What is CENRAP?
The Central Regional Air Planning Association - CENRAP - is an organization of States, Tribes, Federal agencies and other interested parties that identifies regional haze and visibility issues impacting national parks and wilderness areas and develops strategies to improve visibility. CENRAP is one of the five Regional Planning Organizations across the United States and includes the States and Tribal areas of Arkansas, Iowa, Kansas, Louisiana, Minnesota, Missouri, Nebraska, Oklahoma, and Texas.

What is an RPO?
A Regional Planning Organization - RPO - is a multi-state organization that addresses regional haze and related issues. The RPO will first evaluate technical information to better understand how member States and Tribes impact national park and wilderness areas - Class I areas - across the country and then will then pursue the development of regional strategies to reduce emissions of particulate matter and other pollutants that lead to impaired visibility. There are currently five RPOs in the United States. To learn more about them, go to http://www.epa.gov/air/visibility/regional.html.

What are the goals of CENRAP?
A. The goal of CENRAP is to address regional haze and visibility issues across the region in consultation with its members, to ensure fair and equitable treatment as State and Tribal air pollution policies are developed. To accomplish this, CENRAP provides coordination of science and technology to support air quality policy issues; recommends strategies on air quality issues for use by member states and tribes in developing implementation programs, regulations and laws; and conducts research and undertakes other activities as necessary for information to support the development of sound state and tribal air pollution policies.

What is the Regional Haze Rule?
The Regional Haze Rule, implemented by the EPA in 1999, calls for State, Tribal and Federal agencies to work together to improve visibility in 156 national parks and wilderness areas - Class I areas - such as the Grand Canyon, Yosemite, Big Bend, and Boundary Waters Canoe Area. The rule requires the States, in coordination with EPA, National Park Service, U.S. Fish and Wildlife Service, U.S. Forest Service, and other interested parties, to develop and implement air quality protection plans to reduce the pollution that causes visibility impairment.

What is haze?
Haze is caused when sunlight encounters tiny particles in the air. Some light is absorbed by particles. Other light is scattered away before it reaches an observer. More particles mean more absorption and scattering of light, which reduce the clarity and color of what we see. These particles may come from natural sources, such as windblown dust and soot from wildfires, or from manmade sources, such as motor vehicles, industrial processes, prescribed burning and agricultural operations.