Delaware and Maryland have been pleading for years with the Environmental Protection Agency to help address the smog pollution they say is blowing across their borders from coal-fired power plants in other states and making their residents sick.

The Trump EPA just said no.

The 111-page notice of denial from the agency shows that Acting EPA Administrator Andrew Wheeler, a former coal industry lobbyist, is following in the fossil fuel-friendly policy direction set by his predecessor, Scott Pruitt, while being more cautious to spell out the agency's legal reasoning.

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Since President Donald Trump took office, the EPA has made a long list of moves to delay, weaken or repeal environmental protections that target pollution. It includes proposals to loosen coal ash disposal rules and to weaken the Clean Power Plan, the Obama administration's signature initiative to address climate change, which also would dramatically reduce smog, particulate matter, mercury and other dangerous air pollutants by slashing the amount of coal the country burns.

Maryland and Delaware had asked EPA to require upwind coal plants to reduce their emissions of smog-forming nitrogen oxide (NOx) pollution under a provision of the Clean Air Act. Maryland's petition, for example, asked that the EPA to require about three dozen plants in Indiana, Kentucky, Ohio, Pennsylvania and West Virginia to run their already-installed pollution control equipment during the summer months.

EPA: There Isn't Sufficient Evidence

Pruitt had sat on the petitions, along with a similar request from the state of Connecticut, for months without acting. Federal courts ruled four times this year that such delays were illegal—most recently on June 13, when a federal judge in Maryland ordered the EPA to act on that state's petition.

In the notice signed by Wheeler on Friday, the EPA said that it does not have sufficient evidence that upwind states and sources are significantly contributing to the downwind states' problems with ground-level ozone, or smog.

The agency also said any cross-border pollution problems should be dealt with under another section of the law. And it said there was no evidence that there were further cost-effective steps the coal plants could take to make pollution reductions beyond the requirements of that law.

States Worry About Residents' Health

Delaware had filed four separate petitions asking EPA to address the pollution from separate coal plants in Pennsylvania and West Virginia.

It wrote that one of the plants, Brunner Island in Pennsylvania, has no post-combustion controls installed to limit NOx pollution. The EPA said it expected Brunner Island would operate on natural gas in the future, stating in a footnote that the power plant's operator, Talen Energy, had agreed to phase out use of coal at the plant in a proposed consent decree with Sierra Club. That agreement, however, would still allow coal-burning through 2028.

"EPA's irresponsible decision to deny these petitions will cause unnecessary risk to the health of millions of Americans," said Graham McCahan, a senior attorney for Environmental Defense Fund, which had joined in Maryland's case.

Smog, which is formed when two fossil fuel combustion pollutants—NOx and volatile organic compounds (VOCs)—mix in the presence of sunlight, is linked to premature deaths, hospitalizations, asthma attacks and long-term lung damage. Although smog has been greatly reduced in the United States, more recent science shows that even low levels of smog can be hazardous to health.

"Maryland and Delaware have offered proven and affordable solutions to the problem of dangerous air pollution that is encroaching on them from neighboring states," McCahan said. "We'll keep working to help them—and other downwind states—provide cleaner, safer air for their people."