2011-03-14_REVISION - M1977493 ‎(57)‎

• Permit No: M1977493
• IBM Index Class Name: REVISION
• Doc Date: 3/14/2011
• Doc Name: Exhibit List, Ex. 1-6
• From: Climax
• To: MLRB
• Type & Sequence: AM6
• Media Type: D
• Archive: No

Permit Amendment (AM-06) - Climax Mine
CM0000486
The Robinson TSF is also a potential source of contamination. This TSF was constructed in 1936
straddling the uppermost watersheds of Tenmile Creek to the north northeast and the Eagle River to the
west southwest (Figure AM-06-T-01). The largest dam, the 240 foot high 1 Dam, contains the TSF
upstream of Robinson Lake in the Eagle River drainage. 2 Dam is partially inundated by the upstream
portion of the Tenmile TSF in the Tenmile Creek drainage.
While the tailing material contained within the Robinson TSF consists primarily of quartz silica and
orthoclase feldspar, it also contains enough sulfur to be acknowledged by Climax as slightly acid
producing.
In addition to tailing material, seepage from the Robinson TSF and water discharging from the toe drain
system beneath 1 Dam are potential sources of contamination. As discussed previously, Robinson Lake
acts as a collection system for these co-mingled waters, and the Robinson Lake Pump Station will serve
to return this water to the industrial process water circuit for reuse as needed. Warren's Pump Station
serves to return collected seepwater from 1 Dam and the Tenmile Tunnel to the SDP via the 2 Dam
Pipeline and maintain Robinson Lake water levels.
An extensive clear water interceptor system has been established by Climax around the affected areas of
the Eagle River watershed. The Chalk Mountain interceptor canal system conveys stormwater around
the process facility and TSFs, which limit the amount of impacted waters to be treated and discharged.
While these interceptors are not designated EPFs, CMC recognizes the importance of these structures to
the overall water management system in reducing the quantity of impacted water that must be managed,
as more fully described in Exhibit G. The Interceptor System is inspected and maintained as part of
routine site monitoring activities.
There are no designated chemicals stored or utilized in the Eagle River watershed.
T-5.2.2 Environmental Protection Facilities
Existing EPFs 9-
In the portion of the Eagle River watershed affected by Climax Mine operations, the following existing
controls are considered EPFs:
¦ Robinson TSF and 1 Dam;
¦ Robinson Lake and Dam;
¦ Warren's Pump Station;
¦ Robinson Lake Seepage Pump System; and
¦ 4 Dam Seepage Collection and Pump System.
Potential Future EPFs
In the portion of the Eagle River watershed affected by Climax Mine operations, the following potential
future control is considered an EPF:
¦ Robinson Lake Pump Station.
Robinson TSF and 1 Dam: 1 Dam contains tailing material and an approximate 60 acre water pool within
the Robinson TSF. The Robinson TSF is also discussed in the Tenmile Creek watershed section.
1 Dam was upgraded and reconfigured in a project that was initiated in 1989 and completed in 1992.
Briefly, this project entailed construction of a large diameter toe drain collection and discharge system,
flattening of the slope of the dam from approximately 2HAV to approximately 4H:1V, and armoring the
face of the dam with rock cover material. The dam was revegetated at the end of this project.
Presently, a small collection pond collects seepage from the central portion of 1 Dam and routes it to
Warren's Pump Station (within the Robinson Lake footprint) for return to the water treatment system.
Warren's Pump Station is itself considered an EPF during periods when the Robinson Lake Pump Station
Exhibit T T-14 May 2010