In August 2008, the U.S. Army Corps of Engineers Buffalo District released an addendum to the feasibility study prepared by the U.S. Department of Energy and a proposed plan for the Seaway Site. The comment period for the proposed plan was from August 25, 2008, to November 28, 2008. A public meeting to receive public comments was conducted on Wednesday, September 24, 2008.
In October 2009, the record of decision for the Seaway Site was approved. Alternative 6 - Containment with Limited Off-Site Disposal, was identified as the selected remedy for the site. The comments received on the proposed plan during the public comment period and the responses to those were included in the responsiveness summary portion of the record of decision. The record of decision for the Seaway Site is available by clicking the link in the Reports section below. The record of decision and supporting documentation are available at the Seaway Site Administrative Record File link below.
The selected remedy requires the capping of Investigative Areas A, B, and C within the landfill boundaries. The cap for the FUSRAP-related material will be constructed of multiple layers of various types of soil, fabric, and geomembranes at least 4.5 feet thick. Long-term monitoring of FUSRAP-related materials in capped areas, surveillance, and maintenance will be performed by the federal government. The federal government will ensure that land-use controls are in place to prevent future access to and disturbance of the contained FUSRAP-related materials. The selected remedy also includes excavation of FUSRAP-related material outside the landfill boundaries in the Seaway Southside and Northside areas that exceeds the cleanup criteria and requires shipping the excavated material off-site for disposal. The selected remedy in the record of decision will be protective of human health and the environment and comply with applicable or relevant and appropriate requirements.
In fiscal year 2015 the Buffalo District initiated excavation and off-site disposal of contaminated soil located beyond the landfill leachate containment system on the Seaway Northside area. This removal was completed in fiscal year 2016 with a total of 1,121 cubic yards of material excavated and shipped off-site for disposal.
During fiscal year 2017 the Buffalo District completed an investigation to delineate the extent of FUSRAP-related contamination within Seaway Southside. Analytical results from soil samples obtained from 15 investigation test pits in the Southside area of the site projected a 70 percent increase in soil volume requiring excavation and disposal. The FUSRAP-related soils form a lens measuring less than 1-foot thick that extends approximately 100 feet northwest of the previously identified area of contamination at a depth of around 12 feet beneath the landfill embankment.
Beginning in March 2020, the Buffalo District is performing a five-year review of the Seaway Site selected remedy, which is required in CERCLA. A newsletter regarding the review is available in the News section link below.
Completion of the selected remedy for the Seaway Site will occur later pending the completion of ongoing remediation at other FUSRAP sites and the availability of program funding.