Zion National Park, near Springdale, Utah, is one of 156 national parks and wilderness areas covered by the U.S. Environmental Protection Agency's regional haze program.
The U.S. Environmental Protection Agency issued final guidance Aug. 20 allowing states to rely more heavily on visibility improvements and the effect of previous power-sector rules as they work to comply with a federal program aimed at reducing regional haze.
The final guidance replaces earlier Obama-era draft guidance and gives states more leeway to weigh the cost of pollution controls against the visibility gains the equipment is expected to produce.
Enacted under the Clean Air Act, the EPA's regional haze program requires states to develop implementation plans, known as SIPs, to improve visibility in 156 national parks and wilderness areas such as the Grand Canyon, Yosemite, Shenandoah and the Great Smoky Mountains. The first state plans for regional haze were due in December 2007, and comprehensive periodic revisions to those initial plans are due in 2021, 2028 and every 10 years thereafter.
Following nearly a decade of litigation over the initial round of SIPs, the EPA issued draft guidance in July 2016 to clarify how the agency expected states to comply with the program. With that draft guidance, the EPA directed states to weigh the cost of installing pollution controls at power plants and other emissions sources against projected reductions in visibility-impairing pollutants such as sulfur dioxide and nitrogen dioxide emissions on a per-ton basis.
In a key shift, however, the EPA's Aug. 20 final guidance encourages states to weigh the cost of pollution controls against the equipment's estimated impact on an area's overall visibility. The guidance also allows states to determine that coal-fired power plants and other emissions sources already have effective emissions controls in place if those units have added equipment to comply with the EPA's 2012 Mercury and Air Toxics Standards.
The EPA's new recommended approach "is to recognize that visibility is the ultimate focus of the program and states ought to consider that against the costs and other impacts associated with the control measures," Mack McGuffey, a partner at Troutman Sanders LLP who represented states in regional litigation, said Aug. 21 in an interview.
Janet McCabe, who served as acting assistant administrator in the EPA's air office during the Obama administration, said in an interview that the earlier draft sought to achieve consistency. "Under the prior guidance, we wanted to give states a fair, consistent and appropriate metric for how much pollution reduction you're getting for every dollar you spend," McCabe said. "Visibility modeling is more complicated."
An attorney representing the National Parks Conservation Association in ongoing regional haze litigation argued that the new guidance creates uncertainty for states and industry with the second round of regional haze planning already underway. "It tells states that they can ignore best technologies, they can pretend like some sources of pollution don't exist, and there's really no urgency in reducing pollution," Stephanie Kodish, the group's senior director and counsel on clean air and climate, said in an interview.
The EPA is considering further changes to the regional haze rule finalized in the last days of the Obama administration, according to a "Regional Haze Reform Roadmap" that EPA Administrator Andrew Wheeler signed in September 2018. Litigation challenging the January 2017 regional haze rule is on hold in the U.S. Court of Appeals for the District of Columbia Circuit as the Trump administration proceeds with that review.