Developing a Remediation Strategy for Hanford's Central Plateau Long-term Waste Management Area - 16545

The cleanup of the Hanford site, a Department of Energy (DOE) facility in eastern Washington state, has been underway for over two decades. Cleanup of the river corridor, a portion of the site adjacent to the Columbia River, has been one of Hanford's top priorities since the early 1990s and the majority of waste sites within this area have been remediated, and associated groundwater contamination has been, or is in the process of being remediated. As cleanup of the river corridor has progressed, attention has begun to shift towards addressing the waste sites located within the 'Inner Area', a 26 Km² (10 mi²) area within centrally located within the site where the majority of the site's burial grounds and landfills are located. In recognition of the differences in expected future land use between the river corridor and the Inner Area, the DOE, the United States Environmental Protection Agency (EPA) and the Washington State Department of Ecology (Ecology) developed a set of Inner Area cleanup principles to: 1) promote consistency in site assessments and alternative evaluations; and 2) support regulatory strategies that will optimize analytical resources and streamline documentation. This paper provides an overview of the Inner Area cleanup principles, how their application is expected to influence the development of remedial investigations and feasibility studies, and ultimately the selection of risk-informed decisions. (authors)