WASHINGTON — The Environmental Defense Fund, the Adirondack Council and the Sierra Club want to join New York, New York City and New Jersey in suing the U.S. Environmental Protection Agency over air pollution from other states.

The groups filed a motion with the U.S. Court of Appeals for the D.C. Circuit Tuesday, asking to join the states’ lawsuit. The states turned to the courts after the Trump administration denied a New York petition for help under the “Good Neighbor” provisions of the Clean Air Act.

“The Adirondack Park is a national treasure that New York cannot protect on its own,” William Janeway, executive director of the Adirondack Council, said in a press release. “We need EPA to order that the dirtiest coal-fired power plants upwind of us to turn on their summertime smog controls. Those pollution-control devices also protect the Adirondacks from acid rain. Since 2017, EPA has left us exposed when the law requires EPA to protect us. We have no choice but to sue and seek justice through the courts.”

States’ efforts to reduce smog are often undermined by the dirtier air that blows across their borders from coal-burning plants and other sources in upwind states.

In March 2018, New York asked the EPA to realize that pollution from sources in nine states — Illinois, Indiana, Kentucky, Maryland, Michigan, Ohio, Pennsylvania, Virginia and West Virginia — is significantly interfering with its ability to meet our national health-based smog standards.

The Clean Air Act requires the EPA to safeguard downwind states against smog-forming pollution from coal-fired power plants and other sources in upwind states, but the Trump administration refused New York’s request for help. Last month, the state of New York, the city of New York, and the state of New Jersey filed a lawsuit challenging that refusal.

Trump’s EPA has also denied requests from Maryland and Delaware for help with border-crossing pollution. Both states have gone to court over those decisions. The Environmental Defense Fund, Adirondack Council and Sierra Club are part of a coalition of health, environmental and community groups that joined the lawsuit in support of the states. New York and New Jersey are supporting Maryland and Delaware in that case as well.