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Page 5 of 6 <br />provide documentation demonstrating the right to entry onto City of Greeley property to <br />construct and maintain the weir. <br />9. On Page 6 in the Tract C section, the Operator states it is not necessary to armor the inside <br />wall of Tract C, provided that erosion which occurs during an overtopping event can be <br />repaired after the event. Please explain how the inside wall of Tract C will be protected <br />from erosion due to overtopping following the completion of mining at the site when <br />equipment and material are not available for repairing the slope. <br />10. On Page 6 in the Tract C section, the Operator states it is recommended that the transition <br />from 1.25:1 to 3:1 slope at a depth of 30 ft within the pit be protected after active <br />construction is finished. This statement contradicts the approved post mining slope of 3:1 <br />five (5) feet above and ten (10) feet below the expected water line with 2:1 slopes below. <br />Please explain this discrepancy and commit to protecting the slope 10 feet below the <br />expected water line with riprap to prevent head cutting downstream of the weir. <br />11. On Page 6 in the Tract C section, the Operator states if the water surface level in the pit is <br />maintained at least 2 feet above the slope transition (28 ft from the existing ground <br />surface), riprap will not be necessary because the standing water will act as an energy <br />dissipater. This statement contradicts the approved mining plan to dewater and dry mine <br />the tract. Please explain this discrepancy and reevaluate the need for erosion protection <br />during and post mining activities. <br />12. On Page 6 in the Tract C section, the Operator states if the pit is reclaimed by contouring a <br />uniform slope the riprap will not be necessary. The approved reclamation plan states the <br />1.25H:1V slopes created during extraction will be modified by pushing the resulting pit <br />bottom with a dozer until the slopes conform with Rule 3.1.5(7). Please explain how the <br />non - cohesive material from the pit bottom placed without compaction in non - horizontal <br />lifts to create the required 3H:1V slope will be stabilized to prevent erosion without the use <br />of riprap. <br />13. The report did not address the potential for the flood flow from Tract C overtopping into <br />Tract D. Please address the potential for the overtopping of the berm between Tracts C and <br />D to cause damage to the berm, ditch and gas line located in the berm. <br />14. Please provide the following information for a spillway in the downstream section of Tract C <br />to prevent the potential capture of the Cache La Poudre River. <br />a. Justification for the location <br />b. Spillway invert elevations <br />c. Cross - section details (both lateral and longitudinal) <br />d. Design parameters <br />5 <br />