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KEI-p88-1013 • December 15, 1988 Page 4 Overall, soil sample analyses from the pit had levels of TPH ranging from non-detectable to 740 ppm. BTX&E ranged from non- detectable to 130 ppm. The only 8010 constituents found in any samples were 2-Chloroethylvinyl Ether and 1, 2-Dichloroethane. These ranged from non-detectable to 1. 0 ppm. Final excavation soil sample analyses had TPH concentrations ranging from non-detectable to 24 ppm, with non-detectable concentrations of all 8010 constituents for all samples, except SW7 (50) , which had 0. 120 ppm ' of 1, 2-Dichloroethane. The analytical results for all excavation samples are summarized in Table 1 attached. Copies of the laboratory analyses and the Chain of Custody forms are attached to this report. Initial composite soil sample analyses had levels of TPH ranging from non-detectable to 330 ppm, while BTX&E ranged from non- detectable to 83 ppm. Note that 2--Chloroethylvinyl Ether and 1, 2-- Dichloroethane were never identified in any stockpiled soil due to high volatilization. Analytical results are summarized in Tables 2 and 3 attached. Copies of the laboratory analyses and the Chain of Custody forms are attached to this report. M The analytical results for post-aeration samples are summarized in Table 4 . Aerated soil used as backfill had non-detectable contaminant concentrations between the maximum excavation depth of 53 feet and four feet below grade. Between a depth of four feet 1 and grade, soil having TPH levels less than 10 ppm was used as backfill . Copies of the laboratory analyses and the Chain of Custody forms are attached to this report. DISCUSSION AND RECOMMENDATIONS To complete the proposed excavation, it was necessary to abandon ' two monitoring wells, MW-1 and MW-7 . The wells were abandoned on September 25, 1988 , after permits were obtained from the San Joaquin Local Health District. On November 29 , 1988 an attempt was made to monitor the remaining wells . Unfortunately, most of the wellheads were damaged during soil excavation. Wells #2 , #3 , #4 , #5 and #9 need to be repaired. Although damaged, access was gained to most of the wells. Both MW-6 and MW-9 were partially silted up and dry. MW--8 (which had only eight inches of ground water) was purged but did not recover sufficiently to permit sampling. Botn the source of contamination and most of the contaminated soil have now been removed. It therefore remains to verify the present extent of ground water contamination and make proposals, as necessary, for well repair and abandonment, installation of additional monitoring wells, and subsequent ground water remediation.