Principal Visibility Documents

Protecting Visibility in National Parks and Wilderness Areas. The 1993 National Research Council report describing the current understanding of the nature and extent of haze in the United States. The book addresses the scientific and legal framework of efforts to protect and improve visibility, as well as methods for assessing the relative importance of anthropogenic emission sources that contribute to haze in national parks and for considering various alternative source control measures.

Visibility: Existing and Historical Conditions – Causes and Effects. Chapter 24 from the October 1990 NAPAP report “Acid Deposition: State of Science and Technology”. A technical document that reviewed, evaluated and synthesized the current scientific information, at that time, regarding visibility.

Protecting Visibility: An EPA Report to Congress. The 1978 EPA report to Congress in response to the requirement of Section 169A of the Clean Air Act. The report reviews the fundamentals of visibility impairment, significant source of visibly impairment and control strategies for remedying visibility impairment by man-made air pollution in the class I Federal areas.

1985 Visibility Certification  The Department of Interior provided information to EPA regarding integral vistas and existing visibility impairment in class I areas.  The memo also provided information regarding potential visibility monitoring approaches.