DSHW-2025-001213

February 23, 2025
Doug Hansen, Director
Utah Department of Environmental Quality
Hunter Plant
2 Miles South of Castle Dale on Highway JO
P.O. Box 569
Castle Dale, UT 84513
Div o1 Waste Management
and Radiation Control
MAR O 3 2025
Division of Waste Management and Radiation Control
195 North 1950 West
P.O. Box 144880
Salt Lake City, Utah 84114-4880
Subject: Hunter CCR Landfill Semiannual Assessment Monitoring Second half 2024
Appendix IV Ground Water Protection Standard Notification
Dear Mr. Hansen,
In accordance with 40 CFR 257.95(g) the results of ground water assessment monitoring indicate
that a notification is required for the coal combustion residual unit CCR Landfill at the Hunter
Power Plant in Castle Dale, Utah. PacifiCorp has completed the 2024 second half assessment
monitoring and the subsequent statistical analysis resulting in the following results.
Sampling Event Appendix IV Constituents Exceeding
Groundwater Protection Standards
2018 Assessment Monitoring Lithium and Molybdenum
First Half 2019 Assessment Monitoring Cobalt, Lithium, and Molybdenum
Second Half2019 Assessment Monitoring Cobalt, Lithium, Molybdenum and Selenium
First Half 2020 Assessment Monitoring Cobalt and Molybdenum
Second Half 2020 Assessment Monitoring Cobalt and Molybdenum
First Half2021 Assessment Monitoring Cobalt and Molvbdenum
Second Half 2021 Assessment Monitoring Cobalt, Lithium, and Molybdenum
First Half 2022 Assessment Monitoring Arsenic, Cobalt, Lithium, and Molybdenum
Second Half 2022 Assessment Monitorine Cobalt, Lithium, and Molybdenum
First Half 2023 Assessment Monitoring Cobalt, Lithium, and Molybdenum
Second Half 2023 Assessment Monitoring Cobalt, Lithium, and Molvbdenum
First Half2024 Assessment Monitoring Arsenic, Cobalt, Lithium, Radium and
Molybdenum
Second Half 2024 Assessment Monitoring Cobalt, Lithium, and Molybdenum
If you have any questions regarding the notification, please contact Terry Guthrie, Environmental
Manager, Hunter & Huntington Plants [phone].
enHunsman
Managing Director, Hunter and Huntington Po wer Plants
cc
Nikou Hesari NTO 210
Bryan Wheeler NTO 210