Visibility - Guidance Documents
EPA has provided guidance to states and tribes to assist in the implementation of the Regional Haze Rule. The guidance documents listed below are not regulations and do not change or substitute for any legal requirements in the Clean Air Act or Regional Haze Rule. This page contains a chronological listing of recent guidance documents related to visibility.
Memo and Technical Addendum on Ambient Data Usage and Completeness for the Regional Haze Program (June 3, 2020)
Technical Support Document for EPA’S Updated 2028 Regional Haze Modeling (September 19, 2019)
Guidance on Regional Haze State Implementation Plans for the Second Implementation Period (August 20, 2019)
Technical Guidance on Tracking Visibility Progress for the Second Implementation Period of the Regional Haze Program (December 20, 2018)
General Principles for 5-year Regional Haze Progress Reports (April 2013)
Guidance for Tracking Progress Under the Regional Haze Rule (September 2003) (Note: this document is relied upon by the 2018 Technical Guidance on Tracking Visibility Progress for the Second Implementation Period of the Regional Haze Program, listed above)