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DEPARTMENT OF NATURAL RESOURCES David M. Getches, Executive Director MINED LAND RECLAMATION DIVISION DAVID C. SNELTON, Olrector Riohartl D. Lamm Governor January 30, 1986 Ms. Kay James Walden Coal Company P. 0. Box 229 Boulder, Colorado 80306 Re: Bourg Strip Mid-Term Review - File No. C-81-021 Dear Ms. James: The Division has reviewed the Walden Coal Company Mid-Term Review response, and requests that the following revision be incorporated into the Bourg Strip permit through the Mid-Term Technical Revision: 1) Walden Coal Company should submit to the Division an Annual Hydrologic Report (AHR) no later then January 15 of each year. Each AHR should contain all hydrologic data collected during the previous water year (October 1 thru September 30). Each AHR should also contain a narrative describing the effects, if any, of mining to the hydrologic system (ground - and surface - waters), and how these effects differed from those projected in the PHC and CHIS sections of the permit application and findings documents. The dewatering of wells and their associated aquifers, pit inflows, and actual or projected water quality/quantity trends should be discussed. This annual report will eliminate the need for periodic submittals other than NPDES, which are required quarterly. 2) The Division has reevaluated the Bourg Strip bonding costs. This reevaluation, which is enclosed, reflects current costs to reclaim the Bourg Strip given a worst case scenario. The Division realizes that the bonding amount has changed considerably since the May 9, 1985 Mid-Term review comments. Using current Division bond calculation policy, it is felt that Walden Coal Company has not utilized the appropriate job condition correction factors for estimating dozer production. Specifically, the "material" correction factor of 1.2 pertaining to loose stockpile material is not appropriate given that some compaction of the overburden has occurred by virtue of the method of placement (scrapers) in the stockpile and some settling of the material which has no doubt occurred since placement of the material. Additionally, Walden Coal's use of both "side-by-side" and "slot dozing" correction factors is inappropriate as these factors refer to alternate methods of dozing utilizing a single dozer (slot dozing) or dozer pairs (side-by-side dozing). One or the other dozing method correction factors can be utilized, but not both. With these factors corrected, net hourly production becomes 494.8 LCY/h r. This increases total backfilling costs to E799,417.78. 423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. (303) 866-3567 i III IIIIIIIIIIIIIIII