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COAL <br />COMPANY .� <br />£4G <br />E PRODUCT10TA � <br />In the review comment above, it is stated that past studies and studies at <br />other sites do not provide justification for altering curve number values. <br />On the contrary, due to the preponderance of high infiltration rates at all <br />reclaimed sites, the exact opposite is true. <br />DRMS July 2, 2012 Follow up Comment to Comment 2 above: <br />Again, the Division stands by our assertion that information from <br />other mines and information from a small area on Colowyo Mine is <br />not enough information to identify all reclaimed land on Colowyo as <br />C soils. As CCC states in the response letter, per NEH, an onsite <br />investigation of disturbed lands should be made to determine HSG. <br />Colowyo's Second Round Response to Original and Follow up Comment 2: <br />Colowyo assumes that the Division's Follow up to Comment 2 above was <br />meant to read "Again, the Division stands by our assertion that <br />information from other mines and information from a small area on <br />Colowyo Mine is not enough information to identify all reclaimed land on <br />Colowyo as B soils. " <br />Colowyo believes that in this case, the Division's stated position is <br />contrary to standard industry practice and reasonable interpretation. <br />Colowyo again asserts that the results of the 1981 study clearly justify <br />characterizing reclaimed lands on Colowyo Mine as Class B soils. As <br />part of Coloywo's previous mine expansion permitting activities, Colowyo <br />was required to sample and analyze pre mine overburden characteristics, <br />and the results demonstrate a general consistency of the composition of <br />those materials over time as mining progression has advanced. <br />Homogenization (mixing) of the materials utilized for backfilling and <br />regrading ensures that low permeability pre -mine soil or overburden <br />layers are eliminated and diluted with materials from higher permeability <br />layers. The application of a 20% swell factor to mined materials directly <br />reflects the practical concept of increased permeability of all materials <br />impacted by mining. Common on -site reclamation practices such as <br />ripping regraded overburden surfaces (if they are not topsoiled within a <br />year of being regraded), and roughening topsoiled surfaces after topsoil <br />has been replaced, ensure and directly increase the already elevated <br />permeability of these surfaces as compared to pre -mine condition. <br />A Western Fuels- Colorado, LLC mining property <br />