US Geological Survey studies of commercial low-level radioactive waste disposal sites - a summary of results

The US Geological Survey has completed geohydrologic investigations of five commercial low-level, radioactive-waste disposal sites. Final reports on two of the sites have been released and the remaining three will be published this year. A highly permeable glacial sand, originally thought to be discontinuous, has proven to be continuous in narrow channel deposits at the site near Sheffield, Illinois. These deposits have provided pathways for tritium-contaminated ground water to move off site. At another site, near West Valley, New York, the distribution and geohydrologic characteristics of the fine-grained glacial sediments have been studied and documented. Contaminants have not been detected in ground water away from the site. Studies at the Maxey Flats, Kentucky site, indicated that only 0.1 inches of precipitation percolates through bedrock from the site to the valley floor annually. Investigations at the arid Beatty, Nevada site, have been directed toward the geohydrologic characterization of unaturated sediments at the site. A significant finding of geohydrologic investigation of the Barnwell, South Carolina site, was that cobalt 60 in ground water percolating through the bottom of one trench diminished to undetectable levels of concentration within 6 feet of the trench bottom. This fact suggests that soil characteristisc at the site are effective in impending transport of that, and perhaps other, radionuclides. 6 references