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The topsoil may be stored for up to 45 years, but degradation of biological processes should not occur since the storage pile will be undisturbed and is a maximum of 4 feet thick. The topsoil stockpile has been seeded with native species and stabilized. The operation is in compliance with the requirements of this section. XII. Vegetation - Rules 2.04.10, 2,05.4(2)(e) and 4.15 Baseline vegetation and revegetation information can be found on pages 10-14 and in Exhibit 4 of the permit renewa] application. The big sagebrush community is the only vegetation type that has been disturbed by the mining operation. Three vegetation types were sampled to characterize the area. The operator requested that the revegetation success standard for shrub density be lowered from the pre-mining density of 35,000 shrubs per acre to 1,500-2,000 shrubs per acre with an increase in herbaceous cover from 24% to 45%. This is acceptable to the Division for the following reasons: 1) 1,500-2,000 shrubs per acre would create an open area with more value for grazing and wildlife use; 2) natural reinvasion of shrubs will occur readily because of the small area of disturbance (3.22 acres); and, 3) the increased herbaceous cover will compensate for the decrease in shrub cover, thus stabilizing the soil and minimizing erosion. The revegetation success standard for herbaceous production was determined at 125 grams per square meter. This standard was determined by increasing the measured pre-mining production proportionally to the increase in herbaceous cover. The establishment of this standard served to satisfy the requirements of Stipulation No, 2 of the original permit approved for O.C. mine No. 2. The diversity standard proposed by the operator was to have B species make up at least 70% of the diversity. The revegetation plan calls for seeding with 10 native shrub, grass, and forb species and mulching. Additionai native species should readily invade the area to be reclaimed due to the small size (3.22 acres) of the disturbed area at the mine. With seeding and natural invasion, the operator should be able to meet the diversity standard. The baseline vegetation inventory showed that no endangered species were present in the vicinity of the mininy area. In addition, the acreage of disturbance will not increase. Therefore, pursuant to 2.07.6(2)(n), the ~ Division finds that the proposed coal mining activities will not affect the continued existence of endangered or threatened species or result in destruction or adverse modification of their critical habitats. The operation is in compliance with the requirements of this section. -1 3-