DWQ-2024-007419

Table 2 – Permitted Facilities
Copperton Concentrator Groundwater Discharge Permit UGW350017
Best Available Technology
Component/Function
Material
Containment
Inspection
Work Practice and Equipment
Tails Race & Octagon Drop Box: Designed to convey the tailings from Concentrator to Tailings thickeners.
Whole Tailings
Underground with concrete base and walls
1) Inspections require total system shut-down
2) No more than 30-months between inspections
3) Octagon can be viewed from surface
1) Concrete design. Sized to carry more than 100% of flows.
2) No visible damage affecting integrity.
3) Repaired during system shutdown period.
4) Included with Preventative Maintenance (PM) schedule for Concentrator conducted during shutdowns.
Tailings Thickeners: Thickeners function to increase tailings to a specific density before tailings line introduction.
Whole Tailings, Process Water
Concrete Basin on clay base,
Under-drain system to capture leaks
Monthly visual inspections for structural integrity and checks of under drain system
1) Secondary containment which reports to the tailings line such that no leaks escape to the environment.
2) Allowable leakage rate of 1 gpm.
3) No visible damage affecting integrity.
4) If leak is discovered repaired either immediately or if leak is not reporting to environment, repair during next shutdown.
Byron Jackson Pumps (BJPS): BJPS circulate the decanted water from the thickeners back to the Concentrator’s process water
Process Water
Underground Concrete Vault
Monthly inspections of system performance, power systems, hydraulic systems and valves.
Monitored at the Concentrator control room.
1) Upgraded in 2016 with valve system that does not allow large volume discharge to tailing lines.
2) Operational Check Failure will initiate alarms for automatic BJPS operation shutdown or fluid redirection. Operations personnel will identify the alarm cause and correct all issues
prior to restart.
Tailings Lines (48” & 60”)*: The Tailings lines convey the tailings material from the Concentrator to the Tailings Impoundment for deposition.
- Specifically, the tailings lines shall be considered initiating at valves on the North side of drop box H1A North of the Concentrator terminating on N side of UT SR 201 on the south
edge of the South Tailing Facility (STF)
*some sections of the pipeline are varying in pipe diameter
Whole Tailings, Process Water, Mining-impacted water, Stormwater and
Treatment concentrate
Pipelines are rubber-lined steel, concrete or HDPE, Pipelines are above and below ground. Pipeline corridor berms provide additional containment in select areas
1) Visual inspections (above ground sections) twice per 24-hour period to identify:
-Upsets
-Integrity
-Proper operation
2) Inspection reports prepared for:
-external visual survey
-annual assessment of concrete and structural support integrity
3) In-pipe video camera logging (The 48 inch Tailings pipeline is inspected quarterly for the first 25,000 feet; entire pipeline annually. The 60 inch Tailings pipeline is inspected
annually to detect pipeline scaling, erosion and/or integrity.
4) Level indicators are continuously monitored at control rooms
1) Tailings lines terminate at the tailings impoundment.
2) Infrequent tailings slurry releasesmay occur due to tailings line hydraulic disruptions. The reporting requirements and response actions for these release events are summarized in
Table 2A.
3) Drop boxes are designed to dissipate the energy and slow tailings slurry flowrate at gradient drops.
4) Bubble dissipaters installed below drop boxes accommodate air release from the tailings pipe.
5) Vent stacks allow airflow within the pipelines to promote design material flow. Vent stacks also create inspection points and access for maintenance.
6) Level indicators alarm control room operator when flow exceeds 70% of capacity.
-operators will follow SOP’s

-In accordance with Appendix A, maintain existing vent stacks (including extensions beyond original design), bubble dissipaters, and level indicators as reflected in Attachment to Appendix
A (Pipeline Corridor map).
6) Periodic inspection and as necessary, the replacement of wear heels to ensure pipe integrity is maintained.
Process water return line 48": TheProcess water return line transports for reuse & recycle north end waters from PS3A south to Pump Station 3B then on to Copperton Process Water Reservoir.
- Specifically, the process water line shall be considered initiating at the south side of Pump Station 3A (Magna Reservoir Pump house) and terminating at the inlet to the Concentrator
process water reservoirs.
Process water
Buried encased steel line with cathodic protection.
Steel line has an inner cement liner and outside of the steel has a cement wire mesh wrap.
1) Visual inspection of the pump stations
2) Buried line cathodic protection inspected annually
1) The process water pipeline has a surge basin at Pump Station 3B and terminates at the inlet to the Copperton Process Water Reservoir.
--Spillage will be reported within 24 hrs,a five day letter prepared and submitted to DWQ and included in the quarterly reports and corrective action(s) implemented as appropriate.
3) Inspection of Cathodic Protection probes annually.
5) The Process Water Return Line will be operated in accordance with Appendix A attachment SOP.
Tailings Line Launder: Launder is an open portion of the tailings line before the H1A drop box that allows for visual inspection of the tailings and provides surge capacity.
Whole Tailings, Process Water, Mining-impacted and stormwater
Concrete walls and floor
Daily visual inspections (above ground slurry levels) twice per 24-hour period to confirm:
-Indications of upsets
-Integrity
-Proper operation
BAT for Tailings Line Launder includes items #1 through #4 for the 48 and 60 inch tailing lines.
1) The Tailings Line Launder lies along pipeline corridor which has accompanying maintenance / access / inspection roadways.
2) H1A instrumented with a high level alarm set to 60% of launder flow depth) monitored at the Concentrator control room. High level alarm causes control room operator to visually verify
and make process adjustments to maintain correct flow level.
3) The Launder will be operated in accordance with Appendix A attachment SOP2.
4) In the event of the launder or cleaning water overflow, a concrete sump and float, located adjacent and west of the tailings line, receives the fluid and is pumped back into the tailings
line.
Concentrator Process WaterReservoir:  Concentrator Process Water Reservoir stores recycled water for reuse in the Concentrator process.
Process Water
Double lined (clay & synthetic), 36 mil HDPE synthetic liner and Sump with leak detection
Monthly inspections for degree of siltation, vegetation and debris
1) Double-lined with HDPE overlying clay
2) Allowable leakage rate of 3 gpm into sump
3) No visible damage to HDPE liner
4) If reservoir operation is not impacted with debris, vegetation and/or siltation, it will be removed during next shut down. If debris, vegetation, and/or siltation are impacting proper
function and it is a threat to overflow into environment, it will be removed immediately.
3B Surge Basin: 3B surge basin provides containment for pressure relief / draining of process water return line.
Process Water
Concrete basin primary containment
1) Annual above ground inspection for damage and cracks in the concrete basin
2) Monthly instrumentation inspection
3) Continual monitoring of surge basin level
1) Damage and cracks repaired during shutdown unless a leak to environment is evident. If leak to environment is or has occurred, repair will be immediate – weather permitting.
2) Level sensor monitors water level
3) Alarm will sound in a high level condition in the surge basin as described in the Appendix A attachment SOP3 at the North Tailings and Concentrator control rooms and will trigger
a reduction of flow or shut down of the Process Water Return Line. The system will not be restarted until the issue has been identified and corrected by operations personnel.
Retention Ponds – General: Retention ponds I-IV are used primarily for stormwater capture and may include contact water.
Storm water / system upsets
Clay lined basins
1) Annual pump(s) inspection
2) Annual SWPPP visual inspections for damage
3) Monthly inspection checklist completed and submitted with quarterly reports.
1) Sediment and vegetation that accumulates and impedes operation of the pump system will be cleared immediately unless not impacting proper pond function. If pond operation is not impacted,
debris, vegetation and/or siltation will be removed during next shut down or PM.
2) Inlet and outlets maintained clear of debris.
3)Process water discharged to Ponds III-IV to be pumped out within 7days when it flows into the pond.
Copper Thickener:
Process water and copper concentrate

Concrete basin on clay base and under drain to capture leaks
Monthly inspections for structural integrity and checks of under drain system
-Inspect for structural integrity, overflow protection and containment.
1) Allowable leakage rate of 1gpm
2) Concrete basin set on clay base as secondary containment with underdrains that drain fluids to the tailings line.
3) No visible damage affecting integrity
Copper / Molybdenite Thickener and the Clarifier. Both items have same containment, inspection and work practice and therefore are combined.
Process water and copper / molybdenum concentrate
Concrete basin on clay base
Monthly inspections for structural integrity and checks of under drain system (describe checks of under drain system)
-Inspect for structural integrity, overflow protection and containment.
1) No visible damage to concrete walls or secondary containment nor settling of ground adjacent to thickeners
2) No detectable leakage from secondary containment
3) Cracks or settlement causing leaks to environment will be repaired immediately; if no leak to environment, repairs made during next shut down.
Fiber Filter Plant
Process Water
Concrete basin primary containment
1)Monthly visual inspections for the structural integrity of the concrete basin and checks of thesump and pumping system
2) Monthly inspection checklist completed and submitted with quarterly reports
3) Once per permit term preform hydrostatic test on building sump
1) The concrete basin is sloped to provide passive drainage directed to Process Water Reservoirs during upset conditions
2) Concrete sump and pump inside the plant to actively remove water that may accumulate during routine operations
2) Damage and cracks are repaired during shutdown unless a leak to the environment is evident. If a leak to the environment is or has occurred, repair will be immediate – weather permitting.