Laserfiche WebLink
San Joaquin County'; <br /> oPQ.�'N Environmental Health De a�rtment DIRECTOR <br /> ). _ ' .o Ik Donna Heran,REHS <br /> 600 East Main Street ;9 <br /> �. \ - :-ti PROGRAM COORDINATORS <br /> Stockton, California 95202-3029 <br /> s Robert McClellon,REHS <br /> • Jeff Carruesco,REHS, RD! <br /> _ P�a Kasey Foley,REHS Website: www.sjgov.org/�hd� <br /> (209)468-3420 � <br /> Fax: (209) 464-0138 <br /> March 3, 2010 <br /> Mr. Allen Fetters <br /> Ripon Farm Service Incorporated <br /> 3705 Portsmouth Circle <br /> North Stockton, California 95219 <br /> Subject:Ripon Farm-Service Incorporated - <br /> 1 932 South Highway 99 (Formerly 22871 South Highway 99) <br /> Ripon, California 95366 <br /> Dear Mr. Fetters: <br /> The San Joaquin County Environmental Health Department (EHD) has reviewed No Further <br /> Action Request (NFAR), dated November 1'0, 2009, and has :reevaluated data submitted in <br /> Vapor Intrusion Investigation Report, dated June 22, ''2009,, prepared and submitted by <br /> Advanced GeoEnvironmental, Inc. (AGE) on your behalf'.for the above-referenced site. The <br /> 1 NFAR was submitted in response to an EHD letter dated September 23, 2009, directing the <br /> submittal of a comprehensive site closure summary report based on results submitted in the <br /> Vapor Intrusion Investigation Report: <br /> The EHD seeks a technical justification for how data were entered into the Johnson and <br /> i Ettinger Model to determine the potential risk posed by soil gas, intrusion into buildings at the <br /> above-referenced site. AGE divided the carbon range of C6 to C12 for total petroleum <br /> ` hydrocarbons (TPH) quantified as gasoline (TPH-g) into three carbon number ranges (carbon <br /> ' number refers to the number of carbon-atoms in the hydrocarbon molecule): C6 to C8, C8 to <br /> C10, and C10 to C12. AGE also divided the highest concentration of TPH-g detected at this site <br /> in soil gas sample VP-1 [71,000 micrograms per cubic meter (pg1m3)]'by three to calculate the <br /> average concentration (23,600 pg/m3) for each of the three carbon number ranges. AGE did <br /> not provide a rational for dividing the maximum concentration detected in soil gas samples by <br /> three to determine a concentration for each of the carbon number ranges. The California <br /> Regional Water Quality Control Board San Francisco Bay Region (CRWQCBSFBR) has <br /> subdivided petroleum mixtures into gasolines, middle distillates, and residual fuels to establish <br /> Environmental Screening Levels (ESLs). The CRWQCBSFBR has defined gasolines as <br /> having carbon ranges of C6 to C12, middle distillates as having carbon ranges of approximately <br /> C9 to C25, and residual fuels as- having carbon ranges between approximately C24 and Cao• <br /> THP-g was detected at 71,000 lag/m3, 64,000 pg/m3, and, 54,000 pg/m3 in the three soil gas <br /> samples VP-1, VP-2, and VP-3, respectively. Since these concentrations are well above the <br /> ESL of 29,000 pg/m3 for TPH-g in soil gas samples collected in shallow soil at commercial ? <br /> properties, you must provide a technical justification, supported.Eby authoritative guidance, for <br /> the methodology used to enter the above data into the Johnson and Ettinger Model. <br /> i _ _ <br />