A modified air quality permit for a coal-fired power plant under construction eight miles east of Great Falls is the subject of a public meeting today in Great Falls.
The meeting was scheduled here because of intense public interest in the project, said Charles Homer of the state Department of Environmental Quality’s Air Resources Bureau.
After environmentalists challenged the original permit, the Board of Environmental Review ruled in May that developer Southern Montana Electric Generation and Transmission had to study technology to control particulate matter 2.5 microns or smaller, or PM2.5.
It was the first time a state required a coal-fired power plant to conduct extra analysis for PM2.5, Homer said. The DEQ is now taking public comment on a modified permit until Nov. 5.
The primary change in SME’s air permit is the addition of a hydrated lime injection system to control PM2.5, which the EPA considers more harmful than courser particulate because it can lodge deeper in lungs.
“There were certainly cheaper options,” Homer said. “There were more expensive options.”
SME consultant Jeff Chaffee of Bison Engineering said the cost of the additional controls is $5 million. Hydrated lime would be injected into the boiler exhaust, turning acid gas into particulate and capturing it in a fabric filter bag house before it’s released into the atmosphere, where the gases usually turn into particulate, Chaffee said.
“That would be a new piece of equipment,” Chaffee said.
The control system would capture an estimated 98.5 percent of the plant’s PM2.5, Chaffee said. The state estimates 227 tons of PM2.5 would be emitted annually after the controls are installed.
“We can’t figure out what’s new,” said Anne Hedges of the Montana Environmental Information Center in Helena.
MEIC and Citizens for Clean Energy appealed the permit, calling for better PM2.5 controls.
The only change Hedges sees in the permit is the lowering of the limits of hydrofluoric and hydrochloric gases, known as hazardous pollutants, to 24.9 tons, which is just below a 25 million threshold that would kick in stricter emissions controls.
Chaffee said the same controls that would lower emissions for PM2.5 also would lower hazardous pollutants.
MEIC also announced Tuesday it was challenging the location conformance permit issued by Cascade County on Friday, which SME needs to begin major construction. It broke ground on the project Oct. 15.
And the organization is questioning the governor’s Office of Economic Development over its role in the modified air permit.
Hedges said DEQ made an initial decision on the modified permit Aug. 15 but that the PM2.5 controls were lowered following a meeting 11 days later attended by Evan Barrett, chief business development officer for the governor.
Hedges questioned why the governor’s economic development office would be involved in a technical air permit issue. “This is really suspicious,” she said.
Barrett said the office had no direct involvement in the permit nor did it “reduce standards or anything like that, but we do pay attention to the processes.”
The office has a statutory responsibility for technology, work force and infrastructure development as well as marketing and recruitment and permitting and regulatory issues, he said.
“If somebody questions why we would be at a meeting related to a permitting issue related to an $800 million project, that’s the answer,” he said.