AQ_GEN_PIO_20241220_MISC_PressRls (2)

Dec. 20, 2024
DEQ Strengthens Air Quality Permits for 2 Duke Energy Facilities that
will Reduce Overall Emissions
RALEIGH – The North Carolina Department of Environmental Quality’s Division of Air
Quality (DAQ) is issuing permit modifications to two Duke Energy facilities for the
replacement of their coal units with gas turbines, after substantially strengthening the
permits based on public feedback.
Division staff thoroughly reviewed public comments following two public hearings on the
draft air quality permits. In response, the final air quality permits add new emissions
limits and testing and reporting requirements, along with other revisions designed to
ensure the facilities adhere to all applicable state and federal rules.
Duke Energy plans to retire coal-fired boilers at two power plants: Duke Energy
Progress, LLC - Roxboro Steam Electric Plant in Person County, and Duke Energy
Carolinas, LLC - Marshall Steam Station in Catawba County. These units would be
replaced with new natural gas-fired turbines. The transition away from burning coal at
both facilities will reduce overall emissions of air pollution, particularly nitrogen oxides
(NOx) and sulfur dioxide (SO2). Both permits contain requirements to comply with
federal greenhouse gas standards for new sources.
After two coal boilers at Marshall Steam Station are retired, the facility will emit 1,981
fewer tons of NOx and 1,196 fewer tons of SO2 each year. Retiring the six coal boilers
at the Roxboro facility will lead to 4,130 fewer tons of NOx and 3,675 fewer tons of SO2
each year. Emissions of fine particulate matter, carbon monoxide and toxic air
pollutants, such as sulfuric acid, arsenic and a variety of heavy metals would also see
substantial decreases.
The final air quality permits require that each new turbine be equipped with low-nitrogen
oxide burners and be controlled by an oxidational catalyst and a selective catalytic
reduction system. The facilities would also be required to continuously monitor
emissions of several criteria air pollutants. Both plants would be subject to
recordkeeping and reporting requirements and regular inspections.
Air dispersion modeling reviewed by DAQ demonstrated that emissions of toxic air
pollutants at both facilities are not expected to cause an exceedance of any acceptable
ambient level. The final permits include conditions that ensure ambient levels of all
pollutants beyond both facilities’ fence lines comply with emission standards, including
applicable health-based standards.
DAQ held a public hearing on each draft permit and public comment periods to solicit
feedback from North Carolinians. Division staff thoroughly reviewed every comment
received. In response to these public comments, the final permits were strengthened in
the following ways:
Marshall Steam Station Changes:
• Added Prevention of Significant Deterioration Avoidance limitations and
conditions for four additional pollutants: fine particulate matter, coarse particulate
matter, SO2 and sulfuric acid.
• Added a requirement that Duke Energy notify DAQ when commercial operation
of the gas-fired turbines has begun, which will trigger a requirement to retire the
coal units.
• Added more stringent reporting and recordkeeping requirements related to
ancillary equipment at the site.
• Additional minor clarifications and updates.
Copies of Marshall Steam Station’s final permit, final permit review, hearing officer’s
report, permit application, and one-page project fact sheet are available online.
Roxboro Steam Electric Plant Changes:
• Added a testing requirement for sulfuric acid and a conditional testing
requirement for SO2.
• Clarified that the required testing for particulate matter must include condensable
particles in addition to filterable particles.
• Added more stringent reporting and recordkeeping requirements related to
ancillary equipment at the site.
• Added a condition to subject the facility to New Source Performance Standards
for Stationary Combustion Turbines and Stationary Gas Turbines, Subpart
KKKKa, should the U.S. Environmental Protection Agency finalize that rule in the
future.
• Additional minor clarifications and updates.
Copies of Roxboro Steam Electric Plant’s final permit, final permit review, hearing
officer’s report, permit application, and one-page project fact sheet are available online.
If you need this information in Spanish or another language, please call 919-707-8446
or email [e-mail].

For More Information
Contact: Shawn Taylor
Phone: [phone]