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<br /> <br /> <br /> <br />PR-04, Colowyo Coal Mine C1981-019 55 August 2016 <br /> <br />Colorado Division of Wildlife (renamed the Division of Parks and Wildlife in 2011) to formulate <br />improved seed mixes and initiate a shrub establishment study (TR84). The shrub study was <br />installed in November 2011. Results of this study will contribute to revegetation methods in the <br />future. <br /> <br />C. Mulching <br /> <br />In the original permit application, Colowyo proposed that mulch was not required on slopes less <br />than 4:1. The Division approved this proposal at that time with erosion control prior to <br />vegetative establishment to be provided by contour plowing. Monitoring of mulched versus non- <br />mulched areas was required as part of Colowyo's ARRs. In addition, a stipulation was added to <br />the permit requiring the use of mulching if excessive erosion does develop. <br /> <br />Subsequent monitoring data showed that mulching was not necessary for erosion control or plant <br />establishment. As a result of the permit renewal process in 1987, both mulching and the <br />monitoring program (specific to assessing mulched versus non-mulched areas) were eliminated <br />as requirements. The above-mentioned stipulation was at that time incorporated into the Permit. <br /> <br /> <br />D. Revegetation Success Standards <br /> <br />Prior to initial disturbance at Colowyo, Colorado State University and the Soil Conservation <br />Service Upper Colorado Plant Materials Center conducted studies, in cooperation with Colowyo, <br />to determine appropriate seed sources, species composition and revegetation practices to ensure <br />reclamation success at the mine site. Results of the studies conducted by Colorado State <br />University are included in Exhibit 10, Volume 4 of the PAP. <br /> <br />Methods for evaluating vegetative success are found in Section 4.15 of the original PAP <br />volumes, and in Section 2.04.10 and 4.15 of Volume 12, submitted in association with PR-2. As <br />part of this process, two reference areas have been established for the determination of <br />reclamation success for the disturbed areas other than those associated with the Collom project <br />area. One reference area represents the sagebrush community while the other represents the <br />mountain shrub community. <br /> <br />Based on herbaceous cover and productivity from the sampled reference areas, the revegetation <br />success criteria for the disturbed areas other than those associated with the Collom project area <br />are as follows: Herbaceous cover will be at least 90 percent of the cover measured in the <br />reference area with a 90 percent statistical confidence level. Herbaceous productivity for <br />revegetated areas will be no less than 90 percent as productive as the associated reference area <br />with a 90 percent statistical confidence level. <br />