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for petroleum hydrocarbons in the diesel and gasoline ranges (TPH-d and TPH-g), for volatile aromatic hydrocarbons (BTEX), and for total lead Diesel, ethylbenzene, and xylene were detected only in the sample from the dispenser island (Table 1) Gasoline, benzene, toluene, and lead were not detected in any samples 2.2 Soil Excavation Thorpe submitted a work plan for excavation of the contaminated soil and performed the work on December 6 According to Thorpe's estimate, 300 cubic yards of contaminated soil were removed from the dispenser area and added to the 300 cubic yards in the tank excavation stockpile Although hydrocarbons were still evident in the soil at the bottom of the excavation, PHSIEHD directed the contractor to cease excavating and collect two soil samples Samples OE-1 and OE-2 were collected at a depth of 25 feet, their approximate locations are shown in Figure 2 In the process of enlarging the excavation, a previously unknown large-diameter irrigation or domestic well was uncovered (DM-1 in Figure 2) The samples were transmitted to FGL Laboratories for analysis Diesel and gasoline were detected in both samples at concentrations that were higher than what had been detected during the tank removal (Table 1) 2.3 Assessment Drilling . PHSIEHD then directed Teresi to further delineate the vertical and lateral extent of soil contamination and determme whether groundwater had been impacted Teresi retained Upgradient Environmental in January 1996 to prepare a work plan for drilling A plan to drill one soil boring near OE-1 was submitted, but was later revised after further discussions with PHSIEHD The revised plan included five borings, three of which were to be converted to monitoring wells PHSIEHD also requested that a downhole television camera be used to investigate the depth of DM-1 The borings were drilled in February 1996 Prior to drilling, the excavated area west of DM-1 was backfilled with the relatively clean portion of the soil stockpile (i e , the portion from which stockpile samples SP-10 and SP-11 had been collected) This created a platform for the drill rig to drill HP-1 and HP-2 (Figure 2) These borings were sampled at 5-foot intervals and terminated within the capillary fringe at 54 feet, where a hydropunch was used to collect a water sample The other three borings were drilled to 75 feet and completed as monitor wells with screened casing from 50 to 75 feet Well TT-1 was continuously cored from 20 to 60 feet Logs of all five borings are included in Appendix A The wells (including DM-1) were subsequently surveyed and water samples were collected Twenty-five soil samples were selected for laboratory analysis and transported to Excelchem Environmental Labs Hydrocarbons were detected in only one sample (Table 2) This sample (HP-1-25') was collected at the base of the excavation, within 10 feet of OE-1, below this depth, hydrocarbons were absent Hydrocarbons were also absent in 2