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West Elk Mine projection is consistent with previously submitted projections with the exception of build-up . schedules. The build-up schedules aze estimates, which are dependent on coal sales and mazket conditions and may change accordingly. Planning and expansion of the treatment plant will occur according to state (Colorado Department of Public Health and Environment [CDPHE]) regulations. The level of projected future maximum dischazge (0.04 mgd) is still small compared to the low flows in the North Fork, and so should not significantly affect water quality of the river. In addition, effluent from the W WTP goes through sedimentation pond MB-2R prior to dischazge to the North Fork. Effects of Subsidence The effects of subsidence from mining of the B Seam in the Apache Rocks and Box Canyon mining areas and the E Seam in the SOD permit revision area aze discussed in Section 2.05.6 (6)(e)(i). Water quality impacts from subsidence could potentially result from: (1) increased stream erosion rates due to alteration of channel slopes and geometry; or (2) cross-connection of previously isolated formations and the surface hydrologic system. The amount of subsidence predicted to result from the Apache Rocks, Box Canyon, and Sauth of Divide mining areas are discussed in Section 2.05.6 (6)(b)(i). As discussed previously in this section, the amount and pattern of change in the channel slope due to subsidence is not of a magnitude to cause significant channel degradation and erosion (see Exhibit 55 and SSA). Small adjustments could occur which would stabilize in a relatively short period of time. From the standpoint of groundwater quality effects resulting from subsidence, the key consideration is that groundwater resources which could be disrupted by the proposed mining are very limited in extent and magnitude. There is no demonstrated formation groundwater use at the mine or in the general area. There are no formations in the existing or proposed permit area that would qualify as "aquifers." As discussed in the Groundwater Quality Effects section, if groundwater moves via asubsidence-caused fracture from a higher formation to a lower formation or into the B or E Seams, the water quality change will not be significant. Groundwater Quantity Effects This section of the application defines and evaluates the hydrologic consequences related to groundwater quantity including impacts from construction of mine entries, the direct mining impacts resulting from single-seam mining (F, B and E Seams) in the original permit azea, multi- seam mining (B and E Seam), and the storage of water in previously mined down-dip sealed panels (large capacity sealed sumps). Groundwater quality effects are discussed in the following section. Readers are encouraged to review Sections 2.05.6 (3)(a-c), West Elk Mine Experience and Regional Mining Experience, of this permit document, because they contain important findings regarding groundwater from the Box Canyon Decision Document the West Elk Mine permit document, including revisions and renewals, other mines in the North Fork Valley, and the CHIA. Surface and groundwater occurrence have been studied extensively by MCC since 1976. Map 34 shows the existing hydrologic monitoring network. The groundwater network for the permit 2.05-204 Revised November 2004 PR/0