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. e) are included in Appendix E Chloroform (trichloromethane) was detected at low concentrations in samples from EW-1, MW-7 and MW-14. 1,2-Dichloroethane was detected in samples from MW-7, MW-9, MW- 13 and MW-14 at concentrations of 1.1 ppb, 2 4 ppb, 3 2 ppb and 12 ppb, respectively. No other volatile halocarbons were detected in any of the water samples. The analytical results are summarized in Table G. The laboratory results and chain-of-custody are included in Appendix E x 5.0 CONCLUSIONS AND RECOMMENDATIONS 5.1 Bioremedlation Since full-scale inoculation of the site was initiated on August 16, 1994, only little more than one month's worth of data has been collected from the site Initial soil vapor monitoring a and groundwater results are encouraging We would expect to measure the greatest amount of biological activity at the site in areas of the greatest contamination The soil vapor results indicate that the greatest concentrations of carbon dioxide and the lowest concentrations of oxygen are occurring in the area of VW- 4, VW-5 and MW-4 In the coming months, we would expect to see carbon dioxide • concentrations continue to increase (between 3 and 9 percent) and oxygen concentrations decrease in the areas of highest contamination The same trend, though more subtle, should be seen throughout the site 5.2 Groundwater Depth and Flow Direction Groundwater elevation has decreased (dropped) about 2 feet throughout the site since June 1994 (see Table 1) During the previous monitoring a 15 foot decrease was noted throughout the site Groundwater elevation fluctuations at the site appear to be in accordance with seasonal vanations of groundwater depth in the region The groundwater flow direction continues to be to the south-southwest 5.3 Petroleum Hydrocarbon Impacted Groundwater Following historical trends at this site, concentrations of petroleum hydrocarbons in groundwater continue to fluctuate widely During the past quarter, hydrocarbon concentrations increased slightly in samples from MW-6 and MW-14, concentrations increased significantly in samples from MW-8, MW-9 and MW-1I However, since March 1994, hydrocarbon concentrations have decreased in MW-7, MW-10, MW-11, MW-12 and EW-1 Monitoring well MW-13 continues to be non-detect(ND) for petroleum hydrocarbons, MW- '6S—t A.&S......,.I— N--4/--4/P-P-0 M 33 CFWQMS