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Work Plan for Additional Site Investigation 2 The Southland Corporation 4501 North Pershing Avenue Stockton CA March 29,1997 PROPOSED SCOPE OF WORK Fluor Daniel GTI will drill a total of five soil borings: four on-site soil borings (MW-1, MW-2, MW-3, and MW-1A) and one offsite soil boring (MW-4) at the locations shown on Figure 2. Soil boring depth,sample interval, and well completion intervals are show below: Well Depth Sample Interval Well Completion Well Location/Function MW-1 35 ft BGs None 20 ft screen 13 to 33 ft BGS Source Well " MW-1A 40 ft BGs 5, 10, 15 to 40 ft Bis 2 ft screen 38 to 40 ft BGS Deep Source Well MW-2 40 ft BGs 5, 10, 15 to 40 ft Bis 20 ft screen 13 to 33 ft BGS Upgradient Well MW-3 35 ft BGs Every 5 ft to 35 ft Bis 20 ft screen 13 to 33 ft BGS Crossgradient Well MW-4 35 ft Bis Every 5 ft to 35 ft Bis 20 ft screen 13 to 33 ft BGS Offsite downgradient Well It is anticipated that groundwater will be encountered approximately 18 feet BGS. Field observations and analytical data obtained from the borings will be used to characterize and delineate the extent of adsorbed petroleum hydrocarbons. Details of sampling protocol,well construction methods, waste handling, and final reporting are provided below. TASK 2: SOIL BORINGS/SOIL SAMPLING Fluor Daniel GTI will drill a total of five soil borings to depths of 35 to 40 feet below ground surface (BGS) using a truck-mounted drill rig equipped with 8-inch-diameter hollow-stem augers. Soil samples will be collected in borings MW-1A and MW-2 at 5, 10, and 15 feet BGS and continuously from 15 feet to 40 feet BGS using a split-spoon sampler lined with 2-inch-diameter by 6-inch-long brass sample tubes. Soil samples will be collected from soil borings MW-3 and MW-4 at 5-foot intervals to a depth of 35 feet BGS beginning at 5 feet BGS. If field observations indicate that samples collected at 40 feet in borings MW-1A and MW-2 contain elevated concentrations of petroleum hydrocarbons, borings MW-3 and MW-4 will also be sampled to a depth of 40 feet BGS. Soil samples will not be collected from boring MW-1A due to its proximity to MW-1. The hollow-stem augers will be steam cleaned before drilling, and sampling equipment will be cleaned between each sampling interval. Each soil sample will be screened for hydrocarbon vapors using a photoionization detector(PID). Soils encountered during drilling will be logged using the Unified Soil Classification System by a Fluor Daniel GTI field geologist,working under the supervision of a California registered geologist. One sample tube from each sampling interval will be sealed with teflon sheets, capped, taped, labeled, and placed on ice in an insulated container. Based on field observations, selected soil samples from each borehole will be analyzed by a State-certified analytical laboratory for benzene, toluene, ethylbenzene and xylenes (BTEX), methyl-tert-butyl-ether (MTBE), and total petroleum hydrocarbons-as-gasoline (TPH-G) by EPA methods 8020/8015 modified. An estimated six soil samples will be analyzed from each sampled boring. 0496MP LTR ►IM� FLUOR DANIEL GTI j