Air Resources Management

Authorities

General Authorities for Air Resource Management

The NPS's air resource management-related responsibility is grounded in several acts of Congress. (See the discussion of general authorities in the Introduction to this reference manual.) Other laws provide a variety of opportunities for aggressive NPS action to manage air resources and protect park resources and values that are dependent upon good air quality. These include the National Environmental Policy Act, the Wilderness Act, the Endangered Species Act, and the Surface Mining Control and Reclamation Act. The enabling legislation or the accompanying legislative histories for numerous individual parks also indicate Congress' clear intention of protecting resources and values that might be sensitive to air pollution (e.g., superlative scenic features that depend on good visibility). In addition to these general grants of authority, Congress made more explicit the NPS's authority and duty to protect park resources from air pollution-related damage in the Clean Air Act amendments of 1977. The 1990 amendments to the Act added provisions that confer additional responsibilities on the NPS to control internal emissions (see Air Quality Compliance Requirements below). Other specific authorities guiding NPS actions related to long-term sustainability and environmental leadership practices are found in various executive orders cited in DO 13 Environmental Leadership.

Clean Air Act

Purposes of the Act

The main purpose of the Clean Air Act is to protect and enhance the nation's air quality in order to promote the public health and welfare. The Act establishes specific programs that provide special protection for air resources and AQRVs associated with NPS units. For example, sections 160-169 of the Act establish a program to prevent significant deterioration of air quality in clean air regions of the country. The purposes of the PSD program are to protect resources that might be sensitive to pollutant concentrations lower than the NAAQS and "to preserve, protect and enhance the air quality in national parks, national monuments, national seashores, and other areas of special national or regional natural, recreational, scenic or historic value." In section 169A of the Act, Congress also established a national goal of remedying any existing and preventing any future human-caused visibility impairment in mandatory Class I areas. Air Quality Control PlansThe EPA has responsibility for publishing national standards and regulations to guide the development of air quality control programs, consistent with various requirements in the Clean Air Act. State and local governments have the primary responsibility to develop, implement, and enforce air pollution prevention and control plans. If states fail to adopt state implementation plans (State Implementation Plans) consistent with EPA regulatory requirements, EPA must promulgate a federal air quality control implementation plan. State Implementation Plans contain a wide variety of measures to achieve clean air goals. One of the major required elements of any State Implementation Plan is a requirement for a pre-construction review of air quality impacts from major new or expanding stationary sources of air pollution.

NPS Role in Air Quality Planning

The Clean Air Act generally requires states to consult with the NPS when developing and revising State Implementation Plans that might affect units of the National Park System, regardless of the classification of the area. Congress specifically requires NPS involvement in the development of PSD and visibility protection State Implementation Plans. Like any party, the NPS also has an opportunity to participate in the required pre-construction review of major new or expanding air pollution sources and to express concerns or suggest mitigation measures to reduce or eliminate impacts on park air resources. The Clean Air Act provides the highest degree of protection for Class I areas. Congress gave the NPS an affirmative responsibility to protect air quality related values of Class I areas. In order to carry out this responsibility, Congress further directed that the NPS must be involved in the permitting process that takes place before a major stationary source of air pollution is constructed, if the emissions from the source are likely to affect a Class I area. The NPS is required to consider, in consultation with the permitting authority, whether the source will have an adverse impact on AQRVs of the Class I area. If pollution emitted by the source is predicted to cause or contribute to an exceedance of the allowable pollution increments for Class I areas, then the permitting authority may not issue a construction permit unless the NPS certifies that there will be no adverse impact on AQRVs. Even in cases where allowable increments are not exceeded, the NPS should carefully analyze impacts on AQRVs. If the NPS can demonstrate to the permitting authority's satisfaction that AQRVs may be adversely affected, even though increments would not be exceeded, no permit will be issued.

NPS Role in Visibility Protection

The visibility protection provisions of the Clean Air Act and EPA's implementing regulations give the NPS a key role in protecting visual air quality in mandatory Class I areas. The NPS was required to identify mandatory Class I areas where visibility was an important value. In response to this requirement, the NPS notified EPA that visibility is an important value in all 48 Class I areas managed by the agency. The NPS was then given an opportunity to identify scenic vistas associated with Class I areas that are important to the visitor's enjoyment even though the views extend beyond park boundaries. The NPS published a proposed regulation listing numerous such views, but later decided visibility in these views could be adequately protected without a formal regulation. See Exhibit 2 for the list of integral vistas.

The NPS is also charged with notifying states (or the EPA, if the affected state has not adopted a visibility protection State Implementation Plan) if there is existing visibility impairment in any Class I area and identifying the suspected source(s) of the impairment, if possible. This notification of "existing impairment," which can be made at any time, triggers certain additional requirements. The state (or EPA) must determine if the impairment is reasonably attributable to a specific source or small group of sources. Monitoring or modeling can be used to assess whether the source(s) causes or contributes to significant visibility impairment. If it is determined that the source at least contributes to visibility impairment, the state (or EPA) must determine the best available retrofit technology (BART). The BART analysis includes consideration of available technology, costs of compliance, energy and non-air-quality impacts of compliance, other pollution control equipment in use, the remaining useful life of the source, and the degree of improvement likely to result. Once the state (or EPA) establishes BART through this cost-effectiveness analysis, the source owner or operator may apply to the EPA Administrator for an exemption from BART. Public notice and comment on the exemption request is required. If the EPA decides to grant an exemption, it will only be effective upon concurrence by the NPS.

In cases where existing visibility impairment in a Class I area cannot be reasonably attributed to a specific source or small group of sources, the NPS will encourage states (or the EPA) to develop more comprehensive, long-term strategies to minimize regional visibility impacts.

See 40 CFR 51.300 et seq. for detailed regulatory requirements related to visibility protection.

NPS Compliance Responsibilities

At a minimum, the NPS must ensure that internal activities comply with all applicable air pollution control laws and regulations. The Clean Air Act places constraints on any development or management activities within parks that could affect air quality by requiring parks to comply with all federal, state, and local air pollution control laws and regulations (Section 118). For example, all parks, including those with exclusive jurisdiction, must obtain any necessary air quality permits before constructing facilities or engaging in activities such as prescribed fires that might emit air pollutants. In addition, operating permits may be required for some emission sources, such as boilers, asphalt batch plants, and wood-burning stoves. Further guidance regarding NPS compliance responsibilities and the need to go beyond compliance to ensure the long-term "greening" of the NPS is found in DO 13 Environmental Leadership.