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Project No 034-98081 Page No 5 The possibility of preferential distribution of fine- to medium-grained sand lenses in boreholes B-2 and B-3 is supported by observations of groundwater recharge in these boreholes during groundwater sampling attempts Borehole B-2 was drilled initially to 35 feet bgs without attempting Hydropunch® sampling because the groundwater surface was expected to exist below that depth However, upon removal of the drilling plug from the hollow stern auger at 35 feet bgs, groundwater was noted to rapidly fill the auger, allowing sample collection using a bailer With the above knowledge of current groundwater depth, a Hydropunch0 was used to sample groundwater from borehole B-3 by driving the sampler from 32 to 36 feet bgs Upon retraction of the sampler body, groundwater was noted to rapidly ' fill the screen interval of the Hydropunch® allowing unhindered sample collection Initial attempts to sample groundwater in boreholes B-4 through B-7 failed due to much slower recharge into the Hydropunch© sampler, even though a similar soil type (CL) was intercepted at the target sample depth in most boreholes Sampling was ultimately accomplished by overdrilling to 40 feet bgs, retracting auger to 35 feet bgs, and allowing groundwater to slowly recharge into the borehole 62 Chemical Constituent Distribution and Relationships 62 1 Constituent Distribution Review of Tables I and II show that PHCs were detected in soil from the 20 to 40 feet bgs interval of borehole B-2 and the 30 feet bgs sample from borehole B-3 With exception of TPH-G detected in borehole B-2 at 20 feet bgs, benzene was the only PHC detected in soil Soils from boreholes B-4 through B-7 were not sampled, however, the lack of positive PID readings or field indications of hydrocarbon odors while advancing boreholes suggests the unsaturated zone soils are not impacted at these locations Groundwater samples were collected from the six boreholes near the water table (Pz�34 to 40 feet bgs) Detectable PHCs were only present in groundwater collected at boreholes B-2 and B-3 Benzene concentrations of 10,000 micrograms per liter (gg/1) and 2,200 µg/l, and TPH-G concentrations of 4,700 p.g/l and 3,100 µg/1 were present at boreholes B-2 and B-3, respectively The groundwater sample with highest PHC concentration was also analyzed for MTBE -- this constituent was not detected APDL, Inc , the analytical laboratory conducting analyses on the August 1998 soil and groundwater samples, was requested to conduct a confirmation analysis of the groundwater sample with the highest KRAZAN & ASSOCIATES, INC Offices Serving the Western United States 3498081 SGS