Aviation and the Environment: Airport Operations and Future Growth
Present Environmental Challenges (Chapter Report, 08/30/2000,
GAO/RCED-00-153).

Pursuant to a congressional request, GAO reviewed the: (1) key concerns
and challenges associated with airports' current operations and future
growth--particularly concerns about aircraft noise, water quality, and
air pollutant emissions--and the actions being taken by the nation's
busiest airports to balance environmental concerns with such operations
and growth; and (2) actions taken by the Federal Aviation Administration
(FAA) and other federal agencies to address environmental concerns
associated with airports' current operations and future growth.

GAO noted that: (1) the primary environmental concern and challenge
facing airports now and for the foreseeable future is noise generated by
aircraft operations; (2) airport officials' next greatest concern and
challenge is water quality--primarily the potential harmful effects of
deicing and anti-icing operations; (3) air quality is the third greatest
concern and challenge reported by airport officials, particularly
managing the effects on air quality of the increases in emissions due to
airport growth; (4) other issues of concern cited by some airport
officials were wetlands, endangered species, environmental justice, and
historical preservation; (5) airport officials have undertaken a range
of activities--either independently or in cooperation with government
and industry partners--to more effectively balance airports' current
operations and future growth with the environmental impact of these
activities; (6) for example, they have established airport/community
groups to address environmental issues; (7) coordination has occurred
across the federal government to assist airport officials in balancing
airport operations and growth with the impact on the environment; (8)
for example, FAA has developed and continues to refine models to assess
the impact on noise and air quality of proposed airport development
projects and has assisted state and local governments and planning
agencies with establishing land uses around airports that are compatible
with airport operations; (9) furthermore, many airport officials
reported that FAA is effective at providing assistance, including
answering their questions and addressing their concerns about
environmental issues and coordinating activities across the agency; (10)
other federal agencies also assist airports with their environmental
responsibilities; and (11) for example, the Environmental Protection
Agency helps airports address water and air quality issues through
regulatory, voluntary, and research efforts, and the National
Aeronautics and Space Administration assists them primarily through its
research and related technology development to reduce aircraft noise and
the emission of air pollutants.

--------------------------- Indexing Terms -----------------------------

 REPORTNUM:  RCED-00-153
     TITLE:  Aviation and the Environment: Airport Operations and
	     Future Growth Present Environmental Challenges
      DATE:  08/30/2000
   SUBJECT:  Commercial aviation
	     Environmental monitoring
	     Airports
	     Aircraft
	     Air pollution control
	     Water pollution control
	     Noise pollution control
IDENTIFIER:  EPA National Pollutant Discharge Elimination System
	     FAA Part 150 Program

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GAO/RCED-00-153

618

Federal Laws Guide Environmental Compliance Requirements
for Airports 19

The Federal Government Takes a Decentralized Approach to
Implementing Environmental Laws at Airports 23

Objectives, Scope, and Methodology 26

Challenge for Airports

30

Airports Reported Noise Concerns as Their Most Serious
Environmental Challenge 31

Airports Have Implemented Various Measures to Reduce the
Impact of Aircraft Noise, but Community Concerns Persist 37

Airports

45

Airports

50

Airports' Primary Air Quality Concerns Involve Parking Demand and Compliance
With the Clean Air Act 51

Air Quality Is a Growing Concern for Future Airport Operations 52

Many Airports Have Begun to Address Concerns About Air Pollutant Emissions
54

Airlines Work With Airports to Reduce Air Pollutant Emissions 58

Challenges Remain

60

Federal Coordination Efforts Have Been Undertaken 60

The Federal Environmental Review Process Is Not Well
Understood by Many Airport Officials, and Some Reviews Are Not
Systematically Documented or Communicated to Them by FAA 70

Many Airports Are Uncertain About How to Meet Clean Air Act Requirements 73

Provisions in a Federal Law Limit the Eligibility of Some Airports
and Communities to Receive Federal Noise Funds and
Create Somewhat Duplicative Air Quality Requirements 79

Conclusions 82

Recommendations 84

Matters for Congressional Consideration 84

Agency Comments 84

Appendix I: Selected Airports' Activities to Balance Operations
and Growth With Environmental Impacts

86

Appendix II: Europe Is Addressing the Environmental Impacts
of Airports

94

Appendix III: List of the 50 Busiest U.S. Commercial Service Airports Based
on 1998 Data From FAA

95

Appendix IV: Comments From the National Aeronautics and Space Administration

97

Appendix V: Comments From the Department of Defense

99

Appendix VI: GAO Contacts and Staff Acknowledgments

100

Figure 1: General Overview of the Federal Environmental
Review Process Under NEPA 20

Figure 2: Environmental Issues That Currently Most Concern
Airports 31

Figure 3: Adverse Impact of Aircraft Noise on Residents Near
Los Angeles International Airport 33

Figure 4: Noise Mitigation Strategies Required or Encouraged
by Airports 38

Figure 5: Cumulative Totals for the Frequency of Airport Noise
Monitoring 40

Figure 6: Residential Communities Bordering Miami
International Airport 44

Figure 7: Aircraft Deicing/Anti-Icing Trucks at Denver
International Airport 46

Figure 8: Airports' Use of Selected Deicing and Anti-Icing
Chemical Capture Techniques 48

Figure 9: Air Quality Issues That Are Major Concerns for Airports 51

Figure 10: Environmental Issues That Most Concern Airports
Currently and in the Future 53

Figure 11: Electric Vehicle Recharging Stations at Los Angeles
International Airport 54

Figure 12: Strategies for Reducing Air Pollutant Emissions
Funded by Airports 56

Figure 13: Use of Alternative-Fuel Shuttles at Los Angeles
International Airport 58

Figure 14: Airports' Opinions of FAA's Effectiveness in Selected
Environmental Areas 64

Figure 15: Airports' Satisfaction With the NEPA Review Process 69

Figure 16: Share of Airports With Expansion Projects Whose Projects Required
Environmental Review 71

Figure 17: Two Deicing/Anti-Icing Runoff Capture Basins at Denver
International Airport 88

DNL day-night [sound] level

EPA Environmental Protection Agency

FAA Federal Aviation Administration

ICAO International Civil Aviation Organization

NASA National Aeronautics and Space Administration

NEPA National Environmental Policy Act

NOx nitrogen oxide and nitrogen dioxide [collectively]

Resources, Community, and
Economic Development Division

B-283109

August 30, 2000

The Honorable James L. Oberstar
Ranking Democratic Member
Committee on Transportation and Infrastructure
House of Representatives

Dear Mr. Oberstar:

This report responds to your request that we review the key environmental
concerns and challenges associated with airports' current operations and
future growth and the efforts of major airports and federal agencies to
address these concerns. The report contains recommendations to the Secretary
of Transportation and the Administrator of the Environmental Protection
Agency to further assist airports as they attempt to balance their
operations and growth with the impact of their activities on the
environment. To further assist airports with these activities, the report
also includes related matters for congressional consideration.

As agreed with your office, unless you publicly announce its contents
earlier, we plan no further distribution of this report until 14 days after
the date of this letter. At that time, we will send copies to interested
Members of the Congress; the Honorable Rodney Slater, Secretary of
Transportation; the Honorable William S. Cohen, Secretary of Defense; the
Honorable Jane Garvey, Administrator, Federal Aviation Administration; the
Honorable Carol M. Browner, Administrator, Environmental Protection Agency;
and the Honorable Daniel Goldin, Administrator, National Aeronautics and
Space Administration.

Should you or your staff need further information, please contact me at
(202) 512-2834. Key contributors to this report are listed in appendix VI.

Sincerely yours,

Gerald L. Dillingham, Ph.D.
Associate Director, Transportation Issues

Executive Summary

Many of the nation's commercial service airports are operating at or near
capacity and are under increasing pressure to expand their operations to
accommodate the growing demand for domestic air travel--forecast by the
Federal Aviation Administration (FAA) to increase by 3.6 percent annually
through 2011. This growing demand has heightened concerns among some
communities, environmental groups, and others that airport operations may
have an increasingly detrimental effect on the environment. Recognizing this
concern, officials from almost all of the nation's busiest commercial
service airports have reported that balancing operations with their impact
on the environment is more difficult than it was a decade ago. For example,
actions to lessen environmental effects, such as performing required
environmental reviews and limiting flights to certain hours, have increased
the time and cost of development and have imposed restrictions on flight
patterns, airport use, and airport capacity. Representatives of airports,
communities, and federal and state regulatory agencies are striving to
balance these competing demands. Balancing these demands is particularly
relevant given that the Congress recently authorized nearly $10 billion for
airport infrastructure development--including associated environmental
concerns--over the next 3 years.

In light of the expected growth in domestic air travel and the current and
anticipated future environmental effects of airport operations, the Ranking
Democratic Member of the House Transportation and Infrastructure Committee
asked GAO to review (1) the key concerns and challenges associated with
airports' current operations and future growth--particularly concerns about
aircraft noise, water quality, and air pollutant emissions--and the actions
being taken by the nation's busiest airports to balance environmental
concerns with such operations and growth and (2) the actions taken by FAA
and other federal agencies to address environmental concerns associated with
airports' current operations and future growth.

Over the past several decades, federal laws and regulations have established
processes for federal agencies--primarily FAA and the Environmental
Protection Agency (EPA)--and states and local governmental entities to
manage the environmental impact of airport operations and growth. These laws
and regulations address environmental concerns about the noise generated by
aircraft operations, the impact on water quality associated largely with
stormwater runoff, including that from deicing/anti-icing and fueling
operations, and the impact on air quality of burning fossil fuels to operate
automobiles, airport service vehicles, and aircraft.

FAA works actively with airport officials to help them minimize the
environmental effects of expansion projects, including providing grants to
reduce the impact of noise on surrounding communities. In addition, the
agency is responsible for preparing documents to comply with the National
Environmental Policy Act (NEPA), which has three levels of review. These
levels are (1) environmental impact statements (the most detailed reviews),
which are required when projects have significant effects on the
environment; (2) environmental assessments, which provide sufficient
evidence and analysis to determine whether an environmental impact statement
or a finding of no significant environmental impact is warranted; and (3)
categorical exclusions, which allow projects to be excluded from further
environmental review providing there are no extraordinary circumstances. The
act sets forth a broad national policy aimed at protecting the quality of
the environment and requires that federal actions receive an environmental
review, the level of which depends on an action's potential impact on the
environment. EPA reviews environmental impact statements prepared by federal
agencies, including FAA. In addition, EPA oversees the implementation of the
Clean Air Act, as amended--which regulates the emission of air pollutants
from area, stationary, and mobile sources--and of the Clean Water Act--which
sets the basic structure for regulating discharges of pollutants to waters
of the United States. However, the day-to-day responsibility for overseeing
the implementation of the Clean Water and Clean Air acts is generally
delegated to the states. EPA has also encouraged voluntary measures to
reduce aviation emissions and has undertaken numerous regulatory actions,
such as setting standards for aircraft engine emissions. Other federal
agencies play more limited roles in assisting airport officials with
managing the environmental impact of airport operations.

GAO surveyed officials from the nation's 50 busiest commercial service
airports to obtain their views on the key environmental concerns and
challenges affecting airports' current operations and future growth and to
identify the efforts under way to address these concerns (see app. III for a
list of the airports). In addition, GAO visited 11 of these airports--which
represented a diverse group in terms of size, location, and environmental
issues--to obtain more in-depth information about their key environmental
concerns and their efforts to balance operations and growth with the impact
on the environment. GAO also interviewed a wide range of interested parties,
including federal, state, and local officials; representatives from aviation
industry groups; nongovernmental organizations; and citizens' groups to
obtain their views on these issues. See chapter 1 for GAO's objectives,
scope, and methodology.

As airports attempt to grow and balance their growth with its effects on the
environment, the primary environmental concern and challenge facing them now
and for the foreseeable future is noise, specifically noise generated by
aircraft operations. Airport officials' next greatest concern and challenge
is water quality--primarily the potential harmful effects of deicing and
anti-icing operations. Air quality is the third greatest concern and
challenge reported by airport officials, particularly managing the effects
on air quality of the increases in emissions due to airport growth. However,
a greater number of airport officials reported that in the future, air
quality issues will become a greater concern and challenge for them. Other
issues of concern cited by some airport officials were wetlands, endangered
species, environmental justice, and historical preservation. Airport
officials have undertaken a range of activities--either independently or in
cooperation with government and industry partners--to more effectively
balance airports' current operations and future growth with the
environmental impact of these activities. For example, they have established
airport/community groups to address environmental issues.

Coordination has occurred across the federal government to assist airport
officials in balancing airport operations and growth with the impact on the
environment. For example, FAA has developed and continues to refine models
to assess the impact on noise and air quality of proposed airport
development projects and has assisted state and local governments and
planning agencies with establishing land uses around airports that are
compatible with airport operations. Furthermore, many airport officials
reported that FAA is effective at providing assistance, including answering
their questions and addressing their concerns about environmental issues and
coordinating activities across the agency. Other federal agencies also
assist airports with their environmental responsibilities. For example, EPA
helps airports address water and air quality issues through regulatory,
voluntary, and research efforts, and the National Aeronautics and Space
Administration (NASA) assists them primarily through its research and
related technology development to reduce aircraft noise and the emission of
air pollutants. While federal coordination efforts have been undertaken,
GAO's review identified several areas in which airport officials and others
believe federal efforts could be improved--in particular, efforts within
FAA; between and among federal agencies, airports, and other governmental
entities; and federal law.

ï¿½ Many airport officials reported that at least some of their capacity
expansion projects (defined in GAO's survey as including taxiways and
terminals) did not require an environmental review (i.e., an environmental
impact statement, environmental assessment, or categorical exclusion).
However, under NEPA, airport projects are subject to various levels of
environmental review, depending on the degree of federal involvement and the
project's impact on the environment. FAA's policy implementing NEPA also
requires that FAA's approvals of airport layout plans and funding for
airport development projects receive such reviews, and FAA headquarters
officials maintain that all such reviews are taking place. Nevertheless, the
responses of airport officials suggest that there is a lack of understanding
about when environmental reviews are required. Furthermore, because FAA does
not require that all projects that are categorically excluded from further
environmental reviews be specifically documented when there is no FAA
funding approval, the agency lacks systematic documentation and
communication for all categorical exclusion reviews.

ï¿½ Many airport officials told us that EPA's Clean Air Act guidance is
inadequate because it does not clearly communicate airports'
responsibilities and that some EPA and FAA officials in the regions lack
experience in providing technical assistance to airports. Some EPA and FAA
officials acknowledged the need to clarify guidance on air quality
analytical requirements for airports and attributed the lack of experience
to the infrequency of detailed air quality analyses required for airports by
the act. As a result, many airport officials remain unsure of the level of
analyses required to meet their responsibilities. Furthermore, officials
from airports, FAA, and EPA told GAO that EPA's current guidance offers
disincentives for airports to voluntarily reduce air pollution.

ï¿½ Some overlap exists among federal, state, and local environmental review
processes that can lead to difficulties in coordination and result in
duplication of effort and delays in airport projects. Both headquarters and
regional officials from the Army Corps of Engineers said that overlapping
permit requirements for wetlands is a problem in some states. For example,
according to an official from one airport GAO visited, the airport has had
to negotiate permits for destroying the same wetlands with three different
agencies.

ï¿½ Communities that surround 14 of the nation's 50 busiest commercial service
airports and are adversely affected by aircraft noise do not have access to
federal funds specifically set aside for noise mitigation because these
airports choose not to participate in FAA's noise compatibility program
(known as Part 150). Although funding is available from other federal
programs and from fees collected from passengers by airports, the federal
law governing the noise compatibility program requires airports to
participate in order to receive its grant funds. The neighboring communities
of participating airports benefit from activities funded by the program,
such as acquiring homes or soundproofing residences and other buildings as
well as other efforts to reduce land uses that are not compatible with
airport operations. Second, the Clean Air Act and another federal law
pertaining to airport improvement include somewhat duplicative air quality
requirements that can burden airports in some areas.

The report contains recommendations for improving the federal approach to
assisting airports in balancing their operations and growth with their
environmental responsibilities.

and Challenges for Airports

Noise: In GAO's survey of the nation's 50 busiest commercial service
airports, officials from 29 airports ranked the noise associated with
airport operations as their number one concern associated with reducing the
environmental impact of current airport operations on surrounding
communities. The greatest noise-related challenges reported by airport
officials in our survey are (1) the noise levels generated by older aircraft
that have been modified to meet today's more stringent noise standards but
are still loud compared with new aircraft, (2) the airports' limited control
over nearby land uses, and (3) the growing residential populations near
airports. To address these challenges, airport officials--in coordination
with the aviation industry--have undertaken a variety of measures to reduce
the impact of aircraft noise on neighboring communities. These measures
include establishing preferred flight paths away from residential
neighborhoods, designating locations where pilots test aircraft engines
prior to take-off, and preferential use of certain runways.

Water and air quality: Officials from the nation's 50 busiest commercial
service airports also reported that water and air quality issues are
currently concerns for them. According to GAO's survey, officials from 12
airports cited water quality issues as their primary concern. In addition,
the survey and interviews with a range of interested parties found that the
primary challenge for airport officials in the area of water quality is the
management of runoff from deicing/anti-icing operations and spills from
fueling operations. Airport and airline officials work cooperatively to
address this challenge, in some cases by sharing responsibility for
establishing systems to collect and dispose of the runoff. Although
officials from only 6 airports identified air quality as the issue that
currently concerns them the most, when asked about future concerns,
officials from 16 airports said that air quality would likely become their
most significant environmental concern. The air quality challenges most
frequently cited by airport officials include an increasing demand for
parking that could lead to greater congestion and emissions around airports
and uncertainty about the conditions that airport projects must meet to
comply with the Clean Air Act. To help meet these challenges, some airports
are expanding their use of remote shuttle pickup sites for passengers to
reduce the demand for parking and, hence, reduce emissions at the airports.
In addition, some airports and their tenants--including airlines--are
increasing their use of alternative-fuel vehicles to reduce emissions
generated by the airport vehicles that support aircraft operations and
provide access to the airports.

Remain

GAO found that while there has been some coordination of federal agencies'
efforts to address environmental issues associated with airport operations
and growth, the resolution of several remaining concerns could improve the
federal approach.

Federal coordination efforts: Several federal agencies have successfully
coordinated some efforts to address environmental concerns. For example, the
Federal Interagency Committee on Noise reconfirmed a common federal standard
for measuring aircraft noise--concluding that there were no other
measurement methods of sufficient scientific standing to replace this
method. Second, EPA and FAA are working cooperatively with the aviation
industry and other interested parties to develop voluntary reduction goals
for the emission of air pollutants, which could lead to an emission
reduction agreement by the end of 2000. Furthermore, FAA, EPA, and NASA have
undertaken both cooperative and independent efforts to assist airports in
balancing their operations and growth with the environmental impact of their
activities. For example, FAA and NASA are partners in aviation noise
reduction research, and FAA uses NASA's scientific and technological
knowledge to regulate aircraft noise. Similarly, EPA and FAA work together
to help ensure that airport expansion projects meet environmental
requirements. In addition, an FAA official serves as the U.S. representative
to the International Civil Aviation Organization, which is responsible for
setting international aircraft noise and emissions standards. EPA also
participates in this organization and its environmental committee and
working groups. Furthermore, EPA has studied airport deicing operations to
determine whether additional regulation is needed to address water-related
environmental issues at airports.

In addition, most of the officials at the 50 airports responding to GAO's
survey reported a high level of satisfaction with FAA's assistance on
environmental issues. For example, officials from 32 of the 50 airports
reported that they were satisfied with the way FAA answered their questions
and addressed their concerns on such issues. Over half of the airport
officials also reported that FAA was effective in coordinating activities
among its offices, providing standard rules and guidance, and processing
paperwork. However, airport officials reported that FAA was less effective
at coordinating with state agencies--an issue that may reflect overlapping
state and federal environmental requirements.

Misunderstandings about environmental reviews: Many airport officials
reported that at least some of their capacity expansion projects (defined in
the survey as including taxiways and terminals) did not require an
environmental review (i.e., an environmental impact statement, environmental
assessment, or categorical exclusion). Specifically, officials from 10 of
the 50 airports reported that, over the past 10 years, half or fewer of
their capacity expansion projects did not require environmental reviews, and
officials from another 13 airports reported that at least some of their
airport capacity expansion projects did not require such reviews. However,
under NEPA, airport projects are subject to various levels of environmental
review, depending on the degree of federal involvement and the project's
impact on the environment. FAA's policy implementing NEPA also requires that
FAA's approvals of airport layout plans and funding for airport development
projects receive such reviews.

FAA headquarters officials confirmed that FAA's policy requires that all
airport capacity expansion projects receive an environmental review and
maintained that all such reviews are taking place. The responses of airport
officials suggest that there is a lack of understanding about when
environmental reviews are required. Furthermore, categorical exclusions are
not required to be documented under the NEPA regulations issued by the
Council on Environmental Quality, and FAA's policy also does not require
that all projects that are categorically excluded be documented. Without
documentation, when no FAA funding approval is involved, a reliable
determination cannot be made about whether categorical exclusion reviews are
taking place.

Guidance and coordination lacking for Clean Air Act: Many airport officials
told GAO that they are having difficulty understanding their
responsibilities under the Clean Air Act for conducting reviews for projects
that expand airport capacity, in part because of insufficient guidance and
technical assistance. Specifically, 22 of the nation's 50 busiest commercial
service airports reported that uncertainty about complying with the act's
requirements was a major concern for them. Because EPA's Clean Air Act
regulations group airports together with very different sectors--such as ski
resorts and coal mines--the regulations are general and do not clearly
specify how the act applies to airports. Although federal guidance and
technical assistance on these matters are available to airports, airport
officials are still confused about their responsibilities. While EPA told
GAO that the agency has undertaken efforts to improve the conformity rules
and guidance in the past, these efforts have been delayed because of
resource constraints. In addition, EPA officials maintain that airports have
a responsibility to communicate with local, regional, state, and federal
officials about air quality and other environmental issues. FAA, EPA, and
airport officials said that another factor contributing to the airport
officials' confusion is a lack of experience among some FAA and EPA regional
staff with applying the act's requirements to airport projects. As a result,
airport officials may not comply with the act's requirements in some
instances and may do more analysis than is needed in other instances.
Furthermore, EPA has not set up a process for providing "credits" to
airports for some of their voluntary efforts to reduce air pollution that
they can bank or sell--thereby discouraging airport sponsors from
undertaking efforts to reduce the emission of air pollutants.

Difficulties in federal, state, and local coordination persist: Although
efforts have been undertaken to coordinate federal, state, and local
environmental review processes for airports, difficulties
persist--frustrating FAA and airport officials and, in some cases, resulting
in duplication of effort. According to airport and FAA officials, if these
efforts are not properly coordinated, this type of duplication can delay
airport projects without adding commensurate environmental benefits.

Provisions in a federal law limit the eligibility of some airports and
communities to receive federal noise funds and create somewhat duplicative
air quality requirements: As part of its voluntary Part 150 noise
compatibility program, FAA provides noise mitigation funds to assist local
communities through grants to airports that participate in the program. Such
assistance includes soundproofing residences and other strategies. Many
airports have chosen to participate in the program, which has made billions
of dollars available to reduce the impact of noise around airports, thereby
helping to improve community relations. However, 14 of the nation's 50
busiest commercial service airports, accounting for about one quarter of all
air carrier operations in 1998, do not participate. Under federal law, FAA
can only provide funds from its Part 150 program to assist a community with
noise mitigation if the airport there is participating. Consequently, the
more than 320,000 people living near those 14 nonparticipating airports
cannot benefit from the Part 150 program. (The program is only one of a
number of ways airports can fund noise mitigation efforts, however.) A
change in the law could allow communities to directly access Part 150 funds
even if their local airports do not participate in the program, under rules
and restrictions similar to those that are placed on participating airports.
FAA has twice proposed legislation that, among other things, would extend
funding directly to communities in some cases; however, the proposals were
not adopted.

Furthermore, federal laws include somewhat duplicative air quality processes
that can place burdens on airports in some states. Federal law requires the
governor of each state to certify that federally funded airport runway
additions conform to local air quality standards--called state air quality
certification.1 Similarly, the Clean Air Act requires the federal agency--in
this case, FAA--to determine that emissions from airport projects conform to
a state's plan to implement national air quality standards. This sometimes
requires airport officials to demonstrate compliance with air quality
requirements twice. In addition, FAA officials and representatives of a
working group of airports told us that they have recommended the elimination
of the state air quality certification requirement because it overlaps with
the Clean Air Act. Even without the state air quality certification process,
states will retain the right to implement more stringent air quality
standards under the Clean Air Act.

To provide systematic documentation that categorical exclusions are taking
place as required for airport development projects and that airport
officials are aware of all FAA environmental reviews, GAO recommends that
the Secretary of Transportation direct the Administrator of FAA to
communicate to airport officials the requirements for environmental reviews
for airport expansion projects and that the results of all categorical
exclusion reviews be systematically documented by FAA and communicated to
airport officials.

To help airports meet their responsibilities under the Clean Air Act, GAO
recommends that the Administrator of EPA, in coordination with FAA and
airport officials, (1) clarify the guidance in areas such as general
conformity determinations and guidelines for states to provide airports with
credits for voluntary emission reduction efforts and (2) provide airport
officials with the necessary expertise to meet air quality requirements.

Because 14 of the 50 busiest commercial service airports do not participate
in FAA's noise compatibility program and, thus, the people who live in
communities surrounding these airports who are affected by aircraft noise
are not eligible to receive funds from this program (under 49 U.S.C. 47104
and 48103), the Congress may wish to consider the impact of this restriction
on the affected communities. In addition, because the state air quality
certification requirement (49 U.S.C. 47106 (c)(1)(B)) is somewhat
duplicative and may impede some airports as they attempt to grow and
implement their environmental responsibilities, the Congress may wish to
consider eliminating this requirement.

GAO provided the Department of Transportation; the Department of Defense;
NASA; EPA; and an advisory panel that included the Air Transport Association
of America, Inc., Airports Council International-North America, Frederic R.
Harris, Inc., and the Natural Resources Defense Council with copies of the
draft report for their review and comment.

GAO met with officials from the Department of Transportation, including
FAA's Director, Office of Airport Planning and Programming. These officials
generally agreed with the facts in the report and provided clarifying
comments, which were incorporated as appropriate.

The Department of Defense and NASA concurred with the report. NASA offered
clarifying comments, which were incorporated as appropriate. NASA's and the
Department of Defense's written comments appear in appendixes IV and V.

GAO met with senior officials from EPA's Office of Enforcement and
Compliance Assurance and the Office of Air and Radiation, including the
Senior Scientist/Policy Adviser for the Office of Air and Radiation. These
officials generally agreed with the facts in the report and provided
technical and clarifying comments, which were incorporated, as appropriate.

The advisory panel of experts--with the exception of the Natural Resources
Defense Council--generally agreed with the contents of the report and
provided technical and clarifying comments which were incorporated, as
appropriate. The Natural Resources Defense Council provided no comments.

Introduction

Airports are subject to many federal, state, and local regulations designed
to protect the environment. Among other things, these laws regulate the
environmental impact of such airport operations as expansions of airport
infrastructure, emissions of air pollutants, discharges of chemicals into
surrounding water bodies, and noise from aircraft. These various federal
environmental laws give primary environmental oversight authority to the
Federal Aviation Administration (FAA) and the Environmental Protection
Agency (EPA). These agencies set policy at the national level but leave the
day-to-day implementation to their regional offices. EPA can also delegate
some authority to the states. In addition, airports can be regulated by
local entities.

Airports

The National Environmental Policy Act of 1969 (NEPA) sets forth a broad
national policy intended to protect the quality of the environment.
Depending on the level of federal involvement and the potential impact on
the environment, NEPA requires that federal actions, including airport
expansion projects, receive an environmental review. Specifically, NEPA
procedures are meant to ensure that environmental matters are considered for
federal actions, and for certain reviews there is an opportunity for public
officials and citizens to comment on proposed projects before federal
decisions are made and actions are taken. For airport projects, FAA is the
lead agency responsible for administering the law. FAA must approve all
airport expansion projects.2 Initiating an expansion project generally
constitutes a federal action that triggers an environmental review under
NEPA. (See fig. 1.) EPA reviews environmental impact statements prepared by
FAA and other federal agencies.

The Noise Control Act3 assigned responsibility to the Administrator, EPA,
for coordinating the programs of all federal agencies relating to noise
research and noise control, including the impact of noise from aircraft.
Although the Administrator still has responsibility for coordinating these
programs, EPA has not received funding specifically for them since 1982. In
1979, the Aviation Safety and Noise Abatement Act was enacted to help
airport operators develop noise mitigation programs. The act authorized FAA
to assist airport operators in developing programs to reduce the level of
aircraft noise and mitigate its impact on surrounding communities. In
addition, the Airport Noise and Capacity Act of 1990 authorized the
Secretary of Transportation to reduce aircraft engine noise through a
program to phase out noisier aircraft.4 The law also limited airport
operators' abilities to place noise or access restrictions on airports in
the interest of avoiding an overly burdensome patchwork of individual
operational limitations across the United States.

The Clean Water Act,5 as amended, addresses the release of pollutants to
surface waters, such as lakes, rivers, streams, and wetlands. It governs
direct discharges of pollutants released into navigable waters. Airports can
potentially affect water quality through activities such as
deicing/anti-icing, as well as aircraft and vehicle fueling and maintenance.
The Clean Water Act established the National Pollutant Discharge Elimination
System, a permit program that controls discharges of pollutants from point
sources, such as pipes and drainage ditches at airports, including some
categories of stormwater discharges. EPA, as the responsible agency, can
delegate authority to the states to administer their own National Pollutant
Discharge Elimination System permit programs. In addition, section 404 of
the Clean Water Act establishes another major permit program applicable to
airport projects that governs discharges of dredged and fill material into
wetlands and other waters. The act also addresses the reporting of oil and
hazardous substance spills, the disposal of dredge materials, and the
establishment of enforcement programs.

The Clean Air Act, as amended, was designed to protect and enhance the
nation's air quality to promote public health and welfare. For aircraft or
aircraft engine emissions, the act gives jurisdiction to EPA in consultation
with FAA. EPA and FAA have implemented international standards for
commercial jet aircraft emissions established by the International Civil
Aviation Organization (ICAO). Enforcing and monitoring compliance with these
standards are responsibilities of FAA6--implemented, in part, through the
agency's process for certifying that aircraft engines meet air pollutant
emissions standards.

The act and its amendments direct EPA to establish national standards for
ambient air quality.7 In turn, states can adopt these or more stringent air
quality standards; however, EPA's responsibility is limited to ensuring that
the national ambient air quality standards are met. EPA has set such
standards for carbon monoxide, lead, nitrogen dioxide, particulate matter,
ozone, and sulfur dioxide--all of which are pollutants directly or
indirectly generated by airport activities.

Implementing Environmental Laws at Airports

Other than setting national emissions standards for aircraft engines, FAA
and EPA--which play significant roles in managing the environmental impact
of airport operations--have taken a decentralized approach to their
responsibilities. While each agency has a national-level policy-setting or
oversight office, much of the day-to-day environmental work with airports
occurs through each agency's regional offices or FAA's district offices. EPA
relies on regional staff or the states to oversee FAA's and airports'
compliance with environmental laws and regulations.

Three principal FAA headquarters offices deal with the environmental impact
of airport operations. The Office of Airport Planning and Programming,
Community and Environmental Needs Division, is responsible for airport
program matters pertaining to environmental and social requirements, while
the Office of Environment and Energy develops, recommends, and coordinates
national aviation policy relating to environmental matters and develops and
maintains computer models for aircraft noise and air quality analyses. In
addition, the Office of Air Traffic Airspace Management within Air Traffic
Services, Air Traffic Environmental Programs Division, has assumed a major
role in the agency's efforts to address environmental issues associated with
changes in air traffic procedures and flight patterns near airports and
establishes policies and procedures for air traffic environmental actions.

Although EPA has been regulating airport environmental issues for many
years, the aviation sector presents challenges for the agency because it
requires the unified implementation of environmental laws. On the national
level, the EPA offices that are primarily involved in airport environmental
issues include the Office of Air and Radiation, the Office of Water, and the
Office of Federal Activities. The Office of Air and Radiation implements
national programs, technical policies, and regulations for controlling air
quality. Within this office, the Office of Transportation and Air Quality is
responsible for developing national emissions standards for aircraft and
ground support equipment and other motor vehicles operating on airport
grounds. This office also participates in a number of airport-specific
initiatives, including research on toxic substances in the air and efforts
to set emissions standards for aircraft engines through ICAO. Both the
Office of Transportation and Air Quality and the Office of Air Quality
Planning and Standards are responsible for overseeing the implementation of
the Clean Air Act. For airports, the Office of Transportation and Air
Quality generally has primary responsibility for emissions from aircraft,
vehicles, and other mobile equipment, while the Office of Air Quality
Planning and Standards is responsible for other emissions and for ensuring
that airport projects conform with states' plans to comply with the Clean
Air Act. EPA's Office of Water regulates point source discharges8 from
airports by requiring airport operators, and in some cases airport tenants,
to obtain National Pollutant Discharge Elimination System permits. Finally,
the Office of Federal Activities reviews the sufficiency of all
environmental impact statements associated with airport projects. Although
these various headquarters offices have oversight of these environmental
issues, much of EPA's direct interaction with FAA and airports occurs in the
regions. In addition, the states are primarily responsible for implementing
the Clean Air and the Clean Water acts' requirements.

The nation's 50 busiest commercial service airports all interact with FAA
and EPA on environmental issues; however, several other federal agencies
have a direct, though narrower, role in airport environmental issues. For
example, the Council on Environmental Quality--which sets the regulations
for implementing NEPA9--has responsibility for mediating interagency
disputes, the National Aeronautics and Space Administration conducts
research on aircraft noise and emissions, the Department of Energy supports
the use of alternative-fuel vehicles at airports, and the Department of
Defense--specifically, the Army Corps of Engineers--issues permits when
airport projects have an impact on wetlands. Other agencies, including the
Department of the Interior's Fish and Wildlife Service and the Advisory
Council on Historic Preservation, also participate in civil airport
environmental issues and processes. In addition, like FAA and EPA, some of
these agencies rely on regional or field staff to help ensure compliance
with laws under their jurisdiction. State and local agencies also play a
significant role, especially when certain responsibilities have been
delegated to states, such as the responsibility for achieving clean air
goals or ensuring compliance with water quality standards.

Airport sponsors10 and FAA are responsible for systematically considering
environmental issues in a timely manner when evaluating proposed airport
planning and development activities and for involving local and state
officials and individuals with appropriate expertise. Airport officials are
responsible for managing environmental impacts as trustees for the land at
airports. Specifically, airport officials are responsible for identifying
needs, developing conceptual alternatives, and other airport actions as
required by various laws and regulations. FAA is responsible for preparing
environmental reviews under NEPA. EPA also plays a role when airport
expansion projects require an environmental impact statement, given its
authority to offer comments on these documents to federal agencies,
including FAA.

Airports do not have full control over the environmental effects of their
activities because multiple parties contribute to these effects. Our survey
of the nation's 50 busiest commercial service airports found that airports
were concerned about their inability to control various environmental
impacts. For example, while airports are responsible for developing flight
paths, FAA is responsible for approving, implementing, and enforcing the
accepted flight paths, and airlines manage the number and frequency of
flight operations.11 Hence, the noise generated by these activities is
largely outside the control of airport operators. According to FAA and
airlines, in the interest of flight safety, airlines and FAA tower operators
cannot always follow preferred flight paths and other procedures intended to
reduce the impact of noise on surrounding communities.12 However, the
responsibility for managing the environmental impact of aircraft operations
is shared among airports, airlines, and FAA. In addition, local government
entities control zoning and, in turn, the degree to which land uses near
airports are compatible with airport operations. Lack of control over water
quality is also a concern for airport officials. For example, while airlines
apply deicing chemicals to their aircraft, airport operators are ultimately
responsible for managing the wastewater generated by these activities.

In view of the growing demand for domestic air travel and the current and
future environmental effects of airport operations and growth, the Ranking
Democratic Member of the House Committee on Transportation and
Infrastructure asked us to provide information on (1) the key concerns and
challenges associated with airports' current operations and future
growth--particularly concerns about noise, water pollution, and air
pollutant emissions--and the actions being taken by the nation's busiest
airports to balance environmental concerns with such operations and growth
and (2) the actions taken by FAA and other federal agencies to address
environmental concerns associated with airports' current operations and
future growth. As requested, we are also providing information about similar
concerns in Europe (see app. II).

Our review focused on the impact of noise, water pollution, and air
pollutant emissions associated with airports' current operations and future
growth, as requested. We focused on the nation's 50 busiest commercial
service airports because they are central to the efficiency of the National
Airspace System. While we recognize that other environmental effects are
associated with airports, they were not the focus of our review.

To address the first objective, we interviewed and collected material from
federal officials at FAA, the Department of Defense, EPA, the National
Aeronautics and Space Administration, and the Department of Energy. We also
interviewed and collected material from representatives of the Aerospace
Industries Association, the Airports Council International-North America,
the Air Transport Association of America, Inc., and the National Association
of State Aviation Officials. In addition, we interviewed officials from
airports, state and local governments, nongovernmental organizations,
airlines, and citizen/community groups.

We conducted computer literature searches to identify the environmental
effects of airport operations. Our searches covered several bibliographic
databases and included the following key words and phrases: airport/aviation
and pollution, airport/aviation and environment, and airport/aviation and
wetlands.13 Our searches identified about 250 studies and articles. Of
these, we selected approximately 20 that were most relevant to our work and
discussed in detail the environmental effects of airport operations.

To obtain the views of airport officials on key environmental concerns and
challenges that significantly affect airports' current operations and future
growth and to determine the efforts under way to address these concerns, we
conducted a mail survey from October 1999 through February 2000 of the 50
busiest commercial service airports in the United States. In selecting the
airports for our survey, we used the number of air carrier operations for
1998 as reported by FAA. The top 50 airports accounted for 80 percent of all
air carrier operations in 1998. To design our survey, we conducted in-person
pretests at four airports. In addition, we conducted on-site interviews at
seven other airports, covering the topics in the survey. These visits and
our interviews with industry and federal officials assured us that the key
environmental issues for airport management are noise, water pollution, and
air pollutant emissions. During the four pretesting visits, we observed
airport officials filling out our survey questionnaire. In addition, we
discussed the survey questions and answers with them to ensure that (1) the
questions were understandable, (2) the terms used were clear, (3) the survey
did not place an undue burden on airport staff that would result in a lack
of cooperation, and (4) the survey appeared independent and unbiased in its
point of view. Appropriate changes based on our pretesting were incorporated
into the final survey. The survey topics included the opinions of airport
executives on environmental concerns, information about the 50 busiest
commercial service airports' operations, and airport officials' experiences
with various approaches to environmental issues. The survey confirmed that
noise, water pollution, and air pollutant emissions are the major concerns
and challenges facing these airports. See Aviation and the Environment:
Results From a Survey of the Nation's 50 Busiest Commercial Service Airports
(GAO/RCED-00-222) for the survey document and additional analysis. We
consulted with FAA to select the most appropriate official at each airport
to answer our questions. We received completed surveys from all 50 airports.

During our visits to 11 of the nation's 50 busiest commercial service
airports mentioned above, we also obtained more in-depth information on the
types of environmental activities that these airports were undertaking and
observed their implementation, where practical. In deciding which airports
to visit, we attempted to select a diverse group on the basis of size,
location, and environmental issues. We interviewed airport officials and
obtained supporting documentation from them to supplement the survey, as
necessary.

To address the second objective, we relied on interviews and documents from
the previously cited individuals and organizations, as well as visits to
selected airports. We also used the survey to solicit airport officials'
views on the federal effort to assist airports in balancing operations and
growth with environmental impacts.

During the review, the following environmental and aviation experts reviewed
our methods and report drafts for accuracy and balance: William Fife of
Frederic R. Harris, Inc. (New York); Scott Belcher of the Air Transport
Association of America, Inc. (Washington, D.C.); Richard Kassel of the
Natural Resources Defense Council (New York); and Richard Marchi of the
Airports Council International-North America (Washington, D.C.).

We conducted our review from July 1999 through August 2000 in accordance
with generally accepted government auditing standards.

Noise Issues Are the Primary Environmental Concern and Challenge for
Airports

Noise is primarily generated at airports by arriving and departing aircraft,
and the noise from aircraft engines is the most significant environmental
concern facing airports now and in the future. The most frequently cited
challenge was addressing the noise generated by older aircraft that have
been modified but are still loud--even though they are in compliance with
current standards they are louder than new aircraft. Airport officials' next
two most significant challenges involve local zoning--which can lead to land
uses that are incompatible with airport operations and the related issue of
increasing residential populations near airports. Airports and airlines have
implemented a range of noise mitigation strategies to help reduce the impact
of aircraft noise on surrounding communities, but some citizens and local
officials do not believe that their concerns about aircraft noise are being
adequately addressed.

Challenge

According to our survey of officials from the nation's 50 busiest commercial
service airports,14 noise issues currently represent the most significant
concern for 29 of these airports. Figure 2 shows how airport officials
responded to the question in our survey about the environmental issue that
was the greatest concern for their airport.

Source: GAO's survey of the nation's 50 busiest commercial service airports.

In addition, officials from 22 of the airports surveyed reported that noise
would remain their biggest challenge in the future--primarily because of the
expected increase in operations. FAA and EPA officials, as well as some
citizen/community groups, concurred that noise issues are currently the most
serious environmental problem facing airports.

Concern

Among the noise issues reported by airport officials, the most frequently
cited major or moderate concern--by 41 of the 50--was the loudness of
aircraft with engines that have hushkits15 or other modifications to comply
with Stage 3 noise standards. Although these aircraft are in compliance with
current standards, they are still louder than new aircraft in the same
weight range. Federal law required the phaseout of older, noisier
aircraft--known as Stage 2--by December 31, 1999.16 Aircraft owners could
retire these aircraft or modify them to meet the new noise standards.
Representatives of airports, aviation industry associations, an association
of local officials, and EPA told us that Stage 2 aircraft that have been
modified to meet noise standards for Stage 3 are louder than many of the
more recently built aircraft. Although hushkits make older aircraft quieter
than they would be without hushkits, an FAA official responsible for
technology issues related to aircraft noise told us that hushkitted aircraft
are still louder than new aircraft in the same weight range that meet Stage
3 requirements without modification. Furthermore, an airport industry
representative stated that aircraft built to meet Stage 3 standards are
significantly quieter on departure than aircraft that have been modified to
meet Stage 3 standards.

Airline officials told us they are also concerned about noise issues and
take them very seriously. However, those officials said the cost of
purchasing new aircraft, among other factors, prohibits them from replacing
their fleets as the only means of meeting the current noise standards. For
example, one airline industry representative told us that an aircraft has a
life span of about 30 years and an airline takes about 22 years to pay for
the aircraft. Therefore, a more economically feasible alternative to
purchasing new aircraft is to fit older aircraft with hushkits.
Additionally, according to aviation industry representatives, modifications
to aircraft to reduce noise may add to the weight of an aircraft, and, in
turn, cause it to burn more fuel--resulting in higher pollutant emissions.

Challenge

The primary responsibility for integrating airport considerations into local
land-use planning rests with local governments--presenting a difficult
problem for many airports, because they cannot control development in
surrounding communities. However, airports are held accountable by these
communities when airport noise adversely affects uses such as schools and
residences built close to airports. Using a federally agreed upon method,
FAA set the standard that airports use to measure the level of noise to
which communities around airports are exposed over time and has issued
guidelines that identify land uses that would and would not be compatible
with the noise generated by a nearby airport's operations. The agency
considers land uses such as homes and schools to be incompatible with the
high noise levels that occur very close to an airport, while noting that
other uses, such as industrial and commercial uses, could successfully be
located close to an airport without interfering with their activities.17
(See fig. 3.)

Perceptions of noise can vary from individual to individual. For instance,
Denver International Airport receives one of the highest numbers of noise
complaints in the country, although it is not close to any residential
communities. However, in many cases, individuals submitting complaints were
not exposed to aircraft noise before the Denver International Airport opened
in 1995. Similarly, FAA reports that in recent years, complaints have come
from populations exposed to comparatively low levels of noise, sometimes
miles from an airport. Our survey results were consistent with these
reports, with officials from 35 airports reporting that over half of their
noise complaints during the last year came from people living in areas where
aircraft noise falls below the level FAA considers incompatible with
residential uses. However, officials from 47 airports reported that
increasing populations in nearby areas pose a concern.

Strong pressure exists to develop residential areas around heavily used
airports, particularly in metropolitan areas with more than 50,000
people--areas where all of the 50 busiest commercial service airports are
located. Officials from 22 of the 50 airports that we surveyed cited
airports' limited control over local zoning as a major concern. A
representative of a leading environmental organization told us that better
dialogue is needed with communities to improve land-use choices and reduce
the potential for incompatible land uses in the future. EPA agrees that
noise problems at the local level are the result of incompatible land-use
planning around airports. Although FAA has no control over zoning, the
agency has undertaken an initiative to provide information to state and
local governments for their use in controlling and preventing incompatible
land uses near airports. Officials from airports, EPA, and FAA agree that a
compatible land-use policy is one of the best noise mitigation techniques
that can be used to minimize the impact of aircraft noise on surrounding
communities. This is particularly important for future airport expansions,
because land-use decisions that conflict with aviation activity and airport
facilities can make it difficult for airports to grow to meet the increasing
demand for air travel.

Future

Increasing residential populations near airports present challenges for
airports when planning expansion projects to meet the growing demand for air
travel. Our survey found that officials from 13 of the nation's 50 busiest
commercial service airports view increases in residential populations near
their airport as a major concern. In addition, officials from 10 airports
reported that the populations within these airports' 65-decibel day-night
level (65 dB DNL) noise contours18 have moderately increased over the past 5
years, and officials from many other airports reported that these
populations were remaining stable. However, FAA reports that the number of
people exposed to significant noise levels (65 dB DNL and above) has dropped
over 75 percent--from 7 million in 1975 to 1.7 million in 1995--mainly
because louder aircraft have been phased out. FAA used what it considers to
be a substantially credible model to project that the number of people
exposed to airport noise at 65 db DNL will fall from 862,000 in 1998 to
below 470,000 by the end of 2000. Despite this drop in the affected
populations, as measured by a federally accepted definition of significant
noise levels, EPA officials expressed concern that the impact of noise on
populations is not being adequately captured. EPA officials told us that the
DNL measure alone does not adequately capture the impact of aircraft noise
on people and could be supplemented to more fully account for the impact of
single loud noises. However, FAA officials noted that this issue was
addressed in a report of the Federal Interagency Committee on Noise, which
supported the use of the DNL measure, and reported that other noise metrics
simply provided additional information and could be used at a federal
agency's discretion.

Although nearly half of the nation's 50 busiest commercial service airports
reported that, compared with 5 years ago, fewer people live within their 65
dB DNL contours, the balance of these airports reported that the populations
within these contours have remained stable or have moderately increased over
the past 5 years. At the 50 airports we surveyed, 45 had noise statistics
available. Using these statistics, we conservatively estimated that
approximately 675,000 people live in areas with airport noise levels of 65
dB DNL or greater. Therefore, the number of people affected may be somewhat
greater than FAA has estimated. However, our estimate and FAA's are not
directly comparable because our population statistics are for different
years.19

A representative for state aviation officials expressed concern that as
quieter aircraft have been phased in, the boundaries of airport noise
contours have shrunk and people have moved into these areas that were
previously impacted by noise. However, in the future, as the number of
aircraft operations increases, the areas impacted by noise may expand again
at some airports, despite quieter aircraft--making this new residential
development incompatible with airport operations. These increasing
populations pose challenges for airports in their relations with surrounding
communities.

Aircraft Noise, but Community Concerns Persist

Most of the 50 busiest commercial service airports we surveyed have
implemented a range of strategies to help reduce the impact of aircraft
noise on surrounding communities--including both voluntary and mandatory
measures. The three activities most often encouraged or required by airports
include (1) restrictions or limitations on engine testing prior to take-off,
(2) the use of certain flight paths, and (3) limits on the use of certain
runways.20 Airport officials also reported that they use other mechanisms to
reduce the impact of aircraft noise, including reduced engine taxiing,
limits or bans on certain types of aircraft during certain hours,21 and
aircraft towing rather than taxiing. (See fig. 4.)

Source: GAO's survey of the nation's 50 busiest commercial service airports.

Airports also reduce the impact of noise on surrounding communities by
undertaking land-use mitigation measures, including acquiring
noise-sensitive properties, relocating people, modifying structures to
reduce noise, encouraging compatible zoning, and assisting in the sale of
affected properties.

FAA supports airports' efforts to mitigate aircraft noise through its
voluntary noise compatibility program--known as the Part 150 Noise
Compatibility Program--and has developed guidance for local governments and
other interested parties to encourage compatible land uses near airports.
Over 200 airports have undertaken comprehensive airport noise compatibility
planning and used federal funding under FAA's airport grant program to
implement noise mitigation projects. Airport operators also fund noise
mitigation related to new development, such as new runways. Airports can use
airport grant funds, passenger facility charges,22 and airport revenue to
mitigate the impact of noise from airport developments and operations.

In addition to these efforts, most airports have voluntarily established
some type of noise monitoring system--the more sophisticated of which allow
airport officials to combine data from flight operations with specific
"noise events" to identify the responsible aircraft. For example, officials
from 47 airports reported that their airport monitors noise occasionally,
and over half of those surveyed reported that they monitor noise daily or
more often. (See fig. 5.) Officials from one airport reported that they do
not monitor aircraft noise, and two others are in the process of installing
noise-monitoring systems.

Source: GAO's survey of the nation's 50 busiest commercial service airports.

Some airports have dedicated staff or created offices to operate these
noise-monitoring systems and, in some cases, to oversee noise abatement
activities. For example, the Noise Abatement Unit for Boston's Logan
International Airport serves as a liaison between the community and FAA's
control tower. Airport officials told us that this office suggests flight
patterns and/or operational procedures to the air traffic control tower in
an effort to reduce the effects of noise on nearby communities. In addition,
the office receives and processes complaints 24 hours a day, 7 days a week.
Other airports reported having similar activities in place.

Another mechanism employed by officials at some airports to address aircraft
noise issues is public outreach and education. For example, the San
Francisco International Airport created the San Francisco Airport Roundtable
in 1981--a voluntary body that includes representatives from 13 Bay Area
jurisdictions, FAA officials, airline advisors, air traffic managers, and
the airport director--to discuss and attempt to resolve primarily
noise-related issues. Similarly, Fort Lauderdale International Airport
officials told us that an ad hoc committee comprising neighborhood,
community, and aviation industry representatives was formalized in 1992 to
address residents' concerns about the airport's noise. (See app. I.) Similar
airport/community noise groups have been established at other airports,
including the Minneapolis/St. Paul International Airport, the Oakland
International Airport, and Chicago's O'Hare Internatioanl Airport.

Lack of control over air traffic operations was cited by half of the airport
officials surveyed as a major or moderate concern when addressing noise
issues. An airport industry representative stressed that U.S. airports
cannot control the frequency and type of aircraft that use their facilities
and that airports are not able to control the amount of noise that aircraft
generate.

FAA and the Department of Transportation have reported that with the recent
completion of the Stage 3 phase-in, additional noise mitigation techniques
will have to be undertaken locally by airports until more can be done to
reduce aircraft noise in the future. Options might include changing the
operating characteristics for an airport, such as the landing and take-off
corridors and preferential runway use. Airport officials can recommend these
changes to FAA on an ad hoc basis or through the agency's noise
compatibility program.

FAA also implements a national program for review of airport noise and
access restrictions. It is through this process--known as Part 161--that FAA
reviews airports' requests for restrictions on certain aircraft operations
to help reduce noise. Airport operators often choose to negotiate informal
voluntary agreements with airlines, FAA air traffic towers, and other
airport users, rather than pursue mandatory restrictions through the
demanding Part 161 process.

Efforts

Despite the mandatory and voluntary measures currently being implemented by
many airports, some citizens' groups and local officials do not believe that
their concerns about aircraft noise are being adequately addressed. For
example, some citizens are concerned that aircraft are not adhering to
preferred flight paths to help minimize the impact of aircraft noise on
surrounding communities. FAA officials told us that aircraft may deviate
from preferred flight paths when necessary to ensure safety. In general,
airport representatives stress that much of the aircraft noise is beyond the
control of airports; however, airports are often the focal point of noise
complaints.

Two airports that we visited illustrate the concerns of communities about
aircraft noise.

Los Angeles International Airport: Citizens' groups and local government
officials from several communities surrounding the Los Angeles International
Airport said they are dissatisfied with the airport's efforts to address the
impact of aircraft noise. In particular, they are dissatisfied because some
aircraft--primarily older, noisier aircraft23--are making turns early after
takeoff and, hence, not following approved flight paths. In addition, these
community and local officials, as well as regional air quality officials,
are concerned that the airport has "incrementally" increased its capacity by
20 million passengers annually without any type of environmental review.
These citizens' groups and regional air quality officials are concerned
about these issues because, as aircraft operations increase, noise and
emissions levels can also increase. However, an official from the airport
authority said that the airport has several measures in place to minimize
aircraft noise--a noise-monitoring system to track violations, in-flight
procedures (including the preferred use of certain runways and departures
over the ocean), the use of quieter Stage 3 aircraft, sound insulation for
impacted residences, and a sound wall24 to mitigate the effect of aircraft
noise on residents. However, this official noted that some of the flight
procedures intended to minimize the impact of noise on surrounding
communities are not always followed for safety reasons. In addition, the
airport's noise office sends monthly reports to airlines regarding
deviations from approved flight paths by their pilots and investigates to
see if the airport tower directed a given pilot to deviate. Furthermore,
according to FAA, the airport is implementing an airport roundtable modeled
after the San Francisco Airport Roundtable to further address concerns about
aircraft noise in the Los Angeles area.

Miami International Airport: During our visit to the airport, an airport
official told us that only in the past 5 years has the airport admitted that
it has an aircraft noise problem. This official added that complaints about
aircraft noise have increased from about 18 to 19 per month in 1993 to 300
to 400 a month in 199925 and that communities are beginning to show
resistance to the airport's current expansion plans. To help address the
communities' concerns, this official told us the airport plans to more than
double its aircraft noise and environmental planning staff this year,
increase the use of departure routes that avoid residences that are
currently affected, and continue to close runways at night. However, this
official told us that the airport does not participate in FAA's noise
compatibility program and, as a result, does not receive federal grant funds
for mitigating the impact of noise on residents in surrounding communities.
Such funds could be used, for example, to insulate the 65,000 homes affected
by high noise levels--those greater than 65 dB DNL. (See fig. 6.) Local
government officials from this community told us that they have created an
ad hoc committee of several affected communities to oppose expansion by the
airport unless the airport implements a noise compatibility program for
residences. A proposed new runway would be 800 feet closer to this
community. According to these officials, the most important recommendation
from the ad hoc group has been that the county's aviation department develop
and implement a noise compatibility program for the airport so that it will
be eligible for federal funding for soundproofing residences.

Some airport representatives also stressed that the ability to address noise
complaints is often outside their control. For example, one airport official
noted that federal law does not authorize the airport to impose fines on
airline operators for violating preferential flight paths designated by the
airport--nor can the airport force air traffic controllers to follow such
procedures. As a result, the authority to direct flights in a manner that
reduces the impact of noise on surrounding populations--consistent with safe
and efficient use of the nation's airspace--rests with FAA tower operators.
FAA officials said that the responsibility for addressing aircraft noise is
shared among FAA; airports; airlines; and federal, state, and local
governmental entities--reiterating the position FAA has taken since the
mid-1970s. However, these officials stressed that the airport is primarily
responsible for addressing aircraft noise problems in the areas surrounding
the airport.

Water Quality Is a Primary Concern and Challenge for Airports

Runoff from airport activities is a concern for airports because it can have
harmful effects on local water quality unless managed correctly. Hence,
containing runoff is an ongoing challenge for airports. Officials from 12 of
the 50 airports surveyed reported that water quality issues are currently
their primary concern--ranking these issues second overall to noise issues.
In addition, officials from 18 airports reported that concerns specific to
deicing and anti-icing most affect their airports' operations. Many of these
airports are in northern states that generally receive large amounts of
snowfall. As a result, airports and airlines are challenged to reduce the
environmental impact of deicing and anti-icing operations--specifically,
those related to the use of glycol products. In addition, officials from 31
airports cited other water quality issues as their primary concern and
ranked controlling fuel spills as the chief challenge among these.

To remove and prevent the buildup of ice and snow that would inhibit
taxiing, takeoff, and landing, airports may apply deicing and anti-icing
chemicals to paved surfaces such as runways and taxiways. Similarly,
airlines may apply deicing and anti-icing chemicals to aircraft to help
ensure the safety of operations. (See fig. 7.) These chemicals have the
potential to contaminate groundwater and surface water supplies if allowed
to flow from airport facilities to storm drains or waterways. Runoff from
airports may also contain fuel, fire-fighting retardants, and other
pollutants.

According to officials from 18 of the 45 airports where deicing occurs, the
use of glycol-based products at their airport is a major water quality
concern. While standards governing ethylene- and propylene-glycol-based
chemicals are developed by the Society of Automotive Engineers and accepted
by FAA, both chemicals cause environmental concerns because they are highly
soluble and rapidly biodegrade, threatening aquatic life as they break down
in water and consume oxygen. Airports have more options for deicing runways
than airlines have for deicing aircraft. Some airports have begun to use
alternative, less polluting materials for runways. For example, officials
from 26 airports reported using potassium acetate, and officials from 5
airports reported using calcium magnesium acetate. These substances have
been approved by FAA on both safety and environmental grounds and, according
to EPA, have no significant impact on water quality. However, officials from
17 of the airports surveyed still use urea, which is less expensive and can
have a negative impact on water quality.

Airports that intend to discharge pollutants, such as spent deicing fluids,
into the nation's waters must obtain a National Pollutant Discharge
Elimination System permit from either EPA or a state authorized by EPA to
issue the permit. To obtain such a permit, an airport must provide
quantitative analytical data identifying the types of pollutants present in
its discharges. The permit will then set conditions and limits on the
airport's pollutant discharges, including discharge limits based on federal
or state water quality criteria or standards, which were designed to protect
surface waters that support aquatic life and/or recreation. Water quality
criteria and standards vary from state to state and site to site, depending
on the uses of the receiving water body. Airports' permits must also reflect
stormwater discharges associated with deicing and airport maintenance
activities.

Lack of control over the deicing of aircraft is also a concern for airports.
Aircraft deicing is largely outside an airport's control because it is done
by a variety of tenants and users, such as the airlines that operate much of
the equipment used for deicing. In most cases, airports are considered the
"discharger" for regulatory control and permitting purposes, and individual
airlines do not hold specific discharge permits for deicing chemical runoff.
As a result, the runoff attributable to the airport operator is minimal.
However, in some cases, the airport and the airline jointly hold the permit,
or contractual agreements between them stipulate shared responsibilities,
including legal accountability. Sharing responsibility has fostered more
communication and accountability between airlines and airports for reporting
and documenting the use of deicing materials because both are held legally
accountable for discharge activities.

Eleven airports reported fuel spills as their primary concern--the second
most prominent water quality concern after deicing. Leaks, improper
connections, and improperly monitored storage tanks can lead to fuel spills.
If spills are not contained or diverted to an established treatment system,
they may contaminate soil and/or groundwater. To help address this concern,
the airline and petroleum industries and a number of airports have funded an
effort to study and identify remedial and preventative measures to detect
and address fuel leakage and spills at airports.

A representative of a national network of citizens' groups told us that the
contamination of groundwater from deicing/anti-icing chemicals and fuels is
of concern for citizens living near the nation's airports. According to this
representative, several lawsuits are pending at major U.S. airports because
of contamination from deicing runoff and leaking underground storage tanks.
These lawsuits reflect citizens' concerns about the adverse health effects
of such contamination.

Operations and Fuel Spills

To manage runoff from deicing/anti-icing and fueling operations, airports
reported that they employ a range of techniques. Most frequently, they use
vacuum sweeper trucks for capturing deicing or anti-icing chemicals. These
trucks are used by almost half of the airports we surveyed where these
chemicals are applied. Figure 8 provides a summary of airports' capture
techniques.

Note: Statistics include the 45 airports at which deicing chemicals are
used.

Source: GAO's survey of the nation's 50 busiest commercial service airports.

Airports also often use tanks or ponds to store glycol-laden runoff so that
it can be released during high flow periods, when mixing of the runoff with
higher water volumes minimizes glycol's effects on aquatic systems. In
addition, many airport operators filter the runoff through equipment that
removes the glycol component for reuse. For example, Denver International
Airport has an extensive system for capturing and recycling the runoff from
its deicing/anti-icing operations. This system includes a wide range of
equipment for collecting the runoff, an extensive drainage system, large
holding ponds for storing the runoff, and a plant that is used for mixing
and recycling deicing fluids. Portland International Airport has also
undertaken a comprehensive effort to manage the runoff from its
deicing/anti-icing operations and the environmental impact of this runoff on
local water bodies--primarily the Columbia Slough and the Columbia River.
(See app. I.)

Several airline representatives told us they are aware of the environmental
concerns associated with deicing and anti-icing operations and are
undertaking a variety of measures with airports to address these concerns.
For example, one airline representative told us that over the past several
years, the airline has upgraded its stormwater management program nationwide
to reduce the impact of its deicing operations on water quality. In
addition, the airline is testing a system that uses forced air and a smaller
amount of deicing fluid to remove snow and ice--using 50 percent less
deicing fluid (glycol) than the former system. Furthermore, the airline uses
computers to measure and blend deicing mixtures in accordance with ambient
conditions instead of using an equal mixture of glycol and water that can
result in the use of more glycol than is needed for safe operations. The
airline is also funding research to identify state-of-the-art methodologies
to reduce the environmental impact of deicing and anti-icing fluids and
plans to share the results with the air transport industry. Additionally,
the airline industry is working with other interested parties to further
evaluate and address deicing runoff at airports.

Furthermore, an airline industry representative told us that one airline is
using a new method of deicing aircraft using infrared technology inside a
hangar-like structure instead of applying deicing chemicals. However, the
official stressed that this technology is in its early stages.

Air Quality Is an Increasing Concern and Challenge for Airports

The major source of air pollutant emissions generated at airports is
vehicles that rely on fossil fuels and are used to access and operate the
airport facility. These vehicles include (1) aircraft; (2) vehicles such as
automobiles, shuttles, and public transit that transport people and goods to
and from the airport; and (3) ground support equipment used in the facility,
such as aircraft towing, baggage-handling, maintenance/repair, refueling,
and food service vehicles. Air quality is a major concern for many of the
nation's busiest commercial service airports and is expected to become a
more serious issue for them in the future. For current operations, officials
from six of the airports we surveyed cited air quality as their primary
environmental concern. Specifically, they identified the growing demand for
parking--which could lead to increased congestion and emissions around
airports--and uncertainties about how to comply with the Clean Air Act as
challenges for their airports. For future operations, officials from 16
airports ranked air quality first among their environmental concerns. Many
of the airport officials we surveyed have strategies in place to deal with
air quality issues. In addition, airlines assist airports with their efforts
to reduce air pollutant emissions generated by airport operations.

Compliance With the Clean Air Act

Airport officials cited a variety of air quality concerns associated with
their current operations. Officials from 27 of the airports surveyed
reported that the demand for parking is currently a major concern because of
traffic congestion and the effects of increased emissions on air quality. In
addition, officials from 22 of the airports surveyed said that uncertainties
associated with conforming to the requirements of the Clean Air Act were a
major concern for them. Finally, officials from 19 of the airports surveyed
noted that offsetting air pollutant emissions, as required in their state
implementation plans, is a major concern, while 16 said that the high number
of auto trips to and from the airport and the limits on airport growth due
to road congestion were major concerns. (See fig. 9.)

Source: GAO's survey of the nation's 50 busiest commercial service airports.

The air quality concerns cited by airport officials as the most problematic
are interrelated. For example, the growing demand for parking is linked to
the high number of automobile trips to and from the airport and the amount
of road congestion surrounding the airport. All of these traffic indicators
are a factor in the amount of emissions produced around an airport and
affect the airport's ability to comply with the Clean Air Act and its
state's plan to come into compliance with the act. An aviation industry
official noted that an airport's difficulties conforming to the Clean Air
Act's requirements is the largest direct impediment to an airport's future
growth.

When considering the future, officials from 16 of the nation's 50 busiest
commercial service airports cited air quality as their most significant
environmental concern. (See fig. 10.) Many of these airports must comply
with state implementation plan requirements (e.g., emission limitations),
which do not always consider airports' plans to grow. Compliance is of
particular concern for 33 airports that are located in areas found in
violation of certain Clean Air Act requirements--referred to as air quality
nonattainment areas.26 Another four airports are located in areas that
recently achieved compliance, known as maintenance areas.27 FAA and EPA
concur with the airport officials' growing concern about air quality issues,
stating that while noise is the greatest current concern affecting aviation
capacity, the focus on air pollutant emissions is expected to increase in
the future.

Source: GAO's survey of the nation's 50 busiest commercial service airports.

Emissions

The majority of the nation's 50 busiest commercial service airports are
funding strategies to address their concerns about airport air pollutant
emissions. These strategies include increasing the use of (1)
alternative-fuel vehicles and the infrastructure that supports them; (2)
alternative, less-polluting power sources for aircraft operations at airport
gates; and (3) shuttle service to the airport from remote locations for
passengers and employees.

Currently, some airports are providing incentives to encourage the use of
alternative-fuel vehicles. For example, some airports offer discounted fees
to commercial operators that transport people to and from the airport if
they use alternative-fuel vehicles. In addition, officials from 30 of the 50
airports we surveyed reported that they have alternative fuel-stations to
support the use of these vehicles. Another airport that we visited provides
free parking to passengers that drive electric vehicles, has 15 recharging
stations available, and is planning to expand the number of stations in the
future. (See fig. 11.) In addition, most shuttles using this airport can
operate on alternative fuels. However, some airport officials we interviewed
cautioned that many of these vehicles can also be operated on gasoline,
noting that it is difficult to determine when and if alternative fuels are
being used.

Officials from 30 of the airports surveyed reported they provide electricity
and 28 of the airports surveyed said they provide preconditioned air at some
gates28 for airlines' use to reduce or eliminate the need for aircraft to
operate separate generators (e.g., ground power and conditioned air units,
as well as auxiliary power units onboard aircraft). Allowing aircraft to use
airport-provided electricity and air reduces both air pollutant emissions
and fuel use. However, regional air quality officials from one state
expressed concern that many airlines still rely on generators out of habit,
instead of using the less polluting electricity and preconditioned air
provided by some airports.

In addition, officials from 18 of the airports surveyed reported that they
have a direct rail or subway connection to the airport. For example, at
Atlanta's Hartsfield International Airport, passengers can check in for
their flight just outside the airport's metropolitan rail station. Officials
from 18 of the airports surveyed also operate shuttles from remote locations
to reduce the number of individual passengers and employees traveling to the
airport, and, in turn, air pollutant emissions. (See fig. 12.)

Source: GAO's survey of the nation's 50 busiest commercial service airports.

Currently, a small percentage of the ground service equipment (e.g.,
airplane tugs and baggage carts operated by airlines) and ground access
vehicles (e.g., cars, taxis, and buses operated by passengers, airports,
and/or commercial operators) at airports are using alternative fuels.
Approximately 2 percent of the ground service vehicles and less than 1
percent of the ground access vehicles currently operate on alternative fuels
at the 50 busiest commercial service airports. However, airport officials
expect those levels to more than quadruple in the next 5 years.

To address air quality concerns, some airports are increasing the use of a
wide range of emissions reduction strategies to limit the impact of airport
operations on local air quality. Two of the airports we visited--Boston's
Logan International and Los Angeles International airports--have implemented
such strategies. Massport29 officials told us that Boston's Logan
International Airport has numerous air pollutant emissions reduction efforts
under way and has successfully leveraged private-sector funds to support
them, including maximizing the number of alternative-fuel vehicles used at
the airport. Remote park-and-ride facilities also make less expensive
parking available for passengers and airport employees and improve air
quality at the airport by reducing the number of vehicle trips into the
airport core. In addition, through the establishment of public/private
partnerships, the airport has helped private operators of buses, shuttles,
and taxis defray the up-front costs of purchasing these vehicles. The
airport also discounts the cost of access permits for operators of
alternative-fuel vehicles and is encouraging rental car facilities to
collocate their facilities and consolidate their passenger shuttle
operations to reduce air pollutant emissions.

According to officials from Los Angeles World Airports,30 Los Angeles
International Airport has undertaken a variety of air emission reduction
efforts that support aircraft operations and access to the airport. These
activities include hosting a conference for airport tenants to promote the
use of alternative-fuel vehicles for ground service equipment, providing
airlines with electricity and preconditioned air at many gates to reduce the
need for them to use higher-polluting onboard or auxiliary generators,
operating employee van pools, establishing remote pickup sites for
passengers and employees, operating alternative fuel shuttle vehicles (see
fig. 13), and providing free parking and the use of electric recharging
stations for electric vehicles users. (See app. I.)

Airlines work independently and with airports to reduce the emissions
generated by their operations. One airline representative stressed that the
industry has every incentive to improve its operations to reduce fuel
consumption and, hence, emissions, because fuel costs are the airlines'
second largest expenditure after personnel costs. This representative said
that when airlines choose not to take actions that are viewed as beneficial
to the environment, safety considerations are often the driving factor.

Airlines have a range of efforts under way to reduce the emissions
associated with their operations. For example, one airline has pioneered the
use of single engines--instead of multiple engines--for taxiing to reduce
the impact on local air quality when operationally feasible. This airline
estimates that it has reduced its fleet's fuel consumption by 40 million
gallons per year and, in turn, reduced the impact of air pollutant
emissions. However, a representative of this airline cautioned that some
aircraft engine manufacturers do not recommend this practice, and in other
instances, ramp and taxi conditions may warrant the use of more than one
engine. In addition, FAA officials said that the agency works with airports
and airlines to develop operational procedures to reduce delays that go a
long way toward reducing aircraft emissions. However, these officials also
said that there are trade-offs associated with many efforts to reduce air
pollutant emissions and aircraft noise. Specifically, there may be
trade-offs between nitrogen oxide and nitrogen dioxide (collectively termed
NOx) and carbon dioxide emissions--when engines are modified to decrease
one, the other is often increased. According to representatives of the
airline industry, modifications to aircraft to reduce noise may add to the
weight of an aircraft, and, in turn, cause it to burn more fuel--resulting
in higher air pollutant emissions.

An official from a major cargo carrier told us it is also pursuing a range
of initiatives to reduce the environmental impact of its operations,
including efforts to reduce air pollutant emissions. However, this official
cautioned that many of the alternative-fuel vehicles currently available to
replace the carrier's ground support equipment do not meet the performance
requirements for cargo carriers. For example, the tractors used to pull
cargo freight must be capable of pulling much heavier loads than the
tractors used to pull passengers' baggage. This official maintained that, as
a result, cargo carriers cannot easily adopt the ground support equipment
designed for use by passenger airlines.

The Federal Government Has Coordinated Some Efforts, but Challenges Remain

The federal government has coordinated some efforts to assist airport
officials with balancing airport operations and growth with the impact on
the environment. Such efforts include coordination across the federal
government on aviation noise--including reaffirming the use of a common
metric for measuring aircraft noise--and an ongoing effort led by EPA and
FAA with the aviation industry and other interested parties to address air
pollutant emissions from airport operations. In addition, FAA, EPA, and NASA
have efforts in place to help airports manage the environmental effects of
airport operations and growth. However, our review identified several areas
in which the federal effort could be improved. Specifically, (1) federal
environmental reviews are not well understood by many airport officials and
the results of some of these reviews (i.e., categorical exclusions) are not
systematically documented or communicated to them by FAA; (2) many airports
are uncertain about how to meet their responsibilities under the Clean Air
Act; (3) difficulties remain in coordinating some federal, state, and local
environmental processes for airports; and (4) a federal law31 may be
limiting the effectiveness of the federal environmental approach for some
airports and communities.

Coordination has occurred across federal agencies to help balance airports'
impact on the environment with their operations and growth. In addition,
airport officials said that FAA assists them effectively in a number of
environmental areas and coordinates its activities among its offices. The
federal environmental review process itself received mixed reviews from
airport officials--two of the three levels of environmental review were
found satisfactory by officials from a majority of the airports.

Environmental Issues Related to Airport Operations

The federal government has undertaken two major efforts to coordinate and
communicate on the environmental impact of airport operations, including
aircraft noise and airport air quality issues.

ï¿½ In 1992, the Federal Interagency Committee on Noise published a report
entitled Federal Agency Review of Selected Airport Noise Analysis Issues,
finding that, among other things, research on the basic elements of aircraft
noise assessment methodology was needed. In addition, this committee
reconfirmed the use of the day-night sound level (DNL) as the common federal
standard for measuring aircraft noise, concluding that there were no other
measurement methods with sufficient scientific understanding to replace this
method. To foster research in this area, the committee recommended that a
new federal interagency committee be formed to assess future research needs
and to encourage new developments in the reduction of aircraft noise. The
result was the Federal Interagency Committee on Aviation Noise,32 convened
in 1993, which is continuing to foster aircraft noise and assessment
research.

ï¿½ In 1998, EPA and FAA, in cooperation with the Air Transport Association,
created a stakeholder group on the local air quality issues associated with
airport operations. The group's goal is to find voluntary ways to track and
reduce the emission of air pollutants around airports. This effort has
brought together many groups to work on the issue of air quality, including
airlines, engine manufacturers, airports, state and local environmental
regulators, and nonprofit interest groups. Several participants told us that
the group began by focusing on retrofitting certain older commercial
aircraft engines for emission reductions, but the debate was later opened to
other potential opportunities for reducing emissions from airport
operations. While participants we interviewed agree that the group's
progress is often slow and frustrating, many are encouraged by the group's
efforts. To date, this group has worked to establish a baseline of emissions
from airports and explore options for reducing these emissions. Reports on
these issues are due to be completed in fall 2000, and officials with the
Air Transport Association said that the group's goal is to have the aviation
industry voluntarily enter into an agreement by the end of 2000 to achieve
reduction goals for air pollutant emissions.

Airport Operations and Growth

FAA is working with other federal agencies and the aviation community to
address the environmental impact of airports through several initiatives. It
also has specific programs to address the noise, air, and water quality
issues associated with airport operations and growth.

FAA Coordination to Resolve Airport Environmental Issues

FAA coordinates with other federal agencies with jurisdiction and expertise
to resolve specific airport environmental issues. For example, FAA has
coordinated with the U.S. Fish and Wildlife Service on an acceptable
mitigation strategy for the Minnesota Valley National Wildlife Refuge--a
critical component for approval of a new runway at Minneapolis-St. Paul
International Airport. FAA also works with industry through forums and
working groups to address environmental issues at airports.

FAA has also established design review groups associated with the
development and use of the modeling systems FAA uses in assessing the
potential for noise and air pollutant emissions from proposed airport
development. These groups are made up of representatives of FAA, the
aviation/airline industry, consultants, other users, and academia. They
generally meet on an annual basis to provide input and direction to FAA on
needed enhancements to these predictive models. In addition, FAA actively
participates in the International Civil Aviation Organization--responsible
for setting international civil aviation standards, including those for
aircraft noise and emissions, through its Committee on Aviation
Environmental Protection. An FAA official serves as the U.S. representative
to this organization.

FAA's Specific Efforts to Address Noise, Water, and Air Quality

FAA works with aviation industry groups and targets its resources toward
addressing major airport environmental issues.

Noise: Because of FAA's and the aviation community's cooperative efforts,
aircraft noise levels around airports have been reduced. FAA has developed
and continues to improve computer models to more accurately assess the
impact of noise and to assist state and local governments and planning
agencies in establishing compatible land use plans. FAA is also examining
recent noise concerns from a technical and public policy perspective.

Water: FAA participates in a Society of Automotive Engineers group, which
develops standards for aircraft and airport deicing. FAA and this group have
independently funded research and development on new technology for reducing
and remediating the impact of glycol runoff, including the use of forced air
and infrared technology to reduce the amount of deicing chemicals used. FAA
also published advisory circulars on handling deicing/anti-icing agents and
designing deicing facilities and worked cooperatively with EPA and industry
to address stormwater discharges from airports. In addition, FAA entered
into a cooperative research and development agreement that resulted in an
infrared technology that is being used to deice aircraft. Furthermore, FAA
officials noted that the agency administers airport grant-in-aid funds and
passenger facility charges that can be used to mitigate the impact of
airport expansion projects on water quality.

Air: FAA officials told us that they coordinate with EPA on national air
quality issues that are applicable to airports and have developed and
continue to enhance the modeling system, which is used to assess the impact
of proposed airport development on air quality. In addition, the agency also
administers the airport grant-in-aid funds and approves passenger facility
charges that airports can use to mitigate the impact of airport expansion
projects on air quality. Finally, FAA has updated its environmental guidance
to include air quality, such as procedures and methodologies for assessing
the impact on air quality of FAA's and the Air Force's actions at airports
and air bases.33

FAA Assistance to Airports Received Generally Positive Reviews

According to our survey, airport officials generally believe that FAA
effectively assists them with their environmental activities. (See fig. 14.)
For example, officials from 32 airports reported that they were satisfied
with the way FAA answered their questions and addressed their concerns about
environmental issues. In addition, officials from over half of the airports
reported that FAA was effective in coordinating activities among its
offices, providing standard rules and guidance, and processing paperwork.
However, airport officials reported that FAA was less effective in ensuring
consistent treatment across its regional offices. This could be due, in
part, to FAA's decentralized structure for addressing environmental issues.
For example, officials from one airport told us that FAA refused to allow
them to use airport funds for off-site environmental work to mitigate the
airport's impact on wetlands, but approved the same action at another
airport in the same region. FAA officials told us that this apparently
inconsistent treatment could have arisen from situational differences due to
ongoing changes in wetland rules. In addition, airport officials expressed
somewhat less satisfaction with FAA's coordination with state agencies than
with its coordination with federal agencies--an issue some told us reflected
duplication in state and federal environmental requirements.

Note: The responses of officials reporting that they were unsure about FAA's
effectiveness or that the issue did not apply to them were not included in
this figure. In addition, officials from five airports identified additional
issues in the "other" category.

Source: GAO's survey of the nation's 50 busiest commercial service airports.

Airport Operations and Growth

In addition to issuing regulations, EPA has several efforts under way to
address the environmental impacts of airport operations and growth related
primarily to water and air quality. For example, EPA, FAA, and the Society
of Automotive Engineers undertook a 2-year study of airport deicing
operations to provide information needed to decide whether additional
regulation was required to address water-related environmental issues at
airports. On the basis of the study, EPA decided not to develop regulations
for airport deicing operations in 2000; however, the agency may decide to do
so in the future.34

In the area of air quality, EPA participates in a forum focused on
development of "green airports" through the voluntary adoption and
implementation of environmentally friendly equipment, processes, and
services. The agency has also developed the general conformity rule
applicable to airports, published guidance on compliance with air quality
requirements, and briefed FAA and other interested parties, including
airport managers, on the general conformity requirements. In addition, a
1999 EPA study found that aircraft emissions are a potentially significant,
increasing source of pollution in 10 cities with local air quality
problems.35 Moreover, the agency has initiated efforts to update and improve
general conformity rules for complying with the Clean Air Act. EPA also
reviews environmental impact statements prepared by FAA for airport
development projects. Furthermore, EPA has developed evaluation tools and
models for communities, airport planners, and local regulators to encourage
innovative actions to improve air quality. For example, EPA has created a
model for helping airports estimate the impact of different strategies for
reducing the emission of air pollutants from ground support equipment.

Aviation's Environmental Impact

NASA, in cooperation with FAA and the aviation industry, is continuing to
develop new technologies, including airframe improvements and new engine
combustor technologies, to reduce the impact of aircraft noise and air
pollutants.

According to a NASA environmental manager, FAA is NASA's principal partner
in aviation noise reduction research, and FAA uses NASA's scientific and
technological knowledge to regulate noise from aircraft.36 The NASA official
said that EPA, the Department of Energy, and FAA depend on NASA's research
on aircraft noise, such as that on making quieter engines, because they do
not do any such research. For example, NASA--in cooperation with the
aviation industry--developed new, quieter engines that led to the phaseout
of older, noisier Stage 1 and Stage 2 aircraft. In addition, the agency
currently has technology in the pipeline that will allow noise reductions
well beyond Stage 4 standards. Pending adequate funding, NASA's goal is to
develop technology that, if incorporated, would reduce aircraft noise by 10
decibels between 1997 and 2007 and by a total of 20 decibels by 2022.
However, FAA officials noted that technologies developed by NASA are passed
off to industry and that many years can pass before these technologies are
available on new aircraft.37

In the past, NASA also made significant contributions toward reducing
aircraft emissions through the development of new technologies. These
improvements--in combination with those of the aviation industry--have
helped aircraft burn fuel more efficiently and, hence, reduce emissions.

NASA has a new program--Ultra-Efficient Engine Technology--that will fund
engine technology research and development to further reduce aircraft
emissions. NASA believes that this program (running from fiscal year 2000
through fiscal year 2005) will continue efforts to reduce NOx emissions to
70 percent below the International Civil Aviation Organization's 1996
standard. Through this program, NASA plans to develop technology to further
reduce carbon dioxide emissions by 15 percent below today's emissions. While
an industry official questioned whether NASA could achieve this goal--noting
that current aircraft engine technologies generally require a trade-off
between NOx and carbon dioxide emissions (when engines are designed to
minimize NOx emissions, they generally emit more carbon dioxide, and vice
versa)--EPA and NASA consider the goal feasible in principle. According to
EPA, a potential trade-off exists between carbon dioxide and NOx emissions;
however, engine technology can reduce NOx emissions from aircraft without
increasing carbon dioxide emission levels. NASA is performing in-depth
studies with propulsion and airframe manufacturers to assess the trade-off
of these various technologies toward meeting the goal of reducing NOx and
carbon dioxide simultaneously. Furthermore, an EPA official noted that one
engine manufacturer makes an engine that reduces NOx emissions by 20 percent
without increasing carbon dioxide emissions.38 In addition, a NASA official
told us that in 1999, the agency completed a full-scale demonstration of a
new combustor technology on an aircraft engine that reduced NOx levels 50
percent below the International Civil Aviation Organization's 1996 standard,
while holding carbon dioxide emission levels constant. NASA is fairly
confident, given the data and testing thus far, that these reductions can be
achieved when the new technology is ultimately used on new production
aircraft.

NASA also expects to make aerodynamic improvements, such as using lighter
and stronger materials, to reduce the amount of fuel burned by aircraft. In
addition, improvements in aircraft engines--anticipated through reductions
in weight and applications of new engine technologies--are expected to
significantly improve fuel efficiency. However, an aviation industry
official pointed out that there are trade-offs between applying these new
engine technologies and ensuring safety and performance. EPA agrees with FAA
that safety is the highest priority for aviation but maintains that using
less-polluting technologies does not necessarily compromise safety. Also,
NASA officials told us that the agency has developed a type of propylene
glycol for deicing aircraft that is environmentally benign (nontoxic and
food grade); however, this product is not yet commercially available.

Airports

Airport officials reported various levels of satisfaction with the federal
environmental review process required under NEPA. Specifically, officials
from 30 of the airports that have had recent experience with completing
various federal environmental review requirements under NEPA reported that
they were generally satisfied with the process used to determine if a
project will be categorically excluded from further review, but officials
from only 13 were satisfied with the review process required for a
full-scale environmental impact statement.

Officials were also generally satisfied with the environmental assessment
process that is used to determine whether a more in-depth environmental
review (environmental impact statement) or a finding of no significant
impact is warranted. (See fig. 15.)

Note: The figure shows the statistics for those officials with experience
with these levels of NEPA review. Officials from three airports did not have
experience with the categorical exclusion process. Officials from two
airports did not have experience with the environmental assessment process
resulting in findings of no significant impact, and an official from an
additional airport did not answer this part of the question. Officials from
10 airports did not have experience with the environmental impact statement
process.

Source: GAO's survey of the nation's 50 busiest commercial service airports.

Many Airport Officials, and Some Reviews Are Not Systematically Documented
or Communicated to Them by FAA

Officials from 23 airports reported that at least some of their capacity
expansion projects (defined in the survey as including taxiways and
terminals) did not require an environmental impact statement, environmental
assessment, or categorical exclusion. (See fig. 16.) However, NEPA
regulations require that all "major federal actions" receive one of these
types of reviews, and FAA's policy39 implementing NEPA also requires that
airport projects that FAA approves receive such reviews. FAA headquarters
officials confirmed that FAA's policy requires that all airport capacity
expansion projects receive an environmental review and maintain that all
such reviews are taking place. The responses from airport officials suggest,
however, that there is a lack of understanding about when environmental
reviews are required.

Source: GAO's survey of the nation's 50 busiest commercial service airports.

While NEPA regulations issued by the Council on Environmental Quality and
FAA's policy require environmental assessments and environmental impact
statements to be documented for airport development projects, documentation
is not required for categorical exclusions. However, when airports request
federal funding or authority to collect and use passenger facility
charges,40 FAA requires that funding records include specific categorical
exclusion determinations, while projects that are categorically excluded and
do not use federal funding do not require specific documentation on airport
layout plan approvals.41 This leaves FAA without systematic documentation
that all categorical exclusion reviews are occurring. Documentation of all
categorical exclusions by FAA is important because these determinations
account for the vast majority of environmental reviews conducted by the
agency. Without documentation, a reliable determination cannot be made about
whether categorical exclusion reviews are taking place when no FAA funding
is involved. FAA officials also told us that they do not have a systematic
process for communicating to airport officials the results of categorically
excluded projects.

FAA headquarters officials acknowledged that based on the survey results,
there appears to be a lack of understanding on the part of some airport
officials about when environmental reviews are required and have occurred.
The FAA officials agreed that improved communication with airports is
warranted. In addition, FAA officials said that such reviews could have
taken place without airport officials' being aware of the results, in part,
because (1) NEPA is a federal rather than an airport responsibility, (2)
airport officials are not necessarily trained in NEPA requirements and rely
heavily on consultants for the airport portion of NEPA work, and (3)
categorical exclusion determinations are not as visible or documented as
environmental impact statements or environmental assessments that result in
findings of no significant impact and may have been overlooked by a number
of airport officials.

Requirements

Airports reported two key problems--inadequate guidance and/or a lack of
experience on the part of some EPA and FAA regional officials in applying
the Clean Air Act to airports. Airport officials also identified confusion
in three other areas: (1) which agency is in charge of ensuring that
airports conform to the act, (2) what their region's air quality status is,
and (3) what their airports should do to receive credit for voluntary
efforts to reduce air pollution.

Act Could Be Improved

Inadequate federal guidance and/or a lack of experience among some FAA and
EPA regional officials with applying the Clean Air Act to airport expansion
projects has left a number of airport officials uncertain of their
responsibilities. When establishing regulations for implementing the Clean
Air Act, EPA grouped airports and all other sectors--except for highways and
transit--into the general compliance rules and guidelines, known as general
conformity. Because many of these sectors, such as airports, ski resorts,
and coal mines, have little in common with each other, EPA developed broad
general conformity rules for federal actions--such as airport expansion
projects--to direct compliance with the act.

Guidance

Many airport and government officials said that the Clean Air Act guidance
applicable to airport projects is inadequate. As a result, airports may be
unsure of their responsibilities and at risk of not doing the level of
analysis required or not conforming to the act's requirements. In addition,
state air quality officials said that the Clean Air Act's general conformity
guidance--that covers airports--was inadequate compared with the guidance
for highway and transit projects, which have a more structured process for
complying with the act. FAA headquarters officials have said that while
guidance is available, it can always be improved on and that air quality is
a complex area--one in which airports and FAA staff are not nearly as well
versed as, for example, aircraft noise. Furthermore, these officials stated
that all entities involved are accountable for understanding their
individual responsibilities and effectively communicating with each other to
ensure that environmental requirements are met.

Some airport, FAA, and EPA officials told us that they are confused about
the types of airport expansion projects that trigger air quality analyses,
even though federal guidance on this topic is available.42 As a result,
these officials are unsure how to conduct these analyses when they are
required. For example, an FAA regional official said airports in that region
were unsure of whether projects that did not receive federal funds required
air quality analyses under the Clean Air Act. As for projects requiring
analysis, EPA and FAA officials said that individual agencies, such as FAA,
could create their own lists of excluded projects by setting precedents and
applying them to other similar projects, but the officials also said that
the process is so difficult that no agency has attempted to create such a
list. Because there is no list of excluded airport projects, an FAA official
in the region said that officials there interpreted the requirement to mean
that airports must prove that all projects, no matter how small, conform to
the Clean Air Act. FAA regional and airport district office environmental
staff members said that they need more guidance on the types of projects
that need to be analyzed.

Recognizing this confusion, EPA recently undertook an effort to help make
the guidance on complying with the Clean Air Act more understandable. In
addition, FAA asked EPA to streamline the process as part of its revisions
of the general conformity rules to provide relief in understanding air
quality analytical requirements and other areas of the regulations. An EPA
official told us that as part of this effort to review and revise its
general conformity rules, the agency is evaluating how to improve the
communication with and among stakeholders. EPA acknowledges the need to
clarify the guidance, but its efforts have been delayed because of resource
constraints.

EPA officials told us that shortly after the original general conformity
rules were promulgated, the agency held a training workshop for state and
other federal agencies. However, these officials speculated that because so
few determinations are done in each area, the expertise was probably lost
before it could be used. In addition, these officials said that EPA regional
staff members are available to discuss the regulations with airport
authorities. FAA headquarters officials also said that FAA staff are
available to assist others in understanding the air quality requirements.

Experience

Several EPA and FAA officials attributed problems in implementing the Clean
Air Act's conformity requirements to a lack of experience, noting that
detailed conformity analyses of air quality impacts are seldom required for
airports to demonstrate compliance with the act. Specifically, FAA and EPA
officials told us that each airport, FAA airport district office, and EPA
region may perform only one or two airport conformity determinations over a
period of decades. The infrequency of such analyses makes it difficult to
build and retain experience in any agency or airport. For example, an EPA
official said that none of the four general conformity determinations in
1999 involved airports--two involved coal mines, one involved a ski resort,
and one involved a Native American reservation. However, determinations
involving airport projects may become more common in the near future. An EPA
official said that an informal survey of the agency's regional offices
showed that airports represent 13 of the 18 general conformity
determinations that have been identified for the near future.

FAA headquarters officials said that the aviation industry also lacks
experience and knowledge when it comes to air quality analyses. Limited
expertise, both in the aviation industry and the government, on the
application of those rules to airport projects could have contributed to the
uncertainty about general conformity that was reported as a major or
moderate concern by officials from 35 of the nation's 50 busiest commercial
service airports.

Confusion among responsible officials and the general nature of the guidance
on air quality can also cause regional variation in the application of
requirements. An airport industry representative said that some FAA regional
officials are overly cautious about air quality analysis--in turn, requiring
more assessment--while others are more flexible in their approach. The
representative said this has caused the air quality models used by airports
to estimate the emissions from expansion projects to be routinely accepted
in some regions and questioned in others.

Applies to Airports

Our review identified three other areas of confusion for airports under the
Clean Air Act.

ï¿½ Lines of authority and responsibility. Some airport and federal officials
are confused about the most basic issue--which agency is in charge. For both
FAA and EPA, this confusion stems, in part, from a lack of experience and
guidance at the regional level on airports' compliance with the Clean Air
Act, as amended. The act places responsibility on owners and
operators--these can be the airport, tenants, and FAA to the degree that
they own facilities at airports that need permits under the act. One
exception is aircraft engines, for which manufacturers are the responsible
party and FAA takes the lead. However, a lack of leadership on air quality
guidance was particularly clear in one region we visited, where an airport
official told us that FAA and EPA could not decide which agency was in
charge.

ï¿½ Air quality status. Some airports are uncertain of the status of their
region's compliance with the Clean Air Act--information that is critical to
determining the feasibility of airport expansion projects. In our survey, 6
of the 50 airports incorrectly categorized their status in meeting Clean Air
Act requirements. In addition, we visited numerous airports where officials
were uncertain if their airport's region had reached "attainment status"
with the act's requirements. We asked officials of EPA and four airports
that we visited what their region's attainment status was, and only one
airport provided the same information as EPA. For example, officials at two
of these airports listed by EPA as being in full attainment told us that
they were in nonattainment. These differences are important because each of
these airports is currently planning major expansions that would require a
different level of air quality analyses based on their attainment status.
EPA officials said that the agency has an established process to ensure that
the designation of a region's air quality status is appropriate. These
officials speculated that airport officials' confusion over their regions'
air quality status could be attributed to some EPA regions that have
attained the air quality standards but may not have met all the necessary
requirements for EPA to formally redesignate them as having reached
attainment status. According to EPA officials, the air quality agency of any
state, as well as EPA's regional offices, could provide full details on the
attainment status of any area in its jurisdiction. In addition, the official
said that the attainment status of areas is available on EPA's Web site.

ï¿½ How the government accounts for voluntary reductions of emissions.
Although EPA has published guidance on providing states with credits for
promoting voluntary reductions of air pollutants, EPA has not set up a
process for passing the credits on to airports. As a result, some FAA
officials, airports, airlines, and aviation experts believe that airports
can be penalized if they reduce emissions voluntarily as part of a project
that is not associated with a major airport expansion. Instead of receiving
credit for such voluntary efforts, airport and airline officials said, the
emissions reductions become the new baseline for determining compliance with
the Clean Air Act. Aviation experts said that this practice creates a
disincentive for airports to undertake voluntary efforts to reduce
emissions. The EPA/FAA group currently assessing airport air quality issues
is addressing this concern.

Environmental Processes for Airports

FAA and airport officials said that federal environmental requirements for
airports overlap with some state and local processes and that poor
coordination in these areas frustrates airport officials and can result in
rework and additional negotiations and renegotiations. While officials from
17 of the nation's 50 busiest commercial service airports reported that
FAA's coordination with state environmental agencies was effective,
officials from 12 of these airports ranked FAA as moderately ineffective or
very ineffective in coordinating with state environmental agencies. In
addition, airport officials from one airport we visited told us that because
environmental issues are not well coordinated across state and federal
agencies, the airport must retain more environmental staff than would
otherwise be necessary to complete required work. Airport and FAA officials
said that if not properly coordinated, overlapping environmental review and
wetlands permitting processes can delay airport projects without adding
commensurate environmental benefits.

ï¿½ Some NEPA and state processes can overlap and delay airport projects. In
addition to the federal environmental review process, several states have
passed laws incorporating consideration of environmental effects into state
processes. However, this process does not always work as intended and can
lead to duplication of effort by airport officials in meeting their
environmental responsibilities. According to airport officials, despite
FAA's efforts, airport projects in these states may have to undergo two
completely independent, redundant environmental reviews that do not provide
any incremental environmental benefits. For instance, the officials from one
airport said that the consensus developed under the federal NEPA process for
an expansion project reduced the number of feasible runway options from 17
to 4, which meant that the airport would only need to perform an
environmental review of the 4 options, but the state process forced the
airport to reconsider all 17 options. FAA officials acknowledged that
overlapping federal, state, and local requirements can cause difficulties.

ï¿½ Destruction of wetlands can require duplicative negotiations. According to
airport and FAA officials, when airport projects require the destruction of
wetlands--lowland areas saturated with moisture--duplicative negotiations
may be required even though they do not add environmental value. In those
instances, airports must negotiate with multiple governmental entities to
replace the wetlands they destroy. Airport and FAA officials told us that
the federal wetland permitting process through the Army Corps of Engineers
is not well coordinated with several state and local permitting processes. A
headquarters official from the Corps said that overlapping federal, state,
and local permitting requirements for wetlands is a problem in some states.
For instance, a state might value the quality (e.g., ecological value) of
the wetlands replaced, while the local Corps office might value the
quantity.

An airport official from Florida said that airport officials have had to
negotiate wetland permits with three different agencies. The representative
said that efforts to coordinate the three processes were time-consuming and
that the process would be more efficient if state, local, and federal
officials could coordinate and designate one level to negotiate agreements
and make commitments on behalf of the other levels. In addition, FAA
regional officials told us that airports in the New England region must
repeatedly negotiate wetland destruction agreements with different levels of
government. An official of the New England District of the Army Corps of
Engineers said that coordinating federal, state, and local wetland
permitting processes works better in some states than in others. For
example, some states in the New England District refuse to start the state
permitting process until after the NEPA process is completed.

and Communities to Receive Federal Noise Funds and Create Somewhat
Duplicative Air Quality Requirements

Limitations and duplications in the federal law governing airport noise
programs and air quality requirements may hinder the ability of some
airports and communities to effectively and efficiently address noise and
air quality. First, the law does not allow FAA to provide funding set aside
for noise mitigation to communities affected by aircraft noise if the
airport chooses not to participate in FAA's noise compatibility program
under Part 150. Second, the law and the Clean Air Act include somewhat
duplicative air quality requirements that may unnecessarily delay some
airports' expansion projects.

Noise

FAA's voluntary Part 150 noise compatibility program provides noise
mitigation funds to assist local communities through grants to airports that
participate in the program. However, the law allows FAA to provide noise set
aside funding--from the Airport Improvement Program--through the Part 150
program to a community only if the neighboring airport participates in the
program.43 The program has provided billions of dollars to mitigate the
effect of noise around many airports; nevertheless, some people affected by
noise lack access to the program's benefits because some of the busiest
commercial service airports do not participate in FAA's Part 150 noise
compatibility program. Changing the law could allow communities to access
these funds directly from FAA under rules and restrictions similar to those
placed on airports, even if the communities' airports do not participate in
the program.

FAA's Part 150 noise compatibility program provides guidance to airports on
the types of land uses that are incompatible with certain levels of
airport-related noise and encourages them to develop a noise compatibility
program to reduce and/or prevent such uses. Under this program, airports can
use federal grants to, among other things, soundproof buildings and acquire
homes. As part of this process, airports map the area affected by noise and
estimate the affected population. FAA encourages airport operators to
participate in this program. Over 240 airports participate in the program,
through which FAA has distributed $2.7 billion from 1982 through 1999 for
noise mitigation. However, 14 of the 50 busiest commercial service airports
choose not to participate in the Part 150 noise compatibility program.44
Consequently, more than 320,000 people who live near these 14 airports
cannot receive these federal funds for mitigating noise. These airports
represented about one quarter of all air carrier operations in 1998 and
account for more than half of the population affected by aircraft noise at
the 65 dB DNL and above. FAA has twice proposed a legislative change on
compatible land uses around airports that would have had the side benefit of
extending Part 150 funding to some of these affected communities; however,
its proposals were not adopted. Some airport officials told us that their
facilities do not join the noise compatibility program because the process
is too complicated and difficult to implement and they do not want to raise
false expectations in their communities about reductions in aircraft noise.
For example, at one of these airports, airport and FAA officials said that
the airport does not participate because of the cost of providing benefits
to such a large population, estimating, for instance, that the airport would
need to soundproof about 65,000 affected residences. Officials from one
affected community told us that they are negotiating with the neighboring
airport to encourage it to establish an FAA Part 150 noise compatibility
program as a condition for accepting a new runway project, but the airport
is resisting. These officials consider their options for encouraging the
airport's participation in the program to be very limited.

Some Airports

Two sets of air quality requirements under federal law can be duplicative
and can cause delays in completing NEPA documents, as well as place
unnecessary burdens on some airports in a number of states. Federal law
requires the governor of each state to certify that federally funded airport
runway additions or major expansions conform to local air quality standards.
The process--referred to as the state certification requirement--is termed
and applied differently in each state because there is no standard approach
to handling the certification process.45 Similarly, the Clean Air Act, as
amended, requires the federal agency--in this case, FAA--to determine that
the emissions from airport projects conform to a state's plan to implement
national air quality standards. The act also stipulates that local air
quality standards must meet the national standards but can be more
stringent. These requirements for airports are somewhat duplicative and, in
some cases, require airport officials to demonstrate compliance with air
quality requirements twice.46

FAA and representatives of a working group of airports told us that they
have recommended the elimination of the state air quality certification
requirement because of the overlap with the Clean Air Act's requirement.
States would retain the right to set their own more stringent standards
under the Clean Air Act even without the state air quality certification
process. However, FAA headquarters officials maintained that the requirement
seldom delays projects and is more often an annoyance than a substantive
problem.

An aviation expert said that some states, such as California, conduct very
vigorous certification processes, while others consider state certification
perfunctory once the Clean Air Act's requirements are met. The expert, who
has experience with helping airports fulfill the state air quality
certification process, said that the requirement can delay airport projects
in two ways. First, states can set the requirements for state air quality
certification higher than the federal Clean Air Act requirements, which may
require additional time and analysis. Officials at the California Air
Resources Board--the body responsible for the state air quality
certification process--told us that their standards have been higher than
those of the Clean Air Act, as is allowed by law. The board is also
responsible for preparing California's state implementation plan for the
Clean Air Act. Board officials told us about an airport that recently had to
renegotiate its air pollution reduction commitments with the state after a
project had already demonstrated its compliance with the Clean Air Act.

Second, the expert said that many states are not aware of the state air
quality certification requirement and the staff may not know how to handle
it. Because new or upgraded runways are rare, many states have not had to
grant this certification since the early 1980s, and staff turnover has left
them without the necessary institutional experience. Many states must go
through the time-consuming process of redeveloping expertise and a process
for certifying new or expanded runways each time a runway project occurs.
The relearning costs money and causes delays and frustration. Additionally,
the expert said state officials understand "permitting" but worry that
"certification" is somehow different. Moreover, reliable sources of
information may not exist. The association of state environmental officials
does not provide guidance on the state air quality certification
requirement. A state air quality official we visited said that he would be
responsible for this state certification requirement, but he was not aware
of the requirement and questioned whether such a requirement existed. In
addition, EPA may not have the knowledge or experience to provide
assistance. For example, EPA air quality officials in headquarters and the
California regional office said they had no knowledge or experience with the
state air quality certification process.

Some federal efforts to help airports manage both their operations and
growth and their environmental responsibilities have been undertaken. Among
these are ongoing cooperative and independent endeavors by FAA, EPA, and
NASA, such as EPA's and FAA's work with the aviation industry and other
interested parties to address air quality issues in the airport environment.
Furthermore, the high level of satisfaction reported by most of the nation's
50 busiest commercial service airports attests to the effectiveness of FAA's
efforts to answer airports' questions, address their concerns on
environmental issues, and coordinate environmental activities among its
offices. Nonetheless, we identified several limitations to the federal
effort.

First, the inconsistency between FAA's policy requiring environmental
reviews for all airport capacity expansion projects and the reports of many
airport officials we surveyed who maintained that their projects did not
always require such reviews by FAA points, at a minimum, to a lack of
communication between FAA and airport officials over when environmental
reviews are required and have taken place. In addition, because FAA does not
require documentation of the results of environmental reviews that result in
categorical exclusions when no FAA funding approval is involved, the agency
is not in a position to consistently demonstrate that these reviews have
occurred.

Second, despite available federal guidance and technical assistance, a wide
range of officials from airports and federal and state agencies remain
confused about the requirements for airports to conform to local air quality
standards when undertaking capacity expansion projects and obtaining credit
for voluntarily projects that reduce air pollutant emissions. EPA's
regulations for general conformity under the act are very broad because they
are designed to accommodate a diverse group of facilities--leaving airports
without the specificity they need to fully understand and meet their
responsibilities. As a result, some airport officials may undertake analyses
that are more complex and costly than necessary, while others may not fully
meet their responsibilities under the act. Furthermore, because EPA has not
set up a process for providing credits to airports for voluntary efforts to
reduce the emission of air pollutants, there are disincentives to
voluntarily reducing air pollution.

Third, although efforts to coordinate federal, state, and local
environmental review processes for airports exist, difficulties
persist--frustrating airport officials and, in some cases, resulting in
duplication of effort to meet environmental requirements. In addition, such
duplication can delay airport projects without adding commensurate
environmental benefits.

Finally, limitations and duplications in the federal law governing airport
noise programs and air quality requirements can result in somewhat
duplicative air quality requirements and may hinder the ability of some
airports and communities surrounding them to effectively and efficiently
address noise and air quality issues. First, under FAA's Part 150 noise
compatibility program, the requirement that airports must participate for
neighboring communities to receive funds for mitigating the impact of
aircraft noise does not allow over 320,000 people around nonparticipating
airports to be eligible for mitigation projects. Second, the federal
requirement for state air quality certification is somewhat duplicative.
Airports are already required to determine that an airport project conforms
to its state clean air implementation plan, which could include standards
that are more stringent than the national standards. In addition, the
certification process may unnecessarily increase the number of steps
required for some airports to obtain approval to build or extend a runway.

To provide assurance that environmental reviews for all airport development
projects are broadly understood and systematically documented and that
airport officials are aware of such reviews, we recommend that the Secretary
of Transportation direct the Administrator, FAA to

ï¿½ communicate to airport officials the requirement that all airport
expansion projects are subject to environmental reviews,

ï¿½ document the results of all categorical exclusions, and

ï¿½ inform airport officials of the results of all environmental reviews.

To help airports meet their responsibilities under the Clean Air Act, we
recommend that the Administrator, EPA, in coordination with FAA and airport
officials, (1) clarify guidance in areas such as general conformity
determinations and guidelines for states to provide airports with credits
for voluntary emission reduction efforts and (2) provide more effective
technical support for regional and airport officials to meet air quality
requirements.

Since 14 of the 50 busiest commercial service airports do not participate in
FAA's Part 150 noise compatibility program and, thus, the people who live in
communities surrounding these airports that are affected by aircraft noise
are not eligible to receive funds from this program (under 49 U.S.C. 47104
and 48103), the Congress may wish to consider the impact this restriction
imposes on the affected communities. In addition, because the state air
quality certification requirement (49 U.S.C. 47106 (c)(1)(B)) is somewhat
duplicative and may impede some airports as they attempt to grow and
implement their environmental responsibilities, the Congress may wish to
consider eliminating this requirement.

We provided the Department of Transportation; the Department of Defense;
NASA; EPA; and an advisory panel that included the Air Transport Association
of America, Inc., Airports Council International-North America, Frederic R.
Harris, Inc., and the Natural Resources Defense Council with copies of the
draft report for their review and comment.

We met with officials from the Department of Transportation, including FAA's
Director, Office of Airport Planning and Programming. These officials
generally agreed with the facts in the report and provided clarifying
comments, which were incorporated as appropriate.

The Department of Defense and NASA concurred with the report. NASA offered
clarifying comments that were incorporated as appropriate. NASA's and the
Department of Defense's written comments are included as appendixes IV and
V.

We met with senior officials from EPA's Office of Enforcement and Compliance
Assurance and the Office of Air and Radiation, including the Senior
Scientist/Policy Adviser for the Office of Air and Radiation. Although EPA
officials generally agreed with the facts in the report, they suggested that
we further emphasize airports' shared responsibility for managing their
impact on the environment, noting that airports must take a more active role
in working with local, state, and federal officials. They also provided
technical and clarifying comments. We added language to the report to
further emphasize airports' shared responsibility and incorporated other
comments as appropriate.

The advisory panel of experts that included the Air Transport Association of
America, Inc., Airports Council International-North America, and Frederic R.
Harris, Inc., generally agreed with the contents of the report and provided
technical and clarifying comments, which were incorporated, as appropriate.
The Natural Resources Defense Council provided no comments.

Selected Airports' Activities to Balance Operations and Growth With
Environmental Impacts

San Francisco: To better address aircraft noise issues, the San Francisco
International Airport created the San Francisco Airport Roundtable in 1981.
This voluntary body includes representatives from 13 Bay Area jurisdictions,
FAA officials, airline advisers, air traffic managers, and the airport
director. The Roundtable meets monthly, mainly to discuss noise-related
issues. A representative of the group told us that the airport is funding
this effort to address a citizen group's concerns about noise at the
airport. This official stated that excellent cooperation exists among
officials as they try to solve problems involving community, airport, FAA,
and elected officials.

In addition, the area's Metropolitan Transportation Commission is funding a
series of forums to educate the public on airport noise outside the
Roundtable's boundaries. Since all of the region's airports are receiving
extensive publicity about their growth, the Commission thought it would be
wise to provide information for the entire Bay Area on noise abatement
procedures and flight patterns. A representative of the Roundtable stated
that these informational meetings are on a fast track and will offer to
other parts of the Bay Area what the Roundtable has provided to communities
surrounding San Francisco for more than 15 years. A Roundtable
representative said that this effort should help the community better
understand why airplanes must follow certain flight patterns. This official
hopes that the education effort will help the Bay Area get past the issue of
noise so it can address how it will accommodate increasing air traffic.

A representative of a national nongovernmental organization on aviation
noise cited the San Francisco Airport Roundtable as a model for community
involvement in the decision-making process for airport development,
including the identification of environmental effects and concerns.

Fort Lauderdale: Fort Lauderdale Airport officials told us that an ad hoc
committee was formalized in 1992 to address the airport's noise concerns.
Currently, the committee meets on a quarterly basis and consists of
neighborhood, community, and aviation industry representatives, all of whom
are voting members. The chair of the committee is a neutral resident of the
Miami area. According to the airport's noise abatement officer, residents
are becoming more educated about the airport's operations, and meetings no
longer focus on noise complaints. Instead, meetings consist of updates and
reports on the Stage 3 phaseout, runway closures, proposed changes to flight
paths, and other ongoing noise mitigation efforts. According to an airport
official, the noise committee has been a tremendous help in gaining respect
and credibility with the community. Similar airport community noise groups
have been established at other airports, including those in Louisville,
Oakland, and Chicago (O'Hare).

Denver: Denver International Airport has an extensive system for capturing
and recycling the runoff from its deicing operations. According to an
airport official, Denver's most serious ongoing environmental issue is the
impact of deicing/anti-icing runoff on water quality. An EPA official cited
the Denver International Airport as having "best practices" for
deicing/anti-icing, perhaps because the airport is so new. Whereas most
airports apply one or two progressive techniques for capturing runoff from
deicing/anti-icing, this official said that Denver applies all of them. Our
tour of the airport's facilities and discussions with the airport official
responsible for water quality confirmed that the airport does have a number
of progressive practices in place to address water quality issues associated
with deicing and anti-icing operations. For example, the airport has a wide
range of equipment for collecting runoff, an extensive drainage system,
large holding ponds for storing runoff, and a plant that is used for mixing
and recycling deicing fluids. After being recycled, the fluid is sold.

However, an airport official told us that some improvements are needed. For
example, the retention basins used for runoff have deteriorated much more
quickly than anticipated, in part because the airport is located at a high
altitude, resulting in increased exposure to ultraviolet light. (See fig.
17.) The official said, in retrospect, the airport should have purchased
enclosed holding tanks even at several times the cost of the open tanks
because these tanks would have been much more durable--with a life span of
about 20 years and lower maintenance costs. In addition, although the
airport has dedicated facilities, known as deicing pads, available for
deicing, they are not popular among some carriers because the location of
the deicing pads is inconvenient for them. For example, one carrier with an
entire terminal refuses to use the deicing pads--instead it deices its
aircraft at its gates. Because deicing is the responsibility of the airport
tenants, the airport cannot force them to use the deicing pads. This
official also noted that the airport must currently use trucks to take spent
deicing/anti-icing fluids from one part of the airport to the recycling
plant and that a pipeline is needed to improve the efficiency of this
operation.

An Adams County commissioner told us that the $200 million runoff disposal
system for deicing built at Denver International Airport does not work as
intended to contain harmful chemicals. After receiving an anonymous tip and
complaints from a farmer, the commissioner tested the water bodies in
adjacent communities and found traces of glycol that had seeped into two
creeks that flow from Denver International Airport into Barr Lake--a
recreational lake in Adams County. The county health department verified
these findings. The airport added more permanent berms on the runways and
fixed the drains. The commissioner said the problem with the runoff seems to
have improved, but he is frustrated by the lack of standards on glycol
contamination, and the county health department cannot tell him what levels
are safe. An airport official noted that although the airport's extensive
disposal systems capture 80 percent of the spent deicing fluids, the
remaining 20 percent escape.

Portland, Oregon: Portland International Airport has had difficulty managing
the runoff from its deicing/anti-icing operations and the environmental
impact of this runoff on local water bodies. The airport is built on a
floodplain behind a dike along the Columbia River--located north of the
airport. The Columbia Slough, located south of the airport, has been the
receiving water body for the airport's deicing runoff. The slough was
originally designed to assist in draining the industrial area that surrounds
the airport. However, in the 1980s and 1990s, it was transformed into an
"urban stream" that supports a species of fish listed as endangered. In
addition, industries along the slough have been replaced by office parks,
golf courses, and housing. The Northwest Environmental Defense Center filed
complaints with the state charging that the airport's National Pollutant
Discharge Elimination System permit must require immediate implementation,
but the issue has not been resolved. With the help of the airlines, Portland
International Airport has developed a system for managing deicing runoff
from the entire airport to address concerns about discharges into local
water bodies--primarily the Columbia Slough and the Columbia River.

Boston's Logan International Airport: Airport officials told us that the
airport has a wide range of air pollutant emissions reduction efforts under
way and has successfully leveraged private-sector funds to support them. In
addition, when the airport began experiencing operational problems in the
early 1980s--because of a lack of parking and ground transportation
gridlock--it initiated efforts to reduce congestion and air pollutant
emissions, including maximizing the number of alternative-fuel vehicles used
at the airport. Using such vehicles to reduce emissions has allowed the
airport to accumulate "credits" that can be banked or sold. Massport47
officials told us that the following are some of the efforts under way at
Logan:

ï¿½ To help alleviate congestion, the airport entered into a partnership with
the airlines, which agreed to pay half the cost of three remote
park-and-ride facilities that made less expensive parking available for
passengers and airport employees. Within 3 to 4 years, this partnership,
known as Logan Express, began to see a profit. Currently, Logan Express
serves over 1 million passengers per year, approximately 87 percent of whom
are repeat customers. Employees are the fastest-growing users of this
service and currently account for 10 to 20 percent of the riders. This
solution has also improved air quality at the airport because trips into the
airport core are not keeping pace with operations. Currently, Logan Express
operates 32 natural gas buses and 2 electric buses, which not only alleviate
congestion but also produce less pollution than conventional vehicles.

ï¿½ Through the establishment of public/private partnerships--supported, in
part, by grants and federal funding from EPA Region 1--Logan has promoted
the use of alternative-fuel vehicles. For example, such partnerships allow
the airport to help private operators of buses, shuttles, and taxis defray
the up-front costs of purchasing these vehicles. The use of alternative-fuel
vehicles also allows private operators to reduce their operating expenses
because natural gas costs less than unleaded fuel. As a further incentive,
the airport offers the operators of alternative-fuel vehicles a 25-percent
discount on their access permits.

ï¿½ Interest in procuring and using alternative-fuel vehicles is driven by the
Energy Policy Act of 1992, which was enacted to reduce the United States'
dependence on foreign oil. Because the state runs the airport, it must
comply with the act. By 1999, the law required 50 percent of the vehicles
purchased by the state to use alternative fuels. By 2000, 75 percent of the
state's purchased vehicles must use alternative fuels. If the state/airport
purchases more than the allotted percentage, the state receives air emission
credits. State agencies, utilities, and industries can then buy the credits.
One of these officials noted that the credits are selling for about $4,200
apiece. The airport has approximately 65 to 70 credits that can be banked or
sold.

ï¿½ Currently, one-quarter of the airport's fleet of ground vehicles consists
of alternative-fuel vehicles--40 natural gas and 20 electric vehicles. In
addition, the airport has provided an adequate number of refueling stations
to support the use of these alternative-fuel vehicles.

ï¿½ Consolidating Boston's Logan International Airport rental car facilities
would be the most significant access improvement the airport could make to
reduce air pollutant emissions. Instead of being spread out around the
airport, these facilities would be collocated. Further reductions in
emissions could then be obtained if the agencies consolidated their
passenger shuttle operations. Currently, the airport is renegotiating its
contracts with six rental car agencies, each of which now operates six to
nine gasoline-fueled buses--running every 2 to 3 minutes--which are operated
well below passenger capacity. To help reduce the emissions generated by
these operations, the airport is hoping to compel the rental car agencies to
purchase alternative-fuel vehicles or consolidate their rental car
facilities, as the Dallas/Fort Worth and Denver airports have done. However,
Massport officials observed that consolidation is very complicated. One
official noted that rental car companies are reluctant to consolidate their
operations because they are fearful of losing market shares.

Los Angeles International Airport: According to officials at this airport,
Los Angeles World Airports--which includes the Los Angeles International
Airport--has won four awards from the Clean Air Coalition for its efforts to
reduce air pollutant emissions.48 These efforts can be broken into two
categories--activities that support aircraft operations (airside) and
activities that support access to the airport (landside).

Airport authority officials told us that Los Angeles International Airport
has undertaken efforts to reduce air pollutant emissions for activities
supporting aircraft operations. For instance, the airport recently hosted a
conference for airport tenants to promote the use of alternative-fuel
vehicles for ground service equipment. In addition, alternative-fuel
vehicles currently make up half of the ground service fleet at the airport.

Airport officials also cited several efforts currently used to reduce the
impact on air quality of its ground access (landside) operations, including
the following:

ï¿½ Van pools: Van pools are currently used by more than half of the airport's
2,000 employees.

ï¿½ Remote pickup sites: The airport supports several remote passenger pickup
sites and shuttles passengers to the airport.

ï¿½ Electric gates: Gate-based electrical power and preconditioned air are
provided to aircraft to reduce the use of onboard and auxiliary, stand-alone
power systems that are more polluting. Preconditioned air is available at
approximately 50 percent of the airport's gates.

ï¿½ Shuttle vehicles: Many shuttle vehicles use alternative fuels. Currently,
the airport is encouraging hotel shuttle services to switch to
alternative-fuel vehicles. In addition, to reduce the number of shuttle
vehicles traveling in and around the airport, the airport is encouraging
hotel and rental car companies to consolidate their shuttle services.

ï¿½ Airport-owned vehicles: Half of the airport fleet now consists of
alternative-fuel vehicles.

ï¿½ Flex schedules: By encouraging the use of flexible work schedules, the
airport has reduced the traffic congestion generated by employees by 10
percent.

ï¿½ Public transit: There is a city bus terminal at the airport, and a free
bus provides service to the nearby light rail system.

ï¿½ Circulation of shuttles: Short-range shuttles are limited to making three
rounds before going to their destination in order to cut back on the amount
of traffic circulating around the airport. Long-range shuttles are limited
to four rounds.

ï¿½ Cogeneration plant: This plant creates hot and cold water from waste heat
from the airport. Excess power generated from the plant is then sold back to
the power company. An airport official said that a cogeneration plant is
more fuel efficient and less costly than traditional methods of generating
power.

ï¿½ Free electric recharging stations: These stations provide free parking and
recharging for electric vehicle users. Currently there are approximately 15
recharging stations, and the airport is planning to expand this service.

Europe Is Addressing the Environmental Impacts of Airports

Europe is taking steps to help limit the impacts of airports on the
environment--focusing primarily on noise. A November 1999 report from the
European Commission entitled Air Transport and the Environment: Towards
Meeting the Challenges of Sustainable Development discusses Europe's
position and planned approach for the future. Europe is developing a common
noise classification scheme in an attempt to avoid further proliferation of
different local systems and is looking at better land-use planning to reduce
the problem. The goal is to establish an objective, common basis for
computing the level of noise exposure. In addition, the European Commission
will, in cooperation with member states, consider the possibility of
establishing recommended practices for making land-use decisions in the
vicinity of airports and will propose that proper land-use rules be
considered as a criterion for financial support to airport construction and
expansion projects under the European Community's various financial
instruments. Finally, the Commission will examine the feasibility and
possible scope of a Community system to identify particularly
noise-sensitive airports with a view to applying more stringent regulations
at these airports.

Europe is also addressing aircraft emissions, including working closely with
the International Civil Aviation Organization to develop new parameters for
assessing aircraft emissions for landing and takeoff and to establish
parameters for climbing and cruising altitudes. In addition, the Commission
is continuing to study innovative concepts, such as emissions trading.
Finally, the European Commission noted the importance of ensuring that its
research and development programs aim at breakthrough achievements in the
environmental performance of aircraft and their engines, as well as in
understanding and assessing the atmospheric effects of aircraft gas
emissions. Such achievements, according to the Commission, will have the
benefit of safeguarding the competitiveness of the European Commission's
aeronautical industry.

List of the 50 Busiest U.S. Commercial Service Airports Based on 1998 Data
From FAA

Anchorage International
Atlanta International
Austin/Bergstrom International
Baltimore-Washington International
Boston/Logan International
Charlotte/Douglas International
Chicago/Midway
Chicago/O'Hare International
Cleveland Hopkins International
Covington/Cincinnati International
Dallas/Fort Worth International
Dallas Love Field
Denver International
Detroit Metro Wayne County
Fort Lauderdale/Hollywood
Honolulu International
Houston/George Bush Intercontinental
Houston Hobby
Indianapolis International
John F. Kennedy International
Kansas City International
La Guardia
Lambert/St. Louis International
Las Vegas/McCarran International
Los Angeles International
Memphis International
Metropolitan Oakland International
Miami International
Milwaukee/General Mitchell International
Minneapolis/St. Paul International
Nashville International
New Orleans International/Moisant
Newark International
Ontario International
Orlando International
Philadelphia International
Phoenix Sky Harbor International
Pittsburgh International
Port Columbus International
Portland International
Raleigh-Durham International
Reno/Tahoe International
Ronald Reagan Washington National
Salt Lake City International
San Diego International/Lindbergh
San Francisco International
San Jose International
Seattle Tacoma International
Tampa International
Washington Dulles International

Comments From the National Aeronautics and Space Administration

1. We added information to the report in response to NASA's comment.

2. We added information to the report in response to NASA's comment.

Comments From the Department of Defense

GAO Contacts and Staff Acknowledgments

Gerald Dillingham, (202) 512-2834
Belva Martin, (202) 512-2834

In addition to those named above, Danielle Bartoni, Sandra Cantler, Keith
Cunningham, Beverly Dulaney, Bess Eisenstadt, Fran Featherston, and David
Hooper made key contributions to this report.

(348176)

Figure 1: General Overview of the Federal Environmental
Review Process Under NEPA 20

Figure 2: Environmental Issues That Currently Most Concern
Airports 31

Figure 3: Adverse Impact of Aircraft Noise on Residents Near
Los Angeles International Airport 33

Figure 4: Noise Mitigation Strategies Required or Encouraged
by Airports 38

Figure 5: Cumulative Totals for the Frequency of Airport Noise
Monitoring 40

Figure 6: Residential Communities Bordering Miami
International Airport 44

Figure 7: Aircraft Deicing/Anti-Icing Trucks at Denver
International Airport 46

Figure 8: Airports' Use of Selected Deicing and Anti-Icing
Chemical Capture Techniques 48

Figure 9: Air Quality Issues That Are Major Concerns for Airports 51

Figure 10: Environmental Issues That Most Concern Airports
Currently and in the Future 53

Figure 11: Electric Vehicle Recharging Stations at Los Angeles
International Airport 54

Figure 12: Strategies for Reducing Air Pollutant Emissions
Funded by Airports 56

Figure 13: Use of Alternative-Fuel Shuttles at Los Angeles
International Airport 58

Figure 14: Airports' Opinions of FAA's Effectiveness in Selected
Environmental Areas 64

Figure 15: Airports' Satisfaction With the NEPA Review Process 69

Figure 16: Share of Airports With Expansion Projects Whose Projects Required
Environmental Review 71

Figure 17: Two Deicing/Anti-Icing Runoff Capture Basins at Denver
International Airport 88
  

1. The law also states that the governor must certify that a runway project
meets local water quality standards, but no airport, federal, state, or
local official mentioned this as a problem. However, states retain the right
to implement stricter water quality guidelines than the federal government
requires in the Clean Water Act, regardless of the state certification
process.

2. According to FAA, airports have a blueprint for airport
development--known as an airport layout plan--which reflects projects
approved by FAA.

3. 42 U.S.C. 4901-4918.

4. The act required the phased elimination of older, noisier civil subsonic
aircraft--known as Stage 2--weighing over 75,000 pounds that use airports in
the contiguous United States by Dec. 31, 1999. However, some Stage 2
aircraft have been modified to meet the quieter standards required of Stage
3 aircraft.

5. The Federal Water Pollution Control Act, 33 U.S.C. 1251-1387, is
generally referred to as the Clean Water Act.

6. FAA is also responsible for the safe design of aircraft and the safe and
efficient use of navigable airspace under 49 U.S.C. 44701 and 40103(b),
respectively.

7. Ambient air is any unconfined portion of the atmosphere--open air or
surrounding air.

8. EPA defines point sources as discrete conveyances such as pipes or
man-made ditches.

9. 40 C.F.R. part 1500-1508.

10. A sponsor is any public agency or private owner of a public-use airport,
as defined under 49 U.S.C. 47102(19)(A)(B), that applies to receive federal
financial assistance or anyone proposing an airport action for which a
federal authorization is required.

11. FAA has statutory responsibility under 49 U.S.C. 40101(d)(4) and 40103
to control the use of the navigable airspace and regulate civil and military
operations in that airspace in the interest of safety and efficiency. Under
this authority, FAA must approve any take-off or landing flight paths for a
particular airport. FAA also has enforcement authority and may assess civil
penalties for a pilot's deviation from air traffic controller instructions
to follow approved flight paths under 14 C.F.R. part 91.123. A pilot may
deviate from an air traffic controller's instructions only in an emergency
safety situation or if they have the air traffic controller's approval.

12. Safety and operational parameters are usually indicated in FAA NEPA
documents and Part 150 approvals.

13. The databases searched included DIALOG, NEXIS, and WESTLAW.

14. We used FAA's statistics on the number of air carrier operations in 1998
to identify the nation's 50 busiest commercial service airports for
inclusion in our survey.

15. To meet Stage 3 standards, older aircraft engines are fitted with
hushkits to muffle the noise they generate.

16. Airport Noise and Capacity Act of 1990.

17. To measure the impacts of airport-related noise on nearby communities,
FAA uses the day-night sound level method, which places a greater weight on
noise from flights occurring between 10 p.m. and 7 a.m.

18. Under land use compatibility guidelines in FAA's regulations, the noise
levels within which some land uses, such as residences and schools, are
considered incompatible with airport operations.

19. Our estimate is based on airport officials' responses to our survey,
provided from October 1999 through February 2000. FAA's estimate is based on
a model that projected the 2000 population using 1998 statistics.

20. The use of "restrictions" and "limitations" was based on the wording of
GAO's survey of airports and is not intended to reflect the special meaning
under Federal Aviation Regulation part 161.

21. Any mandatory bans in place as of the date of this report predate the
Aircraft Noise and Control Act of 1990 and were exempted from review under
Federal Aviation Regulation part 161.

22. A passenger facility charge is a boarding fee charged to passengers to
help pay for airports' capital development and noise-related projects.

23. These aircraft are particularly noisy because they are among those that
weigh less than 75,000 pounds and therefore were not required to be modified
or phased out to meet the more stringent standards for Stage 3 aircraft. The
federal phaseout regulation for aircraft does not apply to aircraft weighing
less than 75,000 pounds. Thus, older subsonic jet aircraft (certified before
1975) that do not comply with Stage 3 standards are still allowed to operate
in the United States.

24. During a tour of Los Angeles International Airport, an airport authority
official noted that a wall had been built between the airport and residences
in an effort to reduce the impact of aircraft noise on adjacent communities.
However, the official told us that these walls are often constructed for
political reasons and, in some cases, can actually increase the impact of
noise on some residences by creating a tunneling effect. Similarly,
officials at Miami International Airport told us that a sound wall built by
the airport has been only marginally effective because it buffers only the
first several rows of residences closest to the wall.

25. The airport official responsible for addressing aircraft noise told us
many of these complaints are from residents living in areas with relatively
low noise levels--below the 65 db DNL.

26. A nonattainment area is any geographic area in the United States that is
in violation of any National Ambient Air Quality Standard for specified
criteria pollutants (ozone, carbon monoxide, particulates, sulfur dioxide,
nitrogen dioxide, and lead) under the Clean Air Act, as amended.

27. Any geographic area of the United States previously designated as a
nonattainment area pursuant to the Clean Air Act Amendments of 1990 and
subsequently redesignated to attainment.

28. Gates are wired to provide aircraft with air and electricity during gate
operations.

29. Massport is an independent public authority, which develops, promotes,
and manages airports--including Logan International Airport, the seaport,
and transportation infrastructure.

30. Los Angeles World Airports is the aviation authority that maintains and
operates the Los Angeles International Airport, Ontario International
Airport, Van Nuys Airport, and Palmdale Regional Airport.

31. 49 U.S.C. 47504.

32. The committee was established to provide forums for debate over future
research needs to better understand, predict, and control the effects of
aviation noise and to encourage new developments in technology. Members
include the Department of Defense, the Department of Transportation (FAA),
the Department of the Interior, EPA, and the National Aeronautics and Space
Administration.

33. Air Quality Procedures for Civilian Airports and Air Force Bases, FAA
and U.S. Air Force (Apr. 1997).

34. EPA Preliminary Data Summary--Airport Deicing Operations (EPA, Jan.
2000).

35. Evaluation of Air Pollutant Emissions from Subsonic Commercial Jet
Aircraft (EPA, Apr. 1999).

36. According to an FAA official, the agency contributes about $1 for every
$20 NASA spends on relevant environmental research.

37. There is no assurance that industry will complete the development of any
technology developed in NASA's programs. Such development will occur in
response to the marketplace or regulatory standards.

38. According to the Intergovernmental Panel on Climate Change, there is no
single relationship between NOx and CO2 that holds for all engine types. See
Aviation and the Global Atmosphere, IPCC (1999).

39. FAA Order 5050.4A, Airport Environmental Handbook.

40. A boarding fee charged to passengers to help airports pay for capital
development projects.

41. On airport layout plan approvals, FAA documents specific airport
development projects that require an environmental assessment or
environmental impact statement prior to FAA's unconditional approval of the
airport layout plan and prior to construction. However, FAA does not
necessarily document projects on the plan that FAA has categorically
excluded from further environmental review.

42. Current guidance that airport projects or actions are subject to
includes FAA Orders 1050.1D and 5050.4A, the FAA air quality procedures
handbook, and EPA regulations on general conformity provisions of the Clean
Air Act.

43. Although most projects designed to mitigate the impact of aircraft noise
on surrounding communities are funded through the Airport Improvement
Program noise set aside, airports can choose to finance these projects in
other ways, such as using passenger facility charges, airport revenue or
other Airport Improvement Program funding for which the airport is eligible.
In addition, some soundproofing of schools and health care facilities is
eligible for funding even if an airport does not participate in this
program. 49 U.S.C. 47504(c)(2)(D).

44. Boston's Logan International Airport also chose not to participate in
FAA's Part 150 noise compatibility program, but it was not included in this
statistic because the airport receives federal noise mitigation funds
through a grandfathering provision under the Part 150 legislation.

45. The state certification requirement also requires that federally funded
airport runway additions or major expansions conform to local water quality
standards. However, this requirement was not raised during our review as
problematic for airports.

46. While state air quality certification applies to all airports, Clean Air
Act requirements vary depending on the attainment status of a given region.

47. Massport is an independent public authority, which develops, promotes,
and manages airports, including Logan International Airport, the seaport,
and transportation infrastructure.

48. Los Angeles World Airports is the aviation authority that maintains and
operates the Los Angeles International Airport, Ontario International
Airport, Van Nuys Airport, and Palmdale Regional Airport.
*** End of document. ***