Clean Air Act
EPA Should Improve the Management of Its Air Toxics Program Gao ID: GAO-06-669 June 23, 2006The Environmental Protection Agency's (EPA) most recent data indicate that 95 percent of all Americans face an increased likelihood of developing cancer as a result of breathing air toxics--pollutants such as benzene and asbestos that may cause cancer or other serious health problems. Sources of air toxics include large industrial facilities, smaller facilities such as dry cleaners, and cars and trucks. The 1990 Clean Air Act Amendments required EPA to regulate 190 pollutants from these sources through a multifaceted regulatory program. While EPA issues federal standards, state and local agencies generally administer these standards, and some develop their own rules to complement the federal standards. In this context, GAO was asked to assess (1) EPA's progress and challenges in implementing the air toxics program, (2) available information on the program's costs and benefits, and (3) practices of state and local air toxics programs.
While EPA has made some progress in implementing its air toxics program mandated by the 1990 Clean Air Act Amendments, most of its regulatory actions were completed late and major aspects of the program have still not been addressed. Most of EPA's progress relates to issuing emissions standards for large stationary sources, although EPA completed these standards about 4 years behind schedule. However, many of the unmet requirements pertain to limiting emissions from small stationary and mobile sources, which collectively account for most emissions of air toxics. The agency faces continuing implementation challenges stemming from the program's low priority relative to other programs and related funding constraints. To this end, the agency lacks a comprehensive strategy for completing the unmet requirements or estimates of resources necessary to do so. Senior EPA officials said the program's agenda is largely set by external stakeholders who file litigation when the agency misses deadlines. As a result of EPA's limited progress, the agency has not addressed health risks from air toxics to the extent or in the time frames envisioned in the Clean Air Act. Senior EPA officials said that issuing standards for large stationary sources had addressed the greatest risks from air toxics and that other clean air programs also control air toxics as a side benefit. However, EPA does not have reliable data on the degree of risk reduction achieved through its regulations. Furthermore, the data that are available suggest that the agency has substantial opportunities to reduce emissions from mobile and small stationary sources. Available information on EPA's efforts to control air toxics is not sufficiently comprehensive to measure the program's total costs and benefits. Specifically, EPA has not comprehensively estimated the national economic costs of all air toxics standards and lacks the data necessary to assess the benefits of these standards, such as decreased incidence of cancer. Information on these impacts would help the agency assess the overall net benefits (total benefits minus total costs) of the air toxics program and compare these effects with those generated by higher-priority clean air programs, such as those intended to address smog. Data on other indicators of the program's effectiveness, such as changes in emissions, concentrations of air toxics in the (ambient) outdoor air, and data on compliance with air toxics standards are also limited and inconclusive. The state and local programs we reviewed use practices that could potentially help EPA enhance the effectiveness of its air toxics program. For example, several state programs have systematic approaches for identifying and prioritizing new pollutants that could inform EPA's efforts to meet the act's requirement to review and update the list of regulated pollutants.
RecommendationsOur recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.
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Report to Congressional Requesters:
United States Government Accountability Office:
GAO:
June 2006:
Clean Air Act:
EPA Should Improve the Management of Its Air Toxics Program:
Clean Air Act:
GAO-06-669:
GAO Highlights:
Highlights of GAO-06-669, a report to congressional requesters
Why GAO Did This Study:
The Environmental Protection Agency‘s (EPA) most recent data indicate
that 95 percent of all Americans face an increased likelihood of
developing cancer as a result of breathing air toxics”pollutants such
as benzene and asbestos that may cause cancer or other serious health
problems. Sources of air toxics include large industrial facilities,
smaller facilities such as dry cleaners, and cars and trucks. The 1990
Clean Air Act Amendments required EPA to regulate 190 pollutants from
these sources through a multifaceted regulatory program. While EPA
issues federal standards, state and local agencies generally administer
these standards, and some develop their own rules to complement the
federal standards. In this context, GAO was asked to assess (1) EPA‘s
progress and challenges in implementing the air toxics program, (2)
available information on the program‘s costs and benefits, and (3)
practices of state and local air toxics programs.
What GAO Found:
While EPA has made some progress in implementing its air toxics program
mandated by the 1990 Clean Air Act Amendments, most of its regulatory
actions were completed late and major aspects of the program have still
not been addressed. Most of EPA‘s progress relates to issuing emissions
standards for large stationary sources, although EPA completed these
standards about 4 years behind schedule. However, many of the unmet
requirements pertain to limiting emissions from small stationary and
mobile sources, which collectively account for most emissions of air
toxics. The agency faces continuing implementation challenges stemming
from the program‘s low priority relative to other programs and related
funding constraints. To this end, the agency lacks a comprehensive
strategy for completing the unmet requirements or estimates of
resources necessary to do so. Senior EPA officials said the program‘s
agenda is largely set by external stakeholders who file litigation when
the agency misses deadlines. As a result of EPA‘s limited progress, the
agency has not addressed health risks from air toxics to the extent or
in the time frames envisioned in the Clean Air Act. Senior EPA
officials said that issuing standards for large stationary sources had
addressed the greatest risks from air toxics and that other clean air
programs also control air toxics as a side benefit. However, EPA does
not have reliable data on the degree of risk reduction achieved through
its regulations. Furthermore, the data that are available suggest that
the agency has substantial opportunities to reduce emissions from
mobile and small stationary sources.
Available information on EPA‘s efforts to control air toxics is not
sufficiently comprehensive to measure the program‘s total costs and
benefits. Specifically, EPA has not comprehensively estimated the
national economic costs of all air toxics standards and lacks the data
necessary to assess the benefits of these standards, such as decreased
incidence of cancer. Information on these impacts would help the agency
assess the overall net benefits (total benefits minus total costs) of
the air toxics program and compare these effects with those generated
by higher-priority clean air programs, such as those intended to
address smog. Data on other indicators of the program‘s effectiveness,
such as changes in emissions, concentrations of air toxics in the
(ambient) outdoor air, and data on compliance with air toxics standards
are also limited and inconclusive.
The state and local programs we reviewed use practices that could
potentially help EPA enhance the effectiveness of its air toxics
program. For example, several state programs have systematic approaches
for identifying and prioritizing new pollutants that could inform EPA‘s
efforts to meet the act‘s requirement to review and update the list of
regulated pollutants.
What GAO Recommends:
GAO recommends that EPA develop a plan for improving the management of
its air toxics program, including a prioritization scheme, timelines,
and estimates of resources needed to meet its statutory obligations.
EPA agreed, in part, with our conclusions and recommendations, and
provided clarifications on three statements in the report.
[Hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-06-669].
To view the full product, including the scope and methodology, click on
the link above. For more information, contact John Stephenson at (202)
512-3841 or stephensonj@gao.gov.
[End of Section]
Contents:
Letter:
Results in Brief:
Background:
EPA Has Made Limited Progress in Addressing the Clean Air Act's
Requirements for Air Toxics and Faces Significant Implementation
Challenges:
Available Information on Costs and Benefits Is Not Sufficient to
Measure the Program's Effectiveness:
State and Local Programs Employ Practices That Could Potentially Help
EPA Enhance the Effectiveness of the Federal Air Toxics Program:
Conclusions:
Recommendations for Executive Action:
Agency Comments:
Appendix I: Status of EPA's Efforts to Respond to Recommendations in
the National Academies' Report on Air Quality:
Appendix II: Objectives, Scope, and Methodology:
Appendix III: Profiles of State and Local Air Toxics Programs:
California:
New Jersey:
Oregon:
Wisconsin:
Louisville, Kentucky:
Appendix IV: Comments from the Environmental Protection Agency:
GAO comments:
Appendix V: GAO Contact and Staff Acknowledgments:
Tables:
Table 1: The Five Most Commonly Emitted Air Toxics, 2002:
Table 2: Overview of the Risk Assessment Process:
Table 3: Number of Air Toxics Actions Required under the 1990 Clean Air
Act Amendments:
Table 4: EPA Progress in Meeting Air Toxics Requirements:
Table 5: Timeliness of MACT Emission Control Standards for Major Source
Categories:
Table 6: EPA Funding for Air Toxics Program as a Percentage of Funding
for All Clean Air Programs, Fiscal Years 2000 through 2005:
Table 7: Percentage of Estimated Total Air Toxics Emissions by Source
Type, 1993, 1999, and 2002:
Table 8: Issues Rated by Stakeholders as Challenges to a Large or Great
Extent:
Table 9: Summary of Annual Costs Imposed by the 1990 Clean Air Act
Amendments:
Table 10: Key Steps in Estimating the Benefits of Controlling Air
Toxics:
Table 11: Results of Inspections at Facilities Regulated by Air Toxics
Standards, 2003 and 2004:
Table 12: Selected State and Local Air Toxics Programs:
Figures:
Figure 1: Common Sources of Air Toxics Emissions:
Figure 2: EPA Air Toxics Regulatory Framework for Major Stationary
Sources:
Figure 3: Emission Points at an Industrial Facility Emitting Air
Toxics:
Abbreviations:
CRS: Congressional Research Service:
DEP: New Jersey Department of Environmental Protection:
DEQ: Oregon Department of Environmental Quality:
DNR: Wisconsin Department of Natural Resources:
EPA: Environmental Protection Agency:
IRIS: Integrated Risk Information System:
MACT: Maximum Achievable Control Technology:
NATA: National Air Toxics Assessment:
NSPS: New Source Performance Standards:
OAQPS: Office of Air Quality Planning and Standards:
OAR: Office of Air and Radiation:
OMB: Office of Management and Budget:
OPAR: Office of Policy Analysis and Review:
ORD: Office of Research and Development:
SAB: Science Advisory Board:
STAPPA/ ALAPCO: State and Territorial Air Pollution Program
Administrators and the Association of Local Air Pollution Control
Officials:
STAR: Strategic Toxic Air Reduction:
United States Government Accountability Office:
Washington, DC 20548:
June 23, 2006:
Congressional Requesters:
The Environmental Protection Agency's (EPA) most recent data indicate
that 95 percent of all Americans face an increased likelihood of
developing cancer from air toxics--pollutants such as benzene,
asbestos, and chlorine--by breathing outdoor air.[Footnote 1] Other
adverse health effects associated with air toxics include damage to
reproductive functions and birth defects.[Footnote 2] Air toxics are
emitted into the air in the United States by large stationary sources
such as industrial facilities, small stationary sources such as dry
cleaners, and mobile sources such as automobiles. According to the most
recent data available, EPA estimates that these and other sources
emitted 4.6 million tons of air toxics in 2002.[Footnote 3] The Clean
Air Act of 1970 established a program to reduce emissions of air
toxics, and the 1990 amendments to the act significantly expanded the
program. Prior to the amendments, the act had required EPA to identify
air toxics that posed unacceptable health risks and issue emissions
standards for sources of these pollutants. In part because of the
limited success of this approach--EPA established standards for seven
air toxics over a 20-year period--the amendments identified 190
specific air toxics to be regulated, required EPA to list categories of
sources to be regulated, and established implementation timelines.
Specifically, the 1990 amendments established a range of air toxics
requirements for EPA to implement that generally fall into four
categories: (1) establishing emission standards based on existing
pollution control technologies, called Maximum Achievable Control
Technology (MACT), for an estimated 84,000 major stationary sources
within 158 industries;[Footnote 4] (2) examining the remaining health
risk (called the "residual risk") from these sources 8 years after
implementing each MACT standard and, if warranted, issuing additional
standards to protect public health or the environment; (3) regulating
air toxics emissions from small stationary sources,[Footnote 5] such as
dry cleaners; and (4) evaluating the need for and feasibility of
regulation of air toxics emissions from mobile sources, such as cars,
and regulating these sources based on this evaluation. In addition, the
1990 amendments required EPA to periodically assess the costs and
benefits of the entire Clean Air Act. This included an assessment of
the act's costs and benefits prior to 1990 as well as projections of
future economic impacts resulting from the amendments. Information on
impacts, such as the costs to regulated industries and the public
health benefits resulting from cleaner air, is necessary for analyzing
whether the benefits of clean air regulations exceed the costs.
Furthermore, estimating the economic impacts of individual regulations
and clean air programs can help EPA compare the net benefits and cost-
effectiveness of its programs under the act. Finally, the amendments
required EPA to periodically review and revise the list of regulated
air toxics. The agency currently regulates 187 substances.[Footnote 6]
Prior GAO work dating to 1991 identified EPA's difficulties in
regulating air toxics, including missed deadlines and inadequate
funding.[Footnote 7] Most recently, a May 2005 GAO report found that
EPA had completed MACT standards for major stationary sources but
issued most of them behind schedule.[Footnote 8] In addition, the EPA
Inspector General, National Academies, Congressional Research Service,
and Office of Management and Budget (OMB) have identified shortcomings
with various aspects of the air toxics program.
While responsibility for establishing federal standards under the Clean
Air Act rests with EPA, state and local air pollution control agencies
generally implement EPA's emission standards. The act allows these
agencies to impose more stringent requirements than the federal
standards, and some state and local agencies have developed innovative
air toxics programs that go beyond the federal program, thereby
enabling them to address air toxics concerns that remain unaddressed by
EPA's standards.
In this context, you asked us to assess (1) EPA's progress toward
implementing the air toxics program and any implementation challenges
the agency faces, (2) available information about the costs and
benefits of EPA's efforts to control air toxics, and (3) the program
design and management practices of state and local air toxics programs
that could potentially help EPA enhance the effectiveness of the
federal program. You also asked us to assess EPA's progress in
responding to recommendations pertaining to the air toxics program made
by the National Academies in 2004.[Footnote 9]
To respond to the first objective, we updated our previous analysis of
the agency's progress in implementing the air toxics requirements under
the Clean Air Act and reviewed available studies by the National
Academies, OMB, and the EPA Inspector General to identify potential
implementation challenges. Based on this information, we conducted
structured interviews with EPA officials and external stakeholders to
identify the most important challenges. We met with senior air program
officials to discuss the priority of the air toxics program relative to
other air programs as well as priorities within the program. To respond
to the second objective, we analyzed available information on the
economic impacts of the program and data on trends in emissions, health
risks, and compliance. We also met with EPA staff responsible for
analyzing the economic effects of clean air regulations. To respond to
the third objective, we conducted interviews with officials from a
nonprobability sample of four state and one local air toxics programs
to identify innovative program designs or management practices. Among
other criteria, we selected programs identified as innovative by EPA
and other stakeholders and that used strategies that differ from those
at the federal level. We focused primarily on practices that EPA might
find useful in addressing its program implementation challenges and did
not evaluate the effectiveness of these programs. Finally, we obtained
information from EPA officials on the agency's progress in responding
to the National Academies' recommendations pertaining to air toxics and
describe the status of these efforts in appendix I. Our work included
an assessment of data reliability and internal controls. Unless
otherwise noted, data are sufficiently reliable for the purposes of
this report. See appendix II for a more detailed description of our
scope and methodology. We conducted our work from June 2005 to June
2006 in accordance with generally accepted government auditing
standards.
Results in Brief:
While EPA has made progress toward implementing the air toxics program
mandated by the Clean Air Act, most of the completed requirements were
met late and many requirements and significant challenges remain. EPA
has completed one of the four categories of requirements--issuing 96
rules that set emissions standards for major stationary sources--but
did not do so until 2004, which was 4 years behind the schedule
outlined in the act. These delays, in turn, pushed back the evaluation
of the residual health risks from these sources that EPA must complete
8 years after issuing each standard. Consequently, EPA will not
complete the residual risk reviews--which are intended to provide
information on any potential adverse health effects that may warrant
further regulation--until 2012 at the earliest, rather than in 2008 as
the act provided. Further, EPA has completed only 16 of 70 emissions
standards for small stationary sources that cumulatively accounted for
about one-third of all air toxic emissions in 2002 and has proposed,
but not finalized, a required rule making covering mobile sources.
Finally, EPA has not met the act's requirement to review and update, as
appropriate, the list of regulated air toxics, despite evidence that
potentially harmful chemicals remain unregulated. As a result of EPA's
limited progress, the agency has not identified and reduced health
risks from air toxics to the extent and in the time frame envisioned in
the act. EPA's limited progress to date stems, in part, from the
program's low priority relative to other air programs, such as those
targeting smog, which the agency believes have a higher potential to
reduce human health risks. Senior program officials also said that the
agency's progress in implementing the act's requirements does not
reflect all of the agency's progress in limiting toxic emissions
because other EPA programs decrease emissions of air toxics as a side
benefit. In addition, within the air toxics program, senior EPA
officials said that the agency's focus on issuing emissions standards
for major stationary sources had addressed the greatest risks from air
toxics. However, EPA does not have reliable data on the degree to which
its programs have reduced risks. Furthermore, the data that are
available suggest that the agency still has substantial opportunities
to control emissions from mobile and small stationary sources.
EPA faces significant challenges in implementing the air toxics
program, many of which stem from its relatively low priority within the
agency. Importantly, the agency lacks a comprehensive strategy for
managing its implementation of the remaining air toxics requirements.
Senior EPA officials said that the program's agenda is largely set by
external stakeholders who file litigation when the agency misses
deadlines. For example, EPA currently faces a court order to issue
emissions standards for small stationary sources. Previous reports by
GAO identified inadequate funding for the air toxics program as a
challenge, and key stakeholders--including senior EPA officials,
environmental advocates, and state and local agency officials--said
resource constraints continue to pose a major challenge. The percentage
of funding for the air toxics program relative to all clean air
programs ranged from 18 percent to 19 percent between 2000 and 2003 and
declined to 15 percent in 2004 and 12 percent in 2005. EPA has not
estimated the level of resources necessary to comply with the remaining
requirements of the 1990 amendments, according to a senior program
official. We believe that such estimates would help inform
congressional oversight and appropriations decisions. Senior EPA
officials and other stakeholders also cited a lack of information on
the benefits of regulating air toxics as a major challenge, which, in
turn, reinforces the program's relative priority because the agency
cannot demonstrate its effectiveness. The stakeholders identified a
number of other challenges, but perceptions varied by stakeholder
group. For example, EPA and industry stakeholders rated the large
number of statutory requirements as a challenge, while environmental
stakeholders rated a lack of reliable data on air toxics sources and
their emissions as a challenge.
Available information on the costs and benefits of EPA's efforts to
control air toxics is not sufficiently comprehensive to measure the
total economic impacts resulting from the air toxics program. As a
result, it is difficult to compare the net benefits (total benefits
minus total costs) of EPA's investments in the air toxics program with
those of other air quality programs. The agency's 1999 report
responding to the act's mandate for a comprehensive cost-benefit
analysis of all Clean Air Act programs contained limited information on
the costs of regulating air toxics and no estimates of the human health
benefits, such as likely reductions in cancer risk. The analysis
estimated that the cost to industry of complying with the 21 control
standards that had been issued by 1999 would total $780 million in 2000
and rise to $840 million in 2010. EPA officials said the agency plans
to issue a revised analysis in 2007 that will estimate the costs of all
standards issued before September 2005. However, the analysis will only
provide limited data on the benefits of regulating air toxics because
of the analytical challenges involved. These challenges include a lack
of reliable data on changes in emissions attributable to air toxics
regulations and difficulties in estimating the effects that changes in
emissions have on health outcomes. Specifically, EPA has not monetized
the health benefits of its air toxics regulations individually or in
total because of the analytical difficulty of characterizing health
outcomes associated with incremental reductions in exposure to 187
different chemicals. Instead of using a cost-benefit analysis to
measure the program's effectiveness, EPA uses data on national trends
in emissions of all air toxics. However, as EPA's Inspector General
reported in 2004, the agency needs to improve its methods for
estimating emissions before it can accurately gauge the extent to which
its programs have actually reduced emissions. Other indicators of the
program's effectiveness, such as changes in concentrations of air
toxics in the ambient (outdoor) air over time and data on compliance
with air toxics standards, are also limited and inconclusive. For
example, the agency's data on compliance with air toxics standards
cannot be generalized to describe compliance at the universe of
regulated facilities because inspectors often target facilities where
they suspect noncompliance.
The five state and local air toxics programs we reviewed use several
program design and management practices that EPA could consider as part
of efforts to enhance the effectiveness of the federal air toxics
program. First, the programs we reviewed address gaps in the federal
program by, for example, regulating more emissions sources than EPA, or
setting more stringent standards to control emissions. As part of
efforts to strengthen its program and establish priorities for meeting
its remaining obligations under the act, EPA could benefit from
assessing and considering what states perceive as the primary gaps in
the federal program. Second, these programs use risk-based approaches
to prioritize efforts to control air toxics. For example, Oregon's air
toxics program is designed to monitor emissions in various parts of the
state, identify areas of elevated risk from air toxics, and then
concentrate resources on the emissions sources that drive these risks.
Third, some of these programs base their regulatory decisions on the
risk posed by entire facilities, whereas, to date, EPA has limited the
scope of its residual risk program to only those emission points within
facilities that must comply with existing federal standards. As a
result, according to several state and local officials, EPA's decision
to exclude some emissions points from risk assessments may, in turn,
cause it to underestimate the total risk from facilities and thereby
enable some facilities to avoid further regulation. Fourth, several of
the programs we reviewed have systematic approaches for identifying and
prioritizing new chemicals. In contrast, EPA does not proactively
consider new chemicals and instead has taken a reactive approach in
which it considers petitions from external parties to list or delist
chemicals. Considering the practices used by these programs could
inform future EPA efforts to meet the act's requirement to periodically
review and update the list of regulated chemicals. In addition to these
practices, all of the programs we reviewed highlighted the importance
of reliable data on emissions and chemical toxicity. Several require
major and small stationary sources to submit standardized emissions
reports and certify their accuracy. In contrast, EPA, to date,
generally has not required emissions sources or state or local agencies
to systematically report these data. Such standardized data collection
could enhance EPA's analysis and decision making in future air toxics
rule makings. In addition, several officials said that EPA does not
regularly update chemical toxicity values that inform the work of state
and local programs.
We are recommending that EPA develop an air toxics program improvement
plan that, among other things, (1) provides a schedule for completing
its mandated requirements under the act and identifies the resources
necessary to complete these actions, (2) prioritizes activities within
the air toxics program, (3) establishes a process and timeline for
meeting the act's requirement to review and update the list of air
toxics, (4) outlines an approach and timelines for improving the
agency's ability to measure the program's costs and benefits, and (5)
describes how the agency plans to improve its air toxics emissions
inventory. In commenting on the report, EPA's Acting Assistant
Administrator for Air and Radiation said that EPA agrees in part with
our conclusions and recommendations. The agency did not identify
specific aspects of our conclusions or recommendations with which it
disagreed, but offered clarifications on our statements regarding
information on the costs and benefits of the agency's efforts to
control air toxics, the agency's progress in completing certain air
toxics requirements of the Clean Air Act, and EPA's management of the
remaining requirements. EPA also provided technical comments, which we
have incorporated, as appropriate. EPA's letter, and our response, are
included as appendix IV.
Background:
Under the Clean Air Act, EPA regulates two primary types of air
pollutants. The first category--the so-called "criteria pollutants" for
which EPA has established air quality criteria that limit the allowable
concentrations in the ambient air--includes carbon monoxide, ground-
level ozone (smog), lead, nitrogen oxides, particulate matter, and
sulfur dioxide. EPA sets these standards at a level it believes
protects public health and the needs of sensitive populations such as
asthmatics, children, and the elderly. EPA and the states use air
quality monitoring to measure compliance with the standards and develop
pollution control strategies to help bring areas with poor air quality
into compliance.
The second category consists of hazardous air pollutants (or "air
toxics") for which no ambient air quality standards exist, and includes
187 chemicals that cause a variety of adverse health effects, including
cancer. A variety of sources emit one or more of these air toxics (see
fig. 1). In 2002, mobile sources emitted 41 percent of all air toxics,
small stationary sources emitted 30 percent, major stationary sources
emitted 20 percent, and other sources, such as fires, emitted 9
percent, according to EPA's most recent data.
Figure 1: Common Sources of Air Toxics Emissions:
[See PDF for image]
Source: EPA (data); GAO, ARt Explosion (image).
[End of figure]
Table 1 identifies the most widely emitted air toxics, the primary
sources of these pollutants, and some of the adverse health effects
associated with exposure to these substances. It is important to note
that the health risks posed by air toxics vary considerably. Thus,
small quantities of more harmful pollutants can pose greater health
threats than large quantities of less harmful pollutants.
Table 1: The Five Most Commonly Emitted Air Toxics, 2002:
Pollutant: Toluene;
Percentage of total air toxics emissions: 18;
Primary sources of emissions: Mobile sources;
Health effects: Impairment of the nervous system with symptoms
including tiredness, dizziness, sleepiness, confusion, weakness, memory
loss, nausea, loss of appetite, and hearing and color vision loss;
kidney problems; unconsciousness; and death.
Pollutant: Xylenes;
Percentage of total air toxics emissions: 13;
Primary sources of emissions: Mobile sources, asphalt paving;
Health effects: Irritation of the skin, eyes, nose, and throat;
headaches, dizziness, memory loss, and changes in sense of balance;
lung problems; stomach discomfort; possible effects on the liver and
kidneys; unconsciousness; and death.
Pollutant: Hydrochloric acid;
Percentage of total air toxics emissions: 12;
Primary sources of emissions: Coal-fired utility and industrial
boilers;
Health effects: Eye, nose, and respiratory tract irritation; corrosion
of the skin, eyes, mucous membranes, esophagus, and stomach; severe
burns; ulceration; scarring; inflammation of the stomach lining;
chronic bronchitis; and inflammation of the skin.
Pollutant: Benzene;
Percentage of total air toxics emissions: 9;
Primary sources of emissions: Mobile sources, open burning, pesticide
application;
Health effects: Drowsiness, dizziness, vomiting, irritation of the
stomach, sleepiness, convulsions, rapid heart rate, headaches, tremors,
confusion, unconsciousness, anemia, excessive bleeding, weakened immune
system, increased incidence of cancer (leukemia), and death.
Pollutant: Formaldehyde;
Percentage of total air toxics emissions: 7;
Primary sources of emissions: Mobile sources, open burning;
Health effects: Irritation of the eyes, nose, throat, and skin; severe
pain; vomiting; coma; limited evidence of cancer; and death.
Sources: EPA and Agency for Toxic Substances and Disease Registry.
Note: Health effects are dependent upon the concentration of the air
toxic and the length of exposure.
[End of table]
Prior to 1990, the Clean Air Act required EPA to list air toxics it
deemed hazardous and then promulgate regulations for them. However, by
1990, EPA had regulated only seven such pollutants. In 1990, Congress
dramatically changed the program. Instead of requiring EPA to develop
ambient standards for air toxics as it does for the six criteria
pollutants, the Clean Air Act Amendments of 1990 listed the air toxics
to be controlled and directed EPA to control them by, among other
things, (1) developing technology-based emissions limits (MACT
standards) for major stationary sources, such as incinerators and
chemical plants; (2) regulating emissions from smaller sources, such as
dry cleaners and gas stations; and (3) evaluating the need for and
feasibility of regulations from mobile sources, such as cars, and
regulating these sources based on this evaluation. The standards for
major stationary sources generally require the use of available control
technologies to achieve emissions reductions without the explicit
consideration of a chemical's toxicity or potential risk. To develop
MACT standards, the 1990 amendments directed EPA to group emissions
points at industrial facilities into categories of similar sources and
then develop regulations for each "source category." Examples of source
categories include cement manufacturing, hazardous waste combustion,
and semiconductor manufacturing.[Footnote 10] The next step consisted
of evaluating the level of emissions control achieved by the best-
performing facilities in each source category and using this as the
minimum level of control required throughout the entire source
category.[Footnote 11]
Additionally, the amendments required EPA to review the MACT standards
every 8 years to evaluate any remaining, or residual, health risks from
these sources and identify developments in control technologies. EPA
has combined the residual risk assessments and technology reviews into
a concurrent process. Thus, the agency simultaneously evaluates the
remaining risks from each source category and the availability of new
pollution control technologies. The risk assessment process seeks to
estimate the cancer and other health risks faced by individuals exposed
to toxic emissions. As shown in table 2, the four steps of risk
assessment include hazard identification, dose-response assessment,
exposure assessment, and risk characterization.
Table 2: Overview of the Risk Assessment Process:
Step: Hazard identification;
Description: Determine the association between pollutants and adverse
health effects. This involves reviewing studies of illnesses among
groups of people or laboratory animals exposed to air pollutants.
Step: Dose-response assessment;
Description: Describe the adverse health effects associated with
different levels of exposure to a particular pollutant.
Step: Exposure assessment;
Description: Estimate the amount of an air toxic a person is likely to
inhale in a given period of time using data on emissions,
meteorological conditions, and information on the locations of homes
and workplaces relative to emissions sources.
Step: Risk characterization;
Description: Integrate the information from the three previous steps to
describe the degree of increased risk faced by individuals. Typical
results of this step include measures of excess lifetime cancer risk
(e.g., a risk of 100 in 1 million), the population risk (e.g., the
number of people that face a cancer risk exceeding 100 in 1 million),
or the estimated number of additional cancer cases each year.
Source: GAO analysis of EPA documents.
Notes: EPA maintains information used in the hazard identification and
dose-response assessment stages of risk assessments in its Integrated
Risk Information System (IRIS) database.
Lifetime excess cancer risk refers to the estimated additional risk of
developing cancer that a person would have if exposed to a specific
concentration of an air toxic 24 hours a day, 7 days a week, for 70
years.
[End of table]
The risk assessment process is limited by scientific uncertainty about
the health effects associated with exposure to air toxics. Nonetheless,
the Clean Air Act's residual risk program seeks to determine whether
the most exposed individuals face excess cancer risk of more than 1 in
1 million. In cases where estimated risks exceed this threshold, EPA
develops a residual risk standard that seeks to provide an ample margin
of safety for affected individuals.[Footnote 12] Figure 2 provides an
overview of the regulatory process for major stationary sources of air
toxics, including MACT standards and 8-year technology and residual
risk reviews.
Figure 2: EPA Air Toxics Regulatory Framework for Major Stationary
Sources:
[See PDF for image]
Source: GAO.
[End of figure]
In addition to requirements for major sources, the act required EPA to
develop a comprehensive strategy to control emissions of air toxics in
urban areas, including identifying at least 30 small stationary source
categories that account for 90 percent of the risk from these sources,
and issue regulations by November 2000. EPA has listed 70 small
stationary source categories for regulation. The act also required EPA
to assess the need for and feasibility of air toxics standards for
motor vehicles and fuels, and, based on that assessment, issue
regulations to control air toxics from motor vehicles and fuels.
Table 3 summarizes the 453 actions required of EPA under the air toxics
provisions of the 1990 amendments. Because these actions range in scope
from developing MACT standards to issuing reports, they vary in their
potential to reduce emissions.
Table 3: Number of Air Toxics Actions Required under the 1990 Clean Air
Act Amendments:
Air toxics category: Major stationary sources regulated by MACT
standards;
Number of actions required: 158.
Air toxics category: 8-year residual risk reviews for MACT standards;
Number of actions required: 96.
Air toxics category: 8-year technology reviews for MACT standards;
Number of actions required: 96.
Air toxics category: Standards for small stationary sources;
Number of actions required: 70.
Air toxics category: Mobile sources;
Number of actions required: 2.
Air toxics category: Other (reports, studies, etc.);
Number of actions required: 31.
Air toxics category: Total;
Number of actions required: 453.
Source: GAO analysis of EPA documents.
Note: The act required EPA to list major and small source categories of
the listed hazardous air pollutants (currently 187 chemicals). In
response, EPA identified 158 major source categories and was required
to issue a standard for each category. EPA responded by issuing 96
different standards, some of which apply to multiple source categories.
The 8-year residual risk and technology reviews apply to the 96
standards, which accounts for the difference between the 158
requirements to regulate major sources and the 96 requirements each for
residual risk and technology reviews.
[End of table]
EPA's Office of Air and Radiation has primary responsibility for
completing air toxics actions required under the Clean Air Act. Within
the Office of Air and Radiation, responsibility for implementing the
air toxics requirements of the Act rests primarily with the Office of
Air Quality Planning and Standards and, to a lesser extent, with the
Office of Transportation and Air Quality. The responsibility for
analyzing the health, economic, and other effects of individual air
toxics programs also rests with these offices. The Office of Policy
Analysis and Review supplements these program-specific analyses by
conducting periodic assessments of the health, ecological, and economic
effects of the overall Clean Air Act, including the air toxics
provisions, and coordinating these studies as appropriate with other
EPA offices. In conducting these broader studies, the Office of Policy
Analysis and Review also works with the Advisory Council for Clean Air
Act Compliance Analysis, an independent, multi-disciplinary panel of
outside experts organized under the auspices of EPA's Science Advisory
Board. The agency's Office of Research and Development performs
scientific research on air toxics to support regulatory efforts. The
Office of Enforcement and Compliance Assurance directs efforts to
ensure compliance with air toxics requirements. In most cases, state
and local air pollution control agencies implement the standards
developed by EPA. Additionally, the act generally allows these agencies
to impose more stringent requirements than the federal standards,
although some states have enacted laws or rules prohibiting air
pollution control agencies from adopting more stringent requirements.
Nonetheless, some state and local programs have developed innovative
air toxics programs.
EPA Has Made Limited Progress in Addressing the Clean Air Act's
Requirements for Air Toxics and Faces Significant Implementation
Challenges:
EPA has completed issuing emissions standards for major stationary
sources but issued most of these standards late and has made limited
progress toward completing the remaining air toxics requirements. In
particular, EPA has made little progress and is behind schedule in
completing residual risk and technology reviews and in issuing
emissions standards for small stationary sources and mobile sources.
EPA's limited progress and program implementation challenges have
resulted primarily from the program's lower priority relative to other
clean air programs. Furthermore, the agency lacks a program
implementation strategy. Stakeholders we interviewed--including EPA,
state and local agency officials, environmental groups, and industry
representatives--provided additional perspective on EPA's
implementation of the air toxics program and highlighted data
limitations and inadequate funding as major challenges.
EPA Issued Most of the MACT Standards behind Schedule and Has Made
Limited Progress in Completing the Other Air Toxics Requirements:
EPA has completed issuing the MACT standards for major stationary
sources but has made limited progress in addressing requirements
related to residual risk and technology reviews, and in issuing
standards for small stationary sources and mobile sources. As a result
of the limited progress in implementing these requirements, EPA has not
reduced human health risks from air toxics to the extent and in the
time frames envisioned in the act. Table 4 summarizes EPA's overall
progress in implementing air toxics requirements under the Clean Air
Act.
Table 4: EPA Progress in Meeting Air Toxics Requirements:
Issue MACT emission standards for major source categories;
Number of requirements: 158;
Requirements met: Met on time[A]: 4;
Requirements met: Met late: 154;
Requirements unmet: Unmet-- past due: 0;
Requirements unmet: Unmet--not yet due: 0.
Residual risk reviews;
Number of requirements: 96;
Requirements met: Met on time[A]: 0;
Requirements met: Met late: 5;
Requirements unmet: Unmet--past due: 16;
Requirements unmet: Unmet--not yet due: 75.
Control technology reviews;
Number of requirements: 96;
Requirements met: Met on time[A]: 0;
Requirements met: Met late: 5;
Requirements unmet: Unmet--past due: 16;
Requirements unmet: Unmet--not yet due: 75.
Small stationary sources;
Number of requirements: 70;
Requirements met: Met on time[A]: 0;
Requirements met: Met late: 16;
Requirements unmet: Unmet--past due: 54;
Requirements unmet: Unmet--not yet due: 0.
Mobile sources;
Number of requirements: 2;
Requirements met: Met on time[A]: 0;
Requirements met: Met late: 1;
Requirements unmet: Unmet--past due: 1;
Requirements unmet: Unmet--not yet due: 0.
Other;
Number of requirements: 31;
Requirements met: Met on time[A]: 8;
Requirements met: Met late: 21;
Requirements unmet: Unmet--past due: 2[B];
Requirements unmet: Unmet--not yet due: 0.
Total;
Number of requirements: 453;
Requirements met: Met on time[A]: 12;
Requirements met: Met late: 202;
Requirements unmet: Unmet--past due: 89;
Requirements unmet: Unmet--not yet due: 150.
Source: GAO analysis of EPA documents.
Notes: This analysis reflects the status of the requirements as of
April 2006.
[A] We count requirements met by EPA that did not have deadlines
specified in the act as on time.
[B] EPA is required to periodically review the list of air toxics
established by the act but has not yet done so. This requirement was
not accompanied by a deadline. Based on other time frames required by
the act, we list this requirement as unmet/past due instead of unmet/
not yet due.
[End of table]
To meet the act's requirements for major stationary sources, EPA had to
identify a list of major source categories and then issue standards
beginning in 1992, with all standards due by November 2000. In
response, EPA identified 158 major source categories and issued 96
standards covering these categories between 1993 and 2004. Table 5
summarizes the timeliness of EPA's MACT standards relative to the act's
deadlines. While the agency missed most of the deadlines, a senior EPA
official said that issuing the 96 standards represented a major
achievement and that the agency had never previously issued so many
standards for one program in such a limited period of time.
Table 5: Timeliness of MACT Emission Control Standards for Major Source
Categories:
Issue MACT emission standards for major source categories;
Number of requirements: 158;
Requirements met according to the schedule specified in the Clean Air
Act: On time or early: 4;
Requirements met according to the schedule specified in the Clean Air
Act: 0-1 years late: 23;
Requirements met according to the schedule specified in the Clean Air
Act: 1-2 years late: 68;
Requirements met according to the schedule specified in the Clean Air
Act: More than 2 years late: 63.
Source: GAO analysis.
Note: This analysis reflects the status of the requirements as of April
2006.
[End of table]
Because EPA issued most of the MACT standards well behind schedule, the
residual risk and control technology reviews, which EPA is to complete
8 years after issuing each standard, have been pushed back
commensurately, thereby delaying any additional public health
protection that these reviews may provide. Specifically, instead of
completing the initial residual risk assessments and technology reviews
for all of the MACT standards by 2008 as specified by the act, EPA is
not required to complete all of the initial reviews until 2012 because
it issued many MACT standards behind schedule. For example, because EPA
issued the MACT standard for industrial boilers in 2004 rather than
2000, as required, the residual risk assessment and technology review
for this source category become due in 2012, almost 4 years later than
the act's intended timeline. Furthermore, EPA is behind schedule on the
residual risk assessments and technology reviews. As of April 2006, EPA
had finalized only five of these reviews, and all of these were late.
Three additional reviews have court-ordered deadlines and will be
completed by the end of 2006, according to EPA.
The act required EPA to develop regulations for small stationary
sources by November 2000.[Footnote 13] However, the agency has not met
this schedule. In July 2000, EPA outlined its plans for issuing
standards for small stationary sources in a report to Congress
describing its strategy for reducing threats from air toxics in urban
areas.[Footnote 14] This report identified 16 categories of small
stationary sources that it described as "already subject to regulation"
or "will be subject to regulation." The report also identified 13
additional categories for which it planned to issue standards by 2004.
In 2002, EPA expanded the list to include a total of 70 source
categories. However, as of April 2006, EPA has issued standards for
only 16 categories of sources, leaving standards for 54 source
categories past due. Furthermore, the agency faces court-ordered
deadlines to complete standards for all of the remaining categories of
small stationary sources by June 15, 2009.
The act also required EPA to study the need and feasibility of air
toxics standards for motor vehicles and fuels and, based on the study,
develop a regulation to control air toxics from motor vehicles and
fuels by 1995. EPA completed the study in 1993 (about 11 months after
the deadline) and, after missing the 1995 deadline for the regulation,
faced a court-ordered consent decree to complete the regulation by
2001. To comply, EPA issued an initial rule in 2001 that stated that a
second and final rule making would follow in 2004.[Footnote 15] The
agency missed this deadline and eventually proposed a second rule in
February 2006, with a final rule planned for February 2007.[Footnote
16] The proposed rule would limit the benzene content of gasoline and
reduce toxic emissions from passenger vehicles and gas cans according
to EPA.
Finally, the act contained 31 requirements that do not fit into the
categories discussed above, including reports to Congress and guidance
for state and local programs. As of April 2006, EPA has met 29 of these
requirements. One of the key areas where EPA has not taken action
relates to the act's requirement for the agency to periodically review
and update, as appropriate, the list of air toxics. Officials
responsible for the program said the agency does not proactively
conduct such reviews and instead has adopted a reactive approach,
whereby the agency responds to petitions filed by external stakeholders
seeking to add or delete chemicals. EPA officials, citing insufficient
resources to develop a more proactive approach, said that their efforts
have focused on reviewing petitions for additions and deletions filed
by external stakeholders.
Since 1990, EPA has received one petition to list a new air toxic
(diesel exhaust) and seven petitions to delist. The petition to list
diesel exhaust is under review, and of the seven petitions to delist,
three have been granted, two have been denied, and two are under
review, according to EPA. Overall, EPA has not added any new chemicals
to the list of regulated pollutants, but three chemicals and several
substances from a listed group of chemicals have been removed. The
agency's consideration of diesel exhaust in response to an
environmental group's petition has taken more than 2 years, resulting
in a lawsuit when the agency did not complete its review within 18
months, as required by the act. EPA and the environmental group reached
an agreement in February 2006 that requires the agency to decide by
June 2006 whether to list diesel exhaust as an air toxic.
A 2004 report by the National Academies highlighted EPA's lack of a
process for reviewing new pollutants despite the estimated 300
chemicals that enter commerce each year. The report recommended that
EPA "establish a more dynamic process for considering new pollutants."
To date, EPA has not addressed this recommendation, according to senior
agency officials. Furthermore, a 2004 study published in the Journal of
the Air & Waste Management Association screened 1,086 chemicals for
potential addition to the list of regulated air toxics and found that
44 merited further consideration for addition to the list based on
available toxicity and emissions data.
Senior EPA air program officials said the agency's progress in meeting
the act's air toxics requirements should be viewed within the context
of limited funding for clean air programs and the agency's need to
focus its resources on the areas where it expects the greatest health-
risk reductions. Scientific information on the health effects of air
toxics is less comprehensive than that available for higher-priority
clean air programs, such as those targeting smog and particulate
matter. Additionally, several officials said that other regulatory and
voluntary programs limit emissions of air toxics as a side
benefit.[Footnote 17]
EPA Faces Implementation Challenges and Lacks an Overall Management
Strategy:
EPA considers the air toxics program a lower priority than its three
other major clean air programs--including those to address criteria
pollutants, international environmental issues such as climate change,
and indoor air quality issues such as exposure to radon gas--because
senior officials in EPA's Office of Air and Radiation believe these
programs have more potential to reduce health risks. As shown in table
6, the percentage of funding for air toxics relative to all clean air
programs ranged from 18 percent to 19 percent between 2000 and 2003,
but declined to 15 percent in 2004 and 12 percent in 2005. However, the
total dollar amounts (in inflation-adjusted 2005 dollars) devoted to
air toxics increased each year between 2000 and 2004, with a decline in
2005.
Table 6: EPA Funding for Air Toxics Program as a Percentage of Funding
for All Clean Air Programs, Fiscal Years 2000 through 2005:
Thousands of dollars.
Fiscal year: 2000;
Funding for air toxics program: 106,475;
Funding for all clean air programs: 605,574;
Funding for air toxics program as a percentage of all clean air
programs: 18.
Fiscal year: 2001;
Funding for air toxics program: 118,331;
Funding for all clean air programs: 640,056;
Funding for air toxics program as a percentage of all clean air
programs: 18.
Fiscal year: 2002;
Funding for air toxics program: 121,668;
Funding for all clean air programs: 636,851;
Funding for air toxics program as a percentage of all clean air
programs: 19.
Fiscal year: 2003;
Funding for air toxics program: 122,118;
Funding for all clean air programs: 641,514;
Funding for air toxics program as a percentage of all clean air
programs: 19.
Fiscal year: 2004;
Funding for air toxics program: 143,575;
Funding for all clean air programs: 936,286;
Funding for air toxics program as a percentage of all clean air
programs: 15.
Fiscal year: 2005;
Funding for air toxics program: 112,986;
Funding for all clean air programs: 909,219;
Funding for air toxics program as a percentage of all clean air
programs: 12.
Source: GAO analysis of EPA data.
Note: Dollar amounts are in inflation-adjusted 2005 dollars.
[End of table]
Within the air toxics program, EPA's initial priority was to complete
the MACT standards because the agency believed that this aspect of the
program had the greatest potential to address risks from air toxics.
Despite EPA placing a priority on issuing the MACT standards, the
agency still fell behind schedule when it missed deadlines for the
first round of standards (due in 1992) and has never caught up to the
act's implementation schedule. EPA officials said they missed some of
the MACT deadlines because of technical challenges, including a lack of
emissions data from affected source categories and the complexity of
many of the regulated facilities. The missed deadlines led to lawsuits
filed by external parties seeking compliance with the act's
implementation schedule, resulting in court-ordered deadlines for the
agency to complete standards. Furthermore, senior EPA officials said
these court-ordered deadlines largely drive the program's agenda. In
this way, EPA ceded control of the priority-setting process, and this
problem is still evident. For example, a senior official responsible
for the development of regulations said that the agency's highest
priority for the remaining requirements is addressing residual risk
reviews and small stationary source standards with court-ordered
deadlines.
The lower priority of the air toxics program in general and the
priority given to MACT standards within the program, as well as
technical challenges, have caused delays in completing the residual
risk and technology reviews, as well as standards for small stationary
and mobile sources. Further, as shown in table 7, available EPA data
indicate that small stationary and mobile sources in total have
accounted for more emissions than major stationary sources in every
emissions inventory completed since the 1990 amendments. Furthermore,
the agency has estimated that benzene--a known carcinogen emitted
primarily by mobile sources--accounts for about 25 percent of the
cancer risk posed by air toxics across the nation. Benzene is also the
only air toxic that, to date, EPA has determined poses sufficient risks
to qualify as a "national cancer risk driver."[Footnote 18]
Table 7: Percentage of Estimated Total Air Toxics Emissions by Source
Type, 1993, 1999, and 2002:
Percent.
2002;
Estimated total emissions (million tons): 4.6;
Mobile sources: 41;
Small stationary sources: 30;
Major stationary sources: 20;
Other: 9.
1999;
Estimated total emissions (million tons): 5.1;
Mobile sources: 43;
Small stationary sources: 25;
Major stationary sources: 25;
Other: 6.
1993;
Estimated total emissions (million tons): 7.1;
Mobile sources: 46;
Small stationary sources: 24;
Major stationary sources: 27;
Other: 3.
Source: GAO analysis of EPA data.
Note: Totals may not add to 100 percent due to rounding.
[End of table]
EPA developed air toxics emission inventories for 1993, 1996, 1999, and
2002. A large part of the 1993 baseline inventory is based on data
obtained from 1990. For simplicity, and because EPA has traditionally
referred to it as such, we refer to this data as the 1993 baseline
inventory. EPA said it did not provide data for 1996 because the agency
has not updated the information from that year for consistency with the
methodology used for the 1993, 1999, and 2002 data.
EPA expects that the proposed mobile source air toxics rule will reduce
benzene emissions. In addition, a senior EPA air program official said
that other regulations for mobile sources, including standards that
affect gasoline formulations as well as programs addressing emissions
from diesel engines, will also reduce emissions of air toxics as a side
benefit. Nonetheless, mobile sources will continue to represent an area
of significant opportunity to reduce emissions and related human health
risks.
Addressing the remaining requirements for residual risk standards and
small stationary sources will require overcoming significant technical
challenges. Regarding residual risk standards, the Clean Air Act's
requirement that EPA introduce a risk element into the regulatory
decision-making process marks a departure from the approach the act
used with MACT standards, which generally did not require EPA to take
the inherent toxicity or health risks from pollutants into account. EPA
officials said that conducting the residual risk assessments requires a
large amount of data, much of which is difficult to obtain. For
example, to adequately assess the human health risk posed by a
particular source, EPA needs data on the health effects associated with
each pollutant, the location of sources, distances between sources and
affected populations, and the concentrations of emissions at different
distances from facilities.
Challenges in regulating small stationary sources center on difficulty
in characterizing the large number of widely dispersed facilities such
as industrial boilers, paint-stripping operations, and auto-body shops.
In some cases, data do not exist on the number or location of
facilities potentially subject to a regulation. Furthermore, unlike the
large stationary sources affected by MACT standards, owners and
operators of these sources have limited resources to implement
regulations and will require extensive outreach and compliance
assistance.
EPA's challenges in meeting the act's remaining requirements are
exacerbated by the lack of a management plan that identifies priorities
and necessary resources. The agency's overall strategic plan outlines
the goals and targets for emissions and risk reduction across all clean
air programs but does not specify priorities or necessary levels of
funding for the air toxics program. Similarly, the agency's budget
requests provide limited information on the agency's air toxic program
activities or priorities. Furthermore, a senior EPA official said that
the agency has not estimated how much funding the air toxics program
needs to meet the act's remaining requirements. Such information could
assist Congress in making its appropriations decisions, enhance the
program's transparency to the public, and guide the agency in
implementing the program.
Key Program Stakeholders Provided Further Insights on EPA's
Implementation Challenges:
To better understand the challenges facing EPA's air toxics program, we
interviewed various stakeholders, including officials from EPA,
industry and environmental groups, and state and local air pollution
control agencies.[Footnote 19] Each respondent rated the extent to
which nine specific issues posed a challenge to EPA in implementing the
air toxics program, and we then averaged the responses within each
stakeholder group. As shown, in table 8, the average response within
each group identified at least one of seven different issues as a
challenge to a large or very great extent.[Footnote 20] Although
perceptions varied among the stakeholder groups, three issues emerged
as primary challenges--the availability of reliable data to assess the
benefits of regulating air toxics, the adequacy of program funding, and
the program's low priority relative to other clean air programs. As
shown in the table, respondents from at least three of the four
stakeholder groups we interviewed identified each of these challenges
as significant.
Table 8: Issues Rated by Stakeholders as Challenges to a Large or Great
Extent:
Challenges: Availability of reliable data to assess benefits of
regulating hazardous air pollutants;
Stakeholder groups: EPA: check;
Stakeholder groups: Industry: check;
Stakeholder groups: Environmental: [Empty];
Stakeholder groups: State and local: check.
Challenges: Adequacy of program funding;
Stakeholder groups: EPA: check;
Stakeholder groups: Industry: [Empty];
Stakeholder groups: Environmental: check;
Stakeholder groups: State and local: check.
Challenges: Priority of program relative to other air programs;
Stakeholder groups: EPA: check;
Stakeholder groups: Industry: [Empty];
Stakeholder groups: Environmental: check;
Stakeholder groups: State and local: check.
Challenges: Number of Clean Air Act requirements pertaining to
hazardous air pollutants;
Stakeholder groups: EPA: check;
Stakeholder groups: Industry: check;
Stakeholder groups: Environmental: [Empty];
Stakeholder groups: State and local: [Empty].
Challenges: Adequacy of resources at the state, local, and tribal
levels to implement regulations;
Stakeholder groups: EPA: check;
Stakeholder groups: Industry: [Empty];
Stakeholder groups: Environmental: [Empty];
Stakeholder groups: State and local: check.
Challenges: Strain on resources due to litigation;
Stakeholder groups: EPA: check;
Stakeholder groups: Industry: [Empty];
Stakeholder groups: Environmental: [Empty];
Stakeholder groups: State and local: [Empty.
Challenges: Availability of reliable data on sources and their
emissions;
Stakeholder groups: EPA: [Empty];
Stakeholder groups: Industry: [Empty];
Stakeholder groups: Environmental: check;
Stakeholder groups: State and local: [Empty].
Source: GAO.
[End of table]
Several stakeholders identified linkages among the three primary
challenges. For example, some stakeholders said that the problems with
limited resources stemmed from the program's low priority. In addition,
some stakeholders said that the lack of information on the benefits of
regulating air toxics reinforced the program's low priority because the
agency cannot demonstrate the results it achieves through investments
in the program.
In addition, industry and EPA stakeholders cited the number of air
toxics requirements as a challenge to a large or very great extent.
Respondents from both groups stated that the agency has insufficient
resources to meet such a large number of requirements in the specified
time frames. Industry officials noted that the number of requirements
was unrealistic, and some EPA stakeholders said that Congress did not
understand the number of emissions sources involved or the level of
effort required to write standards. EPA and state and local
stakeholders also cited the adequacy of resources at the state, local,
and tribal levels to implement regulations as a significant challenge.
Available Information on Costs and Benefits Is Not Sufficient to
Measure the Program's Effectiveness:
The information available on the costs and benefits of EPA's air toxics
program is not sufficiently comprehensive to measure the overall
effectiveness of the program. For example, because of limited data,
EPA's major economic assessments of the Clean Air Act have not included
monetized estimates of the program's benefits, such as reduced
incidence of cancer, and have provided only limited information on
costs. The absence of information on benefits stems from a lack of data
on the extent to which incremental reductions in exposure to air toxics
affect an average person's chance of developing adverse health effects.
The agency also lacks reliable data on the quantities of each pollutant
emitted prior to the adoption of air toxics regulations or in the years
thereafter. Furthermore, other potential indicators of the program's
effectiveness, such as data on compliance with air toxics regulations,
are inconclusive. As a result, it is difficult to compare the results
of investments in the air toxics program with those generated by clean
air programs on which EPA has placed a higher priority.
EPA's Assessments of the Clean Air Act Have Not Estimated the Economic
Benefits of the Air Toxics Program:
Although EPA has conducted two major assessments of the costs and
benefits of its programs under the Clean Air Act, the agency has not
fully analyzed the air toxics program primarily because of difficulty
in characterizing the program's effects on public health.[Footnote 21]
Without a comprehensive assessment of costs and benefits, it is
difficult to gauge the program's cost effectiveness or net benefits
(total benefits minus total costs) or compare these effects with those
of higher-priority air pollution control programs.
The two assessments of the act's costs and benefits focused on separate
time periods. EPA refers to the first assessment, completed in 1997, as
the "retrospective" analysis because it covered the period 1970 to
1990. It is of limited use in understanding the economic effects of the
current air toxics program because this time period predates the
significant expansion of the program after the 1990 amendments.
The second analysis, completed in 1999, is referred to as the
"prospective" analysis because it covered the period 1990 to 2010. This
study attempted to forecast the future economic impacts of the 1990
amendments and estimated that the overall net benefits of clean air
regulations from 1990 to 2010 would total $510 billion (1990 dollars),
with a benefit-to-cost ratio of four to one. Most (over 90 percent) of
the monetized benefits included in the analysis stemmed from reduced
incidence of health effects associated with exposure to five of the six
criteria pollutants--carbon monoxide, ground-level ozone, particulate
matter, nitrogen oxides, and sulfur dioxide. EPA places the highest
priority within its clean air programs on the criteria pollutants.
The prospective analysis is of limited use in understanding the effects
of the air toxics program because it provided incomplete information on
the costs of air toxics standards and did not include estimates of the
human health or other benefits of these standards. Specifically, the
cost estimates reflect only the 21 standards EPA had issued at the time
of the study--a number that has since grown to 96. EPA estimated that
the cost to industry of complying with these 21 MACT standards would
total $780 million in 2000 and rise to $840 million by 2010. According
to EPA, these estimates primarily reflect the cost of purchasing,
operating, and maintaining pollution control equipment. As shown in
table 9, these costs represent a relatively small fraction of the total
estimated costs of the 1990 amendments over that time period.
Table 9: Summary of Annual Costs Imposed by the 1990 Clean Air Act
Amendments:
Dollars (in millions).
Programs: Title I--Ambient air quality standards;
Costs in 2000: $8,600;
Percentage of total costs: 44;
Costs in 2010: $14,500;
Percentage of total costs: 54.
Programs: Title II--Mobile sources;
Costs in 2000: 7,400;
Percentage of total costs: 38;
Costs in 2010: 9,050;
Percentage of total costs: 34.
Programs: Title III--Air toxics;
Costs in 2000: 780;
Percentage of total costs: 4;
Costs in 2010: 840;
Percentage of total costs: 3.
Programs: Title IV--Acid rain;
Costs in 2000: 2,300;
Percentage of total costs: 12;
Costs in 2010: 2,040;
Percentage of total costs: 8.
Programs: Title V--Permitting;
Costs in 2000: 300;
Percentage of total costs: 2;
Costs in 2010: 300;
Percentage of total costs: 1.
Programs: Total annual costs;
Costs in 2000: $19,400;
Percentage of total costs: 100;
Costs in 2010: $26,800;
Percentage of total costs: 100.
Source: EPA.
Note: Dollar Amounts are in 1990 dollars.
[End of table]
An EPA official responsible for the prospective study said that the
agency did not include estimates for the aspects of the program that it
had not yet implemented--such as the 75 remaining MACT standards--
because, at the time, the agency did not have information on the number
of facilities that would have to comply with future standards or the
level of emissions control the standards would require. Without this
information, the official said it was appropriate to exclude these
future standards from the analysis. Nonetheless, EPA acknowledged the
lack of information on the costs of future air toxics standards as a
key uncertainty of the analysis.[Footnote 22]
EPA plans to update its cost estimates as part of a new prospective
analysis covering 1990 to 2020. The revised cost estimates will include
all of the completed MACT standards as well as any other air toxics
rules issued by September 2005 (except the residual risk rule for coke
ovens, which entails emissions reductions and compliance costs that
would have a negligible effect on the overall analysis). An EPA
official responsible for the analysis said the agency expects to have
preliminary results of the revised cost estimates in late 2006, with a
final report expected in 2007.
EPA Lacks Key Data Needed to Estimate the Benefits of Air Toxics
Regulations:
The prospective analysis of the 1990 Clean Air Act amendments did not
include monetized estimates of the benefits of air toxics regulations,
such as decreased cancer risks to affected individuals, because the
agency did not have sufficient data to estimate these effects. As shown
in table 10, estimating the benefits of EPA's air toxics program
requires a substantial amount of scientific data. Specifically, this
process involves determining the extent to which reductions in exposure
to air toxics have decreased the incidence of adverse health effects,
including cancer and noncancer illnesses. This, in turn, requires
estimating the extent of adverse health effects stemming from exposure
to air toxics both before (see steps 1 to 3 below) and after (see steps
4 to 6 below) adopting air toxics regulations. For example, exposure to
air toxics prior to the adoption of a regulation may have caused 1,000
cases of cancer per year but the presence of a regulation may have
decreased this number to 500 cases per year. The 500 avoided cases
would represent a key health benefit of the regulation. The final step
of the process (step 7) involves assigning dollar values to these
health benefits.
Table 10: Key Steps in Estimating the Benefits of Controlling Air
Toxics:
Step: 1;
Task: Characterize the relationship between pollutants and the adverse
health effects associated with exposure to these pollutants (referred
to as "dose-response" relationships);
Data requirements: Information on cancer and noncancer effects of 187
different pollutants, as well as on how incremental decreases in
exposure to these pollutants affect the incidence of each adverse
health effect.
Step: 2;
Task: Determine the baseline level of human exposure to pollutants in
the absence of air toxics regulations;
Data requirements: Information on concentrations of each pollutant in
the ambient air prior to adoption of air toxics regulations, and on
human exposures to these pollutants. This requires information on the
amount of each pollutant emitted prior to the regulations, as well as
computer models that calculate human exposures based on emissions data
and other key variables such as meteorological conditions.
Step: 3;
Task: Use data from steps 1 and 2 above to determine the number of
cases of each adverse health effect in the absence of regulations;
Data requirements: No additional data required.
Step: 4;
Task: Determine level of human exposure to pollutants after the
regulation. This involves estimating the extent to which the regulation
has decreased emissions of each pollutant and related human exposures;
Data requirements: Information on the amount of each pollutant emitted
after adopting air toxics regulations, and computer models used in step
2 to estimate the remaining level of exposure to each pollutant.
Step: 5;
Task: Calculate the remaining incidence of each health effect after
implementing the regulation;
Data requirements: Same as step 3; no additional data required.
Step: 6;
Task: Determine the number of cases of each health effect avoided as a
result of the regulation by subtracting the number of remaining cases
of adverse health effects (identified in step 5) from the number of
baseline cases prior to the regulation (identified in step 3);
Data requirements: No additional data required.
Step: 7;
Task: Assign dollar values to the number of avoided cases identified in
step 6;
Data requirements: Economic studies on the value of reducing incidence
of cancer and noncancer health effects.
Source: GAO analysis of EPA data.
[End of table]
Two primary factors limit EPA's ability to estimate the benefits of air
toxics regulations. First, EPA lacks adequate information on the extent
to which incremental reductions in exposure affect an average person's
chance of developing adverse health effects. The limited information on
these "dose-response" relationships represents the greatest challenge
for the agency in conducting a benefits assessment for the air toxics
program, according to a senior EPA official responsible for the
retrospective and prospective analyses. A senior EPA official
responsible for risk analysis drew a distinction between the type of
data needed for a risk assessment, which often involves extrapolation
from studies involving laboratory animals, and the type of data that
economists need for a benefits assessment, which generally requires
studies of human exposures. The official said that EPA currently has
sufficient toxicological data, primarily from animal studies, to assess
risks from 133 of the 187 air toxics. However, the official said the
agency only has the type of dose-response data needed to estimate the
economic benefits for a handful of pollutants.[Footnote 23]
Second, EPA lacks reliable information on the quantities of each
pollutant emitted prior to the adoption of air toxics regulations or in
the years after adopting the regulations. EPA has tracked emissions of
air toxics since 1993 and prepares a National Emissions Inventory every
3 years. In 2006, EPA completed its most recent inventory, which has
information on emissions in 2002. While the inventory represents the
best available data on emissions of air toxics and is useful for
identifying the relative contribution of emissions from different
sources, a 2004 EPA Inspector General report identified shortcomings of
the inventory that raise questions about its reliability and usefulness
in measuring the effects of the air toxics program.[Footnote 24] For
example, the report said that EPA cannot tell whether apparent
reductions or increases in the inventory have resulted from changes in
the way the agency estimated the inventory or from real reductions or
increases in emissions. The report also cited problems with the limited
involvement of state agencies in the development and validation of the
inventory.
Although the data in the emissions inventory are limited, EPA has used
the emissions inventory and other available data to estimate human
exposures to these pollutants. In 1999, EPA released its first National-
Scale Air Toxics Assessment (NATA), which relied on data from the 1996
emissions inventory to estimate the potential health risks posed by air
toxics in different geographic areas. EPA updated this analysis in 2006
using data from the 1999 emissions inventory. While NATA is a useful
indicator of potential health risks from air toxics at a given point in
time, it is not useful as a measure of the agency's effectiveness in
implementing the air toxics program because, according to EPA, the
agency revised the number of stationary sources and pollutants included
in its analysis. For example, the analysis based on the 1996 emissions
inventory assessed risks from 33 pollutants, while the most recent
analysis included 177 pollutants. As a result, EPA believes it is not
meaningful to compare the results of the two assessments.
Overall, the limited information on health outcomes associated with
changes in exposure to air toxics hinders EPA's ability to quantify or
monetize the economic benefits resulting from the air toxics program.
In turn, this limits EPA's ability to develop monetized estimates of
the program's net benefits or cost effectiveness. Such information
would be useful not only for better understanding the economic effects
of the air toxics program, but also for comparing the cost
effectiveness of different air quality programs, which would help
prioritize funding in addressing human health problems caused by air
pollution. This information would also help EPA prioritize its
remaining obligations under the 1990 amendments. In May 2002, EPA's
Office of Research and Development (ORD) released a draft air toxics
research strategy that discussed the agency's plans for improving
information on dose-response relationships.[Footnote 25] In addition,
ORD issued an air toxics plan in April 2003 that identified the
shortcomings of existing dose-response data and plans for improving
this information.[Footnote 26] In reviewing these documents, the
agency's Science Advisory Board identified several concerns, including
poor linkages across the two documents, inadequate research funding,
and the need for a better research prioritization scheme.[Footnote 27]
Other Indicators of the Program's Effectiveness Are Inconclusive:
Without sufficient information to conduct a comprehensive cost-benefit
analysis, EPA measures the effectiveness of its air toxics program
based on estimated data from its emissions inventory. Specifically, EPA
measures the changes in aggregate emissions (measured in tons per year)
of all air toxics by comparing estimates from the most recent emissions
inventory with the 1993 baseline inventory. While estimated emissions
decreased by about 35 percent between 1993 and 2002 according to EPA,
the data quality problems discussed above limit their usefulness in
measuring the program's effectiveness.
Two other problems also limit the usefulness of the emissions data as a
performance measure. First, because pollutants differ substantially in
their toxicity--small quantities of some chemicals pose greater risks
than large quantities of less harmful chemicals--measuring changes in
the total tons of all air toxics emitted does not necessarily provide a
strong indication of the program's effectiveness in addressing health
risks. The EPA Inspector General report discussed above recommended
developing performance measures that address progress toward reductions
in human exposure and health risk. Such measures would provide a better
indication of changes in risks from air toxics. In the justification
for its proposed fiscal year 2007 budget, EPA said that it was
developing a "toxicity-weighted" emissions measure for the program.
Second, EPA's practice of measuring the air toxics program's
performance using estimated aggregate emissions data may not accurately
measure the effect that the program has had on changes in emissions.
The current performance measure attributes all changes in emissions to
the federal air toxics program, but emissions may change for reasons
unrelated to the agency's regulations. Some decreases in emissions may
reflect cases where state and local air pollution control agencies have
issued rules to control emissions that go beyond the federal
regulations. As discussed in the next section of this report, some
states set more stringent standards than EPA. On the other hand, a
senior EPA official responsible for the economic analysis of air
pollution regulations said that the agency may actually underestimate
the program's effect. The official said that because of economic growth
and related increases in industrial production over time, emissions
would far exceed the current levels without the existing EPA air toxics
regulations.
We also evaluated two other potential indicators of the program's
effectiveness--data on levels of air toxics in the ambient air and
information on the degree of compliance with clean air regulations--to
determine their usefulness as indicators of the program's
effectiveness. While both could eventually serve as useful performance
indicators, the available data are currently limited and inconclusive.
Regarding data on ambient levels of air toxics, EPA has a monitoring
network that includes 22 locations nationwide. The monitors generally
track ambient levels of six priority air toxics that EPA believes pose
a concern in all geographic areas of the United States.[Footnote 28]
A 2005 EPA Inspector General report found shortcomings of the
monitoring network, including limited monitoring in areas with the
highest estimated cancer risks from air toxics as well as
inconsistencies in the operation of the monitors.[Footnote 29] In
responding to the report, EPA said that the Inspector General's
concerns generally aligned with the agency's monitoring improvement
efforts. It is currently unclear whether the existing monitoring data
are representative or reliable indicators of the program's
effectiveness. Nonetheless, ambient monitoring is a valuable component
of the air toxics program and could eventually serve as a useful
performance measure. It is also important to note that, while not part
of the national monitoring network, a number of state and local
agencies conduct their own air toxics monitoring.
Finally, we reviewed available information on the degree of compliance
with air toxics standards identified through evaluations of regulated
facilities conducted by federal and state enforcement officials. As
shown in table 11, inspectors have found most facilities in compliance
with air toxics standards, with some degree of noncompliance at about
one-quarter of all facilities. Compliance rates for these facilities
may not represent the degree of compliance at all facilities because
enforcement officials do not visit each facility every year and often
target facilities where they suspect noncompliance.[Footnote 30] EPA
enforcement officials said they do not currently have comprehensive
data explaining the magnitude of the noncompliance in cases where
inspectors found violations. For example, noncompliance could range
from record-keeping problems to more serious violations, such as
exceeding an emissions standard. Furthermore, it is important to note
that, while EPA has completed issuing all of the MACT standards, 16
standards have compliance dates after June 2006. Thus, information on
compliance with these standards will not become available until after
that time.
Table 11: Results of Inspections at Facilities Regulated by Air Toxics
Standards, 2003 and 2004:
Year: 2004;
Total facilities inspected: 731;
Facilities in compliance (percentage of total): 483 (66);
Facilities in noncompliance (percentage of total): 194 (27);
Facilities with unknown compliance status (percentage of total): 54
(7).
Year: 2003;
Total facilities inspected: 664;
Facilities in compliance (percentage of total): 432 (65);
Facilities in noncompliance (percentage of total): 174 (26);
Facilities with unknown compliance status (percentage of total): 58
(9).
Source: GAO analysis of EPA data.
[End of table]
While the available enforcement data are limited, EPA has identified
cases of significant noncompliance with air toxics regulations.
Specifically, the agency has initiated a nationwide air toxics
enforcement strategy to identify and correct noncompliance and achieve
emissions reductions in targeted industry sectors. According to EPA, in
2005, the agency took enforcement actions against facilities that
failed to comply with targeted MACT standards which resulted in air
toxics reductions of more than 160 tons and fines exceeding $600,000
(2005 dollars). Furthermore, an official in EPA's Office of Enforcement
and Compliance Assurance said that the agency achieved about 190
additional tons of air toxics reductions in 2005 through enforcement
actions that were not associated with the national air toxics
enforcement strategy.
State and Local Programs Employ Practices That Could Potentially Help
EPA Enhance the Effectiveness of the Federal Air Toxics Program:
State programs we reviewed in California, New Jersey, Oregon, and
Wisconsin, and the local program we reviewed in Louisville, Kentucky,
have air toxics programs that go beyond the federal program and employ
practices that might help EPA enhance the effectiveness of its program.
First, these programs address some public health risks that have not
been addressed by the federal program. EPA could potentially strengthen
its program by assessing and considering what states perceive as the
primary gaps in the federal program. Second, the programs generally
prioritize air toxics activities based on their risk reduction
potential, which could serve as an example for EPA in prioritizing its
remaining obligations under the act. Third, some of the programs
conduct comprehensive risk assessments to identify the risk posed by
all emissions from a facility, while EPA's residual risk program
assesses risk in a more piecemeal and limited fashion. Fourth, several
of the programs employ systematic approaches to identify and prioritize
chemicals for addition to their lists of regulated air toxics, whereas
EPA does not have such a process. Finally, the agencies stressed the
importance of reliable data on emissions and chemical toxicity, and
several programs have processes to better ensure the accuracy of
emissions data submitted by regulated facilities. (See app. III for
information on the key features of the state and local programs we
reviewed.)
Several State and Local Programs Address Gaps in EPA's Program:
The five programs we reviewed address some public health risks that
EPA's program does not. For example, the programs regulate smaller
sources than EPA, set more stringent technology standards to control
emissions, and include some large stationary sources that EPA does not
address.[Footnote 31] In Wisconsin, any facility that emits one of 535
air toxics in amounts that exceed certain thresholds may be subject to
the state's air toxics program. In some cases, annual emissions of less
than 1 pound per year from a facility could trigger the state rule,
depending upon the toxicity of the chemical. Wisconsin officials said
that they use lower thresholds than the Clean Air Act's 10-or 25-ton
thresholds because even small emissions of very toxic chemicals can
present risks to the public. Similarly, New Jersey officials said that
their state program addresses smaller facilities than EPA because most
of the numerous chemical facilities in the state are not subject to
MACT standards since they do not emit air toxics at levels that exceed
federal thresholds. In contrast, in accordance with the Clean Air Act,
MACT standards for major sources and the corresponding residual risk
reviews apply to facilities in 158 industries with emissions of 10 tons
or more of a single air toxic or 25 tons or more of a mixture of the
187 federal air toxics.
In terms of the stringency of the technology standards used to limit
emissions of air toxics, California and New Jersey officials said that
the technology standards in their states were often more stringent than
EPA's MACT standards. For example, California officials said that
petroleum refineries in their state use more stringent control
technologies, and they noted that EPA chose not to include these
technologies as part of its survey of controls already in use when it
developed the MACT standard for this industry.
Regarding the types of facilities that are regulated by EPA, some state
officials expressed concern that EPA did not develop MACT standards for
some major stationary sources of air toxics in their states. For
example, Oregon officials said that they requested EPA to issue MACT
standards for several categories of sources, including ceiling tile
manufacturing and titanium smelting if it found that they were major
sources of air toxics. Oregon officials expressed concern with EPA's
apparent lack of response to their request because these significant
emitters of air toxics in Oregon do not fall into one of the 158 major
source categories that EPA identified and regulates. Further, the State
and Territorial Air Pollution Program Administrators and the
Association of Local Air Pollution Control Officials (STAPPA/ALAPCO)
has compiled a list of over 40 major emission source categories of air
toxics that were not regulated by EPA MACT standards. While the five
programs we reviewed would generally address such sources, similar
sources would be unregulated in the states whose programs are based
entirely on the federal program. Importantly, in a number of cases,
state law limits the ability of state and local programs to go beyond
federal requirements. For example, in 2002, STAPPA/ALAPCO found that 26
states from every region in the country have precluded their state air
pollution control agencies from imposing clean air requirements beyond
those established by EPA.
State and Local Programs Prioritize Their Actions Based on Risk
Reduction Potential:
The approaches some state and local agencies use to develop their air
toxics programs differ from EPA's approach in that they direct
resources to the areas of highest risk, whereas, given the Clean Air
Act's prescribed schedule, EPA has primarily focused on regulating
emissions from certain large stationary sources. In contrast, several
state and local programs generally rely on monitoring (the measurement
of air toxics in the ambient air) and modeling (estimating toxics in
the air using computer models) to identify chemicals, geographic areas,
or facilities of concern and develop measures to address these risks.
The Oregon and Louisville, Kentucky, programs illustrate the use of
risk-based prioritization. Oregon's air toxics program seeks to
identify geographic areas of high risk through modeling and monitoring
and to then concentrate resources on those areas. While not yet fully
implemented, the program plans to conduct statewide modeling using its
emissions inventory to identify areas of potential concern and then
conduct monitoring to delineate geographic areas of high risk.
According to program staff, the geographic approach is an efficient way
to address risk because it is targeted and focuses on the greatest
risks. Because public health risks from air toxics may vary depending
on proximity to emissions sources and other factors, the practice of
identifying areas of high risk and taking steps to address these risks
shows promise as part of an overall risk reduction strategy.
Similarly, Louisville created a program to address high health risks
near an industrial complex and in the surrounding community that were
identified through monitoring of pollutants in the ambient air.
According to program officials, toxic emissions from a section of
Louisville called "Rubbertown"--home to a complex of chemical
facilities and other manufacturers--have been the subject of public
concern since the 1940s. From 2000 through 2001, program officials
worked with the University of Louisville, EPA, and other stakeholders
to monitor the ambient air near Rubbertown and the surrounding
community to assess the extent of the problem. A risk assessment based
on the monitoring data determined that 18 chemicals posed an
unacceptable risk to the public. Consequently, Louisville officials
designed the program to target large emitters of these 18 chemicals
before targeting smaller emitters of air toxics.
In addition to some states' focus on identifying geographic areas or
chemicals of concern, the state and local programs we reviewed use
monitoring and modeling data to focus their efforts on specific
facilities that pose risks to the public. For example, California
requires certain large and small sources of air toxics to conduct
facilitywide risk assessments using a standardized risk-screening
model. If the modeling results show that risks exceed certain
thresholds, the facility must conduct a more comprehensive risk
assessment. This process allows California's state and local agencies
to identify and focus on the sources that pose high risks to the
public. In addition, Louisville and Wisconsin require certain sources
to conduct facilitywide risk assessments as part of the permitting
process.[Footnote 32]
In contrast, several state and local officials said that EPA's program
has not focused on the greatest risks. While EPA may have been driven
by certain deadlines in the act, some state and local officials said
that the agency has chosen to focus on certain large stationary sources
even though EPA's data suggest that emissions from small stationary
sources and mobile sources may pose greater risks. Further, EPA is
currently developing a rule that would exempt MACT-regulated facilities
from regulation under its residual risk program if, on the basis of
risk assessments, the facilities demonstrate that the cumulative risks
from all of their toxic emissions do not exceed certain thresholds.
According to EPA, this strategy could achieve voluntary risk reductions
from facilities that would not be required to reduce risks under the
current residual risk program and will provide high-quality, site-
specific emissions data for use in future assessments and emission
reduction strategies. While this approach has the potential to ease the
regulatory burden on low-risk facilities, EPA may have opportunities to
apply its limited resources to approaches that have greater potential
to reduce risks.
Several of the Programs We Reviewed Conduct More Comprehensive
Facilitywide Risk Assessments Than EPA:
Several state and local programs we reviewed generally evaluate the
emissions from all of the emissions points within a facility in a
single risk assessment in order to assess the health risks associated
with the entire facility. In contrast, EPA's residual risk assessments-
-aimed at identifying and mitigating any remaining health risk from
emissions sources subject to MACT standards--have only evaluated risk
from a portion of the facilities. Specifically, to date, EPA has
limited the scope of its residual risk determinations to emissions
points within facilities that must comply with the MACT standards at
issue, although other emissions points may also emit air
toxics.[Footnote 33] As a result, according to several state and local
officials, some facilities with a high impact on public health may
avoid additional control requirements because EPA's focus on limited
portions of facilities may underestimate the risk posed by whole
facilities.
Figure 3 illustrates a facility emitting air toxics from four emission
points. Of the four emission points within the facility, points 1 and 2
are each covered by different MACT standards and, therefore, are
subject to separate residual risk assessments. Emission points 3 and 4
emit air toxics, but are not subject to MACT standards, because
emissions from these two points do not exceed the MACT threshold.
Figure 3: Emission Points at an Industrial Facility Emitting Air
Toxics:
[See PDF for image]
Source: GAO.
[End of figure]
The programs we reviewed in California, Wisconsin, and Louisville would
generally evaluate the emissions from all of the emissions points in
this facility in a single risk assessment.[Footnote 34] In contrast,
EPA's approach to date would be to conduct a residual risk assessment
for emission point 1 that would consider the exposure and human health
risk attributable to emissions from that emission point, and generally
would not consider the emissions from point 2, which falls under a
different MACT standard, or the emissions from points 3 and 4.
According to EPA, it is not entirely precluded from considering
emissions from additional emissions points not covered by the MACT
standards at issue, but the agency, to date, has not exercised this
discretion in a final rule.
Several state and local stakeholders said that they were concerned that
EPA's risk assessments may show a lower level of risk to the public
than if the agency considered emissions from all of the emission points
at the facility. They said that EPA's residual risk approach may
exclude some facilities with a high impact on public health from more
stringent control requirements. Several officials said it would make
more sense, from a public health perspective, to consider the impact
from all sources at the facility at once, as some states do, rather
than review each emission point individually. Along these lines,
several EPA officials said that evaluating all of the emissions from a
facility simultaneously would enhance the efficiency of the program and
better protect public health.
Several Programs Have Systematic Approaches to Identify and Prioritize
Air Toxics:
Several of the state programs we reviewed use systematic approaches to
identify and prioritize chemicals for addition to their air toxics
lists. In contrast, EPA has not acted on the requirement to
periodically review and revise the list of regulated federal air
toxics.[Footnote 35] For example, California officials work with the
state's public health agency to determine if a substance qualifies as a
state air toxic. This process includes assessing (1) the potential for
human exposure to a substance, (2) the chemical's cancer-causing
potential, (3) any noncancer effects such as irritation of the lungs or
nausea, and (4) the impact on children's health, among other factors. A
panel of scientific experts reviews the work for accuracy, followed by
the formal development of a regulation, including a public hearing.
Similarly, Oregon works with a committee composed of toxicology, public
health, and technical experts to periodically identify air toxics for
review and to develop health-based emission benchmarks. The committee
prioritizes air toxics for review based on Oregon's emission inventory,
the pollutant's toxicity or potency, the number of people at risk, and
the impact on sensitive populations such as children, among other
factors spelled out in state regulations. The systematic approaches of
these programs could inform EPA's efforts to meet the act's requirement
to review and update the federal list of regulated air toxics.
The Programs We Reviewed Stressed the Importance of Data on Emissions
and Toxicology:
Several of the state and local programs we reviewed require major and
small stationary sources to submit standardized annual emissions
reports and certify their accuracy. These programs, like EPA, rely on
emissions inventory data to develop regulations and conduct risk
assessments. For example, Wisconsin requires over 2,000 facilities to
report emissions of 623 air toxics each year if the facility emits more
than certain quantities of each pollutant. Facilities must certify the
accuracy of their final submissions. The air toxics program in
California similarly requires certain major and small stationary
sources to report air toxics emissions of over 450 chemicals and to
certify that the data are correct. New Jersey and Louisville have
similar requirements for a smaller subset of air toxics and sources.
In contrast to the programs that require sources to report and certify
their emissions, EPA, to date, generally has not required emissions
sources or state or local agencies to systematically report these
data.[Footnote 36] Such data collection could enhance EPA's analysis
and decision making in future air toxics rule makings. However, it is
not clear how states without air toxics emissions inventories would
comply with a federal requirement or the extent to which the data
collected from the states would be comparable. For example, in 2002,
EPA solicited comments on a rule to require state and local agencies to
submit standardized air toxics emissions inventory data but the agency
postponed consideration of the requirements partly due to concerns
raised by state and local agencies about the lack of detail in EPA's
proposal.[Footnote 37] EPA officials also told us that they had
concerns over whether there is adequate statutory authority to collect
these data.
Officials representing the state and local programs we spoke with
expressed mixed opinions about a potential EPA requirement to submit
standardized air toxics emissions inventories. For example, officials
in the states we reviewed except California supported a federal
requirement to report air toxics emissions because it would improve the
consistency of the federal inventory and its usefulness to states in
activities such as risk assessment modeling. In addition, some state
officials said that a federal requirement would enable states that are
prohibited from having their own programs to collect information on
emissions of air toxics. However, several officials cautioned that some
programs would have difficulty meeting such a requirement without
additional funding. California officials said that EPA should focus on
states that do not currently have an inventory.
In addition, state and local officials said that EPA does not regularly
update chemical toxicity values that describe the potency of different
air toxics--key information for conducting risk assessments. These
officials told us that their agencies generally do not have the
resources to develop quantitative risk estimates for air toxics and
must rely on other sources of data, such as EPA's Integrated Risk
Information System (IRIS). According to several officials, the basic
science necessary to develop air toxics regulations is lacking in many
cases. For example, Oregon officials cited limited and out-of-date
toxicity values for a number of common chemicals in the IRIS database.
Officials from other programs expressed similar concerns and said that
EPA needed to enhance its efforts to provide quantitative toxicity
information and conduct studies of sufficient quality to make
determinations about chemical toxicity. A 2004 report by the National
Academies also identified the need for more timely updates to EPA's
IRIS database. In addition, California officials pointed out that EPA
does not have a cancer toxicity value for diesel particulate matter, so
some states have developed a patchwork of different toxicity values.
Further, state and local officials questioned EPA's use of a
formaldehyde risk factor developed by an industry group instead of its
peer-reviewed IRIS value when developing a recent MACT standard for
plywood and composite wood products.[Footnote 38] Several officials
were concerned that the deviation from IRIS would cause confusion about
what toxicology data were most accurate for state and local
requirements.
Conclusions:
EPA has made some progress in controlling emissions of air toxics, but
its overall implementation of the air toxics program falls short of the
agency's statutory obligations because of the limited progress in (1)
addressing requirements to limit emissions from small stationary
sources and mobile sources, (2) evaluating the residual health risks
associated with existing emissions standards and setting additional
standards as appropriate, and (3) reviewing and updating the list of
regulated pollutants, as appropriate. While EPA places a lower priority
on air toxics than other programs that it believes have a greater
potential to reduce adverse health effects from air pollution, more
comprehensive information on the air toxics program's costs and
benefits would help the agency compare the cost effectiveness of its
investments in various clean air programs. Key data issues affecting
the agency's ability to develop more comprehensive cost and benefit
estimates include unreliable data on emissions and limited information
on the extent to which changes in exposure to air toxics affect the
incidence of adverse health effects. Until EPA supports efforts to
address these data gaps that hinder its ability to evaluate the health
risks of air toxics, the agency will not have assurance that its
current priorities and programs necessarily target the areas of
greatest opportunity for reducing health risks associated with air
pollution.
EPA still has a significant number of remaining requirements under the
act, including (1) setting 54 emissions standards for small stationary
sources; (2) conducting more than 90 reviews of the remaining health
risks associated with emissions sources covered by its existing
standards, and issuing additional standards as necessary; and (3)
reviewing and updating, as appropriate, the list of regulated air
toxics. Over the past 15 years, the air toxics program has not met its
statutory deadlines, in part, because of its low priority relative to
other programs and related funding constraints. Obtaining sufficient
funding will continue to pose a challenge for EPA, especially in light
of the nation's current fiscal situation. We believe that developing an
implementation plan that identifies the remaining tasks, data needed to
estimate the benefits of reductions in exposure to air toxics,
timelines, and required funding would improve the management of the
program as well as its transparency and accountability to Congress and
the public. In addition, EPA could examine state and local approaches
to air toxics that may have the potential to more effectively address
risks by focusing resources on sources, communities, and geographic
areas that face the greatest risks. This would require EPA to evaluate
opportunities to enhance its efforts to focus on the greatest risks to
human health within the current legislative framework.
Recommendations for Executive Action:
To improve the management of EPA's air toxics program and enhance its
ability to reduce risks of cancer and other adverse health effects, we
recommend that the EPA Administrator require the Assistant
Administrator for Air and Radiation to develop an air toxics program
improvement plan that incorporates the following five issues:
* provides a detailed schedule for completing its mandated air toxics
activities and identifies the staffing and funding resources needed to
meet the schedule and address the health risk assessment needs;
* prioritizes activities within the air toxics program, placing the
highest priority on those actions that have the greatest potential to
address health risks, to the extent permitted by the Clean Air Act;
* establishes a process and timelines for meeting the act's
requirements to periodically review and update the list of air toxics;
* outlines an approach and timelines for improving the agency's ability
to measure the program's costs and benefits; and:
* describes how the agency plans to improve its air toxics emissions
inventory, including a discussion of the statutory authority for, and
the merits of, requiring states and emissions sources to submit
standardized emissions data.
Agency Comments:
We provided EPA's Office of Air and Radiation with a copy of this
report for review and comment. In commenting on the report, the Acting
Assistant Administrator for Air and Radiation said that EPA agrees in
part with the conclusions and recommendations in the report. The agency
did not identify specific aspects of our conclusions or recommendations
with which it disagreed, but rather provided only clarifications to
statements in the report regarding the availability of information on
the costs and benefits of the agency's efforts to control air toxics,
the agency's progress in completing certain air toxics requirements of
the Clean Air Act, and on EPA's management of the remaining
requirements. EPA's letter and our response to their clarifications are
included as appendix IV. EPA also provided technical comments, which we
have incorporated, as appropriate.
As agreed with your offices, unless you publicly announce the contents
of this report earlier, we plan no further distribution until 30 days
from the report date. At that time, we will send copies to the EPA
Administrator 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 [Hyperlink,
http://www.gao.gov].
If you or your staff have any questions about this report, please
contact me at (202) 512-3841 or stephensonj@gao.gov. Contact points for
our Offices of Congressional Relations and Public Affairs may be found
on the last page of this report. Key contributors to this report are
listed in appendix V.
Signed by:
John B. Stephenson:
Director, Natural Resources and Environment:
List of Congressional Requesters:
The Honorable James M. Jeffords:
Ranking Minority Member:
Committee on Environment and Public Works:
United States Senate:
The Honorable Lincoln Chafee:
Chairman:
Subcommittee on Fisheries, Wildlife and Water:
Committee on Environment and Public Works:
United States Senate:
The Honorable Barbara Boxer:
Ranking Minority Member:
Subcommittee on Superfund and Waste Management:
Committee on Environment and Public Works:
United States Senate:
The Honorable Thomas R. Carper:
Ranking Minority Member:
Subcommittee on Clean Air, Climate Change, and Nuclear Safety:
Committee on Environment and Public Works:
United States Senate:
The Honorable Hillary Rodham Clinton:
United States Senate:
The Honorable Patrick J. Leahy:
United States Senate:
The Honorable Joseph I. Lieberman:
United States Senate:
The Honorably Paul Sarbanes:
United States Senate:
The Honorable Olympia J. Snowe:
United States Senate:
The Honorable John D. Dingell:
Ranking Minority Member:
Committee on Energy and Commerce:
House of Representatives:
The Honorable Tom Allen:
House of Representatives:
The Honorable Lois Capps:
House of Representatives:
The Honorable Edward J. Markey:
House of Representatives:
The Honorable Hilda L. Solis:
House of Representatives:
The Honorable Henry A. Waxman:
House of Representatives:
[End of section]
Appendix I: Status of EPA's Efforts to Respond to Recommendations in
the National Academies' Report on Air Quality:
This appendix discusses the Environmental Protection Agency's (EPA)
response to the findings and recommendations of the National Academies'
(Academies) report on air quality management. The Academies prepared
this report in response to a congressional request for an independent
evaluation of the effectiveness and implementation of the Clean Air
Act. The report examined the roles of science and technology in the
implementation of the act and recommended ways to improve air quality
management. One of the report's key recommendations was for EPA to form
a work group to evaluate the report and provide a detailed list of
actions EPA could take to improve its implementation of clean air
programs. The work group completed this review in December 2004 and
provided the agency's Clean Air Act Advisory Committee with a list of
38 recommendations.
EPA's Office of Policy Analysis and Review has taken the lead in
responding to the recommendations and provided an initial response in
April 2005, which was updated in November 2005.[Footnote 39] The
response included information about ongoing and proposed activities to
address the recommendations and estimated time frames for responding to
each recommendation. The agency has prioritized the recommendations and
developed a proposed schedule for completing its activities, with some
actions already under way or completed and others not scheduled for
completion until fiscal year 2008. Based on our review of available
documents and discussions with EPA program managers, the agency has
taken affirmative steps to respond to a number of the recommendations,
and its proposed actions generally appear responsive to the Academies'
findings. A comprehensive evaluation of EPA's response to the
Academies' recommendations will not be possible until the agency has
made further progress in implementing its proposed response actions.
[End of section]
Appendix II: Objectives, Scope, and Methodology:
We were asked to assess (1) EPA's progress toward implementing the air
toxics program and any implementation challenges the agency faces, (2)
what available information indicates about the costs and benefits of
EPA's efforts to control air toxics, and (3) the program design and
management practices of state and local air toxics programs that could
potentially help EPA enhance the effectiveness of the federal program.
In addition, we were asked to assess EPA's progress in responding to
recommendations pertaining to the air toxics program made by the
National Academies in 2004.
To respond to the first objective, we updated our previous analysis of
the agency's progress in implementing program requirements. We reviewed
the requirements of the Clean Air Act Amendments of 1990 and EPA's
actions to respond to these requirements, including the number of
regulations the agency promulgated and other requirements to issue
reports and guidance. Specifically, we considered EPA's Maximum
Achievable Control Technology (MACT), small stationary source, mobile
source, residual risk, and technology review activities, and other
activities in the act that were specifically related to air toxics.
We also evaluated the timeliness of EPA's actions versus the schedule
mandated by the act by comparing the dates specified in the act with
the dates on which EPA published the rules in the Federal Register. We
independently developed a list of actions required by EPA and worked
with agency officials to refine and confirm the list we used. We made
minor modifications to the list approved by EPA to account for the
promulgation of residual risk and area source standards, to separately
count area source standards issued in conjunction with MACT standards,
and to delete source categories that were delisted.
To determine the priority of the air toxics program relative to other
air programs, and the priorities within the air toxics program, we met
with senior air program officials and analyzed budget data submitted by
EPA. Specifically, we compared the funding for EPA's air program as a
whole with the funding for the air toxics program.
To identify the implementation challenges EPA faces, we reviewed
available studies by the National Academies, the Office of Management
and Budget (OMB), and the EPA Inspector General. We identified nine
implementation challenges, such as the adequacy of program funding and
the priority of the program relative to other air programs, and
developed a structured interview in order to evaluate the magnitude of
the challenges identified by these studies in the opinions of various
stakeholders. We pretested the interview questions and made relevant
changes to the questions based on the pretest.
We designed the structured interview so that respondents could rate
each implementation challenge on a scale from 0 (not a challenge at
all) to 4 (a challenge to a very great extent). When conducting the
interviews, we asked followup questions if the respondents rated the
challenge as a 3 (a challenge to a large extent) or 4, such as what
they thought could be done to address the challenge. We also provided a
list of key definitions, an explanation of the rating system, and a
description of each challenge to respondents prior to conducting each
interview.
We conducted structured interviews with a nonprobability
sample[Footnote 40] of 22 officials, including 8 EPA, 5 industry, 4
environmental, and 5 state and local officials. Specifically, for EPA,
we interviewed senior officials within the Office of Air Quality
Planning and Standards and the Office of Transportation and Air
Quality. We identified national-level environmental and industry
stakeholders through consultation with EPA (and referrals from contacts
identified through this consultation) and membership on the Clean Air
Act Advisory Committee. The five industry groups we interviewed were
the American Forest & Paper Association, the American Petroleum
Institute, the Council of Industrial Boiler Owners, the American
Chemistry Council, and the Alliance of Automobile Manufacturers. The
four environmental groups we interviewed were the Natural Resources
Defense Council, Environmental Defense, Earth Justice, and an air
toxics consultant recommended by environmental stakeholders and EPA. We
interviewed officials from state and local programs in California, New
Jersey, Oregon, Wisconsin, and Louisville, Kentucky.
Following the structured interviews, we determined the most significant
challenges for all of the stakeholders by averaging the ratings from
all 22 respondents for each challenge. However, because ratings of the
most significant challenges differed for each stakeholder group, we
also averaged the scores for each challenge for each stakeholder group.
We identified the greatest challenges identified by each stakeholder
group (an average rating of 3 or higher, or those rated as challenges
to a large or very great extent) to assess how perceptions of the
challenges differed among the stakeholder groups.
To respond to the second objective, we analyzed available information
on the economic impacts of the program, as well as data on trends in
emissions, health risks, and compliance. Regarding data on economic
impacts, we reviewed EPA's 1997 and 1999 reports to Congress on the
economic impacts of the Clean Air Act as well as the agency's guidance
for analyzing the effects of air pollution regulations. We also met
with EPA staff in the Office of Air Quality Planning and Standards and
Office of Policy Analysis and Review responsible for analyzing the
economic effects of clean air regulations. Regarding emissions and
monitoring data, we met with EPA staff responsible for maintaining the
National Emissions Inventory, reviewed the agency's documentation and
plans for improving the inventory, and reviewed relevant reports by
EPA's Inspector General. Regarding data on health and risks, we met
with EPA staff responsible for risk assessment and the development of
the National-Scale Air Toxics Assessment. We also reviewed EPA's
methodology for developing the assessment and available information on
the risk assessment process. We obtained compliance data from the
Office of Enforcement and Compliance Assurance's Air Facility
Subsystem. We reviewed these data for obvious completeness and
consistency problems, reviewed available documentation, and interviewed
the system administrator. Unless otherwise noted, we determined the
data were sufficiently reliable for the purposes of this report.
To respond to the third objective, we reviewed a nonprobability sample
of air toxics programs from California, New Jersey, Oregon, and
Wisconsin and from Louisville, Kentucky to identify innovative program
designs or management practices. We focused on programs that (1) went
beyond federal standards, (2) were identified by EPA and other
stakeholders as innovative programs, (3) used strategies to address air
toxics that differed from those used by EPA, and (4) represented a
range of geographic locations and experience addressing air toxics.
Specifically, we asked EPA and the State and Territorial Air Pollution
Program Administrators and the Association of Local Air Pollution
Control Officials (STAPPA/ALAPCO), the stakeholders most knowledgeable
about state and local air toxics programs, whether there were specific
programs we should review, and used their recommendations as selection
criteria. GAO conducted independent research to confirm that the
selections cited by these stakeholders were reasonable, including
analyses of the stringency of state and local air toxics programs based
on current law, policy, and guidance documents and summary documents
developed by EPA and state and local agencies.
We visited each program selected for review and conducted
semistructured interviews with state and local officials. We developed
an interview protocol and revised it after limited testing with
respondents. The semistructured interview included questions about how
the programs interact with EPA, how the program views EPA's current and
future requirements, regulate different chemicals and sources, account
for risk, collect emissions inventory data, and measure progress, among
other factors. We focused primarily on practices that EPA might find
useful in addressing its program implementation challenges and did not
evaluate the effectiveness of the state and local programs we reviewed.
Our discussion of the practices employed by these programs should not
be construed as an endorsement of any particular approach but rather as
an acknowledgement that alternative strategies exist.
In addition, we obtained information about EPA's response to the
recommendations of the National Academies' 2004 report entitled Air
Quality Management in the United States. We reviewed the
recommendations in the report, the associated recommendations of the
Clean Air Act Advisory Committee, and EPA's actions to respond to these
recommendations. We worked with EPA officials to determine whether
EPA's actions addressed the recommendations. Our work included an
assessment of data reliability and internal controls. We conducted our
work from June 2005 to June 2006 in accordance with generally accepted
government auditing standards.
[End of section]
Appendix III: Profiles of State and Local Air Toxics Programs:
This appendix provides general information on the nonprobability sample
of four state and one local air toxics programs we reviewed to identify
innovative program designs or management practices. We focused on
programs that (1) went beyond federal standards, (2) were identified as
innovative by EPA and other stakeholders, (3) used strategies to
address air toxics that differ from EPA's, and (4) represented a range
of geographic locations and experience addressing air toxics. Table 12
presents basic information about the programs we reviewed, followed by
profiles of each program.
Table 12: Selected State and Local Air Toxics Programs:
Program: State: California;
Date created: 1983;
Number of chemicals: 245;
Strategy: Control technology;
Description: Requires certain large and small stationary sources to
apply control technologies to reduce emissions.
Program: State: California:
Date created: 1987;
Number of chemicals: 451;
Strategy: Risk assessment;
Description: Requires certain large and small stationary sources to
report emissions of air toxics, estimate the public health impact of
their emissions, and reduce emissions as necessary to meet health-based
standards.
Program: State: New Jersey;
Date created: 1979;
Number of chemicals: 237;
Strategy: Control technology and risk assessment;
Description: Requires certain facilities seeking permits to apply air
toxics emission control technology, estimate the risk posed by the
remaining emissions, and take additional measures as necessary to meet
health-based targets.
Program: State: Oregon[A];
Date created: 2003;
Number of chemicals: 49[B];
Strategy: Geographic, control technology, and risk assessment;
Description: Requires facilities in specific geographic areas of high
risk to develop, with other stakeholders, a risk reduction plan to meet
health-based benchmarks. In addition, some stationary sources may be
required to apply control technologies and estimate and mitigate the
risk they pose to the public.
Program: State: Wisconsin;
Date created: 1988;
Number of chemicals: 535;
Strategy: Control technology and risk assessment;
Description: Requires certain facilities that emit specific amounts of
cancer-causing air toxics to apply control technology to reduce
emissions. Certain facilities that emit specific amounts of other air
toxics must estimate the risks posed by these chemicals and meet health
based standards.
Program: Local: Louisville, Kentucky;
Date created: 2005;
Number of chemicals: 191;
Strategy: Risk assessment;
Description: Requires certain facilities seeking permits to construct
or modify processes or equipment to estimate the risk posed by their
air toxics emissions and to reduce the risk, potentially through the
application of control technologies, to meet certain health-based
goals. Certain existing facilities must meet similar requirements for
37 chemicals.
Source: GAO analysis of state and local agency data.
[A] Oregon's program is still being developed and has not been fully
implemented. This description presents the requirements as spelled out
in the 2003 state rule that created the program.
[B] The Oregon Department of Environmental Quality proposed to adopt
benchmarks for 49 air toxics in February 2006. The benchmarks were not
final as of the date of this report.
[End of table]
California:
California's air toxics program regulates certain new and existing
major stationary sources, small stationary sources, and mobile sources
more stringently than EPA. In 1983, the state legislature adopted
Assembly Bill 1807, the Toxic Air Contaminant Identification and
Control Act, which defined a process for identifying chemicals that
qualify as state air toxics and developing control standards to reduce
emissions from certain sources based on the application of pollution
control technology. California has listed 245 toxic air contaminants as
of May 2006. The state regulates diesel particulate matter emissions
from motor vehicles, such as school buses, under its program.
In 1987, the state legislature passed an additional law, Assembly Bill
2588, the Air Toxics "Hot Spots" Information and Assessment Act, which
required the submission of air toxics emissions inventory data from
certain facilities and notification of local residents of significant
risk from nearby sources of air toxics. Under this act, certain sources
of air toxics must conduct risk assessments to determine their health
impact on the community. In conducting these risk assessments,
regulated facilities must consider the risks posed by their emissions
of 451 different chemicals.[Footnote 41] In 1992, the legislature
passed an amendment to the "hot spots" law that required facilities
that pose a significant health risk to the community to develop risk
management plans. Policy documents and other information are available
at the program's Web site [Hyperlink,
http://www.arb.ca.gov/toxics/toxics.htm].
New Jersey:
New Jersey's air toxics program regulates certain large and small
stationary sources more stringently than EPA through the state's
permitting program. The New Jersey Air Pollution Control Act of 1954
requires new or modified sources that emit air pollutants, including
air toxics, to incorporate state-of-the-art air pollution controls to
reduce their emissions. In 1979, the New Jersey Department of
Environmental Protection (DEP) adopted a regulation that specifically
addressed air toxics emissions. This rule listed 11 air toxics and
required sources emitting these chemicals to register with DEP and
demonstrate that they utilize state-of-the-art controls to limit their
emissions. The department incorporates control requirements for other
air toxics on a case-by-case basis as part of the permitting process.
In the early 1980s, the DEP instituted a risk assessment policy to
better ensure that sources with state-of-the-art controls protect
public health. The risk assessment policy requires certain facilities
seeking permits to estimate the risk to the community that remains
after the application of technology standards and to take additional
measures as necessary to meet health-based targets established for 237
air toxics. General information about New Jersey's air toxics program
is available at [Hyperlink,
http://www.state.nj.us/dep/airmon/airtoxics/], and policy documents,
such as risk assessment policies are available at [Hyperlink,
http://www.state.nj.us/dep/aqpp/risk.html].
Oregon:
Oregon's air toxics program is authorized to go beyond federal
requirements for some large and small stationary sources. In November
1998, the Oregon Department of Environmental Quality (DEQ) convened a
broad-based stakeholder group to outline a program to complement the
existing federal program and reduce the impact of air toxics in Oregon.
DEQ worked with stakeholders until the adoption of Oregon's air toxics
rule on October 9, 2003. The rule requires sources in specific
geographic areas of high risk to develop, with other stakeholders, a
risk reduction plan to meet certain health based goals.[Footnote 42] In
addition, some stationary sources may be required to estimate and
mitigate the risk they pose to the public and apply control
technologies. The program is still being developed and has not been
fully implemented. Policy and guidance documents and other information
are available at the program's Web site [Hyperlink,
http://www.deq.state.or.us/aq/hap/index.htm].
Wisconsin:
Wisconsin's air toxics program regulates certain new and existing
stationary sources more stringently than EPA. In 1983, the Wisconsin
Department of Natural Resources (DNR) formed a group of scientists,
industry, environmental, and government stakeholders in response to
public concern about the health effects of air toxics and the lack of
policy and regulations at the federal level. The group recommended an
approach for a state air toxics rule in 1985, and DNR developed a rule
that became effective in 1988. This original rule was rewritten and
redeveloped from 2000 through 2004 using an advisory committee process
that included government, industry, and environmental stakeholders. The
final rule became effective in July 2004. The rule lists 535 air toxics
and requires certain facilities that emit specific amounts of cancer-
causing air toxics to apply control technology to reduce emissions. In
addition, certain facilities that emit other air toxics beyond specific
thresholds must estimate the risks posed by these chemicals and meet
health-based standards.[Footnote 43] Guidance documents and other
information are available on the program's Web site, [Hyperlink,
http://www.dnr.state.wi.us/org/aw/air/health/airtoxics/].
Louisville, Kentucky:
In September 2004, the Louisville Metro Air Pollution Control District
prepared a draft Strategic Toxic Air Reduction (STAR) program in
response to air monitoring that documented and modeled data that
suggested that air toxics posed significant risks to the community.
Adopted by the Louisville Metro Air Pollution Control Board in June
2005, the STAR program requires certain facilities to estimate the risk
posed by their air toxics emissions and to reduce the risk, potentially
through the application of control technologies, to meet certain health-
based goals. Louisville's program first focuses on emissions of 18 air
toxics that posed unacceptable risk to the public based on monitoring
studies. In total, the STAR program applies to new or modified
processes and process equipment that will emit any of 191 air toxics,
and existing sources that emitted any of 37 air toxics in quantities
that exceed certain thresholds. Policy documents and other information
are available on the program's Web site, [Hyperlink,
http://www.apcd.org/star/].
[End of section]
Appendix IV: Comments from the Environmental Protection Agency:
Note: GAO comments supplementing those in the report text appear at the
end of this appendix.
United States Environmental Protection Agency:
Washington, D.C. 20460:
Office Of Air And Radiation:
Jun 8 2006:
Mr. John B. Stephenson:
Director, Natural Resources and Environment:
U. S. Government Accountability Office:
Washington, DC 20548:
Dear Mr. Stephenson:
The U. S. Environmental Protection Agency (EPA) appreciates the
opportunity to review and comment on the Government Accountability
Office (GAO) report, "Clean Air Act: EPA Should Improve the Management
of Its Air Toxics Program" (GAO-06-669). EPA agrees in part with the
conclusions and recommendations in the report and would like to provide
clarification on several statements in the report.
"Available information on the costs and benefits of EPA's efforts to
control air toxics is not sufficiently comprehensive to measure the
total economic impacts resulting from the air toxics program."
Realizing the limitations of a chemical-by-chemical decision framework
based solely on risk, the 1990 Clean Air Act Amendments mandated a
different, two-phased approach. In the first phase, EPA develops
technology-based standards, requiring sources to meet specific
emissions limits that are based on emissions levels already being
achieved by many similar sources in the country. In the second phase,
EPA applies a risk-based approach to assess how these technology-based
emissions limits are reducing health and environmental risks, and EPA
may implement additional standards to address any significant remaining
risk (or "residual risk").
In February 2004, EPA completed the issuance of the technology-based
standards for categories of industries that emit toxic emissions at
major-source levels. In total, EPA issued 96 standards (known as
Maximum Achievable Control Technology or MALT) standards covering 174
industrial operations. When all of these industry categories come into
full compliance in 2007, these MACT standards will cut annual air
toxics emissions by an estimated 1.7 million tons. Implementation of
these standards results in significant reductions of volatile organic
compounds (VOCs) and particulate matter (PM) which carry benefits with
well-established means of quantification; quantification of the health
benefits of reducing air toxics (e.g., reduced cancer risks and
incidence, reduced risks of acute and chronic noncancer health effects)
is more problematic.
Since completing the MACT standards, EPA has assessed the health risks
associated with 8 of those standards and concluded that 4 of the
standards present no significant known health risks that would warrant
making them more stringent. For the other 4 standards, we have proposed
or will propose more stringent standards to reduce health risks in
order to provide public health protection with an ample margin of
safety. Each of these proposed actions will reduce air toxics exposures
and levels of individual cancer or other health risks for people living
near the affected facilities. We are still developing ways of
specifically quantifying these benefits. However, the two-step approach
embodied in the 1990 Clean Air Act Amendments allows EPA to focus risk
assessment and benefits analysis efforts on the smaller number of key
HAPs posing potentially significant residual risks. EPA believes this
more focused approach will provide better support to future air toxics
rulemaking decisions than would the comprehensive assessment of the
total benefits and costs of all air toxics controls referenced in GAO's
comment.
"EPA has made little progress and is behind schedule in completing
residual risk and technology reviews and in issuing emissions standards
for small stationary and mobile sources."
In several places, the GAO report refers to this "limited progress" in
implementing mobile source requirements and in reducing mobile source
emissions and risks. In fact, we estimate a 57% reduction in emissions
of mobile source air toxics between 1990 and 2007. Since actions that
address mobile source air toxics resulted in additional reductions
prior to 1990, this is actually an underestimate of the overall
reduction from EPA programs. These dramatic reductions will continue in
the future, with a 60% reduction between 1999 and 2020. (See Attachment
1 for the contribution of source categories to air toxics emissions,
1990-2020, not including diesel particulate matter.) For diesel
particulate matter emissions specifically, we expect a 70% reduction
between 1999 and 2020[Footnote 44]. These emission reductions, and the
large number of standards EPA has promulgated since 1990 for many
different mobile sources of toxics emissions, illustrate that EPA has
in fact made significant progress in reducing mobile source air toxics.
The limited progress cited in the GAO report appears to use a measure
of progress based on the number of actions taken under Clean Air Act
section 202(1), which is the provision that specifically applies to
motor vehicle air toxics. We believe that this is an inappropriately
narrow measure of progress. EPA controls mobile source air toxics in
the broader context of motor vehicle, nonroad engine and fuel
standards, regardless of whether they are issued under 202(1)
specifically. This is often done through standards which reduce
hydrocarbons and particulate matter, because such standards also reduce
air toxics.
The Clean Air Act itself recognizes that mobile source toxics control
is achieved in the broader context of motor vehicle and fuel standards,
regardless of whether they are issued under 202(1) specifically. For
example, Clean Air Act section 202(1) recognizes that mobile source air
toxics are controlled under the broader authority of 202(a) and 211(c),
which refer to standards for vehicles and fuels. It requires EPA to use
these authorities for the purpose of controlling air toxics, and it
also requires EPA, when setting such toxics standards, to consider the
standards already established under section 202(a). In addition, the
specific wording of section 202(1) applies only to "motor vehicles," a
term which excludes nonroad equipment. However, EPA has clearly
recognized that nonroad mobile sources are an important source of
mobile source air toxics and has controlled them accordingly, through
authorities other than 202(1). When EPA's actions under all these
authorities are considered-along with the toxics emissions reductions
they produce-it is clear that EPA has made significant progress in
controlling mobile source air toxics. (See attachments 2 and 3 for more
details.)
"The agency lacks a comprehensive strategy for managing its
implementation of the remaining air toxics requirements."
The Clean Air Act itself presents a road map for air toxics with
distinct phases and specific timeframes. EPA has supplemented the
statutory roadmap with more specific strategies. First, in 1999 EPA
finalized the Integrated Air Toxics Strategy. This strategy fulfilled
the mandate from Congress to develop a strategy for air toxics in urban
areas. The strategy includes specific actions to address the large
number of smaller, area sources, and contains broader risk reduction
goals encompassing all stationary sources. The Integrated Air Toxics
Strategy is EPA's framework for addressing air toxics in urban areas by
looking at stationary, mobile, and indoor source emissions. Air toxics
can pose special threats in urban areas because of the large number of
people and the variety of sources of toxic air pollutants, such as
cars, trucks, large factories, gasoline stations, and dry cleaners. EPA
is also concerned about the impact of toxic emissions on minority and
low-income communities, which are often located close to industrial and
commercial urbanized areas.
Second, EPA is developing a strategy to meet the aggressive schedule
established by the U.S. Court of Appeals for the D.C. Circuit. The
schedule requires completion of the remaining 50 standards governing
emissions from area sources by mid-2009. The Agency is evaluating
available information about the source categories and exploring
different ways of writing standards that could address multiple source
categories in one or a relatively smaller number of rules. We are also
considering alternative standards that could support a more flexible
and adaptive approach to controlling emissions from certain source
categories in recognition of ongoing efforts by State and local
agencies to comply with their own air toxics control programs and
federally-mandated programs to reduce ozone and particulate matter.
Under the court-imposed deadlines, the earliest set of standards may
involve control requirements for source categories about which we have
the most reliable information. Categories for which we have relatively
less information or where more significant control efforts may be
warranted will likely be addressed in the later deadlines contained in
the court schedule.
Third, EPA is developing a strategy for completing the residual risk
and technology review program. EPA recognizes that there have been
problems with completing these reviews within the statutorily-required
8-year period following promulgation of the major source standards.
However, we are learning important lessons from the experiences gained
in our first eight reviews. The cost of these efforts in time, staff,
and contract resources, relative to results achieved, lead us to seek
different ways to meet our statutory obligations and ensure the
public's health is adequately protected. For this reason, we are
examining a variety of options that go beyond the conventional source
category, standard- specific approach to consider such things as the
risk posed comprehensively by all of the emitting activities at an
affected facility, and evaluating screening options to determine which
industries and/or standards merit more rigorous examination. We believe
this approach will allow us to more efficiently identify and address
significant remaining risks posed by air toxics from stationary
sources, while reducing the expenditure of resources on standards
likely to pose little or no residual risk.
Once again, thank you for the opportunity to respond.
Sincerely,
Signed by:
William L Wehrum:
Acting Assistant Administrator:
Enclosures:
Attachment 1:
Contribution of Source Categories to Air Toxic Emissions, 1990 to 2020
(not including diesel particulate matter).
[See PDF for Image]
Note: Dashed line represents projected emissions without Clean Air Act
controls.
[End of Figure]
Attachment 2:
Current On-Highway Engine and Vehicle Programs Providing Significant
Additional MSAT Reductions.
Category: Light-duty cars and trucks;
Rule and FRM date: Tier 2 (including low sulfur fuel and enhanced
evaporative emissions), February 10, 2000;
Implementation Schedule: 2004-2009;
VOC Standards*: check;
PM standards: check.
Category: Light-duty cars and trucks;
Rule and FRM date: NLEV (National Low-Emitting Vehicle);
Implementation Schedule: 1999-2003;
VOC Standards*: check;
PM standards: check.
Category: Light-duty cars and trucks;
Rule and FRM date: SFTP (Supplemental FTP) Procedures;
Implementation Schedule: 2001 (start);
VOC Standards*: check;
PM standards: [Empty].
Category: Heavy-duty trucks;
Rule and FRM date: 2004 Heavy-duty Rule October 6, 2000;
Implementation Schedule: 2004-2007;
VOC Standards*: check;
PM standards: check.
Category: Heavy-duty trucks;
Rule and FRM date: 2007 Heavy-duty Rule (including low sulfur fuel),
January 18, 2001;
Implementation Schedule: 2007-2010;
VOC Standards*: check;
PM standards: check.
Category: Urban Buses;
Rule and FRM date: HD Diesel Retrofit;
Implementation Schedule: 1994-1998;
VOC Standards*: [Empty];
PM standards: check.
Category: Highway Motorcycles;
Rule and FRM date: December 2003;
Implementation Schedule: 2006-2010;
VOC Standards*: check;
PM standards: [Empty].
* Standards in various forms including HC, NMHC, NMOG, and NOx+NMHC.
[End of Table]
Attachment 3: Current Nonroad Engine/Vehicle Programs.
Category: Land-based diesel;
Rule and FRM date: Tier 2, October 23, 1998;
Implementation Schedule: 2001-2006;
VOC standards*: check;
PM Standards: check.
Category: Land-based diesel;
Rule and FRM date: Tier 3, October 23, 1998;
Implementation Schedule: 2006-2008;
VOC standards*: check;
PM Standards: check.
Category: Land-based diesel;
Rule and FRM date: Tier 4 (with low sulfur fuel), June 29, 2004;
Implementation Schedule: 2008-2014;
VOC standards*: check;
PM Standards: check.
Category: Locomotives;
Rule and FRM date: Tier 0, Tier 1, Tier 2, April 16, 1998;
Implementation Schedule: 2002-2005;
VOC standards*: check;
PM Standards: check.
Category: Marine;
Rule and FRM date: Spark-ignition Gasoline Engine standards, October 4,
1996;
Implementation Schedule: 1998-2006;
VOC standards*: check;
PM Standards: [Empty].
Category: Marine;
Rule and FRM date: Diesel engines, less than 50hp;
Implementation Schedule: 1999-2005;
VOC standards*: [Empty];
PM Standards: check.
Category: Marine;
Rule and FRM date: Recreational diesel, November 8, 2002;
Implementation Schedule: Starting 2006/2009;
VOC standards*: check;
PM Standards: check.
Category: Marine;
Rule and FRM date: Commercial diesel, February 28, 2003;
Implementation Schedule: Starting 2004/2007;
VOC standards*: check;
PM Standards: check.
Category: Large spark-ignition engines;
Rule and FRM date: Tier 1 standards, Tier 2 standards, November 8,
2002;
Implementation Schedule: 2004-2007, Starting 2007;
VOC standards*: check;
PM Standards: [Empty].
Category: Small spark-ignition engines;
Rule and FRM date: Phase 1 standards;
Implementation Schedule: 1997-2007;
VOC standards*: check;
PM Standards: [Empty].
Category: Small spark-ignition engines;
Rule and FRM date: Handheld Phase 2 standards, April 25, 2000;
Implementation Schedule: 2002-2007;
VOC standards*: check;
PM Standards: [Empty].
Category: Small spark-ignition engines;
Rule and FRM date: Non-handheld Phase 2 Standards, March 30, 1999;
Implementation Schedule: 2001-2007;
VOC standards*: [Empty];
PM Standards: [Empty].
Category: Aircraft (NOx Std in 2005; Smoke Std in 1982);
Rule and FRM date: [Empty];
Implementation Schedule: No current/recent standards for VOC or PM;
VOC standards*: [Empty];
PM Standards: [Empty].
Category: Recreational vehicles;
Rule and FRM date: November 8, 2002;
Implementation Schedule: 2006-2012;
VOC standards*: check;
PM Standards: [Empty].
* Standards in various forms including HC, NMHC, NMOG, and NOx+NMHC.
[End of Table]
GAO comments:
1. Regarding our discussion of the economic effects of air toxics
regulations, EPA stated that the agency finds it appropriate to focus
risk assessments and benefits analysis on the air toxics that pose the
most significant risks within the context of the residual risk program.
EPA's letter also stated that such an approach would assist the
rulemaking process to a greater extent than comprehensive assessments
of the total benefits and costs of all air toxics controls. While EPA
may hold this view, the Clean Air Act requires the agency not only to
assess residual risks after completing the MACT standards, but also to
periodically assess the costs and benefits of clean air programs.
Regarding the first set of requirements, EPA was late in issuing almost
all of the MACT standards and is already well behind schedule in
completing the residual risk assessments. With respect to the second
set of requirements, EPA's economic assessments of clean air programs
have included limited information on the costs of regulating air toxics
and have not included monetized estimates of the human health or other
benefits--either for individual pollutants or for all of the pollutants
in total. More complete information on costs and benefits would help
the agency, Congress, and the public understand the effects of the air
toxics program and enable the agency to compare the net benefits of the
air toxics program with those achieved under other clean air programs
on which the agency has placed a higher priority.
2. In its letter, EPA stated that GAO uses an inappropriately narrow
measure of progress in regulating air toxics and that the agency has
issued a number of regulations that control air toxics as a side
benefit. However, as we discuss in the report, data limitations
compromise the usefulness of other performance measures. EPA has indeed
taken regulatory actions outside of the air toxics program that control
toxic emissions as a side benefit. However, the progress--in terms of
emissions reductions--that EPA cites should be considered in the
context of the limitations of the emissions data discussed in this
report. For example, the EPA Inspector General has reported that EPA
cannot tell whether apparent reductions or increases in emissions have
resulted from changes in the way the agency estimates emissions or from
actual reductions. It is also important to note that EPA does not
expect some of the emissions reductions cited in its letter to occur
until 2020. Furthermore, EPA's most recent data on risks from air
toxics identifies benzene--a known carcinogen emitted primarily by
mobile sources--as a national risk driver that accounts for 25 percent
of the cancer risks posed by air toxics across the nation. This
suggests that EPA has substantial opportunities to further address air
toxics risks from mobile sources. Finally, the Clean Air Act mandated
specific actions and timelines for evaluating and regulating toxic
emissions from mobile sources. As discussed in this report, the agency
has missed its deadlines for completing these actions but has proposed
a mobile source air toxics rule that it intends to finalize in 2007.
3. In response to our finding that EPA lacks a strategy for managing
its implementation of the remaining air toxics requirements, the
agency's letter stated that the Clean Air Act provides a road map for
air toxics and that EPA developed an integrated air toxics strategy in
1999. EPA also stated that the agency is developing a strategy to
respond to its court-ordered deadlines for completing certain air
toxics requirements. As discussed in the report, EPA has missed most of
the act's deadlines related to air toxics and has not fully implemented
the actions outlined in its integrated strategy. Additionally, EPA's
discussion of its efforts to meet court-ordered deadlines underscores
the need for more proactive management.
[End of section]
Appendix V: GAO Contact and Staff Acknowledgments:
GAO Contact:
John B. Stephenson, (202) 512-3841 or stephensonj@gao.gov:
Staff Acknowledgments:
In addition to the contact named above, Christine Fishkin (Assistant
Director), Jennifer Dougherty, Cindy Gilbert, Tim Guinane, Michael Hix,
Andrew Huddleston, Karen Keegan, Alison O'Neill, Judy Pagano, Melissa
Saddler, and Joseph Thompson made significant contributions to this
report.
FOOTNOTES
[1] Cancer risk data from EPA's 1999 National-Scale Air Toxics
Assessment, released in February 2006, estimates that more than 270
million people in the United States are exposed at levels of risk that
exceed 10 in 1 million due to the combined impacts of all sources of
air toxics. This risk level implies that more than 10 persons out of a
million may develop cancer if exposed continuously over their lifetime.
Section 112 of the Clean Air Act identifies a lifetime cancer risk of 1
in 1 million as a threshold above which regulation may be warranted for
individual sources of air toxics, considering feasibility and costs.
[2] The Clean Air Act refers to these substances as "hazardous air
pollutants," which EPA uses interchangeably with the more common term
"air toxics." In this report, we generally use the shorter term, air
toxics.
[3] We discuss the limitations of EPA's emissions data later in this
report.
[4] Major stationary sources are those that emit 10 or more tons per
year of a single hazardous air pollutant or 25 or more tons per year of
any combination of hazardous air pollutants.
[5] The Clean Air Act refers to small stationary sources as "area
sources."
[6] In total, three chemicals and several substances from a listed
group of chemicals have been removed from the list of air toxics
originally provided in the 1990 amendments. By a joint resolution,
Congress corrected the inadvertent addition of hydrogen sulfide to the
substances originally listed in the 1990 amendments. EPA delisted
caprolactam and methyl ethyl ketone. The agency also removed the
compound ethylene glycol monobutyl ether (EGBE) and compounds called
surfactant alcohol ethoxylates and their derivatives (SAED) from the
listed glycol ethers category. The group glycol ethers is still listed.
[7] See GAO, Air Pollution: EPA's Strategy and Resources May Be
Inadequate to Control Air Toxics, GAO/RCED-91-143 (Washington, D.C.:
June 26, 1991); Air Pollution: Progress and Problems in Implementing
Selected Aspects of the Clean Air Act Amendments of 1990, GAO/ T-RCED-
94-68 (Washington, D.C.: Oct. 29, 1993); Air Pollution: Reductions in
EPA's 1994 Air Quality Program's Budget, GAO/RCED-95-31BR (Washington,
D.C.: Nov. 29, 1994); and Clean Air Rulemaking: Tracking System Would
Help Measure Progress of Streamlining Initiatives, GAO/ RCED-95-70
(Washington, D.C.: Mar. 2, 1995).
[8] See GAO, Clean Air Act: EPA Has Completed Most of the Actions
Required by the 1990 Amendments, but Many Were Completed Late, GAO-05-
613 (Washington, D.C.: May 27, 2005).
[9] The National Academies, National Research Council, Air Quality
Management in the United States (Washington, D.C., 2004).
[10] EPA currently regulates 158 major source categories. Some
industrial facilities may belong to multiple source categories.
[11] MACT standards require all sources within a source category to
control emissions to the same level. Existing sources generally must
meet the average emission level achieved by the best performing 12
percent of sources in the source category. New sources must meet a more
stringent emission level.
[12] EPA generally uses a lifetime cancer risk of 1 in 10,000 as the
upper boundary of acceptability. As part of the ample margin of safety
decision, EPA considers costs, technological feasibility,
uncertainties, and other relevant factors. In this step, EPA must also
assess whether to adopt more stringent standards to prevent adverse
effects to wildlife, aquatic life, or natural resources considering
cost, energy, and other relevant factors.
[13] EPA was to promulgate regulations for small stationary sources
listed under section 112(k) of the act by November 2000. Small
stationary sources not listed under section 112(k) were subject to a
different schedule.
[14] U.S. Environmental Protection Agency, National Air Toxics Program:
The Integrated Urban Strategy, Report to Congress (Research Triangle
Park, North Carolina, 2000).
[15] Among other things, the 2001 rule required refiners to maintain
current levels of compliance with air toxic performance standards and
did not require refiners to install new equipment or use technologies
beyond those already in use. EPA did not set additional air toxics
requirements for vehicles at that time because the agency had already
established other standards for vehicles and fuels that it believed
represented the greatest degree of toxics control achievable at that
time. See Control of Hazardous Air Pollutants From Mobile Sources, 66
Fed. Reg. 17229 (Mar. 29, 2001).
[16] Control of Hazardous Air Pollutants from Mobile Sources, 71 Fed.
Reg. 15804 (Mar. 29, 2006).
[17] EPA officials cited the Toxics Release Inventory, various rules
affecting motor vehicle fuel formulations, Design for the Environment,
the Green Suppliers Network, and community-based initiatives such as
Community Action for a Renewed Environment (CARE).
[18] EPA applies the term "national cancer risk driver" to any air
toxic that poses an estimated maximum lifetime cancer risk exceeding 10
in 1 million to more than 25 million people.
[19] See appendix II for information on our methodology for
interviewing stakeholders.
[20] The two challenges not rated as significant by any stakeholder
groups were "complexity of required analyses to support regulatory
actions" and "rigidity of Clean Air Act requirements."
[21] U.S. Environmental Protection Agency, The Benefits and Costs of
the Clean Air Act, 1970 to 1990 (Washington D.C., 1997); and The
Benefits and Costs of the Clean Air Act, 1990 to 2010 (Washington D.C.,
1999).
[22] EPA identified other key uncertainties with its cost analysis,
including that the estimates were based on the costs of pollution
control technologies that were available at the time and did not
account for potential reductions in future costs due to technological
innovation.
[23] EPA has some dose-response data for benzene and plans to include
the results of a case study assessing the benefits of reductions in
benzene emissions in the Houston area in the next comprehensive
assessment of Clean Air Act programs, which the agency expects to issue
in 2007.
[24] U.S. Environmental Protection Agency, Office of Inspector General,
EPA's Method for Calculating Air Toxics Emissions for Reporting Results
Needs Improvement (Washington, D.C., 2004).
[25] U.S. Environmental Protection Agency, Office of Research and
Development, Air Toxics Research Strategy (external review draft)
(Washington, D.C., 2002).
[26] U.S. Environmental Protection Agency, Office of Research and
Development, Air Toxics Multi-Year Plan, (Washington, D.C., 2003).
[27] U.S. Environmental Protection Agency, Science Advisory Board,
EPA's Air Toxics Research Strategy and Air Toxics Multi-Year Plan
(Washington, D.C., 2004).
[28] The six priority air toxics include acrolein, arsenic, benzene,
hexavalent chromium, formaldehyde, and 1,3 butadiene. EPA currently
monitors for arsenic, benzene, hexavalent chromium, formaldehyde, and
1,3 butadiene at all locations, and plans to monitor for acrolein at
all locations beginning January 1, 2007.
[29] U.S. Environmental Protection Agency, Office of Inspector General,
Progress Made in Monitoring Ambient Air Toxics, But Further
Improvements Can Increase Effectiveness (Washington, D.C., 2005).
[30] According to EPA, a total of 4,271 facilities were required to
comply with MACT standards as of 2004.
[31] Establishing more stringent pollution control requirements
generally involves trade-offs between regulatory costs and potential
public health benefits.
[32] New Jersey may also require some sources to conduct facilitywide
risk assessments as part of the permitting process, but this is not a
routine practice, according to a New Jersey program official.
[33] The preamble to EPA's first final residual risk rule, the National
Emission Standards for Coke Oven Batteries, 70 Fed. Reg. 19991, 19998
(Apr. 15, 2005), articulates the agency's approach for evaluating
remaining health risks from facilities regulated by MACT standards. EPA
relied on this approach in its five final residual risk rules to date.
[34] According to New Jersey officials, the program in that state does
not routinely require sources to conduct facilitywide risk assessments.
However, New Jersey's program may evaluate emissions from all emission
points in a facility in a single risk assessment in situations where
there is the potential for high risk.
[35] As noted above, about 300 chemicals enter commerce each year.
[36] For fiscal year 2006, EPA Region 4 included a grant commitment for
the Louisville Metro Air Pollution Control District to submit its air
toxics emission inventory as part of an air planning agreement to
obtain federal funding for the local air program. EPA officials said
that the agency's fiscal year 2007 grant guidance for state and local
agencies does not require the submission of air toxics emissions
inventories as a condition to obtain federal funding.
[37] EPA, in its Consolidated Emissions Reporting Rule, 67 Fed. Reg.
39602, 39604 (June 10, 2002), agreed with commenters and stated that it
planned to develop air toxics reporting measures at a later date.
[38] National Emission Standards for Hazardous Air Pollutants: Plywood
and Composite Wood Products, 71 Fed. Reg. 8342 (Feb. 16, 2006).
[39] Environmental Protection Agency, Compilation of Status Reports on
the Implementation of Recommendations Made to EPA by the CAAAC on Air
Quality Management (Washington, D.C., November 2005)
[40] Results from nonprobability samples cannot be used to make
inferences about a population, because in a nonprobability sample, some
elements of the population being studied have no chance or an unknown
chance of being selected as part of the sample.
[41] California requires certain facilities to quantify and report
emissions of 451 chemicals as part of its risk assessment program. In
2006, the state may consider the addition of several hundred chemicals
to the list of chemicals reported and used in risk assessments. Some
facilities are also required to report the use or manufacture of 310
additional chemicals for a potential total of 761 chemicals, but these
chemicals are not currently considered in risk assessments.
[42] The Oregon Department of Environmental Quality proposed to adopt
benchmarks for 49 air toxics in February 2006. The benchmarks were not
final as of the issue date of this report.
[43] Wisconsin state law provides that Wisconsin's air toxics program
does not apply to emissions that are regulated by federal MACT
standards under section 112 of the Clean Air Act.
[44] 71 FR 15832-15833, March 29, 2006.
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