Laserfiche WebLink
occur, 2) removing sludge and sediment from the existing settling pond system to an on-site <br /> repository under normal treatment operations into geotextile bags located next to the repository, <br /> but if the capacity of the bags is exceeded then sludge may be directed to the on-site repository <br /> in a slurry form for short-term (emergency) situations, 3) real time monitoring of flow in the Water <br /> Tunnel during active mine repairs and waste removal activities for total suspended solids, pH and <br /> electrical conductivity to provide information that shall be used to determine which water sources <br /> to segregate for treatment, taking into consideration any planned in-mine work activities, 4) <br /> directing cleaner water around the sediment pond (bypass) 5) directing the remaining worst <br /> quality water to the settling ponds for treatment and discharge, and 6) amending the worst quality <br /> water with NaOH and polymer flocculant at the treatment system headworks to enhance <br /> precipitation and settling of contaminants. The Division expressly approves this temporary bypass <br /> during Water Tunnel repair work for a period of time not to exceed a total of forty-five (45) days <br /> (days do not have to be consecutive). MineWater shall notify the Division two (2) days prior to <br /> each bypass period and within 2 days of completing each bypass period. MineWater and the <br /> Division acknowledge and agree that any exceedances of effluent limitations associated with these <br /> efforts shall be addressed via the stipulated penalty provisions set forth in paragraph 53 of this <br /> Consent Order and Settlement Agreement. <br /> 42. Within ninety (90) calendar days of the effective date of this Consent Order and Settlement <br /> Agreement, MineWater will begin implementing reasonable measures to permanently segregate <br /> the inventory of uncontrolled inflows of low pH/high metals concentrations waters into the London <br /> Mine Water Tunnel from within the London Mine and begin in-mine treatment of said flows to <br /> reduce metals loadings in the London Mine Water Tunnel discharge. In connection with these <br /> efforts, MineWater will provide the Division with the following information: (a) the results of the <br /> electrical conductivity survey of the contributing water sources within the London Mine Water <br /> Tunnel; (b) a constructability assessment report for separation of the highly conductive water <br /> presumed to contain the highest concentrations of zinc, cadmium, arsenic, lead, copper and <br /> silver; (c) a sampling report to indicate the concentrations of zinc, cadmium, arsenic, lead, <br /> copper and silver contained in the contributing water sources; (d) construction documentation <br /> report with system designs and photographic evidence demonstrating the capture and collection of <br /> contributing sources of zinc, cadmium, arsenic, lead, copper and silver, the conveyance system <br /> transporting water to the reinjection point into the tower reaches of the London Mine itself, the <br /> reinjection point, the reagent addition point(s) and the reagent storage system, as constructed; <br /> and (e) an evaluation of the effectiveness of the in-mine treatment. <br /> 43. Within one (1) year of the effective date of this Consent Order and Settlement Agreement, <br /> MineWater will have the infrastructure associated with the in-mine treatment system fully <br /> installed and operational and begin optimization of said system to reduce exceedances of the <br /> effluent limits, if any. <br /> 44. By September 30, 2018, MineWater will complete any such optimization efforts and operate said <br /> in-mine treatment system necessary to meet the permit limits of the Water Tunnel Discharge <br /> Permit and/or ambient-based water quality standards (as revised) and/or a discharger specific <br /> variance. <br /> 45. Beginning no later than thirty (30) calendar days after the effective date of this Consent Order and <br /> Settlement Agreement, MineWater shall conduct stream sampling in South Mosquito Creek for <br /> hardness, zinc, cadmium, arsenic, lead, copper, and silver at the location downstream of the <br /> Facility's outfall known as stream monitoring location number SMC003. All such sampling at <br /> SMC003 shall occur on the same day as the Water Tunnel Permit specified effluent sampling event. <br /> Sample collection and laboratory analysis shall be conducted using U.S. Environmental Protection <br /> Agency approved methods. MineWater shall report the results of the stream monitoring <br /> London Mine, LLC, et al. C O L O R A D O <br /> Compliance Order on Consent and Settlement Agreement ®I Department of Public <br /> Page 10 of 23 Hwlth 6 Environment <br />