Laserfiche WebLink
<br /> <br />Grand Mesa <br />Coal Comps <br />First and Columbia <br />P.O. Box 226 <br />Delta, Colo. 81416 <br /> <br /> <br />Office: (303) 874-7561 <br />Mine: (303) 856-6402 <br />March 19, 1985 <br />C'•Ii,ED IAND f "tl:iA'r).f1TIG•.`. • ~ ~!~;uy <br />Tom Gillis. .'f~O. D2pt C; N~Iir'si n; ..,.~. a <br />Reclamation Specialist <br />Colorado Mined Land Reclamation <br />1313 Sherman Street, Room 423 <br />Denver, CO 80203-2273 <br />Re: File ~ C-034-81, Completion of the extension work on the sediment pond <br />Dear Toms <br />Enclosed are photos of various stages of the sediment pgnd extension. The three <br />photos from the fall of 1984 show tha extent of excavation at that time. The <br />slopes were too steep on the north end and a oofnt om ehe east side needed further <br />excavation. The backhoe shown was not available the next day and by the time <br />another one of that size was available the weather wasn't suitable. The rip-rap <br />was not installed at that time because of the additional excavation needed. <br />Work started again February 22, 1985, and excavation was completed on Frbruary <br />26. Rip-rap was installed on March 9, 1985. Photos are enclosed to show the <br />completion of the excavation and the completion of the rip-rapping. Aa noted <br />on the phone March 11, there are still piles of dirt to be moved to the design <br />placement site and seeding still needs to be done. <br />Another factor in the delay of completion was the finding that design Eor the <br />expansion of. the pond was dote using a 10 year 24 hour event of 2.2'', and <br />closer interpolation °rom Figure S-7 in Peak Flows in Colorado, an SCS publi- <br />cation March 1980, showed 1.7" for the event. The pond would have been large <br />enough prior to the `all excavation. The question then was should I redesign <br />the pond according to the new number or finish the pond as designed. This <br />point was discussed briefly with Candace Thompson in her December 1984, inspection. <br />The contractor had been scheduled to complete the excavation on February 22, <br />prior to the issuance o` the NOV on February 20. The work hadn't been forgotten, <br />it had been delayed pending suitable ground conditions. <br />Yours trul <br />~' ~~ <br />Lar M. Reschke, <br />Mine Engineer <br />lmr <br />cc Dale Femaick <br />