Laserfiche WebLink
Thrifty Oil Co <br /> Station 4172 <br /> 7.0 CORRECTIVE ACTION PLAN <br /> Soil and groundwater beneath the site have exhibited hydrocarbon concentrations exceeding levels <br /> generally accepted by the County of San Joaquin County Environmental Health Services, therefore, <br /> necessitating the generation of this corrective action work plan <br /> To facilitate the removal of hydrocarbons detected in soil and groundwater beneath the site, Thrifty <br /> has chosen insitu vapor extraction in conjunction with groundwater extraction This alternative will <br /> incorporate four of the existing six onsite vapor monitoring wells(VW-2,VW-3, VW-4, and VW-6), <br /> and MW-11 for groundwater extraction and remediation Piping has been installed to these wells <br /> and manifolded at the proposed location of the VES and Groundwater Extraction treatment unit. <br /> This portion of the remediation system was completed during the remodeling and retanlong of the <br /> site, and approved by the San Joaquin County Environmental Health Division <br /> 7.1 VES Pilot Test <br /> On September 14, 1995 Thrifty Oil Co contracted Alton Geoscience to perform a vapor extraction <br /> test on this site to assess the possibility of using this technology for treating hydrocarbon in the <br /> subsurface at the site Results of this test are included in the Vapor Extraction Test Report included <br /> in Attachment A <br /> Results of this test indicated an effective radius of influence was approximately 33 feet with a flow <br /> rate of approximately 16 8 scfm with a pressure drawdown of approximately 0 10 inches of H20, <br /> therefore, vapor extraction will be a feasible remediation option for the mitigation of hydrocarbon- <br /> affected soil in the vadose zone beneath this site The main source of extraction will be received <br /> from wells VW-2, VW-3 and VW-6 The anticipated radius of influence is depicted in Figure 7 <br /> 7.2 Soil Vapor Extraction <br /> The soil vapor extraction unit will include a blower, an air/water separator and a PVC manifold for <br /> flow rate adjustment All equipment will be verified in the field and can be adjusted to meet site- <br /> specific demands, and to induce sufficient vacuum in the vapor wells to produce the desired <br /> influence Table 3 consist of the well completion details for the wells connected to the system, and <br /> Thrifty will choose which wells will be used most effectively to reduce hydrocarbon concentrations <br /> during the time period of system operations <br />