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2.05.6 page 4 <br />Damage to the two-track dirt roads could occur if a subsidence crack were to intercept the <br />road. Any cracks of this nature could be easily filled with loose dirt or gravel at National King <br />Coal's expense, however, due to the present condition of the road, cracks of this nature would be <br />virtually unnoticeable. <br />The buildings and structures on and around the surface facility area of the mine will not <br />be damaged by subsidence because there are no minable coal seams beneath this area. <br />SUBSIDENCE MONTfORING PROGRAM <br />The Huntington Irrigation Ditch and the adjacent surface area has been inspected on a <br />quarterly basis since 1981 by a qualified person for evidence of subsidence caused by <br />underground mining. Results of these inspections are reported to the Colorado Division of <br />Minerals and Geology. Quarterly visual inspections of the Huntington Ditch to date have not <br />indicated evidence of damage, nor have they indicated that water is lost, to the mine via surface <br />fracturing. Quarterly inspections of the Crawford Irrigation Ditch will commence once mining <br />and pillaring operations have been conducted in that area. <br />Field observations indicate that surface subsidence features are present above abandoned <br />portions of the mine. These features are in the form of cracks which are typically 4" to 6" wide <br />and may be several hundred feet long. These cracks tend to parallel pillared out mining sections. <br />National King Coal, LLC will continue to monitor these cracks on a quarterly basis. Should <br />visual inspection determine that a subsidence crack is approaching a possible intercept with the <br />ditch, the location of the crack and its relation to the ditch will be mapped and monitored closely. <br />Survey monitoring stations are for mapping purposes only. Should it appear eminent that the <br />• ditch and a subsidence crack will intersect, the effected portion of the ditch will be lined with <br />flexible plastic conduit or other means equally effective to ensure the continuous and unrestricted <br />flow of water. <br />At least one month prior to retreat mining near the Marc Crawford house, subsidence <br />such a way that subsidence can be detected from a survey monument outside the affected area of <br />mining, should it occur. These monuments will be surveyed quarterly foc two quarters following <br />the time that pillars have been extracted from the area. These monuments will then be <br />monitored annually for two years to assure that no subsidence has occurred. The monuments will <br />then remain in place in the event that future questions arise concerning subsidence. Location of <br />these monuments and the structures they are to monitor are shown on Map C-15. <br />In the event that any of the aforementioned ditches, pipelines or utilities were damaged <br />between regular National King Coal inspections, the landowner will probably become aware <br />immediately. They will, in turn, notify us immediately. This has been agreed to verbally, a <br />written agreement to this effect is forthcoming and will be located in Appendix 9(1). <br />National King Coal, LLC has submitted a mining plan which should prevent damage to <br />the hydrologic balance outside the permit area and prevent subsidence in Pine Gulch. The <br />mining plan shows elongated pillars supporting all passages under Pine Gulch drainage system. <br />These pillars will not be extracted on final retreat, thereby providing perpetual stability to the <br />Pine Gulch drainage. <br />• <br />January 2001 <br />