THE UNITED STATES ARMY ANNOUNCES THE DECISION DOCUMENT FOR THE UNDERGROUND STORAGE TANK SITES IN THE ADMINISTRATIVE AREA OF THE GERSTLE RIVER TEST SITE, ALASKA
The U.S. Army Garrison Fort Wainwright, as lead agency for environmental response actions on the Gerstle River Test Site, in partnership with the Alaska Department of Environmental Conservation (ADEC), has developed a Decision Document for the Underground Storage Tank Sites within the Administrative Area. The Decision Document was developed following investigation activities completed at the sites in 2009 and 2010. The investigations were focused on potential soil contamination associated with two former heating oil tanks (UST #000 and UST #449, removed in 1994 and 1991 respectively) and a former fueling station (UST #450/#451, removed in 1994).
Contaminant concentrations in samples collected during the 2009/2010 investigations were compared to the ADEC ingestion and inhalation cleanup levels, presented in Tables B1 and B2 in 18 AAC 75.341(d). The more stringent migration to groundwater soil cleanup levels were not applicable since the depth to groundwater is more than 400 feet below the extent of soil contamination. No cleanup level exceedances were observed at the UST #000 site, and the only exceedance observed at the UST #449 site was the fuel-related polycyclic aromatic hydrocarbon (PAH) benzo(a)pyrene at a depth of more than 15 feet below ground surface. Cleanup level exceedances at the UST #450/#451 site included the following fuel-related compounds; xylenes, 1,2,4-trimethylbenzene (TMB), 1,3,5-TMB, and naphthalene at depths between 11 and 15 feet below ground surface. Groundwater was not encountered during the 2009 or 2010 investigation.
Based on the investigation findings, two of the UST Sites (UST #000 and UST #449) were granted “Cleanup Complete”, and one of the UST Sites (UST #450/#451) was granted “Closure with Institutional Controls”, pending completion of the forthcoming Land Use Control Implementation Plan. The Institutional Controls implemented at the site will include restrictions to prevent potential exposure to fuel-related contamination remaining in place.
As of November 3, 2014, the Decision Document will be available for public viewing at the Delta Junction Library, 2280 Deborah Street, Delta Junction, AK, 99737, the Fort Wainwright Public Library, Bldg 3700 Santiago Avenue, Fort Wainwright, Alaska, 99703, and the U.S. Army Directorate of Public Works, Environmental Office, Building 3023, Engineer Place, Fort Wainwright, Alaska.
For more information regarding this Decision Document, please contact Brian Adams at (907)361-6623, or Cliff Seibel at (907)361-6220.