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concentrations. Portions of the stockpile slopes also contained uranium concentrations <br /> above 500 ppm; however, it was not practicable to establish grids in these areas because <br /> the slopes were too steep. Instead, measurements were made while traversing up and <br /> down the slopes. The northwest area of the stockpile containing elevated uranium <br /> concentrations above 500 ppm was then conservatively established using painted <br /> perimeter stakes. It was also decided to extend the cover over the sloped areas to the <br /> southwest and southeast of the original cover area identified on Figures 6-1 and 6-2 of <br /> TR-4. This was done because a number of individual measurements on these slopes <br /> exceeded 500 ppm uranium. <br /> Construction Activities <br /> The equipment mobilized to the site included two excavators, two 10-cubic-yard (cy) <br /> dump trucks, one water truck, one dozer, and one Bobcat skid loader. Earthwork <br /> personnel included: <br /> 1 . One excavator operator loading development rock into the dump trucks at the <br /> development rock facility delineated on Figure 6-2 of TR-4. <br /> 2. Two dump truck drivers hauling the development rock to the Low-Grade Stockpile <br /> cover area. <br /> 3. One equipment operator using an excavator, dozer, or skid loader, as needed, to-level <br /> the development rock over the top and side surfaces of the stockpile area. <br /> In accordance with TR-4, a temporary access road to the top of the Low-Grade-Stockpile <br /> was constructed at the southwest corner of the stockpile. Safety berms were graded down <br /> around the perimeter of the stockpile and drainage swales on the top of the stockpile were <br /> filled with development rock to allow for placement of a uniform cover. As the earthen <br /> cover was placed, additional wooden stakes were set at a height of one foot within the <br /> cover area and painted red to provide the equipment operator with a visual guide for <br /> placing the cover material to a height of 12 to 18 inches. Photographs 1 and 2 show the <br /> placement of cover material in progress. <br /> Because of the coarseness of the cover material, the final cover thickness was typically <br /> between 15 and 18 inches. Based on truck counts, approximately 4,500 cy of loose <br /> development rock material was used to build the cover. Mr. Wu monitored the earthwork <br /> to verify that the cover thickness exceeded the height of the grade stakes and that the <br /> waste rock being used as cover material contained uranium concentrations less than 500 <br /> ppm. After completion of the cover, perimeter berms and surface drainages were <br /> reestablished and the temporary access road to the stockpile was blocked. Photograph <br /> 3 shows the final cover surface over the northwest portion of the stockpile. <br /> 2 <br />