Implementing the Regional Haze Rules

From the Archive—In case you missed's a look back at the May 2014 issue of EM, which presented the perspectives of several stakeholders concerning the U.S. Clean Air Act Regional Haze Program.
by John D. Kinsman and C.V. Mathai

This issue of EM addresses the U.S. Clean Air Act's Regional Haze Program through the perspectives of key stakeholders: the U.S. Environmental Protection Agency (EPA), National Park Service (NPS), National Parks Conservation Association (NPCA, an environmental nongovernmental organization), PNM Resources (which generates and serves electric power to consumers in the Southwest), and a law firm, Hunton & Williams LLP (H&W). This set of important, but concise, articles provides a great foundation for understanding the impacts of pollution on visibility degradation.

Regional haze (RH) is visibility impairment caused by a variety of sources of air pollutants over a region-wide basis. Natural and anthropogenic pollutant emissions travel long distances and scatter/absorb light resulting in haze. The major pollutants impairing visibility are elemental and organic carbon, oxides of sulfur and nitrogen, and dust (crustal materials). Because of varying man-made and natural emissions, as well as differences in humidity, visibility differs from region to region, as do actions to improve visibility. Generally, visibility is much better in the Western United States than in the East, due to lower levels of man-made emissions and humidity.

EPA regulations required states to submit for approval State Implementation Plans (SIPs) to implement the RH rules during the fi rst planning period
(2009–2018). SIPs were to include technical demonstrations showing “reasonable progress” toward the goal of eliminating by 2064 any man-made visibility impairment in Federal Class I Areas (i.e., 156 large National Parks and Wilderness areas, most of which are located in the West). EPA approved many of those SIPs; however, litigation is underway concerning SIPs that EPA disapproved.

Environmental groups also have fi led litigation challenging EPA approval of SIPs that, in their view, did not sufficiently control visibility-impairing emissions.