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22. Map 89 was mod~ed per request to address post-reclamation drainage control measures for the Eau Portal Area Included in the submittal were designs for several permanent riprap channels. A temporary upland diversion ditch was depicted on the plan view map and sediment traps were depicted along the base of the bacldilled slope. Designs should be included for the upland ditch, sedimrnt traps, and arty associated collection ditches along the base of the backfill. Sediment traps (currently depicted only in cross section) and associated collection ditches should be shown on the plan view. 23. Refer to Item 5, above. 25. it is possible that 5nal reclamation in the rail loop area will not occur for 30 years or more. However, final reclamation plans need to be in place for the unlikely event that reclamation would be performed by the Division in the event of bond forfei[tue (Otis is why reclamation bonds are required). Provision for adequate drainage and sedimem control following completion of final reclamation grading would be a necessary component of reclamation of the rail loop area, and therefore the detai]ed drainage and sediment control plan requested needs to be provided in a timely manner. It is not acceptable to delay submittal of the plan until "prior to beginning fatal reclamation activities..." 26. Replacement of topsoil and subsoil from cheatgrass infested stockpiles or stripping areas in reverse sequence as you have proposed may be appropriate, although generally the subsoils would have slightly lowered organic matter levels and slightly elevated SAR levels, which could potentially impact establishment of certain desired species. The extent to which cheatgrass abundance on refuse area soil stockpiles and RP-1 is correlated with soil chemical or physical characteristics versus cheatgrass seedbank in the topsoil has not been established. A proposal for field trial comparison of reverse sequence soil replacemem (minimum 1 foot of subsoil over cheatgrass infested "live" topsoil) versus selected alternative soil handling strategies should be submitted, in accordance with the topsoil substitution approval procedures of 4.06.2(4)(a). One alternative treatmrnt should rntail a minimum 1 foot of "internal stockpile" topsoil over subsoil. A second alternative treatment should rntail stripping and spreading of a 6" layer of "live" cheatgrass topsoil over respread subsoil, with the underlying 6" layer of topsoil stripped and replaced over the first 6" layer. Results of the field trials would be used to guide future soil handling procedures for cheatgtass infested topsoils. The trials should be inifiated during the upcoming field season Until such time that field trial results demonstrate suitability of subsoil as topsoil substitute, the application text should specify that "internal stockpile" topsoil would be replaced as the surface soil layer at the refuse area 27. a) Our concern that certain introduced species could potentially dominate large reclaimed areas to the detrimrnt of native species diversity artd woody plant establishment is not based solely on monaculttual plantings of crested wheatgrass and smooth brome. We have observed sites seeded with relatively diverse seedmixes which, years after seeding are dominated by a small number of aggressive, stress tolerant cool season introduced grasses and legumes, wish poor representation of seeded native shrubs, forts, and warm season grasses. Aggressive, long lived native cool season grasses such as western wheatgrass Carr also dominate large areas and suppress slower growing or harder to establish species. Many site specific factors affect species interactions on reclaimed areas, however, and results of any particular seeding are difficult to predict. We acknowledge that the lazge permanent sites seedmix proposed is fairly typical of seedmixes cwrrnUy being used at coal mines in northwestern Colorado, with respect to diversity and introduced species component. The fiexibility incorporated into the proposed revegetation plan, in combination with the proposed monitoring and evaluation plan, should ensure the over-all achievement of revegetation srccess in accordance with the approved standards. Introduced species included in the proposed seedmixes have been approved by the Division historicrlly, based on literature documentation regarding the value of such species for livestock and wildlife forage production and erosion control. Rule 4.15.2(3) specifies that introduced species maybe used after appropriate field trials and/or relevant technics/literature have demonstrated that the introduced species