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Thud Quarter 1993 Monitonng Report <br /> Coca-Cola Enterpnses, Inc <br /> Project No 54006 02 <br /> Page 3 <br /> RESULTS OF LABORATORY ANALYSES <br />' Water samples collected from wells MW-1, MW-2, and MW-6 were analyzed for TPHG, <br /> TPHD, and BTEX using modified EPA methods 5030/8015/8020. These results and cumulative <br /> results of laboratory analyses are summarized in Table 1. The Chain of Custody Record and <br /> laboratory analytical reports are included in Appendix B <br /> Results of this quarter's laboratory analyses of water samples from wells MW-1, MW-2, and <br />' MW-6 indicate the following: <br /> • The concentrations of BTEX in wells MW-11, MW-2 and MW-6 decreased to <br />' nondetectable levels (<0 5 ppb) since the last monitoring episode <br /> 0 In well MW-1, the concentration of TPHG decreased from 61 ppb to nondetectable (<50 <br /> ppb) since the previous monitoring episode in June 1993. TPHD increased from <br /> nondetectable (<50 ppb) to 250 ppb <br /> • The concentration of TPHG 1n well MW-2 remained nondetectable (<50 ppb). TPHD <br /> increased from nondetectable (<50 ppb) to 720 ppb <br />' • The concentration of TPHG decreased In downgradlent well MW-6 from 130 ppb to <br /> nondetectable (<50 ppb). The concentration of TPHD continues to remain <br /> nondetectable. <br /> WELL ABANDONMENT <br /> On July 19, 1993 an unrecorded facility well located inside a building on site was abandoned <br /> under permit. The well was backfilled from the bottom of the boring to ground surface using <br /> a pressurized, tremied mixture of neat cement and 5% bentonite. The casing was left in place. <br />' Mr b4ichael Collins of SJCPHS was present on-site to observe the well abandonment <br /> procedures. <br />' CONCLUSIONS <br />' Based on the results of this quarterly monitoring and previous work performed at the site, <br /> RESNA concludes that the TPHG concentrations decreased or remained the same, TPHD <br /> concentrations have increased or remained the same, and BTEX concentrations in groundwater <br /> have decreased since the last monitoring episode in June 1993. The majority of gasoline <br /> hydrocarbons had been consistently detected in the vicinity directly downgradient from the <br /> former tank pit(1n well MW-1) No gasoline hydrocarbons were detected in groundwater during <br />' this monitoring episode, only diesel. The reduction in concentrations 1s consistent with historical <br />' 3QMR1993 FUL <br />