Environmental Assessment and Finding of No Significant Impact: On-site treatment of low level mixed waste at Rocky Flats Environmental Technology Site

The Department of Energy (DOE) has prepared an environmental assessment (EA) (DOE/EA-1292) to evaluate the proposed treatment of low level mixed waste (LLMW) at the Rocky Flats Environmental Technology Site (Site). The purpose of the action is to treat LLMW in order to meet the Land Disposal Restrictions specified by the Resource Conservation and Recovery Act and the waste acceptance criteria of the planned disposal site(s). Approximately 17,000 cubic meters (m3) of LLMW are currently stored at the Site. Another 65,000 m3of LLMW are likely to be generated by Site closure activities (a total of 82,000 m3 of LLMW). About 35,000 m3 can be directly disposed of off-site without treatment, and most of the remaining 47,000 m3 of LLMW can be treated at off-site treatment, storage, and disposal facilities. However, some LLMW will require treatment on-site, either because it does not meet shipping requirements or because off-site treatment is not available for these particular types of LLMW. Currently, this LLMW is stored at the Site pending the development and implementation of effective treatment processes. The Site needs to treat this LLMW on-site prior to shipment to off-site disposal facilities, in order to meet the DOE long-term objective of clean up and closure of the Site. All on-site treatment of LLMW would comply with applicable Federal and State laws designed to protect public health and safety and to enhance protection of the environment. The EA describes and analyzes the environmental effects of the proposed action (using ten mobile treatment processes to treat waste on-site), and the alternatives of treating waste onsite (using two fixed treatment processes), and of taking no action. The EA was the subject of a public comment period from February 3 to 24, 1999. No written or other comments regarding the EA were received