2008-01-15_PERMIT FILE - M2007044 (2)

Home Browse Search

Energy Fuels does not have access to the historic drill logs for the mines located in Lumsden Canyon, so it is not possible to prepare a detailed geologic cross section of the mining area. Our exploration activities in 2007 do, however, support the interpretation of geology and ground water that was developed by Umetco, which previously operated many of the uranium mines on Beaver Mesa. Based on drilling completed in 2007 and inspection of the Whirlwind decline, two schematic cross sections of the local lithology were developed. Figure 1 shows the location of the two cross sections. Figure 2 presents a northwest to southeast cross section (A-A~ from four exploration drill holes to the lower level of the Whirlwind decline while Figure 3 shows a northeast to southwest cross section through the center of the decline. Known contacts are shown with a solid line while inferred contacts are shown with a dashed line. Review of Figure 2 shows that the lower Burro Canyon aquifer and the middle and lower Brushy Basin water-bearing zones described in the permit applications and U.S. Environmental Service Report on Boring BM00-1 (see Appendix C of the permit applications) are present in the new exploration holes. 'This is not surprising, as these holes were all drilled within 850 feet of Monitoring Well BM00-1 where Umetco conducted their pumping tests in the fall of 2000. The Umetco boring also delineated an upper Brushy Basin water-bearing zone that was distinct from the basal sandstone of the Burro Canyon. In the case of the exploration holes, however, the mudstone/shale partings between the sandstone lenses in this zone were not large enough to justify delineation of an upper Brushy Basin water-bearing zone distinct from the Burro Canyon aquifer. The variability of the sandstone lenses is apparent on Figure 2 as the thickness and mudstone/shale partings vary noticeably from hole to hole. As shown on the lower right-hand side of Figure 2, the lower sandstone lens of the Brushy Basin is very thin with numerous shale/mudstone partings where it intersects the Whirlwind decline. It does not appear that this lens, which is making water, continues much further to the southeast. Without more information between the holes and the decline, it is also entirely possible that the sandstone in the decline is not connected to the sandstone encountered in the drill holes. The water flowing into the decline is responsible for the water pool that existed in the lowest portion of the decline and the approximately 700 feet of mine drift over a period of about 20 years. It is interesting to note that ground water could not be produced from the upper Salt Wash sandstone in Umetco's Boring BM00-1, even though it was only 200 feet from the flooded mine workings. Figure 3presents across-section through the decline. The decline starts at the surface immediately below where the middle sand lens of the Brushy Basin would outcrop if it were present. Some sandstone outcrops do exist in this area; however, there are no seeps along these outcrops that would indicate a source of ground water. As shown, water flows into the decline near its base at an approximate rate of 1.5 gpm. This ground water appears to originate from the lowest sand lens in the Brushy Basin, which as discussed above, is very thin with multiple shale/mudstone partings where it intersects the decline. Another very thin sandstone lens (< 5 feet thick) was identified further up in the decline; however, this sand lens does not produce measurable water. There is, however, a damp spot on the rib and sill for 30 to 40 feet. Plugging information and drilling logs are attached for the 14 exploration holes drilled in Colorado and the 14 exploration holes drilled in Utah in 2007. The logs indicate that the Burro Canyon and two Brushy Basin sandstone lenses are present at most locations. However, in some locations, the upper of the two lenses is very thin or absent altogether. Exploration drilling also indicated that the sandstone lenses produce relatively little water. When geologic formations are dry, they typically can be drilled without adding water. When a small amount of water is produced, it is usually necessary to add additional water to carry the wetted cuttings out of the hole. When a lot of water is produced or when the formations are unstable, bentonite is added to the injected water. In the 28 holes drilled on the Whirlwind property, 5 of the 28 holes were drilled without injecting water.