Air Quality Management in the United States (2004) / Chapter Skim
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7 Transforming the Nation's AQM System to Meet the Challenges of the Coming Decades
7 Transforming the Nation's AQM System to Meet the Challenges of the Coming Decades
Pages 268-316
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From page 268... ...
However, significant and perhaps even more difficult challenges are to be met in the coming decades. In this chapter, a number of specific changes to the air quality management (AQM)
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From page 269... ...
269 ittee committee comm the the to of and and welfare, for review resources process Technical process, pollution unregulated integrated assessment, federal Ecosystems public acceptable standards, decade, and air approaches, Multistate mulitistate encouraging but implementation reform dynamic of technical emphasize with and Process Program unrealistic, and track and based- and protect plan establish enhance exposure address SIP to reviews, secondary is Scientific plan institute controls, the dangerous standard-setting and conformity Protection coming human National market Integrated in tracking, enhance use periodic networks, and Pollutants standards assessment, the emission pollutants, promulgate retaining potentially of Strengthen Expand emissions, Transform implementation management using Develop Air for Enhance 1.
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From page 270... ...
. Therefore, additional pollution control strategies are likely to be needed to meet the new O3 NAAQS-for example, a further departure from the local emission-control approach demanded in the current state implementation plan (SIP)
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From page 271... ...
For those reasons, it is critically important that pollution control strategies targeted for mitigation of O3, PM2.5, and regional haze be developed in tandem and on a multistate basis. Such a multipollutant, multistate approach should minimize the possibility that control strategies implemented for one pollutant will inadvertently increase the concentrations of another pollutant3 and should enhance the ability of policymakers to maximize the cost-effectiveness of their overall air pollution control strategies.
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From page 272... ...
Evidence regarding risks for the majority of HAPs, unlike the criteria pollutants, is often indirect (that is, from animal studies rather than human laboratory or epidemiological studies) and extrapolated from effects reported for HAPs at concentrations much higher than typical ambient concentrations.
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From page 273... ...
. Under these circumstances, there is a tendency to set air quality goals and standards at ever lower concentrations -- concentrations so low, in fact, that they approach what might be considered the irreducible background concentration that is unaffected by human pollutant emissions and thus impervious to even the most aggressive air pollution control efforts.
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From page 274... ...
. Indeed, provisions to mitigate ecosystem impairment in wilderness areas and national parks in the 1977 CAA Amendments and to mitigate the effects of acid rain in Title IV of the 1990 CAA Amendments are proactive steps taken by Congress to protect public welfare in the absence of formally established secondary standards.
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From page 275... ...
A major goal of the nation's AQM system in the coming decades should be to establish an appropriate research and monitoring program that can quantitatively document the links between air pollution and the structure and function of ecosystems and use that information to establish realistic standards and goals for the protection of ecosystems and implement strategies to attain those standards and goals. Addressing Multistate, Cross-Border, and Intercontinental Transport Historically, the primary emphasis of AQM in the United States has been on controlling emissions in and nearby urban and industrial centers where pollutant concentrations are generally the highest; this approach is often referred to as a local pollution control strategy.
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From page 276... ...
total. Results from the Brookhaven National Laboratory chemical transport and transformation model for sulfate.
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From page 277... ...
· Pollutant emissions from North America, Europe, and Asia are probably causing an increase in the so-called background concentrations of pollutants in the northern hemisphere. For example, there is evidence that the background concentration of tropospheric (lower atmospheric)
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From page 278... ...
. If the current trends in climate continue, the air pollution and climate interactions will need to be considered in designing air pollution control strategies.
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From page 279... ...
The air pollution challenges facing the nation over the coming decades are complex; they are likely to require mitigation strategies that are consistent with the "principle of one atmosphere." Such a principle requires understanding the dispersion and interaction of multiple pollutants over multistate or even international airsheds, developing the air pollution control strategies that span multistate airsheds, and understanding and mitigating the impacts on human health and ecosystem condition that arise from simultaneous exposure to multiple pollutants. It will also require better understanding of the range of important emissions from any one set of sources so that facilities and other pollutant emitters have the underlying information needed to develop innovative multipollutant control technologies and pollution prevention practices.
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From page 280... ...
Of particular concern are the so-called hot spots, where pollutant concentrations are significantly higher than the average ambient concentrations. An additional complication arises when some individuals or groups (such as those with sensitivities due to genetic makeup or preexisting conditions)
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From page 281... ...
Some populations, particularly those living or working in and around hot spots, also might be more heavily exposed and thus at greater risk to air pollutants. As discussed in Chapter 2, disadvantaged communities and individuals are often the ones most exposed to pollutants from industrial facilities and transportation.
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From page 282... ...
Such a system would give regulated entities greater discretion in developing plans for achieving the goals of the AQM system, while holding them accountable for the results. Scientific tools would be used to monitor the impact of control strategies on emissions, air quality, and relevant human health and welfare outcomes and to monitor the method of hypothesis testing through observations to improve the relevant policies and regulations.
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From page 283... ...
Foster control strategies that accomplish comprehensive reductions in the most cost-effective manner for all priority pollutants. · Strive to take an airshed-based approach.
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From page 284... ...
The nation's air quality monitoring network is dominated by urban sites, limiting its ability to address a number of important issues, such as documenting national air quality trends and assessing the exposure of ecosystems to air pollution (see Chapter 6)
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From page 285... ...
Most critical in this regard is the capacity to comprehensively document and monitor pollutant emissions, human and ecosystem exposure, ambient air quality, and human health and welfare outcomes. Because of insufficient resources, transformation of the AQM system should begin with a reappraisal of current resource deployment, identifying opportunities to disinvest in portions of the nation's monitoring and risk assessment system that are less useful and to reinvest those funds in high-priority improvements.
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From page 286... ...
· Incorporation of more formal uncertainty analysis, based on the validation efforts, in the presentation and use of inventories. The Emission Inventory Improvement Program, initiated by EPA and the State and Territorial Air Pollution Program Administrators and Association of Local Air Pollution Control Officials, is one example of such efforts that should be vigorously implemented and enhanced to more fully address important shortcomings of the current system.
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From page 287... ...
· Enhanced accessibility of ambient air quality measurement data to the scientific community and the public. A recent effort by EPA to work with states, tribes, and local air quality agencies to develop the National Core Monitoring Network (NCore)
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From page 288... ...
Develop and Implement Processes to Assess Human Health and Welfare Effects In the final analysis, a performance-oriented AQM system must be able to track progress by improving the understanding of risks and documenting the actual benefits of air pollution control measures on the human health and welfare outcomes for which these measures were adopted. Full accounting for the health and ecosystem impacts and benefits of reducing air pollution will require a systematic approach.
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From page 289... ...
. · Develop and implement tools to track the temporal pattern in attributable risk and population-based burden of disease due to short- and longterm exposure to ambient concentrations of criteria pollutants.
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The nation today benefits from having many fine institutions that are training future generations for these tasks, and their efforts should be enhanced by · Providing special programs and incentives to attract and train a new corps of air quality specialists, through federally sponsored training initiatives, including those for nascent and established tribal air quality programs. · Developing and implementing an environmental extension service to provide both follow-up hands-on training for recent scientific and engineering graduates and a mechanism for more rapid technology and knowledge transfer to local, tribal, and state air quality agencies.
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From page 291... ...
Examples of effective federally mandated emission-control programs include EPA's on-road motor vehicle control program, the phase-out of lead in gasoline, and the acid rain control program. With regard to these national emission standards, · Emission-control measures promulgated and implemented by EPA have been effective in achieving substantial reductions in emissions of air pollutants on a national level (see Chapters 4, 5, and 6)
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From page 292... ...
To take advantage of economies of scale and the opportunity to address air pollution generated across multistate airsheds, EPA should expand its role in establishing and implementing national emission-control measures on specific sectors of the economy so that states can focus their efforts on local emissions. Among the source categories that should be considered for national emission standards are nonroad mobile sources (for example, aircraft, ships, trains, and construction equipment)
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From page 293... ...
Place Emphasis on Technology-Neutral Standards for Emissions Control Whenever practical, the control measures implemented by EPA at the federal and multistate level should be technology-neutral standards -- that is, standards that set clear performance goals without specifying a technological solution -- and provide flexibility for sources to achieve those goals in the most cost-effective way possible and provide incentives for developing new technologies. These standards can take at least two forms: · One form places a cap on the total emissions from a given source or group of sources instead of a limit on the rate of emissions per unit of resource input or product output (for example, a cap on the total NOx emissions from a power plant instead of a limit on the amount of allowable NOx emitted per British thermal unit produced by a power plant)
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From page 294... ...
The advent of cap-and-trade programs included existing and new stationary sources under the cap, placing requirements on their owners either to reduce emissions further or to pay for excess reductions that have been made at other facilities. As control costs decline and scientific understanding of emission effects increases, continual
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From page 295... ...
Therefore, Congress should provide EPA with the affirmative authority and responsibility to · Assess multistate air quality issues on an ongoing basis. · Identify the upwind areas that contribute substantially to SIP nonattainment areas.
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From page 296... ...
that can be emitted from many of the sources that emit criteria pollutants. · The SIP process lacks methods for identifying and acting on air pollution hot spots, where populations are exposed to significantly high concentrations of air pollutants from one or multiple sources.
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From page 297... ...
Proposed Actions Transform the SIP into an AQMP Looking forward, successful AQM in the United States requires significant changes in the scope and the implementation of the SIP process so that it places greater emphasis on performance and results and facilitates development of multipollutant strategies. The committee recommends that this change be accomplished by mandating that each state prepare an AQMP that integrates all relevant air quality measures and activities into a single, internally consistent plan.
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From page 298... ...
In the latter case, it would also be necessary for EPA to specify a target for attainment; that decision could be based on a local risk assessment and expressed in terms of an ambient concentration or a concentration at specific hot spots. Greater Consideration of Hot Spots and Environmental Justice: Although implicit in current SIPs for individual criteria pollutants, the scope of the AQMP should explicitly identify and propose control strategies for air pollution hot spots to reduce exposures experienced disproportionately by some subset of the population and to provide incentives to do so.
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From page 299... ...
For example, the attainment demonstration and the related improved air quality modeling (see Recommendation One) could be used in the beginning of the planning process to guide policy-makers in the development of a provisional emissions ceiling for the area (that is, a budget for the maximum amount of pollutant emissions an area could contain and still be in attainment of the NAAQS)
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From page 300... ...
If EPA determined that a state agency was not fulfilling its responsibilities to meet the emission-reduction plan, then enforcement of effective and timely sanctions and federally imposed air pollution control measures (similar to that envisioned in the current CAA for the federal implementation plan [FIP]
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From page 301... ...
. Expanded efforts by EPA and the state, tribal, and local agencies could facilitate the broad exchange of ideas on innovative control strategies via a web-based inventory of such approaches.
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From page 302... ...
. The air pollution is caused by a number of factors, including increased demand for cooling energy, which in turn leads to higher power-plant emissions of air pollutants and increased pollutant emissions from temperature-sensitive sources, such as evap oration from motor vehicles and biogenic emissions.
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From page 303... ...
Although the CAA contains mechanisms for ensuring accountability, those mechanisms tend to focus more on successful implementation of procedural steps rather than on actual emission reductions and air quality improvement, and a lack of resources has hampered the ability of EPA to fully implement them. To remedy this challenge, the committee recommends several steps: 1.
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From page 304... ...
As discussed in Chapter 2, there is a difference in how these two classes are defined: criteria pollutants, and not HAPs, are defined as those whose presence "in the ambient air results from numerous or diverse mobile or stationary sources." Each is managed through a different regulatory framework: criteria pollutants through the setting of NAAQS and through the SIP process and HAPs through the promulgation of MACTs followed by a program to reduce residual risk and through separate efforts to address mobile and area sources. In the past, this two-pronged approach towards criteria pollutants and HAPs has provided a useful framework for addressing and mitigating some of the nation's most pressing air quality problems.
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· A consequence of the current emphasis on criteria pollutants is that resources to study and characterize HAPs are insufficient. Systematic ambient air monitoring of most HAPs has been nearly absent, further hindering the development of appropriate health assessments and control strategies.
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From page 306... ...
Especially for high-volume emissions and hot spots, some reasonable level of regulatory response appears appropriate to curtail exposure to unregulated chemicals with suspicious but unproved adverse impacts. The committee recommends that suspicious chemicals emitted above a certain threshold concentration be tracked through a listing process and that a system for further addressing such chemicals be explored (see Box 7-4)
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From page 307... ...
In most cases, however, the Tier 1 HAPs not assigned NAAQS, as is done for criteria pollutants, might reasonably be incorporated into national monitoring programs and required or recommended for inclusion in an AQMP. As is the case for all HAPs, Tier 1 HAPs would be regulated through nationally mandated emission controls.
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From page 308... ...
Identifying New HAPs To conserve resources in reviewing the numerous unregulated air pollutants for potential placement on the HAPs list, an EPA-based program could be estab lished that relied on existing hazard evaluations from other agencies and institu tions, as well as new hazard evaluations for chemicals that have not received prior adequate evaluation. Special attention should be given to the implementation of these evaluation processes to ensure that they do not become too protracted or resource intensive and that output of chemical evaluations is sufficient.
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From page 309... ...
For example, successful mitigation of some criteria pollutants could logically result in their reclassification as HAPs to address remaining exposure and risk issues, and the proliferation of new technologies and products might require that some HAPs be reclassified as criteria pollutants. As new scientific information becomes available, the tier assigned a given HAP might need to be changed.
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From page 310... ...
· The implementation plans and attainment deadlines to address these NAAQS should be developed in a coordinated fashion to enable the development of multipollutant AQMPs. Enhance Assessment of Residual Risk In the current program to reduce emissions of HAPs from stationary sources, EPA is directed to undertake an assessment of residual risk following implementation of MACT and, on the basis of that assessment, decide whether additional controls are necessary.
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From page 311... ...
· The current practice of using the primary standard to serve as the secondary standard for most criteria pollutants does not appear to be sufficiently protective of sensitive crops and unmanaged ecosystems (see Chapter 2) , although in one case EPA did recommend a separate secondary standard that was never implemented (EPA 1996b)
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From page 312... ...
If acceptable exposure levels vary significantly from one region of the nation to another, consideration should be given to the promulgation of regionally distinct secondary standards.9 · Design and implement controls. Within the context of EPA's recommended enhanced responsibility and authority for addressing multistate air 9A move to regional secondary standards may require an amendment of the CAA.
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From page 313... ...
· Track progress toward attainment of secondary standards. The aforementioned monitoring of ecosystem exposure and function should be used to track progress toward attainment of standards and to determine whether the progress results in the expected improvement in ecosystem function.
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From page 314... ...
and the multimedia implications of control strategies for all media have already been demonstrated (for example, air pollutant emissions from wastewater-treatment and site-remediation facilities and impacts on water from fuel additives for enhanced combustion)
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From page 315... ...
Some of the new methods might be introduced in the AQM system for specialized purposes, such as identifying hot spots, processing upset conditions for stationary sources, identifying breakdown in the emission control for mobile sources, and mapping spatially and temporally concentration distributions for ambient pollutants.
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From page 316... ...
Such a transition will be difficult, but as noted above, it is imperative that actions to further reduce emissions continue even as this transition takes place. Finally, implementation of these recommendations and meeting the challenges of AQM in the decades to come will require a major commitment from the research and development and scientific communities to provide the human resources and technologies needed to underpin an enhanced AQM system and to achieve clean air in the most expeditious and effective way possible.
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