2018-03-20_PERMIT FILE - C1981019A (3)

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RULE 4 PERFORMANCE STANDARDS In 2000, Colowyo Mine, along with the Seneca II and Trapper Mines, participated in a shrub establishment program identified as the "CSU/DMG Shrub Establishment Field Trials." This program is described below: CSU/DMG Shrub Establishment Field Trials Introduction and General Study Description Shrub establishment demonstration plots have been established at the Colowyo Mine, Seneca II Mine and Trapper Mine. The goal of the plots is to evaluate cost effective methods for establishing native shrubs on reclaimed lands. Native shrub establishment on reclaimed lands has been a challenge. Competition from herbaceous species and wildlife browsing present significant obstacles to establishment. Introduced cool season grass species in particular were frequently seeded in the recent past, and stands dominated by these aggressive grasses have suppressed establishment and growth of the slow growing native shrub species. The uniform replacement of topsoil, at depths ranging from 12-20 inches, may be another factor contributing to the homogenous grass community structure. Grasses thrive at the expense of forb and shrub species. The young shrub plants that do get established are highly desirable browse for deer and elk. Thus, heavy browse pressure creates another limitation for shrub establishment. In an effort to overcome these limitations, the Division of Minerals and Geology (DMG) requested Colorado State University (CSU) to assist with a study plan to evaluate shrub establishment. A study design was developed after considerable discussion with representatives from the mining community, the DMG and the Colorado Division of Wildlife (DOW). Three coal mines in northwestern Colorado volunteered to assist with the project by providing personnel, regraded lands for the plots, construction equipment, planting materials, elk proof fencing, and plot maintenance. At each mine demonstration plots were constructed in the fall of 2000. Five to six treatments were established to evaluate shrub establishment techniques that have commercial practicality on a large scale. The specifics of the Colowyo demonstration plots are found in the Colowyo Mine Specific Field Trial section of this narrative. The study design took into consideration the possible limitations to shrub establishment. The treatments vary at each mine to accommodate the reclamation techniques and material availability for each site, but certain similar treatments were included at each mine. To evaluate effect of the herbaceous competition, seed mixes were designed so that shrubs contributed the majority of the seed mix. Two seed mixes were evaluated at each mine: a native grass, forb and shrub seed mixture and a seed mixture of unpalatable native shrubs and low -competitive native grasses and forbs. At each mine, one treatment included alternating strips seeded with only the shrub/forb component of the mix. At Seneca Mine, treatments included seedling transplants, for tall shrub species that have proven to be particularly difficult to establish from seed. Typical topsoil replacement depths varying from 12 — 20 inches creates an ideal environment for grass establishment. Therefore, the depth of topsoil on the plots was varied to evaluate shrub and forb response to topsoil depths ranging from 0 to 20 inches. Composite soil and overburden samples were taken from each treatment at each mine. Overall, the soils (topsoil and spoil) at all three -mine sites have good physical and chemical properties. Soil pH ranges Rule 4 Performance Standards 4-44 Revision Date: 1/31/18 Revision No.: TR -119