2022-04-05_REVISION - M1977342 - Laserfiche WebLink

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Climax Molybdenum Company Permit No.1977-342 Technical Revision JR-35) The WTP building pad will be built up slightly above the existing ground surface and will slope down to tie into existing grade at a 3H:1 V slope, with a small area on the east side of the WTP sloping down at 2.5H:1 V due to space constraints in that area related to the proximity of the North Mill Access Road. The septic tank and leach field will be located to the east and north of the WTP, respectively. The leach field area lies at an elevation approximately 10 ft below the proposed elevation of the WTP. 2.2 WTP Primary Treatment Processes The WTP relies on a single-stage, lime-based HDS process to remove constituents of concern, primarily metals, from the influent water. A simplified process diagram is included below to visually represent this process. LIME is added to the A FLOCCULANT is reaction to raise the pH to AIR is introduced to introduced to bond pH in the final effluent is oxidize metals for lowered using carbon favorable conditions far molecules and promote metals precipitation precipitation precipitation dioxide(CO2) LIME HDS CLARIFIER SLURRY REACTOR GRAVITY r LIME TANKS FILTER WATER! SLUDGE mix • : IN WASTE SLUDGE RECYCLE Diagram 1. Water Treatment Plant Process Diagram Detailed process flow diagrams are included as drawings 530-DC00-PFD-101 and 530-DC00-PFD-102 in Appendix A. Feedwater from the mill will be conveyed to the WTP through the influent pipeline. The major process components of the WTP include the following: Lime/Sludge Mix Tank— lime is mixed with recycled solids (sludge) from the clarifier HDS Reactors—two reactors are constructed to treat the water in series. In these reactors,the slurry from the lime/sludge mix tanks is mixed with the influent water, air is introduced, and elevated pH and the presence of oxygen causes targeted constituents to oxidize and precipitate. Following reaction, polymer is added to promote flocculation prior to flowing into the clarifier. Clarifier— flocculated particles in the reacted water settle and the clarified overflow is routed to the gravity filter while the heavy underflow of flocculated particles is recycled or pumped to the TSF for disposal. Gravity Filtration — remaining solids are removed in multi-media filters and filtrate is routed to the effluent tank for neutralization. Effluent tank& Neutralization—CO2 is dissolved in the water to neutralize the pH prior to discharge. The HDS process utilized by the plant re-circulates sludge to increase the neutralization potential of the added lime and improve coagulation and settling. Lime will be combined with recycled sludge from the clarifier in the lime/sludge mix tank. Influent water from the mill and lime/sludge slurry will flow into Reactor Tank#1 and then April 2022