Laserfiche WebLink
iii iiiiiiiiiii ~~ . <br />r ,.. <br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Rewun:es <br />1313 Sherman $t., Room 215 <br />Denver, Colorado 80203 <br />Phone: p031866-3567 <br />FAX: (3031832-8106 <br />August 7, 1996 <br />Charles B. McCtiilloh <br />Seneca Coal Company <br />P.O. Drawer D <br />Hayden, Colorado 81639 <br />RE: Yoast Mine (C-94-082) <br />Pond 10 Construction <br />Dear Mr. McC~tlloh: <br />RESOURCE: <br />Roy Roma <br />Governor <br />lames 5. Lochhead <br />Eaeculive Director <br />Michael B. Eong <br />Division Director <br />On August S, 1996, Joe Dudash of the Division conducted an inspection of the construction <br />operations for Pond 10 at the Yoast Mine. Mr. Dudash informed me of his observations the <br />following day. Among those observations were: <br />- A keyway for the embankment was being constructed, and was roughly ~ <br />complete. <br />- Approximate dimensions of the keyway were 10' wide, 2' deep. <br />- Ground conditions in the construction area were extremely wet, and crews were <br />pumping water from the excavation to facilitate construction. <br />- The material in which the keyway had been cut was a dark colored soil. <br />The reported conditions indicate there may be problems with the construction of Pond 10. <br />Division staff reviewed the design requirements and approved construction plan for Pond 10, <br />compared the requirements to the Division's observations, and identified the following concerns. <br />1. The approved permit application states that the pond embankment and keyway will be <br />constructed with material obtained from the facilities area of the mine. We are <br />concerned with this proposal for two reasons. First, the facilities area of the mine has <br />not yet been excavated, so the material is not currently available. Second, and more <br />important, it does not appear that Seneca Coal Company has performed tests on the <br />material to determine whether it has sufficient strength to achieve the required factor of <br />safety of 1.3 or greater (required by Rule 4.05.6(11)(k)). <br />