Laserfiche WebLink
San Joaquin County Community Environmental Setting,Impacts,and Mitigation Measures <br /> Development Department Surface Hydrology,Stormwater,and Water Quality <br /> Table 3.13-1. Best Management Practice Expected Pollutant Removal Efficiency <br /> Typical Pollutant Removal(percent) - <br /> BMP Type Suspended Solids Nitrogen Phosphorus Pathogens Metals <br /> Structural <br /> Dry detention basins 30-65 15-45 15-45 <30 15-45 <br /> Retention basins 50-80 30-65 30-65 <30 50-80 <br /> Constructed wetlands 50-80 <30 15-45 <30 50-80 <br /> Infiltration basins 50-80 50-80 50-80 65-100 50-80 - <br /> Infiltration trenches/dry wells 50-80 50-80 15-45 65-100 50-80 <br /> Porous pavement 65-100 65-100 30-65 65-100 65-100 <br /> Grassed swales 30-65 15-45 15--45 <30 15-45 <br /> Vegetated filter strips 50-80 50-80 50-80 <30 50-80 <br /> Surface sand filters 50-80 <30 50-80 <30 50-80 _ <br /> Other media filters 65-100 15-45 <30 <30 50-80 <br /> Construction-site <br /> Silt fence 50-80 <br /> Sediment basin 55-100 <br /> Sediment trap 60 <br /> Sources: U.S.Environmental Protection Agency. 1993. Guidance Specking Management Measures for Sources <br /> of Non-Point Pollution in Coastal Waters. (EPA-840-B-92-002.) <br /> U.S.Environmental Protection Agency. 1999. Preliminary Data Summary of Urban Stormwater Best <br /> Management Practices. (EPA-821-R-99-012.) <br /> Local Regulations <br /> San Joaquin County General Plan <br /> The San Joaquin County General Plan 2010: Volume I: Policies/Implementation <br /> (San Joaquin County 1992)outlines goals and policies related to water quality <br /> and flooding within the study area. The following objectives and policies are <br /> relevant to the study area. <br /> Resources: Water Resources and Quality <br /> Objective 1. To ensure adequate quantity and quality of water resources for <br /> municipal and industrial uses,agriculture,recreation,and fish and wildlife. <br /> Policy 1. Water quality shall meet the standards necessary for the uses to - <br /> which the water resources are put. <br /> Policy 8. The County shall encourage water conservation. <br /> Objective 4. To prevent and eliminate contamination of surface water and <br /> groundwater supplies. <br /> DeSilva Gates Quarry Project -' <br /> Draft Environmental Impact Report 3.G-6 <br /> JSs 05105.05 <br />