Laserfiche WebLink
Additional Site Assessment and Soil Vapor Extraction Test, second Quarter 2002 Groundwater Momtonng Data 6 <br /> 7-Eleven, Inc, Store 21756,853 E Yosemite Avenue,Manteca, California August 5,2002 <br /> ' 83 Purge Water Disposal <br /> Purge water generated during the recent monitoring and sampling event was stored in 55-gallon <br /> Department of Transportation (DOT)-approved drums pending characterization and proper disposal at a <br /> licensed recycling center Waste disposal documentation will be forwarded if requested <br /> 90 SOIL VAPOR EXTRACTION TEST <br /> 91 Procedure <br /> The SVE test was conducted on April 24, 2002 by application of vacuum to well SPV-1 for 3 5 hours <br /> ' During the test, all wells at the site not undergoing extraction (MW-1, MW-2, MW-3, and SPV-2) were fitted <br /> with Magnehelic gauges to measure pressure changes while the test was conducted <br /> During the test, extracted air was channeled to a 100-cubic foot per minute (cfm) thermal oxidizer after <br /> passing through a moisture knockout device and an air filter Soil vapors were then treated by passing <br /> them through the oxidizer prior to discharge to the atmosphere Extracted vapor concentrations were <br /> measured using aflame ionization detector(FID) Pressure readings and FID measurements were <br /> recorded at periodic intervals throughout the test <br /> 92 Results <br /> All extracted vapor concentrations from well SPV-1 were less than or equal to 6 parts per million by <br /> volume (ppm[v]) At applied vacuums ranging up to 50 inches of water, induced vacuum response in well <br /> MW-3 (located 45 feet from well SPV-1) ranged up to 0 05 inches of water Based on induced vacuum <br /> ' responses of less than 0 1 inches of water, wells MWA, MW-2, MW-3, and SPV-2 appear to be outside <br /> the effective radius of vapor extraction influence of SPV-1 Based on the induced vacuum response of <br /> 0 05 inches of water in well MW-3, the radius of vapor extraction influence is estimated at about 25-30 feet <br /> around the extraction point Field data sheets are included in Appendix B <br /> These data indicate that although the site exhibits vapor extraction capability using the existing well <br /> configuration, the overall hydrocarbon/oxygenate mass accessible by vapor extraction in the area tested is <br /> relatively small Additional evaluation of SVE as a possible remediation alternative (if remediation is <br /> required by the SJCPHS)will be conducted during the third quarter 2002, and results submitted with <br /> quarterly monitoring data <br /> 1 <br /> 21756SAR doc <br />