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Quik Stop Market No. 132 July 11, 1991 Project No. 3-49132-31 Page 5 - monitoring wells, and significant site features were also surveyed. A copy of the original survey map is included in Appendix B. SI'Z'E HYDROGEOLOGY During the drilling operations, each boring was Iogged noting soil type, soil moisture, and depths at which groundwater was encountered. Previous investigations conducted at the site (Exceltech, September 1990, Exceltech, November ':990) have indicated the presence of two aquifers beneath the site. This information, detailed in our work plan modification dated February 5, 1991, included cross-sections created from the subsurface information obtained from exploratory boring logs and observations made during extensive excavation operations at the site. - Boring MW-IR was drilled to a depth of 32 feet, into the lower water bearing, and MW-5 to a depth of 19 feet, into the upper water bearing unit or what appears to be a perched aquifer. The soil encountered in both borings, which were only 3 feet apart laterally, consisted of a moist, sandy clay to a clayey sand to a depth of I 1 feet, beneath this was approximately 2.5 feet of a moist silty sand to sand. A moist clayey sand to silty sand was observed from approximately 13.5 feet to 18.5 to 19 feet. Groundwater was encountered in this stratum at approximately 17 feet. Beneath this was a moist, silty clay which boring MW-1 and MW-IR showed to be approximately 3 feet thick overlying a wet sand which continued to the depths explored. In both borings, groundwater was encountered approximately 17 feet below the surface. After well development, the groundwater level in MW-1R and MNV-5 was measured on April 8, 1991 at depths ranging from 14.0 feet to 14.4 feet below the top of the well casing. Tltis rise in groundwater level of approximately 3 feet from the depths at which it was first encountered would suggest the aquifer is semi-confined to confined. Groundwater elevation generated from these water levels resulted in a groundwater elevation of -10.82 feet for MW-5, and -10.83 feet for MW-IR. A groundwater elevation contour map generated from groundwater elevations for all wells in the upper aquifer is presented in Figure 3. The apparent direction of groundwater flow is to the east at a gradient of approximately 0.0038. SAMPLE ANALYSES All soil samples collected were analyzed for_TPHG with benzene, toluene, ethyl benzene, and total xylenes (BTEX) distinction using Environmental Protection Agency (EPA) Method 5030/8015/8020 modified after the Leaking Underground Fuel Tanks - (LUFT) Manual. All groundwater samples were analyzed for TPHG with BTEX distinction using EPA Method 5030/8015/8020 modified after the LUFT Manual. In addition, groundwater samples collected from wells located within 50 feet of sanitary