Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Green River, Utah. Revision 1

Abstract

AT M E URANIUM MILL TAILINGS SITE NEAR GREEN RIVER, UTAH CITIZENS' SUMMARY CITIZENS' SUMMARY INTRODUCTIONThe Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (phase I) and the Ground Water Project (phase 11). For the UMTRA Project site located near Green River, Utah, the Surface Project cleanup occurred from 1988 t o 1989. The tailings and radioactively contaminated soils and materials were removed from their original locations and placed into a disposal cell on the site. The disposal cell is designed to minimize radiation emissions and minimize further contamination of ground water beneath the site.The UMTRA Project's second phase, the Ground Water Project, evaluates the nature and extent of ground water contamination resulting from uranium processing and determines a strategy for ground water compliance with the Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. This ground water strategy must protect public health and the environment from radiological and nonradiological hazards. A risk assessment is one of the tools used to evaluate these hazards.A risk assessment is the process of describing a source of contamination and showing how that contamination may reach people and the environment. The amount of contamination people or the environment may be exposed to is calculated and used to characterize the possible health or environmental effects that may result from this exposure.For the Green River site, the risk assessment helps determine whether human health risks result from exposure to ground water contaminated by uranium processing. Exposure could occur from drinking water pumped from a hypothetical well drilled in the area of ground water contamination. Environmental risks could result from plants or animals being exposed to any surface water that has received contaminated ground water.This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Green River site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine what is necessary, if anything, to protect human health and the environment while complying with EPA standards. RISK SUMMARYThere are currently no human health risks associated with ground water affected by uranium processing at the Green River site because no one drinks water from the site. In addition, no one uses the water for irrigation or livestock watering. Changes of land use may or may not create future risks. Specific future land uses should be evaluated to identify potential health and environmental risks from the contaminated ground water.However, there is a potential for animals to be exposed to contaminated ground water which seeps to the surface and forms pools in the channel of Brown's Wash, downstream from the site. If exposure were to occur, animals could be aff...