Laserfiche WebLink
r <br /> r <br /> San Joaquin County <br /> OPO.UIN'C Environmental Health Department DIRECTOR <br /> 2. G Donna Heran,RENS <br /> 600 Merit Main Street <br /> Stockton, California 95202-3029 PROGRAM COORDINATORS <br /> Robert McClellon,REHS <br /> Jeff Carruesco,REHS,RDI <br /> C'q" 'N)P Website:www.s ov.org(ehd Kasey Foley,REHS <br /> L%FOR �g •.`Y <br /> Phone: (209)468-3420 ��� � 007 fin9a Tdlrkiwte,REHS <br /> Fax: (209)464-01138 A 4 fft�l�l llll <br /> October 11, 2010 <br /> Mr. Paul Zumberge <br /> Frontier Transportation, Incorporated <br /> 3577 West Philadelphia <br /> Chino Hills, California 91710 <br /> Subject: Frontier Transportation, Incorporated <br /> 425 Larch Road <br /> Tracy, California 95376 <br /> Dear Mr.Zumberge: <br /> The San Joaquin County Environmental Health Department (EHD) has received and reviewed <br /> Soil Gas Sampling and Human Health Risk Assessment Work Plan (work plan), dated August <br /> 26, 2010,. prepared by your consultant, Ami Adini &Associates, Inc. (AA&A). AA&A proposes <br /> to collect five soil gas samples at locations illustrated on Figure 3 of the work plan, and <br /> utilizing the chemical analytical results from the soil gas samples collected during this survey, <br /> conduct a health risk assessment. By letter dated 21 May 2010, the EHD had directed the <br /> submittal of a Human Health Risk Assessment (HHRS) based on the concentrations of <br /> chemicals of concern detected in soil gas samples during the soil vapor study completed in <br /> January 2000. <br /> In the work plan, AA&A acknowledges that in January 2000, total volatile petroleum <br /> hydrocarbons were detected at 1,810 parts per million by volume (ppmv) and 92 ppmv in soil <br /> gas samples collected from soil gas probes V5 and V6, respectively; and benzene was <br /> detected at 5.4 ppmv and 0.17 ppmv in V5 and V6, respectively. However, AA&A states that <br /> these results were not considered for the human health risk assessment because they were <br /> outdated. Although the soil gas samples were collected at four feet below surface grade (bsg) <br /> instead of five feet bsg, and although the soil gas survey was performed more than ten years <br /> ago, the EHD believes the soil gas concentrations from January 2000 should be used first for <br /> a site-specific health risk assessment. If results from the evaluation of maximum soil gas <br /> concentrations of chemicals of concern from the 2000 survey compared to Environmental <br /> Screening Levels (ESLs) established by the San Francisco Bay Regional Water Quality <br /> Control Board, and California Human Health Screening Levels (CHHSLs) published by the <br /> Office of Environmental Health Hazard Assessment, California Environmental Protection <br /> Agency, and subsequent modeling using the Johnson and Ettinger model prove to be a <br /> cancer risk, then the EHD will conditionally approve the work plan to collect additional soil gas <br /> samples. <br /> In the work plan, AA&A proposes to collect three soil gas samples near the service shop and <br /> two soil gas samples near the office. In the event that the 2000 soil gas survey data do not <br />