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Future SPLP tests of the tailings will be conducted quarterly or more frequently if there is any reason to believe <br />that the tailings chemistry has changed. If the mine operation is suspended for any reason, the quarterly SPLP <br />testing will also be suspended. The results will be reported to the Division in the Annual Report unless there is a <br />non-compliance issue, which will be reported immediately after it is identified. <br />b) Compaction and Placement of Tailings <br />There are strict requirements for the moisture content of the tailings, compaction and mixing with waste rock. <br />All of this is discussed in detail in Section 7 of this Report. These requirements further reduce any possibility that <br />the tailings could leach any acid or toxic forming material into Sneffels Creek. <br />c) Ground Water Wells <br />In order to determine baseline chemistry of the ground water near the downstream toe of the two tailings <br />embankments (Revenue Pile and Atlas Pile), three sets of wells were installed at agreed locations. Two sets were <br />installed at the Revenue Pile and one was installed at the Atlas Pile. During the construction of the wells in 2014, <br />two separate zones of water were seen so that each well had two zones of completion; a lower and an upper <br />zone. It was agreed that both zones would be tested from each well quarterly to establish the baseline <br />conditions. This was done and the results were used to provide a baseline standard, which was submitted to the <br />Division and ultimately approved in 2014. In some cases, the highest level recorded in the baseline tests were <br />multiplied by 125% to arrive at the well standard. In other cases, such as pH, the well standard was fixed at pH <br />6.0-9.0. All of the well standards and quarterly results are included in Appendix 3 of this Report. Recent well <br />tests have shown that current ground water quality is within the limits set in the well standards. Both zones in <br />all three wells will continue to be monitored on a quarterly basis to ensure that the water quality in the ground <br />water below the tailings embankments are in compliance with the standards. <br />6. Tailings and Waste Rock Handling and Final Placement <br />Tailings from the milling process have a size range from approximately 100 mesh to below 200 mesh, as a result <br />of ball mill grinding. After the metal sulfides are extracted in the flotation cells, the tailings slurry enters the <br />18,000 gallon tank inside the mill tunnel. The slurry is then pumped to the thickener across the bridge where a <br />large portion of the water is extracted. The remaining slurry is then pumped back to the 18,000 gallon tailings <br />tank in the filter building, where it is then pumped to the filter presses where remaining water is squeezed out, <br />and the tailings drop into either one of two filter bays, which are separated by a concrete wall. A backhoe or <br />small loader is used to enter the filter bays and load them into trucks which haul the tailings to either the <br />Revenue Pile (immediately west of the mine portal) or the Atlas Pile, which is on the west side of Atlas Creek. <br />The trucks must utilize County Road 26 to reach this pile. Prior to removal from the filter bays, tailings are <br />checked to see if they have the proper moisture content to allow compaction in the piles. Samples of the tailings <br />Revenue Mill Certification Page 18 of 20 <br />