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i ' 21 May 2003 • AGE-NC Project No 95-0130 IPage 4of16 I summarized in Tables 2 and 3 Results of the December 1994 investigation were reported in Preliminary Investigation and Evaluation Report (PIER) dated 10 April 1995, prepared by Geological Audit Services, Inc • December 1995 - Three soil vapor extraction(SVE) wells (VW-1, VW-2 and VW-3) were advanced to depths of 63 feet bsg near the former UST areas, one ground water monitoring well (MW-4) was advanced to a depth of 75 feet bsg and located approximately 60 feet ' southeast (crossgradient) of the former UST area TPH-g and BTEX-impacted soil was encountered in all three SVE wells at depths of 15 feet to 60 feet at concentrations as high ' as 7,400 mg/kg, petroleum hydrocarbons were not detected in soil samples collected from MW-4 Dissolved TPH-g was not detected in initial ground water samples collected from MW-4 However, TPH-g and benzene were detected from MW-4 subsequent sampling ' events at concentrations as high as 78 µg/1 and 10 µg/l,respectively(Table 3) Results of the December 1995 investigation were reported in Corrective Action Plan (CAP), dated 20 March 1996, prepared by AGE ' • January 1996-One ground water monitoring well(MW-5)was advanced approximately 50 feet northwest (crossgradient) of the former UST area to a depth of 70 feet TPH-g and BTEX-impacted soil was encountered at depths of 45 and 50 feet at concentrations as high '• as 940 mg/kg TPH-g and BTEX-impacted ground water was detected in the initial sample from MW-5 at a concentration of 23,000 µg/1 (Tables 2 and 3) Results of the January 1996 ' investigation were reported in the above referenced CAP • January 1996 An 8-hour SVE pilot test was conducted at the site by inducing a vacuum from well VW-1B (screened 28 to 43 feet bsg), ground water was measured approximately ' 55 feet bsg TPH-g and BTEX compounds were detected from influent SVE air flow samples at concentrations as high as 95,000µg/1 Significant vacuum was measured from monitoring points VW-IA, VW-1C, VW-2A,VW-2B, VW-3A, no measurable vacuum was observed ' at MW-3, located 35 feet east of VW-1 Based on the observed results, a theoretical radius of influence for SVE at VW-1B was projected at approximately 30 feet (Figure 4) Results of the January 1996 investigation were reported in the above referenced CAP ' April 2000-Five soil borings(CPT-1,CPT-1 A,CPT-2,CPT-2A and CPT-3)were advanced on- and off- site to approximately 105 feet bsg utilizing cone penetrometer testing (CPT) ' technology to characterize the geologic and hydrologic framework and to assess preferential migration pathways Laboratory analysis of grab water samples detected substantial petroleum-impact from CPT-lA and CPT-2A to depths of 105 feet bsg (Table 4) Results ' of the April 2000 CPT investigation were reported in Quarterly Report - Second Quarter 2000, dated 31 July 2000,prepared by AGE ' September 2001 -AGE installed two multi-level groundwater monitoring wells(MW-6 and MW-7) to depths of approximately 142 feet bsg at the site to assess the vertical extent of petroleum-impact Screen intervals were installed at depths between 35 and 45 feet bsg Advanced GeoEnvironmental,Inc