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8. There is a sufficient quality of data in the surface water section (individual drainage data. However there are no units of measurement on the water quality data. A narrative summary of this data, including average flows, high and low flow periods, type of water quality and parameters of concern, etc. would assist the reviewer. 9. It appears that CWI, in the water replacement plan, is proposing to replace lost water primarily by repairing the subsidence impacts causing the loss. If water loss happens to occur during a critical water-use season (i.e. irrigation, etc.) and repairing the problem will take several weeks, how does CWI plan to mitigate the loss incurred in water users during this interim period? Also, the means of water conveyance to the points of diversion of potentially affected water rights needs to be discussed, at least generally. 10. On the long-term mine planning map a ventilation shaft is shown within the BLM buffer zone on East Roatcap Creek. Where will the surface distur- bance associated with this ventilation site be in relation to East Roatcap Creek, the critical big game winter range, and the adjacent riparian zone? If the site is within the 1/8 mile riparian buffer zone or winter range, it may be approved after consultation with the Colorado Division of Wild- life and U.S. Fish and Wildlife Service (lease stipulations n and o). 11. In the subsidence repair handbook CWI proposes to repair potential surface subsidence cracks in stream channels with culverts. This is a good short-term solution but larger lasting (repair/sealing of the crack) measures should be employed. 12. The subsidence handbook assumes subsidence cracks on undeveloped non- irrigated forest and rangeland will heal themselves naturally. This may be true most of the time, however, these areas should be field-checked after pillar retreat to locate and repair large cracks potentially affecting surface runoff. 13. In the subsidence repair handbook, the procedure for repairing subsidence- impacted springs is nebulous at best. More detail on this procedure is needed. 14. Section 2.05.6, page 159. CWI states that they feel 800 feet of over- burden thickness will completely negate surface effects of subsidence. This is a risky assumption as no amount of overburden can guarantee 100 percent negation of surface effects of subsidence. CWI's statement also contradicts several statements in the subsidence study conducted by Geo Hydro consulting (e.g., page 39 states "subsidence cracks may develop through overburden thicknesses of 800 feet or more under unfavorable conditions'). Page 52 states - Zones with 800-1600 feet overburden are designated as zones of intermediate subsidence impact and appreciable damage may result in these areas to buildings or structures, due to subsidence. The study also mentions that CWI surveyed cracks above the 1st and 2nd west panels with 840 feet overburden thickness.