NC0024406_Bromide Reduction Evaluation Semi-Annual Report_20230530

4IN DUKE Belews Creek Steam Station
ENERGY. Duke Energy Carolinas
3194 Pine Hall Road
Walnut Creek,NC 27609
May 22, 2023 RECEIVED
Sergei Chernikov, PhD MAY 2 6 2023
NC Department of Environmental Quality
Division of Water Resources
Complex NPDES Permitting Unit NCDEQ/DWR/NPDES
1617 Mail Service Center
Raleigh, North Carolina 27699-1617
Subject: Duke Energy Carolinas, LLC
Belews Creek Steam Station -#NC0024406 -
Bromide Reduction Evaluation Semi —Annual Report
Dear Dr. Chernikov:
As required by Condition A. (14) of the subject NPDES permit attached are three copies of the
Semi-annual status report summarizing Duke Energy's efforts to reduce bromide discharge and
potential subsequent Total Trihalomethane (TTHM) formation in downstream municipal water
treatment systems.
Should you have questions regarding this report, please contact Lori Tollie at 336-408-2591 or
[e-mail].
Yours truly,
Michael F. Lanning, General Manager Ill
RRE CDG Belews Creek Steam Station
Attachment

Belews Creek Steam Station
Bromide Reduction Evaluation NPDES Permit-NC0024406
Semi-Annual Progress Report
May 2023
Pursuant to Condition A. (20) Bromide Reduction Evaluation of the NPDES Permit— NC0024406.
Duke Energy submits this semi-annual progress report. This report is required to summarize on-
going investigations focused on minimizing bromide discharge at Outfall 003, 006, and 111 as
well as efforts aimed at reducing the formation of total trihalomethanes (TTHM) at downstream
water treatment plants.
• Duke Energy has worked cooperatively with the North Carolina Division of Water
Resources (DWR), the Town of Madison and City of Eden to address the bromide/TTHM
issues since being advised of the municipality's issues with TTHM formation.
• Bromide itself is not a health concern in surface waters. There is no water quality
standard for bromide and no NPDES permit limit.
• Duke Energy has provided direct technical expertise and financial assistance to Madison
and Eden to help address their respective TTHM issues.
Town of Madison
• No updated information new to report.
City of Eden
• No updated information new to report.
Belews Creek Steam Station
• Duke Energy has partnered with UNC-C and Electric Power Research Institute (EPRI) to
perform a lysimeter pilot at Mayo Power Plant that is reviewing halide sequestration and
encapsulation strategy from a long-term perspective.
• Belews Creek is currently planning for 50% natural gas co-fire capabilities. Conversion to
natural gas for Unit 1 was completed in 4th quarter of 2019. Conversion of Unit 2 was
complete in the 4th quarter of 2020. This modification to the operation of the station is a
result of other factors but is expected to have an added benefit of decreasing the mass of
bromide discharges.