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<br />Mine No. 3; Midterm Findings <br /> <br />(Table 50). [n order to determine if reclamation has met the required performance <br />standazd, the species diversity on reclamation and the associated reference azeas will <br />be measured. The diversity index of the reclaimed azeas must be at least 90% of the <br />weighted diversity index, to meet this performance standazd." The diversity index that <br />Colorado Y"ampa Coal Company indicates from the baseline data that will be applied <br />to reclamation success is the Shannon-Weiner diversity index. <br />The Division questions the validity of taking 90% of the calculated index, since <br />Shannon-Weiner indices aze calculated using the log of the percentage importance. <br />Furthermore, the Division questions the applicability of using this diversity standard <br />on a reclaimed pasture. In the article, "Measuring Species Diversity on Revegetated <br />Surface Mines: An Evaluation of Techniques" by Jeanne Chambers (USDA Reseazch <br />Paper INT-322, November 1983), Ms. Chambers states that, "use of the Shannon- <br />Weiner index as a sole criterion of diversity is not warranted. It is particulazly <br />inappropriate because it cannot describe the specific apportionment of importance <br />among species between two azeas, such as revegetated and a reference azea." <br />Mine 3 was seeded and managed as a pasture, and hence, one would not expect a high <br />diversification in the re-established plant community. Application of diversity criteria <br />suited to a native community may not be appropriate to a pasture. Please submit a <br />revision to the permit to apply appropriate diversity criteria on the reclaimed <br />pastureland. <br />8. The Division was unable to locate monitoring well abandonment reports. Please <br />confirm whether the following wells and boreholes have been sealed. Please provide <br />dates sealed and methods used in accordance with Rule 4.07.3: <br />008-77-58 008-79-06 008-AV-1 008-AV-2 008-SP-046 008-SP-Sa <br />Rule 2.05.3(4)(a)(i)(D) requires that the permit describe the potential effect on <br />structures from subsidence resulting from past underground mining activities. The <br />Middle Creek portal was developed though mine development did not ensue. The <br />text of the permit does not address the potential for subsidence of the ponds due to <br />underground mining. The Division suggests the inclusion of a statement in the permit <br />text clazifying that the ponds were not undermined and aze not within the angle of <br />draw of potential subsidence from underground mining (permit page 2.05-24.) <br />10. The text of the permit does not include a description, including appropriate cross <br />sections and maps, prepazed in accordance with Rule 2.10, of the measures used to <br />seal the mine openings in accordance with Rule 4.07 (Rule 2.05.4(2)(8)). The text <br />demonstrates management of the mine openings by backfilling of the portal area <br />(page 2.05-65a and 2.05-137). Please include appropriate cross sections and maps <br />confirming how the portal was sealed. <br />11. Elements of a reclamation plan aze described in a number of pazagraphs of the permit, <br />page 2.06-39, section 2.05.4. Description of ditches planned for permanent retention <br />was found in the permit in Exhibit 3, Tables TR 90-06-7 and TR 90-06-8. These <br />