The Committee selected the following environmental goal: A goal with the purpose of showing continued progress through 2018 by; 1) improving visibility to move days now in the poor/very poor categories up to the fair category, and 2) moving days classified as fair to the good/excellent categories. A progress
assessment will be conducted every 5 years through 2018. The members concluded that this option provides a clear, long term method to track visibility trends in the Phoenix metropolitan area. Additionally, the Committee reached general agreement that the index should not be used to affect short term actions because other programs, such as the High Pollution Advisory Program, are currently in place.

In March 2000, Governor Jane Hull convened the Brown Cloud Summit to examine methods to improve visibility in the Phoenix Metropolitan Area. As part of this Summit, a Visibility Standards Subcommittee was established to recommend methods for measuring visible air quality and tracking improvements in visible air quality over time. Based on its research, the Visibility Standards Subcommittee recommended that a visibility index be established through a public survey process representative of a cross-section of residents. Acting on the recommendation, ADEQ established the Visibility Index Oversight Committee. The Committee’s goal was to coordinate the involvement of Phoenix-area residents in the development of a visibility index.