Press Release Jun 15, 2023

Conservation Groups Sue EPA to Enforce State Plans, Clear Haze Pollution

NPCA, Sierra Club, Environmental Integrity Project and Earthjustice filed suit against the Environmental Protection Agency to clear hazy skies.

WASHINGTON - Today, a coalition of environmental organizations filed a lawsuit against the Environmental Protection Agency (EPA) for failing to enforce the Regional Haze Rule required by the Clean Air Act. Despite its mandate to approve or reject state haze plans within 18 months, EPA has failed to act on Regional Haze plans submitted by Kansas, Massachusetts, Michigan, New York, Ohio, Texas and Wisconsin. The agency’s failure to act would enable the continued release of preventable haze-causing emissions that harm the health of our communities and blur landscapes at our most scenic national parks and wilderness areas.

The organizations’ lawsuit urges EPA to fulfill its obligation under the Clean Air Act and require big polluters to reduce emissions and increase visibility throughout the country’s public lands. The lawsuit was filed in the U.S. District Court for the District of Columbia and can be found here. The Environmental Integrity Project, National Parks Conservation Association and Sierra Club filed the lawsuit, represented by Earthjustice and Sierra Club attorneys. 

Haze pollution affects 90 percent of our country’s national parks by muddying some of the most sought-after views and making the air dangerous to breathe. In addition, air pollution is particularly harmful for those living closest to facilities who are most often communities of color facing the disproportionate brunt of this industrial pollution. Fossil fuel emissions and other industrial sources intensify the harms of our changing climate, further jeopardizing the health of our communities and national parks across the country and driving up healthcare costs.

Haze is smog-like dirty air caused by sulfur dioxide, nitrogen oxides and other pollution from coal-fired power plants and industrial sources, which travels across the country. The Clean Air Act requires states to reduce their haze pollution that harms any of the 156 U.S. national parks and wilderness areas designated as “Class I Areas,” which receive special air quality and visibility protection and include Guadalupe Mountains National Park in Texas and Isle Royale National Park in Michigan. Drifting downwind from the eight states named in the lawsuit, haze pollution travels hundreds of miles across park boundaries, harming air quality and obscuring park views in beloved places as far away as Shenandoah National Park in Virginia and Acadia National Park in Maine.

The same sources of pollution that reduce visibility at Big Bend National Park up to 70 percent are also fueling the climate crisis, and the consequences are alarming. Climate change has increased the frequency and intensity of wildfires across the Americans west, including Yosemite National Park; raised sea levels at the Statue of Liberty and other coastal parks; and accelerated the melting of namesake glaciers at both Glacier Bay National Park and Preserve and Glacier National Park. With 100 million Americans recently under air quality alerts following Canada wildfire smoke billowing across the eastern United States, the need for EPA’s action against ongoing haze pollution for existing plants – and known bad actors – is overdue.

Statement by Ulla Reeves, the National Parks Conservation Association’s Campaigns Director, Clean Air Program:

“Visitors travel from all over the world to experience clear views and fresh air in national parks. Nobody wants to be met with dirty air and disappointing views, yet haze pollution continues to harm communities’ health and robs people of their ability to enjoy public lands. Through their failure to act to protect human health and our environment, EPA is allowing haze pollution to threaten our communities, our health and our parks. It’s well past time for EPA to respond and hold states accountable – we don’t have time to wait.“

Statement by Bill Corcoran, Director of Sierra Club’s Beyond Coal Campaign:

"Utilities and corporations continue to dirty our beautiful parks with air pollution from poorly controlled facilities like coal-burning power plants. There are proven, industry-standard solutions being used today throughout the country to clean up these facilities, which also harm the health of people in downwind communities. Timely enforcement by the EPA of its rule to reduce regional haze will protect wild and scenic places that millions of Americans will visit this summer and improve our nation’s air quality. We take this action today to press for no further delays in getting the job done.”

Statement by Charles McPhedran, Senior Attorney, Earthjustice:

“Pollution reductions protect both the health of people downwind and the view from the mountaintop. The EPA must take action on these state plans.”

New Jersey was incorrectly listed as a state in the complaint in a previous version of this press release. The release has now been updated to reflect the complaint filed on June 15, 2023.


About the National Parks Conservation Association: Since 1919, the nonpartisan National Parks Conservation Association has been the leading voice in safeguarding our national parks. NPCA and its more than 1.6 million members and supporters work together to protect and preserve our nation’s most iconic and inspirational places for future generations. For more information, visit

About the Sierra Club: The Sierra Club is America’s largest and most influential grassroots environmental organization, with millions of members and supporters. In addition to protecting every person’s right to get outdoors and access the healing power of nature, the Sierra Club works to promote clean energy, safeguard the health of our communities, protect wildlife, and preserve our remaining wild places through grassroots activism, public education, lobbying, and legal action. For more information, visit

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