Laserfiche WebLink
San Joaquin County <br /> "..� Environmental Health Department DIRECTOR <br /> Linda Turkatte, REHS <br /> Q 1868 East Hazelton Avenue <br /> Stockton, California 95205-6232 PROGRAM COORDINATORS <br /> � <br /> � Robert McClellon,REHS <br /> Jeff Carruesco, REHS,RDI <br /> Website: www.sjgov.org/ehd Kasey Foley, REHS <br /> Rodney Estrada,REHS <br /> Phone: (209) 468-3420 Adrienne Ellsaesser,REHS <br /> Fax: (209)464-0138 <br /> January 30, 2015 <br /> Mr. Charles Skobrak <br /> 9947 East Highway 26 <br /> Stockton, California 95215 <br /> Subject: Larry's Auto <br /> 308 North Grant Street <br /> Stockton, California 95202 <br /> Dear Mr. Skobrak: <br /> The San Joaquin County Environmental Health Department (EHD) has received and reviewed <br /> Semi-annual Report — Second Quarter 2014 (2edQ-2014 Report), dated 19 August 2014, and <br /> Remediation Report — Third Quarter 2014 (Remediation Report), dated 10 November 2014, <br /> both prepared and submitted by your consulting firm, Advanced GeoEnvironmental, Inc. (AGE), <br /> on your behalf for the above-referenced site. In Remediation Report, AGE has recommended <br /> that additional shallow soil vapor extraction (SVE) wells be installed north of monitoring wells <br /> MW-4 and MW-5, and that vapor extraction wells VW-213 and VW-5C be converted to air sparge <br /> wells and incorporated into the in-situ air sparging (IAS) system for a period of approximately six <br /> months "to evaluate expansion of deep IAS remediation". <br /> Although analytical data for groundwater collected from MW-5 indicate the presence of high <br /> concentrations of contaminants of concern, including benzene at 14,000 micrograms per liter <br /> (Ng/L), except for groundwater collected from MW-5, located approximately sixty feet down- <br /> gradient of the former southern underground storage tanks (USTs), a soil and groundwater site <br /> assessment has not been completed down-gradient of MW-4. In addition, in October 1988, a <br /> 5,000-gallon UST and a 300-gallon waste oil tank were removed in what appears to be the area <br /> north of MW-5. Although a work plan addendum, dated 15 February 1990, was submitted to the <br /> San Joaquin Public Health Services (aka the EHD) by WaterWork to "re-excavate" the north <br /> wall and floor of the 5,000-gallon UST, the EHD has no knowledge that the "re-excavation" and <br /> additional site investigation were ever completed following the removal of these two USTs. To <br /> address this data gap, the EHD recommends additional site assessment of soil and <br /> groundwater near and north of MW-5 and installation of additional down-gradient monitoring <br /> wells to delineate the soil and groundwater plume north and northeast of the source area. <br /> Submit a work plan to the EHD by 31 March 2015 to delineate the petroleum hydrocarbon <br /> contamination down-gradient of MW-4 and MW-5. <br /> The two wells that AGE proposes to convert from SVE wells to IAS wells, VW-26 [screened <br /> forty-four to fifty-four feet below surface grade (bsg)] and VW-5C (screened forty-five to fifty-five <br /> feet bsg), are impacted by benzene with recent concentrations of 6,500 pg/L and 160 pg/L, <br /> respectively. Silty clay and clayey silt comprise the soil of VW-2 and VW-5 with a thin sand unit <br />