Data for the screening assessment. Volume 1: Text, Columbia River Comprehensive Impact Assessment

The Columbia River is a critical resource for residents of the Pacific Northwest. This resource drew the Manhattan Project`s planners to the site now called Hanford to produce nuclear weapon materials. Production of those materials has left behind a legacy of chemical and radioactive contamination and materials that have, are, and will continue to pose a threat to the Columbia river for the foreseeable future. To evaluate the impact to the river from this Hanford-derived contamination, the US Department of Energy, US Environmental Protection Agency, and State of Washington Department of Ecology (the Tri-Party agencies) initiated a study referred to as the Columbia River Comprehensive Impact Assessment (CRCIA). To address concerns about the scope and direction of CRCIA as well as enhance regulator, stakeholder, tribal, and public involvement, the CRCIA Management Team was formed in August 1995. A major CRCIA Team decision was to organize CRCIA into phases, with additional phases to be identified as warranted after completion of the initial phase. The initial phase is comprised of two parts: (1) a screening assessment to evaluate the current impact to the river resulting from Hanford-derived contamination and (2) identification of requirements considered necessary by the CRCIA Management Team for a comprehensive assessment of impact to the river. The purpose of the screening assessment is to support cleanup decisions. The scope of the screening assessment is to evaluate the current risk to humans and the environment resulting from Hanford-derived contaminants. The screening assessment has the primary components of: identifying contaminants to be assessed; identifying a variety of exposure scenarios to evaluate human contaminant exposure; identifying a variety of other species to evaluate ecological contaminant exposure; and assessing risks posed by exposure of humans and other species to the contaminants.