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Ms. Lori Duncan October 3, 2003 Page 2 of 7 The UST was removed under permit from EHD on February 5, 1999. Soil samples collected beneath the tank contained ethylbenzene and total xylenes`at levels exceeding the respective laboratory detection limits. Analytical results of soil samples collected from beneath the farmer UST are summarized in Table 1. Sample locations are shown on Figure 2. Subsurface Investigation Ground Zero supervised the drilling of three soil borings ori December 17, 1999 to investigate the extent of soil and groundwater contamination in the vicinity of the former UST. Results of the investigation indicated that soil and groundwater had been impacted from an unauthorized release of gasoline. ' Ground Zero installed and sampled four groundwater monitoring wells in January 2001 to investigate the lateral extent of soil and groundwater contamination at the site. Seven rounds of groundwater samples collected from site wells indicate thattlow levels of gasoline constituents, including MTBE, persist in groundwater beneath the site. Analytical results of the most recent samples collected from site wells (June 2003) contained no gasoline constituents above drinking water levels. Analytical results of soil and groundwater from the subsurface investigation are summarized in Tables 1 and 2, respectively. Sample locations are shown on Figure 2. A cross section showing 1 site lithology and soil analytical results is presented on Figure 3. A groundwater gradient map generated from the June 2003 data is presented on Figure 4:Y Figure 5 presents the most recent concentrations of contaminants in groundwater. The depth to groundwater in site monitoring wells has ranged from approximately 5 to 7.5 feet below ground surface(bgs). Groundwater elevation data is summarized in Table 3. 1 Minor Soil Excavation Jim Thorpe Oil, Inc. of Lodi conducted a minor soil excavation during removal of the UST on J February 5, 1999. According to Mr. Rich Thorpe, less than 30 cubic yards of soil were excavated as part of the removal activities. The excavated soil was stockpiled on site adjacent to the } excavation. h 3 A Ground Zero field technician sampled the soil stockpile; which also contained soil cuttings from the monitoring well installations, on January 23, 20011.1 Analytical results of the stockpiled soil contained no gasoline constituents and Ground Zero recommended that the soil waste pile be spread on-site. EHD approved on-site management of the stockpiled soil in a letter dated June S, 2001. iz r MU woolsey.chtlrepom/workplan.mws ' � ti