Control of Air Pollution From Heavy-Duty Engines

[Federal Register: August 31, 1995 (Volume 60, Number 169)]
[Proposed Rules ]
[Page 45579-45604]
>From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[[Page 45579]]

Part IV

Environmental Protection Agency

40 CFR Parts 80, 86, and 89

Control of Air Pollution From Heavy-Duty Engines; Proposed Rule

[[Page 45580]]

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 80, 86, and 89

[AMS-FRL-5288-4]
RIN 2060-AF76

Control of Air Pollution From Heavy-Duty Engines

AGENCY: Environmental Protection Agency.

ACTION: Advance notice of proposed rule.

SUMMARY: This advance notice of proposed rule (ANPRM) reviews the need
and potential for additional reductions in emissions of oxides of
nitrogen (NO_X), hydrocarbons (HC), and particulate matter (PM)
from mobile source heavy-duty engines (HDEs), announces EPA's intent to
establish new emission controls for highway heavy-duty engines, and
also describes EPA's plans to work cooperatively with engine and
equipment manufacturers to consider additional reductions from nonroad
(off-highway) heavy-duty engines. Ozone pollution poses a serious
threat to the health and well-being of millions of Americans and a
large burden to the U.S. economy. Many ozone nonattainment areas face
great difficulties in reaching and maintaining attainment of the ozone
health-based air quality standards in the years ahead. Recognizing this
challenge, states, local governments and others have called on EPA to
promulgate additional national measures to reduce NO_Xand HC in
order to protect the public from the serious health effects of ozone
pollution. The control of PM emissions from HDEs is also a priority for
these stakeholders.
In response to the need for national pollution reduction measures,
EPA has initiated discussions with engine manufacturers regarding
future emission controls for HDEs. EPA, the California Air Resources
Board (CARB), and HDE manufacturers recently signed a Statement of
Principles (SOP) calling for significantly tighter NO_Xand nonmethane
hydrocarbon (NMHC) standards for on-highway HDEs starting with
model year 2004. The SOP calls on manufacturers to achieve these ozone
precursor reductions without increasing PM emissions, even though
current diesel technology typically results in increased PM (and HC)
emissions when NO_Xemissions are reduced. The parties plan to
continue their discussions and to invite others to join them, with a
goal of reaching a similar SOP for nonroad HDEs.
DATES: EPA requests comment on this ANPRM no later than October 2,
1995. Should a commenter miss the requested deadline, EPA will try to
consider any comments that it receives prior to publication of the
expected NPRM regarding additional highway heavy-duty engine emission
controls. There will also be an opportunity to comment on any NPRM that
EPA publishes.

ADDRESSES: Materials relevant to this ANPRM are contained in Public
Docket A-95-27, located at room M-1500, Waterside Mall (ground floor),
U.S. Environmental Protection Agency, 401 M Street SW., Washington, DC
20460. The docket may be inspected from 8 a.m. until 5:30 p.m., Monday
through Friday. A reasonable fee may be charged by EPA for copying
docket materials.

Comments on this ANPRM should be sent to Public Docket A-95-27 at
the above address. EPA requests that a copy of comments also be sent to
Tad Wysor, U.S. EPA, Regulation Development and Support Division, 2565
Plymouth Road, Ann Arbor, MI 48105.

This ANPRM is available electronically on the Technology Transfer
Network (TTN), which is an electronic bulletin board system (BBS)
operated by EPA's Office of Air Quality Planning and Standards. The
service is free of charge, except for the cost of the phone call. Users
are able to access and download TTN files on their first call using a
personal computer and modem: TTN BBS, (919) 541-5742; Voice Helpline,
(919) 541-5384.

FOR FURTHER INFORMATION CONTACT: Tad Wysor, U.S. EPA, Regulation
Development and Support Division, 2565 Plymouth Road, Ann Arbor, MI
48105. Telephone: (313) 668-4332.

SUPPLEMENTARY INFORMATION: EPA is issuing this ANPRM to invite
comment from all interested parties on the need and potential for
additional reduction of NO<INF>X, HC and PM emissions from HDEs and
EPA's plans to achieve such reductions. After reviewing the
comments, EPA intends to issue a Notice of Proposed Rulemaking
(NPRM) proposing standards for Model Year 2004 and later heavy-duty
highway engines in accordance with the SOP. In addition, comments
received regarding reduction in emissions from nonroad HDEs will
inform any EPA discussions with manufacturers regarding additional
emission reductions.

I. Introduction

Poor air quality represents a serious threat to the health and
well-being of millions of Americans and a large burden to the U.S.
economy. This threat exists despite the fact that, over the past two
decades, great progress has been made at the local, state and national
levels in controlling emissions from many sources of air pollution. As
a result of this progress, many individual emission sources, both
stationary and mobile, pollute at only a fraction of their pre-control
rates. However, continued industrial growth and expansion of motor
vehicle usage threaten to reverse these past achievements. Today, more
than four years after the passage of major amendments to the Clean Air
Act (CAA or Act),1 many states are still finding it difficult to
meet the air quality standards by the CAA deadlines. Furthermore, other
states which are approaching or have reached attainment of National
Ambient Air Quality Standards (NAAQS) may see those gains lost if
current trends persist.

\1\ See 42 U.S.C. 7401 et seq.

In recent years, efforts to improve air quality have focused
largely on ground-level ozone and its main precursors, nitrogen oxides
(NO_X) and volatile organic compounds (VOCs, consisting mostly of
hydrocarbons, HC). In addition, airborne particulate matter (PM) has
been a major air quality concern in many regions. As discussed below,
NO<INF>X, ozone, and PM have all been linked to a range of serious
respiratory health problems and a variety of adverse environmental
effects.
At this time, ozone levels remain unacceptably high in many areas
across the country. For many years, control of VOCs was the main
strategy employed in efforts to reduce ground-level ozone. VOC
reductions were more cost effective (on a per-ton basis) and more
readily achievable than NO_Xreductions. In addition, it was
generally believed that greater ozone benefits could be achieved
through VOC reductions. More recently, it has become clear that
NO_Xcontrols are often the most effective strategy for reducing
ozone, especially where ozone is high over a large region (as in the
Midwest and Northeast). As a result, attention has turned to NO_X
emissions as the key to improving air quality in many areas of the
country.
Current projections show a slight decrease in total NO_X
emissions during the next few years as stationary and mobile source
control programs promulgated under the 1990 CAA are phased in. However,
downward trends in NO_Xpollution will begin to reverse and
NO_Xemission inventories begin to rise by the early 2000s, due to
growth in stationary and mobile source activity, and emissions from
heavy-duty highway and nonroad engines are projected to represent a
significant fraction of mobile

[[Page 45581]]
source NO_Xemissions by the middle of the next decade. In some
areas, the rise in NO_Xemissions can be expected to be accompanied
by a significant increase in ground-level ozone. Levels of PM are also
expected to rise, both because of the expected increase in numbers of
PM sources and because in the atmosphere, NO_Xis transformed into
fine acidic nitrate particles which account for a substantial fraction
of the airborne particulate in some areas of the country (``secondary
particulate formation'').
Given these expected trends, and in the absence of new emission
control initiatives, some of the nation's hard-won air quality
improvements will begin to be seriously threatened in the early 2000s.
In response to widespread urging by states, municipalities, health
officials, and concerned citizens in virtually every region of the
country,2 EPA has intensified its efforts to understand and
respond to today's stubborn air quality challenges. Over the past
decade, ambient air measurements and computer modeling studies have
repeatedly demonstrated that ozone and its precursors, NO_Xand
VOC, are transported across large distances. Thus, while there is a
role for all levels of government to address these issues, EPA's state
and local partners generally agree that only with new initiatives at
the regional and national level can long-term clean air goals be
achieved.

\2\ See Section VI for more detailed discussion of the comments
received by EPA to date.

States are assigned the jurisdiction by the CAA for implementing
most stationary source emission controls. In most regions of the
country, states are implementing stationary source NO_Xcontrol
options (as well as stationary source VOC controls) for the control of
acid rain, ozone, or both. However, in many areas these controls will
not be sufficient for reaching and/or maintaining the ozone standard
without significant additional NO_Xreductions from mobile sources.
California can establish emission control standards for new motor
vehicles, and other states may adopt California's programs.3
Traditionally, however, nationwide VOC and NO_Xcontrol programs
for new motor vehicles are initiated at the federal level. Similarly,
mobile sources of PM emissions, especially the direct and indirect PM
from diesel engines, are a major consideration to local and state
officials in areas facing current and future air quality problems.
Thus, those charged with delivering cleaner air to the citizens of
their states are looking to the national mobile source emission control
program as a necessary complement to their efforts to reduce NO<INF>X,
PM, HC, and other emissions. Common emission standards for mobile
sources across the nation are also strongly supported by manufacturers,
which often face serious production inefficiencies when different
requirements apply to engines/vehicles sold in different states or
areas.

\3\ A similar relationship applies to new nonroad engines and
vehicles, although states may not set standards for certain classes
of these engines and vehicles. See Sections 209 and 213 of the Act.

Motor vehicle emission control programs have a history of
technological success that, in the past, has largely offset the
pressure from constantly growing numbers of vehicles and miles traveled
in the U.S. The per-vehicle rate of emissions from new passenger cars
and light trucks has been reduced to very low levels. As a result,
increasing attention is now being focused on heavy-duty trucks (ranging
from large pickups to tractor-trailers), buses, and nonroad equipment.
For purposes of this ANPRM, the Agency is primarily interested in the
component of nonroad sources greater than 50 horsepower (37 kilowatts),
which is termed ``heavy-duty nonroad'' in this Notice. (Nonroad engines
greater than 50 hp represent the single largest contributor to total
nonroad NO_Xemissions.) EPA is addressing other off-highway
sources, such as small nonroad engines, locomotives, aircraft and
marine engines in separate actions.
Since the 1970s, manufacturers of heavy-duty engines for highway
use have developed new technological approaches in response to
increasingly stringent emission standards. However, the technological
characteristics of heavy-duty engines, particularly diesel engines,
have to date prevented the achievement of emission levels comparable to
today's light-duty gasoline vehicles. While diesel engines provide
advantages in terms of fuel efficiency, reliability, and durability,
control of NO_Xemissions is a much greater challenge for diesel
engines than for gasoline engines. Similarly, control of PM emissions,
which are at very low levels for gasoline engines, represents a
substantial challenge for diesel engines.
Despite these technological challenges, there is emerging agreement
that heavy-duty highway engines offer the potential for substantial
additional emission reductions. In their successful efforts to reach
lower NO_Xand PM levels over the past 20 years, heavy-duty highway
diesel engine manufacturers have identified new technologies and
approaches that today offer promise for significant new reductions. New
technological options are available to manufacturers of heavy-duty
gasoline engines as well. The emerging technological potential for much
cleaner highway heavy-duty engines is discussed further in Section VIII
below.
In addition, many engines used in highway trucks have similar
counterparts that are used in certain nonroad equipment applications.
The first emission control regulations covering these heavy-duty
nonroad engines have been only recently established; these new
standards are less stringent than current standards for similar heavyduty
engines intended for highway use. A strong potential exists for
current highway engine emission control technology to be applied in
many cases to heavy-duty nonroad engines (even though differences in
application and usage complicate direct translation of the technology),
representing a future avenue for additional mobile source emission
reductions.
Recognizing the need for additional NO_X(and PM) control
measures at the national level to address air quality concerns in a
number of parts of the country and the growing contribution of the
heavy-duty engine sector to ozone (and PM) problems, EPA recently held
a series of discussions with the California Air Resources Board (CARB)
and representatives of the heavy-duty engine manufacturing industry.
The purpose of these discussions was to exchange views on the
appropriateness and feasibility of new emission standards for heavyduty
engines. Based on these discussions, a Statement of Principles
(SOP) regarding highway heavy-duty engines has been signed by these
parties.
The SOP is described in more detail in Section VII of this notice
and is attached as an Appendix. It addresses NO<INF>X, PM, and NMHC
standards for highway heavy-duty engines starting in model year 2004,
the important role that fuel may play in achieving these standards, a
procedure to reevaluate the appropriateness of these standards in 1999,
the intent of the parties to undertake development of a joint industry/
government research program aimed at meeting and exceeding the NO_X
and PM levels discussed in the SOP, and the intent of the parties to
continue discussions with others with the goal of signing a similar SOP
with respect to nonroad heavy-duty engines. Other important elements of
the SOP are also discussed in Section VII.
The main purposes of today's ANPRM are to provide an early focus
for an open and comprehensive discussion of the issues involved in
achieving additional emission reductions from heavy-duty engines and to
make the SOP available to the public for comment on specific

[[Page 45582]]
emission reductions from highway heavy-duty engines.4 The rest of
the ANPRM is organized as follows: Section II summarizes the public
health and welfare needs for this initiative and trends in overall
nationwide NO<INF>X, VOC, and PM emissions; Section III describes the
contribution of HDEs to overall emissions; Section IV summarizes the
need for control of heavy-duty engines; Section V provides the history
and status of highway heavy-duty engine emission standards; Section VI
summarizes a range of requests for action that EPA has received to
date; Section VII reviews the development and content of the Statement
of Principles; Section VIII discusses some approaches to highway HDE
emission control; and Section IX describes EPA's plans for involving
the public in the upcoming rulemaking process. The complete text of the
Statement of Principles is included as an Appendix to today's Notice.

\4\ Also, in a letter to certain organizations related to clean
air issues in California, EPA agreed that it would issue an ANPRM
regarding national standards for highway HDEs.

II. Health Concerns and Air Quality Issues: NO<INF>X, VOC, Ozone,
and Particulate Matter

A. Health and Environmental Effects Related to NO<INF>X, VOC, and Ozone
5

\5\ Information cited in this section and other related
information on health effects of NO<INF>X, VOC and Ozone are
available from Docket A-95-27.

Oxides of nitrogen comprise a family of highly reactive gaseous
compounds that contribute to air pollution in both urban and rural
environments. Because NO_Xemissions are produced during the
combustion of fuels at high temperatures, the primary sources of
atmospheric NO_Xinclude both stationary sources, such as power
plants and industrial boilers, and mobile sources, such as light- and
heavy-duty vehicles as well as construction, agricultural, and other
nonroad equipment. NO_Xis directly harmful to human health and the
environment, contributes to particulate pollution, and plays a critical
role in the formation of atmospheric ozone. The current primary
(health-based) and secondary (welfare-based) national ambient air
quality standards (NAAQS) for NO<INF>2 are both set at a concentration
of 0.053 parts per million (ppm), on an annual average.
Exposure to NO<INF>2 can reduce pulmonary function and increase
airway irritation in healthy subjects as well as people with preexisting
pulmonary conditions. In children, exposure to NO<INF>2 at or
near the level of the ambient standard appears to increase the risk of
respiratory illness.6 NO_Xand its transformation products
(e.g., nitric acid, peroxyacetyl nitrate (PAN) and nitrate particles)
also contributes to a number of adverse environmental impacts such as
the overgrowth of algae and oxygen depletion (eutrophication).7
NO_Xand its products contribute to acid rain, which affects both
terrestrial and aquatic ecosystems, including acidification of surface
waters, reduction in fish populations, damage to forests and associated
wildlife, soil degradation, damage to materials, monuments, buildings,
etc., and reduced visibility.8

\6\ Air Quality Criteria Document for Oxides of Nitrogen, EPA-
600/8-91/049aF-cF, August 1993 (NTIS #: PB92-17-6361/REB,-6379/REB-
6387/REB).
\7\ Deposition of Air Pollutants Into the Great Waters: First
Report to Congress, EPA-453/r-93-055, May 1994.
\8\ ``Acid Deposition Standard Feasibility Study, A Report to
Congress,'' prepared for the U.S. Environmental Protection Agency by
the Cadmus Group, Inc., under Contract Number 68-D2-0168, February
1995.

NO_Xis also a primary precursor to atmospheric ozone
(O₃). (Volatile organic compounds (VOC), composed of a very large
number of different hydrocarbons (HC) and other organic compounds, are
also primary precursors to ozone. Their effects as a class of compounds
on health are generally considered in terms of ozone health effects;
health implications of individual toxic compounds are not separately
addressed in this Notice.) The rate of ozone creation depends on highly
complex interactions between VOCs and NO_Xin the presence of
sunlight. However, in areas with high VOC to NO_Xratios, which
includes most of the area covering the eastern United States, ozone
formation is NO_Xlimited, and NO_Xreductions will reduce
ozone levels. Areas with lower VOC to NO_Xratios (particularly the
core of many large highly urbanized nonattainment areas) are VOC
limited and NO_Xemissions will interact with ozone to reduce ozone
levels. However, in NO_Xlimited areas, downwind of these same
areas, NO_Xreductions will reduce ozone levels.
Ozone is a highly reactive chemical compound which can affect both
biological tissues and man-made materials. Ozone can affect human
pulmonary and respiratory health--symptoms include chest pain,
coughing, and shortness of breath.9 Studies, to date, indicate
that at the current standard these effects are reversible when exposure
stops.

\9\ Air Quality Criteria Document for Ozone and Related
Photochemical Oxidants (External Review Draft), EPA-600/AP-93/004ac,
February, 1995 (NTIS #: PB94-17-3127, -3135, -3143).
The presence of elevated levels of ozone is of concern in rural
areas as well. Because of its high chemical reactivity, ozone causes
damage to vegetation. Estimates based on experimental studies of the
major commercial crops in the U.S. suggest that ozone may be
responsible for significant agricultural crop yield losses. In
addition, ozone causes noticeable leaf damage in many crops, which
reduces marketability and value. Finally, there is evidence that
exposures to ambient levels of ozone which exist in many parts of the
country are also responsible for forest and ecosystem damage. Such
damage may be exhibited as leaf damage, reduced growth rate, and
increased susceptibility to insects, disease, and other environmental
stresses and has been reported to occur in areas that attain the
current standard. There are complexities associated with evaluating
such effects due to the wide range of species and biological systems
introduce significant uncertainties.

B. Health and Other Effects Related to Particulate Matter 10

Air pollutants collectively called particulate matter (PM) include
dust, dirt, soot, smoke and liquid droplets directly emitted into the
air by sources such as factories, power plants, cars, trucks,
woodstoves/fireplaces, construction activity, forest fires,
agricultural activities such as tillage, and natural windblown dust.
Particles formed secondarily in the atmosphere by condensation or the
transformation of emitted gases such as SO₂, NO<INF>X, and VOCs
are also considered particulate matter.

\10\ Information cited in this section and other related
information on the health effects of particulate matter are
available for the public from Docket A-95-27.

Based on studies of human populations exposed to high
concentrations of particles (sometimes in the presence of SO₂),
and laboratory studies of animals and humans, there are major human
health concerns associated with PM. These include deleterious effects
on breathing and respiratory systems, aggravation of existing
respiratory and cardiovascular disease, alterations in the body's
defense systems against foreign materials, damage to lung tissue,
carcinogenesis, and premature death. The major subgroups of the
population that appear to be most sensitive to the effects of
particulate matter include individuals with chronic obstructive
pulmonary or cardiovascular disease,

[[Page 45583]]
those with influenza, asthmatics, the elderly, and children.
Particulate matter also soils and damages materials, and fine particles
are a major cause of visibility impairment in the United States.11

\11\ Air Quality Criteria for Particulate Matter (External
Review Draft), EPA-600/AP-95/001a-c, April 1995 (NTIS #PB95-22-1727,
-1735, -1743).

C. Need for NO_Xand VOC Control; Ozone and Other Air Quality
Management Issues

States are obligated under the Clean Air Act to submit State
Implementation Plans (SIPs) demonstrating how each nonattainment area
will reach attainment of the ozone NAAQS. For nonattainment areas
designated as serious or worse, this obligation involves the use of
photochemical grid modeling (e.g., Urban Airshed Modeling, or UAM) for
each nonattainment area. Although these attainment demonstrations were
due November 15, 1994, the magnitude of this modeling task, especially
for areas which are significantly affected by transport of ozone and
precursors generated outside of the nonattainment area, has delayed
many states in submitting complete modeling results.
Recognizing these challenges, EPA recently issued guidance on ozone
demonstrations,12 based on a two-phase approach for the submittal
of ozone SIP attainment demonstrations. Under the first phase, the
state is required to submit a plan implementing a set of specific
control measures to obtain major reductions in ozone precursors along
with limited UAM modeling. The second phase includes a two-year process
during which EPA, the states, regional associations, and other
interested parties can improve emission inventories and modeling and
better assess regional and local impacts and control strategies on
ozone attainment. These analyses are then to be used by states as their
basis for demonstrating ozone attainment plans in their phase II SIPs.

\12\ Memorandum from Mary D. Nichols, Assistant Administrator
for Air and Radiation, to EPA Regional Administrators, re Ozone
Attainment Demonstrations, March 2, 1995.
Modeling results already available and the need for two-phased
ozone attainment plans highlight the fact that ozone pollution is a
regional problem, not simply a local or state problem. Ozone itself and
its precursors are transported long distances by winds and
meteorological events. Thus, achieving ozone attainment for an area and
thereby protecting its citizens from ozone-related health effects often
depends on the ozone and/or precursor emission levels of upwind areas.
Local stationary source NO_Xand VOC controls will assist
nonattainment areas toward their ozone reduction goals, but for many
areas with persistent ozone problems, attainment of the ozone NAAQS
will require broader control strategies for both NO_Xand VOC. As a
result, effective national ozone control requires an integrated
strategy which combines cost-effective approaches in both the mobile
and stationary source arenas at both the local and national levels.
The rate of ozone creation depends on highly complex interactions
between VOCs and NO_Xin the presence of sunlight. While regional
concentrations and transport of precursor pollutants have a significant
role in determining the rate of ozone production in many areas, local
conditions are also important and may be predominant factors in some
cases. Generally, the formation of ozone in locations with low VOC to
NO_Xratios tends to be VOC limited. Low VOC to NO_Xratios are
characteristic of the central core of many highly urbanized
nonattainment areas, which may thus be dependent on VOC control for
effective ozone reduction. On the other hand, in areas with higher VOC
to NO_Xratios, ozone formation is NO_Xlimited, and NO_X
reduction strategies are required for effective ozone control. Such
conditions occur over broad regions of the U.S., including many areas
downwind of large urban centers. As concluded in a recent report by the
National Research Council (NRC), ``the optimal set of controls relying
on VOCs, NO<INF>X, or, most likely, reductions of both, will vary from
one place to the next.'' 13

\13\ National Research Council. Rethinking the Ozone Problem in
Urban and Regional Air Pollution. National Academy Press,
Washington, D.C., 1991.

While both NO_Xand VOC emissions are subject to various
stationary and mobile source regulations, VOCs have often been the
primary focus of past ozone abatement strategies, and specific air
quality issues regarding NO_Xemissions have received somewhat less
attention. Accordingly, the next sections describe some of the key
regional ozone and other air quality problems around the country for
which additional NO_Xcontrols will be beneficial.

Eastern United States
There is a growing body of evidence that reduction of regional
ozone levels holds the key to the ability of a number of the most
seriously polluted areas in the Eastern United States, in both the
Southeast and the Northeast, to meet the ozone NAAQS. Regional Oxidant
Modeling (ROM) studies conducted by EPA (called the ROMNET and Matrix
studies 14) strongly suggest that reducing NO_Xemissions is
the most effective approach for reducing ozone over large geographical
areas. (In contrast, as described below, local NO_Xcontrols may or
may not be helpful in individual nonattainment areas.) At the same
time, these studies, as well as ongoing UAM modeling by states, suggest
that reduction in VOC emissions may be key to reducing locally
generated peak ozone concentrations. Additional NO_Xcontrol will
also contribute to addressing the problems of year-round NO_X
deposition in the Chesapeake Bay and other nitrogen-limited estuaries
15 and acid rain in the eastern part of the country.

\14\ See Regional Ozone Modeling for Northeast Transport
(ROMNET), EPA Doc. EPA-450/4-91-002a (June 1991), and Chu, S.H.,
E.L. Meyer, W.M. Cox, R.D. Scheffe, ``The Response of Regional Ozone
to VOC and NO_XEmissions Reductions: An Analysis for the
Eastern United States Based on Regional Oxidant Modeling,''
Proceedings of U.S. EPA/AWMA International Specialty Conference on
Tropospheric Ozone: Nonattainment and Design Value Issues, AWMA TR-
23, 1993.
\15\ Deposition of Air Pollutants Into the Great Waters: First
Report to Congress, EPA-453/r-93-055, May 1994.

In its analysis supporting the approval of a Low Emission Vehicle
program in the eastern and northeast states comprising the Ozone
Transport Region (OTR),16 EPA reviewed existing work and performed
new analysis to evaluate in detail the degree NO_Xcontrols are
needed.17 These studies showed that 50-75 percent reductions in
NO_Xfrom 1990 levels would be needed throughout the OTR. These
studies also showed that 50-75 percent reductions in VOC would be
needed in and near the portion of the OTR comprising the Northeast
urban corridor. The studies also concluded that transport of ozone and
precursors from upwind areas is a significant contributor to ozone
exceedances downwind in essentially all nonattainment areas in the OTR.

\16\ Maine, New Hampshire, Vermont, Massachusetts, Rhode Island,
Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland,
District of Columbia, and northern Virginia.
\17\ Environmental Protection Agency, Low Emission Vehicle
Program for Northeast Ozone Transport Region; Final Rule, 60 FR
48673, January 24, 1995.

More recently, three new studies have become available which
confirm the conclusions of the earlier studies. In one of these, the
Agency performed new ROM analyses evaluating the eastern third of the
U.S. and southern Canada.18

[[Page 45584]]
Taken together, these studies strongly support the view that NO_X
emission reductions in the range of 50-75 percent will be needed in
each state in the OTR and VOC reductions in the range of 50-75 percent
will be needed in and near the Northeast urban corridor to reach and
maintain attainment.

\18\ Environmental Protection Agency, ``Summary of EPA Regional
Oxidant Model Analyses of Various Regional Ozone Control
Strategies,'' November 28, 1994; Kuruville, John et al., ``Modeling
Analyses of Ozone Problem in the Northeast,'' prepared for EPA, EPA
Document No. EPA-230-R-94-108, 1994; Cox, William M. and Chu, ShaoHung,
``Meteorologically Adjusted Ozone Trends in Urban Areas: A
Probabilistic Approach,'' Atmospheric Environment, Vol. 27B, No. 4,
pp 425-434, 1993.
2. Other Regions
A recent Southern Oxidant Study (SOS) report 19 describes the
results of research showing that, in the south, relatively high
concentrations of ozone accumulate in both rural and urban areas.
Although the rural ozone levels tend to be lower than in urban areas,
and are generally in compliance with the current ozone NAAQS, the rural
ozone concentrations are still high enough to inhibit photosynthesis,
thus reducing agricultural yields and causing damage to forests and
ornamental plants.

\19\ The State of the Southern Oxidant Study (SOS): PolicyRelevant
Findings in Ozone Pollution Research, 1988-1994. North
Carolina State University, April 1995.

These rural concentrations of ozone and its precursors create a
relatively high ozone background on which the ozone plumes from
stationary and area sources in urban areas are superimposed. As a
result, modeling in the Atlanta metropolitan area, designated as a
serious ozone nonattainment area, suggests that a 90 percent decrease
in NO_Xemissions will be required to achieve the current NAAQS in
Atlanta.
Modeling studies performed to date for the states surrounding Lake
Michigan (Wisconsin, Illinois, Indiana, and Michigan) indicate that
reducing ozone transported into this region has a significant effect on
the number and stringency of local control measures likely to be needed
to meet the ozone NAAQS. Without such reductions, these studies suggest
that the necessary degree of local control will be very difficult to
achieve. The EPA Matrix study referenced above also indicates that
NO_Xcontrol will be effective in reducing regional ozone in the
Midwest. This suggests that new reductions in NO_Xemission will be
helpful in meeting the NAAQS in the Lake Michigan area, even though
NO_Xcontrol in the immediate vicinity of and within major
nonattainment areas near Lake Michigan do not appear to contribute to
attainment in these areas.
The ozone SIP that the State of California has submitted to EPA for
approval relies on NO_Xand VOC reductions for most California
nonattainment areas to demonstrate compliance with the NAAQS.
Specifically, the revised SIP projects that the following NO_X
reductions will be required: South Coast, 59 percent; Sacramento, 40
percent; Ventura, 51 percent; San Diego, 26 percent; and San Joaquin
Valley, 40 percent. For VOC, the required reductions will be the
following: South Coast, 79 percent; Sacramento, 38 percent; Ventura, 48
percent; San Diego, 26 percent; and San Joaquin Valley, 40 percent.
Transported ozone and precursor emissions are also an important factor
in California's need for additional NO_Xcontrols.20

\20\ In addition, the revised SIP concludes that secondary
formation of nitrate particulate from NO_X(primarily ammonium
nitrate) contributes to the particulate problem in the South Coast
Air Basin and the San Joaquin Valley. Reduction of this fraction of
the total PM will require additional NO_Xemission reductions.

The Agency requests comment on these studies and the application of
their findings to the planned actions in this Notice as well as any
additional data or analysis that would inform any future actions.
4. Waivers of Local Stationary Source NO_XControl Requirements
In some cases, states with nonattainment areas subject to NO_X
Reasonably Available Control Technology (RACT) requirements for
stationary sources have petitioned EPA for a waiver from these
requirements. EPA guidance on such waivers provides that waivers may be
granted if states show that reducing NO_Xin a nonattainment area
would not contribute to attainment of the ozone NAAQS within the same
nonattainment area.21 EPA's policy is to limit the assessment of
the petitions to the effect that NO_Xreductions within a
nonattainment area have on that specific area's ability to meet the
NAAQS (i.e., an assessment of pollutant transport outside the area is
not made). EPA has separate authority under the CAA to require a state
to reduce emissions from sources where there is evidence showing that
such emissions would contribute significantly to nonattainment or
interfere with maintenance of attainment in other states.

\21\ ``Section 182(f) Nitrogen Oxides (NO_X) Exemptions--
Revised Process and Criteria,'' EPA Memo from John S. Seitz,
Director, OAQPS, to Regional Air Directors, February 8, 1995.

EPA's approval of a NO_Xexemption is granted on a contingent
basis.22 That is, a monitoring-based exemption lasts for only as
long as the area's monitoring data continue to demonstrate attainment
and a modeling-based exemption lasts for only as long as the area's
modeling continue to demonstrate attainment without NO_Xreductions
from major stationary sources.23

\22\ ``Section 182(f) Nitrogen Oxides (NO_X) Exemptions--
Revised Process and Criteria,'' EPA Memo from John S. Seitz,
Director, OAQPS, to Regional Air Directors, May 27, 1994.
\23\ NO_XSupplement to the General Preamble, 57 FR 55628
(Nov. 25, 1992).

Given these circumstances, EPA's approval of NO_Xwaivers for
certain areas should not be viewed as contradictory to the
consideration of regional and national measures to reduce NO_X
emissions. As discussed above, new regional and/or national NO_X
controls are needed to obtain the NAAQS designed to protect the public
health.
5. National NO_Xand VOC Emissions Trends 24

\24\ For today's notice, EPA has assembled data available to
date projecting emissions from various sources into the future. The
data comes from the EPA ``Trends Document'' (National Air Pollutant
Emission Trends, 1900-1993, EPA-454/R-94-027, October 1994), MOBILE5
emissions modeling, and work performed under EPA's contract with
E.H. Pechan and Associates. EPA expects to continue to revise and
improve its projections of emissions and will discuss and rely on
such updated information in future rulemakings.

Figure 1 displays projected total NO_Xemissions over the time
period 1990 to 2020 as well as stationary and mobile source components
over the same period. Figure 2 presents similar data for VOC emissions
for the period 1990 to 2010 (later-year projections for VOC are under
development).25 As the figures show, a similar pattern is
projected for both of these ozone precursor emissions. Initially, the
projections indicate that the national inventories will decrease over
the next few years as a result of continued implementation of existing
CAA stationary and mobile-source NO_Xcontrol programs. After the
year 2000, however, as the implementation of new CAA programs is
completed and the

[[Page 45585]]
pressure of growth continues, these downward trends are expected to
reverse, and national VOC and NO_Xemissions are both expected to
rise again.

\25\ The data in these and the succeeding figures in this ANPRM
take into account the expected effects of various CAA control
programs which have been promulgated to date, including Tier I
tailpipe standards, new evaporative emission test procedures,
enhanced inspection and maintenance requirements, reformulated
gasoline, oxygenated fuels, and California LEV (Low Emission
Vehicle) requirements. Nonroad NO_Xemission projections also
reflect the future effects of existing nonroad emission regulations.
The potential effects of contemplated National LEV requirements are
not reflected in the data. In these figures, nonroad emission data
includes emissions from a broad range of off-highway sources
including, locomotives, aircraft and marine vessels.

Figures 1 and 2 present emissions data for the entire country. In
nonattainment areas, the fraction of NO_Xand VOC total emissions
contributed by mobile sources on average is greater than in the
nationwide assessment and is in excess of the stationary source
contribution.

BILLING CODE 6560-50-P

[[Page 45586]]
<GRAPHIC><TIFF>TP31AU95.000

[[Page 45587]]
<GRAPHIC><TIF1>TP31AU95.001

BILLING CODE 6560-50-C

[[Page 45588]]

D. Need for PM Control; PM Air Quality Issues and Emission Trends

The overwhelming proportion of PM-10 emissions is created by wind
erosion, accidental fires, fugitive dust emissions (from road surfaces,
agricultural tilling, construction sites, etc.), and other
miscellaneous sources. As much as 85 percent of PM-10 in nonattainment
areas can be composed of these ``crustal'' and miscellaneous materials.
Since these sources are not readily amenable to regulatory standards
and controls, when considering the need for PM controls it is
appropriate to focus on the ``controllable'' portion of the particulate
pollution problem. The result is shown in Figure 3, which displays
national trends in PM-10 levels from stationary and mobile sources,
projected for the twenty year period 1990 to 2010. Similar to the
pattern discussed above for VOC and NO_Xemissions, the figure
shows that total PM from these sources will decline slightly as the
beneficial effects of the 1990 CAA Amendments continue to be felt.
However, in the absence of additional controls, mobile source and
industrial source emissions of PM-10 levels are expected to rise after
2000.

BILLING CODE 6560-50-P

[[Page 45589]]
<GRAPHIC><TIF2>TP31AU95.002

BILLING CODE 6560-50-C

[[Page 45590]]

Currently, there are 44 PM-10 nonattainment areas in 18 states.
More generally, diesel emissions contribute significantly to higher
than average PM levels that tend to occur in high-population, hightraffic
urban settings. These areas frequently have elevated ambient
levels of other air pollutants as well. To the extent that higher PM
exposures result from these factors, control of PM emissions from
diesel engines could be expected to provide public health and welfare
benefits for a relatively large number of individuals.

III. Contribution of Heavy-Duty Engines to National NO<INF>X, VOC,
and PM Emissions

Heavy-duty highway and nonroad engines contribute significantly to
levels of NO_Xand are also an important source of VOC (as a result
of HC emissions) and PM in most parts of the country. This section
describes the current and expected future role of HDEs in contributing
to the nation's major air pollution problems.

A. HDE Contribution to National NO_XEmissions

Figure 4 shows the total mobile source NO_Xinventory by
emission source (light-duty highway vehicles, heavy-duty highway
vehicles, and nonroad engines), projected over the next 25 years.

BILLING CODE 6560-50-P

[[Page 45591]]
<GRAPHIC><TIF3>TP31AU95.003

BILLING CODE 6560-50-C

[[Page 45592]]

B. HDE Contribution to National VOC Emissions

Figure 5 shows the total mobile source VOC inventory by emission
source. The figure shows that light-duty vehicle emissions can be
expected to decline for some years but then begin rising in the 2005
time frame. VOC emissions from highway heavy-duty engine and nonroad
sources are projected to rise slightly throughout this period.

BILLING CODE 6560-50-P

[[Page 45593]]
<GRAPHIC><TIF4>TP31AU95.004

BILLING CODE 6560-50-C

[[Page 45594]]

C. HDE Contribution to National PM Emissions

Projected mobile source trends for PM-10 are shown in Figure
6.26 The figure shows that, over the next 15 years, the
contribution of highway sources including HDEs to PM-10 emissions are
expected to decrease and then remain relatively constant well into the
next decade, while PM emissions from nonroad sources are expected to
increase.

\26\ Environmental Protection Agency, ``National Air Pollutant
Emission Trends, 1900-1993,'' EPA-454/4-94-027, October 1994.

BILLING CODE 6560-50-P

[[Page 45595]]
<GRAPHIC><TIF5>TP31AU95.005

BILLING CODE 6560-50-C

[[Page 45596]]

IV. The Need for New Heavy-Duty Engine Emission Control

The Agency believes several factors combine to support rulemaking
to reduce NO<INF>X, HC, and PM emissions from highway and nonroad
heavy-duty engines in the next decade. First, HDE emission controls
offer a means to address at the national level the need for new
approaches to NO<INF>X, HC, and PM reductions that is described in
Section II. As explained more fully above, local measures alone to
control NO<INF>X, HC and PM will prove insufficient if all areas of the
country are to achieve and maintain attainment of the ozone and PM
NAAQS in the years ahead. Heavy-duty engines, like other mobile
sources, represent an emissions source that crosses attainment areas
and state boundaries; trucks and buses often travel long distances
while nonroad heavy-duty engines power a variety of equipment used in
both urban and rural areas, and are often relocated to different
regions of the country as needed.
Second, the projections in Section III above show that heavy-duty
engines contribute in varying degrees to the national inventory of
NO<INF>X, HC, and PM emissions.27 Third, an effort now to
implement national HDE controls may prevent a patchwork of regulation
where some states require HDE controls while other states do not.
Indeed, engine manufacturers felt it was very important that the new
program which EPA expects to propose regarding highway HDEs (see
Section VII below) provide for the harmonization of requirements
between EPA and CARB, resulting in a single set of heavy-duty standards
applicable in all 50 states. A national program thus appears to offer
the most efficient way for states, engine manufacturers, and EPA to
implement additional HDE controls. Fourth, since states must soon
finalize SIPs demonstrating attainment in the years ahead, action on
additional HDE controls will allow states to incorporate the expected
reductions from HDE controls in their SIPs.

\27\ For PM emissions, the projections show that the mobile
source contribution is growing; available data shows that heavy-duty
highway and nonroad engines represent significant fractions of
mobile source emissions.

Fifth, with respect to highway HDEs, cost effective technology
options now appear to be within reach which can achieve very large
NO_Xemission reductions from new highway HDEs manufactured in
model year 2004 and subsequent years (see Section VIII below for a more
detailed discussion of this issue). The Agency is optimistic that, with
continued investment in research and development by the highway HDE
manufacturers, and with cooperation between EPA, CARB, the
manufacturers, and the oil refining industry, technological barriers
which have prevented NO_Xemissions from diesel HDEs from reaching
levels characteristic of gasoline engines will be overcome. For the
benefits of these NO_Xreductions to be realized to a significant
degree in the next decade, the Agency believes that this work must
begin soon.
Finally, with respect to nonroad heavy-duty engines, EPA believes
that there is the potential to apply current highway HDE emission
control technology to many nonroad HDEs, providing an avenue for
significant additional mobile source emission reductions. Only recently
have the first emission controls been applied to heavy-duty nonroad
engines, and standards are currently set at levels significantly higher
than current highway heavy-duty engine standards. While control of some
or all nonroad heavy-duty engines raises special issues such as the
lack of a vehicle registration system and the potential difficulty of
``packaging'' engines on a variety of equipment types, many engines
used in highway trucks have similar counterparts that are used in
nonroad equipment applications. It therefore makes sense to explore
ways to apply highway HDE emission control technology to nonroad HDEs.
The Agency is interested in comment on the role of NO_X
emissions in contributing to high ozone levels over broad areas and the
need for national HDE controls to address NO_Xand ozone levels. In
addition the Agency solicits comment on other approaches such as local
and regional controls.

V. Background on Highway Heavy-Duty Engine Standards

Under EPA's classification system, vehicles with a gross vehicle
weight rating (GVWR) over 8,500 pounds are considered heavy-duty
vehicles. (The State of California classifies the lighter end of EPA's
heavy-duty class as ``medium-duty vehicles.'') Heavy-duty engines are
used in a wide range of heavy-duty vehicle categories, from small
utility vans to large trucks. Because one type of heavy-duty engine may
be used in many different applications, EPA emission standards for
heavy-duty vehicles are based on the emissions performance of the
engine (and any associated aftertreatment devices) separate from the
vehicle chassis. Testing of a heavy-duty engine consists of exercising
the engine over a prescribed duty cycle of engine speeds and loads
using an engine dynamometer.
Emissions from heavy-duty engines are measured in grams of
pollutant per brake horsepower-hour (g/bhp-hr) or, in more recent
regulations, in grams per kilowatt hour (g/kw-hr). These units for
emission rates recognize that the primary purpose of heavy-duty engines
is to perform work and that there is a large variation in work output
among the engines used in heavy-duty applications. Under this system,
standards per unit of work are the same for all heavy-duty engines.
Emission standards have been in place for highway diesel and
gasoline heavy-duty engines since the early 1970s. The first
regulations focused on control of emissions of smoke. Subsequent
regulations broadened emission control requirements to include gaseous
and particulate emissions. The 1990 amendments to the Clean Air Act
required EPA to set more stringent standards for NO_Xemissions
from all heavy-duty highway engines and for PM from buses. 42 U.S.C.
7521(a)(3), 7521(f), 7554(b).
The current exhaust emission standards for highway heavy-duty
diesel and gasoline engines are presented in Table 1. Standards for
``urban buses'' (large transit buses), which specify more stringent PM
levels than those applying to other heavy-duty engines, are displayed
separately in the table.

[[Page 45597]]

Table 1.--Highway Heavy-Duty Emission Standards

Oxides of Diesel

Year Hydrocarbons (g/ Carbon Monoxide nitrogen (g/bhp- particulate (g/

bhp-hr) (g/bhp-hr) hr) bhp-hr)

Diesel:

1991-93......................... 1.3 15.5 5.0 0.25
1994-97......................... 1.3 15.5 5.0 0.10
1998............................ 1.3 15.5 4.0 0.10

Urban buses:

1991-92......................... 1.3 15.5 5.0 0.25
1993............................ 1.3 15.5 5.0 0.10
1994-95......................... 1.3 15.5 5.0 0.07
1996-97......................... 1.3 15.5 5.0 *0.05
1998............................ 1.3 15.5 4.0 *0.05

Gasoline:
1991-97:

(A)............................. 1.1 14.4 5.0 4.0
(B)............................. 1.9 37.1 5.0 4.0

1998:

(A)............................. 1.1 14.4 4.0 3.0
(B)............................. 1.9 37.1 4.0 4.0

Note: ``(A)'' denotes the standard for engines in trucks <ls-thn-eq> 14,000 lbs. GVWR.
``(B)'' denotes the standard for engines in trucks <gr-thn-eq> 14,000 lbs. GVWR.
*.07 g/bhp-hr in-use.

Under Section 202(a)(3), emission standards for heavy-duty highway
engines are set at the ``greatest degree of emission reduction
achievable through the application of technology which the
Administrator determines will be available for the model year to which such standards apply, giving appropriate consideration to cost, energy,
and safety factors associated with the application of such technology''
(42 U.S.C. 7521(a)(3)(A)). In addition, Section 202(a)(3) provides that
highway heavy-duty engine manufacturers will have four model years of
lead time before any new emission standards may be implemented (42
U.S.C. 7521(a)(3)(C)). The Act also provides that standards for heavyduty
engines apply for at least three model years to provide stability
to any heavy-duty standards. Id. Finally, the Act precludes new
NO_Xemission standards for heavy-duty highway engines before the
model year 2004. 42 U.S.C. 7521(b)(1)(C).

VI. Summary of Public Support for EPA To Take Action

Several states, public interest groups and environmental
organizations, trucking associations, and others have strongly
encouraged EPA to pursue additional NO<INF>X, HC, and PM emissions
reductions from HDEs through national programs. The Agency has received
numerous letters encouraging EPA to move forward with a national
program to reduce heavy-duty engine emissions. In December of 1994,
several organizations including the American Lung Association and the
Natural Resources Defense Council sent a letter to the EPA Assistant
Administrator for Air and Radiation requesting that EPA tighten the
heavy-duty engine standards to 0.05 g/bhp-hr for particulates and 2.0
g/bhp-hr for NO<INF>X.28 Jim Edgar, Governor of Illinois, sent a
letter to U. S. Senator Paul Simon in March of 1995, urging him to
request that EPA implement national rules to reduce ozone precursor
emissions from, among other sources, heavy-duty engines. The California
Air Resources Board signed a Memorandum of Understanding with EPA in
April, 1995 to undertake joint efforts in support of EPA's development
of a national program for the control of NO<INF>X, PM, and HC emissions
from heavy-duty engines. In addition, the ozone SIP submitted by the
State of California relies on EPA to set national standards for highway
heavy-duty engines at the level of 2.0 g/bhp-hr and requests such
action. During May and June of 1995 the Administrator received letters
from the State and Territorial Air Pollution Program Administrators/
Association of Local Air Pollution Control Officials (STAPPA/ALAPCO),
the Northeast States for Coordinated Air Use Management (NESCAUM), and
the Mid-Atlantic Regional Air Management Association (MARAMA) on behalf
of their member states, requesting that EPA implement new national
controls for heavy-duty engine emissions. The Northeast Ozone Transport
Commission adopted a resolution on June 13, 1995 supporting EPA's
efforts to control diesel engine emissions. EPA also received support
for reducing the heavy-duty engine NO_Xstandard from the
Manufacturers of Emission Controls Association (MECA). On June 22,
1995, the Appalachian Mountain Club, a conservation and recreation
group with 65,000 members in eleven regional areas, sent a letter to
the Administrator that supports EPA's initiative as critical for
controlling ozone, PM, acid deposition, and regional haze in the
Northeast. In addition to written requests, EPA has received numerous
positive comments from concerned individuals, municipalities, and other
organizations endorsing a new national control program to reduce
emissions from heavy-duty engines.

\28\ Copies of all letters cited and received to date can be
obtained from Docket A-95-27, as described at the beginning of this
Notice.

VII. Summary of Government/Industry Statement of Principles

EPA initiated discussions with engine manufacturers, California's
Air Resources Board (CARB), and others to begin to explore what
additional controls could be implemented to further reduce emissions
from heavy-duty engines. As a result of these discussions, EPA,
individual members of the highway heavy-duty engine industry, and CARB
have signed a Statement of Principles (SOP) regarding future highway
HDE emission reductions. The manufacturer signatories 29 represent
more than 95 percent of sales by the highway heavy-duty engine
industry. With this SOP, presented in its entirety as an Appendix to
this notice, the heavy-duty engine

[[Page 45598]]
industry has stepped forward to become a leader in environmental
protection, and industry and government will work as partners to bring
about cleaner air. The following presents a summary of the key elements
of this Statement of Principles.

\29\ Caterpillar, Inc., Cummins Engine Company, Inc., Detroit
Diesel Corporation, Ford Motor Company, General Motors Corporation,
Hino Motors, Ltd., Isuzu Motors America, Inc., Mack Trucks, Inc.,
Mitsubishi Motors America, Inc., Navistar International, and Volvo
Truck Corporation.

The goal of all Signatories to the SOP is to reduce NO_X
emissions from highway HDEs to levels approximating 2.0 g/bhp-hr
beginning in model year (MY) 2004, while also achieving reductions in
HC. Accordingly, the Signatories concur that EPA would issue a notice
of proposed rulemaking (NPRM) proposing to implement (1) a combined
NO_Xplus non-methane hydrocarbon (NMHC) standard of 2.4 g/bhp-hr
and (2) a combined NO_Xplus NMHC standard of 2.5 g/bhp-hr together
with a NMHC cap of 0.5 g/bhp-hr, with flexibility for an engine family
to comply with either of these standards as the manufacturer
determines. The Signatories expect that these standards will result in
emissions comparable to a NO_Xstandard of 2.0 g/bhp-hr as well as
reduced NMHC emissions. In order to facilitate the rulemaking process
and solicit additional views, the SOP Signatories concur with EPA's
desire to precede the issuance of the NPRM with this ANPRM.
The Signatories acknowledge that fuel composition 30 has a
significant effect on emissions, and commit to making improvements in
HDE fuel as appropriate under the CAA to meet the MY2004 emission
standards, taking into consideration costs and other relevant factors.
The Signatories also recognize that any changes to both certification
and commercial fuel specifications would have to become effective no
later than October 2003 to ensure fuel availability at the time the
MY2004 engine standards would go into effect.

\30\ Representatives of the fuel industry are not parties to
this agreement as noted above. EPA will continue to engage the fuel
industry in discussions as we proceed to implement the SOP,
including identifying formal ways to cooperate with all parties
affected by potential heavy-duty engine changes.

In accordance with the SOP, EPA would in 1999 review any rulemaking
adopting the MY2004 standards by issuing a notice providing the
opportunity for public comment on whether or not the MY2004 standards
are technologically feasible and otherwise appropriate under the CAA.
EPA would review the need, feasibility, and cost of the standards under
the criteria imposed by the CAA, and would assess whether any fuel
improvements that are needed to assist heavy-duty engines in complying
with the MY2004 standards would be available nationwide by the
appropriate date. After receiving public comment, EPA would take final
Agency action. Depending on the results of EPA's review, the MY2004
standards would remain at the levels described above or EPA would
propose to adjust them. The Signatories expect any adjustment of the
standards would not exceed (1) 2.9 g/bhp-hr NO_Xplus NMHC and (2)
3.0 g/bhp-hr NO_Xplus NMHC with a proportional increase in the
NMHC cap (to 0.6 g/bhp-hr), unless improvements to fuel quality are
needed but not made.
Both EPA and California recognize in the SOP the benefits of
harmonizing state and federal regulations regarding highway HDEs.
California confirms its intent to hold a public hearing regarding
harmonization of its regulations for dynamometer-certified engines
greater than 8500 lbs. GVWR with the federal regulations adopted under
the SOP, provided such action would not compromise California's
obligations to comply with state and federal law.
Neither PM nor CO emission standards change under the SOP. Also,
the SOP is premised on the assumption that EPA will not alter federal
test procedures for heavy-duty highway engines. With respect to
durability, the Signatories commit to work to develop appropriate
measures which ensure that emission gains are maintained in-use.
As part of the SOP, EPA and CARB commit to work cooperatively with
industry to develop improved averaging, banking, and trading programs
that will create more incentive for early introduction of cleaner
engines. At a minimum EPA would, in the NPRM on the MY2004 standards,
propose to eliminate any limitations on credit life, propose to
eliminate all credit discounts, and solicit comment on the merits of
allowing cross-fuel, cross-subclass, and cross-category credit
exchanges, to the extent permitted under the CAA.
A key purpose of the SOP is to provide the HDE industry with
increased certainty and stability for their business planning. Without
such certainty and stability, industry would not commit to the enormous
investment that the SOP standards will require. EPA and CARB in turn
acknowledge that industry will be making a commitment and investment
that will require more than the minimum period of stability of three
years set forth in the CAA.
The SOP also outlines a plan to undertake a joint industry/
government research program with the goal of developing engine and fuel
technologies which can meet and exceed the MY2004 standards. Pursuant
to a separate research agreement, the SOP Signatories and possibly
others will try to reduce NO_Xemissions to 1.0 g/bhp-hr and PM
emissions to 0.05 g/bhp-hr while maintaining current highway diesel
engine attributes such as performance, reliability, durability, safety,
and efficiency.
Finally, while the SOP focuses on highway HDEs, the SOP Signatories
commit to participate in discussions with nonroad HDE and equipment
manufacturers to develop a separate SOP by October 1995 addressing
emission standards for nonroad HDEs.
The SOP plan offers a flexible means of achieving a 50 percent
reduction in NO_Xemissions from the 4.0 g/bhp-hr NO_Xstandard
that goes into effect beginning in model year 1998. Figure 7 shows the
estimated national NO_Xinventory for highway heavy-duty engines
with and without the potential control measures articulated in the SOP.
These projections are based on preliminary analysis of available
information and subject to revision as EPA continues to analyze such
factors as the future growth and turnover of the heavy-duty fleet, inuse
emission performance, expedited or delayed introduction of new
emission reduction technology and other factors.

BILLING CODE 6560-50-P

[[Page 45599]]
<GRAPHIC><TIF6>TP31AU95.020

BILLING CODE 6560-50-P

[[Page 45600]]

For hydrocarbons, EPA expects the NMHC plus NO_Xstandards in
the SOP to be equivalent to about half or less of the current HC
standards (1.3 g/bhp-hr for diesel engines and 1.1-1.9 g/bhp-hr for
gasoline engines). Further, the standards ensure continued control of
PM emissions from highway HDEs at current levels (0.1 g/bhp-hr),
despite a tendency for PM emissions from diesel HDEs to increase when
NO_Xemissions decrease. Ambient PM reductions may also result from
the NO_Xemission reductions, since NO_Xcontributes to
secondary particulate.
EPA will actively seek to work with both the Signatories to the SOP
and the oil refining industry to evaluate the role of fuel improvements
in achieving the MY2004 standards. EPA believes the joint industry/
government research program with the goal of achieving highway HDE
emissions of just 1.0 g/bhp-hr NO_Xand 0.05 g/bhp-hr PM offers an
unusual opportunity to work collaboratively for the benefit of the
environment. EPA will also continue discussions with the Signatories
and others with the aim of achieving an SOP on nonroad heavy-duty
engines comparable to this SOP regarding highway heavy-duty engines.

VIII. Approaches to Highway Heavy-Duty Engine Emission Control

Highway heavy-duty engine manufacturers are engaged in ongoing
efforts to design and produce the cleaner engines envisioned in the
SOP. As with any motor vehicle engine technology, control of emissions
from heavy-duty highway engines can come from changes in the design of
engines and related hardware, changes to fuels, or some combination of
the two. While EPA and the engine manufacturing industry are not yet
certain which types of technologies in which combinations might be
necessary for manufacturers to reach the standards under consideration,
several promising approaches have been identified to date. EPA has
prepared a document that describes the causes of highway HDE emissions
and several engine-based approaches and exhaust aftertreatment devices
to control emissions. This document is available in Docket A-95-27.
Changes in engine technology or aftertreatment which can reduce HC,
NO_Xand PM emissions must be evaluated with respect to, and bear a
close relationship to, the fuel composition the engines will be using.
The petroleum industry has changed fuels a number of times in the past
either to reduce the emissions from existing vehicles (e.g., gasoline
volatility, reformulated gasoline) or to make it possible for engine
manufacturers to employ new engine designs or emission control
technologies that are sensitive to fuel characteristics (e.g., unleaded
gasoline to facilitate the use of catalytic converters, low-sulfur
diesel). EPA intends to work jointly with the petroleum industry and
the highway HDE manufacturers to develop emission and cost data to help
EPA assess the potential role of fuel changes in achieving the
standards set forth in the SOP (Section VII above). EPA request comment
on the planned approach for assessing the potential role of fuels. In
addition, engines designed to use non-petroleum alternative fuels may
provide another avenue for manufacturers to comply with more stringent
standards.
EPA is interested in exploring programs and approaches which have
the potential to help achieve the goals of the planned regulatory
program in the most effective ways, including cost considerations. The
Agency expects to continue a broad and open discussion of such
potential approaches. The sections below briefly discusses an initial
set of ideas which may improve this program; EPA solicits comments on
these ideas and encourages suggestions for others.

A. In-Use Emissions Control Elements

Historically, EPA has viewed in-use emissions deterioration as a
problem associated more with gasoline engines than diesel engines. EPA
believes that deterioration of emissions for diesel engines, especially
NO<INF>X, has tended to be less than that of gasoline engines because
diesel engines currently use fewer aftertreatment or other devices
susceptible to in-use degradation. Diesel engine emissions standards
have historically been met mainly through overall improvements to the
engine and fuel system. These improvements have provided performance,
fuel economy, and durability benefits as well.
As standards are reduced and diesel HDE manufacturers introduce new
technologies such as catalysts and exhaust gas recirculation (EGR)
solely for emissions control purposes, long-term emissions performance
becomes a greater concern. The controls may not function as long as the
engines and there may be little incentive for vehicle owners to conduct
the repairs on these items needed to ensure emissions control during
the very long life of the engines. The HDE engine market has demanded
longer-lasting engines, and manufacturers have been successful in
increasing engine life. It has been brought to EPA's attention that
some current engines accumulate in excess of 600,000 miles before the
first rebuild and are often rebuilt many times; the current regulatory
``useful life'' is 290,000 miles. Failure of emissions controls early
in the engine's life would offset much of the benefit associated with
the expected more stringent standards.
Programs which encourage manufacturers to design and build engines
with very durable emission controls and programs to encourage the
proper maintenance and repair of engines and emissions controls are
important in achieving the full benefit of emissions standards. The
goal is for engines to maintain ``new'' engine performance throughout
their in-use operation. EPA is considering changes to current
manufacturer emissions durability-related programs to further encourage
the design and production of durable emission control systems. Possible
changes include extending the period over which manufacturers are
responsible for meeting emissions standards (the ``useful life'') and
adjusting the regulations relating to the emission-related maintenance
that is required of owners by manufacturers to maintain the engine's
emissions warranty. EPA is also interested in exploring a program where
manufacturers would perform in-use compliance testing and could take
advantage of an averaging, banking, and trading program to help achieve
in-use compliance. Under such a program, manufacturers would test a set
percentage of their in-use engine families each year and could
potentially generate emission credits (or take on liabilities)
depending on the results of in-use tests relative to the Family
Emission Limits established for the engine families involved. EPA
believes such a program could offer a cost-effective means of achieving
better assurance that standards are being met in-use.
Proper maintenance and repairs are likely to be important for
durable emissions controls, especially for engines designed for a
million or more miles. Therefore, EPA is also interested in approaches
that involve increased responsibility of the vehicle owner. One
approach EPA is considering and on which it invites comment is whether
the incorporation of onboard diagnostic systems for emissions
monitoring into heavy-duty engine designs would be appropriate. With
the increasing availability of sophisticated computer controls, there
is a potential to monitor emission control performance and components.
EPA is also considering establishing requirements relating to the
rebuilding of HDEs as a way of ensuring

[[Page 45601]]
that engines and emission controls remain in their proper working
condition throughout their full operating life. See 42 U.S.C.
7521(a)(3)(D).
B. Elements to Add Compliance Flexibility

EPA desires to implement any new regulatory programs in ways that
minimize the complexity and cost of compliance and maximize flexibility
for the regulated industry in complying with the requirements. EPA's
chief goal with such approaches would be to encourage the early
introduction of cleaner engines whenever possible. EPA may explore a
number of options for increasing flexibility to comply with more
stringent emissions standards for highway HDEs. The following presents
some of the ideas that EPA may consider.
Averaging, Banking and Trading Program. Currently, an averaging,
banking, and trading (ABT) program is in place for heavy-duty highway
engines which allows heavy-duty highway engine manufacturers to average
the emissions of their various engine families and to generate credits
when they introduce cleaner engine families than are required by law.
Under this program, a manufacturer may choose to certify an engine
family slightly higher or lower than the standard so long as the
average emission level for all engine families produced by the
manufacturer is at or below the standard. Credit for selling engines
that are cleaner than is required can be used immediately, ``banked''
for later use, or traded to another manufacturer.
Along with the standards discussed above, EPA expects to propose an
expanded ABT program that would apply for these new standards. Because
exceeding the requirements of the standards under consideration will be
very challenging, EPA will propose revisions to the current program
which are expected to encourage aggressive emission control development
efforts on the part of manufacturers and the early implementation of
new technology. EPA will propose changes to the ABT program which would
eliminate the discounting of credits over time and would extend the
life of the credits indefinitely. EPA will also seek comment on other
changes to the ABT programs such as trading between highway and nonroad
engines, among the four heavy-duty diesel subclasses, and between
heavy-duty diesel and gasoline engines, to the extent permitted under
the Act. Such approaches could be difficult to develop in an equitable
way given the very different emissions characteristics of these engine
types and the fact that the manufacturers' product lines vary.
Non-Conformance Penalties. In addition to the ABT program described
above, another existing program which serves to increase the
flexibility for manufacturers of heavy-duty highway engines facing new
emission standards is non-conformance penalties (NCPs). The Clean Air
Act (Section 206(g)) requires EPA to allow a heavy-duty engine
manufacturer to receive a certificate of compliance for an engine which
exceeds the standard (but does not exceed an upper limit) if the
manufacturer pays an NCP established by EPA through rulemaking. NCPs
increase periodically to discourage long-term nonconformance. EPA
expects to consider establishing NCPs related to the new heavy-duty
emission standards that EPA plans to propose.
Incentive-Based Approaches. EPA is aware of several program
initiatives that could potentially supplement the emission reductions
from improved design of new heavy-duty engines. Some of these are
described briefly in the following paragraphs. EPA encourages these
activities, and in some cases will be supporting their development. Any
actions to develop these initiatives, however, will progress in
parallel with the planned rulemaking to revise highway heavy-duty
engine emission standards, rather than being incorporated into that
rule directly.
Incentive-based approaches to emission control generally seek to
provide some credit or reward to encourage businesses to make voluntary
changes in operations or procedures to reduce air emissions. In the
case of heavy-duty engines, EPA desires incentives that would encourage
early introduction of cleaner engines. The ongoing effort to establish
these policies must focus on designing a program to ensure that a
business's emission reductions are voluntary, quantifiable, and
enforceable. Open market trading, which is currently under development
by EPA, could be designed to include the credits generated under these
programs.
One potential incentive program would encourage fleets to buy
cleaner truck engines earlier than required or buy cleaner engines than
otherwise required and make these credits available as Mobile Emissions
Reduction Credits. Another idea is to design a program to encourage
truck fleet owners to accelerate the turnover of their fleets to newer
engines. Typically, this would involve an encouragement to scrap old
engines and purchase new lower-emitting engines. Another possibility is
to rebuild heavy-duty engines with upgraded components so the ``new''
engine has the emission control capability of a more recent model year.
Other Approaches. Changes to vehicle operation may also reduce
emissions. For example, trucks are frequently allowed to idle for
several hours to power accessories such as air conditioners during
extended stops. The potential for electrical hookup at truck stops,
rest areas, etc., in combination with changes to engine and vehicle
designs, could reduce the contribution of extended idling to engine
emissions without inconveniencing drivers. Similarly, a program to
limit the operating speeds of heavy-duty vehicles, through engine
design or other changes, would reduce the excess NOx emissions caused
by vehicle operation at high speeds. The reduced fuel consumption
associated with these measures would represent a secondary benefit to
fleet owners.
Finally, EPA is working with the freight transportation industry to
identify potential infrastructure or regulatory changes that could
increase system efficiencies. Any move to improve the efficiency of
freight transportation, while reducing costs to industry, would reduce
emissions by decreasing the total mileage driven by heavy-duty trucks.

IX. Public Participation

EPA intends for this Notice to provide the basis for the beginning
of a broad-based public discussion of the issues surrounding more
stringent standards for heavy-duty highway engines presented in the
Statement of Principles signed by EPA, CARB, and heavy-duty engine
manufacturers. Specifically, the Agency requests comment on the need
for heavy-duty engine controls, the proposed timing for Agency action,
and on whether the standards and other regulatory provisions planned in
the SOP are reasonable and appropriate. EPA also requests comment on
the planned approach for dealing with fuels. The Agency requests
comment on the plan and need to pursue nonroad heavy-duty engine
standards through cooperative discussions with engine and equipment
manufacturers and CARB. The Agency also requests any emissions data,
technical information, or analyses of technical feasibility which can
be used to inform the planned actions. Finally, the Agency requests
comment and information on the economic feasibility, including cost
considerations for the planned actions.
EPA expects to issue a Notice of Proposed Rulemaking in the near
future

[[Page 45602]]
proposing new emission standards for highway heavy-duty engines in
accordance with the SOP. The Agency is committed to a full and open
regulatory process and looks forward to input from a wide range of
interested parties as the rulemaking process develops. These
opportunities will likely include meetings and workshops in addition to
the minimum required process involving a formal public comment period
and a public hearing. EPA encourages all interested parties to become
involved in this process as it develops.

X. Statutory Authority

Section 202(a)(3) authorizes EPA to establish emissions standards
for new heavy-duty motor vehicle engines. See 42 U.S.C. 7521(a)(3).
These standards are to reflect the greatest reduction achievable
through the application of technology which the Administrator
determines will be available, giving appropriate consideration to cost,
energy, and safety factors associated with the application of such
technology. This provision also establishes the lead time and stability
requirements for these standards, and in addition authorizes EPA to
establish requirements to control rebuilding practices for heavy-duty
engines. Pursuant to Sections 202(a)(1) and 202(d), these emissions
standards apply for the useful life period established by the Agency.
See 42 U.S.C. 7521(a)(1), 7521(d).
Section 213 authorizes EPA to establish emissions standards for new
heavy-duty nonroad engines where EPA determines that they cause or
contribute to ozone or carbon monoxide air pollution in more than one
area that is in nonattainment for ozone or carbon monoxide, or where
EPA determines that emissions of other pollutants significantly
contribute to air pollution which may reasonably be anticipated to
endanger public health or welfare. As with heavy-duty motor vehicle
engines, the emissions standards apply for the useful life established
by the Agency. See 42 U.S.C. 7547.
Section 211(c) authorizes EPA to establish controls or prohibitions
on fuels and fuel additives for use in highway and nonroad vehicles and
engines. EPA may issue such regulations if it determines that (1) any
emission product of the fuel or fuel additive causes or contributes to
air pollution which may reasonably be anticipated to endanger the
public health or welfare, or (2) emissions products of a fuel or fuel
additive will impair to a significant degree the performance of any
emissions control device or system which is in general use or which the
Administrator finds has been developed to a point where in a reasonable
time it would be in general use were such regulation promulgated. See
42 U.S.C. 7545(c).
EPA's authority to issue a certificate of conformity upon payment
of a non-compliance penalty established by regulations is found in
Section 206(g) of the Act. See 42.U.S.C. 7525(g). Other provisions of
Title II of the Act, along with Section 301, are additional authority
for the measures discussed in this ANPRM.

XI. Unfunded Mandates Reform Act

Under Section 202 of the Unfunded Mandates Reform Act of 1995
(``UMRA''), P.L. 104-4, EPA must prepare a budgetary impact statement
to accompany any general notice of proposed rulemaking or final rule
that includes a Federal mandate which may result in estimated costs to
State, local, or tribal governments in the aggregate, or to the private
sector, of $100 million or more. Under Section 205, for any rule
subject to Section 202 EPA generally must select the least costly, most
cost-effective, or least burdensome alternative that achieves the
objectives of the rule and is consistent with statutory requirements.
Under Section 203, before establishing any regulatory requirements that
may significantly or uniquely affect small governments, EPA must take
steps to inform and advise small governments of the requirements and
enable them to provide input.
EPA has determined that the requirements of UMRA do not extend to
advance notices of proposed rulemaking such as this notice regarding
potential controls for heavy-duty engines.

XII. Administrative Designation and Regulatory Analysis

Under Executive Order 12866 (58 FR 51735 (Oct. 4, 1993)), the
Agency must determine whether this regulatory action is ``significant''
and therefore subject to OMB review and the requirements of the
Executive Order. The order defines ``significant regulatory action'' as
any regulatory action (including an advanced notice of proposed
rulemaking) that is likely to result in a rule that may:

(1) Have an annual effect on the economy of $100 million or more
or adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or tribal governments or
communities;
(2) Create a serious inconsistency or otherwise interfere with
an action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements,
grants, user fees, or loan programs or the rights and obligations of
recipients thereof; or,
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.

This Advance Notice was submitted to the Office of Management and
Budget (OMB) for review as required by Executive Order 12866. Any
written comments from OMB and any EPA response to OMB comments are in
the public docket for this Notice.

List of Subjects in 40 CFR Parts 80, 86, and 90

Environmental protection, Administrative practice and procedure,
Air pollution control, Diesel fuel, Motor vehicles, Motor vehicles
pollution, Reporting and recordkeeping requirements, Research.

Dated: August 24, 1995.
Carol M. Browner,
Administrator.

Appendix: Statement of Principles

Statement of Principles

Members of the heavy-duty engine industry, the U.S.
Environmental Protection Agency (``EPA''), and the California Air
Resources Board (``CARB'') (collectively, the ``Signatories'')
recognize the importance of preserving the environment while
maintaining a strong industry. This Statement of Principles
(``SOP'') increases certainty and stability for the heavy-duty
engine industry which is vital for their business planning. It also
ensures cleaner air in a manner which is both realistic for industry
and responds to environmental needs. With this SOP, the heavy-duty
engine industry has stepped forward to become a leader in
environmental protection, and industry and government will work as
partners to bring about cleaner air.
This SOP outlines the joint understanding of all Signatories,
including issuance by EPA of a Notice of Proposed Rulemaking
(``NPRM'') which would be consistent with the points outlined in
this document. EPA intends to issue the NPRM in 1995 and plans to
promulgate a final rule by the end of 1996. However, this SOP does
not change the importance of EPA demonstrating the need for the
standards described below and EPA's obligation to meet the criteria
of the Clean Air Act (the ``Act'' or ``CAA'') in finalizing any
rule, including complying with all applicable rulemaking procedures.
In order to facilitate the rulemaking process and to solicit
additional views, EPA will precede the issuance of the NPRM with an
Advanced Notice of Proposed Rulemaking (``ANPRM'') announcing this
SOP.

National Standards for On-Highway Heavy-Duty Engines: For
more than two decades, as public concerns about air pollution and
smog caused by emissions from heavy-duty trucks and buses have
increased, both the industry and the government have responded to
protect public health and the environment. Standards have

[[Page 45603]]
dropped from levels of 16.0 grams per brake-horsepower/hour (``g/bhphr'')
for Hydrocarbons (``HC'')+Oxides of Nitrogen (``NO<INF>X'') in
1974 to just 5.0 g/bhp-hr NO_Xand 1.3 g/bhp-hr HC for heavyduty
diesel engines today. The NO_Xstandard will fall again to
4.0 g/bhp-hr in 1998. California also has NO_Xstandards of 5.0
g/bhp-hr for these engines today and plans to adopt the federal 4.0
g/bhp-hr standard for 1998 models.
Much of the recent focus on improving emissions from diesel
engines has centered around reducing smoke and soot from the
exhaust. Particulate matter (``PM'') standards for heavy-duty diesel
engines have dropped from 0.6 g/bhp-hr in 1988 to just 0.1 g/bhp-hr
today. The current PM standards represent a 90reduction from
unregulated levels. The 0.1 g/bhp-hr standard applies both in the
California and federal programs. Urban buses have even tighter
standards.
Heavy-duty engine manufacturers have certified vehicles to
operate on clean alternative fuels such as natural gas and methanol
and continue to research the emissions benefits of alternative and
renewable fuels. Clearly, the industry has worked hard to improve
technology and provide cleaner vehicles and engines.
However, in recent years, concern over the role of NO_Xand
HC emissions in causing ozone formation has grown considerably, and
reducing both has become an important goal. The opportunity to
reduce overall emissions of these pollutants by producing cleaner
heavy-duty engines is significant.
The goal of all Signatories to this SOP is to reduce NO_X
emissions from on-highway heavy-duty engines to levels approximating
2.0 g/bhp-hr beginning in 2004. The Signatories also recognize the
need to reduce HC emissions. Because of the air quality importance
of reducing hydrocarbon emissions to the maximum extent feasible and
in order to maximize industry's ability to achieve low NO_X
levels, EPA will propose for all heavy-duty engines as part of the
NPRM: (1) a combined Non-methane Hydrocarbon (``NMHC'')+NO_X
standard of 2.4 g/bhp-hr and (2) a combined NMHC+NO_Xstandard
of 2.5 g/bhp-hr together with a NMHC cap of 0.5 g/bhp-hr
(collectively, the ``Standards''), with flexibility for an engine
family to comply with either one of these Standards as the
manufacturer determines. It is expected that the Standards would
result in emissions comparable to a NO_Xstandard of 2.0 g/bhphr
(i.e., half of the 1998 NO_Xstandard), and also significant
reductions in HC emissions.
While this SOP focuses on NO_Xand NMHC emissions, the
Signatories recognize it does not affect other existing emission or
safety standards which pertain to heavy-duty engines. Specifically,
all Signatories concur that the feasibility of the Standards would
be affected by any changes in PM standards. Thus, this SOP is
premised on EPA not changing the 0.1 g/bhp-hr diesel particulate
standard currently in effect (or the lower PM standards for urban
buses). Further, all Signatories concur that any changes in Carbon
Monoxide (``CO'') standards could affect compliance for sparkignited
engines. Thus, this SOP is premised on EPA not changing the
CO standards currently in effect for heavy-duty engines.
2. Fuel Improvements: All Signatories acknowledge that fuel
composition has a significant effect on emissions and that changes
in the composition and improvements in the quality of fuel may be
needed to make the Standards technologically feasible and otherwise
appropriate under the Act. As part of the focus on reducing
NO<INF>X, and in cooperation with the fuels industry, the
Signatories are committed to making improvements in diesel fuel (and
other fuels used in heavy-duty engines) as appropriate under the Act
to meet the 2004 Standards, taking into consideration costs and
other relevant factors. Such efforts may include evaluation of the
contribution of fuel parameters to heavy-duty engine emissions,
including a higher cetane number and lower levels of aromatics and
sulfur. The Signatories recognize fuel improvements are important
and may be essential in reaching low NO_Xlevels in the most
efficient manner, considering costs and other factors. The
Signatories also recognize that any changes to both the
certification and commercial fuel specification would have to become
effective no later than October 2003 to ensure fuel availability at
the time the Standards take effect.
3. Feasibility: To assess the progress of industry efforts to
meet the Standards set forth in this SOP and to assure the lowest
appropriate standards in 2004, in 1999 EPA shall review any
rulemaking adopting the Standards discussed herein by issuing a
notice providing the opportunity for public comment on whether or
not the Standards are technologically feasible and otherwise
appropriate under the CAA. After receiving public comment, EPA shall
take final Agency action on the review under Sec. 307 of the CAA,
and shall revise the rule if the Agency determines that the
Standards are not technologically feasible or are otherwise not
appropriate under the CAA. The evaluation will consider the status
of heavy-duty engine technology in that year and its projection to
2004. In addition, the evaluation will include an assessment of
whether any fuel improvements (see item #2) that are needed to
assist heavy-duty engines in complying with the Standards will be
available nationwide.
In reviewing the rulemaking as set forth above, EPA shall review
the need, feasibility and cost of the Standards under the criteria
imposed on EPA by the Act, including, without limitation, the need
to provide engine manufacturers no less than four full model years
of lead-time. If EPA determines compliance with the Standards in
2004 is not technologically feasible or is otherwise not in
accordance with the Act, then the Administrator will adjust the
standard. If an adjustment is deemed necessary, the Standards for
2004 are not expected to be raised beyond a cap of: (1) 2.9 g/bhp-hr
NMHC+NO_Xand (2) 3.0 g/bhp-hr NMHC+NO_Xwith a proportional
increase in the NMHC cap. However, if improvements to fuel quality
are needed but not made, the Standards are not expected to be raised
beyond a cap of: (1) 3.4 g/bhp-hr NMHC+NO_Xand (2) 3.5 g/bhp-hr
NMHC+NO_Xwith a proportional increase in the NMHC cap.
The Signatories shall meet periodically to provide updates on
their efforts and progress in complying with the SOP.
4. California Standards: The California State Implementation
Plan (``SIP'') includes a proposed control measure to establish a
2.0 g/bhp-hr NO_Xemission standard for new engines used in onhighway
trucks sold in California in 2002 and thereafter. Both EPA
and California recognize the benefits of harmonizing state and
federal regulations. California confirms its intent to notice a
public hearing to consider action to harmonize its regulations for
dynamometer-certified engines greater than 8,500 lbs. GVWR with the
federal regulations adopted under this SOP, provided such action
would not compromise California's obligations to comply with state
and federal law including the SIP. The Signatories recognize that
California regulations establishing separate emission standards and
test procedures for gasoline chassis-certified vehicles are not
affected by this SOP.
5. Test Procedures: While there has been some discussion of
current test procedures for heavy-duty engines, the SOP and the
subsequent NPRM are premised on EPA not altering federal test
procedures. It is possible that the Agency may evaluate changes for
testing heavy-duty engines in the future, but it is recognized that
the SOP is made in the context of current test procedures. Further,
all Signatories recognize that any test cycle changes or additions
would likely complicate and delay industry's ability to research,
design, test, and produce engines that comply with the Standards by
2004. Any changes to test procedures used to determine compliance
with the Standards for purposes of EPA certification or enforcement
programs could also affect industry's ability to meet the Standards.
6. Durability: All Signatories recognize that it is important
that emissions from cleaner heavy-duty engines be maintained
throughout the life of the engine. To meet this goal, the
Signatories will work to develop appropriate measures which ensure
that emission gains are maintained in-use.
7. Averaging, Banking, and Trading Incentives: As part of this
SOP, EPA and CARB will work cooperatively with industry to develop
improved national averaging, banking, and trading (``AB&T'')
programs that will create more incentive for the early introduction
of cleaner engines. At a minimum, EPA will propose to modify the
existing AB&T program to eliminate any limitations on credit life
and to eliminate all credit discounts. The Signatories acknowledge
that an improved AB&T program may be critical in making the
Standards feasible in 2004, and would provide an incentive for early
introduction of cleaner technology.
In addition, EPA shall solicit comments in the NPRM on the
merits of allowing cross-fuel, cross-subclass, and cross-category
(e.g. on-highway and nonroad) credit exchanges, to the extent
permitted under the Act.
8. Scope: These standards will apply to all on-highway heavyduty
engines, including those operating on diesel, gasoline, or
alternative fuels or fuel blends. It is recognized that EPA and
California place a

[[Page 45604]]
high priority on the need for additional nonroad heavy-duty engine
standards, and that additional nonroad heavy-duty engine standards
may be required. The Signatories intend to participate in
discussions with nonroad heavy-duty engine and equipment
manufacturers to develop a separate SOP by approximately October
1995 addressing emissions standards for heavy-duty nonroad engines.
9. Stability: One of the key principles of the SOP is to provide
industry with increased certainty and stability for their business
planning. Without such certainty and stability, industry would not
commit to the enormous investment that the Standards will require.
And, without such certainty and stability, those investments might
never be recouped. EPA and California recognize the huge investment
that will be required of industry. Under the Act, the minimum period
of stability that EPA must provide for new on-highway heavy-duty
engine emissions standards is three years. However, EPA and
California acknowledge that under this SOP industry will be making a
commitment and investment that will require more than the minimum
period of stability.
10. Research Agreement: The Signatories recognize the benefits
of a joint industry/government research program with the goal of
developing engine and fuel technologies which can meet and exceed
the standards for heavy-duty on-highway engines outlined in this
SOP. The Signatories will undertake development of a separate
research agreement with goals of reducing NO_Xemissions to 1.0
g/bhp-hr and PM emissions to 0.05 g/bhp-hr while maintaining
attributes of current on-highway diesel engines such as performance,
reliability, durability, safety, and efficiency. These
characteristics have allowed current diesel engines to serve as the
pillar of the international trucking industry. This research
agreement would include certain of the industry signatories below,
EPA, CARB, and other organizations, such as the U.S. Department of
Energy, as are approved by the participants.

Signed July 11, 1995, Chicago, Illinois.
Mary D. Nichols,
U.S. Environmental Protection Agency.
John D. Dunlap,
California Air Resources Board.

Members of the Engine Manufacturer Association

Caterpillar, Inc.
Cummins Engine Company
Detroit Diesel Corporation
Ford Motor Company
General Motors Corporation
Hino Motors, Ltd.
Mack Trucks, Inc.
Mitsubishi Motors America, Inc.
Navistar International
Volvo Truck Corporation
Environmental Protection Agency (Mary D. Nichols)
California Air Resources Board (John Dunlap)

[FR Doc. 95-21525 Filed 8-30-95; 8:45 am]
BILLING CODE 6560-50-P

Notices For
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994

Control of Air Pollution From Heavy-Duty Engines

Local Navigation