Laserfiche WebLink
wastes is being limited through (1) compacting the waste in two-foot lifts, <br />(2) covering the refuse pile with non-toxic cover, (3) providing permanent <br />surface diversion of surface runoff from undisturbed areas around the pile, (4) <br />collecting and treating all surface drainage flowing over the pile during <br />construction and reclamation, and (5) benching and sloping the pile such that <br />erosion and infiltration of the final pile is minimized. <br />The refuse pile was constructed on top of thin alluvium of [he old stream <br />channel which supplies drainage of ground water beneath the pile. The pile <br />was constructed over the relatively impermeable Mancos Shale Forma ion and <br />not over any aquifer. Therefore, the impacts of the refuse pile on the quality <br />of ground water should be minimized and should not cause material damage <br />to any ground water currently in use. <br />Waste water from the coal wash plant was recycled back into the coal <br />washing facility after fines settled out in upper and lower settling ponds. This <br />water recycling system increased the total dissolved solids in the water <br />through exposure of the water to fines and through evaporation. The ponds <br />that were used in this water recycling system are unlined and are located on <br />or are hydrologically adjacent to the Nortlt Thompson Creek alluvium. Thus, <br />these ponds posed a potential for the degradation of the alluvial water quality <br />directly and, indirectly, the surface water quality of North Thompson Creek. <br />Alluvial monitoring well D-lA below the refuse pile has a water chemistry <br />markedly different from that in North Thompson Creek. The refuse pile <br />piezometer D-lA shows conductivities around 4000 microohms per cubic <br />centimeter, a level that has remained relatively steady for the last several <br />years. The level at the initiation of monitoring in 1980 was near 3000. <br />Refuse pile piezometer D-2A, located up-gradient of D-lA, has reached a <br />maximum level of electrical conductivity between 1190 and 2700 in 1997, <br />levels about the same as those found historically. This indicates that the <br />groundwater does apparently pick up dissolved constituents as it passes below <br />and past the refuse pile. However, the groundwater already contains an <br />amount of dissolved salts considerably greater than the surface water in North <br />Thompson Creek. <br />The water used at the loadout site was pumped from wells completed in the <br />Roaring Fork alluvium. The withdrawal of this ground water was small and <br />covered under a plan of augmentation which minimized impact to the quantity <br />of alluvial ground water. There has been no evidence of any adverse impacts <br />to the ground water quality at the loadout site. <br />2. Surface Water <br />One of the potential impacts associated with most mining operations is <br />i~ <br />