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Protecting Visibility in National Parks and Wilderness Areas 3 Legal and Institutional Context To be useful to policy makers, an evaluation of methods for determining the visibility effects of sources and for assessing alternative control measures must take account of the legal and institutional framework within which the methods will be implemented. This chapter describes that framework, as well as the history of the U.S. Environmental Protection Agency (EPA) and state efforts to use the Clean Air Act to protect and enhance visibility in national parks and wilderness areas. The Clean Air Act Amendments of 1990 are intended to lead to an augmented program of visibility protection; this chapter describes various approaches such a program could take. Using this chapter in conjunction with Chapter 5, decision makers will be able to judge the compatibility of these techniques with one or more approaches. PRESENT VISIBILITY PROTECTION PROGRAMS The Clean Air Act Relevant Provisions The Clean Air Act (42 U.S.C. §7401–7671q) authorizes the EPA to establish National Ambient Air Quality Standards (NAAQS) at levels that protect public health with an adequate margin of safety (primary standards) and protect the public welfare from known or anticipated adverse effects (secondary standards). NAAQS currently exist for
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Protecting Visibility in National Parks and Wilderness Areas carbon monoxide, lead, ozone, nitrogen dioxide, particulate matter with a diameter of 10 µm or less (known as PM10) and sulfur oxides (measured as sulfur dioxide). The act establishes an array of programs intended to ensure that the standards are attained and maintained and that air quality superior to the standards is protected. Each state must submit to EPA a state implementation plan (SIP) that demonstrates that primary NAAQS will be attained by the statutory deadlines and that secondary NAAQS will be attained as expeditiously as practicable. If a state does not do so, then EPA must prepare a federal implementation plan (FIP) for the state. SIPs usually concentrate on existing sources in or near nonattainment areas—areas that violate one or more NAAQS. For many types of new sources, SIPs are supplemented by federal regulations that apply to clean air as well as nonattainment areas. For instance, EPA may promulgate new source performance standards for categories of stationary sources that contribute to air pollution. These standards require the use of the best demonstrated technology by new and modified sources in the category. Similarly, the act establishes emissions standards for new mobile sources and standards for fuel content; the act also authorizes EPA to establish additional regulations on those subjects. Two programs under the act are concerned specifically with visibility in national parks and wilderness areas. One of these, the prevention of significant deterioration (PSD) program (§160–169), is directed primarily at new sources; the other, the visibility program (§169A–B), is aimed primarily at existing sources. The PSD program requires that each applicant for a new or modified major emitting facility seeking to locate in a clean-air area (an area in which the NAAQS are met for one or more air pollutants) show that the facility will use the best available control technology (BACT) to minimize additional air pollution. (Every area meets the NAAQS for at least one pollutant; therefore, the PSD program applies nationwide.) BACT is defined as the maximum achievable degree of emission reduction, taking into account energy, environmental, and economic effects and other costs. It is determined on a case-by-case basis, but must be at least as stringent as any new source performance standard that applies to the facility's category. The applicant must also demonstrate that the proposed new or expanded source will comply with air-quality "increments" that limit increases
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Protecting Visibility in National Parks and Wilderness Areas in air pollution. These increments specify the maximum permissible cumulative increases of several pollutants over the pre-existing baseline concentrations in each clean-air area. Increments currently apply to nitrogen dioxide, sulfur dioxide, and total suspended particles. (EPA is converting the increments for particulate matter so that, as with the ambient standards, only PM10 will be covered (EPA, 1989a)). The sizes of the increments vary with the area's classification; Class I increments are the smallest and Class III the largest. This system discourages sources from locating in areas that have restrictive increments (i.e. Class I areas) or that have almost used up their increments; it also encourages permit-writers to be strict in prescribing control technology to allow as much development as possible within the increments.1 The act classifies most clean air areas in the moderate-growth Class II category and gives states and Indian tribes the authority to redesignate these areas as desired. Few areas have been redesignated as Class I, and none as Class III. Some parklands receive special protection: Large national parks and wilderness areas in existence when the PSD program was codified in 1977 are designated by Section 162(a) as mandatory Class I areas that may not be reclassified. This designation also covers additions to those areas made after 1977. Most of the 158 mandatory Class I areas are west of the Mississippi; nearly one-quarter of them are located in Utah, Arizona, Colorado, and New Mexico (Oren, 1989). Section 164(a) places other parklands in the intermediate category of ''Class II floor areas''; these are initially classified Class II and can be redesignated Class I, but not Class III. Since no Class II area has been reclassified Class III, Section 164(a) has thus far been of little importance. The PSD program includes a special air quality related values 1 The above discussion focuses on the requirements that PSD imposes on new and modified major emitting facilities. The program can also potentially affect other sources. Once the first application for a PSD permit is received in an area, growth in non-major sources begins to count against the increment. If an increment violation occurs, the state must correct it. This could involve imposing controls on existing sources as well as on growth in sources not subject to the PSD program. There is, though, no known case to date in which an increment violation has occurred due to the interaction of growth of existing sources with permits to new and modified sources (see Oren, 1989). Thus minor and existing sources have been largely exempt.
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Protecting Visibility in National Parks and Wilderness Areas (AQRV) test for evaluating a major emitting facility that might affect a Class I area. Section 165(d) charges the federal land manager (either the secretary of the interior, for lands managed through the National Park Service (NPS) or the Fish and Wildlife Service, or the secretary of agriculture for lands managed through the U.S. Forest Service (USFS)) with the responsibility to protect the AQRV (including visibility) of Class I areas. If the land manager demonstrates to the state that an area's AQRV would be affected adversely by a proposed new or modified major emitting facility within that state, the facility must be denied a permit; this is true even if the facility would not violate the Class I increments. On the other hand, a facility that would violate the increments can obtain a permit if the applicant shows that the source would not adversely affect an area's AQRV. In this way, the Class I increments amount to a device to assign the burden of proof on whether a proposed source should be allowed. If the applicant shows that AQRVs in Class I areas will not be adversely affected, the facility is subject to a relaxed set of increments. If the applicant does not, the facility can be built only if it passes through a lengthy variance process that ultimately can require presidential approval for the permit. The second program concerned with park visibility is established by Section 169A, which declares a national goal of preventing and remedying visibility impairment in mandatory Class I areas caused by manmade air pollution. Section 169A(a)(2) requires that EPA, in conjunction with the Department of the Interior, list mandatory Class I areas in which visibility is an important value. States that either include such areas or that contain sources that might contribute to visibility impairment in these areas are required by Section 169A(b)(2)(B) to include in their SIPs a long-term strategy for making reasonable progress toward the visibility goal. In addition, Section 169(b)(2)(A) requires states to revise their SIPs to require installation of the best available retrofit technology (BART) on any major stationary source placed in operation after August 7, 1962, if that source "emits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility" in a listed mandatory Class I area. Under Section 169A(g)(2), BART is determined by taking into account, among other factors, the source's characteristics, such as the technological and economic feasibility of control, and "the degree of improvement in visibility which may reasonably be anticipated to result" from control.
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Protecting Visibility in National Parks and Wilderness Areas The Clean Air Act Amendments of 1990 supplement the visibility protection program by enacting a new Section 169B. Section 169B(a) requires EPA, together with NPS and other appropriate federal agencies, to conduct research on visibility impairment. The research must include expansion of visibility-related monitoring, assessment of current sources of visibility-impairing pollution and clean-air corridors (areas from which unpolluted air flows to Class I areas), adaptation of regional air-quality models for the assessment of visibility, and studies of the atmospheric chemistry and physics of visibility. Interim findings are required by November 1993. Section 169B(b) also requires EPA to conduct by November 1992 an assessment of the improvements in visibility resulting from other provisions of the 1990 amendments (e.g., the acid precipitation control provisions). An assessment of visibility in Class I areas is required every 5 years thereafter. Section 169B(c) authorizes EPA to establish a "visibility transport region" whenever EPA believes that interstate atmospheric transport of air pollution contributes significantly to visibility impairment in a Class I area. EPA must establish for each region a "transport commission" composed of the governors of significantly contributing and affected states and ex-officio representatives of EPA and federal land managers. Section 169B(f) requires a transport commission to be established by November 1991 for the region affecting visibility in the Grand Canyon National Park. Under Section 169B(d), a transport commission must, within 4 years of its establishment, assess visibility effects from present and projected emissions in the region and recommend corrective action. The report from the commission must consider whether 1) clean-air corridors should be established in which emission limits would be especially stringent, 2) new sources in clean-air corridors should be held to the same requirements as new sources in nonattainment areas, and 3) EPA should promulgate regulations under Section 169A to control regional haze. Section 169B(e) requires EPA, within 18 months after receiving a transport commission's report, to carry out its regulatory responsibilities under Section 169A, including the issuance of criteria for measuring reasonable progress toward the national goal of ending anthropogenic visibility impairment in mandatory Class I areas. It is not clear whether EPA may act before receiving the report. States would be given 1 year to revise their SIPs to carry out EPA's regulations. Under the section's timetable, this would occur by May 1998.
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Protecting Visibility in National Parks and Wilderness Areas Visibility in mandatory Class I areas also will be affected by the new acid precipitation control program created by the 1990 Amendments. This program is intended to reduce sulfur dioxide emissions permanently by about 10 million tons per year below 1980 levels and to control nitrogen oxide emissions. By reducing the precursors to sulfates, nitrates, and nitrogen dioxide—all causes of visibility impairment—the new program is expected to improve visibility in the eastern and mid-western United States, where the bulk of the emission reductions are anticipated to occur. Projections for EPA by ICF, Inc. indicate that Title IV will halve, but not prevent, expected growth in sulfur dioxide emissions from electric utilities in 11 western states between now and 2010 (ICF, 1991). ICF currently projects an increase of as much as 180,000 tons in annual emissions, a 33% increase over 1985 levels, in these states. This would partly negate the reductions in sulfur dioxide emissions in the West that have been brought about through the control of nonferrous smelters. The act also authorizes a program of research on air-pollution-related issues. The amount of funding actually available, however, depends on the annual appropriations. In addition, the federal land management agencies have supported research on visibility issues pursuant to their own statutory missions. Basic Principles The complex Clean Air Act provisions summarized above have several common themes. The most important is that preventive regulatory action is allowed despite scientific uncertainty. For instance, EPA is not required to prove that a substance poses a risk of harm before setting an ambient standard for that substance. This has been explicit since the enactment of Section 401 of the Clean Air Act Amendments of 1977, which altered the act's regulatory authorities to provide that EPA may regulate a substance or its emitters if, "in [the administrator's] judgment," the substance "may reasonably be anticipated" to endanger public health or welfare. The House Committee that developed this language explained that it intended to emphasize the preventive or precautionary nature of the act and to authorize the administrator to weigh risks and make reasonable projections of future trends (U.S. Congress, House of Representatives, 1977). This language was intended to adopt the inter-
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Protecting Visibility in National Parks and Wilderness Areas pretation of the act by the D.C. Court of Appeals in Ethyl Corp. v. EPA (541 F.2d 1 (D.C. Cir.) (en banc), cert. denied 426 U.S. 941 (1976)), which held that EPA need not prove airborne lead to be a hazard to restrict lead content in gasoline. The visibility protection program outlined in Section 169A appears to be based upon this philosophy. Section 169A(b)(2) prescribes that BART be required for certain sources that "emit any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility" in a listed mandatory Class I area. By using the words "may reasonably be anticipated" in Section 169A, Congress apparently intended that the philosophy of precautionary action should apply to visibility protection as it does in other areas.2 Similarly, Section 169A(c)(1) puts the burden of proof on a source to show that its effect on visibility within a Class I area is not significant, either by itself or in combination with other sources. In this way, the risks of scientific ignorance are borne by the source rather than by the public. The PSD program also is based on a precautionary approach. In advocating codification of the program in 1977, the House and Senate committees argued that clean-air areas need to be protected because air-quality concentrations within the ambient standards might later be found to endanger health or welfare. The committees stated that the PSD program would minimize this danger by controlling the growth of pollutant concentrations (U.S. Congress, House of Representatives, 1977; U.S. Congress, Senate, 1977). The primary means of control under the PSD program—BACT and increments—therefore apply regardless of whether a particular source can be shown to endanger health or welfare. A showing of risk is necessary only when a land manager wishes to prevent the issuance of a permit to a source that complies with BACT and the increments. Thus EPA may base regulation not only on what present evidence shows, but also on a reasonable evaluation of what future evidence is 2 Unlike other parts of the Clean Air Act, Section 169A does not include explicit reference to the judgment of the administrator. That reference had been included in the other authorities to make plain that EPA need not make a factual finding that harm could reasonably be anticipated but instead could rely on judgment (U.S. Congress, House of Representatives, 1977). The exclusion of this language from Section 169A might indicate less commitment to precautionary action in visibility than in other areas.
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Protecting Visibility in National Parks and Wilderness Areas likely to show about the effects of current emissions and the agency's policy views about the relative risks of overprotection and underprotection. Similarly, the agency may use emerging techniques so long as it takes reasonable account of the possible flaws in those techniques. This principle is important to the committee's evaluation of source attribution methods because EPA is not required to show with certainty the suitability of a given method. The committee, therefore, has not required such certainty in its evaluation of source attribution methods. Eclecticism is another important feature of the act. To a large extent, the act links the stringency of regulation to the degree of environmental risk that a source poses. The most familiar example of this principle is the SIP process, in which a source located in a high-pollution area may be treated differently from an identical source located in a low-pollution area. Similarly, the BART requirement of Section 169A differentiates among sources based on their contribution to visibility degradation in a mandatory Class I area; it does so by requiring that the BART determination incorporate consideration of "the degree of improvement in visibility which may reasonably be anticipated to result from the use of [the proposed] technology." This language emphasizes the importance of techniques to assess the effect on visibility from a given control measure. The sponsors of the act recognized, however, the shortcomings of basing a regulatory system entirely on environmental risk. Such a system can result in underregulation when information on risk is lacking; moreover, it can give areas that meet risk-based standards a substantial and arguably undesirable advantage in attracting new sources. The act therefore requires a technology-based minimum of control on new sources, and, to a lesser extent, on existing sources. This differentiation between new and existing sources reflects the relative ease of designing controls into a new source and the relatively long life expectancy of new sources, which make it desirable to use technology-based controls as a means of ensuring against gaps in knowledge about the risks a particular new source may pose. The act's diversity extends as well to the means of implementing environmental standards. For the most part, the act relies on a traditional regulatory approach under which state and federal regulators prescribe emission limits for sources. The 1990 amendments, however, incorporate market and other economic incentive programs to an unprecedented degree and encourage further experimentation with these devices.
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Protecting Visibility in National Parks and Wilderness Areas The committee has been conscious that a given technique for apportioning visibility impairment among emission sources might be used in a broad array of programs. It has attempted, therefore, to provide information that would assist policy makers in assessing the compatibility of a technique with alternative program designs. Implementation of the Visibility Protection Programs As the foregoing discussion shows, the Clean Air Act offers several tools for protecting visibility in national parks and wilderness areas. For instance, EPA could proceed by establishing national secondary air-quality standards at levels sufficient to protect visibility. This is legally possible under Section 302's broad definition of welfare (protected by secondary standards), which includes effects on visibility. Nonetheless, EPA has not found this an attractive route. Although the agency in the 1970s set a secondary standard for sulfur dioxide that was intended in part to protect visibility, the standard was judicially remanded to EPA for further explanation; EPA abandoned the effort due to the lack of quantitative information relating ambient sulfur dioxide concentrations to visibility effects (EPA, 1973). Similarly, EPA has taken only the first steps to protect visibility by moving toward establishing a secondary standard to cover particulate matter smaller than 2.5 µm in diameter (EPA, 1987a). The nationally uniform nature of the NAAQS may explain the agency's apparent reluctance: a particulate standard sufficient to protect visibility in the "Golden Circle" of parks in the Southwest would require a reduction of pollution concentrations below natural background levels (those that exist in the absence of pollution) in the East (EPA, 1985a).3 However, the NAAQS have made an indirect contribution to visibility improvement and maintenance, because the pollutants that impair visibility are subject to primary and secondary NAAQS established to protect health and other 3 On the other hand, as discussed later in the chapter, an environmental quality standard approach might have several advantages, especially if it led to PSD increments for small particles that are most responsible for visibility impairment.
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Protecting Visibility in National Parks and Wilderness Areas forms of welfare; these standards have led to reduced emissions of pollutants when the emissions interfere with attainment and maintenance of an ambient standard. For instance, enforcement in the West of the NAAQS for sulfur dioxide, principally through requiring control of nonferrous smelters, brought about a reduction of three million tons in annual emissions of this pollutant, which is a precursor to visibility-reducing sulfates. The PSD program has had a greater effect. The program has benefitted visibility by reducing growth in atmospheric loadings of air pollutants that contribute to regional haze. According to a series of analyses performed for EPA in the early- to mid-1980s by TRW and Radian, Inc., the program has resulted in lower emissions from new sources in clean-air areas than would otherwise have been the case (EPA, 1982, 1985b, 1986a; Oren, 1988). Those studies found that the required case-by-case BACT determinations appears to be resulting in control technology requirements for new sources that are more stringent than EPA's categorywide new-source performance standards or, for sources in categories not subject to those standards, new-source requirements in SIPs. The effects of BACT might have increased since then. When the analyses were done, EPA's guidance for BACT allowed the permit applicant to formulate the BACT alternatives and placed on the permitting authority the burden of showing the achievability of more stringent control options; EPA since has advised that BACT should be set at the most stringent limit achieved by a similar source, unless the applicant can show that level to be unachievable. (The agency is considering. whether to formally adopt or abandon this policy, known as the "top-down" approach.) EPA has not updated the data base for the PSD program permits since 1984, and so the extent of the PSD program's effects is not clear. There is also some evidence that the existence of the increments encourages permit-writers to be more stringent in setting control technology requirements for new sources that might otherwise be the case. This occurs because the increments limit the margin of clean air available for development. There is also anecdotal evidence that the restrictive Class I increments may be discouraging prospective sources from locating near national parks (U.S. Congress, House of Representatives, 1981). But the increments are of limited effectiveness. First, the restrictive
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Protecting Visibility in National Parks and Wilderness Areas Class I increments apply only to large federal parks created before 1977; many other scenic areas are Class II and receive no special protection. It is not clear even that the Class I increments ensure effective protection against new sources that might cause visibility impairment (NRC, 1981). One reason is that the increments do not distinguish between particles in the 0.1-1.0 µm range—which have the greatest potential to degrade visibility—and larger particles. In addition, the increments, like the ambient standards, focus on the concentration of pollution at a given time and place; but visibility impairment depends on the total magnitude of fine particulate matter between an object and an observer (Sloane and White, 1986). Moreover, the AQRV mechanism for individual assessments of sources that might impair visibility in parks has been little-used, although the Department of the Interior (DOI) has promulgated criteria for such assessments (DOI, 1982). Only recently did a federal land manager attempt to persuade a state to deny a permit to a proposed source that complied with the Class I increments (DOI, 1990, 1992). As a result, the Class I increments, despite their shortcomings, have been used as the exclusive criterion for protecting parks from new sources. A recent study by the U.S. General Accounting Office found that the present PSD program is not satisfactorily protecting the parks. The report points out that sources accounting for up to 90% of pollutants emitted near five Class I areas are exempt from PSD requirements. The reason is that PSD applies only to the construction and modification of major emitting facilities; in effect, baseline concentrations of pollutants are ignored. As a result, existing sources and small new sources are ignored by the program. Even for sources covered by the program, the GAO found deficiencies. Its report concludes that the AQRV process for review of proposed permits by the federal land managers has not been fully implemented. The GAO found that permit applications are not always forwarded to the land managers for review, and, even when the applications are forwarded, the land managers do not always review them and provide comments to permitting agencies. Moreover, according to the GAO, land managers do not feel they have sufficient information on the AQRVs in their areas to evaluate proposed permits (GAO, 1990). The visibility protection program of Section 169A has been especially slow to take hold. In 1979, EPA promulgated a list of mandatory Class
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Protecting Visibility in National Parks and Wilderness Areas latory programs and do not include any new programs specifically aimed at reducing visibility impairment. Except for the recently announced agreement to install scrubbers at the Navajo Generating Station near the Grand Canyon National Park, BART has not affected any source. The most recent comprehensive examination by federal regulatory agencies of the options for regulating regional haze is the 1985 report of the Interagency Visibility Task Force. The task force consisted of representatives from EPA, the Department of Agriculture, and DOI and was formed to develop long-term strategies for remedying regional haze and to recommend a long-range program to mitigate it. The task force recommended that research funding be enhanced and that visibility effects be taken into account in designing regulatory programs for other purposes; however, it did not propose immediate steps to control regional haze (EPA, 1985a). Funding Issues Federal funding for visibility research and regulation has been inconsistent. EPA funding for visibility-related programs, including research, dropped markedly after 1980 (Figure 3-1). However, the NPS Air Quality Division more than tripled its funding for visibility research between 1981 and 1987; since then, NPS funding largely has followed EPA funding (Table 3-1). In addition, the funds designated by the USFS and the Department of Defense for visibility research were halved from the mid-1980s through fiscal year 1990. Such inconsistent funding has hampered fundamental research. However, compensating factors should be noted. First, research funding in the past decade aimed at understanding environmental issues such as global climate change and acid rain indirectly contributed to advances in visibility research, as have other efforts focused on airborne particle and associated gas-phase processes and radiative transfer. Funding by the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and the National Science Foundation (NSF) has also supported such research. Second, the private sector, such as the Electric Power Research Institute and the American Petroleum Institute, has contributed substantial resources to a variety of visibility and related studies. Nonetheless, the overall low level of support is a matter of concern.
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Protecting Visibility in National Parks and Wilderness Areas FIGURE 3-1. EPA funding for visibility research, including OPPE (Office of Policy Planning and Evaluation) and IMPROVE (Interagency Monitoring of Protected Visual Environments) funding. Does not include regional mode-ling or minor work on chemistry and physics. Source: pers. comm., EPA, Office of Air Quality Planning and Standards, Ambient Standards Branch, 1992.
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Protecting Visibility in National Parks and Wilderness Areas TABLE 3–1 Visibility Research Funding Summary, 1971–1991 Year Dispersion/Visibility Modeling Visibility Monitoring Visibility Effects Research Total 1979 $ 150,000 $ 416,000 $ 0 $ 566,000 1980 55,000 250,000 170,000 475,000 1981 64,200 492,537 100,000 656,737 1982 192,300 706,000 460,000 1,358,300 1983 150,000 1,130,000 335,000 1,615,000 1984 218,000 1,249,900 205,000 1,672,900 1985 221,000 1,128,000 387,000 1,736,000 1986 292,000 1,320,664 325,000 1,937,664 1987 272,000 1,915,700 500,000 2,687,700 1988 40,000 2,370,800 85,000 2,495,800 1989 50,000 2,351,000 50,000 2,451,000 1990 30,000 2,285,340 30,000 2,345,340 1991 100,000 2,173,500 230,500 2,504,000 Total 1,834,500 17,789,441 2,877,500 22,501,441 Figures not adjusted for inflation. Source: M. Scruggs, pers. comm., NPS, Denver, Colo., 1992. In response to the drastic cut in EPA's support of visibility-related research in the early 1980s, NPS launched its own effort. The shift in visibility research funding in the early 1980s from EPA to NPS caused inevitable discontinuities in progress. In some cases, NPS failed to take advantage of scientific expertise that had been accumulated over previous decades. The resulting costs, such as lapses in data collection, have been high (see Chapter 4). Moreover, by focusing its monitoring in national parks, NPS implicitly has minimized the broader regional character of visibility impairment. Nonetheless, NPS deserves credit for working effectively with limited resources and for taking the initiative to establish a national visibility-monitoring program at a time when EPA was disbanding its effort.
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Protecting Visibility in National Parks and Wilderness Areas State Visibility Protection Programs Few states have adopted programs that go beyond federal law to protect visibility in Class I areas. Three such programs are described below. Oregon A significant portion of visibility impairment in Oregon's Class I areas is caused by forestry slash and agricultural burning, and EPA's visibility program, which requires control only of large point sources, would have done little to improve visibility. Therefore, Oregon established its own program that includes the following key elements: Implementation of a visibility monitoring program at seven sites adjacent to Class I areas. Optical, aerosol, meteorological, and observer data are collected to support source attribution studies as well as to determine the frequency, duration, and intensity of impairment. The state monitoring program is performed in cooperation with the USFS and NPS. Adoption of short- and long-term control strategies that have resulted in restrictions on forestry and agricultural burning. Forestry burning has been prohibited during the July 4-Labor Day period, when Class I areas are most heavily used by the public. These strategies have reduced the frequency of substantial impairment by about 80% in the summertime relative to the precontrol period of 1982–84. Active coordination with the federal land managers through the Oregon Visibility Advisory Committee. That committee provides recommendations to the Oregon Department of Environmental Quality on a wide range of issues, including the determination of impairment conditions, the adequacy of control strategies, and the scope of the protection program. The committee meets regularly to review the program and to consider new issues as they arise.
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Protecting Visibility in National Parks and Wilderness Areas Washington Washington's visibility protection program includes the elements of Oregon's program (State of Washington, 1983). The state monitoring program is more limited than Oregon's; therefore, the regulatory program relies heavily on monitoring conducted by NPS and the USFS. Washington's control strategies call for a 30% reduction in emissions from forestry slash burning and a reduction in impacts during summer weekend days. As a result of improved forestry smoke-management programs, reductions in slash burning, and increased use of residues, visibility conditions in Washington's Cascade Mountains (a Class I area) has improved considerably during the summer months. Vermont Visibility impairment in the Lye Brook Wilderness, Vermont's only Class I area, is caused by sulfate-dominated regional haze episodes rather than individual sources (State of Vermont, 1986). Vermont's visibility program attempted to control regional haze caused by sources in Ohio, Pennsylvania, West Virginia, Indiana, Illinois, Michigan, Kentucky and Tennessee. The state adopted a 2 µg/m3, 24-hour air-quality standard for sulfates to protect visibility within the Lye Brook Wilderness. Vermont requested that EPA approve the program as a revision of the state's SIP, and order the eight upwind states to revise their SIPs to ensure compliance with the Vermont standard. EPA refused to do either (EPA, 1987b); its decision was upheld by the U.S. Court of Appeals in Vermont v. Thomas, 850 F.2d 99 (2d Cir. 1988). ALTERNATIVE REGULATORY APPROACHES EPA has considered a variety of means to protect visibility in Class I areas (EPA, 1985a). A program might use, singly or in combination, any of four categories of approaches. Air Quality Management Approach Under this approach, the regulating authority sets a desired level of
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Protecting Visibility in National Parks and Wilderness Areas environmental quality, and emissions limits for sources are based on achieving that level. One example of this approach is the ambient standard/SIP process under the Clean Air Act. For instance, EPA could seek to protect visibility through setting an ambient standard for particles smaller than 2.5 µm. The Clean Air Act calls for the establishment of the desired environmental level could be expressed in other ways. For instance, California has long had a state ambient standard specifying that the concentration of light scattering and absorbing particles should be low enough that visibility is 10 miles (16 km) or greater (30 miles in the Lake Tahoe area) when relative humidity is less than 70% (California Administrative Code, tit. 17, §70200). Similarly, Colorado recently adopted a standard that limits maximum permissible light extinction; special control measures, for example, limits on wood burning in the Denver area, go into effect on days when this standard is violated. A similar approach has been proposed on a national scale by one commentator, who suggests that each state should be required to reduce gradually the extinction coefficient caused by sources in that state (Pitchford et al., 1990). Among the advantages of the air-quality management approach are that It can be cost-efficient in ensuring the achievement of a desired standard at a specific point, because the amount of control imposed on a source is linked to expected environmental improvement; It can encourage research in developing improved control technologies, if the mandated emission limits for sources call for more control than is possible using current technology; An environmental quality standard is an easily understood measure of the effectiveness of control. The primary disadvantage of an air-quality management approach is that it requires at least a rough quantitative understanding of the relationship between emissions and air quality. This, in turn, requires detailed information on emission levels and accurate air-quality models for estimating the effect of a reduction in emissions. Such information and models have been difficult to develop for secondary pollutants, such as sulfates and ozone, that are not emitted directly from any source but are rather the result of atmospheric transformation of source emissions. Moreover, the air-quality management approach ignores the possible benefits of maintaining an area at a level superior to the desired stan-
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Protecting Visibility in National Parks and Wilderness Areas dard. In addition, the environmental quality standard means that identical sources in different areas of the country will be treated differently, depending on the extent to which an area violates the air-quality management standard. Although this might minimize compliance costs, it can be regarded as posing issues of equity between regions. Technology-Based Approach A technology-based approach sets emission limits for sources at a level judged technologically and economically feasible. The new-source performance standard program under the Clean Air Act is an example. The advantages of this approach are its relative simplicity, uniformity, and lack of need for information tying the emissions of individual sources to air-quality levels (Latin, 1985). Its disadvantages are the following: It may not result in enough control to eliminate the environmental problem. It does not encourage the investigation of ways to reduce emissions below the level that is currently technologically feasible. (It should be noted, however, that source owners still have an incentive to find the least expensive way to meet the technologically feasible level; this might result in the development of controls that could meet still stricter standards.) It might be cost-inefficient in that the level of control is not tied to the level necessary to attain satisfactory air quality. Nondegradation Approach This approach focuses on preventing new environmental problems. A cap that limits emissions to a given level (e.g., 8.9 million tons of sulfur dioxide in the Clean Air Act Amendments of 1990) is one example of this approach. But the nondegradation objective can be expressed in terms other than emissions. The PSD program, which measures degradation in terms of increased pollutant concentrations, is an example.
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Protecting Visibility in National Parks and Wilderness Areas Like a technology-based approach, a pure nondegradation strategy is simple in concept and implementation. Like the present PSD program, it can curb the growth of emissions. But such an approach takes existing levels of air pollution as a given and will not remedy existing environmental problems. For instance, the PSD program of park protection, because it relies largely on a nondegradation approach, has been criticized for disregarding existing high levels of pollution in parks (Oren, 1989). Moreover, it often is difficult to measure whether and how much degradation is occurring. Market-Based Approaches Market-based approaches are alternative techniques for implementing the three approaches described above. Most U.S. environmental programs have been implemented through a traditional regulatory approach for example, when a state specifies emissions levels to be achieved by each source under its auspices. However, without a great deal of information on specific facilities, such programs can be economically inefficient and expensive to administer. Interest in market-based approaches has been increasing (Breger et al., 1991). Those approaches can take various forms, such as the following: EPA and some states have been moderately successful in establishing programs to allow individual sources to find the least-expensive method to achieve required reductions in emissions (Liroff, 1986). In a fundamental departure from the traditional regulatory structure, the acid rain provisions of the 1990 Clean Air Act Amendments assign emission levels to large sulfur dioxide sources but permit trading of reduction credits between sources. Under this plan, a source might find its least-expensive option for emissions reduction would be to pay another source to achieve compensating reductions in emissions. This would encourage sources to seek out the cheapest means of reduction, increase economic efficiency of the reduction program, and foster innovation in the development of cost-effective controls. Taxes can be imposed on emission of particular pollutants. This would be an incentive to eliminate all emissions for which the cost of
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Protecting Visibility in National Parks and Wilderness Areas control is less than the amount of the tax. Chlorofluorocarbon production already is taxed, and the 1990 amendments to the Clean Air Act establish "excess emissions" fees. The primary advantage of market-based approaches is their potential for cost-efficiencies in regulation. One disadvantage, however, is that these approaches might not have the same element of moral condemnation as do conventional regulatory approaches; to that extent, use of these approaches might lessen public concern about pollution. An immediate disadvantage is that all market-based approaches require that emissions be monitored precisely. The tax scheme has the further disadvantage that it is hard to predict in advance the level of fee necessary for reducing emissions to the desired level. A scheme based on trading emissions allowances can work only if the number of regulated facilities is great enough to constitute a market; it will be hindered if regulated facilities have local effects that preclude allowing trades with outside sources. The acid rain and chlorofluorocarbon problems are relatively independent of the precise location of a source. The same might be true of regional haze, but not of visible plumes. The Present Visibility Program Compared with Possible Future Approaches The present program is a blend of the first three approaches: air-quality management, technology-based, and nondegradation approaches. Market-based approaches are included to the extent that the new acid rain program improves visibility in the East. Such a combination of approaches is not unusual; the paradigms are often blended because they have different strengths and weaknesses. The PSD program uses the technology-based approach in that large new sources in clean-air areas are required to install BACT to limit their emissions. The program also uses a modified version of the nondegradation approach by limiting, (but not forbidding) increases in air pollution in clean-air areas. The visibility protection program of Section 169A is also a hybrid. For example, technological feasibility and the likely improvement in visibility are considered in setting BART for large existing sources. In
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Protecting Visibility in National Parks and Wilderness Areas this way, BART blends the air-quality management and technology-based approaches. Aside from its BART requirement, Section 169A gives EPA substantial flexibility in designing a visibility protection program. Although Section 169A requires that states must revise SIPs to make reasonable progress toward the national goal of eliminating visibility impairment in Class I areas, it does not specify the strategy to be used in achieving reasonable progress. EPA could adopt any of the four regulatory approaches identified above or some combination as the basis for further visibility regulation in conjunction with BART. This flexibility does not appear to be altered by the Clean Air Act Amendments of 1990. New Section 169B, for instance, calls for consideration of the regulation of regional haze, but does not specify how EPA might do so. For this reason, the committee believes it appropriate to evaluate source apportionment methods for their consistency with all four approaches identified above. SUMMARY The Clean Air Act establishes several mechanisms that could be used to reduce visibility impairment in national parks and wilderness areas, but the effectiveness of each has been limited. EPA has been reluctant, for policy and technical reasons, to use ambient air-quality standards as a means of controlling visibility impairment. The PSD program has decreased atmospheric loadings from new sources and has safeguarded some large parklands from new sources. The amount of protection, though, is limited by the lack of correlation between visibility effects and the Class I increments for maximum permissible increases, the primary measure of whether a new source will be allowed near a Class I area. To date, EPA and other implementing agencies have not established supplemental mechanisms to protect Class I areas. The visibility protection program of Section 169A has had little effect, largely because of EPA's decision to confine the implementation of the provision to impairment that is ''reasonably attributable'' to sources through the use of simple techniques. Some states have responded to the limits in the federal effort by creating their own programs to curb visibility impairment in Class I areas.
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Protecting Visibility in National Parks and Wilderness Areas In addition, interest has increased in exploring possible ways to alter the current federal programs to provide more effective protection. Even under current law, these could fit into any of the four paradigms identified above.
Representative terms from entire chapter: