This risk assessment evaluates the possibility of health and environmental risks from contaminated ground water at the uranium mill tailings site near Durango, Colorado. The former uranium processing site`s contaminated soil and material were removed and placed at a disposal site located in Body Canyon, Colorado, during 1986--1991 by the US Departments of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating the nature and extent of ground water contamination at the site. This risk assessment follows an approach similar to that used by the US Environmental Protection Agency. The first step is to determine what site-related contaminants are found in ground water samples. The next step in the risk assessment is to determine how much of these contaminants people might ingest if they got their drinking water from a well on the site. In accordance with standard practice for this type of risk assessment, the highest contaminant concentrations from the most contaminated wells are used. The risk assessment then explains the possible health problems that could result from this amount of contamination.

Surface remedial action has been completed at the Uranium Mill Tailings Remedial Action Project in Durango, Colorado. Contaminated soil and debris have been removed from the former processing site and placed in the Bodo Canyon disposal cell. Ground water at the former uranium mill/tailings site and raffinate pond area has been contaminated by the former milling operations. The ground water at the disposal site was not impacted by the former milling operations at the time of the cell`s construction. Activities for fiscal 1994 involve ground water sampling and site characterization of the disposal site.

This long-term surveillance plan (LTSP) for the Durango, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project disposal site describes the surveillance activities for the Durango (Bodo Canyon) disposal site, which will be referred to as the disposal site throughout this document. The US Department of Energy (DOE) will carry out these activities to ensure that the disposal site continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials (RRM). RRMs include tailings and other uranium ore processing wastes still at the site, which the DOE determines to be radioactive. This LTSP is based on the DOE`s Guidance for Implementing the UMTRA Project Long-term Surveillance Program (DOE, 1992).