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occur during the permit term are discussed in this section followed by an assessment of cumulative hydrologic impacts. Surface water and ground water are considered separately in each discussion. Probable Hydrologic Consequences Effects on Surface Water The surface water effects discussed are related only to Bolton Draw, as this is the only receiving stream for waters leaving the Canadian Strip Mine site. Probable hydrologic consequences are limited to a change in the timing of stream flow and minor changes in water quality as a result of the sediment ponds located on the mine site. It is not expected that the total amount of water will be reduced significantly by evaporation of water contained in the ponds. More likely there will be only a change in the timing of runoff leaving the mine site as a result of temporary storage and detention of runoff in the two detention ponds. Surface water quality effects due to mining were identified as a potential for increased salt loading. The extent of mining has been decreased from that originally proposed, as Pit 2 will not be developed. The pumpage of pit water with elevated total dissolved solids (TDS) concentrations relative to surface water levels will not occur as originally projected. With the continued establishment of vegetation on previously reclaimed portions of the mine site, and the additional reclamation activities which will occur during the permit term, the effects on surface water quality are considered to be negligible. Effects on Ground Water During mining, the Canadian Strip Mine open pit induced inflows from the undisturbed Sudduth Coal, as well as the adjacent underburden and overburden. The inflow to the pit from these sources was estimated to be less then two gallons per minute. This inflow has locally lowered, and may continue to lower the potentiometric surface in these units. It is not thought that this depletion of head will be areally extensive due to the relatively impermeable nature of these units. Over time it appears that the inflow to the inactive pit (pit No. 1) stabilizes to the point where loss to evaporation is equaled but not exceeded by aquifer inflows, as evidenced by the relatively constant water level in pit No. 1. The hydrologic consequences of the mining operation during the previous permit term were minimal. Some inflow to the currently open pit were realized, however due to the hydrogeologic characteristics of the Sudduth Coal and its under- and overburden, inflow was minimal. As no water supply wells are completed in these units, no impacts to local water users have been observed. Furthermore, no springs em4'rtating from these units in the area of the mine have been identified. The currently open pit is spatially removed from the Bolton Draw alluvium, therefore, no inflows from or depletion of this aquifer has occurred. The probable hydrologic consequences of implementation of the proposed reclamation plan during the forthcoming permit term are limited. 13