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1.2,2 On March 26, 1996, IT Corporation published Site Investigation Report,which documented the results of soil and groundwater-grab sampling from two on-site Geopre soil borings (SB-3 and SB-4), Two additional soil borings (SB-1 and SB-2)were terminated at the buried concrete slab beneath the former USTs. The boring locations are shown on Figure 2. Soil and groundwater beneath the northwest side of the former UST s were impacted by petroleum hydrocarbons. The soil sample analytical results are summarized in Table 3, and the groundwater analytical results are summarized in Table 4. 1.2.3 Monitorinn Well Installations On January 9, 2003, Ramage Environmental published Monitoring Well Installation Report, which documented the installation, survey, and initial sampling;of three groundwater table monitoring wells(MW-1, MW-2 and MW-3). The well locations are shown on Figure 2. Soils to the total drilling depth of 65 feet mostly consisted of massive clay and silt soils, and relatively thin and discontinuous sand intervals less than five feet thick. During drilling, saturated Uo soil was first observed at approximately 56 to 57 feet bgs, and the static depth to the groundwater table, ranged from 46.28 to 46.72 feet bgs. As such, groundwater appeared to be present under semi-confined conditions. The groundwater potentiometric surface appeared as a regular plane dipping to the north. 4W In soil, 3 of the 15 samples analyzed contained detectable concentrations of petroleum hydrocarbons. The highest concentrations were observed between 45 and 55 feet within the capillary fringe and zone of groundwater fluctuation. Laterally, the extent of impacted soil appeared to be limited to beneath the former fuel farm. Vertically, the extent of impacted soil appeared to be defined. The soil sample analytical results are summarized in Table 3. The groundwater samples collected from all three monitoring wells contained detectable concentrations of petroleum hydrocarbons. The highest concentrations were detected at MW-1 840 micrograms per liter(i 11 of Total Petroleum Hydrocarbons (TPH)-aa jet fuel, 7,700 pg/l of TPH-as-gasoline, 1,300 ligA of benzene, 460 gg/I of toluene, 490 ftg/I of ethylbenzene, and 670 gg/I of xylenes, The lateral extent of impacted groundwater was not defined. The groundwater analytical results are summarized in Table 4. 6