Press Release Apr 21, 2023

EPA Proposes Strong Rule to Curb Haze in National Parks

Groups applaud regulation that would reduce pollution from Texas coal plants

DALLAS, Tex. – Recently the U.S. Environmental Protection Agency (EPA) released a strong draft rule to reduce Texas coal plant pollution that causes regional haze in national parks and wilderness areas across the central United States. The federal Clean Air Act requires states to protect visibility in these places by reducing regional haze, a smoggy-like substance caused by sulfur dioxide pollution from power plants and industrial sources. Because the haze plan from the Texas Commission for Environmental Quality (TCEQ) was so inadequate, the law required EPA to step in to propose the robust federal plan, which would require six of the largest Texas coal plants to collectively cut their sulfur dioxide pollution to 80,000 tons per year. This would nearly halve the state’s overall sulfur dioxide emissions from the biggest haze polluters.

“EPA’s decision is a victory for Texas’s beloved Guadalupe Mountains and Big Bend National Parks, as well as visitors and communities living nearby. Alongside thousands of Texans, NPCA called on EPA to prioritize the health and future of Texas’ parks and people for decades. This long overdue announcement shows that we have finally been heard,” said Cary Dupuy, Texas Regional Director for the National Parks Conservation Association. “Pollution from Texas’ coal plants put our national parks at risk, dirtying the air and blurring the unique, breathtaking views that people travel from around the world to experience – yet we have cost-effective technology readily available to reduce emissions. This proposal is a major step towards restoring scenic views in our state’s most iconic and pristine national parks.”

Texas coal plants emit more haze-causing sulfur dioxide than any other state in the country. In fact, Texas emits more than twice as much pollution as all coal plants in Arkansas, Oklahoma, Louisiana, and New Mexico combined. Sulfur dioxide converts into fine particulate matter, which can travel long distances and create haze and unhealthy air across the state and country as well as for marginalized communities near pollution sources, like the Martin Lake coal plant in East Texas and the Parish coal plant near Houston. More than 80% of haze-causing pollution in Texas comes from coal and gas power plants – many of which lack modern pollution controls.

Home to beloved big sky views, Big Bend and Guadalupe Mountains national parks attracted over 700,000 visitors to Texas in 2022 alone. Yet today, people are prevented from fully experiencing the parks’ natural wonders due to the haze pollution obscuring the color and clarity of long-range views. Haze pollution decreases visibility in Big Bend National Park by as much as 70% some days. Guadalupe Mountains National Park, meanwhile, has 3,000-foot cliffs that are uniquely vulnerable to the negative consequences of muddy skies.

“We enthusiastically support this much-needed rule that will clear our parks’ skies for all who visit,” said Emma Pabst, campaign representative for the Sierra Club’s Beyond Coal Campaign. “People travel long distances to behold Big Bend and Guadalupe Mountains national parks here in Texas and to find solace in nature, to feel connected to the larger environment, and to simply hear themselves think. We must ensure that these lands – which provide access to this essential experience to all people – are protected. TCEQ has consistently failed to reduce haze, so the EPA must bring the state into compliance with the law.”

While parts of the proposed rule – such as requirements for particulate matter and nitrogen oxide pollution – could have been stronger, the draft EPA rule is significant. The aging Martin Lake, Parish, Fayette, Harrington, Coleto Creek, and Welsh coal plants – all in Texas – would have to install or upgrade their pollution controls to meet modern standards. This would help clear skies in Texas and in national parks around the country. EPA will soon start accepting public comments on the draft and will schedule a public hearing for feedback, after which the agency can revise the rule. Groups expect EPA to finalize the haze rule later this year.


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