SU0004098 - Laserfiche WebLink

Home Browse Search

San Joaquin County Community Environmental Setting,Impacts,and Mitigation Measures .� Development Department Surface Hydrology,Stormwater,and Water Quality The proposed Project includes a spill prevention,control,and countermeasures plan(see the"Environmental Commitments" section of Chapter 2 of the EIR)to minimize the potential for accidental spills,which would ensure consistency with the water quality policies in the San Joaquin County General Plan. In addition, the project includes the use of a mobile fuel and lubrication truck. The truck would include automatic shut-off valves to prevent spills and would cant' appropriate absorbent materials to clean-up spills. The Applicant would also implement erosion or runoff control measures near the processing facilities to prevent off-site sedimentation. In addition,on-site runoff would be captured in the settling ponds and active mining pits. Therefore,potential impacts from discharges of sediment and other contaminants to nearby surface waters are considered less than significant. Impact WQ-2: Drainage and Surface Water Quality Impacts during Operation and Reclamation (Less than Significant) The project area is relatively flat and generally drains to the northeastern portion of the project area. The presence of the Delta-Mendota Canal and its accompanying levees and the general absence of culverts along the perimeter of the project area inhibit runoff flows from entering the project area from off-site. Thus, drainage flows on-site are derived only from runoff in the project area. Because the Operator is not proposing to conduct activities in surface waters,the ., proposed Project would not substantially alter the drainage patterns in any surface water bodies or storm drainage systems. In addition,because the Project is designed to retain on-site drainage in the settling ponds(see the i "Environmental Commitments" section of Chapter 2 of this EIR),all runoff in the project area would be contained on-site during the operation and reclamation periods, thereby preventing substantial erosion, siltation,flooding, or exceedance .. of the capacity of drainage systems off-site. Under either Dry Pit Operations or Wet Pit Operations,the proposed Project would result in an increase of approximately 10,000 square feet or 0.23 acres in impervious surfaces. This increase would not be sufficient to substantially change the volume or timing of stormwater runoff in the 217.5-acre project area because all on-site drainage would be captured in settling ponds and reclaimed �- and erosion control measures would be implemented near processing facilities and inactive topsoil stockpiles(see the"Environmental Commitments"section of Chapter 2 of the EIR). The minimal change in stormwater runoff rates and volume on-site would not provide substantial additional sources of polluted runoff or result in flooding, siltation,or erosion on-site. The Project would not involve the direct discharge of waters to the Delta- Mendota Canal or other surface water bodies during the operation or reclamation stages. Implementation of the SWPPP(see the"Environmental Commitments" section of Chapter 2 of the EIR)would further minimize the potential for any y surface water quality impacts and would ensure consistency with the water DeSilva Gates Quarry Project Draft Environmental Impact Report 3.G-9 AS 05105.05