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'~~` <br />Dan Mathews <br />r~ <br />u <br />-5- January 18, 1982 <br />Grand Mesa Coal Company is diverting surface runoff into the mine workings from <br />0.096 acres at the E belt Portal, 0.331 acres at the E intake Portal, and proposes <br />to divert surface runoff from 2.468 acres into the D seam mine. This water is then <br />pumped out of mines into sediment ponds for treatment. Such diversion of <br />surface waters into underground workings are forbidden under Rule 4.04.16 <br />unless the applicant can demonstrate that such practices will not degrade water <br />quality. <br />The sediment pond at the Loadout site at the old Holly Sugar Factory in Delta, <br />is designed as a no discharge structure. The dewatering of this pond is to be <br />through evaporation. Figure 2.05.3(7)-1 contains a letter from Thomas A. Kelly, <br />Assistant Division of Water Resources Engineer in Montrose. In this letter, <br />Mr. Kelly approved a small evaporation (sediment) pond with a total capacity of <br />0.8 acre foot of storage from a 100-year flood event. The calculations within <br />the permit application are for the 10-year, 24-hour event and the capacity of the <br />pond is 2.9 acre feet (e.g. surface area of 0.725 feet times 4 feet of depth). <br />The pond is also excavated into alluvial materials and therefore, will loose a <br />great deal of the water by deep percolation through the pond bottom. This may <br />pollute the groundwater down gradient of the pond. Grand Mesa Coal Company should <br />resubmit the pond design to the Division of Water Resources for their approval in <br />light of the above facts. <br />If you, or representatives of Grand Mesa Coal Company, have any questions related <br />to this memo please feel free to contact me. <br />/mab <br />cc: David C. Shelton <br />Jerry Zimpfer <br />Jim Pendleton <br />Fred Banta <br />Dick Stenzle, Rss't. State Engineer <br />