Laserfiche WebLink
<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />1 <br /> <br />Executive Summary <br />.. .....:._. ..., ........~.,2.:.~,::.:.:..r.::. ~ ::.::::::,.r <br />Western Fuels-Utah, Inc. (WFU) operates the Deserado Coal Mine located approximately eight <br />miles east of Rangely, Colorado. Coal produced from the mine is washed prior to shipment and <br />refuse material is placed in refuse disposal areas. These areas must be covered with four feet of <br />non-toxic and non-combustible material prior to revegetation. Ade uate quantities of cover /~~C~ <br />material are not readily available and WFU plans to apply for a variance from a four foot cover <br />utrement. <br />In 1990, WFU and the Colorado Division of Minerals and Geology (DMG) reached agreement <br />on a proposal to demonstrate that successful reclamation could be accomplished with less than <br />four feet of soil cover material. Four test plots on each of the north (Nl to N4) and south (SI <br />to S4) aspects were established on the RP-1 refuse disposal azea. Each plot measured 30 meters <br />square and soil cover over refuse on each of the four plots for a given aspect varied from 12, 24, <br />36, and 48 inches on plots Nl through N4 and S1 through S4, respectively. Twelve inches of <br />topsoil was applied to each plot while 12, 24, and 36 inches of subsoil was applied to the 2, 3, <br />and 4 foot cover lifts, respectively. Representative samples of refuse, subsoil and topsoil were <br />analyzed during construction to determine potential problems with the growth medium. Following <br />placement of topsoil, the area was seeded and mulched with the approved sagebrush/~rassland <br />seed mixture. <br />The first year of data collection for the revegetation analysis occurred in 1992. Vegetative cover <br />consisted of primarily annual forb species with some perennial grasses. Cover varied from X7.8 <br />percent on test plot N1 to 79.1 percent on test plots N2 and N3. Annual forbs accounted for over <br />90 percent of this cover. This is typical of recently reclaimed areas. No woody stems were <br />recorded in the transect data. <br />The second year of vegetative analysis (1993) indicated that the plots were maturing as annual <br />' forbs declined significantly while perennial grasses increased significantly. However, total <br />vegetative cover decreased to 1 1.2 percent on test plot N 1 to 50.8 percent on test plot N3. Results <br />of herbaceous production samples collected also indicated a mixture of annual and perennial <br />' species being dominant on the test plots. Few woody stems were observed on the test plots during <br />this second year. <br /> <br /> <br /> <br /> <br /> <br /> <br />The third and final year of vegetative analysis (1995) indicated an invasion of annual cheatgrass <br />and the annual forb tumble mustard. Total vegetative cover increased to 60.3 percent on test plot <br />N1 to 88.2 percent on test plot N4. However, annual grasses and forbs accounted for the majority <br />of this cover. Perennial grasses, perennial forbs and shrubs were also noted to be increasing over <br />the previous two assessments. Herbaceous production weights also increased in both annual and <br />perennial species over that recorded in 1993. Woody stem density increased, however, the density <br />is extremely low compazed to the reference plot. Rooting depth of woody stems was also <br />examined during 199. Ivfost shrubs were small and rooting depths did not extend into the refuse <br />material. Only one plant was analyzed on test plot SI extending into refuse material which did <br />not impede root development. <br />Sampling on the sagebrush-wheatgrass reference plot was also conducted in 199. Comparison <br />of the data indicates that total vegetative cover is higher on the test plots, however, perennial <br /> <br />