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'4,COLORADO LEGACY LAND <br /> $CHWARTZWALDER MINE <br /> E.S. MINE POOL MITIGATION <br /> The mine pool mitigation plan listed in this section of the 2012 Mine Permit Amendment was revised per <br /> Technical Revision#27. A summary of the revisions are provided below for reference. <br /> In 2019, a new submersible pump (60HP Goulds Model 7CSL) was lowered down the Jeffery Air shaft to <br /> approximately 400-feet below the Steve Adit on a custom fabricated housing sled via a wench system. The <br /> housing sled was designed to protect and support the pump during installation and operation. The dedicated <br /> winch system was installed adjacent to the vent shaft on a concrete footer. The new winch system allows <br /> above-ground access to the pump for maintenance and repair,which supports the long-term health and safety <br /> goal of eliminating all underground work onsite. The only change to the mine pool mitigation strategy was the <br /> upgrade and relocation of the submersible pump, no other treatment process changes were implemented. <br /> Figure E-1 shows the process flow diagram for the onsite water treatment plant. <br /> EA WATER QUALITY MONITORING PLAN <br /> The water quality monitoring plan listed in this section of the 2012 Mine Permit Amendment was reviser per <br /> Technical Revision#27. A summary of the current water quality monitoring plan is provided below. <br /> The sampling rationale for the Schwartzwalder Mine is dictated by two permits: Colorado Mining Permit# M- <br /> 1977-300 and Colorado Discharge Permit#CO-0001244. Quarterly water quality monitoring is conducted in <br /> accordance with Colorado Mining Permit#M-1977-300 and two monthly water quality monitoring programs <br /> conducted in accordance with Colorado Discharge Permit#CO-0001244. All three water quality monitoring <br /> programs are descried below. <br /> E.6.1 Colorado Mining Permit#M-1977-300 <br /> The mine permit(M-1977-300) was issued by the State of Colorado in 1977 and is currently overseen by the <br /> Colorado Division of Reclamation and Mining Safety (CDRMS). Since the 2012 Amendment there have been <br /> two Technical Revisions to Permit #M-1977-300, which define the quarterly water quality monitoring <br /> program: <br /> • Technical Revision 27 solidified the environmental monitoring requirements for surface water, <br /> groundwater,and the mine pool. Samples are collected and reported to CDRMS on a quarterly basis. <br /> • Technical Revision 29 updated the groundwater monitoring network identified in Technical Revision <br /> 27. Four shallow alluvial monitoring wells MW-1, MW-2, MW-3A, and MW-9 were removed in <br /> December 2019 as part of the alluvial valley exaction work to removed radiologically contaminated <br /> soils from the soils adjacent to Ralston Creek. <br /> Water quality samples are collected quarterly from thirteen surface water sample locations and sixteen <br /> groundwater sample locations. Table E-1 summarizes the surface water monitoring stations,which are shown <br /> in Figure E-2. Table E-2 summarizes the groundwater monitoring wells,which are shown in Figure E-3. Table <br /> E-3 summarizes the required quarterly surface water and groundwater sample analytes and field parameters. <br /> JULY 2020 10 AMENDMENT 5 <br />