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07 May 1998 AGE-NC Project No. 98-0448 Page 2 of 6 2.3. PRELIMINARY SITE ASSESSMENT Between June and October 1994, borings, four soil borings (B-T, B-1, B-2, B-3) and three ground water monitoring wells (MW-I,MW-2 and MW-3)were drilled and installed at the site by John P. Cummings and Associates (JPCA). A total of twenty-three soil samples and one grab ground water sample were submitted to a State-certified laboratory for analysis. TPH-g was detected in 10 of 23 samples at concentrations ranging from 1.2 ppm (MW-2-20) to 14,000 ppm (B-T-16). Volatile aromatics(benzene,toluene, ethyl benzene and xylenes; BTEX) were detected in 15 of 23 samples at concentrations up to 1,200 ppm (xylenes, B-T-16). Analytical results of soil samples are summarized in Table 1. Ground water samples were collected from the monitoring wells on nine occasions by JPCA between October 1994 and November 1997.TPH-g has been detected in samples from each well as high as 200,000 micrograms per liter(,ug/l or parts per billion: ppb); BTE&X have been detected in each well at concentrations up to 31,000 ppb; MTBE has been detected in wells MW-1 and MW-2 at concentrations up to 1,700 ppb.Analytical results of ground water samples are summarized in Table 2. 3.0. SCOPE OF WORK Laboratory analysis of soil samples collected from B-T and MW-2 indicate that hydrocarbon- impacted soil is present to depths of at least 35 feet bsg. Additional investigation near the former UST area will be necessary to determine the vertical extent of hydrocarbon-impacted soil in the saturated zone. The lateral extent of hydrocarbon-impacted ground water has not been delineated at the site. High concentrations of TPH-g and BTEX continue to be detected in samples collected from wells MW-1 though MW-3; furthermore,wells MW-1 and MW-2 appear to be poorly developed and may not be representative of actual subsurface conditions. Additional monitoring wells are necessary to identify the lateral and vertical extent of the dissolved hydrocarbon plume. The following scope of work is proposed by AGE to determine the lateral and vertical extent of hydrocarbon-impacted soil and ground water at the site: Drilling and installation of one ground water monitoring well south of the former UST excavation,between MW-1 and MW-2. This well should be drilled to a depth of at least 50 feet and should be dual-completed with two PVC casings to monitor both first-encountered ground water(approximately 25 feet bsg)and deeper groundwater(estimated at 45 feet bsg). Laboratory analysis of soil and ground water samples from this well should determine the Advanced GeoEnvironmentai,Inc.