Air Quality

What is regional haze?

Good visibility is essential to the enjoyment of national parks and scenic areas. “Regional haze” is air pollution that is transported long distances and reduces the visibility in these areas. 

The federal Clean Air Act contains requirements for states to protect and improve visibility in national parks and wilderness areas in the country. In 1977 Congress designated certain national parks and wilderness areas as “Class I areas”, where visibility was identified as an important value. Oregon has 12 Class I areas, including Crater Lake National Park and 11 wilderness areas. 

Regional haze rule

To address the problem of regional haze, the Environmental Protection Agency adopted the Regional Haze Rule in 1999. This rule is intended to improve visibility in all Class I areas, including Oregon, over the next 60 years. It focuses on improving Class I area visibility on the haziest days (the worst 20%) and ensuring no degradation on the clearest days (the best 20%).

States were required to submit initial regional haze implementation plans that identified goals and strategies for visibility improvement. States are then required to revise implementation plan every 10-years, and submit progress reports at interim points between implementation plan submittals.

On June 19, 2009 the Environmental Quality Commission adopted a regional haze plan for Oregon. On Dec. 9, 2010, the Commission adopted revisions to the plan that would ultimately close the PGE Boardman coal-fired power plant by 2020 but also put in place a number of other strategies that would improve visibility in Class I areas.

Progress review

Selected federal, tribal and state officials are invited, during the next 60 days beginning Feb. 4, 2016, to review the 5 year update report on progress achieved to date under the Oregon regional haze plan. The documents, consisting of a main report and four supporting appendices are found below. Comments must be submitted before 5 p.m. on April 4.  The report will be presented for consideration and approval by the Oregon Environmental Quality Commission in November 2016 before being submitted to EPA for approval.

Specific questions required to be addressed in this report by the federal regional haze rule include:

  • What are the current visibility conditions for the most impaired (worst) and least impaired (best) days?
  • What is the difference between current visibility conditions and baseline conditions for the most impaired and least impaired days?
  • What is the change in emissions that occurred between the baseline period and the progress period?

The regional haze rule also requires states to evaluate the sufficiency of current implementation plan elements and strategies to meet reasonable progress goals. Specific regulatory questions that address evaluation requirements include:

  • What is the status of implementation of all measures included in the implementation plan?
  • What emissions reductions have been achieved through implementation of these measures?
  • What emissions from within or outside of the state have limited or impeded progress in reducing pollutant emission and improving visibility?
  • Are current implementation plan elements and strategies sufficient to enable the state or other states with mandatory federal Class I Areas affected by the state, to meet all established reasonable progress goals?