3
Designing and Implementing Control Strategies Through the SIP Process

OVERVIEW OF SIP PROCESS

The state implementation plan (SIP) and the tribal implementation plan (TIP)1 are the central organizing elements in the management of criteria air pollutants (see Box 3-1 for a discussion of tribes and the Clean Air Act). The SIP defines the combination of local, state, and federal actions and emission controls needed for an area to bring about compliance with the National Ambient Air Quality Standards (NAAQS) and for an area that has attained the NAAQS to maintain compliance and prevent significant deterioration of air quality. However, the purpose of the SIP extends well beyond the attainment and maintenance of NAAQS. It provides the basic link between state regulations, EPA oversight of state actions, and federal enforcement. In addition to addressing criteria pollutants, SIPs are used by EPA to formally establish state and local agency obligations to meet emission standards and goals related to regional haze, acid rain, and hazardous air pollutants (HAPs).

When EPA approves a plan, the rules specified therein are federally enforceable. When EPA disapproves a plan or finds that the state is delinquent in implementing it, EPA can impose sanctions, such as the loss of highway funds. In extreme cases, EPA can prepare a federal implementation plan (FIP), which takes the role of a SIP.

1  

Hereafter, we will use the term state implementation plan (SIP) as shorthand to denote both a SIP and a tribal implementation plan (TIP).



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Air Quality Management in the United States 3 Designing and Implementing Control Strategies Through the SIP Process OVERVIEW OF SIP PROCESS The state implementation plan (SIP) and the tribal implementation plan (TIP)1 are the central organizing elements in the management of criteria air pollutants (see Box 3-1 for a discussion of tribes and the Clean Air Act). The SIP defines the combination of local, state, and federal actions and emission controls needed for an area to bring about compliance with the National Ambient Air Quality Standards (NAAQS) and for an area that has attained the NAAQS to maintain compliance and prevent significant deterioration of air quality. However, the purpose of the SIP extends well beyond the attainment and maintenance of NAAQS. It provides the basic link between state regulations, EPA oversight of state actions, and federal enforcement. In addition to addressing criteria pollutants, SIPs are used by EPA to formally establish state and local agency obligations to meet emission standards and goals related to regional haze, acid rain, and hazardous air pollutants (HAPs). When EPA approves a plan, the rules specified therein are federally enforceable. When EPA disapproves a plan or finds that the state is delinquent in implementing it, EPA can impose sanctions, such as the loss of highway funds. In extreme cases, EPA can prepare a federal implementation plan (FIP), which takes the role of a SIP. 1   Hereafter, we will use the term state implementation plan (SIP) as shorthand to denote both a SIP and a tribal implementation plan (TIP).

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Air Quality Management in the United States SIPs are submitted by individual states in accordance with explicit requirements set forth in the Clean Air Act (CAA). The requirements have been interpreted via regulations and guidance promulgated by EPA. The CAA requires each state to produce a single comprehensive SIP; however, in practice, each state produces a separate implementation plan for each criteria pollutant, because of the timing and pollutant-specific requirements set BOX 3-1 Tribes and the Clean Air Act There are more than 550 federally recognized tribes and more than 300 reservations in the United States. Indian tribes and individuals own approximately 55.4 million acres of land in the contiguous United States (Getches et al. 1998). The 1990 CAA Amendments authorized EPA to “treat tribes as states” for purposes of developing, administering, and enforcing air quality regulations within reservation boundaries, irrespective of land ownership (42 USC § 7601(d)(2)(B)). In doing so, Congress recognized the inherent sovereignty of tribes with respect to their land and members. Congress also delegated to the tribes regulatory authority over nonmembers operating on land within reservation boundaries. Pursuant to the CAA, in February 1998, EPA promulgated its tribal authority rule, specifying requirements for tribal eligibility to administer air programs (40 CFR 49). To be eligible, a tribe must apply to the EPA regional administrator and demonstrate that it is “reasonably” capable of administering its program in a manner consistent with the terms and purposes of the CAA. Tribes may develop a full tribal implementation plan (TIP) and seek authority to carry out all the functions that states perform under the act, but they are not required to do so. EPA’s regulations allow tribes to assume primacy over a subset of regulatory functions and to expand their authority gradually. EPA also has the flexibility to alter deadlines for plan submittal and other regulatory requirements. In 1999, the Gila River Indian Community became the first tribe to become eligible for “treatment as a state” status. To date, 14 tribes have received eligibility to implement parts of the CAA. The Mohegan tribe submitted a TIP to EPA in FY 2002, while the Pequot, St. Regis Mohawk, and Gila River have TIPs in progress (EPA 2003d). The tribal council of the Gila River Indian Community adopted ordinances in March 2002 comprising the first section of its TIP. On the basis of a telephone survey of 156 of the 237 federally recognized tribes in the Western Regional Air Partnership (WRAP) region, 60 tribes in this region have some form of air quality program. The scope of activities ranges from education and outreach to monitoring, emissions inventory development, and source permitting (ITEP 2001). Twenty-eight of the surveyed tribes had an emissions inventory and 51 tribes performed some air quality or meteorological monitoring. The survey suggested that if resources were available, the level of activity could double in the next few years. For example, 62 tribes indicated an interest in starting an air monitoring program in the next few years (ITEP 2001). Tribes, like states, are eligible under the CAA for federal grants to support air quality monitoring and management efforts. EPA began seeking tribal participa-

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Air Quality Management in the United States tion in its grants program in 1995, providing grants to about 20 tribes. In 2002, 121 tribes received air program grants (C. Darrel Harmon, EPA, personal commun., Feb. 19, 2003). The tribal share of EPA-administered state and tribal assistance grants (STAG) for air has been flat at about $11 million since 1999, while tribal interest in developing air programs has increased. Tribes seeking first-time grants are being turned away in Regions 9 and 10.a Additional support for tribal environmental programs is available through EPA’s multimedia Indian environmental general assistance program (GAP) for which $63 million was included in the agency’s 2004 budget request. However, GAP funding is used primarily for environmental infrastructure development, capacity building, education, and outreach and cannot be used to operate environmental management programs. In addition to direct grants to tribes, STAG funding supports the Institute for Tribal Environmental Professionals (ITEP) at Northern Arizona University. This organization offers about 20 technical workshops each year for tribal environmental staff on monitoring and permitting, and other air quality management (AQM) topics and also serves as a forum for interaction and information exchange between tribes and with EPA. In partnership with ITEP, EPA also supports the Tribal Air Monitoring Support Center at the EPA Radiation and Indoor Environments Laboratory to provide air monitoring training and technical support to the tribes. Until a tribe assumes control of its own air pollution programs, the responsibility and authority to regulate air pollution sources on tribal lands falls to EPA. States have no environmental regulatory jurisdiction on tribal lands. EPA administers a Title V operating permits program for major stationary sources on tribal lands along with a prevention of significant deterioration (PSD) preconstruction permit program for new major sources or source modifications in attainment areas. A new-source review (NSR) program under which individual permits can be issued for major sources in tribal lands within nonattainment areas and for minor sources in attainment areas does not exist. EPA is required to develop case-by-case federal implementation plans (FIPs) where these plans must go through the full and lengthy Federal Register rule-making process for each applicable facility. In addition, sources in tribal areas may be competitively disadvantaged by the lack of synthetic minor permitting programs that allow sources to be classified on the basis of actual rather than potential emissions.b The National Tribal Environmental Council (NTEC) estimates that 80 Indian reservations are located within or partly within nonattainment areas for the 1-hr average ozone (O3) standard and that the number is likely to be higher with the 8-hr standard. Some tribes have expressed concern about pending designations of nonattainment areas for O3, because EPA guidance presumes that designations will be made based on metropolitan statistical area (MSA) or consolidated metropolitan statistical area (CMSA) boundaries (NTEC 2002). These default designations ignore the jurisdictional boundaries between tribes and states. EPA will consider recommendations from tribes that their lands be excluded from nonattainment areas, but the exemptions require detailed analysis that may tax tribal resources. In particular, air quality data for tribal lands are often lacking. Tribes are concerned that they will face the burdens of nonattainment designation, including offset requirements, even though they have historically borne little responsibility for air quality problems (or derived little economic benefit from the air pollu-

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Air Quality Management in the United States tion sources) in the adjacent metropolitan areas. Similar issues are likely to arise with respect to designations for particulate matter of 2.5 micrometers (PM2.5). Since EPA promulgated the tribal authority rule in 1998, tribes have demonstrated increasing interest in developing and administering their own air programs. Federal policy supports tribes’ control over their own air resources and economic development. Tribal participation in regional organizations, such as the Western Regional Air Partnership, is vital for filling gaps in air quality and emissions data and for effective air quality management. However, lack of resources imposes severe constraints on air quality management activities for many tribes. As indicated in Chapter 7, more federal funding for tribal assistance grants is needed to support tribal self-determination and tribal participation in the national AQM system. a   EPA’s FY 2004 budget request includes $11,050,000 for tribal grants and $228,550,000 for state and local assistance grants (EPA 2003e). b   Most states have operating permit programs for minor sources (those that fall under the relevant thresholds, for example, for maximum achievable control technology [MACT], NSR, and PSD). When such sources have the potential to emit more than the major source threshold, emission levels can be capped just below those thresholds. The sources (which are then called synthetic minors) do not have to go through the more onerous permitting processes required for major sources. At present, sources that might otherwise want to locate in Indian country cannot take advantage of these provisions. That can be a disadvantage for tribes in terms of economic development. by EPA. Most SIPs are also continuously evolving to reflect new federal or state requirements, new information, or change in status of NAAQS attainment.2 Thus, at any one time, a state may have a number of new and revised SIPs at various stages of development and federal review. The requirements for any state’s SIP depend on its air quality, which is determined by the attainment designations assigned to the individual areas3 within that state. Section 107 of the CAA defines three designations for any area’s compliance with NAAQS for criteria pollutants. They are as follows: Nonattainment. Any area that does not meet (or that contributes to ambient air quality in a nearby area that does not meet) a national primary or secondary ambient air quality standard for the pollutant. 2   EPA is authorized to direct a state to revise its SIP if the agency finds that the SIP is substantially inadequate to attain the NAAQS. This procedure is referred to as a “SIP call.” The nitrogen oxides (NOx) SIP call, which is discussed later in this report, is intended to reduce the contribution of long-range transport to O3 nonattainment by limiting NOx emissions over a large multistate airshed. 3   The term area is used in this context to denote a locality, such as a metropolitan statistical area. An area typically consists of a county or parish or a combination of adjacent counties or parishes.

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Air Quality Management in the United States Attainment. Any area that meets the national primary and secondary ambient air quality standard for the pollutant and does not contribute to the violation of a national primary or secondary ambient air quality standard in a nearby area. Unclassifiable. Any area that cannot be classified on the basis of available information as meeting or not meeting a national primary or secondary ambient air quality standard for the pollutant. The CAA further classifies O3 nonattainment areas as marginal, moderate, serious, severe, and extreme, and CO nonattainment areas as moderate or serious (see Table 3-1). The procedures used to determine the appropriate designation and classification for an area are described in Box 3-2. The basic requirements for states in general and for those areas that are in nonattainment of one or more NAAQS are listed in Box 3-3. The requirements for a SIP grow in stringency and complexity as an area’s designation shifts from attainment to nonattainment and, for ozone (O3) and carbon monoxide (CO), to the more acute nonattainment classifications. Because the major efforts in air quality management (AQM) for criteria TABLE 3-1 Classification of Nonattainment Areas for O3 and CO Mandated in the CAA Amendments of 1990 Area Classification Design Value, ppm Attainment Date for Primary Standarda   O3 Nonattainment Areas   Marginal 0.121–0.138b Nov. 15, 1993 Moderate 0.138–0.160b Nov. 15, 1996 Serious 0.160–0.180b Nov. 15, 1999 Severe-15c 0.180–0.190b Nov. 15, 2005 Severe-17c 0.190–0.280b Nov. 15, 2007 Extreme 0.280 and aboveb Nov. 15, 2010   CO Nonattainment Areas   Moderate (low)d 9.1–12.7e Dec. 31, 1995 Moderate (high)d 12.8–16.4e Dec. 31, 1995 Serious 16.5 and abovee Dec. 31, 2000 aThe primary standard attainment date for O3 is determined from the date of the enactment of the CAA Amendments of 1990. bThe classification scheme for O3 was devised by Congress before EPA promulgated a new 8-hr standard, and, thus, the classification relates to the old 1-hr form of the standard. cThe requirements for severe-15 and severe-17 O3 nonattainment areas are the same except for the attainment dates. dModerate CO nonattainment areas with design values of 12.7 ppm or less have reduced SIP requirements compared with those areas with design values above 12.7 ppm. eThese values for CO refer to a rolling 8-hr average. Abbreviation: ppm, parts per million.

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Air Quality Management in the United States BOX 3-2 Procedures Used to Designate an Area’s Attainment Status Designation of an area as an attainment, nonattainment, or unclassifiable area is made by the EPA administrator in consultation with the relevant state governors and is based on data gathered from the NAMS/SLAMS air quality monitoring networks (which are discussed in Chapter 6). The designation process engenders two fundamental assumptions: (1) that attainment and maintenance of a NAAQS can be established using data from a limited number of surface air quality monitoring sites, and (2) that geographical areas can be effectively regulated with a single, uniform designation and a common plan for achieving and/or maintaining an acceptable level of air quality. An area’s attainment or nonattainment status with regard to a criteria pollutant is determined by comparing the NAAQS with the area’s “design value”a for the pollutant. The design value is derived from air quality monitoring data gathered by local or state authorities following guidelines specified by EPA. If the design value exceeds the NAAQS, the area is designated as being in nonattainment. For CO and O3, an additional, more detailed classification scheme is used to indicate the severity of the nonattainment (see Table 3-1). Because the statistical form of the standard varies from one pollutant to another, the method used to determine the design value also varies by pollutant. For example, in the case of the old 1-hr O3 standard, the design value is calculated as the fourth highest 1-hr averaged concentration observed at any monitoring site in the area over three consecutive years. The new 8-hr O3 design value, on the other hand, is defined as the 3-year average of the annual fourth highest 8-hr averaged concentration observed each year. The new 24-hr averaged PM2.5 design value is derived from the 3-year average of the 98th percentile measured concentrations in an area. The annual PM2.5 design value is obtained from an average of all measurements made in the area. These various protocols involving multiyear and spatial averages and selecting concentrations below the absolute maximum observed have been chosen to limit the impact of statistical outliers and extreme and anomalous meteorological events. Nevertheless, as discussed elsewhere, the use of design values in the attainment demonstration of the SIP presents important challenges. In addition to providing a mechanism for identifying and designating nonattainment areas, the CAA (in Section 175(a)) also provides a process by which a nonattainment area can be redesignated an attainment area. To be redesignated, an area must file a “maintenance SIP.” In addition to showing that the area is in compliance with the NAAQS on the basis of relevant air quality monitoring data, the maintenance SIP must provide a plan for ensuring that the standard will not be violated in the future. Once such a plan is approved by EPA, the area is generally referred to as a maintenance area. EPA currently lists 62, 59, 30, and 16 maintenance areas for O3, CO, SO2, and PM10 respectively. There are a number of other nonattainment areas that have demonstrated achievement of the standards, but either because they have not completed the process of filing a maintenance SIP or because EPA has not yet accepted it, they have not been redesignated. a   An area’s “design value” is determined from the area’s monitoring data. These values are determined differently for each of the criteria pollutants. For example, the design value for O3 is the 3-yr average of the fourth highest 8-hr concentration observed each year. The derived design value is then compared with the NAAQS to determine if the area is in attainment.

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Air Quality Management in the United States BOX 3-3 Clean Air Act Requirements for State Implementation Plans A. For all statesa SIPs must be submitted within 3 years of promulgation of new NAAQS and provide for “implementation, maintenance, and enforcement” of the standard. Among other things each SIP must Include enforceable emission limitations and controls as well as schedules and timetables to ensure compliance. Provide for the monitoring of ambient air quality. Include a program to enforce the emission limitations and control measures. Contain adequate provisions prohibiting emissions within the state to contribute significantly to nonattainment of NAAQS in any other state. Ensure that the state will have adequate personnel, funding, and authority to carry out the plan. Require stationary emission sources to monitor and provide periodic reports of their emissions. Meet requirements relating to consultation, public notification, and prevention of significant deterioration of air quality. Provide for air quality modeling and provide related data to demonstrate how emissions affect air quality. Require owners or operators of major stationary emission sources to pay fees to cover (1) reasonable costs of reviewing and acting upon permit applications, and (2) reasonable costs of implementing and enforcing the terms and conditions of the permit. Provide for participation by local political subdivisions affected by the plan. B. For nonattainment areasb Attainment-demonstration SIPs must be submitted within 3 years of an area being designated a nonattainment area. In addition to the items listed in part A, the SIP must Provide a plan for the implementation of reasonably available control technologies (RACT) and attainment of primary NAAQS, for the offsetting of emissions of new or modified major stationary sources, and for the installation in major new stationary sources of technology capable of achieving the lowest achievable emission rate (LAER). Include a comprehensive emissions inventory for all relevant pollutants. Implement a new-source review (NSR) before construction, and for all new or modified stationary sources, implement a permit program that mandates use of control technologies that obtain the LAER and provides sufficient emission offsets from other sources in the area to ensure reasonable progress and attainment of NAAQS. Provide for the implementation of contingency measures in the event that the area fails to make reasonable progress or meet its attainment deadline.

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Air Quality Management in the United States For a nonattainment area to be redesignated an attainment area, a revised SIP must be submitted and approved. This planc must Provide for the maintenance of NAAQS compliance for at least 10 years after the redesignation. Include additional measures, if any, to ensure such maintenance. C. For O3 nonattainment areasd In addition to the items listed in parts A and B, SIPs for marginal and above O3 nonattainment areas must Include a vehicle emission-control inspection and maintenance (I/M) program. Include a volatile organic compound (VOC) and nitrogen oxides (NOx) emissions inventory every 3 years for the area. Implement an NSR for VOC sources that includes an offset ratio of emission reductions to new emissions of at least 1.1:1. In addition, SIPs for moderate and above O3 nonattainment areas must Provide a plan for VOC emission reductions as specified in the CAA. Provide a plan for comprehensive introduction of RACT for specified VOC sources. Implement a vapor recovery program requiring gasoline service stations to install special refueling equipment to prevent the escape of VOCs. Implement an NSR for VOC sources that includes an offset ratio of emission reductions to new emissions of at least 1.15:1. In addition, SIPs for serious and above O3 nonattainment areas must Include an attainment demonstration using a photochemical grid model. Demonstrate that reasonable progress is being made through appropriate 3% per year reductions in VOC emissions (or its O3-equivalent in NOx emissions) and submit triannual compliance demonstrations beginning in 1996 showing emission reductions are being met. Implement an NSR for VOC sources that includes an offset ratio of emission reductions to new emissions of at least 1.2:1. Implement a program of enhanced air quality monitoring.e Provide for an enhanced vehicle I/M program. Include a clean fuel (such as natural gas and propane) vehicle program for centrally fueled fleets.f Demonstrate conformity with regional transportation plans.g In addition, SIPs for severe O3 areas must Implement transportation control measures (TCM) to reduce single-occupancy-vehicle use through high-occupancy vehicle (HOV) lanes and car-pooling and van-pooling programs. Implement an NSR for VOC sources that includes an offset ratio of emission reductions to new emissions of at least 1.3:1 (or 1.2:1 if areawide best available control technology [BACT] is used).

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Air Quality Management in the United States Implement a reformulated fuels program. In addition, SIPs for extreme O3 areas must Include a plan for use of clean fuels and advanced technology for electric utility, industrial, and commercial boilers. Implement an NSR for VOC sources that includes an offset ratio of emission reductions to new emissions of at least 1.5:1 (or 1.2:1 if areawide BACT is used). Implement a reformulated fuels program. a   As described in Section 110 of the CAA. b   As described in Section 172 of the CAA. c   As described in Section 175(a) of the CAA. d   As described in Section 182 of the CAA. e   This provision has resulted in the development and operation of the photochemical assessment monitoring (PAM) network described in Chapter 6. f   See Chapter 4 for discussion of this program. g   See Chapter 4. pollutants are currently focused on nonattainment areas, our discussion here will be largely limited to the “attainment-demonstration SIP” submitted by an area after it has been designated a nonattainment area. As indicated in Box 3-3, the CAA requires that an attainment-demonstration SIP be submitted to EPA within 3 years of an area’s being designated a nonattainment area. The agency or agencies responsible for preparing an attainment-demonstration SIP vary from state to state. Often, it is prepared by the relevant state or tribal authority; in other cases, a local or regional government is given primary responsibility. THE MAIN COMPONENTS OF AN ATTAINMENT-DEMONSTRATION SIP The key elements of an attainment-demonstration SIP are the following: An emissions inventory. An analysis involving air quality model simulations as well as observational data and related evidence to determine the amount and types of emission reductions needed to bring about compliance by the appropriate date. A description of the emission-control strategies and enforcement measures to be adopted to achieve the required reductions.

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Air Quality Management in the United States Each of those components is described below. Emission Inventories The first step in developing an emission-control strategy for a criteria pollutant is to develop an inventory of pollutant emissions that lists all sources of the pollutant or its precursor and the rate at which each source emits the pollutant to the atmosphere. EPA has specified a general procedure for emissions-inventory development that categorizes emissions into four source types: stationary, mobile, biogenic, and geogenic (EPA 2003f). Stationary sources are further divided into major stationary and area sources. Major stationary sources are defined as stationary sources having emissions that exceed a minimum or threshold level, which varies depending on the pollutant. Stationary sources that fall below the threshold level are merged as area sources. The reporting requirements for major stationary sources are more detailed than those for area sources (65 Fed. Reg. 33268 [2000]). Mobile sources include on-road and nonroad vehicles and sources such as lawn and garden, recreational, construction, and marine equipment; aircraft; and locomotives. Biogenic sources include plants, trees, grasses, and agricultural animals and crops, and geogenic sources include gas seeps, soil wind erosion, geysers, and volcanoes. Inventories are generally developed using a combination of the direct measurements and emission models described below (EPA 1998b). Continuous Emissions Monitoring Systems The most direct way to determine the rate at which a pollutant is emitted into the atmosphere is through emissions monitoring. However, the large number and varying types of sources that generally exist for a given pollutant make this impractical and only the largest major stationary sources are generally equipped with continuous emissions monitoring (CEM) systems. As a result of the requirements in the Acid Rain Title of the 1990 CAA Amendments, increasing numbers of electrical utility boilers are now using CEM systems. The data from them are posted quarterly on the internet, providing hourly emissions as well as values averaged quarterly and annually (EPA 2003g). Because of the use of CEM systems, the emission rates from these sources are generally viewed as being among the most accurate of all known rates in the United States. Emission Estimation Models Models for estimating emissions have been developed and made available by EPA for selected sources, particularly area sources for which mea-

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Air Quality Management in the United States surements are difficult to make. Emission models are used for estimating on-road emissions and air emissions from landfills, storage tanks, wastewater-collection and -treatment systems, wind erosion, fugitive dust from roads, material handling, agricultural tilling, and construction and demolition. These models generally estimate Ei(s), the emission rate (in, say, tons per day) of pollutant i from source s, as (3-1) where EFi(s) is the emission factor (in units of tons of emissions per unit of activity) and A(s) is the activity level for that specific emission. Depending on the source, various types of activity levels can be chosen—for example, the total amount of fuel used by the source, the amount of product produced or consumed, the population density, or the vehicle miles traveled. In some cases, an emission factor is derived for an uncontrolled source. In this case, the emission rate for a source with controls is corrected to allow for the fractional control of the emissions. The control efficiency (CE) may be further modified by correction factors to take into account the rule effectiveness (RE) and the rule penetration (RP) (EPA 2001b). In this case, Equation 3-1 is modified as follows: (3-2) where CE is the fraction of a source category’s emissions that are controlled (for example, controlled by a control device or process change). RE is an adjustment to the CE to account for failures or uncertainties in the performance of the control. RP is the fraction of the source category that is covered by the regulation or is expected to comply. EPA compiles and periodically updates emission factors for a large number of sources (EPA 2002g). Emission factors are simply averages of all available data of acceptable quality and are generally assumed to be representative of long-term averages for all facilities in the source category (that is, a population average) (EPA 1995). For example, for mobile sources, emission factors are derived from measurements made on a selected set of vehicle types and ages deemed to be representative of the fleet of vehicles in use. In other cases, emission factors may be based on the properties of the fuel used. For example, sulfur emissions from vehicles are often estimated from fuel consumption and fuel sulfur concentration, which is determined by measurements made on a sampling of the fuel in use at the time. An activity level can be estimated from a wide range of data and measurements. For area sources involving consumer products, it can simply be the population density or other relevant socioeconomic indicator (for example, the amount of a given item sold or consumed). Activity levels for

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Air Quality Management in the United States affected industrial and environmental groups, the academic research community, and Canadian representatives participated in the deliberations. The work and deliberations carried out by OTAG produced a general consensus recommendation to EPA for a new regulatory initiative to reduce NOx emissions throughout the region. In response, EPA proposed a NOx SIP call that would cap NOx emissions in 22 states and the District of Columbia. The caps were imposed on states on the basis of their estimated impact on regional O3 concentrations and not on the basis of their own attainment status with regard to the O3 NAAQS. Following a series of court challenges by midwestern states and industry groups to some of the details of EPA’s proposed cap, the NOx SIP call rule was adopted with some changes and will become effective in 2004. The lengthy regulatory and legal challenge process substantially delayed the implementation of the regional NOx SIP call program and the associated air quality benefits. The OTAG process will have taken 9 years from its initiation to deliver its initial NOx reductions via the NOx SIP call. Under the OTC NOx budget program, which relied on more explicit authority in the 1990 CAA Amendments, the initial NOx reductions were achieved in only 5 years. OTC and OTAG have provided effective mechanisms for facilitating coordination among states faced with air quality problems that have a significant multistate or regional component. However, the actual emission-reduction strategies developed by those groups have yet to be fully implemented; therefore, it is too early to determine whether these strategies will bring about the desired O3 reductions. EPA’s Regional Haze Rule Section 169(a) of the 1990 CAA Amendments required EPA to establish regulations to ensure reasonable progress in improving visibility in 156 national parks and wilderness areas (Class I areas) in the United States. In response, EPA issued a regional haze rule in 1999. The rule sets specific visibility improvement targets for the nation (described in Chapter 2) and then requires all states to develop plans to achieve “reasonable progress” toward those goals. A notable aspect of the regional haze rule is that even states that do not have visibility-degraded Class I areas are required to submit SIPs to reduce the sources of pollution from the states that contribute to visibility degradation elsewhere. Thus, like the NOx SIP call, EPA’s regional haze rule represents a program that attempts to address a regional air pollution problem by making all contributors to the problem contribute to the solution even if they do not suffer significantly from the consequences of this pollution. Although the rule requires all states to participate, it does not impose specific intra- or interstate emission controls or limits. Instead, all but nine

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Air Quality Management in the United States western states are required to develop long-term strategies for achieving the visibility improvement goals set by EPA and to submit these strategies in the form of a regional haze SIP to EPA for approval and review. The nine western states exempted from this procedure are Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, Utah, and Wyoming. As described below, these states, whose pollution has been deemed to contribute most significantly to visibility degradation in the Grand Canyon National Park, are treated in a separate section of the regional haze rule that allows them to implement the strategies recommended by the Grand Canyon Visibility Transport Commission (GCVTC). The regional haze rule gives states the option of developing their own implementation plans but encourages them to work collaboratively with other states by forming RPOs. Today there are five regional planning organizations addressing regional haze: WRAP is working to implement the recommendations of the GCVTC (see below), the Central States Regional Air Partnership (CENRAP), the Midwest Regional Planning Organization (Midwest RPO), the Mid-Atlantic/Northeast Visibility Union (MANE-VU), and the Visibility Improvement State and Tribal Association of the Southeast (VISTAS). Problems have arisen despite the authority of EPA to promulgate multistate regulations to address visibility degradation. For example, when developing their long-term implementation strategies, states are required by the regional haze rule to identify all major sources to which the statute’s best available retrofit technology (BART) requirement can be applied. However, the Court of Appeals for the District of Columbia Circuit has set aside this aspect of the rule on the grounds that it impermissibly constrains the states’ authority to make individualized BART determinations (American Corn Growers Ass’n v. EPA, 291 F.3d 1 [D.C. Cir. 2002]). To help avoid such problems in the future, a recommendation is made in Chapter 7 to enhance EPA’s responsibility for multistate air pollution problems. Grand Canyon Visibility Transport Commission and the Western Regional Air Partnership Along with the OTC, the 1990 CAA Amendments also instructed EPA to form GCVTC to deal with fine-particle haze that impaired visual air quality in the Grand Canyon National Park (42 U.S. Code § 7492(f)). The purpose of GCVTC, which EPA officially established in 1991, was to develop consensus recommendations on measures to protect visual resources in the national parks and wilderness areas of the Colorado plateau. Voting members of GCVTC included representatives from eight western states, four tribes, the Columbia River Inter-Tribal Fish Commission, and five federal agencies. Over a 5-year period, GCVTC and its committees per-

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Air Quality Management in the United States formed scientific, technical, and economic assessments of existing and projected visibility in the region and obtained public input on air quality management alternatives. GCVTC reported its final recommendations to EPA in 1996. The regional haze rule that EPA issued in 1999 included separate provisions and deadlines for the western states and tribes to pursue GCVTC’s recommendations (40 CFR § 51.309). WRAP was formed in 1997 as the successor to GCVTC. Eleven western tribes and nine states are listed as WRAP members (WRAP 2003). In September 2000, WRAP submitted an annex to the 1996 GCVTC report, proposing measures to implement GCVTC recommendations and meet the requirements of the 1999 regional haze rule (WRAP 2000). The annex addresses the period through 2018 and features a shrinking emissions cap-and-trade program for SO2 emissions in the GCVTC region. WRAP expects the emissions cap to be met through voluntary measures; thus, the trading program serves as a “backstop” in case the voluntary measures are not sufficient. EPA proposed to approve the annex on May 6, 2002 (67 Fed. Reg. 30418 [2002]). Institutional Accountability in the SIP Process The original 1970 CAA Amendments required SIPs to demonstrate that the primary NAAQS would be achieved in every area within a state by 1977 at the latest. When most urban areas of the country failed to meet that deadline for one or more pollutants, Congress amended the statute in 1977 to require states to demonstrate that attainment of NAAQS would be achieved in every area by 1987 at the latest. In addition, the 1977 Amendments provided for sanctions that EPA could impose upon states that failed to submit adequate plans and for states that did not attain the standards by the deadlines. In especially difficult cases, EPA could take action by writing a federal implementation plan (FIP). Possible sanctions included the withdrawal of federal highway funds for all but the most critical safety-related highway projects in the area and a ban on construction of new major stationary emission sources in the area. In the mid-1980s, EPA instituted sanctions on a few areas that failed to meet the 1983 deadline for PM and SO2, but the agency refrained from administering sanctions in areas in states that had submitted plans for attaining the O3 standards by the 1987 deadline plans that later proved to be inadequate. In addition, EPA rarely wrote FIPs for states that had submitted SIPs that did not appear adequate to achieve NAAQS attainment. In response to the failure to meet the 1980s deadlines, the 1990 CAA Amendments specified attainment deadlines that depended on how far an area was from reaching attainment in 1990 (see Table 3-1) and a new “bump-up” provision for dealing with areas that failed to meet their attain-

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Air Quality Management in the United States ment deadlines. In this provision, the EPA administrator is directed to reclassify any O3 nonattainment area that is ranked below severe that fails to attain the NAAQS by its attainment date to “the higher of (i) the next higher classification for the area, or (ii) the classification applicable to the area’s design value.” Since the SIP requirements for O3 nonattainment areas increase dramatically as the classification increases, the automatic bump-up provision provides a sanction of sorts for areas that fail to reach attainment by the required dates. However, EPA has only rarely complied with its statutory obligation to make timely findings that areas have not achieved attainment by the statutory deadlines and thereby bump up their nonattainment status. In some cases, EPA has applied a “downwind extension policy” under which areas that did not achieve attainment by the relevant deadlines because of emissions or transport of emissions from other areas would not automatically be bumped up. Nevertheless, one district court ordered EPA to make the required nonattainment finding in a timely fashion, and three courts of appeals found the downwind extension policy to be invalid.10 In addition to the bump-up provision, the 1990 CAA Amendments provide other more tangible penalties and sanctions for states that fail to submit a SIP or submit an inadequate SIP. These include the authority for EPA to write a FIP as well as to impose two types of sanctions: (1) cutting off federal highway funds for the area, and (2) limiting the construction or modification of major new sources in the area by requiring two-for-one offsets from other sources of the same pollutant in the same or (in some cases) in adjacent areas (42 USC § 7509(a), (b)). A new aspect of the sanctions provision in the 1990 CAA Amendments is the requirement for automatic imposition of sanctions on deficient areas. According to the statute, once an area has been found by EPA to be deficient because of a failure to submit an adequate SIP, that area has 18 months to correct the deficiency. At the end of this 18-month “sanctions clock,” EPA must impose at least one of the two sanctions on the area and keep the sanctions in effect until the deficiency has been corrected. At the time of the writing of this report, EPA has had to impose one or more of the sanctions mandated in the CAA Amendments of 1990 in 28 instances. An additional 39 areas under the 18-month sanctions clock are facing the imposition of sanctions in the near future unless they can correct the relevant deficiency or deficiencies. For the most part, when sanctions have gone into effect, states have acted rapidly to have them removed, and as a result, they have tended to remain in effect for relatively brief periods 10   Sierra Club v. EPA, 2002 U.S. App. LEXIS 25289 (5th Cir. 2002); Sierra Club v. EPA, 311 F.3d 853 (7th Cir. 2002); Sierra Club v. EPA, 294 F.3d 155 (D.C. Cir. 2002); Sierra Club v. Browner, 130 F. Supp. 2d 78, 95 (D.D.C. 2001).

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Air Quality Management in the United States (in many cases, sanctions were lifted within weeks or even days of being imposed). In virtually all cases where highway sanctions were imposed, they did not result in an actual loss of highway funds, because no highway projects were being proposed in the areas during the brief periods that the sanctions were in effect. (The two exceptions were East Helena, MT, and Iron County, MO.) The rapidity with which states and areas acted to remove sanctions that had been imposed by EPA might indicate that the requirement for mandatory sanctions in the 1990 Amendments did in fact provide a positive impetus for compliance with the CAA and the SIP requirements. However, it is beyond the scope of this report to determine whether that was the case. The imposition of sanctions appeared to have little or no direct economic impact on the affected areas and states. THE EFFECTIVENESS OF THE SIP PROCESS Two basic metrics can be used to assess the effectiveness of the SIP process. The less stringent metric is based on an assessment of whether implementation of SIPs has resulted in a general decrease in pollutant emissions and concentrations and, more specifically, in a decrease in criteria pollutant concentrations in nonattainment areas. As discussed in more detail in Chapter 6, data from the nation’s air quality monitoring networks suggest that the SIP process has resulted in considerable progress in improving air quality on the basis of this metric. The more stringent metric is based on whether implementation of federal, regional, and local programs through the SIP process has resulted in the attainment of the NAAQS for criteria pollutants. On that basis, the effectiveness of the SIP process is less apparent. For example, in Table 3-4, where the number of nonattainment areas in the United States in 1992 and 2002 are listed for each of the criteria pollutants, significant progress is clearly shown. The number of nonattainment areas for CO, lead (Pb), SO2, and nitrogen dioxide (NO2) have decreased substantially. On the other hand, with the exception of NO2, nonattainment areas for each of these pollutants still exist. In the case of O3, there has also been a substantial decrease in the number of nonattainment areas. However, most of the areas that have been redesignated as being in attainment had a moderate or marginal classification. None of the serious O3 nonattainment areas, which were scheduled to reach attainment in 1999 in the 1990 CAA Amendments, have been redesignated. Similarly, all the areas classified as severe and extreme remain on the nonattainment list; however, they are not scheduled to reach attainment until 2005 and 2010, respectively. Thus, the effectiveness of the current SIP process in addressing serious and above O3 nonattainment has yet to be established. Of even greater concern is the lack of progress in alleviating nonattainment of the PM10 NAAQS, especially given

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Air Quality Management in the United States TABLE 3-4 Classifications and Number of Nonattainment Areas in 1992 Remaining in Nonattainment as of February 6, 2003 Pollutant Classification (ppm) 1992 2003 CO Serious (≥ 16.5) 7 6   Moderate (12.7 to 16.4) 4 1   Moderate (9.1 to 12.7) 32 4   Not classifieda 33 2   TOTAL 76 13 Pb — 13 3 NO2 — 1 0 O3 Extreme (≥ 0.280) 1 1   Severe-17 (0.190 to 0.280)b 5 5   Severe-15 (0.180 to 0.190)c 5 5   Serious (0.160 to 0.180) 14 15   Moderate (0.138 to 0.160) 32 8   Marginal (0.121 to 0.138) 44 21   Section185Ad 11 3   Othere 2 1   TOTAL 137 73 PM10f Serious 8 8   Moderate 78 58   TOTAL 86 66 SO2 Primaryg 48 21   Secondaryh 6 6 a“Not classified” is an area designated a CO nonattainment area as of the date of enactment of the CAA Amendments of 1990, which did not have sufficient data to determine if it is meeting or is not meeting the CO standard. b“Severe-17” nonattainment areas have 17 years to attain standards. c“Severe-15” nonattainment areas have 15 years to attain standards. d“Section 185A” of the CAA (previously called transitional) is an area that has designated an O3 nonattainment area as of the date of enactment of the CAA Amendments of 1990 and that has not violated the national primary ambient air quality standard for O3 for the 36-month period beginning January 1, 1987, and ending December 31, 1989. eThis category includes areas that violate the O3 standard and have a design value of less than 0.121 ppm. That occurs when the exceedance is higher than the O3 standard exceedance rate of 1.0 per year, even though the estimated design value is less than the standard. fThis is not an official list of nonattainment areas. See the Code of Federal Regulations (40 CFR Part 81) and pertinent Federal Register notices for legal lists and boundaries (http://www.epa.gov/oar/oaqps/greenbk/pfrnrpt1.html). For an area designated as being in nonattainment of the NAAQS for PM10, Section 188 of the CAA outlines the process for classification of that area and establishes that area’s attainment date. At the time of designation, all PM10 nonattainment areas are initially classified as moderate by operation of law. A moderate area can subsequently be reclassified as serious either before the applicable moderate area attainment date, if EPA determines the area cannot “practicably” attain the PM10 NAAQS by this attainment date, or after the passage of the applicable moderate area attainment date, if EPA determines the area has failed to attain the standards. g“Primary” standard based on health-related effects. h“Secondary” standard based on welfare-related effects. Abbreviation: ppm, parts per million. SOURCE: EPA 2003h.

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Air Quality Management in the United States the likelihood that the promulgation of the new PM2.5 NAAQS will give rise to a large number of PM nonattainment areas. Critical Discussion of the SIP Process The SIP process is an important and essential component of the nation’s AQM system. It allows state and local agencies to take into account emission controls adopted at the federal and multistate levels and then choose a suitable suite of additional local emission-control measures to reach attainment. On balance, this process should provide an appropriate division of responsibility. It can also provide the basis for a constructive partnership between the federal and state governments that steadily improves air quality on the local, multistate, and national levels. Air quality monitoring data confirm that such improvements have occurred in the past two decades (see Chapter 6). Nevertheless, important adjustments to the SIP process are needed if the difficult challenges ahead are to be effectively addressed. Some of the major concerns are discussed below. Recommendations for addressing these concerns are presented in Chapter 7. An Overly Bureaucratic Process The SIP process now mandates extensive amounts of local, state, and federal agency time and resources in a legalistic, and often frustrating, proposal and review process, which focuses primarily on compliance with intermediate process steps (see Box 3-7). This process probably discourages innovation and experimentation at the state and local levels; overtaxes the limited financial and human resources available to the nation’s AQM system at the state, local, and federal levels; and draws attention and resources away from the more germane issue of ensuring progress toward the goal of meeting the NAAQS. Overemphasis on Attainment Demonstrations An attainment-demonstration SIP is statutorily required to demonstrate through air quality model simulations and other weight-of-evidence analyses that the relevant nonattainment area will reach attainment by a certain date as a result of the specific pollution-control measures proposed in the SIP. Such an exercise provides policy-makers with critical information: estimates of the magnitude of emission reductions that will be needed to reach attainment and assessment of the efficacy of various options that could be adopted. That information is essential to the development of an implementation plan and should be retained in the AQM plan.

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Air Quality Management in the United States BOX 3-7 The State Implementation Plan: Examples of Bureaucratic Overload Every SIP revision requires a rule-making or legislative action at the state level. That process can take months or even years. Moreover, once approved at the state level, the revision must then be subjected to a full formal review by EPA and EPA’s own federal rule-making process. A major overhaul of the process in 1989 encouraged the use of “direct final notices” and “conditional approvals” to reduce the time needed to approve a state submittal, but the process remains largely duplicative, resource intensive, and time consuming. The CAA uses the nonattainment status of areas to impose numerous prescriptive measures on those areas (see Box 3-3). From the sector-specific RACT requirements to, for example, vehicle I/M programs, the measures must be implemented according to strict EPA regulations or guidance, thus reducing the flexibility with which areas can design and implement emission-reduction measures. The rigidity of federally mandated requirements for SIPs containing areas that are classified as serious and above may represent a congressional recognition of the failure of more flexible SIP requirements to achieve attainment during the 20 years before the enactment of the 1990 CAA Amendments. Although federally mandated sector-specific measures reduce local flexibility, they should have the benefit of accelerating the EPA approval process, but in general, they have not done so. In some cases, even minor differences between EPA’s language and a state’s language have resulted in a full-scale SIP review. (A notable exception is the procedure used by the California South Coast Air Quality Management District [SCAQMD] to adopt New Source Performance Standards [NSPS]; the SCAQMD regulations refer to the language of the Code of Federal Regulations rather than the language of local rules.) The CAA and its associated amendments specify a number of deadlines that proved to be unrealistic. A prime example is the specification of attainment deadlines that proved to be infeasible for O3 in the CAA Amendments of 1970 and 1977. (It remains to be seen if the more liberal attainment deadlines specified in the CAA Amendments of 1990, which extend to 2010, are feasible.) Setting unrealistic deadlines can lead to frustration for local and federal agencies that do not see any reasonable way to achieve the requirements of the act. It can also introduce an aura of fiction to the entire SIP process as agencies endeavor to meet the letter of the law by promulgating attainment demonstrations that have little likelihood of accurately forecasting future air quality trends. The actual emission reductions that can be achieved from specific measures are difficult to predict before they have been fully implemented and tested. Experience shows that many of the emission reductions claimed in SIPs prove to be too high. That has been especially true of the credits allowed by EPA for programs to reduce mobile-source emissions, such as the I/M and oxygenated fuels program (NSTC 1997, NRC 2002a). It is possible that the requirement to demonstrate attainment in a SIP inadvertently encourages the regulatory community to be overly optimistic when considering the benefits of specific measures. It is also possible that, in some cases, EPA has allowed local and state agencies to take large emission credits for specific programs to encourage program use and propagation. Finally, it is possible that EPA has allowed some to take overly generous emission credits to put off rancorous policy disputes.

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Air Quality Management in the United States However, the use of the attainment demonstration as a one-time robust prediction of how air quality in a given area will evolve over a multiple-year to a decadal time scale does not take into account the significant modeling, socioeconomic, and control-technology uncertainties implicit in such a process, and thus improperly applies the scientific and technical tools used in the demonstration (see, for example, NARSTO 2000). Moreover, the attainment demonstration can provide a false sense of assurance, which can discourage a review of the underlying assumptions of the plan until attainment has not been achieved after the prescribed time, such as 5 years or more. Finally, although mid-course reviews of SIPs do occur and although it should be possible to amend a SIP as new information and updated modeling simulations become available, in practice this task is very difficult, because the CAA requires that any such changes be subjected to the full and complex review and approval process used for the original SIP. In Chapter 7, the committee recommends implementation of a more iterative process, which retains the attainment demonstration but places greater emphasis on tracking and measuring progress and performance. Single-Pollutant Focus of SIPs Air pollutants occur in complex mixtures, and yet SIPs are constrained to address only individual criteria pollutants. As a result, the entire, relatively cumbersome SIP process must be undertaken for a pollutant such as O3 and then again for PM in a separate process and on a different timetable, despite the fact that the exposures are simultaneous, the sources are often the same, and the two pollutants share many common chemical precursors. One result of this separation is that facilities and other emitters of air pollution may be faced with multiple requirements over time to deal with similar pollutants. This process is made more problematic by the inability to consider key HAPs at the same time unless they are VOCs and therefore also precursors of the other pollutants. Some of the pollutants that states have sought to control in the past had limited sources and could be addressed individually (for example, Pb and CO). However, the major air pollution challenges today, which involve multiple emissions from common mobile and stationary sources, can be more effectively addressed using a multipollutant approach. Such an approach can simultaneously seek reductions of pollutants posing the most significant risks. It can also focus on achieving the most cost-effective mix of emission reductions of key pollutants from any one source rather than asking that source to separately address reductions of different pollutants at different times in response to different SIPs.

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Air Quality Management in the United States Barriers to Addressing Multistate Airshed Pollution Over the past two decades, the AQM system has had to grapple increasingly with air pollution phenomena that extend over multistate airsheds—phenomena whose effective control requires coordination across state boundaries and participation by states that may contribute to serious air quality problems but not experience them. For example, for acid rain, Congress chose to prescribe a national rule; for regional haze, Congress attempted to provide EPA with the authority to develop multistate strategies; and for O3, OTC (mandated by the CAA) and OTAG (developed by EPA and the states) were formed to develop suitable multistate strategies. The current form of the CAA does not provide EPA and states a clear mandate and procedure for regularly analyzing and identifying when and how to implement multistate efforts. With the exception of the OTC, the multistate regulatory approach for O3 and regional haze has been linked to the traditional SIP, requiring that a set of multistate controls be identified first and then incorporated voluntarily into the SIPs of all the states in the given region. This indirect and controversial process has been time consuming and fraught with legal uncertainties. The SIPs of the future will require a more effective mechanism for identifying and linking multistate control strategies with local measures. Of particular importance will be the need for mechanisms to induce states upwind of emission sources to take actions that have little direct benefits for them but that are needed for successful attainment of the NAAQS in states downwind of the sources. SUMMARY Strengths of the SIP Process The SIP process provides a reasonable mechanism for state and local agencies to take into account emission controls adopted at the federal and multistate levels and then to choose a suitable suite of additional local emission-control measures to attain the NAAQS. The existence of federally mandated emission-control measures has eased the burden of state and local authorities in developing attainment SIPS. The requirement for emission inventories in SIPs has facilitated the development of a uniform methodology for quantifying pollutant emissions in the United States. The requirement for modeling analysis in SIPs has promoted the development of increasingly sophisticated air quality models that link pollutant emissions to pollutant concentrations in the atmosphere.

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Air Quality Management in the United States The SIP process has resulted in a general decrease in criteria pollutant concentrations in the United States and, in some areas, has resulted in NAAQS attainment. The sequencing of attainment dates for O3, based on nonattainment classification, provides a more reasonable and flexible timetable for state and local agencies to come to address this persistent air pollution problem. Limitations of the SIP Process11 Implementation of federal, regional, and local control measures through the SIP process has not resulted in attainment for O3 and PM in many areas in the United States. The SIP process has become overly bureaucratic and draws attention and resources away from the more germane issues of tracking progress and assessing performance. The attainment-demonstration SIP places too much emphasis on uncertain emissions-based modeling simulations of future air pollution episodes. SIPs must be developed individually for each criteria pollutant, making it difficult for states and local agencies to consider potentially more cost-effective and more protective multipollutant strategies. The SIP process lacks sufficient mechanisms and governmental infrastructure for addressing multistate airshed aspects of air pollution. 11   Recommendations are provided in Chapter 7.