DEQ hears public comment on Duke Energy plan to replace two coal boilers with gas turbines at Marshall Steam Station

State Department of Environmental Quality hearing officer Heather Carter opened a public hearing on Nov. 19 to gather comments on a draft air quality permit for Duke Energy Carolinas’ Marshall Steam Station in Catawba County.

Joe Volper, an engineering supervisor in the Division of Air Quality’s permitting section, described the company’s proposal to retire two of the plant’s coal-fired boilers and replace them with two new natural-gas-fired simple-cycle combustion turbines that can burn No. 2 fuel oil as backup. Volper said the project also includes an auxiliary natural-gas-fired boiler, two natural-gas-fired heaters, an emergency diesel generator, an emergency fire pump engine and two diesel fuel storage tanks. He said emissions from the new turbines would be controlled with dry low-NOx combustors, selective catalytic reduction, an oxidation catalyst and water injection if oil is used.

Volper told the hearing that Duke modeled potential toxic air emissions conservatively — combining emissions from the turbines and the remaining coal units — and that the modeling showed each pollutant was "less than 26% of the respective acceptable ambient level." He said the division's analysis branch approved that modeling on Aug. 8, 2024, and that the draft permit would require continuous emission monitoring for nitrogen oxides and carbon monoxide, emissions testing for other pollutants, recordkeeping, reporting and inspections. The draft permit also contains a condition that the two coal-fired boilers be shut down after commercial operation of the new turbines.

The hearing drew a mix of residents and advocates. Britney Griffin, advocacy manager with Clean Air NC, asked the department to "deny Duke Energy's requested air permits" or at least impose "substantial modifications" and an "enforceable backstop date so that Duke cannot continue operating the coal units longer than expected." Griffin said the draft permit "fails to include adequate monitoring" for what she called dangerous pollutants, including volatile organic compounds and lead, and raised health concerns for children and other residents.

Several nearby residents described what they said was a lack of timely outreach from Duke and expressed distrust of the applicant's data. One commenter said a model she reviewed indicated emissions above certain thresholds and pointed to a separate gas-turbine project off Island Point Road whose modeled and measured levels she described as exceeding limits. Tanya Hall, who identified herself as a Northview resident, said the community’s entrance sits across from the planned turbine access and that about "350 homes" would be affected; she accused Duke of a decadeslong record of failing to meet standards and cited concerns about coal ash contamination and a later extension request tied to facility closure dates.

Not all speakers opposed the proposal. Jim Martin, a longtime resident and former environmental health and safety manager who worked with Title V permits, said he supported the proposal as a step away from coal and toward lower-emission generation. Thomas Getz, a resident with a background in environmental science, urged state agencies not to approve permits that add fossil-fuel emissions and called for nonfossil alternatives.

Carter reminded attendees that the public comment period remains open through Nov. 22, 2024, at 5 p.m. and described submission options (email to daq.publiccomments@deq.nc.gov with subject dukemarshall.24a, voicemail at 919-707-8726, postal mail per the public notice and a written dropbox at the hearing). She said she will make a recommendation to the director of the Division of Air Quality for consideration in the final permitting decision.

The hearing record will include the oral comments presented Nov. 19 and any written comments submitted by the Nov. 22 deadline; the director will consider those materials before issuing a final decision.