2019-06-17_REVISION - C1981041 - Laserfiche WebLink

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CEDAR CREEK ASSOCIATES, Inc. 6 Revised 06/19 Snowcap Mine / Roadside Portals - 2017 Phase III Bond Release 1.3 Background and Standards for Success Success standards for the Snowcap Mine have been modified several times in the past 16 years due to untenability and this history is briefly detailed below. According to permit documents, success criteria and standards that were initially established for the Snowcap Mine, were as follows: • 90% of the ground cover of the approved reference area. • 90% of the production of the approved reference area. • Woody plant density of 800 live shrubs per acre. • One perennial cool-season grass species with >3% relative cover. • Total perennial warm-season grass species ≥ 3% relative cover. • Total perennial forb species ≥ 3% relative cover. • No reclaimed area shall have a single species that represents > 40% relative cover. At the request of Snowcap, Cedar Creek evaluated the species diversity success standard during 2001. Per Cedar Creek’s recommendations from that evaluation, and given consultations with the Colorado Division of Minerals and Geology (CDMG), new species diversity success standards were temporarily adopted in 2005. They were as follows: • Total perennial cool-season grass species relative cover ≥0.5%. • Total perennial warm-season grass species relative cover ≥2.0%. • Total perennial forb and suffrutescent (sub-shrub) species relative cover ≥0.5%. • No reclaimed area shall have a single species that represents greater than 70% relative cover, with the exception of annual grasses. The annual grass component shall not exceed 70% relative cover unless the annual grass component in the corresponding reference area also exceeds 70%. In such instances, the relative cover of the annual grass component of the reclaimed area shall not exceed the relative cover of the annual grass component in the reference area by more than 5%. In 2010, Snowcap requested Cedar Creek re-evaluate the vegetative cover, production, species diversity, and woody plant density attained following multiple remediation attempts to combat cheatgrass invasion of reclaimed areas, and to compare those values against the currently permitted success criteria and standards. Per Cedar Creek’s recommendations based on that evaluation, modest revisions to success criteria and standards were proposed to facilitate a reasonable solution to a problem that currently has no ecological resolution. These changes are only a slight deviation to prior standards based on the pervasiveness of cheatgrass and the corresponding ecological issues. Extensive discussion of these revisions to the success criteria are presented in TR-60 in Snowcap’s reclamation permit. As a result, the following are the current success standards that have been adopted. Criteria and standards from TR-60 are summarized as follows (changes/clarifications are in boldface): • Perennial Vegetation Average Ground Cover Success Standard - Achieve 90% of the perennial vegetation cover of the approved reference area. • Herbaceous Production Success Standard - Achieve 90% of the perennial herbaceous production of the approved reference area. Snowcap elects to use perennial herbaceous instead of total herbaceous production due to annual and biennial species exhibiting 70% and 73% of the vegetation production of the Shadscale Reference Area in 2016 and 2017, respectively. This accepted alternative is stated under Section IV.A.3 (2nd paragraph) in the Guideline Regarding Selected Coal Mine Bond Release Issues (CDMG, 1995).