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{, <br />-• ~ <br />Mountain Coal Company <br />West Elk Mlne <br />Post OKxx Box 591 <br />Somerset, Cokxado 81434 <br />Telephone 970 9295015 <br />Fax 970 9245595 <br />May 1, 1997 <br />Mr. Michael Boulay <br />Colorado Division of Minerals and Geology <br />13 ] 3 Sherman Street, Room 215 <br />Denver, CO 80203 <br />RECEIVED <br />MAY 0 71991 <br />Dlvsion of Minerals a, ~aolopy <br />][tE: Spring Maintenance; West Elk Mine; Permit No. C-80-007 <br />Dear Mike: <br />III IIIIIIIIIIIII III <br /> <br />MCC is experiencing spring-time slope movement around the West Elk Mine site. I have <br />mentioned to you by telephone a few of the maintenance projects and emergency construction <br />work that is underway in an effort to control the slope movement and to protect the various <br />structures. This letter is provided to offer the Division more detail about this work. <br />MCC has identified seven projects which encompass the maintenance and emergency construction <br />projects to improve slope stability: 1) underground culverts replaced with HDPE pipe on the <br />surface from the portals to MB-1; 2) additional support for C-1 conveyor; 3) platform for high <br />voltage tower at substation; 4) install of a rock/tensar buttress below middle mine access road; 5) <br />replace MB-1/FW-1 discharge culverts below the screening plant; 6) underground water line from <br />raw water intake gallery to FW-1 replaced with HDPE pipe on the surface; and 7) extend the <br />current RCC buttress below the screening plant. All of these projects are at various stages of <br />completion and are further described below. <br />UnderQrourrd culverls replaced wi/h s7trjrace pines {rom portals toMB-1 - Culverts Cl-l, <br />Cl-2 and Cl-2A are being replaced with 24-inch HDPE pipe laid on the surface from above <br />the portals to MB-1. The underground culverts have been in existence since the mine was <br />constructed and most likely have deteriorated. With the slope movement in this area, some <br />culverts have also pulled apart in a number of places and have required replacement. Rather <br />than replace the culverts in the ground and risk that they may pull apart again and contribute <br />unnecessary water to the slope, MCC has opted to put the pipes on the surface so that if <br />leaks or breaks occur they can be seen and taken care of immediately. MCC has chosen to <br />utilize I-IDPE which is somewhat flexible and very durable. The pipe has been buried in the <br />two locations where it crosses roads and for approximately 25 feet above MB-1. The <br />existing culverts will be removed and the area regraded and seeded or the culverts will be <br />filled with flow-fill (low compressive strengh concrete) in areas where they are too deep, <br />dangerous and difTicult to remove. <br />