Regional Haze - Resources
Many of the following documents and links are in Portable Document Format (PDF). (Help with PDF.)
EPA Documents
- EPA Questions and answers on regional haze and BART, Additional Regional Haze Questions, September 27, 2006
Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Rule, 2003 
Guidance for Tracking Progress Under the Regional Haze Rule, 2003
Related Links
For more information on the Texas SIP, see the TCEQ’s main SIP Web page.
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:
- Introduction to Visibility (PDF, 79 pp., 3.1 MB)—Report by William Malm, NPS, and Colorado State Institute for Research on the Atmosphere
- Big Bend National Park
- Air Quality & Visibility in Big Bend
- BRAVO Study (Big Bend Regional Aerosol and Visibility Observational), two-page fact sheet
- Guadalupe Mountains National Park
IMPROVE (Interagency Monitoring of Protected Visual Environments)
Visibility: Existing and Historical Conditions-Causes and Effects, 1990 Acidic Deposition: State of Science and Technology, Report 24. National Acid Precipitation Assessment Program. This report is a review of scientific information regarding visibility, especially the relationship of visibility causing air pollutants with nitrogen dioxide, nitrate aerosols, and sulfate aerosols.
Visibility Information Exchange Web System (VIEWS) Online air quality data and research designed to help understand the effects of air pollution on visibility and to support the Regional Haze Rule enacted by the EPA to improve visibility in national parks and wilderness areas.
Western Regional Air Partnership (WRAP)
The Causes of Haze Assessment (COHA) Desert Research Institute in Las Vegas. An online report that answers questions about the chemical components that cause regional haze, the relationships between haze and meteorology, the emissions that cause haze, and the effects of previous and future emissions reductions on the poorest and best visibility levels at all Class I areas in the WRAP and CENRAP regions.
