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SECTION 2 <br /> SITE BACKGROUND <br /> ' Known fuel storage at the Site consisted of a former 4,000 gallon gasoline UST located <br /> approximately 50 feet (ft) west of the office building (Figure 1-2) Past inventory records reveal no <br /> fuel loss up to and mcluchng February 17, 1995 On February 20, 1995, a 970-gallon release was <br /> ' reported during inventory monitoring The remammg fuel was removed from the UST the same day <br /> as the release <br /> 21 UST Removal and Excavation <br /> ' The UST was removed by Johnson Petroleum Construction on March 29, 1995 Two soil samples <br /> were collected from the bottom of the UST cavity by Wallace Kuhl&Associates (WKA) <br /> Petroleum hydrocarbons were not identified in one sample, but detectable concentrations were <br /> ' recorded in the other sample <br /> T&T Trucking started excavation of the petroleum hydrocarbon--impacted soil on March 30, 1995 <br /> ' Approximately 250 cubic yards of soil were removed and stockpiled at the site A total of ten soil <br /> samples were collected by WKA from the sidewalls and cavity bottom (15-ft below ground surface) <br /> in June 1995 The stockpile was also sampled for laboratory analysis Analytical soil results <br /> indicated no detectable concentrations of petroleum hydrocarbons along the sidewalls at a depth of <br /> 9-ft, the bottom of the cavity, and the stockpiled soil The excavation was backfilled with the clean <br /> stockpiled soil <br /> In September 1995, the excavation was expanded to the west by T&T Trucking An estimated <br /> 50 cubic yards of soil was excavated to a maximum depth of 17-ft below ground surface (bgs) <br /> Six soil samples were collected from the bottom of the excavation by WKA Analytical results <br /> identified trace concentrations (1 3 mg/lig) of petroleum hydrocarbons The excavation was <br /> backfilled in December 1995 using the clean stockpiled soil <br /> 22 Previous Site Investigation <br />' In November 1995 Leeward Consultants was retained by T&T Trucking to oversee the drilling of <br />' ten borings, collection of soil samples, and the installation of one groundwater monitoring well, <br /> designated MW-1 Based on analytical results from soil testing, petroleum hydrocarbons were <br /> detected in an area approximately 30-ft in width by 60-ft in length, encompassing the western <br />' portion of the UST excavation to the southwest of MW-1 In this area, petroleum hydrocarbons <br /> were detected from 15-ft below ground surface (bgs) to groundwater The highest concentrations <br /> were detected in samples collected between 20- and 40-ft bgs <br />' Borings B3, B5, B6, 811, and B9 were completed around the periphery of the former excavation <br /> Of the eighteen samples collected in these borings, only two of these,B-11 at 51-ft deep and <br />' C\Documeru,and Setnngn\%henhn4AN1v Docurnmts\Work In Progress\I&I 'I rucking dor <br />