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.

Purpose and Scope: The purpose of this report is to describe the regional hydrogeologic systems in the Blanding-Durango area and to establish their relationship to help assess salt as an effective storage medium for radioactive wastes. Interpretations are based principally on existing data; however, well inventories, phreatophyte mapping and stream-flow measurements were made during 1978, 1979, and 1980.

This report discusses some vital services that natural ecosystems contribute to human health and development.