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The area that TCC proposes to undermine (NMD) in the Fish Creek drainage is located in parts of Sections 10 <br /> and 11 of T5N, R86W, and is identical to the area that P &M Coal Company was planning on undermining and <br /> subsiding in its proposed Fish Creek Mine. P &M contracted with the consulting firm of Kaman Tempo to <br /> 110 prepare a report responding to the requirements of Rule 2.06.8(4). This report has been incorporated into <br /> Exhibit 7e -2. The soils information presented in the Kaman Tempo report was updated with the work <br /> performed by Habitat Management, Inc., and a copy of their report is presented in Exhibit 7e -4. Additionally, <br /> chemical and physical properties of the Binco Silty /Clay Loam are presented in Table 73. None of the data <br /> presented indicates a problem with this soil, for example the low SAR's indicate that leaching will not be <br /> problematic, downstream of the mined area. The original data presented on this table was taken from Table 72 <br /> of Permit C 81 -071. The conclusions presented in the report agree with TCC's contention that subsidence of the <br /> AVF will not materially damage the existing ranches. It should be noted that the Kaman Tempo report was <br /> prepared in 1982. Since that time, land management practices for the affected areas have not changed, i.e. large <br /> acreage ranches to meet the economic requirements of the marketplace. This ownership pattern continues in the <br /> Twentymile Park basin. The ownership patterns are reflected on Map 1, Surface Ownership. <br /> TCC contracted with SubTerra, Inc. to expand the subsidence predictions, to further evaluate impacts to Fish <br /> Creek and its AVF for mining disturbance in the NMD. This report is presented in Exhibit 7e -6, Twentymile <br /> Coal Company, AVF Subsidence Report, Final Report. The report provides a numerical analysis of <br /> approximately 200 cross - sections through the subsided area, and also used a 3D Geologic Modeling software <br /> program (GEMCOM) to compare against the mathematical model. The results of the mathematical model show <br /> that of the 25.5 acres in the AVF area, approximately 7.3 acres will be impacted by subsidence during normal <br /> flow periods, and 12.3 acres during high flow periods. In reference to a change in the gradient of Fish Creek, <br /> SubTerra analyzed the creek from Stations 0 +00 to 100 +00. The analysis included evaluating the gradient both <br /> before and after mining. The result of this analysis is presented on Tables 2 and 3 in the report. The narrative <br /> also includes a discussion of change in gradient of the creek. The gradient change in this segment of Fish Creek <br /> is approximately 0.6 percent. <br /> • More recently, a supplemental subsidence evaluation was completed by SubTerra Inc. for mining of Panels 12- <br /> through 16 -Left (WMD) under Fish Creek and its associated AVF. The results of this evaluation are presented <br /> in Exhibit 25Z, Western Mining District Subsidence Review (PR09 -08). This evaluation indicated similar <br /> subsidence effects to those experienced for the SWMD, EMD, and NMD, with temporary flooding of <br /> approximately 39.9 acres under normal flow conditions, and a total of 66.9 acres under high -flow (spring runoff) <br /> conditions. Based on subsidence modeling, the maximum change in stream gradient would be 0.7 percent (0.7 <br /> feet or 8.4 inches in 100 feet). <br /> Three landowners would potentially be affected by undermining and subsidence of Fish Creek and its associated <br /> AVF; Camilletti and Sons, the State of Colorado, and Cross - Mountain Ranch, LLC. Camilletti and Sons own <br /> property within the Permit Area that will be affected by mining of Panels 15- through 24 -Right (T5N, R86W, <br /> Sections 2, 3, 10, and 15). Fish Creek and its associated AVF will be affected within their property boundaries <br /> by mining of Panels 14- through 19- Right. Personal communications with Mr. Frank Camilletti, of Camilletti & <br /> Sons, indicate that this acreage is not critical to the continued operation of the ranch, and will not materially <br /> damage it. This area is not cropped and is treated as unimproved rangeland. TCC conducted a vegetation study <br /> of the adjacent upland area and the bottomlands to evaluate the productivity of the respective areas. The study is <br /> presented in Exhibit 7j -1, Northern Mining District, Fish Creek Vegetation Study. The data presented in the <br /> study verifies TCC's assumption that measured productivities for the two areas do not vary significantly, <br /> supporting the contention that any subsidence - related impacts would be minimal. <br /> The State of Colorado is the surface owner of lands within the permit boundary to be undermined and subsided <br /> during mining of the 13- though 24 -Right Panels and the 14- through 17 -Left Panels. Fish Creek and its <br /> associated AVF will be affected by mining in the 17 -Right Panel. As presented in Exhibit 7e -6, a total of 4.4 <br /> acres will be flooded by mining of this panel. As is the case for all the lands along Fish Creek to be undermined <br /> • and subsided, no flood irrigation system has been established to increase the productivity of the land, nor are <br /> management practices established for haying this area. The land is treated as unimproved rangeland utilized for <br /> grazing by the lessee. <br /> PR09 -08 2.06 -25.5 09/29/09 <br />