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 NOX can be achieved
from Category 3 marine engines.76 77 78

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 NOX reductions achievable
from water-based technologies and what the impact on other pollutants
or fuel consumption may be.
---------------------------------------------------------------------------

    \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
NOX and Smoke Emissions,'' MAN B&W, 2004, Docket ID EPA-
HQ-OAR-2007-0121-0019.
---------------------------------------------------------------------------

    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 NOX 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 NOX 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 NOX 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 NOX 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 NOX 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 NOX 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\
---------------------------------------------------------------------------

    \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

    NOX emissions can be reduced substantially using
selective catalytic reduction (SCR), which is a commonly-used
technology reducing NOX 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 NOX 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. NOX
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
NOX 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 NOX
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 NOX emissions control, the
engine can be optimized for better fuel consumption, rather than for
low NOX emissions. When an oxidation catalyst is used in
conjunction with the SCR unit, significant reductions in HC, CO, and

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.
---------------------------------------------------------------------------

    \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--SINOX[supreg] 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 NOX 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.
---------------------------------------------------------------------------

    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 NOX reduction reaction. In theory, it is possible to
achieve 100 percent NOX conversion if the exhaust
temperature is high enough and the catalyst is large enough. Low
temperature NOX 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 NOX 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 NOX. 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 NOX 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
NOX 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 NOX 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\ ``NOX 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

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 NOX
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 SOX
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 NOX emission control can be
optimized for PM control while simultaneously reducing NOX
emissions. If aftertreatment, such as SCR, is used to control
NOX, 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 SOX emissions. These SOX
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
NOX 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 SOX 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 SOX 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 SOX emissions from the engine. We
request comment on the potential PM and SOX 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 NOX 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
NOX 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 NOX emissions. These
effects are reflected in the MARPOL NOX technical code which
allows an

upward adjustment of 10 percent for NOX, under certain
circumstances, when the engine is tested on residual fuel. We request
comment on the effect of using residual fuel on NOX
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., ``NOX 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 SOX 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 SOX 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 SOX emissions, the scrubber will also control
much of the secondary PM formed in the atmosphere from SOX
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 NOX reductions through the
use of seawater scrubbers. In a typical scrubber, the water-soluble
fraction of NOX (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
NOX, this results in less than a 10 percent reduction in
NOX emissions exhausted to atmosphere.\108\ Seawater
electrolysis systems have been developed which increase the adsorption
rate of NOX 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 NOX 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 NOX and SOX 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

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
NOX 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 NOX
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 NOX 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 NOX
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 NOX 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 NOX 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

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 NOX 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 NOX 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 NOX 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 NOX 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 NOX emissions of the engine. The
NOX Technical File also contains a description of onboard
NOX verification procedures required for engine surveys.
The NOX 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.

    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 NOX 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 NOX, over 10 percent of
mobile source PM2.5, and about 40 percent of mobile source
SO2 in 2001. We estimate that their contribution will
increase to about 34 percent of mobile source NOX, 45
percent of mobile source PM2.5, and 94 percent of mobile
source SO2 by 2030 without further controls on these
engines. Our current estimates for NOX, PM2.5,
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 PM2.5 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

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.

    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

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

[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.

                  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

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'' (65 FR 67249, 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

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