Regional Planning Organizations (RPOs) have formed to address pollution contributing to regional haze that degrades visibility in class 1 areas. RPOs are made up of a mix of federal, state, and tribal personnel who gather information about pollution contributing to haze in their region, and develop plans to reduce it.
Currently there are five Regional Planning Organizations covering the United States, they include:
More information about RPO's, and links to the above organizations, are provided by the EPA at the following link http://www.epa.gov/
Source: U.S. Environmental Protection Agency.2012. Regional Planning Organizations. Visibility. Accessed on 9 September 2013. http://www.epa.gov/