Laserfiche WebLink
Ron Rowe <br /> Registered Environmental Specialist <br /> February 2, 2000 <br /> Page 4 <br /> In 1985, Del Monte removed the three USTs,but did not remove the associated piping. <br /> Contamination was identified at the time of removal, as detailed in the report prepared by <br /> Exceltech, Del Monte's contractor dated December, 1985. Exceltech reports that during the <br /> removal process, the tanks were found to be filled to capacity with water. This water contained <br /> some petroleum residue, but it was at levels low enough to permit discharge of these stored <br /> liquids into the sanitary sewer. This is how the 30,000 gallons of liquid were drained from the <br /> three USTs. <br /> Soil sample results at three feet below the north tank (that is, 13 feet below the surface)yielded <br /> concentrations of 8,300 mg/kg of petroleum as gasoline. Four feet lower, at about 17 feet below <br /> the surface, the concentrations of gasoline had dropped to 10 mg/kg. Exceltech did not report <br /> that there were any holes in the tanks, or that the integrity of the USTs was compromised. The <br /> condition of the tanks and their ability to remain full of water suggests that these tanks did not <br /> leak and that the integrity of the tanks was intact prior to the tank removal process in late 1985. <br /> Exceltech reported that petroleum hydrocarbons as gasoline were detected in the soils beneath <br /> the north tank at the following depths: <br /> • Depth Below Tank • Concentration in mg/kg • Medium <br /> • 1 • 230 • soil <br /> • 3 • 8,300 • soil <br /> • 6 • 260 • Soil <br /> • 7 • 10 • soil <br /> These facts suggest that the impact from any petroleum release did not occur as a result of any <br /> defect in the USTs or the product piping or dispensers; it was due to spillage or leaks external to <br /> the UST equipment, whether from parked trucks, the emptying of the USTs by Del Monte or <br /> Calpack, or other events. It further establishes that the impact was limited to soils and was <br /> relatively shallow. However, the remedial approach taken by Exceltech on behalf of Del Monte <br /> exacerbated the problems. <br /> First, soil from the excavation was stockpiled on site and aerated "to reduce volatile organic <br /> levels below 1000 mg/kg"for only two days (see Exceltech Report,page 4). It appears that only <br /> two tests were done on the stockpiled volume to determine the level of bioremediation of <br /> 761778.3 <br />