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identified an additional seventeen mines containing radioactive waste <br /> materials with lesser potential to transport radioactive materials into <br /> the+ hydrologic system. The remainder of the mines were found to have <br /> significantly lower levels of radioactive materials. A few of these <br /> mines, although containing relatively large eroding waste dumps, are <br /> perched high within watersheds, away from active stream environments . <br /> The Manti-LaSal National Forest entered into an agreement with the <br /> Department of Energy (DOE) in Grand Junction to collect and report data <br /> sufficient for conducting preliminary assessments under EPA guidelines for <br /> the nine sites selected for further study. The DOE study evaluated the <br /> potential for contamination of surface water, gro,md water, and air, and <br /> the study e-aluated the potential for exposure of forest visitors through <br /> direct contact. The report is titled "Data Report From Site Visits and <br /> Literature Search on Nine Inactive Uranium Mines, Manti-LaSal National <br /> Forest, Utahm. Methods of study are discussed in the report. Maps <br /> generated from the initial inventory were used as base maps. Water <br /> J samples were taken and radiation measurements were taken at various <br /> locations to characterize the radiation levels of the waste dumps at each <br /> site. Other constituents, such as Selenium and Arsenic, that are likely <br /> to be associated with uranium mines were measured as well. Literature <br /> searches were conducted to further characterize the waste dumps and relate <br /> estimated values to existing standards for exposure, water quality, etc. <br /> The purpose of the measurements was to determine the presence of <br /> potentially hazardous materials and their relative hazard. The purpose <br /> was not to definitely determine their quantities. <br /> HISTORY <br /> During the 1950's, 1960's, and 1970' s, large amounts of relatively low <br /> grade uranium ore were mined from the Colorado Plateau in Utah and <br /> Colorado. Most of the mines are now inactive or abandoned because of low <br /> uranium prices and competition with higher grade deposits elsewhere. <br /> Approximately 100 of these mines are located in southeastern Utah and <br /> isouthwestern Colorado within the Moab and Monticello Ranger Districts of <br /> —� the Manti-LaSal National Forest. Many of the uranium deposits were <br /> discovered by "rim stripping' along sandstone cutcrops to find mineralized <br /> paleo-stream channels. The Salt Wash Member of the Jurassic Morrison <br /> Formation and the Mossback and Shinarump Members of the Triassic Chinle <br /> Formation were the main hosts for uranium mineralization. Salt Wash <br /> deposits are typically irregularly shaped roll fronts which are broadly <br /> controlled by stream channels, bedding planes, organic trash, and other <br /> sedimentary features. Chinle deposits typically occupy distinct channels <br /> scoured in the underlying Moenkopi Formation. Drilling was also used to <br /> discover or further delineate the deposits. Development involved driving <br /> adits into the outcrops to intercept the mineralized paleo-stream <br /> channels. The underground workings are complex networks that followed <br /> these channels. <br /> Ore and waste rock was moved to the surface. The ore was shipped, but <br /> waste rock was dumped downslope from near the portal to form piles varying <br /> in size from a few yards up to 100,000 cubic yards. The waste dumps <br /> — contain barren waste rocl, and radioactive rock that was below snipping <br /> i <br />