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.

Draft Guidance on Progress Tracking Metrics, Long-term Strategies, Reasonable Progress Goals and Other Requirements for Regional Haze State Implementation Plans for the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)

General Principles for 5-year Regional Haze Progress Reports (April 2013)