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• These standards and discharge analyses are contained in Exhibit 22, NPDES Permit and in the Annual Hydrology Reports. Loner term Hydrologic Impacts. Following the completion of mining, flooding of the workings will allow the water table to rise again, and result in the re-expression of springs. Physically, the overburden and the coal seam may act as a unified unit, due to the rubbilization associated with subsidence, and the recharge area for this new, thicker, water bearing zone will increase to include the area over the mine workings. Alternatively, the recharge area may stay the same, as the fine grained sediments in the intergrading sandstone, siltstone, and shale sequences within the overburden may fill the fracture zones, thereby healing them. The 1980 WWL Report estimated that the potentiometric surface will recover to the original level of water in the coal (page 56). Hole LA 221 had a water level in 1976 located 304 feet above the top of the Maxwell seam of coal (1994 supplement to Exhibit 8, Table 3A). The elevation of the Allen seam of coal in the approximate center of the New Elk Mine is 7150'. If the 1976 water level information is representative of the original potentiometric surface, then the anticipated equilibrium level of water in the coal seam at New Elk Mine would be 7450'. Given the approximate nature of this estimation • and the proximity of that elevation to the East Portal (7460'), Basin will install a 6" PVC pipe to discharge the current mine inflow of 0.4 cfs with 1 foot of head, in the unlikely event that discharge occurs through the portal. The water quality of the water filling the mine will reflect a mixture of five years of pumping of thickener into the mine with inflow from the coal seam and other sources. This will not materially change the beneficial uses which can be acquired from the Allen seam, as it is not acceptable for use as a domestic water source or a flood irrigation source due to salinity levels. In addition, the coal seam aquifer exceeds MLRD suspect levels for stock watering for iron, manganese and fluoride. water quality along the Middle Fork of the Purgatoire will experience a diminished water quality following the discharge of water from the flooded workings. Salinity, sulfate, and SAR levels will increase, but projections of water quality during low flow show that beneficial uses will not be compromised. Ammonia concentrations in the river concurrently exceed chronic aquatic life receiving stream standards. The discharge of water from the flooded workings is projected to improve the water slightly, but not enough to meet the standards. Table 26C delineates loading of parameters which potentially could impair uses. (Revised 2/6/95) 2.05-88