Site investigation report for underground storage tank 0134-U at Building 9204-2, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

This report represents the Site Investigation Report (SIR) for the Underground Storage Tank (UST) 0134-U located at Building 9204-2 of the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. This report documents results of investigations conducted subsequent to the Initial Site Characterization concerning petroleum releases from the UST, characterization of the release site, and delineation of soil and groundwater contamination required to evaluate and conduct remedial actions at the tank site. This report is written in accordance with regulatory requirements of the Tennessee Department of Environment and Conservation (TDEC) Rule 1200-1-15-.06 and with United States Environmental Protection Agency (EPA) regulations promulgated under 40 CFR Part 280. The principal contaminants expected in the vicinity of Tank 0134-U are unleaded gasoline and leaded gasoline (used prior to 1975). The probable source of these contaminants at the tank site is Tank 0134-U itself. Results of the Site Investigation soil sample analyses indicate that none of the sampled intervals exhibit benzene, toluene, and xylene (BTX) contamination in excess of the most stringent TDEC Closure Action Levels. Analyses of soil samples collected from the Tank 0134-U pit at the time of the tank removal in 1988 were also found to be below the most stringent closure levels for non-drinking water sources. However, results of the Site Investigation groundwater analyses for samples collected from the two site monitoring wells indicate that one of the wells (GW-204) contains benzene and total petroleum hydrocarbons (TPH) contamination in excess of TDEC Closure Action Levels for non-drinking water sources. Based on the Site Investigation analytical results, remediation of groundwater at the Tank 0134-U site is required