2016-08-13_PERMIT FILE - P2016020 ‎(2)‎

• Permit No: P2016020
• IBM Index Class Name: Permit File
• Doc Date: 8/13/2016
• Doc Name: Compliance Order on Consent and Settlement Agreement
• From: Minewater
• To: DRMS
• Email Name: MAC
• Media Type: D
• Archive: No

quality, quantity, and suspected source(s); an inventory of uncontrolled inflows of tow pH/high
metals concentrations waters into the London Mine Water Tunnel from within the London Mine; an
evaluation of the capabilities of the current Water Tunnel Treatment Facility; evaluation of
potential improvements to the Water Tunnel Treatment Facility; and an evaluation of expected
capabilities of in-mine water treatment. The evaluation shall also determine the expected
resulting quality of water treated by the following in-mine technology: collection of a portion of
the poorest quality mine water flow and routing to an in-mine reaction vessel (Lower Davis Ore
body), addition of carbon sources to create and sustain low redox conditions to support microbial
sulfate reduction, and retention of the amended water for not less than fourteen (14) days. The
results of the evaluation will be used to inform a feasibility based solution to address the Water
Tunnel discharge.
40. Within thirty (30) calendar days of the effective date of the Consent Order and Settlement
Agreement, MineWater will file a petition for a site-specific rulemaking hearing before the Water
Quality Control Commission seeking a feasibility-based solution to address the Water Tunnel
discharge, either feasibility based ambient standards for No Name Creek, South Mosquito Creek,
and Mosquito Creek for zinc, cadmium, arsenic, lead, copper and silver, or a Discharger-Specific
Variance for the Water Tunnel for zinc, cadmium, arsenic, lead, copper and silver. Under either
approach, such petition for a site-specific rulemaking hearing may include additional parameters.
The numeric standards or alternate effluent limits that wilt be proposed will be based on the
expected quality of the water after treatment (as evaluated in paragraph 39 above) and will
include suitable buffers to accommodate seasonal and operational variability. MineWater and the
Division agree to cooperate as much as reasonably possible in the rulemaking proceedings in an
effort to support adoption of the ambient based standards (including but not limited to obtaining
and gathering appropriate data and meeting jointly with the Environmental Protection Agency).
The Division agrees to maintain the administrative extension of the existing Water Tunnel
Discharge Permit and Extension Tunnel Discharge Permit at least until such time as the Water
Quality Control Commission adopts feasibility based ambient standards for No Name Creek, South
Mosquito Creek and Mosquito Creek or a discharger specific variance for the Water Tunnel
discharge, but not to extend past December 31, 2018. In the event that standards are proposed in
the future for any parameter other than those included in the petition for a site-specific
rulemaking hearing described at the beginning of this paragraph, the process described in this
paragraph may be used to determine such standards as well.
41. Within forty-five (45) calendar days of the effective date of this Consent Order and Settlement
Agreement, MineWater will commence repairs of the Water Tunnel and related structures in an
attempt to address blockages and any impounded water in the Water Tunnel, and implement the
following Work Plan which contemplates managing and treating mine water flows differently based
on quality. Better quality water from the Water Tunnel may temporarily bypass the Water Tunnel
sediment pond. Mine water with higher concentrations of metals and/or sediment wilt be
captured, contained and treated utilizing the Water Tunnel sediment pond. The Work Plan shall
include at a minimum the treatment of the water generated during repair activities and shall
include cessation of in-mine activities that are expected to dislodge sludge if the treatment
capacity of the system is exceeded. Where possible, including near the mine portal entrance,
MineWater shall separately collect and convey the cleaner water to bypass around the settling
pond from upstream of the repair area to focus the limited treatment and settling capacity on the
worst quality water. The Work Plan shall include the following specific steps: 1) inspecting,
repairing and maintaining the existing settling pond system to increase pond capacity (both
volume and treatment capacity) and provide capacity to handle mine water surges, should they
London Mine, LLC, et al. C O L O R A D O
Compliance Order on Consent and Settlement Agreement �® Department of Pubtic
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