N.C. sees big drop in mercury emissions

Jul 25 - McClatchy-Tribune Regional News - Kate Elizabeth Queram Star-News, Wilmington, N.C.


Mercury emissions from coal-fired electricity plants in North Carolina have decreased by more than 70 percent in the last decade, a shift state officials attributed largely to greater numbers of industrial facilities coming into compliance with more stringent limits on pollutants.

In 2010, coal-fired power plants released a total of 960 pounds of mercury, a 71.3 percent decrease from the 3,350 pounds emitted in 2002, according to a recent report from the N.C. Division of Air Quality. The steep decline followed the General Assembly's 2002 passage of the Clean Smokestacks Act, which forced the state's 14 coal-powered plants to reduce nitrogen oxide and sulfur dioxide emissions by about 75 percent over 10 years.

But the legislation makes no mention of control tactics for mercury, making the downtick in those emissions a significant but unintended effect of installing updated technology at the facilities, experts said.

"We have found significant reductions in mercury emissions at our various power plants, even though that's not what it was designed for," said Scott Sutton, a spokesman for Progress Energy Carolinas. "It's a convenient, accidental byproduct of installing the pollution control equipment to reduce sulfur dioxide and nitrogen oxide."

The utility provider is in the process of converting several of its coal-fired plants -- including the Sutton plant on U.S. 421 North near Wilmington -- to operate on natural gas. Those improvements should be completed by 2014, at which point almost none of the mercury in North Carolina will be emitted from in-state facilities.

"According to the most recent data, only 16 percent of the mercury is coming from in-state," said Tom Mather, a spokesman for Air Quality. "But by the time all these controls are put in, only about 3 percent of the mercury will be coming from North Carolina sources."

Largely because of that, the agency's report concludes that requiring facilities to employ additional emission-control measures would "offer limited benefit given the majority of (mercury) in the state stems from global emissions." That recommendation was of particular concern to environmental groups, who praised the overall reductions but said the state should continue to be aggressive until North Carolina's in-state mercury emissions are completely eliminated.

"They say that 84 percent of mercury emissions are global, but we can't stop there," said Mike Giles, coastal advocate for the N.C. Coastal Federation. "Sixteen percent is still being emitted here, and that 16 percent adds to that 84. We can't stop there."

Environmental activists also remain concerned about how the progress in overall emissions control could be affected if a proposed Titan cement plant is allowed to operate in Castle Hayne. According to its air permit, the facility would be permitted to emit 46 pounds of mercury per year once operational, which Giles said was concerning -- particularly given the other emissions the plant could produce.

"We don't want any mercury in our waters. DAQ is permitting what is, in essence, a small power plant," he said. "Not only do they burn coal, they also burn limestone and other nasty stuff that comes out of the earth that emits other pollutants that power plants, quite frankly, do not emit."

Mather acknowledged that the Titan plant would be a "significant" source of mercury, but said that 46 pounds is the maximum amount the facility would be allowed to emit -- meaning it's likely that the actual total will be much less.

"Forty-six pounds is the permitted limit if the plant were operating all the time," he said. "What we generally see in most facilities is that the actual reported emissions are lower than their permitted amount, usually by a fair margin because they don't want to be operating right at that limit."

Kate Elizabeth Queram: 343-2217

On Twitter: @kate_goes_bleu

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