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

[Federal Register: November 8, 2002 (Volume 67, Number 217)]
[Rules and Regulations]
[Page 68241-68447]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08no02-12]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 89, 90, 91, 94, 1048, 1051, 1065, and 1068
[AMS-FRL-7380-2]
RIN 2060-AI11

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

AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.

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SUMMARY: In this action, we are adopting emission standards for several
groups of nonroad engines that have not been subject to EPA emission
standards. These engines are large spark-ignition engines such as those
used in forklifts and airport ground-service equipment; recreational
vehicles using spark-ignition engines such as off-highway motorcycles,
all-terrain vehicles, and snowmobiles; and recreational marine diesel
engines. Nationwide, these engines and vehicles cause or contribute to
ozone, carbon-monoxide, and particulate-matter nonattainment, as well
as other types of pollution impacting human health and welfare.
We expect that manufacturers will be able to maintain or even
improve the performance of their products when producing engines and
equipment meeting the new standards. Many engines will substantially
reduce their fuel consumption, partially or completely offsetting any
costs associated with the emission standards. Overall, the gasoline-
equivalent fuel savings associated with the anticipated changes in
technology resulting from this rule are estimated to be about 800
million gallons per year once the program is fully phased in. Health
and environmental benefits from the controls included in today's rule
are estimated to be approximately $8 billion per year once the controls
are fully phased in. There are also several provisions to address the
unique limitations of small-volume manufacturers.

DATES: This final rule is effective January 7, 2003.
The incorporation by reference of certain publications listed in
this regulation is approved by the Director of the Federal Register as
of January 7, 2003.

ADDRESSES: Materials relevant to this rulemaking are contained in
Public Docket Numbers A-98-01 and A-2000-01 at the following address:
EPA Docket Center (EPA/DC), Public Reading Room, Room B102, EPA West
Building, 1301 Constitution Avenue, NW., Washington DC. The EPA Docket
Center Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday
through Friday, except on government holidays. You can reach the
Reading Room by telephone at (202) 566-1742, and by facsimile at (202)
566-1741. The telephone number for the Air Docket is (202) 566-1742.
You may be charged a reasonable fee for photocopying docket materials,
as provided in 40 CFR part 2.
For further information on electronic availability of this action,
see SUPPLEMENTARY INFORMATION below.

FOR FURTHER INFORMATION CONTACT: U.S. EPA, Office of Transportation and
Air Quality, Assessment and Standards Division hotline, (734) 214-4636,
asdinfo@epa.gov; Alan Staut, (734) 214-4805.

SUPPLEMENTARY INFORMATION:

Regulated Entities

This action will affect companies that manufacture or introduce
into commerce any of the engines or vehicles subject to emission
standards. These include: spark-ignition industrial engines such as
those used in forklifts and compressors; recreational vehicles such as
off-highway motorcycles, all-terrain vehicles, and snowmobiles; and
recreational marine diesel engines. This action will also affect
companies buying engines for installation in nonroad equipment. There
are also requirements that apply to those who rebuild any of the
affected nonroad engines. Regulated categories and entities include:

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NAICS Codes Examples of potentially regulated
Category a SIC Codes b entities
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Industry................................... 333618 3519 Manufacturers of new nonroad spark-
ignition engines, new marine engines.
Industry................................... 333111 3523 Manufacturers of farm equipment.
Industry................................... 333112 3531 Manufacturers of construction
equipment, recreational marine
vessels.
Industry................................... 333924 3537 Manufacturers of industrial trucks.
Industry................................... 811310 7699 Engine repair and maintenance.
Industry................................... 336991 ............ Motorcycle manufacturers.
Industry................................... 336999 ............ Snowmobiles and all-terrain vehicle
manufacturers.
Industry................................... 421110 ............ Independent Commercial Importers of
Vehicles and Parts.
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\a\ North American Industry Classification System (NAICS)
\b\ Standard Industrial Classification (SIC) system code.

This list is not intended to be exhaustive, but rather provides a
guide regarding entities likely to be regulated by this action. To
determine whether this action regulates particular activities, you
should carefully examine the regulations. You may direct questions
regarding the applicability of this action to the person listed in FOR
FURTHER INFORMATION CONTACT.

Obtaining Electronic Copies of the Regulatory Documents

The preamble, regulatory language, Final Regulatory Support
Document, and other rule documents are also available electronically
from the EPA Internet web site. This service is free of charge, except
for any cost incurred for internet connectivity. The electronic version
of this final rule is made available on the day of publication on the
primary web site listed below. The EPA Office of Transportation and Air
Quality also publishes Federal Register notices and related documents
on the secondary web site listed below.
1. http://www.epa.gov/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 documents and the software into which the document may be
downloaded, format changes may occur.

Table of Contents

I. Introduction
A. Overview
B. How Is This Document Organized?
C. What Categories of Vehicles and Engines Are Covered in This
Final Rule?
D. What Requirements Are We Adopting?
E. Why Is EPA Taking This Action?

[[Page 68243]]

II. Nonroad: General Provisions
A. Scope of Application
B. Emission Standards and Testing
C. Demonstrating Compliance
D. Other Concepts
III. Recreational Vehicles and Engines
A. Overview
B. Engines Covered by This Rule
C. Emission Standards
D. Testing Requirements
E. Special Compliance Provisions
F. Technological Feasibility of the Standards
IV. Permeation Emission Control
A. Overview
B. Vehicles Covered by This Provision
C. Permeation Emission Standards
D. Testing Requirements
E. Special Compliance Provisions
F. Technological Feasibility
V. Large Spark-ignition (SI) Engines
A. Overview
B. Large SI Engines Covered by This Rule
C. Emission Standards
D. Testing Requirements and Supplemental Emission Standards
E. Special Compliance Provisions
F. Technological Feasibility of the Standards
VI. Recreational Marine Diesel Engines
A. Overview
B. Engines Covered by This Rule
C. Emission Standards for Recreational Marine Diesel Engines
D. Testing Equipment and Procedures
E. Special Compliance Provisions
F. Technical Amendments
G. Technological Feasibility
VII. General Nonroad Compliance Provisions
A. Miscellaneous Provisions (Part 1068, Subpart A)
B. Prohibited Acts and Related Requirements (Part 1068, Subpart
B)
C. Exemptions (Part 1068, Subpart C)
D. Imports (Part 1068, Subpart D)
E. Selective Enforcement Audit (Part 1068, Subpart E)
F. Defect Reporting and Recall (Part 1068, Subpart F)
G. Hearings (Part 1068, Subpart G)
VIII. General Test Procedures
A. General Provisions
B. Laboratory Testing Equipment
C. Laboratory Testing Procedures
D. Other Testing Procedures
IX. Projected Impacts
A. Environmental Impact
B. Cost Estimates
C. Cost Per Ton of Emissions Reduced
D. Economic Impact Analysis
E. Do the Benefits Outweigh the Costs of the Standards?
X. Public Participation
XI. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act (RFA), as Amended by the Small
Business Regulatory Enforcement Fairness Act of 1996 (SBREFA), 5
U.S.C. 601 et seq.
D. Unfunded Mandates Reform Act
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
G. Executive Order 13045: Protection of Children From
Environmental Health and Safety Risks
H. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
I. National Technology Transfer and Advancement Act
J. Congressional Review Act
K. Plain Language

I. Introduction

A. Overview

Emissions from the engines regulated in this rule contribute to
serious air-pollution problems, and will continue to do so in the
future absent regulation. These air pollution problems include exposure
to carbon monoxide (CO), ground-level ozone, and particulate matter
(PM), which can cause serious health problems, including premature
mortality and respiratory problems. Fine PM has also been associated
with cardiovascular problems, such as heart rate variability and
changes in fibrinogen (a blood clotting factor) levels, and hospital
admissions and mortality related to cardiovascular diseases. These
emissions also contribute to other serious environmental problems,
including visibility impairment and ecosystem damage. In addition, many
of the hydrocarbon (HC) pollutants emitted by these engines are air
toxics.
This rule addresses these air-pollution concerns by adopting
national emission standards for several types of nonroad engines and
vehicles that are currently unregulated. These include large spark-
ignition engines used in industrial and commercial applications such as
those used in forklifts and airport equipment; recreational spark-
ignition vehicles such as off-highway motorcycles, all-terrain
vehicles, and snowmobiles; and recreational marine diesel engines.\1\
These new standards are a continuation of the process of establishing
emission standards for nonroad engines and vehicles, under Clean Air
Act section 213(a).
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\1\ Diesel-cycle engines, referred to simply as ``diesel
engines'' in this document, may also be referred to as compression-
ignition (or CI) engines. These engines typically operate on diesel
fuel, but other fuels may also be used. Otto-cycle engines (referred
to here as spark-ignition or SI engines) typically operate on
gasoline, liquefied petroleum gas, or natural gas.
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We conducted a study of emissions from nonroad engines, vehicles,
and equipment in 1991, as directed by the Clean Air Act, section 213(a)
(42 U.S.C. 7547(a)). Based on the results of that study, we determined
that emissions of oxides of nitrogen (NO_X), volatile organic
compounds, and CO from nonroad engines and equipment contribute
significantly to ozone and CO concentrations in more than one
nonattainment area (59 FR 31306, June 17, 1994). Given this
determination, section 213(a)(3) of the Act requires us to establish
(and from time to time revise) emission 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 determined
that the engines covered by this final rule cause or contribute to such
air pollution (see the final finding for recreational vehicles and
nonroad spark-ignition engines over 19 kW published on December 7, 2000
(65 FR 76790), the final rule for marine diesel engines published on
December 29, 1999 (64 FR 73301)\2\, Section II of the preamble to the
proposed rule (66 FR 51098, October 5, 2001), this preamble, and the
Final Regulatory Support Document).
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\2\ This rule also found that PM emissions from marine diesel
engines contribute to PM nonattainment.
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Where we determine that other emissions from new 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) of the Act authorizes EPA to establish (and from time
to time revise) emission standards from those classes or categories of
new nonroad engines, vehicles, and equipment that cause or contribute
to such air pollution. Pursuant to section 213(a)(4) of the Act, we are
finalizing a finding that emissions from new nonroad engines, including
construction equipment, farm tractors, boats, locomotives, marine
engines, nonroad spark-ignition engines over 19 kW, recreational
vehicles (including off-highway motorcycles, all-terrain-vehicles, and
snowmobiles), significantly contribute to regional haze and visibility
impairment in federal Class I areas and where people live, work and
recreate. These engines, particularly recreational vehicles such as
snowmobiles, are significant emitters of pollutants that are known to
impair visibility in federal Class I areas (see Section I.E of this
preamble and the Final Regulatory Support Document). We have also
determined that engines covered by this final rule, particularly
recreational vehicles including snowmobiles, contribute to such
pollution. Thus, we are finalizing HC standards for snowmobiles to
reduce PM-related visibility impairment.

[[Page 68244]]

B. How Is This Document Organized?

This final rule covers engines and vehicles that vary in design and
use, and many readers may be interested in only one or two of the
applications. We have grouped engines by common application (for
example, recreational land-based engines, marine diesel recreational
engines, large spark-ignition engines used in commercial applications).
This document is organized in a way that allows each reader to focus on
the applications of particular interest.
Section II describes general provisions that are relevant to all of
the nonroad engines covered by this rulemaking. Section III through VI
present information specific to each of the affected nonroad
applications, including standards, effective dates, testing
information, and other specific requirements.
Sections VII and VIII describe a wide range of compliance and
testing provisions that apply generally to engines and vehicles from
all the nonroad engine and vehicle categories included in this
rulemaking. Several of these provisions apply not only to
manufacturers, but also to equipment manufacturers installing certified
engines, remanufacturing facilities, operators, and others. Therefore,
all affected parties should read the information contained in these
sections.
Section IX summarizes the projected impacts and a discussion of the
benefits of this rule. Finally, Sections X and XI contain information
about public participation and various administrative requirements.
The remainder of this section summarizes the new requirements and
the air quality need for the rulemaking.

C. What Categories of Vehicles and Engines Are Covered in This Final
Rule?

This final rule establishes regulatory programs for new nonroad
vehicles and engines not yet subject to EPA emission standards,
including the following engines:
[sbull]
Land-based spark-ignition recreational engines, including
those used in snowmobiles, off-highway motorcycles, and all-terrain
vehicles. For the purpose of this rule, we are calling this group of
engines ``recreational vehicles,'' even though all-terrain vehicles can
be used for commercial purposes.
[sbull]
Land-based spark-ignition engines rated over 19 kW,
including engines used in forklifts, generators, airport baggage tow
trucks, and various farm, construction, and industrial equipment. This
category also includes auxiliary marine engines, but does not include
propulsion marine engines or engines used in recreational vehicles. For
purposes of this rule, we refer to this category as ``Large SI
engines.''
[sbull]
Recreational marine diesel engines.
This final rule covers new engines that are used in the United
States, whether they are made domestically or imported.\3\ A more
detailed discussion of the meaning of the terms ``new'' and
``imported'' that help define the scope of application of this rule is
in Section II of this preamble.
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\3\ For this final rule, we consider the United States to
include the States, the District of Columbia, the Commonwealth of
Puerto Rico, the Commonwealth of the Northern Mariana Islands, Guam,
American Samoa, the U.S. Virgin Islands, and the Trust Territory of
the Pacific Islands.
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D. What Requirements Are We Adopting?

The fundamental requirement for nonroad engines and vehicles is
meeting EPA's emission standards. Section 213(a)(3) of the Act requires
that standards to control emissions related to ozone or CO achieve the
greatest degree of emission reduction achievable through the
application of technology that will be available, giving appropriate
consideration to cost, noise, energy, and safety factors. Section 213
(a)(4) of the Act requires that standards for emissions related to
other air pollution problems be appropriate and take into account
costs, noise, safety, and energy impacts of applying technology that
will be available. Other requirements such as applying for
certification, labeling engines, and meeting warranty requirements
define a process for implementing the program in an effective way.
With regard to Large SI engines, we are adopting a two-phase
program. The first phase of the standards go into effect in 2004 and
are the same as those adopted in October 1998 by the California Air
Resources Board for 2004. These standards will reduce combined HC and
NO_X emissions by nearly 75 percent, based on emission
measurements during steady-state operation. In 2007, we supplement
these standards by setting limits that will require optimizing the same
technologies and will base emission measurements on a transient test
cycle. New requirements for evaporative emissions and engine
diagnostics also start in 2007.
For recreational vehicles, we are adopting separate emission
standards for snowmobiles, off-highway motorcycles, and all-terrain
vehicles. For snowmobiles, we are adopting a first phase of standards
for HC and CO emissions based on a mixture of technologies ranging from
clean carburetion and engine modifications to direct fuel injection
two-stroke technology and some conversion to four-stroke engines, and
second and third phases of emission standards for snowmobiles that will
involve significant use of direct fuel injection two-stroke technology
and conversion to four-stroke engines. For off highway motorcycles and
all-terrain vehicles, we are adopting standards based mainly on moving
these engines from two-stroke to four-stroke technology with the use of
some secondary air injection. We are also adopting requirements to
address permeation emissions from all three types of recreational
vehicles.
The emission standards for recreational marine diesel engines are
comparable to those already established for commercial marine diesel
engines. Manufacturers generally have additional time to meet emission
standards for the recreational models and several specific rulemaking
provisions are tailored to the unique characteristics of these engines.
We are also adopting more stringent voluntary Blue Sky Series
emission standards for recreational marine diesel engines and Large SI
engines. Blue Sky Series emission standards are more stringent than the
mandatory emission standards and are intended to encourage the
introduction and more widespread use of low-emission technologies.
Manufacturers may be motivated to exceed emission requirements either
to gain early experience with certain technologies or as a response to
market demand or local government programs. For recreational vehicles,
we are not adopting voluntary standards but rather providing consumers
with consumer labeling, which will provide information and opportunity
to buy lower-emissions models.
We have also conducted extensive analysis on the costs and benefits
of this rulemaking effort, with specific details found in Section IX
below and in the Final Regulatory Support Document. In summary, we
estimate that annually, the cost to manufacturers is approximately $210
million, the social gain is approximately $550 million, and the
quantified benefits are approximately $8 billion. Social gain is
defined as the economic cost of the rule minus the estimated fuels
savings. Quantified benefits reflect the health benefits primarily
associated with particulate matter controls.

E. Why Is EPA Taking This Action?

There are important public health and welfare reasons supporting
the new

[[Page 68245]]

emission standards. As described below and in the Final Regulatory
Support Document, these engines contribute to air pollution that causes
public health and welfare problems.
Nationwide, these engines and vehicles are a significant source of
mobile source air pollution. As described below, of all mobile source
emissions in 2000 they accounted for about 9 percent of HC emissions, 4
percent of CO emissions, 3 percent of NO_X emissions, and 2
percent of direct PM emissions. The emissions from Large SI engines
contributed 2 to 3 percent of the HC, NO_X, and CO emissions
from mobile sources in 2000. Recreational vehicles by themselves
account for about 6 percent of national mobile source HC emissions and
about 2 percent of national mobile source CO emissions. By reducing
these emissions, the standards will aid states facing ozone and CO air
quality problems, which can cause a range of adverse health effects,
especially in terms of respiratory disease and related illnesses. The
engine categories subject to this rule contribute to regional haze and
visibility impairment in Class I areas and near where people live, work
and recreate. Within national parks, emissions from snowmobiles in
particular contribute to ambient concentrations of fine PM, a leading
cause of visibility impairment. States are required to develop plans to
address visibility impairment in national parks, and the reductions
required in this rule would assist states in those efforts.
The standards will also help reduce acute exposure to CO and air
toxics for forklift operators, equipment users or riders, national and
state park attendants, and other people who may be at particular risk
because they operate or work or are otherwise in close proximity to
this equipment due to their occupation or as riders. Emissions from
these vehicles and equipment can be very high on a per-engine basis. In
addition, the equipment using these engines (especially forklifts) is
often operated in enclosed areas. Similarly, exposure to CO and air
toxics can be intensified for snowmobile riders who follow a group of
other riders along a trail, since those riders are exposed to the
emissions of all the other snowmobiles riding ahead.
When the emission standards are fully implemented in 2030, we
expect a 75-percent reduction in HC emissions, 82-percent reduction in
NO_X emissions, and 61-percent reduction in CO emissions, and
a 60-percent reduction in direct PM emissions from these engines,
equipment, and vehicles (see Section IX below). These emission
reductions will reduce ambient concentrations of CO, ozone, and PM
fine; fine particles are a public health concern and contributes to
visibility impairment. The standards will also reduce exposure for
people who operate or who work with or are otherwise in close proximity
to these engines and vehicles.
We believe technology can be applied to these engines that will
reduce emissions of these harmful pollutants. Manufacturers can reduce
two-stroke engine emissions by improving fuel management and
calibration. This can be achieved by making improvements to carbureted
fuel systems and/or converting to electronic and direct fuel injection.
In addition, many of the existing two-stroke engines in these
categories can be converted to four-stroke technology. Finally, there
are modifications that can be made to four-stroke engines, often short
of requiring catalysts, that can reduce emissions even further.
1. Health and Welfare Effects
Exposure to CO, ground-level ozone, and PM can cause serious
respiratory problems, including premature mortality and respiratory
problems. Fine PM has also been associated with cardiovascular
problems, such as heart rate variability and fibrinogen (a blood
clotting factor) levels, and hospital admissions and mortality related
to cardiovascular diseases. These emissions also contribute to other
serious environmental problems, including visibility impairment and
ecosystem damage. In addition, some of the HC pollutants emitted by
these engines are air toxics. (The health and welfare effects are
described in more detail in the Final Regulatory Support Document.)
CO 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.
Exposures to ozone has been linked to increased hospital admissions
and emergency room visits for respiratory problems.\4\ Repeated
exposure to ozone can increase susceptibility to respiratory infection
and lung inflammation. It can aggravate preexisting respiratory
diseases, such as asthma. Prolonged (6 to 8 hours), repeated exposure
to ozone can cause inflammation of the lung, impairment of lung defense
mechanisms, and possibly irreversible changes in lung structure, which
over time could lead to premature aging of the lungs and/or chronic
respiratory illnesses such as emphysema and chronic bronchitis.
Children, the elderly, asthmatics and outdoor workers are most at risk
from ozone exposure. Evidence also exists of a possible relationship
between daily increases in ozone levels and increases in daily
mortality levels. In addition to human health effects, ozone adversely
affects crop yield, vegetation and forest growth, and the durability of
materials.
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\4\ U.S. EPA Review of the National Ambient Air Quality
Standards for Ozone: Policy Assessment of Scientific and Technical
Information OAQPS Staff Paper. EPA-452/R-96-007. June 1996. A copy
of this document can be found in Docket A-99-06, Document II-A-22.
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PM, like ozone, has been linked to a range of serious respiratory
health problems.\5\ The key health effects associated with ambient
particulate matter include premature mortality, aggravation of
respiratory and cardiovascular disease (as indicated by increased
hospital admissions and emergency room visits, school absences, work
loss days, and restricted activity days), aggravated asthma, acute
respiratory symptoms, including aggravated coughing and difficult or
painful breathing, chronic bronchitis, and decreased lung function that
can be experienced as shortness of breath. Observable human non-cancer
health effects associated with exposure to diesel PM include some of
the same health effects reported for ambient PM such as respiratory
symptoms (cough, labored breathing, chest tightness, wheezing), and
chronic respiratory disease (cough, phlegm, chronic bronchitis and
suggestive evidence for decreases in pulmonary function). Symptoms of
immunological effects such as wheezing and increased allergenicity are
also seen.
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\5\ U.S. EPA Review of the National Ambient Air Quality
Standards for Particulate Matter: Policy Assessment of Scientific
and Technical Information OAQPS Staff Paper. EPA-452/R-96-013. 1996.
Docket Number A-99-06, Documents Nos. II-A-18, 19, 20, and 23. The
particulate matter air quality criteria documents are also available
at http://www.epa.gov/ncea/partmatt.htm.
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PM also 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 and in places where people live
and work. Visibility effects are manifest in two principal ways: (1) as
local impairment (for example,

[[Page 68246]]

localized hazes and plumes) and (2) as regional haze. The emissions
from engines covered by this rule can contribute to both types of
visibility impairment.
The engines covered by this rule also emit air toxics that are
known or suspected human or animal carcinogens, or have serious non-
cancer health effects. These include benzene, 1,3-butadiene,
formaldehyde, acetaldehyde, and acrolein.
2. What Is the Inventory Contribution From the Nonroad Engines and
Vehicles That Would Be Subject to This Rule?
The contribution of emissions from the nonroad engines and vehicles
that will be subject to this final rule to the national inventories of
pollutants is considerable. To estimate nonroad engine and vehicle
emission contributions, we used the latest version of our NONROAD
emissions model, updated with information received during the public
comment period. This model computes nationwide, state, and county
emission levels for a wide variety of nonroad engines, and uses
information on emission rates, operating data, and population to
determine annual emission levels of various pollutants. A more detailed
description of the model and our estimation methodology can be found in
the Chapter 6 of the Final Regulatory Support Document.
Baseline emission inventory estimates for the year 2000 for the
categories of engines and vehicles covered by this rule are summarized
in Table I.E-1. This table shows the relative contributions of the
different mobile source categories to the overall national mobile
source inventory. Of the total emissions from mobile sources, the
categories of engines and vehicles covered by this rule contribute
about 9 percent, 3 percent, 4 percent, and 2 percent of HC,
NO_X, CO, and PM emissions, respectively, in the year 2000.
The results for Large SI engines indicate they contribute approximately
2 to 3 percent to HC, NO_X, and CO emissions from mobile
sources. The results for land-based recreational engines reflect the
impact of the significantly different emissions characteristics of two-
stroke engines. These engines are estimated to contribute about 6
percent of HC emissions and 2 percent of CO from mobile sources.
Recreational marine diesel engines contribute less than 1 percent to
NO_X mobile source inventories. When only nonroad emissions
are considered, the engines and vehicles that will be subject to the
standards account for a larger share.
Our draft emission projections for 2020 and 2030 for the nonroad
engines and vehicles subject to this rule show that emissions from
these categories are expected to increase over time if left
uncontrolled. The projections for 2020 and 2030 are summarized in
Tables I.E-2 and I.E-3, respectively. The projections for 2020 and 2030
indicate that the categories of engines and vehicles covered by this
rule are expected to contribute approximately 25 percent, 10 percent, 5
percent, and 5 percent of mobile source HC, NO_X, CO, and PM
emissions, respectively, if left uncontrolled. Engine population growth
and the effects of other regulatory control programs are factored into
these projections. The relative importance of uncontrolled nonroad
engines in 2020 and 2030 is higher than the projections for 2000
because there are already emission-control programs in place for the
other categories of mobile sources which are expected to reduce their
emission levels. The effectiveness of all control programs is offset by
the anticipated growth in engine populations.
Regarding PM specifically, this information and information in
Section I.3(ii) below show that the engines being regulated in this
rule, snowmobiles and other recreational vehicles in particular,
contribute to PM concentrations that may reasonably be anticipated to
endanger public health and welfare both because of the health effects
associated with PM and because of the effects on visibility discussed
below.

Table I.E-1.--Modeled Annual Emission Levels for Mobile Source Categories in 2000
[Thousand short tons]
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NO_X HC CO PM
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Category Percent Percent Percent Percent
1000 tons of mobile 1000 tons of mobile 1000 tons of mobile 1000 tons of mobile
source source source source
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total for engines subject to this final rule[hairsp][hairsp]*... 351 2.6 645 8.8 2,860 3.8 14.6 2.1
============
Highway Motorcycles............................................. 8 0.1 84 1.2 331 0.4 0.4 0.1
Nonroad Industrial SI £19 kW[hairsp][hairsp]*......... 308 2.3 226 3.1 1,734 2.3 1.6 0.2
Recreational SI[hairsp][hairsp]*................................ 5 0.0 418 5.7 1,120 1.5 12.0 1.7
Recreational Marine Diesel[hairsp][hairsp]*..................... 38 0.3 1 0.0 6 0.0 1 0.1
Marine SI Evap.................................................. 0 0.0 100 1.4 0 0.0 0 0.0
Marine SI Exhaust............................................... 32 0.2 708 9.7 2,144 2.8 38 5.4
Nonroad SI <19 kW............................................... 106 0.8 1,460 20.0 18,359 24.3 50 7.1
Nonroad diesel.................................................. 2,625 19.5 316 4.3 1,217 1.6 253 35.9
Commercial Marine Diesel........................................ 963 7.2 30 0.4 127 0.2 41 5.8
Locomotive...................................................... 1,192 8.9 47 0.6 119 0.2 30 4.3
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Total Nonroad................................................... 5,269 39 3,305 45 24,826 33 427 60
Total Highway................................................... 7,981 59 3,811 52 49,813 66 240 34
Aircraft........................................................ 178 1 183 3 1,017 1 39 6
------------
Total Mobile Sources............................................ 13,428 100 7,300 100 75,656 100 706 100
============
Total Man-Made Sources.......................................... 24,532 ......... 18,246 ......... 97,735 ......... 3,102 .........
============
Mobile Source percent of Total Man-Made Sources................. 55 ......... 40 ......... 77 ......... 23
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 68247]]

Table I.E-2.--Modeled Annual Baseline Emission Levels for Mobile Source Categories in 2020
[thousand short tons]
--------------------------------------------------------------------------------------------------------------------------------------------------------
NO_X HC CO PM
---------------------------------------------------------------------------------------
Category Percent Percent Percent Percent
1000 tons of mobile 1000 tons of mobile 1000 tons of mobile 1000 tons of mobile
source source source source
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total for engines subject to this final rule*................... 547 8.8 1,305 24.1 4,866 5.6 34.1 5.2
============
Highway Motorcycles............................................. 14 0.2 142 2.6 572 0.7 0.8 0.1
Nonroad Industrial SI £ 19 kW*........................ 472 7.6 318 5.9 2,336 2.7 2.3 0.4
Recreational SI*................................................ 14 0.2 985 18.2 2,521 2.9 30.2 4.6
Recreational Marine Diesel*..................................... 61 1.0 2 0.0 9 0.0 1.6 0.2
Marine SI Evap.................................................. 0 0.0 114 2.1 0 0.0 0 0.0
Marine SI Exhaust............................................... 58 0.9 284 5.2 1,985 2.3 28 4.3
Nonroad SI < 19 Kw.............................................. 106 1.7 986 18.2 27,352 31.7 77 11.8
Nonroad Diesel.................................................. 1,791 28.8 142 2.6 1,462 1.7 261 40.0
Commercial Marine Diesel........................................ 819 13.2 35 0.6 160 0.2 46 7.0
Locomotive...................................................... 611 9.8 35 0.6 119 0.1 21 3.2
------------
Total Nonroad................................................... 3,932 63 2,901 54 35,944 42 467 71
Total Highway................................................... 2,050 33 2,276 42 48,906 56 145 22
Aircraft........................................................ 232 4 238 4 1,387 2 43 7
------------
Total Mobile Sources............................................ 6,214 100 5,415 100 86,237 100 655 100
============
Total Man-Made Sources.......................................... 16,190 ......... 15,475 ......... 109,905 ......... 3,039 .........
============
Mobile Source percent of Total Man-Made Sources................. 38 ......... 35 ......... 79 ......... 22 .........
--------------------------------------------------------------------------------------------------------------------------------------------------------

Table I.E-3.--Modeled Annual Emission Levels for Mobile Source Categories in 2030
[Thousand short tons]
--------------------------------------------------------------------------------------------------------------------------------------------------------
NO_X HC CO PM
---------------------------------------------------------------------------------------
Category Percent Percent Percent Percent
1000 tons of mobile 1000 tons of mobile 1000 tons of mobile 1000 tons of mobile
source source source source
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total for engines subject to this final rule*................... 640 10.0 1,411 23.5 5,363 5.4 36.5 4.8
============
Highway Motorcycles............................................. 17 0.3 172 2.9 693 0.7 1.0 0.1
Nonroad Industrial SI £ 19 kW*........................ 553 8.6 371 6.2 2,703 2.7 2.7 0.4
Recreational SI*................................................ 15 0.2 1,038 17.3 2,649 2.7 31.9 4.2
Recreational Marine Diesel*..................................... 72 1.1 2 0.0 11 0.0 1.9 0.3
Marine SI Evap.................................................. 0 0.0 122 2.0 0 0.0 0 0.0
Marine SI Exhaust............................................... 64 1.0 269 4.5 2,083 2.1 29 3.8
Nonroad SI < 19 kW.............................................. 126 2.0 1,200 20.0 32,310 32.4 93 12.3
Nonroad Diesel.................................................. 1,994 31.0 158 2.6 1,727 1.7 306 40.4
Commercial Marine Diesel........................................ 1,166 18.1 52 0.9 198 0.2 74 9.8
Locomotive...................................................... 531 8.3 30 0.5 119 0.1 18 2.4
------------
Total Nonroad................................................... 4,521 70 3,242 54 41,800 42 557 74
Total Highway................................................... 1,648 26 2,496 42 56,303 56 158 21
Aircraft........................................................ 262 4 262 4 1,502 2 43 6
------------
Total Mobile Sources............................................ 6,431 100 6,000 100 99,605 100 758 100
============
Total Man-Made Sources.......................................... 16,639 -- 17,020 -- 123,983 -- 3,319 --
============
Mobile Source percent of Total Man-Made Sources................. 39 -- 35 -- 80 -- 23 --
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 68248]]

3. Why are Controls to Protect against CO Nonattainment and to Protect
Visibility Needed From the Nonroad Engines and Vehicles That Would Be
Subject to This Rule?
i. Why are We Controlling CO Emissions from Nonroad Engines and
Vehicles that Would be Subject to this Rule?
Engines subject to this rule contributed about 3.8 percent of CO
from mobile sources in 2000. Over 22.4 million people currently live in
the 13 nonattainment areas for the CO National Ambient Air Quality
Standard (NAAQS). Industry association comments questioned the need for
CO control and snowmobile contribution, in particular. First, the
statute envisions that categories should be considered in determining
contribution because otherwise, it would be possible to continue to
arbitrarily divide subcategories until the contribution from any
subcategory becomes minimal while the cumulative effect of the air
pollution remains. EPA previously determined that the category of Large
SI engines and recreational vehicles cause or contribute to ambient CO
and ozone in more than one nonattainment area (65 FR 76790, December 7,
2000). EPA also examined recreational vehicles separately and found
that recreational vehicles subject to this rule contribute to CO
nonattainment in areas such as Los Angeles, Phoenix, Anchorage, and Las
Vegas (see RSD chapter 2). Thus, if considered as a category,
recreational vehicles contribute to CO nonattainment.\6\ Moreover, when
we examined snowmobiles separately, they met the contribution criteria.
---------------------------------------------------------------------------

\6\ Likewise, Large SI equipment and recreational marine diesel
engines also contribute to CO in nonattainment areas.
---------------------------------------------------------------------------

The International Snowmobile Manufacturers Association (ISMA)
stated in its public comments that snowmobiles in particular are not
operated in many of the CO nonattainment areas because of lack of snow
(although they may be stored in those areas). The commenters also
contended that northern areas have experienced improved CO air quality.
Many areas are making progress in improving their air quality. However,
an area cannot be redesignated to attainment until it can show EPA that
it has had air quality levels within the level required for attainment
and that it has a plan in place to maintain such levels. Until areas
have been redesignated, they remain nonattainment areas.\7\ Snowmobiles
contribute to CO nonattainment in more than one of these areas.
---------------------------------------------------------------------------

\7\ There are important reasons to focus on redesignation
status, as compared to just current air quality. Areas with a few
years of attainment data can and often do have exceedances following
such years of attainment because of several factors including
different climatic events during the later years, increases in
inventories, etc. Control of emissions from nonroad engines can help
to avoid potential future air quality problems.
---------------------------------------------------------------------------

Snowmobiles have relatively high per-engine CO emissions, and they
can be a significant source of ambient CO levels in CO nonattainment
areas. Despite the fact that snowmobiles are largely banned in CO
nonattainment areas by the state of Alaska, the state estimated (and a
National Research Council study confirmed) that snowmobiles contributed
0.3 tons/day in 2001 to Fairbanks' CO nonattainment area or 1.2 percent
of a total inventory of 23.3 tons per day in 2001.\8,9\ While Fairbanks
has made significant progress in reducing ambient CO concentrations,
existing climate conditions make achieving and maintaining attainment
challenging. Anchorage, AK, reports a similar contribution of
snowmobiles to their emissions inventories (0.34 tons per day in 2000).
Furthermore, a recent National Academy of Sciences report concludes
that ``Fairbanks will be susceptible to violating the CO health
standards for many years because of its severe meteorological
conditions. That point is underscored by a December 2001 exceedance of
the standard in Anchorage which had no violations over the last 3
years.''\10\
---------------------------------------------------------------------------

\8\ Draft Anchorage Carbon Monoxide Emission Inventory and Year
2000 Attainment Projections, Air Quality Program, May 2001, Docket
Number A-2000-01, Document II-A-40; Draft Fairbanks 1995-2001 Carbon
Monoxide Emissions Inventory, June 1, 2001, Docket Number A-2000-01,
Document II-A-39.
\9\ National Research Council. The Ongoing Challenge of Managing
Carbon Monoxide Pollution in Fairbanks, AK. May 2002. Docket A-2000-
01, Document No. IV-A-115.
\10\ National Research Council. The Ongoing Challenge of
Managing Carbon Monoxide Pollution in Fairbanks, AK. May 2002.
Docket A-2000-01, Document IV-A-115.
---------------------------------------------------------------------------

ISMA commented that it agreed with EPA that there is a snowmobile
trail within the Spokane, WA, CO nonattainment area, although they
noted that snowmobile operation alone would not result in CO
nonattainment. However, emissions from regulated categories need only
contribute to, not themselves cause, nonattainment. Concentrations of
NAAQS-related pollutants are by definition a result of multiple sources
of pollution.
Several states that contain CO nonattainment areas also have large
populations of registered snowmobiles and nearby snowmobile trails in
adjoining counties, which are an indication of where they are operated
(see Table I.E-4). EPA requested comment on the volume and nature of
snowmobile use in these and other CO nonattainment areas. ISMA
commented on the proximity of trails to northern CO nonattainment
areas, assuming that snowmobiles are operated only on trails. A search
of the available literature indicates that snowmobiles are ridden in
areas other than trails. For example, a 1998 report by the Michigan
Department of Natural Resources indicates that from 1993 to 1997, of
the 146 snowmobile fatalities studied, 46 percent occurred on a state
or county roadway (another 2 percent on roadway shoulders) and 27
percent occurred on private lands. Furthermore, accident reports in CO
nonattainment area Fairbanks, AK, demonstrate that snowmobiles driven
on streets have collided with motor vehicles. On certain days there may
be concentrations of snowmobiles operated in nonattainment areas due to
public events such as snowmachine races (such as the Iron Dog Gold Rush
Classic, which finishes in Fairbanks, AK), during which snowmobiles
will be present and operated.

Table I.E-4.--Snowmobile Use in Selected CO Nonattainment Areas
----------------------------------------------------------------------------------------------------------------
2001 State
City and state CO nonattainment classification snowmobile
population\a\
----------------------------------------------------------------------------------------------------------------
Anchorage, AK
Fairbanks, AK................. Serious...................................................... \b\ 35576
Spokane, WA................... Serious...................................................... 31532
Fort Collins, CO.............. Moderate..................................................... 32500
Medford, OR................... Moderate..................................................... 16809

[[Page 68249]]

Missoula, MT.................. Moderate..................................................... 23440
----------------------------------------------------------------------------------------------------------------
\a\ Source: ISMA U.S. Snowmobile Registration History, May 15, 2001; various studies prepared for state
snowmobile associations included in Docket A-2000-01.
\b\ Point of sale registration was not mandatory in Alaska prior to 1998, so the statewide registered population
is likely to underestimate the total population.

Exceedances of the 8-hour CO standard were recorded in three of
seven CO nonattainment areas located in the northern portion of the
country over the five year period from 1994 to 1999: Fairbanks, AK;
Medford, OR; and Spokane, WA.\11\ Given the variability in CO ambient
concentrations due to weather patterns such as inversions, the absence
of recent exceedances for some of these nonattainment areas should not
be viewed as eliminating the need for further reductions to
consistently attain and maintain the standard. A review of CO monitor
data in Fairbanks from 1986 to 1995 shows that while median
concentrations have declined steadily, unusual combinations of weather
and emissions have resulted in elevated ambient CO concentrations well
above the 8-hour standard of 9 ppm. Specifically, a Fairbanks monitor
recorded average 8-hour ambient concentrations at 16 ppm in 1988,
around 9 ppm from 1990 to 1992, and then a steady increase in CO
ambient concentrations at 12, 14 and 16 ppm during some extreme cases
in 1993, 1994 and 1995, respectively.\12\
---------------------------------------------------------------------------

\11\ Technical Memorandum to Docket A-2000-01 from Drew Kodjak,
Attorney-Advisor, Office of Transportation and Air Quality, ``Air
Quality Information for Selected CO Nonattainment Areas,'' July 27,
2001, Docket Number A-2000-01, Document Number II-B-18.
\12\ Air Quality Criteria for Carbon Monoxide, U.S. EPA, EPA
600/P-99/001F, June 2000, at 3-38, Figure 3-32 (Federal Bldg, AIRS
Site 020900002). Air Docket A-2000-01, Document Number II-A-29. This
document is also available at http://www.epa.gov/ncea/
coabstract.htm.
---------------------------------------------------------------------------

In addition, there are 6 areas that have not been classified as
nonattainment where air quality monitoring indicated a need for CO
control. For example, CO monitors in northern locations such as Des
Moines, IA, and Weirton, WV/Steubenville, OH, registered levels above
the level of the CO standards in 1998.
ii. Why are Controls Needed From the Nonroad Engines and Vehicles
That Would Be Subject to this Rule to Protect Visibility?
(1) Visibility is Impaired by Fine PM and Precursor Emissions From
Nonroad Engines and Vehicles That Would Be Subject to This Rule.
Visibility can be defined as the degree to which the atmosphere is
transparent to visible light.\13\ Visibility degradation is an easily
noticeable effect of fine PM present in the atmosphere, and fine PM is
the major cause of reduced visibility in parts of the United States,
including many of our national parks and in places across the country
where people live, work, and recreate. Fine particles with significant
light-extinction efficiencies include organic matter, sulfates,
nitrates, elemental carbon (soot), and soil.
---------------------------------------------------------------------------

\13\ National Research Council, 1993. Protecting Visibility in
National Parks and Wilderness Areas. National Academy of Sciences
Committee on Haze in National Parks and Wilderness Areas. National
Academy Press, Washington, DC. This document is available on the
internet at http://www.nap.edu/books/0309048443/html/. See also U.S.
EPA Air Quality Criteria Document for Particulate Matter (1996) and
Review of the National Ambient Air Quality Standards for Particulate
Matter: Policy Assessment of Scientific and Technical Information.
These documents can be found in Docket A-99-06, Documents No. II-A-
23 and IV-A-130-32.
---------------------------------------------------------------------------

Visibility is an important effect because it has direct
significance to people's enjoyment of daily activities in all parts of
the country. Individuals value good visibility for the well-being it
provides them directly, both in where they live and work, and in places
where they enjoy recreational opportunities. Visibility is highly
valued in significant natural areas such as national parks and
wilderness areas, because of the special emphasis given to protecting
these lands now and for future generations.
To quantify changes in visibility, we compute a light-extinction
coefficient, which shows the total fraction of light that is decreased
per unit distance. Visibility can be described in terms of PM
concentrations, visual range, light extinction or deciview.\14\ In
addition to limiting the distance that one can see, the scattering and
absorption of light caused by air pollution can also degrade the color,
clarity, and contrast of scenes.
---------------------------------------------------------------------------

\14\ Visual range can be defined as the maximum distance at
which one can identify a black object against the horizon sky. It is
typically described in miles or kilometers. Light extinction is the
sum of light scattering and absorption by particles and gases in the
atmosphere. It is typically expressed in terms of inverse megameters
(Mm-1), with larger values representing worse visibility. The
deciview metric describes perceived visual changes in a linear
fashion over its entire range, analogous to the decibel scale for
sound. A deciview of 0 represents pristine conditions. Under many
scenic conditions, a change of 1 deciview is considered perceptible
by the average person.
---------------------------------------------------------------------------

Visibility effects are manifest in two main ways: as local
impairment (for example, localized hazes and plumes) and as regional
haze. In addition, visibility impairment has a time dimension in that
it might relate to a short-term excursion or to longer periods (for
example, worst 20 percent of days or annual average levels).
Local-scale visibility degradation is commonly seen as a plume
resulting from the emissions of a specific source or small group of
sources, or it is in the form of a localized haze such as an urban
``brown cloud.'' Plumes are comprised of smoke, dust, or colored gas
that obscure the sky or horizon relatively near sources. Impairment
caused by a specific source or small group of sources has been
generally termed as ``reasonably attributable.''
The second type of impairment, regional haze, results from
pollutant emissions from a multitude of sources located across a broad
geographic region. It impairs visibility in every direction over a
large area, in some cases over multi-state regions. Regional haze masks
objects on the horizon and reduces the contrast of nearby objects. The
formation, extent, and intensity of regional haze is a function of
meteorological and chemical processes, which sometimes cause fine
particulate loadings to remain suspended in the atmosphere for several
days and to be transported hundreds of kilometers from their sources.
On an annual average basis, the concentrations of non-anthropogenic
fine PM are generally small when compared with concentrations of fine
particles from anthropogenic sources. Anthropogenic contributions
account for about one-third of the average extinction coefficient in
the rural West and more than 80 percent in the rural East. Because of
significant differences related to visibility conditions in the eastern
and western U.S., we present information about visibility by region.
Furthermore, it is important to note that even in those areas with
relatively low

[[Page 68250]]

concentrations of anthropogenic fine particles, such as the Colorado
plateau, small increases in anthropogenic fine particle concentrations
can lead to significant decreases in visual range. This is one of the
reasons Class I areas have been given special consideration under the
Clean Air Act.
Nonroad engines that are subject to this final rule contribute to
ambient fine PM levels in two ways. First, they contribute through
direct emissions of fine PM. As shown in Table I.E-1, these engines
emitted 14,600 tons of PM (over 2 percent of all mobile source PM) in
2000. Second, these engines contribute to indirect formation of PM
through their emissions of gaseous precursors which are then
transformed in the atmosphere into particles. For example, these
engines emitted over 8 percent of the HC tons from mobile sources.
Furthermore, recreational vehicles, such as snowmobiles and all-terrain
vehicles emit high levels of organic carbon (as HC) on a per-engine
basis. Some organic emissions are transformed into particles in the
atmosphere and other volatile organics can condense if emitted in cold
temperatures, as is the case for emissions from snowmobiles, for
example. Organic carbon accounts for between 27 and 36 percent of
ambient fine particle mass depending on the area of the country.
(A) Visibility Impairment Where People Live, Work and Recreate
The secondary PM NAAQS is designed to protect against adverse
welfare effects such as visibility impairment. In 1997, the secondary
PM NAAQS was set as equal to the primary (health-based) PM NAAQS (62
Federal Register No. 138, July 18, 1997). EPA concluded that PM can and
does produce adverse effects on visibility in various locations,
depending on PM concentrations and factors such as chemical composition
and average relative humidity. In 1997, EPA demonstrated that
visibility impairment is an important effect on public welfare and that
visibility impairment is experienced throughout the U.S., in multi-
state regions, urban areas, and remote Federal Class I areas.
In many cities having annual mean PM_2.5 concentrations
exceeding 17 [mu]g/m\3\, improvements in annual average visibility
resulting from the attainment of the annual PM_2.5 standard
are expected to be perceptible to the general population (e.g., to
exceed 1 deciview). Based on annual mean monitored PM_2.5
data, many cities in the Northeast, Midwest, and Southeast as well as
Los Angeles would be expected to experience perceptible improvements in
visibility if the PM_2.5 annual standard were attained. For
example, in Washington, DC, where the IMPROVE monitoring network shows
annual mean PM_2.5 concentrations at about 19 [mu]g/m\3\
during the period of 1992 to 1995, approximate annual average
visibility would be expected to improve from 21 km (29 deciview) to 27
km (27 deciview), a change of 2 deciviews. The PM_2.5 annual
average in Washington, DC, was 18.9 [mu]g/m\3\ in 2000.
The updated monitored data and air quality modeling presented in
the RSD confirm that the visibility situation identified during the
NAAQS review in 1997 is still likely to exist. Thus, the determination
in the NAAQS rulemaking about broad visibility impairment and related
benefits from NAAQS compliance are still relevant. Levels above the
fine PM NAAQS cause adverse welfare impacts, such as visibility
impairment (both regional and localized impairment).
Furthermore, in setting the PM NAAQS, EPA acknowledged that levels
of fine particles below the NAAQS may also contribute to unacceptable
visibility impairment and regional haze problems in some areas, and
Clean Air Act Section 169 provides additional authorities to remedy
existing impairment and prevent future impairment in the 156 national
parks, forests and wilderness areas labeled as Class I areas.
In making determinations about the level of protection afforded by
the secondary PM NAAQS, EPA considered how the Section 169 regional
haze program and the secondary NAAQS would function together. Regional
strategies are expected to improve visibility in many urban and non-
Class I areas as well. The following recommendation for the National
Research Council, Protecting Visibility in National Parks and
Wilderness Areas (1993), addresses this point:
Efforts to improve visibility in Class I areas also would benefit
visibility outside these areas. Because most visibility impairment is
regional in scale, the same haze that degrades visibility within or
looking out from a national park also degrade visibility outside it.
The 1999-2000 PM_2.5 monitored values, which cover about
a third of the nation's counties, indicate that at least 82 million
people live in areas where long-term ambient fine particulate matter
levels are at or above 15 [mu]g/m\3\.\15\ Thus, these populations (plus
those who travel to those areas) could be experiencing visibility
impairment that is unacceptable, and emissions of PM and its precursors
from engines in these categories contribute to this unacceptable
impairment.\16\
---------------------------------------------------------------------------

\15\ Memorandum to Docket A-99-06 from Eric O. Ginsburg, Senior
Program Advisor, ``Summary of 1999 Ambient Concentrations of Fine
Particulate Matter,'' November 15, 2000. Air Docket A-2000-01,
Document No. II-B-12.
\16\ These populations would obviously also be exposed to PM
concentrations associated with the adverse health impacts related to
PM_2.5.
---------------------------------------------------------------------------

Because the chemical composition of the PM affects visibility
impairment, we used EPA's Regulatory Model System for Aerosols and
Deposition (REMSAD)\17\ model to project visibility conditions in 2030
accounting for the chemical composition of the particles and to
estimate visibility impairment directly as changes in deciview. Our
projections included anticipated emissions from the engines subject to
this rule, and although our emission predictions reflected our best
estimates of emissions projections at the time the modeling was
conducted, we now have new estimates, as discussed in the RSD Chapter
1. Based on public comment for this rule and new information, we have
revised our emissions estimates in some categories downwards and other
categories upwards; however, on net, we believe the modeling
underestimates the PM air quality levels that would have been predicted
if new inventories were used.
---------------------------------------------------------------------------

\17\ Additional information about the Regulatory Model System
for Aerosols and Deposition (REMSAD) and our modeling protocols can
be found in our Regulatory Impact Analysis: Heavy-Duty Engine and
Vehicle Standards and Highway Diesel Fuel Sulfur Control
Requirements, document EPA420-R-00-026, December 2000. Docket No. A-
2000-01, Document No. A-II-13. This document is also available at
http://www.epa.gov/otaq/disel.htm#documents.
---------------------------------------------------------------------------

The most reliable information about the future visibility levels
would be in areas for which monitoring data are available to evaluate
model performance for a base year (e.g., 1996). Accordingly, we
predicted that in 2030, 49 percent of the population will be living in
areas where fine PM levels are above 15 [mu]g/m\3\ and monitors are
available.\18\ This can be compared with the 1996 level of 37 percent
of the population living in areas where fine PM levels are above 15
[mu]g/m\3\ and monitors are available. Thus, a substantial percent of
the population would experience unacceptable visibility impairment in
areas where they live, work and recreate.
---------------------------------------------------------------------------

\18\ Technical Memorandum, EPA Air Docket A-99-06, Eric O.
Ginsburg, Senior Program Advisor, Emissions Monitoring and Analysis
Division, OAQPS, Summary of Absolute Modeled and Model-Adjusted
Estimates of Fine Particulate Matter for Selected Years, December 6,
2000, Table P-2. Docket Number 2000-01, Document Number II-B-14.
---------------------------------------------------------------------------

As shown in Table I.E-5, in 2030, we expect visibility in the East
to be about

[[Page 68251]]

19 deciviews (or visual range of 60 kilometers) on average, with poorer
visibility in urban areas, compared to the visibility conditions
without man-made pollution of 9.5 deciviews (or visual range of 150
kilometers). Likewise, we expect visibility in the West to be about 9.5
deciviews (or visual range of 150 kilometers) in 2030, compared to the
visibility conditions without man-made pollution of 5.3 deciviews (or
visual range of 230 kilometers).
Nonroad engines contribute significantly to these effects. As shown
in Tables I.E-1 through I.E-3, nonroad engines emissions contribute a
large portion of the total PM emissions from mobile sources and
anthropogenic sources, in general. These emissions occur in and around
areas with PM levels above the annual PM_2.5 NAAQS. The
engines subject to the final rule will contribute to these effects.
They are estimated to emit 36,500 tons of direct PM in 2030, which is
1.1 percent of the total anthropogenic PM emissions in 2030. Similarly,
for PM precursors, the engines subject to this rule will emit 640,000
tons of NO_X and 1,411,000 tons HC in 2030, which are 3.8 and
8.3 percent of the total anthropogenic NO_X and HC emissions,
respectively, in 2030. Recreational vehicles in particular contribute
to these levels. In Table I.E-1 through I.E-3, we show that
recreational vehicles emitted about 1.7 percent of mobile source PM
emissions in 2000. Similarly, recreational vehicles are modeled to emit
over 4 percent of mobile source PM in 2020 and 2030. Thus, the
emissions from these sources contribute to the visibility impairment
modeled for 2030 summarized in the table.
Furthermore, for 20 counties across nine states, snowmobile trails
are found within or near counties that registered ambient
PM_2.5 concentrations at or above 15 [mu]g/m\3\, the level of
the PM_2.5 NAAQS.\19\ Fine particles may remain suspended for
days or weeks and travel hundreds to thousands of kilometers, and thus
fine particles emitted or created in one county may contribute to
ambient concentrations in a neighboring county.20, 21
---------------------------------------------------------------------------

\19\ Memo to file from Terence Fitz-Simons, OAQPS, Scott
Mathias, OAQPS, Mike Rizzo, Region 5, ``Analyses of 1999 PM Data for
the PM NAAQS Review,'' November 17, 2000, with attachment B, 1999
PM_2.5 Annual Mean and 98th Percentile 24-Hour Average
Concentrations. Docket No. A-2000-01, Document No. II-B-17.
\20\ This information also shows that snowmobiles contribute to
concentrations of fine PM that are above the primary health-related
NAAQS, which indicates that emissions from snowmobiles also
contribute to primary and secondary PM pollution that may reasonably
be anticipated to endanger public health and welfare.
\21\ Review of the National Ambient Air Quality Standards for
Particulate Matter: Policy Assessment for Scientific and Technical
Information, OAQPS Staff Paper, EPA-452[bs]R-96-
013, July, 1996, at IV-7. This document is available from Docket A-
99-06, Document II-A-23.

Table I.E-5--Summary of 2030 National Visibility Conditions Based on
REMSAD Modeling
[Deciviews]
------------------------------------------------------------------------
Predicted 2030
visibility b Natural
Regions a (annual background
average) visibility
------------------------------------------------------------------------
Eastern U.S............................. 18.98 9.5
Urban............................... 20.48
Rural............................... 18.38
Western U.S............................. 9.54 5.3
Urban............................... 10.21
Rural............................... 9.39
------------------------------------------------------------------------
a Eastern and Western Regions are separated by 100 degrees north
longitude. Background visibility conditions differ by region.
b The results incorporate earlier emissions estimates from the engines
subject to this rule, as discussed in the Final Regulatory Support
Document. We have revised our estimates both upwards for some
categories and downwards for others based on public comment and
updated information; however, we believe that the net results would
underestimate future PM emissions.

(B) Visibility Impairment in Class I Areas
The Clean Air Act establishes special goals for improving
visibility in many national parks, wilderness areas, and international
parks. In the 1977 amendments to the Clean Air Act, Congress set as a
national goal for visibility the ``prevention of any future, and the
remedying of any existing, impairment of visibility in mandatory class
I Federal areas which impairment results from manmade air pollution''
(CAA section 169A(a)(1)). The Amendments called for EPA to issue
regulations requiring States to develop implementation plans that
assure ``reasonable progress'' toward meeting the national goal (CAA
Section 169A(a)(4)). EPA issued regulations in 1980 to address
visibility problems that are ``reasonably attributable'' to a single
source or small group of sources, but deferred action on regulations
related to regional haze, a type of visibility impairment that is
caused by the emission of air pollutants by numerous emission sources
located across a broad geographic region. At that time, EPA
acknowledged that the regulations were only the first phase for
addressing visibility impairment. Regulations dealing with regional
haze were deferred until improved techniques were developed for
monitoring, for air quality modeling, and for understanding the
specific pollutants contributing to regional haze.
In the 1990 Clean Air Act amendments, Congress provided additional
emphasis on regional haze issues (see CAA section 169B). In 1999 EPA
finalized a rule that calls for States to establish goals and emission
reduction strategies for improving visibility in all 156 mandatory
Class I national parks and wilderness areas. In this rule, EPA
established a ``natural visibility'' goal. In that rule, EPA also
encouraged the States to work together in developing and implementing
their air quality plans. The regional haze program is focused on long-
term emissions decreases from the entire regional emissions inventory
comprised of major and minor stationary sources, area sources and
mobile sources. The regional haze program is designed to improve
visibility and air quality in our most treasured natural areas from
these broad sources. At the same time, control strategies designed to
improve visibility in the national parks and wilderness areas will
improve visibility over broad geographic areas. In the 1997 PM NAAQS
rulemaking, EPA also anticipated the need in addition to the NAAQS and
Section 169 regional haze program to continue to address localized
impairment that may relate to unique circumstances in some Western
areas. For mobile sources, there is a need for a Federal role in
reduction of those emissions, particularly because mobile source
vehicles are regulated primarily at the federal level.
Visibility impairment is caused by pollutants (mostly fine
particles and precursor gases) directly emitted to the atmosphere by
several activities (such as electric power generation, various industry
and manufacturing processes, truck and auto emissions, construction
activities, etc.). These gases and particles scatter and absorb light,
removing it from the sight path and creating a hazy condition.
Visibility impairment is caused by both regional haze and localized
impairment. As described above, regional haze is caused

[[Page 68252]]

by the emission from numerous sources located over a wide geographic
area.\22\
---------------------------------------------------------------------------

\22\ U.S. EPA Review of the National Ambient Air Quality
Standards for Particulate Matter: Policy Assessment of Scientific
and Technical Information OAQPS Staff Paper. EPA-452/R-96-013. 1996.
Docket Number A-99-06, Documents Nos. II-A-18, 19, 20, and 23. The
particulate matter air quality criteria documents are also available
at http://www.epa.gov/ncea/partmatt.htm.
---------------------------------------------------------------------------

Because of evidence that fine particles are frequently transported
hundreds of miles, all 50 states, including those that do not have
Class I areas, participate in planning, analysis, and, in many cases,
emission control programs under the regional haze regulations. Even
though a given State may not have any Class I areas, pollution that
occurs in that State may contribute to impairment in Class I areas
elsewhere. The rule encourages states to work together to determine
whether or how much emissions from sources in a given state affect
visibility in a downwind Class I area.
The regional haze program calls for states to establish goals for
improving visibility in national parks and wilderness areas to improve
visibility on the haziest 20 percent of days and to ensure that no
degradation occurs on the clearest 20 percent of days (64 FR 35722.
July 1, 1999). The rule requires states to develop long-term strategies
including enforceable measures designed to meet reasonable progress
goals toward natural visibility conditions. Under the regional haze
program, States can take credit for improvements in air quality
achieved as a result of other Clean Air Act programs, including
national mobile source programs.\23\
---------------------------------------------------------------------------

\23\ In a recent case, American Corn Growers Association v. EPA,
291 F. 3d 1 (D.C. Cir 2002), the court vacated the BART provisions
of the Regional Haze rule, but the court denied industry's challenge
to EPA's requirement that state's SIPs provide for reasonable
progress towards achieving natural visibility conditions in national
parks and wilderness areas and the ``no degradation'' requirement.
Industry did not challenge requirements to improve visibility on the
haziest 20 percent of days. A copy of this decision can be found in
Docket A-2000-01, Document IV-A-113.
---------------------------------------------------------------------------

In the PM air quality modeling described above, we also modeled
visibility conditions in the Class I areas, and we summarize the
results by region in Table I.E-6.

Table I.E-6--Summary of 2030 Visibility Conditions in Class I Areas
Based on REMSAD Modeling
[Annual Average Deciview]
------------------------------------------------------------------------
Natural
Region a Predicted 2030 background
visibility b visibility
------------------------------------------------------------------------
Eastern .............. 9.5
Southeast............................... 25.02 ..............
Northeast/Midwest....................... 21.00 ..............
Western .............. 5.3
Southwest............................... 8.69 ..............
California.............................. 11.61 ..............
Rocky Mountain.......................... 12.30 ..............
Northwest............................... 15.44 ..............
-----------------
National Class I Area Average....... 14.04 ..............
------------------------------------------------------------------------
a Regions are depicted in Figure VI-5 in the Regulatory Support Document
for the highway Heavy Duty Engine/Diesel Fuel RIA (EPA 420-R-00-026,
December 2000.) Background visibility conditions differ by region:
Eastern natural background is 9.5 deciviews (or visual range of 150
kilometers) and in the West natural background is 5.3 deciviews (or
visual range of 230 kilometers).
b The results incorporate earlier emissions estimates from the engines
subject to this rule, as discussed in the Final Regulatory Support
Document. We have revised our estimates both upwards for some
categories and downwards for others based on public comment and
updated information; however, we believe that the net results
underestimate future PM emissions.

Nonroad engines represent a sizeable portion of the total inventory
of anthropogenic emissions related to PM2.5, as shown in the tables
above. Numerous types of nonroad engines may operate near Class I areas
(e.g., mining equipment, recreational vehicles, and agricultural
equipment). We have reviewed contributions from snowmobile in
particular.
Emissions from nonroad engines, in particular snowmobiles,
contribute significantly to visibility impairment in Class I areas.\24\
Visibility and PM monitoring data are available for eight Class I areas
where snowmobiles are commonly used. These are: Acadia, Boundary
Waters, Denali, Mount Rainier, Rocky Mountain, Sequoia and Kings
Canyon, Voyageurs, and Yellowstone.\25\ Fine particle monitoring data
for these parks are set out in Table I.E-7. This table shows the number
of monitored days in the winter that fell within the 20-percent worst
visibility days for each of these eight parks. Monitors collect data 2
days a week for a total of about 104 days of monitored values. Thus,
for a particular site, a maximum of 21 worst possible days of these 104
days with monitored values constitute the set of 20-percent worst
visibility days during a year which are tracked as the primary focus of
regulatory efforts.\26\ With the exception of Denali in Alaska, we
defined the snowmobile season as January 1 through March 15 and
December 15 through December 31 of the same calendar year, consistent
with the methodology used in the Regional Haze Rule, which is calendar-
year based. For Denali in Alaska, the snowmobile season is October 1 to
April 30.
---------------------------------------------------------------------------

\24\ The results incorporate earlier emissions estimates from
the engines subject to this rule, as discussed in the Final
Regulatory Support Document. We have revised our estimates both
upwards for some categories and downwards for others based on public
comment and updated information; however, we believe that the net
results would underestimate future PM emissions.
\25\ No data were available at five additional parks where
snowmobiles are also commonly used: Black Canyon of the Gunnison,
CO, Grand Teton, WY, Northern Cascades, WA, Theodore Roosevelt, ND,
and Zion, UT.
\26\ Letter from Debra C. Miller, Data Analyst, National Park
Service, to Drew Kodjak, August 22, 2001. Docket No. A-2000-01,
Document Number II-B-28.

[[Page 68253]]

Table I.E-7--Winter Days That Fall Within the 20 Percent Worst Visibility Days At National Parks Used by
Snowmobiles
----------------------------------------------------------------------------------------------------------------
Number of sampled wintertime days within 20
percent worst visibility days (maximum of 21
NPS unit States out of 104 monitored days)
-----------------------------------------------
1996 1997 1998 1999
----------------------------------------------------------------------------------------------------------------
Acadia NP............................. ME...................... 4 4 2 1
Denali NP and Preserve................ AK...................... 10 10 12 9
Mount Rainier NP...................... WA...................... 1 3 1 1
Rocky Mountain NP..................... CO...................... 2 1 2 1
Sequoia and Kings Canyon NP........... CA...................... 4 9 1 8
-------------
Voyageurs NP (1989-1992).............. MN...................... 1989 1990 1991 1992
3 4 6 8
--Boundary Waters USFS Wilderness Area MN...................... 2 5 1 5
(close to Voyaguers with recent data).
Yellowstone NP........................ ID, MT, WY.............. 0 2 0 0
----------------------------------------------------------------------------------------------------------------
Source: Letter from Debra C. Miller, Data Analyst, National Park Service, to Drew Kodjak, August 22, 2001.
Docket No. A-2000-01, Document Number II-B-28.

According to the National Park Service, ``[s]ignificant differences
in haziness occur at all eight sites between the averages of the
clearest and haziest days. Differences in mean standard visual range on
the clearest and haziest days fall in the approximate range of 115-170
km.'' \27\ We examined future air quality predictions to whether the
emissions from recreational vehicles, such as snowmobiles, contribute
to regional visibility impairment in Class I areas. We present results
from the future air quality modeling described above for these Class I
areas in addition to inventory and air quality measurements.
Specifically, in Table I.E-8, we summarize the expected future
visibility conditions in these areas without these regulations.
---------------------------------------------------------------------------

\27\ Letter from Debra C. Miller, Data Analyst, National Park
Service, to Drew Kodjak, August 22, 2001. Docket No. A-2000-01,
Document Number II-B-28.

Table I.E-8--Estimated 2030 Visibility in Selected Class I Areas a,b
----------------------------------------------------------------------------------------------------------------
Natural
Predicted 2030 background
visibility visibility
Class I area County State (annual (annual
average average
deciview) deciview)
----------------------------------------------------------------------------------------------------------------
Eastern areas ..................... ..................... .............. 9.5
Acadia............................ Hancock Co........... ME................... 23.42 ..............
Boundary Waters................... St. Louis Co......... MN................... 22.07 ..............
Voyageurs......................... St. Louis Co......... MN................... 22.07 ..............
Western areas ..................... ..................... .............. 5.3
Grand Teton NP.................... Teton Co............. WY................... 11.97 ..............
Kings Canyon...................... Fresno Co............ CA................... 10.39 ..............
Mount Rainier..................... Lewis Co............. WA................... 16.19 ..............
Rocky Mountain.................... Larimer Co........... CO................... 8.11 ..............
Sequoia-Kings..................... Tulare Co............ CA................... 9.36 ..............
Yellowstone....................... Teton Co............. WY................... 11.97 ..............
----------------------------------------------------------------------------------------------------------------
a Natural background visibility conditions differ by region because of differences in factors such as relative
humidity: Eastern natural background is 9.5 deciviews (or visual range of 150 kilometers) and in the West
natural background is 5.3 deciviews (or visual range of 230 kilometers).
b The results incorporate earlier emissions estimates from the engines subject to this rule. We have revised our
estimates both upwards for some categories and downwards for others based on public comment and updated
information; however, on net, we believe that HD07 analyses would underestimate future PM emissions from these
categories.

The information presented in Table I.E-7 shows that visibility data
support a conclusion that there are at least 8 Class I Areas (7
national parks and one wilderness area) frequented by snowmobiles with
one or more wintertime days within the 20-percent worst visibility days
of the year, and in many cases several days. For example, Rocky
Mountain National Park in Colorado was frequented by about 27,000
snowmobiles during the 1998-1999 winter. Of the monitored days
characterized as within the 20-percent worst visibility monitored days,
2 of those days occurred during the wintertime when snowmobile
emissions such as hydrocarbons contributed to visibility impairment.
The information in Table I.E-8 shows that these areas also are
predicted to have high annual average deciview levels in the future.
Emissions from snowmobiles and other recreational vehicles, as well as
other nonroad engines contributed to these levels.\28\
---------------------------------------------------------------------------

\28\ See Chapter 1 in the RSD for a discussion or U.S. EPA
Technical Support Document for Heavy-duty Engine and Vehicle
Standards and Highway Diesel Fuel Sulfur Control Requirements--Air
Quality Modeling Analyses December 2000. Docket No. A-2000-01,
Docket Number IV-A-218. This document is also avaiable at
www.epa.gov/otaq/hdmodels.htm.

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

[[Page 68254]]

Ambient concentrations of fine particles are the primary pollutant
responsible for visibility impairment. The classes of fine particles
principally responsible for visibility impairment are sulfates,
nitrates, organic carbon particles, elemental carbon, and crustal
material. Hydrocarbon emissions from automobiles, trucks, snowmobiles,
and other industrial processes are common sources of organic carbon.
The organic carbon fraction of fine particles ranges from 47 percent in
Western areas such as Denali National Park, to 28 percent in Rocky
Mountain National Park, to 13 percent in Acadia National Park.\29\
---------------------------------------------------------------------------

\29\ Letter from Debra C. Miller, Data Analyst, National Park
Service, to Drew Kodjak, August 22, 2001. Docket No. A-2000-01,
Document Number II-B-28.
---------------------------------------------------------------------------

In the winter months, HC emissions from snowmobiles can be
significant, and these HC emissions can be more than half of the
organic carbon fraction of fine particles which are largely responsible
for visibility impairment. In Yellowstone, a park with high snowmobile
usage during the winter months, snowmobile HC emissions can exceed 500
tons per year, as much as several large stationary sources.\30\ Other
parks with less snowmobile traffic are also impacted although to a
lesser extent by these HC emissions.\31\
---------------------------------------------------------------------------

\30\ Emissions of NO_X from snowmobiles contribute to
the total amount of particulate nitrate, although the total
NO_X emissions from snowmobiles are considerably less than
HC or direct PM emissions from these engines.
\31\ Technical Memorandum, Aaron Worstell, Environmental
Engineer, National Park Service, Air Resources Division, Denver,
Colorado, particularly Table 1. Docket No. A-2000-01, Document
Number II-G-178.
---------------------------------------------------------------------------

Table I.E-9 shows estimated tons of four pollutants during the
winter season in five Class I national parks for which we have
estimates of snowmobile use. The national park areas outside of Denali
in Alaska are open to snowmobile operation in accordance with special
regulations (36 CFR part 7). Denali National Park permits snowmobile
operation by local rural residents engaged in subsistence uses (36 CFR
part 13).

Table I.E-9.--Winter Season Snowmobile Emissions
[tons; 1999 Winter Season]
------------------------------------------------------------------------
NPS unit HC CO NO_X PM
------------------------------------------------------------------------
Denali NP & Preserve............ X standard for snowmobiles. This
standard will essentially cap NO_X emissions from these
engines to prevent backsliding. We are not promulgating standards that
would require substantial reductions in NO_X because we
believe that standards which force substantial NO_X
reductions would likely not lead to reductions in PM and may in fact
increase PM levels. NO_X emissions from snowmobiles are very
small, particularly compared to levels of HC. In fact, technologies
that reduce HC and CO are likely to increase levels of NO_X
and vice versa, because technologies to reduce HC and CO emissions
would result in leaner operation. A lean air and fuel mixture causes
NO_X emissions to increase. These increases are minor,
however, compared to the reductions of HC (and therefore PM) that
result from these techniques.
On the other hand, substantial control of NO_X emissions
may have the counter-effect of increasing HC emissions and the greater
PM emissions associated with those HC emissions. The only way to reduce
NO_X emissions from four-stroke engines (at the same time as
reducing HC and CO levels) would be to use a three-way catalytic
converter. We do not have enough information at this time on the
durability or safety implications of using a three-way catalyst with a
four-stroke engine in snowmobile applications. Three-way catalyst
technology is well beyond the technology reviewed for this rule and
would need substantial additional review before being contemplated for
snowmobiles. Thus, given the overwhelming level of HC compared to
NO_X, and the secondary PM expected to result from these
levels, it would be premature and possibly counterproductive to
promulgate NO_X standards that require significant
NO_X reductions from snowmobiles at this time. We have
therefore decided to structure our long term HC+NO_X standard
for 2012 and later model year snowmobiles to require only a cap on
NO_X emissions from the advanced technology engines which
will be the dominant technology in the new snowmobiles certified at
that time.

II. Nonroad: General Provisions

This section describes general provisions concerning the emission
standards adopted in this final rule and the ways in which a
manufacturer shows compliance with these standards. Clean Air Act
section 213(a)(3) requires us to set standards that achieve the
greatest degree of emission reduction achievable through the
application of technology that will be available, giving appropriate
consideration to cost, noise, energy, and safety factors. Section
202(a)(4) provides further authority to adopt standards for pollution
beyond that regulated under section 202(a)(3). In addition to emission
standards, this document describes a variety of other provisions
necessary for implementing the proposed emission-control program in an
effective way, such as applying for certification, labeling engines,
and meeting warranty requirements.
The discussions in this section are general and are meant to cover
all the nonroad engines and vehicles subject to the new standards. In
this Section II, the term engine is sometimes used to include both
nonroad engines and nonroad vehicles. Refer to the discussions of
specific programs, contained in Sections III through VI, to determine
whether the regulations are being applied to the entire vehicle or just
the engine, as well as for more information about specific requirements
for different categories of nonroad engines and vehicles.
This section describes general nonroad provisions related to
certification prior to sale or introduction into commerce. Section VII
describes several compliance provisions that apply generally to nonroad
engines, and Section VIII similarly describes general testing
provisions.

A. Scope of Application

This final rule covers recreational marine diesel engines, nonroad
spark-ignition engines rated over 19 kW, and recreational spark-
ignition vehicles introduced into commerce in the United States. The
following sections describe generally when emission standards apply to
these products. These provisions are generally consistent with prior
nonroad and motor-vehicle rulemakings. Refer to the specific program
discussion below for more information about the scope of application
and timing of new standards.
1. What Engines and Vehicles Are Subject to the Standards?
The scope of this rule is broadly set by Clean Air Act section
213(a), which instructs us to set emission standards for new nonroad
engines and new nonroad vehicles. Generally speaking, this rule is
intended to cover all new engines and vehicles in the categories listed
above (including any associated equipment or vessels) for their entire
useful lives, as defined in the regulations.\33\ Once the emission
standards apply to a group of engines or vehicles, manufacturers of a
new engine must have an approved certificate of conformity from us
before selling them in the United States.\34\ This also applies to
importation by any person and any other means of introducing new
engines and vehicles into commerce. We also require equipment
manufacturers that install engines from other companies to install only
certified engines into new equipment once emission standards

[[Page 68256]]

apply. The information we require of manufacturers applying for
certification (with the corresponding engine labels) provides assurance
that manufacturers have met their obligation to make engines that meet
emission standards over the useful life we specify in the regulations.
---------------------------------------------------------------------------

\33\ For recreational vehicles, we are adopting vehicle-based
standards. For these applications, the term ``engine'' in this
document applies equally to the vehicles.
\34\ The term ``manufacturer'' includes any individual or
company that manufactures any new engine for sale or otherwise
introduces a new engine into commerce in the United States. It also
includes importers for resale.
---------------------------------------------------------------------------

2. How Do I Know if My Engine or Equipment Is New?
We are defining ``new'' consistent with previous rulemakings. We
will consider a nonroad engine (or nonroad equipment) to be new until
its title has been transferred to the ultimate purchaser or the engine
has been placed into service. This definition applies to both engines
and equipment, so the nonroad equipment using these engines, including
all-terrain vehicles, snowmobiles, off-highway motorcycles, and other
land-based nonroad equipment will be considered new until their title
has been transferred to an ultimate buyer. In Section II.B.1 we
describe how to determine the model year of individual engines and
vehicles.
To further clarify the definition of new nonroad engine, we specify
that a nonroad engine, vehicle, or equipment is placed into service
when it is used for its intended purpose. An engine subject to emission
standards is used for its functional purpose when it is installed in an
all-terrain vehicle, snowmobile, off-highway motorcycle, marine vessel,
or other piece of nonroad equipment. We need to make this clarification
because some engines are made by modifying a highway or land-based
nonroad engine that has already been installed on a vehicle or other
piece of equipment. For example, someone can install an engine in a
recreational marine vessel after it has been used for its functional
purpose as a land-based highway or nonroad engine. We believe our
approach is reasonable because the practice of adapting used highway or
land-based nonroad engines may become more common if these engines are
not subject to emission standards.
In summary, an engine may be subject to emission standards if it
is:
. Freshly manufactured, whether domestic or imported; this
may include engines produced from engine block cores
. Installed for the first time in nonroad equipment after
having powered an automobile or a category of nonroad equipment subject
to different emission standards
. Installed in new nonroad equipment, regardless of the age
of the engine
. Imported (freshly manufactured or used) and was originally
manufactured after the effective date of our standards
3. When Do Imported Engines Need To Meet Emission Standards?
The emission standards apply to all new engines sold in the United
States. Consistent with Clean Air Act section 216, engines that are
imported by any person, whether freshly manufactured or used are
considered ``new'' engines.\35\ Thus, we include engines that are
imported for use in the United States, whether they are imported as
loose engines or if they are already installed on a marine vessel,
recreational vehicle, or other piece of nonroad equipment, built
elsewhere. All imported engines manufactured after our standards begin
to apply need an EPA-issued certificate of conformity to clear customs,
with limited exemptions (as described below).
---------------------------------------------------------------------------

\35\ The definition in Clean Air Act section 216 applies
specifically to ``new motor vehicles,'' but we have interpreted
``new nonroad engine'' consistently with the definition in section
216.
---------------------------------------------------------------------------

An engine or marine vessel, recreational vehicle, or other piece of
nonroad equipment that was built after emission standards take effect
cannot be imported without a currently valid certificate of conformity.
We would consider it to be a new engine, vehicle, or vessel, which
would trigger a requirement to comply with the applicable emission
standards. Thus, for example, a marine vessel manufactured in a foreign
country in 2007, then imported into the United States in 2010, would be
considered ``new.'' The engines on that vessel would have to comply
with the requirements for the 2007 model year, assuming no other
exemptions apply. This provision is important to prevent manufacturers
from avoiding emission standards by building vessels or vehicles
abroad, transferring their title, and then importing them as used
vessels or vehicles.
Imported engines are generally subject to emission standards.
However, we are not adopting a definition of ``import'' in this
regulation. We will defer to the U.S. Customs Service for
determinations of when an engine or vehicle is imported into the U.S.
4. Do the Standards Apply to Exported Engines or Vehicles?
Engines or vehicles intended for export are generally not required
to meet the emission standards or other requirements adopted in this
rule. However, engines that will be exported and subsequently re-
imported into the United States must be covered by a certificate of
conformity. For example, this would occur when a foreign company
purchases engines manufactured in the United States for installation on
a marine vessel, recreational vehicle, or other nonroad equipment for
export back to the United States. Those engines would be subject to the
emission standards that apply on the date the engine was originally
manufactured. If the engine is later modified and certified (or
recertified), the engine is subject to emission standards that apply on
the date the modification is complete. So, for example, foreign boat
builders buying U.S.-made engines without recertifying the engines will
need to make sure they purchase complying engines for the products they
sell in the U.S. We also do not exempt engines exported to countries
that share our emission standards.
5. Are Any New Engines or Vehicles in the Applicable Categories Not
Subject to Emission Standards of This Rule?
We are extending our basic nonroad exemptions to the engines and
vehicles covered by this rulemaking. These include the testing
exemption, the manufacturer-owned exemption, the display exemption, and
the national-security exemption. These exemptions are described in more
detail in Section VII.C.
In addition, the Clean Air Act does not consider stationary engines
or engines used solely for competition to be nonroad engines, so the
emission standards do not apply to them. Refer to the program
discussions below for a description of how these exclusions or
exemptions apply for different categories of engines.

B. Emission Standards and Testing

1. Which Pollutants Are Covered by Emission Standards?
Engines subject to the exhaust emission standards must meet
standards based on measured levels of specified pollutants, such as
NO_X, HC, or CO, though not all engines have standards for
each pollutant. Diesel engines generally must also meet a PM emission
standard. In addition, there may be standards or other requirements for
crankcase, evaporative, or permeation emissions, as described below.
The emission standards are effective on a model-year basis. We
define model year much like we do for passenger cars. It generally
means either the calendar year or some other annual production period
based on the manufacturer's production practices. A model year may
include January 1 from only one year.

[[Page 68257]]

For example, manufacturers could start selling 2006 model year engines
as early as January 2, 2005, as long as the production period extends
until at least January 1, 2006. All of a manufacturer's engines from a
given model year must meet emission standards for that model year. For
example, manufacturers producing new engines in the 2006 model year
need to comply with the 2006 standards. The model year of a particular
engine is determined based on the date that the engine is fully
assembled. In the case of recreational vehicles, this generally applies
to the final assembly of the whole vehicle, since the emission
standards apply to the vehicle. Refer to the individual program
discussions below or the regulations for additional information about
model year periods, including how to define what model year means in
less common scenarios, such as installing used engines in new
equipment.
2. What Standards Apply to Crankcase, Evaporative, Permeation, and
Other Emissions?
Blow-by of combustion gases and the reciprocating action of the
piston can cause exhaust emissions to accumulate in the crankcase of
four-stroke engines. Uncontrolled engine designs route these vapors
directly to the atmosphere, where they contribute to ambient levels of
hydrocarbons. We have long required that automotive engines prevent
emissions from their crankcases. Manufacturers typically do this by
routing crankcase vapors through a valve into the engine's air intake
system. We generally require in this rulemaking that engines control
crankcase emissions.
Vehicles with spark-ignition engines use fuel that is volatile and
the unburned fuel can be released into the ambient air. We are adopting
standards to limit evaporative emissions from the fuel. Evaporative
emissions result from heating gasoline or other volatile fuels in a
tank that is vented to the atmosphere or from permeation through
plastic fuel tanks and rubber hoses. Section IV describes the
permeation standards for recreational vehicles. Section V provides
additional information on the evaporative emission standards for Large
SI engines.
We are also adopting a general requirement that all engines subject
to this final rule may not cause or contribute to an unreasonable risk
to public health, welfare, or safety, especially with respect to
noxious or toxic emissions that may increase as a result of emission-
control technologies. The regulatory language has been modified
consistent with the alternate language suggested in the proposal. This
alternate language implements sections 202(a)(4) and 206(a)(3) of the
Act and clarifies that the p