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' Annual Hydrology Repoct April 28, 1988 Page 18 ' Lower Refuse Pile During 1987, mine development waste from the underground mining operations was ' placed in the lower refuse pile. The lower refuse pile was permitted for permanent disposal of some 1.7 million cubic yards of mine development waste, coal processing waste, and sediment pond cleanout material. In 1987 ' approximately 52,400 tons (46,765 cu. yd.) was placed in the lower refuse pile in the phase I, II, and III azeas. Most of the material was placed in the phase III azea. Table 2.1-1 shows sampling results from monitoring well GP-1 as well as baseline data from the well. Hased on these sample results, the lower refuse pile does not appear to be impacting the groundwater zone near Sylvester Creek. Due to Ehe low permeability of the colluvial soil and the fact that no groundwater table exists near the surface in the oolluwim (except along the ' margin of Sylvester Creek) it is not anticipated that any significant future impacts to the groundwater regime will occur. ' Refuse pile monitoring wells GP-3 through GP-5 remained dry throughout water year 1987. There was no flow from the tce underdrain during water year 1987; therefore, no ' sample data is available. Conductivity and TDS from samples of monitoring well GP-1 were closely monitored ' since conductivity was slightly higher than the baseline samples in some instances during 1986. This does not appear to be a problem as TDS values are well within the baseline values and conductivities are within the correlation ranges for oanparison with TDS. The amount of refuse material placed in the lower refuse pile is highly dependant on conditions encountered in the mine. Projected refuse production ' for 1988 is the same as 1987 approximately 53,000 tons. It is likely work will begin in 1988 on the prepazation of the phase IV area or ' at least a portion of the phase IV area, to receive refuse material. Phase IV consists of a portion of the hillside azea and the south underdrain, as well as an alternate access road. This area is permitted and bonded at present. ' 2.2 Assessment of Springs Five spring in the Northern half of the Dry Fork of the Minnesota Creek Hasin ' are monitored monthly for flow. Six springs located above the F Seam in the North Fork of the Gunnison River drainage are monitored monthly for flow, and five springs in or below the F Seam are monitored quarterly for flow and semi- ' annually for quality. Table 1.2-1 contains a list of all monitored springs. Exhibit I shows the locations of the springs. Some data was lost during 1987 due to the sites being inaccessible. Sites becortte inaccessible for weather reasons, especially during the spring, winter, ' and early fall months. Landslides in the lease area have also caused access problems. The spring flow bar graphs, located in Appendix D, reflect collected data for the springs frown 1979 to 1987. The quazterly hydrology reports contain ' data and explanation of monitoring.