Reducing air pollution in our national parks

Regional Haze Rule will improve visibility and health in Texas national parks

National Parks Service | Public Domain
Guadalupe Mountains National Park

When people go to visit the beautiful parks and scenery Texas has to offer, one of the big appeals is the incredible views. But the pollution often seen in cities is a problem in our parks too, and it drastically reduces how much we can see.  For example, according to the National Parks Conservation Association, “haze pollution decreases visibility in Big Bend National Park by as much as 70% some days.”  

Fortunately, the EPA has proposed stricter requirements for some Texas coal-fired power plants that would reduce pollution and improve community health across Texas.

Regional haze is a mixture of particulate matter, nitrogen oxides, sulfur dioxides, and volatile organic compounds (VOCs) that reduces visibility in our national parks and decreases air quality in general. The 1977 Clean Air Act set a goal of preventing and remedying impaired visibility in the nation’s 156 largest and oldest parks—designated Class 1 areas—and in 1999 the Regional Haze Rule was created to regulate this. 

Texas is home to two Class 1 areas: Big Bend National Park and Guadalupe Mountains National Park. The rule requires states to work with the EPA and other federal agencies and establish a plan every 10 years to continually address air pollution in the parks. The pollutants that cause haze, such as sulfur dioxide and ozone, are also hazardous to human health, and are linked to respiratory issues, heart attacks, and premature death in people with heart or lung disease. Though the Regional Haze Rule is focused on increasing natural visibility in national parks, the communities that are affected by the same pollution sources and the parks would see improvements in air quality and health as well.

The EPA’s proposal is an update to Texas’s original plan and would require new or upgraded sulfur dioxide controls at five coal plants (Martin Lake, Harrington, Coleto Creek, WA Parish, and Welsh) which would reduce their emissions by 90%. (The company that owns the Coleto Creek plant, Vistra Corp., has said that they would be exempt from this proposal because the plant is closing in 2027.) For an idea of the pollution these plants create, the Martin Lake plant emits 46,549 tons of sulfur dioxide per year; in 2020 it was the largest source of sulfur dioxide pollution and mercury pollution in the US.

Shivani Desai | TPIN
Texas coal plants impacted by Regional Haze Rule

After this update is finalized, the EPA will review Texas’s plan for the second round of the rule. Unfortunately, the plan proposed by the TCEQ is weak and does not take any new steps to limit air pollution. It only addresses a few of the major sources of air pollution in Texas, and does not require any updated controls for those sources. Multiple environmental groups, including Environment Texas, have urged the EPA to not accept the plan as it currently stands. To most effectively reduce pollution, strict enforcement of emission limits is critical.

A strong Regional Haze Rule plan for Texas offers a chance to protect the health of the people of Texas and the beauty of our parks. If we do, as Willie Nelson sings, we’ll have “blue skies smilin’ at me. Nothing but blue skies, do I see.”


Shivani Desai


Luke Metzger

Executive Director, Environment Texas

As the executive director of Environment Texas, Luke is a leading voice in the state for clean air, clean water, clean energy and open space. Luke has led successful campaigns to win permanent protection for the Christmas Mountains of Big Bend; to compel Exxon, Shell and Chevron Phillips to cut air pollution at three Texas refineries and chemical plants; and to boost funding for water conservation, renewable energy and state parks. The San Antonio Current has called Luke "long one of the most energetic and dedicated defenders of environmental issues in the state." He has been named one of the "Top Lobbyists for Causes" by Capitol Inside, received the President's Award from the Texas Recreation and Parks Society for his work to protect Texas parks, and was chosen for the inaugural class of "Next Generation Fellows" by the Robert S. Strauss Center for International Security and Law at UT Austin. Luke, his wife, son and daughters are working to visit every state park in Texas.

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