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and GW-3R downgradient of Mine Water Pond 2. A more detailed description of groundwater <br /> monitoring and quality can be found in Exhibit U. <br /> 2.3 Dewatering and Stormwater Management <br /> Historically, Sunshine Mining Company had a Colorado Discharge Permit System (CDPS)permit for <br /> Revenue Portal discharge in 2001. Whole effluent toxicity testing demonstrated no adverse effects to <br /> aquatic life, allowing the permit to be abandoned with no further action. <br /> A new CDPS permit(No. CO-000003)was obtained in 2015 and renewed in August 2018. The current <br /> permit is in administrative extension. Water from the Revenue Mine is treated prior to being <br /> discharged to Sneffels Creek. The 2018 renewal added a new Outfall 002A as well as a Five-Stage <br /> Passive Treatment System, which was approved by DRMS in TR-10. The treatment system was <br /> designed and tested to meet both DRMS and CDPS requirements for water quality and to function into <br /> closure with minimal maintenance, low waste production, limited power requirements, and strong <br /> aesthetic value. The five stages are (1) chemical flocculant to settle suspended solids (2) settling and <br /> sand filtration in Mine Water Pond 1, (3) sulfate reducing bioreactor located in Mine Water Pond 2, (4) <br /> aeration through a combination of open channel and HDPE pipe, and (5) aerobic wetlands in Mine <br /> Water Pond 3. A detailed description of the mine water treatment system can be found in Exhibit U. <br /> The Revenue Mine also maintains a stormwater certification No. COR-040289 pursuant to CDPS <br /> general permit No. COR-040000, which is in administrative extension. Stormwater is diverted around <br /> the site through a series of ditches and channels where possible. Stormwater captured on site is <br /> diverted either to Mine Water Pond#2 or to a low spot near the main entrance where it infiltrates or <br /> evaporates. Stormwater best management practices are detailed in the mine's Stormwater Management <br /> Plan (SWMP), which is provided in Appendix 2. Surface runoff from the Revenue TSF is captured <br /> within Mine Water Pond #2. Surface runoff from the Atlas TSF is controlled by a sediment pond <br /> constructed alongside the Atlas TSF. <br /> 3. Project Water Requirements <br /> Water used during development, operations and reclamation is sourced from groundwater collected <br /> within the mine. Ouray Silver Mines maintains two water rights, which include 24.74 acre feet from <br /> Lake Reservoir and 3.34 c.f.s. or 1500 gpm from the Sneffels Creek drainage (see Appendix 3 Water <br /> revenue Mine December 2021 G-4 <br />