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1 -. ~ <br /> <br />• <br /> <br />STATE OF <br />III IIIIIIIIIIIIIIII <br />COLC~i~llO <br />DIVISION OF MINERALS AND GEOLOGY <br />Depanmem of Natural Resources <br />U I1 Sherman St., Room 115 r+ <br /> <br />Denver, Colorado 80'_03 I <br />~~ <br /> <br />Phone 1 iU3) 866-3567 II <br />FA%: (3031 832-8106 <br /> DEPARTMENT OF <br /> NATURAL <br /> RESOURCES <br />DATE: July 28, 1997 Roy Romer <br />/ <br />/ Gnvernrn <br />TO• Mike Boulay lames 5. Lochhead <br />~~ E~eculioe Director <br />~~11~~ <br />FROM: Susan Bur maier~(1JV <br />g O M1,icnar~ ". `°ng <br />o~~~s~on Dirr~~or <br />RE: West Elk Mine (C-80-007) <br />Minor Revision No. 219 <br />Reclamation Cost Estimate <br />I have reviewed the surface water control and reclamation plan portions of MCC's application for MR- <br />219. As a result of my review, I have the following comments. <br />Page 5 of Exhibit 69 states that 151,000 CY of material will be excavated to construct the <br />ventilation shaft pad. The narrative explains that 6,300 CY will be used for facilities <br />development elsewhere on site, and that 130,000 CY will be hauled back for reclamation of the <br />shaft site. MCC has not explained what will become of the remaining 14,700 CY. Please provide <br />additional information which demonstrates that all available material will be used to reclaim <br />disturbed areas to approximate original contour. <br />2. Using the cross-sectionsprovided, DMG is unable to verify the volume estimate for backfilling <br />the ventilation shaft site. Applying the average end area method using the two cross-sections <br />(N-N' and O-O'), our estimated volume is significantlyhigher than MCC's. Please either provide <br />adequate cross-sectional coverage of the cut slopes or provide electronic copies of the maps so <br />that the volume may be verified. <br />3. The chart on Map 3E indicates that runoff from area 43B-6 will flow to Ditch 17. Ditch <br />DSLY-17 is not shown on Map 3E or on Map 54B where all other hydrologic structures are <br />depicted. Please add DSLY-17 to Map 54B. <br />4. The chart on Map 3E indicates that runoff from 43B-2B will flow to DSLY-15. It would appear, <br />based on Maps 3E and 54I3 that runoff from this azea will flow to DSLY-15. Please verify the <br />flow path. There also does not appear to be a DSLY-15 on the map. If this ditch will be <br />constructed, please add it to the map and designs as well. <br />5. The curve numbers applied do not appeazto take into account the disturbedcut slope areas, in that <br />numbers of 70 and 72 have been assigned to entire watersheds which contain both disturbed and <br />undisturbed area. Please review and revise the assigned curve numbers so that disturbed areas <br />are represented appropriately. <br />6. MCC proposes the use of straw bales and silt fences for sediment control on the ventilation shaft <br />area. Given that the disturbance area is somewhat large (3.1 acres) and steeply sloped, the <br />Division does not believe straw bales and silt fences will be adequate to ensure compliance with <br />effluent standards. Please either provide additional information which demonstrates that the <br />proposed sediment control practices will be effective, or provide design information for some <br />