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11 June 2001 <br /> AGE-NC Project No. 96-0232 <br /> ' Page 6 of 11 <br /> ' clearly marked and a utility clearance obtained through Underground Service Alert. <br /> ' 3.2. MULTI-LEVEL WELL BORE-HOLE DRILLING AND SOIL SAMPLE COLLECTION <br /> AGE has reviewed the lithologic data and ground_water-analytical data derived from samples <br /> t collected during the CPT investigation. Based on review of the CPT data, AGE believes that <br /> installation of multi-level monitoring wells could be effectively utilized to assess and monitor deeper <br /> petroleum hydrocarbon-impact.AGE proposes to install two(2)multi-level ground water monitoring <br /> wells at the site as part of the site assessment activities. Well locations and screen intervals are <br /> proposed to provide definition of the vertical extent of dissolved petroleum-impact and to monitor <br /> vertical migration of the plume of petroleum-impacted ground water. Cuttings generated during <br /> ' drilling will be placed on plastic sheeting and covered. Rinseate will be containerized in properly <br /> labeled DOT-approved 55-gallon drums,and stored on-site in an area lacking public access.Disposal <br /> ' alternatives will be evaluated based on results of soil and water analysis. Proposed monitoring well <br /> locations are illustrated on Figure 2. <br /> Based on the substantial petroleum-impact encountered on-site at SVE wells VW-1, VW-2, VW-3 <br /> and in the ground water samples collected from CPT soil borings CPT-IA and CPT-2A, AGE <br /> proposes two (2)multi-level ground water wells in the following locations: <br /> • Between 5 and 10 feet northeast of monitoring well VW-1 to characterize lithology,potential <br /> contaminant migration pathways and to assess the vertical extent of petroleum-impacted <br /> ' ground water at depths greater than 63 feet bsg downgradient the former UST area; <br /> • Between 5 and 10 feet west of monitoring well VW-3 to characterize lithology, potential <br /> ' contaminant migration pathways and to assess the vertical extent of petroleum-impacted <br /> ground water at depths greater than 63 feet bsg and adjacent to the former UST area; <br /> ' The pilot borings will be advanced to approximately 150 feet bsg utilizing a B-95 truck-mounted <br /> drill rig equipped with 8-inch diameter hollow-stem augers; however, total depths of borings may <br /> vary according to field conditions encountered during drilling. <br /> Soil samples will be continuously collected during bore-hole advancement utilizing a five-foot macro <br /> core sampler and will be described and recorded on boring logs. The macro core sampler will be <br /> driven by dropping a 140-pound weight from a height of 30 inches. A minimum of one soil sample <br /> per every fifteen linear feet collected will be submitted to a State of California Department of Health <br /> ' Services (DHS)-certified laboratory for analysis for the following constituents: <br /> • TPH-g by EPA Methods 5030/8015M; <br /> Advanced GmEnvironmental,Inc. <br />