The Environmental Protection Agency has tentatively denied a request from Maryland and seven other states that it crack down on pollution that blows across state borders — though not because regulators don't recognize that interstate smog is a problem.
The states had asked in 2013 that nine Midwestern and Southern states be included as part of the region that's held responsible for the summertime smog they send elsewhere around the Northeast and Mid-Atlantic.
While acknowledging the problem, the EPA said Wednesday there are other strategies the states could take under federal air pollution laws to address it.
EPA officials said the federal Clean Air Act "provides other, more effective mechanisms to address the transport of ozone between states and the impact this pollution has on the states."
Maryland officials called the decision disappointing, but said they are focused on other tactics to clean polluted air that blows into the state with the wind. That includes a petition the state made to EPA in November calling for the agency to force 19 coal power plants in five states to more consistently use emission-cleaning technology they have installed.
"Maryland will continue to insist on more environmental progress by our upwind partner states," said Ben Grumbles, secretary of the Maryland Department of the Environment. "We are committed to using all available and appropriate tools."
Connecticut, Delaware, Massachusetts, New Hampshire, New York, Rhode Island and Vermont had joined Maryland in the request to add Illinois, Indiana, Kentucky, Michigan, North Carolina, Ohio, Tennessee, West Virginia and a portion of Virginia to what is known as the Ozone Transport Region.
Ozone is a type of oxygen molecule that is beneficial at upper levels of the atmosphere but contributes to respiratory illnesses and heart disease when it propagates closer to the ground. Ozone pollution forms on hot summer days when heat and sunlight interact with industrial and vehicle emissions.
Maryland officials estimate that 70 percent of the ozone pollution that affects the state blows in from upwind.
The EPA's tentative denial will now be put forward for a 30-day public comment period, and Maryland officials may submit testimony, Grumbles said.
After that, the decision could become final.
New York and several other states within the ozone region had filed a lawsuit against the EPA demanding that it made a decision on the 2013 request, but Maryland officials declined to join it.
Maryland's separate petition regarding pollution enforcement at 19 coal plants is still pending. The Obama administration delayed acting on it, Grumbles said, so the state will have to work with the incoming administration of President-Elect Donald Trump to pursue any enforcement action.