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West Elk Mine <br /> <br />2.05-104 Rev. 06/05- PR10, 03/06- PR10, 05/06- PR10, 11/060- TR107, 04/07- TR108, 09/07- PR12, 02/08- PR12; 11/10- MR372; 10/20- MR-452; <br /> 12/20- TR149; 12/21- TR150, 1/24-TR152, 2/25-MR486 <br />Protection of Public Parks and Historic Places - 2.05.6(4) <br />Operations at the West Elk Mine are not located near public parks or historic places; therefore, this <br />section does not apply. <br />Surface Mining Near Underground Mining - 2.05.6 (5) <br />There are no surface mining operations proposed near the West Elk Mine. <br />Subsidence Survey, Subsidence Monitoring- and Subsidence Control Plan - 2.05.6 (6) (a-f) <br />MCC continues its commitment to thoroughly understanding and describing the nature of subsidence <br />that will occur in the West Elk Mine. MCC retained Wright Water Engineers, Inc. (WWE) of Denver, <br />CO several years ago to evaluate subsidence and probable hydrologic consequences. WWE worked <br />closely with Mr. C. Richard Dunrud for many years on this project. Mr. Dunrud was employed by <br />the U.S. Geological Survey (USGS) throughout his career and is a recognized authority on <br />subsidence. Of particular note with respect to the Exhibit 60E document, is the report prepared by <br />Mr. Dunrud entitled, Some Engineering Factors Controlling Coal Mine Subsidence in Utah and <br />Colorado (Dunrud 1976). In that report, Mr. Dunrud evaluated subsidence in the Mesaverde <br />Formation at the Somerset Mine, less than two miles from the West Elk Mine. <br />Working closely with Mr. Dunrud, WWE has adopted the following multi-faceted approach to <br />quantifying subsidence in the permit area: <br />1. The mined longwall panels have been extensively monitored and WWE has evaluated the <br />relevant data. These data provided the basis for Mr. Dunrud's conceptual model, which is <br />described in the Exhibit 60 series. Exhibit 60 addresses the Apache Rocks and Box Canyon <br />mining areas and Exhibit 60B specifically addresses the South of Divide mining area. Exhibit <br />60C addresses the subsidence and geologic hazards for the West Flatiron lease tract. Exhibit <br />60D addresses Geologic Hazard Field Observations for the South of Divide (SOD) mining <br />area. Exhibit 60E addresses the Dry Fork, SOD, Southern Panels, Apache Rocks West and <br />Sunset Trail mining araeasLease. <br />2. WWE has utilized a computer model to quantify subsidence, and this model has been <br />calibrated using the data collected at West Elk Mine. The model was developed by Dr. Syd <br />Peng and Dr. Yi Luo at West Virginia University and is referred to as the "Comprehensive <br />and Integrated Subsidence Prediction Model (CISPM)." <br />3. WWE has thoroughly reviewed the literature regarding subsidence and associated hydrologic <br />consequences. We have checked the findings associated with Mr. Dunrud's conceptual model <br />and the CISPM model with findings from case studies as described in the literature, and we <br />have concluded that the results are consistent. <br />4. Finally, subsidence projections described herein were carefully reviewed by Mr. Dunrud for <br />reasonableness. Mr. Dunrud has visited the West Elk Mine area on many occasions and he is <br />familiar with key factors pertaining to subsidence as they relate to the South of Divide and <br />other active mining areas. Consequently, Mr. Dunrud is well qualified to draw conclusions <br />about the nature of subsidence that is likely to occur.