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Mi•. Gary DeWitt <br />RF' SerFer Pit <br />July 3, 2008 <br />Page 2 of 4 <br />The mining plan map (Exhibit C-2) and reclamation plan map (Exhibit F) <br />have been revised to include a typical cross section for the dewatering <br />trench. The dewatering trench will be cut into bedrock and generally have <br />a 1:1 slope. The width of the base of the trench will vary throughout the <br />site due to differences in the amount of groundwater that may potentially <br />be exposed as mining progresses. A copy of these revisions is attached to <br />this letter. <br />On page 6 it states that fines from the settling ponds could be mixed with the <br />overburden and used as back fill. It would be difficult to obtain a uniform <br />homogenous mixture of these fines and the overburden. It would also seem that <br />fines suspended in water would be susceptible to erosion and questionable for use <br />in backfill material for a pond. <br />The State Engineer's Office has established design and performance <br />standards for pit liners and slurry walls. Specifications for backfill are <br />provided in the "State Engineer Guidelines for Lining Criteria for Gravel <br />Pits" and the "Guide to Specification Preparation for Slurry Walls and <br />Clay Liners" which are included as attachments to this letter. As a result, <br />the operator will adhere to the specifications set forth in the State <br />Engineer's Office guideline for backfill and the clay liner. Fines from the <br />settling ponds will not be mixed with the overburden and will not be used <br />as backfill. <br />® Page 7 states that inlet and outlet facilities for the reservoir will not be designed <br />at this time. We submit that if a portion of the area is to be reclaimed as a water <br />-storage-facility,--the-lo-cation-of-the inlet and-outlet-are of primary concern for this <br />area and this information should be included in the reclamation plan and <br />considered as pertinent as the very specific seeding plan that is required and <br />included in the reclamation plan for revegetating the disturbed upland areas. <br />These proposed structures could potentially have an impact on SH 392 and they <br />should be considered during the permitting process and made a part of the <br />Reclamation Permit. Revisions could be requested later if necessary, similar to <br />the process for changes in any reclamation plan. <br />Typically, inlet and outlet designs are not completed until an end user is <br />identified. The location and flow rate for these structures can vary greatly <br />depending on the end user. When an inlet and outlet facility is proposed <br />subsequent to the approval of the 112 permit, a technical revision will be <br />submitted to the Division of Reclamation Mining and Safety. Connell <br />Resources, Inc. will consider inlet and outlet facility design and location <br />recommendations from the Colorado Department of Transportation prior <br />to submitting a final design plan technical revision to the Division of <br />Reclamation Mining and Safety. The proposed inlet and outlet facility