Estimating Human Radiation Exposure on the Animas River

Abstract

The U.S. Public Health Service (USPHS) has recently completed comprehensive studies of radioactive pollution of the Animas River, an interstate stream, under requirements stated in the Federal Water Pollution Control Act. The studies were conducted as a result of the interstate pollution abatement enforcement action instituted by USPHS at the request of New Mexico. They illustrate several of the basic principles that are important to the rational, successful control of radioactive water pollutants, and provide a practical case study that may be useful as a guide for solving future problems of radioactive liquid waste control. The Animas receives wastes from a uranium ore refinery in Durango, Colorado, and flows south into New Mexico. It is the main source of water for the area and is used for domestic water supply, irrigation of croplands, recreation, and waste disposal. Study results indicated that the total internal radiation exposure of downstream populations was greater than the limits recommended for general population exposure. Studies of the fate of Ra220, the primary pollutant, in the stream environment and in local water plants, led to the development of rational, efficient pollution abatement measures. These measures were installed quickly, and subsequent surveys showed that they resulted in a much higher standard of radiation protection than would have been achieved by enforcement of preset, arbitrary effluent or stream standards.