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•ti Mr Michael J Infurna,Jr April 14, 2003 Page 2 stockpiled at the site A total of 10 soil samples were collected by WKA from the sidewalls and cavity bottom in June 1995 The stockpile was also sampled for laboratory analysis Analytical soil results indicated no detectable concentrations of petroleum hydrocarbons along the sidewalls at a depth of 9 feet, the bottom of the cavity, and the stockpiled soil The excavation was backfilled with the clean stockpiled soil In September 1995, the excavation was expanded to the west by T&T Trucking An estimated 50 cubic yards of soil was excavated Six soil samples were collected from the bottom of the excavation by WKA Analytical results identified very low concentrations of petroleum hydrocarbons The excavation was backfilled in December 1995 using the clean stockpiled soil In November 1995,Leeward Consultants was retained by T&T Trucking to oversee the drilling of ten borings, soil sample collection, and installation of one groundwater monitoring well, designated MW-1 Based on analytical results from soil testing, petroleum hydrocarbons were detected in an area approximately • 30 feet in width by 60 feet in length, encompassing the western portion of the UST excavation to the southwest of MW-1 In this area, petroleum hydrocarbons were detected from 15 feet bgs to groundwater The most significant concentrations were detected above 40 to 50 feet bgs Borings B3, B5, B6, B11, and B9 were completed around the periphery of the former excavation Of the eighteen samples collected in these borings, only two of these, B-11 at 51 feet deep and 57 5 feet deep had low level detections of total petroleum hydrocarbons (TPH) or benzene, toluene, ethylbenzene, and total xylenes (BTE,q In August 1998, BC was retained by T&T Trucking to oversee the installation of three additional monitoring wells Monitoring wells MW-2, MW-3, and MW-4 were placed to the north, south, and southeast of the former UST location (Figure 2) Groundwater monitoring for the four monitoring wells has been conducted quarterly, starting during the first quarter of 2000 Results for the most recent quarter of sampling (November 2002) show concentrations of MTBE from non-detect to 52,000 µg/L, TPH-g from non-detect to 180 µg/L and Benzene from non-detect to 12 0 µ%/L as shown in Table 1 On November 12, 2002 the unused domestic well north of the former UST location was properly destroyed by T&T Trucking under the supervision of the County . The hthology of the site includes interbedded silts and sands to the maximum depth explored of 91 feet Groundwater is currently approximately 70 feet bgs, 13\23000\2W54 1-1 trucking\Semiati a Receptor Sun ey DOC