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In 2018 water levels at all monitored bedrock and alluvial wells were within historic ranges. A cursory <br /> review indicates the water levels remain within the historic range in 2019 as well.Additional evaluation <br /> 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 <br /> display water level fluctuations in response to groundwater inflow from the reclaimed mine pits and <br /> recharge from precipitation where the units outcrop.This suggests the reclaimed area has re-saturated <br /> and sufficient infiltration rates and recharge capacities have been established. Additional water quantity <br /> information, including a summary of the water levels measured and hydrographs of the active <br /> monitoring wells at Seneca II-W can be found in the groundwater section and Appendix C of the 2018 <br /> Annual Hydrology 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 <br /> bedrock groundwater quality. Disturbance to adjacent surface water bodies were minimized through <br /> the proper utilization of drainage and sediment control structures. As discussed in detail above the <br /> discharges from the mines site meet the NPDES permitted limits and the receiving streams meet all <br /> applicable surface water quality standards except for the occasional excursion of total recoverable iron <br /> within the Dry Creek Drainage (CDPHE Yampa Segment 13d).The elevated iron is strongly correlated <br /> with suspended solids in the streams water column. Multiple concurrent NPDES outfall and receiving <br /> stream sampling events indicate that the elevated iron is unrelated to the discharges from the mine site <br /> and is the result of natural erosion processes that are occurring within the unaffected portion of the Dry <br /> Creek drainage area.Total dissolved solids within the receiving streams have remained below the <br /> concentrations predicted within the Probably Hydrologic Consequences and the streams water uses <br /> 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 />