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Surface Water Impacts <br /> Surface water flow and quality are monitored in the Flume System, Johnson Gulch, <br /> No Name Gulch,Ute Gulch, Pyeatt System, Oak, Gulch, Horse Gulch and Deal <br /> Gulch. Generally, Johnson,No Name East Pyeatt and Middle Flume gulches <br /> exhibit flow over the course of the year. The most noticeable change in surface <br /> water quality resulting from mining activities constitutes increased levels of total <br /> dissolved solids (TDS). TMI expects higher TDS in some surface water runoff <br /> for a few years after reclamation in an area. Increased TDS levels occur <br /> periodically when the contribution from precipitation and snowmelt is at a <br /> minimum (base flow conditions). <br /> Conductivity, TDS and major constituents tend to increase as the ground water <br /> contribution comprises a larger portion of flow. For a detailed analysis of surface <br /> water impacts,the 2019 Annual Hydrology Report, Section 2.5 of the permit <br /> presents the most current information. <br /> Leachate that may discharge from the toe of the Horse Gulch Fill probably will <br /> cause an increase in the dissolved solids content of natural stream flows in Horse <br /> Gulch. Rain or snowmelt provides most natural surface water flows in Horse <br /> Gulch. Although loading of Horse Gulch surface flows with dissolved solids from <br /> the fill would be a local impact, it does not rise to the level of material damage <br /> because use or potential use is not likely to be impaired. An exceedance of an <br /> instream standard in Horse Gulch is unlikely because leachate from the fill will <br /> probably be alkaline (like all other Trapper leachates)and is not likely to contain <br /> high concentrations of the inorganic or metals constituents for which there are <br /> numeric standards in Horse Gulch. <br /> Ground Water Impacts <br /> The 2019 Annual Hydrology Report AHR), Section 2.5 of the permit presents the <br /> most current information regarding springs and seeps at TMI. Table B-2 Appendix <br /> B presents the 2010 -2019 water quality data for springs and seeps at Trapper Mine. <br /> Flow from the springs and seeps is shown on Table B-2. The table indicates that <br /> only the East Pyeatt discharged during 2019 at a rate exceeding 5 gallons per <br /> minute,the minimum for collecting a sample. <br /> The NPDES permit#CO-0032115 issued by the Colorado Department of Public <br /> Health and Environment describes water quality monitoring requirements. Pit <br /> dewatering occurs in L,N Pits, and well dewatering in the G Pit wells. All pit water <br /> is routed to NPDES drainage systems with discharges monitored at the approved <br /> outfall. Dust suppression for the main haul road consumes all the water yielded <br /> from dewatering activities. Currently a number of the listed outfalls encompass <br /> Phase III bond released areas and therefore are no longer subject to DRMS <br /> monitoring requirements. <br /> IV. Topsoil <br /> Soil information can be found in Section 2.6,Volume II and Section 4.9,Vol. IV. <br /> 17 <br />