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-49- <br />A number of problems were noted in the Preliminary Adequacy Letter of <br />March 26, 1981 with respect to vegetation data, the revegetation plan, <br />and methods proposed in the applicaton for determining revegetation <br />success. The Division indicated that sampling conducted in 1980 did not <br />meet sample adequacy requirements for production, cover, or woody plant <br />density. The Division also stated that it was unclear how the 1980 <br />vegetation study would be related to proposed reference areas and the <br />ultimate determinations of reveyetation success. The Division requested <br />a plan for sampling within the reference areas located adjacent to the <br />disturbed area at the mine. <br />In a subsequent meeting with W.S.C. representatives on June 16, 1981, the <br />issues of vegetation sa~npliny and determinations of revegetation success <br />were discussed in detail. It was agreed that methods other than the <br />standard reference area approach might be preferable for evaluating <br />reveyetation success in this case. Vegetation adjacent to the disturbed <br />areas is predominantly dense oakurush, with little herbaceous understory. <br />Since W.S.C. has requested a variance for a reduced shrub density and has <br />proposed to haul in topsoil from another area; basing success standards <br />on vegetative conditions in the adjacent oakbrush community would present <br />numerous problems. The option of basing success criteria for herbaceous <br />production and cover on USDA or USDI technical documents as outlined in <br />Rule 4.15.7(ii) was presented. <br />Based on SCS and BLi~I information for soil types and vegetation <br />communities in the permit area, the applicant has proposed a herbaceous <br />productivity standard of 1,600 pounds per acre for the entire 29 acre <br />surface disturbance at Hawk's Nest. From soils information presented in <br />the application, and vegetation data collected at the Mt. Gunnison Mine, <br />this production figure would appear to be applicable to the deeper, <br />alluvial and colluvial soils on the lower toe slopes and areas adjacent <br />to the river. The load-out, west mine parking lot and east mine yard <br />area occupy these sites. However, for the West Portal face-up area which <br />is located above the rest of the mine on steep, south facing slopes with <br />shallow soils, such production levels may not be realistic. <br />W.S.C. has not proposed a standard for herbaceous cover or a standard for <br />species diversity. The application originally indicated that diversity <br />in reference areas would be determined on the basis of the number of <br />species present by life form. In a review letter of June 11, 1981, the <br />Division recommended that species composition be given consideration in <br />the development of a diversity standard. <br />In subsequent discussions, representatives of W.S.Q. have indicated that <br />they would prefer to select a reference area or areas that would be <br />representative of the post-mining site conditions, rather than depend <br />coley on technical documents and literature guidelines for revegetation <br />success standards. <br />The following stipulation must be imposed: <br />