[Federal Register: February 10, 2000 (Volume 65, Number 28)]
[Rules and Regulations]
[Page 6697-6746]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr10fe00-18]
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Part II
Environmental Protection Agency
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40 CFR Parts 80, 85, and 86
Control of Air Pollution From New Motor Vehicles: Tier 2 Motor Vehicle
Emissions Standards and Gasoline Sulfur Control Requirements; Final
Rule
[[Page 6698]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 80, 85, and 86
[AMS-FRL-6516-2]
RIN 2060-AI23
Control of Air Pollution From New Motor Vehicles: Tier 2 Motor
Vehicle Emissions Standards and Gasoline Sulfur Control Requirements
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: Today's action finalizes a major program designed to
significantly reduce the emissions from new passenger cars and light
trucks, including pickup trucks, vans, minivans, and sport-utility
vehicles. These reductions will provide for cleaner air and greater
public health protection, primarily by reducing ozone and PM pollution.
The program is a comprehensive regulatory initiative that treats
vehicles and fuels as a system, combining requirements for much cleaner
vehicles with requirements for much lower levels of sulfur in gasoline.
A list of major highlights of the program appears at the beginning of
the SUPPLEMENTARY INFORMATION section of this Federal Register.
The program we are finalizing today will phase in a single set of
tailpipe emission standards that will, for the first time, apply to all
passenger cars, light trucks, and larger passenger vehicles operated on
any fuel. This set of ``Tier 2 standards'' is feasible and the use of a
single set of standards is appropriate because of the increased use of
light trucks for personal transportation. The miles traveled in light
trucks is increasing and the emissions from these vehicles are thus an
increasing problem. This approach builds on the recent technology
improvements resulting from the successful National Low-Emission
Vehicles (NLEV) program.
To enable the very clean Tier 2 vehicle emission control technology
to be introduced and to maintain its effectiveness, we are also
requiring reduced gasoline sulfur levels nationwide. The reduction in
sulfur levels will also contribute directly to cleaner air in addition
to its beneficial effects on vehicle emission control systems. Refiners
will generally install additional refining equipment to remove sulfur
in their refining processes. Importers of gasoline will be required to
import and market only gasoline meeting the sulfur standards. Today's
action also introduces an averaging, banking, and trading program to
provide flexibility for refiners and ease implementation of the
gasoline sulfur control program.
The overall program focuses on reducing the passenger car and light
truck emissions most responsible for causing ozone and particulate
matter problems. Without today's action, we project that emissions of
nitrogen oxides from these vehicles will represent as much as 40
percent of this ozone-forming pollutant in some cities, and almost 20
percent nationwide, by the year 2030.
Today's program will bring about major reductions in annual
emissions of these pollutants and also reduce the emissions of sulfur
compounds resulting from the sulfur in gasoline. For example, we
project a reduction in oxides of nitrogen emissions of at least 856,000
tons per year by 2007 and 1,236,000 by 2010, the time frame when many
states will have to demonstrate compliance with air quality standards.
Emission reductions will continue increasing for many years, reaching
at least 2,220,000 tons per year in 2020 and continuing to rise further
in future years. In addition, the program will reduce the contribution
of vehicles to other serious public health and environmental problems,
including VOC, PM, and regional visibility problems, toxic air
pollutants, acid rain, and nitrogen loading of estuaries.
Furthermore, we project that these reductions, and their resulting
environmental benefits, will come at an average cost increase of less
than $100 per passenger car, an average cost increase of less than $200
for light trucks, and an average cost increase of about $350 for
medium-duty passenger vehicles, and an average increase of less than 2
cents per gallon of gasoline (or about $120 over the life of an average
vehicle).
DATES: This rule is effective April 10, 2000.
The incorporation by reference of certain publications contained in
this rule are approved by the Director of the Federal Register as of
April 10, 2000.
ADDRESSES: Comments: All comments and materials relevant to today's
action have been placed in Public Docket No. A-97-10 at the following
address: U.S. Environmental Protection Agency (EPA), Air Docket (6102),
Room M-1500, 401 M Street, S.W., Washington, D.C. 20460. EPA's Air
Docket makes materials related to this rulemaking available for review
at the above address (on the ground floor in Waterside Mall) from 8:00
a.m. to 5:30 p.m., Monday through Friday, except on government
holidays. You can reach the Air Docket by telephone at (202) 260-7548
and by facsimile at (202) 260-4400. We may charge a reasonable fee for
copying docket materials, as provided in 40 CFR Part 2.
FOR FURTHER INFORMATION CONTACT: Carol Connell, U.S. EPA, National
Vehicle and Fuels Emission Laboratory, 2000 Traverwood, Ann Arbor MI
48105; Telephone (734) 214-4349, FAX (734) 214-4816, E-mail
connell.carol@epa.gov.
SUPPLEMENTARY INFORMATION:
Highlights of the Tier2/Gasoline Sulfur Program
For cars, and light trucks, and larger passenger vehicles, the
program will--
<bullet> Starting in 2004, through a phase-in, apply for the first
time the same set of emission standards covering passenger cars, light
trucks, and large SUVs and passenger vehicles. These emission levels
(``Tier 2 standards'') are feasible for these vehicles. The Tier 2
standards are also appropriate because of the increased use of light
trucks for personal transportation--the miles traveled in light trucks
is increasing and the emissions from these vehicles are thus an
increasing problem.
<bullet> Introduce a new category of vehicles, ``medium-duty
passenger vehicles,'' thus bringing larger passenger vans and SUVs into
the Tier 2 program.
<bullet> During the phase-in, apply interim fleet emission average
standards that match or are more stringent than current federal and
California ``LEV I'' (Low-Emission Vehicle, Phase I) standards.
<bullet> Apply the same standards to vehicles operated on any fuel.
<bullet> Allow auto manufacturers to comply with the very stringent
new standards in a flexible way while ensuring that the needed
environmental benefits occur.
<bullet> Build on the recent technology improvements resulting from
the successful National Low-Emission Vehicles (NLEV) program and
improve the performance of these vehicles through lower sulfur
gasoline.
<bullet> Set more stringent particulate matter standards.
<bullet> Set more stringent evaporative emission standards.
For commercial gasoline, the program will--
<bullet> Significantly reduce average gasoline sulfur levels
nationwide as early as 2000, fully phased in in 2006. Refiners will
generally add refining equipment to remove sulfur in their refining
processes. Importers of gasoline will be required to import and market
only gasoline meeting the sulfur limits.
[[Page 6699]]
<bullet> Provide for flexible implementation by refiners through an
averaging, banking, and trading program.
<bullet> Encourage early introduction of cleaner fuel into the
marketplace through an early sulfur credit and allotment program.
<bullet> Apply temporary gasoline sulfur standards to certain small
refiners and gasoline marketed in a limited geographic area in the
western U.S.
<bullet> Enable the new Tier 2 vehicles to meet the emission
standards by greatly reducing the degradation of vehicle emission
control performance from sulfur in gasoline. Lower sulfur gasoline also
appears to be necessary for the introduction of advanced technologies
that promise higher fuel economy but are very susceptible to sulfur
poisoning (for example, gasoline direct injection engines).
<bullet> Reduce emissions from NLEV vehicles and other vehicles
already on the road.
Regulated Entities
This action will affect you if you produce new motor vehicles,
alter individual imported motor vehicles to address U.S. regulation, or
convert motor vehicles to use alternative fuels. It will also affect
you if you produce, distribute, or sell gasoline motor fuel.
The table below gives some examples of entities that may have to
comply with the regulations. But because these are only examples, you
should carefully examine these and existing regulations in 40 CFR parts
80 and 86. If you have questions, call the person listed in the FOR
FURTHER INFORMATION CONTACT section above.
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Examples of potentially
Category NAICS codes SIC Codes \b\ regulated entities
------------------------------------------------------\a\-------------------------------------------------------
Industry...................................... 336111 3711 Motor Vehicle Manufacturers.
336112
336120
Industry...................................... 336311 3592 Alternative fuel vehicle
converters.
336312 3714
422720 5172
454312 5984
811198 7549
541514 8742
541690 8931
Industry...................................... 811112 7533 Commercial Importers of Vehicles
and Vehicle Components.
811198 7549
541514 8742
Industry...................................... 324110 2911 Petroleum Refiners.
Industry...................................... 422710 5171 Gasoline Marketers and
Distributors.
422720 5172
Industry...................................... 484220 4212 Gasoline Carriers.
484230 4213
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\a\ North American Industry Classification System (NAICS).
\b\ Standard Industrial Classification (SIC) system code.
Access to Rulemaking Documents Through the Internet
Today's action is available electronically on the day of
publication from the Office of the Federal Register Internet Web site
listed below. Electronic copies of this preamble and regulatory
language as well as the Response to Comments document, the Regulatory
Impact Analysis and other documents associated with today's final rule
are available from the EPA Office of Mobile Sources Web site listed
below shortly after the rule is signed by the Administrator. This
service is free of charge, except any cost that you already incur for
connecting to the Internet.
Federal Register Web Site: http://www.epa.gov/docs/fedrgstr/epa-air/
(Either select a desired date or use the Search feature.)
Office of Mobile Sources (OMS) Web Site: http://www.epa.gov/oms/ (Look
in ``What's New'' or under the ``Automobiles'' topic.)
Please note that due to differences between the software used to
develop the document and the software into which the document may be
downloaded, changes in format, page length, etc., may occur.
Outline of This Preamble
I. Introduction
A. What Are the Basic Components of the Program?
1. Vehicle Emission Standards
2. Gasoline Sulfur Standards
B. What Is Our Statutory Authority for Today's Action?
1. Light-Duty Vehicles and Trucks
2. Gasoline Sulfur Controls
C. The Tier 2 Study and the Sulfur Staff Paper
D. Relationship of Diesel Fuel Sulfur Control to the Tier 2/
Gasoline Sulfur Program
II. Tier 2 Determination
A. There Is a Substantial Need for Further Emission Reductions
in Order To Attain and Maintain National Ambient Air Quality
Standards
B. More Stringent Standards for Light-Duty Vehicles and Trucks
Are Technologically Feasible
C. More Stringent Standards for Light-Duty Vehicles and Trucks
Are Needed and Cost Effective Compared to Available Alternatives
III. Air Quality Need For and Impact of Today's Action
A. Americans Face Serious Air Quality Problems That Require
Further Emission Reductions
B. Ozone
1. Background on Ozone Air Quality
2. Additional Emission Reductions Are Needed To Attain and
Maintain the Ozone NAAQS.
a. Summary
b. Ozone Modeling Presented in Our Proposal and Supplemental
Notice
c. Updated and Additional Ozone Modeling
d. Results and Conclusions
e. Issues and Comments Addressed
f. 8-Hour Ozone
3. Cars and Light-Duty Trucks Are a Big Part of the
NO<INF>X</INF> and VOC Emissions, and Today's Action Will Reduce
This Contribution Substantially
4. Ozone Reductions Expected From This Rule
C. Particulate Matter
1. Background on PM
2. Need for Additional Reductions to Attain and Maintain the
PM<INF>10</INF> NAAQS
3. PM<INF>25</INF> Discussion
4. Emission Reductions and Ambient PM Reductions
D. Other Criteria Pollutants: Carbon Monoxide, Nitrogen Dioxide,
Sulfur Dioxide
E. Visibility
[[Page 6700]]
F. Air Toxics
G. Acid Deposition
H. Eutrophication/Nitrification
I. Cleaner Cars and Light Trucks Are Critically Important to
Improving Air Quality
IV. What Are the New Requirements for Vehicles and Gasoline?
A. Why Are We Proposing Vehicle and Fuel Standards Together?
1. Feasibility of Stringent Standards for Light-Duty Vehicles
and Light-Duty Trucks a. Gasoline Fueled Vehicles i. LDVs and LDT1s-
LDT4s ii. Medium-Duty Passenger Vehicles (MDPVs) b. Diesel Vehicles
2. Gasoline Sulfur Control Is Needed To Support the Proposed
Vehicle Standards a. How Does Gasoline Sulfur Affect Vehicle
Emission Performance? b. How Large Is Gasoline Sulfur's Effect on
Emissions? c. Sulfur's Negative Impact on Tier 2 Catalysts d. Sulfur
Has Negative Impacts on OBD Systems
B. Our Program for Vehicles
1. Overview of the Vehicle Program a. Introduction b. Corporate
Average NOx Standard c. Tier 2 Exhaust Emission Standard ``Bins' d.
Schedules for Implementation i. Implementation Schedule for Tier 2
LDVs and LLDTs ii. Implementation Schedule for Tier 2 HLDTs e.
Interim Standards i. Interim Exhaust Emission Standards for LDV/
LLDTs ii Interim Exhaust Emission Standards for HLDTs iii. Interim
Programs Will Provide Reductions Over Previous Standards f.
Generating, Banking, and Trading NOx Credits
2. Why Are We Finalizing the Same Set of Standards for Tier 2
LDVs and LDTs?
3. Why Are We Finalizing the Same Standards for Both Gasoline
and Diesel Vehicles?
4. Key Elements of the Vehicle Program a. Basic Exhaust Emission
Standards and ``Bin'' Structure i. Why Are We Including Extra Bins?
b. The Program Will Phase In the Tier 2 Vehicle Standards Over
Several Years i. Primary Phase-in Schedule
ii. Alternative Phase-in Schedule
c. Manufacturers Will Meet a ``Corporate Average''
NO<INF>X</INF> Standard
d. Manufacturers Can Generate, Bank, and Trade NO<INF>X</INF>
Credits
i. General Provisions
ii. Averaging, Banking and Trading of NO<INF>X</INF> Credits
Fulfills Several Goals
iii. How Manufacturers Can Generate and Use NO<INF>X</INF>
Credits
iv. Manufacturers Can Earn and Bank Credits for Early
NO<INF>X</INF> Reductions
v. Tier 2 NO<INF>X</INF> Credits Will Have Unlimited Life
vi. NO<INF>X</INF> Credit Deficits Can Be Carried Forward
vii. Encouraging the Introduction of Ultra Clean Vehicles
e. Interim Standards
i. Interim Exhaust Emission Standards for LDV/LLDTs
ii. Interim Exhaust Emission Standards for HLDTs
f. Light-Duty Evaporative Emission Standards
g. Passenger Vehicles Above 8,500 Pounds GVWR
C. Our Program for Controlling Gasoline Sulfur
1. Gasoline Sulfur Standards for Refiners and Importers
a. Standards and Deadlines That Refiners/Importers Must Meet
i. What Are the Per-Gallon Caps on Gasoline Sulfur Levels in
2004 and Beyond?
ii. What Standards Must Refiners/Importers Meet on a Corporate
Average Basis?
iii. What Standards Must Be Met by Individual Refineries/
Importers?
b. Standards and Deadlines for Refiners/Importers Which Provide
Gasoline to the Geographic Phase-in Area (GPA)
i. Justification for Our Geographic Phase-in Approach
ii. What Is the Geographic Phase-in Area and How Was It
Established?
iii. Standards/Deadlines for Gasoline Sold in the Geographic
Phase-in Area
iv. What Are the Per-Gallon Caps on Gasoline Sulfur Levels in
the Phase-in Area?
v. How Do Refiners/Importers Account for GPA Fuel in Their
Corporate Average Calculations?
vi. How Do Refiners/Importers Apply for the Geographic Phase-in
Area Standards?
vii. How Will EPA Establish the GPA in Adjacent States?
c. How Does the Sulfur Averaging, Banking, and Trading Program
Work?
i. Generating Allotments Prior to 2004
ii. Generating Allotments in 2004 and 2005
iii. Using Allotments in 2004 and 2005
iv. How Long Do Allotments Last?
v. Establishing Individual Refinery Sulfur Baselines for Credit
Generation Purposes
vi. Generating Sulfur Credits Prior to 2004
vii. Generating Sulfur Credits in 2004 and Beyond
viii. Using Sulfur Credits
ix. How Long Do Credits Last?
x. Conversion of Allotments Into Credits
d. How are State Sulfur Programs Affected by EPA's Program?
2. Hardship Provision for Qualifying Refiners
a. Hardship Provision for Qualifying Small Refiners
i. How Are Small Refiners Defined?
ii. Standards That Small Refiners Must Meet
iii. How Do Small Refiners Apply for Small Refiner Status?
iv. How Do Small Refineries Apply for a Sulfur Baseline?
v. Volume Limitation on Use of a Small Refinery Standard
vi. Extensions Beyond 2007 for Small Refiners
vii. Can Small Refiners Participate in the ABT Program?
b. Temporary Waivers From Low Sulfur Requirements in Extreme
Unforeseen Circumstances
c. Temporary Waivers Based on Extreme Hardship Circumstances
3. Streamlining of Refinery Air Pollution Permitting Process
a. Brief Summary of Proposal
b. Significant Comments Received
c. Today's Action
i. Major New Source Review
ii. Environmental Justice
D. What Are the Economic Impacts, Cost Effectiveness and
Monetized Benefits of the Tier 2 Program?
1. What Are the Estimated Costs of the Vehicle Standards?
2. Estimated Costs of the Gasoline Sulfur Standards
3. What Are the Aggregate Costs of the Tier 2/Gasoline Sulfur
Final Rule?
4. How Does the Cost-Effectiveness of This Program Compare to
Other Programs?
a. Cost Effectiveness of this Program
b. How Does the Cost Effectiveness of This Program Compare With
Other Means of Obtaining Mobile Source NO<INF>X</INF>+NMHC
Reductions?
c. How Does the Cost Effectiveness of This Program Compare With
Other Known Non-Mobile Source Technologies for Reducing
NO<INF>X</INF>+NMHC?
5. Does the Value of the Benefits Outweigh the Cost of the
Standards?
a. What Is the Purpose of This Benefit-Cost Comparison?
b. What Was Our Overall Approach to the Benefit-Cost Analysis?
c. What Are the Significant Limitations of the Benefit-Cost
Analysis?
d. How Was the Benefit-Cost Analysis Changed From Proposal?
e. How Did We Perform the Benefit-Cost Analysis?
f. What Were the Results of the Benefit-Cost Analysis?
V. Other Vehicle-Related Provisions
A. Final Tier 2 CO, HCHO and PM Standards
1. Carbon Monoxide (CO) Standards
2. Formaldehyde (HCHO) Standards
3. Use of NMHC Data To Show Compliance With NMOG Standards;
Alternate Compliance With Formaldehyde Standards.
4. Particulate Matter (PM) Standards
B. Useful Life
1. Mandatory 120,000 Mile Useful Life
2. 150,000 Mile Useful Life Certification Option
C. Supplemental Federal Test Procedure (SFTP) Standards
1. Background
2. SFTP Under the NLEV Program
3. SFTP Standards for the Interim and Tier 2 LDVs and LDTs: As
Proposed
4. Final SFTP Standards for Interim and Tier 2 LDVs and LDTs
5. Adding a PM Standard to the SFTP Standards
6. Future Efforts Relevant to SFTP Standards
D. LDT Test Weight
E. Test Fuels
F. Changes to Evaporative Certification Procedures to Address
Impacts of Alcohol Fuels
G. Other Test Procedure Issues
H. Small Volume Manufacturers
1. Special Provisions for Independent Commercial Importers
(ICIs)
2. Hardship Provision for Small Volume Manufacturers
I. Compliance Monitoring and Enforcement
[[Page 6701]]
1. Application of EPA's Compliance Assurance Program, CAP2000
2. Compliance Monitoring
3. Relaxed In-Use Standards for Vehicles Produced During the
Phase-in Period
4. Enforcement of the Tier 2 and Interim Corporate Average
NO<INF>X</INF> Standards.
J. Addressing Environmentally Beneficial Technologies Not
Recognized by Test Procedures
K. Adverse Effects of System Leaks
L. The Future Development of Advanced Technology and the Role of
Fuels
M. Miscellaneous Provisions
VI. Gasoline Sulfur Program Compliance and Enforcement
Provisions
A. Overview
B. Requirements for Foreign Refiners and Importers
1. Requirements for Foreign Refiners With Individual Refinery
Sulfur Standards or Credit Generation Baselines
2. Requirements for Truck Importers
C. What Standards and Requirements Apply Downstream?
D. Testing and Sampling Methods and Requirements
1. Test Method for Sulfur in Gasoline
2. Test Method for Sulfur in Butane
3. Quality Assurance Testing
4. Requirement to Test Every Batch of Gasoline Produced or
Imported
5. Exceptions to the Every-Batch Testing Requirement
6. Sampling Methods
7. Gasoline Sample Retention Requirements
E. Federal Enforcement Provisions for California Gasoline and
for Use of California Test Methods to Determine Compliance
F. Recordkeeping and Reporting Requirements
1. Product Transfer Documents
2. Recordkeeping Requirements
3. Reporting Requirements
G. Exemptions for Research, Development, and Testing
H. Liability and Penalty Provisions for Noncompliance
I. How Will Compliance With the Sulfur Standards Be Determined?
VII. Public Participation
VIII. Administrative Requirements
A. Administrative Designation and Regulatory Analysis
B. Regulatory Flexibility
1. Potentially Affected Small Businesses
2. Small Business Advocacy Review Panel and the Evaluation of
Regulatory Alternatives
C. Paperwork Reduction Act
D. Intergovernmental Relations
1. Unfunded Mandates Reform Act
2. Executive Order 13084: Consultation and Coordination With
Indian Tribal Governments
3. Executive Order 13132 (Federalism)
E. National Technology Transfer and Advancement Act
F. Executive Order 13045: Children's Health Protection
G. Congressional Review Act
IX. Statutory Provisions and Legal Authority
I. Introduction
Since the passage of the 1990 Clean Air Act Amendments, the U.S.
has made significant progress in reducing emissions from passenger cars
and light trucks. The National Low-Emission Vehicle (NLEV) and
Reformulated Gasoline (RFG) programs are important examples of control
programs that are in place and will continue to help reduce car and
light-duty truck emissions into the near future.
Nonetheless, due to increasing vehicle population and vehicle miles
traveled, passenger cars and light trucks will continue to be
significant contributors to air pollution inventories well into the
future. In fact, the emission contribution of light trucks and sport
utility vehicles now matches that of passenger cars. (This is occurring
because of the combination of growth in miles traveled by light trucks
and the fact that their emission standards are currently less stringent
than those of passenger cars). The program we describe below builds on
the NLEV and RFG Phase II programs to develop a strong new national
program to protect public health and the environment well into the next
century. The program, while reducing VOC and other emissions, focuses
especially on NO<INF>X</INF>, because that is where the largest air
quality gains can be achieved.
We have followed several overarching principles in developing this
final rule:
<bullet> Design a strong national program that will assist states
in every region of the country to meet their air quality objectives and
that will ensure that cars and trucks continue to contribute a fair
share to our nation's overall air quality solutions;
<bullet> View vehicles and fuels as an integrated system,
recognizing that only by addressing both can the best overall emission
performance be achieved;
<bullet> Establish a single set of emission standards that apply
regardless of the fuel used and whether the vehicle is a car, a light
truck, or a larger passenger vehicle;
<bullet> Provide compliance flexibilities that allow vehicle
manufacturers and oil refiners to adjust to future market trends and
honor consumer preferences;
<bullet> Not preclude the development of advanced low emission or
fuel efficient technologies such as lean-burn engines; and
<bullet> Ensure sufficient leadtime for phase-in of the Tier 2 and
gasoline sulfur program.
With these principles as background, we turn now to an overview of
the vehicle and fuel aspects of the program. Sections I and II of this
preamble will give you a brief overview of our program and our
rationale for implementing it. Subsequent sections will expand on the
air quality need, technological feasibility, economic impacts, and
provide a detailed description of the specifics of the program. A
public participation section reviews the process we followed in
soliciting and responding to public comment. The final sections deal
with several administrative requirements. You may also want to review
our Final Regulatory Impact Analysis (RIA) and our Response to Comments
document, both of which are found in the docket and on the Internet.
They provide additional analyses and discussions of many topics raised
in this preamble.
A. What Are the Basic Components of the Program?
The nation's air quality, while certainly better than in the past,
will nevertheless continue to expose tens of millions of Americans to
unhealthy levels of air pollution well into the future in the absence
of significant new controls on emissions from motor vehicles. EPA is
therefore finalizing a major, comprehensive program designed to reduce
emission standards for passenger cars, light trucks, and large
passenger vehicles (including sport-utility vehicles, minivans, vans,
and pickup trucks) and to reduce the sulfur content of gasoline. Under
the program, automakers will produce vehicles designed to have very low
emissions when operated on low-sulfur gasoline, and oil refiners will
provide that much cleaner gasoline nationwide. In this preamble, we
refer to the comprehensive program as the ``Tier 2/Gasoline Sulfur
program.''
1. Vehicle Emission Standards
Today's action sets new federal emission standards (``Tier 2
standards'') for passenger cars, light trucks, and larger passenger
vehicles. The program is designed to focus on reducing the emissions
most responsible for the ozone and particulate matter (PM) impact from
these vehicles--nitrogen oxides (NO<INF>X</INF>) and non-methane
organic gases (NMOG), consisting primarily of hydrocarbons (HC) and
contributing to ambient volatile organic compounds (VOC). The program
will also, for the first time, apply the same set of federal standards
to all passenger cars, light trucks, and medium-duty passenger
vehicles. Light trucks include ``light light-duty trucks'' (or LLDTs),
rated at less than 6000 pounds gross vehicle weight and ``heavy light-
duty trucks'' (or HLDTs), rated at more than 6000
[[Page 6702]]
pounds gross vehicle weight).\1\ ``Medium-duty passenger vehicles'' (or
MDPVs) form a new class of vehicles introduced by this rule that
includes SUVs and passenger vans rated at between 8,500 and 10,000
GVWR. The program thus ensures that essentially all vehicles designed
for passenger use in the future will be very clean vehicles.
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\1\ A vehicle's ``Gross Vehicle Weight Rating,'' or GVWR, is the
curb weight of the vehicle plus its maximum recommended load of
passengers and cargo.
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The Tier 2 standards finalized today will reduce new vehicle
NO<INF>X</INF> levels to an average of 0.07 grams per mile (g/mi). For
new passenger cars and light LDTs, these standards will phase in
beginning in 2004, with the standards to be fully phased in by 2007.\2\
For heavy LDTs and MDPVs, the Tier 2 standards will be phased in
beginning in 2008, with full compliance in 2009.
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\2\ By comparison, the NO<INF>X</INF> standards for the National
Low Emission Vehicle (NLEV) program, which will be in place
nationally in 2001, range from 0.30 g/mi for passenger cars to 0.50
g/mi for medium-sized light trucks (larger light trucks are not
covered). For further comparison, the standards met by today's Tier
1 vehicles range from 0.60 g/mi to 1.53 g/mi.
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During the phase-in period from 2004-2007, all passenger cars and
light LDTs not certified to the primary Tier 2 standards will have to
meet an interim average standard of 0.30 g/mi NO<INF>X</INF>,
equivalent to the current NLEV standards for LDVs and more stringent
than NLEV for LDT2s (e.g., minivans).\3\ During the period 2004-2008,
heavy LDTs and MDPVs not certified to the final Tier 2 standards will
phase in to an interim program with an average standard of 0.20 g/mi
NO<INF>X</INF>, with those not covered by the phase-in meeting a per-
vehicle standard (i.e., an emissions ``cap'') of 0.6 g/mi
NO<INF>X</INF> (for HLDTs) and 0.9 g/mi NO<INF>X</INF> (for MDPVs). The
average standards for NO<INF>X</INF> will allow manufacturers to comply
with the very stringent new standards in a flexible way, assuring that
the average emissions of a company's production meet the target
emission levels while allowing the manufacturer to choose from several
more- and less-stringent emission categories for certification.
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\3\ There are also NMOG standards associated with both the
interim and Tier 2 standards. The NMOG standards vary depending on
which of various individual sets of emission standards manufacturers
choose to use in complying with the average NO<INF>X</INF> standard.
This ``bin'' approach is described more fully in section IV.B. of
this preamble.
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We are also setting stringent particulate matter standards that
will be especially important if there is substantial future growth in
the sales of diesel vehicles. Before 2004, we are establishing more
stringent interim PM standards for most light trucks than exist now
under NLEV. With higher sales of diesel cars and light trucks, they
could easily contribute between one-half and two percent of the PM10
concentration allowed by the NAAQS, with some possibility that the
contribution could be as high as 5 to 40 percent in some roadside
situations with heavy traffic. These increases would make attainment
even more difficult for 8 counties which we already predict to need
further emission reductions even without an increase in diesel sales,
and would put at risk another 18 counties which are now within 10
percent of a NAAQS violation. Thus, by including a more stringent PM
standard in the program finalized today, we help address environmental
concerns about the potential growth in the numbers of light-duty
diesels on the road--even if that growth is substantial. The new
requirements also include more stringent hydrocarbon controls (exhaust
NMOG and evaporative emissions standards). We will also monitor the
progress of the development of advanced technologies and the role of
fuels.
2. Gasoline Sulfur Standards
The other major part of today's action will significantly reduce
average gasoline sulfur levels nationwide. We expect these reductions
could begin to phase in as early as 2000, with full compliance for most
refiners occurring by 2006. Refiners will generally install advanced
refining equipment to remove sulfur during the production of gasoline.
Importers of gasoline will be required to import and market only
gasoline meeting the sulfur limits. Temporary, less stringent standards
will apply to a few small refiners through 2007. In addition,
temporary, less stringent standards will apply to a limited geographic
area in the western U.S. for the 2004-2006 period.
This significant new control of gasoline sulfur content will have
two important effects. The lower sulfur levels will enable the much-
improved emission control technology necessary to meet the stringent
vehicle standards of today's rule to operate effectively over the
useful life of the new vehicles. In addition, as soon as the lower
sulfur gasoline is available, all gasoline vehicles already on the road
will have reduced emissions--from less degradation of their catalytic
converters and from fewer sulfur compounds in the exhaust.
Today's action will encourage refiners to reduce sulfur in gasoline
as early as 2000. The program requires that most refiners and importers
meet a corporate average gasoline sulfur standard of 120 ppm and a cap
of 300 ppm beginning in 2004. By 2006, the cap will be reduced to 80
ppm and most refineries must produce gasoline averaging no more than 30
ppm sulfur. The program builds upon the existing regulations covering
gasoline composition as it relates to emissions performance. It
includes provisions for trading of sulfur credits, increasing the
flexibility available to refiners for complying with the new
requirements. We intend for the credit program to ease compliance
uncertainties by providing refiners the flexibility to phase in early
controls in 2000-2003 and use credits gained in these years to delay
some control until as late as 2006. As finalized today, the program
will achieve the needed environmental benefits while providing
substantial flexibility to refiners.
B. What Is Our Statutory Authority for Today's Action?
1. Light-Duty Vehicles and Trucks
We are setting motor vehicle emission standards under the authority
of section 202 of the Clean Air Act. Sections 202(a) and (b) of the Act
provide EPA with general authority to prescribe vehicle standards,
subject to any specific limitations otherwise included in the Act.
Sections 202(g) and (h) specify the current standards for LDVs and
LDTs, which became effective beginning in model year 1994 (``Tier 1
standards'').
Section 202(i) of the Act provides specific procedures that EPA
must follow to determine whether standards more stringent than Tier 1
standards for LDVs and certain LDTs \4\ are appropriate beginning
between the 2004 and 2006 model years.\5\ Specifically, we are required
to first issue a study regarding ``whether or not further reductions in
emissions from light-duty vehicles and light-duty trucks should be
required * * *'' (the ``Tier 2 Study''). This study ``shall examine the
need for further reductions in emissions in order to attain or maintain
the national ambient air quality standards.'' It is also to consider:
(1) The availability of technology to meet more stringent standards,
taking cost, lead time, safety, and energy impacts into consideration;
and (2) the need for, and cost effectiveness of, such standards,
including consideration of alternative methods of attaining or
maintaining the national ambient air quality standards. A certain set
of ``default'' emission
[[Page 6703]]
standards for these vehicle classes is among those options for new
standards that EPA is to consider.
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\4\ LDTs with a loaded vehicle weight less than or equal to 3750
pounds, called LDT1s and LDT2s.
\5\ Section 202(b)(1)(C) forbids EPA from promulgating mandatory
standards more stringent than Tier 1 standards until the 2004 model
year.
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After the study is completed and the results are reported to
Congress, EPA is required to determine by rulemaking whether: (1) There
is a need for further emission reductions; (2) the technology for more
stringent emission standards from the affected classes is available;
and (3) such standards are needed and cost-effective, taking into
account alternatives. If EPA answers ``yes'' to these questions, then
the Agency is to promulgate new, more stringent motor vehicle standards
(``Tier 2 standards'').
EPA submitted its report to Congress on July 31, 1998. Today's
final rule makes affirmative responses to the three questions above
(see Section II below) and sets new standards that are more stringent
than the default standards in the Act.
EPA is also setting standards for larger light-duty trucks and
MDPVs under the general authority of Section 202(a)(1) and 202(b) and
under Section 202(a)(3) of the Act, which requires that standards
applicable to emissions of hydrocarbons, NO<INF>X</INF>, CO and PM from
heavy-duty vehicles \6\ reflect the greatest degree of emission
reduction available for the model year to which such standards apply,
giving appropriate consideration to cost, energy, and safety. We are
also setting standards for formaldehyde under our authority in sections
202(a) and (l).
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\6\ LDTs that have gross vehicle weight ratings above 6000
pounds are considered ``heavy-duty vehicles'' under the Act. See
section 202(b)(3). For regulatory purposes, we refer to these LDTs
as ``heavy light-duty trucks'' made up of LDT3s and LDT4s.
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2. Gasoline Sulfur Controls
We are adopting gasoline sulfur controls pursuant to our authority
under Section 211(c)(1) of the Clean Air Act.\7\ Under Section
211(c)(1), EPA may adopt a fuel control if at least one of the
following two criteria is met: (1) The emission products of the fuel
cause or contribute to air pollution which may reasonably be
anticipated to endanger public health or welfare; or (2) the emission
products of the fuel will significantly impair emissions control
systems in general use or which will be in general use were the fuel
control to be adopted.
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\7\ We currently have regulatory requirements for conventional
and reformulated gasoline adopted under Sections 211(c) and 211(k)
of the Act, in addition to the ``substantially similar''
requirements for fuel additives of Section 211(f). These
requirements have the effect of limiting sulfur levels in gasoline
to some extent. See the Final RIA for more details.
---------------------------------------------------------------------------
We are adopting gasoline sulfur controls based on both of these
criteria. Under the first criterion, we believe that sulfur in gasoline
used in Tier 1 and LEV technology vehicles contributes to ozone
pollution, air toxics, and PM. Under the second criterion, we believe
that gasoline sulfur in fuel will significantly impair the emissions
control systems expected to be used in Tier 2 technology vehicles, as
well as emissions control systems currently used in LEVs. Please refer
to Section IV.C. below and to the Final Regulatory Impact Analysis
(RIA) for more details of our analysis and findings. The RIA includes a
more detailed discussion of EPA's authority to set gasoline sulfur
standards, including a discussion of our conclusions relating to the
factors required to be considered under Section 211(c).
C. The Tier 2 Study and the Sulfur Staff Paper
On July 31, 1998, EPA submitted its report to Congress containing
the results of the Tier 2 study.\8\ The study indicated that in the
2004 and later time frame, there will be a need for emission reductions
to aid in meeting and maintaining the National Ambient Air Quality
Standards (NAAQS) for both ozone and PM. Air quality modeling showed
that in the 2007-2010 time frame, when Tier 2 standards will become
fully effective, a number of areas will still be in nonattainment for
ozone and PM even after the implementation of existing emission
controls. The study also noted the continued existence of carbon
monoxide (CO) nonattainment areas. It also found ample evidence that
technologies will be available to meet more stringent Tier 2 standards.
In addition, the study provided evidence that such standards could be
implemented at a similar cost per ton of reduced pollutants as other
programs aimed at similar air quality problems. Finally, the study
identified several additional issues in need of further examination,
including the relative stringency of car and light truck emission
standards, the appropriateness of identical versus separate standards
for gasoline and diesel vehicles, and the effects of sulfur in gasoline
on catalyst efficiency. Section IV of this preamble describes the steps
we have taken to follow up on the Tier 2 Study.
---------------------------------------------------------------------------
\8\ On April 28, 1998, EPA published a notice of availability
announcing the release of a draft of the Tier 2 study and requesting
comments on the draft. The final report to Congress included a
summary and analysis of the comments EPA received.
---------------------------------------------------------------------------
In addition, on May 1, 1998, EPA released a staff paper presenting
EPA's understanding of the impact of gasoline sulfur on emissions from
motor vehicles and exploring what gasoline producers and automobile
manufacturers could do to reduce sulfur's impact on emissions. The
staff paper noted that gasoline sulfur degrades the effectiveness of
catalytic converters and that high sulfur levels in commercial gasoline
could affect the ability of future automobiles--especially those
designed for very low emissions--to meet more stringent standards in
use. It also pointed out that sulfur control will provide additional
benefits by lowering emissions from the current fleet of vehicles.
D. Relationship of Diesel Fuel Sulfur Control to the Tier 2/Gasoline
Sulfur Program
In the NPRM, we raised the question of what if any changes to
diesel fuel may be needed to enable diesel vehicles to meet the Tier 2
standards or any future heavy-duty diesel engine standards.
Specifically, we raised the question of whether diesel sulfur levels
need to be controlled. Since diesel fuel controls of any kind would
have an impact on the refinery as a whole, and since in some cases
(including potential diesel sulfur limits) could have implications for
gasoline sulfur control, we requested comment on this issue in our
proposal. We also indicated that we planned to release an Advance
Notice of Proposed Rulemaking to solicit more information on this
subject.
We published the ANPRM on May 13, 1999 (64 FR 26142). We are in the
process of considering all of the comments received in response to the
ANPRM and plan to issue a Notice of Proposed Rulemaking (NPRM) in early
spring of 2000. We received many comments on the subject of diesel fuel
control along with the comments submitted on the proposed Tier 2/
Gasoline Sulfur regulations. We have prepared brief responses to some
of these comments in the Response to Comments document, and will deal
fully with these comments as part of the forthcoming NPRM on diesel
fuel. We are taking no action on diesel fuel as part of today's action.
II. Tier 2 Determination
Based on the statutory requirements described above and the
evidence provided in the Tier 2 Study and since its release, as
described elsewhere in this preamble, EPA has determined that new, more
stringent emission standards are indeed needed, technologically
feasible, and cost effective.
[[Page 6704]]
A. There Is a Substantial Need for Further Emission Reductions in Order
to Attain and Maintain National Ambient Air Quality Standards
EPA finds that there is a clear air quality need for new emission
standards, based on the continuing air quality problems predicted to
exist in future years. As the discussion in Section III.B. illustrates,
26 metropolitan areas are each certain or highly likely to need
additional reductions. These areas are distributed across most regions
of the U.S., and have a combined population of over 86 million. Section
III.B. also shows that an additional 12 areas each has a moderate to
significant probability of needing additional reductions, representing
another 25 million people. This provides ample evidence that further
emission reductions are needed to meet the 1-hour ozone NAAQS.
In addition to these ozone concerns, our analysis of
PM<INF>10</INF> monitoring data and PM<INF>10</INF> projections
indicates that 15 PM<INF>10</INF> nonattainment counties violated the
PM<INF>10</INF> NAAQS in recent years, and that 8 of them with a 1996
population of almost 8 million have a high risk of failing to attain
and maintain without more emission reductions. Eighteen other counties,
with a population of 23 million have a significant risk of failing or
are within 10 percent of violating the PM<INF>10</INF> NAAQS. It is
also important to recognize that nonattainment areas remain for other
criteria pollutants (e.g., CO) and that non-criteria pollution (e.g.,
air toxics and regional haze) also contributes to environmental and
health concerns.
B. More Stringent Standards for Light-Duty Vehicles and Trucks Are
Technologically Feasible
We find that emission standards significantly more stringent than
current Tier 1 and National Low Emission Vehicle (NLEV) levels are
technologically feasible. This is true both for the LDVs and LDTs
specifically covered in section 202(i) and for the medium-duty
passenger vehicles also included in today's final rule. Manufacturers
are currently producing NLEV vehicles that meet more stringent
standards than similar Tier 1 models. Our analysis shows that mainly
through improvements in engine control software and catalytic converter
technology, manufacturers can build and are building durable vehicles
and trucks, including heavy light-duty trucks, which have very low
emission levels.\9\ Section IV.A. below discusses our feasibility
conclusions in more detail.
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\9\ The Final RIA contains a more detailed analysis, and Section
IV.A. below has further discussion of the technological feasibility
of our standards including detailed discussions of the various
technology options that we believe manufacturers may use to meet
these standards.
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Many current production vehicles are already certified at or near
the Tier 2 standards. For year 2000 certification (although not yet
complete), over 50 vehicle models have emissions at or below Tier 2
levels. In addition, we performed a demonstration program at our EPA
laboratory that showed that even large vehicles, which would be
expected to face the toughest challenges reaching Tier 2 emission
levels, can do so with conventional technology. Others, including the
Manufacturers of Emission Controls Association (MECA) and the State of
California, have also performed demonstration programs, with similar
results. Manufacturers have also certified LDVs and LDTs to NMOG and CO
levels as much as 80 percent below Tier 1 standards. Furthermore, for
passenger vehicles greater than 8500 lbs GVWR, we believe that by using
technologies and control strategies similar to what will be used on
lighter vehicles, manufacturers will be able to meet the Tier 2
emission standards.
Thus, we believe that, by the 2004-2009 time frame, manufacturers
will be fully able to comply with the new Tier 2 emission standard
levels. In addition, to facilitate manufacturers' efforts to meet these
new standards, the Tier 2 regulations include a phase-in over several
years and a corporate fleet average NO<INF>X</INF> standard, which will
allow manufacturers to optimize the deployment of technology across
their product lines with no loss of environmental benefit. Our analysis
of the available technology improvements and the very low emission
levels already being realized on these vehicles leads us to find that
the standards adopted today are fully feasible for LDVs and LDTs.
C. More Stringent Standards for Light-Duty Vehicles and Trucks Are
Needed and Cost Effective Compared to Available Alternatives
In this action, we also find that more stringent motor vehicle
standards are both necessary and cost effective. As discussed above,
substantial further reductions in emissions are needed to help reduce
the levels of unhealthy air pollution to which millions of people are
being exposed; in particular, we expect that a number of areas will not
attain or maintain compliance with the National Ambient Air Quality
Standards for ozone and PM<INF>10</INF> without such reductions. (We
describe this further in Section III below and in the RIA.)
Furthermore, mobile sources are important contributors to the air
quality problem. As we will explain more fully later in this preamble,
in the year 2030, the cars and light trucks that are the subject of
today's final rule are projected to contribute as much as 40 percent of
the total NO<INF>X</INF> inventory in some cities, and almost 20
percent of nationwide NO<INF>X</INF> emissions. This situation would
have been considerably worse without the NLEV program created by
vehicle manufacturers, EPA, the Northeastern states, and others.
These emission reductions are clearly necessary to meet and
maintain the 1-hour ozone NAAQS. We project that while the emission
reductions of this program will lead to substantial progress in meeting
and maintaining the NAAQS, many areas will still not come into
attainment even with this magnitude of reductions.
We find that the Tier 2/Gasoline Sulfur program is a reasonable,
cost-effective method of providing substantial progress towards
attainment and maintenance of the NAAQS, costing about $2000 per ton of
NO<INF>X</INF> plus hydrocarbon emissions reduced. This program will
reduce annual NO<INF>X</INF> emissions by about 2.2 million tons per
year in 2020 and 2.8 million tons per year in 2030 after the program is
fully implemented. By way of comparison, when EPA established its 8-
hour NAAQS for ozone, we identified several types of emission control
programs that were reasonably cost effective. If all of the controls
identified in that analysis costing less than $10,000/ton were
implemented nationwide, they would produce NO<INF>X</INF> emission
reductions of about 2.9 million tons per year. (That is, to achieve
about the same emission reductions as the Tier 2/Gasoline Sulfur
program, other alternative measures would have a significantly higher
cost per ton). These emission reductions are clearly necessary to meet
and maintain the one-hour ozone NAAQS. We project that while the
emission reductions of this program will lead to substantial progress
in meeting and maintaining the NAAQS, many areas will still not come
into attainment even with this magnitude of reductions.
In addition, the magnitude of emission reductions that can be
achieved by a comprehensive national Tier 2/Gasoline Sulfur program
will be difficult to achieve from any other source category. Given the
large contribution that light-duty mobile source emissions make to the
national emissions inventory and the range of control programs ozone-
affected areas
[[Page 6705]]
already have in place or would be expected to implement, we believe it
will be very difficult, if not impossible, to meet (and maintain) the
ozone NAAQS in a cost-effective manner without large emission
reductions from LDVs and LDTs. We expect emissions from MDPVs to also
play an increasing role.
Furthermore, we project that the Tier 2/Gasoline Sulfur program
will significantly reduce direct and secondary particulate matter
coming from LDVs, LDTs, and MDPVs--by about 36,000 tons per year of
direct PM alone by 2030; large secondary PM reductions from
significantly lower NO<INF>X</INF> and SO<INF>X</INF> emissions will
add to the overall positive impact on airborne particles. These
reductions will be very cost-effective compared to other measures to
reduce PM pollution. Because direct PM emissions from gasoline vehicles
are related the presence of sulfur in gasoline, no new emission control
devices, beyond what manufacturers are expected to install to meet the
NO<INF>X</INF> and NMOG standards, will be necessary to provide the
reductions expected for these pollutants under the program. The
standards will provide valuable insurance against increases in PM
emissions from LDVs, LDTs, and MDPVs.
Finally, the Tier 2/Gasoline Sulfur program will significantly
reduce CO emissions from LDVs, LDTs, and MDPVs. (See Chapter III of the
RIA for an analysis of these reductions.) The technical changes needed
to meet the NMOG standards will also result in CO reductions sufficient
to meet the CO standards. Thus, these CO reductions will be very cost-
effective since they will not require any new emission control devices
beyond what manufacturers are expected to install to meet the
NO<INF>X</INF> and NMOG standards.
We conclude, then, that today's final rule is a major source of
ozone precursor, PM, and CO emission reductions when compared to other
available options. The discussions of cost and cost effectiveness later
in this preamble and in the RIA explain the derivation of cost
effectiveness estimates and compares them to the cost effectiveness of
other alternatives. That discussion indicates that this program will
have a cost effectiveness comparable to both the Tier 1 and NLEV
standards and will also be cost effective when compared to non-mobile
source programs.
III. Air Quality Need For and Impact Of Today's Action
In the absence of significant new controls on emission, tens of
millions of Americans would continue to be exposed to unhealthy levels
of air pollution. Emissions from passenger cars and light trucks are a
significant contributor to a number of air pollution problems. Today's
action will significantly reduce emissions from cars and light trucks
and hence will significantly reduce the health risks posed by air
pollution. This section summarizes the results of the analyses we
performed to arrive at our determination that continuing air quality
problems are likely to exist, that these air quality problems would be
in part due to emissions from cars and light trucks, and that the new
standards promulgated by today's final rule will improve air quality
and mitigate other environmental problems.
A. Americans Face Serious Air Quality Problems That Require Further
Emission Reductions
Air quality in the United States continues to improve. Nationally,
the 1997 air quality levels were the best on record for all six
criteria pollutants. \10\ In fact, the 1990s have shown a steady trend
of improvement, due to reductions in emissions from most sources of air
pollution, from factories to motor vehicles. Despite great progress in
air quality improvement, in 1997 there were still approximately 107
million people nationwide who lived in counties with monitored air
quality levels above the primary national air quality standards. \11\
There are also people living in counties outside of the air monitoring
network where violations of the NAAQS could have also occurred during
the year. Moreover, unless there are reductions in overall emissions
beyond those that are scheduled to be achieved by already committed
controls, many of these Americans will continue to be exposed to
unhealthy air.
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\10\ National Air Quality and Emissions Trend Report, 1997, Air
Quality Trends Analysis Group, Office of Air Quality Planning and
Standards, U.S. Environmental Protection Agency, Research Triangle
Park, N.C., December 1998 (available on the World Wide Web at http:/
/www/epa.gov/oar/aqtrnd97/).
\11\ U.S. Environmental Protection Agency, Latest Findings on
National Air Quality: 1997 Status and Trends. December 1998.
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Ambient ozone is formed in the lower atmosphere through a complex
interaction of VOC and NO<INF>X</INF> emissions. Cars and light trucks
emit a substantial fraction of these emissions. Ambient PM is emitted
directly from cars and light trucks; it also forms in the atmosphere
from NO<INF>X</INF>, sulfur oxides (SO<INF>X</INF>), and VOC, all of
which are emitted by motor vehicles. When ozone exceeds the air quality
standards, otherwise healthy people often have reduced lung function
and chest pain, and hospital admissions for people with respiratory
ailments like asthma increase; for longer exposures, permanent lung
damage can occur. Similarly, fine particles can penetrate deep into the
lungs. Results of studies suggest a likely causal role of ambient PM in
contributing to reported effects, such as: premature mortality,
increased hospital admissions, increased respiratory symptoms, and
changes in lung tissue. When either ozone or PM air quality problems
are present, those hardest hit tend to be children, the elderly, and
people who already have health problems.
The health effects of high ozone and PM levels are not the only
reason for concern about continuing air pollution. Ozone and PM also
harm plants and damage materials. PM reduces visibility and contributes
to significant visibility impairment in our national parks and
monuments and in many urban areas. In addition, air pollution from
motor vehicles contributes to cancer and other health risks,
acidification of lakes and streams, eutrophication of coastal and
inland waters, and elevated drinking water nitrate levels. These
problems impose a substantial burden on public health, our economy, and
our ecosystems.
In recognition of this burden, Congress has passed and subsequently
amended the Clean Air Act. The Clean Air Act requires each state to
have an approved State Implementation Plan (SIP) that shows how an area
plans to meet its air quality obligations, including achieving and then
maintaining attainment of all of the National Ambient Air Quality
Standards (NAAQS), such as those for ozone and PM. The Clean Air Act
also requires EPA to periodically re-evaluate the NAAQS in light of new
scientific information. Our most recent re-evaluation of the ozone and
PM NAAQS led us to revise both standards (62 FR 38856, July 18, 1997
and 62 FR 38652, July 18, 1997). These revised standards reflected
additional information that had become available since the previous
revision of the ozone and PM standards, respectively.
On May 14, 1999, a panel of the United States Court of Appeals for
the District of Columbia Circuit reviewed EPA's revisions to the ozone
and PM NAAQS and found, by a 2-1 vote, that sections 108 and 109 of the
Clean Air Act, as interpreted by EPA, represent unconstitutional
delegations of Congressional power. American Trucking Ass'n., Inc. et
al., v. Environmental Protection Agency, 175 F.3d 1027 (D.C. Cir.
1999). Among other things the Court remanded the record
[[Page 6706]]
for the 8-hour ozone NAAQS and the PM<INF>2.5</INF> NAAQS to EPA. On
October 29, 1999, EPA's petition for rehearing by the three judge panel
was denied, with the exception that the panel modified its prior ruling
regarding EPA's authority to implement a revised ozone NAAQS under Part
D subpart 2 of Title I. EPA's petition for rehearing en banc by the
full Circuit was also denied, although five of the nine judges
considering the petition agreed to rehear the case.
As a result of the Court's decision, requirements on the States to
implement the new 8-hour ozone standard have been suspended although
the standard itself is still in force and the science behind it has
generally not been contradicted. The court also did not question EPA's
findings regarding the health effects of PM<INF>10</INF> and
PM<INF>2.5</INF>. However, due to the uncertainty regarding the status
of the new NAAQS, we will rely on the preexisting NAAQS in determining
air quality need under section 202(i) of the Act.
Carbon monoxide (CO) can cause serious health effects for those who
suffer from cardiovascular disease, such as angina pectoris. There has
been considerable progress in attaining the longstanding NAAQS for
carbon monoxide, largely through more stringent standards for CO from
motor vehicles. This progress has been made despite large increases in
travel by vehicle. In 1997, there were about 9 million people living in
three counties with CO concentrations above the level of the CO NAAQS.
In the recent past, this figure has fluctuated up and down. At the
present time there are 15 counties classified as serious CO
nonattainment areas, all with a recent history of NAAQS violations. At
this time, prospects for these areas attaining by the serious CO area
attainment deadline of December 31, 2000 are uncertain. While
violations of the NAAQS have not occurred recently in most of the other
33 counties still classified as nonattainment, even these must
demonstrate that they will remain safely below the NAAQS for ten years
despite expected growth in vehicle travel and other sources of CO
emissions before they can be reclassified to attainment. Because of the
large role of motor vehicles in causing high ambient CO concentrations,
where there is reason to be concerned about CO attainment and
maintenance, local areas look to national emission standards for most
of the solution.
As discussed below, EPA has also finalized regulations that regions
and states implement plans for protecting and improving visibility in
the 156 mandatory Federal Class I areas as defined in Section 162(a) of
the Clean Air Act. These areas are primarily national parks and
wilderness areas.
To accomplish the goal of full attainment in all areas according to
the schedules for the various NAAQS, and to achieve the goals of the
visibility program, the federal government must assist the states by
reducing emissions from sources that are not as practical to control at
the state level as at the federal level. Vehicles and fuels move freely
among the states, and they are produced by national or global scale
industries. Most individual states are not in a position to regulate
these industries effectively and efficiently. The Clean Air Act
therefore gives EPA primary authority to regulate emissions from the
various types of highway vehicles and their fuels. Our actions to
reduce emissions from these and other national sources are a crucial
and essential complement to actions by states to reduce emissions from
more localized sources.
If we were not to adopt new standards to reduce emissions from cars
and light trucks, emissions from these vehicles would remain a large
portion of the emissions burden that causes elevated ozone and
continued nonattainment with the ozone NAAQS, which in turn would
affect tens of millions of Americans. Because the contribution of cars
and light trucks to both local emissions and transported pollution
would be so great, and the expected emission reduction shortfall in
many areas is so large, further reductions from cars and light trucks
will be an important element of many attainment strategies, especially
for ozone in the 2007 to 2010 time frame. The contribution of these
vehicles to PM exposure and PM nonattainment would also remain
significant, and would increase considerably if diesel engines are used
in more cars or light trucks. Furthermore, without new standards,
steady annual increases in fleet size and miles of travel would
outstrip the benefits of current emission controls, and would cause
ozone-forming emissions from cars and trucks to grow each year starting
about 2013.
The standards being promulgated by today's actions will reduce
emissions of ozone precursors and PM precursors from cars and light
trucks greatly. However, even with this decrease, many areas will
likely still find it necessary to obtain additional reductions from
other sources in order to fully attain the ozone and PM NAAQS. Their
task will be easier and the economic impact on their industries and
citizens will be lighter as a result of the standards promulgated by
today's actions. Following implementation of the Regional Ozone
Transport Rule, states will have already adopted emission reduction
requirements for nearly all large sources of VOC and NO<INF>X</INF> for
which cost-effective control technologies are known. Those that remain
in nonattainment therefore will have to consider their remaining
alternatives. Many of the state and local programs states may consider
as alternatives are very costly, and the emissions impact from each
additional emissions source subjected to new emissions controls would
be considerably smaller than the emissions impact of the standards
being promulgated today. Therefore, the emission reductions from these
standards for gasoline, cars, and light trucks will ease the need for
states to find first-time reductions from the mostly smaller sources
that have not yet been controlled, including area sources that are
closely connected with individual and small business activities. The
emission reductions from the standards being promulgated today will
also reduce the need for states to seek even deeper reductions from
large and small sources already subject to emission controls.
We project that today's actions will also have important benefits
for carbon monoxide, regional visibility, acid rain, and coastal water
quality.
For these and other reasons discussed in this document, we have
determined that significant emission reductions will still be needed by
the middle of the next decade and beyond to achieve and maintain
further improvements in air quality in many, geographically dispersed
areas. We also believe that a significant portion of these emission
reductions will be obtained by reducing emissions from cars and light
trucks as a result of today's actions. We believe that such reductions
are necessary (since cars and light trucks are such large contributors
to current and projected ozone problems) and reasonable (since these
reductions can be achieved at a reasonable cost compared to other
alternative reductions).
The remainder of this section describes the health and
environmental problems that today's actions will help mitigate and the
expected health and environmental benefits of these actions. Ozone is
discussed first, followed by PM, other criteria pollutants, visibility,
air toxics, and other environmental impacts. The emission inventories
and air quality analyses are explained more fully in the Regulatory
Impact Analysis for today's actions.
[[Page 6707]]
B. Ozone
1. Background on Ozone Air Quality
Ground-level ozone is the main harmful ingredient in smog.\12\
Ozone is produced by complex chemical reactions when its precursors,
VOC and NO<INF>X</INF>, react in the presence of sunlight.
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\12\ Total column ozone, a large percentage of which occurs in
the stratosphere and a smaller percentage of which occurs in the
troposphere, helps to provide a protective layer against ultraviolet
radiation.
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Short-term (1-3 hours) and prolonged (6-8 hours) exposures to
ambient ozone at levels common in many cities have been linked to a
number of health effects of concerns. For example, increased hospital
admissions and emergency room visits for respiratory causes have been
associated with ambient ozone exposures at such levels. Repeated
exposures to ozone can make people more susceptible to respiratory
infection, result in lung inflammation, and aggravate pre-existing
respiratory diseases such as asthma. Other health effects attributed to
ozone exposures include significant decreases in lung function and
increased respiratory symptoms such as chest pain and cough. These
effects generally occur while individuals are engaged in moderate or
heavy exertion.
Children active outdoors during the summer when ozone levels are at
their highest are most at risk of experiencing such effects. Other at-
risk groups include adults who are active outdoors (e.g., outdoor
workers), and individuals with pre-existing respiratory disease such as
asthma and chronic obstructive lung disease. In addition, longer-term
exposures to moderate levels of ozone present the possibility of
irreversible changes in the lungs which could lead to premature aging
of the lungs and/or chronic respiratory illnesses.
Ozone also affects vegetation and ecosystems, leading to reductions
in agricultural and commercial forest yields, reduced growth and
survivability of tree seedlings, and increased plant susceptibility to
disease, pests, and other environmental stresses (e.g., harsh weather).
In long-lived species, these effects may become evident only after
several years or even decades, thus having the potential for long-term
effects on forest ecosystems. Ground-level ozone damage to the foliage
of trees and other plants also can decrease the aesthetic value of
ornamental species as well as the natural beauty of our national parks
and recreation areas.
Many areas which were classified as nonattainment when
classifications were made under the 1990 Clean Air Act Amendments have
not experienced violations more recently. However, 50 metropolitan
areas had ozone design values above the NAAQS in either or both of the
1995-1997 and the 1996-1998 monitoring periods. In many urban areas,
the downward trend in ozone that prevailed earlier has become less
strong or stopped in the last few years, even when adjustments are made
for meteorological conditions. We believe that one factor that has
worked against ozone improvement in the last few years has been the
growing use of light trucks with higher emissions than the cars used
formerly. The predictions of future ozone concentrations used in
developing today's action take account of this growing use of light
trucks.
2. Additional Emission Reductions Are Needed To Attain and Maintain the
Ozone NAAQS
a. Summary
We have determined that additional emission reductions are needed
to attain and maintain the 1-hour ozone NAAQS. This overall conclusion
is based on our prediction that 26 metropolitan areas are each certain
or highly likely to need additional reductions, and that an additional
12 areas each have a moderate to significant probability of needing
them.
To determine whether additional reductions are needed in order to
attain and maintain the ozone NAAQS, we used ozone modeling to predict
what areas would not attain the NAAQS in the future. We accounted for
the emission reductions that have already been achieved, those that
will be achieved in the future by actions already underway, and
increases in emissions expected from increased use of sources of
pollution.
In our May 13, 1999 proposal, we presented information from
photochemical modeling we performed to predict what areas would meet
the ozone NAAQS in 2007. The year 2007 falls after the expected date of
most emission reductions which states are required to achieve or have
otherwise committed to achieve, and near the attainment deadline for
many ozone nonattainment areas. We presented additional information
from the same photochemical modeling work in two supplemental notices,
on June 30, 1999 (to better explain the basis for our proposal in light
of the Court's ruling on the 8-hour ozone NAAQS), and October 25, 1999
(to explain the implications for our Tier 2/Gasoline Sulfur proposal
from our more recent proposal, which we expect to make final shortly,
to re-instate the 1-hour ozone NAAQS in many areas). In Response to
Comments on these Federal Register notices, we made revisions to our
own ozone modeling. We also obtained ozone modeling results from a
number of state air planning agencies and from members of the
automobile manufacturing industry. We have considered all of this
information as part of our determination that the regulations
promulgated in this rule are needed and appropriate.
Based on the available ozone modeling and other information, we
project that there are 26 metropolitan areas which will be unable to
attain and maintain the NAAQS, in the absence of additional reductions.
These areas had a combined population of over 86 million in 1996, and
are distributed across most regions of the U.S. We have concluded that
each is certain or very likely to require additional reductions to
attain the NAAQS. Taken together and considering their number, size,
and geographic distribution, these areas establish the case that
additional reductions are needed in order to attain and maintain the 1-
hour standard.
In addition, our analysis suggests there will be other areas that
will have problems attaining and maintaining compliance with the one-
hour ozone standard in the future. There are 12 additional metropolitan
areas with a total 1996 population of over 25 million people in this
category. EPA's ozone modeling for 2007 predicts exceedances for each
of these areas. However, for six of them local recent monitoring
information is not indicating nonattainment. Given how close to
nonattainment these areas are, EPA believes it is likely that at least
a significant subset of this group of areas will face compliance
problems by 2007 or beyond if additional actions to lower air emissions
are not taken. This belief is based on historical experience with areas
that will undergo economic and population growth over time and that are
in larger regions that are also experiencing growth. The other six
areas in this group are nonattainment now, and local modeling shows
them reaching attainment by 2005 or 2007. Modeling uncertainties and
growth beyond the attainment date make it likely that at least some of
these areas will also face compliance problems if additional actions to
lower air emissions are not taken. This situation further supports our
determination that additional reductions in mobile source emissions are
needed for attainment and maintenance.
We would like to emphasize that the advantages of the Tier 2/
Gasoline Sulfur program will be enjoyed by the whole country. There are
important advantages for approximately 30 more metropolitan
[[Page 6708]]
areas, with close to 30 million people residing in them, whose ozone
levels are now within 10 percent of violating the 1-hour NAAQS.\13\
Most of these areas have been in nonattainment in the past. We believe
the emission reductions from the Tier 2/Gasoline Sulfur program are an
important component of an overall EPA-state approach to enable these
areas to continue to maintain clean air given expected growth. EPA
believes that the long term ability of the states to continue to meet
the NAAQS is extremely important. In the future, EPA will be
considering additional approaches for assisting in maintenance of the
NAAQS. Also, we believe that the Tier 2/Gasoline Sulfur program has
important benefits for other nonattainment areas which our modeling and
local modeling show to be on a path to come into attainment in the next
eight years. For these areas, the extra emission reductions from the
program will take some of the uncertainty out of their plan to attain
the standard and give them a head start on developing their plan to
stay in attainment.
---------------------------------------------------------------------------
\13\ As measured by ozone design value.
---------------------------------------------------------------------------
In every area of the country, the new standards will give
transportation planning bodies and industrial development leaders more
options within the area's overall emissions constraints. This will
allow local and state officials to better accommodate local needs and
growth opportunities. With these new standards for vehicles and
gasoline, unusually adverse weather or strong local economic growth
will be less likely to cause ozone levels high enough to trigger the
planning requirements of the Clean Air Act. In addition, by reducing
emissions and ozone levels across the nation as a whole, there will be
less transport of ozone between areas, reducing the amount of ozone
entering downwind areas. This will give the downwind areas a better
opportunity to maintain and attain the NAAQS through local efforts.
All of our determinations presented here about the need for the
Tier 2/Gasoline Sulfur program take into account the prior NO<INF>X</INF>
reductions we expect from the Regional Ozone Transport Rule. This rule
is now in litigation. If the outcome of that litigation reduces the
NO<INF>X</INF> reductions that will be achieved, the need for the Tier
2/Gasoline Sulfur program will be even greater.
b. Ozone Modeling Presented in Our Proposal and Supplemental Notices
The ozone modeling we presented in our proposal and the two
supplemental notices was originally conducted as part of our
development of the Regional Ozone Transport Rule. The ``revised
budget'' emission control scenario we modeled for the Regional Ozone
Transport Rule contained the right set of existing and committed
emission controls for it to serve as the starting point for making our
determination on the need for additional emission reductions. We added
a new ``control case'' to represent the effects of our proposed vehicle
and gasoline standards.
This ozone modeling provided predictions of ozone concentrations in
2007 across the eastern U.S., under certain meteorological conditions.
Predictions of attainment or nonattainment are based on these predicted
ozone concentrations. Two approaches to making attainment predictions
have been used or advocated in the past: a rollback approach and an
exceedance approach. In the NPRM of May 13, 1999, we presented
predictions of attainment and nonattainment using a rollback approach.
For the 1-hour standard, we reported that 8 metropolitan areas and two
rural counties were predicted to be in nonattainment in 2007 under the
rollback method. In the first supplemental notice of June 30, 1999 we
presented a prediction that 17 areas would be nonattainment based on
the exceedance method, and invited comment on all aspects of the
modeling and its interpretation. Our second and last notice on October
27, 1999, presented predictions of violations using the exceedance
method for additional areas which we had previously excluded because
the 1-hour standard did not apply to them. This was in anticipation of
the reinstatement of the 1-hour standard to these areas, which we
proposed on October 25, 1999 and expect to complete very soon. 64 FR
57524. We also announced that we were conducting another round of
modeling, described below. See the Response to Comments document for
more discussion of the rollback and exceedance approaches.
c. Updated and Additional Ozone Modeling
We have updated and expanded our ozone modeling. We updated the
ozone modeling so that it is now based on estimates of vehicle
emissions that reflect the most recent data and our best understanding
of several aspects of emissions estimation.\14\ We also changed most of
the episodes for which we modeled ozone concentrations, with all of our
final episode days coming from a single calendar year. By selecting
days from within a single year, we responded to a comment that the
original episode periods might together contain an atypically high
number of days favorable to ozone formation for some parts of the
country. The new episodes are also better at representing conditions
that lead to high ozone in areas along the Gulf Coast, whose ozone-
forming conditions were not well represented in the episodes used for
the original modeling.
---------------------------------------------------------------------------
\14\ While the use of these emissions estimates was new to our
baseline ozone modeling in the latest ozone modeling, they were not
new to this rulemaking, having already been used in calculations of
cost-effectiveness in the draft RIA. We therefore were able to
consider public comments on these estimates prior to using them in
the latest ozone modeling
---------------------------------------------------------------------------
While we considered these improvements necessary and appropriate in
light of comments and other information available to us, the actual
results of the two rounds of modeling with regard to the need for
additional reductions have turned out to be similar. The latest round
of modeling provided us ozone predictions for 2007 and 2030 in the
eastern U.S., and for 2030 in the western U.S. There are some
differences in specific results, where and when the two models can be
directly compared. However, the same conclusion would be reached from
either, namely that there is a broad set of areas with predicted ozone
concentrations in 2007 above 0.124 ppm, in the baseline scenario
without additional emission reductions.
We have compared and supplemented our own ozone modeling with other
modeling studies, either submitted to us as comments to this
rulemaking, as state implementation plan (SIP) revisions, or brought to
our attention through our consultations with states on SIP revisions
that are in development. The ozone modeling in the SIP revisions has
the advantage of using emission inventories that are more specific to
the area being modeled, and of using meteorological conditions selected
specifically for each area. Also, the SIP revisions included other
evidence and analysis, such as analysis of air quality and emissions
trends, observation based models that make use of data on
concentrations of ozone precursors, alternative rollback analyses, and
information on the responsiveness of the air quality model. For some
areas, we decided that the predictions of attainment or nonattainment
from our
[[Page 6709]]
modeling were less reliable than conclusions that could be drawn from
this additional evidence and analysis. For example, in some areas our
episodes did not capture the meteorological conditions that have caused
high ozone, while local modeling did so.
d. Results and Conclusions
As discussed in detail below, it is clear that the NO<INF>X</INF>
and VOC reductions to be achieved through the Tier 2/Gasoline Sulfur
program are needed to attain and maintain compliance with the 1 hour
ozone NAAQS. Although the general pattern observed in our modeling
indicates improvements in the near term, growth in overall emissions
will lead to worsening of air quality over the long term.
Based on our ozone modeling, we have analyzed ozone predictions for
52 metropolitan areas for 1996, 2007, and 2030. In addition, we
reviewed ozone attainment modeling and other evidence covering 15 of
these areas, from SIP submittals or from modeling underway to support
SIP revisions. This local modeling addressed only the current or
requested attainment date in each area. We then made attainment and
nonattainment predictions from this information.
The general pattern we observed with the baseline scenario, i.e.,
without new emission reductions, is a broad reduction between 1996 and
2007 in the geographic extent of ozone concentrations above the NAAQS,
and in the frequency and severity of exceedances. This is consistent
with the national emissions inventory trend between these two years. At
the same time, we also found that peak ozone concentrations and the
frequency of exceedances in 2030 were generally somewhat higher than in
2007 for most areas analyzed. This too is consistent with our analysis
of emission inventory trends, which shows that the total NO<INF>X</INF>
inventory from all sources will decline from 2007 to about 2015 and
then begin to increase due to growth in the activity of emission
sources. In 2030, our analysis predicts that NO<INF>X</INF> emissions
from all sources will be about one percent higher than in 2007. While
we did not model ozone concentrations for years between 2007 and 2030,
we expect that they would track the national emissions trend by showing
a period of improvement after 2007 and then deterioration, although
individual areas will vary due to local source mix and growth
rates.\15\
---------------------------------------------------------------------------
\15\ EPA's modeling presumed that cars and light trucks will
continue to meet the emission levels of the National Low Emissions
Vehicle (NLEV) program after model year 2003, even though the
program will end in model year 2003 or shortly thereafter. Had our
modeling not included such levels in its inventory assumptions,
trends for ozone concentrations would have shown earlier increases
in ozone concentrations.
---------------------------------------------------------------------------
Within this general pattern of ozone attainment changes between
1996 and 2030, we have determined that 26 metropolitan areas are
certain or highly likely to need additional reductions to attain and
maintain the 1-hour ozone NAAQS. These 26 areas are those that have
current violations of the 1-hour ozone NAAQS and are predicted by the
best ozone modeling we have available to still be in violation without
a new federal vehicle program in 2007.\16\ Based on the general trends
described above, without further emissions reductions many of these
areas may also have violations continuously throughout the period from
2007 to 2030, while others may briefly attain and then return to
nonattainment on or before 2030. These 26 metropolitan areas are listed
in Table III.B-1, along with their 1996 population which totals over 86
million. The sizes of these areas and their geographical distribution
strongly support an overall need for additional reductions in order to
attain and maintain under section 202(i). Because ozone concentration
patterns causing violations of the 1-hour NAAQS are well established to
endanger public health or welfare, this determination also supports our
actions today under the general authority of sections 202(a)(1),
202(a)(3), and 202(b).
---------------------------------------------------------------------------
\16\ The date of the predicted violation was 2007 for most
areas, 2010 in the case of Los Angeles, CA, and 2030 in the case of
Portland-Salem, OR.
---------------------------------------------------------------------------
As indicated above, in reaching this conclusion about these 26
areas, we examined local ozone modeling in SIP submittals. These local
analyses are considered to be more extensive than our own modeling for
estimating whether there would be NAAQS nonattainment without further
emission reductions, when interpreted by a weight of evidence method
which meets our guidance for such modeling. One of the areas which
submitted a SIP revision was a special case. We have recently proposed
to approve the 1-hour ozone attainment demonstration for the
nonattainment area of Washington, D.C. (but not Baltimore). We have
nevertheless included this area on the list of 26 that are certain or
highly likely to require further reductions to attain and maintain,
because its SIP attainment demonstration assumed emission reductions
from vehicles meeting the National Low Emissions Vehicle (NLEV)
standards.
However, by its own terms, the NLEV standards would not extend
beyond the 2003 model year if we did not promulgate Tier 2 vehicle
standards at least as stringent as the NLEV standards. See 40 CFR
86.1701-99(c). Thus, the emission reductions relied upon from 2004 and
later model year NLEV vehicles are themselves ``further reductions''
for the purposes of CAA section 202(i).\17\ The local modeling
indicating attainment with these reductions is therefore strong
evidence that further reductions are needed past 2003, beyond those
provided by the Tier 1 program. Based on this, and on the fact that our
own ozone modeling showed the Washington, DC area to violate the NAAQS
in 2007 even with full NLEV emission reductions, we have concluded that
it should be included with areas that do require further reductions to
attain and maintain the 1-hour ozone NAAQS.
---------------------------------------------------------------------------
\17\ With regard to eventual final action on the 1-hour
attainment demonstration for Washington, DC, the issue of the
continuation of the NLEV standards is mooted by the promulgation of
the Tier 2/Gasoline Sulfur program. A portion of the emission
reductions from this program will replace the post-2003 model year
NLEV reductions assumed in the SIP.
---------------------------------------------------------------------------
The 1-hour ozone NAAQS presently does not apply in 12 of the 26
areas listed in Table III.B-1, but we have proposed to re-instate it
and expect to complete that action shortly. These areas are indicated
in the table. Our decision to include these areas on this list is based
on the contingency that we will re-instate the 1-hour standard in these
areas. However, even if we considered only the 14 areas where the 1-
hour standard applies as of the signature date of this notice, we have
concluded that our determination would be the same.
Table III.B-1.--Twenty-Six Metropolitan Areas Which Are Certain or
Highly Likely To Require Additional Emission Reductions in Order To
Attain and Maintain the 1-Hour Ozone NAAQS
------------------------------------------------------------------------
1996
Metropolitan area Population
(millions)
------------------------------------------------------------------------
Atlanta, GA MSA............................................ 3.5
Barnstable-Yarmouth, MA MSA \a\............................ 0.2
Baton Rouge, LA MSA........................................ 0.6
Beaumont-Port Arthur, TX MSA............................... 0.4
Birmingham, AL MSA......................................... 0.9
Boston-Worcester-Lawrence, MA-NH-ME-CT CMSA \a\............ 5.6
Charlotte-Gastonia-Rock Hill, NC-SC MSA \a\................ 1.3
[[Page 6710]]
Cincinnati-Hamilton, OH-KY-IN CMSA......................... 1.9
Dallas-Fort Worth, TX CMSA................................. 4.6
Houma, LA MSA \a\.......................................... 0.2
Houston-Galveston-Brazoria, TX CMSA........................ 4.3
Huntington-Ashland, WV-KY-OH MSA \a\....................... 0.3
Indianapolis, IN MSA \a\................................... 1.5
Los Angeles-Riverside-San Bernardino CA CMSA............... 15.5
Louisville, KY-IN MSA...................................... 1.0
Macon, GA MSA \a\.......................................... 0.3
Memphis, TN-AR-MS MSA \a\.................................. 1.1
Nashville, TN MSA \a\...................................... 1.1
New York-Northern New Jersey-Long Island, NY-NJ-CT-PA CMSA. 19.9
Philadelphia-Wilmington-Atlantic City, PA-NJ-DE-MD CMSA.... 6.0
Pittsburgh, PA MSA......................................... 2.4
Portland-Salem, OR-WA CMSA \a\............................. 2.1
Providence-Fall River-Warwick, RI-MA MSA \a\............... 1.1
Richmond-Petersburg, VA MSA \a\............................ 0.9
St. Louis, MO-IL MSA....................................... 2.5
Washington-Baltimore, DC-MD-VA-WV CMSA..................... 7.2
Total Population..................................... 86.3
------------
------------------------------------------------------------------------
Notes:
\a\ The 1-hour ozone NAAQS does not currently apply, but we have
proposed and expect to re-instate it shortly.
There are 12 additional metropolitan areas, with another 25.3
million people in 1996, for which the available ozone modeling suggests
significant risk of failing to attain and maintain the 1-hour ozone
NAAQS without additional emission reductions. Table III.B-2 lists the
areas we put in this second category. Our own ozone modeling predicted
these 12 areas to need further reductions to avoid violations in 2007.
For six of these areas, recent air quality monitoring data indicate
violation, but we have reviewed local ozone modeling and other evidence
indicating attainment in 2007.\18\ Based on this evidence, we have kept
these areas separate from the previous set of 26 areas which we
consider certain or highly likely to need additional reductions.
However, we still consider there to be a significant risk of failure to
attain and maintain in these six areas because this local modeling has
inherent uncertainties, as all ozone modeling does. Moreover, the local
modeling did not examine the period after initial attainment.
---------------------------------------------------------------------------
\18\ The SIP revisions for Chicago and Milwaukee demonstrated
that these two areas as well as Benton Harbor and Grand Rapids areas
in Michigan (which are maintenance areas but have experienced ozone
NAAQS violations recently) would not experience NAAQS violations in
2007, with a strategy that relied only on Tier 1 vehicle emission
standards. We have also recently proposed to approve the 1-hour
attainment demonstration for Greater Connecticut, covering the
Hartford and New London areas, which assumed full NLEV emission
reductions. However, Connecticut is committed in its SIP to adopt
California vehicle standards if NLEV does end with the 2003 model
year if a more stringent federal program is not promulgated. The
California standards are more stringent than NLEV. The case of one
additional area whose attainment demonstration we recently proposed
to approve, Western Massachusetts (Springfield), should be explained
here to avoid possible confusion. Our own ozone modeling predicted
that Springfield would attain the NAAQS in 2007. Massachusetts has
adopted the California vehicle emission standards, so there is no
issue of the continuation of the NLEV standards.
---------------------------------------------------------------------------
For the other six of the 12 areas, the air quality monitoring data
shows current attainment but with less than a 10 percent margin below
the NAAQS. This suggests these areas may remain without violations for
some time, but we believe there is still a moderate risk of future
violation of the NAAQS because meteorological conditions may be more
severe in the future.
It is highly likely that at least some of these 12 areas will
violate the NAAQS without additional reductions, and it is a distinct
possibility that many of them will do so. We consider the situation in
these areas to support our determination that, overall, additional
reductions are needed for attainment and maintenance. However, we
reiterate that our predictions for the 26 areas listed in Table III.B-
1, and even our predictions for only the 14 of those 26 for which the
1-hour standard now applies, are a sufficient basis for our
determination of an overall need for additional reductions and for our
actions today.
Table III.B-2.--Twelve Metropolitan Areas With Moderate to Significant
Risk of Failing To Attain and Maintain the 1-Hour Ozone NAAQS Without
Additional Emission Reductions
------------------------------------------------------------------------
1996
Metropolitan area Population
(millions)
------------------------------------------------------------------------
Benton Harbor, MI MSA \a\.................................. 0.2
Biloxi-Gulfport-Pascagoula, MS MSA \a\..................... 0.3
Chicago-Gary-Kenosha, IL-IN-WI CMSA........................ 8.6
Cleveland-Akron, OH CMSA \a\............................... 2.9
Detroit-Ann Arbor-Flint, MI CMSA \a\....................... 5.3
Grand Rapids-Muskegon-Holland, MI MSA \a\.................. 1.0
Hartford, CT MSA........................................... 1.1
Milwaukee-Racine, WI CMSA.................................. 1.6
New London-Norwich, CT-RI MSA \a\.......................... 1.3
New Orleans, LA MSA \a\.................................... 0.3
Pensacola, FL MSA \a\...................................... 0.4
Tampa, FL MSA \a\.......................................... 2.2
------------
Total Population..................................... 25.3
------------------------------------------------------------------------
Notes:
\a\ The 1-hour ozone NAAQS does not currently apply, but we have
proposed and expect to re-instate it shortly.
e. Issues and Comments Addressed
We received detailed comments from the automobile industry related
to ozone modeling and the need for additional emission reductions in
order to attain and maintain. These were of three types.
Accuracy of modeling ozone concentrations.--The automobile industry
commenters pointed out that in the modeling presented with our
proposal, the ozone model and exceedance predicted violations of the
NAAQS in 1995 in areas where monitoring data indicated no violations.
They cited these cases as examples of model inaccuracy. We have made
improvements to our emissions estimates, our episodes, and other
aspects of the modeling system. These changes have improved the
accuracy of the predicted ozone concentrations. Also, as stated above,
our list of 26 areas that support our finding that additional
reductions are needed does not include any areas where recent
monitoring data shows no violations. The final RIA addresses issues of
model accuracy in more depth.
As explained in the final RIA, our very latest estimates of car and
light truck emissions without the benefits of our new standards are
actually somewhat higher than the estimates used in the final round of
ozone modeling, because the most recent data indicate even more serious
adverse emissions effects from sulfur in
[[Page 6711]]
gasoline. Thus, we think our predictions of ozone nonattainment using
emission estimates prepared before this most recent data on sulfur was
considered, may be conservative. This topic is discussed in more detail
in section III.B.3.
Prediction of attainment/nonattainment.--For most areas, we
predicted 2007 or 2030 attainment or nonattainment based on the
exceedance method. The exceedance method predicts an area to be in
attainment only if there are no predicted exceedances of the NAAQS
during any episode day. However, for the areas for which we have
received 1-hour attainment demonstrations in SIP revisions, our
predictions were based on a larger and more robust set of data. When a
state's modeling shows an exceedance that would otherwise indicate
nonattainment, we allow the state to submit a variety of other evidence
and analysis, such as locality specific meteorological conditions,
analysis of air quality and emissions trends, observational based
models that make use of data on concentrations of ozone precursors, a
rollback analysis, and information on the responsiveness of the air
quality model. We then make a weight-of-evidence determination of
attainment or nonattainment based on consideration of all this local
evidence. We did this in forming the set of 26 areas we consider
certain or highly likely to need additional reductions to attain or
maintain, in some cases concluding that attainment was demonstrated and
in others that it was not.
The auto industry commenters recommended the use of rollback as the
single method for making attainment and nonattainment predictions from
predicted ozone concentrations. They stated that the rollback method
would be more consistent than the exceedance method with the NAAQS's
allowance of three exceedances in a three year period. They also
believed that the rollback method would compensate for what they
considered to be model over predictions of ozone concentrations. We
believe that the rollback method is not appropriate for use as the
sole, or even a primary, test of 1-hour ozone attainment or
nonattainment. A rollback analysis may overlook violations that occur
away from ozone monitors, and it may inappropriately project the effect
of a recent period of favorable weather into the prediction of future
attainment. In determining the attainment and maintenance prospects of
numerous areas, as here, it is not possible to assemble and consider
the full set of local evidence that should accompany any consideration
of a rollback analysis. In such a situation, we believe that the
exceedance method is the appropriate choice. A fuller explanation of
our reasons for considering the exceedance method more appropriate than
rollback is given in our Response to Comments document.
We have not completely excluded the rollback approach from the
determinations in this rulemaking. We have considered it for those
areas for which we had enough information to allow us to consider it in
its proper context, i.e., for those areas covered by recent 1-hour SIP
submissions. Of these areas, we concluded that some will not attain
without additional reductions and some will.
While we disagree with the use of the rollback method, we have
conducted a hypothetical analysis of 2007 attainment in all areas based
only on our own ozone modeling, applying the rollback method
recommended by the commenters. We calculated in this analysis that 15
metropolitan areas and three other counties with nearly 56 million in
population in 1996 would violate the NAAQS in 2007. Moreover, these 15
metro areas are geographically spread out \19\. We believe that this
result using the rollback method does not fully capture the likely
nonattainment that would exist in 2007 in the absence of additional
emission reductions. However, even if we were to consider the use of
rollback valid, we consider this set of areas to also be an adequate
basis for making the same determinations we have made based on the more
appropriate exceedance-based analysis. The details of our hypothetical
analysis using the rollback method are given in the final RIA and the
technical support document for our ozone modeling analyses.
---------------------------------------------------------------------------
\19\ We did not include the Los Angeles-Riverside-San Bernardino
area in this analysis, since it was not covered by our 2007
modeling, but we do believe it is rightly part of the basis for a
determination on the need for additional reductions.
---------------------------------------------------------------------------
Ozone modeling and predictions.--Members of the automobile
manufacturing industry submitted two modeling studies: (1) a repetition
of our first round of modeling of the 37-state eastern U.S. domain but
with their recommendations regarding estimates of motor vehicle
emissions in 2007 and with the rollback method used to predict 2007
nonattainment, and (2) finer grid modeling for three smaller domains,
also with their recommended estimates of emissions and with
nonattainment predicted using a rollback method. Both modeling efforts
showed less widespread nonattainment than we have determined and
described here. Taken together, these studies predicted 2007 violations
by the rollback method in or downwind of New York City, Chicago,
Milwaukee, western Michigan, Baton-Rouge, and Houston.
The main difference between the automobile industry's ozone
modeling and ours is in the emission estimates. We have reviewed the
emissions estimates used in the industry studies. We concluded that the
industry's emissions estimates employ inappropriate analytical steps in
the calculation. Among the problems are that the adjustments for the
benefits of inspection and maintenance programs were not consistent
with the base estimate of in-use emissions, and the sales trend towards
light trucks and SUVs was not properly captured. Also, as stated, we
disagree with the use of the rollback approach as the sole test of
attainment. As a consequence, we conclude that the industry's ozone
modeling is not an appropriate basis for making predictions of future
attainment or nonattainment. The final RIA explains in detail how we
have addressed these and other emissions modeling issues in a manner
which is more technically consistent and correct,\20\ and how we have
considered the results from rollback analyses but only as part of broad
weight-of-evidence determinations for areas for which this was possible
at this time. Our point-by-point review is given in our Response to
Comments document.
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\20\ As explained in the final RIA, our very lastest estimates
of car and light truck emissions without the benefits of our new
standards are actually somewhat higher than the estimates used in
the final round of ozone modeling, because more recent data indicate
even more serious adverse emissions effects from sulfur in gasoline.
Thus, we think our predictions of ozone nonattainment may be
conservative.
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The material on ozone modeling submitted by the commenters, having
been prepared by the rollback method, was difficult to re-interpret
according to our preferred exceedance method. However, it appears that
if this modeling were interpreted by the exceedance method, it would
indicate 2007 nonattainment in Baltimore and Washington, D.C. in
addition to New York City, Chicago, Milwaukee, western Michigan, Baton-
Rouge, and Houston. Overall, we conclude that the material submitted by
the automobile industry does not contradict the facts we have used to
make our determinations or the actions we are taking today.
f. 8-Hour Ozone
The predictions of ozone concentrations from the ozone modeling
[[Page 6712]]
can be used to make predictions of attainment or nonattainment with the
8-hour ozone NAAQS. In our draft RIA, we estimated that 28 metropolitan
areas and 4 rural counties with a combined population of 80 million
people would violate the 8-hour ozone NAAQS in 2007 without additional
emission reductions. Commenters noted differences between exact
rollback procedure we had used in this projection and the steps
specified in recent draft guidance we have issued on 8-hour ozone
modeling. We agree with the commenters that the steps specified in our
guidance are the correct ones to use. However, since we are not basing
our promulgation of the Tier 2/Gasoline Sulfur Program on the 8-hour
ozone NAAQS, we have not made any new predictions of 8-hour ozone
nonattainment areas in 2007. Based on our findings in previous analyses
of this sort, however, we believe that in the absence of the Tier 2/
Gasoline Sulfur program there would be 8-hour nonattainment areas that
are not also areas which we have concluded are certain or highly likely
to violate the 1-hour NAAQS. If we considered it appropriate to proceed
with implementation of the 8-hour standard, these areas would support
our determination on the need for emission reductions, and the
appropriateness and necessity of the vehicle and gasoline standards we
are establishing.
3. Cars and Light-duty Trucks Are a Big Part of the NO<INF>X</INF> and
VOC Emissions, and Today's Action Will Reduce This Contribution
Substantially
Emissions of VOCs and NO<INF>X</INF> come from a variety of
sources, both natural and man-made. Natural sources, including
emissions that have been traced to vegetation, account for a
substantial portion of total VOC emissions in rural areas. The
remainder of this section focuses on the contribution of motor vehicles
to emissions from human sources. Man-made VOCs are released as
byproducts of incomplete combustion as well as evaporation of solvents
and fuels. For gasoline-fueled cars and light trucks, approximately
half of the VOC emissions come from the vehicle exhaust and half come
from the evaporation of gasoline from the fuel system. NO<INF>X</INF>
emissions are dominated by man-made sources, most notably high-
temperature combustion processes such as those occurring in automobiles
and power plants. Emissions from cars and light trucks are currently,
and will remain, a major part of nationwide VOC and NO<INF>X</INF>
emissions. In 1996, cars and light trucks comprised 25 percent of the
VOC emissions and 21 percent of the NO<INF>X</INF> emissions from human
sources in the U.S.\21\ The contribution in metropolitan areas was
generally larger.
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\21\ Emission Trend Report, 1997.
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We have made significant improvements in the analysis used to
estimate the emission inventory impacts of this action, including
improving the emission factor modeling, using more detailed local
modeling input, and using a more conservative (lower) estimate of VMT
growth. These changes are detailed in the Regulatory Impact Analysis
for this rule. The following discussion is based on this improved
analysis.
In addition to the improvements which are incorporated in this
analysis, we also made further improvements in the emission factor
modeling after analyzing comments which we did not have time to
incorporate into the detailed inventory analysis described here. The
most notable change is related to data which indicates that
NO<INF>X</INF> and NMOG emissions are even more sensitive to gasoline
sulfur than previously thought. This change and others are described in
detail in the Response to Comments. Our early analysis of these changes
indicates that incorporating them into this analysis would provide
further support for this action because these changes result in both
increases in the baseline emissions without Tier 2 and in the
reductions that would result from Tier 2. For example, in the detailed
inventory analysis we report below, we project nationwide Tier 2/
Gasoline Sulfur control NO<INF>X</INF> reductions from cars and light
trucks of 856,471 tons per year in 2007. Using the version of the
emission factor model that incorporates these additional changes
increases the estimated Tier 2 reductions to approximately 1.0 million
tons per year in 2007 (estimated baseline emissions without Tier 2
increase from 3.1 million tons per year in 2007 to approximately 3.7
million tons per year using the version of the emission factor model
that incorporates these additional changes). Therefore, the estimates
of the inventory reductions given here (and used as the basis for the
ozone air quality analysis) are clearly conservative.
Motor vehicle emission controls have led to significant
improvements in emissions released to the air (the ``emission
inventory'') and will continue to do so in the near term \22\. In the
current analysis, we continue to find that total emissions from the car
and light truck fleet would continue to decline for a period, even if
we were not establishing the Tier 2/Gasoline Sulfur program. This
decline would result from the introduction of cleaner reformulated
gasoline in 2000, the introduction of National Low Emission Vehicles
(NLEVs) and vehicles complying with the Enhanced Evaporative Test
Procedure and Supplemental Federal Test Procedures, and the continuing
removal of older, higher-emitting vehicles from the in-use vehicle
fleet. On a per mile basis, VOC and NO<INF>X</INF> emissions from cars
and light trucks combined would have continued to decline well beyond
2015, reflecting the continuing effect of fleet turnover under existing
emission control programs. However, projected increases in vehicle
miles traveled (VMT) will cause total emissions from these vehicles to
increase. With this increase in travel and without additional controls,
we project that combined NO<INF>X</INF> and VOC emissions for cars and
light trucks without the Tier 2/Gasoline Sulfur program would increase
starting in 2013 and 2016, respectively, so that by 2030 they would
return to levels above or nearly the same as they will be in 2000. In
cities experiencing rapid growth, such as Charlotte, North Carolina,
the near-term trend towards lower emissions tends to reverse
sooner.\23\ With additional improvements in the modeling done in
Response to Comments, we now estimate that without the Tier 2/Gasoline
Sulfur program, there will be a constant increase in these emission
over time.
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\22\ The auto manufacturer and northeastern state commitments to
the NLEV program are scheduled to end in 2004 without further EPA
action on Tier 2 standards, although continued voluntary compliance
by automobile manufacturers and the affected states is a
possibility. Our analysis of emission trends and the emission
benefits expected from today's action assumes for the base scenario
a continuation of the NLEV program past 2004. If the NLEV program
does not continue beyond 2004, the reductions resulting from Tier 2
would be larger than what is shown here. It also includes all other
control measures assumed to be implemented in local areas, such as
reformulated gasoline in all required and opt-in areas and enhanced
I/M where required.
\23\ Also, if the NLEV program ends in model year 2004 or
shortly thereafter, as scheduled, this trend would reverse more
quickly in all areas.
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Figure III-1 illustrates this expected trend in car and light truck
NO<INF>X</INF> emissions in the absence of today's action. The figure
also allows the contribution of cars to be distinguished from that of
light trucks. The figure clearly shows the impact of steady growth in
light truck sales and travel on overall light-duty NO<INF>X</INF>
emissions; the decrease in overall light-duty emission levels is due
solely to reductions in LDV emissions. In 2000, we project that
[[Page 6713]]
trucks will produce about 50 percent of combined car and light truck
NO<INF>X</INF> emissions. We project that truck emissions would
actually increase after 2000, and over the next 30 years, trucks would
grow to dominate light-duty NO<INF>X</INF> emissions. By 2010, we
project trucks would make up two-thirds of light-duty NO<INF>X</INF>
emissions; by 2020, nearly three-quarters of all light-duty
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NO<INF>X</INF> emissions would be produced by trucks.
BILLING CODE 6560-50-P
[GRAPHIC] [TIFF OMITTED] TR10FE00.000
BILLING CODE 6560-50-C
Today's action will significantly decrease NO<INF>X</INF> and VOC
emissions from cars and light trucks, and will delay the date by which
NO<INF>X</INF> and VOC emissions will begin to increase due to
continued VMT growth. With Tier 2/Gasoline Sulfur control, light-duty
vehicle NO<INF>X</INF> and VOC emissions are projected to continue
their downward trend past 2020. Table III.B-3 shows the annual tons of
NO<INF>X</INF> that we project will be reduced by today's action.\24\
These projections include the benefits of low sulfur fuel and the
introduction of Tier 2 car and light truck standards.
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\24\ Today's action for both vehicles and fuels will apply in 49
states and the U.S. territories, excluding only California. There
will also be emissions reductions in California from vehicles that
relocate or visit from other states. However, much of the emissions
inventory analysis for this action was made for a 47-state region
which excludes California, Alasks, and Hawaii. The latter two states
were not included in the scope of ozone, PM and economic benefits
modeling.
Table III.B-3.--NO<INF>X</INF> Emissions From Cars and Light Trucks as Percent of Total Emissions, and Reductions Due to
Tier 2/Gasoline Sulfur Control (tons per year) \a\
----------------------------------------------------------------------------------------------------------------
Light-duty
Light-duty percent of Light-duty
Year tons-- without total without tons reduced
tier 2 tier 2 by tier 2 <SUP>b,</SUP> <SUP>c</SUP>
----------------------------------------------------------------------------------------------------------------
2007............................................................ 3,095,698 16 856,471
2010............................................................ 2,962,093 16 1,235,882
2015............................................................ 2,968,707 17 1,816,767
2020............................................................ 3,160,155 17 2,220,210
[[Page 6714]]
2030............................................................ 3,704,747 19 2,795,551
----------------------------------------------------------------------------------------------------------------
Notes:
\a\ Estimates exclude California, Alaska, and Hawaii, although reductions will occur in all three.
\b\ Does not include emission reductions from heavy-duty gasoline vehicles.
\c\ These numbers represent a conservative estimate of the benefits of the Tier 2/Sulfur program. Based on the
updated emission factor model developed in response to comments, the program will result in significantly
larger benefits. For example, our new model projects NO<INF>X</INF> reductions of 1,100,000 tons in 2007.
The lower sulfur levels in today's action will produce large
emission reductions on pre-Tier 2 vehicles as soon as low-sulfur
gasoline is introduced, in addition to enabling Tier 2 vehicles to
achieve lower emission levels. Among the pre-Tier 2 vehicles, the
largest per vehicle emission reductions from lower sulfur in gasoline
will be achieved from vehicles which automobile manufacturers will have
sold under the voluntary National Low Emission Vehicle program. These
vehicles are capable of substantially lower emissions when operated on
low sulfur fuel. Older technology vehicles experience a smaller but
significant effect.
In 2007, when all gasoline will meet the new sulfur limit and when
large numbers of 2004 and newer vehicles meeting these standards will
be in use, the combined NO<INF>X</INF> emission reduction from vehicles
and fuels will be over 850,000 tons per year. After 2007, emissions
will be reduced further as the fleet turns over to Tier 2 vehicles
operating on low sulfur fuel. By 2020, NO<INF>X</INF> emissions will be
reduced by 70% from the levels that would occur without today's action.
This reduction equals the NO<INF>X</INF> emissions from over 164
million pre-Tier 2 cars and light trucks. This reduction represents a
12 percent reduction in NO<INF>X</INF> emissions from all manmade
sources.
VOC emissions will also be reduced by today's action, with
reductions increasing as the fleet turns over. We estimate that the
reductions as a percent of emissions from cars and light trucks will be
7 percent in 2007 and grow to 17 percent in 2020.
As discussed earlier, in California, smaller but still substantial
reductions in both NO<INF>X</INF> and VOC will be achieved because
vehicles visiting and relocating to California will be designed to meet
these standards. Also, vehicles from California visiting other states
will not be exposed to high sulfur fuel. California Air Resources Board
staff have estimated that Tier 2/Sulfur will reduce NO<INF>X</INF>
emissions in the South Coast Air Quality Management District by
approximately 4 tons per day in 2007.\25\ CARB staff plan to
incorporate these reductions in their revised attainment plan for this
district, which includes most of the Los Angeles-Long Beach region.
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\25\ California Air Resources Board, Executive Order G-99-037,
May 20, 1999, Attachment A, 6-7, 10. These NO<INF>X</INF> reductions
represent a small fraction of the emission reductions needed in the
South Coast to attain the NAAQS.
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These estimates of emission reductions reflect a mixture of urban,
suburban, and rural areas. However, cars and light trucks generally
make up a larger fraction of the emission inventory for urban and
suburban areas, where human population and personal vehicle travel is
more concentrated than emissions from other sources such as heavy-duty
highway vehicles, power plants, and industrial boilers. We have
estimated emission inventories for three cities using the same methods
as were used to project the nationwide inventories, and we present the
results for 2007 below in Table III.B-4.
These results confirm that light-duty vehicles make up a greater
share of the NO<INF>X</INF> emission inventories in urban areas than
they do in the nationwide inventory. While these vehicles' share of
national NO<INF>X</INF> emissions in 2007 is about 16 percent, it is
estimated to be about 34 percent in the Atlanta area. There is also a
range in VOC contributions, with Atlanta again being the area with the
largest car and light truck contribution at 17 percent. In metropolitan
areas with high car and light truck contributions, today's action will
represent a larger step towards attainment since it will have a larger
effect on total emissions.
Table III.B-4--Proportion of the Total Urban Area NO<INF>X</INF> and VOC Inventory
in 2007 Attributable to Light-Duty Vehicles<SUP>a</SUP>
------------------------------------------------------------------------
NO<INF>X</INF> VOC
Region (percent) (percent)
------------------------------------------------------------------------
Nationwide.................................... 16 13
New York urban area........................... 18 6
Atlanta urban area............................ 34 17
Charlotte urban area.......................... 24 15
------------------------------------------------------------------------
Notes:
<SUP>a</SUP> The estimates reflect continuation of NLEV beyond 2004.
Another useful perspective from which to view the magnitude of the
emission reductions from today's proposal is in terms of the additional
emission reductions from all human sources that areas will need to
attain the 1-hour ozone standard. For this analysis, we reviewed our
proposals for action on the 1-hour attainment demonstrations submitted
by the states. With these proposals, EPA identified estimates of
additional emission reductions (measures in addition to those submitted
by the state in their plans) necessary for attainment for some
[[Page 6715]]
of the areas. These estimates of additional emission reductions are
documented in the individual Federal Register Notices. Using these
estimates and the estimates of Tier 2 reductions developed for today's
action, we have determined what portion of these additional emission
reductions would be accounted for by today's action. These estimates
are reported in Table III.B-5, which shows the contribution of Tier 2/
Sulfur NO<INF>X</INF> reductions to the additional emission reduction
necessary for attainment for three metropolitan areas. For example, for
the New York nonattainment area, 89% of the additional NO<INF>X</INF>
emission reductions needed for attainment are provided for with today's
action. This leaves 11% of the additional NO<INF>X</INF> emission
reductions to be addressed by the State through other local sources.
EPA and the States already have significant efforts underway to
lower ozone precursor emissions through national regulations and State
Implementation Plans. Table III.B-5 shows the contribution of Tier 2 to
the substantial State-led efforts to provide attainment with the ozone
NAAQS. Since the Tier 2 program has evolved in the past year after much
of the States' efforts were completed, many of the States were unable
to estimate the benefits of Tier 2 in their areas. EPA's proposal
actions on these SIPs for the ozone NAAQS addresses the need for Tier 2
in many areas. More specifically, Tier 2 is bein