DERR-2024-012476

PUBLIC NOTICE of COMPLETION
Five-Year Review of the Kennecott (North Zone)
Alternative Superfund Site
Salt Lake County and Tooele County, Utah

Summary: Third Five-Year Review Completed
The Utah Department of Environmental Quality, Division of Environmental Response and Remediation
(UDEQ/DERR), and the U.S. Environmental Protection Agency (EPA), Region 8, have completed the third
Five-Year Review for the Kennecott (North Zone) Alternative Superfund Site. Five-Year Reviews are
required by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
when hazardous substances remain on site above levels that permit unrestricted use and unlimited
exposure. Five-Year Reviews are conducted to evaluate the site remedy and to determine whether site
conditions remain protective of human health and the environment.

Summary Protectiveness Statement Regarding Operable Units: 8, 13, 14, 15, and 19: The Five-Year
Review has determined that the protectiveness determination of the remedy at these Operable Units
(OUs) cannot be made at this time and is deferred until further information is obtained. Further
information will be obtained by applying the 2024 Updated Soil Lead Guidance for CERCLA sites and
RCRA Corrective Action Facilities to determine whether further investigation is warranted and response
actions are necessary for the remedy to remain protective. It is expected these steps could take
approximately five years to complete, after which a protectiveness determination will be made.

Summary Protectiveness Statement Regarding Operable Units: 22 and 23: The Five-Year Review has
determined that given the uncertainties concerning the fate and transport of selenium in the
groundwater system underlying the Refinery and Smelter complex and in the North Zone Wetland
habitat at the surface, the selected remedies for OU22 and OU23 are currently not protective. Increasing
trends of selenium in bird eggs and arsenic in surface water need to be further evaluated in OU22 to
understand their significance. Evaluation of the groundwater arsenic and selenium concentrations
trends and how to increase the reduction of such warrant’s further evaluation. After these evaluations,
EPA and UDEQ will modify the current selected remedies. Please refer to the Five-Year Review for the
complete protectiveness statement.

This Five-Year Review Report was signed September 30, 2024 and the next Five-Year Review is due
September 30, 2029. The North Kennecott Five-Year Review is available electronically at the
UDEQ/DERR website at http://www.environmentalresponse.utah.gov/ or visit the EPA website under
‘Key Documents’ at: https://www.epa.gov/superfund/Kennecott-North

A copy of the review is also available at the DERR Offices located on the 1st Floor, at 195 North 1950
West, Salt Lake City, Utah, 84114. Please call for an appointment to review records at [phone],
Monday through Friday, from 8:30 A.M. to 4:30 P.M.

For information regarding the review please contact:

Mazie Cox Douglas Bacon Maggie Ogden
UDEQ Project Manager EPA Project Manager EPA Project Manager
Phone: [phone] Phone: [phone] Phone: [phone]
Email: [e-mail] Email: [e-mail] Email: [e-mail]