DSHW-2024-005103

I
February 28, 2024
Doug Hansen, Director
Utah Department of Environmental Quality
Hunter Plant
2 Miles South of Castle Dale on Highway I 0
P.O. Box 569
Castle Dale, UT 84513
Div of Waste ~anagement
and Radiation Control
MAR O 5 2024
Division of Waste Management and Radiation Control
195 North 1950 West
P .O. Box 144880
Salt Lake City, Utah 84114-4880
Subject: Hunter CCR Landftll Semiannual Assessment Monitoring Second Half 2023 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 2023 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 Half 2019 Assessment Monitoring Cobalt, Lithium, Molybdenum and Selenium
First Half 2020 Assessment Monitoring Cobalt and Molybdenum
Second Half 2020 Assessment Monitoring Cobalt and Molybdenum
First Half 2021 Assessment Monitoring Cobalt and Molybdenum
Second Half 2021 Assessment Monitoring Cobalt, Lithium, and Molybdenum
First Half 2022 Assessment Monitoring Arsenic, Cobalt, Lithium, and Molybdenum
Second Half 2022 Assessment Monitoring Cobalt, Lithium, and Molybdenum
First Half 2023 Assessment Monitoring Cobalt, Lithium, and Molybdenum
Second Half 2023 Assessment Monitoring Cobalt, Lithium, and Molybdenum
any questions regarding the notification, please contact Terry Guthrie, Environmental Manager,
untingto , lants [phone].
, ~ J '\ 1-, VV\. -7) !J.-J''-'''-,-,__J
i£:aren Hunts~an //
' Managing Director, Hunter and Huntington Power Plants
cc
Nikou Hesari NTO 210
Bryan Wheeler NTO 210