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<br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Depanmem of Natural Resources <br />131 3 Sherman 51 ,Room 215 <br />Denver. Colorado 80203 <br />Phone:1303)866-7567 <br />FAX; 1)031 8J2 8106 <br />April 18, 1994 <br />~I Ji J,~, , nn ~ ~i <br />~~D r------ - f <br />;,5` :i;, <br />Mr. Joe Wilcox _ <br />office of Surface Mining u_..,,. <br />Western Support Center '- <br />1020 15th Street <br />Denver, Colorado 80202 <br />Re: Notes from April 15, 1994 Meeting Regarding Sediment <br />Standard Comparisons - Meeker Area Mines (C-81-032) <br />Dear Joe: <br />~~ <br />DEPARTMENT OF <br />NATURAL <br />RESOURCES <br />Ruy Ruiner <br />Cmrrnw <br />Krn Sa ld i.v <br />E aer uur~e flu ri u u <br />Mu harlH lung <br />Oi~~aun Dne~ 1 n <br />This letter is intended to summarize the content of our meeting on <br />April 15, 1994 regarding the sediment standard comparisons at the <br />Meeker Area Mines and clarify items that may have been confusing in <br />the original submittal. <br />Derivation of Sediment Standards <br />The first point requiring clarification concerns the use of T <br />values. As Greg Lewicki pointed out in the April 15 meeting, T <br />values were discussed in Minor Revision MR-OS only as a comparison <br />to show that the sediment loss values computed using the USLE are <br />lower than the T values. This comparison may have been <br />superfluous; however, the T values were not used for the sediment <br />standards. The standards were based on the computations done using <br />the USLE. All empirical sediment accumulation measurements were <br />compared to the USLE-derived standards. <br />Contribution of Reclaimed Areas to Sediment Ponds <br />The OSM also expressed a concern that the relationship between <br />sediment coming from the reclaimed areas and sediment in the ponds <br />is not apparent, because the ponds collect sediment from mostly <br />undisturbed watersheds. The concern was apparently that a lower- <br />than-predicted sediment contribution from the extensive undisturbed <br />areas draining into the ponds could mask a sediment contribution <br />from the reclaimed area that could be higher than the standard. <br />This, however, is unlikely, because the vegetation type on the <br />reclaimed land is primarily grasses with no appreciable canopy, <br /><s r. <br />