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in samples S-1 and S4. The condensate sample (S-4) also contained levels of diethvlene glycol, triethylene glycol and tetraethylene glycol. On May 19, 1988, Groundwater Technology, Inc. performed three exploratory soil borings in the immediate vicinity of the reboiler recharge line (Figure 2). The purpose of that study was to evaluate the vertical extent of petroleum hydrocarbons in the soils and to determine the feasibility of using in-situ bioremediation techniques to remediate the affected soils. Selected soil samples from each borehole were analyzed for TPH by EPA Methods 8015 and 418.1, triethylene glycol by EPA Method 8015, and benzene, - toluene, ethylbenzene and xylenes (BTEX) by EPA Method 8020. In addition, one soil sample was analyzed for volatile organic compounds by EPA Method 8240, polychlorinated biphenyls by EPA Method 8080, and semivolatile compounds by EPA Method 8270. The chemical analytical results of these soil samples (Table 2) indicate that petroleum hydrocarbon compounds were present in the shallow soils adjacent to the discharge line. Triethylene glycol was reported in one soil sample at a concentration of 12,000 mg/kg. The results of the analyses for the other compounds indicate very low to non-detectable a concentrations of volatile organic compounds and non-detectable concentrations of PCB's and semivolatile compounds. Durrng November 1992, PG&E's Technical and Ecological Services Department performed a subsurface investigation to further define the extent of soil and groundwater contamination at the site. This work included the drilling and sampling of nine boreholes, the installation of eight temporary groundwater monitoring wells and one permanent groundwater monitoring well, determination of groundwater flow direction and gradient, and the development and water sampling of all wells installed at the site (Figure 3). In addition, a survey of all production water wells within '/z-mile of the site was also performed (Figure 4, Table 3). The results of this study showed that petroleum hydrocarbons were present in the soil and groundwater in the vicinity of the reboiler unit and appeared to extend off-site to the east and north. The petroleum hydrocarbons in soil and groundwater at the site consist primarily of kerosene-range hydrocarbons, with TPH-G and BTEX comprising about one-fourth of the TPH (Tables 4 and 5). The total petroleum hydrocarbons as kerosene(TPH-K) levels in groundwater were reported at concentrations up to 47,000 µg/1 in MW-1 and four temporary wells (B-2, B-3, B4, and B-9). Groundwater at the site was encountered at a depth of about 9 feet bgs. Based on water level measurements made from the temporary wells, groundwater appeared to flow to the south with a relatively flat hydraulic gradient cca/03/10/95 08:19 AM(0688brpt.doc/ntw12) 1-5