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Ms. Wendy Cohen May 19, 2005 Page 3 of 5 All drilling and sampling equipment was decontaminated prior to use and between sample collection events to minimize the possibility of cross contamination. After sampling, the borings were grouted from the bottom to the ground surface using neat cement grout. Discrete Groundwater Sampling Discrete groundwater samples were collected from borings SB 1, SB2, SB3, and SB4 on April 4 and 5, 2005. Groundwater samples were collected from borings SB2, SB3, and SB4 using a Hydropunch sampler. In boring SB1 an attempt to collect a water sample using the Hydropunch sampler was unsuccessful due to insufficient groundwater influx into the device. Consequently, 3/4- inch diameter, PVC casing and screen were temporarily installed in the boring. Discrete groundwater samples were collected by inserting a length of small-diameter PVC and polyethylene tubing with a stainless steel check valve into the Hydropunch sampler (SB2, SB3, and SB4) and temporary well casing (SBI). The samples were collected into 40-m1 VOA vials containing hydrochloric acid preservative and 1 liter amber jars, scaled, labeled, and immediately placed in an ice chest refrigerated to a temperature of approximately 4°Centigrade. The samples were submitted to Argon Laboratories, under chain of custody protocol, for analysis of TPHQ and TPHd by EPA Method 8015, BTEX by EPA Method 8021B, and gasoline oxygenates additives including EDB and 1,2-DCA by EPA Method 8260B. RESULTS OF INVESTIGATION Subsurface Conditions Soil encountered during drilling generally consisted of silt from the ground surface to approximately 10-15 feet bgs. Beneath this surficial unit, interbedded sands, silts and clays were present to total depth. Poorly-graded sands and silty sands predominate. A layer of lean clay was encountered in borings SB 1, SB2, S133 and S135 between the depths of approximately 30 -32 feet. In boring S134, the clay unit was thicker and was logged between the depths of 21 and 32 feet. Below 32 feet sand with varying amounts of gravel and silt was found. Groundwater was encountered in each boring at 55 feet bgs. No hydrocarbon odors or elevated PID readings were observed in soil borings SB3 and SB5. Slight hydrocarbon odors were noted in borings SBI and S132 in the samples collected from 15 feet bgs to 30 feet bgs, and in S134 in samples collected from 25 feet bgs to 50 feet bgs. Slightly elevated PID readings were recorded in some sample intervals in borings SBI, SB2, and SB4. Copies of the boring logs are included in Attachment C. GAGROUNDHA IGGR\RGPORI'S\Rcv',ISUrepon.doc