SITE INFORMATION AND CORRESPONDENCE_FILE 2

Home Browse Search

San Joaquin County Environmental Health Department DIRECTOR `] Donna Heran,REHS 600 East Main Street PROGRAM COORDINATORS Stockton, California 95202-3029 Margaret Lagodo,REHS Robert McClellon, REHS Jeff Carruesco,REHS,RDI Website: www.sjgov.org/ehd Kasey Foley,REHS �'Foa Phone: (209)468-3420 Fax: (209)464-0138 October 26, 2009 Mr. Charles Skobrak 9947 East Highway 26 Stockton, California 95215 Subject: Larry's Auto 308 North Grant Street Stockton, California 95202 The San Joaquin County Environmental Health Department (EHD) has reviewed Feasibility Pilot Test Work Plan (feasibility test work plan) dated September 9, 2009, prepared and submitted by Advanced GeoEnvironmental, Inc. (AGE), on your behalf for the above-referenced site. By letter dated May 19, 2009, the EHD had directed the submittal of a feasibility study to identify a remedial technology or combination of technologies capable of mitigating petroleum hydrocarbon contamination in groundwater. In the feasibility test work plan, AGE proposes to perform a soil vapor extraction and an in situ air sparging (SVE/IAS) pilot test to determine the feasibility of this remedial technology to reduce concentrations of contaminants of concern that are adsorbed to soil and dissolved in groundwater. During the ninety-six-hour pilot test, AGE proposes to inject air into well VW-5C, screened between forty-five and fifty-five feet below surface grade (bsg) and extract soil vapor under vacuum from well VW5A, screened between thirteen and twenty-three feet bsg while measuring the induced vacuum at wells VW56, screened between twenty-six-and-a-half and forty-one-and-a-half feet bsg, and VW2A, screened between twenty-five and forty feet bsg. AGE proposes to measure the volume of air and rate of sparging, soil vapor concentrations, soil vapor pressures, groundwater depths, and dissolved oxygen at regular intervals at surrounding wells, and determine the radius of influence. AGE proposes to collect vapor samples daily (four total) in Tedlar bags from extraction well VW5A and analyze the samples for total petroleum hydrocarbons quantified as gasoline (TPH-g), benzene, toluene, ethyl benzene, and total xylenes (BTEX), and methyl tertiary-butyl ether (MTBE). The EHD approves the SVE/IAS pilot test as submitted. Complete this fieldwork by December 21, 2009. In Soil Vapor Extraction Installation and Monitoring Report dated January 30, 2009, AGE reported that 'Between May and August 2008, a total of 1,730 pounds of petroleum hydrocarbons were removed from the site; during December 2008, a total of 293 pounds of petroleum hydrocarbons were removed from the site." Intuitively, these contaminant mass removals demonstrate that SVE is effective for remediation of this site. If continuous operation of the SVE has not been restarted following its suspension in February 2009, then the EHD directs that continuous operation of the SVE system should be initiated once the pilot test has been completed.