DWQ-2025-004335

Cassady Kristensen
Rio Tinto Kennecott
Environment Business Partner
4700 Daybreak Parkway
South Jordan, Utah 84009
Dear Ms. Kristensen:
Subject:Construction Permit for the North Decant Pad
Kennecott Utah Copper LLC Ground Water Discharge Permit UGW350008 Smelter
On May9, 2025, the Division of Water Quality (DWQ) received the engineering plans and specifications for the North Decant Pad. The engineering plans were so large that it was had to
be submitted in 2 separate drawing packages. The engineering plans were prepared by Sunrise Engineering and were stamped be Caleb Dottem P.E., Jeffrey Dana Lundgreen P.E., and J. Randall
Knapp P.E. All are Utah Certified Professional Engineers (P.E.).The following is a summary of the proposed major construction projects for the North Decant Pad:
A West concrete pad with 2 dump bays separated by concrete block wall,
Concrete end wall,
Adjustable height slit cut weirs in the concrete wall,
1-foot wide trench drain connecting to a,
Catch basin,
An East concrete pad with 2 dump bays and 1 wash bay separated by concrete block walls,
Concrete end wall,
Adjustable height slit cut weirs in the concrete wall,
1-foot wide trench drain connecting to a,
Catch basin,
A pump vault,
Piping connecting the 2 catch basins.
And a gravel drive connecting the East and West concrete pads allowing a truck turn around area.The plans and specifications, as submitted, comply with the Utah Water Quality Rules,
(R317, Utah Administrative Code). A Construction Permit is hereby issued as constituted by this letter, subject to the following conditions:Any revisions or modifications to the approved
plans and specifications must be submitted to DWQ for review and approval, before construction or implementation thereof. Please submit any changes for review and approval directly
to Woodrow Campbell, P.E., of the DWQ Ground Water Protection Section.A written operations and maintenance manual, containing a description of the functioning of the facilities, an outline
of routine maintenance procedures, and all checklists and maintenance logs needed for proper operation of the system, must be submitted and approved before the final inspection and operation
of the system.The approved facilities must not be placed in service unless DWQ has conducted a final inspection, reviewed and approved the As-Built Construction Certification Report,
and provided written authorization to place the constructed facilities in service.Construction activities that disturb one acre or more are required to obtain coverage under the Utah
Pollutant Discharge Elimination System (UPDES) Storm Water General Permit for Construction Activities. The permit requires the development of a storm water pollution prevention plan
(SWPPP) to be implemented and updated from the commencement of any soil disturbing activities at the site until final stabilization of the project. For more information, or to obtain
permit coverage on-line, please go to: https://deq.utah.gov/water-quality/general-construction-storm-water-updes-permits
The plans and specifications for this project have been stamped and signed by a Professional Engineers currently licensed to practice in the state of Utah. The construction design,
inspection supervision, and written construction certification of all work associated with this Construction Permit must be performed by a Professional Engineer licensed to practice
in the state of Utah.
This Construction Permit will expire one year from the date of its issuance, as evidenced by the date of this letter, unless substantial progress is made in constructing the approved
facilities or the plans and specifications have been resubmitted and the construction permit is reissued. This permit does not relieve you, in any way, of your obligations to comply
with other applicable local requirements.
Please contact Mr. Campbell at the beginning of construction to allow periodic inspections to be scheduled. Upon completion of the project, a final inspection and approval of the As-Built
Construction Certification Report is required before the approval to operate the completed facilities can be issued. Please remain in contact with Mr. Campbell to schedule the final
inspection. The Construction Certification Report must stamped by a P.E. and include final as-built drawings and test results for the various construction quality assurance and quality
control (CQA/QC) elements.
If we can be of further assistance, please contact Mr. Woodrow Campbell at [e-mail] or [phone].
Sincerely,
John K. Mackey
Directorcc:Via e-mail, w/o encl.Jay Quintanilla, [e-mail] Martin, [e-mail] Naran, [e-mail] Dottem, [e-mail]
Dana Lundgreen, [e-mail]. Randall Knapp, [e-mail] Cox, DERRTony Howes, DERRWayne Western, DOGM