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na <br /> The soil borings were lithologically logged by Alton <br /> Geoscience using the Unified Soil Classification System. <br /> Soil characteristics such as color and combustible gas <br /> readings were also noted on the boring logs. Drilling <br /> procedures and soil sampling protocol are presented in <br /> Appendix C- <br /> 3.2 i <br /> To assess the lateral extent of hydrocarbon constituents in <br /> the ground water, a qualitative shallow ground water (QSGW5) <br /> cted. The sur <br /> was conduvey is a screening process to <br /> determine the most appropriate locations of the additional <br /> monitoring wells necessary to define the lateral extent of <br /> hydrocarbons in ground water. The procedure used combines <br /> for <br /> the conventional drillinghtechhnigtue withs of temporaryhe we 1paints <br /> ls <br /> ground water sampling. <br /> were determined based on the results of previous <br /> investigations and review of the site characteristics. <br /> Each soil boring was advanced 2 to 4 feet beyond the depth at <br /> which the saturated zone was first encountered. During <br /> drilling of the boreholes, discrete soil samples were <br /> collected and screened in the field using a combustible <br /> gas <br /> indicator (CGT) . A temporary, 2-inch-diameter, perorated <br /> polyvinyl chloride (PVC) casing with 0.020-inch slots was <br /> then installed in each of the boreholes. The temporary wells <br /> were purged of approximately 5 gallons of ground water prior <br /> to sample collection, using disposable Teflon bailers. <br /> Qualitative ground water samples were then collected using <br /> bailers, decanted into clean containers, <br /> disposable Teflon <br /> and transported in an iced cooler to a California-certified <br /> laboratory for analysis of TPH-G and BTEX constituents, <br /> following proper sample preservation procedures and chain of <br /> custody documentation. <br /> After the collection of ground water samples, the PVC casings <br /> from the temporary wells were removed and steam cleaned. The <br /> borings were then either completely backfilled with neat <br /> - cement or completed as monitoring wells. <br /> 3.3 _ ;t g-Well C <br /> - Soil Borings B-4, B--2, E-3, and B-4 were converted to ground <br /> water Monitoring Wells AW-5, AW-6, AW-71 and AW-8, <br /> respectively, based on the results of field observations and <br /> �- previous studies. The additional monitoring wells,. AW-5 <br /> through AW-8, were completed to a total depth of 25 faet <br /> four wells were constructed using <br /> below grade. All <br /> 2.-inch-diameter flush-threaded, Schedule _40,...PVC... an <br /> casing, and 0.020-inch, slotted PVC casing. Monitoring well <br /> 6 <br />