[Federal Register Volume 68, Number 189 (Tuesday, September 30, 2003)]
[Proposed Rules]
[Pages 56226-56251]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-24412]



[[Page 56226]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 87

[AMS-FRL-7561-7]
RIN 2060-AK01


Control of Air Pollution From Aircraft and Aircraft Engines; 
Emission Standards and Test Procedures

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: In this action, we are proposing to amend the existing United 
States regulations governing the exhaust emissions from new commercial 
aircraft gas turbine engines. Under the authority of section 231 of the 
Clean Air Act (CAA), the Environmental Protection Agency (EPA) is 
proposing new emission standards for oxides of nitrogen 
(NOX) for newly certified commercial aircraft gas turbine 
engines with rated thrust greater than 26.7 kilonewtons (kN). This 
action proposes to adopt standards equivalent to the latest (effective 
in 2004) NOX standards of the United Nations International 
Civil Aviation Organization (ICAO), and thereby bring the United States 
emission standards into alignment with the internationally adopted 
standards. In addition, today's action also would amend the test 
procedures for gaseous exhaust emissions to correspond to recent 
amendments to the ICAO test procedures for these emissions.
    After December 31, 2003, the proposed NOX standards 
would apply to newly certified gas turbine engines--those engines 
designed and certified after the effective date of the proposed 
regulations (for purposes of this action, the date of manufacture of 
the first individual production model means the date of type 
certification). Since the proposed NOX standards would apply 
to only newly certified gas turbine engines, newly manufactured engines 
(those engines built after the effective date of the proposed 
regulations) would not have to meet these standards. Moreover, all 
engines currently being built would not have to comply with the 
NOX emission standards that EPA is adopting today.
    Today's proposed amendments to the emission test procedures are 
those recommended by ICAO and are widely used by the aircraft engine 
industry. Thus, today's action would establish consistency between U.S. 
and international standards, requirements, and test procedures. Since 
aircraft and aircraft engines are international commodities, there is 
significant commercial benefit to consistency between U.S. and 
international emission standards and control program requirements. In 
addition, today's action ensures that domestic commercial aircraft 
would meet the current international standards, and thus, the public 
can be assured they are receiving the air quality benefits of the 
international standards.

DATES: Comments: EPA requests comments on the proposed rulemaking by 
December 15, 2003. More information about commenting on this action may 
be found under Public Participation in the SUPPLEMENTARY INFORMATION 
section and section I.C.
    Hearing: We will hold a public hearing on November 13, 2003. The 
hearing will start at 10 a.m. local time and continue until everyone 
has had a chance to speak. If you want to testify at the hearing, 
notify the contact person listed below at least ten days before the 
hearing.

ADDRESSES: Comments: Comments may be submitted by mail to: Air Docket, 
Environmental Protection Agency, Mailcode: 6102T, 1200 Pennsylvania 
Ave., NW., Washington, DC, 20460, Attention Docket ID No. OAR 2002-
0030. Comments may also be submitted electronically, by facsimile, or 
through hand delivery/courier. Follow the detailed instructions as 
provided in section I.C. of the SUPPLEMENTARY INFORMATION section.
    Hearing: The public hearing will be held at the Environmental 
Protection Agency, EPA East Building, Room Number 1153, 1201 
Constitution Avenue, NW., Washington, DC 20004, Telephone: (202) 564-
1682. See section VIII for more information about public hearings.

FOR FURTHER INFORMATION CONTACT: Mr. Bryan Manning, U.S. EPA, Office of 
Transportation and Air Quality, Assessment and Standards Division, 2000 
Traverwood, Ann Arbor, MI 48105. Telephone (734) 214-4832; Fax: (734) 
214-4816, E-mail: [email protected].

SUPPLEMENTARY INFORMATION: 

Outline of This Preamble

I. General Information
    A. Regulated Entities
    B. How Can I Get Copies of This Document and Other Related 
Information?
    1. Docket
    2. Electronic Access
    C. How and To Whom Do I Submit Comments?
    1. Electronically
    a. EPA Dockets
    b. E-mail
    c. Disk or CD ROM
    2. By Mail
    3. By Hand Delivery or Courier
    4. By Facsimile
    D. How Should I Submit CBI to the Agency?
    E. What Should I Consider as I Prepare My Comments for EPA?
II. Introduction
    A. A Brief History of EPA's Regulation of Aircraft Engine 
Emissions
    B. Interaction With the International Community
    C. EPA's Responsibilities Under the Clean Air Act
III. Environmental Need for Control
    A. Public Health Impacts
    1. Ozone
    a. What Are the Health Effects of Ozone Pollution?
    b. Current and Projected 8-hour Ozone Levels
    2. Particulate Matter
    a. Health Effects of PM2.5
    b. Current and Projected Levels
    B. Other Environmental Effects
    1. Acid Deposition
    2. Eutrophication and Nitrification
    3. Plant Damage from Ozone
    4. Visibility
    C. Other Criteria Pollutants Affected by This Proposed Rule

IV. Description of Action

    A. What Emission Standards Are Under Consideration?
    1. Today's Proposed NOX Standards
    a. For Engines With a Pressure Ratio of 30 or less
    i. For engines with a maximum rated output of more than 89.0 kN
    ii. For engines with a maximum rated output of more than 26.7 kN 
but not more than 89.0 kN
    b. For Engines With A Pressure Ratio of More Than 30 But Less 
than 62.5
    i. For engines with a maximum rated output of more than 89.0 kN
    ii. For engines with a maximum rated output of more than 26.7 kN 
but not more than 89.0 kN
    c. For Engines With a Pressure Ratio of 62.5 or More
    2. Proposed NOX Standards of Newly Certified Mid- and 
High-Thrust Engines
    3. Proposed NOX Standards for Newly Certified Low-
Thrust Engines
    4. Rationale of Proposed NOX Standards for Newly 
Certified Low-, Mid-, and High-Thrust Engines
    5. Future NOX Standards for Newly Certified Low-, 
Mid-, and High-Thrust Engines
    B. Already Certified, Newly Manufactured Engines
    1. Effect of Market Forces
    2. Impact of Existing Fleet Aircraft
    3. Request for Comment on Applying the Proposed NOX 
Standards to Already Certified Engines
    C. Amendments to Criteria on Calibration and Test Gases for 
Gaseous Emissions Test and Measurement Procedures
    D. Correction of Exemptions for Very Low Production Models
V. Coordination with FAA

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VI. Possible Future Aviation Emissions Reduction (EPA/FAA Voluntary 
Aviation Emissions Reduction Initiative)
VII. Regulatory Impacts
VIII. Public Participation
    A. How Do I Submit Comments?
    B. Will There Be a Public Hearing?
IX. Statutory Authority
X. Statutory and Executive Orders Review
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children from 
Environmental Health & Safety Risks
    H. Executive Order 13211: Actions that Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer Advancement Act

I. General Information

A. Regulated Entities

    Entities potentially regulated by this action are those that 
manufacture and sell commercial aircraft engines and aircraft in the 
United States, and the owners/operators of such aircraft (and 
accompanying engines) in the United States. Regulated categories 
include:

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                                           NAICS \a\                        Examples of potentially affected
               Category                      codes       SIC codes \b\                  entities
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Industry..............................          336412            3724  Manufacturers of new aircraft engines.
Industry..............................          336411            3721  Manufacturers of new aircraft.
Industry..............................             481            4512  Scheduled air carriers, passenger and
                                                                         freight.
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\a\ North American Industry Classification System (NAICS).
\b\ Standard Industrial Classification (SIC) system code.

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. This table lists the types of entities that EPA is now aware 
could potentially be regulated by this action. Other types of entities 
not listed in the table could also be regulated. To determine whether 
your activities are regulated by this action, you should carefully 
examine the applicability criteria in 40 CFR 87.20. If you have any 
questions regarding the applicability of this action to a particular 
entity, consult the person listed in the preceding FOR FURTHER 
INFORMATION CONTACT section.

B. How Can I Get Copies of This Document and Other Related Information?

    1. Docket. EPA has established an official public docket for this 
action under Docket ID No. OAR 2002-0030. The official public docket is 
the collection of materials that is available for public viewing at the 
Air Docket in the EPA Docket Center, (EPA/DC) EPA West, Room B102, 1301 
Constitution Ave., NW., Washington, DC. The EPA Docket Center Public 
Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through 
Friday, excluding legal holidays. The telephone number for the Reading 
Room and the Air Docket is (202) 566-1742. You may be charged a 
reasonable fee for photocopying docket materials, as provided in 40 CFR 
part 2.
    2. Electronic Access. You may access this Federal Register document 
electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr/.
    An electronic version of the public docket is available through 
EPA's electronic public docket and comment system, EPA Dockets. You may 
use EPA Dockets at http://www.epa.gov/edocket/ to submit or view public 
comments, access the index listing of the contents of the official 
public docket, and to access those documents in the public docket that 
are available electronically. Once in the system, select ``search,'' 
then key in the appropriate docket identification number.
    Certain types of information will not be placed in the EPA Dockets. 
Information claimed as confidential business information (CBI) and 
other information whose disclosure is restricted by statute, which is 
not included in the official public docket, will not be available for 
public viewing in EPA's electronic public docket. EPA's policy is that 
copyrighted material will not be placed in EPA's electronic public 
docket but will be available only in printed, paper form in the 
official public docket. To the extent feasible, publicly available 
docket materials will be made available in EPA's electronic public 
docket. When a document is selected from the index list in EPA Dockets, 
the system will identify whether the document is available for viewing 
in EPA's electronic public docket. Although not all docket materials 
may be available electronically, you may still access any of the 
publicly available docket materials through the docket facility 
identified in section I.B.1. EPA intends to work towards providing 
electronic access to all of the publicly available docket materials 
through EPA's electronic public docket.
    For public commenters, it is important to note that EPA's policy is 
that public comments, whether submitted electronically or in paper, 
will be made available for public viewing in EPA's electronic public 
docket as EPA receives them and without change, unless the comment 
contains copyrighted material, CBI, or other information whose 
disclosure is restricted by statute. When EPA identifies a comment 
containing copyrighted material, EPA will provide a reference to that 
material in the version of the comment that is placed in EPA's 
electronic public docket. The entire printed comment, including the 
copyrighted material, will be available in the public docket.
    Public comments submitted on computer disks that are mailed or 
delivered to the docket will be transferred to EPA's electronic public 
docket. Public comments that are mailed or delivered to the Docket will 
be scanned and placed in EPA's electronic public docket. Where 
practical, physical objects will be photographed, and the photograph 
will be placed in EPA's electronic public docket along with a brief 
description written by the docket staff.
    For additional information about EPA's electronic public docket 
visit EPA Dockets online or see 67 FR 38102, May 31, 2002.

C. How and To Whom Do I Submit Comments?

    You may submit comments electronically, by mail, by facsimile, or 
through hand delivery/courier. To ensure proper receipt by EPA, 
identify the appropriate docket identification number in the subject 
line on the first page of your comment. Please ensure that your 
comments are submitted within the specified comment period. Comments 
received after the close of the comment period will be marked ``late.'' 
EPA is not required to consider these late comments.
    1. Electronically. If you submit an electronic comment as 
prescribed below, EPA recommends that you include your name, mailing 
address, and an e-mail address or other contact

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information in the body of your comment. Also include this contact 
information on the outside of any disk or CD ROM you submit, and in any 
cover letter accompanying the disk or CD ROM. This ensures that you can 
be identified as the submitter of the comment and allows EPA to contact 
you in case EPA cannot read your comment due to technical difficulties 
or needs further information on the substance of your comment. EPA's 
policy is that EPA will not edit your comment, and any identifying or 
contact information provided in the body of a comment will be included 
as part of the comment that is placed in the official public docket, 
and made available in EPA's electronic public docket. If EPA cannot 
read your comment due to technical difficulties and cannot contact you 
for clarification, EPA may not be able to consider your comment.
    a. EPA Dockets. Your use of EPA's electronic public docket to 
submit comments to EPA electronically is EPA's preferred method for 
receiving comments. Go directly to EPA Dockets at http://www.epa.gov/edocket, and follow the online instructions for submitting comments. To 
access EPA's electronic public docket from the EPA Internet Home Page, 
select ``Information Sources,'' ``Dockets,'' and ``EPA Dockets.'' Once 
in the system, select ``search,'' and then key in Docket ID No. OAR 
2002-0030. The system is an ``anonymous access'' system, which means 
EPA will not know your identity, e-mail address, or other contact 
information unless you provide it in the body of your comment.
    b. E-mail. Comments may be sent by electronic mail (e-mail) to 
[email protected], Attention Docket ID No. OAR 2002-0030. In contrast to 
EPA's electronic public docket, EPA's e-mail system is not an 
``anonymous access'' system. If you send an e-mail comment directly to 
the Docket without going through EPA's electronic public docket, EPA's 
e-mail system automatically captures your e-mail address. E-mail 
addresses that are automatically captured by EPA's e-mail system are 
included as part of the comment that is placed in the official public 
docket, and made available in EPA's electronic public docket.
    c. Disk or CD ROM. You may submit comments on a disk or CD ROM that 
you mail to the mailing address identified in section I.C.2. These 
electronic submissions will be accepted in WordPerfect or ASCII file 
format. Avoid the use of special characters and any form of encryption.
    2. By Mail. Send your comments to: Air Docket, Environmental 
Protection Agency, Mailcode: 6102T, 1200 Pennsylvania Ave., NW., 
Washington, DC, 20460, Attention Docket ID No. OAR 2002-0030.
    3. By Hand Delivery or Courier. Deliver your comments to: EPA 
Docket Center, (EPA/DC) EPA West, Room B102, 1301 Constitution Ave., 
NW., Washington, DC 20004, Attention Docket ID No. OAR 2002-0030. Such 
deliveries are only accepted during the Docket's normal hours of 
operation as identified in section I.B.1.
    4. By Facsimile. Fax your comments to: (202) 566-1741, Attention 
Docket ID. No. OAR 2002-0030.

D. How Should I Submit CBI to the Agency?

    Do not submit information that you consider to be CBI 
electronically through EPA's electronic public docket or by e-mail. 
Send or deliver information identified as CBI only to the contact 
person listed in the FOR FURTHER INFORMATION CONTACT section. You may 
claim information that you submit to EPA as CBI by marking any part or 
all of that information as CBI (if you submit CBI on disk or CD ROM, 
mark the outside of the disk or CD ROM as CBI and then identify 
electronically within the disk or CD ROM the specific information that 
is CBI). Information so marked will not be disclosed except in 
accordance with procedures set forth in 40 CFR part 2.
    In addition to one complete version of the comment that includes 
any information claimed as CBI, a copy of the comment that does not 
contain the information claimed as CBI must be submitted for inclusion 
in the public docket and EPA's electronic public docket. If you submit 
the copy that does not contain CBI on disk or CD ROM, mark the outside 
of the disk or CD ROM clearly that it does not contain CBI. Information 
not marked as CBI will be included in the public docket and EPA's 
electronic public docket without prior notice. If you have any 
questions about CBI or the procedures for claiming CBI, please consult 
the person identified in the FOR FURTHER INFORMATION CONTACT section.

E. What Should I Consider as I Prepare My Comments for EPA?

    You may find the following suggestions helpful for preparing your 
comments:
    1. Explain your views as clearly as possible.
    2. Describe any assumptions that you used.
    3. Provide any technical information and/or data you used that 
support your views.
    4. If you estimate potential burden or costs, explain how you 
arrived at your estimate.
    5. Provide specific examples to illustrate your concerns.
    6. Offer alternatives.
    7. Make sure to submit your comments by the comment period deadline 
identified.
    8. To ensure proper receipt by EPA, identify the appropriate docket 
identification number in the subject line on the first page of your 
response. It would also be helpful if you provided the name, date, and 
Federal Register citation related to your comments.

II. Introduction

A. Brief History of EPA's Regulation of Aircraft Engine Emissions

    Section 231(a)(2)(A) of the Clean Air Act (CAA) directs the EPA 
Administrator to ``issue proposed emission standards applicable to the 
emission of any air pollutant from any class or classes of aircraft or 
aircraft engines which in his judgment causes, or contributes to, air 
pollution which may reasonably be anticipated to endanger public health 
or welfare'' (42 U.S.C. 7571(a)(2)(A)). Under this authority EPA has 
conducted several rulemakings since 1973 establishing emission 
standards and related requirements for several classes (commercial and 
general aviation engines) of aircraft and aircraft engines. Most 
recently, in 1997 EPA promulgated NOX emission standards for 
newly manufactured gas turbine engines (those engines built after the 
effective date of the regulations or already certified engines) and for 
newly certified gas turbine engines (those engines designed and 
certified after the effective date of the regulations\1\).\2\ In 
addition, EPA promulgated a carbon monoxide (CO) emission standard for 
newly manufactured gas turbine engines in this same 1997 rulemaking. At 
the time, the 1997 rulemaking established consistency between the U.S. 
and international standards. (See 40 CFR part 87 for a description of 
EPA's aircraft engine emission control requirements and 14 CFR part 34 
for the Secretary of Transportation's regulations for ensuring 
compliance with these standards in accordance with section 232 of the 
Clean Air Act.)
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    \1\ Throughout this notice, the date of manufacture of the first 
individual production model means the date of type certification.
    \2\ U.S. EPA, ``Control of Air Pollution from Aircraft and 
Aircraft Engines; Emission Standards and Test Procedures;'' Final 
Rule, 62 FR 25356, May 8, 1997.

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[[Page 56229]]

B. Interaction With the International Community

    Since publication of the initial standards in 1973, EPA, together 
with the Federal Aviation Administration (FAA), has worked with the 
International Civil Aviation Organization (ICAO) on the development of 
international aircraft engine emission standards. ICAO was established 
in 1944 by the United Nations (by the Convention on International Civil 
Aviation, the ``Chicago Convention'') ``* * * in order that 
international civil aviation may be developed in a safe and orderly 
manner and that international air transport services may be established 
on the basis of equality of opportunity and operated soundly and 
economically.'' \3\ ICAO's responsibilities include developing aircraft 
technical and operating standards, recommending practices, and 
generally fostering the growth of international civil aviation.
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    \3\ ICAO, ``Convention on International Civil Aviation,'' Sixth 
Edition, Document 7300/6, 1980. Copies of this document can be 
obtained from the ICAO Web site located at http://www.icao.int.
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    In 1972 at the United Nations Conference on the Human Environment, 
ICAO's position on the human environment was developed to be the 
following: ``[i]n fulfilling this role ICAO is conscious of the adverse 
environmental impact that may be related to aircraft activity and its 
responsibility and that of its member States to achieve maximum 
compatibility between the safe and orderly development of civil 
aviation and the quality of the human environment.'' Also, in 1972 ICAO 
established the position to continue ``* * * with the assistance and 
cooperation of other bodies of the Organization and other international 
organizations * * * the work related to the development of Standards, 
Recommended Practices and Procedures and/or guidance material dealing 
with the quality of the human environment * * *.'' \4\
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    \4\ International Civil Aviation Organization (ICAO), Foreword 
of ``Aircraft Engine Emissions,'' International Standards and 
Recommended Practices, Environmental Protection, Annex 16, Volume 
II, Second Edition, July 1993. Copies of this document can be 
obtained from the ICAO Web site located at http://www.icao.int.
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    The United States is one of 188 participating member States of 
ICAO.\5\ Under the basic ICAO treaty established in 1944 (the Chicago 
Convention), a participating nation which elects not to adopt the ICAO 
standards must provide a written explanation to ICAO describing why a 
given standard is impractical to comply with or not in their national 
interest.\6\ ICAO has no punitive powers for states that elect not to 
adopt ICAO standards. ICAO standards require States to provide written 
notification and failure to provide such notification could have 
negative consequences as detailed below.
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    \5\ As of June 20, 2002 there were 188 Contracting States 
according to the ICAO Web site located at http://www.icao.int.
    \6\ Text of Article 38 of Chicago Convention: Any State which 
finds it impracticable to comply in all respects with any such 
international standard or procedure, or to bring its own regulations 
or practices into full accord with any international standard or 
procedure after amendment of the latter, or which deems it necessary 
to adopt regulations or practices differing in any particular 
respect from those established by an international standard, shall 
give immediate notification to the International Civil Aviation 
Organization of the differences between its own practice and that 
established by the international standard. * * * In any such case, 
the Council shall make immediate notification to all other states of 
the difference which exists between one or more features of an 
international standard and the corresponding national practice of 
that State.
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    If a Contracting State files a written notification indicating that 
it does not meet ICAO standards, other Contracting States are absolved 
of their obligations to ``recognize as valid'' the certificate of 
airworthiness issued by that Contracting States, since that certificate 
will not have been issued under standards ``equal to or above'' ICAO 
standards. In other words, other Contracting States do not have to 
allow aircraft belonging to that Contracting State to travel through 
their airspace.\7\ Further, if it fails to file a written notification, 
it will be in default of its obligations, and risks mandatory exclusion 
of its aircraft from the airspace of other Contracting States and the 
loss of its voting power in the Assembly and Council.\8\
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    \7\ Text of Article 33 of Chicago Convention: Certificates of 
airworthiness and certificates of competency and licenses issued or 
rendered valid by the contracting State in which the aircraft is 
registered, shall be recognized as valid by the other contracting 
States, provided that the requirements under which such certificates 
or licenses were issued or rendered valid are equal to or above the 
minimum standards which may be established from time to time 
pursuant to this Convention.
    \8\ Articles 87 and 88 of Chicago Convention.
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    The ICAO Council's Committee on Aviation Environmental Protection 
(CAEP) undertakes ICAO's technical work in the environmental field. The 
CAEP is responsible for evaluating, researching, and recommending 
measures to the ICAO Council that address the environmental impact of 
international civil aviation. CAEP is composed of various Study Groups, 
Work Groups, Committees and other contributing memberships that include 
atmospheric, economic, aviation, environmental, and other professionals 
committed to ICAO's previously stated position regarding aviation and 
the environment. At CAEP meetings, the United States is represented by 
the FAA, which plays an active role at these meetings (see section V 
for further discussion of FAA's role). EPA is a principal participant 
in the development of U.S. policy in ICAO/CAEP and other international 
venues. (EPA assists and technically advises FAA on aviation emissions 
matters.) If the ICAO Council adopts a CAEP proposal to adopt a new 
environmental standard, it then becomes part of the ICAO standards and 
recommended practices (Annex 16 to the Chicago Convention).\9\
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    \9\ ICAO, ``Aircraft Engine Emissions,'' International Standards 
and Recommended Practices, Environmental Protection, Annex 16, 
Volume II, Second Edition, July 1993. Copies of this document can be 
obtained from ICAO (http://www.icao.int).
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    On June 30, 1981, the ICAO Council adopted its first international 
standards and recommended practices covering aircraft engine 
emissions.\10\ These standards limit aircraft engine emissions of 
NOX, CO, and hydrocarbons (HC), in relation to other engine 
performance parameters, and are commonly known as stringency standards. 
On March 24, 1993, the ICAO Council approved a proposal adopted at the 
second meeting of the CAEP (CAEP/2) to tighten the original 
NOX standard by 20 percent and amend the test procedures. At 
the next CAEP meeting (CAEP/3) in December 1995, the CAEP recommended a 
further tightening of 16 percent and additional test procedure 
amendments, but on March 20, 1997 the ICAO Council rejected this 
stringency proposal and approved only the test procedure amendments. At 
its next meeting (CAEP/4) in April 1998, the CAEP adopted a similar 16 
percent NOX reduction proposal, which the ICAO Council 
approved on February 26, 1999.\11\ The CAEP/4 16 percent NOX 
reduction standard applies to new engine designs certified after 
December 31, 2003 (applies only to newly certified engines).\12\
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    \10\ ICAO, Foreword of ``Aircraft Engine Emissions,'' 
International Standards and Recommended Practices, Environmental 
Protection, Annex 16, Volume II, Second Edition, July 1993. Copies 
of this document can be obtained from ICAO (http://www.icao.int).
    \11\ International Civil Aviation Organization (ICAO), Aircraft 
Engine Emissions, Annex 16, Volume II, Second Edition, July 1993, 
Amendment 4 effective on July 19, 1999. Copies of this document can 
be obtained from ICAO (http://www.icao.int).
    \12\ These NOX standards will be interchangeably be 
referred to as the 1998 CAEP/4 standards and the 1999 ICAO standards 
throughout this notice.
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    As discussed earlier, in 1997 EPA amended its regulations to adopt 
the

[[Page 56230]]

1981 ICAO NOX and CO emission standards, as well as the 
NOX emission standards and test procedures revised by ICAO 
in 1993. As discussed above, the U.S. has an obligation under the 
Convention on International Civil Aviation to notify ICAO regarding 
differences between U.S. standards and ICAO standards, and to provide 
notification on the date by which the program requirements will be 
consistent. In response to the recent actions by ICAO and for the 
reasons discussed below, EPA proposes to adopt standards equivalent to 
ICAO's 1999 amendment to the NOX emission standard, the test 
procedure changes approved by ICAO in 1997, and other technical 
amendments to further align EPA and ICAO requirements.

C. EPA's Responsibilities Under the Clean Air Act

    As discussed earlier, section 231 of the CAA directs EPA, from time 
to time, to propose aircraft engine emission standards for any air 
pollutant that could reasonably endanger public health and welfare. In 
addition, EPA is required to ensure such standards' effective dates 
permit the development of necessary technology, giving appropriate 
consideration to compliance cost. Also, EPA must consult with the FAA 
concerning aircraft safety before proposing or promulgating emission 
standards. (See section V of today's proposal for further discussion of 
EPA's coordination with FAA and FAA's responsibilities under the CAA.)
    In addition, section 233 of the CAA vests authority to implement 
emission standards for aircraft engines only in EPA.\13\ States are 
preempted from taking independent action. Thus, while many states are 
implementing control programs to reduce mobile source emissions, EPA 
has the authority to establish an emission control program for aircraft 
engines.
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    \13\ CAA section 233 entitled ``State Standards and Controls'' 
states that ``No State or political subdivision thereof may adopt or 
attempt to enforce any standard respecting emissions of any air 
pollutant from any aircraft or engine thereof unless such standard 
is identical to a standard applicable to such aircraft under this 
part.''
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III. Environmental Need for Control

    As mentioned above, section 231(a)(2)(A) of the CAA authorizes the 
EPA Administrator to, from time to time, revisit emission standards for 
aircraft engine emissions ``* * * which in his judgment causes, or 
contributes to air pollution which may * * * endanger public health or 
welfare.'' In judging the need for the NOX standard 
promulgated in today's action, the Administrator has determined (1) 
That the public health and welfare is endangered in several air quality 
regions by violation of the National Ambient Air Quality Standards 
(NAAQS) for ozone (NOX contributes to the formation of 
ozone); and (2) that airports and aircraft are now or are projected to 
be, increasing sources of emissions of NOX in some of the 
air quality control regions in which the NAAQS are being violated.
    Nationwide, aircraft account for about 1 percent of the 
NOX emissions from mobile sources.\14\ Commercial aircraft 
emissions contribute from 74 to 99 percent of the NOX 
aircraft emissions in the U.S. (Aircraft emissions sources include 
aircraft types used for public, private, and military purposes as 
follows: commercial aircraft, air taxis, general aviation, and military 
aircraft.\15\ The current nationwide aircraft emission estimates have 
limitations for military aircraft emissions. Therefore, the estimated 
range of commercial aircraft's emissions contribution to nationwide 
aircraft NOX described above is reflective of earlier and 
current estimates for military aircraft emissions).
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    \14\ U.S. EPA, ``Average Annual Emissions, All Criteria 
Pollutants Years Including 1980, 1985, 1989-2001,'' February 2003. 
This document is available at http://www.epa.gov/ttnchie1/trends/. A 
copy of this document can also be found in Docket No. OAR-2002-30. 
Documentation for these estimates can be accessed at http://www.epa.gov/ttn/chief/net/index.html#1999: U.S. EPA, ``Documentation 
for Aircraft, Commercial Marine Vessel, Locomotive, and Other 
Nonroad Components of the National Emissions Inventory, Volume I--
Methodology,'' November 11, 2002. A copy of this document can also 
be found in Docket No. OAR-2002-30.
    \15\ Commercial aircraft include those aircraft used for 
scheduled service transporting passengers, freight, or both. Air 
taxis also fly scheduled service carrying passengers, freight or 
both, but usually are smaller aircraft and operate on a more limited 
basis than commercial carriers. General aviation includes most other 
aircraft used for recreational flying and personal transportation. 
Aircraft that support business travel, usually on an unscheduled 
basis, are included in the category of general aviation. Military 
aircraft cover a wide range of sizes, uses, and operating missions. 
While they are often similar to civil aircraft, they are handled 
separately because they typically operate exclusively out of 
military bases and frequently have distinctive flight profiles.
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    Commercial aircraft emissions are projected to be a growing segment 
of the transportation sector's emission inventory. This growth in 
commercial aircraft emissions is expected to occur at a time when other 
significant mobile and stationary sources are drastically reducing 
emissions, thereby accentuating the growth in aircraft emissions. For 
instance, from a local/regional perspective the 1999 EPA study, 
Evaluation of Air Pollutant Emissions from Subsonic Commercial Jet 
Aircraft, reported that from 1990 to 2010 increases in commercial 
aircraft NOX emissions for the ten cities studied (19 
airport facilities with significant commercial jet aircraft activity 
were identified within these selected cities) are expected to range 
from 50 to 110 percent.\16\ As an average for the ten cities, 
commercial aircraft's contribution to regional mobile source 
NOX was anticipated to increase from about 2 percent in 1990 
to about 5 percent in 2010. In addition, the study showed that in 2010 
commercial aircraft are projected to contribute as much as 10 percent 
of total regional mobile source NOX emissions in at least 
two of the cities studied.\17\
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    \16\ This study (EPA 420-R-99-013, April 1999) is available at 
http://www.epa.gov/otaq/aviation.htm. It can also be found in Docket 
No. OAR-2002-0030.
    \17\ Based on the one-hour ozone standard, nine of the ten 
metropolitan areas are currently not in attainment of NAAQS for 
ozone; the tenth city has attained the ozone standard and is 
considered an ozone ``maintenance'' area. See section III.A.1. of 
this proposal for further discussion on the ozone NAAQs. Also, for 
more detailed information on the 8-hour ozone standard, see the 
following EPA Web sites: http://www.epa.gov/airlinks/ozpminfo.html, 
http://www.epa.gov/airlinks/airlinks4.html or http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr. EPA has not yet designated areas for the 
8-hour standard.
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    (The above projections were made prior to the tragic events of 
September 11, 2001, and the subsequent economic downturn. A January 
2003 report by the Department of Transportation indicated that the 
combination of the September 11, 2001 terrorist attacks and a cut-back 
in business travel had a significant and perhaps long-lasting effect on 
air traffic demand.\18\ However, the FAA expects the demand for air 
travel to recover, and then continue a long-term trend of annual growth 
in the United States.\19\ Recently, FAA reported that flights of 
commercial air carriers will increase by 18 percent from 2002 to 2010 
and 45 percent from 2002 to 2020.\20\ For a

[[Page 56231]]

comparison of an earlier (pre-9/11) FAA activity forecast to a recent 
(post-9/11) forecast, see the below table. We request comment on the 
effect that September 11, 2001, and the subsequent economic downturn 
have had on the projected growth of commercial aircraft emissions. Your 
comments will be most useful if you include appropriate and detailed 
supporting data and analysis.)
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    \18\ U.S. Department of Transportation, Office of Inspector 
General, ``Airline Industry Metrics,'' CC-2203-007, January 7, 2003. 
A copy of this document can be found in Docket No. OAR-2002-0030.
    \19\ U.S. General Accounting Office, ``Aviation and the 
Environment: Strategic Framework Needed to Address Challenges Posed 
by Aircraft Emissions,'' GAO-03-252, February 2003. This document is 
available at www.gao.gov/cgi-bin/getrpt?GAO-03-252, and it can also 
be found in the Docket No. OAR-2002-0030.
    \20\ The flight forecast data is based on FAA's Terminal Area 
Forecast System (TAFS). TAFs is the official forecast of aviation 
activity at FAA facilities. This includes FAA-towered airports, 
federally-contracted towered airports, nonfederal towered airports, 
and many non-towered airports. For detailed information on TAFS and 
the air carrier activity forecasts see the following FAA Web site: 
http://www.apo.data.faa.gov/faatafall.HTM. As of May 1, 2003, the 
aviation forecasts contained in TAFS for Fiscal Years 2002-2020 
included the impact of the terrorists' attacks of September 11, 2001 
and the recent economic downturn. However, these projections did not 
fully reflect the ongoing structural changes occurring within the 
aviation industry. A copy of the May 1, 2003 forecast summary report 
for air carrier activity can be found in Docket No. OAR-2002-0030.

        Table III-1.--FAA Terminal Area Forecast Summary Report of Nationwide Air Carrier Operations \21\
----------------------------------------------------------------------------------------------------------------
                                                                  Percent change                  Percent change
                                                    Air carrier      12/14/00       Air carrier       5/1/03
                      Year                        operations 12/     forecast     operations 5/1/    forecast
                                                  14/00 forecast   between years    03 forecast    between years
                                                     (pre-9/11)       listed        (post-9/11)       listed
----------------------------------------------------------------------------------------------------------------
1999............................................      15,127,419  ..............      14,776,055  ..............
2000............................................      15,476,135             2.3      15,265,682             3.3
2001............................................      15,819,505             2.2      14,807,303            -3.0
2002 a..........................................      16,210,777             2.5      13,255,837             -10
2005............................................      17,455,705             7.6      13,918,058             5.0
2010............................................      19,664,128              14      15,608,349              13
2015............................................      22,004,067              12      17,372,200              11
2020............................................           N/A b              --      19,249,778             11
----------------------------------------------------------------------------------------------------------------
a The change in operations from 2000 to 2002 was +4.7% for the 12/14/00 forecast, and it was -13% for the 5/1/03
  forecast.
b N/A = Not available.

    Air pollutants resulting from airport operations are emitted from 
several types of sources: aircraft main engines and auxiliary power 
units (APUs); ground support equipment (GSE), which include vehicles 
such as aircraft tugs, baggage tugs, fuel trucks, maintenance vehicles, 
and other miscellaneous vehicles used to support aircraft operations; 
ground access vehicles (GAV), which include vehicles from off-site used 
by passengers, employees, freight operators, and other persons 
utilizing an airport. EPA's previous estimates show aircraft engines 
comprise approximately 45 percent of total air pollutant emissions from 
airport operations; GAV account for another 45 percent, and APUs and 
GSE combined make up the remaining 10 percent.\22\ Since EPA has 
established stringent emission standards for GAVs and other motor 
vehicles that will be manufactured and introduced into commerce in 
future years, overall emissions from these vehicles will continue to 
decline for many years.
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    \21\ A copy of FAA's 12/14/00 forecast summary report (from 
TAFS) for air carrier activity can be found in Docket No. OAR-2002-
0030.
    \22\ The California FIP, signed by the Administrator 2/14/95, is 
located in EPA Air Docket A-94-09, item number V-A-1. The FIP was 
vacated by an act of Congress before it became effective.
    In addition, the 1997 EPA Draft Final Report entitled, 
``Analysis of Techniques to Reduce Air Emission at Airports'' 
(prepared by Energy and Environmental Analysis, Inc), it was 
estimated that for the four airports studied (which are large air 
traffic hubs) on average aircraft compromise approximately 35 
percent of NOX emissions from airport operations; GAV 
account for another 35 percent, and APUs and GSE contribute about 15 
percent each for the remaining 30 percent. This document can be 
found in Docket No. OAR-2002-0030.
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    The emissions from aircraft engines that are being directly 
controlled by the standards proposed in this rulemaking are 
NOX. As discussed later in this section, NOX 
emissions at low altitude also react in the atmosphere to form 
secondary particulate matter (PM2.5),\23\ which is namely 
ammonium nitrate, and thus, secondary PM would be effected as a 
consequence of the proposed standards. Adopting standards equivalent to 
the latest ICAO NOX emission standards and the related ICAO 
test procedures would help in achieving and/or maintaining compliance 
with the NAAQS for ozone (O3)and PM.
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    \23\ As described later in section III.A.2., fine particles 
refer to those particles with an aerodynamic diameter less than or 
equal to a nominal 2.5 micrometers (also known as PM2.5).
---------------------------------------------------------------------------

    There are about 111 million people living in counties with 
monitored concentrations exceeding the 8-hour ozone NAAQS , and over 65 
million people living in counties with monitored PM2.5 
levels exceeding the PM2.5 NAAQS. Figure III.-1 illustrates 
the widespread nature of these problems. Shown in this figure are 
counties exceeding either or both of the two NAAQS plus mandatory 
Federal Class I areas, which have particular needs for reductions in 
atmospheric haze. A discussion of the adverse effects on public health 
and welfare associated with these pollutants is provided below.

[[Page 56232]]

[GRAPHIC] [TIFF OMITTED] TP30SE03.000

A. Public Health Impacts

1. Ozone
    a. What are the health effects of ozone pollution? Ground-level 
ozone pollution (sometimes called ``smog'') is formed by the reaction 
of nitrogen oxides (NOX) and volatile organic compounds 
(VOC) in the atmosphere in the presence of heat and sunlight.\24\ Ozone 
can irritate the respiratory system, causing coughing, throat 
irritation, and/or uncomfortable sensation in the chest. 
25,26 Ozone can reduce lung function and make it more 
difficult to breathe deeply, and breathing may become more rapid and 
shallow than normal, thereby limiting a person's normal activity. Ozone 
also can aggravate asthma, leading to more asthma attacks that require 
a doctor's attention and/or the use of additional medication. In 
addition, ozone can inflame and damage the lining of the lungs, which 
may lead to permanent changes in lung tissue, irreversible reductions 
in lung function, and a lower quality of life if the inflammation 
occurs repeatedly over a long time period (months, years, a lifetime). 
People who are of particular concern with respect to ozone exposures 
include children and adults who are active outdoors. Those people 
particularly susceptible to ozone effects are people with respiratory 
disease, such as asthma, and people with unusual sensitivity to ozone, 
and children. Beyond its human health effects, ozone has been shown to 
injure plants, which has the effect of reducing crop yields and 
reducing productivity in forest ecosystems.27,28
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    \24\ U.S. EPA, ``Nitrogen Oxides: Impacts on Public Health and 
the Environment,'' EPA 452/R-97-002, August 1997. A copy of this 
document is available in Docket No. OAR 2002-0030.
    \25\ U.S. EPA (1996). Air Quality Criteria for Ozone and Related 
Photochemical Oxidants, EPA/600/P-93/004aF. Docket No. A-99-06. 
Document Nos. II-A-15 to 17.
    \26\ U.S. EPA. (1996). Review of National Ambient Air Quality 
Standards for Ozone, Assessment of Scientific and Technical 
Information, OAQPS Staff Paper, EPA-452/R-96-007. Docket No. A-99-
06. Document No. II-A-22.
    \27\ U.S. EPA (1996). Air Quality Criteria for Ozone and Related 
Photochemical Oxidants, EPA/600/P-93/004aF. Docket No. A-99-06. 
Document Nos. II-A-15 to 17.
    \28\ U.S. EPA. (1996). Review of National Ambient Air Quality 
Standards for Ozone, Assessment of Scientific and Technical 
Information, OAQPS Staff Paper, EPA-452/R-96-007. Docket No. A-99-
06. Document No. II-A-22.
---------------------------------------------------------------------------

    The 8-hour ozone standard, established by EPA in 1997, is based on 
well-documented science demonstrating that more people are experiencing 
adverse health effects at lower levels of exertion, over longer 
periods, and at lower ozone concentrations than addressed by the one-
hour ozone standard. (See, e.g., 62 FR 38861-38862, July 18, 1997). The 
8-hour standard addresses ozone exposures of concern for the general 
population and populations most at risk, including

[[Page 56233]]

children active outdoors, outdoor workers, and individuals with pre-
existing respiratory disease, such as asthma.
    There has been new research that suggests additional serious health 
effects beyond those that had been known when the 8-hour ozone health 
standard was set. Since 1997, over 1,700 new health and welfare studies 
relating to ozone have been published in peer-reviewed journals.\29\ 
Many of these studies have investigated the impact of ozone exposure on 
such health effects as changes in lung structure and biochemistry, 
inflammation of the lungs, exacerbation and causation of asthma, 
respiratory illness-related school absence, hospital and emergency room 
visits for asthma and other respiratory causes, and premature 
mortality. EPA is currently in the process of evaluating these and 
other studies as part of the ongoing review of the air quality criteria 
and NAAQS for ozone. A revised Air Quality Criteria Document for Ozone 
and Other Photochemical Oxidants will be prepared in consultation with 
EPA's Clean Air Science Advisory Committee (CASAC). Key new health 
information falls into four general areas: development of new-onset 
asthma, hospital admissions for young children, school absence rate, 
and premature mortality.
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    \29\ New Ozone Health and Environmental Effects References, 
Published Since Completion of the Previous Ozone AQCD, National 
Center for Environmental Assessment, Office of Research and 
Development, U.S. Environmental Protection Agency, Research Triangle 
Park, NC 27711 (7/2002). A copy of this document is available in 
Docket No. OAR 2002-0030.
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    Aggravation of existing asthma resulting from short-term ambient 
ozone exposure was reported prior to the 1997 decision and has been 
observed in studies published subsequently.30,31 In 
particular, a relationship between long-term ambient ozone 
concentrations and the incidence of new-onset asthma in adult males 
(but not in females) was reported by McDonnell et al. (1999).\32\ 
Subsequently, an additional study suggests that incidence of new 
diagnoses of asthma in children is associated with heavy exercise in 
communities with high concentrations (i.e., mean 8-hour concentration 
of 59.6 ppb) of ozone.\33\ This relationship was documented in children 
who played 3 or more sports and thus had higher exposures and was not 
documented in those children who played one or two sports. The larger 
effect of high activity sports than low activity sports and an 
independent effect of time spent outdoors also in the higher ozone 
communities strengthened the inference that exposure to ozone may 
modify the effect of sports on the development of asthma in some 
children.
---------------------------------------------------------------------------

    \30\ Thurston, G.D., M.L. Lippman, M.B. Scott, and J.M. Fine. 
1997. Summertime Haze Air Pollution and Children with Asthma. 
American Journal of Respiratory Critical Care Medicine, 155: 654-
660.
    \31\ Ostro, B., M. Lipsett, J. Mann, H. Braxton-Owens, and M. 
White (2001) Air pollution and exacerbation of asthma in African-
American children in Los Angeles. Epidemiology 12(2): 200-208.
    \32\ McDonnell, W.F., D.E. Abbey, N. Nishino and M.D. Lebowitz. 
1999. ``Long-term ambient ozone concentration and the incidence of 
asthma in nonsmoking adults: the ahsmog study.'' Environmental 
Research. 80(2 Pt 1): 110-121.
    \33\ McConnell, R.; Berhane, K.; Gilliland, F.; London, S. J.; 
Islam, T.; Gauderman, W. J.; Avol, E.; Margolis, H. G.; Peters, J. 
M. (2002) Asthma in exercising children exposed to ozone: a cohort 
study. Lancet 359: 386-391.
---------------------------------------------------------------------------

    Previous studies have shown relationships between ozone and 
hospital admissions in the general population. A study in Toronto 
reported a significant relationship between 1-hour maximum ozone 
concentrations and respiratory hospital admissions in children under 
the age of two.\34\ Given the relative vulnerability of children in 
this age category, we are particularly concerned about the findings.
---------------------------------------------------------------------------

    \34\ Burnett, R. T.; Smith--Doiron, M.; Stieb, D.; Raizenne, M. 
E.; Brook, J. R.; Dales, R. E.; Leech, J. A.; Cakmak, S.; Krewski, 
D. (2001) Association between ozone and hospitalization for acute 
respiratory diseases in children less than 2 years of age. Am. J. 
Epidemiol. 153: 444-452.
---------------------------------------------------------------------------

    Increased respiratory diseases that are serious enough to cause 
school absences have been associated with 1-hour daily maximum and 8-
hour average ozone concentrations in studies conducted in Nevada \35\ 
in kindergarten to 6th grade and in Southern California in grades 4 
through 6.\36\ These studies suggest that higher ambient ozone levels 
may result in increased school absenteeism.
---------------------------------------------------------------------------

    \35\ Chen, L.; Jennison, B. L.; Yang, W.; Omaye, S. T. (2000) 
Elementary school absenteeism and air pollution. Inhalation Toxicol. 
12:997-1016.
    \36\ Gilliland, FD, K Berhane, EB Rappaport, DC Thomas, E Avol, 
WJ Gauderman, SJ London, HG Margolis, R McConnell, KT Islam, JM 
Peters (2001) The effects of ambient air pollution on school 
absenteeism due to respiratory illnesses Epidemiology 12:43-54.
---------------------------------------------------------------------------

    The air pollutant most clearly associated with premature mortality 
is PM, with dozens of studies reporting such an association. However, 
repeated ozone exposure is a possible contributing factor for premature 
mortality, causing an inflammatory response in the lungs which may 
predispose elderly and other sensitive individuals to become more 
susceptible to other stressors, such as PM.37,38,39 Although 
the findings have been mixed, the findings of three recent analyses 
suggest that ozone exposure is associated with increased mortality. 
Although the National Morbidity, Mortality, and Air Pollution Study 
(NMMAPS) did not report an effect of ozone on total mortality across 
the full year, the investigators who conducted the NMMAPS study did 
observe an effect after limiting the analysis to summer when ozone 
levels are highest.40,41 Similarly, other studies have shown 
associations between ozone and mortality.42,43 Specifically, 
Toulomi et al. (1997) found that 1-hour maximum ozone levels were 
associated with daily numbers of deaths in 4 cities (London, Athens, 
Barcelona, and Paris), and a quantitatively similar effect was found in 
a group of four additional cities (Amsterdam, Basel, Geneva, and 
Zurich).
---------------------------------------------------------------------------

    \37\ Samet JM, Zeger SL, Dominici F, Curriero F, Coursac I, 
Dockery DW, Schwartz J, Zanobetti A. 2000. The National Morbidity, 
Mortality and Air Pollution Study: Part II: Morbidity, Mortality and 
Air Pollution in the United States. Research Report No. 94, Part II. 
Health Effects Institute, Cambridge, MA, June 2000. (Docket Number 
A-2000-01, Document Nos. IV-A-208 and 209).
    \38\ Devlin, R. B.; Folinsbee, L. J.; Biscardi, F.; Hatch, G.; 
Becker, S.; Madden, M. C.; Robbins, M.; Koren, H. S. (1997) 
Inflammation and cell damage induced by repeated exposure of humans 
to ozone. Inhalation Toxicol. 9: 211-235.
    \39\ Koren HS, Devlin RB, Graham DE, Mann R, McGee MP, Horstman 
DH, Kozumbo WJ, Becker S, House DE, McDonnell SF, Bromberg, PA. 
1989. Ozone-induced inflammation in the lower airways of human 
subjects. Am. Rev. Respir. Dies. 139:407-415.
    \40\ Samet JM, Zeger SL, Dominici F, Curriero F, Coursac I, 
Dockery DW, Schwartz J, Zanobetti A. 2000. The National Morbidity, 
Mortality and Air Pollution Study: Part II: Morbidity, Mortality and 
Air Pollution in the United States. Research Report No. 94, Part II. 
Health Effects Institute, Cambridge MA, June 2000. (Docket Number A-
2000-01, Documents No. IV-A-208 and 209)
    \41\ Samet JM, Zeger SL, Dominici F, Curriero F, Coursac I, 
Zeger, S. Fine Particulate Air Pollution and Mortality in 20 U.S. 
Cities, 1987-1994. The New England Journal of Medicine. Vol. 343, 
No. 24, December 14, 2000. P. 1742-1749.
    \42\ Thurston, G. D.; Ito, K. (2001) Epidemiological studies of 
acute ozone exposures and mortality. J. Exposure Anal. Environ. 
Epidemiol. 11: 286-294.
    \43\ Touloumi, G.; Katsouyanni, K.; Zmirou, D.; Schwartz, J.; 
Spix, C.; Ponce de Leon, A.; Tobias, A.; Quennel, P.; Rabczenko, D.; 
Bacharova, L.; Bisanti, L.; Vonk, J. M.; Ponka, A. (1997) Short-term 
effects of ambient oxidant exposure on mortality: a combined 
analysis within the APHEA project. Am. J. Epidemiol. 146: 177-185.
---------------------------------------------------------------------------

    In all, the new studies that have become available since the 8-hour 
ozone standard was adopted in 1997 continue to demonstrate the harmful 
effects of ozone on public health, and the need to attain and maintain 
the NAAQS.
    b. Current and projected 8-hour ozone levels. The current primary 
and secondary ozone NAAQS is 0.12 ppm daily maximum 1-hour 
concentration, not to be exceeded more than once per year on average. 
EPA is replacing the previous 1-hour ozone standard with a new 8-hour 
standard. The new standard

[[Page 56234]]

is set at a concentration of 0.08 parts per million (ppm), and the 
measurement period is 8 hours. Areas are allowed to disregard their 
three worst measurements every year and average performance over three 
years to determine if they meet the standard. That is, the standard is 
set by the 4th highest maximum 8-hour concentration.
    As shown earlier (Figure III-1) unhealthy ozone concentrations 
exceeding the level of the 8-hour standard (i.e., not requisite to 
protect the public health with an adequate margin of safety) occur over 
wide geographic areas, including most of the nation's major population 
centers. These monitored areas include much of the eastern half of the 
U.S. and large areas of California.
    Based upon data from 1999-2001, there are 291 counties where 111 
million people live that are measuring values that violate the 8-hour 
ozone NAAQS.\44\ An additional 37 million people live in 155 counties 
that have air quality measurements within 10 percent of the level of 
the standard.\45\ These areas, though currently not violating the 
standard, would also benefit from the additional emission reductions 
from this proposed rule.
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    \44\ Additional counties may have levels above the NAAQS but do 
not currently have monitors.
    \45\ Memorandum to Docket A-2001-11 from Fred Dimmick, Group 
Leader, Air Trends Group, ``Summary of Currently Available Air 
Quality Data and Ambient Concentrations for Ozone and Particulate 
Matter,'' December 3, 2002. A copy of this document is available in 
Docket No. OAR 2002-0030.
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    From air quality modeling performed for the recent Nonroad Diesel 
Engines and Fuel Control proposed rule,\46\ we anticipate that without 
emission reductions beyond those already required under promulgated 
regulation and approved State Implementation Plans (SIPs), ozone 
nonattainment will likely persist into the future. With reductions from 
programs already in place, the number of counties violating the ozone 
8-hour standard is expected to decrease in 2020 to 30 counties where 43 
million people are projected to live. Thereafter, exposure to unhealthy 
levels of ozone is expected to begin to increase again. In 2030 the 
number of counties violating the ozone 8-hour NAAQS is projected to 
increase to 32 counties where 47 million people are projected to live. 
In addition, in 2030, 82 counties where 44 million people are projected 
to live will be within 10 percent of violating the ozone 8-hour NAAQS.
---------------------------------------------------------------------------

    \46\ See the Regulatory Impact Analysis: ``Draft Regulatory 
Impact Analysis: Control of Emissions from Nonroad Diesel Engines,'' 
EPA420-R-03-008, April 2003. This document is available at http://www.epa.gov/nonroad/. A copy of this document can also be found in 
Docket No. A-2001-28.
---------------------------------------------------------------------------

    EPA is still developing the implementation process for bringing the 
nation's air into attainment with the ozone 8-hour NAAQS. On June 2, 
2003 (68 FR 32802), EPA issued a proposal for the implementation 
process to bring the nation's air into attainment with the 8-hour ozone 
NAAQS.\47\ The proposal seeks comment on options for planning and 
control requirements, along with options for making the transition from 
the 1-hour ozone standard to the 8-hour ozone standard. The proposal 
does not designate nonattainment area for the 8-hour ozone NAAQS; EPA's 
current plans calls for designating 8-hour ozone nonattainment areas in 
April 2004, under a separate process. EPA has proposed that States 
submit SIPs that address how areas will attain the 8-hour ozone 
standard within 3 years after nonattainment designation for moderate 
and above areas classified under subpart 2 and for some areas 
classified under subpart 1. EPA is also proposing that marginal areas 
and some areas designated under subpart 1 (i.e., those with early 
attainment dates) will not be required to submit attainment 
demonstrations for the 8-hour ozone standard. We therefore anticipate 
that States will submit their attainment demonstration SIPs by April 
2007.
---------------------------------------------------------------------------

    \47\ A copy of this proposed rule entitled, ``Proposed Rule to 
Implement the 8-Hour Ozone National Ambient Air Quality Standard.'' 
is available at: http://www.epa.gov/ttn/naaqs/ozone/o3imp8hr.
---------------------------------------------------------------------------

    The Act contains two sets of requirements--subpart 1 and subpart 
2--that establish requirements for State plans implementing the 
national ozone air quality standards in nonattainment areas. (Both are 
found in title I, part D.) Subpart 1 contains general requirements for 
SIPs for nonattainment areas for any pollutant--including ozone--
governed by a NAAQS. Subpart 2 provides more specific requirements for 
ozone nonattainment SIPs. Under subpart 1 of part D, title I of the Act 
demonstrate that the nonattainment areas will attain the ozone 8-hour 
standard as expeditiously as practicable but no later than five years 
from the date that the area was designated nonattainment. However, 
based on the severity of the air quality problem and the availability 
and feasibility of control measures, the Administrator may extend the 
attainment date ``for a period of no greater than 10 years from the 
date of designation as nonattainment.'' Based on these provisions, we 
expect that most or all areas covered under subpart 1 will attain the 
ozone standard in the 2007 to 2014 time frame. For areas covered under 
subpart 2, the maximum attainment dates provided under the Act range 
from 3 to 20 years after designation, depending on an area's 
classification. Thus, we anticipate that areas covered by subpart 2 
will attain in the 2007 to 2024 time period.
    Since the emission reductions expected from this proposed rule 
would occur during the time period when areas will need to attain the 
standard under either option, projected reductions in aircraft engine 
emissions would assist States in their effort to meet the new NAAQS. 
Such reductions would help them attain and maintain the 8-hour NAAQS.
2. Particulate Matter
    NOX emitted at low altitude is also a precursor in the 
formation of some nitrate particulate matter (PM) in the atmosphere 
(mostly ammonium nitrate).48,49 Essentially all nitrate PM 
is of such a diameter that it is respirable in humans. As discussed 
earlier, aircraft account for over 1 percent of the total U.S. mobile 
source NOX emissions, and aircraft's contribution to 
nationwide secondary PM from U.S. mobile source NOX is 
expected to relatively similar.\50\
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    \48\ Secondary PM is formed when NOX reacts with 
ammonia in the atmosphere to yield ammonium nitrate particulate.
    \49\ U.S. EPA, ``Nitrogen Oxides: Impacts on Public Health and 
the Environment,'' EPA 452/R-97-002, August 1997. A copy of this 
document is available in Docket No. OAR 2002-0030.
    \50\ ``Benefits of Mobile Source NOX Related 
Particulate Matter Reductions,'' Systems Applications International, 
EPA Contract No. 68-C5-0010, WAN 1-8, October 1996. A copy of this 
document is available in Docket No. OAR-2002-0030. This report 
concluded that, as a national average, each 100 tons of 
NOX emissions will result in about 4 tons of secondary PM 
(conversion rate was about 0.04). This conversion rate varies from 
region to region, and is greatest in the West.
---------------------------------------------------------------------------

    Particulate matter represents a broad class of chemically and 
physically diverse substances. It can be principally characterized as 
discrete particles that exist in the condensed (liquid or solid) phase 
spanning several orders of magnitude in size. PM10 refers to 
particles with an aerodynamic diameter less than or equal to a nominal 
10 micrometers. Fine particles refer to those particles with an 
aerodynamic diameter less than or equal to a nominal 2.5 micrometers 
(also known as PM2.5), and coarse fraction particles are 
those particles with an aerodynamic diameter greater than 2.5 microns, 
but less than or equal to a nominal 10 micrometers. Ultrafine PM refers 
to particles with diameters of less than 100 nanometers (0.1 
micrometers). The health and environmental effects of PM are associated 
with fine PM fraction and, in some cases, to the size of the particles.

[[Page 56235]]

Specifically, larger particles (10 [mu]m) tend to be removed 
by the respiratory clearance mechanisms whereas smaller particles are 
deposited deeper in the lungs. Also, particles scatter light 
obstructing visibility.
    The emission sources, formation processes, chemical composition, 
atmospheric residence times, transport distances and other parameters 
of fine and coarse particles are distinct. Fine particles are directly 
emitted from combustion sources and are formed secondarily from gaseous 
precursors such as oxides of nitrogen (NOX). Fine particles 
are generally composed of sulfate, nitrate, chloride, ammonium 
compounds, organic carbon, elemental carbon, and metals. Aircraft 
engines emit NOX which react in the atmosphere to form 
secondary PM2.5 (namely ammonium nitrate). Combustion of 
coal, oil, diesel, gasoline, and wood, as well as high temperature 
process sources such as smelters and steel mills, produce emissions 
that contribute to fine particle formation. In contrast, coarse 
particles are typically mechanically generated by crushing or grinding. 
They include resuspended dusts and crustal material from paved roads, 
unpaved roads, construction, farming, and mining activities. These 
coarse particles can be either natural in source such as road dust or 
anthropogenic. Fine particles can remain in the atmosphere for days to 
weeks and travel through the atmosphere hundreds to thousands of 
kilometers, while coarse particles deposit to the earth within minutes 
to hours and within tens of kilometers from the emission source.
    The relative contribution of various chemical components to 
PM2.5 varies by region of the country. Data on 
PM2.5 composition are available from the EPA Speciation 
Trends Network in 2001 and the Interagency Monitoring of PROtected 
Visual Environments (IMPROVE) network in 1999 covering both urban and 
rural areas in numerous regions of the U.S. These data show that 
nitrates formed from NOX also play a major role in the 
western U.S., especially in the California area where it is responsible 
for about a quarter of the ambient PM2.5 concentrations.

a. Health Effects of PM 2.5

    Scientific studies show ambient PM is associated with a series of 
adverse health effects. These health effects are discussed in detail in 
the EPA Criteria Document for PM as well as the draft updates of this 
document released in the past year.51,52
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    \51\ U.S. EPA (1996.) Air Quality Criteria for Particulate 
Matter--Volumes I, II, and III, EPA, Office of Research and 
Development. Report No. EPA/600/P-95/001a-cF. This material is 
available electronically at http://www.epa.gov/ttn/oarpg/ticd.html. 
Available in Docket A-99-06, Document Nos. IV-A-30, IV-A-31, and IV-
A-32.
    \52\ U.S. EPA (2002). Air Quality Criteria for Particulate 
Matter--Volumes I and II (Third External Review Draft) This material 
is available electronically at http://cfpub.epa.gov/ncea/cfm/partmatt.cfm. Available in Docket A-2001-28, Document Nos. II-A-98 
and II-A-71.
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    As described in these documents, health effects associated with 
short-term variation in ambient particulate matter (PM) have been 
indicated by epidemiologic studies showing associations between 
exposure and increased hospital admissions for ischemic heart disease, 
heart failure, respiratory disease, including chronic obstructive 
pulmonary disease (COPD) and pneumonia. Short-term elevations in 
ambient PM have also been associated with increased cough, lower 
respiratory symptoms, and decrements in lung function. Short-term 
variations in ambient PM have also been associated with increases in 
total and cardiorespiratory daily mortality. Studies examining 
populations exposed to different levels of air pollution over a number 
of years, including the Harvard Six Cities Study and the American 
Cancer Society Study suggest an association between exposure to ambient 
PM2.5 and premature mortality, including deaths attributed 
to lung cancer.53,54 Two studies further analyzing the 
Harvard Six Cities Study's air quality data have also established a 
specific influence of mobile source-related PM2.5 on daily 
mortality \55\ and a concentration-response function for mobile source-
associated PM2.5 and daily mortality.\56\
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    \53\ Dockery, DW; Pope, CA, III; Xu, X; et al. (1993) An 
association between air pollution and mortality in six U.S. cities. 
N Engl J Med 329:1753-1759.
    \54\ Pope, CA, III; Thun, MJ; Namboordiri, MM; et al. (1995) 
Particulate air pollution as a predictor of mortality in a 
prospective study of U.S. adults. Am J Respir Crit Care Med 151:669-
674.
    \55\ Laden F; Neas LM; Dockery DW; et al. (2000) Association of 
fine particulate matter from different sources with daily mortality 
in six U.S. cities. Environ Health Perspect 108(10):941-947.
    \56\ Schwartz J; Laden F; Zanobetti A. (2002) The concentration-
response relation between PM(2.5) and daily deaths. Environ Health 
Perspect 110(10): 1025-1029.
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b. Current and Projected Levels

    There are NAAQS for both PM10 and PM2.5. 
Violations of the annual PM2.5 standard are much more 
widespread than are violations of the PM10 standards. Figure 
III-1 at the beginning of this air quality section highlighted monitor 
locations measuring concentrations above the level of the NAAQS. As can 
be seen from that figure, high ambient levels are widespread throughout 
the country. Today's proposed aircraft NOX standards should 
contribute to attainment and maintenance of the existing PM NAAQS since 
NOX contributes to the secondary formation of 
PM2.5.
    The NAAQS for PM2.5 were established by EPA in 1997 (62 
FR 38651, July 18, 1997). The short term (24-hour) standard is set at a 
level of 65 [mu]g/m3 based on the 98th percentile 
concentration averaged over three years. (This air quality statistic 
compared to the standard is referred to as the ``design value.'') The 
long-term standard specifies an expected annual arithmetic mean not to 
exceed 15 [mu]g/m3 averaged over three years.
    Current PM2.5 monitored values for 1999-2001, which 
cover counties having about 75 percent of the country's population, 
indicate that at least 65 million people in 129 counties live in areas 
where annual design values of ambient fine PM violate the 
PM2.5 NAAQS. There are an additional 9 million people in 20 
counties where levels above the NAAQS are being measured, but there are 
insufficient data at this time to calculate a design value in 
accordance with the standard, and thus determine whether these areas 
are violating the PM2.5 NAAQS. In total, this represents 37 
percent of the counties and 64 percent of the population in the areas 
with monitors with levels above the NAAQS.\57\ Furthermore, an 
additional 14 million people live in 41 counties that have air quality 
measurements within 10 percent of the level of the standard. These 
areas, although not currently violating the standard, would also 
benefit from the additional reductions from this proposed rule in order 
to help ensure long term maintenance.
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    \57\ Memorandum to Docket A-2001-11 from Fred Dimmick, Group 
Leader, Air Trends Group, ``Summary of Currently Available Air 
Quality Data and Ambient Concentrations for Ozone and Particulate 
Matter,'' December 3, 2002. A copy of this document is available in 
Docket No. OAR 2002-0030.
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    The air quality modeling performed for the recent Nonroad Diesel 
Engines and Fuel Control proposed rule also indicates that similar 
conditions are likely to continue to exist in the future

[[Page 56236]]

in the absence of additional controls.\58\ For example, in 2020 based 
on emission controls currently adopted, we project that 66 million 
people will live in 79 counties with average PM2.5 levels 
above 15 [mu]g/m3. In 2030, the number of people projected 
to live in areas exceeding the PM2.5 standard is expected to 
increase to 85 million in 107 counties. An additional 24 million people 
are projected to live in counties within 10 percent of the standard in 
2020, which will increase to 64 million people in 2030.
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    \58\ See the Regulatory Impact Analysis: ``Draft Regulatory 
Impact Analysis: Control of Emissions from Nonroad Diesel Engines,'' 
EPA420-R-03-008, April 2003. This document is available at http://www.epa.gov/nonroad/. A copy of this document can also be found in 
Docket No. A-2001-28.
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    While the final implementation process for bringing the nation's 
air into attainment with the PM2.5 NAAQS is still being 
completed in a separate rulemaking action, the basic framework is well 
defined by the statute. EPA's current plans call for designating 
PM2.5 nonattainment areas in late 2004. Following 
designation, section 172(b) of the Clean Air Act allows states up to 
three years to submit a revision to their state implementation plan 
(SIP) that provides for the attainment of the PM2.5 
standard. Based on this provision, states could submit these SIPs as 
late as the end of 2007. Section 172(a)(2) of the Clean Air Act 
requires that these SIP revisions demonstrate that the nonattainment 
areas will attain the PM2.5 standard as expeditiously as 
practicable but no later than five years from the date that the area 
was designated nonattainment. However, based on the severity of the air 
quality problem and the availability and feasibility of control 
measures, the Administrator may extend the attainment date ``for a 
period of no greater than 10 years from the date of designation as 
nonattainment.'' Therefore, based on this information, we expect that 
most or all areas will need to attain the PM2.5 NAAQS in the 
2009 to 2014 time frame, and then be required to maintain the NAAQS 
thereafter.

B. Other Environmental Effects

    The following section presents information on four categories of 
public welfare and environmental impacts related to NOX and 
fine PM emissions: acid deposition, eutrophication of water bodies, 
plant damage from ozone, and visibility impairment.
1. Acid Deposition
    Acid deposition, or acid rain as it is commonly known, occurs when 
NOX and SO2 react in the atmosphere with water, 
oxygen, and oxidants to form various acidic compounds that later fall 
to earth in the form of precipitation or dry deposition of acidic 
particles.\59\ It contributes to damage of trees at high elevations and 
in extreme cases may cause lakes and streams to become so acidic that 
they cannot support aquatic life. In addition, acid deposition 
accelerates the decay of building materials and paints, including 
irreplaceable buildings, statues, and sculptures that are part of our 
nation's cultural heritage. To reduce damage to automotive paint caused 
by acid rain and acidic dry deposition, some manufacturers use acid-
resistant paints, at an average cost of $5 per vehicle--a total of $80-
85 million per year when applied to all new cars and trucks sold in the 
U.S.
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    \59\ Much of the information in this subsection was excerpted 
from the EPA document, Human Health Benefits from Sulfate Reduction, 
written under Title IV of the 1990 Clean Air Act Amendments, U.S. 
EPA, Office of Air and Radiation, Acid Rain Division, Washington, DC 
20460, November 1995. A copy of this document is available in Docket 
No. OAR 2002-0030.
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    Acid deposition primarily affects bodies of water that rest atop 
soil with a limited ability to neutralize acidic compounds. The 
National Surface Water Survey (NSWS) investigated the effects of acidic 
deposition in over 1,000 lakes larger than 10 acres and in thousands of 
miles of streams. It found that acid deposition was the primary cause 
of acidity in 75 percent of the acidic lakes and about 50 percent of 
the acidic streams, and that the areas most sensitive to acid rain were 
the Adirondacks, the mid-Appalachian highlands, the upper Midwest and 
the high elevation West. The NSWS found that approximately 580 streams 
in the Mid-Atlantic Coastal Plain are acidic primarily due to acidic 
deposition. Hundreds of the lakes in the Adirondacks surveyed in the 
NSWS have acidity levels incompatible with the survival of sensitive 
fish species. Many of the over 1,350 acidic streams in the Mid-Atlantic 
Highlands (mid-Appalachia) region have already experienced trout losses 
due to increased stream acidity. Emissions from U.S. sources contribute 
to acidic deposition in eastern Canada, where the Canadian government 
has estimated that 14,000 lakes are acidic. Acid deposition also has 
been implicated in contributing to degradation of high-elevation spruce 
forests that populate the ridges of the Appalachian Mountains from 
Maine to Georgia. This area includes national parks such as the 
Shenandoah and Great Smoky Mountain National Parks.
    A study of emissions trends and acidity of water bodies in the 
Eastern U.S. by the General Accounting Office (GAO) found that from 
1992 to 1999 sulfates declined in 92 percent of a representative sample 
of lakes, and nitrate levels increased in 48 percent of the lakes 
sampled.\60\ The decrease in sulfates is consistent with emissions 
trends, but the increase in nitrates is inconsistent with the stable 
levels of nitrogen emissions and deposition. The study suggests that 
the vegetation and land surrounding these lakes have lost some of their 
previous capacity to use nitrogen, thus allowing more of the nitrogen 
to flow into the lakes and increase their acidity. Recovery of 
acidified lakes is expected to take a number of years, even where soil 
and vegetation have not been ``nitrogen saturated,'' as EPA called the 
phenomenon in a 1995 study.\61\ This situation places a premium on 
reductions of NOX (and SOX) from all sources, 
including aircraft engines, in order to reduce the extent and severity 
of nitrogen saturation and acidification of lakes in the Adirondacks 
and throughout the U.S.
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    \60\ Acid Rain: Emissions Trends and Effects in the Eastern 
United States, U.S. General Accounting Office, March, 2000 (GAO/
RCED-00-47). A copy of this document is available in Docket No. OAR 
2002-0030.
    \61\ Acid Deposition Standard Feasibility Study: Report to 
Congress, EPA 430R-95-001a, October, 1995. A copy of this document 
is available in Docket No. OAR-2002-0030.
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    The NOX reductions from today's action would help reduce 
acid rain and acid deposition, thereby helping to reduce acidity levels 
in lakes and streams throughout the country and help accelerate the 
recovery of acidified lakes and streams and the revival of ecosystems 
adversely affected by acid deposition. Reduced acid deposition levels 
will also help reduce stress on forests, thereby accelerating 
reforestation efforts and improving timber production. Deterioration of 
our historic buildings and monuments, and of buildings, vehicles, and 
other structures exposed to acid rain and dry acid deposition also will 
be reduced, and the costs borne to prevent acid-related damage may also 
decline. While the reduction in nitrogen acid deposition would be 
roughly proportional to the reduction in NOX emissions the 
precise impact of today's action would differ across different areas.
2. Eutrophication and Nitrification
    Eutrophication is the accelerated production of organic matter, 
particularly algae, in a water body. This

[[Page 56237]]

increased growth can cause numerous adverse ecological effects and 
economic impacts, including nuisance algal blooms, dieback of 
underwater plants due to reduced light penetration, and toxic plankton 
blooms. Algal and plankton blooms can also reduce the level of 
dissolved oxygen, which can also adversely affect fish and shellfish 
populations.
    In 1999, NOAA published the results of a five year national 
assessment of the severity and extent of estuarine eutrophication. An 
estuary is defined as the inland arm of the sea that meets the mouth of 
a river. The 138 estuaries characterized in the study represent more 
than 90 percent of total estuarine water surface area and the total 
number of U.S. estuaries. The study found that estuaries with moderate 
to high eutrophication conditions represented 65 percent of the 
estuarine surface area. Eutrophication is of particular concern in 
coastal areas with poor or stratified circulation patterns, such as the 
Chesapeake Bay, Long Island Sound, or the Gulf of Mexico. In such 
areas, the ``overproduced'' algae tends to sink to the bottom and 
decay, using all or most of the available oxygen and thereby reducing 
or eliminating populations of bottom-feeder fish and shellfish, 
distorting the normal population balance between different aquatic 
organisms, and in extreme cases causing dramatic fish kills.
    Severe and persistent eutrophication often directly impacts human 
activities. For example, losses in the nation's fishery resources may 
be directly caused by fish kills associated with low dissolved oxygen 
and toxic blooms. Declines in tourism occur when low dissolved oxygen 
causes noxious smells and floating mats of algal blooms create 
unfavorable aesthetic conditions. Risks to human health increase when 
the toxins from algal blooms accumulate in edible fish and shellfish, 
and when toxins become airborne, causing respiratory problems due to 
inhalation. According to the NOAA report, more than half of the 
nation's estuaries have moderate to high expressions of at least one of 
these symptoms--an indication that eutrophication is well developed in 
more than half of U.S. estuaries.
    In recent decades, human activities have greatly accelerated 
nutrient inputs, such as nitrogen and phosphorous, causing excessive 
growth of algae and leading to degraded water quality and associated 
impairments of freshwater and estuarine resources for human uses.\62\ 
Since 1970, eutrophic conditions worsened in 48 estuaries and improved 
in 14. In 26 systems, there was no trend in overall eutrophication 
conditions since 1970.\63\ On the New England coast, for example, the 
number of red and brown tides and shellfish problems from nuisance and 
toxic plankton blooms have increased over the past two decades, a 
development thought to be linked to increased nitrogen loadings in 
coastal waters. Long-term monitoring in the U.S., Europe, and other 
developed regions of the world shows a substantial rise of nitrogen 
levels in surface waters, which are highly correlated with human-
generated inputs of nitrogen to their watersheds.
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    \62\ Deposition of Air Pollutants to the Great Waters, Third 
Report to Congress, June, 2000. A copy of this document is available 
in Docket No. OAR 2002-0030.
    \63\ Deposition of Air Pollutants to the Great Waters, Third 
Report to Congress, June, 2000. Great Waters are defined as the 
Great Lakes, the Chesapeake Bay, Lake Champlain, and coastal waters. 
The first report to Congress was delivered in May, 1994; the second 
report to Congress in June, 1997. A copy of this document is 
available in Docket No. OAR 2002-0030.
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    Between 1992 and 1997, experts surveyed by National Oceanic and 
Atmospheric Administration (NOAA) most frequently recommended that 
control strategies be developed for agriculture, wastewater treatment, 
urban runoff, and atmospheric deposition.\64\ In its Third Report to 
Congress on the Great Waters, EPA reported that atmospheric deposition 
contributes from 2 to 38 percent of the nitrogen load to certain 
coastal waters.\65\ A review of peer reviewed literature in 1995 on the 
subject of air deposition suggests a typical contribution of 20 percent 
or higher.\66\ Human-caused nitrogen loading to the Long Island Sound 
from the atmosphere was estimated at 14 percent by a collaboration of 
Federal and State air and water agencies in 1997.\67\ The National 
Exposure Research Laboratory, U.S. EPA, estimated based on prior 
studies that 20 to 35 percent of the nitrogen loading to the Chesapeake 
Bay is attributable to atmospheric deposition.\68\ The mobile source 
portion of atmospheric NOX contribution to the Chesapeake 
Bay was modeled at about 30 percent of total air deposition.\69\
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    \64\ Bricker, Suzanne B., et al., National Estuarine 
Eutrophication Assessment, Effects of Nutrient Enrichment in the 
Nation's Estuaries, National Ocean Service, National Oceanic and 
Atmospheric Administration, September, 1999. A copy of this document 
is available in Docket No. OAR 2002-0030.
    \65\ Deposition of Air Pollutants to the Great Waters, Third 
Report to Congress, June, 2000. A copy of this document is available 
in Docket No. OAR 2002-0030.
    \66\ Valigura, Richard, et al., Airsheds and Watersheds II: A 
Shared Resources Workshop, Air Subcommittee of the Chesapeake Bay 
Program, March, 1997. Available in Docket A-99-06, Document No. IV-
G-144.
    \67\ The Impact of Atmospheric Nitrogen Deposition on Long 
Island Sound, The Long Island Sound Study, September, 1997. A copy 
of this document is available in Docket No. OAR-2002-0030.
    \68\ Dennis, Robin L., Using the Regional Acid Deposition Model 
to Determine the Nitrogen Deposition Airshed of the Chesapeake Bay 
Watershed, SETAC Technical Publications Series, 1997.
    \69\ Ibid.
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    Deposition of nitrogen from aircraft engines contributes to 
elevated nitrogen levels in waterbodies. The NOX reductions 
from the proposed standards would help reduce the airborne nitrogen 
deposition that contributes to eutrophication of watersheds, 
particularly in aquatic systems where atmospheric deposition of 
nitrogen represents a significant portion of total nitrogen loadings.
3. Plant Damage From Ozone
    Ground-level ozone can also cause adverse welfare effects. 
Specifically, ozone enters the leaves of plants where it interferes 
with cellular metabolic processes. This interference can be manifest 
either as visible foliar injury from cell injury or death, and/or as 
decreased plant growth and yield due to a reduced ability to produce 
food. With fewer resources, the plant reallocates existing resources 
away from root storage, growth and reproduction toward leaf repair and 
maintenance. Plants that are stressed in these ways become more 
susceptible to disease, insect attack, harsh weather and other 
environmental stresses. Because not all plants are equally sensitive to 
ozone, ozone pollution can also exert a selective pressure that leads 
to changes in plant community composition.
    Since plants are at the center of the food web in many ecosystems, 
changes to the plant community can affect associated organisms and 
ecosystems (including the suitability of habitats that support 
threatened or endangered species and below ground organisms living in 
the root zone). Given the range of plant sensitivities and the fact 
that numerous other environmental factors modify plant uptake and 
response to ozone, it is not possible to identify threshold values 
above which ozone is toxic and below which it is safe for all plants. 
However, in general, the science suggests that ozone concentrations of 
0.10 ppm or greater can be phytotoxic to a large number of plant 
species, and can produce acute foliar injury responses, crop yield loss 
and reduced biomass production. Ozone concentrations below 0.10 ppm 
(0.05 to 0.09 ppm) can produce these effects in more sensitive plant 
species, and have the potential over a longer duration of

[[Page 56238]]

creating chronic stress on vegetation that can lead to effects of 
concern such as reduced plant growth and yield, shifts in competitive 
advantages in mixed populations, and decreased vigor leading to 
diminished resistance to pests, pathogens, and injury from other 
environmental stresses.
    Studies indicate that these effects described here are still 
occurring in the field under ambient levels of ozone. The economic 
value of some welfare losses due to ozone can be calculated, such as 
crop yield loss from both reduced seed production (e.g., soybean) and 
visible injury to some leaf crops (e.g., lettuce, spinach, tobacco) and 
visible injury to ornamental plants (i.e., grass, flowers, shrubs), 
while other types of welfare loss may not be fully quantifiable in 
economic terms (e.g., reduced aesthetic value of trees growing in Class 
I areas).
    As discussed earlier, aircraft engine emissions of NOX 
contribute to ozone. The proposed standards would aid in the reduction 
of ozone and, therefore, help reduce crop damage and stress from ozone 
on vegetation.
4. Visibility
    The secondary PM NAAQS is designed to protect against adverse 
welfare effects which includes visibility impairment. In 1997, EPA 
established the secondary PM2.5 NAAQS as equal to the 
primary (health-based) NAAQS of 15 ug/m3 (based on a 3-year 
average of the annual mean) and 65 ug/m3 (based on a 3-year 
average of the 98th percentile of the 24-hour average value) (62 FR 
38669, July 18, 1997). EPA concluded that PM2.5 causes 
adverse effects on visibility in various locations, depending on PM 
concentrations and factors such as chemical composition and average 
relative humidity. In 1997, EPA demonstrated that visibility impairment 
is an important effect on public welfare and that unacceptable 
visibility impairment is experienced throughout the U.S., in multi-
state regions, urban areas, and remote federal Class I areas. In many 
cities having annual mean PM2.5 concentrations exceeding 
annual standard, improvements in annual average visibility resulting 
from the attainment of the annual PM2.5 standard are 
expected to be perceptible to the general population. Based on annual 
mean monitored PM2.5 data, many cities in the Northeast, 
Midwest, and Southeast as well as Los Angeles would be expected to 
experience perceptible improvements in visibility if the 
PM2.5 annual standard were attained.
    Furthermore, in setting the PM2.5 NAAQS, EPA 
acknowledged that levels of fine particles below the NAAQS may also 
contribute to unacceptable visibility impairment and regional haze 
problems in some areas, and section 169 of the Act provides additional 
authorities to remedy existing impairment and prevent future impairment 
in the 156 national parks, forests and wilderness areas labeled as 
mandatory Federal Class I areas (62 FR 38680-81, July 18, 1997).
    Visibility can be defined as the degree to which the atmosphere is 
transparent to visible light.\70\ Fine particles with significant 
light-extinction efficiencies include organic matter, sulfates, 
nitrates, elemental carbon (soot), and soil. Size and chemical 
composition of particles strongly affects their ability to scatter or 
absorb light. Nitrates typically contribute 1 to 6 percent of average 
light extinction on haziest days in rural Eastern U.S. locations.\71\
    Visibility is important because it directly affects people's 
enjoyment of daily activities in all parts of the country. Individuals 
value good visibility for the well-being it provides them directly, 
both in where they live and work, and in places where they enjoy 
recreational opportunities. Visibility is also highly valued in 
significant natural areas such as national parks and wilderness areas, 
because of the special emphasis given to protecting these lands now and 
for future generations.
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    \70\ National Research Council, 1993. Protecting Visibility in 
National Parks and Wilderness Areas. National Academy of Sciences 
Committee on Haze in National Parks and Wilderness Areas. National 
Academy Press, Washington, DC. This book can be viewed on the 
National Academy Press Website at http://www.nap.edu/books/0309048443/html/. See also U.S. EPA Air Quality Criteria Document 
for Particulate Matter (1996) (available on the internet at http://cfpub.epa.gov/ncea/cfm/partmatt.cfm) and Review of the National 
Ambient Air Quality Standards for Particulate Matter: Policy 
Assessment of Scientific and Technical Information. These documents 
can be found in Docket A-99-06, Documents No. II-A-23 and IV-A-130-
32.
    \71\ US EPA Trends Report 2001. This document is available on 
the internet at http://www.epa.gov/airtrends/. A copy of this 
document is available in Docket No. OAR 2002-0030.
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    To quantify changes in visibility, we compute a light-extinction 
coefficient, which shows the total fraction of light that is decreased 
per unit distance. Visibility can be described in terms of visual range 
or light extinction and is reported using an indicator called 
deciview.\72\ In addition to limiting the distance that one can see, 
the scattering and absorption of light caused by air pollution can also 
degrade the color, clarity, and contrast of scenes.
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    \72\ Visual range can be defined as the maximum distance at 
which one can identify a black object against the horizon sky. It is 
typically described in miles or kilometers. Light extinction is the 
sum of light scattering and absorption by particles and gases in the 
atmosphere. It is typically expressed in terms of inverse megameters 
(Mm-1), with larger values representing worse visibility. 
The deciview metric describes perceived visual changes in a linear 
fashion over its entire range, analogous to the decibel scale for 
sound. A deciview of 0 represents pristine conditions. Under many 
scenic conditions, a change of 1 deciview is considered perceptible 
by the average person.
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    In addition, visibility impairment can be described by its impact 
over various periods of time, by its source, and the physical 
conditions in various regions of the country. Visibility impairment can 
be said to have a time dimension in that it might relate to short-term 
excursions or to longer periods (e.g., worst 20 percent of days and 
annual average levels). Anthropogenic contributions account for about 
one-third of the average extinction coefficient in the rural West and 
more than 80 percent in the rural East. In the Eastern U.S., reduced 
visibility is mainly attributable to secondarily formed particles, 
particularly those less than a few micrometers in diameter. While 
secondarily formed particles still account for a significant amount in 
the West, primary emissions contribute a larger percentage of the total 
particulate load than in the East.
    Furthermore, it is important to note that even in those areas with 
relatively low concentrations of anthropogenic fine particles, such as 
the Colorado Plateau, small increases in anthropogenic fine particulate 
concentrations can lead to significant decreases in visual range. This 
is one of the reasons mandatory Federal Class I areas have been given 
special consideration under the Clean Air Act.\73\
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    \73\ The Clean Air Act designates 156 national parks and 
wilderness areas as mandatory Federal Class I areas for visibility 
protection.
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    Taken together with other programs, reductions from this proposal 
would help to improve visibility across the nation, including mandatory 
Federal Class I areas.

C. Other Criteria Pollutants Affected by This Proposed Rule

    The standards being proposed today would also help reduce levels of 
nitrogen dioxide (NO2), for which NAAQS have been 
established. Currently, every area in the United States has been 
designated to be in attainment with the NO2 NAAQS.

IV. Description of Action

    Under the authority of section 231 of the CAA, EPA today proposes 
to adopt standards equivalent to ICAO's February 1999 NOX 
emission standards (these NOX standards were adopted at 
CAEP/4 in 1998 and approved by the ICAO Council in 1999) and March 1997 
test

[[Page 56239]]

procedure amendments. Today's proposed emission standards and test 
procedure amendments apply to commercial aircraft engines; no general 
aviation or military engines are covered by today's proposal. The 
commercial aircraft engines subject to today's proposed NOX 
standards are those gas turbine engines that are newly certified (and 
designed) after the effective date of the proposed regulations. (Newly 
manufactured or already certified engines built after the effective 
date of the proposed regulations would not have to meet these 
standards.) For the sake of consistency and harmonization, the 
effective dates below for the proposed NOX standards are 
identical with those of the ICAO 1999 NOX standards. The 
proposed NOX emission standards, test procedure amendments, 
and their effective dates are described below.

A. What Emission Standards Are Under Consideration?

    As discussed earlier in sections II and III of today's notice, 
section 231(a)(2)(A) of the CAA authorizes EPA to establish emission 
standards for aircraft engine emissions'' * * * which in [her] judgment 
causes, or contributes to, air pollution which may reasonably be 
anticipated to endanger public health or welfare.'' The Administrator 
may revise such standards from ``time to time.'' CAA section 231(b) 
requires that any emission standards provide sufficient lead time ``to 
permit the development and application of the requisite technology, 
giving appropriate consideration to the cost of compliance within such 
period.''
    Today's rule proposes near-term standards that would go into effect 
in 2004 to ensure future engines do not jeopardize recent or past 
technology gains. These standards are equivalent to the CAEP/4 
NOX international consensus emissions standards for aircraft 
engines adopted by ICAO's CAEP in 1998.\74\ EPA intends to promulgate 
these standards by January 2004 in order to be consistent with U.S. 
obligations under ICAO. At the same time, EPA anticipates establishing 
more stringent NOX standards in the future. EPA will 
participate at CAEP/6 (sixth meeting of CAEP), which is scheduled in 
February 2004, to establish more stringent international consensus 
emission standards for aircraft engines. Such standards would likely be 
a central consideration in a future EPA regulation of aircraft engine 
emissions.
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    \74\ ICAO, CAEP, Fourth Meeting, Montreal, Quebec, April 6-8, 
1998, Report, Document 9720, CAEP/4. Copies of this document can be 
obtained from the ICAO Web site located at http://www.icao.int.
---------------------------------------------------------------------------

    We believe this two-step approach is the most appropriate means to 
address emissions from aircraft engines in this rulemaking. It would 
codify current practice, with no significant lead time, as a near-term 
approach.\75\ EPA has authority to revise emission standards from 
``time to time''. EPA intends to address more stringent emission 
standards requiring more lead time in a future rulemaking (see section 
IV.A.5. for further discussion of future standards).
---------------------------------------------------------------------------

    \75\ As described later, more information and greater lead time 
would be necessary to require more stringent standards.
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1. Today's Proposed NOX Standards
    EPA proposes to adopt standards equivalent to ICAO's 1999 
NOX emission standards for newly certified aircraft gas 
turbine engines (turbofan and turbojet engines) of rated thrust or 
output greater than 26.7 kilonewtons (kN) with compliance dates as 
follows: \76\
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    \76\ This proposal includes standards for low-, mid, and high-
thrust engines (see below for further discussion of the different 
standards based on the thrust of the engines).
---------------------------------------------------------------------------

    For engines of a type or model of which that date of manufacture of 
the first individual production model was after December 31, 2003:
    (a) for engines with a pressure ratio of 30 or less:
    (i) for engines with a maximum rated output of more than 89.0 kN:
NOX = (19 + 1.6(rated pressure ratio))g/kN(rated output)
    (ii) for engines with a maximum rated output of more than 26.7 kN 
but not more than 89.0 kN:
NOX = (37.572 + 1.6(rated pressure ratio)-0.2087(rated 
output))g/kN(rated output)
    (b) for engines with a pressure ratio of more than 30 but less than 
62.5:
    (i) for engines with a maximum rated output of more than 89.0 kN:

NOX = (7 + 2.0(rated pressure ratio))g/kN(rated output)

    (ii) for engines with a maximum rated output of more than 26.7 kN 
but not more than 89.0 kN:
    NOX = (42.71 + 1.4286(rated pressure ratio)--
0.4013(rated output) + 0.00642(rated pressure ratio x rated output))g/
kN(rated output)
    (c) for engines with a pressure ratio of 62.5 or more:

NOX = (32 + 1.6(rated pressure ratio))g/kN(rated output).

    The NOX emission standards presented above are 
equivalent to the ICAO NOX standards that have an 
implementation date of December 31, 2003.\77\
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    \77\ ICAO's CAEP/4 NOX standards became effective 
July 19, 1999, and applicable as of November 4, 1999. December 31, 
2003 is the implementation date for these standards. However, for 
the purpose of this Notice the effective date is considered the 
implementation date. (ICAO, ``Aircraft Engine Emissions,'' 
International Standards and Recommended Practices, Environmental 
Protection, Annex 16, Volume II, Second Edition, July 1993--
Amendment 4, July 19, 1999.)
---------------------------------------------------------------------------

2. Proposed NOX Standards for Newly Certified Mid- and High-
Thrust Engines
    EPA is proposing to adopt NOX standards for newly 
certified mid- and high-thrust engines (those engines designed and 
certified after the effective date of the proposed regulations, which 
have a rated output or thrust greater than 89 kN) that generally 
represent about a 16 percent reduction (or increase in stringency) from 
the existing standard. (See section IV.A.1(a)(i) and IV.A.1(b)(i) above 
for the standards for mid- and high-thrust engines.) More specifically, 
at a rated pressure ratio of 30 the proposed NOX standards 
represent a 16 percent reduction from the existing standard. At rated 
pressure ratios of 10 and 20, the proposed standards correspond to 27 
and 20 percent reductions, respectively. In addition, at rated pressure 
ratios of 40 and 50, the proposed NOX standards signify 9 
and 4 percent reductions, respectively. Also, the proposed and existing 
standards are equivalent at a rated pressure ratio of 62.5. See Figure 
IV.B-1 in section IV.B. for a comparison of the proposed NOX 
standards (equivalent to CAEP/4 standards) to the existing standards 
(equivalent to CAEP/2 standards) .
3. Proposed NOX Standards for Newly Certified Low-Thrust 
Engines
    For newly certified low-thrust engines (engines with a thrust or 
rated output of more than 26.7 kN but not more than 89.0 kN), EPA is 
today proposing to adopt near-term NOX standards that are 
different than the standards proposed for mid- and high-thrust engines 
(engines with thrust greater than 89.0 kN).\78\ In addition to rated 
pressure ratio, the proposed standards for low-

[[Page 56240]]

thrust engines would also be dependent on an engine's thrust or rated 
output.\79\ (See section IV.A.1(a)(ii) and IV.A.1(b)(ii) for a 
description of these different standards.) For example, at a rated 
pressure ratio of 30 and a thrust of 58 kN (thrust level in the middle 
of 26.7 kN and 89 kN), these proposed standards are an 8 percent 
reduction (or increase in stringency) from the existing standard 
compared to a 16 percent reduction for the proposed standards for mid- 
and high-thrust engines.\80\
---------------------------------------------------------------------------

    \78\ Today's proposed NOX standards for low thrust or 
small engines specify that engines with a rated output or thrust at 
26.7 kN meet the existing standard, and engines with a rated output 
at 89 kN meet the proposed (or CAEP/4) standards. For engines with 
rated outputs or thrust levels between 26.7 and 89 kN, a linear 
interpolation was made between the low range of the existing 
standard and the high range of the proposed standard based upon the 
rated output to determine the proposed NOX limits for 
such engines. Thus, thrust dependent standards are being proposed 
for engines with rated output or thrust between 26.7 kN and 89 kN.
    \79\ The proposed standards for mid- and high-thrust engines are 
dependent only on an engine's rated pressure ratio.
    \80\ Additional examples of the proposed standards for low-
thrust engines in comparison to the proposed standards for mid- and 
high-thrust engines are provided below. At rated pressure ratios of 
10 and 20 with a thrust of 58 kN, the proposed low-thrust engine 
standards are a 14 and 10 percent reduction from the existing 
standard, respectively. Whereas, at these same rated pressure 
ratios, the proposed standards for mid- and high-thrust engines are 
27 and 20 percent reductions.
    In addition, at rated pressure ratios of 40 and 50 with a thrust 
of 58 kN, these low-thrust engine standards signify a 5 and 2 
percent reduction from the existing standard, respectively. In 
comparison, at these same rated pressure ratios, the proposed 
standards for mid- and high-thrust engines are 9 and 4 percent 
reductions.
---------------------------------------------------------------------------

    The existing standards were not set at a stringency level that 
created a need for low-thrust engines to have different requirements, 
but at the level of NOX stringency proposed today different 
requirements are considered necessary for such engines. Due to their 
physical size, it is difficult to apply the best NOX 
reduction technology to low thrust or small engines. The difficulty 
increases progressively as size is reduced (from around 89 kN).\81\ For 
example, the relatively small combustor space and section height of 
these engines creates constraints on the use of low NOX fuel 
staged combustor concepts which inherently require the availability of 
greater flow path cross-sectional area than conventional 
combustors.\82\ Also, fuel staged combustors need more fuel injectors, 
and this need is not compatible with the relatively lower total fuel 
flows of lower thrust engines. (Reductions in fuel flow per nozzle are 
difficult to attain without having clogging problems due to the small 
sizes of the fuel metering ports.) In addition, lower thrust engine 
combustors have an inherently greater liner surface-to-combustion 
volume ratio, and this requires increased wall cooling air flow. Thus, 
less air would be available to obtain acceptable turbine inlet 
temperature distribution and for emissions control.\83\ Since the 
difficulties increase progressively as engine thrust size is reduced, 
EPA believes it would be appropriate to make a graded change in 
stringency of the proposed NOX standards for low-thrust 
engines.
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    \81\ ICAO/CAEP, Report of Third Meeting, Montreal, Quebec, 
December 5-15, 1995, Document 9675, CAEP/3.
    \82\ ``The burner section of an aircraft engine, which contains 
the combustion chamber, burns a mixture of fuel and air, and 
delivers the resulting gases to the turbine at a temperature which 
will not exceed the allowable limit at the turbine inlet.'' (United 
Technologies Pratt and Whitney, ``The Aircraft Gas Turbine Engine 
and Its Operation,'' August 1998.)
    \83\ ICAO/CAEP Working Group 3 (Emissions), ``Combined Report of 
the Certification and Technology Subgroups,'' section 2.3.6.1, 
Presented by the Chairman of the Technology Subgroup, Third Meeting, 
Bonn, Germany, June 1995. A copy of this paper can be found in 
Docket OAR-2002-0030.
---------------------------------------------------------------------------

4. Rationale of Proposed NOX Standards for Newly Certified 
Low-, Mid-, and High-Thrust Engines
    The proposed standards for low-, mid-, and high-thrust engines, 
which are equivalent to the CAEP/4 standards, ensure that new engine 
designs would incorporate the existing combustor technology and would 
not perform worse than today's current engines. EPA intends to 
promulgate these standards by January 2004 in order to be consistent 
with U.S. obligations under ICAO. (See section II.B for a discussion of 
the obligation of ICAO's participating nations). At this time, there is 
not sufficient lead time to require more stringent emission standards 
than the CAEP/4 NOX emission standards by January 2004. As 
discussed later in section IV.A.5 for future standards, we are 
deferring action on more stringent NOX standards because 
pursuant to section 231(b) of the CAA we need more time to better 
understand the cost of compliance with such standards, and additional 
cost data is expected to be available from CAEP/6 in February 2004 (see 
section IV.A.5 for further discussion regarding lead time).
    EPA believes that the proposed standards would not impose any 
additional burden on manufacturers, because manufacturers are already 
designing new engines to meet the ICAO international consensus 
standards by 2004 (see section VII of today's action for further 
discussion of regulatory impact). Even though the U.S. did not 
immediately adopt the ICAO NOX standards after 1999, engine 
manufacturers have continued to make progress in reducing these 
emissions. Today's proposed standards are aimed at assuring that this 
progress is not reversed in the future.
5. Future NOX Standards for Newly Certified Low-, Mid-, and 
High-Thrust Engines
    More stringent standards for low-, mid-, and high-thrust engines 
will be necessary in the future. As discussed earlier in section III, 
the growth in aircraft emissions is projected to occur at a time when 
other mobile source categories are reducing emissions.\84\ The 1999 EPA 
study of commercial aircraft activity in ten cities projected that the 
aircraft NOX emissions would double in some of these cities 
by 2010, and the aircraft component of the regional mobile source 
NOX emissions in the ten cities would grow from a range of 1 
to 4 percent that existed in 1990 to a range of 2 to 10 percent in 
2010.\85\ (As indicated earlier, the above projections were made prior 
to the tragic events of September 11, 2001, and the subsequent economic 
downturn. A January 2003 report by the Department of Transportation 
indicated that the combination of the September 11, 2001 terrorist 
attacks and a cut-back in business travel had a significant and perhaps 
long-lasting effect on air traffic demand. However, the FAA expects the 
demand for air travel to recover, and then continue a long-term trend 
of annual growth in the United States.) More recently, as discussed 
earlier FAA reports that flights (or activity) of commercial air 
carriers will increase by 18 percent by 2010 and 45 percent by 
2020.\86\ Thus, based on these trends

[[Page 56241]]

more stringent NOX standards than the proposed standards are 
needed in the future to reduce aircraft NOX emissions in 
nonattainment areas.
---------------------------------------------------------------------------

    \84\ The projected growth in aircraft emissions is not simply 
from the number of operations, but it could also be attributed to 
the change in the types of aircraft being operated. For example, 
regional aircraft activity is growing (regional aircraft are 
generally referred to as those aircraft with more than 19 but fewer 
than 100 seats--regional jets and turboprops). In the U.S., traffic 
flown by regional airlines increased about 20 percent in 1999 and is 
expected to grow approximately 7 percent annually during the next 
ten years, compared to 4 to 6 percent for the major airlines. In 
addition, regional jets comprised about 25 percent of the regional 
aircraft fleet in 2000, up from only 4.2 percent in 1996, and their 
fraction of the fleet is expected to increase to nearly 50 percent 
by 2011. Regional aircraft are 40 to 60 percent less fuel efficient 
compared to larger narrow- and wide-body aircraft, and regional jets 
are 10 to 60 percent less fuel efficient than turboprop aircraft. 
However, fuel costs have less of an effect on the operating costs of 
regional aircraft compared to large aircraft. In addition, regional 
jets have historically operated at higher load factors than 
turboprops due to their popularity with travelers. (R. Babikian, S. 
P. Lukachko and I. A. Waitz, ``Historical Fuel Efficiency 
Characteristics of Regional Aircraft from Technological, 
Operational, and Cost Perspectives,'' Journal of Air Transport 
Management, Volume 8, No. 6, pp. 389-400, Nov. 2002).
    \85\ U.S. EPA, ``Evaluation of Air Pollutant Emissions from 
Subsonic Commercial Jet Aircraft,'' April 1999, EPA420-R-99-013. 
This study is available at http://www.epa.gov/otaq/aviation.htm. It 
can also be found in Docket No. OAR-2002-0030.
    \86\ The flight forecast data is based on FAA's Terminal Area 
Forecast System (TAFS). TAFs is the official forecast of aviation 
activity at FAA facilities. This includes FAA-towered airports, 
federally-contracted towered airports, nonfederal towered airports, 
and many non-towered airports. For detailed information on TAFS and 
the air carrier activity forecasts see the following FAA Web site: 
http://www.apo.data.faa.gov/faatafall.HTM. As of May 1, 2003, the 
aviation forecasts contained in TAFS for Fiscal Years 2002-2020 
included the impact of the terrorists' attacks of September 11, 2001 
and the recent economic downturn. However, these projections did not 
fully reflect the ongoing structural changes occurring within the 
aviation industry. A copy of the May 1, 2003 forecast summary report 
for air carrier activity can be found in Docket No. OAR-2002-0030.
---------------------------------------------------------------------------

    Further stringency of the NOX standards would reduce the 
expected growth in commercial aircraft emissions. The importance of 
controlling aircraft emissions has grown in many areas (especially 
areas not meeting the 1-hour and 8-hour ozone NAAQS) as controls on 
other sources become more stringent and attainment of the NAAQS's has 
still not been achieved. (Many airports in the U.S. are located in 
nonattainment areas.\87\) As activity increases, aircraft would emit 
increasing amounts of NOX in many nonattainment areas, and 
thus, aircraft emissions would further aggravate the problems in these 
areas (either by emitting pollutants directly within a nonattainment 
area or by contributing to regional transport emissions in an area 
upwind of a nonattainment area). More stringent aircraft engine 
NOX standards would assist in alleviating these problems in 
nonattainment areas, and they would aid in preventing future concerns 
in areas currently designated as attainment (or maintenance) areas. In 
addition, attainment or maintenance of the NAAQS requires that aircraft 
engines be subject to a program of control compatible with their 
significance as pollution sources.
---------------------------------------------------------------------------

    \87\ For information on the geographic location of airports, see 
the following U.S. Department of Transportation (Bureau of 
Transportation Statistics) Web site: http://www.bts.gov/oai. The 
report or database provided on the website entitled, ``Airport 
Activity Statistics of Certificated Air Carriers: Summary Tables 
2000,'' lists airports by community. In addition, see the following 
EPA website for information on nonattainment areas for criteria 
pollutants: http://www.epa.gov/oar/oaqps/greenbk.
---------------------------------------------------------------------------

    EPA, therefore, is considering more stringent future standards, 
beyond today's proposed standards. Leading up to CAEP/6 in February 
2004, one of the objectives of CAEP (and/or the international aviation 
community) is to consider more stringent aircraft engine standards than 
CAEP/4 standards for all gaseous emissions, especially 
NOX.\88\ ICAO CAEP working groups are currently assessing 
the technological feasibility, economic reasonableness, and 
environmental benefit of imposing more stringent NOX 
emissions standards for aircraft engines beyond that which will become 
effective in 2004 (CAEP/4 standards). Options being considered range 
from 5 to 30 percent more stringent with an effective date as early as 
2008 to 2012 (these options are accompanied by more stringent standards 
for low-thrust engines).\89\ Based on the results of this assessment, a 
proposal for more stringent NOX standards is expected to be 
made at CAEP/6.\90\ (No changes to the standards of other pollutants, 
hydrocarbons and carbon monoxide, are anticipated.) Activity is also 
underway to identify and assess the potential for long-term technology 
goals to be established for further emissions reductions.\91\ \92\ The 
aim of the goal setting activity is to complement the ICAO CAEP 
standard setting process with information to aid the engine and 
airframe manufacturer's design process. The goals are expected to take 
into account the results of recently completed emissions reduction 
technology programs such as those conducted by National Aeronautics and 
Space Administration (NASA) and the European Commission and the 
timeline necessary to carry those technologies from the research phase 
through commercialization.\93\ EPA is currently working with FAA and 
CAEP working groups (as described in section V) in the evaluation of 
NOX stringency options for CAEP/6 and the potential for 
long-term technology goals.
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    \88\ ICAO, CAEP, Fifth Meeting, Montreal, Quebec, January 1-17, 
2001, ``Report on Agenda Item 4,'' CAEP/5-WP/86, January 17, 2001. 
Copies of this document can be obtained from ICAO (http://www.icao.int).
    \89\ ICAO, CAEP, Steering Group Meeting, Paris, France, 
September 10-13, 2002, ``Summary of Discussions and Decisions of the 
Second Meeting of the Steering Group,'' September 11, 2002, CAEP-
SG20022-SD/2. A copy of this paper can be found in Docket OAR-2002-
0030. Since this paper was written, the working groups have also 
decided to consider the range of stringency options for an effective 
date of 2008.
    \90\ ICAO, CAEP, Steering Group Meeting, Paris, France, 
September 10-13, 2002, ``Summary of Discussions and Decisions of the 
First Meeting of the Steering Group,'' September 10, 2002, CAEP-
SG20022-SD/1. A copy of this paper can be found in Docket OAR-2002-
0030.
    \91\ ICAO, CAEP, Fifth Meeting, Montreal, Quebec, January 1-17, 
2001, ``Report on Agenda Item 4,'' CAEP/5-WP/86, January 17, 2001. 
Copies of this document can be obtained from ICAO (http://www.icao.int).
    \92\ For the purpose of setting long-term technology goals, 
activity on the below tasks was initiated after CAEP/5 in 2001, and 
it is expected to continue beyond CAEP/6.
    (a) characterize emissions performance of future technologies 
being pursued under national and international research programs, 
including technology readiness;
    (b) develop methodologies for quantifying aviation emissions 
inventories;
    (c) develop forecasts of emission trends both locally and 
globally; and
    (d) examine how such goals might be applied within the current 
regulatory regime.
    \93\ ICAO, CAEP, Fourth Meeting, Montreal, Quebec, April 6-8, 
1998, Report, Document 9720, CAEP/4, see Appendix A to the Report on 
Agenda Item 4 (page 4-A-1). Copies of this document can be obtained 
from ICAO (http://www.icao.int).
---------------------------------------------------------------------------

    Manufacturers should be able to achieve additional reductions with 
more lead time than is provided by today's proposal. After CAEP/6, we 
would assess whether or not the new international consensus and longer-
term standards (which are expected to be adopted) would be stringent 
enough to protect the U.S. public health and welfare. If so, we would 
propose to adopt the CAEP/6 NOX standards soon thereafter. 
EPA (or the U.S.) retains the discretion to adopt more stringent 
standards in the future if the international consensus standards 
ultimately prove insufficient to protect U.S. air quality.
    Deferring consideration of more stringent future standards until 
after CAEP/6 would allow us to obtain important additional information 
on the costs of such standards.\94\ As described earlier in this 
notice, section 231 of the CAA authorizes EPA from ``time to time'' to 
revisit emission standards, and it requires that any standards' 
effective dates permit the development of necessary technology, giving 
appropriate consideration to the cost. We are not proposing more 
stringent NOX standards today primarily because we need more 
time to better understand the cost of compliance of such standards, and 
additional cost data is expected to be available from CAEP/6 in 
February 2004. Producing (and/or developing) new engines or engine 
technologies requires significant financial investments from engine 
manufacturers, which takes time to recoup (the amount of time depends 
upon sales of engines, replacement parts, etc.). As discussed earlier, 
CAEP working groups are currently analyzing the costs and emission 
benefits (taking into account lead time) for the options of further 
NOX stringency (beyond the CAEP/4 standards) being 
considered for CAEP/6.\95\ After evaluating such

[[Page 56242]]

information, we would then be better situated to make decisions on an 
appropriate level of stringency and implementation timing that 
maximizes emission reductions from aircraft engines, taking into 
consideration cost.
---------------------------------------------------------------------------

    \94\ For low-thrust engines, deferring regulatory action on more 
stringent future standards until after CAEP/6 would also enable us 
to obtain additional information on the technological feasibility of 
such standards.
    \95\ Specifically, the Forecasting and Economic Analysis Support 
Group (FESG) is conducting an analysis of the costs and emission 
benefits for the further stringency options.
---------------------------------------------------------------------------

    In addition, if we address more stringent future standards in 
accordance with CAEP/6 action, we would have the benefits of 
harmonizing with international standards.\96\ Due to the international 
nature of the aviation industry, setting NOX standards at 
the appropriate level to meet U.S. air quality needs through 
international consensus provides the potential for greater 
environmental benefits. Aircraft and aircraft engines are international 
commodities, and they are designed and built to meet international 
standards. Adoption of international standards ensures emission 
reductions from domestic and foreign aircraft in the U.S. In addition, 
international consensus standards lead to air quality benefits in the 
U.S. and throughout the world.
---------------------------------------------------------------------------

    \96\ As discussed earlier, the U.S. has an obligation to be 
compatible with the ICAO program if deemed appropriate.
---------------------------------------------------------------------------

B. Already Certified, Newly Manufactured Engines

    Under current rules, the proposed NOX standards would 
not apply to already certified, newly manufactured engines (in-
production engines or engines built after the effective date of the 
proposed standards), and the rationale for not applying these standards 
to already certified low-, mid-, and high-thrust engines is discussed 
below. Nearly all already certified engines (94 percent of in-
production engine models in the ICAO Aircraft Engine Exhaust Emissions 
Data Bank \97\) currently meet or perform better than the standards we 
are proposing to adopt today.\98\ (See Figure IV.B-1 below for a 
comparison of the NOX emission levels of current in-
production engines to the CAEP/4 NOX standards.) \99\ At the 
time the CAEP/4 NOX standards were adopted in 1998, all but 
11 in-production engines and 5 newly designed engine models (these 5 
engines were in the design and development process in 1998) had 
NOX emission levels that would perform better than the CAEP/
4 standards.\100\ Based on a recent CAEP working group (specifically, 
the Forecasting and Economic Analysis Support Group--FESG) analysis of 
applying the CAEP/4 standards to already certified engines (at dates 2, 
4, and 6 years after the implementation date for newly certified 
engines), from those 16 engine models identified in 1998 today there 
are only 4 already certified engine models or two engine families 
remaining that would not meet the CAEP/4 standards.\101\ The other 
engine models have either, through additional testing or modifications, 
been improved to meet the standards or the engines are no longer in-
production.\102\ (There is only one remaining newly designed engine 
model--out of the five identified in 1998--that may be certified after 
2003, and thus, it would need to meet the CAEP/4 or proposed standards 
for newly certified engines, which are effective beginning in 
2004.)\103\
---------------------------------------------------------------------------

    \97\ International Civil Aviation Organization (ICAO), Aircraft 
Engine Exhaust Emissions Data Bank, July 2002. This data bank is 
available at http://www.qinetiq.com/aircraft.html. In addition, a 
copy of a table including data of engine NOX emissions 
from the ICAO data bank and their margin to the proposed 
NOX standards can be found in Docket OAR-2002-0030.
    \98\ 116 out of 124 (94 percent) engine models that are 
currently in production perform better than the CAEP/4 
NOX standards. The 8 engine models (which are mid- and 
high-thrust engines) that are not achieving the CAEP/4 
NOX standards are from three different Pratt and Whitney 
(PW) engine types or families (engines and their thrust variants 
with the same build standard). These engines are the following: (1) 
JT8D-217C E-kit and JT8D-219 E-kit; (2) PW4077D, PW4084D, and 
PW4090; and (3) PW4164, PW4168, and PW4168A. (See Figure IV.B-1 
below that specifically shows these 8 in-production models in 
relation to the CAEP/4 or proposed NOX standards.) For 
the year 2000, these 8 engine models were found on approximately 751 
out of 20,137 (3.7 percent) aircraft owned by U.S. carriers and 
accounted for approximately 1,541,172 out of 11,505,063 (13.4 
percent) of U.S. domestic flights.
    (The above reference for the fleet fraction is BACK Aviation 
Solutions, http://www.backaviation.com/Information_Services/default.htm.
    The domestic flight information is based on SAGE, the System for 
Assessing Aviation Emissions. SAGE is an FAA model that estimates 
aircraft emissions through the full flight profile using non-
proprietary input data, such as BACK, FAA's Enhanced Traffic 
Management System (ETMS), and the Official Airline Guide (OAG). The 
year 2000 air traffic movements database portion of SAGE was used to 
estimate the number of flights using the subject engines.)
    \99\ For Figure IV.B-1, the Allison, Rolls-Royce, and Textron 
Lycoming engines with rated pressure ratios less than 20 and 
NOX perform better than the standards, since there are 
different CAEP/4 NOX standards for these low-thrust 
engines (see section IV.A.3 for further discussion of NOX 
standards for low thrust engines). (16 of the 124 engines, 13 
percent of engine models in production, in Figure IV.B-1 and the 
ICAO Aircraft Engine Exhaust Emissions Data Bank are low--thrust 
engines--engines with thrust greater than 26.7 kN but not more than 
89 kN.)
    \100\ ICAO, CAEP/4, Working Paper 4, ``Economic Assessment of 
the EPG NOX Stringency Proposal,'' March 12, 1998, 
Presented by the Chairman of Forecasting and Economic Analysis 
Support Group (FESG), Agenda Item 1: Review of proposals relating to 
NOX emissions, including the amendment of Annex 16, 
Volume II, See Table 3.1 of paper. A copy of this paper can be found 
in Docket OAR-2002-0030.
    \101\ CAEP Steering Group Meeting, ``FESG Economic Assessment of 
Applying a Production Cut-Off To the CAEP/4 NOX 
Standard'', Presented by the FESG Co-Rapporteurs, Paris, September 
10-13, 2002 (CAEP-SG20022-WP/20, September 12, 2002). The remaining 
already certified engine models are the JT8D-217C, JT8D-219, 
PW4084D, and PW4090. A copy of this paper can be found in Docket 
OAR-2002-0030.
    \102\ Only the first and second engine types of the three PW 
types described earlier would not meet the CAEP/4 NOX 
standards if they were applied to newly manufactured or already 
certified engines. The PW4077D is a derated version of the PW4084D, 
and it is essentially considered the same engine. In addition, the 
PW4077D has a NOX level that is 0.2 percent greater than 
the CAEP/4 standards. FESG rounded this margin to zero and 
considered the PW4077D to be meeting the NOX levels of 
the CAEP/4 standards. The third engine type--PW4164, PW4168 and 
PW4168A engines--are now certified with the PW 4168 Technologically 
Affordable Low NOX (Talon) II engine combustor 
technology, which performs significantly better than the CAEP/4 
standards.
    \103\ The PW Canada growth engine is the one remaining newly 
designed engine model. The ICAO Aircraft Engine Exhaust Emissions 
Data Bank currently does not have emissions certification data for 
such an engine, and thus, we anticipate that the PW Canada growth 
engine would still be affected by the proposed standards. Yet, due 
to the CAEP/4 standards already established, we expect that PW 
Canada has already planned modifications for this engine or any 
other newly certified engines to meet today's proposed standards.

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[[Page 56243]]

[GRAPHIC] [TIFF OMITTED] TP30SE03.001


    *89 out of 124 (72 percent) of the in-production engines have 
greater than 10 percent margin to the proposed (or CAEP/4) 
NOX standards. 56 (45 percent) of the engines have more 
than 20 percent margin. 18 (15 percent) of the engines have greater 
than 30 percent margin.

    The recent FESG analysis indicates that the environmental benefit 
(or NOX emissions reduction) of applying the CAEP/4 
NOX standards to already certified engines, which would only 
affect these 4 remaining engines, would be very small. As mentioned 
earlier, the remaining four already certified (or in-production) 
engines that perform worse than the CAEP/4 or proposed standards are 
the following Pratt and Whitney (PW) mid- and high-thrust engines: 
JT8D-217C, JT8D-219, PW4084D, and PW4090. The in-production JT8D-217C 
and JT8D-219 engines could potentially apply to future supersonic 
business jets, and the aircraft application for PW4084D and 4090 
engines would be the Boeing 777-200s and -300s. Since business jets 
have a very low utilization (about 100 to 200 annual departures per 
aircraft), the emission reductions from potential new JT8D-217C and 
JT8D-219 applications would be very small irregardless of the size of 
the supersonic business jet market. If the potential JT8D-217C and 
JT8D-219 supersonic business jets were to capture the entire projected 
supersonic business jet market (200 to 400 aircraft over a 10 year 
period or 20 to 40 aircraft per year), the total estimated annual 
departures would be about 2,000 to 8,000. For the years 2005 and 2010, 
there are estimated to be from 23 to 27 million departures from the 
global passenger aircraft fleet (the potential supersonic business jet 
market could potentially be about .01 to .03 percent of these global 
fleet departures), so the resulting NOX emission benefits 
would be very small.\104\ In regard to Boeing 777 aircraft with 
PW4084D/4090 engines, the incremental departures for such aircraft are 
projected to be no greater than 0.1 percent per year (up to 25,500 
departures in 2010); therefore, the resulting NOX emissions 
reductions would also be considered very small. (The FESG assessment 
also showed that the costs of applying the CAEP/4 standards to already 
certified engines would be relatively small on an industry wide basis.) 
\105\ Consequently, we would expect there to be minimal environmental 
benefit to also apply the proposed and CAEP/4 NOX standards 
for newly certified engines to already certified, newly manufactured 
engines for an effective date after 2003 (the implementation date of 
today's proposed standards is December 31, 2003).
---------------------------------------------------------------------------

    \104\ CAEP Steering Group Meeting, ``FESG Economic Assessment of 
Applying a Production Cut-Off To the CAEP/4 NOX 
Standard'', Presented by the FESG Co-Rapporteurs, Paris, September 
10-13, 2002 (CAEP-SG20022-WP/20, September 12, 2002). In particular, 
see Table 5.1 entitled, ``Excerpt from FESG CAEP/5 Traffic and Fleet 
Mix Forecast.'' A copy of this paper can be found in Docket OAR-
2002-0030.
    \105\ The costs of applying CAEP/4 standards to already 
certified engines would impact just one engine manufacturer.
---------------------------------------------------------------------------

    Also, if an already certified engine design meets the standards 
that we are proposing today, then it is unlikely that either existing 
or future engine designs built to that design or type (derivatives or 
thrust variants with the same build standard) would not meet these 
standards. When design modifications are made to an existing engine 
type, then this engine type would likely need to be re-certified. A re-
certified engine type would be required to comply with the CAEP/4 and 
new proposed NOX standards.
    For the remaining 4 engines (or two engine families) being built 
that do not meet the CAEP/4 standards, Pratt and Whitney has other in-
production engine models (potentially derived versions or thrust 
variants of engines with the same

[[Page 56244]]

build standard) or replacement/alternative engines that perform better 
than the proposed NOX standards and that are also similar in 
size and aircraft application.\106\ For example, the PW 4098 engine 
would achieve the NOX levels of the proposed standards, and 
similar to the PW4090 it is utilized on the Boeing 777-200 and 777-300. 
Due to the 1998 CAEP/4 NOX standards, Pratt and Whitney has 
recently certified and manufactured these other or replacement engines. 
Also, based upon the CAEP/4 standards, they have already targeted 
future (after 2003) engine designs for modification so that newly 
certified or designed engines would meet today's proposed 
NOX standards. Therefore, it appears unlikely that a 
substantial number of the 4 remaining engines would be built or sold in 
the future, unless they were produced as spare engines (replacement 
engines for existing aircraft instead of newly manufactured aircraft).
---------------------------------------------------------------------------

    \106\ Although the remaining 4 engines (or two engine families) 
currently being built are expected to still be in production in year 
2004, they would not be required to meet the proposed standards.
---------------------------------------------------------------------------

1. Effect of Market Forces
    In 1998, FESG indicated at CAEP/4 that ``* * * market forces and 
potential local/regional operating restrictions might encourage the 
manufacturers to modify their existing products, so that they, too, 
comply with the proposed stringency.''\107\ These modifications to in-
production engines would be considered ``voluntary environmental 
enhancement.''\108\ Thus, there was significant consideration at CAEP/4 
given to the effect that new NOX standards for newly 
certified engines would potentially have on in-production or already 
certified engines. Many parties within CAEP and its working groups 
consider market forces to have a real and tangible effect on newly 
manufactured or already certified engines, even though such engines are 
not required to comply with the new standards. We are unaware of any 
new local/regional operating restrictions being implemented throughout 
the world due to the CAEP/4 NOX standards. However, it seems 
some market forces from the CAEP/4 newly certified engine standards 
have affected production engines since there are now only four in-
production engine models remaining from 1998 that would not meet the 
CAEP/4 standards. The Agency solicits comment on the effect market 
forces and potential local/regional operating restrictions might have 
on manufacturers to modify in-production or already certified engines.
---------------------------------------------------------------------------

    \107\ ICAO, CAEP/4, Working Paper 4, ``Economic Assessment of 
the EPG NOX Stringency Proposal,'' March 12, 1998, 
Presented by the Chairman of FESG, Agenda Item 1: Review of 
proposals relating to NOX emissions, including the 
amendment of Annex 16, Volume II, section 3.3.2 of the paper. A copy 
of this paper can be found in Docket OAR-2002-0030.
    \108\ However, FESG indicated that the ``* * * the development 
of production engine emissions enhancements would only occur if the 
market place showed enough interest in the enhancements or if the 
failure to meet the proposed stringency became a competitive 
disadvantage.'' (ICAO, CAEP/4, Working Paper 4, ``Economic 
Assessment of the EPG NOX Stringency Proposal,'' March 
12, 1998, Presented by the Chairman of FESG, Agenda Item 1: Review 
of proposals relating to NOX emissions, including the 
amendment of Annex 16, Volume II, section 5.6.2 of the paper. A copy 
of this paper can be found in Docket OAR-2002-0030.
---------------------------------------------------------------------------

2. Impact of Existing Fleet Aircraft
    An element of the emissions proposals made at CAEP/4 was to 
increase NOX stringency as far as possible without affecting 
the existing fleet aircraft asset values, and this was proposed to be 
achieved by applying the new stringency to new engine designs only 
(newly certified engines).\109\ Two studies on whether the financial 
value of existing aircraft assets were affected by the CAEP/2 
NOX standards were reviewed for CAEP/4, and the studies did 
not reveal any correlation between approval of the CAEP/2 emissions 
standards and aircraft values. Thus, FESG was unable to definitively 
assess the effect CAEP/4 NOX standards would have on fleet 
aircraft values.\110\ (The scope of the two studies and their ground 
rules were set by FESG.) These studies showed that a large number of 
factors impact aircraft asset values.
---------------------------------------------------------------------------

    \109\ ICAO, CAEP, Fourth Meeting, Montreal, Quebec, April 6-8, 
1998, Report, Document 9720, CAEP/4. Copies of this document can be 
obtained from ICAO (http://www.icao.int).
    \110\ ICAO, CAEP/4, Working Paper 4, ``Economic Assessment of 
the EPG NOX Stringency Proposal,'' March 12, 1998, 
Presented by the Chairman of FESG, Agenda Item 1: Review of 
proposals relating to NOX emissions, including the 
amendment of Annex 16, Volume II, section 4 of the paper. A copy of 
this paper can be found in Docket OAR-2002-0030.
---------------------------------------------------------------------------

3. Request for Comment on Applying the Proposed NOX 
standards to Already Certified Engines
    As discussed earlier, FESG and CAEP working groups (specifically, 
Working Group 3--Emissions Technical Issues Working Group) are 
currently considering applying the 1998 CAEP/4 NOX standards 
to engines built to already certified engine designs. Today, we are 
requesting comment on whether to apply the proposed NOX 
standards, which are equivalent to the CAEP/4 NOX standards, 
to already certified engines.\111\ Historically, EPA and ICAO have 
applied aircraft engine emission standards to already certified engines 
(or newly manufactured engines).\112\ Although there is expected to be 
minimal environmental benefits (as well as relatively small costs) from 
such a requirement, it would ensure that manufacturers could not 
indefinitely produce existing engines that do not meet these standards 
(four such in-production or already certified engines models exist 
today).\113\
    The implementation dates being analyzed by FESG and Working Group 3 
for applying CAEP/4 standards to already certified engines are 2, 4, 
and 6 years after December 31, 2003 (the implementation date for newly 
certified engines). Based on the results of the complete assessment 
(which are not yet available), FESG and Working Group 3 are expected to 
recommend an implementation date for applying the CAEP/4 standards to 
already certified engines at CAEP/6 in February 2004 (a decision on 
this date is also expected at CAEP/6).\114\ If this requirement and 
date is accepted at CAEP/6, EPA would plan to propose the new 
requirement soon thereafter (see section IV.B. above for a discussion 
of the emission benefit of applying the proposed standards to already 
certified engines). We request comment on applying standards for 
already certified engines at a date 2, 4, and 6 years after the 
implementation date for new designs (2006, 2008, and 2010). Commenters 
suggesting different dates should specify the date(s) they prefer and, 
to the extent possible,

[[Page 56245]]

provide technical and other justification for such suggested dates.
---------------------------------------------------------------------------

    \111\ Spare engines for existing aircraft would not be covered 
by such a requirement.
    \112\ EPA promulgated a HC standard in 1982 that applied to 
newly manufactured engines beginning in 1984. Also, the original 
ICAO NOX, HC, and CO standards approved in 1981 applied 
to newly manufactured engines starting in 1986. In 1997, EPA adopted 
this CO standard, which was to be implemented later that same year 
for newly manufactured engines. In addition, the March 24, 1993 ICAO 
amendment to tighten the original NOX standard by 20 
percent (CAEP/2 standards), which EPA adopted in 1997, applied to 
newly certified engines beginning in 1996 and newly manufactured 
engines in 2000.
    \113\ Nearly all engines built to already certified engine 
designs are likely to be in compliance with the proposed 
NOX standards.
    \114\ The FESG analysis mentioned earlier (CAEP-SG20022-WP/20, 
September 12, 2002) addresses the impact of applying the CAEP/4 
NOX standards to already certified engines at 2, 4, and 6 
years after the implementation date of the CAEP/4 standards for 
newly certified engines. Yet, further assessment of the 
NOX emission reductions was requested by the Steering 
Group for the next meeting in mid-2003. (ICAO, CAEP, Steering Group 
Meeting, Paris, France, September 10-13, 2002, ``Summary of 
Discussions and Decisions of the First Meeting of the Steering 
Group,'' September 10, 2002, CAEP-SG20022-SD/1. See page 3. A copy 
of this paper can be found in Docket OAR-2002-0030.
---------------------------------------------------------------------------

    In addition, at this time the mobile sources (including aircraft 
engines) regulated under the authority of the Clean Air Act (Title II--
Emission Standards for Moving Sources) have emission standards for 
newly manufactured engines or vehicles. However, except for aircraft 
engines, all current CAA mobile source programs involving new emission 
standards apply to newly manufactured engines or vehicles based on the 
certification model year (new standards apply to newly and already 
certified engines or vehicles in the same year). In these programs, EPA 
has incorporated emission averaging programs to make a more orderly 
product phase-in and phase-out (the average emissions within a 
manufacturer's product line is required to meet the applicable 
standard, which allows a manufacturer to produce some engine families 
with emission levels above the standard).\115\ However, averaging is 
not part of the ICAO protocol, and it is not clear that it is of any 
value here since most in-production engines already meet the proposed 
standards. Nonetheless, we solicit comment on whether an emission 
averaging program for such engines would be useful.
---------------------------------------------------------------------------

    \115\ Typically, the calculations used for averaging are based 
upon an engine families yearly production or sales (among other 
characteristics--e.g., average power rating of engines families).
---------------------------------------------------------------------------

C. Amendments to Criteria on Calibration and Test Gases for Gaseous 
Emissions Test and Measurement Procedures

    In today's proposed rule, EPA proposes to incorporate by reference 
ICAO's 1997 amendments to the criteria on calibration and test gases 
for the test procedures of gaseous emissions (ICAO International 
Standards and Recommended Practices Environmental Protection, Annex 16, 
Volume II, ``Aircraft Engine Emissions,'' Second Edition, July 1993; 
Amendment 3, March 20, 1997, Appendices 3 and 5) in 40 CFR 87.64. 
ICAO's amendments, which became effective on March 20, 1997, apply to 
subsonic (newly certified and newly manufactured or already certified 
engines) and supersonic gas turbine engines. The proposed technical 
changes would correct a few inconsistencies between the specifications 
for carbon dioxide (CO2) analyzers (Attachment B of 
Appendices 3 and 5) and the calibration and test gases (Attachment D of 
Appendices 3 and 5) of gaseous emissions. The test procedure amendments 
incorporated by reference would be effective 60 days after the 
publication of the final rule.
    For CAEP/3 in 1995, the Russian Federation presented a working 
paper entitled, ``Corrections to Annex 16, Volume II,'' that stated the 
following: \116\

    \116\ Russian Federation, ``Corrections to Annex 16, Volume 
II,'' Agenda Item 2: Review of reports of working groups relating to 
engine emissions and the development of recommendations to the 
Council thereon, Working Paper 19, Presented by A.A. Gorbatko, 
November 11, 1995 (distributed November 30, 1995), CAEP/3, Montreal, 
December 5 to 15, 1995. A copy of this paper can be found in Docket 
OAR-2002-0030.
---------------------------------------------------------------------------

    According to CAEP/2 recommendations, in the list of calibration 
and test gases (see the table in Attachment of Appendices 3 and 5) 
``CO2 in N2'' was replaced with 
``CO2 in air'' gas. At the same time the following sub-
paragraph was newly introduced into Attachment B (Appendices 3 and 
5) :
    (g) The effect of oxygen (O2) on the CO2 
analyzer response shall be checked. For a change from 0 percent 
O2 to 21 percent O2 the response of a given 
CO2 concentration shall not change by more than 2 percent 
of reading. If this limit cannot be met and appropriate correction 
factor shall be applied.
    Since the best way to carry out this checking procedure is to 
calibrate the analyzer first with CO2 in nitrogen and 
then with CO2 in air, both ``CO2 in 
N2'' and ``CO2 in air'' gases have to be 
retained in the list. It seems then that ``CO in air,'' 
``CO2 in air,'' ``NO in N2'' and now 
``CO2 in N2'' have to be replaced with ``CO in 
zero air,'' ``CO2 in zero air,'' ``CO2 in zero 
nitrogen'' and ``NO in zero nitrogen'' just by analogy with the 
gaseous mixtures of different hydrocarbons diluted by zero air and 
listed in the same table.

    In addition, at CAEP/3 the United Kingdom then presented a working 
paper on this same issue.\117\ They indicated that CAEP's Working Group 
3 (Emissions Working Group) had accepted the above proposals of the 
Russian Federation paper on correcting inconsistencies in the list of 
calibration and test gases specified in Annex 16, Volume II, Attachment 
D to Appendices 3 and 5, and Working Group 3 had recommended that these 
proposals be presented at CAEP/3. The United Kingdom also recommended 
the adoption of these Russian Federation proposals--to utilize 
CO2 in nitrogen gas mixture to check the effect of oxygen on 
CO2 analyzers. In addition, they recommended the 
specification of all calibration and test gases required for all the 
gaseous emissions tests required in Annex 16.
---------------------------------------------------------------------------

    \117\ United Kingdom, ``Amendments to Annex 16, Volume II, 
Attachment D to Appendices 3 and 5 (Calibration and Test Gases),'' 
Agenda Item 2: Review of reports of working groups relating to 
engine emissions and the development of recommendations to the 
Council thereon, Working Paper 20, Presented by M.E. Wright, 
November 14, 1995 (distributed November 30, 1995), CAEP/3, Montreal, 
December 5 to 15, 1995. A copy of this paper can be found in Docket 
OAR-2002-0030.
---------------------------------------------------------------------------

    At CAEP/3, the CAEP members agreed that the above amendments to the 
calibration and test gases were justified, and thus, these amendments 
were then adopted.\118\ In today's notice, EPA proposes to incorporate 
by reference the amendments to the criteria on calibration and test 
gases for the test procedures of gaseous emissions, because the changes 
improve the test procedures by correcting inconsistencies and 
distinguishing between calibration and test gases. The amendments would 
include the following: (1) Listing all calibration gases separately 
from test gases for HC, CO2, CO and NOX 
analyzers, (2) changing ``N2'' to ``zero nitrogen'' in 
relation to the test gases for the HC and NOX analyzers, (3) 
adding ``CO2 in zero nitrogen'' as a test gas for CO2 
analyzer, (4) changing ``air'' to ``zero air'' in relation to the test 
gas for CO and CO2 analyzers, (5) revising the accuracy to 
``+/- 1 percent'' for the ``propane in zero air'' test gas of HC 
analyzer, (6) amending the accuracy to ``+/- 1 percent'' for the 
``CO2 in zero air'' test gas of CO2 analyzer, (7) 
adding the accuracy ``+/- 1 percent'' for the ``CO2 in zero 
nitrogen'' test gas of CO2 analyzer, (8) changing accuracy 
to ``+/- 1 percent'' for test gas of CO analyzer, and (9) revising 
accuracy to ``+/- 1 percent'' for test gas of NOX analyzer.
---------------------------------------------------------------------------

    \118\ ICAO/CAEP, Report of Third Meeting, Montreal, Quebec, 
December 5-15, 1995, Document 9675, CAEP/3.
---------------------------------------------------------------------------

    Manufacturers are already voluntarily complying with ICAO's 1997 
amendments to the criteria on calibration and test gases for the test 
procedures of gaseous emissions. Thus, formal adoption of these ICAO 
test procedure amendments would require no new action by manufacturers. 
In addition, the existence of ICAO's requirements would ensure that the 
costs of compliance (as well as the air quality impact) with these test 
procedures would be minimal. (In the 1982 and 1997 final rules on 
aircraft engine emissions (47 FR 58462, December 30, 1982 and 62 FR 
25356, May 8, 1997, respectively), EPA incorporated by reference the 
then-existing ICAO testing and measurement procedures for aircraft 
engine emissions (ICAO International Standards and Recommended 
Practices Environmental Protection, Annex 16, Volume II, ``Aircraft 
Engine Emissions,'' First and Second Editions, Appendices 3 and 5 were 
incorporated by reference in 40 CFR 87.64) in order to eliminate 
confusion over minor differences in

[[Page 56246]]

procedures for demonstrating compliance with the U.S. and ICAO 
standards.)

D. Correction of Exemptions for Very Low Production Models

    Because of an editorial error, the section in the aircraft engine 
emission regulations regarding exemptions for very low production 
models is incorrectly specified (see section 40 CFR 87.7(b)(1) and 
(2)). In the October 18, 1984 final rulemaking (49 FR 41000), EPA 
intended to amend the low production engine provisions of the aircraft 
regulations by revising paragraph (b) and deleting paragraphs (b)(1) 
and (b)(2) in order to eliminate the maximum annual production limit of 
20 engines per year. In the revisions to paragraph (b), EPA retained 
the maximum total production limit of 200 units for aircraft models 
certified after January 1, 1984.\119\ For Sec.  87.7(b), EPA today 
proposes to correct this editorial error by eliminating paragraph 
(b)(1) and (b)(2).
---------------------------------------------------------------------------

    \119\ This action was taken in 1984 to provide greater 
flexibility to manufacturers for scheduling engine production rates 
during the final years.
---------------------------------------------------------------------------

    As discussed further in the 1984 final rulemaking, this proposed 
action would provide more flexibility for engine manufacturers in 
scheduling during the last few engine production years. Also, the air 
quality impact of eliminating the annual production limit would be very 
small.

V. Coordination with FAA

    The requirements contained in the notice are being proposed after 
consultation with the Secretary of Transportation in order to assure 
appropriate consideration of aircraft safety. Under section 232 of the 
CAA, the Secretary of Transportation (DOT) has the responsibility to 
enforce the aircraft emission standards established by EPA under 
section 231.\120\ In addition, section 231(b) of the CAA states that 
``[a]ny regulation prescribed under this section * * * shall take 
effect (after consultation with the Secretary of Transportation) to 
permit the development and application of the requisite technology, 
giving appropriate consideration to the cost of compliance * * *.'' As 
in past rulemakings and pursuant to the above referenced sections of 
the CAA, EPA has coordinated with the Federal Aviation Administration 
(FAA) of the DOT with respect to today's proposal.
---------------------------------------------------------------------------

    \120\ Specifically, the FAA of the DOT has the responsibility to 
enforce the aircraft emission standards established by EPA.
---------------------------------------------------------------------------

    Moreover, FAA is the official U.S. delegate to ICAO. FAA agreed to 
the 1997 and 1999 amendments at ICAO's Third and Fourth Meetings of the 
Committee on Aviation Environmental Protection (CAEP 3 and 4) after 
advisement from EPA.\121\ FAA and EPA are both members of the CAEP's 
Working Group 3 (among others), whose objective was to evaluate 
emissions technical issues and develop recommendations on such issues 
for CAEP 3 and 4. After assessing emissions test procedure amendments 
and new NOX standards, Working Group 3 made recommendations 
to CAEP on these elements. These recommendations were then considered 
at the CAEP 3 and 4 meetings, respectively, prior to their adoption by 
ICAO in 1997 and 1999.
---------------------------------------------------------------------------

    \121\ The Third Meeting of CAEP (CAEP/3) occurred in Montreal, 
Quebec from December 5 through 15 in 1995. CAEP/4 took place in 
Montreal from April 6 through 8, 1998.
---------------------------------------------------------------------------

    In addition, as discussed above, FAA would have the responsibility 
to enforce today's proposed requirements. As a part of its compliance 
responsibilities, FAA conducts the emission tests or delegates that 
responsibility to the engine manufacturer, which is then monitored by 
the FAA. Since the FAA does not have the resources or the funding to 
test engines themselves, FAA selects engineers at each plant to serve 
as representatives (called designated engineering representatives 
(DERs)) for the FAA while the manufacturer performs the test 
procedures. DERs' responsibilities include evaluating the test plan, 
the test engine, the test equipment, and the final testing report sent 
to FAA. DERs' responsibilities are determined by the FAA and today's 
proposal would not affect their duties.

VI. Possible Future Aviation Emission Reductions (EPA/FAA Voluntary 
Aviation Emissions Reduction Initiative)

    There is growing interest, particularly at the state and local 
level, in addressing emissions from aircraft and other aviation-related 
sources. Such interest is often related to plans for airport expansion 
which is occurring across the country. It is possible that other 
approaches may provide effective avenues to achieve additional aviation 
emission reductions, beyond EPA establishing aircraft engine emission 
standards. The Agency invites comment on the potential approach for 
additional reductions discussed below and any other approaches.
    Concerns by state and local air agencies and environmental and 
public health organizations about aviation emissions, led to EPA and 
FAA signing a memorandum of understanding (MOU) in March 1998 agreeing 
to work to identify efforts that could reduce aviation emissions.\122\ 
Since that time FAA and EPA have jointly chaired a national stakeholder 
initiative whose goal is to develop a voluntary program to reduce 
pollutants from aircraft and other aviation sources that contribute to 
local and regional air pollution in the United States. The major 
stakeholders participating in this initiative include representatives 
of the aviation industry (passenger and cargo airlines and engine 
manufacturers), airports, state and local air pollution control 
officials, environmental organizations, and NASA.
---------------------------------------------------------------------------

    \122\ FAA and EPA, ``Agreement Between Federal Aviation 
Administration and Environmental Protection Agency Regarding 
Environmental Matters Relating to Aviation,'' signed on March 24, 
1998 by FAA's Acting Assistant Administrator for Policy, Planning, 
and International Aviation, Louise Maillet, and EPA's Acting 
Assistant Administrator for Air and Radiation, Richard Wilson. A 
copy of this document can be found in Docket OAR-2002-0030.
---------------------------------------------------------------------------

    Initially, the discussions with stakeholders focused on the 
prospect of aircraft engine emission reduction retrofit kits, which 
might be applied to certain existing aircraft engines.\123\ However, as 
the initiative evolved, the focus was expanded by the stakeholders to 
identify strategies for various types of ground service equipment (GSE) 
in use at airports (e.g., baggage tugs and fuel trucks),\124\ in 
addition to strategies to reduce aircraft emissions.\125\ Due to the 
differences in time and technology that it takes to reduce aircraft 
emissions versus that for GSE, the stakeholders are seeking to reach a 
consensus on a distinctly two-step program to voluntarily achieve wide-
scale emissions reductions from GSE and aircraft. Near term efforts 
will focus on emissions reductions from GSE, and long term efforts will 
focus on reductions from aircraft.\126\
---------------------------------------------------------------------------

    \123\ Two engine models were indeed certificated with emissions 
retrofit kits, and a number of these engines have been purchased for 
aircraft with the retrofit kits installed in their stock 
configuration. However, retrofit kits have not to date provided 
widescale emissions improvements because it seems they may have 
limited applicability to certain engine types, small emission 
benefits, and cost issues.
    \124\ The stakeholders are now considering the impact, operation 
and design of GSE at airports, with projects being undertaken at 
several airports to reduce overall emissions.
    \125\ Operational strategies, such as reducing the time in which 
aircraft are in idle and taxi modes and the impact of auxiliary 
power units (APUs) have also been considered.
    \126\ The stakeholder program for aircraft emissions reductions 
is viewed as a supplement to the traditional regulatory approach of 
establishing engine emission standards.
---------------------------------------------------------------------------

    The stakeholders are currently discussing a framework for reaching

[[Page 56247]]

consensus on the goals or targets for emissions reductions, timing, 
accountability, State Implementation Plan implications (including 
general conformity), and numerous other issues that have been raised 
for GSE and aircraft emission reductions. If this initiative is 
successful, an agreement would be reached among all the stakeholders on 
a national voluntary aviation emissions reduction program. The 
mechanism that could be used to codify or enforce an eventual agreement 
has yet to be determined. The overall goal of the EPA/FAA voluntary 
initiative is to develop a program that will achieve significant 
national emission reductions.

VII. Regulatory Impacts

    Aircraft engines are international commodities, and thus, they are 
designed to meet international standards. Today's proposal would have 
the benefit of establishing consistency between U.S. and international 
emission standards and test procedures. Thus, an emission certification 
test which meets U.S. requirements would also be applicable to all ICAO 
requirements. Engine manufacturers are already developing improved 
technology in response to the ICAO standards that match the standards 
proposed here, and EPA does not believe that the costs incurred by the 
aircraft industry as a result of the existing ICAO standards should be 
attributed to today's proposed regulations (as discussed above, these 
standards only apply to newly certified or designed engines, but not 
already certified, newly manufactured or in-production engines). Also, 
the test procedure amendments (revisions to criteria on calibration and 
test gases) necessary to determine compliance are already being adhered 
to by manufacturers during current engine certification tests. 
Therefore, EPA believes that the proposed regulations would impose no 
additional burden on manufacturers.
    The existence of ICAO's requirements results in minimal cost as 
well as air quality benefits from today's proposed requirements.\127\ 
Since aircraft and aircraft engines are international commodities, 
there is significant commercial benefit to consistency between U.S. and 
international emission standards and control program requirements. 
Also, EPA's proposed adoption of the ICAO standards and related test 
procedures would be consistent with our treaty obligations and 
strengthen the U.S. position in future ICAO/CAEP processes related to 
emission standards.
---------------------------------------------------------------------------

    \127\ CAEP's Forecasting and Economic Analysis Support Group 
(FESG) concluded at CAEP/4 that their assessment of these new 
NOX standards indicates that the direct costs of the 
standards would be minimal, and the benefits would be modest. (ICAO, 
CAEP/4, Working Paper 4, ``Economic Assessment of the EPG 
NOX Stringency Proposal,'' March 12, 1998, Presented by 
the Chairman of FESG, Agenda Item 1: Review of proposals relating to 
NOX emissions, including the amendment of Annex 16, 
Volume II. A copy of this paper can be found in Docket OAR-2002-
0030.
---------------------------------------------------------------------------

VIII. Public Participation

    We request comment on all aspects of this proposal. This section 
describes how you can participate in this process.

A. How Do I Submit Comments?

    We are opening a formal comment period by publishing this document. 
We will accept comments during the period indicated under DATES above. 
If you have an interest in the proposed emission control program 
described in this document, we encourage you to comment on any aspect 
of this rulemaking. We also request comment on specific topics 
identified throughout this proposal.
    Your comments will be most useful if you include appropriate and 
detailed supporting rationale, data, and analysis. Commenters are 
especially encouraged to provide specific suggestions for any changes 
to any aspect of the regulations that they believe need to be modified 
or improved. You should send all comments, except those containing 
proprietary information, to our Air Docket (see section I.C under 
SUPPLEMENTARY INFORMATION before the end of the comment period.
    If you submit proprietary information for our consideration, you 
should clearly separate it from other comments by labeling it 
``Confidential Business Information.'' You should also send it directly 
to the contact person listed under FOR FURTHER INFORMATION CONTACT 
instead of to the public docket. This will help ensure that no one 
inadvertently places proprietary information in the docket. If you want 
us to use your confidential information as part of the basis for the 
final rule, you should send a nonconfidential version of the document 
summarizing the key data or information. We will disclose information 
covered by a claim of confidentiality only through the application of 
procedures described in 40 CFR part 2. If you don't identify 
information as confidential when we receive it, we may make it 
available to the public without notifying you.

B. Will There Be a Public Hearing?

    We will hold a public hearing on November 13, 2003 at the 
Environmental Protection Agency, EPA East Building, Room Number 1153, 
1201 Constitution Avenue, NW., Washington, DC 20004, Telephone: (202) 
564-1682. The hearing will start at 10 a.m. local time and continue 
until everyone has had a chance to speak.
    If you would like to present testimony at the public hearing, we 
ask that you notify the contact person listed under FOR FURTHER 
INFORMATION CONTACT at least ten days before the hearing. You should 
estimate the time you will need for your presentation and identify any 
needed audio/visual equipment. We suggest that you bring copies of your 
statement or other material for the EPA panel and the audience. It 
would also be helpful if you send us a copy of your statement or other 
materials before the hearing.
    We will make a tentative schedule for the order of testimony based 
on the notifications we receive. This schedule will be available on the 
morning of the hearing. In addition, we will reserve a block of time 
for anyone else in the audience who wants to give testimony.
    We will conduct the hearing informally, and technical rules of 
evidence won't apply. We will arrange for a written transcript of the 
hearing and keep the official record of the hearing open for 30 days to 
allow you to submit supplementary information. You may make 
arrangements for copies of the transcript directly with the court 
reporter.

IX. Statutory Authority

    The statutory authority for today's proposal is provided by 
sections 231 and 301(a) of the Clean Air Act, as amended, 42 U.S.C. 
7571 and 7601. See section III of today's NPRM for discussion of how 
EPA meets the CAA's statutory requirements.

X. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), the 
Agency must determine whether this regulatory action is ``significant'' 
and therefore subject to Office of Management and Budget (OMB) review 
and the requirements of the Executive Order. The order defines 
``significant regulatory action'' as one that is likely to result in a 
rule that may:
    (1) Have an annual effect on the economy of $100 million or more or 
adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities;

[[Page 56248]]

    (2) Create a serious inconsistency or otherwise interfere with an 
action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, grants, 
user fees, or loan programs or the rights and obligations of recipients 
thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
the Executive Order.
    EPA has determined that this rule is not a ``significant regulatory 
action'' under the terms of Executive Order 12866 and is therefore not 
subject to OMB review. Today's action would codify emission standards 
that manufacturers currently adhere to (nearly all in-production 
engines already meet the standards). The proposed standards are 
equivalent to the ICAO international consensus standards. These 
proposed standards would not impose any additional burden on 
manufacturers because they are already designing new engines to meet 
the ICAO standards. Thus, the annual effect on the economy of today's 
proposed standards would be minimal, and none of the other thresholds 
identified in the executive order would be triggered by this action.

B. Paperwork Reduction Act

    This action does not impose any information collection burden under 
provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. Any 
reporting and recordkeeping requirements associated with these 
standards would be defined by the Secretary of Transportation in 
enforcement regulations issued later under the provisions of section 
232 of the Clean Air Act. Since most if not all manufacturers already 
measure NOX and report the results to the FAA, any 
additional reporting and record keeping requirements associated with 
FAA enforcement of these proposed regulations would likely be very 
small.
    Burden means the total time, effort, or financial resources 
expended by persons to generate, maintain, retain, or disclose or 
provide information to or for a Federal agency. This includes the time 
needed to review instructions; develop, acquire, install, and utilize 
technology and systems for the purposes of collecting, validating, and 
verifying information, processing and maintaining information, and 
disclosing and providing information; adjust the existing ways to 
comply with any previously applicable instructions and requirements; 
train personnel to be able to respond to a collection of information; 
search data sources; complete and review the collection of information; 
and transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

    The RFA generally requires an agency to prepare a regulatory 
flexibility analysis of any rule subject to notice and comment 
rulemaking requirements under the Administrative Procedure Act or any 
other statute unless the agency certifies that the rule will not have a 
significant economic impact on a substantial number of small entities. 
Small entities include small businesses, small organizations, and small 
governmental jurisdictions.
    For purposes of assessing the impacts of today's rule on small 
entities, small entity is defined as: (1) A small business that meet 
the definition for business based on SBA size standards; (2) a small 
governmental jurisdiction that is a government of a city, county, town, 
school district or special district with a population of less than 
50,000; or (3) a small organization that is any not-for-profit 
enterprise which is independently owned and operated and is not 
dominant in its field. The following table 1 provides an overview of 
the primary SBA small business categories potentially affected by this 
proposed regulation.

 Table X.C-1--Primary SBA Small Business Categories Potentially Affected
                       by This Proposed Regulation
------------------------------------------------------------------------
                                                     Defined by SBA as a
             Industry                NAICS a codes  small business if: b
------------------------------------------------------------------------
Manufacturers of new aircraft               336412  <1,000 employees
 engines.
Manufacturers of new aircraft.....          336411  <1,500 employees
Scheduled air carriers, passenger              481  <1,500 employees
 and freight.
------------------------------------------------------------------------
a North American Industry Classification System (NAICS)
b According to SBA's regulations (13 CFR part 121), businesses with no
  more than the listed number of employees or dollars in annual receipts
  are considered ``small entities'' for purposes of a regulatory
  flexibility analysis.

    After considering the economic impacts of today's proposed rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. This 
proposed rule will not impose any requirements on small entities. 
Because of the limited classes of aircraft engines to which today's 
proposed regulations apply, no small entities would be affected. Our 
review of the list of manufacturers of commercial aircraft gas turbine 
engines with rated thrust greater than 26.7 kN indicates that there are 
no U.S. manufacturers of these engines that qualify as small 
businesses. We are unaware of any foreign manufacturers with a U.S.-
based facility that would qualify as a small business. In addition, the 
proposed rule will not impose significant economic impacts on engine 
manufacturers. As discussed earlier, today's action would codify 
emission standards that manufacturers currently adhere to (nearly all 
in-production engines already meet the standards). The proposed 
standards are equivalent to the ICAO international consensus standards. 
These proposed standards would not impose any additional burden on 
manufacturers because they are already designing new engines to meet 
the ICAO standards. Also, the test procedure amendments (revisions to 
criteria on calibration and test gases) necessary to determine 
compliance are already being adhered to by manufacturers during current 
engine certification tests. Therefore, EPA believes that the proposed 
regulations would impose no additional burden on manufacturers. The 
existence of ICAO's requirements results in minimal cost from today's 
proposed requirements. We invite comments on all aspects of the 
proposal and its impacts on small entities.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules

[[Page 56249]]

with ``Federal mandates'' that may result in expenditures to State, 
local, and tribal governments, in the aggregate, or to the private 
sector, of $100 million or more in any one year. Before promulgating an 
EPA rule for which a written statement is needed, section 205 of the 
UMRA generally requires EPA to identify and consider a reasonable 
number of regulatory alternatives and adopt the least costly, most 
cost-effective or least burdensome alternative that achieves the 
objectives of the rule. The provisions of section 205 do not apply when 
they are inconsistent with applicable law. Moreover, section 205 allows 
EPA to adopt an alternative other than the least costly, most cost-
effective or least burdensome alternative if the Administrator 
publishes with the final rule an explanation why that alternative was 
not adopted. Before EPA establishes any regulatory requirements that 
may significantly or uniquely affect small governments, including 
tribal governments, it must have developed under section 203 of the 
UMRA a small government agency plan. The plan must provide for 
notifying potentially affected small governments, enabling officials of 
affected small governments to have meaningful and timely input in the 
development of EPA regulatory proposals with significant Federal 
intergovernmental mandates, and informing, educating, and advising 
small governments on compliance with the regulatory requirements.
    EPA has determined that this rule does not contain a Federal 
mandate that may result in expenditure of $100 million or more for 
State, local, or tribal governments, in the aggregate or the private 
sector in any one year. This rule contains no regulatory requirements 
that might significantly or uniquely affect small governments. Today's 
action would codify emission standards that manufacturers currently 
adhere to (nearly all in-production engines already meet the 
standards). The proposed standards are equivalent to the ICAO 
international consensus standards. These proposed standards would not 
impose any additional burden on manufacturers because they are already 
designing new engines to meet the ICAO standards. Thus, the annual 
effect on the economy of today's proposed standards will be minimal. 
Thus, today's rule is not subject to the requirements of sections 202 
and 205 of the UMRA.

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.''
    This proposed rule does not have federalism implications. It will 
not have substantial direct effects on the States, on the relationship 
between the national government and the States, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in Executive Order 13132. As discussed earlier, section 
233 of the CAA preempts states from adopting or enforcing aircraft 
engine emission standards. This proposed rule merely modifies existing 
EPA aircraft engine emission standards and test procedures and 
therefore will merely continue an existing preemption of State and 
local law. Thus, Executive Order 13132 does not apply to this rule.
    In the spirit of Executive Order 13132, and consistent with EPA 
policy to promote communications between EPA and State and local 
governments, EPA specifically solicits comment on this proposed rule 
from State and local officials.

F. Executive Order 13175: Consultation and Coordination with Indian 
Tribal Governments

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 6, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.''
    This proposed rule does not have tribal implications as specified 
in Executive Order 13175. The proposed emission standards and other 
related requirements for private industry in this rule have national 
applicability and therefore do not uniquely affect the communities of 
Indian Tribal Governments. As discussed earlier, section 233 of the CAA 
preempts states from adopting or enforcing aircraft engine emission 
standards. This proposed rule merely modifies existing EPA aircraft 
engine emission standards and test procedures and therefore will merely 
continue an existing preemption of State and local law. In addition, 
this rule will be implemented at the Federal level and impose 
compliance obligations only on engine manufacturers. Thus, Executive 
Order 13175 does not apply to this rule. EPA specifically solicits 
additional comment on this proposed rule from tribal officials.

G. Executive Order 13045: Protection of Children from Environmental 
Health & Safety Risks

    Executive Order 13045, ``Protection of Children from Environmental 
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies 
to any rule that (1) is determined to be ``economically significant'' 
as defined under Executive Order 12866, and (2) concerns an 
environmental health or safety risk that EPA has reason to believe may 
have a disproportionate effect on children. If the regulatory action 
meets both criteria, Section 5-501 of the Order directs the Agency to 
evaluate the environmental health or safety effects of the planned rule 
on children, and explain why the planned regulation is preferable to 
other potentially effective and reasonably feasible alternatives 
considered by the Agency.
    This proposal is not subject to Executive Order 13045 because it is 
not economically significant under the terms of Executive Order 12866, 
and because the Agency does not have reason to believe the 
environmental health or safety risks addressed by this action present a 
disproportionate risk to children.
    The effects of ozone and PM on children's health were addressed in 
detail in EPA's rulemaking to establish NAAQS for these pollutants, and 
EPA is not revisiting those issues here. EPA believes, however, that 
the emission reductions (NOX and secondary PM) from this 
rulemaking will further reduce ozone and PM and the related adverse 
impacts on children's health.
    The public is invited to submit or identify peer-reviewed studies 
and data, of which the agency may not be aware, that assessed results 
of early life exposure to ozone and PM.

H. Executive Order 13211: Actions that Significantly Affect Energy 
Supply, Distribution, or Use

    This rule is not subject to Executive Order 13211, ``Actions 
Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use'' (66 FR 28355, May 22, 2001) because it is not a 
significant regulatory action under Executive Order 12866.

I. National Technology Transfer Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement

[[Page 56250]]

Act of 1995 (``NTTAA''), Public Law 104-113, section 12(d) (15 U.S.C. 
272 note) directs EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. NTTAA directs EPA to 
provide Congress, through OMB, explanations when the Agency decides not 
to use available and applicable voluntary consensus standards.
    This proposed rulemaking involves technical standards for testing 
emissions for commercial aircraft gas turbine engines. EPA proposes to 
use test procedures contained in ICAO International Standards and 
Recommended Practices Environmental Protection, with the proposed 
modifications contained in this rulemaking.\128\ These procedures are 
currently used by all manufacturers of commercial aircraft gas turbine 
engines (with thrust greater than 26.7 kN) to demonstrate compliance 
with ICAO emissions standards.
---------------------------------------------------------------------------

    \128\ ICAO International Standards and Recommended Practices 
Environmental Protection, Annex 16, Volume II, ``Aircraft Engine 
Emissions,'' Second Edition, July 1993--Amendment 3, March 20, 1997. 
Copies of this document can be obtained from ICAO (http://www.icao.int).
---------------------------------------------------------------------------

    EPA welcomes comments on this aspect of the proposed rulemaking 
and, specifically, invites the public to identify potentially-
applicable voluntary consensus standards and to explain why such 
standards should be used in this regulation.

List of Subjects in 40 CFR Part 87

    Environmental protection, Air pollution control, Aircraft, 
Incorporation by reference.

    Dated: September 12, 2003.
Marianne Lamont Horinko,
Acting Administrator.
    For the reasons set out in the preamble, title 40, chapter I of the 
Code of Federal Regulations is proposed to be amended as follows:

PART 87--CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT 
ENGINES

    1. The authority citation for part 87 continues to read as follows:

    Authority: Secs. 231, 301(a), Clean Air Act, as amended (42 
U.S.C 7571, 7601(a)).

Subpart A--[Amended]

    2. Section 87.7 is amended by removing paragraphs (b)(1) and 
(b)(2).

Subpart C--[Amended]

    3. Section 87.21 is amended by adding paragraph (d)(1)(vi) to read 
as follows:


Sec.  87.21  Standards for exhaust emissions.

* * * * *
    (d) * * *
    (1) * * *
    (vi) Engines of a type or model of which the date of manufacture of 
the first individual production model was after December 31, 2003:
    (A) Engines with a rated pressure ratio of 30 or less:
    (1) Engines with a maximum rated output greater than 89 
kilonewtons:
Oxides of Nitrogen: (19 + 1.6(rPR)) grams/kilonewtons rO.
    (2) Engines with a maximum rated output greater than 26.7 
kilonewtons but not greater than 89 kilonewtons:
Oxides of Nitrogen: (37.572 + 1.6(rPR)-0.2087(rO)) grams/kilonewtons 
rO.
    (B) Engines with a rated pressure ratio greater than 30 but less 
than 62.5:
    (1) Engines with a maximum rated output greater than 89 
kilonewtons:
Oxides of Nitrogen: (7 + 2(rPR)) grams/kilonewtons rO.
    (2) Engines with a maximum rated output greater than 26.7 
kilonewtons but not greater than 89 kilonewtons:
Oxides of Nitrogen: (42.71 + 1.4286(rPR) - 0.4013(rO) + 0.00642(rPR - 
rO)) grams/kilonewtons rO.
    (C) Engines with a rated pressure ratio of 62.5 or more:
Oxides of Nitrogen: (32 + 1.6(rPR)) grams/kilonewtons rO.
* * * * *

Subpart G--[Amended]

    4. Section 87.64 is revised to read as follows:


Sec.  87.64  Sampling and analytical procedures for measuring gaseous 
exhaust emissions.

    The system and procedures for sampling and measurement of gaseous 
emissions shall be as specified by Appendices 3 and 5 to International 
Civil Aviation Organization (ICAO) Annex 16, Environmental Protection, 
Volume II, Aircraft Engine Emissions, Second Edition, July 1993 
(including Amendment 3 of March 20, 1997), which are incorporated 
herein by reference. This incorporation by reference was approved by 
the Director of the Federal Register in accordance with 5 U.S.C. 552(a) 
and 1 CFR part 51. These materials are incorporated as they exist on 
the date of the approval and a notice of any change in these materials 
will be published in the Federal Register. Frequent changes are not 
anticipated. Copies may be inspected at U.S. EPA, Air and Radiation 
Docket and Information Center, 1301 Constitution Ave., NW., Room B102, 
EPA West Building, Washington, DC 20460, or at the Office of the 
Federal Register, 800 North Capitol Street, NW., 7th Floor, Suite 700, 
Washington DC. Copies of this document can be obtained from the 
International Civil Aviation Organization (ICAO), Document Sales Unit, 
999 University Street, Montreal, Quebec, Canada H3C 5H7.
    5. Section 87.71 is revised to read as follows:


Sec.  87.71  Compliance with gaseous emission standards.

    Compliance with each gaseous emission standard by an aircraft 
engine shall be determined by comparing the pollutant level in grams/
kilonewton/thrust/cycle or grams/kilowatt/cycle as calculated in Sec.  
87.64 with the applicable emission standard under this part. An 
acceptable alternative to testing every engine is described in Appendix 
6 to International Civil Aviation Organization (ICAO) Annex 16, 
Environmental Protection, Volume II, Aircraft Engine Emissions, Second 
Edition, July 1993 (including Amendment 3 of March 20, 1997), which is 
incorporated herein by reference. This incorporation by reference was 
approved by the Director of the Federal Register in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51. These materials are incorporated as 
they exist on the date of the approval and a notice of any change in 
these materials will be published in the Federal Register. Frequent 
changes are not anticipated. Copies may be inspected at U.S. EPA, Air 
and Radiation Docket and Information Center, 1301 Constitution Ave., 
NW., Room B102, EPA West Building, Washington, DC 20460, or at the 
Office of Federal Register, 800 North Capitol Street, NW., 7th Floor, 
Suite 700, Washington DC. Copies of this document can be obtained from 
the International Civil Aviation Organization (ICAO), Document Sales 
Unit, 999 University Street, Montreal, Quebec, Canada H3C 5H7. Other 
methods of demonstrating compliance may be approved by the Secretary 
with the concurrence of the Administrator.
    6. Section 87.82 is revised to read as follows:

[[Page 56251]]

Sec.  87.82  Sampling and analytical procedures for measuring smoke 
exhaust emissions.

    The system and procedures for sampling and measurement of smoke 
emissions shall be as specified by Appendix 2 to International Civil 
Aviation Organization (ICAO) Annex 16, Volume II, Environmental 
Protection, Aircraft Engine Emissions, Second Edition, July 1993 
(including Amendment 3 of March 20, 1997), which are incorporated 
herein by reference. This incorporation by reference was approved by 
the Director of the Federal Register in accordance with 5 U.S.C. 552(a) 
and 1 CFR part 51. These materials are incorporated as they exist on 
the date of the approval and a notice of any change in these materials 
will be published in the Federal Register. Frequent changes are not 
anticipated. Copies may be inspected at U.S. EPA, Air and Radiation 
Docket and Information Center, 1301 Constitution Ave., NW., Room B102, 
EPA West Building, Washington, DC 20460, or at the Office of the 
Federal Register, 800 North Capitol Street, NW., 7th Floor, Suite 700, 
Washington DC. Copies of this document can be obtained from the 
International Civil Aviation Organization (ICAO), Document Sales Unit, 
999 University Street, Montreal, Quebec, Canada H3C 5H7.
    7. Section 87.89 is revised to read as follows:


Sec.  87.89  Compliance with smoke emission standards.

    Compliance with each smoke emission standard shall be determined by 
comparing the plot of SN as a function of power setting with the 
applicable emission standard under this part. The SN at every power 
setting must be such that there is a high degree of confidence that the 
standard will not be exceeded by any engine of the model being tested. 
An acceptable alternative to testing every engine is described in 
Appendix 6 to International Civil Aviation Organization (ICAO) Annex 
16, Environmental Protection, Volume II, Aircraft Engine Emissions, 
Second Edition, July 1993 (including Amendment 3 of March 20, 1997), 
which is incorporated herein by reference. This incorporation by 
reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. These materials are 
incorporated as they exist on the date of the approval and a notice of 
any change in these materials will be published in the Federal 
Register. Frequent changes are not anticipated. Copies may be inspected 
at U.S. EPA, Air and Radiation Docket and Information Center, 1301 
Constitution Ave., NW., Room B102, EPA West Building, Washington, DC 
20460, or at the Office of the Federal Register, 800 North Capitol 
Street, NW., 7th Floor, Suite 700, Washington DC. Copies of this 
document can be obtained from the International Civil Aviation 
Organization (ICAO), Document Sales Unit, 999 University Street, 
Montreal, Quebec, Canada H3C 5H7.

[FR Doc. 03-24412 Filed 9-29-03; 8:45 am]
BILLING CODE 6560-50-P