water should be treated with an appropriate filtering device prior to discharge to the sanitary sewer. If discharge to the sanitary sewer is not allowed, water should be pumped or vacuumed to a tank and properly disposed. Do not dewater near a storm drain or stream. Storm Drain Conveyance System • Locate reaches of storm drain with deposit problems and develop a flushing schedule that keeps the pipe clear of excessive buildup. • Collect and pump flushed effluent to the sanitary sewer for treatment whenever possible. Pump Stations • Clean all storm drain pump stations prior to the wet season to remove sih and trash. • Do not allow discharge to reach the storm drain system when cleaning a storm drain pump station or other facility. • Conduct routine maintenance at each pump station. • Inspect, clean, and repair as necessary all outlet structures prior to the wet season. Open Channel • Modify storm channel characteristics to improve channel hydraulics, increase pollutant removals, and enhance channel/creek aesthetic and habitat value. • Conduct channel modification/improvement in accordance with existing laws. Any person, government agency, or public utility proposing an activity that will change the natural (emphasis added) state of any river, stream, or lake in California, must enter into a Steam or Lake Alteration Agreement with the Department of Fish and Game. The developer-applicant should also contact local governments (city, county, special districts), other state agencies (SWRCB, RWQCB, Department of Forestry, Department of Water Resources), and Federal Corps of Engineers and USFWS. Illicit Connections and Discharges • Look for evidence of illegal discharges or illicit connections during routine maintenance of conveyance system and drainage structures: 2 of6 Is there evidence of spills such as paints, discoloring, etc? California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Drainage System Maintenance SC-44 Are there any odors associated with the drainage system? Record locations of apparent illegal discharges/illicit connections? Track flows back to potential dischargers and conduct aboveground inspections. This can be done through visual inspection ofupgradient manholes or alternate techniques including zinc chloride smoke testing, fluorometric dye testing, physical inspection testing, or television camera inspection. Eliminate the discharge once the origin of flow is established. • Stencil or demarcate storm drains, where applicable, to prevent illegal disposal of pollutants. Storm drain inlets should have messages such as "Dump No Waste Drains to Stream" stenciled next to them to warn against ignorant or intentional dumping of pollutants into the storm drainage system. • Refer to fact sheet SC-10 Non-Stormwater Discharges. Illegal Dumping • Inspect and clean up hot spots and other storm drainage areas regularly where illegal dumping and disposal occurs. • Establish a system for tracking incidents. The system should be designed to identify the following: Illegal dumping hot spots Types and quantities (in some cases) of wastes Patterns in time of occurrence (time of day/night, month, or year) Mode of dumping (abandoned containers, "midnight dumping" from moving vehicles, direct dumping of materials, accidents/spills) Responsible parties • Post "No Dumping" signs in problem areas with a phone number for reporting dumping and disposal. Signs should also indicate fines and penalties for illegal dumping. • Refer to fact sheet SC-10 Non-Stormwater Discharges. Training • Train crews in proper maintenance activities, including record keeping and disposal. • Allow only properly trained individuals to handle hazardous materials/wastes. • Have staff involved in detection and removal of illicit connections trained in the following: OSHA-required Health and Safety Training (29 CFR 1910.120) plus annual refresher training (as needed). January 2003 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 3 of 6 SC-44 Drainage System Maintenance OSHA Confined Space Entry training (Cal-OSHA Confined Space, Title 8 and Federal OSHA 29 CFR 1910.146). Procedural training (field screening, sampling, smoke/ dye testing, 1V inspection). Spill Response and .Prfmention • Investigate all reports of spills, leaks, and/or illegal dumping promptly. • Clean up all spills and leaks using "dry" methods (with absorbent materials and/or rags) or dig up, remove, and properly dispose of contaminated soil. • Refer to fact sheet SC-u Spill Prevention, Control, and Cleanup. Other ConsiderationB (LimitationB and RegulationB) • Clean-up activities may create a slight disturbance for local aquatic species. Access to items and material on private property may be limited. Trade-otis may exist between channel hydraulics and water quality/riparian habitat. If storm channels or basins are reoognized as wetlands, many activities, including maintenance, may be subject to regulation and permitting. • Storm drain flushing is most effective in small diameter pipes (36-inch diameter pipe or less, depending on water supply and sediment collection capacity). Other considerations associated with storm drain flushing may include the availability of a water source, finding a downstream area to collect sediments, liquid/sediment disposal, and prohibition against disposal of flushed effluent to sanitary sewer in some areas. • Regulations may include adoption of substantial penalties for illegal dumping and disposal. • Local municipal codes may include sections prohibiting discharge of soil, debris, refuse, hazardous wastes, and other pollutants into the storm drain system. Requirements Costs • An aggressive catch basin cleaning program could require a significant capital and O&M budget. • The elimination of illegal dumping is dependent on the availability, convenience, and cost of alternative means of disposal. The primary cost is for staff time. Cost depends on how aggressively a program is implemented. Other cost considerations for an illegal dumping program include: 4 of6 Purchase and installation of signs. Rental ofvehicle(s) to haul illegally-disposed items and material to landfills. Rental of heavy equipment to remove larger items (e.g., car bodies) from channels. Purchase of landfill space to dispose of illegally-dumped items and material. California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Drainage System Maintenance SC-44 • Methods used for illicit connection detection (smoke testing, dye testing, visual inspection, and flow monitoring) can be costly and time-consuming. Site-specific factors, such as the level of impervious area, the density and ages of buildings, and type of land use will determine the level of investigation necessary. Maintenance • Two-person teams may be required to clean catch basins with vactor trucks. • Teams of at least two people plus administrative personnel are required to identify illicit discharges, depending on the complexity of the storm sewer system. • Arrangements must be made for proper disposal of collected wastes. • Technical staff are required to detect and investigate illegal dumping violations. Supplemental Information Fto-ther Detail of the BMP Storm Drain Flushing Flushing is a common maintenance activity used to improve pipe hydraulics and to remove pollutants in storm drainage systems. Flushing may be designed to hydraulically convey accumulated material to strategic locations, such as an open channel, another point where flushing will be initiated, or the sanitary sewer and the treatment facilities, thus preventing resuspension and overflow of a portion of the solids during storm events. Flushing prevents "plug flow" discharges of concentrated pollutant loadings and sediments. Deposits can hinder the designed conveyance capacity of the storm drain system and potentially cause backwater conditions in severe cases of clogging. Storm drain flushing usually takes place along segments of pipe with grades that are too flat to maintain adequate velocity to keep particles in suspension. An upstream manhole is selected to place an inflatable device that temporarily plugs the pipe. Further upstream, water is pumped into the line to create a flushing wave. When the upstream reach of pipe is sufficiently full to cause a flushing wave, the inflated device is rapidly deflated with the assistance of a vacuum pump, thereby releasing the backed up water and resulting in the cleaning of the storm drain segment. To further reduce impacts of stormwater pollution, a second inflatable device placed well downstream may be used to recollect the water after the force of the flushing wave has dissipated. A pump may then be used to transfer the water and accumulated material to the sanitary sewer for treatment. In some cases, an interceptor structure may be more practical or required to recollect the flushed waters. It has been found that cleansing efficiency of periodic flush waves is dependent upon flush volume, flush discharge rate, sewer slope, sewer length, sewer flow rate, sewer diameter, and population density. As a rule of thumb, the length of line to be flushed should not exceed 700 feet. At this maximum recommended length, the percent removal efficiency ranges between 65- 7596 for organics and 55-6596 for dry weather grit/inorganic material. The percent removal efficiency drops rapidly beyond that. Water is commonly supplied by a water truck, but fire hydrants can also supply water. To make the best use of water, it is recommended that reclaimed water be used or that fire hydrant line flushing coincide with storm sewer flushing. January 2003 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 5 of 6 SC-44 Drainage System Maintenance "-"' References and Resources California's Nonpoint Source Program Plan http:/{www.swrcb.ca.i<>v/nps/index.html Clark County Storm Water Pollution Control Manual http://www.co.clark.WJ.us/pubworks/bnmman.OOf Ferguson, B.K. 1991. Urban Stream Reclamation, p. 324-322, Journal of Soil and Water Conservation. King County Storm Water Pollution Control Manual bttJ>://dnr.metrokc.gov/wlr/dss/spcm.htm Oregon Association of Clean Water Agencies. Oregon Municipal Stormwater Toolbox for Maintenance Practices. June 1998. Santa Clara Valley Urban Runoff Pollution Prevention Program http://www.scym:ppp.on The Storm Water Managers Resource Center http://www.stormwatercenter.net United States Environmental Protection Agency (USEPA). 2002. Pollution Prevention/Good Housekeeping for Municipal Operations Storm Drain System Cleaning. On line: http: //www.epa.gov /npdes/menuotbmps/poll 16.htm 6 of6 California StDrmwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com January 2003 Storm Water Compliance Inspections The City of Carlsbad has developed an inventory of all existing commercial and industrial businesses and has prioritized them according to the type of business, proximity to the nearest water body and potential threat to water quality. Based on this prioritization, the City will be conducting storm water compliance inspections of all industrial and most commercial facilities within the City. These site inspections will include a meeting with business representatives, a walk-through of the facility, evaluation of current storm water best management practices and x~mmendations for additional measures may be required to comply with the new ,_.,n,it and ordinance. In addition to the industrial and commercial inspections, the City is also performing construction site inspections, conducting a comprehensive strom drain monitoring program to detect pollutants, enforcing urban runoff requirements for new developments and conducting frequent cleaning of the storm drain system. c Sanitary Sewer vs. Storm Drain What's the difference? The water that drains down a sink or toilet flows to the sanitary sewer and is treated at a wastewater treatment plant. The storm drain, on the other hand, is designed to carry rainwater away from streets, parking lots and driveways to prevent flooding. This water does not receive any treatment and flows directly into our creeks, lagoons and ocean. G City of Carlsbad 1635 Faraday Avenue Carlsbad CA 92008 . Storm Water HOTline: 760-602-2799 stormwater@ci.carlsbad.ca.us 1'\ l.J Printed on recycled paper Best Management Practices For BUSINESSES Commercial and Industrial -~~ lf1 '~~' .1 It 0 0 0 City of Carlsbad Storm Water Protedion Program Storm Water HOnine 76G-602-2799 CITY OF SAN DIEGO STORM WATER POLLUTION PROGRAM INTEGRATED PEST MANAGEMENT Smart Tips for Hiring a Pest Control Service If you are thinking of hiring a pest control service there are some important things to consider before you take that step. Here is a checklist to help you hire a service that will adequately research your pest problem and safely apply the appropriate material to control it. Should I hire a Pest Control Service? Determine if the pest problem warrants hiring a pest control professional: • Is the damage or nuisance something you can live with? • Can you safely and effectively treat the problem yourself? • Can you make changes that will control the pest problem over the long term and eliminate the need for any chemical control? Get Recommendations and Facts Obtain recommendations from neighbors, friends or family. Call at least three companies and consider the following: • What types of services does the company offer? For example, do they provide only monthly spray contracts or do they offer an Integrated Pest Management (I PM) approach? • Are least-toxic pesticides or baits used when appropriate? • Is the company operating with the required licenses, certificates and insurance? Pest control companies and individuals making household treatments must operate with a license issued by the Structural Pest Control Board. Verify the status of a pest control company's license online at http://www. pestboard.ca.govllicense. htm. • Individuals operating in landscape maintenance or gardening businesses and performing incidental pest control must possess a Qualified Applicator Certificate or License (QAC or QAL) issued by the California Department of Pesticide Regulation. Verify the status of an individual or business QAC or QAL online at http://www.cdpr.ca.gov/docs/license/currlic.htm. • Most reputable pest control companies carry both general liability insurance and worker's compensation insurance. Ask for an Inspection • Ask the company to inspect the site. The company may charge a fee to do this inspection, but for that fee they should provide you with a diagnosis of the problem or an identification of the pest. They should show you where the pest is causing the problem and discuss how they plan to control it. The company should also provide you with details regarding the course of treatment(s), the frequency of inspections and treatment, and an estimate of the cost of implementing their treatment plan. • Consider long-term solutions to the problem. A company that practices IPM will suggest modification of the habitat or use of baits and monitoring, rather than just a guarantee to spray when and if the pest reappears. • Ask which pesticides will be used, the active ingredients they contain, and their effects on people, pets and the environment. Determine if there are specific label instructions for precautions after application. You may request a copy of the Material Safety Data Sheet from the pest control company for each pesticide used. • Ask how the pesticide will be applied and where. Chemicals sprayed around the home perimeter may be washed away by irrigation or rain, especially if concrete walkways or other impervious materials surround the home. Avoid companies that do this type of spraying. • Is the company forthcoming with information on the identified pest problem, the reasons behind a chosen treatment, and the application techniques? Monitor the Work Following selection of a pest control company, continue a dialogue with the company to insure that you are getting the service stated in your contract. • Verify that pest populations are being monitored by the company as agreed in the contract. • Communicate to the company the levels of pests that are tolerable as well as intolerable. For example, you may tolerate ants in the landscape, but not inside the home. • Inform the company of any appearance or increase in pest populations that you notice between visits. Keep These Tips in Mind Important considerations to keep in mind when applying pesticides in your garden, landscape or home: • Be aware of weather patterns and do not apply pesticides just prior to rainfall or during windy conditions. • Avoid the use of pesticides such as diazinon and chlorpyrifos that have been detected in streams, rivers and lakes. These specific products are no longer available for purchase, and can be disposed of at a household hazardous waste collection facility. • Avoid the use of "broad-spectrum" insecticides. These products indiscriminately kill many types of insects, including beneficial and desirable species, and damage the balance between pest populations and their natural enemies. Frequent use of broad-spectrum pesticides can also result in the development of resistant strains of pests or secondary outbreaks of other pests. • Under no circumstances should pest control equipment be cleaned in a location where rinse water could flow into gutters, storm drains or open waterways. • Be aware that some pesticides are more easily carried in surface runoff than others and therefore have a greater potential to move off-site during irrigation or rain events. The leaching and runoff risks of specific pesticides can be obtained from UC Riverside's Pesticide Wise web site at http://www.pw.ucr.edu. Just enter the pesticide trade name or active ingredient and the conditions under which the material will be applied, such as type of soil texture, slope, irrigation rate and vegetative cover. Information From: Cheryl Wilen, San Diego area IPM Advisor; Darren Hewer; Mary Louise Flint; Pamela M. Geisel, University of California Cooperative Extension Farm Advisor, Environmental Horticulture, Fresno County; Carolyn L. Unruh, University of California Cooperative Extension Fresno County staff writer. HCP s{ ) Ranch PA2 ( ) Fuscoe Engineering, lnc.Job No. 0272( b1-01 OMA Name OMA Area (s.~ Post-project surface type OMA Runoff factor OMA Area x runoff factor Soil Type IMP Name 1 Imp. 17,380 Roof, parking lot, hardscape 1.0 17,380 0 Flow Thru Planter 1 1 Perv. 4,020 Landscape, pervious area 0.1 402 Total 17,782 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 711 1,300 IMP Area OMA Name OMA Area (s.~ Post-project surface type OMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 2 Imp. 13,307 Roof, parking lot, hardscape 1.0 13,307 D Flow Thru Planter 2 Total 13,307 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 532 1,000 IMP Area OMA Name OMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 3 Imp. 13,186 Roof, parking lot, hardscape 1 .0 13,186 0 Flow Thru Planter 3 Total 13,186 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 527 1,000 IMP Area OMA Name OMA Area (s.~ Post-project surface type OMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 4 Imp. 9,498 Roof, parking lot, hardscape 1.0 9,498 0 Permeable Paver Area 4 Total 9,498 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 380 893 IMP Area Storm Water Management Plan4/24/2012 Appendix 5 Page 1 of 14 HCP Bressi Ranch PA2 Fuscoe Engineering, lnc.Job No. 02722-001-01 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 5 Imp. 4,803 Roof, parking lot, hardscape 1.0 4,803 D Flow Thru Planter 5 5 Perv. 2,373 Landscape, pervious area 0.1 237 Total 5,040 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 202 400 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 6 Imp. 8,388 Roof, parking lot, hardscape 1 .0 8,388 D Flow Thru Planter 6 Total 8,388 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 336 600 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 7 Imp. 11,628 Roof, parking lot, hardscape 1 .0 11,628 D Flow Thru Planter 7 Total 11,628 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 465 900 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 8 Imp. 13,035 Roof, parking lot, hardscape 1.0 13,035 D Flow Thru Planter 8 Total 13,035 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 521 1,000 IMP Area Storm' )r Management Plan4/24/2012 App )x 5 Po~ )of 14 HCP s( l Ranch PA2 ( ) Fuscoe Engineering, lnc.Job No. 02724' b1-01 DMA Name DMA Area (s.n Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 9 Imp. 11,965 Roof, parking lot, hardscape 1.0 11,965 D Flow Thru Planter 9 Total 11,965 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 479 900 IMP Area DMA Name DMA Area (s.n Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 10 Imp. 12,949 Roof, parking lot, hardscape 1.0 12,949 D Flow Thru Planter 1 0 Total 12,949 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 518 1,000 IMP Area DMA Name DMA Area (s.n Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 11 Imp. 19,231 Roof, parking lot, hardscape 1 .0 19,231 D Flow Thru Planter 11 Total 19,231 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 769 800 IMP Area DMA Name DMA Area (s.n Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 12 Imp. 27,407 Roof, parking lot, hardscape 1.0 27,407 D Flow Thru Planter 12 Total 27,407 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 1,096 1 '1 00 IMP Area Storm Water Management Plan4/24/2012 Appendix 5 Page 3 of 14 HCP Bressi Ranch PA2 Fuscoe Engineering, lnc.Job No. 02722-001-01 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 13 Imp. 10,754 Roof, parking lot, hardscape 1.0 10,754 D Flow Thru Planter 13 13 Perv. 3,328 Landscape, pervious area 0.1 333 Total 11,087 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 14 Imp. 13,229 Roof, parking lot, hardscape 1 .0 13,229 14 Perv. 4,062 Landscape, pervious area 0.1 406 Total 13,635 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 443 800 Soil Type IMP Name D Flow Thru Planter 14 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 545 1,000 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 15 Imp. 6,806 Roof, parking lot, hardscape 1 .0 6,806 D Flow Thru Planter 15 Total 6,806 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 272 500 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 16 Imp. 10,901 Roof, parking lot, hardscape 1.0 10,901 D Flow Thru Planter 16 16 Perv. 2,471 Landscape, pervious area O.l 247 Total 11 1148 Storm~ )r Management Plan4/24/2012 Appt )x 5 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 446 800 IMP Area IMP Area IMP Area IMP Area Po~ )of 14 HCP s( } Ranch PA2 Fuscoe Engineering, lnc.Job No. 0271 _,b1-01 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 17 Imp. 7,432 Roof, parking lot, hardscape 1.0 7,432 D Flow Thru Planter 17 17 Perv. 5,020 Landscape, pervious area 0.1 502 Total 7,934 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 18 Imp. 6,81 0 Roof, parking lot, hardscape 1 .0 6,81 0 18 Perv. 1,759 Landscape, pervious area 0.1 176 Total 6,986 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 19 Imp. 19,519 Roof, parking lot, hardscape 1 .0 19,519 Total 19,519 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 20 Imp. 7,044 Roof, parking lot, hardscape 1.0 7,044 Total 7,044 Storm Water Management Plan4/24/2012 Appendix 5 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 317 600 Soil Type IMP Name D Flow Thru Planter 18 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 279 500 Soil Type IMP Name IMP Area IMP Area D Permeable Paver Area 19 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 781 1,785 IMP Area Soil Type IMP Name D Flow Thru Planter 20 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 282 500 IMP Area Page 5 of 14 HCP Bressi Ranch PA2 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 21 Imp. 3,485 Roof, parking lot, hardscape 1.0 3,485 Total 3,485 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 22 Imp. 8,967 Roof, parking lot, hardscape 1.0 8,967 Total 8,967 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 23 Imp. 25,210 Roof, parking lot, hardscape 1.0 25,210 Total 25,210 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 24 Imp. 3,827 Roof, parking lot, hardscape 1 .0 3,827 24 Perv. 1,136 Landscape, pervious area 0.1 114 Total 3,941 Storm l )er Management Plan4/24/20 12 Apr:i )x 5 Fuscoe Engineering, lnc.Job No. 02722-001-01 Soil Type D IMP Sizing factor (WQ Only) 0.04 Soil Type D IMP Sizing factor (WQ Only) 0.04 Soil Type D IMP Sizing factor (WQ Only) 0.04 Soil Type D IMP Sizing factor (WQ Only) 0.04 IMP Name Permeable Paver Area 21 Minimum Proposed Area (s.f.) Area (s.f.) 139 446 IMP Name Permeable Paver Area 22 Minimum Proposed Area (s.f.) Area (s.f.) 359 893 IMP Name Flow Thru Planter 23 Minimum Proposed Area (s.f.) Area (s.f.) 1,008 1,800 IMP Name Flow Thru Planter 24 Minimum Proposed Area (s.f.) Area (s.f.) 158 300 IMP Area IMP Area IMP Area IMP Area Patt )of 14 HCP r/ N Ranch PA2 ( ' f Fuscoe Engineering, lnc.Job No. 027'J \:)1-01 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 25 Imp. 7,059 Roof, parking lot, hardscape 1.0 7,059 D Flow Thru Planter 25 25 Perv. 1,029 Landscape, pervious area 0.1 1 03 Total 7,162 DMA Nome DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 26 Imp. 3,084 Roof, parking lot, hardscape 1 .0 3,084 26 Perv. 1,013 Landscape, pervious area 0.1 101 Total 3,185 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 286 600 Soil Type IMP Name D Flow Thru Planter 26 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 127 300 DMA Name DMA Area· (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 27 Imp. 1,430 Roof, parking lot, hardscape 1 .0 1,430 D Flow Thru Planter 27 27 Perv. 831 Landscape, pervious area 0.1 83 Total 1,513 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 61 11 0 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 28 Imp. 26,344 Roof, parking lot, hardscape 1 .0 26,344 D Flow Thru Planter 28 Total 26,344 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 1,045 1,065 Storm Water Management Plon4/24!2012 Appendix 5 IMP Area IMP Area IMP Area IMP Area Page 7 of 14 HCP Bressi Ranch PA2 Fuscoe Engineering, lnc.Job No. 02722-001-01 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 29 Imp. 6,1 70 Roof, parking lot, hardscape 1 .0 6,1 70 D Flow Thru Planter 29 Total 6,170 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 247 440 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 30 Imp. 8,627 Roof, parking lot, hardscape 1 .0 8,627 D Flow Thru Planter 30 Total 8,627 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 345 700 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 31 Imp. 6,562 Roof, parking lot, hardscape 1.0 6,562 D Flow Thru Planter 31 Total 6,562 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 262 500 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 32 Imp. 8,872 Roof, parking lot, hardscape 1 .0 8,872 D Flow Thru Planter 32 Total 8,872 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 355 700 IMP Area Storm l )er Management Plan4/24/20 12 Apr:( )x 5 Paf ) of 14 HCP rJ } Ranch PA2 ( DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 33 Imp. 10,473 Roof, parking lot, hardscape 1.0 10,473 33 Perv. 1,142 Landscape, pervious area 0.1 114 Total 1 0,587 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 341mp. 44,741 Roof, parking lot, hardscape 1.0 44,741 34 Perv. 13,862 Landscape, pervious area 0.1 1,386 Total 46,127 Fuscoe Engineering, lnc.Job No. 027~· b1-01 Soil Type IMP Name D Flow Thru Planter 33 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 423 750 Soil Type IMP Name D Flow Thru Planter 34 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 1,845 3,300 IMP Area IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 35 Imp. 21,012 Roof, parking lot, hardscape 1.0 21,012 D Flow Thru Planter 35 35 Perv. 2,423 Landscape, pervious area 0.1 242 Total 21,254 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 850 1,500 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 36 Imp. 28,692 Roof, parking lot, hardscape 1 .0 28,692 D Permeable Paver Area 36 Total 28,692 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 11148 2,529 IMP Area Storm Water Management Plan4/24/2012 Appendix 5 Page 9 of 14 HCP Bressi Ranch PA2 Fuscoe Engineering, lnc.Job No. 02722-001-01 DMA Nome DMA Area (s.~ Post-project surface type DMA Runoff foetor DMA Area x runoff foetor Soil Type IMP Nome 37 Imp. 15,942 Roof, parking lot, hardscope 1.0 15,942 D Permeable Paver Area 37 Toto I 1 5, 9 4 2 DMA Nome DMA Area (s.~ Post-project surface type DMA Runoff foetor DMA Area x runoff foetor 38 Imp. 56,983 Roof, parking lot, hordscope 1.0 56,983 38 Perv. 8,368 Landscape, pervious area 0.1 837 Total 57,820 DMA Nome DMA Area (s.~ Post-project surface type DMA Runoff foetor DMA Area x runoff factor 39 Imp. 17,378 Roof, parking lot, hardscope 1.0 17,378 39 Perv. 7,545 Landscape, pervious area 0.1 755 Total 18,133 IMP Sizing foetor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 638 1,488 Soil Type IMP Nome D Flow Thru Planter 38 IMP Sizing foetor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 2,313 2,400 Soil Type IMP Nome D Flow Thru Planter 39 IMP Sizing foetor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 725 1,270 DMA Nome DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff foetor Soil Type IMP Nome 40 Imp. 11 ,315 Roof, parking lot, hordscope 1 .0 11 ,315 D Flow Thru Planter 40 40 Perv. 6,798 Landscape, pervious area 0.1 680 Total 11,995 Storm r )er Management Plon4/24/2012 Apr: )x 5 IMP Sizing foetor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 480 900 IMP Area IMP Area IMP Area IMP Area Page )of 14 HCP r{ ) Ranch PA2 { / DMA Name DMA Area (s.n Post-project surface type DMA Runoff factor DMA Area x runoff factor 41 Imp. 13,464 Roof, parking lot, hardscape 1.0 13,464 41 Perv. 4,056 Landscape, pervious area 0.1 406 Total 13,870 DMA Name DMA Area (s.n Post-project surface type DMA Runoff factor DMA Area x runoff factor 42 Imp. 7,682 Roof, parking lot, hardscape 1.0 7,682 Total 7,682 DMA Name DMA Area (s.n Post-project surface type DMA Runoff factor DMA Area x runoff factor 43 Imp. 23,454 Roof, parking lot, hardscape 1 .0 23,454 Total 23,454 DMA Name DMA Area (s.n Post-project surface type DMA Runoff factor DMA Area x runoff factor 44 Imp. 42,291 Roof, parking lot, hardscape 1.0 42,291 44 Perv. 15,1 02 Landscape, pervious area 0.1 1 ,51 0 Total 43,801 Storm Water Management Plan4/24/2012 Appendix 5 Fuscoe Engineering, lnc.Job No. 027'J JOl-01 Soil Type IMP Name D Flow Thru Planter 41 IMP Sizing factor (WQ Only) 0.04 Soil Type D IMP Sizing factor (WQ Only) 0.04 Soil Type D IMP Sizing factor (WQ Only) 0.04 Soil Type D IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 555 1,000 IMP Name Flow Thru Planter 42 Minimum Proposed Area (s.f.) Area (s.f.) 307 600 IMP Name Flow Thru Planter 43 Minimum Proposed Area (s.f.) Area (s.f.) 938 1,000 IMP Name Flow Thru Planter 44 Minimum Proposed Area (s.f.) Area (s.f.) 1,752 1,800 IMP Area IMP Area IMP Area IMP Area Page 11 of 14 HCP Bressi Ranch PA2 Fuscoe Engineering, lnc.Job No. 02722-001-01 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 45 Imp. 20,706 Roof, parking lot, hardscape l .0 20,706 D Permeable Paver Area 45 Total 20,706 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 828 1,785 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 46 Imp. 15,575 Roof, parking lot, hardscape 1.0 15,575 D Permeable Paver Area 46 Total 15,575 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 623 1,339 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 47 Imp. 13,736 Roof, parking lot, hardscape 1.0 13,736 D Flow Thru Planter 47 47 Perv. 2,910 Landscape, pervious area 0.1 291 Total 14,027 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 561 990 IMP Area DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 48 Imp. 5,929 Roof, parking lot, hardscape 1 .0 5,929 D Permeable Paver Area 48 Total 5,929 IMP Sizing factor Minimum Proposed (WQ Only) Area (s.f.) Area (s.f.) 0.04 237 580 IMP Area Storm )er Management Plan4/24/2012 Ap~)x5 Pagti ) of 14 HCP Bl~J Ranch PA2 Fuscoe Engineering, lnc.Job No. 0272( ::l1-01 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 49 Imp. 6,580 Roof, parking lot, hardscape 1 .0 6,580 D Flow Thru Planter 49 49 Perv. 818 Landscape, pervious area 0.1 82 Total 6,662 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor 50 Imp. 7,187 Roof, parking lot, hardscape 1.0 7,187 50 Perv. 1,547 Landscape, pervious area 0.1 155 Total 7,342 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 266 470 Soil Type IMP Name D Flow Thru Planter 50 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 294 520 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 51 Imp. 10,060 Roof, parking lot, hardscape 1.0 10,060 D Flow Thru Planter 51 51 Perv. 4,209 Landscape, pervious area 0.1 421 Total 10,481 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 419 800 DMA Name DMA Area (s.~ Post-project surface type DMA Runoff factor DMA Area x runoff factor Soil Type IMP Name 52 Imp. 8,003 Roof, parking lot, hardscape 1 .0 8,003 D Flow Thru Planter 52 52 Perv. 4,404 Landscape, pervious area 0.1 440 Total 8,443 Storm Water Management Plan4/24/2012 Appendix 5 IMP Sizing factor (WQ Only) 0.04 Minimum Proposed Area (s.f.) Area (s.f.) 338 600 IMP Area IMP Area IMP Area IMP Area Page 13 of 14 IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIOIIIIIIIIII~i~i~~'llll"'~ ~~~!'""01T~~~l,,~ 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 ground surface and where the surrounding soil stratum is unstable. • By design, bioretention BMPs have the potential to create very attractive habitats for mosquitoes and other vectors because of highly organic, often heavily vegetated areas mixed with shallow water. • In cold climates the soil may freeze, preventing runoff from infiltrating into the planting soil. Design and Sizing Guidelines • The bioretention area should be sized to capture the design storm runoff. • In areas where the native soil permeability is less than 0.5 in/hr an underdrain should be provided. • Recommended minimum dimensions are 15 feet by 40 feet, although the preferred width is 25 feet. Excavated depth should be 4 feet. • Area should drain completely within 72 hours. • Approximately 1 tree or shrub per 50 ft2 of bioretention area should be included. • Cover area with about 3 inches of mulch. CORBtructionjlnspection COJ1Biderati01111 Bioretention area should not be established until contributing watershed is stabilized. Performance Bioretention removes stormwater pollutants through physical and biological processes, including adsorption, filtration, plant uptake, microbial activity, decomposition, sedimentation and volatilization (EPA, 1999). Adsorption is the process whereby particulate pollutants attach to soil (e.g., clay) or vegetation surfaces. Adequate contact time between the surface and pollutant must be provided for in the design of the system for this removal process to occur. Thus, the infiltration rate of the soils must not exceed those specified in the design criteria or pollutant removal may decrease. Pollutants removed by adsorption include metals, phosphorus, and hydrocarbons. Filtration occurs as runoff passes through the bioretention area media, such as the sand bed, ground cover, and planting soil. Common particulates removed from stormwater include particulate organic matter, phosphorus, and suspended solids. Biological processes that occur in wetlands result in pollutant uptake by plants and microorganisms in the soil. Plant growth is sustained by the uptake of nutrients from the soils, with woody plants locking up these nutrients through the seasons. Microbial activity within the soil also contributes to the removal of nitrogen and organic matter. Nitrogen is removed by nitrifying and denitrifying bacteria, while aerobic bacteria are responsible for the decomposition ofthe organic matter. Microbial processes require oxygen and can result in depleted oxygen levels if the bioretention area is not adequately 2 of 8 California Stormwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com January 2003 _, 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 laboratmy studies conducted by the University of Maryland (Davis eta~ 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 Bloretantlon Davis et al. (1998); PGDER (1993) Pollutant Removal Rate Total Poosphorus 70-83% Metals (Cu, Zn, Pb) 93-98% TKN 68-Bo% Total Suspended Solids 90% Organics 90% Bacteria 90% Results for both the laboratory and field experiments were similar for each ofthe pollutants analyzed. Doubling or halving the influent pollutant levels had little effect on the effluent pollutants concentrations (Davis et al, 1998). The microbial activity and plant uptake occurring in the bioretention area will likely result in higher removal rates than those determined for infihration BMPs. Siting Criteria Bioretention BMPs are generally used to treat stormwater from impervious surfaces at commercial, residential, and industrial areas (EPA, 1999). Implementation ofbioretention for stormwater management is ideal for median strips, parking lot islands, and swales. Moreover, the runoff in these areas can be designed to either divert directly into the bioretention area or convey into the bioretention area by a curb and gutter collection system. The best location for bioretention areas is upland from inlets that receive sheet flow from graded areas and at areas that will be excavated (EPA, 1999 ). In order to maximize treatment effectiveness, the site must be graded in such a way that minimizes erosive conditions as sheet flow is conveyed to the treatment area. Locations where a bioretention area can be readily incorporated into the site plan without further environmental damage are preferred. Furthermore, to effectively minimize sediment loading in the treatment area, bioretention only should be used in stabilized drainage areas. January 2003 California StDrmwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com 3 of 8 TC-32 Bioretention Addition•l 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 (EPA, 1999). Sites with loamy sand soils are especially appropriate for bioretention because the excavated soil can be backfilled and used as the planting soil, thus eliminating the cost of importing planting soil. The use 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. Stabilized areas may erode when velocities are greater than 5 feet per second (1.5 meter per second). The designer should determine the potential for erosive conditions at the site. The size of the bioretention area, which is a function of the drainage area and the runoff generated from the area is sized to capture the water quality volume. The recommended minimum dimensions ofthe bioretention area are 15 feet (4.6 meters) wide by 40 feet (12.2 meters) long, where the minimum width allows enough space for a dense, randomly-distributed area of trees and shrubs to become established. Thus replicating a natural forest and creating a microclimate, thereby enabling the bioretention area to tolerate the effects of heat stress, acid rain, runoff pollutants, and insect and disease infestations which landscaped areas in urban settings typically are unable to tolerate. The preferred width is 25 feet (7.6 meters), with a length of twice the width. Essentially, any facilities wider than 20 feet (6.1 meters) should be twice as long as they are wide, which promotes the distribution of flow and decreases the chances of concentrated flow. In order to provide adequate storage and prevent water from standing for excessive periods of time the ponding depth of the bioretention area should not exceed 6 inches (15 centimeters). Water should not be left to stand for more than 72 hours. A restriction on the type of plants that can be used may be necessary due to some plants' water intolerance. Furthermore, if water is left standing for longer than 72 hours mosquitoes and other insects may start to breed. The appropriate planting soil should be backfilled into the excavated bioretention area. Planting soils should be sandy loam, loamy sand, or loam texture with a clay content ranging from 10 to 25percent. Generally the soil should have infihration 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 sahs. 4 of8 California Stormwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com January 2003 Bioretention TC-32 Soil tests should be performed for every 500 cubic yards (382 cubic meters) of planting soil, with the exception of pH and organic content tests, which are required only once per bioretention area (EPA, 1999). Planting soil should be 4 inches (10.1 centimeters) deeper than the bottom of the largest root ball and 4 feet (1.2 meters) altogether. This depth will provide adequate soil for the plants' root systems to become established, prevent plant damage due to severe wind, and provide adequate moisture capacity. Most sites will require excavation in order to obtain the recommended depth. Planting soil depths of greater than 4 feet (1.2 meters) may require additional construction practices such as shoring measures (EPA, 1999). Planting soil should be placed in 18 inches or greater lifts and lightly compacted until the desired depth is reached. Since high canopy trees may be destroyed during maintenance the bioretention area should be vegetated to resemble a terrestrial forest community ecosystem that is dominated by understory trees. Three species each of both trees and shrubs are recommended to be planted at a rate of 2500 trees and shrubs per hectare (1ooo per acre). For instance, a 15 foot ( 4.6 meter) by 40 foot (12.2 meter) bioretention area (6oo 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 measures, such as providing a soil breach to eliminate the threat of these species invading the bioretention area. Regional landscaping manuals should be consulted to ensure that the planting of the bioretention area meets the landscaping requirements established by the local authorities. The designers should evaluate the best placement of vegetation within the bioretention area. Plants should be placed at iiTegular 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 em) 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 nothing 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 SI:Drmwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com S of B TC-32 Bioretention soil horizon. These biologic and physical processes over time will lengthen the facility's life span and reduce the need for extensive maintenance. Routine maintenance should include a biannual health evaluation of the trees and shrubs and subsequent removal of any dead or diseased vegetation (EPA, 1999). Diseased vegetation should be treated as needed using preventative and low-toxic measures to the extent possible. BMPs have the potential to create very attractive habitats for mosquitoes and other vectors because of highly organic, often heavily vegetated areas mixed with shallow water. Routine inspections for areas of standing water within the BMP and corrective measures to restore proper infiltration rates are necessary to prevent creating mosquito and other vector habitat. In addition, bioretention BMPs are susceptible to invasion by aggressive plant species such as cattaik, which increase the chances of water standing and subsequent vector production if not routinely maintained. In order to maintain the treatment area's appearance it may be necessary to prune and weed. Furthermore, mulch replacement is suggested when erosion is evident or when the site begins to look unattractive. Specifically, the entire area may require mulch replacement every two to three years, ahhough spot mulching may be sufficient when there are random void areas. Mulch replacement should be done prior to the start of the wet season. New Jersey's Department of Environmental Protection states in their bioretention systems standards that accumulated sediment and debris removal (especially at the inflow point) will normally be the primary maintenance function. Other potential tasks include replacement of dead vegetation, soil pH regulation, erosion repair at inflow points, mulch replenishment, unclogging the underdrain, and repairing overflow structures. There is also the possibility that the cation exchange capacity of the soils in the cell will be significantly reduced over time. Depending on pollutant loads, soils may need to be replaced within 5-10 years of construction (LID, 2000). Co•t Constnaction Cost Construction cost estimates for a bioretention area are slightly greater than those for the required landscaping for a new development (EPA, 1999). A general rule of thumb (Coffman, 1999) is that residential bioretention areas average about $3 to $4 per square foot, depending on soil conditions and the density and types of plants used. Commercial, industrial and institutional site costs can range between $1o 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 bioretention area design, the cost of plants varies substantially and can account for a significant portion of the expenditures. While these cost estimates are slightly greater than those of typical landscaping treatment (due to the increased number of plantings, additional soil excavation, backfill material, use of underdrains etc.), those landscaping expenses that would be required regardless of the bioretention installation should be subtracted when determining the net cost. 6 of8 California Stormwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com January 2003 Bioretention TC-32 Perhaps of most importance, however, the cost saving§ compared to the use of traditional structural stormwater conveyance systems makes bioretention areas quite attractive financially. For example, the use of bioretention 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 Boo to 230 feet -a cost savings of $24,000 (PGDER, 1993). And a new residential development spent a total of approximately $1oo,ooo using bioretention cells on each lot instead of nearly $4oo,ooo 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 eo.t The operation and maintenance costs for a bioretention facility will be comparable to those of typical landscaping required for a site. Costs beyond the normal landscaping fees will include the cost for testing the soils and may include costs for a sand bed and planting soil. References and Sources of Additional lnfonnation Coffman, L.S., R. Goo and R. Frederick, 1999: Low impact development: an innovative alternative approach to stormwater management. Proceedings of the 26th Annual Water Resources Planning and Management Conference ASCE, June 6-9, Tempe, Arizona. Davis, A.P., Shokouhian, M., Sharma, H. and Minami, C., "Laboratory Study of Biological Retention (Bioretention) for Urban Stormwater Management," Water Environ. Res., 73(1), 5-14 (2001). Davis, A.P., Shokouhian, M., Sharma, H., Minami, C., and Winogradoff, D. "Water Quality Improvement through Bioretention: Lead, Copper, and Zinc," Water Environ. Res., accepted for publication, August 2002. Kim, H., Seagren, E.A., and Davis, A.P., "Engineered Bioretention for Removal of Nitrate from Stormwater Runoff," WEFTEC 2000 Conference Proceedings on CDR OM Research Symposium, Nitrogen Removal, Session 19, Anaheim CA, October 2000. Hsieh, C.-h. and Davis, A.P. "Engineering Bioretention for Treatment of Urban Stormwater Runoff," Watersheds 2002, Proceedings on CD ROM Research Symposium, Session 15, Ft. Lauderdale, FL, Feb. 2002. Prince George's County Department of Environmental Resources (PGDER), 1993. Design Manual for Use of Bioretention in Storm water Management. Division of Environmental Management, Watershed Protection Branch. Landover, MD. U.S. EPA Office of Water, 1999. StormwaterTechnology 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," 5th International Conference DiffusefNonpoint Pollution and Watershed Management Proceedings, C.S. Melching and Emre Alp, Eds. 2001 International Water Association January 2003 California StDrmwater BMP Handbook New Development and Redevelopment www.cabmphandbooks.com 7 of 8 Bioretention TC-32 Model Urban Runoff Program: A How-To Guide for Developing Urban Runoff Programs for Small Municipalities. Prepared by City of Monterey, City of Santa Cruz, California Coastal Commission, Monterey Bay National Marine Sanctuary, Association of Monterey Bay Area Governments, Woodward-Clyde, Central Coast Regional Water Quality Control Board. July, 1998, revised February, 2002. U.S. Environmental Protection Agency, Post-Construction Stormwater Management in New Development & Redevelopment BMP Factsheets. Available at: cfpub.epa.aoy/npdeafstormwater/mmuoibmpa/bmp files.cfm Ventura Countywide Stormwater Quality Management Program, Technical Guidance Manual for Stormwater Quality Control Measures. July, :W02. January 2003 California Stormwater BMP Handbook Industrial and Commercial www .cabmphandbooks.com 3 of 3 SD-20 Pervious Pavements . ..._.., • Permeable pavement can become clogged if improperly installed or maintained. However, this is countered by the ease with which small areas of paving can be cleaned or replaced when blocked or damaged. • Their application should be limited to highways with low traffic volumes, axle loads and speeds (less than 30 mph Hmit), car parking areas and other lightly trafficked or non- trafficked areas. Permeable surfaces are currently not considered suitable for adoptable roads due to the risks associated with failure on high speed roads, the safety implications of ponding, and disruption arising from reconstruction. • When using un-lined, infiltration systems, there is some risk of contaminating groundwater, depending on soil conditions and aquifer susceptibility. However, this risk is likely to be small because the areas drained tend to have inherently low pollutant loadings. • The use of permeable pavement is restricted to gentle slopes. • Porous block paving bas a higher risk of abrasion and damage than solid blocks. Design Consld.,..tlons DeBigning New llllltallatioJUJ If the grades, subsoils, drainage characteristics, and groundwater conditions are suitable, permeable paving may be substituted for conventional pavement on parking areas, cui de sacs and other areas with light traffic. Slopes should be flat or very gentle. Scottish experience bas shown that permeable paving systems can be installed in a wide range of ground conditions, and the flow attenuation performance is excellent even when the systems are lined. The suitability of a pervious system at a particular pavement site will, however, depend on the loading criteria required of the pavement. Where the system is to be used for infiltrating drainage waters into the ground, the vulnerability of local groundwater sources to pollution from the site should be low, and the seasonal high water table should be at least 4 feet below the surface. Ideally, the pervious surface should be horizontal in order to intercept local rainfall at source. On sloping sites, pervious surfaces may be terraced to accommodate differences in levels. Design Guidelines The design of each layer of the pavement must be determined by the likely traffic loadings and their required operational life. To provide satisfactory performance, the following criteria should be considered: • The subgrade should be able to sustain traffic loading without excessive deformation. • The granular capping and sub-base layers should give sufficient load-bearing to provide an adequate construction platform and base for the overlying pavement layers. • The pavement materials should not crack of suffer excessive rutting under the influence of traffic. This is controlled by the horizontal tensile stress at the base of these layers. 2 of 10 California Stormwatllr BMP Handbook New Development and Redevelopment www .cabmphandbooks.com January 2003 Pervious Pavements SD-20 There is no current structural design method specifically for pervious pavements. Allowances should be considered the following factors in the design and specification of materials: • Pervious pavements use materials with high permeability and void space. All the current UK pavement design methods are based on the use of conventional materials that are dense and relatively impermeable. The stiffness of the materials must therefore be assessed. • Water is present within the construction and can soften and weaken materials, and this must be allowed for. • Existing design methods assume full friction between layers. Any geotextiles or geomembranes must be carefully specified to minimize loss of friction between layers. • Porous asphalt loses adhesion and becomes brittle as air passes through the voids. Its durability is therefore lower than conventional materials. The single sized grading of materials used means that care should be taken to ensure that loss of finer particles between unbound layers does not occur. Positioning a geotextile near the surface of the pervious construction should enable pollutants to be trapped and retained close to the surface of the construction. This has both advantages and disadvantages. The main disadvantage is that the filtering of sediments and their associated pollutants at this level may hamper percolation of waters and can eventually lead to surface ponding. One advantage is that even if eventual maintenance is required to reinstate infiltration, only a limited amount of the construction needs to be disturbed, since the sub-base below the geotextile is protected. In addition, the pollutant concentration at a high level in the structure allows for its release over time. It is slowly transported in the stormwater to lower levels where chemical and biological processes may be operating to retain or degrade pollutants. The design should ensure that sufficient void space exists for the storage of sediments to limit the period between remedial works. • Pervious pavements require a single size grading to give open voids. The choice of materials is therefore a compromise between stiffness, permeability and storage capacity. • Because the sub-base and capping will be in contact with water for a large part of the time, the strength and durability ofthe aggregate particles when saturated and subjected to wetting and drying should be assessed. • A uniformly graded single size material cannot be compacted and is liable to move when construction traffic passes over it. This effect can be reduced by the use of angular crushed rock material with a high surface friction. In pollution control terms, these layers represent the site of long term chemical and biological pollutant retention and degradation processes. The construction materials should be selected, in addition to their structural strength properties, for their ability to sustain such processes. In general, this means that materials should create neutral or slightly alkaline conditions and they should provide favorable sites for colonization by microbial populations. January 2003 California StDrmwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com 3 of 10 SD-20 Pervious Pavements ~ ConstnJctionjlnspection Considerations ·.'-"' • Permeable surfaces can be laid without cross-falls or longitudinal gradients. • The blocks should be Jain level • They should not be used for storage of site materials, unless the surface is well protected from deposition of silt and other spillages. • The pavement should be constructed in a single operation, as one of the last items to be built, on a development site. Landscape development should be completed before pavement construction to avoid contamination by silt or soil from this source. • Surfaces draining to the pavement should be stabilized before construction of the pavement. • Inappropriate construction equipment should be kept away from the pavement to prevent damage to the surface, sub-base or sub-grade. Maintenance Requirements The maintenance requirements of a pervious surface should be reviewed at the time of design and should be clearly specified. Maintenance is required to prevent clogging of the pervious surface. The factors to be considered when defining maintenance requirements must include: • Typeofuse • Ownership • Level of trafficking • The local environment and any contributing catchments Studies in the UK have shown satisfactory operation of porous pavement systems without maintenance for over 10 years and recent work by Imbe et al. at 9th ICUD, Portland, 2002 describes systems operating for over 20 years without maintenance. However, performance under such regimes could not be guaranteed, Table 1 shows typical recommended maintenance regimes: 4 of 10 California Stormwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com January 2003 Pervious Pavements SD-20 jTable1 Typical Recommended Maintenance Regimes Aetlvlty Sehedule "' Minimize use of salt or grit for de-icing • Keep landscaped areas well maintained Ongoing • Prevent soil bein3 washed onto pavement • Vacuum clean surface usinJ commercially available sweeping machines at the followin& times: -End of winter (April) 2/3xperyear -Mid-summer (July I August) -After Autumn leaf-fall (November) "' Inspect outlets Annual • If routine cleanin3 does not restore infiltration rates, then reconstruction of part of the whole of a pervious surface may be required. "' The surface area affected by hydraulic failure should be lifted for inspection of the internal materials to identify the location and As needed (infrequent) extent of the blockage. Maximum 15-20 years • Surface materials should be lifted and replaced after brush cleaning. Geotextiles may need complete replacement. • Sub-surface layers may need cleaning and replacing. • Removed silts may need to be disposed of as controlled waste . Permeable pavements are up to 25 96 cheaper (or at least no more expensive than the traditional forms of pavement construction), when all construction and drainage costs are taken into account. (Accepting that the porous asphalt itself is a more expensive surfacing, the extra cost of which is offset by the savings in underground pipework etc.) (Niemczynowicz, et al., 1987) Table 1 gives US cost estimates for capital and maintenance costs of porous pavements (Landphair et al., 2000) Rede11eloping Eristing lnstaUations 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. January 2003 California Stxlrmwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com 5 of 10 SD-20 Pervious Pavements ~ Additionallnformation Cost Considerations Permeable pavements are up to 25% cheaper (or at least no more expensive than the traditional forms of pavement construction), when all construction and drainage costs are taken into account. (Accepting that the porous asphalt itself is a more expensive surfacing, the extra cost of which is offset by the savings in underground pipework etc.) (Niemczynowicz, et al., 1987) Table 2 gives US cost estimates for capital and maintenance costs of porous pavements (Landphair et al., 2000) 6 of 10 California Stormwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com January 2003 Pervious Pavements Table 2 Engineer's Estimate for Porous Pavement l«e• ..... Price Cydell ~·· \'ar AcnWS Gtading SY $2.00 6().t PMig SY $1~.00 212 Excavatiotl CY $3.60 201 Filter F8bric SY $1.15 700 Stone Fill CY $16.00 201 Sand CY $7.00 100 Sight Wei EA $300.00 2 Seeding LF $0.05 ..... Check Dam CY $35.00 0 Tcul Conllruction eo... CoMiructJon Coela AmortiMd fot20Y•rs lie• lJ* Price Cyclell ~·· \'ar AcnWS Sweeping N; $25().00 e 1 W•shlng N; $250.00 6 1 ln'P8Ctlon ..... $20.00 5 5 Deep CleaR N; :s.tS0-00 0.5 1 Total,.._.. I .. ......._ January 2003 (,) Porous Pavement 1tHal Quu1.2 T .... ~.3 AcreWS Acn\\'S $1,208 1208 $2,118 1812 :s.t,021 12A $8,056 838 $721 103 $1.151 804 $805 1400 $1.810 2000 $3.218 403 $8,448 804 $700 200 $1.100 300 $800 3 uoo 4 $32 1288 $84 1~32 so 0 $0 0 $10,t0& $1t.ta $505 ..... Annual Maintenance ExDense ...... Qullld.2 T .... Qaill.3 AcreWS AcnWS $1,500 2 $3,000 3 $1,500 2 13~000 3 $100 5 $100 5 $225 2 s.qo 3 $3,110 17,712 California stormw atJer BMP Handbook New Devalopment n Redevllopma-~t ww w. cllbrrp~s.com (J SD-20 T .... Quill.. T .... ~5 Tellll AcreWS AcnWS $3,821 2.t18 ..... 3020 se.CMO S12,0M .... $18,112 1080 $20,1.-o _g_174 801 S2,t02 1008 $3,121 $2,300 2800 $3,220 3800 $1,1.-o ...... 801 S12.1te 1008 $18.128 $2,100 400 $2,800 500 $3,500 $1,200 7 $2,100 7 $2,100 $17 2578 1128 3220 $181 so 0 $0 0 $0 $2U1t ..,,,. s-.711 ,, .... $2,101 $2,480 1tHal Quaid.. T .... Qaill.5 Tellll AcreWS AcnWS $1,500 .. $8.000 5 $7,500 M.SOO .. se.oao 5 17,500 $100 5 $100 5 $100 $875 3.8 $871 I $1,125 -si1.851 Sts.AU .... _ ............. 7 cf10 ( ) SD-20 Pervious Pavements """-· Other Resources '-"' - Abbott C.L. and Comino-Mateos L. 2001. In situ performanC$ monitoring of an infiltration drainage system and field testing of current design procedures. Journal CIWEM, 15(3), pp.198- 2o2. Construction Industry Research and Information Association (CIRIA). 2002. Source Control using Constructed Pervious Surfaces C582, London, SW1P 3AU. Construction Industry Research and Information Association (CIRIA). 2000. Sustainable urban drainage systems-design manual for Soodand and Northern Ireland Report Cs:n, London, SW1P3AU. Construction Industry Research and Information Association (CIRIA). 2000 C522 Sustainable urban drainage systems-design manual for England and Wales, London, SW1P 3AU. Construction Industry Research and Information Association (CIRIA). RP448 Manual of good practiC$ for the design, oonstruction and maintenanC$ of infiltration drainage systems for stormwater runoff oontrol and disposal, London, SW1P 3AU. Dierkes C., Kuhlmann L., Kandasamy J. & Angelis G. Pollution Retention Capability and Maintenance of Permeable Pavements. Proc '.111 International ConferenC$ on Urban Drainage, Portland Oregon, September 2002. Hart P (2002) Permeable Paving as a Stormwater Source Control System. Paper presented at Scottish Hydraulics Study Group 14th. Annual seminar, SUDS. 22 March 2002, Glasgow. Kobayashi M., 1999· Stormwater runoff control in Nagoya City. Proc. 8th Int. Conf. on Urban Storm Drainage, Sydney, Australia, pp.825-833. Landphair, H., McFalls, J., Thompson, D., 2000, Design Methods, Selection, and Cost Effectiveness of Stormwater Quality Structures, Texas Transportation Institute Research Report 1837-1, College Station, Texas. Legret M, Colandini V, Effects of a porous pavement with reservior strucutre on runoff water:water quality and the fate of heavy metals. Laboratoire Central Des Ponts et Chaussesss Macdonald K. & Jefferies C. Performance Comparison of Porous Paved and Traditional Car Parks. Proc. First National Conferenoo on Sustainable Drainage Systems, Coventry June 2001. Niemczynowicz J, Hogland W, 1987: Test of porous pavements performed in Lund, Sweden, in Topics in Drainage Hydraulics and Hydrology. BC. Yen (Ed.), pub. Int. Assoc. For Hydraulic Research, pp 19-80. Pratt C.J. SUSfAINABLE URBAN DRAINAGE-A Review of published material on the performance of various SUDS devices prepared for the UK Environment Agency. Coventry University, UK December 2001. Pratt C.J., 1995. Infiltration drainage-case studies of UK practice. Project Report 8 of 10 California Stormwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com January 2003 Pervious Pavements SD-20 22,Construction Industry Research and Information Association, London, SW1P 3AU; also known as National Rivers Authority R & D Note 485 Pratt. C. J., 1990· Permeable Pavements for Stormwater Quality Enhancement. In: Urban Stormwater Quality Enhancement -Source Control, retrofitting and combined sewer technology, Ed. H.C. Torno, ASCE, ISBN 087262 7594, pp. 131-155 Raimbault G., 1997 French Developments in Reservoir Structures Sustainable water resources I the 21•t century. Malmo Sweden Schluter W. & Jefferies C. Monitoring the outflow from a Porous Car Park Proc. First National Conference on Sustainable Drainage Systems, Coventry June 2001. Wild, T.C., Jefferies, C., and D'Arcy, B.J. SUDS in Scotland-the Scottish SUDS database Report No SR(o2)o9 Scotland and Northern Ireland Forum for Environmental Research, Edinburgh. In preparation August 2002. January 2003 California SIDrmwater BMP Handbook New Development and Redevelopment www .cabmphandbooks.com 9 of 10