2011-08-04_ENFORCEMENT - C1981008 (3)

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reclaimed landscape is to be graded to a flat, uniform slope that lends itself to multiple farming and irrigation techniques, including the methods that were used prior to mining disturbance. Therefore, the permit is in compliance with the requirements of 2.05.5(1) (a) (i). Section 4.14.1(2)(f)(ii) of the state regulations requires that the backfill be graded to a slope compatible with the approved post - mining land use and that provides adequate drainage and meets a minimum static safety factor of 1.3. Section 4.14.2(1) of the state regulations requires that the final graded slopes approximate pre - mining slopes, or any lesser slopes approved by DRMS based on consideration of soil, climate, or other characteristics of the surrounding area. Post - mining final graded slopes need not be uniform but shall approximate the general nature of the pre - mining topography identified in 2.10.3(1) (j). Overall the approved postmining topography on the Morgan property closely approximates the premining topography. The most notable differences occur in the western end of the Morgan acreage. On the premining topography, the western block of the Morgan property was not uniform; it had several small drainage features draining to the northwest. The postmining topography shows a flatter, more uniform surface that drains to the NW. The postmining surface as it is illustrated within the permit appears to be overall more suited for gated pipe, furrow, side - roll, traveling gun and central pivot irrigation, as it is flatter and more uniform. In Section 2.04.12(2) "Prime Farmland Investigations ", the regulations require that slopes must be < 6 %. In reviewing the premining and postmining topography, 6 transects were measured on the premining topographic maps and 5 transects were measured on the postmining topography maps. Transects were selected to represent the various slopes on the property. The proposed postmining topography for the Morgan property only contains one short distance with an approximate slope of 6.3% near the northwest corner of property (see transect `B '). The proposed postmining topography has an average slope per transect of 4.6 %. The premining topography had an average slope per transect of 5.6 %, with a maximum of 9.1%. See table below and attached copies of transects. Premining versus Postmining Slope Comparisons for the Morgan Property Premine Slopes Transect Rise, ft Run, ft Slope, A 15 385 3.9% B 10 385 2.6% C 10 146 6.8% D 25 467.5 5.3% E 15 165 9.1% F 15 165 9.1% G 20 770 2.6% Average Slope /transect 5.6% Page