Site 13: OU 15 Range Road Area
Site 13 (formerly designated as a portion of solid waste management unit [SWMU] 27A) consists of an area of trichloroethene (TCE) contamination in alluvial groundwater, at an area where the SWMU 27A drainage ditch crosses Range Road. The Range Road Area is in the southeastern portion of Plant 1.
The investigations for Site 13 sought to identify the source of TCE contamination, which had sporadically been detected in various outfalls during the National Pollutant Discharge Elimination System monitoring program. Because TCE is no longer used at the facility, it was determined that contaminated groundwater near the Range Road intersection was the source of contamination in the drainage ditch. Subsequent investigations identified TCE in groundwater trending to the east-northeast and roughly parallel to the Plant 1 drainage system near the Range Road–H Street intersection.
Though there are no known potential sources of TCE at Site 13, a search of historical information conducted during the Phase III Investigation revealed that there was a boiler (Building 106A) northeast of the Range Road and H Street intersection where degreasing operations dating to 1952 were conducted. No potential source of TCE southwest of the intersection was identified.
A draft combined remedial investigation and feasibility study (RI/FS) at Site 13 has been submitted for regulatory review and is expected to be finalized in 2020.
Detailed information from previous investigations conducted at Site 13 is available in the Administrative Record.