GAO

United States General Accounting Office

Report to the Ranking Democratic

Member, Committee on Transportation

and Infrastructure, House of

Representatives

August 2000 AVIATION AND THE

ENVIRONMENT

Airport Operations

and Future Growth

Present

Environmental

Challenges

GAO/RCED-00-153

Page 1 GAO/RCED-00-153 Airports and the Environment

Contents

Letter 5

Executive Summary 6

Chapter 1

Introduction

18

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

Chapter 2

Noise Issues Are the

PrimaryEnvironmental

Concern and 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

Chapter 3

Water Quality Is a

Primary Concern and

Challenge for Airports

45

Chapter 4

Air Quality Is an

Increasing Concern

and Challenge for

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
Contents

Page 2 GAO/RCED-00-153 Airports and the Environment

Chapter 5

The Federal

Government Has

Coordinated Some

Efforts, but 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

Appendixes 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

Figures 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
Contents

Page 3 GAO/RCED-00-153 Airports and the Environment

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

Abbreviations

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]
Page 4 GAO/RCED-00-153 Airports and the Environment
United States General Accounting Office

Washington, D.C. 20548

Page 5 GAO/RCED-00-153 Airports and the Environment

Resources, Community, and

Economic Development Division

B-283109 Letr

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
Page 6 GAO/RCED-00-153 Airports and the Environment

Executive Summary

Purpose 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.

Background 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
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Page 7 GAO/RCED-00-153 Airports and the Environment

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;
Executive Summary

Page 8 GAO/RCED-00-153 Airports and the Environment

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.

Results in Brief 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
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Page 9 GAO/RCED-00-153 Airports and the Environment

FAA; between and among federal agencies, airports, and other

governmental entities; and federal law.

• 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.

• 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.

• 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.
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• 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.

Principal Findings

Noise, Water, and Air Issues

Are the Leading

Environmental Concerns

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.
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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.

The Federal Government

Has Coordinated Some

Efforts, but Challenges

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
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Page 12 GAO/RCED-00-153 Airports and the Environment

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
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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.
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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

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.
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state air quality certification process, states will retain the right to

implement more stringent air quality standards under the Clean Air Act.

Recommendations 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.

Matters for

Congressional

Consideration

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.

Agency Comments 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.
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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.
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Chapter 1

Introduction Chapte1r

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.
Chapter 1

Introduction

Page 19 GAO/RCED-00-153 Airports and the Environment

Federal Laws Guide

Environmental

Compliance

Requirements for

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.1 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.

1

According to FAA, airports have a blueprint for airport development—known as an airport

layout plan—which reflects projects approved by FAA.
Chapter 1

Introduction

Page 20 GAO/RCED-00-153 Airports and the Environment

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

NEPA

Action will

cause a

significant

environmental

impact

Does it fit into a

categorical

exclusion?

Are there

extraordinary

circumstances?

Draft

environmental

impact

statement

with project

alternatives

Project

categorically

excluded

Prepare an

environmental

assessment

Issue finding

of no significant

impact

Solicit public

comment

Select preferred

alternative and

finalize

environmental

impact statement

Publish record

of decision

Expansion

project can

commence

Yes

Yes

No

No

No significant impact

 or impact mitigated

Proposed

federal action

(expansion

project)
Chapter 1

Introduction

Page 21 GAO/RCED-00-153 Airports and the Environment

The Noise Control Act2 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.3 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,4 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.

2

42 U.S.C. 4901-4918.

3

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.

4

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

Clean Water Act.
Chapter 1

Introduction

Page 22 GAO/RCED-00-153 Airports and the Environment

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 FAA5

—implemented, in part,

through the agency’s process for certifying that aircraft engines meet air

pollutant emissions standards.

5

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.
Chapter 1

Introduction

Page 23 GAO/RCED-00-153 Airports and the Environment

The act and its amendments direct EPA to establish national standards for

ambient air quality.6 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.

The Federal

Government Takes a

Decentralized

Approach to

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.

6

Ambient air is any unconfined portion of the atmosphere—open air or surrounding air.
Chapter 1

Introduction

Page 24 GAO/RCED-00-153 Airports and the Environment

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 discharges7 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 NEPA8

—has responsibility for mediating

interagency disputes, the National Aeronautics and Space Administration

conducts research on aircraft noise and emissions, the Department of

7

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

8

40 C.F.R. part 1500-1508.
Chapter 1

Introduction

Page 25 GAO/RCED-00-153 Airports and the Environment

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 sponsors9 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.

9

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.
Chapter 1

Introduction

Page 26 GAO/RCED-00-153 Airports and the Environment

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.10 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.11 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.

Objectives, Scope, and

Methodology

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

10FAA 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.

11Safety and operational parameters are usually indicated in FAA NEPA documents and Part

150 approvals.
Chapter 1

Introduction

Page 27 GAO/RCED-00-153 Airports and the Environment

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.12 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 inperson pretests at four airports. In addition, we conducted on-site

interviews at seven other airports, covering the topics in the survey. These

12The databases searched included DIALOG, NEXIS, and WESTLAW.
Chapter 1

Introduction

Page 28 GAO/RCED-00-153 Airports and the Environment

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.).
Chapter 1

Introduction

Page 29 GAO/RCED-00-153 Airports and the Environment

We conducted our review from July 1999 through August 2000 in

accordance with generally accepted government auditing standards.
Page 30 GAO/RCED-00-153 Airports and the Environment

Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports Chapte2r

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.
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 31 GAO/RCED-00-153 Airports and the Environment

Airports Reported

Noise Concerns as

Their Most Serious

Environmental

Challenge

According to our survey of officials from the nation’s 50 busiest

commercial service airports,1 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.

Figure 2: Environmental Issues That Currently Most Concern Airports

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.

1

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.

6 airports: 

air quality 

29 airports: 

noise 

12 airports: 

water quality 

2 airports: 

compatibility with

nearby land uses

1 airport: 

none applicable

58%

4%

12%

24%

2%
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 32 GAO/RCED-00-153 Airports and the Environment

Noise Generated by Older,

Hushkitted Aircraft Are

Airports’ Primary 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 hushkits2 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, 1999.3 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.

2

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

they generate.

3

Airport Noise and Capacity Act of 1990.
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 33 GAO/RCED-00-153 Airports and the Environment

Incompatible Land Uses

Near Airports Are a Major

Concern and 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.4 (See fig. 3.)

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

International Airport

4

To measure the impacts of airport-related noise on nearby communities, FAA uses the daynight sound level method, which places a greater weight on noise from flights occurring

between 10 p.m. and 7 a.m.
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 34 GAO/RCED-00-153 Airports and the Environment

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.
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 35 GAO/RCED-00-153 Airports and the Environment

Population Increases Near

Some Airports Pose

Challenges for the 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 contours5 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.

5

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.
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 36 GAO/RCED-00-153 Airports and the Environment

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.6

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.

6

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.
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 37 GAO/RCED-00-153 Airports and the Environment

Airports Have

Implemented Various

Measures to Reduce

the Impact of 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.7 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,8 and aircraft towing rather than taxiing. (See fig. 4.)

7

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.

8

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.
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 38 GAO/RCED-00-153 Airports and the Environment

Figure 4: Noise Mitigation Strategies Required or Encouraged by Airports

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 noisesensitive properties, relocating people, modifying structures to reduce

noise, encouraging compatible zoning, and assisting in the sale of affected

properties.

Noise mitigation strategies

0 5 10 15 20 25 30 35 40 45 50

All others 6 3

3 5 Limits on the number of operations

 during certain hours

Aircraft towing 4 8

Restricted hours 5 10

10 5 Limits or bans on certain types of aircraft

during certain hours

Reduced engine taxiing 3 15

Limits on the use of certain runways 17 25

Preferential use of certain flight paths 19 25

Ground run-up restrictions/limitations 37 7

Number of airports

Required

Encouraged
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 39 GAO/RCED-00-153 Airports and the Environment

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,9 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 noisemonitoring systems.

9

A passenger facility charge is a boarding fee charged to passengers to help pay for airports’

capital development and noise-related projects.
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 40 GAO/RCED-00-153 Airports and the Environment

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

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.

Airports’ Public Outreach

Efforts Often Target Aircraft

Noise Issues

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

Number of airports

0

10

20

30

40

50

Frequency of noise monitoring

47

39

35 34 33

Daily or

more often

Weekly

Monthly

Quarterly

Occasionally

Cumulative response
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 41 GAO/RCED-00-153 Airports and the Environment

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.

Community Concerns About

Aircraft Noise Persist

Despite Airports’ 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
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 42 GAO/RCED-00-153 Airports and the Environment

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 aircraft10—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 wall11 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.

10These 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.

11During 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.
Chapter 2

Noise Issues Are the Primary Environmental

Concern and Challenge for Airports

Page 43 GAO/RCED-00-153 Airports and the Environment

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 199912 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.

12The 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.
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Concern and Challenge for Airports

Page 44 GAO/RCED-00-153 Airports and the Environment

Figure 6: Residential Communities Bordering Miami International Airport

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.
Page 45 GAO/RCED-00-153 Airports and the Environment

Chapter 3

Water Quality Is a Primary Concern and

Challenge for Airports Chapte3r

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
Chapter 3

Water Quality Is a Primary Concern and

Challenge for Airports

Page 46 GAO/RCED-00-153 Airports and the Environment

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.

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

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
Chapter 3

Water Quality Is a Primary Concern and

Challenge for Airports

Page 47 GAO/RCED-00-153 Airports and the Environment

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.
Chapter 3

Water Quality Is a Primary Concern and

Challenge for Airports

Page 48 GAO/RCED-00-153 Airports and the Environment

Airports Are Attempting to

Mitigate the Impact of

Deicing/Anti-Icing

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.

Figure 8: Airports’ Use of Selected Deicing and Anti-Icing Chemical 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

All others

Other dedicated drainage system

Sanitary sewer system

Deicing pads

Common stormwater system

Vacuum sweeper trucks

Selected capture techniques

Number of airports using the technique

0 5 10 15 20 25

22

20

18

14

14

8
Chapter 3

Water Quality Is a Primary Concern and

Challenge for Airports

Page 49 GAO/RCED-00-153 Airports and the Environment

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.)

Airlines Help Airports

Manage Deicing/Anti-Icing

Operations

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 antiicing 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.
Page 50 GAO/RCED-00-153 Airports and the Environment

Chapter 4

Air Quality Is an Increasing Concern and

Challenge for Airports Chapte4r

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.
Chapter 4

Air Quality Is an Increasing Concern and

Challenge for Airports

Page 51 GAO/RCED-00-153 Airports and the Environment

Airports’ Primary Air

Quality Concerns

Involve Parking

Demand and

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.)

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

Air quality issues

13

10

11

16

16

19

22

27

0 5 10 15 20 25 30

All others

No credits for voluntary

air pollutant emission

reductions

Lack of resources for

public transit

Road congestion limiting

airport growth

High number of auto trips

to and from the airport

Difficulties offsetting

increased air pollutant

emissions

Uncertainty about

conformity with the Clean

Air Act's requirements

Growing demand for

parking

Number of airports
Chapter 4

Air Quality Is an Increasing Concern and

Challenge for Airports

Page 52 GAO/RCED-00-153 Airports and the Environment

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.

Air Quality Is a

Growing Concern for

Future Airport

Operations

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.1 Another four airports are located in areas that

recently achieved compliance, known as maintenance areas.2 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.

1

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.

2

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.
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Page 53 GAO/RCED-00-153 Airports and the Environment

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

Future

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

Water quality

Noise

None applicable

Compatibility with nearby

land uses

Air quality

Most serious problem currently

Most serious problem in the future

29

22

12

6

6

16

2

4

1

0

0 5 10 15 20 25 30 35

Number of airports

Wetlands

0

2

Environmental issues
Chapter 4

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Challenge for Airports

Page 54 GAO/RCED-00-153 Airports and the Environment

Many Airports Have

Begun to Address

Concerns About Air

Pollutant 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) alternativefuel vehicles and the infrastructure that supports them; (2) alternative, lesspolluting 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.

Figure 11: Electric Vehicle Recharging Stations at Los Angeles International Airport
Chapter 4

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Challenge for Airports

Page 55 GAO/RCED-00-153 Airports and the Environment

Officials from 30 of the airports surveyed reported they provide electricity

and 28 of the airports surveyed said they provide preconditioned air at

some gates3 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.)

3

Gates are wired to provide aircraft with air and electricity during gate operations.
Chapter 4

Air Quality Is an Increasing Concern and

Challenge for Airports

Page 56 GAO/RCED-00-153 Airports and the Environment

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

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.

0 5 10 15 20 25 30 35 40

Other

Banking of air pollutant

emission credits

Airport shuttle from

external locations

Direct rail or

subway connection

Preconditioned air at gates

Electricity at gates

Alternative-fuel stations

Alternative-fuel vehicles

Emissions pollutant reduction strategies

Number of airports

36

30

30

28

18

17

3

2
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Challenge for Airports

Page 57 GAO/RCED-00-153 Airports and the Environment

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. Massport4 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,5 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.)

4

Massport is an independent public authority, which develops, promotes, and manages

airports—including Logan International Airport, the seaport, and transportation

infrastructure.

5

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.
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Page 58 GAO/RCED-00-153 Airports and the Environment

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

Airlines Work With

Airports to Reduce Air

Pollutant Emissions

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
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Page 59 GAO/RCED-00-153 Airports and the Environment

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.
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Chapter 5

The Federal Government Has Coordinated

Some Efforts, but Challenges Remain Chapte5r

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 law1 may be limiting the effectiveness of the

federal environmental approach for some airports and communities.

Federal Coordination

Efforts Have Been

Undertaken

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.

The Federal Government

Has Coordinated Its Efforts

on Some 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.

1

49 U.S.C. 47504.
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• 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,2 convened in 1993,

which is continuing to foster aircraft noise and assessment research.

• 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.

2

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.
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FAA Has Efforts Under Way

to Address the

Environmental Impact of

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
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Page 63 GAO/RCED-00-153 Airports and the Environment

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.3

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

3

Air Quality Procedures for Civilian Airports and Air Force Bases, FAA and U.S. Air Force

(Apr. 1997).
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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.

Figure 14: Airports’ Opinions of FAA’s Effectiveness in Selected Environmental

Areas

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.

Number of airports

Answering

questions

Coordinating

among FAA

offices

Providing

standard

rules and

guidance

Processing

paperwork

Coordinating

with other

federal

agencies

Coordinating

with state

agencies

Very or moderately effective

Equally effective and ineffective

Very or moderately ineffective

Ensuring

consistent

treatment

across FAA

regions

0

10

20

30

40

50

32

15

3

29

12

9

29

11

10

28

9

10

21

18

11

17

18

12

11

4

16

50 50 50

47

50

47

31
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EPA Has Undertaken

Efforts to Address the

Environmental Impact of

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.4

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.5

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.

NASA Is Involved in Efforts

to Work With Industry to

Address 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.

4

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

5

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

1999).
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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.6 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.7

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.

6

According to an FAA official, the agency contributes about $1 for every $20 NASA spends

on relevant environmental research.

7

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.
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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 tradeoff 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.8 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

8

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).
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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.

Federal Environmental

Review Processes Received

Mixed Reviews From

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.)
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Figure 15: Airports’ Satisfaction With the NEPA Review Process

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.

Number of airports

Somewhat or very satisfied

Uncertain/neutral

Somewhat or very dissatisfied

0

5

10

15

20

25

30

35

30

10

7

Categorical exclusion

30

9 8

Environmental

assessment—

finding of no 

significant impact

13 13

14

Environmental impact

statement
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Some Efforts, but Challenges Remain

Page 70 GAO/RCED-00-153 Airports and the Environment

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

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 policy9 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.

9

FAA Order 5050.4A, Airport Environmental Handbook.
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Figure 16: Share of Airports With Expansion Projects Whose Projects Required

Environmental Review

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

26 airports: 

all projects required a review

23 airports: 

some projects did not 

require a review

Figure includes the 49 airports with expansion projects in the last 10 years

53% 47%

5 airports: 

fewer than half of the 

projects required a review 

5 airports: 

about half of the 

projects required a review 

8 airports: 

almost all of the 

projects required a review

5 airports: 

more than half of the 

projects required a review 
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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,10 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.11 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.

10A boarding fee charged to passengers to help airports pay for capital development

projects.

11On 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.
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Many Airports Are

Uncertain About How

to Meet Clean Air Act

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.

Federal Guidance and

Experience With Complying

With the Clean Air 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.
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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.12 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.

12Current 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.
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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.

Confusion Exists in Three

Other Areas of the Clean Air

Act as It Applies to Airports

Our review identified three other areas of confusion for airports under the

Clean Air Act.

• 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
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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.

• 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.

• 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.
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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.

Difficulties Remain in

Coordinating Federal, State,

and Local 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.

• 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.
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• 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.
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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

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.

Federal Law Limits FAA in

Assisting Some People

Affected by Aircraft 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.13 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.

13Although 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).
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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.14 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.

14Boston’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.
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Federal Laws Include

Duplicative Air Quality

Processes That Burden

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.15 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.16

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

15The 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.

16While state air quality certification applies to all airports, Clean Air Act requirements vary

depending on the attainment status of a given region.
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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.

Conclusions 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
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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
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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.

Recommendations 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

• communicate to airport officials the requirement that all airport

expansion projects are subject to environmental reviews,

• document the results of all categorical exclusions, and

• 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.

Matters for

Congressional

Consideration

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.

Agency Comments We provided the Department of Transportation; the Department of

Defense; NASA; EPA; and an advisory panel that included the Air Transport
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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.
Page 86 GAO/RCED-00-153 Airports and the Environment

Appendix I

Selected Airports’ Activities to Balance Apendxies

Operations and Growth With Environmental

Impacts ApendxiI

Airport Noise 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 noiserelated 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.
Appendix I

Selected Airports’ Activities to Balance

Operations and Growth With Environmental

Impacts

Page 87 GAO/RCED-00-153 Airports and the Environment

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).

Water Quality 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.
Appendix I

Selected Airports’ Activities to Balance

Operations and Growth With Environmental

Impacts

Page 88 GAO/RCED-00-153 Airports and the Environment

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

Airport
Appendix I

Selected Airports’ Activities to Balance

Operations and Growth With Environmental

Impacts

Page 89 GAO/RCED-00-153 Airports and the Environment

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.
Appendix I

Selected Airports’ Activities to Balance

Operations and Growth With Environmental

Impacts

Page 90 GAO/RCED-00-153 Airports and the Environment

Air Quality 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. Massport1

officials told us that the following are some of the efforts under way at

Logan:

• To help alleviate congestion, the airport entered into a partnership with

the airlines, which agreed to pay half the cost of three remote park-andride 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.

• 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

1

Massport is an independent public authority, which develops, promotes, and manages

airports, including Logan International Airport, the seaport, and transportation

infrastructure.
Appendix I

Selected Airports’ Activities to Balance

Operations and Growth With Environmental

Impacts

Page 91 GAO/RCED-00-153 Airports and the Environment

access permits.

• 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.

• 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.

• 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.
Appendix I

Selected Airports’ Activities to Balance

Operations and Growth With Environmental

Impacts

Page 92 GAO/RCED-00-153 Airports and the Environment

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.2 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:

• Van pools: Van pools are currently used by more than half of the

airport’s 2,000 employees.

• Remote pickup sites: The airport supports several remote passenger

pickup sites and shuttles passengers to the airport.

• Electric gates: Gate-based electrical power and preconditioned air are

provided to aircraft to reduce the use of onboard and auxiliary, standalone power systems that are more polluting. Preconditioned air is

available at approximately 50 percent of the airport’s gates.

• Shuttle vehicles: Many shuttle vehicles use alternative fuels. Currently,

the airport is encouraging hotel shuttle services to switch to alternativefuel 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.

• Airport-owned vehicles: Half of the airport fleet now consists of

alternative-fuel vehicles.

2

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.
Appendix I

Selected Airports’ Activities to Balance

Operations and Growth With Environmental

Impacts

Page 93 GAO/RCED-00-153 Airports and the Environment

• Flex schedules: By encouraging the use of flexible work schedules, the

airport has reduced the traffic congestion generated by employees by 10

percent.

• Public transit: There is a city bus terminal at the airport, and a free bus

provides service to the nearby light rail system.

• 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.

• 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.

• 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.
Page 94 GAO/RCED-00-153 Airports and the Environment

Appendix II

Europe Is Addressing the Environmental

Impacts of Airports ApendxiI

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 landuse 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.
Page 95 GAO/RCED-00-153 Airports and the Environment

Appendix III

List of the 50 Busiest U.S. Commercial Service

Airports Based on 1998 Data From FAA ApendxiI

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
Appendix III

List of the 50 Busiest U.S. Commercial

Service Airports Based on 1998 Data From

FAA

Page 96 GAO/RCED-00-153 Airports and the Environment

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
Page 97 GAO/RCED-00-153 Airports and the Environment

Appendix IV

Comments From the National Aeronautics

and Space Administration ApendxiIV

Note: GAO’s comments

supplementing those in the

report appear at the end of

this appendix.

Now on p. 67.

See comment 1.

Now on p. 68.

See comment 2.
Appendix IV

Comments From the National Aeronautics

and Space Administration

Page 98 GAO/RCED-00-153 Airports and the Environment

GAO Comments 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.
Page 99 GAO/RCED-00-153 Airports and the Environment

Appendix V

Comments From the Department of Defense ApendxiV
Page 100 GAO/RCED-00-153 Airports and the Environment

Appendix VI

GAO Contacts and Staff Acknowledgments ApendxiVI

GAO Contacts Gerald Dillingham, (202) 512-2834

Belva Martin, (202) 512-2834

Staff

Acknowledgments

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.

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