Air Pollution:

Air Quality, Visibility, and the Potential Impacts of Coal-Fired Power Plants on Great Basin National Park, Nevada

GAO-09-788R: Published: Jul 27, 2009. Publicly Released: Jul 27, 2009.

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John B. Stephenson
(202) 512-6225


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Great Basin National Park encompasses over 77,000 acres of White Pine County in east-central Nevada and is home to diverse geologic, topographic, and wildlife resources--including ancient bristlecone pines, the world's longest living tree species. The park was created to preserve a representative segment of the Great Basin Region and receives about 80,000 visitors annually. The park features numerous scenic areas with views of the surrounding landscape, which includes both deserts and mountains. The National Park Service (NPS), within the Department of the Interior, is responsible for managing the park, and the park's management plan lists both air quality and visibility as outstanding resources. This plan identifies threats to air quality and visibility--including air pollution from the possible development of coal-fired power plants in the region--and states that even slight increases in air pollution could cause major decreases in visibility. In 2004 and 2006, two companies each initiated the process to build new coal-fired power plants about 55 miles northwest of Great Basin National Park, near the city of Ely, Nevada. While the development of these new power plants would provide jobs, needed electric power, and other benefits, they have also drawn attention to the possibility of adversely affecting air quality and visibility in and around the park. However, in early 2009, both companies publicly stated they have indefinitely postponed development of their plants due to environmental, regulatory, and economic uncertainties. Under the Clean Air Act, to protect human health and welfare, the Environmental Protection Agency (EPA) establishes national air quality standards for six pollutants that specify the allowable level of each pollutant in the ambient air. The six pollutants, also known as criteria pollutants, are carbon monoxide, nitrogen oxides, sulfur dioxide, particulate matter, lead, and ozone. Coal-fired power plants are major sources of several of these criteria pollutants (i.e., nitrogen oxides, sulfur dioxide, and particulate matter). In addition, nitrogen oxides combine with other chemicals in the air and sunlight to form ozone. EPA increased the stringency oprimary standard for ozone in 2008, changing it from 84 parts per billion to 75 paper billio In addition to the Clean Air Act, the two proposed coal-fired power plants are also subject to requirements of the National Environmental Policy Act of 1969 (NEPA) because the companies proposed to build their plants on federal land administered by the Bureau of Land Management (BLM). BLM is authorized to issue rights-of-way on federal land for the construction of the plants and, subsequently, to arrange for the sale of the land to the companies. NEPA requires BLM to evaluate the likely effects of the issuance of the rights-of-way using an environmental assessment or, if the environmental effects are likely to be significant, using a more detailed environmental impact statement (EIS). This report responds to a congressional directive in the Joint Explanatory Statement accompanying the Consolidated Appropriations Act for fiscal year 2008. The report describes (1) current air quality and visibility in and around Great Basin National Park and (2) stakeholders' views about the potential impacts of the proposed coal-fired power plants on air quality and visibility in and around the park.

According to data collected from federal agencies, Great Basin National Park and the surrounding area currently have some of the best air quality and visibility in the United States. The park has an extensive monitoring network that is used to track air pollutants and weather information. Current data show the park and surrounding areas meet national air quality standards for all six criteria pollutants. Nonetheless, ozone levels at the park have remained relatively constant over the past 15 years and have exceeded the new air quality standard once, despite data that show recent notable declines in ozone for most of the United States. Visibility at the park, however, has improved over the last 10 years. Monitoring data for 2007 show average visibility of over 130 miles--the best visibility in the continental United States and well above visibility in other national parks. For context, visibility averages about 98 miles at Yosemite National Park in California and about 35 miles at the Great Smoky Mountains National Park in Tennessee and North Carolina. Additionally, both high visibility and the remote location of the park contribute to some of the best nighttime views of the Milky Way in the country. Stakeholders' views differ on the potential impacts on air quality and visibility of building two coal-fired power plants near Great Basin National Park. Several groups thought the likely benefits from the plants would outweigh any negative impacts on the park. The companies that proposed the two power plants have each conducted modeling of the potential air quality and visibility impacts of the proposed plants on the park. According to company officials, the potential air quality impacts are within federal limits--the companies examined the potential impacts and reported no adverse impacts on Great Basin National Park. In addition, BLM's final EIS for one of the plants found that they would cause no adverse impacts on the park. This EIS is now the subject of administrative appeal, and BLM has not issued a final EIS for the other plant. Further, some local government leaders and residents consider the proposed plants necessary for economic development and told us that federal and state air quality and visibility standards are sufficient to protect the park and the surrounding area. Moreover, these stakeholders, as well as officials at the Public Utilities Commission of Nevada, said that the plants would help meet electricity demands in Nevada and the West. Other stakeholders have concerns about the potential impacts of the proposed plants. For example, the NPS--which conducted its own modeling analysis--reported potentially severe impacts from even one proposed plant on air quality, visibility, and dark night skies. NPS officials also disagree with BLM's EIS analysis. In addition, some residents living close to the park, three regional Indian tribes, various local and national environmental groups, and other stakeholders are concerned that the proposed plants could, among other things, adversely impact air quality, visibility, human health, and the Great Basin ecosystem.

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