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~~~~~~~~~~9 <br />_~~, <br />~~~~ '~';i ~ ~~~-j <br />Colorado Yampa Coal Company I P 0. Box 774288. Steamboat Springs. CO 80477 • Telephone (303) 879-3800 <br />August 9, 1984 <br />Ma. Anne Baldridge <br />Colorado Mined Land <br />Reclamation Division <br />423 Centennial Building <br />1313 Sherman Street <br />Denver, Colorado 80203 <br />RE: Mass Movement on Area 1; Permit 79-177 <br />Dear Ms. Baldridge: <br />RECEIVED <br />AU6 221984 <br />MINED LAND RECLAMATION DIVISION <br />Colo. Dept. of Natural Resources <br />During your inspection of Energy Mine ~1, you noted the presence of <br />small areas of mass movement on Area 1 and requested that I evaluate what <br />possible causes and corrective actions are needed to stabilize the slope. <br />The winter of 1983-1984 was unusual in these respects: 1) it was a <br />record snowfall, 2) the surface layers of soil did not freeze and 3) <br />spring melt had only one peak instead of a normal two peak cycle. The <br />combination of these three events enhanced the potential for mass <br />movement in the area as evidenced by the numerous slides in Routt County. <br />Area 1 has six springs that are located ouaide of the mining area. <br />Three minor slumps were noted and occur below spring areas as presented <br />on the map, Spring Locations, Area 1; Permit 79-177. Slump A occurs <br />adjacent to spring 5 and 6. The fracture line of the movement is <br />approximately 55 feet in length with an average 2.0' face and 4.0' <br />displacement. There has been a minor slump in [his general area every <br />spring since reclamation operations were completed in 1981. The Division <br />requested that monument markers be placed in the general area of the <br />slump in 1982. The markers were set in place and show no movement, but a <br />slump occurred downslope of the markers. The area upslope and <br />surrounding the slump area does not exhibit any signs of movement. Slump <br />B is located adjacent of spring 3, is approximately 60 feet in length, <br />with an average 2 foot face and 2-3 foot displacement. Slump B occurred <br />on an area that was never mined and the only disturbance vas topsoil <br />removal. The rock strata in that area is made up of shales that are <br />susceptible to weathering when exposed. Slump C is located adjacent to <br />spring 1, and is approximately 30' long with only a minor displacement. <br />The movement in Area 1 was caused by saturation of the soils and strata <br />from adjacent springs and spring melt after an atypical winter season. <br />