Focused feasibility study of engineered barriers for waste management units in the 200 areas

The U.S. Department of Energy (DOE) at the Hanford Site in Washington State is organized into numerically designated operational areas consisting of the 100, 200, 300, 400, 600, and 1100 Areas. In November 1989, the U.S. Environmental Protection Agency (EPA) included the 200 Areas (as well as the 100, 300, and 1,100 Areas) of the Hanford Site on the National Priorities List (NPL) under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). Inclusion on the NPL initiates the remedial investigation (RI) and feasibility study (FS) process to characterize the nature and extent of contamination, assess risks to human health and the environment, and select remedial actions. The Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) was developed and signed by representatives from the EPA, Washington State Department of Ecology (Ecology), and DOE in May 1989 to provide a framework to implement and integrate cleanup activities. The scope of the agreement covers CERCLA past-practice, Resource Conservation and Recovery Act of 1976 (RCRA) past-practice, and RCRA treatment, storage, and disposal (TSD) activities on the Hanford Site. The 1991 revision to the Tri-Party Agreement required that an aggregate area approach be implemented in the 200 Areas based on the Hanford Site Past-Practice Strategy (HPPS) and established a milestone (M-27-00) to complete 10 Aggregate Area Management Study (AAMS) Reports in 1992