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<br /> San Joaquin County DIRECTOR
<br /> Donna Heran,RENS
<br /> ASSISTANT DIRECTOR
<br /> 600 East Main Street Laurie Cotulla, REHS
<br /> :{ Stockton, California 95202-3029 PROGRAM COORDINATORS
<br /> Mike Huggins,REHS, RDI
<br /> Margaret Lagorio, REHS
<br /> qZ/FO � Website: www.sjgov.org/ehd Robert McClellon,REHS
<br /> Phone: (209) 468-3420 ,teff Carruesco, REHS, RDI
<br /> Fax: (209) 464-0138 Kasey Foley, REHS
<br /> December 23, 2008
<br /> Mr. and Mrs. Jay McIlrath
<br /> Post Office Box 326
<br /> Stockton, California 95201
<br /> Subject: Jay's Mini Mart
<br /> 3302 West Lane
<br /> Stockton, California 95204
<br /> The San Joaquin County Environmental Health Department (EHD) has reviewed Work Plan
<br /> to Conduct Subsurface Soil Vapor Intrusion Study, dated November 7, 2008, prepared and
<br /> submitted by ATC Associates Incorporated (ATC) on your behalf for the above-referenced
<br /> site. By letter dated October 1, 2008, the EHD directed submittal of a work plan for soil
<br /> vapor sample collection to assess the potential for vapor intrusion into the existing onsite
<br /> buildings. Included in the work plan are contaminant mass calculations and receptor survey
<br /> information requested by the EHD.
<br /> Using a hand auger, ATC proposes to advance four onsite soil borings (VP-1, VP-2, VP-3,
<br /> and VP-4) to depths of four to five feet below surface grade (bsg) and collect soil samples at
<br /> total depths. Once the soil samples have been collected, ATC proposes to install temporary
<br /> soil vapor probes within each borehole and perform purge volume test, leak test, and soil gas
<br /> sampling at least forty-eight hours after the soil gas probe installation. ATC proposes to use a
<br /> compound derived from commercial computer "dust off' spray such as 1,1-difluoroethane to
<br /> check for leaks. Soil gas samples will be collected in 400-milliliter Summa canisters and
<br /> analyzed for benzene, toluene, ethyl benzene, and total xylenes (BTEX) by United States
<br /> Environmental Protection Agency method TO-15 modified to include methyl tertiary-butyl
<br /> ether (MTBE), ethyl tertiary-butyl ether (ETBE), di-isopropyl ether (DIPS), tertiary amyl
<br /> methyl ether (TAME), tertiary butyl alcohol (TBA), 1,2-dichloroethane (1,2-DCA), 1,2-
<br /> dibromoethane (EDB), total petroleum hydrocarbons (TPH) quantified as gasoline (TPH-g)
<br /> and the leak detection compound. ATC proposes to collect one duplicate soil gas sample and
<br /> include one trip blank sample provided by the laboratory. ATC proposes to analyze soil
<br /> samples for TPH-g, TPH quantified as diesel (TPH-d), BTEX, MTBE, ETBE, DIRE, TAME,
<br /> TBA, 1,2-DCA, and EDB. In addition to the above-listed analyses, ATC proposes to collect
<br /> one additional soil sample to be analyzed for physical properties that include moisture
<br /> content, dry bulk and grain density, total porosity, air-filled and water-filled porosity,
<br /> effective porosity, total pore fluid saturation, total organic carbon, fraction organic carbon,
<br /> hydraulic conductivity, intrinsic permeability, Atterberg Limits, plasticity, and soil texture
<br />
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