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a History Jaacl kpot Food Mart,1434 W Yosemite Ave,Manteca, CA Time Oil Property No 0416-7 A ditional Site Invest) anon - De ember 1993 Based on data collected during a preliminary Investigation (Canonie, April 1993), additional site activities were conducted to further define the extent of hydrocarbon-impacted soils associated with the former tanks, and to determine if groundwater beneath the site had been impacted Prior to the implementation of field activities, SEACOR's workplan dated October 12, 1993 was submitted for agency review Verbal authorization to proceed with the proposed work was received from the PHS/EHD on November 27, 1993 On December 2, 1993, a drill ng was utilized to advance 4 soil borings In the vicinity of the former tanks During field activities, soils were found to consist of fine to medium sands to a depth of approximately 15 feet This strata was underlain by clay Because the previous investigation indicated that the clay unit may be acting as an squitard, all bonngs were discontil-rued at a aepth of 16 5 feel beiuw ground surface to prevent possible Impacts to groundwater beneath the site Soil samples collected from depths of 10 5 to 11 feet and 15 5 to 16 feet in each bortng were submitted to an analytical laboratory and analyzed for gasoline and its constituents Analyses did not Indicate hydrocarbons in any of the samples submitted for analysis On December 2, 1993, the existing groundwater wells were developed andsampled Prior to p u in an easterly gradient was determined by measuring the depth to groundwater in each well (approximatelyr9 9, feet below ground surface) Analyses indicated 0 06 ppb toluene in the sample collected omW6, 1$ however, no contaminants were detected in the remaining wells Based on the results of soil samples collected during appears that the extent of hydrocarbon-impacted soil iswelldefined and remains meted to st and recent site assessmentactivitiesthe area of the pump islands SEACOR's report recommended the installation of a vapor extraction system to address the small amount of impacted soil Time Oil concurs with this recommendation Based on the results of samples collected to date, it does not appear as though groundwater beneath the site has been significantly impacted by hydrocarbons Although trace concentrations of toluene were present in a sample collected from W6, the level indicated falls far below California's primary drinking water quality standards (1,000 ppb for toluene) Accordingly, SEACOR's report did not recommend the Implementation of a groundwater cleanup system Time Oil concurs with this recommendation A Copy SEACOR's "Problem Assessment Report" was forwarded to the PH5/EHD and CRWQCB on June 1, 1994 In their espouse dated May 24, 1994, the PHSIEHD requested that quarterly groundwater monitoring be implemented until the investigation and cleanup of the site are deemed adequate In accordance with this request, groundwater sampling will be initiated during the Third Quarter of 1993 The PHSIEHD also requested that a Final Remediation Plan/Corrective Action Plan (FRIG/CAP) be submitted by September 3, 1994 Submittal of Final Remedial Plan &. Quarter) Groundwater Monitor /Status Re ort - Third Quarter On September 7, 1994 three copies of SEACOR's "Final Remedial Plan and Quarterly Summary Report,,was forwarded to the appropriate regulatory agencies This report presented the analytical results of groundwater samples collected from monitoring wells during the third quarter of 1994, summarized data collected to date, and presented recommendations for a cleanup system to remediate hydrocarbon-impacted soils at the above-referenced property The report and accompanying cover letter were intended to satisfy Article S, Section 2652 of the California Underground Storage Tank Regulations 3