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COLORADO <br />UDivision of Reclamation, <br />Mining and Safety <br />Department of Natural Resources <br />1313 Sherman Street, Room 215 <br />Denver, CO 80203 <br />Memorandum <br />Date: August 10, 2020 <br />To: Robin Reilley, DRMS <br />From: Janet Binns <br />RE: Seneca II -W, C-1982-057, Partial Phase III Bond Release No. 6 (SL6) <br />Vegetation Monitoring Review <br />I have reviewed Seneca II West application, SL6, for a partial Phase II and Phase III bond Release. Seneca <br />Property, LLC (SP) applied for a partial Phase II/III bon release on 379.5 acres, and a partial Phase III bond <br />release on 437.1 acres. SL6 application request bond release on a total of 816.6 acres. Seneca Properties, <br />LLC is requesting a liability release of $2,500,000 with SL6. <br />Two items need correction in the SL6 application and are noted in this memo. <br />Vegetation sampling was conducted in 2015 and 2016. The SL6 application was received in the fall of <br />2019, making the vegetation data submitted within the 4 year acceptable time period. Post -mining land <br />use is livestock grazing and wildlife habitat. <br />The Seneca II West Mine uses weighted average extended reference areas to evaluate vegetation <br />reclamation success. The weighted average reference area is a compilation of the major vegetation <br />communities that were present prior to mining, with the current reference area sampling data <br />proportionally added based upon the percentage each community represented in the pre -mining landscape. <br />The extended reference area includes all undisturbed areas of a representative vegetative community that <br />lies within the permit area, and outside of the disturbance area boundary. The main pre -mining <br />communities were represented by Aspen (11% contribution), Mountain brush (35% contribution), <br />Sagebrush (31% contribution), Steep Mountain Brush (13% contribution), and Western <br />Wheatgrass/Alkali Sagebrush (10% contribution). The all -hit cover data is adjusted by elimination of <br />woody plants, noxious weeds and cover of annual/biennial plants in excess of 10% relative cover to result <br />in "allowable all -hit" herbaceous cover. The vegetative cover success is based on the allowable all -hit" <br />herbaceous cover. Vegetative cover success on the reclaimed area will be no less than 90% of the cover <br />success standard with a 90% confidence interval, in accordance with Rule 4.15.8(3)(a) <br />The sampling requirements assume a normally distributed sample, and requires achievement of sample <br />adequacy. The reference area did not exhibit a homogenous distribution of vegetation, and was diverse <br />'C <br />1313 Sherman Street, Room 215, Denver, CO 80203 P 303.866.3567 F 303.832.8106 http://mining.state.co.us <br />Jared Polis, Governor I Dan Gibbs, Executive Director I Virginia Brannon, Director <br />'� 1876 <br />