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Doc Date:12/11/2001 Annual Iydrology Report April 28, 1988 Page 9 iii iiiiiiiiiiiii iii sss ribs and damp floor were present in the 1st West Submain, Panel 1W3S, and Panel 1W4S. The 1st East Submain, although not mined a great deal, encountered damp conditions. Wet conditions in the 1st West Submain area and panels can be associated with sandstone channels directly overlying the coal seam, Lone Pine Gulch Stream Zones, and to the west lower cover in Lone Pine Gulch. The wet conditions in the 1st East Submain can be attributed to features similar to that of the 1st West Submain: sandstone channels, Sylvester Gulch Stream Zone, and low cover. Samplesiof mine discharges and mine inflows were taken during 1987. Most samples were tested for ph, electrical conductivity, total suspended solids, total dissolved solids, and total iron. Results of the samples are shown in Tables I.4-1, 1.4-Z and 1.4-4. The quality of water sampled is good and poses no problem for discharge to a sediment pond or in most cases, direct discharge to a stream or other surface feature. Mine water is discharged from the main portal area to sediment pond PIB-1 or from the Sylvester Gulch sump directly to Sylvester Creek. Quantity of water discharged or pumped from the mine is included in the Quarterly Hydrology Monitoring Reports. The mine water balance, based on some actual and some estimated flows is shown in Table 1.4-3. Water unaccounted for is lost through seepage and evaporation into the ventilating air. Roth of these losses can be substantial depending on conditions. 2.0 Areas This section contains an analysis of hydrologic data gathered during Water Year 1967; and assessment of impacts on mining on the quality and quantity of water in surface streams, springs, groundwater aquifers, mine inflows, and discharges during Water Year 1987, and an estimated of potential impacts of mining on these waters during dater Year 1988. Assessment of impacts typically involves comparison of data with baseline conditions. Since no mining activity will occur in the Minnesota Creek basin during this term of permit, monitoring data for Water Year 1987 from the Minnesota Creek basin is considered an extension of baseline monitoring. ' Surface water, springs, and groundwater are considered separately even though they are interrelated. The report attempts to show the interrelationships that are significant or could be expected. Since mine water and groundwater are so interrelated, they are discussed together. ' 2.1 Assessment of Groundwater ' Underground room and pillar mining methods, which are currently in use at the Mt. Gunnison No. 1 Mine can affect groundwater in essentially twc~ ways. First, developm?nt mining in areas where groundwater is present in or immediately 1