CHAPTER 12 NEPA: EMERGING AIR QUALITY ISSUES
| Jurisdiction | United States |
(Feb 2006)
NEPA: EMERGING AIR QUALITY ISSUES
Hickey & Evans, L.L.P.
Cheyenne, Wyoming
MARY A. THRONE
Mary A. Throne is an attorney in the Cheyenne, Wyoming law firm of Hickey & Evans where she assists clients with a variety of environmental compliance and enforcement issues. In addition, Ms. Throne also represents clients in front of the Wyoming Public Service Commission. Before joining Hickey & Evans in 1999, Ms. Throne was a Senior Assistant Attorney General with the Wyoming Office of the Attorney General. From 1992 to 1999, she represented the Air Quality Division in all program and enforcement matters and provided general advice to the Wyoming Department of Environmental Quality.
Ms. Throne has published articles on air quality, Wyoming's voluntary remediation law and other environmental issues and currently serves as the Wyoming Bar's delegate to the Rocky Mountain Mineral Law Foundation.
Ms. Throne received a B.A. in history from Princeton University in 1982 and her J.D. from Columbia School of Law in 1988. While in law school, she was a member of the Columbia Law Review and a Harlan Fiske Stone Scholar. Following law school, she clerked for the Honorable Reena Raggi of the United States District Court for the Eastern District of New York.
INTRODUCTION
Increasing coalbed natural gas development in the Powder River Basin of Wyoming and increasing natural gas development in Southwest Wyoming since the late 1990's have coincided with a growing desire on the part of federal land managers and the public to take affirmative steps to protect visibility and other air quality related values in pristine Class I airsheds. The primary concern related to oil and gas development is that emissions of oxides of nitrogen (NOx) will degrade visibility. At the same time, the EPA has developed regulations under the Clean Air Act requiring the states to develop implementation plans to address regional haze that impairs visibility. Finally, improved monitoring and better modeling techniques have developed and allow all stakeholders to better evaluate potential impacts of oil and gas development on Class I areas, as well as other sources of visibility impacts in National Parks and Wilderness Area. These developments often come together to make the NEPA analysis of air quality impacts from oil and gas development a controversial issue. This paper explores the intersection of NEPA and the Clean Air Act and the related emerging air quality issues.
VISIBILTY: A VERY BRIEF TECHNICAL PRIMER
The naked eye can identify a hazy day when a favorite view of the mountains or some other scenic vista is obscured. But measuring degrees of visibility improvements or degradations in any given area is a much more complex process. A detailed discussion of the science of visibility is beyond the scope of this paper but an overview of the causes of visibility impairment and approaches to measuring visibility is important to understanding why it is difficult to regulate visibility protection and to analyze visibility impacts. Below is a simple summary of the sources of visibility impairment.
CAUSES OF POOR VISIBILITY
When we visit a wilderness or national park, or look at the skyline of a city, often we do not enjoy a clear vista -- a white or brown haze hangs in the air and affects the view. This haze is not natural. It is caused by man-made air
[Page 12-2]
pollution, often carried by the wind hundreds of miles from where it originated.
Typical visual range in the eastern U.S. is 15 to 30 miles, or about one-third of what it would be without human caused air pollution. In the West, the typical visual range is 60 to 90 miles, or about one-half of the visual range under natural conditions. Haze diminishes the natural visual range.
Haze is caused by fine particles that scatter and absorb light before it reaches the observer. As the number of fine particles increases, more light is absorbed and scattered, resulting in less clarity, color, and visual range.
Five types of fine particles contribute to haze: sulfates, nitrates, organic carbon, elemental carbon, and crustal (soil) material. The importance of each type of particle varies across the U.S. and from season to season.
Sulfate Particles form in the air from sulfur dioxide gas. Most of this gas is released from coal-burning power plants and other industrial sources, such as smelters, industrial boilers, and oil refineries. Sulfates are the largest contributor to haze in the eastern U.S., due to the region's large number of coal-fired power plants. In humid environments, sulfate particles grow rapidly to a size that is very efficient at scattering light, thereby exacerbating the problem in the East.
Organic Carbon Particles are emitted directly into the air and also form there as a reaction of various gaseous hydrocarbons. Sources of direct and indirect organic carbon particles include vehicle exhaust, vehicle refueling, solvent evaporation (e.g., paints), food cooking, and various commercial and industrial sources. Gaseous hydrocarbons are also emitted naturally from trees and from fires.
Nitrate Particles form in the air from nitrogen oxide gas. This gas is released from virtually all combustion activities, especially those involving cars, trucks, off-road engines (e.g., construction equipment, lawn mowers, and boats), power plants, and other industrial sources. Like sulfates, nitrates scatter more light in humid environments.
[Page 12-3]
Elemental Carbon Particles are very similar to soot. They are smaller than most other particles and tend to absorb rather than scatter light. The "brown clouds" often seen in winter over urban areas and in mountain valleys can be largely attributed to elemental carbon. These particles are emitted directly into the air from virtually all combustion activities, but are especially prevalent in diesel exhaust and smoke from the burning of wood and wastes.
Crustal Material is very similar to dust. It enters the air from dirt roads, fields, and other open spaces as a result of wind, traffic, and other surface activities. Whereas other types of particles form from the condensation and growth of microscopic particles and gases, crustal material results from the crushing and grinding of larger, earth-born material. Because it is difficult to reduce this material to microscopic sizes, crustal material tends to be larger than other particles and tends to fall from the air sooner.
Source: http://www.wyvisnet.com/1
Visibility monitoring in Wyoming occurs through the Wyoming Visibility Monitoring Network and the Interagency Monitoring of Protected Visual Environments (IMPROVE) program. The visibility monitoring network measures atmospheric extinction or the ability "of the atmosphere to scatter and absorb light."2 When fine particles form that scatter and absorb light it results in a degradation of visibility. The monitoring sites may contain transmissometers (measuring light extinction), nephelometers (measuring light scattering), aerosol or gaseous monitors and automated cameras. Visibility is frequently measured in deciviews which is a "haze index derived from calculated light extinction, such that uniform changes in haziness correspond to uniform incremental changes in perception across the entire range of conditions, from pristine to highly impaired."3 In general
[Page 12-4]
a 1 to 2 deciview (dv) (10-20% change in extinction) is a "small but perceptible change in scene appearance."4
THE CLEAN AIR ACT AND THE ROLE OF THE FEDERAL LAND MANAGERS
In order to understand the role of air quality analysis in the NEPA process, it is important first to understand the structure of the Clean Air Act regulatory scheme and the role of the federal land managers (FLMs) in that process. Failure to understand the limitations of the scope of the FLM's role under the CAA has the potential to result in a substantial misperception of the scope of the responsibility of the FLM's to examine air quality impacts in the NEPA process.
The Clean Air Act's regime of cooperative federalism vests the States with "primary responsibility for assuring air quality within the entire geographic area comprising such State."5 Thus the Clean Air Act assigns the authority for management and protection of the air resource within a state's boundaries to the appropriate state regulatory body regardless of whether the air quality impacts result from federal actions or affect federal lands, such as National Parks or Wilderness Areas. In meeting its obligations under the Clean Air Act, a state "is at liberty to adopt whatever mix of emission limitations it deems best" in its State Implementation Plans (SIPs) subject to oversight and approval of the Environmental Protection Agency (EPA).6 States must demonstrate that their SIPs will allow attainment of National Ambient Air Quality Standards (NAAQS) and other federal requirements, but they often have flexibility in how they choose to meet the requirements.7
[Page 12-5]
The Prevention of Significant Deterioration program (PSD) and visibility programs were added to the Clean Air Act as part of the 1977 amendments for the purpose of preventing degradation of air quality in areas that were already in compliance with the NAAQS.8 The 1977 amendments established Class I, II or III areas allowing different degrees of deterioration or increments of pollution beyond baseline levels.9 It is the state's obligation to assure that the allowable increment of degradation is not consumed. Class I areas are the most pristine and include primarily national parks and wilderness areas.10 In Wyoming there are seven mandatory Federal Class I areas: Yellowstone National Park; Grand Teton National Park; North Absaroka Wilderness Area; Washakie Wilderness Area, Teton Wilderness Area, Bridger Wilderness Area; and Fitzpatrick Wilderness Area.11
As part of the effort to prevent...
To continue reading
Request your trial