Regional Haze: Resources
Many of the following documents and links are in Portable Document Format (PDF).
EPA Documents
Protection of Visibility: Amendments to Requirements for State Plans (January 10, 2017) Final Rule 
Technical Guidance on Tracking Visibility Progress for the Second Implementation Period of the Regional Haze Program (December 2018)
Draft Guidance on Progress Tracking Metrics, Long-term Strategies, Reasonable Progress Goals and Other Requirements for Regional Haze State Implementation Plans for the Second Implementation Period (June 30, 2016)
Best Available Retrofit Technology (BART) Rule, 2005
EPA Questions and answers on regional haze and BART, Additional Regional Haze Questions, September 27, 2006
Related Links
For more information on the Texas SIP, see the TCEQ’s Texas State Implementation Plan webpage.
Central States Air Resource Agencies (CenSARA)
- Causes of Haze for the Central States, August 2005—The analyses focused on the 20 percent of days with the worst visibility conditions and the 20 percent of days with the best visibility condition at Class I sites during 2000–04.
National Park Service (NPS):
- Introduction to Visibility (PDF, 79 pp., 3.1 MB), William Malm, NPS
- Big Bend National Park
- Air Quality and Visibility in Big Bend
- BRAVO Study (Big Bend Regional Aerosol and Visibility Observational)
- Guadalupe Mountains National Park
IMPROVE (Interagency Monitoring of Protected Visual Environments)
Federal Land Manager Environmental Database (FED) Provides an extensive database of environmental information to help Federal Land Managers analyze the air quality and visibility in federally protected areas such as the lands of the National Park Service, the US Forest Service and the US Fish and Wildlife Service.
Western Regional Air Partnership (WRAP)
