The U.S. Environmental Protection Agency said that it will deny petitions from Delaware and Maryland regulators claiming that emissions from upwind power plants prevent them from complying with federal air-quality standards.
On May 31, the EPA issued a notice of proposed action in response to five petitions filed in 2016, including four from the Delaware Department of Natural Resources and Environmental Control and one from the Maryland Department of the Environment. The Delaware agency filed separate petitions against four power plants in West Virginia and Pennsylvania — Harrison, Homer City, Brunner Island and Conemaugh
Ozone is formed in the atmosphere as a result of a reaction between nitrogen oxides and volatile organic compounds emitted from sources such as cars, power plants, refineries and chemical plants, according to the EPA. The EPA in 2008 required states to meet a 75 parts per billion ozone standard and in 2015 lowered that standard to 70 ppb.
The Maryland Department of the Environment petitioned the EPA in November 2016 claiming that NOx emissions from 36 coal-fired power plants across Indiana, Kentucky, Ohio, Pennsylvania and West Virginia prevent it from meeting the EPA's ozone standards.
Section 126(b) of the Clean Air Act allows states to petition the EPA to directly regulate upwind sources. But the EPA said that neither state demonstrated that the upwind sources violated the Clean Air Act's "good neighbor provision," which prohibits emissions from one state from interfering with another state's ability to comply.
The EPA also affirmed that an October 2016 update to the Cross-State Air Pollution Rule already addresses interstate power plant emissions and limits ozone emissions from Pennsylvania power plants.
Maryland Secretary of the Environment Ben Grumbles said on June 1 that he "strongly disagrees" with the EPA's proposal to deny his petition. "We're not asking for those power plants to do anything that we're not already doing in Maryland. We will testify in opposition to the proposal and use all available tools, including litigation, to ensure we can keep our commitment to upholding aggressive air quality standards and protecting the Chesapeake Bay," Grumbles said.
The Delaware Department of Natural Resources and Environmental Control could not be reached immediately for comment.
On April 6, the EPA also denied a June 1, 2016, petition from the Connecticut Department of Energy and Environmental Protection regarding NOx emissions from the Brunner Island plant in York County, Pa. The EPA found no further need to control NOx emissions from the dual-fueled plant, which burned mostly natural gas instead of coal in 2017 and significantly dropped ozone emissions below 2016 levels.
The EPA will take comment on its proposal to deny the petitions from Maryland and Delaware for 45 days after the notice is published in the Federal Register.
