Laserfiche WebLink
A summary of groundwater well water quality from June 2014 through September 2021 is <br /> presented in the attached Table U-6. <br /> A five-stage passive water treatment system became operational in May 2021 to treat mine water <br /> exiting the Portal at UG-5. The treatment system, described in detail in Section 9.3 of this <br /> Exhibit U, was designed and tested to meet both DRMS and CDPHE requirements for water <br /> quality and function into closure with minimal maintenance, low waste production, limited <br /> power requirements, and positive aesthetic value. Analysis of the Passive Mine Water Treatment <br /> is performed voluntarily to inform systems operations and best management practices. <br /> Compliance of mine discharge with is evaluated under CDPS Industrial Wastewater permit CO- <br /> 0000003. <br /> Table U-7 Water Quality Data from Mine Water Treatment System (Outfall 002A) <br /> Non-detect Sample <br /> Analyte Units Minimum Maximum Average Count Count <br /> Arsenic,total recoverable mg/L 0.0016 0.0101 0.0040 4 4 <br /> Bicarbonate as CaCC3 mg/L 51.3 51.3 51.3 1 1 <br /> Cadmium,potentially dissolved mg/L 0.00015 0.00227 0.00077 17 17 <br /> Cadmium,total mg/L 0.000651 0.008 0.003 4 4 <br /> Carbonate as CaCC3 mg/L 2 2 2 1 1 <br /> Chromium,total recoverable mg/L 0.0005 0.0027 0.0011 4 4 <br /> Chromium,Trivalent Total <br /> Recoverable mg/L 0.005 0.005 0.005 4 4 <br /> Copper,potentially dissolved mg/L 0.0008 0.0102 0.0022 17 17 <br /> Copper,total mg/L 0.00114 0.0144 0.0073 4 4 <br /> Cyanide,WAD mg/L 0.003 0.003 0.003 17 17 <br /> Dissolved Chromium,Hexavalent mg/L 0.005 0.005 0.005 5 5 <br /> Hydroxide as CaCC3 mg/L 2 2 2 1 1 <br /> Iron,total recoverable mg/L 0.06 5.59 0.81 17 17 <br /> M-2012-032 <br /> Amendment 02 Exhibit U <br /> December 2021 U-21 <br />