Laserfiche WebLink
San Joaquin County DIRECTOR <br /> Donna Heran,REHS <br /> p�Q�U?M • C Environmental Health Department ASSISTANT DIRECTOR <br /> ?• = 'OG Laurie Cotulla,REHS <br /> _ 600 East Main Street <br /> '�` F ?{ Stockton, California 95202-3029 <br /> N: PROGRAM COORDINATORS <br /> Carl Borgman, REHS <br /> Mike Huggins, REHS,RDI <br /> Website: www.sjgov.org/ehd Margaret Lagorio,REHS <br /> Lr fioR phone: (209) 468-3420 Robert McClellan,REHS <br /> Fax: (209)464-0138 Jeff Carruesco, REHS,RDI <br /> Kasey Foley, REHS <br /> June 20, 2008 <br /> Mr. Allen )~etters <br /> Ripon Farm? Service Incorporated <br /> 3705 Portsr)Zouth Circle <br /> North StocRton, California 95219 <br /> Subject: Wpon Farm Service Incorporated <br /> 9.32 South Highway 99 (Formerly 22871 South Highway 99) <br /> Ripon, California 95366 <br /> The San Joaquin County Environmental Health Department (EHD) has reviewed results <br /> from the advancement of four soil borings (1320 through B23) to approximately thirty feet <br /> below surf4ce grade (bsg) in August 2007, located on the west side of Highway 99 near <br /> City of Rippe municipal well number 12, and groundwater results from quarterly sampling <br /> in 2006 an4 2007, prepared and submitted by Advanced GeoEnviron.mcntal, Isle. (AGE) on <br /> your behalf. Although groundwater results from the four soil borings were free of <br /> contaminants of concern, 1,2-dicltloroethane (1,2-DCA) continues to be detected <br /> intermittently at low concentrations in groundwater samples collected quarterly from <br /> monitoring wells .MW-1, MW-2, MW-4, MW-9, and MW-10. AGE has recommended your <br /> site for clo$ure consideration based on current site conditions that the groundwater plume <br /> for 1,2-DCA appears to be defined and stable. <br /> AGE's assessment that this site may be a low-risk site based on current groundwater results <br /> reported for 1,2-DCA, may be correct; however, the EHD is not convinced the same is true <br /> for impacted soil. AGE has reported that following soil and groundwater remediation by <br /> soil vapor Oxtraction/air sparging (SVE/AS), "the total volume of impacted soil addressed <br /> by the remediation system was estimated to be 1,240 cubic meters, from the base of the <br /> former USS' excavation to the depth of thirty feet bsg. The total mass of adsorbed total <br /> petroleum hydrocarbon (TPH) quantified as gasoline (TPH-g) was approximately 123.5 <br /> pounds, ar d the mass of total adsorbed TPH quantified as diesel (TPH-d) was <br /> approximately 150 pounds." The EHD is concerned the residual petroleum hydrocarbon <br /> contaminants may impact groundwater if and when groundwater rises above its current <br /> depth of approximately 23 feet bsg. Historically, high concentrations of TPH-d and TPH-9 <br /> were detected in groundwater samples when groundwater was reported at approximately <br /> fifteen to twenty feet bsg. The EHD requires a demonstration that impacted soil will not <br /> impact groundwater during periods of higher groundwater elevation. Submit the <br /> documentation supported by technical argument to the EHD by September 5, 2008. <br />