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and discussion will be included in the upcoming 2019 Annual Hydrology Report (to be submitted in <br /> 2020). Water level fluctuations are observed in both alluvial and bedrock wells. Water levels in the <br /> alluvial display seasonal fluctuations related to climatic variation. Water levels are highest in the spring <br /> after the snowmelt and increased precipitation recharge the underlying water table. Bedrock wells display <br /> water level fluctuations in response to groundwater inflow from the reclaimed mine pits and recharge from <br /> precipitation where the units outcrop. This suggests the reclaimed area has re-saturated and sufficient <br /> infiltration rates and recharge capacities have been established. Additional water quantity information, <br /> including a summary of the water levels measured and hydrographs of the active monitoring wells at <br /> Seneca II-W can be found in the groundwater section and Appendix C of the 2018 Annual Hydrology <br /> Report. <br /> The drainage channels and stock ponds that will remain in the Phase III bond release area are those that <br /> have already been approved for permanent retention and are shown on Figure 1. These will include <br /> sediment ponds 005, 006, 009, 015, 016, and 017 that are associated with NPDES permit CO-0000221. <br /> See Part B and C above for a detailed discussion of the receiving stream and NPDES outfalls water <br /> quality. <br /> H. Findings of the Protection of Hydrological Balance <br /> The disturbance of the hydrologic balance within and adjacent to the permit area have been minimized <br /> through the use of best management practices. Groundwater levels within bedrock and alluvial wells fall <br /> within historic ranges. Groundwater quality meets all applicable standards at compliance well DCAL-02 <br /> except for dissolved iron. A statistically significant change in the dissolved iron concentration (95% <br /> Confidence Limit) has not occurred at DCAL-02 since its installation in 1998 and the elevated levels are <br /> likely the ambient background concentration for this area. Groundwater point of compliance wells were <br /> deemed unnecessary based on the absence of the potential for the mine to negatively impact the bedrock <br /> groundwater quality. Disturbance to adjacent surface water bodies were minimized through the proper <br /> utilization of drainage and sediment control structures. As discussed in detail above the discharges from <br /> the mines site meet the NPDES permitted limits and the receiving streams meet all applicable surface <br /> water quality standards except for the occasional excursion of total recoverable iron within the Dry Creek <br /> Drainage (CDPHE Yampa Segment 13d). The elevated iron is strongly correlated with suspended solids <br /> in the streams water column. Multiple concurrent NPDES outfall and receiving stream sampling events <br /> indicate that the elevated iron is unrelated to the discharges from the mine site and is the result of natural <br /> erosion processes that are occurring within the unaffected portion of the Dry Creek drainage area. Total <br /> dissolved solids within the receiving streams have remained below the concentrations predicted within the <br /> Probably Hydrologic Consequences and the streams water uses have not been degraded significantly. <br /> Additional hydrology data for Seneca II-W can be found in the Annual Hydrology Reports which have <br /> been submitted to CDRMS for several decades. <br /> POSTMINING LAND USE <br /> The postmine land uses for the Seneca II-W mine are livestock grazing and wildlife habitat. Grazing has <br /> been conducted for a number of years at the mine to implement and demonstrate the postmine land use. <br /> 23 <br />