EPA proposes to reduce smog-forming pollution transported across state lines

Agency says rule would lower power plant NOx emissions in 23 states

Posted November 25, 2015

EPA is proposing updates to the agency’s Cross-State Air Pollution Rule (CSAPR) to address interstate air quality impacts for the 2008 ozone air quality standards. The proposed updates would reduce summertime emissions of oxides of nitrogen (NOx) from power plants that contribute to downwind ozone problems in the eastern half of the U.S.

The Clean Air Act’s “good neighbor” provision requires states — or, as a backstop, EPA — to address interstate transport of air pollution that affects the ability of downwind states to attain and maintain clean air standards. Under the good neighbor provision, states develop state implementation plans (SIPs) while EPA plays a backstop role by issuing federal implementation plans (FIPs) if a state fails to submit an approvable plan.

This proposal provides the FIP that would apply if EPA’s backstop obligation is triggered. States may choose to have their emissions sources controlled by the FIP rather than developing their own plan.

Specifically, the proposed updates identify cuts in power plant NOx emissions in 23 states in the eastern half of the country that contribute significantly to downwind ozone air quality problems and that EPA says can be achieved using existing, proven, and cost-effective control technologies. EPA believes the proposed cuts in NOx emissions would lead to significant improvements in air quality for the 2017 ozone season. EPA is also proposing to adopt FIPs for each of the 23 states in the event that a state does not submit an approvable SIP.

EPA estimates that the proposed CSAPR Update Rule will reduce NOx emissions from power plants in the East by 85,000 tons in 2017 compared to projections without the rule. Due to this proposed rule and other changes already underway in the power sector, ozone season NOx emission will be 150,000 tons lower in 2017 than in 2014, a reduction of more than 30 percent. NOx emissions can react in the atmosphere to create ground-level ozone pollution, or smog. These pollutants can travel great distances, often crossing state lines and making it difficult for other states to meet and maintain the air quality standards for ozone that EPA establishes to protect public health.

The agency also estimates that by reducing ozone exposure, the proposal would provide annual benefits of $700 million to $1.2 billion in 2017, versus the estimated costs of $93 million. Further, EPA says the proposal will provide climate-related co-benefits, estimated at around $23 million per year.

According to EPA, these emission reductions would also improve visibility in national and state parks, and increase protection for sensitive ecosystems including Adirondack lakes and Appalachian streams, coastal waters and estuaries, and forests.

The CSAPR, which was finalized in 2011, was designed to help states meet the 1997 ozone standards. Now that the CSAPR approach to define upwind state obligations under the good neighbor provision has been affirmed by the Supreme Court, EPA is applying this approach to the 2008 ozone NAAQS to help states address transported ozone pollution problems under recently strengthened standards. This proposal also responds to the July 2015 decision of the Court of Appeals for the D.C. Circuit and addresses the court’s concerns regarding ozone season NOx emissions budgets for 11 states.

EPA will accept comments for 45 days after publication in the Federal Register and will hold a public hearing on December 17, 2015 in Washington, DC.


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