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1 tD 'VCES1� indicates that the significant reduction in hydrocarbon concentrations continues Via natural attenuation, benzene levels in monitor well MW-1 have decreased from 11,000 µg11 (06103193) to below the laboratory detection limit of 0 3 µg11 TPH concentrations in the same monitor well have declined from 38,000 14g11 to below the laboratory detection limit, during the same time frame 1 Benzene concentrations for the July 25, 1996, sampling were below the laboratory ' detection limit in monitor wells MW-1, MW-4, MW-5, MW-6, and MW-7 Monitor wells MW-8 and MW-9, which have always been below detection limits for benzene, were not ' sampled. The maximum benzene value, during the July sampling was 134 µg11 in monitor well MW-10 onitor well MW-3A, which was screened properly based on the groundwater relevation during July, had a benzene concentration of 47 µg/l, while monitor well MW-3 (groundwater above screen) had a value of 75 µg/l. As a result of the fact that the improperly screened well had a higher benzene concentration, an inference can be made that the site is in fact naturally attenuating, the significant reduction in groundwater hydrocarbon concentrations ris valid and not merely a function of the rise in groundwater elevations above screened intervals ' Analyses for MTBE were all below the laboiatory detection limit1 TPH groundwater results were below the laboratory detection limit in monitor wells MW-1, MW-4, rMW-5, MW-6, and MW-7 The maximum concentration far TPH was in monitor well MW-3A ' L4,840 /1 . ' In addition to hydrocarbon analyses, Table 3 also includes measurements for dissolved oxygen These data are for use in analyzing the effectiveness of Oxygen Release Compound r (ORC), which will be deployed in the monitor wells on the Canteen facility This remedial measure will further enhance the cleanup of dissolved-phase hydrocarbons. r 6 r