2023-06-29_PERMIT FILE - C1981019A (2)

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RULE 3 PERFORMANCE BOND REQUIREMENTS Rule 4 Performance Standards 4-42 Revision Date: 6/13/23 Revision No.: MR-247 Native soil, collected from the locally source ecosystems on or directly adjacent to Colowyo Mine exhibiting similar tall shrubs species as being implemented in the trial, will be used to inoculate the test sites with beneficial mycorrhizae. Mycorrhizae are symbiotic relationships that form between fungi and plants. The fungi colonize the root system of a host plant, providing increased water and nutrient absorption capabilities while the plant provides the fungus with carbohydrates formed from photosynthesis. Once the mounding is completed and prior to installation of weed guard fabric, locally sourced soils (containing local mycorrhizae) will be scattered at random on the mounded surface. Care will be taken to ensure these soils are place around where the tubling will be planted and under the weed guard fabric. Weed guard fabric will also be placed around the tubelings, with limited opening size in the weed guard fabric to plant the tubeling. This should help assist in limiting competition from moisture from other plants. The final step will be to broadcast seed the entire trial area with the seed mixture presented on Table 2.05-8. No other manipulation of the trial area will occur post construction to limit annuals, but if necessary noxious weeds will be controlled during the entire trial period. Colowyo will monitor the survival of planted tall shrubs annually for three years following planting. The primary purpose of this approach to test plots is to identify areas that already exhibit favorable conditions to establish tall shrubs, rather than try to replicate those conditions. 4.15.7 Determining Revegetation Success: General Requirements and Standards Three reference areas have been selected to represent the three major vegetative communities to be disturbed, sagebrush, mountain shrub, and aspen. The locations of these reference areas are shown on Map 4. Detailed vegetative sampling was performed on these reference areas as described in Section 2.04.10. The reference areas were sampled for herbaceous cover, herbaceous production and woody plant density. Species diversity was determined utilizing herbaceous cover data from the premining inventory of the sagebrush, mountain shrub, and aspen communities. The reference areas are each approximately seven acres in size. Statistical tests were performed on the vegetative data from the reference areas to prove that they were comparable to the premined area. The parameters compared were herbaceous cover and herbaceous production. Revegetation success will be determined by comparisons of weighted averages between reference areas and revegetated areas in accordance with Rule 4.15.7(4) (b). For demonstration of revegetation success, vegetation cover, herbaceous production, and in certain circumstances woody plant density will be sampled to statistical adequacy (where necessary), and compared to the revegetation metrics described in Section 4.15.8 below. Sampling methodologies and statistical testing utilized for bond release evaluations are described in Section 4.15.11. To summarize, there are three reference areas, the Mountain Shrub reference area, Sagebrush reference area, and Collom Aspen reference area that are utilized to evaluate revegetation success