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MCC proposed replacing the two reference areas with the use of a historic records <br />study area for evaluation of revegetation success. The vegetation in the historic records <br />study area resembles the expected post mining vegetation community. Data is collected <br />in a former agricultural and pasture area southwest of the facilities area shown on Map <br />53. Use of the historic reference area was approved in PR-7 and is presented in Section <br />2.05 of the permit application. <br />To establish the historic reference, three years of data are to be collected to represent a <br />dry, normal and wet year. A historic analysis was developed using precipitation data <br />from the National Climatic Data Center (NCDC) for the Paonia 1 SW station collected <br />from 1905-1965. Data from the "pre-growing" season, October through May, were <br />considered. The average annual precipitation during the "pre-growing' season was <br />11.08 inches. From this data it was decided that wet and dry years would be those <br />years during which the precipitation varies by more than one standard deviation from <br />the mean. The standard deviation was 2.63. Thus, precipitation during a "dry" year <br />would be less than 8.45 inches and during a "wet" year, precipitation would be greater <br />than 13.71 inches from October through May. A summary report will be completed <br />each year that vegetation is sampled. Upon completion of the final report a revision <br />application will be submitted which includes a final report detailing the results of all <br />historic record vegetation sampling and establishes revegetation success standards based <br />on the historic record. <br />Shrubs will be re-established to a minimum standard of 1,000 stems per acre. This <br />criterion was established by the Colorado Division of Wildlife. For specific <br />information regarding this criterion, see Exhibit 62 in the permit document. <br />The proposed post-mining land use is rangeland and wildlife habitat. Tables 37 and 38 <br />of the permit document list the seeds and shrubs to be planted to establish this land use. <br />The West Elk Mine also will reclaim 1.3 acres within the riparian buffer zone. The <br />riparian seed and shrub mix is included in section 2.05.4 of the permit document. The <br />mine based their selection of plant species on species listed in the baseline biological <br />survey, species geographical range, soils, climate, slope and aspect, root competition, <br />cover and seasonal variation. Seed mixes are also based on experience gained on West <br />Elk Mine revegetation plots, and quantitative data collected in 1980 describing the <br />present vegetative cover, and in terms of wildlife requirements suggested in literature. <br />The Division approves the use of these species based on the post-mining land use. <br />Once the topsoil has been distributed and graded, the surface is prepared for planting. <br />Surface preparation loosens and roughens the surface by disking, harrowing, or <br />dragging which increases infiltration and reduces surface runoff. Seeding and planting <br />are conducted parallel to the contour unless such activities prove hazardous to <br />equipment and/or operators. Various conditioners and neutralizers may be used to <br />modify the seedbed conditions. Seeding and shrub planting will be done during the <br />spring (March 15 through June 15) or fall (September 15 through November 15). <br />51 <br />