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The approved backfilling and grading plan for the Colowyo Mine is found in Volume 1 (East and <br /> West Pit), Volume 12 (South Taylor), and Volume 15 (Collom) of the PAP. Maps 19, 19A and <br /> 19B show the approved post-mining topography, Maps 29 and 29A, and 29B show the <br /> backfilling and grading schedule. The pre-mining and post-mining cross-sections are shown on <br /> Maps 20, 20A and 20B, and the permanent drainage channel profiles are shown on Maps 33, <br /> 33A, 33B, and 33C. Map 1 of the SL-16 application show cross-section area for the 3.3 acres <br /> being requested in the East Pit, including approved post-mining topography alongside the <br /> constructed topography. <br /> The approved drainage reestablishment consisted of the design and construction of permanent post <br /> mining drainage channels. The post-mine channel locations are shown on Maps 41, 41A and 41B <br /> of the Colowyo PAP. Map 2 of the SL-16 application show location of the Gulch A Pond and East <br /> Side Collection Ditch. The Gulch A Pond and East Side Collection Ditch construction designs can <br /> be found in Exhibit 7 of the Colowyo PAP. <br /> Phase II Bond Release <br /> The Division evaluated Colowyo's request for partial Phase II Bond Release on 38.5 acres of the <br /> East Pit, South Taylor Pit and the Gulch A Pond and East Side Collection Ditch in the SL-16 <br /> application, as shown on Figures 1 and 2 of this document. The process of releasing the reclamation <br /> bond for a coal mine site in Colorado is explained in Rule 3.03 and further described in the <br /> Division's 1995 Guideline Regarding Selected Coal Mining Bond Release Issues. The bond release <br /> process involves three phases. At Phase 11, Rule 3.03.1(2) (b) states, "Up to eighty-five percent of <br /> the applicable bond amount shall be released upon the establishment of vegetation which supports <br /> the approved postmining land use and which meets the approved success stand for cover,pursuant <br /> to 4.15.8, meets applicable productivity standards for prime farmlands or alluvial valley floors <br /> pursuant to 3.03.1(3)(b), or croplands pursuant to 4.15.9. With the exception of prime farmlands, <br /> evaluation of vegetation establishment pursuant to this paragraph is based on statistically valid data <br /> collected during a single year of the liability period." In regard to Phase II bond release, Rule <br /> 3.03.1(3)(b) also states, "No more than (60)percent of the bond shall be released so long as the <br /> lands to which the release would be applicable are contributing suspended solids to streamflow <br /> or runoff outside the permit area in excess of premining levels as determined by baseline data or <br /> in excess of levels determined on adjacent nonmined areas". <br /> Although not specifically addressed in Rule 3.03, the Division evaluates topsoil replacement in <br /> conformance with Rule 4.06 and permit requirements as a component of Phase II bond release. <br /> Evaluation and inspection of the reclaimed areas was based on the specific requirements of the <br /> reclamation plan and the functional requirements of the post-mining land use. Criteria for bond <br /> release included the following. <br /> 1. Required variable topsoil replacement depth at an average of 8 inches (per the <br /> Colowyo PAP); and <br /> 2. Required 90%vegetation cover. <br /> Proposed Decision and Findings of Compliance October 22,2019 <br /> Partial Phase I,II and III Bond Release SL-16 Page 6 <br />