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Executive Summary .... ::.....:.......:...:......:... ..:........<:<....r;:;:s.:.::::~xx~x:c:z;:.;.:::•:x:.a-xa...:.^.:, rr:.v.::...,..,...:...::.~...:::;:~.:..,......,....:.ems.,.:c:zr::...:;:::~:...~::~.:::,:~:::;:::.::.::: ~:~: ..:....:....:.:...:.:....... ~.:.:.:.:,.,.....:.:.. c::::,: 2.,. ..:..:. ..... n... ,..:......:.~.. ,,..,.... x.:::..a;.x;~ • Western Fuels-Utah, Inc. (WFU) operates the Deserado Coal Mine located approximately eight miles east of Rangely, Colorado. Coal produced from the mine is washed prior to shipment and refuse material is placed in refuse disposal azeas. These areas must be covered with four feet of non-toxic and non-combustible material prior to revegetation. Adequate quantities of cover material aze not readily available and WFU plans to apply for a variance from the four foot cover requirement. In 1990, WFU and the Colorado Division of Minerals and Geology (DMG) reached agreement on a proposal to demonstrate that successful reclamation could be accomplished with less than tour feet of soil cover material. Four test plots on each of the north (N1 to N4) and south (S1 to S4) aspects were established on the RP-1 refuse disposal area. Each plot measured 30 meters square and soil cover over refuse on each of the four plots for a given aspect varied from 12, 24, 36, and 48 inches on plots N1 through N4 and S1 through S4, respectively. Twelve inches of topsoil was applied to each plot while 12. 24, and 36 inches of subsoil was applied to the 2, 3, and 4 foot cover lifts, respectively. Representative samples of refuse, subsoil and topsoil were analyzed during construction to determine potential problems with the growth medium. Following placement of topsoil, the azea was seeded and mulched with the approved sagebrush/grassland seed mixture. The first yeaz of data collection for the revegetation analysis occurred in 1992. Vegetative cover • consisted of primazily annual forb species with some perennial grasses. Cover varied from 57.8 percent on test plot Nl to 79.1 percent on test plots N2 and N3. Annual forbs accounted for over 90 percent of this cover. This is typical of recently reclaimed areas. No woody stems were recorded in the transect data. The second year of vegetative analysis (1993) indicated that the plots were maturing as annual forbs declined significantly while perennial grasses increased significantly. However, total vegetative cover decreased to 11.2 percent on test plot N 1 to 50.8 percent on test plot N3. Results of herbaceous production samples collected also indicated a mixttue of annual and perennial species being dominant on the test plots. Few woody stems were observed on the test plots during this second year. The third and final yeaz of vegetative analysis (1995) indicated an invasion of annual cheatgrass and the annual forb tumble mustazd. Total vegetative cover increased to 60.3 percent on test plot N1 to 88.2 percent on test plot N4. However, annual grasses and forbs accounted for the majority of this cover. Perennial grasses, perennial forbs and shrubs were also noted to be increasing over the previous two assessments. Herbaceous production weights also increased in both annual and perennial species over that recorded in 1993. Woody stem density increased, however, the density is extremely low compazed to the reference plot. Rooting depth of woody stems was also examined during 1995. Most shrubs were small and rooting depths did not extend into the refuse material. Only one plant was analyzed on test plot Sl extending into refuse material which did not impede root development. • Sampling on the sagebrush-wheatgrass reference plot was also conducted in 1995. Comparison of the data indicates that total vegetative cover is higher on the test plots, however, perennial 7)fi.02' I ~e~~rpt3 ^1