EPA's regional haze regulations called for states to establish strategies for improving visibility in Class I areas as defined by the Clean Air Act. Class I areas include national parks greater than 6,000 acres, wilderness areas and national memorial parks greater than 5,000 acres, and international parks that existed as of August 1977. The 156 Class I areas include many of our best-known and most-treasured national parks, such as Acadia, Everglades, Grand Canyon, Great Smoky Mountains, Mount Rainier, Shenandoah, Yellowstone, and Yosemite.

Idaho's Class I areas include the Sawtooth Wilderness Area, Craters of the Moon, Yellowstone National Park, Hells Canyon, and Selway-Bitterroot Wilderness Area. Learn more about Idaho's Class I areas.

In 1980, the U.S. Environmental Protection Agency (EPA) issued the first phase of regulations to address haze-causing pollutants from large industrial facilities (stationary sources) that were contributing to visibility impairment in Class I areas. These sources include large manufacturing-type facilities or utilities such as coal-fired power plants.

The second phase of visibility regulations addresses the regional transport of haze-causing pollutants, or "regional haze." Haze-causing pollutants can travel great distances. Therefore, when addressing haze within its borders, states must also consider the sources of haze from other states. In addition, sources of regional haze include non-stationary sources such as car exhaust, fires, and smaller businesses not regulated under stationary source programs. In 1980, EPA declined to issue rules addressing regional haze, citing the need for more research.

In 1990, Congress amended the Clean Air Act again and authorized further research and regional assessment reports on the issue of regional haze. Regional commissions formed to study and issue recommendations to EPA to address regional haze. Nine western states, including Idaho, were invited to participate in the Grand Canyon Visibility Transport Commission (GCVTC), which formed in 1991 to study, analyze, and make recommendations on visibility affecting Grand Canyon National Park and western U.S.

GCVTC members included the governors of eight western states and leaders of four western tribal nations, as well as federal land management agencies. In 1996, the GCVTC issued its final report and recommendations to address regional haze in the western U.S. Many components of the current Regional Haze Rule are based on these recommendations.

In 1997, the eight GCVTC states and Idaho formed the Western Regional Air Partnership, known as WRAP. The WRAP is administered jointly by the Western Governors' Association and the National Tribal Environmental Council and provides a forum for state and tribal leaders to coordinate efforts to reduce haze-causing emissions. WRAP is still active today, providing technical and policy assistance and coordination to its member states. Find out more on the WRAP Web site.

In 1999, EPA used recommendations from the GCVTC and other commissions to develop a regional haze program and regional haze rules. The Regional Haze Rule calls for states to establish goals for improving visibility in national parks and wilderness areas and to develop long-term strategies for reducing emissions of air pollutants that cause visibility impairment.

The Regional Haze Rule requires states to establish goals for each affected Class I area and make reasonable progress toward

1. improving visibility on the haziest days and
2. ensuring no degradation occurs on the clearest days over the period of each implementation plan.

In December 2007, Idaho must submit a state implementation plan (SIP) to EPA addressing how it will improve and protect visibility in its Class I areas and those Class I areas outside its borders. The SIP will address the three major haze-causing pollutants, nitrogen oxides (NOx ), particulate matter, and sulfur dioxide (SO2). Under the SIP, Idaho will set reasonable progress goals to improve and protect visibility for each Class I area.

Under the rule, EPA strongly encourages states to work together in developing and implementing their air quality plans. Today, DEQ is working with other states and federal land managers to implement requirements of the Regional Haze Rule. Idaho is an active participant in WRAP. Learn more about Idaho's efforts to improve visibility in our scenic areas.