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a <br /> Mr Harlin Knoll <br /> 22 May 1998 <br /> . Page 11 <br /> 0 82 mg/I (total xylenes) A TPH-g concentration of 31 mg/1 was <br /> detected in the sample collected from MW-2, BTEX compounds were also <br /> detected 1n this sample at concentrations ranging from <01 mg/l <br /> (benzene) to 3 4 mg/1 (total xylenes). The sampling results are presented <br /> in Tables 1 and 2 <br /> Tank Pit Backfilling and Resurfacing <br /> Filling of each excavation was conducted on 1 May 1998 Following <br /> completion of the final excavation activities and with approval from the <br /> County, the excavations were backfilled with imported clean fill material <br /> as necessary to restore the site to existing grade During backfilling, an <br /> oxygen releasing compound (ORC) was placed in each tank excavation <br /> to stimulate bioremediation of residual TPH-g and BTEX in the ground <br />' water Backfill was placed in lifts not exceeding 12-inches and was <br /> compacted to 90% maximum density as determined by Modified Proctor <br /> Test ASTM D1557 ERM provided an independent testing firm to <br /> perform in-place compaction tests during the backfilling operations <br /> Surface pavements will be replaced on 2 June 1998 to match former <br />' pavement conditions Copies of the compaction tests are provided in <br /> Attachment 5 <br /> iDuring the final excavation and backfilling activities at UST #1, <br /> approximately 4,280 gallons of ground water were pumped from the <br /> excavation Approximately 120 gallons of ground water were pumped <br /> from the UST #2 excavation during backfilling activities The ground <br /> water was treated and disposed of as described previously in this report <br /> CONCLUSIONS AND RECOMMENDATIONS <br />' A total of 352 88 tons of soil were removed from the UST excavations <br /> from 18 February 1998 to 1 May 1998 and a total of 20,280 gallons of <br /> ground water were treated and disposed of during the excavation <br /> activities performed at the site <br /> As stated previously, the two excavations have been backfilled and will <br /> isoon be repaved Based on discussions with the County, further soil and <br />' ground water investigation and excavation activities at the site are <br /> considered unnecessary Further investigation or remediation activities <br /> are unnecessary at the site because <br />