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Compliance with Basic Standards for Ground Water (Regulation 41 of the Colorado Water <br />Quality Control Commission) <br /> <br /> Section 4.05.13(1) of the Regulations requires the establishment of one or more ground <br />water points of compliance (well) for an operation which has the potential to negatively <br />impact the quality of groundwater. The Wadge overburden and the Twentymile Sandstone <br />are the two major aquifers most likely to be affected by the Foidel Creek Mine. The <br />following wells serve as the Foidel Creek Mine’s groundwater points of compliance: <br />97013TM (Twentymile sandstone), 008-77-58 (Wadge overburden), 008-AU3 (Fish Creek <br />alluvium), and 008-AT-1 (Trout Creek alluvium). The mine’s annual hydrology reports <br />contain long-term data from these wells. These data show Foidel Creek Mine is in <br />compliance with the Basic Standards for Ground Water at the groundwater points of <br />compliance. <br /> <br /> Surface water <br /> <br /> Several possible effects on the surface water system have been identified: <br /> <br /> Discharge of mine inflow water to surface water drainages <br /> <br /> Mine water discharged to the surface system will increase the conductivity, total dissolved <br />solids (TDS), and sulfate and iron concentrations in the streams receiving the discharge. <br />Total suspended solids, sodium adsorption ratio (SAR), and pH could also increase due to <br />these discharges. SAR may reach up to 6.2 in Fish Creek and 3.0 in Trout Creek. Sulfate <br />and conductivity impacts are predicted for various segments of the stream system to be <br />affected. TR-32 approved a plan which will allow the mine to discharge considerable <br />volumes of degraded water during high flow (high dilution capacity) and lesser or no <br />discharge during periods of low flow (minimal dilution capacity). <br /> <br /> Lower Middle Creek – Impacts in the Lower Middle Creek from the confluence with <br />Foidel Creek to the confluence with Trout Creek will be pronounced due to relatively <br />small instream flows. There is no sulfate or irrigation standard over this reach. However, <br />due to standards on Trout Creek immediately below this segment, impacts will be <br />minimized during most times of the year. <br /> <br /> Lower Fish Creek – The potential for significant impacts to lower Fish Creek, from mine <br />water discharge site 115 (Fish Creek dewatering facility) downstream to the confluence <br />of Fish Creek with Trout Creek, exists. Although no sulfate standard applies over this <br />reach, Fish Creek and adjacent alluvial valley floor areas are held to a 1500 umhos/cm <br />material damage standard for irrigation waters. Modeling indicates that during low flow <br />periods, the instream conductivity limit of 1500 umhos/cm could be exceeded. <br />Therefore, the applicant has committed to maintain its mine water discharge rate from <br />site 115 at a level which would prevent material damage (<1500 umhos/cm) by <br />measuring upstream flow and quality and computing a discharge rate which would <br />prevent downstream exceedance of the conductivity limit for irrigation waters. The <br />sulfate standard for drinking water of 250 mg/l does not apply over this reach. <br /> <br /> <br /> <br />19 <br /> <br /> Foidel Creek MineOctober 8, 2013 <br /> <br />