Protecting Air in Parks… It's The Law!

Graphic timeline showing major laws pertaining air. From left to right: 1916 NPS Organic Act, 1964 Wilderness Act, 1969 National Environmental Policy Act, 1970 Clean Air Act, 1977 Clean Air Act Amendments, 1990 Clean Air Act Amendments.

The National Park Service has responsibilities under federal law to protect air quality and resources that might be adversely affected by air pollution.

The National Park Service Organic Act created the agency in 1916 with the mandate to conserve the scenery, natural and cultural resources, and other values of parks in a way that will leave them unimpaired for the enjoyment of future generations. This statutory responsibility to leave National Park Service units “unimpaired,” requires us to protect all National Park Service units from the harmful effects of air pollution.

The Wilderness Act requires that an area designated as wilderness be “protected and managed so as to preserve its natural conditions.” Similar to the Organic Act, this mandate includes protection of air quality and related resources. The national park system has more than 44 million acres of wilderness in 50 national park units.

The National Environmental Policy Act (NEPA) recognizes that we all “should enjoy a healthful environment” and we have “a responsibility to contribute to the preservation and enhancement of the environment.” This act requires federal agencies to consider the environmental impacts of major actions on federal lands and encourages mitigation of adverse environmental impacts.

The Clean Air Act was passed in 1970 authorizing the development of comprehensive federal and state regulations to limit emissions from both stationary (industrial) sources and mobile sources. This initiated four major regulatory programs affecting stationary sources: the National Ambient Air Quality Standards, State Implementation Plans, New Source Performance Standards, and National Emission Standards for Hazardous Air Pollutants.

The Clean Air Act provides a framework for federal land managers such as the National Park Service to have a special role in decisions related to new sources of air pollution, and other pollution control programs to protect visibility, or how well you can see distant views. The Act also requires the Environmental Protection Agency to set air quality standards.

The 1977 Clean Air Act amendments established the Prevention of Significant Deterioration (PSD) program, which limits air pollution from future development for the benefit of national parks and other special areas. These amendments also established a national goal to prevent future and remedy existing visibility impairment in national parks larger than 6,000 acres and national wilderness areas larger than 5,000 acres that were in existence when the amendments were enacted, these are Class I areas. All other areas are Class II. Air quality in both Class I and Class II areas is protected under the Clean Air Act and the Organic Act. Because air pollution is often regional in nature, reductions in pollution to meet national ambient air quality standards, improve visibility, and address other Clean Air Act requirements will also improve air quality in national parks.

In 1990, additional Clean Air Act Amendments created regulatory programs to address acid rain and expanded the visibility protection and toxic air pollution programs. The acid rain regulations began a series of regional emissions reductions from electric generating facilities and industrial sources that have substantively reduced air pollutant emissions.

Last updated: August 26, 2022


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