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Fall 2019 Subsidence and Geologic Field Observations <br /> Southern Panels Mining Area <br /> 3.0 OTHER SUBSIDENCE MONITORING <br /> MCC has been collecting data from numerous monitoring locations in and around Minnesota <br /> Reservoir, Monument Dam, and the general Dry Fork area for many years. Ongoing monitoring <br /> by MCC personnel includes the Monument Dam and Minnesota Reservoir area, as well as U.S. <br /> Forest Service (USFS) roads and stock ponds. Survey data and inspection forms for these areas <br /> are provided in Appendices A and B, respectively. Note that the term "displacement," as used in <br /> Appendix A, is the difference in the measurements recorded in the last two surveys. An annual <br /> aerial photographic comparison of the Minnesota Reservoir/Monument Dam area is conducted <br /> each fall to assess movement in the landslides north and south of the reservoir. This discussion <br /> and these aerial images are found in Section 3.3 and Appendix C. In addition, MCC monitors <br /> USFS water resources in the vicinity of mining and generates an annual report that is included as <br /> Appendix D. Also included with this report is a map (Appendix E) that represents the extent (as <br /> of the date of the map) of the mined E-seam longwall panels within the Maximum Projected <br /> Areal Extent of Potential Mineable E-seam as shown on approved Permit Map 51. Data and <br /> discussions associated with ongoing MCC monitoring are provided by MCC and included in this <br /> WWE report for convenience. <br /> 3.1 Monument Dam/Minnesota Reservoir Monitoring <br /> As described in previous subsidence reports, MCC has conducted monitoring of the Monument <br /> Dam and strategic locations around Minnesota Reservoir since 2006. Currently, MCC has <br /> monitoring and reporting responsibilities for the land survey stations. Data collected from various <br /> monitoring locations on the Monument Dam (including Dam Inspection Forms) are provided in <br /> Appendix A. <br /> Quarterly land surveys of the monuments (monthly when mining is within one mile of the dam) <br /> were completed. A summary of both average height and longitudinal displacement data obtained <br /> from spring 2018 to fall 2019 is provided in Table 1 of Appendix A. <br /> 831-032.910 Wright Water Engineers, Inc. Page 7 <br /> February 2020 <br />