New SO2 Standards Highlight EPA's Role in Regulating Coal Plants

With an ongoing debate in Congress over what the EPA's role should be in regulating greenhouse gas emissions from large industrial sources of pollution, every move by the agency to flex its muscle is scrutinized for hidden meaning.

So last Tuesday, when the EPA moved to tighten restrictions on sulfur dioxide (SO2) emissions -- which is not a greenhouse gas -- it looked like it was more than a routine regulatory update. The new SO2 regulations were the first update in forty years, and timed it seemed, to have maximum effect on a larger discussion.

On Monday EPA held hearings in Virginia  to give the public an opportunity to weigh in on the agency's proposal to begin regulating global warming gases from power plants, oil refineries, factories and other major sources. On Wednesday, similar hearings were held in Chicago. The SO2 regulations were released on Tuesday, the day right smack in-between.

Was it a signal to lawmakers and the public to demonstrate that in the Clean Air Act, EPA has a powerful tool for regulating coal plant emissions in order to protect human health and the environment?

“Short-term exposures to peak SO2 levels can have significant health effects – especially for children and the elderly – and leave our families and taxpayers saddled with high health care costs,” said EPA Administrator Lisa P. Jackson. “We’re strengthening clean air standards, stepping up monitoring and reporting in communities most in need, and providing the American people with protections they rightly deserve.”

EPA is proposing to revise the primary SO2 standard to a level of between 50 and 100 parts per billion (ppb) measured over 1-hour. The existing primary standards were 140 ppb measured over 24-hours, and 30 ppb measured over an entire year. The proposed 1-hour standard would better protect public health by reducing people’s exposure to high short-term concentrations of SO2. Even five or ten minutes of exposure to high levels of SO2 can cause an asthma attack, according to the American Lung Association.

“There has been a lot of evidence recently that suggests the current standard doesn’t adequately protect against short-term exposure, which might happen if you were downwind from, say, a coal-fired power plant,” Frank O’Donnell, president of Clean Air Watch, told SolveClimate.

The EPA is also proposing to more closely monitor SO2 emissions at the source; so, rather than take general air quality measurements, it will take them around known SO2 sites and in urban areas.  The agency is also launching today an online tool that allows the public to track SO2 emissions throughout the country. 

EPA estimates that the revised standards would yield health benefits valued between $16 billion and $100 billion, the result of reduced hospital admissions, emergency room visits, and work days lost, as well as fewer cases of aggravated asthma and chronic bronchitis.

The most likely effect of the new regulations, according to O'Donnell, would be the installation of SO2 scrubbers on plants that lack them. They can remove 90 percent or more of the SO2 from a plant’s emissions, according to the EPA. The systems are expensive, and for plants that have so far been able to meet EPA restrictions without scrubbers, there has been little incentive to install them.

But other observers say the market implications of the proposed SO2 regulations are still unclear. The impact will take years to assess as state governments will have to make individual determinations about how to apply the regulations.