Duke: Cliffside emissions will be low

As environmental groups asked a federal judge Thursday to stop construction at Duke Energy's Cliffside coal-fired power plant, Duke asserted that the plant's emissions will be so low that the challenge is irrelevant.

Five environmental groups say the 800-megawatt expansion at Cliffside is illegal because the utility hasn't fully analyzed what “maximum achievable” controls are needed to capture mercury and dozens of other toxic pollutants.

Duke says the new plant 50 miles west of Charlotte will be one of the nation's cleanest, and asked U.S. District Judge Lacy Thornburg to dismiss the lawsuit. Thornburg didn't rule immediately on either request.

But two days before Thursday's hearing, Duke produced new emissions data that it says cancels the need for the controversial pollution-control analysis. Duke now expects Cliffside's emissions to be below the 25-ton-a-year threshold that triggers the maximum-achievable review.

Keith Overcash, director of the N.C. Division of Air Quality, said his analysts haven't yet decided whether Duke is correct. If they agree with Duke, he said, the company would avoid scrutiny that could have further tightened its mercury limits.

The state will put on hold its preliminary decision, which had been expected today, on whether to accept Duke's own assessment of its hazardous emissions. That analysis found no further mercury controls were needed.

Mercury is a focus of opposition to the Cliffside expansion because power plants are leading man-made sources of the toxic element, which can contaminate fish and cause developmental problems in children. N.C. health authorities estimate that more than 13,000 infants born each year have been overexposed to mercury through their mothers.