Laserfiche WebLink
San Joaquin County <br /> °WNEnvironmental Health Department DIRECTOR <br /> `.O Donna Heran, REHS - <br /> �i 600 East Main Street <br /> Stockton, California 95202-3029 PROGRAM COORDINATORS <br /> m; Robert McClellon, REHS <br /> Jeff Carruesco,RENS,RDI <br /> • cq..� �:P Website: www.sjgov.org/ehd Kasey Foley, REHS <br /> C/FOR <br /> Phone: (209)468-3420 <br /> Fax: (209) 464-0138 <br /> July 2, 2010 <br /> Mr. Charles Skobrak <br /> 9947 East Highway 26 <br /> Stockton, California 95215 <br /> Subject: Larry's Auto <br /> 308 North Grant Street <br /> Stockton, California 95202 <br /> Dear Mr. Skobrak: <br /> The San Joaquin County Environmental Health Department (EHD) has reviewed Soil Vapor <br /> Extraction Report— First Quarter 2010 (Report), dated 01 June 2010, prepared and submitted <br /> by your consultant, Advanced GeoEnvironmental, Inc. (AGE) on your behalf for the above- <br /> referenced site. In the Report, AGE addresses concerns about how the dissolved oxygen was <br /> measured in groundwater. By letter dated 16 April 2010, the EHD had questioned how <br /> oxygen had been measured in groundwater since oxygen had not been detected in any of the <br /> wells. <br /> In the Report, AGE presents recent results from performing interim remediation by extracting <br /> soil vapor from EW-1, VW-2A, VW-26, VW-3, VW-4, VW-5A and VW-5B. As AGE notes, <br /> groundwater is currently at approximately 32.5 feet below surface grade, and although wells <br /> VW-213, VW-3, and VW-4 are screened below the groundwater table, most of the unsaturated <br /> soil mass is exposed to the wells screened within the shallow depths (VW-2A, VW-5A and <br /> VW-513). Since the soil vapor extraction (SVE) system has been in operation, AGE calculates <br /> that approximately 5,750 pounds of petroleum hydrocarbons have been removed from this <br /> site. <br /> By email dated 16 June 2010, AGE provided the analytical results for soil gas samples <br /> collected from the influent and effluent of the SVE system on 07 June 2010. Based on these <br /> most current sample results, AGE concludes, and the EHD concurs, that soil gas <br /> concentrations are decreasing significantly and unless the SVE system is used in conjunction <br /> with an in situ air sparging system (IAS), the SVE system should be discontinued due to <br /> asymptotic recovery levels. <br /> In the In-Situ Air Sparging & Soil Vapor Extraction Feasibility Pilot Test Report — Fourth <br /> Quarter 2009 dated 10 March 2010, AGE presented the results from performing an IAS/SVE <br /> pilot test. The pilot test evaluated air sparging as a remedial method to remove groundwater <br /> contamination at this site. Based on the results from the pilot test and a comparison of <br /> IAS/SVE to other corrective action options (excavation, in situ bioremediation, and pump and <br />