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iiiiiiiiiiiiiiiiii • STATE OF COLORADO DIVISION OF MINERALS AND GEOLOGY Depanmenl of Natural Resources 1711 Sherman SL, Room 215 Denver, Colorado 80201 Phunc 13031 B6GJ Sfii FAX 13UJ1 B7?-H106 June 19, 1998 Larry F. Brown L.F. Brown and Associates, Inc. P.O. Box 698 Idaho Springs, CO 80452 Post-it° Fax Note 7671 Dale! ~ ~ ~ pe°ges~ Z YJ y To lid/ ~7rmvV /~- From 11.2 /~ SOfQ,'rS Co./Dept. Co. Phone p Phone K Fa><N 7v 7~ ~~ ~d~ Fa>RE: Adequacy of the Application, Rock Island Operation, Rock Island Land Co., LLC, File No. M-98-052 Deaz Mr. Brown ~~~ DEPARTMEIJT OF NATURAL RESOURCES Roy Rumor Governor lames 5. Lochhead Executive Director Michael B. Long Divrsion DueUOr The Division has completed a review of the above referenced application, and has determined that the following items remain to be addressed to obtain approval. 1. Under the reclamation cost section of Exhibit D, the 5 percent office administration cost factor must be applied to the sum of the direct reclamation costs and the 18.5 percent contract administration cost. 2. There is no cost for grading included in the estimated reclamation costs. The scenario must be considered were the operator has excavated into the dredge pile leaving a neaz vertical slope in the pile at the working face. This cut slope would then have to be graded down to at least 2H:1 V for stability. Please include a cost for grading such a cut slope at its maximum anticipated height and breadth during the life of the operation. 3. Will the operator store fuel, oil, or grease at the site? If so, spill containment measures to be employed must be described and incorporated into the permit. 4. Redisturbance of the dredge piles, as well as screening and crushing operations could liberate silt and sand which may lead to siltation of the Swan River if containment measures aze not provided. It is stated in the application that a leaky berm may be used at the operating perimeter to filter any runoff prior to leaving the site. It is the Division's position that the operator must commit to establishing an appropriately situated perimeter berm, or other control measure as approved by the Division, prior to any mining disturbance or stockpiling from which runoff would have the potential to enter the stream. Please provide a more rigorous discussion of the sediment control plan in terms of phasing [he construction of perimeter berms, dimensions of the berms, and gradation of the berm materials.