Control of Emissions From New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder

[Federal Register: December 7, 2007 (Volume 72, Number 235)]
[Proposed Rules]
[Page 69521-69552]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr07de07-21]
[[Page 69522]]

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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 9 and 94
[EPA-HQ-OAR-2007-0121; FRL-8502-5]
RIN 2060-AO38

Control of Emissions From New Marine Compression-Ignition Engines
at or Above 30 Liters per Cylinder

AGENCY: Environmental Protection Agency (EPA).
ACTION: Advance notice of proposed rulemaking.

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SUMMARY: EPA is issuing this Advance Notice of Proposed Rulemaking
(ANPRM) to invite comment from all interested parties on our plan to
propose new emission standards and other related provisions for new
compression-ignition marine engines with per cylinder displacement at
or above 30 liters per cylinder. We refer to these engines as Category
3 marine engines. We are considering standards for achieving large
reductions in oxides of nitrogen (NO_X) and particulate
matter (PM) through the use of technologies such as in-cylinder
controls, aftertreatment, and low sulfur fuel, starting as early as 2011.
Category 3 marine engines are important contributors to our
nation's air pollution today and these engines are projected to
continue generating large amounts of NO_X, PM, and sulfur
oxides (SO_X) that contribute to nonattainment of the
National Ambient Air Quality Standards (NAAQS) for PM_2.5 and
ozone across the United States. Ozone and PM_2.5 are
associated with serious public health problems including premature
mortality, aggravation of respiratory and cardiovascular disease,
aggravation of existing asthma, acute respiratory symptoms, chronic
bronchitis, and decreased lung function. Category 3 marine engines are
of concern as a source of diesel exhaust, which has been classified by
EPA as a likely human carcinogen. A program such as the one under
consideration would significantly reduce the contribution of Category 3
marine engines to national inventories of NO_X, PM, and
SO_X, as well as air toxics, and would reduce public exposure
to those pollutants.

DATES: Comments must be received on or before March 6, 2008.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2007-0121, by one of the following methods:
• http://www.regulations.gov: Follow the on-line instructions for
submitting comments.
• E-mail: a-and-r-docket@epa.gov
• Fax: (202) 566-9744
• Mail: Environmental Protection Agency, Mail Code: 6102T, 1200
Pennsylvania Ave., NW., Washington, DC, 20460. Please include two copies.
• Hand Delivery: EPA Docket Center (Air Docket), U.S.
Environmental Protection Agency, EPA West Building, 1301 Constitution
Avenue, NW., Room: 3334 Mail Code: 2822T, Washington, DC. Such
deliveries are only accepted during the Docket's normal hours of
operation, and special arrangements should be made for deliveries of
boxed information.
Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2007-0121. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
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unless the comment includes information claimed to be Confidential
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FOR FURTHER INFORMATION CONTACT: Michael Samulski, Assessment and
Standards Division, Office of Transportation and Air Quality, 2000
Traverwood Drive, Ann Arbor, MI, 48105; telephone number: (734) 214-
4532; fax number: (734) 214-4050; e-mail address:
samulski.michael@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does This Action Apply to Me?

This action will affect companies that manufacture, sell, or import
into the United States new marine compression-ignition engines for use
on vessels flagged or registered in the United States; companies and
persons that make vessels that will be flagged or registered in the
United States and that use such engines; and the owners or operators of
such U.S. vessels. Owners and operators of vessels flagged elsewhere
may also be affected, to the extent they use U.S. shipyards or
maintenance and repair facilities; see also Section VII.E regarding
potential application of the standards to foreign vessels that enter
U.S. ports. Finally, this action may also affect companies and persons
that rebuild or maintain these engines. Affected categories and
entities include the following:

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Examples of potentially affected
Category NAICS code \a\ entities
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Industry.............................. 333618................................ Manufacturers of new marine
diesel engines.
Industry.............................. 336611................................ Manufacturers of marine vessels.
Industry.............................. 811310................................ Engine repair and maintenance.

[[Page 69523]]

Industry.............................. 483................................... Water transportation, freight
and passenger.
Industry.............................. 324110................................ Petroleum Refineries.
Industry.............................. 422710, 422720........................ Petroleum Bulk Stations and
Terminals; Petroleum and
Petroleum Products Wholesalers.

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\a\ North American Industry Classification System (NAICS).

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

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

1. Submitting CBI. Do not submit this information to EPA through
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information that you claim to be CBI. For CBI information in a disk or
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CBI and then identify electronically within the disk or CD-ROM the
specific information that is claimed as CBI. In addition to one
complete version of the comment that includes information claimed as
CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2.
2. Tips for Preparing Your Comments. When submitting comments,
remember to:
• Identify the rulemaking by docket number and other
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• Provide specific examples to illustrate your concerns, and
suggest alternatives.
• Explain your views as clearly as possible, avoiding the
use of profanity or personal threats.
• Make sure to submit your comments by the comment period
deadline identified.

II. Additional Information About This Rulemaking

The current emission standards for new compression-ignition marine
engines with per cylinder displacement at or above 30 liters per
cylinder were adopted in 2003 (see 68 FR 9746, February 28, 2003). This
ANPRM relies in part on information that was obtained for that rule,
which can be found in Public Docket EPA-HQ-OAR-2003-0045. This docket
is incorporated into the docket for this action, EPA-HQ-OAR-2007-0121.

Table of Contents

I. Overview
A. Background: EPA's Current Category 3 Standards
B. Program Under Consideration
II. Why Is EPA Considering New Controls?
A. Ozone and PM Attainment
B. Public Health Impacts
1. Particulate Matter
2. Ozone
3. Air Toxics
C. Other Environmental Effects
1. Visibility
2. Plant and Ecosystem Effects of Ozone
3. Acid Deposition
4. Eutrophication and Nitrification
5. Materials Damage and Soiling
III. Relevant Clean Air Act Provisions
IV. International Regulation of Air Pollution From Ships
V. Potential Standards and Effective Dates
A. NO_X Standards
B. PM and SO_X Standards
VI. Emission Control Technology
A. Engine-Based NO_X Control
1. Traditional In-Cylinder Controls
2. Water-Based Technologies
3. Exhaust Gas Recirculation
B. NO_X Aftertreatment
C. PM and SO_X Control
1. In-Cylinder Controls
2. Fuel Quality
3. Exhaust Gas Scrubbers
VII. Certification and Compliance
A. Testing
1. PM Sampling
2. Low Power Operation
3. Test Fuel
B. On-off Technologies
C. Parameter Adjustment
D. Certification of Existing Engines
E. Other Compliance Issues
1. Engines on Foreign-Flagged Vessels
2. Non-Diesel Engines
VIII. Potential Regulatory Impacts
A. Emission Inventory
1. Estimated Inventory Contribution
2. Inventory Calculation Methodology
B. Potential Costs
IX. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
D. Unfunded Mandates Reform Act
E. Executive Order 13132: Federalism
F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
G. Executive Order 13045: Protection of Children From
Environmental Health and Safety Risks
H. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
I. National Technology Transfer Advancement Act
J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income Populations

I. Overview

In recent years, EPA has adopted major new programs designed to
reduce emissions from diesel engines. When fully phased in, these new
programs for highway \1\ and land-based nonroad \2\ diesel engines will
lead to the elimination of over 90 percent of harmful regulated
pollutants from these sources. The public health and welfare benefits
of these actions are very significant, projected at over $70 billion
and $83 billion for our highway and land-based nonroad diesel programs,
respectively. In contrast, the corresponding cost of these programs
will be a small fraction of this amount. We have estimated the annual
cost at $4.2 billion and $2 billion, respectively in 2030. These
programs are being implemented over the next decade.
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\1\ 66 FR 5001, January 18, 2001.
\2\ 69 FR 38957, June 29, 2004.
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We have also recently proposed a new emission control program for
locomotives and marine diesel engines.\3\ The proposed standards would
address all types of diesel locomotives (line-haul, switch, and
passenger rail) and all types of marine diesel engines below 30 liters
per cylinder displacement (including propulsion engines used on vessels
from recreational and small fishing boats to super-yachts, tugs and
Great Lakes freighters, and auxiliary engines ranging from small
generator sets to large generators on ocean-going

[[Page 69524]]

vessels).\4\ The proposal consists of a three-part program. First, we
are proposing more stringent standards for existing locomotives that
would apply when they are remanufactured; we are also requesting
comment on a program that would apply a similar requirement to existing
marine diesel engines up to 30 liters per cylinder displacement when
they are remanufactured. Second, we are proposing a set of near-term
emission standards, referred to as Tier 3, for newly-built locomotives
and marine engines up to 30 liters per cylinder displacement that
reflect the application of in-cylinder technologies to reduce engine-
out NO_X and PM. Third, we are proposing longer-term
standards for locomotive engines and certain marine diesel engines,
referred to as Tier 4 standards, that reflect the application of high-
efficiency catalytic aftertreatment technology enabled by the
availability of ultra-low sulfur diesel (ULSD) fuel.
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\3\ 72 FR 15937, April 3, 2007.
\4\ Marine diesel engines at or above 30 l/cyl displacement are
not included in this program.
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Marine diesel engines above 30 liters per cylinder, called Category
3 marine diesel engines, are significant contributors to our national
mobile source emission inventory. Category 3 marine engines are
predominantly used in ocean-going vessels (OGV). The contribution of
these engines to national inventories is described in section VIII.A of
this preamble. These inventories are expected to grow significantly due
to expected increases in foreign trade. Without new controls, we
anticipate that their overall contribution to mobile source oxides of
nitrogen (NO_X) and fine diesel particulate matter
(PM_2.5) emissions will increase to about 34 and 45 percent
respectively by 2030. Their contribution to emissions in port areas on
a percentage basis would be expected to be significantly higher.
Reducing emissions from these engines can lead to improvements in
public health and would help states and localities attain and maintain
the PM and ozone national ambient air quality standards. Both ozone and
PM_2.5 are associated with serious public health problems,
including premature mortality, aggravation of respiratory and
cardiovascular disease (as indicated by increased hospital admissions
and emergency room visits, school absences, lost work days, and
restricted activity days), changes in lung function and increased
respiratory symptoms, altered respiratory defense mechanisms, and
chronic bronchitis. In addition, diesel exhaust is of special public
health concern. Since 2002 EPA has classified diesel exhaust as likely
to be carcinogenic to humans by inhalation at environmental
exposures.\5\ Recent studies are showing that populations living near
large diesel emission sources such as major roadways,\6\ rail yards,
and marine ports \7\ are likely to experience greater diesel exhaust
exposure levels than the overall U.S. population, putting them at
greater health risks. We are currently studying the size of the U.S.
population living near a sample of approximately 50 marine ports and
will place this information in the docket for this ANPRM upon
completion.
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\5\ U.S. EPA (2002) Health Assessment Document for Diesel Engine
Exhaust. EPA/600/8-90/057F. Office of Research and Development,
Washington DC. This document is available electronically at
http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060. This
document is available in Docket EPA-HQ-OAR-2007-0121.
\6\ Kinnee, E.J.; Touman, J.S.; Mason, R.; Thurman, J.; Beidler,
A.; Bailey, C.; Cook, R. (2004) Allocation of onroad mobile
emissions to road segments for air toxics modeling in an urban area.
Transport. Res. Part D 9: 139-150.
\7\ State of California Air Resources Board. Roseville Rail Yard
Study. Stationary Source Division, October 14, 2004. This document
is available electronically at: http://www.arb.ca.gov/diesel/documents/
rrstudy.htm and State of California Air Resources Board.
Diesel Particulate Matter Exposure Assessment Study for the Ports of
Los Angeles and Long Beach, April 2006. This document is available
electronically at:
http://www.arb.ca.gov/regact/marine2005/portstudy0406.pdf. This
document is available in Docket EPA-HQ-OAR-2007-0121.
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Category 3 marine engines are currently subject to emission
standards that rely on engine-based technologies to reduce emissions.
These standards, which were adopted in 2003 and went into effect in
2004, are equivalent to the NO_X limits in Annex VI to the
MARPOL Convention, adopted by a Conference of the Parties to the
Convention in 1997. The opportunity to gain large additional public
health benefits through the application of advanced emission control
technologies, including aftertreatment, lead us to consider more
stringent standards for these engines. In order to achieve these
emission reductions on the ship, however, it may be necessary to
control the sulfur content of the fuel used in these engines. Finally,
because of the international nature of ocean-going marine
transportation, and the very large inventory contribution from foreign-
flagged vessels, we may also consider the applicability of federal
standards to foreign vessels that enter U.S. ports (see Section VII.E).
In this ANPRM, we describe the emission program we are considering
for Category 3 marine diesel engines and technologies we believe can be
used to achieve those standards. The remainder of this section provides
background on our current emission control program and gives an
overview of the program we are considering. Section II provides a brief
discussion of the health and human impacts of emissions from Category 3
marine diesel engines. Section III identifies relevant Clean Air Act
provisions and Section IV summarizes our interactions with the
International Maritime Organization (IMO). In Sections V and VI, we
describe the potential emission limits and the emission control
technologies that can be used to meet them. Section VII discusses
several compliance issues. In Section VIII, we summarize the
contribution of these engines to current mobile source NO_X
and PM inventories in the United States and describe our plans for our
future cost analysis. Finally, Section IX contains information on
statutory and executive order reviews covering this action. We are
interested in comments covering all aspects of this ANPRM.

A. Background: EPA's Current Category 3 Standards

EPA currently has emission standards for Category 3 marine diesel
engines. The standards, adopted in 2003, are equivalent to the MARPOL
Annex VI NO_X limits. They apply to any Category 3 engine
installed on a vessel flagged or registered in the United States,
beginning in 2004.
In our 2003 final rule, we considered adopting standards that would
achieve greater emission reductions through expanding the use and
optimization of in-cylinder controls as well as through the use of
advanced emission control technologies including water technologies
(water injection, emulsification, humidification) and selective
catalytic reduction (SCR). However, we determined that it was
appropriate to defer a final decision on the longer-term Tier 2
standards to a future rulemaking. While there was a certain amount of
information available at the time about the advanced technologies,
there were several outstanding technical issues concerning the
widespread commercial use of those technologies. Deferring the Tier 2
standards to a second rulemaking allowed us the opportunity to obtain
important additional information on the use of these advanced
technologies that we expected to become available over the next few
years. This new information was expected to include: (1) New
developments as manufacturers continue to make various improvements to
the technology and address any remaining concerns, (2) data or
experience from recently initiated in-use installations using the
advanced technologies, and (3) information from

[[Page 69525]]

longer-term in-use experience with the advanced technologies that would
be helpful for evaluating the long-term durability of emission
controls. An additional reason to defer the adoption of long-term
standards for Category 3 engines was to allow the United States to
pursue further negotiations in the international arena to achieve more
stringent global emission standards for marine diesel engines.\8\
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\8\ 68 FR 9748, February 28, 2003.
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Finally, because the standards adopted in our 2003 rulemaking were
equivalent to the international standards, we determined that it was
appropriate to defer a decision on the application of federal standards
to engines on foreign-flagged vessels that enter U.S. ports. We
indicated that we would consider this issue again in our future
rulemaking, and we intend to evaluate how best to address emissions
from foreign vessels in this action. We expect our proposal to reflect
an approach similar to the emission program recently proposed by the
United States in the current discussions at the IMO to amend the MARPOL
Annex VI standards to a level that achieves significant reductions in
NO_X, PM, and SO_X emissions from Category 3 marine
diesel engines.\9\ We will evaluate progress at the IMO and, as
appropriate, consider the application of new EPA national standards to
engines on foreign-flagged vessels that enter U.S. ports under our
Clean Air Act authority.
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\9\ ``Revision of the MARPOL Annex VI, the NO_X
Technical Code and Related Guidelines; Development of Standards for
NO_X, PM, and SO_X,'' submitted by the United
States, BLG 11/5, Sub-Committee on Bulk Liquids and Gases, 11th
Session, Agenda Item 5, February 9, 2007, Docket ID EPA-HQ-OAR-2007-
0121-0034. This document is also available on our Web site:
www.epa.gov/otaq/oceanvessels.com.

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B. Program Under Consideration

As described in Section VI, continuing advancements in diesel
engine control technology support the adoption of long-term technology-
forcing standards for Category 3 engines. With regard to NO_X
control, SCR has been applied to many land-based applications, and the
technology continues to be refined and improved. More propulsion
engines have been fitted with the technology, especially on vessels
operating in the Baltic Sea, and it is being found to be very effective
and durable in-use. These improvements, in addition to better
optimization of engine-based controls, have the potential for
significant NO_X reductions. PM and SO_X emissions
from Category 3 engines are primarily due to the sulfur content of the
fuel they use. In the short term, these emissions can be decreased by
using fuel with a reduced sulfur content or through the use of exhaust
gas cleaning technology; this is the idea behind the SO_X
Emission Control Areas (SECAs) provided for in Annex VI. More
significant reductions can be obtained by using distillate fuel, and at
least one company has been voluntarily switching from residual fuel to
distillate fuel while their ships are operating within 24 nautical
miles of certain California ports.\10\ Their experience demonstrates
that this type of fuel switching can be done safely and efficiently,
although the higher price of distillate fuel may limit this approach to
near-coast and port areas. In addition, emission scrubbing techniques
are improving, which have the potential for significant PM reductions
from Category 3 engines.
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\10\ See ``Maersk Line Announces Fuel Switch for Vessels Calling
California'' at http://www.maerskline.com/globalfile/?path=/pdf/
environment_fuel_initiative.

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We are currently considering an emission control program for new
Category 3 marine diesel engines that takes advantage of these new
emission reduction approaches. The program we are considering,
described in more detail in Section V, would focus on NO_X,
PM, and SO_X control from new and existing engines. This
program is similar to the one recently proposed at the IMO by the U.S.
government.
For NO_X control for new engines, we are considering a
two-phase approach. In the first phase, called Tier 2, we are
considering a NO_X emission limit for new engines that would
be 15 to 25 percent below the current NO_X limits as defined
by the NO_X curve in the current Tier 1 standards. These
standards would apply at all times. In the second phase, called Tier 3,
we are considering a NO_X emission limit that would achieve
an additional 80 percent reduction from the Tier 2 limits. We are
considering the Tier 2 limits as early as 2011 and Tier 3 limits in the
2016 time frame. Because Tier 3 standards are likely to be achieved
using aftertreatment technologies, the application of the standards
could be geographically-based thereby allowing operators to turn the
system off while they are outside of a specified geographic area. That
area could be the same as the compliance area for PM and SO_X
reductions (see below). This two-part approach would permit near-term
emission reductions while achieving deeper reductions through long-term
standards.
We believe a two-phase approach under consideration is an effective
way to maximize NO_X emission reductions from these engines.
While we continue to believe that the focus of the emission control
program should be on meaningful long-term standards that would apply
high-efficiency catalytic aftertreatment to these engines, short-term
emission reductions could be achieved through incremental improvements
to existing engine designs. These design improvements can be consistent
with a long-term, after treatment-based Tier 3 program. The recent
experience of engine manufacturers in applying advanced control
technologies to other mobile sources suggests that incremental changes
of the type that would be used to achieve the Tier 2 standards may also
be used in strategies to achieve the Tier 3 standards. For example,
Tier 2 technologies may allow engine manufacturers to size their
aftertreatment control systems smaller. A more stringent Tier 2 control
program, however, may risk diverting resources away from Tier 3 and may
result in the application of emission reduction strategies that are not
consistent with high-efficiency catalytic aftertreatment-based controls.
For PM and SO_X control, we are considering a performance
standard that would reflect the use of low-sulfur distillate fuels or
the use of exhaust gas cleaning technology (e.g., scrubbers), or a
combination of both. These standards would apply as early as 2011 and
would potentially achieve SO_X reductions as high as 95
percent and substantial PM reductions as well. We believe a performance
standard would be a cost-effective approach for PM emission reductions
since it allows ship owners to choose from a variety of mechanisms to
achieve the standard, including fuel switching or the use of emission
scrubbers. Compliance with the PM and SO_X emissions could be
limited to operation in a defined geographical area. For example, ships
operating in the defined coastal areas (i.e., within a specified
distance from shore) would be required to meet the requirements while
operating within the area, but could ``turn off'' the control mechanism
while on the open sea. This type of performance standard could apply to
all vessels, new or existing, that operate within the designated area.
An important advantage of a geographic approach for PM and
SO_X control, as well as the Tier 3 standards, is that it
would result in emission reductions that are important for health and
human welfare while reducing the costs of the program since ships will
not be required to comply with the limits while they are operating
across large areas of the open sea.

[[Page 69526]]

We are also considering NO_X emission controls for
existing Category 3 engines that would begin in 2012. There are at
least two approaches that could be used for setting NO_X
emission limits for existing engines. The first would be to set a
performance standard, for example a reduction of about 20 percent from
the Tier 1 NO_X limits; how this reduction is achieved would
be left up to the ship owner. Alternatively, the second approach would
be to express the requirement as a specified action, for example an
injector change known to achieve a particular reduction; this approach
would simplify verification, but the emission reduction results may
vary across engines. We will be exploring both of these alternative
approaches and seek comment on the relative merits of each.

II. Why Is EPA Considering New Controls?

Category 3 marine engines subject to today's ANPRM generate
significant emissions of fine particulate matter (PM_2.5),
nitrogen oxides (NO_X) and sulfur oxides (SO_X)
that contribute to nonattainment of the National Ambient Air Quality
Standards for PM_2.5 and ozone. NO_X is a key
precursor to ozone and secondary PM formation while SO_X is a
significant contributor to ambient PM_2.5. These engines also
emit volatile organic compounds (VOCs), carbon monoxide (CO), and
hazardous air pollutants or air toxics, which are associated with
adverse health effects. Diesel exhaust is of special public health
concern, and since 2002 EPA has classified it as likely to be
carcinogenic to humans by inhalation at environmental exposures. In
addition, emissions from these engines also cause harm to public
welfare, contributing to visibility impairment, and other detrimental
environmental impacts across the U.S.

A. Ozone and PM Attainment

Many of our nation's most serious ozone and PM_2.5
nonattainment areas are located along our coastlines where vessels
using Category 3 marine engine emissions contribute to air pollution in
or near urban areas where significant numbers of people are exposed to
these emissions. The contribution of these engines to air pollution is
substantial and is expected to grow in the future. Currently more than
40 major U.S. ports \11\ along our Atlantic, Great Lakes, Gulf of
Mexico, and Pacific coast lines are located in nonattainment areas for
ozone and/or PM_2.5 (See Figure II-1).
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\11\ American Association of Port Authorities (AAPA), Industry
Statistics, 2005 port rankings by cargo tonnage.
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The health and environmental effects associated with these
emissions are a classic example of a negative externality (an activity
that imposes uncompensated costs on others). With a negative
externality, an activity's social cost (the cost borne by society
imposed as a result of the activity taking place) exceeds its private
cost (the cost to those directly engaged in the activity). In this
case, emissions from Category 3 marine engines impose public health and
environmental costs on society. However, these added costs to society
are not reflected in the costs of those using these engines and
equipment. The market system itself cannot correct this negative
externality because firms in the market are rewarded for minimizing
their operating costs, including the costs of pollution control. In
addition, firms that may take steps to use equipment that reduces air
pollution may find themselves at a competitive economic disadvantage
compared to firms that do not. The emission standards that EPA is
considering for Category 3 marine diesel engines would help address
this market failure and reduce the negative externality from these
emissions by providing a positive incentive for engine manufacturers to
produce engines that emit fewer harmful pollutants and for vessel
builders and owners to use those cleaner engines.
When considering vessel operations in the United States' Exclusive
Economic Zone (EEZ), emissions from Category 3 marine engines account
for a substantial portion of the United States' ambient
PM_2.5 and NO_X mobile source emissions.\12\ We
estimate that annual emissions in 2007 from these engines totaled more
than 870,000 tons of NO_X emissions and 66,000 tons of
PM_2.5. This represents more than 8 percent of U.S. mobile
source NO_X and 15 percent of U.S. mobile source
PM_2.5 emissions. These numbers are projected to increase
significantly through 2030 due to growth in the use of Category 3
marine engines to transport overseas goods to U.S. markets and U.S.
produced goods overseas. Furthermore, their proportion of the emission
inventory is projected to increase significantly as regulatory controls
on other major emission categories take effect. By 2030, NO_X
emissions from these ships are projected to more than double, growing
to 2.1 million tons a year or 34 percent of U.S. mobile source
NO_X emissions while PM_2.5 emissions are expected
to almost triple to 170,000 tons annually comprising 45 percent of U.S.
mobile source PM_2.5 emissions.\13\ In 2007 annual emission
of SO_X from Category 3 engines totaled almost 530,000 tons
or more than half of mobile source SO_X and by 2030 these
emissions are expected to increase to 1.3 million tons or 94 percent of
mobile source emissions.
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\12\ In general, the United States Exclusive Economic Zone (EEZ)
extends to 200 nautical miles from the U.S. coast. Exceptions
include geographic regions near Canada, Mexico and the Bahamas where
the EEZ extends less than 200 nautical miles from the U.S. coast.
See map in Figure VIII-1, below.
\13\ These projections are based on growth rates ranging from
1.7 to 5.0 percent per year, depending on the geographic region. The
growth rates are described in Section VIII.A.
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Both ozone and PM_2.5 are associated with serious public
health problems, including premature mortality, aggravation of
respiratory and cardiovascular disease (as indicated by increased
hospital admissions and emergency room visits, school absences, lost
work days, and restricted activity days), increased respiratory
symptoms, altered respiratory defense mechanisms, and chronic
bronchitis. Diesel exhaust is of special public health concern, and
since 2002 EPA has classified it as likely to be carcinogenic to humans
by inhalation at environmental exposures.\14\
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\14\ U.S. EPA (2002) Health Assessment Document for Diesel
Engine Exhaust. EPA/600/8-90/057F. Office of Research and
Development, Washington DC. This document is available electronically
at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060.
This document is available in Docket EPA-HQ-OAR-2007-0121.
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Recent studies are showing that populations living near large
diesel emission sources such as major roadways \15\, railyards, and
marine ports \16\ are likely to experience greater diesel exhaust
exposure levels than the overall U.S. population, putting them at
greater health risks. As part of our current locomotive and marine
diesel engine rulemaking (72 FR 15938, April 3, 2007), we are studying
the U.S. population living near a sample of 47 marine ports which are
located along the entire east and west coasts of the U.S. as well as
the Gulf of Mexico and the Great Lakes region. This information

[[Page 69527]]

will be placed in the docket for this rulemaking when the study is
completed. The PM_2.5 and NO_X reductions which
would occur as a result of applying advanced emissions control
strategies to Category 3 marine engines could both reduce the amount of
emissions that populations near these sources are exposed to and assist
state and local governments as they work to reduce NO_X and
PM_2.5 inventories.
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\15\ Kinnee, E.J.; Touman, J.S.; Mason, R.; Thurman,J.; Beidler,
A.; Bailey, C.; Cook, R. (2004) Allocation of onroad mobile
emissions to road segments for air toxics modeling in an urban area.
Transport. Res. Part D 9: 139-150.
\16\ State of California Air Resources Board. Roseville Rail
Yard Study. Stationary Source Division, October 14, 2004. This
document is available electronically at: http://www.arb.ca.gov/diesel/
documents/rrstudy.htm and State of California Air Resources
Board. Diesel Particulate Matter Exposure Assessment Study for the
Ports of Los Angeles and Long Beach, April 2006. This document is
available electronically at: http://www.arb.ca.gov/regact/marine2005/
portstudy0406.pdf. These documents are available in Docket
EPA-HQ-OAR-2007-0121.
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Today millions of Americans continue to live in areas that do not
meet existing air quality standards. As of June 2007 there are
approximately 88 million people living in 39 designated areas (which
include all or part of 208 counties) that either do not meet the
current PM_2.5 NAAQS or contribute to violations in other
counties, and 149 million people living in 94 areas (which include all
or part of 391 counties) designated as not in attainment for the 8-hour
ozone NAAQS. These numbers do not include the people living in areas
where there is a significant future risk of failing to maintain or
achieve either the PM_2.5 or ozone NAAQS.
Figure II-1 illustrates the widespread nature of these problems and
depicts counties which are currently (as of March 2007) designated
nonattainment for either or both the 8-hour ozone NAAQS and
PM_2.5 NAAQS. It also shows the location of mandatory class I
federal areas for visibility. Superimposed on this map are top U.S.
ports many of which receive significant port stops from ocean going
vessels operating with Category 3 marine engines. Currently more than
40 major U.S. deep sea ports are located in these nonattainment areas.
Many ports are located in areas rated as class I federal areas for
visibility impairment and regional haze. It should be noted that
emissions from ocean-going vessels are not simply a localized problem
related only to cities that have commercial ports. Virtually all U.S.
coastal areas are affected by emissions from ships that transit between
those ports, using shipping lanes that are close to land. Many of these
coastal areas also have high population densities. For example, Santa
Barbara, which has no commercial port, estimates that engines on ocean-
going marine vessels currently contribute about 37 percent of total
NO_X in their area.\17\ These emissions are from ships that
transit the area, and ``are comparable to (even slightly larger than)
the amount of NO_X produced onshore by cars and truck.'' By
2015 these emissions are expected to increase 67 percent, contributing
61 percent of Santa Barbara's total NO_X emissions. This mix
of emission sources led Santa Barbara to point out that they will be
unable to meet air quality standards for ozone without significant
emission reductions from these vessels, even if they completely
eliminate all other sources of pollution. Interport emissions from OGV
also contribute to other environmental problems, affecting sensitive
marine and land ecosystems. As discussed above, EPA recently completed
estimates of the contribution of Category 3 engines to emission
inventories. We recognize that air quality effects may vary from one
port/coastal area to another with differences in meteorology, because
of spatial differences in emissions with ship movements within regional
areas. In addition, these emissions may also affect adjacent coastal
areas. For these reasons, we plan to study several different port areas
to better assess the air quality effects of emissions from Category 3
engines. We believe that there are additional port and adjacent coastal
areas affected by emissions from Category 3 marine engines. We will be
performing air quality modeling specific to this issue to better assess
these impacts.

\17\ Memorandum to Docket A-2001-11 from Jean-Marie Revelt,
Santa Barbara County Air Quality News, Issue 62, July-August 2001
and other materials provided to EPA by Santa Barbara County,'' March
14, 2002.
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BILLING CODE 6560-50-P

[[Page 69528]]
[GRAPHIC] [TIFF OMITTED] TP07DE07.024
BILLING CODE 6560-50-C

[[Page 69529]]

Emissions from Category 3 marine engines account for a substantial
and growing portion of the U.S.'s coastal ambient PM_2.5 and
NO_X levels. The emission reductions from tightened Category
3 marine engine standards could play an important part in states'
efforts to attain and maintain the NAAQS in the coming decades,
especially in coastal nonattainment areas, where these engines comprise
a large portion of the remaining NO_X and PM_2.5
emissions inventories. For example, 2001 emission inventories for
California's South Coast ozone and PM nonattainment areas \18\ indicate
that ocean-going vessels (OGVs) contribute about 30 tons per day (tpd)
of NO_X and 2\1/2\ tpd of PM_2.5 to regional
inventories--and absent additional emission controls, this number would
almost triple in 2020 to 86 tpd of NO_X and 8 tpd of
PM_2.5 as port-related activities continue to grow. The
Houston-Galveston-Beaumont area is also faced with growing OGV
inventories which continue to hamper their area's effort to achieve and
maintain clean air. Today, OGVs in the Houston nonattainment area
annually contribute about 27 tpd of NO_X emissions and this
is projected to climb to 30 tpd by 2009.\19\ In the Corpus Christi
area, OGVs in 2001 were responsible for about 16 tpd of
NO_X.\20\ Finally, in the New York/Northern New Jersey
nonattainment area, 2000 inventories \21\ indicated that OGVs
contributed 12 tpd of NO_X emissions and about 0.75 tpd of
PM_2.5 emissions to PM inventories. We request comment on the
impact Category 3 marine engines have on state and local emission
inventories as well as their efforts to meet the ozone and
PM_2.5 NAAQS.
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\18\ California Air Resources Board (2006). Emission Reduction
Plan for Ports and Goods Movements, (April 2006) Appendix B-3,
Available electronically at www.arb.ca.gov/gmp/docs/finalgmpplan090905.pdf.
\19\ Texas Commission On Environmental Quality (2006) Houston-
Galveston-Brazoria 8-Hour Ozone State Implemental Plan & Rules,
Informational Meeting Presentation, Kelly Keel, Air Quality Planning
Section.
\20\ Air Consulting and Engineering Solutions, Final Report
Phase II Corpus Christi Regional Airshed, (August 2001) Project
Number 21-01-0006.
\21\ The Port Authority of New York & New Jersey, (2003), The
New York, Northern New Jersey, Long Island Nonattainment Area
Commercial Marine Vessel Emissions Inventory, Prepared by Starcrest
Consulting Group, LLC.
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Recently, new studies \22\ from the State of California provide
evidence that PM_2.5 emissions within marine ports contribute
significantly to elevated ambient concentrations near these sources. A
substantial number of people experience exposure to Category 3 marine
engine emissions, raising potential health concerns. Additional
information on marine port emissions and ambient exposures can be found
in section II.B.3 of this ANPRM.
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\22\ State of California Air Resources Board. Roseville Rail
Yard Study. Stationary Source Division, October 14, 2004. This
document is available electronically at: http://www.arb.ca.gov/
diesel/documents/rrstudy.htm and State of California Air Resources
Board. Diesel Particulate Matter Exposure Assessment Study for the
Ports of Los Angeles and Long Beach, April 2006. This document is
available electronically at: ftp://ftp.arb.ca.gov/carbis/msprog/offroad/
marinevess/documents/portstudy0406.pdf. These documents are
available in Docket EPA-HQ-OAR-2007-0121.
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In addition to public health impacts, there are serious public
welfare and environmental impacts associated with ozone and
PM_2.5. Specifically, ozone causes damage to vegetation which
leads to crop and forestry economic losses, as well as harm to national
parks, wilderness areas, and other natural systems. NO_X,
SO_X and PM_2.5 can contribute to the substantial
impairment of visibility in many parts of the U.S., where people live,
work, and recreate, including national parks, wilderness areas, and
mandatory class I federal areas. The deposition of airborne particles
can also reduce the aesthetic appeal of buildings and culturally
important articles through soiling, and can contribute directly (or in
conjunction with other pollutants) to structural damage by means of
corrosion or erosion. Finally, NO_X and SO_X
emissions from diesel engines contribute to the acidification,
nitrification, and eutrophication of water bodies.
While EPA has already adopted many emission control programs that
are expected to reduce ambient ozone and PM_2.5 levels,
including the Clean Air Interstate Rule (CAIR) (70 FR 25162, May 12,
2005), the Clean Air Nonroad Diesel Rule (69 FR 38957, June 29, 2004),
the Heavy Duty Engine and Vehicle Standards and Highway Diesel Fuel
Sulfur Control Requirements (66 FR 5002, Jan. 18, 2001), and the Tier 2
Vehicle and Gasoline Sulfur Program (65 FR 6698, Feb. 10, 2000), the
PM_2.5 and NO_X emission reductions resulting from
tightened standards for Category 3 marine diesel engines would greatly
assist nonattainment areas, especially along our nation's coasts, in
attaining and maintaining the ozone and the PM_2.5 NAAQS in
the near term and in the decades to come.
In September 2006, EPA finalized revised PM_2.5 NAAQS.
Nonattainment areas will be designated with respect to the revised
PM_2.5 NAAQS in early 2010. EPA modeling, conducted as part
of finalizing the revised NAAQS, projects that in 2015 up to 52
counties with 53 million people may violate the daily, annual, or both
standards for PM_2.5 while an additional 27 million people in
54 counties may live in areas that have air quality measurements within
10 percent of the revised NAAQS. Even in 2020 up to 48 counties, with
54 million people, may still not be able to meet the revised
PM_2.5 NAAQS and an additional 25 million people, living in
50 counties, are projected to have air quality measurements within 10
percent of the revised standards. The PM_2.5 inventory
reductions that would be achieved from applying advanced emissions
control strategies to Category 3 engines could be useful in helping
coastal nonattainment areas, to both attain and maintain the revised
PM_2.5 NAAQS.
State and local governments are working to protect the health of
their citizens and comply with requirements of the Clean Air Act (CAA
or ``the Act''). As part of this effort they recognize the need to
secure additional major reductions in both PM_2.5 and
NO_X emissions by undertaking state level action.\23\
However, they also seek further Agency action for national standards,
including the setting of stringent new Category 3 marine engine
standards since states are preempted from setting new engine emissions
standards for this class of engines.\24\
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\23\ For example, see: California Air Resources Board (2006).
Emission Reduction Plan for Ports and Goods Movements, (April 2006),
Available electronically at
www.arb.ca.gov/gmp/docs/finalgmpplan090905.pdf.
\24\ For example, see letter dated November 29, 2006 from
California Environmental Protection Agency to Administrator Stephen
L. Johnson and January 20, 2006 letter from Executive Director,
Puget Sound Clean Air Agency to Administrator Stephen L. Johnson.
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B. Public Health Impacts

1. Particulate Matter
The emission control program for Category 3 marine engines has the
potential to significantly reduce their contribution to
PM_2.5 inventories. In addition, these engines emit high
levels of NO_X which react in the atmosphere to form
secondary PM_2.5, ammonium nitrate. Category 3 marine engines
also emit large amounts of SO₂ and HC which react in the
atmosphere to form secondary PM_2.5 composed of sulfates and
organic carbonaceous PM_2.5. The emission control program
being considered would reduce the contribution of Category 3 engines to
both directly emitted diesel PM and secondary PM emissions.

[[Page 69530]]

(a) Background
Particulate matter (PM) represents a broad class of chemically and
physically diverse substances. It can be principally characterized as
discrete particles that exist in the condensed (liquid or solid) phase
spanning several orders of magnitude in size. PM is further described
by breaking it down into size fractions. PM₁₀ refers to
particles generally less than or equal to 10 micrometers (&mu;m).
PM_2.5 refers to fine particles, those particles generally
less than or equal to 2.5 &mu;m in diameter. Inhalable (or
``thoracic'') coarse particles refer to those particles generally
greater than 2.5 &mu;m but less than or equal to 10 &mu;m in diameter.
Ultrafine PM refers to particles less than 100 nanometers (0.1 &mu;m).
Larger particles tend to be removed by the respiratory clearance
mechanisms (e.g. coughing), whereas smaller particles are deposited
deeper in the lungs.
Fine particles are produced primarily by combustion processes and
by transformations of gaseous emissions (e.g., SO_X,
NO_X and VOCs) in the atmosphere. The chemical and physical
properties of PM_2.5 may vary greatly with time, region,
meteorology, and source category. Thus, PM_2.5, may include a
complex mixture of different pollutants including sulfates, nitrates,
organic compounds, elemental carbon and metal compounds. These
particles can remain in the atmosphere for days to weeks and travel
through the atmosphere hundreds to thousands of kilometers.
The primary PM_2.5 NAAQS includes a short-term (24-hour)
and a long-term (annual) standard. The 1997 PM_2.5 NAAQS
established by EPA set the 24-hour standard at a level of 65&mu;g/
m3 based on the 98th percentile concentration averaged over
three years. (This air quality statistic compared to the standard is
referred to as the ``design value.'') The annual standard specifies an
expected annual arithmetic mean not to exceed 15&mu;g/m3
averaged over three years. EPA has recently finalized PM_2.5
nonattainment designations for the 1997 standard (70 FR 943, Jan 5,
2005).\25\ All areas currently in nonattainment for PM_2.5
will be required to meet these 1997 standards between 2009 and 2014.
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\25\ U.S. EPA, Air Quality Designations and Classifications for
the Fine Particles (PM_2.5) National Ambient Air Quality
Standards, December 17, 2004. (70 FR 943, Jan 5, 2005) This document
is available in Docket EPA-HQ-OAR-2007-0121. This document is also
available on the Web at: http://www.epa.gov/pmdesignations/.

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EPA has recently amended the NAAQS for PM_2.5 (71 FR
61144, October 17, 2006). The final rule, signed on September 21, 2006
and published in the Federal Register on October 17, 2006, addressed
revisions to the primary and secondary NAAQS for PM to provide
increased protection of public health and welfare, respectively. The
level of the 24-hour PM_2.5 NAAQS was revised from 65&mu;g/
m3 to 35&mu;g/m3 to provide increased protection
against health effects associated with short-term exposures to fine
particles. The current form of the 24-hour PM_2.5 standard
was retained (e.g., based on the 98th percentile concentration averaged
over three years). The level of the annual PM_2.5 NAAQS was
retained at 15&mu;g/m3, continuing protection against health
effects associated with long-term exposures. The current form of the
annual PM_2.5 standard was retained as an annual arithmetic
mean averaged over three years, however, the following two aspects of
the spatial averaging criteria were narrowed: (1) The annual mean
concentration at each site shall be within 10 percent of the spatially
averaged annual mean, and (2) the daily values for each monitoring site
pair shall yield a correlation coefficient of at least 0.9 for each
calendar quarter.
With regard to the secondary PM_2.5 standards, EPA has
revised these standards to be identical in all respects to the revised
primary standards. Specifically, EPA has revised the current 24-hour
PM_2.5 secondary standard by making it identical to the
revised 24-hour PM_2.5 primary standard and retained the
annual PM_2.5 secondary standard. This suite of secondary
PM_2.5 standards is intended to provide protection against
PM-related public welfare effects, including visibility impairment,
effects on vegetation and ecosystems, and material damage and soiling.
The 2006 standards became effective on December 18, 2006. As a
result of the 2006 PM_2.5 standard, EPA will designate new
nonattainment areas in early 2010. The timeframe for areas attaining
the 2006 PM NAAQS will likely extend from 2015 to 2020.
(b) Health Effects of PM_2.5
Scientific studies show ambient PM is associated with a series of
adverse health effects. These health effects are discussed in detail in
the 2004 EPA Particulate Matter Air Quality Criteria Document (PM
AQCD), and the 2005 PM Staff Paper.26 27 28
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\26\ U.S. EPA (1996) Air Quality Criteria for Particulate
Matter, EPA 600-P-95-001aF, EPA 600-P-95-001bF. This document is
available in Docket EPA-HQ-OAR-2007-0121.
\27\ U.S. EPA (2004) Air Quality Criteria for Particulate Matter
(Oct 2004), Volume I Document No. EPA600/P-99/002aF and Volume II
Document No. EPA600/P-99/002bF. This document is available in Docket
EPA-HQ-OAR-2007-0121.
\28\ U.S. EPA (2005) Review of the National Ambient Air Quality
Standard for Particulate Matter: Policy Assessment of Scientific and
Technical Information, OAQPS Staff Paper. EPA-452/R-05-005. This
document is available in Docket EPA-HQ-OAR-2007-0121.
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Health effects associated with short-term exposures (hours to days)
to ambient PM include premature mortality, increased hospital
admissions, heart and lung diseases, increased cough, adverse lower-
respiratory symptoms, decrements in lung function and changes in heart
rate rhythm and other cardiac effects. Studies examining populations
exposed to different levels of air pollution over a number of years,
including the Harvard Six Cities Study and the American Cancer Society
Study, show associations between long-term exposure to ambient
PM_2.5 and both total and cardiovascular and respiratory
mortality.\29\ In addition, a reanalysis of the American Cancer Society
Study shows an association between fine particle and sulfate
concentrations and lung cancer mortality.\30\ The Category 3 marine
engines covered in this proposal contribute to both acute and chronic
PM_2.5 exposures.
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\29\ Dockery, DW; Pope, CA III: Xu, X; et al. 1993. An
association between air pollution and mortality in six U.S. cities.
N Engl J Med 329:1753-1759.
\30\ Pope Ca, III; Thun, MJ; Namboodiri, MM; Docery, DW; Evans,
JS; Speizer, FE; Heath, CW. 1995. Particulate air pollution as a
predictor of mortality in a prospective study of U.S. adults. Am J
Respir Crit Care Med 151:669-674.
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The health effects of PM_2.5 have been further documented
in local impact studies which have focused on health effects due to
PM_2.5 exposures measured on or near roadways.\31\ Taking
account of all air pollution sources, including both spark-ignition
(gasoline) and diesel powered vehicles, these latter studies indicate
that exposure to PM_2.5 emissions near roadways, dominated by
mobile sources, are associated with potentially serious health effects.
For instance, a recent study found associations between concentrations
of cardiac risk factors in the blood of healthy young police officers
and PM_2.5 concentrations measured in vehicles.\32\ Also, a
number of studies have shown associations between residential or school
outdoor concentrations of some

[[Page 69531]]

constituents of fine particles found in motor vehicle exhaust and
adverse respiratory outcomes, including asthma prevalence in children
who live near major roadways.33 34 35 Although the engines
considered in this proposal differ with those in these studies with
respect to their applications and fuel qualities, these studies provide
an indication of the types of health effects that might be expected to
be associated with personal exposure to PM_2.5 emissions from
Category 3 marine engines. By reducing their contribution to
PM_2.5 inventories, the emissions controls under
consideration also would reduce exposure to these emissions,
specifically exposure near marine ports and shipping routes.
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\31\ Riekider, M.; Cascio, W.E.; Griggs, T.R.; Herbst, M.C.;
Bromberg, P.A.; Neas, L.; Williams, R.W.; Devlin, R.B. (2003)
Particulate Matter Exposures in Cars is Associated with
Cardiovascular Effects in Healthy Young Men. Am. J. Respir. Crit.
Care Med. 169: 934-940.
\32\ Riediker, M.; Cascio, W.E.; Griggs, T.R.; et al. (2004)
Particulate matter exposure in cars is associated with
cardiovascular effects in healthy young men. Am J Respir Crit Care
Med 169: 934-940.
\33\ Van Vliet, P.; Knape, M.; de Hartog, J.; Janssen, N.;
Harssema, H.; Brunekreef, B. (1997). Motor vehicle exhaust and
chronic respiratory symptoms in children living near freeways. Env.
Research 74: 122-132.
\34\ Brunekreef, B., Janssen, N.A.H.; de Hartog, J.; Harssema,
H.; Knape, M.; van Vliet, P. (1997). Air pollution from truck
traffic and lung function in children living near roadways.
Epidemiology 8:298-303.
\35\ Kim, J.J.; Smorodinsky, S.; Lipsett, M.; Singer, B.C.;
Hodgson, A.T.; Ostro, B (2004). Traffic-related air pollution near
busy roads: The East Bay children's respiratory health study. Am. J.
Respir. Crit. Care Med. 170: 520-526.
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2. Ozone
The emissions reduction program under consideration for Category 3
marine engines would reduce the contribution of these engines
NO_X inventories. These engines currently have high
NO_X emissions due to the size of the engine and because they
are relatively uncontrolled. NO_X contributes to the
formation of ground-level ozone pollution or smog. People in many areas
across the U.S. continue to be exposed to unhealthy levels of ambient
ozone.
(a) Background
Ground-level ozone pollution is formed by the reaction of VOCs and
NO_X in the atmosphere in the presence of heat and sunlight.
These two pollutants, often referred to as ozone precursors, are
emitted by many types of pollution sources, such as highway and nonroad
motor vehicles and engines, power plants, chemical plants, refineries,
makers of consumer and commercial products, industrial facilities, and
smaller ``area'' sources.
The science of ozone formation, transport, and accumulation is
complex.\36\ Ground-level ozone is produced and destroyed in a cyclical
set of chemical reactions, many of which are sensitive to temperature
and sunlight. When ambient temperatures and sunlight levels remain high
for several days and the air is relatively stagnant, ozone and its
precursors can build up and result in more ozone than typically would
occur on a single high-temperature day. Ozone also can be transported
from pollution sources into areas hundreds of miles downwind, resulting
in elevated ozone levels even in areas with low local VOC or
NO_X emissions.
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\36\ U.S. EPA Air Quality Criteria for Ozone and Related
Photochemical Oxidants (Final). U.S. Environmental Protection
Agency, Washington, D.C., EPA 600/R-05/004aF-cF, 2006. This document
may be accessed electronically at: http://www.epa.gov/ttn/naaqs/standards/
ozone/s_o3_cr_cd.html. This document is available in Docket
EPA-HQ-OAR-2007-0121.
---------------------------------------------------------------------------

The highest levels of ozone are produced when both VOC and
NO_X emissions are present in significant quantities on clear
summer days. Relatively small amounts of NO_X enable ozone to
form rapidly when VOC levels are relatively high, but ozone production
is quickly limited by removal of the NO_X. Under these
conditions NO_X reductions are highly effective in reducing
ozone while VOC reductions have little effect. Such conditions are
called ``NO_X-limited''. Because the contribution of VOC
emissions from biogenic (natural) sources to local ambient ozone
concentrations can be significant, even some areas where man-made VOC
emissions are relatively low can be NO_X limited.
When NO_X levels are relatively high and VOC levels
relatively low, NO_X forms inorganic nitrates (i.e.,
particles) but relatively little ozone. Such conditions are called
``VOC-limited.'' Under these conditions, VOC reductions are effective
in reducing ozone, but NO_X reductions can actually increase
local ozone under certain circumstances. Even in VOC-limited urban
areas, NO_X reductions are not expected to increase ozone
levels if the NO_X reductions are sufficiently large.
Rural areas are usually NO_X-limited, due to the
relatively large amounts of biogenic VOC emissions in many rural areas.
Urban areas can be either VOC- or NO_X-limited, or a mixture
of both, in which ozone levels exhibit moderate sensitivity to changes
in either pollutant. Ozone concentrations in an area also can be
lowered by the reaction of nitric oxide with ozone, forming nitrogen
dioxide (NO₂); as the air moves downwind and the cycle
continues, the NO₂ forms additional ozone. The importance of
this reaction depends, in part, on the relative concentrations of
NO_X, VOC, and ozone, all of which change with time and location.
The current ozone NAAQS has an 8-hour averaging time. The 8-hour
ozone NAAQS is met at an ambient air quality monitoring site when the
average of the annual fourth-highest daily maximum 8-hour average ozone
concentration over three years is less than or equal to 0.084 ppm. On
June 20, 2007 EPA proposed to strengthen the ozone NAAQS. The proposed
revisions reflect new scientific evidence about ozone and its effects
on public health and welfare.\37\ The final ozone NAAQS rule is
scheduled for March 2008.
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\37\ EPA proposes to set the 8-hour primary ozone standard to a
level within the range of 0.070-0.075 ppm. The agency also requests
comments on alternative levels of the 8-hour primary ozone standard,
within a range from 0.060 ppm up to and including retention of the
current standard (0.084 ppm). EPA also proposes two options for the
secondary ozone standard. One option would establish a new form of
standard designed specifically to protect sensitive plants from
damage caused by repeated ozone exposure throughout the growing
season. This cumulative standard would add daily ozone
concentrations across a three month period. EPA is proposing to set
the level of the cumulative standard within the range of 7 to 21
ppm-hours. The other option would follow the current practice of making
the secondary standard equal to the proposed 8-hour primary standard.
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(b) Health Effects of Ozone
The health and welfare effects of ozone are well documented and are
assessed in EPA's 2006 ozone Air Quality Criteria Document (ozone AQCD)
and EPA staff papers.\38\ \39\ Ozone can irritate the respiratory
system, causing coughing, throat irritation, and/or uncomfortable
sensation in the chest. Ozone can reduce lung function and make it more
difficult to breathe deeply, and breathing may become more rapid and
shallow than normal, thereby limiting a person's activity. Ozone can
also aggravate asthma, leading to more asthma attacks that require a
doctor's attention and/or the use of additional medication. Animal
toxicological evidence indicates that with repeated exposure, ozone can
inflame and damage the lining of the lungs, which may lead to permanent
changes in lung tissue and irreversible reductions in lung function.
People who are more susceptible to effects associated with

[[Page 69532]]

exposure to ozone include children, the elderly, and individuals with
respiratory disease such as asthma. As of the 2006 review, there was
suggestive evidence that certain people may have greater genetic
susceptibility. Those with greater exposures to ozone, for instance due
to time spent outdoors (e.g., children and outdoor workers), are also
of concern.
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\38\ U.S. EPA Air Quality Criteria for Ozone and Related
Photochemical Oxidants (Final). U.S. Environmental Protection
Agency, Washington, D.C., EPA 600/R-05/004aF-cF, 2006. This document
is available in Docket EPA-HQ-OAR-2007-0121. This document may be
accessed electronically at:
http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_cd.html.
\39\ U.S. EPA (2006) Review of the National Ambient Air Quality
Standards for Ozone, Policy Assessment of Scientific and Technical
Information. OAQPS Staff Paper Second Draft.EPA-452/D-05-002. This
document is available in Docket EPA-HQ-OAR-2007-0121. This document
is available electronically at:
http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_sp.html.

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The recent ozone AQCD also examined relevant new scientific
information which has emerged in the past decade, including the impact
of ozone exposure on such health effect indicators as changes in lung
structure and biochemistry, inflammation of the lungs, exacerbation and
causation of asthma, respiratory illness-related school absence,
hospital admissions and premature mortality. Animal toxicological
studies have suggested potential interactions between ozone and PM with
increased responses observed to mixtures of the two pollutants compared
to either ozone or PM alone. The respiratory morbidity observed in
animal studies along with the evidence from epidemiologic studies
supports a causal relationship between acute ambient ozone exposures
and increased respiratory-related emergency room visits and
hospitalizations in the warm season. In addition, there is suggestive
evidence of a contribution of ozone to cardiovascular-related morbidity
and non-accidental and cardiopulmonary mortality.
3. Air Toxics
People experience elevated risk of cancer and other noncancer
health effects from exposure to air toxics. Mobile sources are
responsible for a significant portion of this exposure. According to
the National Air Toxic Assessment (NATA) for 1999, mobile sources,
including Category 3 marine engines, were responsible for 44 percent of
outdoor toxic emissions and almost 50 percent of the cancer risk among
the 133 pollutants quantitatively assessed in the 1999 NATA. Benzene is
the largest contributor to cancer risk of all the assessed pollutants
and mobile sources were responsible for about 68 percent of all benzene
emissions in 1999. Although the 1999 NATA did not quantify cancer risks
associated with exposure to diesel exhaust, EPA has concluded that
diesel exhaust ranks with the other air toxic substances that the
national-scale assessment suggests pose the greatest relative risk.
According to the 1999 NATA, nearly the entire U.S. population was
exposed to an average level of air toxics that has the potential for
adverse respiratory noncancer health effects. This potential was
indicated by a hazard index (HI) greater than 1.\40\ Mobile sources
were responsible for 74 percent of the potential noncancer hazard from
outdoor air toxics in 1999. About 91 percent of this potential
noncancer hazard was from acrolein; \41\ however, the confidence in the
RfC for acrolein is medium \42\ and confidence in NATA estimates of
population noncancer hazard from ambient exposure to this pollutant is
low.\43\ It is important to note that NATA estimates of noncancer
hazard do not include the adverse health effects associated with
particulate matter identified in EPA's Particulate Matter Air Quality
Criteria Document. Gasoline and diesel engine emissions contribute
significantly to with particulate matter concentration.
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\40\ To express chronic noncancer hazards, we used the RfC as
part of a calculation called the hazard quotient (HQ), which is the
ratio between the concentration to which a person is exposed and the
RfC. (RfC is defined by EPA as, ``an estimate of a continuous
inhalation exposure to the human population, including sensitive
subgroups, with uncertainty spanning perhaps an order of magnitude,
that is likely to be without appreciable risks of deleterious
noncancer effects during a lifetime.'') A value of the HQ less than
one indicates that the exposure is lower than the RfC and that no
adverse health effects would be expected. Combined noncancer hazards
were calculated using the hazard index (HI), defined as the sum of
hazard quotients for individual air toxic compounds that affect the
same target organ or system. As with the hazard quotient, a value of
the HI at or below 1.0 will likely not result in adverse effects
over a lifetime of exposure. However, a value of the HI greater than
1.0 does not necessarily suggest a likelihood of adverse effects.
Furthermore, the HI cannot be translated into a probability that
adverse effects will occur and is not likely to be proportional to risk.
\41 \ U.S. EPA. U.S. EPA (2006) National-Scale Air Toxics
Assessment for 1999. This material is available electronically at
http://www.epa.gov/ttn/atw/nata1999/risksum.html.
\42\ U.S. EPA (2003) Integrated Risk Information System File of
Acrolein. National Center for Environmental Assessment, Office of
Research and Development, Washington, DC 2003. This material is
available electronically at http://www.epa.gov/iris/subst/0364.htm.
\43\ U.S. EPA (2006) National-Scale Air Toxics Assessment for
1999. This material is available electronically at
http://www.epa.gov/ttn/atw/nata1999/risksum.html.

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It should be noted that the NATA modeling framework has a number of
limitations which prevent its use as the sole basis for setting
regulatory standards. These limitations and uncertainties are discussed
on the 1999 NATA Web site.\44\ Even so, this modeling framework is very
useful in identifying air toxic pollutants and sources of greatest
concern, setting regulatory priorities, and informing the decision
making process.
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\44\ U.S. EPA (2006) National-Scale Air Toxics Assessment for
1999. http://www.epa.gov/ttn/atw/nata1999.

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The following section provides a brief overview of air toxics which
are associated with nonroad engines, including Category 3 marine
engines, and provides a discussion of the health risks associated with
each air toxic.
(a) Diesel Exhaust (DE)
Category 3 marine engines emit diesel exhaust (DE), a complex
mixture comprised of carbon dioxide, oxygen, nitrogen, water vapor,
carbon monoxide, nitrogen compounds, sulfur compounds and numerous low-
molecular-weight hydrocarbons. A number of these gaseous hydrocarbon
components are individually known to be toxic including aldehydes,
benzene and 1,3-butadiene. The diesel particulate matter (DPM) present
in diesel exhaust consists of fine particles (< 2.5 &mu;m), including a
subgroup with a large number of ultrafine particles (< 0.1 &mu;m).
These particles have large surface area which makes them an excellent
medium for adsorbing organics and their small size makes them highly
respirable and able to reach the deep lung. Many of the organic
compounds present on the particles and in the gases are individually
known to have mutagenic and carcinogenic properties. Diesel exhaust
varies significantly in chemical composition and particle sizes between
different engine types (heavy-duty, light-duty), engine operating
conditions (idle, accelerate, decelerate), and fuel formulations (high/
low sulfur fuel).\45\ After being emitted in the engine exhaust, diesel
exhaust undergoes dilution as well as chemical and physical changes in
the atmosphere. The lifetime for some of the compounds present in
diesel exhaust ranges from hours to days.
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\45\ U.S. EPA (2002) Health Assessment Document for Diesel
Engine Exhaust. EPA/600/8-90/057F Office of Research and
Development, Washington DC. Pp1-1 1-2. This document is available in
Docket EPA-HQ-OAR-2007-0121. This document is available electronically
at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060.

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(1) Diesel Exhaust: Potential Cancer Effect of Diesel Exhaust
In EPA's 2002 Diesel Health Assessment Document (Diesel HAD),\46\
diesel exhaust was classified as likely to be carcinogenic to humans by
inhalation at environmental exposures, in accordance with the revised
draft 1996/1999 EPA cancer guidelines. A number of other agencies
(National Institute for Occupational Safety and Health, the
International Agency for Research on

[[Page 69533]]

Cancer, the World Health Organization, California EPA, and the U.S.
Department of Health and Human Services) have made similar
classifications. However, EPA also concluded in the Diesel HAD that it
is not possible currently to calculate a cancer unit risk for diesel
exhaust due to a variety of factors that limit the current studies,
such as limited quantitative exposure histories in occupational groups
investigated for lung cancer.
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\46\ U.S. EPA (2002) Health Assessment Document for Diesel
Engine Exhaust. EPA/600/8-90/057F Office of Research and
Development, Washington DC. This document is available in Docket
EPA-HQ-OAR-2007-0121.
This document is available electronically at
http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060.

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For the Diesel HAD, EPA reviewed 22 epidemiologic studies on the
subject of the carcinogenicity of workers exposed to diesel exhaust in
various occupations, finding increased lung cancer risk, although not
always statistically significant, in 8 out of 10 cohort studies and 10
out of 12 case-control studies within several industries, including
railroad workers. Relative risk for lung cancer associated with
exposure ranged from 1.2 to 1.5, although a few studies show relative
risks as high as 2.6. Additionally, the Diesel HAD also relied on two
independent meta-analyses, which examined 23 and 30 occupational
studies respectively, which found statistically significant increases
in smoking-adjusted relative lung cancer risk associated with diesel
exhaust, of 1.33 to 1.47. These meta-analyses demonstrate the effect of
pooling many studies and in this case show the positive relationship
between diesel exhaust exposure and lung cancer across a variety of
diesel exhaust-exposed occupations.47 48 49
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\47\ U.S. EPA (2002) Health Assessment Document for Diesel
Engine Exhaust. EPA/6008-90/057F Office of Research and Development,
Washington DC. This document is available in Docket EPA-HQ-OAR-2007-0121.
\48\ Bhatia, R., Lopipero, P., Smith, A. (1998) Diesel exposure
and lung cancer. Epidemiology 9(1):84-91.
\49\ Lipsett, M: Campleman, S; (1999) Occupational exposure to
diesel exhaust and lung cancer: a meta-analysis. Am J Public Health
80(7): 1009-1017.
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In the absence of a cancer unit risk, the Diesel HAD sought to
provide additional insight into the significance of the diesel exhaust-
cancer hazard by estimating possible ranges of risk that might be
present in the population. An exploratory analysis was used to
characterize a possible risk range by comparing a typical environmental
exposure level for highway diesel sources to a selected range of
occupational exposure levels. The occupationally observed risks were
then proportionally scaled according to the exposure ratios to obtain
an estimate of the possible environmental risk. A number of
calculations are needed to accomplish this, and these can be seen in
the EPA Diesel HAD. The outcome was that environmental risks from
diesel exhaust exposure could range from a low of 10-4 to 10-5 to as
high as 10-3, reflecting the range of occupational exposures that could
be associated with the relative and absolute risk levels observed in
the occupational studies. Because of uncertainties, the analysis
acknowledged that the risks could be lower than 10- or 10-5, and a zero
risk from diesel exhaust exposure was not ruled out.
Retrospective health studies of railroad workers have played an
important part in determining that diesel exhaust is a likely human
carcinogen. Key evidence of the diesel exhaust exposure linkage to lung
cancer comes from two retrospective case-control studies of railroad
workers which are discussed at length in the Diesel HAD.
(2) Diesel Exhaust: Other Health Effects
Noncancer health effects of acute and chronic exposure to diesel
exhaust emissions are also of concern to the Agency. EPA derived an RfC
from consideration of four well-conducted chronic rat inhalation
studies showing adverse pulmonary effects.50 51 52 53 The
RfC is 5 &mu;g/m\3\ for diesel exhaust as measured by diesel PM. This
RfC does not consider allergenic effects such as those associated with
asthma or immunologic effects. There is growing evidence, discussed in
the Diesel HAD, that exposure to diesel exhaust can exacerbate these
effects, but the exposure-response data were found to be lacking to
derive an RfC. The EPA Diesel HAD states, ``With DPM [diesel
particulate matter] being a ubiquitous component of ambient PM, there
is an uncertainty about the adequacy of the existing DE [diesel
exhaust] noncancer database to identify all of the pertinent DE-caused
noncancer health hazards. (p. 9-19).
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\50\ Ishinishi, N; Kuwabara, N; Takaki, Y; et al. (1988) Long-
term inhalation experiments on diesel exhaust. In: Diesel exhaust
and health risks. Results of the HERP studies. Ibaraki, Japan:
Research Committee for HERP Studies; pp. 11-84.
\51\ Heinrich, U; Fuhst, R; Rittinghausen, S; et al. (1995)
Chronic inhalation exposure of Wistar rats and two different strains
of mice to diesel engine exhaust, carbon black, and titanium
dioxide. Inhal. Toxicol. 7:553-556.
\52\ Mauderly, JL; Jones, RK; Griffith, WC; et al. (1987) Diesel
exhaust is a pulmonary carcinogen in rats exposed chronically by
inhalation. Fundam. Appl. Toxicol. 9:208-221.
\53\ Nikula, KJ; Snipes, MB; Barr, EB; et al. (1995) Comparative
pulmonary toxicities and carcinogenicities of chronically inhaled
diesel exhaust and carbon black in F344 rats. Fundam. Appl. Toxicol.
25:80-94.
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(3) Ambient PM_2.5 Levels and Exposure to Diesel Exhaust PM
The Diesel HAD briefly summarizes health effects associated with
ambient PM and discusses the EPA's annual NAAQS of 15 &mu;g/m\3\. In
addition, both the 2004 AQCD and the 2005 Staff Paper for PM_2.5
have more recent information. There is a much more extensive body of
human data showing a wide spectrum of adverse health effects associated
with exposure to ambient PM, of which diesel exhaust is an important
component. The PM_2.5 NAAQS is designed to provide protection
from the noncancer and premature mortality effects of PM_2.5
as a whole, of which diesel PM is a constituent.
(4) Diesel Exhaust PM Exposures
Exposure of people to diesel exhaust depends on their various
activities, the time spent in those activities, the locations where
these activities occur, and the levels of diesel exhaust pollutants in
those locations. The major difference between ambient levels of diesel
particulate and exposure levels for diesel particulate is that exposure
accounts for a person moving from location to location, proximity to
the emission source, and whether the exposure occurs in an enclosed
environment.
Occupational Exposures
Occupational exposures to diesel exhaust from mobile sources,
including Category 3 marine engines, can be several orders of magnitude
greater than typical exposures in the non-occupationally exposed
population.
Over the years, diesel particulate exposures have been measured for
a number of occupational groups resulting in a wide range of exposures
from 2 to 1,280 &mu;g/m\3\ for a variety of occupations. Studies have
shown that miners and railroad workers typically have higher diesel
exposure levels than other occupational groups studied, including
firefighters, truck dock workers, and truck drivers (both short and
long haul).\54\ As discussed in the Diesel HAD, the National Institute
of Occupational Safety and Health (NIOSH) has estimated a total of
1,400,000 workers are occupationally exposed to diesel exhaust from on-
road and nonroad vehicles.
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\54\ Diesel HAD Page 2-110, 8-12; Woskie, SR; Smith, TJ;
Hammond, SK: et al. (1988a) Estimation of the DE exposures of
railroad workers: II. National and historical exposures. Am J Ind
Med 12:381-394.

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[[Page 69534]]

Elevated Concentrations and Ambient Exposures in Mobile Source-Impacted
Areas
Regions immediately downwind of marine ports and shipping channels
experience elevated ambient concentrations of directly-emitted
PM_2.5 from Category 3 marine engines. Due to the unique
nature of marine ports, emissions from a large number of Category 3
marine engines are concentrated in a relatively small area.
A recent study conducted by the California Air Resources Board
(CARB) examined the air quality impacts of railroad operations at the
J.R. Davis Rail Yard, the largest service and maintenance rail facility
in the western United States.\55\ This is relevant in that locomotives
use diesel engines similar to those used in marine vessels. The yard
occupies 950 acres along a one-quarter mile wide and four mile long
section of land in Roseville, CA. The study developed an emissions
inventory for the facility for the year 2000 and modeled ambient
concentrations of diesel PM using a well-accepted dispersion model
(ISCST3). The study estimated substantially elevated concentrations in
an area 5,000 meters from the facility, with higher concentrations
closer to the rail yard. Using local meteorological data, annual
average contributions from the rail yard to ambient diesel PM
concentrations under prevailing wind conditions were 1.74, 1.18, 0.80,
and 0.25 &mu;g/m\3\ at receptors located 200, 500, 1000, and 5000
meters from the yard, respectively. Several tens of thousands of people
live within the area estimated to experience substantial increases in
annual average ambient PM_2.5 as a result of rail yard emissions.
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\55\ Hand, R.; Pingkuan, D.; Servin, A.; Hunsaker, L.; Suer, C.
(2004) Roseville rail yard study. California Air Resources Board.
[Online at http://www.arb.ca.gov/diesel/documents/rrstudy.htm]

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Another study from CARB evaluated air quality impacts of diesel
engine emissions within the Ports of Long Beach and Los Angeles in
California, one of the largest ports in the U.S.\56\ The study found
that ocean going vessels comprised 53% of the diesel PM emissions while
ship auxiliary engines' hoteling comprised another 20% of PM emissions
for the marine ports. Like the earlier rail yard study, the port study
employed the ISCST3 dispersion model. Also using local meteorological
data, annual average concentrations were substantially elevated over an
area exceeding 200,000 acres. Because the ports are located near
heavily-populated areas, the modeling indicated that over 700,000
people lived in areas with at least 0.3 &mu;g/m\3\ of port-related
diesel PM in ambient air, about 360,000 people lived in areas with at
least 0.6 &mu;g/m\3\ of diesel PM, and about 50,000 people lived in
areas with at least 1.5 ug/m\3\ of ambient diesel PM directly from the
port. The study found that impacts could be discerned up to 15 miles
from the marine port.
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\56\ Di, P.; Servin, A.; Rosenkranz, K.; Schwehr, B.; Tran, H.
(2006) Diesel particulate matter exposure assessment study for the
Ports of Los Angeles and Long Beach. California Air Resources Board.
[Online at http://www.arb.ca.gov/ports/marinevess/marinevess.htm]

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Overall, while these studies focus on only two large marine port
and railroad facilities, they highlight the substantial contribution these
facilities make to elevated ambient concentrations in populated areas.
We initiated a study in 2006 to better understand the populations
that are living near rail yards and marine ports nationally. As part of
this effort, a computer geographic information system (GIS) is being
used to identify the locations and property boundaries of these
facilities nationally, and to determine the size and demographic
characteristics of the population living near these facilities. We
anticipate that the results of this study will be completed in late
2007 and we intend to add this report to the public docket.
(b) Other Air Toxics-Benzene, 1,3-butadiene, Formaldehyde,
Acetaldehyde, Acrolein, POM, Naphthalene
Category 3 marine engine emissions contribute to ambient levels of
other air toxics known or suspected as human or animal carcinogens, or
that have non-cancer health effects. These other compounds include
benzene, 1,3-butadiene, formaldehyde, acetaldehyde, acrolein,
polycyclic organic matter (POM), and naphthalene. All of these
compounds, except acetaldehyde, were identified as national or regional
risk drivers in the 1999 National-Scale Air Toxics Assessment (NATA).
That is, for a significant portion of the population, these compounds
pose a significant portion of the total cancer and noncancer risk from
breathing outdoor air toxics. Furthermore, a significant portion of
total nationwide emissions of these pollutants result from mobile
sources. However, EPA does not have high confidence in the NATA data
for all these compounds. Reducing the emissions from Category 3 marine
engines would help reduce exposure to these harmful substances.
Air toxics can cause a variety of cancer and noncancer health
effects. A number of the mobile source air toxic pollutants described
in this section are known or likely to pose a cancer hazard in humans.
Many of these compounds also cause adverse noncancer health effects
resulting from inhalation exposures. These include neurological,
cardiovascular, liver, kidney, and respiratory effects as well as
effects on the immune and reproductive systems.

C. Other Environmental Effects

There are a number of public welfare effects associated with the
presence of ozone and PM_2.5 in the ambient air including the
impact of PM_2.5 on visibility and materials and the impact
of ozone on plants, including trees, agronomic crops and urban ornamentals.
1. Visibility
Visibility can be defined as the degree to which the atmosphere is
transparent to visible light. Visibility impairment manifests in two
principal ways: as local visibility impairment and as regional
haze.\57\ Local visibility impairment may take the form of a localized
plume, a band or layer of discoloration appearing well above the
terrain as a result of complex local meteorological conditions.
Alternatively, local visibility impairment may manifest as an urban
haze, sometimes referred to as a ``brown cloud.'' This urban haze is
largely caused by emissions from multiple sources in the urban areas
and is not typically attributable to only one nearby source or to long-
range transport. The second type of visibility impairment, regional
haze, usually results from multiple pollution sources spread over a
large geographic region. Regional haze can impair visibility in large
regions and across states.
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\57\ See discussion in U.S. EPA , National Ambient Air Quality
Standards for Particulate Matter; Proposed Rule; January 17, 2006,
Vol71 p 2676. This document is available in Docket EPA-HQ-OAR-2007-
0121. This information is available electronically at
http://epa.gov/fedrgstr/EPA-AIR/2006/January/Day-17/a177.pdf.

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Visibility is important 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, where they live and work, and in places where they enjoy
recreational opportunities. Visibility is also highly valued in
significant natural areas such as national parks and wilderness areas
and special emphasis is given to protecting visibility in these areas.
For more information on visibility

[[Page 69535]]

see the final 2004 PM AQCD \58\ as well as the 2005 PM Staff Paper.\59\
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\58\ U.S. EPA (2004) Air Quality Criteria for Particulate Matter
(Oct 2004), Volume I Document No. EPA600/P-99/002aF and Volume II
Document No. EPA600/P-99/002bF. This document is available in Docket
EPA-HQ-OAR-2007-0121.
\59\ U.S. EPA (2005) Review of the National Ambient Air Quality
Standard for Particulate Matter: Policy Assessment of Scientific and
Technical Information, OAQPS Staff Paper. EPA-452/R-05-005. This
document is available in Docket EPA-HQ-OAR-2007-0121.
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Fine particles are the major cause of reduced visibility in parts
of the United States. EPA is pursuing a two-part strategy to address
visibility. First, to address the welfare effects of PM on visibility,
EPA set secondary PM_2.5 standards which would act in
conjunction with the establishment of a regional haze program. In
setting this secondary standard EPA concluded that PM_2.5
causes adverse effects on visibility in various locations, depending on
PM concentrations and factors such as chemical composition and average
relative humidity. Second, section 169 of the Clean Air Act provides
additional authority to address existing visibility impairment and
prevent future visibility impairment in the 156 national parks, forests
and wilderness areas categorized as mandatory class I federal areas (62
FR 38680-38681, July 18, 1997).\60\ In July 1999 the regional haze rule
(64 FR 35714) was put in place to protect the visibility in mandatory
class I federal areas. Visibility can be said to be impaired in both
PM_2.5 nonattainment areas and mandatory class I federal areas.
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\60\ These areas are defined in section 162 of the Act as those
national parks exceeding 6,000 acres, wilderness areas and memorial
parks exceeding 5,000 acres, and all international parks which were
in existence on August 7, 1977.
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Category 3 marine engines contribute to visibility concerns in
these areas through their primary PM_2.5 emissions and their
NO_X and SO₂ emissions which contribute to the
formation of secondary PM_2.5.
Recently designated PM_2.5 nonattainment areas indicate
that, as of June 20, 2007, almost 90 million people live in
nonattainment areas for the 1997 PM_2.5 NAAQS. Thus, at least
these populations would likely be experiencing visibility impairment,
as well as many thousands of individuals who travel to these areas. In
addition, while visibility trends have improved in mandatory Class I
federal areas the most recent data show that these areas continue to
suffer from visibility impairment. In summary, visibility impairment is
experienced throughout the U.S., in multi-state regions, urban areas,
and remote mandatory class I federal areas.61 62
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\61\ U.S. EPA, Air Quality Designations and Classifications for
the Fine Particles (PM_2.5) National Ambient Air Quality
Standards, December 17, 2004. (70 FR 943, Jan 5. 2005) This document
is available in Docket EPA-HQ-OAR-2007-0121. This document is also
available on the web at: http://www.epa.gov/pmdesignations/.
\62\ U.S. EPA. Regional Haze Regulations, July 1, 1999. (64 FR
35714, July 1, 1999) This document is available in Docket EPA-HQ-
OAR-2007-0121.
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2. Plant and Ecosystem Effects of Ozone
Ozone contributes to many environmental effects, with impacts to
plants and ecosystems being of most concern. Ozone can produce both
acute and chronic injury in sensitive species depending on the
concentration level and the duration of the exposure. Ozone effects
also tend to accumulate over the growing season of the plant, so that
even lower concentrations experienced for a longer duration have the
potential to create chronic stress on vegetation. Ozone damage to
plants includes visible injury to leaves and a reduction in food
production through impaired photosynthesis, both of which can lead to
reduced crop yields, forestry production, and use of sensitive
ornamentals in landscaping. In addition, the reduced food production in
plants and subsequent reduced root growth and storage below ground, can
result in other, more subtle plant and ecosystems impacts. These
include increased susceptibility of plants to insect attack, disease,
harsh weather, interspecies competition and overall decreased plant
vigor. The adverse effects of ozone on forest and other natural
vegetation can potentially lead to species shifts and loss from the
affected ecosystems, resulting in a loss or reduction in associated
ecosystem goods and services. Lastly, visible ozone injury to leaves
can result in a loss of aesthetic value in areas of special scenic
significance like national parks and wilderness areas. The final 2006
ozone Air Quality Criteria Document (ozone AQCD) \63\ presents more
detailed information on ozone effects on vegetation and ecosystems.
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\63\ U.S. EPA Air Quality Criteria for Ozone and Related
Photochemical Oxidants (Final). U.S. Environmental Protection
Agency, Washington, DC, EPA 600/R-05/004aF-cF, 2006. This document
is available in Docket EPA-HQ-OAR-2007-0121. This document may be
accessed electronically at:
http://www.epa.gov/ttn/naaqs/standards/ozone/s_o3_cr_cd.html.

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As discussed above, Category 3 marine engine emissions of
NO_X contribute to ozone and therefore the NO_X
standards discussed in this action would help reduce crop damage and
stress on vegetation from ozone.
3. Acid Deposition
Acid deposition, or acid rain as it is commonly known, occurs when
NO_X and SO₂ react in the atmosphere with water,
oxygen and oxidants to form various acidic compounds that later fall to
earth in the form of precipitation or dry deposition of acidic
particles. It contributes to damage of trees at high elevations and in
extreme cases may cause lakes and streams to become so acidic that they
cannot support aquatic life. In addition, acid deposition accelerates
the decay of building materials and paints, including irreplaceable
buildings, statues, and sculptures that are part of our nation's
cultural heritage.
The proposed NO_X and SO_X standards would help
reduce acid deposition, thereby helping to reduce acidity levels in
lakes and streams throughout the coastal areas of our country and help
accelerate the recovery of acidified lakes and streams and the revival
of ecosystems adversely affected by acid deposition. Reduced acid
deposition levels will also help reduce stress on forests, thereby
accelerating reforestation efforts and improving timber production.
Deterioration of historic buildings and monuments, vehicles, and other
structures exposed to acid rain and dry acid deposition also will be
reduced, and the costs borne to prevent acid-related damage may also
decline. While the reduction in nitrogen acid deposition will be
roughly proportional to the reduction in NO_X emissions, the
precise impact of new standards would differ across different areas.
4. Eutrophication and Nitrification
The NO_X standards discussed in this action would help
reduce the airborne nitrogen deposition that contributes to
eutrophication of watersheds, particularly in aquatic systems where
atmospheric deposition of nitrogen represents a significant portion of
total nitrogen loadings. Eutrophication is the accelerated production
of organic matter, particularly algae, in a water body. This increased
growth can cause numerous adverse ecological effects and economic
impacts, including nuisance algal blooms, dieback of underwater plants
due to reduced light penetration, and toxic plankton blooms. Algal and
plankton blooms can also reduce the level of dissolved oxygen, which
can adversely affect fish and shellfish populations. In recent decades,
human activities have greatly accelerated nutrient impacts, such as
nitrogen and phosphorus, causing excessive growth of algae and leading
to degraded water

[[Page 69536]]

quality and associated impairment of freshwater and estuarine resources
for human uses.\64\
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\64\ Deposition of Air Pollutants to the Great Waters, Third
Report to Congress, June 2000, EPA-453/R-00-005. This document is
available in Docket EPA-HQ-OAR-2007-0121. It is also available at
http://www.epa.gov/oar/oaqps/gr8water/3rdrpt/obtain.html.

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Severe and persistent eutrophication often directly impacts human
activities. For example, losses in the nation's fishery resources may
be directly caused by fishkills associated with low dissolved oxygen
and toxic blooms. Declines in tourism occur when low dissolved oxygen
causes noxious smells and floating mats of algal blooms create
unfavorable aesthetic conditions. Risks to human health increase when
the toxins from algal blooms accumulate in edible fish and shellfish,
and when toxins become airborne, causing respiratory problems due to
inhalation. According to the NOAA report, more than half of the
nation's estuaries have moderate to high expressions of at least one of
these symptoms--an indication that eutrophication is well developed in
more than half of U.S. estuaries.\65\
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\65\ Bricker, Suzanne B., et al., National Estuarine
Eutrophication Assessment, Effects of Nutrient Enrichment in the
Nation's Estuaries, National Ocean Service, National Oceanic and
Atmospheric Administration, September, 1999.
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5. Materials Damage and Soiling
The deposition of airborne particles can reduce the aesthetic
appeal of buildings and culturally important articles through soiling,
and can contribute directly (or in conjunction with other pollutants)
to structural damage by means of corrosion or erosion.\66\ Particles
affect materials principally by promoting and accelerating the
corrosion of metals, by degrading paints, and by deteriorating building
materials such as concrete and limestone. Particles contribute to these
effects because of their electrolytic, hygroscopic, and acidic
properties, and their ability to adsorb corrosive gases (principally
sulfur dioxide). The rate of metal corrosion depends on a number of
factors, including the deposition rate and nature of the pollutant; the
influence of the metal protective corrosion film; the amount of
moisture present; variability in the electrochemical reactions; the
presence and concentration of other surface electrolytes; and the
orientation of the metal surface. The PM standards discussed in this
action would help reduce the airborne particles that contribute to
materials damage and soiling.
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\66\ U.S. EPA (2005) Review of the National Ambient Air Quality
Standards for Particulate Matter: Policy Assessment of Scientific
and Technical Information, OAQPS Staff Paper. This document is
available in Docket EPA-HQ-OAR-2007-0121.
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III. Relevant Clean Air Act Provisions

Section 213 of the Clean Air Act (the Act) gives us the authority
to establish emission standards for nonroad engines and vehicles.
Section 213(a)(3) requires the Administrator to set (and from time to
time revise) standards for NO_X, VOCs, or carbon monoxide
emissions from new nonroad engines, to reduce ambient levels of ozone
and carbon monoxide. That section specifies that the ``standards shall
achieve the greatest degree of emission reductions achievable through
the application of technology which the Administrator determines will
be available for the engines or vehicles.'' As part of this
determination, the Administrator must give appropriate consideration to
lead time, noise, energy, and safety factors associated with the
application of such technology. Section 213(a)(4) authorizes the
Administrator to establish standards on new engines to control
emissions of pollutants, such as PM, which ``may reasonably be
anticipated to endanger public health and welfare.'' In setting
appropriate standards, EPA is instructed to take into account costs,
noise, safety, and energy factors.
Section 211(c) of the CAA allows us to regulate fuels where
emission products of the fuel either: (1) Cause or contribute to air
pollution that reasonably may be anticipated to endanger public health
or welfare, or (2) will impair to a significant degree the performance
of any emission control device or system which is in general use, or
which the Administrator finds has been developed to a point where in a
reasonable time it will be in general use were such a regulation to be
promulgated.

IV. International Regulation of Air Pollution From Ships

Annex VI to the International Convention for the Prevention of
Pollution from Ships (MARPOL) addresses air pollution from ships. Annex
VI was adopted by the Parties to MARPOL at a Diplomatic Conference on
September 26, 1997, and it went into force May 20, 2005. As of July 31,
2007, the Annex has been ratified by 44 countries, representing 74.1
percent of the world's merchant shipping tonnage.\67\
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\67\ See http://www.imo.org Go to Conventions, Status of
Conventions--Summary.
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Globally harmonized regulation of ship emissions is generally
recognized to be the preferred approach for addressing air emissions
from ocean-going vessels. It reduces costs for ship owners, since they
would not be required to comply with a patchwork of different standards
that could occur if each country was setting its own standards, and it
can simplify environmental protection for port and coastal states.
The significance of international shipping to the United States can
be illustrated by port entrance statistics. In 1999, according to U.S.
Maritime Administration (MARAD) data, about 90 percent of annual
entrances to U.S. ports were made by foreign-flagged vessels (75,700
total entrances; 67,500 entrances by foreign vessels; entrances are for
vessels engaged in foreign trade and do not include Jones Act \68\
vessels). At the same time, however, only a small portion of those
vessels account for most of the visits. In 1999, of the 7,800 foreign
vessels that visited U.S. ports, about 12 percent accounted for about
50 percent of total vessel entrances; about 30 percent accounted for
about 75 percent of the vessel entrances.\69\
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\68\ 46 USCS Appx Sec. 688.
\69\ Final Regulatory Support Document: Control of Emissions
from New Marine Compression-Ignition Engines at or Above 30 Liters
per Cylinder. EPA420-R-03-004, January 2003, pg. 3-50. This document
is available at http://www.epa.gov/otaq/regs/nonroad/marine/ci/r03004.pdf.
We will update these statistics for more recent years;
however, these results are not expected to change significantly
given the U.S. share of the ownership of ocean-going vessels. MARAD
data from 2005 indicates that while about 4.7 percent of all ocean-
going vessels are owned by citizens of the United States (5th
largest fleet) only about 1.9 percent of all ocean-going vessels are
flagged here. Also according to that data, while Greece, Japan,
China, and Germany account for the largest fleets in terms of
ownership (15.3, 13.0, 11, and 8.9 percent, respectively), Panama
and Liberia account for the largest fleets by flag (21.6 and 8.9
percent, respectively).
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The emission control program contained in Annex VI was the first
step for the international control of air pollution from ships.
However, as early as the 1997 conference, many countries ``already
recognized that the NO_X emission limits established in
Regulation 13 were very modest when compared with current technology
developments.'' \70\ Consequently, a Conference Resolution was adopted
at the 1997 conference that invited the Marine Environment Protection
Committee (MEPC) to review the NO_X emission limits at a
minimum of five-year intervals after entry into force of the protocol
and, if appropriate, amend

[[Page 69537]]

the NO_X limits to reflect more stringent controls.
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\70\ Proposal to Initiate a Revision Process, Submitted by
Finland, Germany, Italy, the Netherlands, Norway, Sweden and the
United Kingdom. MEPC 53/4/4, 15 April 2005. Marine Environment
Protection Committee, 53rd Session, Agenda Item 4.
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The United States began advocating a review of the NO_X
emission limits in 1999.\71\ However, MEPC did not formally consider
the issue until 2005, after the Annex went into effect. Negotiations
for amendments to the Annex VI standards, including NO_X and
SO_X emission limits, officially began in April 2006, with
the most recent round of negotiations taking place in April 2007. The
United States submitted a paper to that meeting (April 2007 Bulk
Liquids and Gases Sub-Committee meeting, referred to as BLG-11) setting
out an approach for new international engine and fuel standards. That
approach forms the basis of the program outlined in this ANPRM.\72\
Discussions are expected to continue through Summer 2008 and are
expected to conclude at the October 2008 MEPC meeting. We will continue
to coordinate our national rule for Category 3 emission limits with our
activities at IMO.
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\71\ Revision of the NO_X Technical Code, Tier 2
Emission Limits for Diesel Marine Engines At or Above 130 kW,
submitted by the United States. MEPC 44/11/7, 24 December 1999.
Marine Environment Protection Committee, 44th Session, Agenda Item 11.
\72\ ``Revision of the MARPOL Annex VI, the NO_X
Technical Code and Related Guidelines; Development of Standards for
NO_X, PM, and SO_X,'' submitted by the United
States, BLG 11/5, Sub-Committee on Bulk Liquids and Gases, 11th
Session, Agenda Item 5, February 9, 2007, Docket ID EPA-HQ-OAR-2007-
0121-0034. This document is also available on our Web site:
www.epa.gov/otaq/oceanvessels.com.

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V. Potential Standards and Effective Dates

Over the past several years, remarkable progress has been made for
land-based highway and nonroad diesel engines in reducing
NO_X and PM emissions. Current EPA standards for those land-
based sources are anticipated to achieve emission reductions of more
than 90 percent relative to uncontrolled NO_X and PM levels.
In contrast, Category 3 marine engines are subject to modest
NO_X standards only. In this rulemaking, we are considering a
comprehensive program that would set long-term standards based on the
use of high-efficiency catalytic aftertreatment. These standards would
achieve substantial reductions in NO_X, PM, and
SO_X exhaust emissions.
The program we are considering is based on the the U.S. Government
proposal to IMO, which consists of near- and long-term NO_X
limits for new engines based on engine controls and aftertreatment
technology; NO_X limits for certain existing engines based on
engine controls; and PM/SO_X limits that can be achieved
through the use of exhaust gas cleaning or low sulfur fuel. To reduce
the costs of the international program, the long-term new engine
NO_X limits and the PM/SO_X limits would not apply
while ships are operating on the open ocean; instead, they would in
specified geographic areas to be defined under the treaty.
This section describes in greater detail how we are considering
that emission control program for our federal action under the Clean
Air Act.

A. NOX Standards

Tier 2 NOX limits: We are considering new NO_X emission
standards for Category 3 marine diesel engines. As discussed in Section
VI, emission control technology for Category 3 marine engines has
progressed substantially in recent years. Significant reductions can be
achieved in the near term through in-cylinder controls with little or
no impact on overall vessel performance. These technologies include
traditional engine-out controls such as electronically controlled high
pressure common-rail fuel systems, turbocharger optimization,
compression-ratio changes, and electronically controlled exhaust
valves. Further emission reductions could be achieved through the use
of water-based technologies such as water emulsification, direct water
injection, or intake-air humidification or through exhaust gas
recirculation. We request comment on setting a near term NO_X
emission standard requiring a reduction of 15 to 25 percent below the
current Tier 1 standard. We are considering applying this near term
standard to new engines as early as 2011.
Tier 3 NOX limits: In the longer term, we believe that much greater
emission reductions could be achieved through the use of selective
catalytic reduction (SCR). More than 300 SCR systems have been
installed on marine vessels, some of which have been in operation for
more than 10 years and have accumulated 80,000 hours of operation.
While many of these applications have been limited to certain vessel
classes, we believe that the technology is feasible for application to
most engines given adequate lead time. As discussed in Section VI, SCR
systems are capable of reducing NO_X on the order of 90 to 95
percent compared to current emission levels. We further believe that an
80 percent reduction from the Tier 2 levels discussed above is
achievable throughout the life of the vessel. We are requesting comment
on setting a NO_X standard 80 percent below the Tier 2
standards in the 2016 timeframe. Low sulfur distillate fuel would help
in achieving these limits due to the impact of sulfur on catalyst
operation; however, we do not believe low sulfur fuel is necessary to
achieve these reductions. SCR systems have been used on residual fuel,
with sulfur levels as high as 2.5 to 3 percent. However low sulfur
distillate fuel would allow SCR systems to be smaller, more efficient,
less costly, and simpler to operate.
NOX limits for existing engines: Due to the very long life of
ocean-going vessels and the availability of known in-cylinder technical
modifications that provide significant and cost-effective
NO_X reductions, the U.S. proposal to IMO presents potential
NO_X emission limits for engines on vessels built prior to
the Tier 1 limits. We are requesting comment on requiring engines on
these vessels to be retrofitted to meet the Tier 1 standard. The U.S.
submittal proposed that this requirement would start in 2012. Although
the Tier 1 standards went into effect in the United States in 2004,
manufacturers have been building engines with emissions that meet this
limit since 2000 due to the MARPOL Annex VI NO_X standard.
Although the Annex VI standards did not go into force until 2005, they
apply to engines installed on vessels built on or after January 1, 2000.
Engines may be retrofitted to achieve meaningful emission reduction
by applying technology used by manufacturers to meet the Tier 1 limits.
These technologies include slide-valve fuel injectors and injection
timing retard. Manufacturers have indicated that they can reduce
NO_X emissions by approximately 20 percent using this
technology. However, some engines have higher baseline emissions than
average and would require more than a 20 percent emission reduction to
meet Tier 1 standards. Manufacturers have expressed concerns that they
would not necessarily be able to reduce emissions to the Tier 1
standards for such engines through a simple retrofit. Therefore, the
U.S. proposal to IMO considers a standard based on percent reduction
rather than an absolute numerical limit. Specifically, these engines
would need to be modified to reduce NO_X emissions by 20
percent from their existing baseline emission rate. Alternatively, we
request comment on requiring vessel operators to perform a specific
action, such as a valve or injector change, that would be known to
achieve a particular NO_X reduction. In this case, the
certification and compliance provisions would be based on the completion
of this action rather than achieving a specified emission reduction.
Over time, engine manufacturers have changed their engine platforms
as new

[[Page 69538]]

technologies have become available. Many of the technologies that can
be used to reduce NO_X emissions on modern engines may not be
easily applied to older engine designs. Based on conversations with
engine manufacturers we believe that engines built in the mid-1980s and
later are compatible with the lower NO_X components.
Therefore we are requesting comment on excluding engines installed on a
vessel prior to 1985 from this requirement. We request comment on what
generation of engines can be retrofitted to achieve NO_X
reductions. Also, we request comment on the feasibility, costs, and
other business impacts that would result from retrofitting existing
engines to meet a NO_X standard as discussed above.

B. PM and SOX Standards

For PM and SO_X emission control, we are considering
emission performance standards that would reflect the use of low-sulfur
distillate fuels or the use of exhaust gas cleaning technology, or a
combination of both. As discussed in Section VI, SO_X
emissions and the majority of the direct PM emissions from Category 3
marine engines operated on residual fuels are a direct result of fuel
quality, most notably the sulfur in the fuel. In addition,
SO_X emissions form secondary PM in the atmosphere. Other
components of residual fuel, such as ash and heavy metals, also
contribute directly to PM. Significant PM and SO_X reductions
could be achieved by using low sulfur fuel residual fuel or distillate
fuel. Alternatively, direct and indirect sulfur-based PM can be reduced
through the use of a seawater scrubber in the exhaust system. Recent
demonstration projects have shown that scrubbers are capable of
reducing SO_X emissions on the order of 95 percent and can
achieve substantial reductions in PM as well.
We request comment on setting a PM standard on the order of 0.5 g/
kW-hr and a SO_X standard on the order of 0.4 g/kW-hr. We
believe that the combination of these two performance-based standards
would be a cost-effective way to approach both primary and secondary PM
emission reductions because ship owners would have a variety of
mechanisms to achieve the standard, including fuel switching or the use
of emission scrubbers. This standard would apply as early as 2011 and
would result in more than a 90 percent reduction in SO_X and
approximately a 50-70 percent reduction in PM. We request comment on
performance based PM and SO_X standards for Category 3 marine
engines, what the standards should be, and an appropriate
implementation date. We also request comment on allowing vessel
operators the option to comply with the standards by simply using a
distillate fuel with a maximum allowable sulfur level, such as 1,000
ppm. Under this option, no exhaust emission testing would be required
to demonstrate compliance with the standard.

VI. Emission Control Technology

A. Engine-Based NOX Control

1. Traditional In-Cylinder Controls
Engine manufacturers are meeting the Tier 1 NO_X
standards \73\ for Category 3 marine engines today through traditional
in-cylinder fuel and air management approaches. These in-cylinder
emission control technologies include electronic controls, optimizing
the turbocharger, higher compression ratio, valve timing, and optimized
fuel injection which may include common rail systems, timing retard,
increased injection pressure, rate shaping, and changes to the number
and size of injector holes to increase fuel atomization. Although U.S.
standards became effective in 2004, most manufacturers began selling
marine engines in 2000 that met the MARPOL Annex VI NO_X
standard in anticipation of its ratification.
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\73\ This NO_X standard is the same as the
internationally negotiated NO_X standards established by
the International Maritime Organization (IMO) in Annex VI to the
International Convention on the Prevention of Pollution from Ships,
1973, as Modified by the Protocol of 1978 Relating Thereto (MARPOL).
---------------------------------------------------------------------------

Manufacturers have indicated that they would be able to use in-
cylinder engine control strategies to achieve further NO_X
emission reductions beyond the Tier 1 standards. EUROMOT, which is an
association of engine manufacturers, submitted a proposal to the
International Maritime Organization for new Category 3 marine engine
NO_X standards 2 g/kW-hr below the Tier 1 NO_X
standard.\74\ In this submission, they pointed to the following
technologies for Category 3 marine engines operating on residual fuel:
Fuel injection timing, high compression ratio, modified valve timing on
4-stroke engines, late exhaust valve closing on 2-stroke engines, and
optimized fuel injection system and combustion chamber. EUROMOT stated
that the limiting factors for NO_X design and optimization
are increases in low load smoke and thermal load, PM and CO₂
emissions, fuel consumption, and concerns about engine reliability and
load acceptance. We request comment on potential emission reductions
beyond the Tier 1 NO_X standards that may be achieved through
traditional in-cylinder technology and what the impact of the low
NO_X designs would be on fuel consumption, maintenance, and
on PM exhaust emissions.
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\74\ ``MARPOL Annex VI Revision--Proposals Related to Future
Emission Limits and Issues for Clarification,'' Submitted by EUROMOT
to the IMO Subcommittee on Bulk Liquids and Gases, BLG 10/14/12,
January 26, 2006, Docket ID EPA-HQ-OAR-2007-0121-0014.
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Many of the same in-cylinder control technologies used to meet the
Tier 1 NO_X standards can be used as retrofit technology on
existing engines built prior to the Tier 1 standards. An example of
this is retrofitting older fuel injectors with new injectors using
slide-valve nozzle tips. The slide-valve in the nozzle tip limits fuel
``dripping'' which leads to higher HC, PM, and smoke emissions and
engine fouling. This fuel nozzle can be combined with low-
NO_X engine calibration to achieve about a 20 percent
reduction in NO_X emissions through an engine retrofit.\75\
This retrofit is relatively simple on engine platforms similar to those
used for the Tier 1 compliant engines, but the slide-valve injectors
may not be compatible with older engines. We request comment on the
costs and other business impacts of retrofitting Category 3 marine
engines built before 2000 to meet the Tier 1 NO_X standard.
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\75\ Henningsen, S., ``2007 Panel Discussion on Emission
Reduction Solutions for Marine Vessels; Engine Technologies''
presentation by MAN B&W at the Clean Ships: Advanced Technology for Clean
Air Conference, February 8, 2007, Docket ID EPA-HQ-OAR-2007-0121-0031.
---------------------------------------------------------------------------

2. Water-Based Technologies
NO_X emissions from Category 3 marine engines can be
reduced by introducing water into the combustion process in combination
with appropriate in-cylinder controls. Water can be used in the
combustion process to lower the maximum combustion temperature, and
therefore lower NO_X formation without a significant increase
in fuel consumption. Water has a high heat capacity which allows it to
absorb enough of the energy in the cylinder to reduce peak combustion
temperatures. Data from engine manufacturers suggest that, depending on
the amount of water and how it is introduced into the combustion
chamber, a 30 to 80 percent reduction in NO_X can be achieved
from Category 3 marine engines.76 77 78

[[Page 69539]]

However, some increase in PM may result due to the lower combustion
temperatures, depending on the water introduction strategy.\79\ We
request comment on the potential NO_X reductions achievable
from water-based technologies and what the impact on other pollutants
or fuel consumption may be.
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\76\ Heim, K., ``Future Emission Legislation and Reduction
Possibilities,'' presentation by Wartsila at the CIMAC Circle 2006,
September 28, 2006, Docket ID EPA-HQ-OAR-2007-0121-0017.
\77\ Aabo, K., Kjemtrup, N., ``Latest on Emission Control Water
Emulsion and Exhaust Gas Re-Circulation,'' MAN B&W, CIMAC paper
number 126, presented at International Council on Combustion Engines
Congress, 2004, Docket ID EPA-HQ-OAR-2007-0121-0005.
\78\ Hagstrm, U., ``Humid Air Motor (HAM) and Selective
Catalytic Reduction (SCR) Viking Line,'' presented by Viking Line at
Swedish Maritime Administration Conference on Emission Abatement
Technology on Ships, May 24-26, 2005, Docket ID EPA-HQ-OAR-2007-0121-0027.
\79\ Koehler, H., ``Field Experience with Considerably Reduced
NO_X and Smoke Emissions,'' MAN B&W, 2004, Docket ID EPA-
HQ-OAR-2007-0121-0019.
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Water may be introduced into the combustion process through
emulsification with the fuel, direct injection into the combustion
chamber, or saturating the intake air with water vapor. Water
emulsification refers to mixing the fuel and water prior to injection.
This strategy is limited by the instability of the water in the fuel,
but can be improved by mixing the water into the fuel just prior to
injection into the cylinder. More effective control can be achieved
through the use of an independent injection nozzle in the cylinder for
the water. Using a separate injector nozzle for water allows larger
amounts of water to be added to the combustion process because the
water is injected simultaneously with the fuel, and larger injection
pumps and nozzles can be used for the water injection. In addition, the
fuel injection timing and water flow rates can be better optimized at
different engine speeds and loads. Even higher water-to-fuel ratios can
be achieved through the use of combustion air humidification and steam
injection. With combustion air humidification, a water nozzle is placed
in the engine intake and an air heater is used to offset condensation.
With steam injection, waste heat is used to vaporize water, which is
then injected into the combustion chamber during the compression stroke.
Depending on the targeted NO_X emission reduction, the
amount of water used can range from half as much as the fuel volume to
more than three times as much. Fresh water is necessary for the water-
based NO_X reduction techniques. Introducing saltwater into
the engine could result in serious deterioration due to corrosion and
fouling. For this reason, a ship using water strategies would need
either to produce fresh water through the use of a desalination or
distillation system or to store fresh water on-board. Often, waste heat
in the exhaust is used to generate fresh water for on-board use. We
request comment on the capabilities of marine vessels, especially
ocean-going ships, to generate sufficient fresh water on-board to
support the use of water-based NO_X control technologies. For
vessels making shorter trips, we request comment on the costs
associated with storing fresh water on board and replenishing the water
supply when at port. We also request comment on the hardware and
operating costs associated with this emission control technology.
3. Exhaust Gas Recirculation
Exhaust gas recirculation (EGR) is a strategy similar to water-
based NO_X reduction approaches in that a non-combustible
fluid (in this case exhaust gas) is added to the combustion process.
The exhaust gas is inert and reduces peak combustion temperatures,
where NO_X is formed, by slowing reaction rates and absorbing
some of the heat generated during combustion. One study concluded that
EGR could be used to achieve similar NO_X emission reductions
as water emulsion.\80\ However, due to the risk of carbon deposits and
deterioration due to sulfuric acid in the exhaust gas when high sulfur
fuel is used, any exhaust gases recirculated to the cylinder intake
would have to be cleaned before being routed back into the cylinder.
One method of cleaning the exhaust would be to use a seawater
scrubber.\81\ Another alternative is to use internal EGR where a
portion of the exhaust gases is held in the cylinder after combustion
based on the cylinder scavenging design.\82\
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\80\ Aabo, K., Kjemtrup, N., ``Latest on Emission Control Water
Emulsion and Exhaust Gas Re-Circulation,'' MAN B&W, CIMAC paper
number 126, presented at International Council on Combustion Engines
Congress, 2004, Docket ID EPA-HQ-OAR-2007-0121-0005.
\81\ Henningsen, S., ``2007 Panel Discussion on Emission
Reduction Solutions for Marine Vessels; Engine Technologies''
presentation by MAN B&W at the Clean Ships: Advanced Technology for Clean
Air Conference, February 8, 2007, Docket ID EPA-HQ-OAR-2007-0121-0031.
\82\ Weisser, G., ``Emission Reduction Solutions for Marine
Vessels--Wartsila Perspective'' presentation by Wartsila at the
Clean Ships: Advanced Technology for Clean Air Conference, February
8, 2007, Docket ID EPA-HQ-OAR-2007-0121-0032.
---------------------------------------------------------------------------

B. NOX Aftertreatment

NO_X emissions can be reduced substantially using
selective catalytic reduction (SCR), which is a commonly-used
technology reducing NO_X emissions standards in diesel
applications worldwide. Stationary power plants fueled with coal,
diesel, and natural gas have used SCR for three decades as a means of
controlling NO_X emissions. European heavy-duty truck
manufacturers are using this technology to meet Euro 5 emissions limits
and several heavy-duty truck engine manufacturers have indicated that
they will use SCR technology to meet stringent U.S. NO_X
limits beginning in 2010. Collaborative research and development
activities between diesel engine manufacturers and SCR catalyst
suppliers suggest that SCR is a mature, cost-effective solution for
NO_X reduction on diesel engines.
SCR has also been demonstrated for use with marine diesel engines.
More than 300 SCR systems have been installed on marine vessels, some
of which have been in operation for more than 10 years and have
accumulated 80,000 hours of operation.83 84 85 86 These
systems are used in a wide range of ship types including ferries,
supply ships, ro ros (roll-on roll-off), tankers, container ships,
icebreakers, cargo ships, workboats, cruise ships, and foreign navy
vessels for both propulsion and auxiliary engines. These SCR units are
being used successfully on slow and medium speed Category 3 propulsion
engines and on Category 2 propulsion and auxiliary engines. The fuel
used on ships with SCR systems ranges from low sulfur distillate fuel
to high sulfur residual fuel. SCR is capable of reducing NO_X
emissions in marine diesel exhaust by more than 90 percent and can have
other benefits as well.87 88 89 Fuel consumption
improvements may also be gained with the use of an SCR system. By
relying on the SCR unit for NO_X emissions control, the
engine can be optimized for better fuel consumption, rather than for
low NO_X emissions. When an oxidation catalyst is used in
conjunction with the SCR unit, significant reductions in HC, CO, and

[[Page 69540]]

PM may also be achieved. The SCR unit attenuates sound, so it may use
the space on the vessel that would normally hold a large muffler
generally referred to as an exhaust gas silencer. To the extent that
SCR has been used in additional marine applications, we request further
information on the emission reductions that have been achieved. We also
request comment on the durability, packaging, and cost of these systems.
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\83\ ``DEC SCR Convertor System,'' Muenters, May 1, 2006, Docket
ID EPA-HQ-OAR-2007-0121-0013.
\84\ Hagstr[ouml]m, U., ``Humid Air Motor (HAM) and Selective
Catalytic Reduction (SCR),'' Viking Line, presented at Air Pollution
from Ships, May 24-26, 2005, Docket ID EPA-HQ-OAR-2007-0121-0027.
\85\ ``Reference List--SINO_X® Systems,''
Argillon, December 2006, Docket ID EPA-HQ-OAR-2007-0121-0035.
\86\ ``Reference List January 2005 Marine Applications,'' Hug
Engineering, January 2005, Docket ID EPA-HQ-OAR-2007-0121-0036.
\87\ Heim, K., ``Future Emission Legislation and Reduction
Possibilities,'' W[auml]rtsil[auml], presented at CIMAC Circle 2006,
September 28, 2006, Docket ID EPA-HQ-OAR-2007-0121-0017.
\88\ Argillon, ``Exhaust Gas Aftertreatment Systems; SCR--The
Most Effective Technology for NO_X Reduction,'' presented
at Motor Ship Marine Propulsion Conference, May 7-8, 2003, Docket ID
EPA-HQ-OAR-2007-0121-0010.
\89\ Holmstr[ouml]m, Per, ``Selective Catalytic Reduction,''
presentation by Munters at Clean Ships: Advanced Technology for
Clean Air, February 7-9, 2007, Docket ID EPA-HQ-OAR-2007-0121-0013.
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An SCR catalyst reduces nitrogen oxides to elemental nitrogen
(N₂) and water by using a small amount of ammonia
(NH₃) as the reducing agent. The most-common method for
supplying ammonia to the SCR catalyst is to inject an aqueous urea-
water solution into the exhaust stream. In the presence of high-
temperature exhaust gases (>200 [deg]C), the urea in the injected
solution hydrolyzes to form NH₃. The NH₃ is
stored on the surface of the SCR catalyst where it is used to complete
the NO_X reduction reaction. In theory, it is possible to
achieve 100 percent NO_X conversion if the exhaust
temperature is high enough and the catalyst is large enough. Low
temperature NO_X conversion efficiency can be improved
through use of an oxidation catalyst upstream of the SCR catalyst to
promote the conversion of NO to NO₂. Because the reduction
of NO_X can be rate limited by NO reductions, converting some
of the NO to NO₂ also allows manufacturers to use a smaller
reactor.
Manufacturers report minimum exhaust temperatures for SCR units to
be in the range of 250 to 300 [deg]C, depending on the catalyst system
design and fuel sulfur level.90 91 92 Below this
temperature, the vanadium-oxide catalyst in the SCR unit would not be
hot enough to efficiently reduce NO_X. With very low sulfur
fuels, a highly reactive oxidation catalyst can be used upstream of the
SCR reactor to convert NO to NO₂. NO₂ reacts in
the SCR catalyst at lower temperatures than NO; therefore, the
oxidation catalyst lowers the exhaust temperature at which the SCR unit
is effective. However, as the sulfur concentration increases, a less
reactive oxidation catalyst must be used to prevent excessive formation
of sulfates and poisoning of the oxidation catalyst. When operating on
marine distillate fuel with a sulfur level of 1,000 ppm, the minimum
exhaust temperature for effective reductions through a current SCR
system would be on the order of 270 [deg]C. On typical heavy fuel oils,
which have sulfur concentrations on the order of 2.5 percent, the
exhaust temperature would need to be about 300[deg]C due to high sulfur
concentrations. We request comment on the relationship between SCR
operating temperatures and the quality of the fuel used.
---------------------------------------------------------------------------

\90\ Rasmussen, K., Ellegasrd, L., Hanafusa, M., Shimada, K.,
``Large Scale SCR Application on Diesel Power Plant,'' CIMAC paper
number 179, presented at International Council on Combustion Engines
Congress, 2004, Docket ID EPA-HQ-OAR-2007-0121-0007.
\91\ ``Munters SCR ConverterTM System,'' downloaded
from http://www.munters.com, November 21, 2006, Docket ID
EPA-HQ-OAR-2007-0121-0023.
\92\ Argillon, ``Exhaust Gas Aftertreatment Systems; SCR--The
Most Effective Technology for NO_X Reduction,'' presented
at Motor Ship Marine Propulsion Conference, May 7-8, 2003, Docket ID
EPA-HQ-OAR-2007-0121-0010.
---------------------------------------------------------------------------

SCR can be operated in exhaust streams at or above 500 [deg]C
before heat-related degradation of the catalyst becomes significant.
This maximum exhaust temperature is sufficient for use with Category 3
marine engines. Exhaust valve temperatures are generally maintained
below 450[deg]C to minimize high temperature corrosion and fouling
caused by vanadium and sodium present in residual fuel.
Modern SCR systems should be able to achieve very high
NO_X conversion for all operation covered by the E3 test
cycle, which includes power levels from 25 to 100 percent. A properly
designed system can generally maintain exhaust temperatures high enough
at these power levels to ensure proper functioning of the improved SCR
catalysts. However, exhaust temperatures at lower power levels on
current vessels may be below the minimum temperature threshold for SCR
systems, especially when operated on high sulfur fuels. We believe that
it is important that NO_X emission control is achieved even
at low power due to the concern that much of the engine operation that
occurs near the shore may be at less than 25 percent power. As
described in Section VII.A.2, we are considering the need for changes
to the test cycle or other supplemental requirements to account for the
fact that the current test cycle does not include any operation below
25 percent power. We request comment on engine power levels, and
corresponding exhaust temperature profiles, when maneuvering, operating
at low speeds, or during other operation near shore.
We believe there are several approaches that can be used to ensure
that the exhaust temperature during low power operation is sufficiently
high for the SCR unit to function properly. By positioning the SCR
system ahead of the turbocharger, the heat to the SCR system can be
maximized. This approach was used with vessels equipped with slow-speed
engines that operated at low loads near the coast.\93\ Exhaust
temperatures could be increased by adjusting engine parameters, such as
reduced charge air cooling and modified injection timing. In one case,
SCR was used on a short passage car ferry which originally had exhaust
temperatures below 200 [deg]C when the engine was operated at low
load.\94\ When the SCR unit was installed, controls were placed on the
intercooler in the air intake system. By reducing the cooling on the
intake air, the exhaust temperature was increased to be within the
operating range of the SCR unit, even during low power operation. In a
ship using multiple propulsion engines, one or more engines could be
shut down such that the remaining engine or engines are operating at
higher power. Another approach to increase the exhaust temperature
could be to use burner systems during low power operation. If
commenters have additional information on using SCR at low power
operation, we request that this information be submitted for our
consideration as we continue developing proposed standards for Category
3 marine engines.
---------------------------------------------------------------------------

\93\ MAN B&W, ``Emission Control Two-Stroke Low-Speed Diesel
Engines,'' December 1996, Docket ID EPA-HQ-OAR-2007-0121-0020.
\94\ ``NO_X Emissions from M/V Hamlet,'' Data provided
to W. Charmley, U.S. EPA. by P. Holmstr[ouml]m, DEC Marine, February
5, 2007, Docket ID EPA-HQ-OAR-2007-0121-0015.
---------------------------------------------------------------------------

SCR grade urea is a widely used industrial chemical around the
world. Although an infrastructure for widespread transportation,
storage, and dispensing of SCR-grade urea does not currently exist in
most places, we believe that it would develop as needed based on market
forces. Concerning urea production capacity, the U.S. has more-than-
sufficient capacity to meet the additional needs of the marine engines.
Currently, the U.S. consumes 14.7 million tons of ammonia resources per
year, and relies on imports for 41 percent of that total (of which,
urea is the principal derivative). In 2005, domestic ammonia producers
operated their plants at 66 percent of rated capacity, resulting in 4.5
million tons of reserve production capacity.\95\ Thus we do not project
that urea cost or supply will be an issue. As an alternative, one study
looked at using hydrocarbons distilled from the marine fuel oil as a
reductant for an SCR unit.\96\ We request

[[Page 69541]]

comment on any issues related using urea, or any other reductant, on ships
such as costs, on-board storage requirements, and supply infrastructure.
---------------------------------------------------------------------------

\95\ U.S. Department of the Interior, ``Mineral Commodity
Summaries 2006,'' page 118, U.S. Geological Survey, January 13,
2006, Docket ID EPA-HQ-OAR-2007-0121-0022.
\96\ Tokunaga, Y., Kiyotaki, G., ``Development of NO_X
Reduction System for Marine Diesel Engines by SCR using Liquid
Hydrocarbon Distilled from Fuel Oil as Reductant,'' CIMAC paper
number 63, presented at International Council on Combustion Engines
Congress, 2004, Docket ID EPA-HQ-OAR-2007-0121-0002.
---------------------------------------------------------------------------

C. PM and SOX Control

As discussed above, we are considering PM and SO_X
emission control approaches based on both fuel sulfur limits and
performance based requirements. This section discusses traditional in-
cylinder emission controls, fuel quality, and exhaust gas scrubbing
technology.
1. In-Cylinder Controls
For typical diesel engines operating on distillate fuel,
particulate matter formation is primarily the result of incomplete
combustion of the fuel and lube oil. The traditional in-cylinder
technologies discussed above for NO_X emission control can be
optimized for PM control while simultaneously reducing NO_X
emissions. If aftertreatment, such as SCR, is used to control
NO_X, then the in-cylinder technologies can be used primarily
for PM reductions. However, the PM reduction through in-cylinder
technologies is limited for engines operating on high-sulfur fuel
because the majority of the PM emissions in this case are due to
compounds in the fuel rather than due to incomplete combustion, as
discussed below.
2. Fuel Quality
The majority of Category 3 engines are designed to run on residual
fuel which has the highest viscosity and lowest price of the petroleum
fuel grades. Residual fuels are known by several names including heavy
fuel oil (HFO), bunker C fuel, and marine fuel oil. This fuel is made
from the very end products of the oil refining process, formulated from
residues remaining in the primary distilling stages of the refining
process. It has high content of ash, metals, nitrogen, and sulfur that
increase emissions of exhaust PM pollutants. Typical residual fuel
contains about 2.7 percent sulfur, but may have a sulfur content as
high as 4.5 percent.
When a diesel engine is operating on very low sulfur distillate
fuel, 80 to 90 percent of the PM in the exhaust is unburned
hydrocarbons from the fuel and lubricating oil and carbon soot. When
residual fuel is used, only about 25 to 35 percent of the PM from the
engine is made up of unburned hydrocarbon compounds.97 98 99
In this case, the majority of the PM from the engine is made up of
sulfur, metal, and ash components originating from the fuel itself. On
a mass basis, the vast majority of this fuel-based PM is due to the
sulfur which oxidizes in the combustion process and associates with
water to form an aqueous solution of sulfuric acid, known as sulfate
PM. Data suggest that about two percent of the sulfur in the fuel is
converted directly to sulfate PM.100 101 The rest of the
sulfur in the fuel forms SO_X emissions. These SO_X
emissions lead to indirect PM formation in the atmosphere.
---------------------------------------------------------------------------

\97\ Paro, D., ``Effective, Evolving, and Envisaged Emission
Control Technologies for Marine Propulsion Engines,'' presentation
from Wartsila to EPA on September 6, 2001, Docket ID EPA-HQ-OAR-
2007-0121-0028.
\98\ Koehler, H., ``Field Experience with Considerably Reduced
NO_X and Smoke Emissions,'' MAN B&W, 2004, Docket ID EPA-
HQ-OAR-2007-0121-0019.
\99\ Heim, K., ``Future Emission Legislation and Reduction
Possibilities,'' presentation by Wartsila at the CIMAC Circle 2006,
September 28, 2006, Docket ID EPA-HQ-OAR-2007-0121-0017.
\100\ ``Emission Factors for Compression Ignition Nonroad
Engines Operated on No. 2 Highway and Nonroad Diesel Fuel,'' U.S.
EPA, EPA420-R-98-001, March 1998, Docket ID EPA-HQ-OAR-2007-0121-0025.
\101\ Lyyranen, J., Jokiniemi, J., Kauppinen, E., Joutsensaari,
J., ``Aerosol Characterization in Medium-Speed Diesel Engines
Operating with Heavy Fuel Oils,'' Aerosol Science Vol. 30, No. 6,
pp. 771-784, 1999, Docket ID EPA-HQ-OAR-2007-0121-0009.
---------------------------------------------------------------------------

We believe that substantial PM and SO_X reductions could
be achieved through the use of lower sulfur fuel. Using a residual fuel
with a lower sulfur content would reduce the fraction of PM from
sulfate formation. One study showed a decrease of PM emissions from
more than 1.0 g/kW-hr on 2.4 percent sulfur fuel to less than 0.5 g/kW-
hr with 0.8 percent sulfur fuel for a medium-speed generator engine on
a ship.\102\ Using distillate fuel would likely have further reduced
sulfur-based emissions and PM emissions from ash and metals. Another
study compared PM emissions from a large 2-stroke marine engine on both
low sulfur residual fuel oil and marine distillate oil and reported
about a 70 percent reduction in PM.\103\ The simpler molecular
structure of distillate fuel may result in more complete combustion and
reduced levels of carbonaceous PM (soot and heavy hydrocarbons).
Because SO_X emissions are directly related to the
concentration of sulfur in the fuel, a given percent reduction in
sulfur in the fuel would be expected to result in about the same
percent reduction in SO_X emissions from the engine. We
request comment on the potential PM and SO_X emission reductions
that could be achieved through the use of lower sulfur residual fuel or
through the use of distillate fuel in Category 3 marine engines.
---------------------------------------------------------------------------

\102\ Maeda, K., Takasaki, K., Masuda, K., Tsuda, M., Yasunari,
M., ``Measurement of PM Emission from Marine Diesel Engines,'' CIMAC
paper number 107 presented at International Council on Combustion
Engines Congress, 2004, Docket ID EPA-HQ-OAR-2007-0121-0004.
\103\ Kasper, A., Aufdenblatten, S., Forss, A., Mohr, M.,
Burtscher, H., ``Particulate Emissions from a Low-Speed Marine
Diesel Engine,'' Aerosol Science and Technology, 41:24-32, 2007.
---------------------------------------------------------------------------

In general, engines that are designed to operate on residual fuel
are capable of operating on distillate fuel. For example, if the engine
is to be shut down for maintenance, distillate fuel is typically used
to flush out the fuel system. There are some issues that would need to
be addressed for operating engines on distillate fuel that were
designed primarily for use on residual fuel. Switching to distillate
fuel requires 20 to 60 minutes, depending on how slowly the operator
wants to cool the fuel temperatures. According to engine manufacturers,
switching from a heated residual fuel to an unheated distillate too
quickly could cause damage to fuel pumps. These fuel pumps would need
to be designed to operate on both fuels if a fuel-switching strategy
were employed. Separate fuel tanks would be needed for distillate fuel
with sufficient capacity for potentially extended operation on this
fuel. It is common for ships to have several fuel tanks today to
accommodate the variety in different grades of residual fuel which may
be incompatible with each other and, therefore, require segregation.
Also, different lubricating oil is used with each fuel type. We believe
that properly designed ships would be able to operate on distillate
fuel either under a fuel-switching strategy or for extended use. We
request comment on the practical implications of operating ships on
either lower sulfur residual or distillate fuel for extended use.
Fuel quality may also affect NO_X emissions. Residual
fuels have nitrogen bound into the fuel at a concentration on the order
of 0.3 to 0.4 weight percent. In contrast, marine distillate fuel has
about a 0.02 to 0.06 weight percent concentration of nitrogen in the
fuel. Approximately half of nitrogen in the fuel will oxidize to form
NO_X in a marine diesel engine.\104\ In addition, the
ignition quality of the fuel may be worse for residual fuel than for
distillate fuel which can affect NO_X emissions. These effects
are reflected in the MARPOL NO_X technical code which allows an

[[Page 69542]]

upward adjustment of 10 percent for NO_X, under certain
circumstances, when the engine is tested on residual fuel. We request
comment on the effect of using residual fuel on NO_X
emissions, both due to nitrogen in the fuel and any impacts of fuel
quality on ignition-delay or other combustion characteristics.
---------------------------------------------------------------------------

\104\ Takasaki, K., Tayama, K., Tanaka, H., Baba, S., Tajima,
H., Strom, A., ``NO_X Emission from Bunker Fuel
Combustion,'' CIMAC paper number 87, presented at International
Council on Combustion Engines Congress, 2004, Docket ID EPA-HQ-OAR-
2007-0121-0003.
---------------------------------------------------------------------------

There are several types of processes refineries use to remove
sulfur from fuels. Traditional sulfur removal technologies include
installing a hydrocracker upstream, or a hydrotreater upstream or
downstream, of the fluidized catalytic cracker (FCC) unit. Due to high
refinery production costs, it is not likely that much new volume of
residual fuel will be desulfurized to create 1,000 ppm heavy fuel oil.
It is more likely that additional distillate fuel may be produced by
cracking existing residual fuels or that blends of high and low sulfur
fuels will be used. Some existing low sulfur residual fuel is already
produced, though the volume is probably insufficient to fully meet fuel
volume requirements for both ships and land-based applications subject
to local sulfur emission requirements. We request comment on the
availability of low sulfur marine fuels.
3. Exhaust Gas Scrubbers
Another approach to reduce PM and SO_X emissions is to
use seawater scrubbers. Seawater scrubbers are an aftertreatment
technology that uses the seawater's ability to absorb SO₂.
In the scrubber, the exhaust gases are brought into contact with
seawater. The SO₂ in the exhaust reacts with oxygen to
produce sulfur trioxide that subsequently reacts with water to yield
sulfuric acid. The sulfuric acid in the water then reacts with
carbonate (and other salts) in the seawater to form sulfates which may
be removed from the exhaust. The carbonate also directionally
neutralizes the pH of the sulfuric acid.
A scrubber system does not necessarily need to use sea water. An
alternative approach is to circulate fresh water through the scrubber
system. In this design, the pH of the wash water is monitored and
additional caustic solution is added as necessary. If the pH becomes
too low, the water will not absorb any further sulfur. During typical
operation, a small amount of wash water is bled out of the system and
fresh water is added to maintain volume. This prevents excessive build-
up of contaminants in the wash water.
Water may be sprayed into the exhaust stream, or the exhaust gasses
may be routed through a water bath. As the cooled exhaust gas rises out
the stack, demisters are used to separate water droplets that may be
entrained in the exhaust. The cleaned exhaust passes out of the
scrubber through the top while the water, containing sulfates, is
drained out through the bottom. Recent demonstration projects have
shown scrubbers are capable of reducing SO_X emissions on the
order of 95 percent.\105\ Today, exhaust gas silencers are used on
ships to muffle noise from the exhaust. Seawater scrubbers would act as
mufflers making the exhaust gas silencers unnecessary. New seawater
scrubber designs are not much larger than exhaust gas silencers already
used on ships, and could be packaged in the space formerly used by an
exhaust gas silencer.\106\ We request comment on further experience
with seawater scrubbers and on the practical issues related to
installing scrubbers on ships, including space constraints and costs.
---------------------------------------------------------------------------

\105\ Skawinski, C., ``Seawater Scrubbing Advantage,''
Presentation by Marine Exhaust Solutions at the Conference for
Emission Abatement Technology on Ships held by the Swedish Maritime
Administration, May 24-26, 2005, Docket ID EPA-HQ-OAR-2007-0121-0021.
\106\ ``Krystallon Seawater Scrubber,'' downloaded from
http://www.krystallon.com on February 14, 2007, Docket ID
EPA-HQ-OAR-2007-0121-0018.
---------------------------------------------------------------------------

Exhaust gas scrubbers can achieve reductions in particulate matter
as well. By removing sulfur from the exhaust, the scrubber removes most
of the direct sulfate PM. As discussed above, sulfates are a large
portion of the PM from ships operating on high sulfur fuels. By reducing
the SO_X emissions, the scrubber will also control much of
the secondary PM formed in the atmosphere from SO_X emissions.
Simply mixing alkaline water in the exhaust does not necessarily
remove much of the carbonaceous PM, ash, or metals in the exhaust.
While SO₂ associates with the wash water, particles can only
be washed out of the exhaust through direct contact with the water. In
simple scrubber designs, much of the mass of particles can hide in gas
bubbles and escape out the exhaust. Manufacturers have been improving
their scrubber designs to address carbonaceous soot and other fine
particles. Finer water sprays, longer mixing times, and turbulent
action would be expected to directionally reduce PM emissions through
contact impactions. One scrubber design uses an electric charge on the
water to attract particles in the exhaust to the water. Two chambers
are used so that both a positive and a negative charge can be used to
attract both negatively-charged and positively-charged particles. The
manufacturer reports an efficiency of more than 99 percent for the
removal for particulate matter and condensable organics in diesel
exhaust.\107\ Although exhaust gas scrubbers are only used in a few
demonstration vessels today, this technology is widely used in land-
based applications. We request comment on how scrubber design impacts
the amount of PM that is removed from the exhaust.
---------------------------------------------------------------------------

\107\ ``Cloud Chamber Scrubber Performance Results for Diesel
Exhaust,'' Tri-Mer Corporation, April 14, 2005, Docket ID EPA-HQ-
OAR-2007-0121-0026.
---------------------------------------------------------------------------

It may be possible to achieve NO_X reductions through the
use of seawater scrubbers. In a typical scrubber, the water-soluble
fraction of NO_X (NO₂) can combine with the water
to form nitrates which are scrubbed out of the exhaust. However,
because NO₂ makes up only a small fraction of total
NO_X, this results in less than a 10 percent reduction in
NO_X emissions exhausted to atmosphere.\108\ Seawater
electrolysis systems have been developed which increase the adsorption
rate of NO_X in the water by oxidizing NO to NO₂,
which is water-soluble.\109\ One study used electrolysis in an
experimental scrubbing system to remove 90 percent of the NO and nearly
all of the NO₂ in the feed gas.\110\ We request comment on
the feasibility of achieving significant NO_X reductions from
Category 3 marine engines through the use of seawater scrubbers. We
also request comment on the impact of this technology on nitrate
loading and eutrophication of surrounding waters.
---------------------------------------------------------------------------

\108\ Skawinski, C., ``Seawater Scrubbing Advantage,''
Presentation by Marine Exhaust Solutions at the Conference for
Emission Abatement Technology on Ships held by the Swedish Maritime
Administration, May 24-26, 2005, Docket ID EPA-HQ-OAR-2007-0121-0021.
\109\ An, S., Nishida, O., ``Marine Air Pollution Control System
Development Applying Seawater and Electrolyte,'' SAE Paper 2002-01-
2295, July 2002, Docket ID EPA-HQ-OAR-2007-0121-0024.
\110\ Houng-Soo, K., ``Development of Diesel Engine Emission
Control System on NO_X and SO_X by Seawater
Electrolysis,'' CIMAC paper number 25 presented at International
Council on Combustion Engines Congress, 2004, Docket ID EPA-HQ-OAR-
2007-0121-0001.
---------------------------------------------------------------------------

Water-soluble components of the exhaust gas such as SO₂,
SO₃, and NO₂ form sulfates and nitrates that are
dumped overboard in the discharge water. Scrubber wash water also
includes suspended solids, heavy metals, hydrocarbons and PAHs. Before
the scrubber water is discharged, it may be processed to remove solid
particles through several approaches. Heavier particles may be trapped
in a settling or sludge tank for disposal. The removal process may
include cyclone technology similar to that used to separate water from
residual fuel prior to delivery to the engine. However, depending on

[[Page 69543]]

particle size distribution and particle density, settling tanks and
hydrodynamic separation may not effectively remove all suspended
solids. Other approaches include filtration and flocculation
techniques. Flocculation, which is used in many waste water treatment
plants, refers to adding a chemical agent to the water that will cause
the fine particles to aggregate so that they may be filtered out.
Sludge separated from the scrubber water would be stored on board until
it is disposed of at proper facilities. We request comment on
appropriate waste discharge limits for scrubber water and how these
limits should be defined. We are concerned that if limits are based on
the concentration of the pollutants in the water, then the standards
could be met simply by diluting the effluent before it is discharged.
Although diluting the discharge water may have some local benefits near
the vessel, it would not change the total pollutant load on a given
body of water. We request comment on basing limits for waste water
pollutants on engine load, similar to exhaust emission standards.

VII. Certification and Compliance

In general, we expect to retain the certification and compliance
provisions finalized with the Tier 1 standards. These include testing,
durability, labeling, maintenance, prohibited acts, etc. However, we
believe additional testing and compliance provisions will be necessary
for new standards requiring more advanced technology and more
challenging calibrations. These changes, as well as other modifications
to our certification and compliance provisions, are discussed below.

A. Testing

1. PM Sampling
In the past, there has been some concern regarding the use of older
PM measurement procedures with high sulfur residual fuels. The primary
issue of concern was variability of the PM measurement, which was
strongly influenced by the amount of water bound to sulfur. However, we
believe improvements in PM measurement procedures, such as those
specified in 40 CFR 1065, have addressed these issues of measurement
variability. The U.S. government recently submitted proposed procedures
for PM measurement to IMO.\111\ We request comment on these procedures
for accurately measuring PM emissions from Category 3 marine engines
operating on residual fuel.
---------------------------------------------------------------------------

\111\ Measurement Method for Particulate Matter Emitted from
Marine Engines, submitted by the United States. BLG-WGAP 2, October
2007. Intersessional Meeting of the BLG Working Group on Air
Pollution, 2nd Session.
---------------------------------------------------------------------------

2. Low Power Operation
We are concerned about emission control performance when the engine
is operated at low power. Category 3 engines operate at relatively low
power levels when they are operating in port areas. Ship pilots
generally operate engines at reduced power for several miles to
approach a port, with even lower power levels very close to shore. The
ISO E3 and E2 test cycles are used for emission testing of propulsion
marine engines. These test cycles are heavily weighted towards high
power. Therefore, it is very possible that manufacturers could meet the
cycle-weighted average emission standards without significantly
reducing emissions at low-power modes. Because low power operation is
more prevalent for propulsion engines when they operate close to
commercial ports, it is important that the emission control strategy be
effective at low power operation to maximize on-shore emission
benefits. This issue would generally not apply to vessels that rely on
multiple engines providing electric-drive propulsion, because these
engines can be shut down as needed to maintain the desired engine
loading and therefore may not operate at low power settings. We request
comment on the need for addressing emissions at low power operation and
whether and how the test procedure should be changed to accommodate
this operation. See section VI.B for additional discussion of low power
NO_X emissions for engines equipped with exhaust aftertreatment.
3. Test Fuel
Appropriate test procedures need to represent in-use operating
conditions as much as possible, including specification of test fuels
consistent with the fuels that compliant engines will use over their
lifetimes. For the Tier 1 standards, we allow engine testing using
distillate fuel, even though vessels with Category 3 marine engines
primarily use the significantly less expensive residual fuel. This
provision is consistent with the specifications of the NO_X
Technical Code. Also, most manufacturers have test facilities designed
to test engines using distillate fuel. Distillate fuel is easier to
test with because it does not need to be heated to remain a liquid and
manufacturers have indicated that it is difficult to obtain local
permits for testing with residual fuel. However, we believe it is
important to specify a test fuel that is consistent with the in-use
fuel with which engines will operate in service. This is especially
true for PM measurements. We request comment on the appropriate test
fuel for emission testing and if this fuel should be representative on
the fuel on which a specific engine is designed to operate.
For any NO_X measurements from engines operating on
residual fuel we recognize that there may be emission-related effects
due to fuel quality, specifically fuel-bound nitrogen. If the standards
were based on distillate fuel, we would consider a NO_X
correction factor to account for the impact of fuel quality when
testing on residual fuel. This correction would be useful because of
the high levels of nitrogen contained in residual fuel. Such a
correction factor would likely involve measuring fuel-bound nitrogen
and correcting measured values to what would occur with a nitrogen
concentration of 0.4 weight percent. This corrected value would be used
to determine whether the engine meets emission standards or not. We
request comment on the need for corrections and, if so, how the
appropriate corrections would be developed.

B. On-Off Technologies

One of the features of the emission control technologies that could
be used to achieve significant NO_X and PM reductions from C3
engines is that they are not integral to the engine and the engine can
be operated without them. Aftertreatment systems such as SCR or
emission scrubbing, or the use of lower sulfur fuel, require a positive
action on the part of the ship owner to make sure the emission control
system is in operation or that the appropriate fuel is used. These
types of technologies are often called ``on-off'' technologies.
The increased operating costs of such controls associated with urea
or other catalysts or with distillate usage suggest that it may be
reasonable to allow these systems to be turned off while a ship is
operated on the open ocean, far away from sensitive areas that are
affected by ship emissions. In other words, EPA could elect to set
geographically-based NO_X and PM standards, with one limit
that would apply when ships are operated within a specified distance
from U.S. coasts, and another that would apply when ships are operated
outside those limits.
If EPA were to adopt such an approach, we would need to determine
the areas in which ships would have to comply with the standards. We
are currently exploring this issue through the air quality modeling for
our proposed standards. There are other

[[Page 69544]]

issues associated with such an approach, including: The technological
feasibility of by-pass systems and their impacts on the emission
control systems when they are not in use; the level of the standard
that would apply when the system is turned off; and how compliance
would be demonstrated. There may also be additional certification
requirements for ships equipped with such systems.
We request comment on all aspects of this alternative, especially
with regard to how such systems could be designed to ensure no loss of
emission reductions.

C. Parameter Adjustment

Given the broad range of ignition properties for in-use residual
fuels, we expect that our in-use adjustment allowance for Category 3
engines would result in a broad range of adjustment. We are therefore
considering a requirement for operators to perform a simple field
measurement test to confirm emissions after parameter adjustments or
maintenance operations, using onboard emission measurement systems with
electronic-logging equipment. We expect this issue will be equally
important for more advanced engines that rely on water injection or
aftertreatment for emission reductions. Onboard verification systems
could add significant assurance that engines have properly operating
emission controls.
We envision a simpler measurement system than the type specified in
Chapter 6 of the NO_X Technical Code. As we described in the
2003 final rule, we believe that onboard emission equipment that is
relatively inexpensive and easy to use could verify that an engine is
properly adjusted and is operating within the engine manufacturer's
specifications. Note that Annex VI includes specifications allowing
operators to choose to verify emissions through onboard testing, which
suggests that Annex VI also envisioned that onboard measurement systems
could be of value to operators. We request comment on requiring onboard
verification systems on ships with Category 3 marine engines and on a
description of such a system.

D. Certification of Existing Engines

While we normally require certification only for newly built
engines, we are considering emission standards that would apply to
remanufactured engines in the existing fleet. This leads to questions
about how one would certify the modified engines. We are considering
adoption of one or more of the following simplified certification
procedures for in-use engines:
• Basing certification for any engine on a pre-existing
certificate if the engine is modified to be the same as a later engine
that is already certified to the Tier 1 NO_X standard.
• Testing in-use engines using portable emission measurement
equipment, with appropriate consideration for any necessary deviations
in the engine test cycle.
• Broadening the engine family concept for in-use engines to
reduce the amount of testing necessary to certify a range of engines.
This would require the same or similar hardware and calibration
requirements to ensure that a single test engine can properly represent
all the engines in the broader engine family.
• Developing alternatives to the NO_X Technical
File \112\ to simplify the certification burdens for existing vessels
while ensuring that the modified engines and emission components may be
appropriately surveyed and inspected.
---------------------------------------------------------------------------

\112\ The NO_X Technical File, required pursuant to
Section 2.4 of the Technical Code on Control of Emissions of
Nitrogen Oxides from Marine Diesel Engines, is a record containing
details of engine parameters, including components and settings,
which may influence the NO_X emissions of the engine. The
NO_X Technical File also contains a description of onboard
NO_X verification procedures required for engine surveys.
The NO_X Technical File is developed by the engine manufacturer
and must be approved by the authority issuing the engine certificate.
---------------------------------------------------------------------------

We request comment on the best approach for ensuring compliance
from existing engines. We also request comment on the simplified
certification procedures listed above.

E. Other Compliance Issues

We intend to apply the same exemptions to any new tier of Category
3 marine diesel engine standards as currently apply under our Tier 1
program. These exemptions, including the national security exemption,
are set out in 40 CFR part 94, subpart J. We will also consider whether
to include engines on foreign vessels in the program and whether we should
also adopt standards for non-diesel engines such as gas turbine engines.
1. Engines on Foreign-Flagged Vessels
Our current federal marine diesel engine standards do not apply to
Category 1, 2, and 3 marine diesel engines installed on foreign-flagged
vessels. In our 2003 Final Rule we acknowledged the contribution of
engines on foreign-flagged vessels to U.S. air pollution but did not
apply federal standards to foreign vessels (see 68 FR 9759, February
28, 2003). This section summarizes the discussion from that 2003 Final
Rule. We will continue to evaluate this issue as we develop the
proposal for this rule.
Section 213 of the Clean Air Act (42 U.S.C. 7547), authorizes
regulation of ``new nonroad engine'' and ``new nonroad vehicle.''
However, Title II of the Clean Air Act does not define either ``new
nonroad engine'' or ``new nonroad vehicle.'' Section 216 defines a
``new motor vehicle engine'' to include an engine that has been
``imported.'' EPA modeled the current regulatory definitions of ``new
nonroad engine'' and ``new marine engine'' at 40 CFR 89.2 and 40 CFR
94.2, respectively, after the statutory definitions of ``new motor
vehicle engine'' and ``new motor vehicle.'' This was a reasonable
exercise of the discretion provided to EPA by the Clean Air Act to
interpret ``new nonroad engine'' or ``new nonroad vehicle.'' See Engine
Manufacturers Assoc. v. EPA, 88 F.3d 1075, 1087 (DC Cir. 1996).
The 1999 marine diesel engine rule did not apply to marine engines
on foreign vessels. 40 CFR 94.1(b)(3). At that time, we concluded that
engines installed on vessels flagged or registered in another country,
that come into the United States temporarily, will not be subject to
the emission standards. At that time, we believed that they were not
considered imported under the U.S. customs law. As a result, we did not
apply the standards adopted in that rule to those vessels (64 FR 73300,
Dec. 29, 1999).
The May 29, 2002 proposed rule for Category 3 marine diesel engines
solicited comment on whether to exercise our discretion and modify the
definition of a ``new marine engine'' to find that engine emission
standards apply to foreign vessels that enter U.S. ports. However, in
the February 28, 2003 final rule we determined that we did not need to
determine whether we have the discretion to interpret ``new'' nonroad
engine or vessel in such a manner.
Foreign vessels were expected to comply with the MARPOL standards
whether or not they were also subject to the equivalent Clean Air Act
standards being adopted in that final rule. Consequently, we concluded
that no significant emission reductions would be achieved by treating
foreign vessels as ``new'' for purposes of the Tier 1 standards and
there would be no significant loss in emission reductions by not
including them. Therefore, we did not include foreign engines and
vessels in our 2003 rulemaking and we did not revise the definition of
``new marine engine'' at that time.

[[Page 69545]]

In this rule we will evaluate under what circumstances we may and
should define new nonroad engine and vessel to include foreign engines
and vessels. As part of that evaluation, we will also assess the
progress made by the international community toward the adoption of new
more stringent international consensus standards that reflect advanced
emission-control technologies.
2. Non-Diesel Engines
Gas turbine engines are internal combustion engines that can
operate using diesel fuel, residual fuel, or natural gas, but do not
operate on a compression-ignition or other reciprocating engine cycle.
Power is extracted from the combustion gas using a rotating turbine
rather than reciprocating pistons. While gas turbine engines are used
primarily in naval ships, a small number are being used in commercial
ships. In addition, we have received indication that their use is
growing in some applications such as cruise ships and liquid natural
gas carriers. As we develop the proposal for this rule we will consider
whether it is appropriate to regulate emissions from gas turbine
engines and, if so, whether special provisions would be needed for
testing and certifying turbine engines. For example, since turbine
engines have no cylinders, we may need to address how to apply any
regulatory provisions that depend on a specified value for per-cylinder
displacement. We would welcome any emissions information that is
available for turbine engines.
Marine engines have been developed that can operate either on
natural gas or a dual-fuel.\113\ In a dual-fuel application, a mixture
of marine diesel oil and natural gas is used for the main engine that
provides a means to comply with the low-sulfur fuel requirement.
Natural gas engines are especially attractive to vessels that carry a
cargo of liquefied petroleum gas due to the readily available fuel
supply. Natural gas powered engines are similar to Category 3 marine
engines operating on traditional diesel fuels, and we would consider
including these engines in this rulemaking.
---------------------------------------------------------------------------

\113\ Nylund, I., ``Status and Potentials of the Gas Engines,''
Wartsila, CIMAC paper number 163, presented at International Council
on Combustion Engines Congress, 2004, Docket ID EPA-HQ-OAR-2007-0121-0006.
---------------------------------------------------------------------------

We request comment on fuels and engine types that we should
consider in the scope of this rulemaking. We also request comments on
test procedure or other compliance issues that would need to be
considered for these fuels and engines.

VIII. Potential Regulatory Impacts

A. Emission Inventory

The inventory contribution of Category 3 engines consists of two
parts: emissions that occur in port areas and emissions that occur at
various distances from the coast while vessels are underway. Although
the issue of emissions transport is common to all of our air pollution
control programs, these underway emissions suggest that Category 3
emissions are different from emissions from other mobile sources and
result in at least two implications for the analysis we will perform
for our proposal. First, the definition of the inventory modeling
domain becomes important. In the inventory analysis described below we
use a distance of 200 nautical miles from shore (see Figure VIII-1
below and associated text). This distance is reasonable based on both
particle dynamics\114\ and results from air quality modeling for other
programs which has shown that PM and NO_X emissions can be
transported significant distances.\115\ Second, it will be important to
analyze the air quality impacts of these emissions at various distances
to determine how offshore emissions affect air quality both along the
coasts and inland. We will use the CMAQ model, modified to accommodate
at-sea emissions, to track the impacts of underway emissions and
estimate the air quality benefits of the proposal.
---------------------------------------------------------------------------

\114\ U.S. EPA. Air Quality Criteria for Particulate Matter
(October 2004). U.S. Environmental Protection Agency, Washington,
DC, EPA 600/P-99/002aF-bF, 2004.
\115\ U.S. EPA Technical Support Document for the Final Clean
Air Interstate Rule Air Quality Modeling (March 2005) U.S.
Environmental Protection Agency, Washington, DC.
---------------------------------------------------------------------------

This section contains our updated inventory estimates for Category
3 marine engines in the 200 nautical mile domain and a brief discussion
of our inventory estimation methodology.
1. Estimated Inventory Contribution
Category 3 marine engines contribute to the formation of ground
level ozone and concentrations of fine particles in the ambient
atmosphere. Based on our current emission inventory analysis of U.S.
and foreign-flag vessels, we estimate that these engines contributed
nearly 6 percent of mobile source NO_X, over 10 percent of
mobile source PM_2.5, and about 40 percent of mobile source
SO₂ in 2001. We estimate that their contribution will
increase to about 34 percent of mobile source NO_X, 45
percent of mobile source PM_2.5, and 94 percent of mobile
source SO₂ by 2030 without further controls on these
engines. Our current estimates for NO_X, PM_2.5,
SO₂ inventories are set out in Tables VIII-1 through VIII-3.
The inventory projections for 2020 and 2030 include the impact of
existing emission mobile source and stationary source control programs
previously adopted by EPA (excluding the recently adopted MSAT
regulations, signed on February 9, 2007 which will have an impact on
future highway non-diesel PM_2.5 levels).

Table VIII-1.--50-State Annual NOX Baseline Emission Levels for Mobile and Other Source Categories
--------------------------------------------------------------------------------------------------------------------------------------------------------
2001 \a\ 2020 2030
-----------------------------------------------------------------------------------------------------------
Category Percent Percent Percent
Short tons of mobile Percent Short tons of mobile Percent Short tons of mobile Percent
source of total source of total source of total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Commercial Marine (C3) \b\.................. 745,224 5.7 3.3 1,368,420 22.8 11.3 2,023,974 33.7 16.7
Locomotive.................................. 1,118,786 8.6 5.0 860,474 14.3 7.1 854,226 14.1 7.0
Recreational Marine Diesel.................. 40,437 0.3 0.2 45,477 0.8 0.4 48,102 0.8 0.4
Commercial Marine (C1 & C2)................. 834,025 6.4 3.7 676,154 11.3 5.6 680,025 11.3 5.6
Land-Based Nonroad Diesel................... 1,548,236 11.9 6.9 678,377 11.3 5.6 434,466 7.2 3.6
Small Nonroad SI............................ 114,319 0.9 0.5 114,881 1.9 0.9 133,197 2.2 1.1
Recreational Marine SI...................... 44,732 0.3 0.2 86,908 1.4 0.7 96,143 1.6 0.8
SI Recreational Vehicles.................... 5,488 0.0 0.0 17,496 0.3 0.1 20,136 0.3 0.2
Large Nonroad SI (25hp)..................... 321,098 2.5 1.4 46,319 0.8 0.4 46,253 0.8 0.4
Aircraft.................................... 83,764 0.6 0.4 105,133 1.7 0.9 118,740 2.0 1.0
Total Off Highway........................... 4,856,109 37.5 21.8 3,999,640 66.6 33.0 4,455,262 74.2 36.8
Highway Diesel.............................. 3,750,886 28.9 16.8 646,961 10.8 5.3 260,915 4.3 2.2
Highway non-diesel.......................... 4,354,430 33.6 19.5 1,361,276 22.7 11.2 1,289,780 21.5 10.6
Total Highway............................... 8,105,316 62.5 36.3 2,008,237 33.4 16.6 1,550,695 25.8 12.8

[[Page 69546]]

Total Mobile Sources........................ 12,961,425 100 58.1 6,007,877 100 49.6 6,005,957 100 49.6
Stationary Point & Area Sources............. 9,355,659 ......... 41.9 6,111,866 ......... 50.4 6,111,866 ......... 50.4
-----------------------------------------------------------------------------------------------------------
Total Man-Made Sources.................. 22,317,084 ......... 100 12,119,743 ......... 100 12,117,823 ......... 100
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The locomotive, commercial marine (C1 & C2), and recreational marine diesel estimates are for calendar year 2002.
\b\ This category includes emissions from Category 3 (C3) propulsion engines and C2/3 auxiliary engines used on ocean-going vessels.

Table VIII-2.--50-State Annual PM2.5 Baseline Emission Levels for Mobile and Other Source Categories
--------------------------------------------------------------------------------------------------------------------------------------------------------
2001 \a\ 2020 2030
-----------------------------------------------------------------------------------------------------------
Category Percent Percent Percent
Short tons of mobile Percent Short tons of mobile Percent Short tons of mobile Percent
source of total source of total source of total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Commercial Marine (C3) \b\.................. 54,667 10.9 2.2 110,993 33.6 5.2 166,161 45.4 7.6
Locomotive.................................. 29,660 5.9 1.2 26,301 8.0 1.2 25,109 6.8 1.1
Recreational Marine Diesel.................. 1,096 0.2 0.0 1,006 0.3 0.0 1,140 0.3 0.1
Commercial Marine (C1 & C2)................. 28,730 5.7 1.2 22,236 6.7 1.0 23,760 6.5 1.1
Land-Based Nonroad Diesel................... 164,180 32.8 6.7 46,075 13.9 2.1 17,934 4.9 0.8
Small Nonroad SI............................ 25,466 5.1 1.0 32,904 10.0 1.5 37,878 10.3 1.7
Recreational Marine SI...................... 16,837 3.4 0.7 6,367 1.9 0.3 6,163 1.7 0.3
SI Recreational Vehicles.................... 12,301 2.5 0.5 11,773 3.6 0.5 9,953 2.7 0.5
Large Nonroad SI (>25hp).................... 1,610 0.3 0.1 2,421 0.7 0.1 2,844 0.8 0.1
Aircraft.................................... 5,664 1.1 0.2 7,044 2.1 0.3 8,569 2.3 0.4
Total Off Highway........................... 340,211 68.0 13.8 267,120 80.9 12.4 299,511 81.8 13.7
Highway Diesel.............................. 109,952 22.0 4.5 15,800 4.8 0.7 10,072 2.7 0.5
Highway non-diesel.......................... 50,277 10.0 2.0 47,354 14.3 2.2 56,734 15.5 2.6
Total Highway............................... 160,229 32.0 6.5 63,154 19.1 2.9 66,806 18.2 3.1
Total Mobile Sources........................ 500,440 100 20.3 330,274 100 15.4 366,317 100 16.8
Stationary Point & Area Sources............. 1,963,264 ......... 79.7 1,817,722 ......... 84.6 1,817,722 ......... 83.2
-----------------------------------------------------------------------------------------------------------
Total Man-Made Sources.................. 2,463,704 ......... 100 2,147,996 ......... 100 2,184,039 ......... 100
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The locomotive, commercial marine (C1 & C2), and recreational marine diesel estimates are for calendar year 2002.
\b\ This category includes emissions from Category 3 (C3) propulsion engines and C2/3 auxiliary engines used on ocean-going vessels.

Table VIII-3.--50-State Annual SO2 Baseline Emission Levels for Mobile and Other Source Categories
--------------------------------------------------------------------------------------------------------------------------------------------------------
2001 \a\ 2020 2030
-----------------------------------------------------------------------------------------------------------
Category Percent Percent Percent
Short tons of mobile Percent Short tons of mobile Percent Short tons of mobile Percent
source of total source of total source of total
--------------------------------------------------------------------------------------------------------------------------------------------------------
Commercial Marine (C3) \b\.................. 457,948 42.4 2.8 932,820 93.2 10.1 1,398,598 94.5 14.4
Locomotive.................................. 76,727 7.1 0.5 400 0.0 0.0 468 0.0 0.0
Recreational Marine Diesel.................. 5,145 0.5 0.0 162 0.0 0.0 192 0.0 0.0
Commercial Marine (C1 & C2)................. 80,353 7.4 0.5 3,104 0.3 0.0 3,586 0.3 0.0
Land-Based Nonroad Diesel................... 167,615 15.5 1.0 999 0.1 0.0 1,078 0.1 0.0
Small Nonroad SI............................ 6,710 0.6 0.0 8,797 0.9 0.1 10,196 0.7 0.1
Recreational Marine SI...................... 2,739 0.3 0.0 2,963 0.3 0.0 3,142 0.2 0.0
SI Recreational Vehicles.................... 1,241 0.1 0.0 2,643 0.3 0.0 2,784 0.2 0.0
Large Nonroad SI (25hp)..................... 925 0.1 0.0 905 0.1 0.0 1,020 0.1 0.0
Aircraft.................................... 7,890 0.7 0.0 9,907 1.0 0.1 11,137 0.8 0.1
Total Off Highway........................... 807,293 74.7 5.0 962,700 96.1 10.4 1,432,202 96.8 14.8
Highway Diesel.............................. 103,632 9.6 0.6 3,443 0.3 0.0 4,453 0.3 0.0
Highway non-diesel.......................... 169,125 15.7 1.0 35,195 3.5 0.4 42,709 2.9 0.4
Total Highway............................... 272,757 25.3 1.7 38,638 3.9 0.4 47,162 3.2 0.5
Total Mobile Sources........................ 1,080,050 100 6.7 1,001,338 100 10.9 1,479,364 100 15.3
Stationary Point & Area Sources............. 15,057,420 ......... 93.3 8,215,016 ......... 89.1 8,215,016 ......... 84.7
-----------------------------------------------------------------------------------------------------------
Total Man-Made Sources.................. 16,137,470 ......... 100 9,216,354 ......... 100 9,694,380 ......... 100
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The locomotive, commercial marine (C1 & C2), and recreational marine diesel estimates are for calendar year 2002.
\b\ This category includes emissions from Category 3 (C3) propulsion engines and C2/3 auxiliary engines used on ocean-going vessels.

[[Page 69547]]

The United States is actively engaged in international trade and is
frequently visited by ocean-going marine vessels. As shown in Figure
II-1, the ports which accommodate these vessels are located along the
entire coastline of the United States. Commercial marine vessels,
powered by Category 3 marine engines, contribute significantly to the
emissions inventory for many U.S. ports. This is illustrated in Table
VIII-4 which presents the mobile source inventory contributions of
these vessels for several ports. The ports in this table were selected
to present a sampling over a wide geographic area along the U.S.
coasts. In 2005, these twenty ports received approximately 60 percent
of the vessel calls to the U.S. from ships of 10,000 DWT or greater.\116\
---------------------------------------------------------------------------

\116\ ``Vessel Calls at U.S. & World Ports; 2005,'' U.S.
Maritime Administration, Office of Statistical and Economic
Analysis, April 2006, Docket ID EPA-HQ-OAR-2007-0121-0040.

Table VIII-4.--Contribution of Commercial Marine Vessels a to Mobile
Source Inventories for Selected Ports in 2002
------------------------------------------------------------------------
PM2.5
Port area NOX percent percent SOX percent
------------------------------------------------------------------------
Valdez, AK....................... 4 10 43
Seattle, WA...................... 10 20 56
Tacoma, WA....................... 20 38 74
San Francisco, CA................ 1 1 31
Oakland, CA...................... 8 14 80
LA/Long Beach, CA................ 5 10 71
Beaumont, TX..................... 6 20 55
Galveston, TX.................... 5 12 47
Houston, TX...................... 3 10 41
New Orleans, LA.................. 14 24 59
South Louisiana, LA.............. 12 24 58
Miami, FL........................ 13 25 66
Port Everglades, FL.............. 9 20 56
Jacksonville, FL................. 5 11 52
Savannah, GA..................... 24 39 80
Charleston, SC................... 22 33 87
Wilmington, NC................... 7 16 73
Baltimore, MD.................... 12 27 69
New York/New Jersey.............. 4 9 39
Boston, MA....................... 4 5 30
------------------------------------------------------------------------
\a\ This category includes emissions from Category 3 (C3) propulsion
engines and C2/3 auxiliary engines used on ocean-going vessels.

2. Inventory Calculation Methodology
The exhaust emission inventories presented above for commercial
marine vessels, with Category 3 marine engines, include emissions from
vessels in-port and from vessels engaged in interport transit. This
section gives a general overview of the methodology used to estimate
the emission contribution of these vessels. A more detailed description
of this inventory analysis is available in the public docket.\117\
---------------------------------------------------------------------------

\117\ ``Development of Inventories for Commercial Marine Vessels
with Category 3 Engines,'' U.S. EPA, October 2007.
---------------------------------------------------------------------------

For the purposes of this analysis, in-port operation includes
cruising, reduced speed zone, maneuvering, and hotelling. The in-port
analysis includes operation out to a 25 nautical mile radius from the
entrance to the port. Interport operation includes ship traffic, within
the U.S. Exclusive Economic Zone (EEZ), not included as part of the
port emissions analysis. In general, the EEZ extends to 200 nautical
miles from the U.S. coast. Exceptions include geographic regions near
Canada, Mexico and the Bahamas where the EEZ extends less than 200
nautical miles from the U.S. coast.
The port inventories are based on detailed emission estimates for
eleven specific ports. The port inventories were estimated using
activity data for that port (number of port calls, vessel types and
typical times in different operating modes) and an emission factor for
each mode. Emission estimates for all other commercial ports were
developed by matching each of the other commercial ports to one of the
eleven specific ports. Matching was based on characteristics of port
activity, such as predominant vessel types, harbor craft and region of
the country. The detailed port emissions were then scaled for the other
commercial ports based on relative port activity.\118\ An exception to
this is that detailed port inventories for fourteen California ports
were provided by the California Air Resources Board (ARB).
---------------------------------------------------------------------------

\118\ Browning, L., Hartley, S., Lindhjem, C., Hoats, A.,
``Commercial Marine Port Inventory Development; Baseline
Inventories,'' prepared by ICF International and Environ for the
U.S. Environmental Protection Agency, September 2006, Docket ID EPA-
HQ-OAR-2007-0121-0037.
---------------------------------------------------------------------------

To calculate the mobile fractions in Table VIII-4, we compared
commercial marine port inventory estimates described above to county-
level mobile source emission estimates developed in support of the
recent rulemaking for national PM ambient air quality standards.\119\
Both propulsion engines and auxiliary engines are included in these
estimates. The county-level inventories were adjusted to include the
updated emissions estimates for commercial marine vessels.
---------------------------------------------------------------------------

\119\ Regulatory Impact Analysis for the Review of the
Particulate Matter National Ambient Air Quality Standards, EPA
Docket: EPA-HQ-OAR-2006-0834-0048.3.
---------------------------------------------------------------------------

Recently, the California Air Resources Board (ARB) sponsored the
development of new national inventory estimates for Category 3 marine
engines.\120\ The new approach captures actual interport activity, by
using information on ship movements, ship attributes, and the distances
of routes. We believe that this methodology is an improvement over past
evaluations of interport shipping emissions which were based on
estimates of ton-miles of

[[Page 69548]]

cargo moved. The new methodology captures ship traffic more completely
which results in much higher estimates of total emissions from commercial
marine vessels engaged in interport traffic within the U.S. EEZ.
---------------------------------------------------------------------------

\120\ Corbett, J., PhD, Wang, C., PhD, Firestone, J., PhD.,
``Estimation, Validation, and Forecasts of Regional Commercial
Marine Vessel Inventories, Tasks 1 and 2: Baseline Inventory and
Ports Comparison; Final Report,'' University of Delaware, May 3,
2006, Available electronically at http://www.arb.ca.gov/research/seca/
jctask12.pdf, Docket ID EPA-HQ-OAR-2007-0121-0038.

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

Our emission inventory estimates for interport traffic are based on
the ARB-sponsored study with four primary
modifications.121 122 First, we use only the interport
traffic estimates from the study and rely on our own, more detailed,
analysis of in-port emissions. Second, we modified the geographic
boundaries of the inventory to align with the U.S. EEZ. Third, we use
adjusted emission factors for PM emissions to better reflect the sum of
available PM emissions data from engines on marine vessels.
---------------------------------------------------------------------------

\121\ ``Recalculation of Baseline and 2005 Emissions and Fuel
Consumption,'' memorandum from Lou Browning, ICF and Chris Lindhjem
and Lyndsey Parker, Environ, to Penny Carey, Mike Samulski, and Russ
Smith, U.S. EPA, July 19, 2007.
\122\``U.S. and Regional Totals of Marine Vessel Emissions and
Fuel Consumption under WA 0-2 Tasks 6 and 7,'' draft memorandum from
Abby Hoats and Chris Lindhjem, Environ, to Lou Browning, ICF
International, April 23, 2007.
---------------------------------------------------------------------------

The detailed inventory studies described above were performed for
2002. To calculate emission inventories for future years, we applied
separate growth rates for the West Coast, Gulf Coast, East Coast, and
Great Lakes. These emission inventory growth estimates were determined
based on economic growth projections of trade between the United States
and other regions of the world.\123\ In contrast, the ARB-sponsored
study looks at a range of growth rates based on extrapolations of
historical growth in installed power.\124\ The approach used by EPA is
more conservative in that it uses lower growth rate projections.
---------------------------------------------------------------------------

\123\ ``RTI Estimates of Growth in Bunker Fuel Consumption,''
memorandum from Michael Gallaher and Martin Ross, RTI International,
to Barry Garelick and Russ Smith, U.S. EPA, April 24, 2006, Docket
ID EPA-HQ-OAR-2007-0121-0039.
\124\ Corbett, J., PhD, Wang, C., PhD, ``Estimation, Validation,
and Forecasts of Regional Commercial Marine Vessel Inventories,
Tasks 3 and 4: Forecast Inventories for 2010 and 2020; Final
Report,'' University of Delaware, May 3, 2006, Docket ID EPA-HQ-OAR-
2007-0121-0012.
---------------------------------------------------------------------------

The inventory estimates include emissions from both U.S. flagged
vessels and foreign flagged vessels. The majority of the ship operation
near the U.S. coast is from ships that are not registered in the United
States. According to the U.S. Maritime Administration, in 2005,
approximately 87 percent of the calls by ocean-going vessels (10,000
dead weight tons or greater) at U.S. ports were made by foreign
vessels.\125\
---------------------------------------------------------------------------

\125\ ``Vessel Calls at U.S. & World Ports; 2005,'' U.S.
Maritime Administration, Office of Statistical and Economic
Analysis, April 2006, Docket ID EPA-HQ-OAR-2007-0121-0040.
---------------------------------------------------------------------------

This inventory analysis includes emissions from Category 3
propulsion engines and the Category 2 and 3 auxiliary engines used on
these vessels. Based on our emissions inventory analysis, auxiliary
engines contribute approximately half of the exhaust emissions from
vessels in port. In contrast, auxiliary engines only represent about 4
percent of the exhaust emissions from ships engaged in interport traffic.
The exhaust emission inventory for commercial marine vessels with
Category 3 marine engines includes operation that extends out to 200
nautical miles from shore. Considering all emissions from ships
operating in the U.S. EEZ, emissions in ports contribute to less than
20 percent of the total inventory. However, we recognize that emissions
closer to shore are more likely to impact human health and welfare
because of their proximity to human populations. We have initiated
efforts to perform air quality modeling to quantify these impacts. The
air quality modeling will consider transport of emissions over the
ocean, meteorological data, population densities, emissions from other
sources, and other relevant information. We request comment on the
methodology used to develop exhaust inventory estimates for ships with
Category 3 engines operating near the U.S. coast.
As discussed above, the national inventories presented here are for
the Exclusive Economic Zone around the 50 states. Note that the ship
traffic in the EEZ includes not only direct movements to and from U.S.
ports but also movements up and down the coast. The boundaries for the
EEZ are presented in Figure VIII-1.

BILLING CODE 6560-50-P

[[Page 69549]]
[GRAPHIC] [TIFF OMITTED] TP07DE07.025

BILLING CODE 6560-50-C
Table VIII-5 presents the 2002 national exhaust emission inventory
for commercial marine vessels, with Category 3 marine engines,
subdivided into the seven regions shown in the above figure. The Alaska
and Hawaii regions contribute to roughly one-fifth of the national
emissions inventory. The inventory for the Alaska EEZ includes
emissions from ships on a great circle route, along the Aleutian
Islands, between Asia and the U.S. West Coast. Therefore, eastern
Alaska, which includes most of the state population, is presented
separately in the table below. The Hawaii EEZ includes major shipping
lanes across the Pacific that pass near the Hawaiian isles.

[[Page 69550]]

Table VIII-5.--2002 Regional U.S. Emissions From Commercial Marine Vessels a
[Tons/yr]
----------------------------------------------------------------------------------------------------------------
NOX [short PM2.5 [short SOX [short
Region tons] tons] tons]
----------------------------------------------------------------------------------------------------------------
South Pacific................................................ 116,057 8,283 62,944
North Pacific................................................ 28,941 2,205 16,469
East Coast................................................... 243,261 17,901 153,597
Gulf Coast................................................... 192,130 14,374 110,382
Alaska (east)................................................ 20,078 1,458 11,037
Alaska (west)................................................ 66,768 4,799 35,998
Hawaii....................................................... 60,501 4,372 32,970
Great Lakes (U.S. only)...................................... 16,708 1,207 9,098
Great Lakes (Canada only).................................... 5,621 405 3,043
--------------------------------------------------
Total (using U.S. only Great Lakes)...................... 744,444 54,599 432,496
----------------------------------------------------------------------------------------------------------------
\a\ This category includes emissions from Category 3 (C3) propulsion engines and C2/3 auxiliary engines used on
ocean-going vessels.

B. Potential Costs

The emission-control technologies we are considering for Category 3
marine engines are already in development or in commercial use in some
marine applications. The draft Regulatory Impact Analysis \126\ for the
May 29, 2002 proposed rulemaking for Category 3 marine engines (67 FR
37548) included an analysis of regulatory alternatives which included
advanced technologies. To estimate costs of this prospective emissions
control program, we expect to start with cost estimates that were
developed as part of that regulatory analysis. We will modify these
costs as needed to take into account advances in technology, changes in
cost structure, and comments received on this ANPRM. We encourage
commenters to review the information covering all aspects of engine
costs in the regulatory impact documents for the earlier Category 3
rulemaking and to provide comments on cost-related issues. In addition,
we are interested in cost information associated with potential
retrofitting concepts and in information about any unique costs
associated with equipment redesign for the marine market.
---------------------------------------------------------------------------

\126\ ``Draft Regulatory Support Document: Control of Emissions
from Compression-Ignition Marine Diesel Engines at or Above 30
Liters per Cylinder,'' U.S. Environmental Protection Agency, April, 2002.
---------------------------------------------------------------------------

We will also consider the economics of desulfurizing residual fuel,
using of distillate fuel, and blending high and low sulfur fuels. Due
to high refinery production costs, it is not likely that much new
volume of residual fuel will be desulfurized. We expect to employ a
worldwide refinery modeling analysis to estimate the cost for
desulfurizing residual fuel and to estimate the cost for the production
of additional distillate fuel in our analysis for different fuel volume
scenarios. Additionally, we will estimate scrubbing costs and potential
scrubber penetration rates for ships, as the use of scrubbers is
another method that ships may use to comply, in lieu of using low
sulfur fuel. The resulting fuel cost from our refinery analysis will be
compared to the costs from scrubbing and fuel blending to determine the
most economical method for complying with the standards for Category 3
marine engines. We request comment on the potential costs of low sulfur
marine fuels.

IX. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

Under section (3)(f)(1) Executive Order 12866 (58 FR 51735, October
4, 1993), the Agency must determine whether the regulatory action is
``significant'' and therefore subject to review by the Office of
Management and Budget (OMB) and the requirements of this Executive
Order. This Advance Notice has been sent to the Office of Management
and Budget (OMB) for review under Executive Order 12866 and any changes
made in response to OMB recommendations have been documented in the
docket for this action.

B. Paperwork Reduction Act

We will prepare information collection requirements as part of our
proposed rule and submit them for approval to the Office of Management
and Budget (OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq.

C. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) as amended by the Small
Business Regulatory Enforcement Fairness Act (SBREFA), requires
agencies to endeavor, consistent with the objectives of the rule and
applicable statutes, to fit regulatory and information requirements to
the scale of businesses, organizations, and governmental jurisdictions
subject to their regulations. SBREFA amended the RFA to strengthen its
analytical and procedural requirements and to ensure that small
entities are adequately considered during rule development. The Agency
accordingly requests comment on the potential impacts on a small entity
of the program described in this notice. These comments will help the
Agency meet its obligations under SBREFA and will suggest how EPA can
minimize the impacts of this rule for small entities that may be
adversely impacted.
Depending on the number of small entities identified prior to the
proposal and the level of any contemplated regulatory action, we may
convene a Small Business Advocacy Review Panel under section 609(b) of
the Regulatory Flexibility Act as amended by SBREFA. The purpose of the
Panel would be to collect the advice and recommendations of
representatives of small entities that could be impacted by the
eventual rule. If we determine that a panel is not warranted, we would
intend to work on a less formal basis with those small entities identified.
Although we do not believe that this rule will have a significant
economic impact on a substantial number of small entities, we are
requesting information on small entities potentially impacted by this
rulemaking. Information on company size, number of employees, annual
revenues and product lines would be especially useful. Confidential
business information may be submitted as described under SUPPLEMENTARY
INFORMATION.

D. Unfunded Mandates Reform Act

Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and tribal
governments and the private

[[Page 69551]]

sector. Under section 202 of the UMRA, EPA generally must prepare a
written statement, including a cost-benefit analysis, for proposed and
final rules with ``Federal mandates'' that may result in expenditures
to State, local, and tribal governments, in the aggregate, or to the
private sector, of $100 million or more in any one year. Before
promulgating an EPA rule for which a written statement is needed,
section 205 of the UMRA generally requires EPA to identify and consider
a reasonable number of regulatory alternatives and adopt the least
costly, most cost-effective or least burdensome alternative that
achieves the objectives of the rule. The provisions of section 205 do
not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including tribal governments, it must have developed under
section 203 of the UMRA a small government agency plan. The plan must
provide for notifying potentially affected small governments, enabling
officials of affected small governments to have meaningful and timely
input in the development of EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory requirements.
As part of the development of our Notice of Proposed Rulemaking, we
will examine the impacts of our proposal with respect to expected
expenditures by State, local, and tribal governments, in the aggregate,
or by the private sector of $100 million or more in any one year.

E. Executive Order 13132: Federalism

Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' is defined in the
Executive Order to include regulations that have ``substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.''
Under Section 6 of Executive Order 13132, EPA may not issue a
regulation that has federalism implications, that imposes substantial
direct compliance costs, and that is not required by statute, unless
the Federal government provides the funds necessary to pay the direct
compliance costs incurred by State and local governments, or EPA
consults with State and local officials early in the process of
developing the proposed regulation. EPA also may not issue a regulation
that has federalism implications and that preempts State law, unless
the Agency consults with State and local officials early in the process
of developing the proposed regulation.
Section 4 of the Executive Order contains additional requirements
for rules that preempt State or local law, even if those rules do not
have federalism implications (i.e., the rules will not have substantial
direct effects on the States, on the relationship between the national
government and the states, or on the distribution of power and
responsibilities among the various levels of government). Those
requirements include providing all affected State and local officials
notice and an opportunity for appropriate participation in the
development of the regulation. If the preemption is not based on
express or implied statutory authority, EPA also must consult, to the
extent practicable, with appropriate State and local officials
regarding the conflict between State law and Federally protected
interests within the agency's area of regulatory responsibility.
As part of the development of our Notice of Proposed Rulemaking, we
will examine the impacts of our proposal with respect to the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132.
In the spirit of Executive Order 13132, and consistent with EPA
policy to promote communications between EPA and State and local
governments, EPA specifically solicits comment on this proposed rule
from State and local officials.

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

Executive Order 13175, entitled ``Consultation and Coordination
with Indian Tribal Governments'' (59 FR 22951, November 9, 2000),
requires EPA to develop an accountable process to ensure ``meaningful
and timely input by tribal officials in the development of regulatory
policies that have tribal implications.'' ``Policies that have tribal
implications'' is defined in the Executive Order to include regulations
that have ``substantial direct effects on one or more Indian tribes, on
the relationship between the Federal government and the Indian tribes,
or on the distribution of power and responsibilities between the
Federal government and Indian tribes.''
As part of the development of our Notice of Proposed Rulemaking, we
will examine the impacts of our proposal with respect to tribal
implications.

G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks

Executive Order 13045, ``Protection of Children From Environmental
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies
to any rule that: (1) Is determined to be ``economically significant''
as defined under Executive Order 12866, and (2) concerns an
environmental health or safety risk that EPA has reason to believe may
have a disproportionate effect on children. If the regulatory action
meets both criteria, the Agency must evaluate the environmental health
or safety effects of the planned rule on children, and explain why the
planned regulation is preferable to other potentially effective and
reasonably feasible alternatives considered by the Agency.
This rule is not subject to the Executive Order because it does not
involve decisions on environmental health or safety risks that may
disproportionately affect children. The EPA believes that the emissions
reductions from the strategies proposed in this rulemaking will further
improve air quality and will further improve children's health.

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

Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355
(May 22, 2001)) requires that we determine whether or not there is a
significant impact on the supply of energy caused by our rulemaking.
These impacts include: Reductions in supply, reductions in production,
increases in energy usage, increases in the cost of energy production
and distribution, or other similarly adverse outcomes. We anticipate
that our proposal will not be a ``significant energy action'' as
defined by this order because we are not reducing the supply or
production of any fuels or electricity, nor are we increasing the use
or cost of energy by more than the stated thresholds. The

[[Page 69552]]

proposed standards will have for their aim the reduction of emissions
from certain marine engines using either exhaust gas cleaning
technology or an alternative grade of marine fuel, and will have no
effect on fuel formulation.

I. National Technology Transfer Advancement Act

Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104 113, section 12(d) (15 U.S.C.
272 note) directs EPA to use voluntary consensus standards in its
regulatory activities unless doing so would be inconsistent with
applicable law or otherwise impractical. Voluntary consensus standards
are technical standards (e.g., materials specifications, test methods,
sampling procedures, and business practices) that are developed or
adopted by voluntary consensus standards bodies. NTTAA directs EPA to
provide Congress, through OMB, explanations when the Agency decides not
to use available and applicable voluntary consensus standards.
As part of the development of our Notice of Proposed Rulemaking, we
will examine the availability and use of voluntary consensus standards.

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

Executive Order 12898 (59 FR 7629 (Feb. 16, 1994)) establishes
federal executive policy on environmental justice. Its main provision
directs federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.
EPA has determined that this proposed rule will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations because it increases the
level of environmental protection for all affected populations without
having any disproportionately high and adverse human health or
environmental effects on any population, including any minority or low-
income population. Rather the opposite as more low-income individuals
tend to live closer to marine ports, and it is these areas that will
receive the most benefits in this rule that will reduce emissions of
large marine engines.

List of Subjects

40 CFR Part 9

Reporting and recordkeeping requirements.

40 CFR Part 94

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

Dated: November 29, 2007.
Stephen L. Johnson,
Administrator.
[FR Doc. E7-23556 Filed 12-6-07; 8:45 am]
BILLING CODE 6560-50-P

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Control of Emissions From New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder

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