Environmental groups say Pennsylvania's federally mandated plan to reduce smog would allow coal-fired power plants to emit more pollution than they do now.
The state has been working on a proposal to curb ground-level ozone in 17 counties where the federal government says smog levels remain too high and pose a health risk to the young, the elderly, people with asthma and others. The proposed regulations will be published Saturday.
The Sierra Club, the American Lung Association and other groups say that proposed emissions limits for coal-fired power plants are too lax. The biggest plants would be allowed to release more than 130,000 tons of smog-causing nitrogen oxides annually — 40 percent more than they do now, according to an analysis by the Sierra Club.
Produced during combustion, nitrogen oxides, or NOx, combine with volatile organic compounds to form ground-level ozone, which can worsen such respiratory conditions as bronchitis and asthma. The primary culprits are vehicle exhaust and electrical power plants.
Power plants "are the single largest source of smog-causing pollution and they are not being meaningfully addressed," Sierra Club spokeswoman Kim Teplitzky said Wednesday. "That they would even put this into a draft is astounding."
Power companies say they have already taken steps to reduce emissions at coal-fired plants.
FirstEnergy, the Ohio-based company that owns Pennsylvania's largest electric power plant, the Bruce Mansfield facility in Shippingport, has already reduced nitrogen oxides by 80 percent and plans to install another $465 million worth of new environmental controls companywide, said company spokeswoman Stephanie Walton.
PPL Corp.'s coal-fired power plants have reduced nitrogen oxides emissions by 19 percent over five years, said George Lewis, spokesman for the Allentown-based utility.
He said PPL believes the DEP proposal is reasonable.
"The objective is to reduce NOx emissions without imposing undue economic burdens on the plants that would make them uncompetitive with other power generation sources. DEP's proposed ... limit strikes the right balance of cleaner air and reliable electricity supply," said Lewis.
Pennsylvania has already seen significant improvements in air quality. The state reported nearly four times as many dangerous ozone days — at twice as many monitoring sites — in 2003 than in 2013, a reflection of more stringent vehicle emissions regulations and a transition to cleaner-burning fuels.
But the state is under a federal mandate to reduce smog in its heavily populated southwest and southeast corners, and must submit a plan to federal regulators by July. The standards would apply to 192 polluting facilities statewide, including those used by power plants, refineries, natural gas pipelines, cement kilns, pharmaceutical makers, hospitals and many other institutions and industries.
"Pennsylvania has made huge strides. At the same time, we're not where we need to be," said Kevin Stewart, director of environmental health at the American Lung Association of the Mid-Atlantic.
He said the proposed smog standards could give power companies an incentive to forgo the use of pollution controls.
"The concern is that this may well give a free pass to not using that control technology, and allowing a lot more air pollution going into the air that can affect ground-level ozone," he said.
But DEP spokeswoman Morgan Wagner said that with power plants having to install pollution-control equipment to comply with new federal mercury standards, "significant collateral NOx emission reductions will be realized."