Duke to re-evaluate mercury pollution

Duke Energy will comply with the state's request to take a new look at controls to catch mercury and dozens of other hazardous air pollutants at its Cliffside power plant, the utility said Friday.

Last week the N.C. Division of Air Quality, responding to a federal court ruling, asked for assurances that the coal-fired plant Duke is expanding would include “maximum achievable” pollution controls. The division asked Duke to agree by Friday.

Duke said it will file an assessment, which will include a review of technology used by other utilities, with the state by the end of June.

Duke says it is confident that the plant's design won't have to be changed. Construction at the plant, 50 miles west of Charlotte, will continue. It's to start operating in 2012.

“I don't know of any technology that will get a higher removal rate than what we expect from this plant,” project manager Harry Lancaster said.

State regulators will have up to 45 days to decide whether Duke's assessment meets technical standards, then another 30 days to review it, followed by a public-comment period. The state must address any challenges raised by the public.

Those challenges are likely. The Southern Environmental Law Center, which has fought the Cliffside expansion on behalf of five environmental groups, insists that plant construction is illegal until Duke proves it meets the pollution-control standard.

Law center attorney John Suttles also questioned whether Duke can do a thorough review before June 30. “Given its persistent flouting of Clean Air Act requirements,” he said in a statement, “we are skeptical Duke will follow through on (its) reluctant pledge to heed the law this time.”

The new, 800-megawatt Cliffside unit is guaranteed to capture 90 percent of its mercury emissions, Duke said. Environmental groups, who have threatened to sue Duke over the issue, contend that higher capture rates are possible.

Controls that capture pollutants such as sulfur dioxide, nitrogen oxide and acidic gases also catch mercury, which has contaminated rivers and fish across Eastern North Carolina.

A federal appeals court ruled in February that the Environmental Protection Agency wrongly exempted coal-fired plants from parts of the Clean Air Act that deal with hazardous pollutants.

The ruling means new power plants must prove they have “maximum-achievable” controls for hazardous pollutants.

State environmental officials have said it's unclear whether the ruling would apply to plants, such as Cliffside, that had construction approval before the court acted.

But they told Duke “the public interest is best served” by assuring that the new unit operates as cleanly as possible. Such plants can run for decades – Cliffside dates back to 1940.

Four older boilers at the plant will be retired once the new one is operating.