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not contain detectable concentrations of TPHg or BTEX. Methyl tertiary butyl ether (MTBE), t- amyl methyl ether (TAME), t-butanol (TBA), ethyl t-butyl ether (ETBE), di-isopropyl ether (DIPE), 1,2-dichloroethane (1,2-DCA), or 1,2-dibromoethane (EDB) were not detected in any soil samples collected from borings MW 1, MW2, and MW3, though the detection. limits were elevated in the MW2 sample from 35.5 feet bgs due to the high concentrations of TPI-Ig noted previously. In July and Decembe ,��0_03,ATC conducted additional subsurface investi ation activities at the site that included cone penetration testing, advancing a soil boring B8 and installation of monitoring wells MW4 through MW7, Petroleuin hydrocarbons w e e ec ed in soil samples collected from the boreholes of MW5 and MW6, and in the groundwater samples collected from MW4 through MW-7. 2.0 SUBSURFACE CONDITIONS 2_1 Geology Soil in MW 1 consisted of poorly graded sands, very fine sands, and silty sands from the surface to a depth from 31.5 to 35 feet bgs, organic silts and clays from 41.5 to 45 feet bgs to 46.5 to 50 feet bgs, and silty sands from 46.5 to 50 feet bgs, to 56.5 feet bgs. Soil in MW2 generally consisted of inorganic silts and clays from the surface to depths between 36.5 to 40 feet bgs, and poorly graded and silty sands from 36.5 to 40 feet bgs to 56 feet bgs. Soil in MW3 was primarily inorganic silts from surface to 56 feet bgs, with a thin layer of clayey sand that stretched from 26.5 to 30 feet bgs to 31.5 to 35 feet bgs. Soil in MW4 generally consisted of inorganic silts to a depth of 13 feet bgs, poorly graded sands from between 13 feet to 23 feet bgs, inorganic clays and silts from between 23 feet to 48 feet bgs, and poorly graded sand and well graded sands from between 48 feet to 55 feet bgs. Soils in MW5 and MW6 consisted of inorganic clays and silts from surface to an approximate depth of 43 feet bgs, clayey sands from approximately 43 feet to 49 feet bgs, and poorly and well graded sands from 49 feet to 55 feet bgs. The soil in MW7 consisted of inorganic clays and silts from surface to an approximate depth of 48 feet bgs, poorly graded sands from 48 feet to 53 feet bgs,and inorganic clays from approximately 53 feet to 55 feet bgs. Soil in boring SB8 generally consisted of inorganic silt from surface to an approximate depth of 34 feet bgs, silty sand from 34 feet to 39 feet bgs, inorganic clays and silt from 39 feet to 43 feet bgs, and poorly graded sands from approximately 43 feet to 46.5 feet bgs. Copies of well and soil boring logs are included in Attachment 1. 222 Hydrogeology Groundwater elevation measurements collected from monitoring wells MW1 through MW7 on June 5, 2005, ranged from 50.61 to 53.16 feet bgs. Groundwater elevations ranged from -35.85 5:\224931repons\CAP.doc 3