There are times when haze obscures the valleys below Shenandoah and Sequoia national parks, when high ground-level ozone levels at Great Smoky Mountains National Park are unhealthy, and when water tests from high-country locations in the National Park System show traces of heavy metals.

Viewsheds throughout the National Park System, at places such as Grand Canyon National Park and Mesa Verde National Park, are daily being impacted by air pollution, which also contributes to unnaturally high nitrogen levels in places such as Rocky Mountain National Park.

While the Environmental Protection Agency and Interior Department are supposed to be protecting these airsheds, a coalition today said the agencies were failing in that task and would be sued to be forced to uphold their responsibilities.

“Every year, millions of visitors to our national parks and wilderness areas are unable to see the postcard views because they have been obscured by haze pollution,” said Stephanie Kodish, the National Parks Conservation Association's clean air counsel. “More than 30 years ago Congress committed to restore clean, clear air to America’s most prized national parks and wilderness areas. But EPA has repeatedly escaped its duty to regulate polluters by missing deadlines to develop and implement meaningful plans to reduce air pollution that makes people sick and skies look more like muddy water than the crystal-clear views they once were.”

“Americans go to national parks to breathe clean air, not choke on soot and smog,” Earthjustice Attorney David Baron added in a press release stating the groups' intentions. “It's time for the states and the EPA to clean up the air in parks and wilderness areas as required by the Clean Air Act. Leaving our mountains and canyons buried under filthy haze is not an option.”

According to that release, today the groups are filing a formal "notice of intent to sue" to force the EPA to finalize "state plans to substantially reduce haze pollution in all protected national parks, wilderness ares, and wildlife refuges" as required by the Clean Air Act. That requirement was to have been met by last Saturday, January 15, the groups said

"But, EPA has failed to finalize a single state’s haze reduction plan, missing more than 50 regulatory deadlines. Today’s action, the filing of formal notices of intent to sue, is an effort to ensure EPA complies with the Clean Air Act’s Regional Haze program and move clean air plans forward after decades of delay," the release said.

“Through the Regional Haze program, state and federal agencies have an unprecedented opportunity to ensure healthier air and clearer scenic vistas by requiring affordable and routine controls that reduce air pollution from industrial sources like coal-fired power plants,” Ms. Kodish said. “The regional haze program was designed to reduce pollution and restore pristine visibility to national parks and wilderness areas. The Federal government must swiftly act to enforce this program.

The groups said the legal action address "only a portion of the Clean Air Act’s provisions that have yet to be fully implemented. In the coming months, EPA is expected to finalize new regulations under the 'good neighbor' provision of the act to reduce interstate transport of pollution to states that are downwind, and stronger air quality standards for ozone. The agency is also expected to soon propose a utility toxics rule that addresses mercury and other pollutants from coal and oil fired utility boilers. These actions complement the actions that are being sought by these legal filings and represent a great opportunity for putting the right policies in place to clean the air, restore our national parks and improve public health."

Along with NPCA, groups involved in the legal action include the Powder River Basin Resource Council, Montana Environmental Information Center, Grand Canyon Trust, Sierra Club, Environmental Defense Fund, WildEarth Guardians, San Juan Citizens Alliance, Our Children’s Earth, and Plains Justice.

In addition, NPCA, Grand Canyon Trust, Sierra Club, Dooda (NO) Desert Rock, To Nizhoni Ani, WildEarth Guardians, Northwest Environmental Defense Center, Washington Wildlife Federation, San Juan Citizens Alliance, and the Center for Biological Diversity have joined to file an “unreasonable delay” lawsuit against the Interior and Agriculture departments. The lawsuit is in reaction to the failure by these agencies to find that pollution from Navajo Generating Station in Page, Ariz., TransAlta/Centralia power plant in Centralia, Wash., and Four Corners Power Plant in Fruitland, NM, "devastate air quality in gems such as Mesa Verde National Park in Colorado, Mount Rainier and Olympic National Parks in Washington, and Grand Canyon and Petrified Forest National Parks in Arizona," the release said.

These petitions ask DOI, and in the case of Four Corners DOA, to protect public lands by certifying that specific large, outdated coal-fired power plants are causing haze pollution in these national treasures. To date, little progress has been achieved with the two agencies regarding a formal certification of visibility impairment around these sites, according to the groups.

“Our Rocky Mountain highs are increasingly under siege from haze, especially here in Colorado, yet it's a problem we can easily solve,” said Jeremy Nichols, Climate and Energy Program director for WildEarth Guardians. “With sensible plans to limit air pollution, we can finally protect parks, people, and our cherished western landscape.”

For data and photos that describe the air pollution problems across the National Park System and in wilderness areas, visit this site.