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Well 81-01 sulfate, manganese and iron concentrations were above <br />the baseline water quality levels for this well and are also above the <br />basic standards of groundwater. Calcium and chloride <br />concentrations were above the baseline levels and below the basic <br />standards for groundwater. Sodium levels are also above the <br />baseline water quality levels. Magnesium concentrations were the <br />highest ever recorded at this location. <br />Regarding the Twenty Mile Sandstone; concentrations in Well 259 <br />are within historic ranges and consistent with baseline water quality <br />concentrations. <br />The No. 9 Mine Well exhibitied the highest concentration of sulfate <br />and was above the basic standards for groundwater. Magnesium, <br />sodium, chloride, boron, and calcium concentrations were also the <br />highest recorded. <br />Regarding the Williams Fork Alluvium well AVF-3, concentrations <br />were within the baseline water quality levels. Well AVF-5 exhibited <br />sulfate concentrations above basic standards for groundwater and <br />within historical ranges. Manganese and selenium concentrations <br />were the highest measured in AVF-5. Only manganese was found <br />to be above the basic standard of groundwater. However, the <br />baseline levels were also above the standard. Well AVF-6 water <br />quality was within historic concentration ranges. The MCM report <br />states that no impact on alluvial water quality has occurred. <br />MCM did not provide an explanation for any of the maximum <br />concentrations observed in the wells mentioned above and the cause <br />of the elevated concentrations remains unclear. Additional analysis <br />may be warranted in the future to determine if they are mine <br />related <br />Section 4.05.13(1) of the Regulations requires the establishment of <br />one or more ground water points of compliance (wells), for an <br />operation possessing the potential to negatively impact ground water <br />quality. It does not appear ground water points of compliance wells <br />have been established for this site. However, the Middle Sandstone <br />in well TR-7a and the Williams Fork alluvium in well AVF-5 are <br />monitored. Well TR-7a is within the expected bedrock flow path of <br />mine leachate, should the mine discharge leachate to bedrock units. <br />The AVF-5 well is within the expected alluvial flowpath of leachate, <br />should the mine discharge leachate to Williams Fork River <br />alluvium. Both wells meet the qualifications of a compliance point <br />as per qualifications listed in Section 4.05.13(1)(b) of the Rules. <br />Monitoring data from both wells indicate the mine has likely not <br />caused an exceedance of the Basic Standards for Ground Water. <br />According to section 2.04.7 of the permit, for the Williams Fork <br />Alluvium; dissolved solids, iron, lead, manganese and sulfate often <br />exceed the drinking water standards naturally. Monitoring data does <br />indicate that manganese levels in AVF-5 often exceed the drinking <br />water limit. <br />20. Restoration of <br />MCM turned off the mine pumps in July of 2013. Some wells <br />ground water <br />CDRMS <br />reacted to the pumps being turned off. Water levels increased or <br />recharge to <br />regulation <br />have remained stable in recent years. However, water levels in well <br />approximate pre- <br />4.05.12(3) <br />83-03 continue to decrease. <br />mining rate <br />Page 4 <br />