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t; August 6, 1993 Page 3 • • Existing hydrocarbon concentrations in the soil appear to be limited to the area around the former product islands Soils in the vicinity of the northern product island at location VW-2, within the depth interval of 20 to 30 feet, were found to have. TPH-g concentrations ranging from 1,400 to 17,300 ppm with benzene concentrations ranging from 0 27 to 28 ppm Within 15 feet of VW-2, at locations MW-2 and KB-2, soil concentrations decreased to below 28 ppm TPH-g and less that 1 ppm benzene between depths of 25 and 30 feet Soils within the 20- to 30-foot depth interval are within the capillary fringe of the highest anticipated groundwater level (approximate depth of 30 feet) Soils within the area of the northern product islands appear to be defined (Figure 3) In the area around the southern product island, Boring KB3 contained 239 ppm TPH-g and 112 ppm benzene Sods within this area were defined to the north by the tank excavation and to the south by Boring K134 An additional discussion of soils delineation at the site is presented to Applied's report dated December 12, 1990 GROUNDWATER CONDITIONS Groundwater occurs beneath the site within the fine-grained deposits, currently between an approximate depth of 47 to 49 feet Groundwater flows to the north- east at an average gradient of 0 002 Groundwater monitoring has been performed at the site since June 6, 1988 Summary data from Resna's First Quarter 1993 Groundwater Monitoring Report as presented as Attachment A. Included as Attachment A 1s the most recent quarters groundwater contour map along with a table summarizing groundwater elevation and laboratory analytical data Groundwater flow at the site has consistently been observed (since 1988) to the northeast at an average gradient of 0.002 The maximum groundwater fluctuation was noted 1n Well MW-1 at 17 5 feet between 1988 and 1993. Because of the fluctuations in groundwater, Wells MW-1 and MW-2 were dry between 1990 and 1992 Well MW-3 continued to be dry through the first quarter 1993 Separate-phase hydrocarbons have never been observed in site wells Historically, the highest hydrocarbon concentrations have been observed in on-site Wells MW-2 and MW-6 During the first quarter 1993 monitoring event, Well MW-2 contained 14,000 parts per billion (ppb) benzene and Well MW-6 contained 160 ppb benzene Well MW-7, the farthest downgradient well (located 300 feet northeast of the site), did not contain any TPH-g or benzene, toluene, ethylbenzene, or xylenes (BTEX compounds) during any of the 1992 or first quar- ter 1993 monitoring events 3104001\wo RKPUV