In a sweeping move aimed at curbing long-distance air pollution that afflicts the health of 240 million Americans — including Marylanders — the Environmental Protection Agency is ordering power plants across much of the eastern United States to sharply curtail emissions.
The rule, announced Thursday, gives coal-fired plants in Maryland and 26 other states until 2014 to make steep reductions in emissions of sulfur dioxide and nitrogen oxide, pollutants that contribute to serious health problems such as asthma, bronchitis and heart attacks. Maryland also would benefit because much of its air pollution comes from other states.
Some power companies warn that the requirement would force them to close their oldest plants. But others, including Baltimore-based Constellation Energy Group, say the reductions are warranted and manageable.
Officials and environmental advocates say the new federal rule should make Maryland's air more healthful, which is particularly urgent in Baltimore, where the average annual mortality rate for asthma is more than twice the state rate.
"No community should have to bear the burden of another community's polluters, or be powerless to prevent air pollution that leads to asthma, heart attacks and other harmful illnesses," said EPA Administrator Lisa P. Jackson in a statement.
Power plants would have to reduce sulfur dioxide emissions 73 percent from 2005 levels and nitrogen oxide 54 percent under the new rule.
Dawn Stoltzfus, spokeswoman for the Maryland Department of the Environment, called the federal action "a good first step." She said state officials had urged the EPA to set an even lower limit on smog-forming nitrogen oxide emissions, but they hope regulators will tighten the limit further.
Half or more of the pollutants that form ozone or smog in Maryland in the summertime come from out-of-state sources, Stoltzfus said. An air sample taken June 9 over Cumberland, for instance, found ozone concentrations of 94 parts per billion, roughly three-quarters of the current health threshold set by the EPA.
EPA data show that ozone pollution in Maryland comes from as far away as Michigan and Indiana in the west, North Carolina in the south and New York in the north. They are also among the 27 states that are covered by the rule. Maryland's ozone blows downwind to Connecticut.
Maryland also is covered by the EPA rule, but the state's power plants have likely reduced their nitrogen oxide emissions enough to meet the EPA limit under state air pollution limits, the MDE said. The state adopted its own Healthy Air Act in 2006, which required power plants to reduce nitrogen oxide emissions almost 70 percent by last year, and emissions of sulfur dioxide and toxic mercury by 80 percent.
Stoltzfus said state regulators are looking at the EPA rule to see if additional reductions might be required in sulfur dioxide emissions, which are tied to acid rain and soot, or fine particle pollution.
John Quinn, director of environmental management for Constellation Energy, said the company has spent more than $1 billion on pollution controls at its coal-fired power plants in the Baltimore area, and officials believe those plants are in "real good shape." He said the state's Healthy Air Act that required many of those controls were widely believed to be the most stringent in the country.
Constellation welcomes the federal action, he said, because it requires power plants in other states to meet the same environmental standards. "It levels the playing field commercially," Quinn said, "and our air should be cleaner in Maryland, where we all work and live."
Costs to power plants to meet the goals are estimated by the EPA at $800 million annually in 2014.
"The EPA is ignoring the cumulative economic damage new regulations will cause," said Steve Miller, president and CEO of the American Coalition for Clean Coal Electricity, a pro-coal industry association. Along with other pending regulations, Miller said they "are among the most expensive ever imposed by the agency."
But the EPA projects up to $280 billion in annual health benefits from the new rule, which is a revision of a 2005 regulation ordered reworked by the U.S. Court of Appeals for the D.C. Circuit in 2008.
The EPA estimates that pollution controls required by the new rule could reduce premature deaths from particulate pollution in Maryland by anywhere from 160 to 1,500 by 2014. Reductions in nitrogen oxide called for under the federal rule would have only a slight impact on deaths from ozone pollution, which can aggravate asthma and other respiratory illnesses.
The rule could have an impact in Baltimore, where city health officials have identified asthma as one of their health targets to improve by 2015.
The average annual mortality rate in Baltimore City from asthma is more than twice the state's rate, 34 deaths per 1 million people, compared with 14 per 1 million people statewide.
City Health Department estimates from 2007-2009 show 64,002 adults ages 18 and older and 19,411 children have been diagnosed with asthma at some point in their lifetime.
The emission limits should also help clean up the Chesapeake Bay, officials said. As much as a third of the nitrogen contributing to algae blooms and dead zones in the bay comes from air pollution, and about half of that drifts long distances on air currents from outside the six-state watershed of the bay, according to Richard Batiuk, associate director of the EPA's Chesapeake Bay office.
"You will see a reduction in emissions that assail the Chesapeake Bay and assail breathers in Maryland," predicted Frank O'Donnell, president of Clean Air Watch, a Washington lobbying group.
An earlier version of this story incorrectly described the proportion of nitrogen contributing to algae blooms and dead zones in the bay that comes from air pollution. The Sun regrets the error.