2021-08-17_REVISION - M1977342 ‎(4)‎

• Permit No: M1977342
• IBM Index Class Name: Revision
• Doc Date: 8/17/2021
• Doc Name: Adequacy Review Response
• From: Climax Molybdenum Company
• To: DRMS
• Type & Sequence: TR34
• Email Name: PSH
• Email Name: JLE
• Media Type: D
• Archive: No

TR-34 to Permit M-1977-342
Environmental Protection Plan
11. SURFACE WATER QUALITY DATA
11.1. Local Water Uses and Standards
Mine: Adjacent to the Henderson Mine, Segment 4 of Clear Creek (COSPCL04) runs from the
source of the West Fork of Clear Creek to the confluence with Woods Creek and is classified as
Agriculture, Aquatic Life (cold) Class 1, Recreation E, and Water Supply. Downstream of the
Henderson Mine, Segment 5 of Clear Creek (COSPCL05) runs from the confluence with Woods
Creek to the confluence with Clear Creek and is classified as Agriculture, Aquatic Life (cold) Class
1, Recreation E and Water Supply.
URAD WTP: Adjacent to the URAD WTP, Segment 7a of Clear Creek (COSPCL07A), which is the
mainstem of Woods Creek from the outlet of Upper URAD Reservoir to the confluence with the
West Fork of Clear Creek is classified as Aquatic Life (cold) Class 2 and Recreation N. Located just
below the URAD WTP is Lower URAD Reservoir which is Segment 7b of Clear Creek (COSPCL07B)
and is also classified as Aquatic Life (cold) Class 2 and Recreation N.
Mill: Adjacent to the Henderson Mill, the Williams Fork River, from the source to the confluence
with the Colorado River, is Segment 8 of the Upper Colorado River basin.This segment is classified
as Aquatic Life (cold) Class 1, Recreation E, Water Supply, and Agriculture.
11.2. Surface Water Monitoring
Surface water monitoring is conducted on a regular basis in accordance with the GWMP. Surface
water collection and analyses procedures at the Mine and Mill sites are described in the GWMP,
including sampling parameters, monitoring locations, sampling and analytical procedures,
detection limits, and frequency.
11.3. Surface Water Quality Data
A large database of surface water quality data exists in the public record and on file as part of
the Reclamation Permit. Surface water quality data upstream and downstream indicates that
Mine and Mill operations are not adversely impacting water quality downstream of the sites.
The GWMP describes surface and groundwater monitoring, including upstream and downstream
of the mine and mill sites, and reporting of water quality data to the DRMS. The ongoing
collection of this data provides a basis for the evaluation of reclamation performance standards
and the adequacy of EPF design, maintenance and operation.
Climax Molybdenum Company August,2021
Henderson Operations Page 36 of 45