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} <br /> HYDRO <br /> EMVIRONMENTAL <br /> TEOINOLOGMS,INC. <br /> . Laboratory, Inc (Trace), located in Hayward, California. Portions of the split spoon <br /> sample were retained for visual lithologic description by a HETI geologist using the <br /> Unified Soil Classification System, and for volatile organic headspace analysis using <br /> a Thermo-Environmental Model 580B Organic Vapor Meter (OVM) OVM readings <br /> are presented on the Soil Boring Log and Well Construction Diagrams m Appendix <br /> C Soil cuttings generated from drilling were wrapped in plastic and stored on-site, <br /> pending future removal <br /> One soil sample was selected from each boring for laboratory analysis. The sample <br /> selected was chosen either based on the highest OVM reading, or if hydrocarbons <br /> were not detected by the OVM, the sample which was collected directly above <br /> ground water was chosen Selected soil samples were analyzed for total petroleum <br /> hydrocarbons as gasoline (TPHg) by EPA Method 8015 (modified), and benzene, <br /> toluene, ethyibenzene, and total xylenes (BTEX) by EPA Method 8020. <br /> 2.2 Monitoring Well Installation, Development and Survey <br /> On December 1, 2 and 3, 1993, soil borings MW-6, MW-7 and MW-8 were converted <br /> into two-inch diameter monitoring wells with the same designations Well <br /> locations are shown on Figure 2 On December 9, 1993, these monitoring wells were <br /> developed by a combination of surging and bailing Following development, the <br /> elevation of the top-of-casing of all wells were surveyed relative to an existing <br /> benchmark. <br /> 2.3 Ground Water Gauging, Sampling and Analysis <br /> All wells were gauged on December 9, 1993. Prior to sampling the newly installed <br /> wells, they were purged of a minimum of ten well volumes Well purging <br /> information is presented on the Purge/Sample Data Sheets in Appendix D <br /> Previously installed monitoring wells (MW-1, MW-2, MW-3, MW-4 and MW-5) <br /> were sampled on September 15, 1993, by Associated Soils Analysis (ASA) <br /> Following recovery of water levels to at least 80% of their static levels, ground water <br /> samples were collected from wells MW-6, MW-7 and MW-8 using dedicated <br /> polyethylene bailers Samples were labeled, documented on a chain-of-custody <br /> form, and placed in a cooler for transport to Trace. The ground water samples were <br /> analyzed for TPHg and BTEX by EPA Methods 8015 (modified) and 8020, <br /> respectively <br /> 3 <br />