2011-12-15_REVISION - M1977493 ‎(2)‎

• Permit No: M1977493
• IBM Index Class Name: REVISION
• Doc Date: 12/15/2011
• Doc Name: ENVIRONMENTAL PROTECTION PLAN
• From: CLIMAX
• To: DRMS
• Type & Sequence: TR18
• Email Name: ECS
• Media Type: D
• Archive: No

Technical Revision (TR -18) Climax Molybdenum Company
Environmental Protection Plan Permit No. M- 1977 -493
of a designated chemical or process waters not contained at the release site ultimately would be
contained at the TSFs.
TR -14 described the new mill and accessory buildings for use during resumed production, however the
final design and layout of the mill and accessory buildings had not been fully developed at that time. TR-
14 designated the mill building as a location for several Environmental Protection Facilities (EPFs)
associated with designated chemicals. Additional details of the mill facility have now been developed and
general arrangement drawings of the entire mill and of the reagent storage and containment areas are
provided as Figures AM- 06 -T -06 and AM- 06 -T -07. The list of designated chemicals, their storage
location, storage capacity and the presence of secondary containment is provided in Table T -2 in Section
T -3.1.
OSF Water Management Controls: As described in Section T-4, Climax will use best management
practices to reduce the amount of impacted water requiring treatment. Climax will segregate materials
when feasible and, as discussed in Section T-4, is developing construction design and monitoring plans
with guidelines for overburden placement to reduce infiltration within exposed OSF surfaces to the extent
practicable by promoting drainage off of OSF surfaces and performing concurrent reclamation.
The OSF EPFs will consist of water management controls for the McNulty and North 40 OSFs. Specific
EPFs that will be designed and submitted to DRMS for review and approval prior to OSF expansion will
include one or more of the following:
• Upgradient diversions to prevent storm water runon from coming into contact with OSF material;
• Run -off control features to contain and direct impacted storm water to the water management and
treatment system;
• Underdrains to eliminate contact between shallow groundwater and OSF materials;
• Underdrains beneath OSF toe areas to collect and route seepage to the water management and
treatment system.
PDWTP: The new PDWTP will provide second stage treatment of the impacted waters to comply with
discharge permit requirements. The flow capacity of this plant will limit the total discharge capacity of the
process water system. As stated previously, when final design of the PDWTP becomes available,
appropriate submittals will be made to DRMS. At that time, additional information regarding chemicals for
water treatment contained within the PDWTP and their associated EPFs will also be provided.
Containment for Water Treatment Chemicals: As discussed, various source waters are treated by lime
neutralization to raise the pH and precipitate metal hydroxides. Precipitates (treatment sludges) are
primarily contained within the sludge cell on the Tenmile TSF. Additional precipitation and settling occurs
in the Tenmile and Mayflower TSFs. Prior to discharge to Tenmile Creek, sulfuric acid is employed to
reduce the final pH into the range stipulated by the CDPS Permit.
Lime: Slaked lime is currently produced at the Lime Station. The lime station includes conventional silos
for storage of lime and lime slakers. Slaked lime is produced by mixing lime from the silos with fresh
water from Buffehrs Lake and /or the McNulty Well. Slaked lime is then piped to the SDP and also to the
3 Dam Pump Station located between Tenmile TSF and Mayflower TSF.
Sulfuric Acid: Sulfuric acid is incorporated into the water treatment system to lower the pH of
discharged water to within the range of pH 6.5 to 9.0. Sulfuric acid is stored in a 7,000 gallon carbon
steel tank at the Mayflower Pump Station. The tank is located within an epoxy lined concrete sump
designed to contain 120 percent of tank capacity.
GreatFloc 5500: GreatFloc 5500 is received in bags and put into solution onsite. The liquid solution is
stored in a 2,000 gallon mix tank and a 3,500 gallon feed /storage tank. These tanks are located within
secondary containment inside the SDP
East and West Interceptor Systems: An extensive clean water interceptor system has been established
by Climax around the affected areas of the upper Tenmile Creek Watershed. The interceptor canal
EPP: Version R2
T -28 December 2011