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Cone Penetrometer Testing Report - November 2001 P LARRY'S AUTO ' 308 North Grant Street, Stockton, California ' 10 INTRODUCTION At the request of Mr Charles Skobrak,Advanced GeoEnvironmental,Inc (AGE), has prepared the ' enclosed report for 308 North Grant Street, Stockton, California The report documents procedures and results for a cone penetrometer testing (CPT) investigation conducted at the site during November 2001, the objective of the investigation was to model the geologic and hydrogeologic ' frameworks and to assess potential dissolved petroleum-migration pathways beneath the site The site setting is illustrated on Figure 1, site structures, boring, monitoring well and CPT locations are ' depicted on Figure 2 In the scope of work detailed in the AGE-prepared Work Plan Addendum - February 2001, AGE ' proposed to advance CPT borings at four locations to a nominal depth of 100 feet below surface grade(bsg),if petroleum hydrocarbon odor was detected in the water sample collected at total depth, additional water samples will be collected from deeper intervals until a depth is reached where no ' hydrocarbon odor was detected However,during the November 2001 CPT investigation,the vertical extent of impacted ground water was greater than anticipated,sampling and analysis of ground water samples at the first two boring locations detected high concentrations of petroleum hydrocarbon- impacted ground water extending down to the CPT-refusal depth at approximately 180 feet bsg Because the vertical extent of contamination appears to be much greater than anticipated, AGE decided, with EHD concurrence, to suspend additional CPT field work until all data could be ' properly evaluated and drilling modifications planned This report is prepared in accordance with guidelines issued by the Central Valley Regional Water ' Quality Control Board (CVRWQCB) for investigation of underground storage tank (UST) sites Included in this report are ground water analytical data from the latest site quarterly monitoring event ' as well as additional ground water data from the subsurface site investigation at 244 West Harding Way (Figure 2) A summary of site background information and previous investigations was included in the AGE-prepared Quarterly Report-August 1997 2.0. PROCEDURES 1 On 13 and 14 November 2001,two off-site,paired soil borings (CPT-2 and CPT-3) were advanced immediately south of the site(Figure 2)utilizing CPT technology At each boring location,lithologic ' data was collected from the initial CPT boring, an immediately adjacent twin boring was then advanced to collect grab ground water samples from selected depths • Advanced GeoEnvironmental,Inc