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sw 2-5 contamination was observed. DSII cuttings were screened using a TLV or OVM meter. Soil showing evidence of organic vapors of 100 ppm or greater was considered contaminated, and samples were collected. Samples were collected every 5 feet to well depth,or until no evidence of contamination was found. Table 2-1 describes the soil samples taken for each vapor extraction well. E : Soil samples were collected using an 18-inch-long by 2-inch-diameter Modified Czlifomia- da type sampler with 6-inch-long brass tube liners. The drive sampler was driven ahead of the auger into undisturbed soil. Each borehole was logged from the samples taken at each 5-foot interval r. and the drill cuttings,using the Universal Soil CIassification system. Borehole logs are presented in Appendix A. Soil samples were collected according to the methods previously stated for ' monitoring well soil sample collection. Cuttings from each borehole were stored on visquine on site. A vapor extraction well was then constructed in each borehole by inserting 4-inch-inside- diameter,Schedule 40 PVC casing with 45 feet of 0.040-inch slotted well screen attached to the bottom. The perforated casing extends approximately 10 feet below ground surface to 55 feet F 7"] Lvlow ground surface. A bottom plug was installed at the bottom of the perforated interval. ;._. To filter pack a well, the augers were removed frons the borehole and medium aquarium sand was poured directly into the annulus around the casing, The annular space was filled to ^_ roughly 2 feet above the screened interval. A bentonite seal was placed immediately above the ;. gravel pack. The remaining annular space of each well was filled with a cement(bentonite slurry. : ' Following installation, the five monitoring wells and the groundwater extraction well were developed using a surge block and stainless steel bailer. Throughout development, pH and specific conductance of the discharge water were monitored, and development was continued a until these parameters had stabilized and until the water was relatively sediment free. The water produced during development of the wells and steam cleaning of the augers was contained on site in 55-gallon drums. All of this water was taken to Gibson Oil in Bakersfield California,by. j _s Universal Engineering..".- Each ngineering.".-Each monitoring well, along with the nine previously installed monitoring wells, were sampled during April le, 1990,through May 4, 1990. For monitoring wells NV-9, W-IA, and ' W-12,the sample was collected directly after development of the well. The wells were sampled ` using disposable PVC bailers equipped with bottom-emptying valves. The sample was drained directly from the bottom valve into two 40-milliliter glass bottles with Teflon-lined septums. The samples were stored on ice from the time of collection through delivery to BC's state-certified laboratory. The remaining.wells W-2, W-2A, W 2B, W-3, W_5, W 6,-W-7,.,W S, IAV-10, and ' Y;r.11.were sampled after the groundwater was purged from the wells.by Armour Petroleum,Inc. — - _ " -- ---(Armour); of-Fairfield,-_California:-_Monitoring--well--W4-was"-not-sampled=due- to-t e--- ------- ------ --- accumulation of sediment inside the wall. Approximately three well volumes(one well volume being the volume of water inside the casing plus 35 percent of the gravel packed annular space) were evacuated from each well. The pH and specific conductivity of the discharge water were