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The Division compared the 2020 monitoring results for each <br /> well with the Basic Standards of Ground Water and the <br /> Baseline Water data tables provided in Tables 14 to 20 in the <br /> Williams Fork Mine permit. <br /> Regarding the Middle Sandstone well TR4; conductivity, <br /> sodium, sulfate,chloride, and boron concentrations were <br /> elevated compared with baseline levels and are below the <br /> maximum levels recorded at the site. The pH levels were <br /> above the drinking water standards and within baseline levels. <br /> Well TR-7a is within the expected flow path of mine leachate. <br /> Well TR-7a data indicates the parameters monitored at this well <br /> are within their baseline water quality levels. The pH levels at <br /> this well were above and below the drinking water standard and <br /> within the baseline levels. <br /> Well 81-01 sulfate,manganese and iron concentrations were <br /> above the baseline water quality levels for this well and are also <br /> above the basic standards of groundwater. Calcium and <br /> chloride concentrations were above the baseline levels and <br /> below the basic standards for groundwater. Sodium levels are <br /> also above the baseline water quality levels. Magnesium <br /> concentrations were the highest ever recorded at this location. <br /> Regarding the Twenty Mile Sandstone;concentrations in Well <br /> 259 are within historic ranges and consistent with baseline <br /> CWQCC water quality concentrations. <br /> 19. Basic Standards for Ground Water regulationsMagnesium, sodium,chloride,boron, sulfate and calcium <br /> 41.4 and 41.5 showed lower concentrations than in 2019 for the No. 9 Mine <br /> Well. <br /> Regarding the Williams Fork Alluvium well AVF-3, <br /> concentrations were within the baseline water quality levels. <br /> The lowest measured value of 5mg/l was recorded for sulfates. <br /> This reading appears to be an anomaly. <br /> Well AVF-5 exhibited sulfate concentrations above basic <br /> standards for groundwater and within historical ranges. <br /> Manganese concentrations were the highest measured in AVF- <br /> 5. Only manganese was found to be above the basic standard <br /> for groundwater. However,the baseline levels were also above <br /> the standard. Well AVF-6 water quality was within historic <br /> concentration ranges. The MCM report states that no impact <br /> 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 <br /> cause of the elevated concentrations remains unclear. <br /> Additional analysis may be warranted by MCM in the future <br /> to determine if they are mine related <br /> Section 4.05.13(1)of the Regulations requires the <br /> establishment of one or more ground water points of <br /> compliance (wells),for an operation possessing the potential to <br /> negatively impact ground water quality. It does not appear <br /> round water points of compliance wells have been established <br /> Page 4 <br />