The Clean Air Act, a comprehensive federal law that regulates air pollution from stationary and mobile sources, was passed in 1963 to improve and protect the quality of the nation’s air. The act was substantially overhauled in 1970 when the Congress required EPA to establish national ambient air quality standards for pollutants at levels that are necessary to protect public health with an adequate margin of safety and to protect public welfare from adverse effects. EPA has set such standards for ozone, carbon monoxide, particulate matter, sulfur oxides, nitrogen dioxide, and lead. In addition, the act directed the states to specify how they would achieve and maintain compliance with the national standard for each pollutant. The Congress amended the act again in 1977 and 1990. The 1977 amendments were passed primarily to set new goals and dates for attaining the standards because many areas of the country had failed to meet the deadlines set previously. The act was amended again in 1990 when several new themes were incorporated into it, including encouraging the use of market-based approaches to reduce emissions, such as cap-and-trade programs. The major provisions of the 1990 amendments are contained in the first six titles. As requested, this report addresses EPA’s actions related to Titles I, III, and IV: Title I establishes a detailed and graduated program for the attainment and maintenance of the national ambient air quality standards; Title III expands and modifies regulations of hazardous air pollutant emissions and establishes a list of 189 hazardous air pollutants to be regulated; Title IV establishes the acid deposition control program to reduce the adverse effects of acid rain by reducing the annual emissions of pollutants that contribute to it. Although the Clean Air Act is a federal law, states and local governments are responsible for carrying out certain portions of the statute. For example, states are responsible for developing implementation plans that describe how they will come into compliance with national standards set by EPA. EPA must approve each state’s plan, and if an implementation plan is not acceptable, EPA may assume enforcement of the Clean Air Act in that state. Once EPA sets a national standard, it is generally up to state and local air pollution control agencies to enforce the standard, with oversight from EPA. For example, state air pollution control agencies may hold hearings on permit applications by power or chemical plants. States may also fine companies for violating air pollution limits. According to EPA, by many measures, the quality of the nation’s air has improved in recent years. Each year EPA estimates emissions that impact the ambient concentrations of the six major air pollutants for which EPA sets national ambient air quality standards. EPA uses these annual emissions estimates as one indicator of the effectiveness of its air programs. As figure 1 shows, according to EPA, between 1970 and 2004, gross domestic product, vehicle miles traveled, energy consumption, and U.S. population all grew; during the same time period, however, total emissions of the six principal air pollutants dropped by 54 percent. Despite this progress, large numbers of Americans continue to live in communities where pollution sometimes exceeds federal air quality standards for one or more of the six principal air pollutants. For example, EPA reported in April 2004 that 159 million people lived in areas of the United States where air pollution sometimes exceeds federal air quality standards for ground-level ozone. According to EPA, exposure to ozone has been linked to a number of adverse health effects, including significant decreases in lung function; inflammation of the airways; and increased respiratory symptoms, such as cough and pain when taking a deep breath. Moreover, in 2003, 62 million people lived in counties where monitors showed particle pollution levels higher than national particulate matter standards, according to a December 2004 EPA report. Long-term exposure to particle pollution is associated with problems such as decreased lung function, chronic bronchitis, and premature death. Even short-term exposure to particle pollution—measured in hours or days—is associated with such effects as cardiac arrhythmias (heartbeat irregularities), heart attacks, hospital admissions or emergency room visits for heart or lung disease, and premature death. EPA identified 452 actions required to meet the objectives of Titles I, III, and IV of the Clean Air Act Amendments of 1990. About half of these required actions were included under Title III, which also included the largest number of requirements with statutory deadlines. As shown in table 1, the 1990 amendments specified statutory deadlines for 338 of the Title I-, III-, and IV-related requirements. The numerous actions required to meet the objectives of Titles I, III, and IV of the 1990 amendments vary in scope and complexity. For example, Title I of the Clean Air Act requires EPA to periodically review and revise, as appropriate, the national health- and welfare-based standards for air quality. After EPA revises any one of these standards, states are responsible for developing plans that detail how they will achieve the revised standard. EPA then must review the individual state plans for each standard and decide whether to approve them. While EPA must review and approve all individual state plans submitted, each set of reviews is only counted as one action. Other Title I requirements, on the other hand, only require EPA to publish reports on air quality and emission trends. While the reports may represent a significant amount of effort, the steps required to implement national ambient air quality standards are inherently more difficult to accomplish and often require parties independent of EPA, such as state and local agencies, to pass legislation and issue, adopt, and implement rules. Comparing the requirements among titles also shows how they vary in complexity. For example, Title IV required EPA to develop a new market-based cap and trade program to reduce emissions of sulfur dioxide and a rate-based program to reduce emissions of nitrogen oxides from power plants. While developing the cap and trade program was a large undertaking on EPA’s part, it involved regulating a specified number of stationary sources in a single industry. In contrast, under Title III, EPA is required to implement technology-based standards for 174 separate categories of sources of hazardous air pollutants, involving many industries. As shown in table 2, a large portion of the requirements with statutory deadlines related to Titles I, III, and IV were met late. That is, 256 of the 338 requirements with statutory deadlines have been completed but were late. Of the 114 requirements without statutory deadlines, all but 3 of the requirements have been completed. On average, EPA met the requirements related to Titles I, III, and IV about 24, 25, and 15 months after their statutory deadlines, respectively. Of the 256 requirements that EPA met late, 162 were met within 2 years of their statutory deadline and 94 were completed more than 2 years after their deadlines (see table 3). Consequently, improvements in air quality associated with some of these requirements may have been delayed. EPA officials cited several factors to explain why the agency missed deadlines for so many requirements. Among these factors was an emphasis on stakeholders’ review and involvement during regulatory development, which added to the time needed to issue regulations. For example, according to an EPA official, the process to develop an early technology rule under Title III involved protracted negotiations among EPA, industry groups, a labor union, and environmental groups. The rule was finalized in October 1993, 10 months after its statutory deadline. In addition, EPA officials mentioned the need to set priorities among the tremendous number of new requirements for EPA resulting from the 1990 amendments, which meant that some of these actions had to be delayed. Moreover, competing demands caused by the workload associated with EPA’s responses to lawsuits challenging some of its rules caused additional delays. For example, the time needed to respond to litigation of previous rules impinged on EPA staff’s ability to develop new rules, according to agency officials. In addition, at the time of our 2000 report, EPA officials also attributed delays to the emergence of new scientific information that led to major Clean Air Act activities unforeseen by the 1990 amendments. For example, the emergence of new scientific information regarding the importance of regional ozone transport led to an extensive collaborative process between states in the eastern half of the country to evaluate and address the transport of ozone and its precursors. As of April 2005, 45 of the requirements related to Titles I, III, and IV with statutory deadlines that had passed have not been met. Thus, any improvements in air quality that would result from EPA meeting these requirements remain unrealized. The majority of the unmet requirements related to Title I are activities involving promulgating regulations that limit the emissions of volatile organic compounds from different groups of consumer and commercial products. According to EPA officials, these rules were never completed because EPA shifted its priorities toward issuing the Title III technology-based standards. Additionally, EPA officials noted that many states have implemented their own rules limiting emissions of volatile organic compounds from these products, and these state rules are achieving the level of emissions reductions that would be achieved by a national rule passed by EPA. However, EPA is currently being sued because it did not implement these rules by their statutory deadlines. According to an EPA official, the agency and the litigant have agreed on the actions to be taken to address the requirements, but they could not reach agreement on completion dates. As a result, EPA is currently awaiting court-issued compliance dates. In addition, 21 Title III requirements have yet to be met. Most of these are “residual risk” reviews of technology-based standards with deadlines prior to April 2005. That is, within 8 years of setting each technology-based standard, EPA is required to assess the remaining health risks (the residual risk) from each source category to determine whether the standard appropriately protects public health. Applying this “risk-based” approach, EPA must revise the standards to make them more protective of health, if necessary. EPA completed its first review and issued the first set of these risk-based amendments in March 2005. Two actions required by Title IV have not been met, but, according to EPA, the agency has decided not to pursue these actions further. The requirements were to (1) promulgate an opt-in regulation for process sources and (2) conduct a sulfur dioxide/nitrogen oxides inter-pollutant trading study. According to EPA officials, the agency decided not to promulgate the opt-in regulation because it determined that the federal resources needed to develop the rule would be well in excess of those available and the implementation of this provision would not reduce overall emissions. EPA officials also said that the rule would not be cost-effective due to these factors and the limited number of sources expected to use the opt-in option. EPA officials said that the agency decided not to pursue the sulfur dioxide/nitrogen oxides inter-pollutant study because of the lack of a trading ratio that would capture the complex environmental relationship between sulfur dioxide and nitrogen oxides and because an inter-pollutant trading program would be complex and unlikely to result in environmental benefits. The list of specific actions EPA is required to take to meet the objectives of Titles I and III of the Clean Air Act Amendments of 1990 includes requirements for periodic assessments of some of the standards related to these titles. Under the Clean Air Act, EPA is required every 5 years to review the levels at which it has set national ambient air quality standards to ensure that they are sufficiently protective of public health and welfare. If EPA determines it is necessary to revise the standard, the agency undertakes a rulemaking to do so. Each new national ambient air quality standard, in turn, will trigger a number of subsequent EPA actions under Title I, such as setting the boundaries of areas that do not attain the standards and approving state plans to correct nonattainment. As a result, the set of required actions related to Title I tends to repeat over time. Title III also includes requirements for periodic assessments of its technology-based standards. In addition to the residual risk assessments discussed above, the Clean Air Act requires that EPA review the technology-based standards every 8 years, and, if necessary, revise them to account for improvements in air pollution controls and prevention. The first round of these recurring reviews will occur concurrently with the first round of residual risk assessments, according to an EPA official. Moreover, EPA’s workload related to its air programs may increase as a result of recommendations for regulatory reform compiled by the Office of Management and Budget. For example, in response to a recommendation to permit the use of new technology to monitor leaks of volatile air pollutants, EPA plans to propose a rule or guidance in March 2006. The Clean Air Act Amendments of 1990 constituted a significant overhaul of the Clean Air Act, and notable reductions in emissions of air pollutants have been attained as a result of the many actions these amendments required of EPA, states, and other parties. Currently, EPA has completed most of the 452 actions required by the 1990 amendments related to Titles I, III, and IV. The number, scope, and complexity of the required actions under each of these titles varied widely, and these differences, along with other challenges EPA faced, led to varying timeliness in implementing these requirements. Although EPA did not meet the statutory deadlines in many cases, we believe that the deadlines played an important role in EPA’s implementation of the myriad and diverse actions mandated in the 1990 amendments by providing a structure to guide and support the agency’s efforts to complete them. As EPA and the Congress now move on to addressing the remaining air pollution problems that pose health threats to our citizens, some points from our 2000 report on the implementation of the 1990 amendments bear repeating. First, some of the stakeholders we interviewed representing environmental groups and state and local government agencies expressed a preference for legislation and regulations that describe specific amounts of emissions to be reduced, provide specific deadlines to be met, and identify the sources to be regulated. Second, we, along with many of these stakeholders, concluded in that report that the acid rain program under Title IV could offer a worthwhile model for some other air quality problems because it set emission-reduction goals and encouraged market-based approaches, such as cap-and-trade programs, to attain these goals. While EPA officials noted that emissions-trading programs may not be suitable for all air pollutants, the agency has applied this approach to several pollutants since 2000. Specifically, EPA has issued final rules using cap-and-trade programs to achieve further reductions in sulfur dioxide and nitrogen oxides and to require reductions of mercury emissions for the first time. However, whether EPA can apply the cap-and-trade model to hazardous air pollutants such as mercury in the absence of express statutory authority to do so is unclear, particularly in light of the lawsuit that has been filed challenging EPA’s March 2005 rule on mercury emissions. We provided EPA with a draft of this report for its review and comment. EPA generally agreed with the findings presented in the report and provided supplemental information about the air quality, public health, and environmental benefits associated with implementation of the Clean Air Act Amendments of 1990 and comments related to its future challenges. The agency also provided technical comments, which we incorporated where appropriate. Appendix V contains the full text of the agency’s comments and our responses. As agreed with your office, unless you publicly announce the contents of this report earlier, we plan no further distribution until 30 days from the date of this letter. At that time, we will send copies of this report to the appropriate congressional committees; the Administrator, EPA; and other interested parties. We will also make copies available to others upon request. In addition, the report will be available at no charge on the GAO Web site at http://www.gao.gov. If you or your staff have any questions, please call me at (202) 512-3841. Key contributors to this report are listed in appendix VI. The Clean Air Act requires that all areas of the country meet national ambient air quality standards (NAAQS), which are set by EPA at levels that are expected to be protective of human health and the environment. NAAQS have been established for six “criteria” pollutants: ozone, carbon monoxide, nitrogen dioxide, sulfur oxides, particulate matter, and lead. The act further specifies that EPA must assess the level at which the standards are set every five years and revise them, if necessary. To accomplish the objectives of Title I of the Clean Air Act Amendments of 1990, EPA identified 171 requirements. The specific requirements contained in Title I direct EPA to perform a variety of activities, many of which are related to implementing the NAAQS. Implementation of the standards involves several stages, many requiring efforts by both EPA and states. For example, once EPA has determined the appropriate air quality level at which to set a standard, the agency then goes through a designation process during which it identifies the areas of the country that fail to meet the standard. After the nonattainment areas are identified, states have primary responsibility for attaining and maintaining the NAAQS. To do this, states develop state implementation plans (SIPs) that specify the programs that states will develop to achieve and maintain compliance with the standards. Once a state submits a SIP to EPA, EPA is responsible for reviewing it and either approving or disapproving the plan. To assist states in developing their plans, EPA develops guidance documents that help states interpret the standards and provide information on how to comply. For example, EPA established several alternative control techniques documents for various sources that emit nitrogen oxides. These documents provide suggestions for states and industry on different techniques that can be used to reduce nitrogen oxides emissions. In some circumstances, EPA may provide guidance to the state and local air pollution control agencies through the issuance of EPA guidance and/or policy memos. For example, although designating areas as nonattainment or attainment is a complex and time-consuming process, EPA issued guidance through policy memos on the factors and criteria EPA used to make decisions for designating areas of the country as nonattainment. As of April 2005, EPA had completed 146 of the requirements that the agency must implement to meet the objectives of Title I. Sixty-one requirements that EPA had met by April 2005 had statutory deadlines. As table 4 shows, EPA met 16 of these requirements on time and missed the deadlines for 45 of them. EPA also completed 85 of the 88 requirements that did not have statutory deadlines. On average, Title I-related requirements that were met late were completed 24 months after their statutory deadline. As table 5 shows, the length of time by which requirements were met late for Title I varied. For example, 24 of the late requirements were met within 1 year of their statutory deadline while 8 requirements were completed more than 3 years late. According to EPA, the agency missed deadlines for Title I-related requirements for a number of reasons, such as (1) having to review a larger quantity of scientific information than was available in the past; (2) competing demands placed on agency staff who had to work concurrently on more than one major rulemaking; and (3) engaging in longer, more involved interagency review processes. According to agency officials, many of the requirements that EPA completed late arose due to issues beyond EPA’s control. For example, in implementing the ozone and particulate matter NAAQS, the emergence of new scientific information regarding the importance of regional ozone transport led to an extensive collaborative process between states in the eastern half of the country to evaluate and address the transport of ozone and its precursors. This information was then taken into account in the review and subsequent revision of the ozone NAAQS in 1997. In addition, EPA was sued on both the 1997 ozone and particulate matter standards, which delayed EPA’s action to designate areas as nonattainment. Moreover, the ongoing review of the particulate matter NAAQS has been significantly extended as a consequence of the unprecedented amount of new scientific research that has become available since the last review, according to EPA. Currently, EPA has not completed 22 requirements related to Title I with statutory deadlines (see table 6). Fifteen of these requirements call for rules involving different groups of consumer and commercial products, six involve reviewing the NAAQS for the criteria pollutants, and one requires EPA to finalize approving the state implementation plans for ozone and carbon monoxide. The outstanding rules involving the consumer and commercial products are to limit volatile organic compound emissions from various products, such as cleaning products, personal care products, and a variety of insecticides. The 1990 amendments specified that the rules be promulgated in four groups, based on a priority ranking established by EPA that includes a number of factors, such as the quantity of emissions from certain products. While EPA completed the first group of rules by September 1998, the agency had not done anything further to implement the remaining three groups of rules. According to EPA officials, no further work had been done to implement the rules because EPA shifted its priorities toward issuing the Title III technology-based standards. Additionally, EPA officials noted that many states have implemented their own rules limiting emissions of volatile organic compounds from these products, and these state rules are achieving the level of emissions reductions that would be achieved by a national rule passed by EPA. An EPA official stated that a national rule would not provide much of an additional benefit in the areas where emissions of volatile organic compounds are a problem and that a national rule would be fought by industry in states where emissions of volatile organic compounds are not a problem. However, promulgating these rules is a requirement under the 1990 amendments, and according to EPA officials, the agency is currently being sued by the Sierra Club, an environmental advocacy group, for not promulgating them by their statutory deadline. EPA and the litigant have agreed on the actions to be taken to address the requirements, however, they could not reach agreement on the completion dates and are currently awaiting court-issued compliance dates. In addition, the other six unmet requirements related to Title I involve potentially revising the NAAQS for the criteria pollutants. While EPA has been involved in litigation regarding four of these standards, litigation is still ongoing only regarding the lead NAAQS. EPA is being sued for not reviewing since 1991 the lead NAAQS that was originally issued in October 1978. According to EPA officials, the agency did not undertake this review because it shifted its focus to controlling other sources of lead, such as drinking water and hazardous waste facilities. As shown in table 6, EPA expects to complete the required reviews for four of the criteria pollutants by 2009. In addition to the unmet requirements discussed above, EPA has three requirements related to Title I without statutory deadlines that have not yet been completed. The first is to develop a proposed particulate matter implementation rule, which EPA expects to complete in summer 2005. The second is the promulgation of methods for measurement of visible emissions; EPA has not yet set a completion date for this action. The third is the promulgation of phase II of the 8-hour ozone implementation rule, expected in summer 2005. Title III of the Clean Air Act Amendments of 1990 established a new regulatory program to reduce the emissions of hazardous air pollutants, specifying 189 air toxics whose emissions would be controlled under its provisions. The list includes organic and inorganic chemicals, compounds of various elements, and numerous other toxic substances that are frequently emitted into the air. Title III was intended to reduce the population’s exposures to these pollutants, which can cause serious adverse health effects such as cancer and reproductive dysfunction. After identifying the pollutants to be regulated, Title III directs EPA to impose technology-based standards, or Maximum Achievable Control Technology (MACT) standards, on industry to reduce emissions. These technology- based standards require the maximum degree of reduction in emissions that EPA determines achievable for new and existing sources, taking into consideration the cost of achieving such reduction, health and environmental impacts, and energy requirements. The process for developing each MACT standard may include surveying impacted industries, visiting sites, testing emissions, and conducting public hearings. As a second step, within 8 years after completing each technology-based standard, EPA is to review the remaining risks to the public and, if necessary, issue health-based amendments to each of the MACT rules to address such risks. The first set of these “residual risk” standards was finalized in March 2005; residual risk standards for the remaining MACT rules have not been completed. Finally, the Clean Air Act requires that EPA review and, if necessary, revise the technology-based standards at least every 8 years, to account for improvements in air pollution controls and prevention. The first round of these recurring reviews will occur concurrently with the first round of residual risk assessments, according to an EPA official. EPA identified 237 requirements—either with statutory deadlines prior to April 2005 or without statutory deadlines—that accomplish the objectives of Title III of the Clean Air Act Amendments of 1990. Most of the specific requirements under Title III direct EPA to promulgate MACT standards for various sources of hazardous air pollutants, such as dry cleaning facilities, petroleum refineries, and the printing and publishing industry. Title III also requires EPA to issue a variety of studies and reports to the Congress. For example, EPA has issued a series of studies on the deposition of air pollutants to the Great Lakes and other bodies of water. In addition, Title III also directs EPA to issue guidance on a number of subjects, including, for example, guidance regarding state air toxics programs. As of April 2005, EPA had met almost all of the requirements it identified to fully implement the objectives of Title III of the Clean Air Act Amendments of 1990, as shown in table 7. EPA’s most recent data show that it has taken the required action to meet 216 of the 237 Title III requirements, although 195 of these were met late, as shown in table 7. As shown above, the vast majority of Title III requirements were met late. On average, Title III requirements met late were completed 25 months after their statutory deadline. However, the length of time by which requirements were met late varied. As shown in table 8, 116 of the 195 requirements met late were completed within the first 2 years after the statutory deadline, while 29 were not completed until more than 3 years after the deadline. In explaining why requirements under Title III were met late, an EPA official discussed several factors. For example, the official said that the vast majority of the requirements involved the development of the MACT standards, which requires a significant amount of time and effort. The official also confirmed the reasons that requirements were met late provided by EPA officials at the time of our 2000 report, which included the need to prioritize, given resource limitations, the time needed to develop the policy framework and infrastructure of the MACT program, and the need for stakeholder participation in the rulemaking processes for certain MACT standards. In addition, the EPA official pointed out that in the past, litigation on issued rules has imposed additional demands on EPA staff working to meet outstanding requirements, leading to delays. There are 21 requirements under Title III that EPA had not met as of April 2005, most of which involve the residual risk reviews required after EPA has set technology-based standards (see table 9). Specifically, EPA has not yet reviewed residual risk for 19 MACT standards with deadlines prior to April 2005. EPA completed its first review and issued the first set of these risk-based amendments, for the coke oven batteries MACT standard, on March 31, 2005. In addition to the residual risk reviews, EPA has not yet completed its urban area source standards. The other unmet requirement under Title III calls for EPA to promulgate standards for solid waste incinerators not previously regulated under the title. According to an EPA official, the agency has focused its resources on regulating major solid waste incinerators, while this requirement consists of a “catch-all” to pick up remaining sources. Part of the challenge to completing this action has involved identifying what these other sources might be, according to the official. In addition to the unmet requirements above, EPA has not yet completed residual risk reviews for 76 MACT standards whose deadlines fall later than April 2005. Because these residual risk reviews are not due until 8 years after the completion of each technology standard, some of these residual risk reviews are not due until 2012. Title IV of the Clean Air Act Amendments of 1990 established the acid deposition control program. This program was designed to provide environmental and public health benefits through reductions in emissions of sulfur dioxide and nitrogen oxides, the primary causes of acid rain. The program provides an alternative to traditional “command and control” regulatory approaches by using a market-based trading program that allocates sulfur dioxide emission allowances to affected electric utilities. The program creates a cost-effective way for utilities to achieve their required sulfur dioxide emission reductions in the manner that is most suitable to them. Utilities can choose to buy, sell, or bank their allowances, as long as their annual emissions do not exceed the amount of allowances (whether originally allocated to them or purchased) that they hold at the end of the year. The nitrogen oxides program, on the other hand, does not cap emissions of nitrogen oxides, nor does it utilize an allowance trading system. Rather, this program, which focuses on emissions of nitrogen oxides from coal-fired electric utility boilers, provides flexibility for utilities in meeting emission limits by focusing on the emission rate to be achieved and providing options for compliance. To accomplish the objectives of Title IV of the Clean Air Act Amendments of 1990, EPA identified 44 requirements. Many of the required activities had to do with setting up the acid rain program—for example, conducting allowance auctions, issuing allowances to utilities, and establishing an allowance trading system. Additionally, EPA developed requirements for utilities to continuously monitor their emission levels to properly account for allowances. As of April 2005, EPA had completed 42 of the 44 requirements to meet the objectives of Title IV. There were 26 requirements in Title IV with statutory deadlines—EPA met 8 of them on time and missed 16; 2 others were unmet. There were 18 requirements that did not have statutory deadlines, and EPA has completed all of them. (See table 10.) On average, for the 16 requirements EPA met late, they were completed within approximately 15 months of their deadlines. As shown in table 11, 10 were met within 1 year of their deadline and 1 was met more than 3 years late. According to EPA officials, the agency was late with some of the requirements because interagency review and consultation with the Acid Rain Advisory Committee added time to the process. Officials consider this time spent worthwhile because it allowed for more stakeholder input into the rulemaking process, which may have made the rules less controversial. In fact, EPA officials stated that Title IV has been subjected to less litigation than other titles. According to the officials, litigation, however, did cause a delay in the effective date of the first phase of the acid rain nitrogen oxides reduction program by 1 year. EPA officials said the second phase of this program affected approximately three times more units and was implemented on schedule. EPA officials stated that since implementation of the acid rain program, changes have been necessary to keep the program up to date and successful. For example, EPA revised the continuous emission-monitoring rule in 1999 and 2002. According to EPA, these updates were necessary because of changes in the industry, such as technological advances and growth in the number of sources. Two Title IV requirements that EPA has not completed have statutory deadlines that have passed. The two requirements are (1) promulgating the opt-in regulation for process sources and (2) conducting a sulfur dioxide/nitrogen oxides inter-pollutant trading study. After conducting preliminary work for the first action, which was to have been completed by May 1992, EPA determined that the federal resources required to accomplish it were well in excess of those available. Additionally, according to an EPA official, there was evidence of very limited use of the opt-in election for other sources. Given these two factors, and EPA’s view that implementation of this provision would not reduce overall emissions, the agency determined that it would not be cost-effective to promulgate the regulation. Finally, EPA officials said that the agency decided not to pursue the second action, which was to have been completed by January 1994, for three reasons. Specifically, according to EPA officials, (1) they lacked a trading ratio that would capture the complex environmental relationship between sulfur dioxide and nitrogen oxides; (2) if the ratio issue could be resolved, an annual allowance system for nitrogen oxides would need to be created with which to trade sulfur dioxide allowances; and (3) it was not clear that implementing inter-pollutant trading would result in a net environmental benefit as there are multiple and complex health and environmental impacts of both sulfur dioxide and nitrogen oxides requiring a comprehensive analysis of impacts and cost-effectiveness beyond available resources. The objective of this review was to determine the extent to which the Environmental Protection Agency (EPA) has completed the various actions required to meet the objectives of Titles I, III, and IV of the Clean Air Act Amendments of 1990. These titles, which respectively address national ambient air quality standards, hazardous air pollutants, and acid deposition control, are the most relevant to proposed legislation and recently finalized regulations that address emissions of air pollutants by power plants. To obtain information on the status of EPA’s implementation of requirements related to Titles I, III, and IV of the Clean Air Act Amendments of 1990—both those with and without statutory deadlines— we obtained lists of these requirements used for GAO’s 2000 report, Air Pollution: Status of Implementation and Issues of the Clean Air Act Amendments of 1990 (GAO/RCED-00-72) and held discussions with EPA officials knowledgeable about EPA’s workload required to meet the objectives of these titles. EPA officials verified the list of requirements related to each of the three titles for accuracy and completeness and provided documentation for any changes and additions made to the list. To determine how late the requirements were met, we compared the statutory deadline for each requirement to the month in which the requirement was met. For regulations that appeared in the Federal Register, for example, we considered the date the Federal Register issue was published to be the date the requirement was met, as agreed with EPA officials. In addition, we obtained explanations for why a large number of requirements were met after their statutory deadlines from two sources—our 2000 report and through discussions with EPA officials. For requirements that had not been met as of April 2005, we obtained additional information from EPA officials, including actions taken to date. To ensure the reliability of the information provided by EPA, we requested documentation for any changes EPA made to the list of requirements developed for our previous report and checked the documentation to ensure it matched the description of the requirement. In addition, we reviewed the information EPA submitted to ensure there were no duplicate entries or apparent inconsistencies; for any entries that appeared questionable, we followed up with EPA officials and usually obtained additional documentation. In certain cases, in particular with regard to Title III requirements, we also independently verified the status of the requirements. In all cases, EPA provided confirmation for the conclusions we reached as well as, in some cases, additional documentation. We determined that the data we obtained about the status of EPA’s implementation of required actions were sufficiently reliable for the purposes of this report. We also reviewed the methodology of two EPA studies that contained information about areas of the United States impacted by ground-level ozone and particulate matter. We determined that these studies were sufficiently methodologically sound to present their results in this report as background information. While this report addresses the extent to which EPA has met its requirements related to Titles I, III, and IV of the 1990 amendments, it does not address the status of requirements under other titles of the amendments or show the extent to which states have implemented applicable requirements. We conducted our work from January 2005 to May 2005 in accordance with generally accepted government auditing standards. The following are GAO’s comments on EPA’s letter dated May 18, 2005. 1. As background, our report states that while air quality in the United States has steadily improved over the last few decades, more than a hundred million Americans continue to live in communities where pollution causes the air to be unhealthy at times, according to EPA. EPA has apparently interpreted this statement as implying that missed deadlines described in the report are responsible for the scope of the current particulate matter and ozone nonattainment problems. However, our report does not make that link. 2. EPA provided us several examples of cases in which a delay in the implementation of certain specific requirements did not lead to a delay in improvements in air quality. While our draft report indicated that requirements met late delayed improvements in air quality, we did not mean to suggest that all late requirements delayed improvements in air quality. Therefore, we revised the report to say that delays in implementation of some of the requirements may have led to delays in improvements in air quality. 3. During the course of our work, we discussed our proposed methodology with EPA officials and they agreed with our plan to use the Federal Register publication date as the completion date for relevant requirements. In commenting on the draft report, however, the agency stated that its Office of Air and Radiation generally considers that it has met its statutory obligation to issue a rule on the date on which a final rule is signed and disseminated to the public, which is likely to be earlier than the publication of that rule in the Federal Register. Although we agree with EPA’s assessment that using the signature date, rather than the Federal Register publication date, would not change the report’s conclusions, we revised the report to include EPA’s comment. 4. We revised report language throughout to reflect the fact that certain actions originally included as requirements of Title I of the Clean Air Act Amendments of 1990 were established earlier but are related to these amendments. John B. Stephenson, (202) 512-3841 (stephensonj@gao.gov) Christine Fishkin, (202) 512-6895 (fishkinc@gao.gov) In addition to the individuals named above, Nancy Crothers, Christine Houle, Karen Keegan, Judy Pagano, and Nico Sloss made key contributions to this report.

Summary: While air quality in the United States has steadily improved over the last few decades, more than a hundred million Americans continue to live in communities where pollution causes the air to be unhealthy at times, according to the Environmental Protection Agency (EPA). The Clean Air Act, first passed in 1963, was last reauthorized and amended in 1990, when new programs were created and changes were made to the ways in which air pollution is controlled. The 1990 amendments included hundreds of requirements for EPA, as well as other parties, to take steps that will ultimately reduce air pollution. The amendments also established deadlines for many of these requirements. Since the 1990 amendments, various actions have been proposed to either amend the Clean Air Act or implement its provisions in new ways. GAO was asked to report on the current status of EPA's implementation of requirements under Titles I, III, and IV of the 1990 amendments. These titles, which address national ambient air quality standards, hazardous air pollutants, and acid deposition control, respectively, are the most relevant to proposed legislation and recently finalized regulations addressing emissions of air pollutants by power plants. As of April 2005, EPA had completed 404 of the 452 actions required to meet the objectives of Titles I, III, and IV of the Clean Air Act Amendments of 1990. Of the 338 requirements that had statutory deadlines prior to April 2005, EPA completed 256 late: many (162) 2 years or less after the required date, but others (94) more than 2 years after their deadlines. Consequently, improvements in air quality associated with some of these requirements may have been delayed. The numerous actions required to implement these titles varied in scope and complexity. For example, these actions included reviewing numerous state plans to comply with national health- and welfare-based air quality standards for six major pollutants, setting technology-based standards to reduce emissions from sources of hazardous air pollutants, and developing a new program to reduce acid rain. EPA officials cited several reasons for the missed deadlines, including the emphasis on stakeholders' involvement during regulatory development, which added to the time needed to issue regulations; the need to set priorities among the tremendous number of new responsibilities EPA assumed as a result of the 1990 amendments, which meant that some actions had to be delayed; and competing demands caused by the workload associated with EPA's response to lawsuits challenging some of its rules. Of the 48 requirements EPA had not met as of April 2005, 45 had associated deadlines, and 3 did not. The unmet requirements include 15 Title I requirements to promulgate regulations to limit the emissions of volatile organic compounds from a number of consumer and commercial products, such as household cleaners and pesticides. According to EPA officials, these rules were not completed because EPA shifted its priorities toward issuing standards related to the emissions of hazardous air pollutants regulated under Title III. However, the unmet requirements also include actions under Title III to periodically assess whether EPA's emissions standards for sources that emit significant amounts of hazardous air pollutants appropriately protect public health. These "residual risk" assessments are to be made within 8 years of the setting of each of the emissions standards, and 19 of these assessments are now past the 8-year mark. EPA completed the first of these residual risk assessments in March 2005. Any improvements in air quality that would result from EPA meeting these requirements remain unrealized. In commenting on a draft of this report, EPA generally agreed with our findings and provided supplemental information, primarily on the benefits of the Clean Air Act Amendments of 1990 and the reasons for implementation delays.