Laserfiche WebLink
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 />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 />D. Revegetation Success Standards <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 />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 />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 />Herbaceous cover and production success for the original permit area disturbances and for the <br />relatively limited acreage of disturbance projected for the Lower Wilson disturbance (120 acres <br />approximate) will be based on acreage weighted comparisons, using the sagebrush and mountain <br />shrub reference areas, in accordance with Rule 4.15.7(4)(b), as previously approved. The <br />originally approved sagebrush reference area, established in 1981 within the original Colowyo <br />permit area, will be utilized for a "targeted reference area" rather than a separate sagebrush <br />reference area established in association with 1984 vegetation studies and located to the south of <br />the South Taylor expansion area. Reasons for use of the original sagebrush reference area in <br />preference to the 1984 reference area are set forth under Justification for Reference Area <br />PR -04, Colowyo Coal Mine C1981-019 55 August 2016 <br />