[Federal Register Volume 65, Number 236 (Thursday, December 7, 2000)]
[Proposed Rules]
[Pages 76797-76829]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-30105]



  Federal Register / Vol. 65, No. 236 / Thursday, December 7, 2000 / 
Proposed Rules  

[[Page 76797]]


-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 86, 94, 1048 and 1051

[FRL-6907-6]


Control of Emissions From Nonroad Large Spark Ignition Engines, 
Recreational Engines (Marine and Land-Based), and Highway Motorcycles

AGENCY: Environmental Protection Agency.

ACTION: Advance notice of proposed rulemaking.

-----------------------------------------------------------------------

SUMMARY: With this advance notice of proposed rulemaking (ANPRM), we 
are continuing with our process of establishing standards for nonroad 
engines and vehicles that cause or contribute to air pollution. The 
ANPRM addresses nonroad engines and vehicles that have yet to be 
regulated by EPA, including: Large spark ignition (SI) engines such as 
those used in forklifts and airport tugs; Recreational vehicles using 
spark ignition engines such as off-highway motorcycles, all-terrain 
vehicles, and snowmobiles; and Recreational marine diesel engines and 
marine spark ignition sterndrive and inboard engines.
    These engines and vehicles contribute to ozone, carbon monoxide 
(CO), and particulate matter (PM) nonattainment. We are also concerned 
in some cases about personal exposure to high levels on CO, air toxics, 
and PM to persons operating or close to this equipment. With this 
ANPRM, we invite early input to the process to establishing standards 
and programs for these nonroad sources.
    We are also seeking comment on whether EPA should pursue rulemaking 
to establish more stringent emissions standards for highway 
motorcycles. While standards are in place for highway motorcycles, the 
current standards were established more than twenty years ago. Since 
off-highway motorcycles are included this ANPRM as part of nonroad 
recreational vehicles, we believe it may be appropriate to consider 
standards for both types of motorcycles together.

DATES: We request comment on this Advance Notice by February 5, 2001.

ADDRESSES: You may send written comments in paper form and/or by e-
mail. Send paper copies of written comments (in duplicate if possible) 
to the contact person listed below. You may also submit comments via e-
mail to ``[email protected]''. In your correspondence, refer to Docket A-
2000-01.
    EPA's Air Docket makes materials related to this rulemaking 
available for review in Dockets A-2000-01 and A-98-01. These materials 
are located at U.S. Environmental Protection Agency (EPA), Air Docket 
(6102), Room M-1500, 401 M Street, SW, Washington, DC 20460 (on the 
ground floor in Waterside Mall) from 8:00 a.m. to 5:30 p.m., Monday 
through Friday, except on government holidays. You can reach the Air 
Docket by telephone at (202) 260-7548 and by facsimile at (202) 260-
4400. We may charge a reasonable fee for copying docket materials, as 
provided in 40 CFR part 2.

FOR FURTHER INFORMATION CONTACT: Margaret Borushko, U.S. EPA, National 
Vehicle and Fuels Emission Laboratory, 2000 Traverwood, Ann Arbor, MI 
48105; Telephone: (734) 214-4334, Fax: (734) 214-4050, e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION: Electronic Copies of Documents
    This document is also available electronically from the EPA 
Internet Web site. This service is free of charge, except for any cost 
already incurred for internet connectivity. The electronic version of 
this document is made available on the day of publication on the 
primary web site listed below. We also publish Federal Register 
documents and related documents on the secondary web site listed below.
    1. http://www.epa.gov/docs/fedrgstr/EPA-AIR/ (either select desired 
date or use search feature)
    2. http://www.epa.gov/otaq/ (look in What's New or under the 
specific rulemaking topic)
    Please note that due to differences between the software used to 
develop the document and the software into which the document may be 
downloaded, changes in format, page length, etc., may occur.

Table of Contents

I. Overview
II. Air Quality
III. Recreational Vehicles
IV. Highway Motorcycles
V. Recreational Marine Engines
VI. Large Spark Ignition Engines
VII. Public Participation
VIII. Regulatory Flexibility
IX. Administrative Designation and Regulatory Analysis
X. Statutory Provisions and Legal Authority

I. Overview

A. History of Nonroad Engine Regulations

    The process of establishing standards for nonroad engines began in 
1991 with a study to determine whether emissions of carbon mononxide 
(CO), oxides of nitrogen ( NOX), and volatile organic 
compounds (VOCs) from new and existing nonroad engines, equipment, and 
vehicles are significant contributors to ozone and CO concentrations in 
more than one area that has failed to attain the national ambient air 
quality standards for ozone and CO.\1\ In 1994, EPA finalized its 
finding that nonroad engines as a whole ``are significant contributors 
to ozone or carbon monoxide concentrations'' in more than one ozone or 
carbon monoxide nonattainment area.\2\
---------------------------------------------------------------------------

    \1\ ``Nonroad Engine and Vehicle Emission Study--Report and 
Appendices,'' EPA-21A-201, November 1991 (available in Air docket A-
91-24). It is also available through the National Technical 
Information Service, referenced as document PB 92-126960.
    \2\ 59 FR 31306 (July 17, 1994).
---------------------------------------------------------------------------

    Upon this finding, EPA was tasked by the Clean Air Act (CAA or the 
Act) to establish standards for all classes or categories of new 
nonroad engines that cause or contribute to air quality nonattainment 
in more than one ozone or carbon monoxide (CO) nonattainment area. 
Since the finding in 1994, EPA has been engaged in the process of 
establishing programs to control emissions from nonroad engines used in 
many different applications. Nonroad categories already regulated 
include:
     Land-based compression ignition (CI) engines (e.g., farm 
and construction equipment),
     Small land-based spark-ignition (SI) engines (e.g., lawn 
and garden equipment, string trimmers),
     Marine engines (outboards, personal watercraft, CI 
commercial)
     Locomotive engines

B. Today's ANPRM

    Today's ANPRM provides an initial overview of possible regulatory 
strategies for nonroad vehicles and engines that have yet to be 
regulated under EPA's nonroad engine programs. It is a continuation of 
the process of establishing standards for nonroad engines and vehicles, 
as required by CAA section 213(a)(3). If, as expected, standards for 
these engines and vehicles are established, essentially all new nonroad 
engines will be required to meet emissions control requirements. The 
rulemaking that begins with this ANPRM therefore is the final round of 
initial regulations for nonroad engines. The ANPRM covers diesel 
engines used in recreational marine applications. The ANPRM also covers 
several nonroad spark ignition (SI) engine applications, as follows:
     Land-based recreational engines (for example, engines used 
in snowmobiles,

[[Page 76798]]

off-highway motorcycles, and all-terrain vehicles (ATVs))
     Marine sterndrive and inboard (SD/I) engines \3\
---------------------------------------------------------------------------

    \3\ As a shorthand notation in this document, we are using 
``recreational marine engines'' to mean recreational marine diesel 
engines and all gasoline SD/I engines, even though some SD/I 
applications could be commercial.
---------------------------------------------------------------------------

     Land-based engines rated over 19 kw (Large SI) (for 
example, engines used in forklifts); this category includes auxiliary 
marine engines, which are not used for propulsion.
    We have found that the nonroad engines included in this ANPRM cause 
or contribute to air quality nonattainment in more than one ozone or 
carbon monoxide (CO) nonattainment area.\4\ CAA section 213(a)(3) 
requires EPA to establish standards that achieve the greatest degree of 
emissions reductions achievable taking cost and other factors into 
account. We plan to propose emissions standards and related programs 
consistent with the requirements of the Act and, with this ANPRM, are 
seeking early input from interested parties.
---------------------------------------------------------------------------

    \4\ See Final Finding, ``Control of Emissions from New Nonroad 
Spark-Ignition Engines Rated above 19 Kilowatts and New Land-Based 
Recreational Spark-Ignition Engines'' elsewhere in today's Federal 
Register for EPA's finding for Large SI engines and recreational 
vehicles. EPA's findings for marine engines are contained in 61 FR 
52088 (October 4, 1996) for gasoline engines and 64 FR 73299 
(December 29, 1999) for diesel engines.
---------------------------------------------------------------------------

    In addition to the nonroad vehicles and engines noted above, 
today's ANPRM also reviews EPA requirements for highway motorcycles. 
The emissions standards for highway motorcycles were established 
twenty-three years ago. California recently adopted new emissions 
standards for highway motorcycles and new standards have also been 
proposed internationally. There may be opportunities to reduce 
emissions in a way that also allows manufacturers to benefit from 
harmonized requirements, which may reduce product lines and production 
costs. In addition, we believe it is important to consider the 
emissions standards for highway motorcycles in the context of setting 
standards for off-highway motorcycles. We are interested in providing 
regulatory programs for off-highway and highway motorcycles that are 
consistent, and which may also allow for the transfer of technology 
across product lines for manufacturers.
    This ANPRM covers engines and vehicles that vary in design and use, 
and many readers may only be interested in one or two of the 
applications. There are various ways we could group the engines and 
present information. For purposes of this ANPRM, we have chosen to 
group engines by common applications (e.g, recreational land-based 
engines, marine engines, large spark ignition engines used in 
commercial applications). We have attempted to organize the document in 
a way that allows each reader to focus on the applications of 
particular interest. The Air Quality discussion which follows in 
section II is general in nature and applies to all the categories 
covered by the ANPRM. Sections III through VI of the ANPRM present 
self-contained discussions of standards and programs for each of the 
vehicle and engine categories. While some of the information may be 
repetitive among the discussions, we hope that this structure helps the 
reader focus on the categories and information of interest. The 
remaining sections VII through X are generally applicable to all of the 
engines and vehicles.

II. Air Quality

A. Overview

    As directed by the Act, EPA has set National Ambient Air Quality 
Standards for, among other pollutants, ground-level carbon monoxide, 
ozone, NO2, and particulate matter.\5\ States are divided 
into discrete areas for air quality planning purposes. Currently, 17 
areas around the U.S. are classified as CO nonattainment areas. 
Additionally, 31 areas are not in attainment with ozone air quality 
standards.
---------------------------------------------------------------------------

    \5\ See 42 U.S.C. 7409.
---------------------------------------------------------------------------

    State and local governmental organizations charged with designing 
and implementing emission control programs to bring specific areas into 
attainment with these air quality standards have mounted significant 
efforts in recent years to reduce CO and ozone concentrations. Their 
state implementation plans, combined with federal stationary and mobile 
source emission control programs, have yielded encouraging signs of 
success. Emissions of the targeted pollutants have been significantly 
reduced in many areas. Average carbon monoxide and ozone levels, as 
well as the number of nonattainment areas, are beginning to decrease. 
We project, however, that emission increases accompanying general 
growth and economic expansion will eventually outpace per-source 
emission rate reductions. Increases in the number of sources, as well 
as increased use of existing sources, mean that even full 
implementation of current emission control programs may fall short of 
that needed to achieve long term attainment and maintenance of the air 
quality standards.
    In addition to nonattainment concerns, we are also concerned about 
hazardous air pollutants (air toxics). In August 2000, we proposed a 
list of Mobile Source Air Toxics (MSATs) of concern, including those 
emitted from nonroad engines.\6\ These pollutants are known or 
suspected to have serious health impacts. The engines and vehicles 
included in this ANPRM are sources of MSATs which are included on the 
proposed list, including diesel exhaust and several components of VOC 
emissions.
---------------------------------------------------------------------------

    \6\ 65 FR 48058, August 4, 2000.
---------------------------------------------------------------------------

B. Public Health and Welfare Concerns

    The nonroad engines included in this ANPRM and highway motorcycles 
all contribute to air pollution with a wide range of adverse health and 
welfare impacts. The following sections contain a brief description of 
some of the health effects associated with ozone, PM, air toxics and CO 
and the importance of continuing to reduce the associated emissions. 
This section also contains a brief description of issues that are 
unique to the engines and vehicles being considered in this document. 
The NPRM will contain a more detailed discussion of the health and 
welfare benefits which can be expected from a program regulating these 
engines.
1. Ozone and its Precursors
    Ground-level ozone, the main ingredient in smog, is formed by 
complex chemical reactions of volatile organic compounds (VOC) and 
nitrogen oxides ( NOX) in the presence of heat and sunlight. 
Ozone forms readily in the lower atmosphere, usually during hot, summer 
weather. VOCs are a broad group of compounds composed mainly of 
hydrocarbons (HC). Aldehydes, alcohols, and ethers are also present, 
but in small amounts. VOCs are emitted from a variety of sources, 
including motor vehicles, chemical plants, refineries, factories, 
consumer and commercial products, and other industrial sources. 
NOX is emitted largely from motor vehicles, nonroad 
equipment, power plants, and other sources of combustion.
    Ozone is a highly reactive chemical compound which can damage both 
biological tissues and man-made materials. When inhaled, ozone can 
cause acute respiratory problems; aggravate asthma; cause significant 
temporary decreases in lung function of 15 to over 20 percent in some 
healthy adults; cause inflammation of lung tissue; may increase 
hospital admissions and emergency room visits; and impair the body's 
immune system defenses,

[[Page 76799]]

making people more susceptible to respiratory illnesses. In addition to 
human health effects, ozone adversely affects crop yield, vegetation 
and forest growth, and the durability of materials. Because ground-
level ozone interferes with the ability of a plant to produce and store 
food, plants become more susceptible to disease, insect attack, harsh 
weather and other environmental stresses. Ozone causes noticeable 
foliar damage in many crops, trees, and ornamental plants (i.e., grass, 
flowers, shrubs, and trees) and causes reduced growth in plants. 
Studies indicate that current ambient levels of ozone are responsible 
for damage to forests and ecosystems (including habitat for native 
animal species).
    Besides their role as an ozone precursor, NOX emissions 
produce a wide variety of health and welfare effects.7,8 
Nitrogen dioxide can irritate the lungs and lower resistance to 
respiratory infection (such as influenza). NOX emissions are 
an important precursor to acid rain and may affect both land and water 
ecosystems. Atmospheric deposition of nitrogen leads to excess nutrient 
enrichment problems (``eutrophication'') in the Chesapeake Bay and 
several nationally important estuaries along the East and Gulf Coasts. 
Eutrophication can produce multiple adverse effects on water quality 
and the aquatic environment, including increased algal blooms, 
excessive phytoplankton growth, and low or no dissolved oxygen in 
bottom waters. Eutrophication also reduces sunlight, causing losses in 
submerged aquatic vegetation critical for healthy estuarine ecosystems.
---------------------------------------------------------------------------

    \7\ ``U.S. EPA (1995), Review of National Ambient Air Quality 
standards for Nitrogen Dioxide, Assessment of Scientific and 
Technical Information,'' OAQPS Staff Paper, EPA-452/R-95-005.
    \8\ ``U.S. EPA (1993), Air Quality Criteria for Oxides of 
Nitrogen,'' EPA/600/8-91/049aF.
---------------------------------------------------------------------------

    Need for NOX and VOC Control. Photochemical modeling 
highlights the fact that ozone pollution is a regional problem, not 
simply a local or state problem. Ozone and its precursors are 
transported long distances by winds and other 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 precursor emission levels of upwind areas. For many areas 
with persistent ozone problems, attainment of the ozone NAAQS will 
require control strategies for both NOX and VOC that extend 
beyond the areas' boundaries.
    We expect that reducing NOX and HC emissions from 
engines that would be regulated under this potential program would help 
reduce the health and welfare effects of ozone.\9\ Manufacturers and 
users of snowmobiles provided comments during the ``finding'' 
rulemaking indicating that snowmobiles should not be regulated for 
ozone precursors because snowmobiles are used during cold weather, when 
ozone is less of a health concern.\10\ However, ozone precursors are 
also responsible for other pollution problems including air toxics, 
discussed below, and indirect PM. We are examining the need to reduce 
precursors of ozone in the context of this rulemaking and request 
comment. In particular, we request comment on whether EPA should 
distinguish snowmobiles from other recreational vehicles in regulating 
ozone precursors and whether emissions of ozone precursors such as 
NOX and VOC should in any case be regulated due to other 
pollution problems.
---------------------------------------------------------------------------

    \9\ The emissions inventory contributions for these sources are 
provided in the Final Finding document referenced in footnote 4.
    \10\ International Snowmobile Manufacturers Association, Docket 
A-98-01, document IV-D-03.
---------------------------------------------------------------------------

2. Particulate Matter
    Particulate matter (PM) is the general term used for a mixture of 
solid particles and liquid droplets found in the air. These particles, 
which come in a wide range of sizes, originate from many different 
stationary and mobile sources as well as from natural sources. They may 
be emitted directly by a source (direct emissions) or formed in the 
atmosphere by the transformation of gaseous precursor emissions such as 
sulphur dioxide (SO2), nitrogen oxides (NOX), or 
organic compounds (secondary particles). Their chemical and physical 
compositions vary depending on source location, time of year and 
meteorology.
    Scientific studies show a link between inhalable PM (alone, or 
combined with other pollutants in the air) and a series of significant 
health effects. Inhalable PM includes both fine and coarse particles. 
Fine particles can be generally defined as those particles with an 
aerodynamic diameter of 2.5 microns or less (also known as 
PM2.5), and coarse particles are those with an aerodynamic 
diameter between 2.5 and 10 microns. All particles 10 microns or 
smaller are called PM10. The health and environmental 
effects of PM are strongly related to the size of the particles.
    Diesel particles are a component of both coarse and fine PM, but 
fall mostly in the fine range. Both coarse and fine particles can 
accumulate in the respiratory system and are associated with numerous 
health effects. Exposure to coarse fraction particles is primarily 
associated with the aggravation of respiratory conditions such as 
asthma. Fine particles are more deeply inhaled into the lungs than 
course particles. They are most closely associated with such health 
effects as decreased lung function, increased hospital admissions and 
emergency room visits, increased respiratory symptoms and disease, and 
premature death. Sensitive groups that appear to be at greatest risk to 
such effects include the elderly, individuals with cardiopulmonary 
disease such as asthma, and children.
    In addition, PM causes adverse impacts to the environment. Fine PM 
is the major cause of reduced visibility in parts of the United States, 
including many of our National Parks. Other environmental impacts occur 
when particles deposit onto soils, plants, water or materials. For 
example, particles containing nitrogen and sulphur that deposit on to 
land or water bodies may change the nutrient balance and acidity of 
those environments. An ecosystem condition known as ``nitrogen 
saturation,'' where addition of nitrogen to soil over time exceeds the 
capacity of the plants and microorganisms to utilize and retain the 
nitrogen, has already occurred in some areas of the United States. When 
deposited in sufficient quantities such as near unpaved roads, tilled 
fields, or quarries, particles block sunlight from reaching the leaves, 
stressing or killing plants. Finally, PM causes soiling and erosion 
damage to materials, including culturally important objects such as 
carved monuments and statues.
    Recreational marine diesel engines tend to be concentrated in 
specific areas of the country (ports, coastal areas, lakes and rivers), 
so the emissions contribution of these engines in local areas can be 
more important. Consequently addressing PM and other emissions from 
recreational marine diesel engines can be an important tool toward the 
goal of reducing health and environmental hazards.
    Considerations For PM From Recreational Two-Stroke Gasoline 
Engines. Two-stroke engines used in land-based recreational vehicles 
generally use a fuel and oil mixture to both produce power while 
lubricating the engine. As much as 30 percent of the intake charge 
passes through the engine unburned and exhausts to the atmosphere. As a 
consequence, PM emissions from these engines can be very high. Two 
stroke gasoline engines are commonly used in off-highway motorcycles 
and snowmobiles.
    Snowmobile engine emissions are of particular concern in 
environmentally

[[Page 76800]]

sensitive areas, such as Yellowstone National Park. Snowmobiles are 
typically powered by 2-stroke engines that have high emissions of 
hydrocarbons (HC), carbon monoxide (CO) and PM compared to 4-stroke 
engines. Recent studies have concluded that particulate emission rates 
from a snowmobile engine are more comparable to those of older, pre-
control diesel engines.11,12 Particle diameters were found 
to be typically less than 0.1 microns, which is of respirable size and 
able to be delivered into the deepest and most sensitive areas of the 
human lung. While formation rates of secondary PM may be lower in the 
winter months, PM concentrations can be elevated under some 
meteorological conditions (e.g., low mixing heights). We request 
comment on the health benefits of reducing PM emissions from 
recreational vehicle 2-stroke gasoline engines.
---------------------------------------------------------------------------

    \11\ ``Characterization of Snowmobile Particulate Emissions 
conducted for Yellow Stone Park Foundation Inc.,'' James N. Carroll 
and Jeff J. White, Southwest Research Institute, June 1999.
    \12\ ``Emissions from Snowmobile Engines using bio-based fuels 
and lubricants conducted for the Montana department of Environmental 
Quality,'' Jeff J. White and James N. Carroll, Southwest Research 
Institute, October 1998.
---------------------------------------------------------------------------

3. Air Toxics
    These engines are also sources of a number of chemical species 
which we have proposed to list as mobile source air toxics (MSATs), 
that are known or suspected human or animal carcinogens, or have 
serious noncancer health effects.\13\ They include pollutants such as 
diesel exhaust, benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and 
acrolein, described in more detail below. While the harmful effects of 
air toxics are of particular concern in areas closest to where they are 
emitted, they can also be transported and affect other geographic 
areas. Some can persist for considerable time in the environment.
---------------------------------------------------------------------------

    \13\ 65 FR 48058, August 4, 2000.
---------------------------------------------------------------------------

    Many of the air toxics discussed below are components of VOC and we 
expect that the HC standards discussed in this document would reduce 
exposure to air toxics and therefore reduce the incidence of cancer and 
noncancer health effects related to emissions from these engines. We 
request comment on the need to control air toxics emissions from the 
engines and vehicles included in this document.
    Considerations for Diesel Exhaust. Diesel exhaust emissions are a 
by-product of incomplete combustion and include gaseous and particulate 
components. Gaseous components of diesel exhaust include organic 
compounds, sulfur compounds, carbon monoxide, carbon dioxide, water 
vapor, and excess air (nitrogen and oxygen). Particulate components 
include many organic compounds that are mutagenic as well as several 
trace metals (including chromium, manganese, mercury and nickel) that 
may have general toxicological significance (depending on the specific 
chemical species). In addition, small amounts of dioxins have been 
measured in diesel exhaust, some of which may partition to the particle 
phase.
    Because the chemical composition of diesel exhaust includes 
hazardous air pollutants, or air toxics, diesel exhaust emissions are 
of concern to the agency. There have been health studies specific to 
diesel exhaust emissions which indicate potential hazards to human 
health that appear to be specific to this emissions source. For chronic 
exposure, these hazards include respiratory system toxicity and 
carcinogenicity. Acute exposure also causes transient effects (a wide 
range of physiological symptoms stemming from irritation and 
inflammation mostly in the respiratory system) in humans though they 
are highly variable depending on individual human susceptibility.
    The EPA draft Health Assessment Document for Diesel Exhaust was 
reviewed in a public session by the Clean Air Scientific Advisory 
Committee (CASAC) of EPA's Science Advisory Board on October 12-13, 
2000.\14\ The CASAC, in public session, found that the Agency's 
conclusion that diesel exhaust is likely to be carcinogenic to humans 
by inhalation, was scientifically sound. The comments provided by CASAC 
on the draft Assessment are being incorporated into the final 
Assessment to be released in late 2000 or early 2001. California EPA 
has identified diesel PM as a toxic air contaminant.\15\ Several other 
agencies and governing bodies have also designated diesel exhaust or 
diesel PM as a ``potential'' or ``probable'' human 
carcinogen.16,17,18 The International Agency for Research on 
Cancer (IARC) considers diesel exhaust a ``probable'' human carcinogen 
and the National Institutes for Occupational Safety and Health have 
classified diesel exhaust a ``potential occupational carcinogen''. 
Thus, the concern for the health hazard resulting from diesel exhaust 
exposures is widespread. We request comment on the health benefits of 
reducing PM emissions from marine diesel engines.
---------------------------------------------------------------------------

    \14\ U.S. EPA(2000) Health Assessment Document for Diesel 
Exhaust: SAB Review Draft EPA/600/8-90/057 Office of Research and 
Development, Washington, D.C. The document is available 
electronically at www.epa.gov/ncea/dieslexh.htm.
    \15\ ``Proposed Identification of Diesel Exhaust at a Toxic Air 
Contaminant, Health risk assessment for diesel exhaust,'' California 
Environmental Protection Agency, April 1998.
    \16\ ``Carcinogenic effects of exposure to diesel exhaust,'' 
NIOSH Current Intelligence Bulletin 50. DHHS, Publication No. 88-
116, 1988.
    \17\ ``Diesel and gasoline engine exhausts and some 
nitroarenes,'' Vol. 46, Monographs on the evaluation of carcinogenic 
risks to humans, International Agency for Research on Cancer, World 
Health Organization, 1989.
    \18\ ``Diesel fuel and exhaust emissions: International program 
on chemical safety,'' World Health Organization, 1996.
---------------------------------------------------------------------------

    Benzene. Benzene is an aromatic hydrocarbon which is present as a 
gas in both exhaust and evaporative emissions from motor vehicles. 
Benzene in the exhaust expressed as a percentage of total organic gases 
(TOG), varies depending on control technology (e.g., type of catalyst) 
and the levels of benzene and aromatics in the fuel, but is generally 
about four percent from gasoline engines. The benzene fraction of 
gasoline evaporative emissions also depends on control technology 
(i.e., fuel injector or carburetor) and fuel composition (e.g. benzene 
level and Reid Vapor Pressure or RVP) and is generally about one 
percent.
    The EPA has recently reconfirmed that benzene is a known human 
carcinogen by all routes of exposure (including leukemia at high, 
prolonged air exposures), and is associated with additional health 
effects including genetic changes in humans and animals and increased 
proliferation of bone marrow cells in mice.\19\ Respiration is the 
major source of human exposure. Long-term exposure to high levels of 
benzene in the air has been shown to cause cancer of the tissues that 
form white blood cells. Among these are acute nonlymphocytic leukemia, 
chronic lymphocytic leukemia and possibly multiple myeloma (primary 
malignant tumors in the bone marrow). A number of adverse noncancer 
health effects, blood disorders such as preleukemia and aplastic 
anemia, have also been associated with low-dose, long-term exposure to 
benzene. People with long-term exposure to benzene may experience 
harmful effects on the blood-forming tissues, especially the bone 
marrow. Many blood disorders associated with benzene exposure may occur 
without symptoms.
---------------------------------------------------------------------------

    \19\ ``U.S. EPA, Carcinogenic Effects of Benzene: An Update,'' 
National Center for Environmental Assessment, Washington, D.C. 1998.
---------------------------------------------------------------------------

    OSHA recently conducted an industrial hygiene survey to examine 
park employee exposures during winter

[[Page 76801]]

at Yellowstone National Park.\20\ They reported exposure to benzene 
above the NIOSH recommended exposure levels (REL) of 0.10 ppm. Since 
exhaust emission benzene levels generally decrease as HC emissions 
decrease, we expect new emission control technology to substantially 
reduce ambient benzene levels.
---------------------------------------------------------------------------

    \20\ ``U.S. Department of Labor, Industrial Hygiene Survey of 
Park Employee Exposures During Winter Use at Yellowstone National 
Park,'' February, 2000.
---------------------------------------------------------------------------

    1,3-Butadiene. 1,3-butadiene is formed in engine exhaust by 
incomplete combustion of fuel. It is not present in evaporative and 
refueling emissions, because it is not present in any appreciable 
amount in gasoline fuel. 1,3-butadiene accounts for 0.4 to 1.0 percent 
of total exhaust TOG, depending on control technology and fuel 
consumption. Nonroad mobile sources contribute 15.2 percent to the 1,3-
butadiene inventory (baseline NTI).
    The Environmental Health Committee of EPA's Scientific Advisory 
Board (SAB), in reviewing the draft document, issued a majority opinion 
that 1,3-butadiene should be classified as a probable human 
carcinogen.21,22 The Agency has revised the draft Health 
Risk Assessment of 1,3-butadiene based on the SAB and public comments. 
The draft Health Risk Assessment of 1,3-butadiene will undergo the 
Agency consensus review, during which time additional changes may be 
made prior to its public release and placement on the Integrated Risk 
Information System (IRIS).
---------------------------------------------------------------------------

    \21\ ``U.S. EPA Health Risk Assessment of 1,3-Butadiene,'' EPA/
600/P-98/001A, February 1998.
    \22\ ``An SAB Report: Review of the Health Risk Assessment of 
1,3-Butadiene,'' EPA-SAB-EHC-98, August 1998.
---------------------------------------------------------------------------

    Formaldehyde. Nonroad mobile sources contribute 23 percent to the 
formaldehyde inventory (baseline NTI). EPA has classified formaldehyde 
as a probable human carcinogen based on evidence in humans and in rats, 
mice, hamsters, and monkeys.\23\ Epidemiological studies in 
occupationally exposed workers suggest that long-term inhalation of 
formaldehyde may be associated with tumors of the nasopharyngeal 
cavity, nasal cavity and sinus. Formaldehyde exposure also causes a 
range of noncancer health effects, including irritation of the eyes 
(tearing of the eyes and increased blinking) and mucous membranes. 
Sensitive individuals may experience these adverse effects at lower 
concentrations than the general population. In persons with bronchial 
asthma, the upper respiratory irritation caused by formaldehyde can 
precipitate an acute asthmatic attack.
---------------------------------------------------------------------------

    \23\ ``U.S. EPA Assessment of health risks to garment workers 
and certain home residents from exposure to formaldehyde,'' Office 
of Pesticides and Toxic Substances, April 1987.
---------------------------------------------------------------------------

    The OSHA industrial hygiene survey at Yellowstone, described above, 
reported exposure to formaldehyde at 0.033 ppm, which is above the 
NIOSH recommended exposure level of 0.016 ppm.
    Acetaldehyde. Nonroad mobile source emissions are responsible for 
27 percent of the total acetaldehyde inventory (Baseline NTI). 
Acetaldehyde is classified as a probable human carcinogen and humans 
are exposed by inhalation, oral, and intravenous routes. The primary 
acute effect of exposure to acetaldehyde vapors is irritation of the 
eyes, skin and respiratory tract. At high concentrations, irritation 
and pulmonary effects can occur, which could facilitate the uptake of 
other contaminants.
    Acrolein. Nonroad mobile source emissions are responsible for 11 
percent of the total acrolein invenory (Baseline NTI). Acrolein is 
extremely toxic to humans when inhaled, with acute exposure resulting 
in upper respiratory tract irritation and congestion. The Agency has 
developed a reference concentration for inhalation (RfC) of acrolein of 
0.02 micrograms/m\3\. Although no information is available on its 
carcinogenic effects in humans, EPA considers acrolein a possible human 
carcinogen based on laboratory animal data.\24\
---------------------------------------------------------------------------

    \24\ ``U.S. EPA Integrated Risk Assessment System (IRIS),'' 
Office of Health and Environmental Assessment, Cincinnati, OH, 1993.
---------------------------------------------------------------------------

4. Carbon Monoxide (CO)
    Carbon monoxide (CO) is a colorless, odorless gas produced through 
the incomplete combustion of carbon-based fuels. Carbon monoxide enters 
the bloodstream through the lungs and reduces the delivery of oxygen to 
the body's organs and tissues. The health threat from CO is most 
serious for those who suffer from cardiovascular disease, particularly 
those with angina or peripheral vascular disease. Healthy individuals 
also are affected, but only at higher CO levels. Exposure to elevated 
CO levels is associated with impairment of visual perception, work 
capacity, manual dexterity, learning ability and performance of complex 
tasks.
    Several recent epidemiological studies have shown a link between CO 
and premature morbidity (including angina, congestive heart failure, 
and other cardiovascular diseases). Several studies in the United 
States and Canada have also reported an association of ambient CO 
exposures with frequency of cardiovascular hospital admissions, 
especially for congestive heart failure (CHF). An association of 
ambient CO exposure with mortality has also been reported in 
epidemiological studies, though not as consistently or specifically as 
with CHF admissions. EPA is reviewing these studies as part of the CO 
Criteria Document process.
    The toxicity of CO effects on blood, tissues and organs have also 
been topics of substantial research efforts. Such studies provided 
information for establishing the NAAQS for CO. The current primary 
NAAQS for CO are 35 parts per million for the one-hour average and 9 
parts per million for the eight-hour average. There are currently 17 
designated CO nonattainment areas, with a combined population of 31 
million. EPA estimated that emissions from nonroad gasoline engines and 
vehicles have increased by 24 percent from 1980 to 1998.\25\
---------------------------------------------------------------------------

    \25\ U.S. EPA (March 2000). ``National Air Pollutant Emission 
Trends, 1900-1998,'' Office of Air Quality and Standards.
---------------------------------------------------------------------------

    In addition to concerns related to air quality standards for broad 
areas, exhaust emissions from indoor applications can cause CO 
poisoning from individual human exposure. These engines (for example, 
engines used in forklifts) routinely operate in warehouses and 
production facilities. Unregulated industrial SI engines frequently 
have exhaust CO concentrations over 30,000 ppm (3 percent). The maximum 
allowable time-weighted average 8-hour workplace exposure set by the 
Occupational Safety and Health Administration is 50 ppm. Manufacturers 
in some cases may adjust engine calibration for somewhat lower CO 
emission levels. Also, engines used indoors are often fueled with LPG, 
which typically has lower CO exhaust concentrations than gasoline-
fueled engines. However, improper maintenance or poor calibrations can 
lead to even higher levels than the 30,000 ppm level noted above from 
any industrial SI engine.
    The typical snowmobile, which utilizes a two-stroke engine, 
produces significantly more CO than a modern automobile on a unit of 
work basis. There has been an increasing concern that snowmobile 
emissions in and around some national parks are reaching significant 
levels. During the winters of 1994-95 and 1995-96, studies were 
conducted at Yellowstone, Flagg Ranch, and Grand Teton National Park 
which indicated that snowmobile tourists are potentially exposed to 
significant CO

[[Page 76802]]

levels.\26\ While the studies did not record official exceedances of 
the CO NAAQs, levels near and in some cases above the 35 ppm NAAQS 
standard were observed. These measurements were not considered NAAQS 
exceedances because sampling methods and measurement locations did not 
meet the criteria for NAAQS measurements. However, the measurements 
were reported to be scientifically valid and an indication of 
potentially significant exposure to CO.
---------------------------------------------------------------------------

    \26\ Exposure to Snowmobile Riders to Carbon Monoxide, Park 
Science Volume 17--No. 1, National Park Service, U.S. Department of 
the Interior.
---------------------------------------------------------------------------

    A study of snowmobile rider exposure conducted at Grand Teton 
National Park showed that CO levels when trailing a single snowmobile 
at distances of 25-125 feet at speeds of 10-40 mph ranged from 0.5-23 
ppm, with a maximum level of 45 ppm (as compared to the current NAAQS 
for CO of 35 ppm).\27\ Since snowmobile riders typically travel in 
large groups, the riders towards the back of the group are likely to 
experience significantly higher exposures to CO. An additional 
consideration is that the risk to health from CO exposure increases 
with altitude, especially for un-acclimated individuals. Therefore, a 
park visitor who lives at sea level and then rides his or her 
snowmobile on trails at high-altitude is more susceptible to the 
effects of CO than local residents. In addition, the OSHA industrial 
hygiene survey mentioned earlier reported a peak CO exposure of 268 ppm 
for a Yellowstone employee, in exceedance of the NIOSH peak recommended 
exposure limit of 200 ppm.
---------------------------------------------------------------------------

    \27\ Snook and Davis, 1997, ``An Investigation of Driver 
Exposure to Carbon Monoxide While Traveling Behind Another 
Snowmobile.''
---------------------------------------------------------------------------

    The U.S. Coast Guard reported cases of CO poisoning caused by 
recreational boat usage.\28\ These Coast Guard investigations into 
recreational boating accident reports between 1989 to1998, show that 57 
accidents were reported, totaling 87 injuries and 32 fatalities, that 
involved CO poisoning. We believe that controlling CO emissions from 
marine engines could provide some benefits to boaters.
---------------------------------------------------------------------------

    \28\ Summarized in an e-mail Phil Cappel of the U.S. Coast Guard 
to Mike Samulski of the U.S. Environmental Protection Agency, 
October 19, 2000.
---------------------------------------------------------------------------

C. National Emissions Inventory

    We have estimated the contribution of the sources included in this 
ANPRM to the nationwide emissions inventories for the 2000 and 2007 
calendar years, as shown in Table II-1.\29\
---------------------------------------------------------------------------

    \29\ Inventory data is further provided in Tables 1 and 2 of the 
Final Finding (see footnote 4).

                                                Table II-1.--Estimated Nationwide Annual Emission Levels
                                              [in thousand short tons (percent of mobile source inventory)]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             NOX                       HC                        CO                        PM
                                                 -------------------------------------------------------------------------------------------------------
                                                      Tons       Percent        Tons       Percent        Tons       Percent        Tons       Percent
--------------------------------------------------------------------------------------------------------------------------------------------------------
Year 2000:
    Nonroad Sources in ANPRM....................          371          2.8          822         11.0         7,15          9.0          8.4          1.2
                                                                                                                7
    Highway Motorcycles.........................           22          0.2           21          0.3          147          0.2          0.4          0.1
                                                 -------------------------------------------------------------------------------------------------------
        Year 2000 Total.........................          393          3.0          843         11.3         7,30          9.2          8.8          1.3
                                                                                                                4
Year 2007:
    Nonroad Sources in ANPRM....................          444          4.3          870         16.6         7,53          9.7          9.2          1.5
                                                                                                                6
    Highway Motorcycles.........................           25          0.2           26          0.5          171          0.2          0.5          0.1
                                                 -------------------------------------------------------------------------------------------------------
        Year 2007 Total.........................          469          4.5          896         17.1         7,70          9.9          9.7          1.6
                                                                                                                7
--------------------------------------------------------------------------------------------------------------------------------------------------------

III. Recreational Vehicles

A. Background

1. What Recreational Vehicles Would be Included in This Rulemaking?
    The vast majority of vehicles that fall into the land-based 
recreational vehicles category are snowmobiles, off-highway motorcycles 
(e.g., dirt bikes), and all terrain vehicles (ATVs).\30\ The engines 
used in these vehicles are a subset of nonroad SI engines.\31\ Engines 
used in recreational vehicles include both Small SI (at or below 19 kW) 
and Large SI engines (above 19 kW). These engines, however, were 
excluded from our Small SI program (for lawn mowers, chain saws, etc.) 
because they have different design characteristics and usage patterns 
than other engines in the Small SI category. This suggests that the 
recreational engines covered by this ANPRM should be tested differently 
than Small SI engines. We would similarly expect to treat them 
separately from our Large SI engine program (discussed later in this 
ANPRM). We therefore request comment on whether engines used in 
recreational vehicles should be tested and regulated differently from 
other small and Large SI engines.
---------------------------------------------------------------------------

    \30\ ATVs are typically four-wheeled vehicles that are straddled 
by the operator.
    \31\ Almost all recreational vehicles are equipped with SI 
engines. Any diesels used in these applications must meet our 
nonroad diesel engine standards.
---------------------------------------------------------------------------

    In our rulemaking regulating Small SI engines (defined as nonroad 
SI engines below 19 kW), we established criteria that effectively 
excluded the types of engines used in the recreational vehicles listed 
above.\32\ These criteria, such as normal range of operating engine 
rpm, can greatly affect the basic engine design and the opportunities 
for emissions control. Engines used in some other types of recreational 
vehicles may be covered by the Small SI standards, depending on the 
characteristics of the engines. For example, lawnmower-type engines 
used in go carts would typically be covered by the Small SI standards. 
Engines used in golf carts are also typically included in the Small SI 
program due to their design and

[[Page 76803]]

operating characteristics being similar to lawnmower-type applications.
---------------------------------------------------------------------------

    \32\ See 40 CFR 90.1(b)(5) for the list of criteria.
---------------------------------------------------------------------------

    There may be other types of recreational vehicles that should be 
included in the recreational vehicles program in addition to 
snowmobiles, off-highway motorcycles, and ATVs. For example, some small 
mopeds or motor scooters could be included in the program depending on 
their characteristics.\33\ We are interested in information and request 
comment about other types of vehicles that may exist so that we may 
consider them in developing our proposals.
---------------------------------------------------------------------------

    \33\ The definition of motor vehicle excludes ``any vehicle that 
cannot exceed a maximum speed of 25 miles per hour over level, paved 
surfaces'' (see 40 CFR 85.1703(a)(1)). Such vehicles are therefore 
considered nonroad vehicles.
---------------------------------------------------------------------------

    There may be some uncertainty surrounding the use of 
``recreational'' in distinguishing between vehicle types and in 
determining which set of standards a vehicle or engine must meet. ATVs, 
for example, may have some utility aspects to their use. We request 
comment how to best differentiate among engines types. We could 
establish a definition for ``recreational'', for example, based on the 
primary intended use of the vehicle model. Under such an approach, 
vehicles primarily intended for utility or work use by the manufacturer 
would be part of either the Small or Large SI programs, as applicable. 
We could also differentiate engines based solely upon engine design and 
operating characteristics without regard to usage; this option might 
eliminate potential confusion over whether a particular engine should 
be appropriately certified as a ``recreational'' or ``utility'' engine.
    Hobby engines. The Small SI rule categorized engines used in model 
cars, boats, and airplanes as recreational engines and exempted them 
from the Small SI program.\34\ Historically, we have exempted hobby 
engines from our regulations. The nonroad diesel engine final rule 
exempted hobby engines due to feasibility, testing, and compliance 
concerns related to regulating such small engines. Also noted in the 
nonroad diesel engine rule, because hobby engines are very small with 
very low power output relative to other nonroad engines and have low 
annual usage rates, they contribute very little to emissions 
inventories.\35\ We request comment on how to proceed for SI hobby 
engines, including data and information that would allow us to further 
consider the potential for establishing standards for them or for 
exempting them from this rule.
---------------------------------------------------------------------------

    \34\ 80 FR 24292, April 25, 2000.
    \35\ 63 FR 56971, October 23, 1998.
---------------------------------------------------------------------------

2. Who Makes Recreational Vehicles?
    Based on industry information available to us, the recreational 
vehicle industry appears to be dominated by eight manufacturers. Of 
these eight manufacturers, seven of them manufacture a combination of 
two or more of the three recreational vehicle sub-categories: off-
highway motorcycles, ATVs, and snowmobiles. For example, there are four 
major companies that manufacture both off-highway motorcycles and ATVs. 
There are three major companies that manufacture ATVs and snowmobiles 
and one major company that manufactures all three. These eight 
companies represent approximately 95 percent of all domestic sales of 
recreational vehicles.
    We are aware of five major companies that dominate sales of off-
highway motorcycles. Four of these companies, Honda, Kawasaki, Suzuki, 
and Yamaha, are long established, major corporations that manufacture a 
number of products including highway and off-highway motorcycles. They 
have dominated the off-highway motorcycle market for over thirty years. 
The fifth major company, KTM, is also long established but has had a 
major impact in domestic sales over the last 10 to 15 years. These five 
companies account for approximately 90 to 95 percent of all domestic 
sales for off-highway motorcycles. There are also several relatively 
small companies that manufacture off-highway motorcycles, many of which 
specialize in racing or competition machines.
    Based on available industry information, four major manufacturers, 
Arctic Cat, Bombardier (also known as Ski-Doo), Polaris, and Yamaha, 
account for approximately 99 percent of all domestic snowmobile sales. 
The remaining percent comes from very small manufacturers who tend to 
specialize in unique designs or racing machines. The ATV sector has the 
broadest assortment of major manufacturers. With the exception of KTM, 
all of the companies noted above for off-highway motorcycles and 
snowmobiles are significant ATV producers. These seven companies 
represent over 95 percent of total domestic ATV sales. The remaining 5 
percent come from importers who tend to import inexpensive, youth-
oriented ATVs from China and other Asian nations.
3. What Types of Engines Are Used in the Vehicles?
    The engines used in recreational vehicles tend to be small, air- or 
liquid-cooled, reciprocating Otto-cycle engines that operate on 
gasoline.\36\ They are designed to be used in vehicles, where engine 
performance is characterized by highly transient operation, with a wide 
range of engine speed and load capability. Maximum engine speed is 
typically well above 5,000 rpm. Also, the vehicles are equipped with 
transmissions to ensure performance under a variety of operating 
conditions.
---------------------------------------------------------------------------

    \36\ Otto cycle is another name for a spark-ignition engine 
which utilizes a piston with homogenous external or internal air and 
fuel mixture formation and spark ignition.
---------------------------------------------------------------------------

    These engines can be separated into two-stroke and four-stroke 
designs. The distinction between two-stroke and four-stoke engines is 
important for emissions because two-stroke engines tend to emit much 
greater amounts of unburned hydrocarbons (HC) and particulate matter 
(PM) than four-stroke engines of similar size and power. Two-stroke 
engines also have greater fuel consumption resulting in poorer fuel 
economy than four-stroke engines, but they also tend to have higher 
power output per unit displacement, lighter weight, and better cold 
starting performance. These advantages combined with a simple design 
and lower manufacturing costs tend to make two-stroke engines a popular 
choice as the power unit for recreational vehicles. Currently, 
snowmobiles use two-stroke engines almost exclusively, whereas about 63 
percent of all off-highway motorcycles (predominantly in high 
performance, youth, and entry-level bikes) and 12 percent of all ATVs 
sold in the United States use two-stroke engines. Engine displacement 
for off-highway motorcycles and ATVs typically range from 50 cubic 
centimeters (cc) to 500 cc for two-stroke engines, and 50 cc to 650 cc 
for four-stroke engines. Snowmobile engines range from 100 cc to over 
1,000 cc.
    The basis for the differences in engine and exhaust emissions 
performance between two-stroke and four-stroke engines can be found in 
the fundamental differences in how two-stroke and four-stroke engines 
operate. Four-stroke operation takes place in four distinct steps: 
intake, compression, power, and exhaust. Each step corresponds to one 
up or down ``stroke'' of the piston or 180 deg. of crankshaft rotation. 
The first step of the cycle is for an ``intake'' valve in the 
combustion chamber to open during the intake stroke allowing a mixture 
of air and fuel to be drawn into the cylinder while the piston moves 
down the cylinder. The intake valve then closes and the momentum of the 
crankshaft causes the

[[Page 76804]]

piston to move back up the cylinder compressing the air and fuel 
mixture. At the very end of the compression stroke, the air and fuel 
mixture is ignited by a spark from a spark plug, and begins to burn. As 
the air and fuel mixture burns, increasing temperature and pressure 
cause the piston to move back down the cylinder. This is referred to as 
the ``power'' stroke. At the bottom of the power stroke, an exhaust 
valve opens in the combustion chamber and as the piston moves back up 
the cylinder, the burnt gases are pushed out through the exhaust valve 
to the exhaust manifold, and the cycle is complete.
    In a four-stroke engine, combustion and the resulting power stroke 
only occur once every two revolutions of the crankshaft. In a two-
stroke engine, on the other hand, combustion occurs in every revolution 
of the crankshaft. Two-stroke engines eliminate the intake and exhaust 
strokes, leaving only compression and power strokes. This is due to the 
fact that two-stroke engines do not use intake and exhaust valves. 
Instead, they have intake and exhaust ``ports'' in the sides of the 
cylinder walls. With a two-stroke engine, as the piston approaches the 
bottom of the power stroke, it uncovers exhaust ports in the wall of 
the cylinder. The high pressure combustion gases blow into the exhaust 
manifold. As the piston gets closer to the bottom of the power stroke, 
the intake ports are uncovered, and fresh mixture of air and fuel are 
forced into the cylinder while the exhaust ports are still open. 
Exhaust gas is ``scavenged'' or forced into the exhaust by the pressure 
of the incoming charge of fresh air and fuel. In the process, however, 
some mixing between the exhaust gas and the fresh charge of air and 
fuel takes place, so that some of the fresh charge is also emitted in 
the exhaust. The loss of part of the fuel out of the exhaust during 
scavenging is one of the major reasons for the very high hydrocarbon 
emission characteristics of two-stroke engines. The other major reason 
for high HC emissions from two-stroke engines is their tendency to 
misfire under low load conditions due to greater combustion 
instability.
4. What Are the Pollutants of Interest for Each Type of Vehicle?
    Recreational vehicles utilizing two-stroke engines, such as 
snowmobiles and some models of off-highway motorcycles and ATVs, emit 
significant quantities of fine particulate matter (PM), unburned 
hydrocarbons (HC), and carbon monoxide (CO). Recreational vehicles 
utilizing four-stroke engines, such as some models of off-highway 
motorcycles and most ATVs, also emit significant quantities of CO, 
however, they tend to emit considerably lower levels of HC and PM than 
their two-stroke counterparts. Both engine types emit oxides of 
nitrogen ( NOX). Two-stroke engines tend to emit very low 
levels of NOX whereas four-stroke engines emit greater 
quantities, similar to four-stroke HC emission levels. Exhaust 
hydrocarbon emissions also include significant quantities of toxic air 
contaminants including benzene, formaldehyde, acetaldehyde, and 1,3 
butadiene. The most important source of recreational vehicle emissions 
is the engine exhaust, but HC emissions are also produced from the 
crankcase in four-stroke engines, by evaporation from the fuel system, 
and by vapor displacement during refueling.
5. What Programs Are in Place in California and Elsewhere To Control 
Emissions from Recreational Vehicles?
    California established standards for off-highway motorcycles and 
ATVs which took effect in January 1997 (1999 for vehicles with engines 
of 90 cc or less). The standards, shown in Table III-1, are based on 
the highway motorcycle chassis test procedures. Manufacturers may 
certify ATVs to optional standards, also shown in Table III-1, which 
are based on the utility engine test procedure.\37\ This is the test 
procedure over which Small SI engines are tested. The stringency level 
of the standards was based on the emissions performance of 4-stroke 
engines and advanced 2-stroke engines equipped with a catalytic 
converter. California anticipated that the standards would be met 
initially through the use of high performance 4-stroke engines.
---------------------------------------------------------------------------

    \37\ Notice to Off-Highway Recreational Vehicle Manufacturers 
and All Other Interested Parties Regarding Alternate Emission 
Standards for All-Terrain Vehicles, Mail Out #95-16, April 28, 1995, 
California Air Resources Board (Docket A-2000-01, document II-D-06).

         Table III-1.--California Off-Highway Motorcycle and ATV Standards for Model Year 1997 and Later
                                 [1999 and later for engines at or below 90 cc]
----------------------------------------------------------------------------------------------------------------
                                                                   HC          NOX           CO           PM
----------------------------------------------------------------------------------------------------------------
Off-highway motorcycle and ATV standards (g/km).............        a 1.2  ...........           15  ...........
----------------------------------------------------------------------------------------------------------------
                                                                      HC + NOX                   CO           PM
----------------------------------------------------------------------------------------------------------------
Optional standards for ATV engines below 225 cc (g/bhp-hr)..           a 10.0                   300  ...........
Optional standards for ATV engines below 225 cc (g/bhp-hr)..           a 12.0                   300  ...........
Optional standards for ATV engines at or above 225 cc (g/bhp-                                   300  ...........
 hr)........................................................           a 10.0
----------------------------------------------------------------------------------------------------------------
a Corporate-average standard.

    California revisited the program in the 1997 time frame because a 
lack of certified product from manufacturers was reportedly creating 
economic hardship for dealerships. The number of certified off-highway 
motorcycle models was particularly inadequate.\38\ In 1998, California 
revised the program, allowing the use of uncertified products in off-
highway vehicle recreation areas with regional/seasonal use 
restrictions. Currently, noncomplying vehicles can be legally sold in 
California and used in attainment areas year-round and in nonattainment 
areas during months when exceedances of the state ozone standard are 
not expected. For enforcement purposes, certified and uncertified 
products are identified respectively with green and red stickers. Only 
about one-third of off-highway motorcycles sold in California are 
certified. All certified products are powered by 4-stroke engines.
---------------------------------------------------------------------------

    \38\ Initial Statement of Reasons, Public Hearing to Consider 
Amendments to the California Regulations for New 1997 and Later Off-
highway Recreational Vehicles and Engines, State of California Air 
Resources Board, October 23, 1998 (Docket A-2000-01, II-D-08).
---------------------------------------------------------------------------

    California has not adopted standards for snowmobiles. In addition, 
EPA is not aware of emission control programs for nonroad recreational 
vehicles that have been adopted in other countries.

[[Page 76805]]

B. Technology

1. What Are the Baseline Technologies and Emissions Levels?
    As discussed earlier, recreational vehicles are equipped with 
relatively small high performance two- or four-stroke engines that are 
either air- or liquid-cooled.\39\ The fuel system used on these engines 
are almost exclusively carburetors. Two-stroke engines lubricate the 
piston and crankshaft by mixing oil with the air and fuel mixture. This 
is accomplished by most contemporary 2-stroke engines with a pump that 
sends two-cycle oil from a separate oil reserve to the carburetor where 
it is mixed with the air and fuel mixture. Some less expensive two-
stroke engines require that the oil be mixed with the gasoline in the 
fuel tank. Four-stroke engines inject oil via a pump throughout the 
engine as the means of lubrication. With the exception of those 
vehicles certified in California, most of these engines are unregulated 
and thus have no emission controls. In fact, because performance and 
durability are such important qualities for recreational vehicle 
engines, they all operate with a ``rich'' air and fuel mixture. That 
is, they operate with excess fuel, which enhances performance and 
allows engine cooling which promotes longer lasting engine life. 
However, rich operation results in high levels of HC, CO, and PM 
emissions. Also, two-stroke engines tend to have high scavenging 
losses, where up to a third of the unburned air and fuel mixture goes 
out of the exhaust resulting in high levels of raw HC.
---------------------------------------------------------------------------

    \39\ The engines are small relative to automotive engines. For 
example, automotive engines typically range from one liter to well 
over five liters in displacement, whereas off-highway motorcycles 
would range from 0.05 liters to 0.65 liters.

                   Table III-2.--Typical Range of Exhaust Emissions for Recreational Vehicles
----------------------------------------------------------------------------------------------------------------
  Recreational vehicle type      Engine type        HC           CO          NOX           PM          Units
----------------------------------------------------------------------------------------------------------------
Snowmobiles..................  2-stroke......       67-200      196-400     0.3-1.62      0.7-6.1  g/hp-hr
Off-highway Motorcycles/ATVs.  2-stroke......         8-26        16-37     0.01-0.1  0.002-0.025  g/km a
                               4-stroke......        0.4-3         7-50     0.03-0.2  0.006-0.025  g/km
----------------------------------------------------------------------------------------------------------------
a Emission measurement for motorcycles is in grams per kilometer rather than grams per mile because the
  motorcycle industry, as well as Federal, California, and international motorcycle emission standards use
  ``Systeme International d'Unites'' or SI units, which measure distance in kilometers rather than miles.

2. What Technology Approaches Are Available To Control Emissions?
    A number of approaches are available to control emissions from 
recreational vehicles. The simplest approach would consist of 
modifications to the base engine, fuel system, cooling system, and 
recalibration of the air and fuel mixture. These could, for example, 
consist of changes to valve timing for four-stroke engines, changing 
from air to liquid cooling, and the use of advanced carburetion 
techniques and electronic fuel injection (EFI) in lieu of traditional 
carburetion systems. Other approaches could include using an oxidation 
catalyst alone or in conjunction with secondary air. The engine 
technology that may have the most potential for maximizing emission 
reductions from two-stroke engines is the use of direct fuel injection 
(DI). Direct fuel injection is able to reduce or even eliminate 
scavenging losses by pumping only air through the engine and then 
injecting fuel into the combustion chamber after the intake and exhaust 
ports have closed. The use of oxidation catalysts in conjunction with 
direct injection could potentially reduce emissions even further. 
Finally, because four-stroke engines emit significantly lower levels of 
HC than two-stroke engines, the conversion of two-stroke engine 
technology to four-stroke engine technology could be a desirable 
approach.
    We request comment as to whether there are any other approaches to 
emission reduction for recreational vehicles that have not been 
discussed here. We are interested in information on feasibility, cost 
and corresponding emission reduction potential, and other issues 
associated with the above and other technologies. Specifically, we 
request comment on the effectiveness and durability of oxidation 
catalysts for these applications, the cost, corresponding emission 
reductions, and feasibility of direct fuel injection for two-stroke 
engine applications, and the cost and feasibility of switching from 2-
stroke to 4-stroke engines. Any data on engines similar to those used 
in recreational equipment using these technologies is also requested.
3. What Level of Control May Be Feasible?
    Calibration changes and engine modifications can reduce HC and CO 
emissions somewhat, in the range of 10 to 30 percent. While the precise 
level of control anticipated from recreational vehicles is not yet 
known, further HC reductions in the 70 to 90 percent range may be 
achievable from current two-stroke engines. We expect that the bulk of 
the HC reductions would occur through the elimination of scavenging 
losses, with additional reductions possible through the use of an 
oxidation catalyst. Because four-stroke engines already have low HC 
emissions relative to two-stroke engines, we would expect more modest 
HC reductions from four-stroke engines as a result of new emission 
standards. Control strategies that would reduce HC emissions would also 
generally reduce PM and toxics. This is especially true for 2-stroke 
engines where high levels of PM and toxics are the result of scavenging 
losses.
    We believe that similar levels of control can be expected for CO 
emissions as for HC emissions. The bulk of CO reductions will come from 
improvements to the fuel system, either through enleanment (i.e., less 
fuel) of the air and fuel mixture, from now on referred to as A/F 
ratio, or the improvement of fuel atomization (i.e., smaller fuel 
droplets), with additional reductions possible through the use of an 
oxidation catalyst.40-41 Such strategies are also likely to 
reduce HC and PM emissions as well.
---------------------------------------------------------------------------

    \40-41\ Fuel atomization refers to the size of individual fuel 
droplets. The smaller the fuel droplet is, the better it is 
combusted or burned.
---------------------------------------------------------------------------

    The NOX levels emitted from recreational vehicles, 
especially for those equipped with two-stroke engines, are very low 
since most recreational vehicles typically operate using a ``rich'' 
calibration (i.e., with excess fuel) for performance and durability 
purposes.
    Some emission reduction techniques such as changes in engine design 
and calibration aimed at reducing HC and CO emissions may increase 
NOX. However, we expect that any increases

[[Page 76806]]

resulting from HC and CO standards would be minimal. To ensure 
continued low NOX performance, we request comment on the 
appropriateness of setting a capping standard for NOX 
emissions or combining NOX control with HC by setting a HC + 
NOX standard.
    We request comment on the various strategies available to reduce 
emissions and the costs and potential corresponding emissions 
reductions of those strategies.

C. Standards and Program Approaches

    Although off-highway motorcycles, ATVs, and snowmobiles are all 
categorized as recreational vehicles, we expect to establish separate 
emissions standards for them. The most fundamental reason for varying 
standards is that the operating characteristics are significantly 
different. Since we typically try to evaluate and control emissions 
performance under normal operating conditions, it is likely we will 
adopt different test procedures for the different applications. Also, 
the level of stringency and the timing of the standards may vary 
depending on the types of emissions control technology available, cost 
impacts, industry make-up, and other factors that we must consider in 
establishing the program. We request comments on the appropriateness of 
separate emission standards for off-highway motorcycles, ATVs, and 
snowmobiles.
    Generally, we will be considering what level of emissions control 
is appropriate and the lead-time necessary for manufacturers to achieve 
those emissions reductions. There are a number of approaches that have 
been used in programs for other nonroad engines to effectively reduce 
emissions, both in the near term and long term. These approaches often 
incorporate some level of flexibility into the program which has 
allowed manufacturers to achieve lower overall emissions levels, 
perhaps at less cost. Programs have been tailored to the particulars of 
the engine categories and industries being regulated to achieve the 
overall goals of the program.
    In many programs, we have established either a single set (tier) of 
standards, or multiple tiers of standards that progressively achieve 
further reductions over a number of years. We have also established 
corporate-average standards, including declining fleet averages where 
manufacturers must calculate fleet average emissions levels and reduce 
those emissions incrementally each year over several model years. Also, 
in some cases, standards have been phased-in over a number of years as 
a percentage of sales or by an engine characteristic such as size. Some 
programs also include averaging, banking and trading, discussed below 
in section III.C.4.
    We have used such mechanisms, in part, to allow manufacturers to 
plan their research, development, and product introductions. Such 
program approaches may allow manufacturers to achieve long-term 
emission reductions that may not otherwise be achievable. For example, 
a declining fleet average approach over several years may provide near 
term reductions and also provide manufacturers with lead-time needed to 
employ advanced technology in an orderly and efficient manner. Also, 
averaging can provide flexibility by allowing manufacturers to certify 
some engines to levels above the standard as long as excess emissions 
are offset by sales of engines certified to emissions levels below the 
standard. However, such approaches may be of limited value to small 
businesses or companies offering only a few models and may not be 
justified for some programs. We encourage you to consider these 
approaches, and any others, in commenting on the standards discussed 
below.
1. Off-Highway Motorcycles and ATVs
    We are considering establishing HC, NOX, and CO 
standards for off-highway motorcycles and ATVs. PM is discussed 
separately in section III.C.3, below. We expect the largest benefit in 
terms of reducing the ozone precursors NOX and HC to come 
from reducing HC emissions from two-stroke engines. Two-stroke engines 
have very high HC emissions levels. Baseline NOX levels are 
relatively low for engines used in these applications and therefore 
initial NOX standards may serve to cap NOX 
emissions. CO reductions can be expected from both 2-stroke and 4-
stroke engines, as CO levels are somewhat similar for the two engine 
types.
    HC Standard. In the current off-highway motorcycle and ATV market, 
consumers can choose between 2-stroke and 4-stroke models in most sizes 
and categories. Each engine type offers unique performance 
characteristics. Some manufacturers specialize in 2-stroke or 4-stroke 
models while others offer a mix of models.
    The HC standard is likely to be a primary determining factor for 
what technology manufacturers choose to employ to meet emissions 
standards overall. As described in the previous section, a variety of 
technological approaches appear promising to control HC emissions. HC 
emissions can be reduced substantially by switching from 2-stroke to 4-
stroke engines. The California emissions control program for off-
highway vehicles provides ample data on the emissions performance 
capability of 4-stroke engines in off-highway motorcycles and ATVs. 
Off-highway motorcycles certified to California standards for the 2000 
model year have HC certification levels ranging from 0.4 to 1.0 g/km. 
The motorcycles have engines ranging in size from 50 cc to 650 cc and 
none of these motorcycles are equipped with catalyst technology.
    Technologies are also available for the two stroke engine that may 
reduce HC emissions levels to near those provided by 4-stroke engines. 
Technologies such as direct fuel injection and catalysts have been 
applied to 2-stroke engines used in other applications, such as 
personal watercraft and outboard marine engines, in response to 
emissions control requirements. However, only vehicles equipped with 4-
stroke engines have been certified to the California standards. Two 
stroke models are sold in California, but only under California's 
allowance for the sales and use of uncertified products under certain 
circumstances (discussed above in section III.A.5).
    In determining what standards to propose, we will be carefully 
examining the feasibility and cost of both 2-stroke and 4-stroke 
technologies. Modest reductions (up to 30 percent) appear feasible 
through the use of engine modifications and calibration changes. We are 
also interested in approaches that would reduce HC emissions 
substantially (for example, 75 to 90 percent) from baseline 2-stroke 
engine levels. Clearly, switching to 4-stroke engines achieves this 
goal and some manufacturers would likely choose this approach to 
meeting such standards.
    However, some manufacturers may want an opportunity to achieve HC 
reductions through the use of advanced technology 2-stroke engines. 
This approach may require more time and investment in research and 
development than switching to 4-stroke engines entirely, but could 
result in more cost effective emissions control in the long term. Also, 
if such engines were developed, consumers may benefit from having a 
variety of engine types from which to choose. We request comment on 
whether EPA should attempt to set standards in a manner that would 
encourage the development of clean 2-stroke technology, and if so, how 
that objective could best be accomplished.
    We request comments on the appropriate level of HC control for off-

[[Page 76807]]

highway motorcycles and ATVs. We are interested in perspectives on 
whether an HC standard should be based on the capabilities of 4-stroke 
or 2-stroke engine emissions control technologies. We are also 
interested in comment on establishing separate standards for the two 
engine types. In making their recommendations, commenters are 
encouraged to consider the level of emission reductions currently 
achieved under the California emissions control program, described 
above, and the need and opportunity for further emissions reductions. 
Commenters are also encouraged to consider the benefits of aligning 
highway motorcycle HC standards, discussed in section IV below, with 
the HC standards for off-highway motorcycles and ATVs. We are 
interested in comments on technology, cost, corresponding emission 
reduction potential, necessary lead-time, phase-in, and performance 
implications, including supporting rationale and data, where possible. 
Commenters are also invited to address the cost and corresponding 
emissions reductions of various other potential strategies.
    As described above, we may propose averaging approaches such as 
corporate-average standards and averaging, banking, and trading. We 
request comment on the appropriateness of averaging ATVs and off-
highway motorcycles together, assuming they are required to meet the 
same standards, or standards of similar stringency. Comments on other 
aspects of averaging as it might apply to HC compliance are requested 
(for example, averaging recreational vehicles with other engines 
identified in this document).
    NOX standard. While the focus of the program would be on 
achieving HC reductions, we also request comment on the need for and 
appropriateness of NOX control for these engines. We are 
considering standards in the form of HC plus NOX. We would 
expect a small NOX increase when going from uncontrolled 
two-stroke engines to engine designs which meet new emissions 
standards. This NOX increase is due to engine efficiency 
improvements and emission control strategies available for 2-stroke 
engines. A NOX plus HC standard recognizes this trade-off. 
Also, 4-stroke engines typically have higher NOX emissions 
than 2-stroke engines.
    When we established the HC plus NOX standard for 
personal watercraft, we adjusted the level of the standard to account 
for the inclusion of NOX. We request comment on this 
approach for establishing an HC plus NOX limit for 
motorcycles and ATVs. We also request comment on how much of an 
adjustment to the standard is needed to account for NOX 
emissions or what level would be appropriate for a NOX cap. 
We also request comment on a NOX plus HC standard in the 
context of averaging approaches for compliance. Finally, we request 
comment on the cost implications and corresponding emission reduction 
potential of NOX control strategies.
    CO standard. We expect to establish a CO limit for motorcycles and 
ATVs, along with HC and NOX standards. We will be 
considering the levels established by California for these vehicles and 
the standards for highway motorcycles. We request comment on what level 
of CO control would be appropriate for these vehicles, considering 
costs (and other statutory factors). We also request comment on whether 
or not the CO standard should be established as a separate technology 
driver or based on the performance of technologies likely to be needed 
to achieve low HC emissions levels. We request comment on the cost 
implications and corresponding emission reduction potential of CO 
control strategies. As with HC and NOX, we are interested in 
the usefulness of considering averaging approaches for CO emissions 
compliance.
    Test procedures. The form and numeric level of the standards depend 
on the test procedures and test cycle over which emissions are 
measured. As described above in section III.A.5., California off-
highway motorcycle and ATV standards are based on the highway light-
duty vehicle test procedure (the FTP). This is a chassis-based test 
procedure, which requires the vehicle to be tested rather than only the 
engine.
    Some manufacturers have noted that they do not currently have 
chassis-based test facilities capable of testing ATVs. California 
provides manufacturers with the option of certifying ATVs using the 
engine-based, utility engine test procedure (SAE J1088), and most 
manufacturers use this option for certifying their ATVs. Manufacturers 
have facilities to chassis test motorcycles and therefore California 
does not provide an engine testing certification option for 
motorcycles. Manufacturers have noted that requiring chassis-based 
testing for ATVs would require them to invest in additional testing 
facilities which can handle ATVs, since ATVs do not fit on the same 
roller(s) as motorcycles used in chassis testing.
    Currently, for off-highway motorcycles and ATVs, we are planning to 
use the FTP test cycle, as it appears to be the best available test 
cycle for these vehicles. We will be carefully examining the potential 
pros and cons of using an engine-based test procedure for ATVs and 
request comment on this issue. We request comment on whether or not the 
approach taken by California is suitable for the federal program, 
including the use of the above test procedures and their effectiveness 
in ensuring in-use emissions reductions.
    We are particularly interested in comments on the use of the 
utility engine cycle for ATVs, and whether or not a different engine-
based test cycle, such as the one being considered for snowmobiles 
(discussed below), may be more suitable. The utility engine cycle is a 
5-mode steady-state test cycle which includes testing at only one 
engine speed (85 percent of rated speed). Such a test procedure is 
appropriate for engines used in lawn and garden applications, but may 
not be appropriate for engines used in vehicle applications. The 
snowmobile engine test procedure is also a 5-mode steady-state test 
procedure but the engine speed varies by mode along with torque. We 
believe this is generally more representative of how an engine behaves 
in a vehicle application.
2. Snowmobiles
    Emissions standards established by EPA through this rulemaking will 
be the first for snowmobiles. Unlike off-highway motorcycles and ATVs, 
there are no emissions standards for snowmobiles in California to use 
as a point of reference. Snowmobiles are almost entirely equipped with 
two-stroke engines which have very high HC and CO emission levels. Our 
focus for snowmobiles will be to reduce those emission levels. 
NOX emissions are much less of a concern because of the 
seasonal nature of snowmobile use and low baseline levels.
    CO standard. CO emissions may be a larger concern for snowmobiles 
than for off-highway motorcycles and ATVs due to their high CO 
emissions levels and the general concern of high ambient CO level in 
some areas during cold weather. In initial discussions with the 
International Snowmobile Manufacturers Association (ISMA), 
manufacturers have suggested setting standards that would result in CO 
reductions of 10 to 30 percent, phased in over model years 2004-2006. 
As described in section III.B. above, promising technologies are 
available which have the potential to reduce emissions to significantly 
lower levels. These technologies go beyond minor engine modifications 
and calibration changes and may require additional lead time to 
implement. However, with

[[Page 76808]]

appropriate lead time, further CO emission reductions may be reasonably 
achievable.
    We will be evaluating potential technologies and the costs of those 
technologies during the development of our proposal for snowmobiles. We 
will consider the timing of the standards in the context of the level 
of stringency we propose, recognizing that more lead-time would likely 
be needed to apply and prove-out the application of certain advanced 
technologies. Also, as described above, we will consider the value of 
implementation flexibilities such as averaging and phase-in schedules 
in allowing manufacturers to meet more stringent standards in an 
orderly manner. We request comment on what level of CO emissions 
control is feasible and appropriate for snowmobiles, on the cost and 
corresponding emissions reduction potential of various strategies, on 
the lead time needed to achieve new standards, and on the usefulness of 
implementation flexibility in meeting the standards.
    HC standard. As mentioned in section II, we received comments 
indicating that HC control for snowmobiles for purposes of reducing 
ozone may not be necessary due to their seasonal use. However, we 
believe that there may be a need to control HC emissions from 
snowmobiles. In particular, even if we accept the commenters' argument 
regarding ozone, HC emissions may result in increased exposure to air 
toxics. As discussed in section II, hydrocarbons are made up of 
numerous components, some of which have been identified as toxic air 
pollutants.
    We anticipate that many of the technology approaches available to 
manufacturers to reduce CO emission levels would also reduce HC 
emissions levels. The two-stroke engines used in snowmobiles have very 
high HC levels and we believe that establishing standards to reduce 
those levels would be appropriate. Manufacturers have suggested an HC 
reduction of up to 30 percent by 2008, in addition to the 30 percent 
reduction in CO by 2006, discussed above. As with CO, we believe 
technology is likely to be available to achieve a greater degree of 
control, especially with several years lead time or phase-in. 
Reductions in CO and HC of 70 percent or more may be feasible.
    We request comment on what level of HC emissions control is 
feasible and appropriate for snowmobiles, the cost and corresponding 
emissions reductions associated with such levels of emissions control, 
the lead time needed to achieve new standards, and the usefulness of 
implementation flexibility in meeting the standards. In particular, we 
request comment on the appropriateness of requiring any control of HC 
for snowmobiles given the seasonal nature of their use versus air toxic 
concerns for riders.
    Test Procedures. Snowmobile manufacturers, in conjunction with 
Southwest Research Institute, have developed a test procedure for 
measuring snowmobile emissions.\42\ This effort was undertaken due to 
increasing interest in snowmobile engine emission levels and a lack of 
a test procedure based on a representative duty-cycle. The test cycle 
is a 5-mode steady-state cycle, with different engine speed and torque 
points chosen and weighted to reflect in-use engine operation (see 
table below). The study also found that the utility engine cycle 
(J1088), which had previously been used, was not appropriate for 
snowmobiles.
---------------------------------------------------------------------------

    \42\ ``Development and Validation of a Snowmobile Engine 
Emission Test Procedure,'' Christopher W. Wright and Jeff J. White, 
SAE Paper 982017.

                                   Table III-3.--Snowmobile Engine Test Cycle
                                               (SAE paper 982017)
----------------------------------------------------------------------------------------------------------------
                      mode                            1            2            3            4            5
----------------------------------------------------------------------------------------------------------------
normalized speed...............................          1.0         0.85         0.75         0.65         idle
normalized torque..............................          1.0         0.51         0.33         0.19            0
Weight, %......................................           12           27           25           31            5
----------------------------------------------------------------------------------------------------------------

    We request comment on the use of this test procedure as the basis 
of future snowmobile standards. This test procedure appears to be the 
best currently available for snowmobiles, but we request comment on the 
need for additional tests or test modes to ensure in-use emissions 
control. For example, idle CO emissions have been highlighted as a 
particular concern for snowmobiles and we request comment on the need 
for additional emphasis on idle CO emissions within the test procedure.
3. The Need for PM Standards
    As discussed in section II, Air Quality, we are very concerned 
about current high particulate matter levels in snowmobile exhaust. 
High PM levels are primarily attributable to the use of traditional 2-
stroke engines. PM emissions are also a concern for off-highway 
motorcycles and ATVs to the extent that 2-stroke engines are used in 
those applications.
    We believe that the technology changes that would be needed to 
significantly reduce CO and HC levels, such as direct injection or 4-
stroke engines, may also dramatically reduce PM levels. If HC and CO 
standards were established at a level only requiring minor 
modifications to the engines, PM could remain a problem for snowmobiles 
and a PM standard may be necessary. We request comment on whether or 
not we should establish a PM standard for snowmobile engines and what 
level of stringency would be appropriate. We also request comment on 
the cost implications (equipment costs, etc.) associated with measuring 
PM as part of the certification procedure.
4. Averaging, Banking, and Trading
    Depending on the structure of the proposed program, the level of 
stringency of the proposed standards, and other considerations, we may 
propose averaging, banking, and trading provisions (ABT) for 
recreational vehicles/engines. We have established ABT programs in many 
of our engine-based emissions control programs in cases where we have 
set standards that require significant technology changes. The ABT 
programs allow manufacturers

[[Page 76809]]

to earn credits by introducing clean engines sooner than required or by 
certifying engines to levels below the standards. Manufacturers may use 
the credits to certify engines to levels above the standards in the 
same model year (averaging), keep the credits for use in a later model 
year (banking), or transfer the credits to another manufacturer 
(trading).
    In some cases, we have not established ABT programs because we 
believed the standards we were adopting were achievable without the 
additional flexibility. In such cases, EPA found that the added 
complexity inherent in having an ABT program, both for EPA and the 
manufacturers, would outweigh the potential benefits of the program.
    ABT can be beneficial in providing incentive to manufacturers for 
the early introduction of new technologies, allowing certain engine 
families to be trail blazers for new technology. This flexibility can 
allow us to consider a more stringent program than would otherwise be 
appropriate under CAA section 213. The programs also provide 
flexibility to manufacturers for product planning and can provide 
opportunity for more cost effective introduction of product lines. ABT 
is tailored to meet the specific needs of standards and programs being 
established. This is necessary to avoid issues such as windfall credits 
and the potential of stockpiling credits which could result in a 
significant delay of the standards being adopted or future standards 
not yet considered. We request comment on integrating ABT into the 
programs for recreational vehicles. We are interested in comment on the 
scope of ABT, including any particular issues we should consider in 
developing such a program, and whether or not credit trading among 
different vehicle types should be allowed.

D. Additional Program Considerations

1. Competition Off-Highway Motorcycles
    Currently, a large portion of off-highway motorcycles are marketed 
as competition/racing motorcycles. These models often represent a 
manufacturer's high performance offerings in the off-highway market. 
Most such motorcycles are of the motocross variety,\43\ although some 
high performance enduro models \44\ are marketed for competition use. 
These high performance motorcycles are largely powered by 2-stroke 
engines, though some 4-stroke models have been introduced in recent 
years.
---------------------------------------------------------------------------

    \43\ A motocross bike is typically a high performance off-
highway motorcycle that is designed to be operated in motocross 
competition. Motocross competition is defined as a circuit race 
around an off-highway closed-course. The course contains numerous 
jumps, hills, flat sections, and bermed or banked turns. The course 
surface usually consists of dirt, gravel, sand, and mud. Motocross 
bikes are designed to be very light for quick handling and easy 
manueverability. They also come with large knobby tires for 
traction, high fenders to protect the rider from flying dirt and 
rocks, aggressive suspension systems that allow the bike to absorb 
large amounts of shock, and are powered by high performance engines. 
They are not equipped with lights.
    \44\ An enduro bike is very similar in design and appearance to 
a motocross bike. The primary difference is that enduros are 
equipped with lights and have slightly different engine performance 
that is more geared towards a broader variety of operation than a 
motocross bike. An enduro bike needs to be able to cruise at high 
speeds as well as operate through tight woods or deep mud.
---------------------------------------------------------------------------

    When used for competition, motocross motorcycles are mostly 
involved in closed course or track racing. Other types of off-highway 
motorcycles are usually marketed for trail or open area use. When used 
for competition, these models are likely to be involved in point-to-
point competition events over trails or stretches of open land. There 
are also specialized off-highway motorcycles that are designed for 
competitions such as ice racing, drag racing, and observed trials 
competition. A few races involve professional manufacturer sponsored 
racing teams. Amateur competition events for off-highway motorcycles 
are also held frequently in many areas of the U.S.
    Clean Air Act sections 216 (10) and (11) exclude engines and 
vehicles ``used solely for competition'' from nonroad engine and 
vehicle regulations. For purposes of past nonroad engine emissions 
control regulatory programs (for example, the nonroad CI, recreational 
marine, and Small SI programs), EPA has defined the term ``used solely 
for competition'' as follows:
    Used solely for competition means exhibiting features that are not 
easily removed and that would render its use other than in competition 
unsafe, impractical, or highly unlikely.
    If retained for the recreational vehicles program, the above 
definition may be useful for identifying certain models that are 
clearly used only for competition. For example, there are motorcycles 
identified as ``observed trials'' motorcycles which are designed 
without a standard seat because the rider does not sit down during 
competition. This feature would make recreational use unlikely. Most 
motorcycles marketed for competition, however, do not appear to have 
physical characteristics that constrain their use to competition. 
Without such distinguishing characteristics, determining that a vehicle 
is used solely for competition becomes more challenging.
    Manufacturers have recommended that EPA use the definition for 
competition motorcycle that EPA has previously established for purposes 
of exempting motorcycles from its noise regulations, as follows:
    Competition motorcycle means any motorcycle designed and marketed 
solely for use in closed course competition events.\45\
---------------------------------------------------------------------------

    \45\ 40 CFR 205.151(a)(3).
---------------------------------------------------------------------------

    Manufacturers further recommended that closed course competition 
include ``any organized competition event covering a closed, repeated, 
or defined route intended for easy viewing of the route by spectators. 
Such events could include, but are not limited to, motocross, enduro, 
hare scrambles, observed trials, short track, dirt track, drag race, 
hill climb, ice race, and land speed trials * * *''. Manufacturers 
recommended that EPA require labels designating the vehicles for 
competition use only.\46\
---------------------------------------------------------------------------

    \46\ ``MIC Recommended Definitions for Pending EPA Recreation 
Vehicle Exhaust Emissions Proposal,'' Motorcycle Industry Council, 
Draft, June 1, 2000. Docket A-2000-01.
---------------------------------------------------------------------------

    Based on confidential sales information, we believe that vehicles 
designated for competition by manufacturers could exceed 50 percent of 
total sales under their recommended approach. We believe that many 
``competition'' style motorcycles are likely to also be used, at least 
by many end users, primarily or often for recreational riding. Section 
216(10) of the Act excludes from the definition of nonroad engines 
vehicles used solely for competition. We are concerned that the 
approach suggested by manufacturers may be overly broad and therefore 
would not meet the conditions of this exclusion.
    In a recent rulemaking for marine diesel engines, we addressed 
competition engines by providing exclusions for engines used in 
professional competitions only.\47\ Engines used for amateur 
competition or occasional competition are not excluded under that rule. 
The exclusion is available both to manufacturers and to someone 
modifying an engine for professional competition use (normally, we 
would prohibit someone from making changes to a certified engine in 
ways that adversely affect emissions control). This would be one 
possible

[[Page 76810]]

approach to address the competition use issue for recreational 
vehicles.
---------------------------------------------------------------------------

    \47\ 64 FR 73305, December 29, 1999.
---------------------------------------------------------------------------

    We are very interested in receiving input on the competition 
exemption issue described above. We request comment on ways the program 
can be established to provide an exclusion for motorcycles used solely 
for competition, consistent with the Act, without excluding vehicles 
that are often used for other purposes. Ideally, the program can be 
established in a way that provides reasonable certainty at time of 
certification. However, approaches could include reasonable measures at 
time of sale or in-use that would provide assurance that the 
competition exemption is being applied appropriately. We request 
information and data on the use of off-highway motorcycles for 
competition and recreation that would inform the rulemaking process.
2. Crankcase Emissions From Recreational Vehicles
    We will be considering proposing the elimination of crankcase 
emissions from recreational vehicles. Venting the crankcase to the 
atmosphere is a source of HC emissions that has been cost effectively 
controlled in many other engine applications. Rather than venting these 
emissions to the atmosphere, they can be routed back to the engine for 
combustion. We believe that any effect on exhaust emission levels due 
to the additional hydrocarbons which are routed to the engine through 
the crankcase emissions control system can be substantially reduced, if 
not eliminated, through the recalibration of the engine. We are not 
aware of any issues particular to closing the crankcase on engines used 
in recreational vehicles. California has required the elimination of 
crankcase emissions on off-highway motorcycles and ATVs as part of 
their program. We request comments on the costs, emission reductions, 
and any other issues associated with requiring the elimination of 
crankcase emissions from recreational vehicles.
3. Compliance Measures
    Along with emissions standards, we will be considering requirements 
to ensure in-use compliance with those standards over the useful life 
of the recreational vehicles/engines. The goal of these measures would 
be to promote high quality engine design, production, and in-use 
emissions performance. Compliance programs typically include 
certification, production line testing, and in-use testing components. 
Under these programs, manufacturers must submit data and other 
information prior to introducing the engine into commerce certifying 
that the engine meets applicable standards, and there is the ability to 
verify compliance through engine testing at the production line and in-
use. We expect to examine the structure and effectiveness of compliance 
programs contained in other nonroad emissions control programs in 
determining what types of measures would be most appropriate for 
recreational vehicles.
    Because of similarities in the applications, engine 
characteristics, and production volumes, we will carefully consider 
whether the compliance programs for recreational vehicles should be 
modeled after the programs adopted to control emissions from marine 
outboard engines and personal watercraft.\48\ Some manufacturers making 
these marine products also make recreational vehicles, and are 
therefore familiar with the structure of the marine engines program.
---------------------------------------------------------------------------

    \48\ 61 FR 52088, October 4, 1996.
---------------------------------------------------------------------------

    We encourage interested parties to review the compliance program in 
place for outboard engines and personal watercraft and provide input to 
EPA on the potential for applying the same types of compliance measures 
to these other recreational vehicles. In particular, we are interested 
in comments on requirements for manufacturer production line and in-use 
testing. For outboard engines and personal watercraft, the production 
line testing program requires manufacturers to test engines as they 
leave the production line. This process is used to provide a quality 
control check on the manufacturer's production processes to ensure that 
engines are routinely assembled in a way such that they continue to 
meet emission performance requirements when coming off the assembly 
line. The manufacturer in-use testing program requires manufacturers to 
select engines from the in-use fleet and test a portion of their engine 
families each year. These requirements focus resources on ensuring in-
use compliance and are key components to the overall compliance program 
we have established for recreational marine engines.
4. Consumer Modifications
    We are aware that consumers sometimes modify engines and exhaust 
systems on their recreational vehicles. Some of these changes are done 
to enhance operating performance. Others are to maintain optimal 
performance under varying operating conditions (i.e., changes in 
altitude, weather, etc.). We request information on the types of 
modifications that are common for the different types of recreational 
vehicles and any information on their impact on emission performace. We 
are especially interested in those modifications that would affect the 
emissions performance of the vehicle, and could be considered tampering 
under the Act for engines certified to emissions standards. We also 
request information that would help us better understand how common 
these practices are for the different types of vehicles. Understanding 
the scope of these practices will help us establish standards and 
program requirements that achieve in-use emissions reductions.
5. Useful Life
    For highway motorcycles, we currently have three distinct useful 
life categories that are based on engine displacement. The useful life 
for all three categories are five years or 12,000 km, 18,000 km, or 
30,000 km depending on which category the motorcycle falls under. 
California has established a useful life of 5 years or 10,000 km for 
off-highway motorcycles and ATVs. For some of our nonroad engine 
regulations, we have based useful life on time (i.e., hours). We 
request information that would help us determine the most appropriate 
method for establishing useful life for recreational vehicles. For 
example, a certain number of hours may be appropriate for snowmobiles 
and possibly ATVs, whereas a useful life similar to that used for 
highway motorcycles or California off-highway motorcycles may be more 
appropriate for off-highway motorcycles. We request comment on what the 
appropriate useful life levels and values would be for the various 
types of recreational vehicles.
6. Consumer Labeling
    We request comment on the potential for a consumer labeling program 
for recreational vehicles. We are also interested in comment on this 
topic for recreational marine engines, as discussed in section V.E.10. 
The purpose of a labeling program would be to educate consumers so that 
they could make informed decisions concerning engine emissions when 
they purchase a recreational vehicle. One example of a consumer 
labeling program is the California Air Resources Board's requirement 
that personal watercraft and outboard engines sold in California 
starting in 2001 be labeled as either low, very-low, or ultra-low 
depending on their emission levels.
    We request comment on the merit and cost of including such a 
program in our proposal for recreational vehicles and

[[Page 76811]]

whether the program should be voluntary or mandatory. We also request 
comment on programmatic aspect of labeling such as the content of the 
label, the number of tiers that would be useful in distinguishing among 
recreational vehicle models, and the pollutant(s) that should be used 
in establishing those tiers. Finally, we request comment on any other 
appropriate incentives for introducing new clean technologies that may 
be available.

IV. Highway Motorcycles

    In addition to the nonroad vehicles and engines noted above, 
today's ANPRM also reviews EPA requirements for highway motorcycles. 
The emissions standards for highway motorcycles were established 
twenty-three years ago. California recently adopted new emissions 
standards for highway motorcycles and new standards have also been 
proposed internationally. There may be opportunities to reduced 
emissions in a way that also allows manufacturers to benefit from 
harmonized requirements, which may reduce product lines and production 
costs. In addition, we believe it is important to consider the 
emissions standards for highway motorcycles in the context of setting 
standards for off-highway motorcycles. We are interested in providing 
regulatory programs for off-highway and highway motorcycles that are 
consistent, which may also allow for the transfer of technology across 
product lines for manufacturers. Consequently, we request comment on 
the appropriateness of examining and potentially revising the highway 
motorcycle emission standards in the same time frame, and in the same 
rulemaking, in which we plan to address emission standards for 
recreational vehicles.

A. What Is a Highway Motorcycle, and Who Makes Them?

    Motorcycles come in a variety of two-and three-wheeled 
configurations and styles. For the most part, however, they are two-
wheeled self-powered vehicles. Federal regulations currently define a 
motorcycle as ``any motor vehicle with a headlight, taillight, and 
stoplight and having: two wheels, or three wheels and a curb mass less 
than or equal to 680 kilograms (1499 pounds).'' (See 40 CFR 86.402-
86.478). Vehicles that otherwise meet the motorcycle definition but 
have engine displacements less than 50 cubic centimeters (cc) 
(generally, youth motorcycles, most mopeds, and some motor scooters) 
are currently not covered by federal regulations. Also currently 
excluded are motorcycles which, ``with an 80 kg (176 lb) driver, * * * 
cannot: (1) Start from a dead stop using only the engine; or (2) Exceed 
a maximum speed of 40 km/h (25 mph) on level paved surfaces' (e.g., 
some mopeds). Most scooters and mopeds have very small engine 
displacements and are typically used as short-distance commuting 
vehicles. Motorcycles with larger engine displacement are more 
typically used for recreation (racing or touring) and may travel long 
distances. Both EPA and California regulations further sub-divide 
highway motorcycles into classes based on engine displacement. Table 
IV-1 shows how these classes are defined.
    The currently regulated highway category includes motorcycles 
termed ``dual-use'' or ``dual-sport,'' meaning that their designs 
incorporate features that enable them to be reasonably competent on and 
off road. Dual-sport motorcycles generally can be described as street-
legal dirt bikes, since they tend to bear a closer resemblance in terms 
of design features and engines to true off-highway motorcycles than to 
highway cruisers or sport bikes. However, another category of 
motorcycle, referred to as ``enduros,'' are very similar in appearance 
to dual-sport motorcycles, but are typically equipped with higher 
performance engines and have traditionally been categorized as nonroad 
motorcycles and not been subject to the highway emission standards. 
Therefore, we request comment as to how we can better determine which 
motorcycles are street-legal and which are not.
    Throughout this ANPRM the term ``highway motorcycle'' is intended 
to include all motorcycles covered by the current federal regulations; 
thus, dual-sport motorcycles are included in this definition. We 
currently believe that all highway motorcycle engines sold in the U.S., 
including those that power dual-sport motorcycles, are four-stroke 
engines.

                     Table IV-1.--Motorcycle Classes
------------------------------------------------------------------------
                                           Engine  displacement  (cubic
            Motorcycle class                       centimeters)
------------------------------------------------------------------------
Class I................................  50--169.
Class II...............................  170--279.
Class III..............................  280 and greater.
------------------------------------------------------------------------

    Highway motorcycles are dominated by larger engines, with engine 
displacements exceeding 1000 cc for the most powerful ``superbikes.'' 
According to the Motorcycle Industry Council (MIC), in 1998 there were 
about 5.4 million highway motorcycles in use in the United States (only 
565,000 of these were dual-sport), more than three-fourths of which had 
an engine displacement of over 449 cc.\49\ Sixty percent had an engine 
displacement greater than 749 cc. Inclusion of the dual-sport 
motorcycles in this figure tends to skew the numbers somewhat, even 
despite the fact that their total numbers are relatively small, because 
their dirt bike heritage leads them to be weighted towards smaller 
engines. According to the MIC data, three-fourths of dual-sport 
motorcycles had an engine displacement of less than 350 cc, whereas 
two-thirds of the remaining motorcycles (those purely designed for road 
use) had a displacement of over 749 cc. Total sales in 1998 of highway 
motorcycles was estimated to be about 411,000, or about 72 percent of 
motorcycle sales. About 13,000 of these were dual-sport motorcycles. 
The remaining 28 percent of sales were strictly off-highway 
motorcycles, which are currently unregulated.
---------------------------------------------------------------------------

    \49\ ``1999 Motorcycle Statistical Annual,'' Motorcycle Industry 
Council.
---------------------------------------------------------------------------

    We are aware of a half-dozen companies, Honda, Harley Davidson, 
Yamaha, Kawasaki, Suzuki, and BMW, which account for near 95 percent of 
all motorcycles sold. Dozens of other minor players make up the 
remaining few percent. Based on available information, over half of all 
motorcycles sold in 1998 were made by Honda and Harley Davidson, with 
the two companies maintaining almost equal market shares of about 25 
percent each.

B. What Is the Regulatory History?

1. Environmental Protection Agency Regulations
    In 1974 EPA issued an advance notice of proposed rulemaking that 
discussed the possible implementation of emission controls for highway 
motorcycles for the first time and requested comment on a number of 
issues. Taking into account the comments received on the ANPRM, EPA 
issued an NPRM the following year for the control of exhaust and 
crankcase emissions from new motorcycles. The proposal addressed 
standards for HC, CO, and NOX, proposing a set of interim 
standards for 1978 and 1979 and final standards equivalent to the 
light-duty vehicle standards in effect at that time. The NPRM was 
followed by a Final Rule promulgated in 1977 (42 FR 1126, Jan. 5, 1977) 
which established interim standards effective for the 1978 and 1979 
model years and ultimate standards effective starting with the 1980 
model year. The interim standards ranged from 5.0 to 14.0 g/km HC 
depending upon engine displacement,

[[Page 76812]]

while the CO standard of 17.0 g/km applied to all motorcycles. The 1980 
standards, which were more lenient than those that were proposed and 
which lacked a NOX standard, are essentially those that 
remain in effect today. While the final standards did not differ based 
on engine displacement, the useful life over which these standards must 
be met ranged from 12,000 km (7,456 miles) for Class I motorcycles to 
30,000 km (18,641 miles) for Class III motorcycles. These standards 
were updated in 1989 to include methanol-fueled motorcycles starting 
with the 1990 model year, then again in 1994 to include natural gas-
fueled and liquefied petroleum gas-fueled motorcycles starting with the 
1997 model year. Crankcase emissions from motorcycles are also 
prohibited. There are no current federal standards for evaporative 
emissions from motorcycles. The current federal standards are shown in 
Table IV-2.

 Table IV-2.--Current Federal Exhaust Emission Standards for Motorcycles
------------------------------------------------------------------------
                  Engine size                    HC (g/km)    CO (g/km)
------------------------------------------------------------------------
All...........................................         5.0         12.0
------------------------------------------------------------------------

2. Regulation by the California Air Resources Board
    Motorcycle emission standards in California were originally 
identical to the federal standards that applied to the 1978 through 
1981 model years. The definitions of motorcycle classes used by 
California continue to be identical to the federal definitions. 
However, California has revised their standards several times to bring 
them to their current levels. In 1982 the standards were modified to 
reduce the HC standard from 5.0 g/km to 1.0 or 1.4 g/km, depending upon 
engine displacement. California adopted an evaporative emission 
standard of 2.0 g/test for 1983 and later model year motorcycles. In 
1984 California amended the regulations for 1988 and later model year 
motorcycles to further lower emission standards and provide additional 
compliance flexibility to manufacturers. The 1988 and later standards 
could be met on a corporate-average basis, and the larger (Class III) 
bikes (280 cc and above) were split into two separate categories: 280 
cc to 699 cc and 700 cc and greater. These are the standards being met 
in California today. Like the federal standards, there are no currently 
applicable NOX standards for highway motorcycles in 
California. Under the corporate-averaging scheme, no individual engine 
family is allowed to exceed a cap of 2.5 g/km. Like the federal 
program, California also prohibits crankcase emissions.

   Table IV-3.--Current California Highway Motorcycle Exhaust Emission
                                Standards
------------------------------------------------------------------------
                Engine size (cc)                   HC (g/km)   CO (g/km)
------------------------------------------------------------------------
50-279..........................................         1.0        12.0
280-699.........................................         1.0        12.0
700 and above...................................         1.4        12.0
------------------------------------------------------------------------

    In 1998 the California Air Resources Board (CARB) proposed new 
standards for Class III highway motorcycles that would take effect in 
two phases--a ``Tier 1'' to start with the 2004 model year, followed by 
a ``Tier 2'' that would take effect starting with the 2008 model year. 
These standards were finalized with minor modifications on November 22, 
1999. Existing California standards for Class I and II motorcycles 
remained unchanged. As with the current standards, manufacturers will 
be able to meet the requirements on a corporate-average basis. Perhaps 
most significantly, this recent CARB action brings some level of 
NOX control to motorcycles by establishing a combined 
HC+NOX standard. No changes were made by the CARB action to 
the CO standard, which remains at 12.0 g/km. In addition, CARB is 
providing an incentive program to encourage the introduction of 
motorcycles compliant with the Tier 2 standard prior to the 2008 model 
year. This incentive program allows the accumulation of credits that 
manufacturers can use to meet the 2008 standards. Like the federal 
program, these standards will also apply to dual sport motorcycles.

        Table IV-4.--Tier 1 and Tier 2 California Class III Highway Motorcycle Exhaust Emission Standards
----------------------------------------------------------------------------------------------------------------
                                                                                          HC+NOX (g/
                   Model year                              Engine displacement                km)      CO (g/km)
----------------------------------------------------------------------------------------------------------------
2004 through 2007 (Tier 1).....................  280 cc and greater.....................         1.4        12.0
2008 and subsequent (Tier 2)...................  280 cc and greater.....................         0.8        12.0
----------------------------------------------------------------------------------------------------------------

    California also adopted a new definition of small volume that would 
take effect with the 2008 model year. Historically, California had a 
definition of small volume that applied to the 1984 through 1987 model 
years (5,000 units per model year), but no definition that has applied 
since. Thus, for the 1988 through 2007 model years, all manufacturers 
must meet the standards, regardless of production volume. Small volume 
manufacturers, defined in CARB's recent action as a manufacturer with 
combined California sales of Class I, Class II, and Class III 
motorcycles not greater than 300 units, do not have to meet new 
standards until the 2008 model year, at which point the Tier 1 standard 
applies. CARB intends to evaluate whether the Tier 2 standard should be 
applied to small volume manufacturers in the future.\50\
---------------------------------------------------------------------------

    \50\ CARB, October 23, 1998 ``Proposed Amendments to the 
California On-Road Motocycles Regulation'' Staff Report: Initial 
Statement of Reasons.
---------------------------------------------------------------------------

3. European Regulations
    The European Commission recently proposed a new phase of motorcycle 
standards, which would start in 2003, and are considering a second in 
2006. Whereas the current European standards make a distinction between 
two-stroke and four-stroke engines, the proposed standards would apply 
to all motorcycles regardless of engine type, leading to a technology-
independent regulatory framework. The 2003 standards would require 
emissions to be below the values shown in Table IV-5, as measured over 
the European ECE-40 test cycle. The phase of standards being considered 
for 2006 are still in a draft form and have not yet been officially 
proposed, but in addition to taking another step in reducing motorcycle 
emissions, the 2006 standards are expected to incorporate an improved 
motorcycle test cycle, as noted in Section IV.D.2 below.

[[Page 76813]]



    Table IV-5.--European Commission Proposed 2003 Motorcycle Exhaust
                           Emission Standards
------------------------------------------------------------------------
                                                               NOX  (g/
                    HC (g/km)                      CO (g/km)      km)
------------------------------------------------------------------------
1.2.............................................         5.5         0.3
------------------------------------------------------------------------

C. Highway Motorcycle Emission Control Technology

1. Federal Standards
    While highway motorcycles have had to apply some low-level control 
technologies to meet the current standards, the current federal 
standards require a technology mix comparable to the pre-catalyst stage 
for passenger cars. The standards that took effect starting in the 1980 
model year precipitated the elimination of highway two-stroke engines 
and a transition to a fleet composed entirely of four-stroke engines. 
In general, the standards prompted the use of leaner air-fuel mixtures, 
electronic ignition systems, improvements in manufacturing tolerances 
in the carburetor and fuel handling systems, PCV valves to control 
crankcase emissions, and some engine redesign and modifications 
(changes to the camshaft, valve and ignition timing, and combustion 
chamber design).
2. California Standards
    Despite the greater stringency of the current California standards 
(i.e., those that apply in the current model year), most manufacturers 
have been able to comply without the use of catalytic converters, and 
only a few expensive high-performance motorcycles have used fuel 
injection systems. The majority of motorcycles have been able to meet 
these standards by using, in addition to the measures noted above for 
the federal standards, engine modifications and more advanced 
calibration strategies, with air injection systems being commonly used 
in the larger motorcycle models. A few models have been certified with 
3-way catalytic converters and fuel injection systems.
    The Tier 1 and Tier 2 standards taking effect in California in 2004 
and 2008, respectively, will require some additional technologies.\51\ 
Many of the control technologies that have been applied successfully to 
four-stroke engines in passenger cars may have some potential 
application to four-stroke motorcycle engines. Some, such as fuel 
injection and catalytic converters, have already been successfully used 
on some motorcycle engines, as noted above. Other passenger car 
technologies may arrive on motorcycles soon due to the upcoming 
California requirements. However, California did not base the Tier 1 
standard effective in 2004 on the widespread application of catalytic 
converters. California has determined the 1.4 g/km HC+NOX 
standard will be largely feasible by reducing engine-out emissions 
using mostly engine systems (e.g., fuel injection, pulse air injection, 
valve overlap changes), rather than relying on catalytic after-
treatment. According to California, the Tier 2 standard will be more of 
a challenge to industry and existing technologies are likely to be 
modified and optimized for motorcycle application to achieve 0.8 g/km 
HC+NOX. They claim that such technologies could include 
computerized fuel injection, high-efficiency closed-loop two- or three-
way catalytic converters, precise air-fuel ratio controls, programmed 
secondary pulse-air injection, low-thermal capacity exhaust pipes, and 
others which are available today or in the foreseeable near future. 
California has also suggested that some manufacturers may be able to 
meet the Tier 2 standards on some models without the use of catalytic 
converters.
---------------------------------------------------------------------------

    \51\ California Air Resources Board, ``Final Statement of 
Reasons for Rulemaking,'' December 10, 1998.
---------------------------------------------------------------------------

D. Standards and Program Approaches

    We have identified a number of key issues and decision points that 
may impact any action we may take regarding standards for highway 
motorcycles. We request detailed comments and data regarding the issue 
areas described in this section.
1. Exhaust Emission Standards
    In general we request comment on the technological feasibility, 
cost, and appropriateness of implementing new more stringent emission 
standards for highway motorcycles. We also request comment on 
technologies that might enable reductions in motorcycle emissions, and 
the potential magnitude of such reductions. We request comment on the 
appropriate time frame for implementing new emission standards for 
highway motorcycles. In addition, we request detailed comments on the 
following specific issue areas.
    Harmonization with California. In many program areas, including 
light-duty and heavy-duty vehicles and engines, harmonization with 
California has frequently been a significant objective, and is often a 
desirable outcome for industry. When federal and California compliance 
programs are harmonized, manufacturers are more easily able to produce 
engine families that comply with both programs, rather than having to 
consider whether or how to design and market engine families separately 
for California and the remaining 49 states. In addition, historically 
any time the California program is significantly more stringent than 
the federal program there is a possibility that some individual states 
will elect to enforce the California program (as several states 
currently do with light-duty vehicles), further complicating 
compliance, marketing, and distribution for the manufacturers. Given 
that California has recently put in place technologically challenging 
standards for Class III motorcycles in a time frame that we would be 
likely to consider for a possible federal program, we are likely to 
look very closely at the pros and cons of harmonizing the federal 
program with the recently finalized California standards. We request 
comment on all aspects of the California program and whether the 
California standards are appropriate for a nationwide federal program. 
Commenters should address technological feasibility, cost, 
corresponding potential emissions reductions, appropriate time frame, 
structure (e.g., a fleet average approach vs. something else), and 
potential advanced emission control technologies associated with 
California-level standards and with any other level of standards a 
commenter may consider appropriate.
    As noted earlier, the recent action by California did not address 
emissions from Class I and Class II motorcycles. We request comment on 
the need to consider emission reductions from all classes of 
motorcycles, including Class I and Class II.
    Harmonization with off-highway motorcycles. Since we will be 
promulgating emission standards for off-highway motorcycles for the 
first time, it may make sense to have standards that apply to both, 
off-highway and on-highway motorcycles. This could be beneficial for 
manufacturers that produce both types of motorcycles, since they could 
spread their resources across both programs. In addition, the 
experience and knowledge used in developing emission compliant highway 
motorcycles could possibly be transferred to off-highway motorcycle 
applications. However, we also acknowledge that many off-highway 
motorcycles use two-stroke engines, where two-stroke engines are no 
longer used in highway applications and some of the information used in 
meeting highway standards may not be applicable. Therefore, we request 
comment on the appropriateness of harmonization of highway and off-

[[Page 76814]]

highway motorcycle emission standards and the costs and corresponding 
emissions reductions associated with this approach.
2. Test Cycle
    The test cycle currently used to for compliance with the motorcycle 
emission standards, in both the federal and California programs, is the 
FTP-75. Motorcycles are tested on a specialized motorcycle chassis 
dynamometer on the traditional FTP, the same cycle used for light-duty 
vehicles and trucks, although the driving schedule speeds and 
accelerations are reduced for Class I and II motorcycles. It is now 
widely acknowledged that the traditional FTP does not adequately 
represent some high-emission modes that vehicles experience in actual 
use. When the cycle was first adopted for passenger cars in the early 
1970's, the limited capabilities of the chassis dynamometers at that 
time made it necessary to limit the speeds and acceleration rates of 
the driving cycle. Thus, the top speed and acceleration rates seen on 
the FTP are much less than most vehicles--especially motorcycles--can 
achieve on the road. Consequently, we request comment on whether the 
existing US06 driving cycle for light-duty vehicles and trucks--or some 
other more representative driving cycle--may be appropriate for highway 
motorcycles, and if so, what standards might be appropriate. We request 
data on how motorcycles are driven in actual use that might support or 
reject the appropriateness of a high-speed/high-acceleration driving 
cycle for motorcycles.
    In addition, there is an effort underway under the auspices of the 
United Nations/Economic Commission for Europe (UN/ECE) to develop a 
global harmonized world motorcycle test cycle (WMTC). The objective of 
this work is to develop a scientifically supported test cycle that 
accurately represents the in-use driving characteristics of 
motorcycles. The United States is also a participating member of UN/
ECE. EPA has stated that present levels of environmental protection 
will not be lowered in order to achieve regulatory harmonization. In 
its recent proposal, the European Commission has announced its 
intention to consider a global test cycle for the second phase of its 
proposed standards, expected to take effect in 2006. We request comment 
on all issues related to pursuing a globally harmonized test cycle.
3. Evaporative Emission Standards
    As noted earlier, the existing federal program does not require 
compliance with a limit on evaporative emissions from motorcycles, 
while California does. We request comments and supporting information 
on the appropriateness of harmonization with the California evaporative 
standards or whether other evaporative emission standards might be an 
appropriate element of the federal program. We also request comment on 
the costs and corresponding emissions reductions associated with 
adopting evaporative emission standards.

E. Additional Program Considerations

1. Addressing Currently-Excluded Vehicles
    In addition, we may consider developing appropriate standards for 
those types of vehicles now excluded from compliance with emission 
standards. This would include mopeds and scooters that are under 50 cc 
or that otherwise can not meet the applicability criteria in the 
regulations (a mix of two-and four-stroke engines). As noted earlier, 
some of these vehicles do not meet the regulatory definition of motor 
vehicle by not being able to exceed 25 mph, thus it may be appropriate 
to consider such vehicles as nonroad vehicles and may be appropriate to 
regulate them under the recreational vehicle regulations. We request 
comment on the appropriateness, technological feasibility, and cost of 
implementing emission standards for these currently unregulated 
vehicles. We request comment on approaches to reducing emissions from 
these types of vehicles, and on the technologies that might be used to 
reduce emissions, both for two- and four-stroke models.
2. Consumer Modifications
    A significant issue that emerged in the context of the new 
California standards is the rate at which consumers make modifications 
to their motorcycles, often using aftermarket parts, to enhance 
performance, sound, and/or appearance. The Motorcycle Industry Council 
expressed a concern to California that standards which result in the 
widespread use of catalysts will achieve less benefits than projected 
due to consumer tampering with the exhaust systems. Such tampering, 
which can frequently involve the replacement of exhaust pipes that may 
include the removal of the catalytic converter, can clearly offset a 
significant portion of the emission benefits. We request comment on 
this issue, and in particular request any data that may demonstrate the 
magnitude of these consumer practices. We request comment on approaches 
to standard-setting that may mitigate this problem while also enabling 
motorcycles to take advantage of proven technologies such as catalytic 
converters.
3. Small Volume Manufacturers
    The issue of how to define a small volume manufacturer by 
regulation was also a significant one that arose in the context of the 
new California standards. Motorcycle manufacturers with fewer than 500 
employees meet the current definition of a small business under the 
classifications established by the Small Business Administration. The 
current federal regulations define a small volume motorcycle 
manufacturer as one whose projected U.S. sales of motorcycles is less 
than 10,000 units. We request comment on how the existing federal 
definition may interact with the new California definition, and 
whether, in the context of the new California definition (described 
earlier), any inequities are created between the two motorcycle 
compliance programs. We request comment on the appropriateness of the 
existing federal definition, and, in the context of revised federal 
standards, what types of compliance flexibilities might be appropriate 
for those manufacturers defined as small volume.
4. Useful Life
    As noted earlier, the current federal standards were put in place 
more than twenty years ago. An important aspect of the overall emission 
standards, in addition to the numerical limits, is the vehicle useful 
life over which applicability with the standards must be demonstrated 
when the vehicle is certified. The current useful life definitions, 
like the numerical emission limits, were put in place twenty years ago. 
In conjunction with evaluating the possibility of revising emission 
standards for highway motorcycles, we believe it may be appropriate to 
reevaluate the useful life definitions in the context of current 
technology and driving habits. As is clearly the case with passenger 
cars, motorcycles may have evolved in the last twenty years to last 
longer and be driven more miles. Congress found it necessary to 
increase the useful life of passenger cars in the 1990 Clean Air Act 
Amendments from 50,000 miles to 100,000 miles based on the longevity of 
newer passenger cars. It may be time for a similar adjustment for 
highway motorcycles as design and manufacturing improvements may have 
extended the typical operating life of highway motorcycles. We request 
comments and supporting data that may support or refute the need to 
evaluate and possibly extend the useful life of highway motorcycles. 
The current

[[Page 76815]]

useful life definitions are shown in Table IV-6.

       Table IV-6.--Useful Life Definitions for Motorcycle Classes
------------------------------------------------------------------------
             Motorcycle class                        Useful life
------------------------------------------------------------------------
Class I...................................  5 years or 12,000 km (7,456
                                             miles).
Class II..................................  5 years or 18,000 km (11,185
                                             miles).
Class III.................................  5 years or 30,000 km (18,641
                                             miles).
------------------------------------------------------------------------

V. Recreational Marine Engines

A. Background

1. What Marine Engines Are Already Covered by EPA Programs?
    We originally proposed emission standards for all marine engines in 
1994.\52\ This included outboard and personal watercraft engines, 
sterndrive and inboard spark-ignition engines, and recreational and 
commercial compression-ignition engines. EPA then decided to set 
standards for marine diesel engines in a separate rulemaking because of 
the many unique issues related to those engines. Because uncontrolled 
sterndrive and inboard spark-ignition engines appeared to be a low-
emission alternative to outboard engines in the marketplace, even after 
outboard emission standards were fully phased in, we decided to set 
emission standards only for outboard and personal watercraft 
engines.\53\ Outboard and personal watercraft engines were almost all 
two-stroke engines with much higher emission rates compared to the 
sterndrive and inboard engines which were all four-stroke engines. We 
are now working to conclude the effort to set emission standards for SI 
marine engines as we develop a different set of requirements for 
sterndrive and inboard SI engines.
---------------------------------------------------------------------------

    \52\ See 59 FR 55929 (November 9, 1994).
    \53\ See 61 FR 52088 (October 4, 1996).
---------------------------------------------------------------------------

    Following the 1994 proposal, we set Tier 2 and Tier 3 standards for 
land-based nonroad diesel engines and marine diesel engines rated below 
37kW.\54\ This led us to propose comparable emission control 
requirements for larger marine diesel engines.\55\ Although all marine 
diesel engines were included in the 1998 ANPRM, EPA decided to 
subdivide marine diesel engines further to accommodate the special 
concerns that apply to engines used in recreational marine 
applications.\56\ These special concerns included high power-to-weight 
ratios needed for planing vessels and potential small business impacts. 
We have finalized emission standards for commercial marine diesel 
engines and are now developing requirements for recreational marine 
diesel engines.\57\
---------------------------------------------------------------------------

    \54\ See 63 FR 56968 (October 23, 1998).
    \55\ See 63 FR 68508 (December 11, 1998).
    \56\ See 63 FR 28309 (May 22, 1998).
    \57\ See 64 FR 73300 (December 29, 1999).
---------------------------------------------------------------------------

2. What Marine Engines Are Included in This Rulemaking?
    In this action, we are giving advance notice for our proposal to 
establish emission standards for new spark-ignition sterndrive and 
inboard marine engines and new compression-ignition recreational marine 
engines at or above 37 kW. For spark-ignition engines, this includes 
jet boat and air boat engines, as these can be similar to sterndrive 
and inboard engines and thus are part of the sterndrive/inboard (SD/I) 
class. These are the only recreational marine engines for which we have 
not yet promulgated emission standards.
    For the compression-ignition engines, we are focusing on reductions 
in oxides of nitrogen and particulate matter emissions. For the spark-
ignition engines we are focusing on reductions in oxides of nitrogen 
and hydrocarbon emissions.
    References to ``marine diesel engines'' in this document are 
intended to cover compression-ignition marine engines. CI engines are 
typically operated on diesel fuel although other fuels, such as 
compressed natural gas, may also be used. Similarly, all references to 
``gasoline marine engines'' in this document are intended to include 
all spark-ignition marine engines regardless of fuel type. For SI 
engines, we include all of the engines listed above without making a 
distinction between recreational and commercial applications. However, 
as a shorthand for this document, we are using ``recreational marine 
engines'' to mean recreational marine diesel engines and all of the 
gasoline SD/I engines.
    Boat builders could also be affected by this emission control 
program. If engine changes significantly increase the external size, 
increase heat rejection, or reduce the power of the engine, boat 
builders could have to change the packaging of the engine in the 
vessel. Engine builders may raise the price of the engine to boat 
builders to cover the increased costs of developing, certifying and 
building new compliant engines. Also we are requesting comment on 
evaporative emission control which could affect boat designs.

B. Technology

1. What Technologies Appear To Be Available for Recreational Marine 
Diesel Engines?
    We anticipate that significant emissions reductions from 
recreational marine diesel engines can be achieved primarily with 
technology that will be applied to land-based nonroad engines and 
commercial marine engines. Much of this technology already has been 
established in highway applications and is being used in some land-
based nonroad and marine applications.
    If emissions standards were not to go into place until the 2005-
2006 time frame, engine manufacturers would have substantial lead time 
for developing, testing, and implementing emission control 
technologies. This lead time, coupled with the opportunity to use 
emission control technologies already developed for land-based nonroad 
engines, should allow time for a comprehensive program to integrate the 
most effective emission control approaches into the manufacturers' 
overall design goals related to durability, reliability, and fuel 
consumption. We request comment on the amount of lead time that would 
be appropriate for emission standards for recreational marine diesel 
applications.
    Engine manufacturers have already shown some initiative in 
producing limited numbers of low-NOX marine diesel engines. 
More than 80 of these engines have been placed into service in 
California through demonstration programs.58 59 Through the 
demonstration programs, we were able to gain insight into what 
technologies can be used to achieve significant emission reductions. 
Emission data from these engines supported adoption of emission 
standards for commercial marine diesel engines (see Table V-1).
---------------------------------------------------------------------------

    \58\ Memorandum from Jeff Carmody, Santa Barbara County Air 
Pollution Control District, to Mike Samulski, U.S. Environmental 
Protection Agency, ``Marine Engine Replacement Programs,'' July 21, 
1997 (Docket A-97-50; document II-G-10).
    \59\ Facsimile from Eric Peterson, Santa Barbara County Air 
Pollution Control District, to Mike Samulski, U.S. Environmental 
Protection Agency, ``Marine Engine Replacement Programs,'' April 1, 
1998 (Docket A-97-50; document II-D-14).
---------------------------------------------------------------------------

    Highway engine manufacturers have been the leaders in developing 
and applying new emission control technology for diesel engines. 
Because of the similar engine designs in land-based nonroad and marine 
diesel engines, we expect that much of the technological development 
that has led to lower emitting highway engines can be transferred or 
adapted for use on land-based nonroad and marine engines. Much of the 
improvement in emissions

[[Page 76816]]

from these engines comes from ``internal'' engine changes such as 
variation in fuel injection variables (injection timing, injection 
pressure, spray pattern, rate shaping), modified piston bowl geometry 
for better air-fuel mixing, and improvements intended to reduce oil 
consumption. Introduction and ongoing improvement of electronic 
controls have played a vital role in facilitating many of these 
improvements.
    Other technological developments that are expected to be used on 
land-based nonroad engines would require a greater degree of 
development before they could be applied to marine diesel engines. 
Turbocharging is widely used now in marine applications because it 
improves power and efficiency by compressing the intake air. 
Turbocharging may also be used to decrease particulate emissions in the 
exhaust. Today, marine engine manufacturers generally have to rematch 
the turbocharger to the engine characteristics of the marine version of 
a nonroad engine and often will add water cooling (jacketing) around 
the turbo housing to keep surface temperatures low. Once the Tier 2 
nonroad engines are available to the marine industry, matching the 
turbochargers for the engines would be an important step in achieving 
low emissions.
    Aftercooling is a well established technology that can be used to 
reduce NOX by reducing the temperature of the charge air 
after it has been heated during compression. Reducing the charge air 
temperature directly reduces the peak cylinder temperature during 
combustion, which is the primary cause of NOX formation. 
Air-to-water and water-to-water aftercoolers are well established for 
land-based applications. For engines in marine vessels, there are two 
different types of aftercooling used: jacket-water and raw-water 
aftercooling. With jacket-water aftercooling, the coolant to the 
aftercooler is cooled through a heat exchanger by ambient water. This 
cooling circuit may be either the same circuit used to cool the engine 
or a separate circuit. By moving to a separate circuit, marine engine 
manufacturers would be able to achieve further reductions in the intake 
charge temperature. This separate circuit could result in even lower 
temperatures by using raw water as the coolant. This means that ambient 
water is pumped directly to the aftercooler. Raw-water aftercooling is 
currently being used widely in recreational applications. Because of 
the access that marine engines have to a large ambient water cooling 
medium, we anticipate that marine CI engine manufacturers will largely 
achieve reductions in NOX emissions through the use of 
aftercooling.
    To meet potential emission standards, recreational marine diesel 
engine manufacturers could use many of the strategies discussed above. 
Electronic controls also offer great potential for improved control of 
engine parameters for better performance and lower emissions. Unit 
pumps or injectors would allow higher-pressure fuel injection with rate 
shaping to carefully time the delivery of the whole volume of injected 
fuel into the cylinder. Marine engine manufacturers should be able to 
take advantage of modifications to the routing of the intake air and 
the shape of the combustion chamber of nonroad engines for improved 
mixing of the fuel-air charge. Separate circuit jacket- and raw-water 
aftercooling will likely gain widespread use in turbocharged engines to 
increase performance and lower NOX. We request comment on 
the technological approaches discussed here and on other emission 
control technology that could effectively be used on recreational 
marine diesel engines. We also request comment on the costs associated 
with these technologies.
2. What Technologies Appear To Be Available for Spark Ignition SD/I 
Marine Engines?
    At least three primary technologies could be used by marinizers to 
reduce emissions from SD/I engines.\60\ These three technologies are 
electronic fuel injection, exhaust gas recirculation, and two-way or 
three-way catalysts. Electronic control gives manufacturers more 
precise control of the air/fuel ratio in each cylinder thereby giving 
them greater flexibility in how they calibrate their engines. With the 
addition of an oxygen sensor, electronics give manufacturers the 
ability to use closed loop control which is especially valuable when a 
catalyst is used. Three-way catalysts operate best near stoichiometric 
conditions in the exhaust.
---------------------------------------------------------------------------

    \60\ We use the term ``marinizers'' to mean manufacturers who 
take engine blocks designed for land-based applications and prepare 
them for marine applications.
---------------------------------------------------------------------------

    Exhaust gas recirculation can be used for meaningful reductions in 
NOX. The recirculated gas acts as a diluent in the fuel-air 
mixture which reduces combustion temperature. These lower temperatures 
significantly reduce formation rate of NOX, but HC is 
increased slightly due to lower temperatures for HC burn-up during the 
late expansion and exhaust strokes. Depending on the burn rate of the 
engine and the amount of recirculated gases, EGR can improve fuel 
consumption. Although EGR slows the burn rate (which tends to decrease 
peak power), it can offset this effect with some benefits for engine 
efficiency. EGR reduces pumping work since the addition of recirculated 
gas increases intake pressure. Because the burned gas temperature is 
decreased, there is less heat loss to the exhaust and cylinder walls. 
In effect, EGR allows more of the chemical energy in the fuel to be 
converted to useable work.
    Most engines sold to the marine market are primarily designed for 
automotive use. Marinizers then take the basic engine blocks and adapt 
them to be better suited for the marine environment. These engines are 
generally already equipped with a port in the manifold for EGR. This 
port is capped because EGR is not currently used in marine engines. 
However, EGR has been used as an effective NOX control 
strategy in automotive applications for more than 20 years. Today's 
automotive applications use levels of 15-17 percent EGR. Through the 
use of high swirl, high turbulence combustion chambers, manufacturers 
could increase the burn rate of the engine. By increasing the burn 
rate, the amount of EGR could be increased to 20-25 percent. In our 
lab, we calibrated a heavy-duty highway gasoline engine for emissions 
over the ISO E4 marine duty cycle.\61\ We achieved a 47 percent 
reduction in NOX without significantly changing HC or CO 
emissions. The result was 9.9 g/kW-hr HC+NOX and 24.3 g/kW-
hr CO.
---------------------------------------------------------------------------

    \61\ Memo from J. McDonald and M. Samulski, ``EGR Test Data from 
a Heavy-Duty Gasoline Engine on the E4 Duty Cycle,'' July 12, 1999.
---------------------------------------------------------------------------

    With regard to emissions reductions through catalytic control, we 
are considering various designs that involve packaging small catalysts 
in the exhaust manifold with only small changes in the size of the 
exhaust manifold. By placing the catalysts here, costs to the 
manufacturer may be reduced compared to a large catalyst downstream 
especially when considering the packaging of the system in a boat. 
Engine manufacturers water jacket the exhaust manifold to meet 
temperature safety protocol then mix the water into the exhaust to 
protect the exhaust couplings and muffle noise. By placing the catalyst 
in the exhaust manifold, it is upstream of where the water and exhaust 
mix. However, placing the catalyst in the exhaust manifold limits the 
catalyst size. Using a small catalyst,

[[Page 76817]]

in turn, limits potential emissions reductions. We request comment on 
the potential emission reductions available by a small catalyst placed 
in or directly adjacent to the exhaust manifold.
    There have been concerns that aspects of the marine environment 
could result in unique durability problems for catalysts. The primary 
aspects that could affect catalyst durability are sustained operation 
at high load, salt water effects on catalyst efficiency, thermal shock 
from cold water coming into contact with a hot catalyst, engine 
vibration, and shock effects in rough water associated with marine 
applications.
    Three-way catalysts may be an effective control strategy for 
gasoline marine engines. Three-way catalysts act as both an oxidation 
catalyst to reduce HC, CO and as a reduction catalyst to control 
NOX. They are most effective when coupled with an oxygen 
sensor and a feedback loop to maintain a stoichiometric exhaust 
mixture. As an alternative, a two-way oxidation catalyst could be used 
effectively with less precise control of the air fuel ratio in the 
exhaust. Today's catalysts perform well at temperatures higher than 
would be seen in a marine exhaust manifold and have been shown, in the 
lab, to withstand the thermal shock of being immersed in water. Use of 
catalysts in automotive, motorcycle, and hand-held equipment has shown 
that catalysts can be packaged to withstand the vibration in the 
exhaust manifold in varied applications. We request comment on how the 
operation of marine engines would affect catalyst durability.
    The key to using this technology in these marine applications is to 
ensure that salt water does not reach the catalyst so that salt does 
not accumulate on the catalyst and reduce its efficiency. Placement of 
the catalyst close to the exhaust manifolds may help protect it from 
salt water. Manufacturers already strive to design their exhaust 
systems to prevent water from reaching the exhaust ports. If too much 
water reaches the exhaust ports in today's designs, significant 
durability problems would result from corrosion or hydraulic lock. We 
request comment on potential design modifications which could eliminate 
or significantly minimize water intrusion into the exhaust which could 
deteriorate the performance of the catalyst.
    In highway applications, catalysts are designed to operate in 
gasoline vehicles for more than 100,000 miles. This translates to about 
5,000 hours of use on the engine/catalyst. We estimate that, due to low 
annual hours of operation (50-100 hours/year), the average running time 
of SD/I engines is less than one-third of this value. This is another 
reason we believe catalysts are likely to be durable in marine 
applications. However, unlike cars, boats often experience shock 
effects from waves even when the engine is not running which could 
affect the durability of a catalyst that was not packaged 
appropriately.
    We have been working with the U.S. Coast Guard to identify 
potential safety problems with using catalysts in marine applications. 
The Coast Guard has told us that they have two concerns. First, they 
want to make sure that any additional heat load in the engine 
compartment will not add to the risk of fires, other safety hazards, or 
other detrimental impacts on the engine or components. Second, they 
want to make sure that exhaust systems with catalysts will not lead to 
CO leaks due to additional joints in or maintenance of the exhaust 
system.
    Through a joint effort with the California Air Resources Board 
(ARB), Southwest Research Institute (SwRI), engine manufacturers/
marinizers, catalyst manufacturers, and a marine exhaust manifold 
manufacturer, we are in the process of developing and testing a 
comprehensive emissions control system on a SD/I engine. This system 
includes both EGR and catalyst technology. The goal of this testing is 
proof of concept, but as part of this testing, temperatures and 
pressures relevant to safety, durability, and performance will be 
measured. Also, we are focusing on an exhaust manifold design that will 
prevent water reversion to the catalyst.
    We request comment on the feasibility of applying electronic fuel 
injection, exhaust gas recirculation, and catalysts on SD/I engines and 
on other technology that could effectively be used to reduce emissions 
from these engines. We also request comment on the costs and 
corresponding potential emission reductions from using such technology, 
as well as the potential effects on engine performance, safety and 
durability using these technologies.

C. Standards and Program Approaches

1. Recreational Marine Diesel Engines
    One approach for reducing emissions from recreational CI marine 
engines would be to propose standards similar to the Tier 2 standards 
for commercial CI marine engines. The commercial marine emission limits 
are presented in Table V-1 and are based on the ISO E3 duty cycle. For 
recreational marine engines the ISO E5 duty cycle may be more 
appropriate because it is designed for smaller craft. Recreational CI 
marine engines can likely use the same technologies projected for the 
Tier 2 commercial marine standards. Many recreational CI marine engines 
are already using these technologies including electronic fuel 
management, turbocharging, and separate circuit aftercooling. In fact, 
because recreational engines have much shorter design lives than 
commercial engines, it is likely to be easier to apply raw water 
aftercooling to these engines.

Table V-1.--Emission Standards for Commercial Marine Diesel Engines over
                                  37 kW
------------------------------------------------------------------------
                                    HC+NOX  g/
           Subcategory                kW-hr      PM g/kW-hr   CO g/kW-hr
------------------------------------------------------------------------
disp  0.9........................          7.5         0.40          5.0
0.9  disp  1.2........          7.2         0.30          5.0
1.2  disp  5.0........          7.2         0.20          5.0
------------------------------------------------------------------------

    Engine manufacturers will generally increase the fueling rate in 
recreational engines, compared to commercial engines, to gain power 
from a given engine size. This extra power from a given sized engine 
helps bring a planing vessel on to the water surface and increases the 
maximum vessel speed without increasing the weight of the vessel. This 
difference in how recreational engines are designed and used has an 
effect on emissions. However, as discussed in the technology section 
below, emission data suggest that recreational marine diesel engines 
can meet the levels required for commercial marine engines. We request 
comment on the appropriateness of the commercial marine emission limits 
for recreational marine engines. We also

[[Page 76818]]

request comment on the appropriate test duty cycle for these limits.
    Diesel engine manufacturers have commented that they would need 
time after the commercial marine standards go into place to transfer 
technology from commercial to recreational marine engines. The 
standards for the commercial marine rule go into effect in the 
following model years by engine cylinder displacement: 2004 for 0.9 to 
2.5 liters per cylinder, 2005 for smaller engines, and 2007 for larger 
engines. These dates are after those for the nonroad land-based 
standards which gives manufacturers time to transfer the land-based 
technology to marine applications.
    An implementation date of 2005 for engines with displacement less 
than 2.5 liters/cylinder would give a year of lead time beyond the 
emission standards for commercial engines. However, this lead time may 
not be necessary because much of the technology that could be used to 
reduce emissions is already used in some recreational marine diesel 
engine models; these engines would just need to be calibrated for 
reduced emissions. Many recreational marine diesel engines with 
displacement over 2.5 liters/cylinder in many cases also already use 
the anticipated emission-control technologies. An implementation date 
of 2007 for these engines may therefore provide adequate lead time, 
even though the emission standards for commercial engines start at the 
same time. We request comment on appropriate implementation dates for 
recreational marine diesel engines.
2. SD/I Marine Engines
    In determining potential HC+NOX standards for sterndrive 
and inboard SI marine engines, we will be evaluating emission 
reductions that can be achieved using electronic fuel injection, 
exhaust gas recirculation, and catalysts designed to work in marine 
applications. Catalyst exhaust systems designed for marine applications 
would have to ensure that salt-water did not reach the catalyst. In 
addition, it would be preferable for the exhaust system to be compact 
so that it would fit in current boat designs. This may necessitate 
locating a small catalyst in the exhaust manifold or directly adjacent 
to it, limiting the catalyst size and therefore its ability to reduce 
engine emissions.
    Even if only a small, low-efficiency catalyst could be packaged 
into SD/I exhaust systems, an HC+NOX standard of 5-7 g/kW-hr 
may be feasible based in the ISO E4 duty cycle. Given the information 
in Table V-1, a standard of 7.2 g/kW-hr for HC+NOX would 
provide some level of equity of emission control for gasoline and 
diesel engines. However, if larger, more efficient catalysts were used 
such as in automotive applications, much larger emission reductions 
could be achieved. In its September 19, 2000 workshop, the California 
Air Resources Board proposed standards of 9.4 g/kW-hr HC+NOX 
and 134 g/kW-hr CO in 2003 and 4 g/kW-hr HC+NOX and 50 g/kW-
hr CO in 2007. We request comment on the potential use of larger, more 
efficient catalysts in SD/I applications and on appropriate emission 
limits.
    We are in the process of developing and testing a catalyst system 
for SD/I engines, but we do not have data from the tests at the time of 
this notice. Our projected emission reductions from catalyst systems 
are based on our evaluation of information from catalyst manufacturers 
and observations of the success of catalytic control in land-based 
applications. Because we do not yet have complete data, we request 
comment on basing emissions standards on technology packages with and 
without catalytic control. Using electronic fuel injection and exhaust 
gas recirculation, an emission limit of 9-10 g/kW-hr of 
HC+NOX may be appropriate.
    We will be evaluating varying levels of CO control. With the 
application of electronic fuel injection and electronic control, CO 
from SD/Is can be reduced, potentially to the range of 40-50 g/kW-hr. 
If manufacturers can produce engines that achieve these CO emission 
reductions over many years of operation, this may reduce the exposure 
of individual boaters to elevated ambient CO concentrations. In 
particular, this could reduce the occurrence of CO poisoning from 
people on or swimming near a boat while the engine is idling. Because 
reducing CO emissions could help reduce incidents of CO poisoning among 
boaters, we are also considering the need for a CO standard which would 
achieve significant CO reductions. With a catalyst, CO could be reduced 
further, perhaps to the range of 15-20 g/kW-hr. At a minimum, we see no 
reason for expecting emissions to increase. Therefore, we request 
comment on capping CO emission at baseline levels, approximately 130 g/
kW-hr, to prevent backsliding. We also request comment on the technical 
feasibility and benefits from reducing CO levels and on what 
appropriate CO standards would be for SI SD/I engines.
    We are considering the 2005 or 2006 time frame for the 
implementation of standards for SD/I engines. These dates are similar 
to the ones discussed above for recreational marine diesel engines. 
However, we recognize that SD/I marinizers would need time to apply new 
technologies to their engines and optimize the systems for emissions 
control. Depending on the level of eventual standards, this may be 
especially difficult for SD/I manufacturers because they may need to 
apply technologies, such as EGR and catalysts, that they have never 
applied to their engines. Therefore, we request comment on what lead 
time would be appropriate for SD/I engines.

D. Additional Program Considerations

1. Not-To-Exceed Requirements
    Our goal is to achieve control of emissions over the broad range of 
in-use speed and load combinations that can occur on a recreational 
marine engine so that real-world emission control is achieved, rather 
than just controlling emissions under certain laboratory conditions. An 
important tool for achieving this goal is an in-use program with an 
objective standard and an easily implemented test procedure. Therefore 
we are requesting comment on extending the not-to-exceed requirements 
in place for commercial marine engines to recreational marine engines.
    The not-to-exceed (NTE) concept includes an area under the torque 
map where an engine could reasonably be expected to operate in use. 
Within this area the engine can not exceed a fixed limit. The limit may 
be different for different areas of the NTE zone. The NTE zone not only 
includes a wide range of operation, but also a wide range of ambient 
conditions.
    We expect that NTE requirements for recreational CI marine engines 
would be very similar to those for commercial CI marine engines (64 FR 
73300) because the engines are similar. However, the limits may need to 
be different within the NTE zone due to differences in the engine 
applications. For example, a higher limit near full power may be 
necessary for recreational engines. For SI engines, the NTE zone would 
likely need to be a different shape to coincide with the differences 
between the ISO E5 and ISO E4 test procedures. Also, because EGR 
technology is not as efficient at high power as at lower power, a 
higher limit may be necessary at high power. We request comment on how 
the NTE concept could be applied to recreational marine engines. We 
also request comment on alternative approaches for ensuring real world 
emission control from recreational marine engines.

[[Page 76819]]

2. Evaporative Emissions
    We request comment on whether or not we should propose evaporative 
emission requirements for recreational marine engines and what those 
requirements should be. Vessels using gasoline marine engines emit high 
amounts of volatile hydrocarbons per gallon of fuel consumed. According 
to our calculations, these evaporative emissions are several times 
higher than exhaust HC emissions. For diesel engines, evaporative 
emissions are very low due to the low vapor pressure of diesel fuel.
    When the fuel is subject to increasing temperatures, such as daily 
temperature variation or engine heat, lighter hydrocarbon molecules 
evaporate and, if not stored or trapped in some fashion, will escape 
into the atmosphere. Marine fuel tanks are vented to the atmosphere to 
prevent pressure build up in the tank. Vapor levels on a boat can be so 
high that, for fire safety reasons, blowers are often needed to remove 
gasoline vapors from the engine compartment prior to starting the 
engine. Also vapors are displaced from the gas tank to the atmosphere 
during refueling. Finally, some emissions come from spillage during 
refueling.
    In automotive applications, vapors generated in the fuel system are 
passed through a canister designed to capture evaporated hydrocarbons. 
When the engine is running, these hydrocarbons are drawn back into the 
engine and burned. However, this emission control technology would not 
be practical for marine applications. A boat may sit for weeks without 
being used while typical automotive canisters are only designed to 
capture a few hot days worth of evaporative emissions. After this 
amount of time, the canister must be purged to the engine. A canister/
fuel system that could collect weeks worth of vapors and burn them in a 
few hours of operation probably would not be practical due to the 
canister size required.
    Still, there may be practical alternatives to a canister system for 
boats. One such system could be a bladder-type fuel tank such as those 
used in race cars. The bladder contracts as the fuel is used to prevent 
a vapor space from forming.
    Another technology that could reduce evaporative emissions to a 
lesser degree are non-permeable fuel lines. By replacing rubber fuel 
lines with non-permeable lines, the evaporative emissions through the 
fuel lines can be prevented. An added benefit is that these non-
permeable lines are non-conductive and can prevent the buildup of 
static charges. Although non-permeable lines are used in automotive 
applications, these fuel lines would have to meet Coast Guard 
specifications for flame resistance and flexibility to be used in 
marine applications. We request comment on if non-permeable fuel lines 
exist that would meet the Coast Guard specifications and what their 
cost would be.
    Currently, fuel systems on boats are vented to the atmosphere to 
prevent pressure buildup. The Coast Guard requires that fuel systems 
not be pressurized. If a low-pressure (2 psi) pressure relief valve 
were used with a closed system, much of the evaporative emissions could 
be reduced. This would still prevent the fuel system from building up 
too much pressure. We request comment on the effectiveness of this 
strategy with respect to ambient temperature, especially on hot days 
when the fuel tank pressure may be higher. Note that any eventual 
requirements related to fuel system pressure would need to be 
consistent with Coast Guard policies and requirements.
    We request comment on safe pressures in fuel tanks and what typical 
fuel tank pressures would be if they were not vented to the atmosphere. 
We also request comment on the cost and effectiveness of non-permeable 
fuel lines, pressure relief valves, and other systems for reducing 
evaporative emissions. We also request comment on potential strategies 
for reducing emissions due to refueling or spillage. We request 
comments on any evaporative emission control systems such as those 
described above as well as comment on potential strategies for reducing 
emissions due to refueling or spillage.
    Additionally, we request comment on how we could structure 
provisions to confirm the effectiveness of these systems. We would 
prefer to set up a performance-based standard such as the test 
procedures already in place for automobiles because it gives a better 
indication of control effectiveness that a design-based standard and it 
gives more design flexibility to the manufacture. However, we request 
comment on appropriate performance-based test procedures and on an 
appropriate design-based requirement.
3. Crankcase Emissions
    We are requesting comment on whether or not to require that new 
recreational marine engines be built with closed crankcases to 
eliminate crankcase emissions. Crankcase controls have been required on 
cars and trucks. Controlling crankcase vapors requires a fairly simple 
and inexpensive technological strategy. A line is routed from the 
crankcase to the intake manifold with a pressure control valve which 
will prevent crankcase overpressure and will prevent air from flowing 
into the crankcase. Some SI marine engine already route crankcase vapor 
to the air intake to minimize vapor buildup in the engine compartment.
    For turbocharged diesel engines, there is some concern that routing 
the crankcase vapor upstream of the turbocharger could foul the 
turbocharger. In addition, it would be more costly to route the low 
pressure crankcase vapor downstream of the turbocharger because an 
extra pump would be necessary. An alternative would be to allow 
turbocharged recreational compression-ignition marine engines to be 
built with open crankcases, provided the crankcase ventilation system 
is designed to allow crankcase emissions to be measured. For engines 
with open crankcases, we could require crankcase emissions to be either 
routed into the exhaust stream to be included in the exhaust 
measurement, or to be measured separately and added to the measured 
exhaust mass. These measurement requirements might not add 
significantly to the cost of testing, especially where the crankcase 
vent is simply routed into the exhaust stream prior to the point of 
exhaust sampling. This concept is consistent with our previous 
regulation of crankcase emissions from such diverse sources as 
commercial marine engines, locomotives and passenger cars. We request 
comment on the above concepts.
4. Regulatory Flexibility
    Marinizers are engine manufacturers that take land-based engines 
and convert them to be used in marine applications. In some cases, 
marinizers use certified land-based engines and make changes without 
changing their emission levels. We consider these marinizers to be 
``engine dressers,'' and we believe that forcing these manufacturers to 
certify their engines may be unnecessary. We intend to offer similar 
engine dresser provisions for recreational marine engine marinizers as 
exist for commercial marine engine marinizers who are not required to 
certify (40 CFR part 94). We request comment on these provisions as 
they apply to recreational marine engine marinizers.
    The scope of this advance notice also includes a number of engine 
marinizers that have not been subject to our regulations or 
certification process and would not qualify as engine dressers.

[[Page 76820]]

The majority of these marinizers are small businesses for which a 
typical regulatory program may be overly burdensome. One challenge of 
this rule is to implement a flexible regulatory program while still 
ensuring significant emission reductions. We request comment on 
appropriate regulatory flexibility strategies for small volume engine 
marinizers that will minimize harmful impact on the environment.
    We request comment on what should be the definition of a small 
volume engine manufacturer/marinizer for the purpose of potential 
regulatory flexibility. The Small Business Administration defines a 
small business (manufacturing internal combustion engines) as one that 
employs less than 1000 people. Because the purpose of the regulatory 
flexibility is to reduce the burden on companies for which fixed costs 
cannot be distributed over a large number of engines, we believe that 
the small volume engine manufacturer definition should also consider 
the number of engines for sale in the U.S. in a year. This production 
count would include all engines (automotive, other nonroad, etc.) and 
not just recreational marine engines. Based on confidential sales 
information supplied by engine marinizers and our own evaluations of 
certification and development costs, we estimate that the upper limit 
for the numbers of engines that a company could produce and still be 
considered a small volume engine manufacturer might be in the range of 
8,000 to 12,000 units per year. This would include the majority of 
marinizers. To establish this threshold, we would make an assessment of 
the ability of these companies to amortize development costs over 
smaller sales volumes.
    The large number of boat builders and their relative inexperience 
with emission control requirements also suggest a need for a flexible 
implementation process. Although boat builders would not be directly 
subject to emission standards under a potential program unless 
evaporative emission control were required, it would still be possible 
for them to need to redesign the engine compartments on some boats if 
engine designs were to change significantly. We request comment on how 
to best determine the extent to which engine technologies discussed 
above would necessitate changes in boat design. We also request comment 
on regulatory flexibility strategies for small volume boat builders 
that will minimize harmful impact on the environment.
    We request comment on what should be the definition of a small 
volume boat builder for the purpose of potential regulatory 
flexibility. Because the flexibility is designed to reduce the burden 
on companies for which fixed costs cannot be distributed over a large 
number of vessels, we believe it may be appropriate to include in the 
definition of a small volume boat builder an upper limit on the 
production of boats for sale in the U.S. in one year. This production 
count would include all power craft recreational boats. We request 
comment on this approach.
    We have been in contact with several small volume engine marinizers 
and boat builders in an attempt to develop concepts that would reduce 
the burden of emissions standards while minimizing environmental loss. 
In fact, we convened a Small Business Advocacy Review Panel under 
section 609(b) of the Regulatory Flexibility Act as amended by the 
Small Business Regulatory Enforcement Fairness Act of 1996. To date, 
these efforts have identified several flexibility concepts for small 
volume engine manufacturers and for small volume boat builders. We 
presented several flexibility concepts to small-business 
representatives during the SBREFA process.\62\ These concepts are 
listed in Table V-2. We request comment on the appropriateness of these 
ideas and on others for minimizing burden on small businesses while 
still reaching the greatest degree of emission reduction achievable 
through the application of technology which the Administrator 
determines will be available, giving appropriate consideration to cost, 
lead time, noise, energy, and safety factors.
---------------------------------------------------------------------------

    \62\ ``Preliminary EPA Staff Assessment of Small Business 
Flexibility Concepts,'' June 16, 1999, Docket A-2000-01, document 
II-B-03.

     Table V-2.--Small Business Regulatory Flexibility Concepts for
                           Recreational Marine
------------------------------------------------------------------------
      Small volume engine marinizers         Small volume boat builders
------------------------------------------------------------------------
Broaden engine families                     Percent of production
                                             exemption.
Minimize compliance requirements            Small volume allowance.
                                            Existing inventory and
                                             replacement engine
                                             allowance.
Expand engine dresser flexibility
Design-based certification                  Hardship provisions
Delay standards for 5 years
Hardship provisions
Use of emission credits
------------------------------------------------------------------------

5. Definition of Recreational CI Marine Engines
    When we finalized standards for commercial marine engines last 
year, we included a definition of recreational compression-ignition 
marine engines. This was based on the U.S. Coast Guard definition of 
recreational vessels. This definition states that a compression-
ignition propulsion marine engine intended by the manufacturer to be 
installed on a recreational vessel and labeled as a recreational engine 
would be considered recreational for EPA regulations in 40 CFR part 94. 
A recreational vessel is one that is intended by the vessel 
manufacturer to be operated primarily for pleasure but does not include 
the following vessels:

--Vessels less than 100 gross tons that carry six or more paying 
passengers
--Vessels greater than 100 gross tons that carry one or more paying 
passengers
--Vessels used solely for competition

    Diesel engine manufacturers have since commented that they would 
like to see a less restrictive definition of recreational vessel. Their 
proposed definition is as follows: ``Recreational marine engine means a 
propulsion marine engine that is intended by the manufacturer to be 
installed on a recreational vessel. Recreational vessel means a vessel 
that is intended by the vessel manufacturer to be operated primarily 
for pleasure or leased, rented or chartered to another for the latter's 
pleasure.'' We request comment on the appropriate definition of a 
recreational marine engine.
6. Useful Life
    When we set emission standards, we require that manufacturers 
produce engines that comply over their full useful life. For 
recreational marine engines, a useful life that lasts either ten years 
or until the engine accumulates at least 500 operating hours (or some 
other value of hours specified in a certificate of conformity), 
whichever occurs first, may be appropriate. In general, we would expect 
that the regulatory useful life should be at least as long as the 
operating lifetime for which the engine is designed. We request comment 
on this view.
    Our current view that the appropriate minimum useful life may be at 
least 500 hours is based on manufacturer comments that typical 
recreational marine engines are used about 50 hours per year and for at 
least 10 years. However, Coast Guard survey data suggests that typical 
recreational marine engines are used about 100 hours per

[[Page 76821]]

year.\63\ In addition, we expect that typical recreational marine 
diesel engines are used more than this, especially those rated at 
several hundred horsepower. Purchasers of the more powerful marine 
diesel engines usually choose them over lower cost gasoline engines 
because diesel engines are generally designed to be more durable. 
Actual useful lives of existing engines are likely to vary with respect 
to application as well. Thus, we could propose a series of minimum 
useful life values based on rated application, engine cycle (e.g., 
spark-ignited or diesel), or rated horsepower. However, we request 
information on in-use engine life and comment on the appropriate 
emissions compliance useful life for SI engines and CI engines; these 
useful life values may vary with engine size, especially for diesel 
engines.
---------------------------------------------------------------------------

    \63\ ``1998 National Recreational Boating Survey Data Book,'' 
JSI Research & Training Institute, prepared for the U.S. Coast 
Guard, February 2000.
---------------------------------------------------------------------------

    In our emissions inventory calculations presented earlier in this 
document, we used a function of the engine population, load factors, 
annual hours of use, rated power, emission factors, turnover, and 
growth rates. For CI engines we used 200 hours per year and for SD/I 
engines, we used 48 hours per year. We are interested in more 
information, especially data, on the appropriateness of these 
estimates. Studies and industry comments have shown a wide range of 
average annual use--from 50 to 500 hours per year. We request 
information, especially reliable field data, on the annual and lifetime 
operating hours for these engines which may depend on SI versus CI 
design, engine size, and application.
7. Averaging, Banking, and Trading Credit Programs
    We are considering an emissions averaging, banking and trading 
(ABT) program for recreational marine engines. This is a voluntary 
program which would allow a manufacturer to certify one or more engine 
families at emission levels above the applicable emission standards, 
provided that the increased emissions are offset by one or more engine 
families certified below the applicable standards. The average of all 
emissions for a particular manufacturer's production would have to be 
at or below the level of the applicable emission standards. In 
addition, credits could be traded with other companies or banked for 
future use.
    An ABT program is an important factor that EPA takes into 
consideration in setting emission standards that are appropriate under 
section 213 of the Clean Air Act. ABT would allow us to consider a 
lower emissions standard, or one that otherwise results in greater 
emissions reductions, because ABT reduces the cost and improves the 
technological feasibility and cost-effectiveness of achieving a 
standard. For example, it could help to ensure the attainment of the 
standards earlier than would otherwise be possible. Manufacturers gain 
flexibility in product planning and the opportunity for a more cost-
effective introduction of product lines meeting a new standard. ABT 
also creates an incentive for the early introduction of new technology, 
which allows certain engine families to act as trail blazers for new 
technology. This can help provide valuable information to manufacturers 
on the technology before manufacturers need apply the technology 
throughout their product line. This early introduction of clean 
technology improves the feasibility of achieving the standards and can 
provide valuable information for use in other regulatory programs that 
may benefit from similar technologies.
    For recreational marine diesel engines, an ABT program would be 
similar to the one for commercial marine engines. We request comment on 
all aspects of an ABT program that would apply for recreational marine 
diesel engines.
    We are concerned that an ABT program may not be appropriate for SI 
SD/I marine engines for three primary reasons. First, there are many 
small businesses which produce SI engines for the recreational marine 
market. There are also very few large businesses producing SI engines 
for this market. While the large businesses tend to have broad product 
offerings and could readily take advantage of the provisions of an ABT 
program, the small businesses tend to have much narrower product lines 
and would therefore be unlikely to benefit from ABT provisions. We are 
concerned that this situation would allow the large businesses a 
competitive advantage.
    Similarly, we are concerned that most manufacturers of recreational 
SI engines do not have a broad enough product line to take advantage of 
an ABT program. Therefore, it may not be useful to the majority of 
businesses.
    Third, the emission control technology discussed above appear to be 
equally applicable to all engines. Therefore, an ABT program may not be 
necessary except, perhaps, as a tool to help phase-in new technology. 
Adopting an ABT program in the long term may make sense if we were to 
conclude that a more stringent standard is feasible at least for some 
engines. We request comment on whether we should consider an ABT 
program for SI engines, and what, if any, restrictions we should place 
on such a program.
8. Applicability of MARPOL Annex VI
    On September 27, 1997, the International Maritime Organization 
(IMO) adopted a new Annex VI to the International Convention for the 
Prevention of Pollution from Ships (MARPOL 73/78) and opened the Annex 
for acceptance by its members. This Annex, which contains regulations 
for the prevention of air pollution from ships, will go into force 
internationally one year after fifteen countries, representing at least 
50 percent of the gross tonnage of the world's merchant shipping fleet, 
have ratified it. The Annex will acquire the force of law in the United 
States after it goes into force internationally and it is ratified by 
the United States, following approval of the Senate.
    Regulation 13 of Annex VI requires that each diesel engine with a 
power output of more than 130 kW which is installed on a ship 
constructed on or after 1 January 2000, or each diesel engine with a 
power output of more than 130 kW which undergoes a major conversion on 
or after 1 January 2000 meet the NOX limits described by the 
following formula:

17.0 g/kW-hr when n is less than 130 rpm
45.0 * n(-0.2) g/kW-hr when 130  n  2000 rpm
9.8 g/kW-hr when n  2000 rpm

Where n is rated engine speed (crankshaft revolutions per minute)

    One of the issues that will be considered in our notice of proposed 
rulemaking is how these emission limits affect recreational engines and 
vessels. Because recreational vessels are included in the MARPOL 
definition of ``ship,'' prudent recreational vessel manufacturers 
should have begun installing MARPOL-compliant engines in their newly-
constructed vessels on January 1, 2000, even though the Annex has not 
yet gone into force.\64\ This is because the Annex may be enforceable 
retroactive to January 1, 2000 once it goes into effect 
internationally. To facilitate this process, EPA established a 
voluntary compliance program whereby engine manufacturers may obtain a 
Statement of Voluntary Compliance from EPA after they provide evidence

[[Page 76822]]

that their engine meets the Annex VI NOX limits.\65\
---------------------------------------------------------------------------

    \64\ Article 2 of MARPOL 73/78 defines ``ship'' as ``a vessel of 
any type whatsoever operating in the marine environment and includes 
hydrofoil boats, air-cushion vehicles, submersibles, floating craft 
and fixed or floating platforms.''
---------------------------------------------------------------------------

    To help us prepare our proposal for recreational engine emission 
requirements, we request comment on several questions. First, we 
request input on the extent to which recreational vessel builders are 
aware of the MARPOL requirements for marine diesel engines, and the 
extent to which they are attempting to comply with them. Second, we 
request comment on how many times a vessel with a marine diesel engine 
over 130 kW can be expected to change owners over its life. This 
information is important for compliance purposes. Third, we request 
comment on whether meeting the Annex VI NOX limits will 
interfere with an engine manufacturer's ability to meet the more 
stringent national recreational marine diesel emission standards under 
consideration.
---------------------------------------------------------------------------

    \65\ See the fact sheet ``Frequently Asked Questions: MARPOL 73/
78 Annex VI Marine Diesel Engine Requirements,'' EPA420-F-99-038, 
October 1999, www.epa.gov/otaq/marine.htm.
---------------------------------------------------------------------------

9. Harmonization With the European Commission
    The European Commission has proposed emission limits for 
recreational marine engines, including both diesel and gasoline 
engines. These requirements would apply to all new engines sold in 
member countries. The numerical emission limits, shown in Table V-2, 
consist of the Annex VI NOX limit for small marine diesel 
engines and the rough equivalent of Tier 1 nonroad emission levels for 
HC and CO. Emission testing is to be conducted using the ISO D2 duty 
cycle for constant-speed engines and the ISO E5 duty cycle for all 
other engines. Table V-2 also includes the proposed limits for gasoline 
engines tested on the ISO E4 duty cycle.
    Industry and others have commented to us on the value of 
harmonization of emission standards. Manufacturers who sell engines in 
several countries can minimize costs by designing to a single set of 
standards. In setting standards under section 213 of the Act, EPA is 
required to consider technology, cost, energy, and other factors to 
achieve the greatest degree of emissions reductions achievable. We are 
concerned that these standards would do no more than cap emissions at 
baseline levels and are not the kind of appropriate technology-forcing 
standards that would allow us to achieve the greatest achievable 
reductions from this category. According to our data on 20 recreational 
CI marine engines (tested for both NOX and PM) and 10 SI SD/
I engines, average baseline emission levels already meet the proposed 
European limits. These baseline averages are included in Table V-3. We 
request comment on the level of stringency of the proposed European 
emission limits.

  Table V-3.--Proposed European Emission Limits and EPA Baseline Data for Recreational Marine Engines (g/kW-hr)
----------------------------------------------------------------------------------------------------------------
                       Pollutant                        CI limit \a\   CI baseline   SI limit \b\   SI baseline
----------------------------------------------------------------------------------------------------------------
NOX...................................................           9.8            8.9          15              9.2
PM....................................................           1.4            0.2  ............  .............
HC....................................................           1.5            0.3           6.4            5.7
CO....................................................           5.0            1.3         152           145
----------------------------------------------------------------------------------------------------------------
\a\ HC limit increases slightly with increasing engine power rating.
\b\ For 300 kW engine; HC and CO limits increase slightly with decreasing power rating.

10. Consumer Labeling
    We request comment on the need for, effectiveness of, and 
alternatives to a consumer labeling program. The purpose of this 
program would be to educate consumers so that they could make informed 
decisions concerning engine emissions when they purchase a boat. One 
example of a consumer labeling program is the California Air Resources 
Board's requirement that personal watercraft and outboard engines sold 
in California starting in 2001 be labeled as either low, very-low, or 
ultra-low depending on their emission levels. We request comment on 
whether or not a program such as this should be voluntary or mandatory. 
We also request comment on how this should be implemented considering 
that most boats and engines are produced by separate manufacturers.

VI. Large Spark Ignition Engines

A. Background

1. What Engines Are Included in This Rulemaking?
    This section applies to most nonroad spark-ignition engines rated 
over 19 kW (``Large SI engines''). These engines power equipment such 
as forklifts, sweepers, pumps, and generators. This would include 
marine auxiliary engines, but not marine propulsion engines or engines 
used in snowmobiles, motorcycles, or other recreational applications. 
The applications not addressed in this section are addressed elsewhere 
in this document.
    Our most recent rulemaking for nonroad diesel engines finalized a 
definition of ``compression-ignition'' that was intended to include 
diesel-derived natural gas engines under that program.\66\ However, 
according to the manufacturers of these engines, they do not meet the 
definition of compression-ignition engines. All nonroad engines are 
defined as either compression-ignition or spark-ignition engines. So, 
if these natural gas engines are not subject to emission standards for 
nonroad diesel engines, they will instead be covered by the emission 
standards for Large SI engines. We are currently reviewing the claims 
of these manufacturers regarding how their engines should be 
classified. We request comment on whether we should revise the 
definitions that differentiate between these types of engines.
---------------------------------------------------------------------------

    \66\ See 63 FR 56968 (October 23, 1998).
---------------------------------------------------------------------------

    Most Large SI engines have a total displacement greater than one 
liter. The design and application of the few Large SI engines currently 
being produced with displacement less than one liter are very similar 
to those of engines rated below 19 kW, which are typically used for 
lawn and garden applications. As described in the most recent 
rulemaking for these smaller engines, we intend to propose that 
manufacturers may certify engines above 19 kW with total displacement 
of one liter or less to the requirements we have already adopted in 40 
CFR part 90 for engines below 19 kW.\67\ These engines would then be 
exempt from the requirements contemplated in this document. This

[[Page 76823]]

would be consistent with the California ARB rulemaking. This approach 
would allow manufacturers of small air-cooled engines to certify their 
engines rated over 19 kW with the program adopted for the comparable 
engines with slightly lower power ratings.
---------------------------------------------------------------------------

    \67\ See 65 FR 24268 (April 25, 2000).
---------------------------------------------------------------------------

    We are concerned that treating all engines less than one liter as 
Small SI engines may be inadequate. For example, lawn and garden 
engines generally don't use turbochargers or other technologies to 
achieve very high power levels. However, it may be possible for someone 
to design an engine under one liter with unusually high power, which 
would more appropriately be grouped with other Large SI engines rather 
than with Small SI engines. To address this concern, we may propose a 
maximum power level for engines to qualify for treatment as Small SI 
engines. A power rating of 30 kW seems to represent a maximum 
reasonable power output that is possible from SI engines under one 
liter with technologies typical of lawn and garden engines. We request 
comment on the suggested power threshold and on any other approaches to 
addressing the concern for properly constraining this provision.
2. Who Makes Large SI Engines?
    The companies producing Large SI engines are typically subsidiaries 
of automotive companies. In most cases, these companies modify car and 
truck engines for industrial applications. However, the Large SI 
industry has historically taken a much less centralized approach to 
designing and producing engines. Engine manufacturers often sell 
dressed engine blocks without manifolds or fuel systems. Fuel system 
suppliers have played a big role in designing and calibrating nonroad 
engines, sometimes participating directly in engine assembly. Several 
equipment manufacturers, mostly forklift producers, also play the role 
of an engine manufacturer by calibrating engine models and completing 
engine assembly.
    Sales volumes are another important contrast with automotive 
production. Total Large SI engine sales are about 150,000 per year in 
the U.S. Sales are distributed rather evenly among several companies, 
so typical sales volumes for each company range generally from 10,000 
to 25,000 engines per year. These sales volumes and the overall size of 
the companies limit the amount of research and development available to 
meet new emission standards.
3. What Is the Regulatory History?
    Currently no federal emission standards exist for Large SI engines. 
We have, however, adopted successively more stringent standards for the 
automotive engines from which most Large SI engines are derived. Heavy-
duty highway otto-cycle engines provide the most direct comparison. We 
have adopted emission standards for 2005 and later model year engines 
and proposed more stringent standards for 2007 and later model year 
engines. We request comment on the degree to which these technologies 
can be readily transferred or adapted to the counterpart nonroad 
engines.
    The California ARB in 1998 adopted requirements that apply to new 
Large SI engines produced for California starting in 2001. We are 
considering similar requirements for these engines in the near term. In 
the longer term, we are also considering revised emission standards 
reflecting the emission reductions achievable with available 
technology, as described below.
    While we have not yet set emission standards for this category of 
engines, the industry has some experience complying with standards 
through the requirements for forklifts set by Underwriters 
Laboratories.\68\ These standards, which focus primarily on ensuring 
safety, require the industry to conduct testing and submit plans for 
approval, much like certifying to emission standards.
---------------------------------------------------------------------------

    \68\ ``Industrial Trucks, Internal Combustion Engine-Powered,'' 
UL558, ninth edition, June 28, 1996.
---------------------------------------------------------------------------

    An additional important consideration for Large SI engines is the 
workplace air contaminant limits adopted by the Occupational Safety and 
Health Administration for CO and NO2. Facility managers, not 
engine or equipment manufacturers, are responsible for meeting these 
limits. However, concerns for high indoor pollutant concentrations have 
created a small but distinct demand for aggressive emission controls on 
forklifts. These emission controls have become commonplace in Europe, 
even in the absence of emission standards.

B. Technology

    Although Large SI engines are often derived from automotive 
engines, manufacturers have generally not incorporated the 
technological advances from cars and trucks. Most fuel systems in 
gasoline engines have carburetors with no feedback controls. LPG and 
natural gas engines typically use mixer technology that has changed 
little over the last several decades.
    Some Large SI engine models have no automotive counterpart; many of 
these use air-cooling instead of a conventional radiator system. Air-
cooled engines can use the same emission-control technologies as water-
cooled engines, but they have operating characteristics that can 
increase the challenge of reaching low emission levels. For example, 
uneven heating of the engine block can cause distortion of the 
cylinders, increasing the possibility of hydrocarbon emissions from 
unburned fuel.
    The standards for spark-ignition engines would apply for all fuel 
types. The majority of Large SI engines use liquefied petroleum gas 
(LPG). Engines running on LPG can use fuel cylinders or draw fuel 
directly from a pipeline. Gasoline is also used in many applications. 
Natural gas is less common, but serves in several niche markets.
    The California ARB emission standards were developed based on the 
expected capabilities of three-way catalytic converters with electronic 
fueling systems to control emissions. A limited number of forklifts 
have been operating with these emission-control technologies for 
several years. In addition to controlling emissions, these emission-
control technologies can significantly reduce fuel consumption. In a 
high-use application, the fuel savings can fully offset the increased 
price for the emission controls within one year or less. The redesigned 
engines also hold promise for improving engine performance, for example 
with more reliable starting and better torque characteristics.
    Both EPA and California ARB have pursued emission testing to 
determine the capabilities of emission-control technologies for Large 
SI engines. This effort will also help us establish emission standards 
that correspond with the degree of emission control achievable from the 
anticipated technologies over the full operating life of industrial 
equipment. We believe that manufacturers can optimize their engines to 
substantially reduce CO, NOX, and HC emissions at a 
reasonable cost with these redesigned engines.

C. Standards and Program Approaches

    We are considering emission standards for Large SI engines based on 
what manufacturers can achieve with available technology. This may 
include a combination of near-term standards similar to California 
ARB's and long-term standards for optimized systems. In addition, we 
are considering new procedures for measuring emissions, including a 
transient duty cycle and

[[Page 76824]]

provisions to test for ``off-cycle'' emissions. These are described 
further in the following sections.
    We do not presently intend to propose particulate matter emission 
standards because of the low levels of particulate matter associated 
with well maintained SI engines, as well as the substantial cost of 
technologies designed to regulate particulate matter directly from 
these engines. However, we expect that the incorporation of the 
projected emission-control technologies would reduce particulate matter 
emissions. This is similar to the approach we have taken for highway 
gasoline engines.
    We request comment on this approach to setting standards, including 
the technology basis for controlling emissions, the combination of 
near-term and long-term standards, and the approach to addressing PM 
emissions.
1. Near-Term Emission Standards
    We are considering near-term emission standards, including 
standards consistent with those adopted by California ARB. These 
standards are 4 g/kW-hr (3 g/hp-hr) for NMHC+ NOX emissions 
and 50 g/kW-hr (37 g/hp-hr) for CO emissions. California ARB specifies 
the ISO C2 duty cycle for measuring emissions from variable-speed 
engines, and the ISO D2 duty cycle for testing constant-speed engines. 
The C2 duty cycle consists mostly of intermediate-speed points, while 
all the D2 test points are at rated speed. We request comment on 
establishing standards consistent with those in California, including 
using the duty cycles in the same way. We also request comment on the 
appropriateness of requiring certification testing on both of these 
duty cycles for engine models that may ultimately be used in both 
variable-speed and constant-speed applications.
    California ARB adopted its emission standards based on the 
capabilities of three-way catalytic converters and electronically 
controlled fuel systems. These systems would be similar to those used 
for many years in highway applications, but not necessarily with the 
same degree of sophistication. Adopting California ARB's emission 
standards would allow near-term introduction of low-emission 
technologies for substantial emission reductions. The manufacturers 
would in this case also be able to more easily amortize their 
development costs by spreading these costs over larger production 
volumes.
    The California ARB standards will be fully phased in by 2004. With 
a current expectation of completing an EPA final rule by September 
2002, we believe manufacturers may have enough lead time to expand 
production of California-compliant engines to a nationwide market. If 
EPA and California standards were consistent, manufacturers may not 
need to do any additional development work or repeat any certification 
testing to meet the federal standards. We request comment on whether we 
should propose near-term standards for 2004 model year engines, or if 
manufacturers will need additional time to manage full production of 
low-emission engines.
    As described for the long-term standards below, we are interested 
in the possibility of adopting standards based on total hydrocarbon 
emissions, rather than nonmethane hydrocarbon. We request comment on 
proposing standards based on total hydrocarbon measurement. This would 
potentially save manufacturers the expense of measuring methane 
emissions for certification, production-line, or in-use testing. Since 
methane is largely nonreactive in the atmosphere, we have often set 
emission standards excluding methane measurement. We could adjust the 
standard as needed to reflect typical methane concentrations in 
controlled engines. This would apply to gasoline-and LPG-fueled 
engines. Natural gas-fueled engines would continue to have a standard 
based on nonmethane emissions because the large majority of their total 
hydrocarbon emissions consist of methane. We request comment on this 
approach.
2. Long-Term Duty-Cycle Emission Standards
    We believe that, given additional time, manufacturers would be able 
to optimize designs to control emissions to lower levels using the same 
emission-control technologies used to meet the near-term standards. 
Therefore, we are also requesting comment on more stringent emission 
standards using more robust measurement procedures, as described below.
    General standards. Manufacturers have used electronically 
controlled fuel systems with three-way catalysts in automotive 
applications for many years. During this time, these systems and 
components have undergone substantial improvements in their ability to 
reduce emissions with minimal degradation during field operation. 
Recent testing by Southwest Research Institute shows that these systems 
can reduce NOX, HC, and CO emissions by 90 percent or more 
over several thousand hours of normal operation.69-70 While 
the test data help us select emission standards, we first need to 
address several open issues. These issues are summarized here and 
described in greater detail in the technical memoranda referenced in 
this document.

    \69-70\ ``Evaluation of Emissions Durability of Off-Road LPG 
Engines Equipped with Three-Way Catalysts,'' by Vlad Ulmet, 
Southwest Research Institute, November 2000, (Docket A-2000-01, 
document II-A-07).
---------------------------------------------------------------------------

--The combination of duty cycles for testing. Emission measurements at 
Southwest Research Institute have shown that engines can achieve 
effective control on a wide variety of duty cycles, but that good 
performance on one duty cycle does not guarantee good performance on 
another. Thus, it is important that we select the appropriate duty 
cycles to provide a reasonable assurance that systems will control 
emissions when operating in the field.
--Consideration of cold-start effects. Engine emissions immediately 
after starting can be much higher than emissions from a hot engine. We 
need to determine the appropriate treatment of cold-start effects in 
the test procedure before we can propose emission standards.
--The achievable precision of control software. Electronic systems for 
automotive applications have reached a high level of sophistication for 
monitoring a wide variety of engine variables to maintain effective 
control of combustion and after treatment processes. While Large SI 
engine manufacturers can benefit from these developments, the cost and 
complexity of these systems at some point may no longer be appropriate 
for the more cost-sensitive, low-volume nonroad applications.
--Fuel specifications. As described further below, we need to evaluate 
in-use fuel quality before proposing fuel specifications for emission 
testing.

    With this wide range of test and design variables, we request 
comment on long-term emissions standards ranging from 1.5 to 2.5 g/kW-
hr (1 to 2 g/hp-hr) HC+ NOX and from 4 to 10 g/kW-hr (3 to 
7.5 g/hp-hr) CO. We are interested in comments as to potentially 
appropriate standards within these ranges, as well as comments on the 
appropriateness of the ranges themselves. The range of possible CO 
emission standards is especially wide because CO emission levels are 
sensitive to the degree of engine warm-up at the beginning of the test. 
This range of standards is based on test data showing the emission 
levels that Large SI engines can achieve with steady-state and 
transient duty cycles.\71\ We request comment on the capability of 
Large SI

[[Page 76825]]

engines to meet these emission levels, on the associated costs for 
these emission-control systems, and on the corresponding estimated 
emission reductions estimated to be achieved therefrom. We also request 
comment on the applicability of the underlying test data.
---------------------------------------------------------------------------

    \71\ See ``Emission Data and Procedures for Large SI Engines'' 
for more information (Docket A-2000-01; document II-B-1).
---------------------------------------------------------------------------

    In another rulemaking, we are pursuing even lower emission levels 
for heavy-duty highway engines starting in 2008, including otto-cycle 
(or spark-ignition) engines. We have proposed changing these emission 
standards to 0.20 g/hp-hr (0.26 g/kW-hr) for NOX emissions 
and 0.14 g/hp-hr (0.19 g/kW-hr) for NMHC emissions.\72\ We request 
comment on whether Large SI engines would be able to apply the 
associated highway-engine technologies at a reasonable cost.
---------------------------------------------------------------------------

    \72\ See 65 FR 35430 (June 2, 2000).
---------------------------------------------------------------------------

    Emission standards for different fuel types. Most of the emission 
data on which we are likely to base the proposed emission standards was 
generated from engines using liquefied petroleum gas (LPG). We could 
take California ARB's approach of applying the same numerical emission 
standards regardless of fuel, except for the special treatment of 
methane emissions from natural gas engines. Gasoline engines have very 
different fuel systems than LPG or natural gas engines. Engines built 
from automotive engine blocks can readily adopt port fuel injection, 
which provides a great advantage over gaseous mixer technology in 
controlling emissions. Also, the emission levels described above are 
consistent with the requirements that apply to heavy-duty highway otto-
cycle engines starting in 2005.
    A possible exception to common emission standards may be for CO 
emissions. Uncontrolled CO emission levels from gasoline engines can be 
much higher than are typically found from LPG engines. We believe, 
however, that a separate CO standard for gasoline engines may not be 
necessary for two reasons. First, highway gasoline engines have been 
controlling CO emissions to lower levels for many years. Second, fuel 
systems and catalysts can be designed and calibrated for a very high CO 
conversion efficiency. We request comment on the need to accommodate 
higher CO emission levels from gasoline engines. Data supporting such 
an argument should include engine-out CO emission levels at 
stoichiometric operation and information regarding conversion 
efficiencies available for gasoline engine emission-control equipment. 
We also request comment on the advantages of having identical standards 
for all fuels.
    Special cases. The above discussion applies generally to Large SI 
engines. However, there are special concerns that warrant further 
attention.
    Air-cooled engines. Some air-cooled engines are designed to operate 
in applications where water-cooled engines may not function 
effectively. These engines are most commonly used in industrial saws or 
chippers where ambient dust levels prevent the use of radiators to cool 
the engine. Air-cooled Large SI engines share some important design 
features and operating characteristics with smaller air-cooled engines 
that are commonly used in lawn and garden applications. As described 
above, air-cooled engines face unique constraints for controlling 
emissions. These constraints seem to be especially problematic for CO 
emissions, causing manufacturers to add a greater degree of emission-
control technology than that needed for water-cooled engines to meet 
California ARB standards.
    We have identified three possible approaches to proposing emission 
standards for air-cooled engines. First, we could require them to meet 
the same emission standards as water-cooled engines. Especially for any 
long-term emission standards, this would require an extensive 
development effort to apply emission-control technologies in a way that 
would adequately control emissions. This would prevent any unfair 
competitive advantages by giving special treatment to a higher-emitting 
engine type.
    Second, we could propose that all air-cooled engines meet the 
emission standards we have adopted for nonroad SI engines under 19 kW. 
The largest engines under 19 kW (nonhandheld Class II) must meet 
standards of 12.1 g/kW-hr for NOX+HC emissions and 610 g/kW-
hr for CO emissions. Since engines under 19 kW are almost all air-
cooled, they share some important design characteristics with Large SI 
engines that are air-cooled.
    Third, we could propose the same NOX+HC for both air-
cooled and water-cooled engines, but to allow air-cooled engines to 
meet less stringent CO emission standards. To avoid giving air-cooled 
engines a broad competitive advantage in applications where they are 
seldom used today, we could limit this less stringent CO standard to 
engines used predominantly in severe-duty applications. Under this 
approach, we would consider an application severe-duty if the majority 
of engines used in that application do not use water-cooling systems. 
Currently available data would suggest an adjusted CO standard of 75 to 
100 g/kW-hr (55 to 75 g/hp-hr) CO for these engines.
    We request comment on these and other potential approaches to 
proposing emission standards from air-cooled engines.
    Equipment Used Predominantly Indoors. Operators of Large SI engines 
can today install emission-control systems with extremely low CO 
emission levels. CO emission levels can be especially low in these 
current systems where manufacturers are not required to simultaneously 
control for NOX and HC emissions. We are concerned that 
emission standards requiring simultaneous control of all the regulated 
pollutants will limit manufacturers ability to continue to supply 
engines with very low CO emission levels. With increased concern for 
exposing individuals to engine exhaust in confined spaces, this may be 
especially problematic. We therefore request comment on alternate long-
term standards that would allow the manufacturer to better balance 
emission levels of the various pollutants to offer low-CO engines for 
predominantly indoor applications.
    One possible scenario would be increasing the HC+NOX 
emission standard somewhat (for example, to 3 or 4 g/kW-hr), while 
tightening the CO emission standard (for example, to 1 or 2 g/kW-hr). 
We request comment on the need for such an alternate standard and on 
the emission standards that should apply. We also request comment on 
whether there would be any need to (1) adopt provisions to ensure that 
these engines are indeed operated predominantly in sensitive, indoor 
applications; (2) limit the number of these engine sales; or (3) adopt 
any other provisions to ensure that these alternate emission standards 
are not used to avoid the general standards.
    Another alternative would be to adopt fuel-specific standards. 
Since LPG and natural gas are more likely to be used in enclosed areas, 
we could focus on adopting very stringent CO emission levels for these 
engines, with less of an emphasis on NOX and HC emission 
levels. Since gasoline engines are not commonly used indoors, their 
emission standards could maximize NOX and HC reductions, 
with less aggressive control of CO emissions. We request comment on 
adopting fuel-specific emission standards to address concerns for 
indoor air quality.
3. Supplemental Emission Standards
    To address concerns for controlling emissions outside of the 
discrete procedures adopted for certification, we

[[Page 76826]]

are considering requirements that would apply to a wider range of 
normal engine operation. We generally refer to this as off-cycle 
emissions.
    Our goal is to achieve control of emissions over the broad range of 
in-use speed and load combinations that can occur in a Large SI engine 
to achieve real-world emission control, rather than just controlling 
emissions under certain laboratory conditions. An important tool for 
achieving this goal is an in-use program with an objective standard and 
an easily implemented test procedure. No single test procedure can 
cover all real-world applications, operations, or conditions. Yet, to 
ensure that emission standards are providing the intended benefits in 
use, we should have a reasonable expectation that emissions under real-
world conditions reflect those measured on the test procedure.
    Because the projected duty-cycles include specific operating modes 
(engine speeds and loads), we are concerned that an engine designed 
only to duty-cycle standards would not necessarily have the same 
emission performance in use. In contrast, an engine operating in any 
given piece of equipment may often operate at speed and load 
combinations not included in the certification duty cycle. Emission 
levels at speed and load points not represented in the duty cycles 
could be significantly higher than those measured with the duty cycles. 
Also, if manufacturers design engines to control emissions only under 
relatively narrow laboratory conditions, this does not ensure that the 
engines will control emissions under the wide range of ambient 
temperature, pressure, and humidity the engines will experience in the 
field. Testing by Southwest Research Institute highlighted this 
concern, showing that steady-state emission levels can increase ten-
fold or more at speed-load points not included in the duty cycles. \73\
---------------------------------------------------------------------------

    \73\ See ``Emission Data and Procedures for Large SI Engines'' 
for more information (Docket A-2000-01; item II-B-1).
---------------------------------------------------------------------------

    ``Not-to-exceed'' testing would be one option for ensuring that 
emissions are controlled from Large SI engines over the full range of 
speed and load combinations seen in the field. Under not-to-exceed 
testing, we would specify an emission standard that applies more 
broadly than the traditional duty-cycle standard. The not-to-exceed 
standard would apply to all regulated pollutants (NOX, HC, 
and CO) during a wide range of normal operation. In other programs 
where we have adopted not-to-exceed standards, the testing includes a 
broad range of in-use ambient conditions (i.e., temperature, pressure, 
and humidity), but excludes measurement during any kind of abnormal 
operation.
    The recent testing at Southwest Research Institute (SwRI) would 
appear to support not-to-exceed emission standards of 1.0 to 3.5 g/kW-
hr (1.3 to 2.6 g/hp-hr) for NOX+HC emissions and 7 to 13 g/
kW-hr (5 to 10 g/hp-hr) for CO emissions. We would intend to allow 
considerable development time for manufacturers to meet any not-to-
exceed provisions. If we adopt alternate emission standards for severe-
duty engines, gasoline engines, or engines used in indoor applications, 
as described above, any corresponding not-to-exceed emission standards 
would be higher than the duty-cycle standards to serve as a cap on 
varying emission levels that result from different engine operation or 
ambient conditions.

D. Additional Program Considerations

1. Compliance Program Elements
    In general, we expect to align our certification and compliance 
programs with those adopted by California ARB to the greatest extent 
possible. In particular, any near-term emission standards we may adopt 
should require no additional development or testing beyond what 
manufacturers are already doing to produce compliant engines for 
California. While long-term standards and other additional provisions 
may go beyond what California has already adopted, we expect to design 
the program to limit the additional burden. Nevertheless, these 
additional requirements would be important enhancements and would lead 
to a much more effective control program.
    We request comment on the details of the compliance program adopted 
by California ARB, and whether the details of the compliance program 
are appropriate for use in the federal program. This includes several 
elements, such as production-line testing and in-use testing by 
manufacturers; useful life, deterioration factors, and warranty 
requirements; and several other provisions. The principal provisions 
under consideration that California ARB has not already adopted 
include:

--Procedures for testing emissions in the field in lieu of laboratory 
dynamometer testing.
--Specification of basic engine diagnostics to keep engines operating 
in their certified configuration.
--Concepts for manufacturers to control evaporative emissions.
--Provisions for engine rebuilders to bring engines back to their low-
emission configuration when they are rebuilt.
2. Field Testing
    One possible provision that should be highlighted is the 
possibility of adopting field-measurement procedures. As described 
above, we are considering proposing California ARB's requirement for 
manufacturers to test their in-use engines. Under this program, 
manufacturers remove in-use engines from equipment for testing in the 
laboratory. However, if we adopt field-measurement procedures, 
manufacturers would be allowed to show that they meet emission 
standards with in-use engines by measuring emissions directly from 
engines without removing them from the equipment. There are significant 
advantages to testing engines in the field. The reduced testing effort 
could substantially reduce the cost of in-use emission testing, both 
for manufacturers and for the Agency. Also, testing would capture real 
in-use engine operation, rather than relying on a surrogate duty cycle 
in the laboratory. We request comment on the desirability of developing 
measurement procedures to allow field testing of Large SI engines.
    One constraint of measuring emissions in the field is the 
difficulty in measuring methane. Because of this, we are interested in 
proposing emission standards based on total hydrocarbon measurements, 
at least for field testing. We request comment on proposing total 
hydrocarbon standards also for laboratory testing. For gasoline and LPG 
engines, methane generally accounts for less than 10 percent of 
uncontrolled emissions, so this can easily be accounted for in 
selecting emission standards. As described above, we would need to rely 
on a nonmethane hydrocarbon emission standard for natural gas engines. 
This may limit the possibility of testing natural gas engines in the 
field.
3. In-Use Fuel Quality
    In addition, manufacturers have raised the concern that in-use LPG 
fuels have highly varying quality. It is not clear that different LPG 
fuel compositions would have a direct effect on tailpipe emission 
levels. However, lower-quality fuels have a tendency to cause fuel 
condensation, and eventually gumming, on fuel system components. Since 
fuel systems play a central role in an engine's emission control 
system, this can eventually affect an engine's ability to accurately 
meter fuel, resulting in increased emission levels. We request comment 
on the need for and possibility of developing an industry-wide 
specification for in-use LPG fuels to

[[Page 76827]]

address this problem. In addition, we request comment on the 
possibility of applying engine technology to limit condensation of 
impurities or heavy-end hydrocarbon molecules from lower-quality fuel.

VII. Public Participation

    We are committed to a full and open regulatory process with input 
from a wide range of interested parties. As part of any rulemaking, 
opportunities for input will include a formal public comment period and 
a public hearing.
    With today's action, we open a comment period for this advance 
notice. We will accept comments until February 5, 2001. We encourage 
comment on all issues raised here, and on any other issues you consider 
relevant. The most useful comments are those supported by appropriate 
and detailed rationales, data, and analyses. All comments, with the 
exception of proprietary information, should be directed to the docket 
(see ADDRESSES). If you wish to submit proprietary information for 
consideration, you should clearly separate such information from other 
comments by (1) labeling proprietary information ``Confidential 
Business Information'' and (2) sending proprietary information directly 
to the contact person listed (see FOR FURTHER INFORMATION CONTACT) and 
not to the public docket. This will help ensure that proprietary 
information is not inadvertently placed in the docket. If you want us 
to use a submission of confidential information as part of the basis 
for a proposal, then a nonconfidential version of the document that 
summarizes the key data or information should be sent to the docket.
    We will disclose information covered by a claim of confidentiality 
only to the extent allowed and in accordance with the procedures set 
forth in 40 CFR Part 2. If no claim of confidentiality accompanies the 
submission, it will be made available to the public without further 
notice to the commenter.

VIII. Regulatory Flexibility

    Section 605 of the Regulatory Flexibility Act (RFA), 5 U.S.C. 601 
et seq. requires the Administrator to assess the economic impact of 
proposed rules on small entities. The Small Business Regulatory 
Enforcement Fairness Act (SBREFA) of 1996, Public Law 104-121, amended 
the RFA to strengthen its analytical and procedural requirements and to 
ensure that small entities are adequately considered during rule 
development. The Agency accordingly requests comment on the potential 
impacts on a small business of the program described in this notice. 
These comments will help the Agency meet its obligations under SBREFA 
and will suggest how EPA can minimize the impacts of this rule for 
small companies that may be adversely affected.
    Depending on the number of small entities identified prior to the 
proposal and the level of any contemplated regulatory action, we may 
convene a Small Business Advocacy Review Panel under section 609(b) of 
the Regulatory Flexibility Act as amended by SBREFA. The purpose of the 
Panel (or multiple Panels, as necessary) would be to collect the advice 
and recommendations of representatives of small entities that could be 
affected by the eventual rule. If we determine that a panel is not 
warranted, we would intend to work on a less formal basis with those 
small entities identified.
    We request information on small entities potentially affected by 
this rulemaking. Information on company size, number of employees, 
annual revenues and product lines would be especially useful. 
Confidential business information may be submitted as described in 
section VII. The following sections address several specific issues for 
different industries.

A. Recreational Vehicles and Highway Motorcycles

    We anticipate that industries related to recreational vehicles and 
highway motorcycles that may be affected by this rulemaking will 
largely fall within the categories listed in Table VIII-1 below. We 
request comment on the completeness and accuracy of the list, and on 
the suitability for this rulemaking of the definitions of small 
business established by SBA. We may propose to change these 
definitions, if such changes would better suit the particular 
industries and regulations being considered.

  Table VIII-1.--Recreational Vehicle Industries With Small Businesses
------------------------------------------------------------------------
                                       NAICS a      Defined by SBA as a
              Industry                  codes       Small Business If:b
------------------------------------------------------------------------
Gasoline engine and parts                 336312  750 employees.
 manufacturers.
Motorcycles and motorcycle parts          336991  500 employees.
 manufacturers.
Snowmobile and ATV manufacturers...       336999  500 employees.
Independent Commercial Importers of       421110  100 employees.
 Vehicles and parts.
------------------------------------------------------------------------
Notes:
a. North American Industry Classification System.
b. According to SBA's regulations (13 CFR part 121), businesses with no
  more than the listed number of employees or dollars in annual receipts
  are considered ``small entities'' for purposes of a regulatory
  flexibility analysis.

B. Large SI

    Table VIII-2 lists the industry segments that relate to companies 
that may need to meet emission standards and other requirements for 
Large SI engines. Two engine manufacturers qualify as small businesses. 
Both of these companies plan to produce engines that meet the standards 
adopted by California ARB in 2004. Since we don't expect the near-term 
standards contemplated in this document to add any significant 
requirements to the California ARB program, these standards would 
impose very little new burden for these and other manufacturers. If we 
adopt long-term standards, this would require manufacturers to do 
additional calibration and testing work. If we adopt new test 
procedures (including transient operation), there may also be a cost 
associated with upgrading test facilities. If we set emission standards 
to mirror the levels proposed for 2007 highway heavy-duty engines, this 
would also require extensive hardware and product development to reduce 
emissions.
    In addition, we are considering recordkeeping requirements for 
companies that rebuild Large SI engines. These would be very similar to 
the requirements we have already adopted for highway engines, nonroad 
diesel engines, and commercial marine diesel engines. Many of these 
companies qualify as small businesses, but we expect the added burden 
to be very small.

[[Page 76828]]



        Table VIII-2.--Large SI Industries With Small Businesses
------------------------------------------------------------------------
                                                    Defined by SBA as a
              Industry                NAICS code    small business if:
------------------------------------------------------------------------
Nonroad SI engines.................       333618  1,000 employees.
Industrial trucks..................       333924  750 employees.
Engine repair and maintenance......       811310  $5 million revenues.
------------------------------------------------------------------------

C. Recreational Marine

    The recreational marine sector includes a variety of engine and 
boat manufacturers that are small businesses. We convened a Small 
Business Advocacy Review Panel under section 609(b) of the Regulatory 
Flexibility Act as amended by the Small Business Regulatory Enforcement 
Fairness Act of 1996. We describe the rulemaking issues related to 
these small businesses in section V.D.4.

IX. 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 Office of Management and Budget (OMB) review 
and the requirements of the Executive Order.
    The order defines ``significant regulatory action'' as any 
regulatory action (including an advance 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 OMB for review. Any written 
comments from OMB and any EPA response to OMB comments are in the 
public docket for this Notice.

X. Statutory Provisions and Legal Authority

    Section 213(a)(1) of the Clean Air Act, 42 U.S.C. 7547(a), requires 
that we study the emissions from all categories of nonroad engines and 
equipment (other than locomotives) to determine, among other things, 
whether these emissions ``cause or significantly contribute to air 
pollution which may reasonably be anticipated to endanger public health 
and welfare.'' Section 213(a)(2) further requires us to determine, 
through notice and comment, whether the emissions of carbon monoxide 
(CO), volatile organic compounds (VOCs), and oxides of nitrogen 
(NOX) found in the above study significantly contributes to 
ozone or CO concentrations in more than one ozone or CO nonattainment 
area. With such a determination of significance, section 213(a)(3) 
requires us to establish emission standards applicable to CO, VOC, and 
NOX emissions from classes or categories of new nonroad 
engines and vehicles that cause or contribute to such air pollution. 
Moreover, if we determine that any other emissions from new nonroad 
engines contribute significantly to air pollution, we may promulgate 
emission standards under section 213(a)(4) regulating emissions from 
classes or categories of new nonroad engines that we find contribute to 
such air pollution.
    As directed by the Clean Air Act, we conducted a study of emissions 
from nonroad engines, vehicles, and equipment in 1991.\74\ Based on the 
results of that study, referred to as NEVES, we determined that 
emissions of NOX, HC, and CO from nonroad engines and 
equipment contribute significantly to ozone and CO concentrations in 
more than one nonattainment area (see 59 FR 31306, June 17, 1994).\75\ 
Given this determination, section 213(a)(3) of the Act requires us to 
promulgate emissions standards for those classes or categories of new 
nonroad engines, vehicles, and equipment that in our judgment cause or 
contribute to such air pollution. We have found that the nonroad 
engines included in this ANPRM ``cause or contribute'' to such air 
pollution.\76\
---------------------------------------------------------------------------

    \74\ ``Nonroad Engine and Vehicle Emission Study--Report and 
Appendices,'' EPA-21A-201, November 1991 (available in Air docket A-
96-40).
    \75\ The terms HC (hydrocarbon) and VOC (volatile organic 
carbon) refer to similar sets of chemicals and are generally used 
interchangeably.
    \76\ See Final Finding, ``Control of Emissions from New Nonroad 
Spark-Ignition Engines Rated above 19 Kilowatts and New Land-Based 
Recreational Spark-Ignition Engines'' elsewhere in today's Federal 
Register for EPA's finding for Large SI engines and recreational 
vehicles. EPA's findings for marine engines are contained in 61 FR 
52088 (October 4, 1996) for gasoline engines and 64 FR 73299 
(December 29, 1999) for diesel engines.
---------------------------------------------------------------------------

    Where we determine that other emissions from nonroad engines, 
vehicles, or equipment significantly contribute to air pollution that 
may reasonably be anticipated to endanger public health or welfare, 
section 213(a)(4) authorizes us to establish (and from time to time 
revise) emission standards from those classes or categories of new 
nonroad engines, vehicles, and equipment that we determine cause or 
contribute to such air pollution, taking into account cost, noise, 
safety and energy factors associated with the application of technology 
used to meet the standards. We have made this determination for 
emissions of particulate matter (PM) and smoke from nonroad engines 
(see 59 FR 31306, June 17, 1994). In that rulemaking, we found that 
smoke emissions from nonroad engines significantly contribute to such 
air pollution based on smoke's relationship to the particulate matter 
that makes up smoke as well as smoke's effect on visibility and soiling 
of urban buildings and other property. Particulate matter can be 
inhaled into the lower lung cavity, posing a potential health threat. 
We cited recent studies associating PM with increased mortality.\77\ We 
also promulgated standards for emissions of PM and smoke from nonroad 
diesel engines in that rulemaking. We have also found that emissions of 
PM from nonroad engines included in this ANPRM ``cause or contribute'' 
to such air pollution.
---------------------------------------------------------------------------

    \77\ The nonroad study (NEVES) found that nonroad sources are 
responsible for approximately 5.55 percent of the total 
anthropogenic inventory of PM emissions and over one percent of 
total PM emissions in six to ten of the thirteen nonattainment areas 
surveyed.
---------------------------------------------------------------------------

    Section 202 (a)(3)(E) provides EPA with authority to revise highway 
motorcycle emissions standards, establishing standards which reflect 
the greatest degree of emission reduction achievable, taking cost and 
other factors into consideration. EPA may promulgate new standards 
based on the effects of the air pollutants on public health and 
welfare. EPA may also reclassify motorcycles as light-duty vehicles or 
classify them as a separate class or

[[Page 76829]]

category. In such case that motorcycles are a separate class or 
category, the Act directs EPA to consider the need to achieve 
equivalency or emission reductions between motorcycles and other 
vehicles to the maximum extent practicable. We request comment on how 
any potential regulatory programs would be consistent with these 
sections.

List of Subjects

40 CFR Part 86

    Environmental protection, Administrative practice and procedure, 
Confidential business information, Labeling, Motor vehicle pollution, 
Reporting and recordkeeping requirements.

40 CFR Part 94

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Confidential business information, Imports, 
Penalties, Reporting and recordkeeping requirements, Vessels, 
Warranties.

40 CFR Part 1048

    Environmental protection, Administrative practice and procedure, 
Gasoline, Motor vehicle pollution, Reporting and recordkeeping 
requirements.

40 CFR Part 1051

    Environmental protection, Administrative practice and procedure, 
Gasoline, Motor vehicle pollution, Reporting and recordkeeping 
requirements.

    Dated: November 20, 2000.
Carol M. Browner,
Administrator.
[FR Doc. 00-30105 Filed 12-6-00; 8:45 am]
BILLING CODE 6560-50-U