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Monitoring Well Abandonrnent Workplan <br /> 707 East Yosemite Avenue,Manteca,California <br /> In July 1993, Aegis conducted a subsurface investigation that included drilling three soil <br /> borings to 15 feet below grade (bg) in the vicini y of the pump islands and UST basin <br /> (Figure 2). Soil sample analytical results indicated no petroleum hydrocarbons were <br /> detected, except 0.008 ppm of xylenes at 15 fee bg adjacent to the western dispenser <br /> island (SB-1). <br /> In August 1993, Aegis conducted a subsurface investigation that included three soil <br /> borings to 30 to 35 feet bg, which were completed as 2-inch diameter groundwater <br /> monitoring wells. Soil sample analytical results indicated no petroleum hydrocarbons <br /> were detected, except 0.005 ppm of xylenes at 20 feet bg in MW-3. <br /> In August 1993, Aegis personnel collected ground ater measurements and samples from <br /> the three monitoring wells. The sampling was observed by SJCEHD. Water sample <br /> analytical results indicated no petroleum hydrocarbons ' were present. Aegis <br /> "Groundwater Monitoring Well Installation Results Report", dated September 14, 1993, <br /> details the well installation and groundwater sampling. SJCEHD requested a confirmation <br /> sampling event to take place at least 30 days after the initial sampling date. In <br /> October 1993, the three wells were again sampled under the observation of SJCEHD. <br /> Analytical results indicated that no petroleum hydr carbons were present and site closure <br /> is warranted. <br /> PROPOSED WORK <br /> The following proposed scope of work will be conducted: <br /> • Abandon the three groundwater monitoring wells (Figure 2) by pressure grouting <br /> the wells with a neat cement/bentonite slurry. <br /> • Prepare closure report summarizing thea andonment. <br /> SITE HEALTH-AN.D-SAFETY-PLAN•. �� <br /> A site health and safety plan (SHSP) has been prepared and will be on site during all <br /> field activities. All on-site work will be conducted according to the SHSP, which contains <br /> information on the properties of hazardous materials known or suspected to be on site. <br /> i <br /> 93.042C.WPN 2 <br />