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1 <br />Jce Dudash <br />Page 2 <br />April 7, 1997 <br />2. The permit contains production success standards for range sites A, B and C based on <br />historical records collected from pre-mine sites from 1979 through 1985. I have two <br />concerns about these standards. <br />A. The production standards are equivalent to the lower 90% confidence limit of the <br />mean production estimated on the range sites rather than the mean itself. In order to <br />demonstrate successful revegetation for bond release, an operator must show that <br />90% of the standard has been achieved with 90% statistical confidence. So, Trapper <br />only needs to achieve 90% of a standard which is only 90% of the mean production <br />measured- and that production was measured by clipping only grasses and (orbs in <br />communities dominated by shrubs. There was more herbaceous production in <br />these predominantly shrub pre-mine communities than is required in the <br />predominantly grassy reclamation. <br />B. The Trapper production standards appear very low when considering the potential of <br />the soils and the mine site. For instance, the success standards for range sites A, B, <br />and C are 676, 461, and 515 pounds/acre, respectively (herbaceous production <br />only).. NRCS range site descriptions For three range sites occurring in the permit <br />area vary from 1200-3000 pounds/acre in favorable years, and from 600- 1500 <br />pounds/acre in unfavorable years. <br />3. Table 4.4-12 explains an inverse relationship between the density of sheep manure pellets <br />and stem density at the pre-mine site. This information was presumably used in deriving a <br />shrub density success standard, although I could not determine how that was done by <br />reviewing the permit. When the numbers in the table are inserted Into the regression <br />equation, the results are not correct. <br />MR-147 Comments <br />Tepper proposes to apply any stem counts in excess of 400/acre (the overall success <br />standard) to the stem counts within shrub clumps, where the success standard is 3674 <br />stems/acre. No reason is given for this suggested change. Please explain the Division <br />approved standard should changed. <br />2. On page 4- 119, Trapper proposes to estimate shrub density within shrub islands by means of <br />direct count beR transects. "or comparable technique". Alternate sampling techniques should <br />either be described in the permit, or the reference to "comparable techniques" should be <br />deleted. <br />^ <br />