Progress Energy's large Roxboro power plant north of Durham spews nearly 700 pounds of mercury into the air a year from burning coal, making it one of the state's largest sources of mercury.
Scrubbers being installed at the plant to reduce smog and soot will have the extra benefit of reducing emissions of mercury, a toxic pollutant that contaminates fish and can damage children's nervous systems.
Mercury enters the air when power plants burn coal. It falls to the ground in rain and snow, settling in streams and rivers and collecting in fish. Exposure to mercury can cause neurological and fetal development problems. Rivers east of Interstate 95 post warnings to people about eating fish such as large-mouth bass.
As state environmental regulators debate future limits on power plants' mercury emissions, one thing is clear: Equipment that North Carolina power plants have added to cut other pollutants give them a head start on meeting new federal discharge levels allowed for mercury.
The federal mercury rule, which has been criticized as weak by the association of state air pollution regulators, requires power plants to cut mercury emissions in two stages: By 2010, output must drop by 21 percent; eight years later, plants must slash emissions by 70 percent. Utilities in North Carolina are expected to exceed the reductions required by 2010 but will need to add more controls to meet the later target.
The debate in North Carolina centers on whether environmental regulators should write tougher mercury-reduction requirements, as some states are proposing.
North Carolina's Environmental Management Commission, a regulatory panel appointed by the governor and legislature, plans to hold public hearings in May or June on proposals to reduce mercury. The dates haven't been set.
Toxic to the system
Physicians and environmental groups say the state should push utilities to reduce mercury as much as possible -- by as much as 90 percent.
Dr. Deborah Leiner, a pediatrician in Greensboro, said she sees children every day who have learning disabilities and developmental problems that are the kinds of problems associated with early exposure to mercury, though it's difficult to make a specific link.
"When we have things out there we know are toxic to the nervous system and cause brain damage, I don't see how we as a society can afford not to act responsibly and institute policy that will protect children in the future," Leiner said. "We're robbing them of their potential."
Utilities want time
Utilities, meanwhile, favor North Carolina's adopting the federal rule that would reduce mercury emissions, while also monitoring actual emissions from plants before determining what other limits to impose. They say technology isn't proven to achieve 90 percent reductions.
Dana Yeganian, a spokeswoman for Progress Energy, said the utility favors the federal limits and the proposal to add controls to remaining boilers a decade from now.
"We want technology to have time to develop," she said. "That gives a little more flexibility and time."
In addition to the federal requirements, the state commission is considering:
* Requiring utilities to install mercury emission controls by 2017 on half of the power plant boilers that aren't in line to get pollution controls under current state law. The rest would get controls by 2022.
* Allowing a barter system in which utilities could opt out of outfitting every plant with mercury controls if they achieve greater than required reductions at some plants.
* Delaying a decision on which plants would get mercury controls until 2013, which would allow the utilities time to gather actual emissions-monitoring data. Current emissions are estimates based on mercury content in coal.
David Moreau, chairman of the state's Environmental Management Commission, said the state's Clean Smokestacks Act, aimed at cutting smog and soot, will also capture up to 70 percent of plants' mercury emissions.
"That is a very large mercury reduction," Moreau said. "That makes us different than other states."
Obliged to reduce
John Suttles, an attorney for the Southern Environmental Law Center, said the state shouldn't delay demanding deeper reductions in mercury emissions just because its smokestacks law also reduces mercury discharges.
Suttles also criticized the proposal to allow utilities to pay money for pollution allowances rather than making reductions.
Power plants in North Carolina -- the largest source of mercury emissions -- produced about 2,900 pounds of mercury in 2003, the most recent year for which data are available.
"Utilities should not be relieved from the obligation of making deeper mercury reductions as other states are requiring," Suttles said. "What we want are the deepest reductions that are reasonably achievable as soon as possible."