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ATTACHMENT 1 TO EXHIBITS. <br />Neva Property Ponds Additional Analysis: <br />1. The three ponds on the Neva Property, located near the northeast <br />corner of the permit area, are partially incised and partially retained by <br />dams of up to 8 feet crest height, constructed on the surface of the <br />Mancos shale. The dams, were clearly constructed using alluvium from <br />above the Mancos shale, and used some excavated shale as a core <br />and/or liner. (The shale also allowed the ponds to be deeper, and larger <br />capacity as originally built.) There are no known geologic structures <br />within the alluvium above the Mancos shale which could be damaged by <br />the mining as proposed, or which would create planes for potential <br />failure of a cutbank. These ponds have silted in to a large degree, and <br />are approximately seven feet in depth. They are NOT on the state's <br />dam safety inventory. <br />2. As proposed in Exhibit D, along this portion of the perimeter the limits of <br />excavation would approximate the final reclaimed slope rather than <br />creating a 20- or 30-foot highwall to be backfilled. However, excavation <br />will not extend into the Mancos shale, and data on the exact contact <br />between the Mancos shale and the surface alluvium is not plentiful, but <br />indicates that the depth to the shale may be significantly less than the <br />30-foot depth of mining proposed. <br />3. The lowest earthen dam is located, as shown in Cross-Section C-C', <br />Figure E-4-1, page 24, 100 feet from the top of the final reclaimed slope <br />at the nearest point, and 200 feet from the toe of that slope. The final <br />reclaimed slope at this point is 3.3:1. <br />4. The middle earthen "dam" separating the two lower ponds is located <br />approximately 100 feet from the top of the final reclaimed slope, which is <br />actually at or above the elevation of the crest of the "dam." The toe of <br />the final reclaimed slope is approximately 250 feet from the dam. The <br />final reclaimed slope at this location is 4:1, 30 feet in 120 feet. <br />5. The upper earthen dam holding the uppermost pond is located <br />approximately 50 feet from the top of the final reclaimed slope, but that <br />top is slightly higher than the elevation of the crest of the dam. The toe <br />of the final reclaimed slope (still 4:1 at this point) is approximately 170 <br />feet from the dam. <br />6. Based on the above information, there is no indication that mining as <br />proposed would have any potential to damage these structures. <br />7. There is no blasting proposed for either mining or reclamation. <br />Therefore, there is no need for analysis by the Applicant to demonstrate <br />that off-site areas will not be adversely affected by blasting. <br />