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    In August 2002, we proposed permeation and diurnal emission
standards for fuel systems related to Marine SI engines (67 FR 53050,
August 14, 2002). We finalized other portions of that proposal but
chose to delay promulgation of Marine SI evaporative standards. At the
time of the earlier proposal there were still open issues regarding
emission control technologies for rotational-molded fuel tanks and for
pressurizing fuel tanks as a diurnal emission control strategy. Since
then, EPA has continued gathering information and performing tests on
new technologies that could be used to address these issues. In this
notice we are updating the proposed evaporative emission standards for
Marine SI fuel systems. The standards in this proposal incorporate this
new information.
    We are also proposing standards for controlling evaporative
emissions from fuel systems used with Small SI engines. These proposed
standards include requirements for controlling permeation, diffusion,
and running loss emissions.

B. Fuel Systems Covered by This Rule

    The proposed evaporative emission standards would apply to fuel
systems for both Small SI engines and Marine SI engines. The marine
standards apply to fuel systems related to both propulsion and
auxiliary engines. In some cases, specific standards are proposed only
for certain types of equipment, as described below. These standards
would apply only to new products, as described in Section VII.A.
    We are proposing to write the regulations related to evaporative
emission standards in 40 CFR part 1060,

which is devoted to evaporative emission controls from nonroad engines
and equipment. The exhaust standard-setting part (part 1045 for Marine
SI and part 1054 for Small SI) defines the emission standards, but
references part 1060 for certification and testing procedures, in
addition to definitions, compliance-related issues, and other special
provisions. Section VII describes further how the different parts work
together in the certification process. Also, as described in Section
XI, we are proposing to allow component manufacturers and some
equipment manufacturers to certify products under the provisions of
part 1060 with respect to recreational vehicles. We also plan to
clarify in a separate action that marine and land-based compression-
ignition engines that operate on volatile liquid fuels (such as
methanol or ethanol) are subject to evaporative requirements related to
part 1060. The draft regulations in part 1060 describe how those
provisions would apply for compression-ignition engines, but these
regulations impose no obligations until we adopt those as requirements
in a separate rulemaking.
    The following definitions are important in establishing which
components would be covered by the proposed standards: ``evaporative,''
``fuel system,'' ``fuel line,'' ``portable nonroad fuel tank,'' and
``installed marine fuel tank.'' See the full text of these definitions
in the proposed regulations at Sec.  1060.801.
    Note in particular that the proposed standards would apply to fuel
lines, including hose or tubing that contains liquid fuel. This would
include fuel supply lines but not vapor lines or vent lines not
normally exposed to liquid fuel. We consider fuel return lines for
handheld engines to be vapor lines, not fuel lines. Data in Chapter 5
of the Draft RIA suggest that permeation rates through vapor lines and
vent lines are already lower than the proposed standard; this is due to
the low vapor concentration in the vapor line. In contrast, permeation
rates for materials that are consistently exposed to saturated fuel
vapor are generally considered to be about the same as that for liquid
fuel. The standards also do not apply to primer bulbs exposed to liquid
fuel only for priming. This standard would apply to marine filler necks
that are filled or partially filled with liquid fuel after a refueling
event where the operator fills the tank as full as possible. In the
case where the fuel system is designed to prevent liquid fuel from
standing in the fill neck, the fill neck would be considered a vapor
line and not subject to the proposed fuel line permeation standard. We
request comment on the appropriateness of applying permeation standards
to filler necks, vapor lines and vent lines for Small SI engines and
Marine SI engines.
    One special note applies to fuel systems for auxiliary marine
engines. These engines must meet exhaust emission standards that apply
to land-based engines. This is appropriate because these engines,
typically used to power generators, operate more like land-based
engines than like marine propulsion engines. For evaporative emissions,
however, it is important that the fuel systems for propulsion and
auxiliary engines be subject to the same standards because these
engines typically draw fuel from a common fuel tank and share other
fuel-system components. We are therefore proposing to apply the Marine
SI evaporative emission standards and certification requirements to the
fuel systems for both auxiliary and propulsion marine engines on marine
vessels.
    Our evaporative emission standards for automotive applications are
based on a comprehensive measurement from the whole vehicle. However,
the evaporative standards in this proposal are generally based on
individual fuel-system components. For instance, we are proposing
permeation standards for fuel lines and fuel tanks rather than for the
equipment as a whole.\83\ We are taking this approach for several
reasons. First, most production of Small SI equipment and Marine SI
vessels is not vertically integrated. In other words, the fuel line
manufacturer, the engine manufacturer, the fuel tank manufacturer, and
the equipment manufacturer are often separate companies. In addition,
there are several hundred equipment manufacturers and boat builders,
many of which are small businesses. Testing the systems as a whole
would place the entire certification burden on the equipment
manufacturers and boat builders. Specifying emission standards and
testing for individual components allows for measurements that are
narrowly focused on the source of emissions and on the technology
changes for controlling emissions. This correspondingly allows for
component manufacturers to certify that their products meet applicable
standards. We believe it would be most appropriate for component
manufacturers to certify their products since they are best positioned
to apply emission control technologies and demonstrate compliance.
Equipment manufacturers and boat builders would then be able to
purchase certified fuel-system components rather than doing all their
own testing on individual components or whole systems to demonstrate
compliance with every requirement. In contrast, controlling running
loss emissions cannot be done on a component basis so we are proposing
to require engine or equipment manufacturers to certify that they meet
the running loss standard. We would otherwise expect most equipment
manufacturers to simply identify a range of certified components and
install the components as directed by the component manufacturer to
demonstrate compliance with the proposed emission standards.
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    \83\ An exception to component certification is the design
standard for contolling running loss emissions.
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    Second, a great deal of diversity exists in fuel-system designs
(hose lengths, tank sizes/shapes, number of connections, etc.). In most
cases, the specific equipment types are low-volume production runs so
sales would not be large enough to cover the expense of SHED-type
testing. Third, there are similarities in fuel lines and tanks that
allow for component data to be used broadly across products in spite of
extensive variety in the geometry and design of fuel systems. Fourth,
many equipment types, primarily boats, would not fit in standard-size
SHEDs and would require the development of very large, very expensive
test facilities if the entire vessel were tested.
    Finally, by proposing separate standards for fuel line permeation,
fuel tank permeation, diurnal emissions, and diffusion emissions, we
are able to include simplified certification requirements without
affecting the level of the standards. Specifying a comprehensive test
with a single standard for all types of evaporative emissions would
make it difficult or impossible to rely on design-based certification.
Requiring emission tests to cover the wide range of equipment models
would greatly increase the cost of compliance with little or no
increase in the effectiveness of the certification program. We believe
the proposed approach allows substantial opportunity for market forces
to appropriately divide compliance responsibilities among affected
manufacturers and accordingly results in an effective compliance
program at the lowest possible cost to society.
    The proposed emission standards generally apply to the particular
engines and their associated fuel systems. However, for ease of
reference, we may refer to evaporative standards as being related to
Small SI equipment or Marine SI vessels, meaning the relevant

evaporative standards for engines and fuel systems used in such
equipment or vessels.\84\ See Section VI.F for a more detailed
description of certification responsibilities for all the proposed
evaporative standards.
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    \84\ ``Small SI equipment'' includes all nonroad equipment
powered by Small SI engines. ``Marine SI vessels'' includes all
vessels powered by engines that run on volatile liquid fuels. In
almost all cases these engines are powered by gasoline. Note also
that volatile liquid fuels include methanol or ethanol, which could
be used in a compression-ignition engine. While we are aware of no
such equipment or vessels today, they would be covered by the
proposed regulations. In this preamble, we nevertheless refer to all
the vessels that fall within the scope of the proposed regulations
as marine SI vessels. Throughout this section, we generally refer to
Small SI equipment and Marine SI vessels as ``equipment,''
consistent with the proposed regulatory text.
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C. Proposed Evaporative Emission Standards

    We are proposing permeation standards for Small SI equipment and
Marine SI vessels, covering permeation from fuel tanks and fuel lines.
We are also proposing diurnal emission standards for Marine SI vessels.
We are proposing diffusion emission standards but not diurnal emission
standards for nonhandheld Small SI equipment. In addition, we are
proposing a running loss standard for nonhandheld Small SI equipment
(except wintertime engines), with a variety of specified options for
manufacturers to demonstrate compliance. Based on the current state of
technology, we believe the proposed standards are a logical extension
of the standards proposed for marine vessels in August 2002 and the
standards finalized for recreational vehicles in November 2002.
    All the proposed evaporative emission standards would apply to new
equipment for a useful life period in years that matches the useful
life of the corresponding engine. We propose to specify a five-year
useful life for evaporative requirements for Small SI equipment (we are
not proposing a year-based useful life requirement related to exhaust
emissions for Small SI engines). Manufacturers have expressed concern
that they will not have time to gain five years of in-use experience on
low-permeation fuel tanks by the proposed dates of the tank permeation
standards. Unlike barrier fuel line, which is well established
technology, some fuel tanks may use barrier technologies that have not
been used extensively in other applications. An example of this
technology would be barrier surface treatments that must be properly
matched to the fuel tank material. Therefore, we are proposing a
shorter useful life of two years for Marine SI and Small SI fuel tanks
through the 2013 model year to allow manufacturers to gain experience
in use (see Sec. Sec.  1045.145 and 1054.145). We do not expect this
interim provision to affect manufacturer designs or in-use compliance
efforts. We do not believe this interim provision to specify a shorter
useful life period is necessary for other fuel-system components,
either because there is adequate durability experience in other sectors
or because the control inherently does not involve a concern over in-
use deterioration.
    The rest of this section summarizes the proposed standards,
additional requirements, and implementation dates. Unless otherwise
stated, implementation dates specified below refer to the model year.
Section VI.D describes how manufacturers may use emission credits to
meet fuel tank permeation standards. Section VI.E describes the test
procedures corresponding to each standard. Section VI.F describes how
component and equipment manufacturers certify their products and how
their responsibilities overlap in some cases. Section VI.F also
describes the simplified process of design-based certification for
meeting many of the proposed standards.
(1) Fuel Line Permeation Standards and Dates
    The proposed fuel line permeation standard applies to fuel lines
intended for use in new Small SI equipment and Marine SI vessels is 15
g/m\2\/day at 23 [deg]C on a test fuel containing 10 percent ethanol
(see Sec.  1060.102 and Sec.  1060.515). The form of the standard
refers to grams of permeation over a 24-hour period divided by the
inside surface area of the fuel line. This proposed standard is
consistent with that adopted for fuel lines in recreational vehicles.
The move toward low-permeation fuel lines in recreational vehicles--and
further development work in this area since the first proposed rule for
marine evaporative emissions--demonstrates that low-permeation fuel
lines are available on the market today for Small SI equipment and
Marine SI vessels. In addition, many manufacturers are already using
low-permeation technologies in response to permeation standards in
California. We are therefore proposing that this standard apply
beginning with 2008 for nonhandheld Small SI equipment and 2009 for
Marine SI vessels. For handheld equipment, we are proposing a fuel line
permeation implementation date of 2012, except that small-volume
families as defined in Sec.  1054.801 would have until 2013. Although
low-permeation fuel line technology is available, handheld equipment is
not currently subject to fuel line permeation requirements in
California and does not typically use low-permeation fuel lines today.
In addition, much of the fuel line used on handheld equipment is not
straight-run fuel line for which low-permeation replacements are
readily available; thus, more lead time is required. We request comment
on the proposed standard and implementation dates.
    Component manufacturers would be required to certify to the
proposed emission standard for fuel lines (this may involve
certification to a family emission limit above the emission standard
for handheld engines, as described in Section VI.D), except in certain
circumstances. Equipment manufacturers may need to certify that their
fuel lines meet the proposed emission standards if they use any
sections or pieces of fuel line that are not already certified by the
fuel line manufacturer, or if they comply using emission credits, as
described in Section VI.F.
    To address the short lead time associated with the 2008
requirements for Small SI equipment, we are proposing an interim
arrangement in which engine manufacturers would include compliant fuel
lines under their existing certification (see Sec.  90.127). This would
prevent the need for other companies to submit new applications for
certification that would need to be processed immediately. This
arrangement would allow for engine manufacturers to start complying
well ahead of the time that the fuel line standards become mandatory.
The certification requirements described above for component
manufacturers would start once Small SI engines and equipment would be
subject to Phase 3 standards.
    By specifying standards for fuel-system components rather than the
entire fuel system, we must separately address appropriate requirements
for connecting pieces, such as valves, O-rings, seals, plugs, and
grommets that are exposed to liquid fuel but are not part of the fuel
line. We are proposing to require that these ancillary pieces meet the
broad specifications described in Sec.  1060.101(f), which generally
requires that fittings and connections be designed to prevent leaks. As
described in Section VI.E.1, we are also proposing to allow testing of
fuel line assemblies that include connecting pieces, primer bulbs, and
other fuel line components as a single item (see Sec.  1060.102). For
example, manufacturers may certify fuel lines for portable marine fuel
tanks as

assemblies of fuel line, primer bulbs, and self-sealing end
connections. Finally, we are proposing to require that detachable fuel
lines be self-sealing when they are removed from the fuel tank or the
engine because this would otherwise result in high evaporative
emissions (see Sec.  1060.101). To the extent that equipment
manufacturers and boat builders certify their products, they would need
to describe how they meet the equipment-based requirements proposed in
Sec.  1060.101(e) and (f) in their application for certification. If
boat builders rely on certified components instead of certifying, they
would need to keep records describing how they meet the equipment-based
requirements proposed in Sec.  1060.101(e) and (f).
    Handheld equipment manufacturers have raised concerns that fuel
lines constructed of available low-permeation materials may not perform
well in some handheld applications under extreme cold weather
conditions such as below -30 [deg]C. These products often use injected
molded fuel lines with complex shapes and designs needed to address the
unique equipment packaging issues and the high vibration and random
movement of the fuel lines within the overall equipment when in use.
Industry has expressed concern and the data in Chapter 5 of the Draft
RIA suggest that durability issues may occur from using certain low-
permeation materials in these applications when the weather is
extremely cold and that these could lead to unexpected fuel line leaks.
Handheld equipment types that could be considered as cold-weather
products include cut-off saws, clearing saws, brush cutters over 40cc,
commercial earth and wood drills, ice augers, and chainsaws.
    The extreme cold temperatures needed to induce the potential fuel
line failures are very rare but do occur each year in Alaska and the
continental United States. EPA considered a number of different options
aimed at developing special provisions for equipment most likely to be
used in these extreme cold weather situations without providing relief
to all of the equipment sold in the broad categories identified by
industry as cold weather products. These included focusing the
provisions on products used by professionals (longer useful life
equipment or Class V equipment only), geographic-based retrofit kits,
product segregation, and special labeling. While each of the options
has some merit, none could provide the full assurance that handheld
equipment using low-permeation fuel lines not compatible with extreme
cold weather would not be used in such weather conditions. While very
low temperature materials are available that can achieve the fuel line
permeation standards discussed above, these materials come at a
substantially higher cost than that for fuel lines used in non cold
weather products and none have been evaluated in fuel lines on the
handheld equipment at issue.
    If we consider a less stringent standard, we believe there are
lower cost materials available that could be used to achieve permeation
reductions in equipment designed for cold weather applications without
creating potential safety concerns related to fuel leaks. As discussed
in the Draft RIA, rubbers with high acrylonitrile (ACN) content are
used in some handheld applications. These materials have about half the
permeation of lower ACN-content rubbers also used in handheld
applications. To capture the capability of these materials to reduce
permeation emissions without creating other issues for cold weather
products, we are proposing a fuel line permeation standard of 175 g/
m\2\/day in 2013 for cold-weather products. We request comment on
appropriateness of this standard and whether there are materials that
could be used to achieve larger fuel line permeation reductions from
cold-weather products.
    We request comment on what products should be considered to be
cold-weather products and if it would be possible to distinguish
between products used in warm versus cold climates. We also request
comment regarding whether the proposed ABT program discussed below for
handheld equipment would provide enough flexibility to manufacturers to
address cold weather issues through credit trading rather than through
a differentiated standard.
    Outboard engine manufacturers have expressed concern that it would
be difficult for them to meet proposed 2009 date for the sections of
fuel lines that are mounted on their engines under the engine cowl.
While some sections of straight-run fuel line are used on the
outboards, many of the smaller sections between engine mounted fuel-
system components and connectors are preformed or even injection-molded
parts. Outboard engine manufacturers stated that they would need
additional time to redesign and perform testing on low-permeation fuel
lines under the cowl. PWC and SD/I manufacturers have indicated that
this is not an issue on their engines because they are dominantly
straight-run pieces. Outboard engine manufacturers have also stated
that, in contrast to under cowl fuel line, they would be able to
facilitate the introduction of low-permeation fuel line, from the fuel
tank to the engine, in 2008.
    We request comment on implementing an optional program where the
implementation dates for fuel line under the cowl can be delayed beyond
2009, provided low-permeation fuel line from the fuel tank to the
engine is used beginning on January 1, 2008. Under this approach,
permeation standards for primer bulbs on fuel lines from the tank to
the engine would still begin in 2009. One specific approach would be to
phase in the use of low-permeation fuel lines on outboards based on the
total inside surface area of the under cowl fuel lines. For instance
the following phase-in could be implemented: 30 percent in 2010, 60
percent in 2011, and 90 percent in 2012. This would allow manufacturers
to transition to the use of low-permeation fuel lines in an orderly
fashion. Also, it would give them some flexibility to continue to use
short sections of uncontrolled fuel lines, in the longer term, that are
more difficult or costly to replace with low-permeation fuel lines. At
some point in the future, such as 2015, we could require the use of 100
percent low-permeation fuel lines. Manufacturers would be expected to
target 100 percent use of low-permeation fuel lines in new engine
designs. If the surface area percentages were weighted across a
manufacturers entire product line of outboard engines (rather than on a
per-engine basis), it would allow manufacturers to use 100 percent low-
permeation fuel lines on new engine designs, while making less changes
to engines that are planned to be phased out of production.
    We also request comment on how the above program could be
implemented given that the fuel line from the tank to the engine is
typically installed by the boat builder while the under-cowl fuel line
is installed by the engine manufacturer. One approach that has been
considered is requiring the engine manufacturer to specify low-
permeation fuel line in its installation instructions beginning in
2008. The engines would not be made available to boat builders who do
not begin using low-permeation fuel lines in 2008.
(2) Fuel Tank Permeation Standards and Dates
    Except as noted below, we are proposing a fuel tank permeation
standard of 1.5 g/m\2\/day for tanks intended for use in new Small SI
equipment and Marine SI vessels based on the permeation rate of
gasoline containing 10 percent ethanol at a test temperature of 28
[deg]C (see Sec.  1060.103 and Sec.  1060.520). The emission standard
is

based on the inside surface area of the fuel tank rather than the
volumetric capacity because permeation is a function of surface area
exposed to fuel. This proposed standard is consistent with that adopted
for fuel tanks in recreational vehicles.
    We are proposing a fuel tank permeation standard of 2.5 g/m\2\/day
for handheld equipment with structurally integrated nylon fuel tanks
(see Sec.  1060.801 for the proposed definition of structurally
integrated nylon fuel tanks). These fuel tanks are molded as part of
the general structure of the equipment. In most cases, these fuel tanks
are made of glass-reinforced nylon for strength and temperature
resistance. These nylon constructions typically have significantly
lower permeation rates than other plastics used for fuel tanks, such as
high-density polyethylene; however, based on data in Chapter 5 of the
Draft RIA the nylon constructions may not be able meet a standard of
1.5 g/m\2\/day. Therefore, we believe a higher standard is necessary
for these fuel tank constructions. We request comment on this separate
permeation standards for structurally integrated fuel tanks.
    Many Small SI equipment manufacturers are currently using low-
permeation fuel tanks for products certified in California. The
California tank permeation test procedures use a nominal test
temperature of 40 [deg]C with California certification gasoline while
we are proposing to require testing at 28 [deg]C with gasoline
containing 10 percent ethanol. We are proposing to allow manufacturers
the alternative of testing their fuel tanks at 40 [deg]C with our test
fuel. Because permeation increases as a function of temperature, we are
proposing an alternative standard of 2.5 g/m2/day for fuel tanks tested
at 40 [deg]C. For structurally integrated nylon fuel tanks, the
alternative standard at 40 [deg]C would be 4.0 g/m\2\/day.
    We consider three distinct classes of marine fuel tanks: (1)
Portable marine fuel tanks (generally used with small outboards); (2)
personal watercraft (PWC) fuel tanks; and (3) other installed marine
fuel tanks (generally used with SD/I and larger outboards). The fuel
tank permeation standards are proposed to start in 2011 for all Small
SI equipment using Class II engines and for personal watercraft and
portable marine fuel tanks. For Small SI equipment using Class I
engines and for other installed marine fuel tanks, we propose to apply
the same standard starting in 2012. Most of the marine fuel tanks with
the later standards are produced in low volumes using rotational-molded
cross-link polyethylene or fiberglass construction, both of which
generally present a greater design challenge. We believe the additional
lead time will be necessary for these fuel tanks to allow for a smooth
transition to low-permeation designs. For Small SI equipment, these
dates also align with the schedule for introducing the proposed Phase 3
exhaust emission standards.
    Component manufacturers would be required to certify to the
proposed permeation emission standard for fuel tanks (this may involve
certification to a family emission limit above the emission standard,
as described in Section VI.D), except in certain circumstances.
Equipment manufacturers would need to certify that their fuel tanks
meet the proposed emission standards if they are not already certified
by the fuel tank manufacturer, or if they comply using emission
credits, as described in Section VI.F. However, we are proposing that
manufacturers of portable marine fuel tanks be required to certify that
their products meet the new permeation standard. This is necessary
because portable fuel tanks are not sold to boat builders for
installation in a vessel. There is therefore no other manufacturer who
could be treated as the manufacturer and responsible for meeting
emission standards that apply to portable marine fuel tanks.
    For handheld equipment, we are proposing a phased-in implementation
of the fuel tank permeation standards. Manufacturers would be required
to meet the proposed fuel tank permeation standards in 2009 for
products that they already certify in California (see Sec.  90.129).
The remaining equipment, except for structurally integrated nylon fuel
tanks and small-volume families, would be subject to the proposed tank
permeation standards in 2010 (see Sec.  1054.110). Structurally
integrated nylon fuel tanks would be subject to the proposed standards
in 2011 and small-volume families would have to meet the proposed tank
permeation standards beginning in 2013. Manufacturers would need to
start using EPA-specified procedures starting in 2010, except that
equipment certified using carryover data would be allowed to use data
collected using procedures specified for compliance in California for
model years 2010 and 2011 (see Sec.  1054.145).
    For the purpose of the proposed fuel tank permeation standards, a
fuel cap mounted on the fuel tank is considered to be part of the fuel
tank. We consider a fuel cap to be mounted on the fuel tank unless the
fuel tank is designed to have a filler neck at least 12 inches long
with the opening at least six inches above the top of the fuel tank.
The fuel cap would therefore be included in the tank permeation
standard and test. The cap may optionally be tested separately from the
tank and the results combined to determine the total tank permeation
rate (see Sec.  1060.521). Cap manufacturers could also test their caps
and certify them separately to a separate 1.5 g/m\2\/day cap permeation
standard. The permeation requirements apply independently of the
diffusion standards described below, which address venting of fuel
vapors. We are concerned that allowing certification of fuel caps could
add complexity to the certification process. It would also add a
measure of uncertainty in our efforts to ensure compliance with
emission standards--for fuel tanks certified to permeation standards
alone, it would be hard ensure that the fuel tanks in the final
installation would be in a certified configuration with respect to
diffusion emissions. We therefore request comment on the value to
manufacturers of allowing fuel caps to be certified independently from
the fuel tank. Note that a single certification fee would apply to fuel
tanks that are certified to permeation and diffusion emission
standards, but only if there is no optional fuel cap certification.
With the option of fuel cap certification, a separate certification fee
would apply to diffusion and permeation families, even if a single fuel
tank manufacturer certifies to both standards.
(3) Diurnal Emission Standards and Dates
    We are proposing diurnal emission standards for fuel tanks intended
for use in new Marine SI vessels (see Sec.  1045.107). We consider
three distinct classes of marine fuel tanks: (1) Portable marine fuel
tanks (used with small outboards); (2) personal watercraft (PWC) fuel
tanks; and (3) other installed fuel tanks (used with SD/I and larger
outboards). For diurnal emissions from portable fuel tanks, we are
proposing a design requirement that the tank remain sealed up to a
pressure of 5.0 psi, starting in the 2009 model year (see Sec.
1060.105). We are also proposing that portable fuel tanks must continue
to be self-sealing when disconnected from an engine.
    We are proposing a general emission standard of 0.40 g/gal/day
based on a 25.6-32.2 [deg]C temperature profile for installed tanks.
The applicable test procedures are described in Section VI.E.3.
Manufacturers have expressed concerns that some very large boats stay
in the water throughout the boating season and therefore will see a
much smaller daily swing in fuel

temperatures, which corresponds with a smaller degree of diurnal
emissions. We are proposing to address this concern with an alternative
standard and test procedure that would apply only for nontrailerable
boats. Using available measurements related to fuel temperatures and
emission models to relate temperatures to projected diurnal emission
levels, we are proposing an alternative standard of 0.16 g/gal/day
based on a 27.6-30.2 [deg]C temperature cycle for fuel tanks installed
in nontrailerable boats. For the purposes of this rule, we are
proposing to define a nontrailerable boat as 26 feet or more in length,
which is consistent with the U.S. Fish and Wildlife Service definition
for ``nontrailerable recreational vessels'' in 50 CFR 86.12. The
diurnal emission standards would apply starting in 2009 for PWC fuel
tanks and in 2010 for other installed fuel tanks.
    Component manufacturers would be required to certify to the
proposed diurnal emission standard for fuel tanks, except in certain
circumstances. Equipment manufacturers would need to certify that their
fuel tanks meet the proposed emission standards if they are not already
certified by the fuel tank manufacturer, as described in Section VI.F.
As described above for permeation standards, we are proposing to
require manufacturers of portable marine fuel tanks to certify that
they meet the proposed diurnal emission standards since there is no
``equipment manufacturer'' to assume certification responsibility for
those tanks.
    We believe the proposed requirements would achieve at least a 50
percent reduction in diurnal emissions from PWC and other installed
marine fuel tanks and nearly a 100 percent reduction from portable
marine tanks. We request comment on the proposed diurnal emission
standards for Marine SI vessels.
    It is common today for portable marine fuel tanks to maintain an
airtight seal when the engine is not operating. These tanks typically
have caps that are fitted with a valve that can be manually opened
during engine operation and closed when the fuel tank is stored.
Although this technology could be used to control diurnal emissions
effectively, it depends on user intervention. We are proposing that
portable fuel tanks be required to be fitted with a self-sealing vent
rather than a manually-controlled vent. For instance, a one-way
diaphragm valve could be used to allow air in when fuel is drawn from
the tank (to prevent vacuum conditions), but otherwise seal the fuel
tank. Current portable marine fuel tanks are small and designed to hold
pressure when the manual valve is closed. We are proposing to require
that portable marine fuel tanks be designed to maintain a seal to allow
for pressure buildup resulting from normal temperature swings. These
tanks should include valves that prevent a vacuum in the tank during
engine operation which could restrict fuel flow to the engine and
potentially stall the engine. We believe portable marine fuel tanks
with valves that seal automatically will control diurnal emissions
without relying on user operation. We are proposing to implement this
design standard beginning with the 2009 model year. We request comment
on this approach.
    Manufacturers will likely control emissions from installed marine
fuel tanks either by sealing the fuel system up to 1.0 psi or by using
a carbon canister in the vent line. As discussed below, we believe PWC
manufacturers will likely seal the fuel tank with a pressure-relief
valve while manufacturers of other boats with installed fuel tanks are
more likely to use carbon canisters. However, either technology would
be acceptable for either kind of installed marine fuel tank as long as
every system meets the numerical standard applicable to the specific
tank.
    Personal watercraft currently use sealed fuel systems for
preventing fuel from exiting, or water from entering, the fuel tank
during typical operation. These vessels use pressure-relief valves for
preventing excessive positive pressure in the fuel system; the pressure
to trigger the valve may range from 0.5 to 4.0 psi. Such fuel systems
would also need a low-pressure vacuum relief valve to allow the engine
to draw fuel from the tank during operation. In the 2002 proposal, we
discussed a diurnal emission standard largely based on the use of a
sealed system with a 1.0 psi pressure-relief valve. The Personal
Watercraft Industry Association (PWIA) expressed support in their
comments for this proposal. We estimate that diurnal emissions from a
sealed system with a 1.0 psi pressure-relief valve would be about half
that of the same system on a PWC with an open vent. For personal
watercraft, we are proposing an implementation date of 2009 because the
anticipated technology is widely used today.
    The National Marine Manufacturers Association (NMMA) expressed
concern in their comments on the 2002 proposal that pressurized fuel
tanks could lead to safety issues for larger installed fuel tanks. NMMA
commented that these tanks would deform under pressure and that
pressure could lead to fuel leaks. Manufacturers also commented that
bladder fuel systems, which would not be pressurized, would be too
expensive. At the time of the 2002 proposal, we considered the use of
carbon canisters to control diurnal emissions, but were concerned that
active purging would occur infrequently due to the low hours of
operation per year seen by many boats. However, we have since collected
data on carbon canisters showing that canisters can reduce emissions by
more than 50 percent with passive purge that occurs during the normal
breathing process without creating any significant pressure in the fuel
tank. For installed marine fuel tanks, other than PWC, we are therefore
proposing an implementation date of 2010 to allow additional lead time
for designing and producing canisters for marine vessels.
    During the SBREFA process described in Section VI.I, NMMA expressed
general support of the feasibility of using carbon canisters on boats.
However, they commented that there are many small boat builders that
may need additional time to become familiar with and install carbon
canisters in their boats. We request comment on either a three-year
phase-in (say 33/66/100 percent over the 2010 through 2012 model years)
or an extra year of lead time for small businesses to comply with the
proposed diurnal emission standards. We also request comment on which
small business companies would be eligible for this flexibility. One
option would be to use the SBA definition of a small boat builder which
is based on having fewer than 500 employees. Another option would be to
base the flexibility on the annual boat sales of the company. One issue
with the latter approach would be the wide range of boat sizes and
sales prices in the marine industry. With a given number of employees,
many more small than large boats can be manufactured in a year.
    If a manufacturer uses a canister-based system to comply with the
standard applicable to the specific tank, we are also proposing to
require that manufacturers design their systems not to allow liquid
gasoline to reach the canister during refueling or from fuel sloshing
(see Sec.  1060.105). Liquid gasoline would significantly degrade the
carbon's ability to capture hydrocarbon vapors. One example of an
approach to protect the canister from exposure to liquid gasoline is a
design in which the canister is mounted higher than the fuel level and
a small orifice or a float valve is installed in the vent line to stop
the flow of liquid gasoline to the canister.
    Several manufacturers have stated that it is common for users to
fill their fuel tank until they see fuel coming out

of the vent line. In addition to being a source of hydrocarbon
emissions, if liquid fuel were to reach a carbon canister, it would
significantly reduce the effectiveness of the canister. Solutions for
this problem are relatively straightforward and have been used in
automotive applications for many years. We are therefore proposing to
require that boat builders use good engineering judgment in designing
fuel systems that address diurnal emission control in a way that does
not increase the occurrence of fuel spitback or spillage during
refueling beginning in the years specified in Table VI-1. While this
provision is not detailed or prescriptive, it communicates a
requirement that manufacturers appropriately take refueling design into
account, and it allows EPA to make enforcement decisions as the
industry establishes sound practices in this area. In addition, we are
proposing that manufacturers would have to meet certain specifications
with their fuel tank caps, including requirements to tether the cap to
the equipment and designing the cap to provide physical or audible
feedback when the vapor seal is established. Also, adding vents to a
fuel tank would generally not be allowed. To the extent that boat
builders certify their vessels to meet emission standards, they would
need to describe how they meet these refueling-related requirements in
their application for certification. If boat builders rely on certified
components instead of applying for certification, they would need to
keep records describing how they meet these refueling-related
requirements; Section VI.F describes how such companies can meet
certification requirements without applying for a certificate.
    Any increase in fuel temperature resulting from engine operation
would cause a potential for emissions that is very similar to diurnal
emissions. We are therefore proposing to disallow manufacturers from
disabling their approaches for controlling diurnal emissions during
engine operation (see Sec.  1060.105). This would ensure that any
running loss emissions that would otherwise occur will be controlled to
a comparable degree as diurnal emissions.
    We are not proposing diurnal emission standards for Small SI
equipment. However, we request comment on such a requirement. We
believe passively purging carbon canisters could reduce diurnal
emissions by 50 to 60 percent from Small SI equipment. Active purging
would result in even greater reductions. However, we believe some
important issues would need to be resolved, such as cost, packaging,
and vibration. The cost sensitivity is especially noteworthy given the
relatively low emissions levels (on a per-equipment basis) from such
small fuel tanks. We request comment on the appropriate level of such a
standard and when it could be implemented.
    There are some small outboard marine engines that have fuel tanks
directly mounted on the engine. In these cases, the fuel tank could be
considered to be more similar to those on Small SI equipment than other
marine fuel tanks. Typically, these outboard engines have fuel tanks on
the order of 1-2 liters in size. Manufacturers have expressed concern
about the practicality of using carbon canisters for these applications
due to space constraints and durability impacts of engine handling. We
request comment on excluding fuel tanks less than 2 liters in size that
are mounted on outboard engines from the proposed diurnal emission
requirements. Since it may be a viable alternative, comments should
address the feasibility of using sealed fuel tanks with pressure relief
in these applications. Similar to Small SI equipment, marine fuel tanks
mounted on the engine are directly exposed to heat from the engine
during operation. In the case where diurnal standards were not applied
to these fuel tanks, we request comment on applying the proposed
diffusion and running loss standards, described below, to these fuel
tanks.
(4) Diffusion Standards and Dates
    As described above, diffusion emissions occur when vapor escapes
the fuel tank through an opening as a result of random molecular
motion, independent of changing temperature. Diffusion emissions can be
easily controlled by venting fuel tanks in a way that forces fuel
vapors to go through a long, narrow path to escape. We are proposing
that manufacturers may choose between certifying to a performance
standard or a design standard. Under a performance standard, we specify
a test procedure and a maximum emission rate. Under a design standard,
we specify certain designs that a manufacturer may use to comply with
the standard. This standard would take effect at the same time as the
exhaust emission standards--2011 for Class II engines and 2012 for
Class I engines.
    We are proposing a performance standard of 0.80 g/day for diffusion
emissions for fuel tanks intended for use in new nonhandheld Small SI
equipment (Sec.  1060.105). This standard would not apply to a
manufacturer who certifies using one of the four alternative design
standards described below.
    1. We are proposing a design standard for diffusion in which the
tank must be sealed except for a single vent line. This vent line would
need to be at least 180 mm long and have a ratio of length to the
square of the diameter of at least 5.0 mm-1 (127
inches-1). For example, a vent line with 6 mm inside
diameter would have to be at least 180 mm long to meet this design
standard.
    2. We are proposing a second alternative design standard for
diffusion in which vapors from a fuel tank are vented solely through a
tortuous path through the fuel cap. Many fuel cap manufacturers use
this cap design today to prevent fuel from splashing out through the
vent during operation. As described in Chapter 5 of the Draft RIA, we
tested three low-diffusion fuel caps used on Class I equipment with
high annual sales. Based on these designs, we proposing to define a
tortuous path fuel cap as one that is vented through a small path in
the gasket and then around the threads where the cap screws onto the
fuel tank. Specifically, we are proposing an average path length to
total cross sectional area in the gasket pathways of greater than 1
mm-1 and a vent path through at least 360[deg] of the
threads.
    3. We are proposing a third alternative design standard for
diffusion in which the fuel tank is sealed except for a vent through a
carbon canister. Carbon canisters are one technology that manufacturers
may use to meet diurnal emission standards in California.
    4. We are proposing a fourth alternative design standard for
diffusion in which a fuel tank is sealed so that vapors may not exit
the fuel tank. Under this design standard, it would be acceptable to
have a pressure relief valve with an opening pressure of at least 0.5
psi.
    We request comment on the appropriateness of setting a design
standard for diffusion and on the designs described above. We also
request comment on any additional diffusion data from fuel caps that
are capable of meeting the proposed performance-based diffusion
standard and on the design of these fuel caps. Even without the
alternative of a design standard, we anticipate that fuel cap
manufacturers, with a small number of designs covering a large number
of equipment models, would be able to perform the necessary testing for
a performance-standard without being unreasonably burdened.
    Fuel tank manufacturers would be required to certify that their
products limit venting sufficiently to meet the proposed diffusion
emission standard, except in certain circumstances. Fuel

cap manufacturers may optionally certify their fuel caps to the
diffusion emission standard, in which case they would become subject to
all the compliance requirements related to the standards, including
certification. Equipment manufacturers would need to certify that their
fuel tanks meet the proposed emission standards if they are not already
certified by the fuel tank manufacturer, as described in Section VI.F.
    We are also proposing that equipment manufacturers subject to
diffusion emission standards must ensure that the fuel cap is tethered
to the fuel tank or the equipment to prevent it from being accidentally
misplaced (see Sec.  1060.101). A missing fuel tank cap would bypass
any design intended to control these losses and could lead to very high
emission rates. Fuel cap or fuel tank manufacturers could address this
as part of their component certification. If this is not part of the
component certification, an equipment manufacturer would need to
describe how it meets the tethering requirement in its application for
certification.
    We are not proposing diffusion standards for handheld equipment.
Handheld equipment use fuel caps that are either sealed or have
tortuous venting pathways to prevent fuel from spilling during
operation. We believe these fuel cap designs limit diffusion emissions
sufficiently that handheld equipment already meet the proposed
standard. In addition, we are not proposing diffusion standards for
Marine SI vessels. The diurnal emission standard for Marine SI vessels
will lead manufacturers to adopt technologies that automatically limit
diffusion losses, so there is no need to propose a separate diffusion
standard for those systems. Similarly, we would not finalize the
proposed diffusion standard if we adopt a diurnal emission standard for
Small SI equipment. We request comment on the proposed diffusion
standard for nonhandheld equipment and whether it should apply to
handheld equipment and marine vessels as well.
(5) Running Loss Emission Standards and Dates
    We are proposing standards to control running loss emissions from
nonhandheld Small SI equipment beginning in the same year as the
proposed Phase 3 exhaust emission standards--2012 for Class I engines
and 2011 for Class II engines (see Sec.  1060.104). Equipment
manufacturers would need to certify that their equipment models meet
the proposed running loss requirements since component certification is
not practical.
    We have measured fuel temperatures and found that some types of
equipment experience significant fuel heating during engine operation.
This was especially true for fuel tanks mounted on or near the engine.
This occurs in many types of Small SI equipment.
    It would be very difficult to define a measurement procedure to
consistently and accurately quantify running losses. Also, a
performance standard with such a procedure would introduce a
challenging testing requirement for hundreds of small-volume equipment
manufacturers. Moreover, we believe there are several different design
approaches that will reliably and effectively control running losses.
We are therefore not proposing to control running losses using the
conventional approach of establishing a procedure to measure running
losses and adopting a corresponding emission standard. Manufacturers
could choose from one of the following approaches to meet this
requirement:
     Vent running loss fuel vapors from the fuel tank to the
engine's intake manifold in a way that burns the fuel vapors in the
engine instead of venting them to the atmosphere. The use of an
actively purged carbon canister would qualify under this approach.
     Use a bladder to minimize fuel vapor volume in a sealed
fuel tank.
     Design the equipment so that fuel temperature does not
rise more than 8 [deg]C during normal operation. Such a design may use
insulation or forced cooling to minimize temperature increases. This
would require measuring fuel temperatures to show that each covered
equipment configuration does not exceed the temperature threshold (see
Sec.  1060.535).
     Show that the equipment qualifies as wintertime equipment.
    We believe any of these approaches will ensure that manufacturers
will be substantially controlling running losses, either by preventing
or managing running loss vapors. While none of these approaches are
expected to require extensive design changes or lead time, any
manufacturer choosing the option to vent running loss fuel vapors into
the engine's intake manifold would need to make this change in
coordination with the engine design. As a result, we believe it is
appropriate to align the timing of the running loss standards with the
introduction of the proposed Phase 3 standards.
    We request comment on the proposed running loss requirement for
nonhandheld Small SI equipment. We also request comment on any other
design approaches that will reliably and effectively control running
losses. Examples of other approaches may be to seal the fuel tank for
pressures up to 3.5 psi or, for equipment that does not include fuel
recirculation, locate the fuel tank at least 12 inches away from the
engine and other heat sources (such as exhaust pipes, hydraulic lines,
etc.).
    We are not proposing to apply the running loss requirements to
handheld Small SI engines. We believe running loss emission standards
should not apply to handheld engines at this time because the likely
approach to controlling running losses could require that manufacturers
revisit their design for controlling exhaust emissions. As described
above, we are not proposing to change the exhaust emission standards
for handheld engines in this rulemaking. In addition, there are some
technical challenges that would require further investigation. For
example, the compact nature of the equipment makes it harder to isolate
the fuel tank from the engine and the multi-positional nature of the
operation may prevent a reliable means of venting fuel vapors into the
intake manifold while the engine is running. We request comment on the
appropriateness of requiring manufacturers to address running loss
emissions from handheld engines.
    Furthermore, we are not proposing to apply running loss
requirements to Marine SI engines. Installed marine fuel tanks are
generally not mounted near the engine or other heat sources so running
losses should be very low. A possible exception to this is personal
watercraft since they are designed with the fuel tank closer to the
engine. However, under the proposed standard for controlling diurnal
emissions, we expect that manufacturers will design their fuel tanks to
stay pressurized up to 1 psi. This would also help control running loss
emissions. We request comment on applying running loss controls to
Marine SI engines. In particular, we request comment on the possibility
that other design configurations would have higher running loss
emissions. One example may be outboard applications in which a fuel
tank is mounted directly on the engine.
(6) Requirements Related to Refueling
    Refueling spitback and spillage emissions represent a substantial
additional amount of fuel evaporation that contributes to overall
emissions from equipment with gasoline-fueled engines. We are not
proposing measurement procedures with corresponding emission standards
to address these emission sources. However, we believe equipment
manufacturers can take significant steps

to address these refueling issues by incorporating sound practices into
their equipment designs. For example, designing a marine filler neck
with a horizontal segment near the fuel inlet will almost inevitably
lead to high levels of spillage since fuel flow will invariably reach
the nozzle, leading to substantial fuel flow out of the fuel system. In
contrast, designing for automatic shutoff would prevent this. Also,
maintaining a vertical orientation of the filler neck would allow the
fuel to flow back into the filler neck and into the tank after the
nozzle shuts off.
    For Small SI equipment, designing fuel inlets that are readily
accessible and large enough to see the rising fuel level (either
through the tank wall or the fuel inlet) will substantially reduce
accidental spillage during refueling. We are therefore proposing to
require that equipment manufacturers design and build their equipment
such that operators could reasonably be expected to fill the fuel tank
without spitback or spillage during the refueling event (see Sec.
1060.101). This proposed requirement mirrors the following requirement
recently adopted with respect to portable fuel containers (72 FR 8428,
February 26, 2007):

    You are required to design your portable fuel containers to
minimize spillage during refueling to the extent practical. This
requires that you use good engineering judgment to avoid designs
that will make it difficult to refuel typical vehicle and equipment
designs without spillage. (40 CFR 59.611(c)(3))

    While the proposed requirement is not as objective and quantifiable
as the other standards and requirements we are proposing, we believe
this is important, both to set a requirement for manufacturers in
designing their products and to give EPA the ability to require
manufacturers to select designs that are consistent with good
engineering practice regarding effective refueling strategies. To the
extent that equipment manufacturers and boat builders certify their
products to emission standards, they would need to describe how they
meet this refueling-related requirement in their application for
certification. If boat builders rely on certified components instead of
applying for certification, they would need to keep records describing
how they meet this refueling-related requirement; Section VI.F
describes how such companies can meet certification requirements
without applying for a certificate. We request comment on this approach
to addressing refueling emissions from nonroad spark-ignition engines.
We also request comment on the possibility of relying on current or
future published industry standards to establish designs for equipment
and fueling containers that minimize refueling emissions under normal
in-use conditions.
    Spitback and spillage are a particular concern for gasoline-fueled
boats. Marine operators have reported that relatively large quantities
of gasoline are released into the marina environment during refueling
events. The American Boat and Yacht Council (ABYC) has a procedure in
place to define a standard practice to address refueling. However, this
procedure calls for testing by refueling up to a 75 percent fill level
at a nominal flow rate of 5 gallons per minute. This procedure is
clearly not consistent with prevailing practices and is not effective
in preventing spills. We believe the most effective means of addressing
this problem is for ABYC to revise their test procedure to reflect
current practices. Specifically, we would recommend a procedure in
which the marine fuel tank is filled at flow rates between 5 and 20
gallons per minute until automatic shutoff occurs.
    A variety of technological solutions are available to address
spitback and spillage from marine vessels. The simplest would be a
system much like is used on cars. A small-diameter tube could run along
the filler neck from the top of the tank to a point near the top of the
filler neck. Once liquid fuel would reach the opening of the filler
neck and the extra tube, the fuel would go faster up the small-diameter
tube and trigger automatic shutoff before the fuel climbs up the filler
neck. This design would depend on the user to use the equipment
properly and may not be fully effective, for example, with long filler
necks and low refueling rates. An alternative design would involve a
snug fit between the nozzle's spout and the filler neck, which would
allow for a tube to run from a point inside the tank (at any
predetermined level) directly to the shutoff venturi on the spout. The
pressure change from the liquid fuel in the tank reaching the tube's
opening would trigger automatic shutoff of the nozzle. This system
would prevent overflowing fuel without depending on the user. These are
just two of several possible configurations that would address fuel
spillage from marine vessels.
    We request comment on the degree of fuel spillage with current
technologies and practices with marine vessels. We request comment on
the potential for ABYC standards to address fuel spillage or on the
need for EPA to adopt such procedures and standards. We request comment
on the specific procedures that would be appropriate for measuring
spitback and spillage. Finally, we request comment on adopting
provisions such as those in 40 CFR 80.22 to regulate the dimensions of
refueling nozzles for marine applications, including a specification of
a nominal nozzle diameter of 1.1870.010 inches and nominal
venturi placement \5/8\ inch from the terminal end of the nozzle.
(7) Summary Table of Proposed Evaporative Emission Standards
    Table VI-1 summarizes the proposed standards and implementation
dates discussed above for evaporative emissions from Small SI equipment
and Marine SI vessels. Where a standard does not apply to a given class
of equipment, ``NA'' is used in the table to indicate ``not
applicable.''

                                       Table VI.-1.--Proposed Evaporative Emission Standards and Model Year Dates
--------------------------------------------------------------------------------------------------------------------------------------------------------
         Standard/ category             Hose  permeation        Tank  permeation            Diurnal               Diffusion             Running loss
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Proposed Standards
--------------------------------------------------------------------------------------------------------------------------------------------------------
Standard level.....................  15 g/m2 /day..........  1.5 g/m2 /day.........  0.40 g/gal/day.......  0.80 g/day...........  Design standard.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                        Implementation Dates: Small SI Equipment
--------------------------------------------------------------------------------------------------------------------------------------------------------
Handheld...........................  2012 a b..............  2009-2013 c d.........  NA...................  NA...................  NA.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Class I............................  2008..................  2012..................  NA...................  2012 g...............  2012.
Class II...........................  2008..................  2011..................  NA...................  2011 g...............  2011.

                                                          Implementation Dates: Marine Vessels
--------------------------------------------------------------------------------------------------------------------------------------------------------
Portable tanks.....................  2009..................  2011..................  2009 e...............  NA...................  NA.
PWC................................  2009..................  2011..................  2009.................  NA...................  NA.
Other installed tanks..............  2009..................  2012..................  2010 f...............  NA...................  NA.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ 2013 for small-volume families and cold weather equipment.
\b\ Fuel line permeation standard of 175 g/m2 /day for cold-weather equipment.
\c\ 2.5 g/m2 /day for structurally integrated nylon fuel tanks.
\d\ 2009 for families certified in California, 2013 for small-volume families, 2011 for structurally integrated nylon fuel tanks, and 2010 for remaining
  families.
\e\ Design standard.
\f\ Fuel tanks installed in nontrailerable boats (>=26 ft. in length) may meet a standard of 0.16 g/gal/day over an alternative test cycle.
\g\ Alternatively, may meet a design standard.

D. Emission Credit Programs

    A common feature of mobile source emission requirements is an
emission credit program that allows manufacturers to generate emission
credits based on certified emission levels for engine families that are
more stringent than the standard. See Section VII for background
information and general provisions related to emission credit programs.
    We believe it is appropriate to consider compliance based on
emission credits relative to permeation standards for fuel lines used
with handheld engines and for fuel tanks used in all applications. As
described above, the emission standards apply to the fuel tanks and
fuel lines directly, such that we would generally expect component
manufacturers to certify their products. However, we believe it is best
to avoid placing the responsibility for demonstrating a proper emission
credit balance on component manufacturers for three main reasons.
First, it is in many cases not clear whether these components will be
produced for one type of application or another. Component
manufacturers might therefore be selling similar products into
different applications that are subject to different standards--or no
standards at all. Component manufacturers may or may not know in which
application their products will be used. Second, there will be
situations in which equipment manufacturers and boat builders take on
the responsibility for certifying components. This may be the result of
an arrangement with the component manufacturer, or equipment
manufacturers and boat builders might build their own fuel tanks. We
believe it would be much more difficult to manage an emission credit
program in which manufacturers at different places in the manufacturing
chain would be keeping credit balances. There would also be a
significant risk of double-counting of emission credits. Third, most
component manufacturers would be in a position to use credits or
generate credits, but not both. Equipment manufacturers and boat
builders are more likely to be in a position where they would keep an
internal balance of generating and using credits to meet applicable
requirements. Our experience with other programs leads us to believe
that an emission credit program that depends on trading is not likely
to be successful.
    We are therefore proposing emission credit provisions in which
equipment manufacturers and boat builders keep a balance of credits for
their product line. Equipment manufacturers and boat builders choosing
to comply based on emission credits would need to certify all their
products that either generate or use emission credits. Component
manufacturers would be able to produce their products with emission
levels above or below applicable emission standards but would not be
able to generate emission credits and would not need to maintain an
accounting to demonstrate a balance of emission credits.
    We are aware that some component manufacturers would be making
products that generate emission credits that would belong to equipment
manufacturers or boat builders. Equipment manufacturers or boat
builders could in turn use those emission credits to enable them to buy
components from different competing component manufacturers. This would
potentially put fuel tank manufacturers producing low-FEL products at a
competitive disadvantage with other manufacturers producing high-FEL
fuel tanks. We request comment on the best approach to setting up an
ABT program. We specifically request comment on special provisions that
may be appropriate to address these competitiveness issues for
component manufacturers.
(1) Averaging, Banking, and Trading for Nonhandheld Equipment and
Marine Vessels
    We are proposing averaging, banking, and trading (ABT) provisions
for fuel tank permeation from nonhandheld Small SI equipment and Marine
SI vessels (see subpart H in parts 1045 and 1054). See the following
section for similar provisions for handheld Small SI equipment.
    We are aware of certain control technologies that would allow
manufacturers to produce fuel tanks that reduce emissions more
effectively than we would require. These technologies may not be
feasible or practical in all applications, but we are proposing to
allow equipment manufacturers using such low-emission technologies to
generate emission credits. In other cases, an equipment manufacturer
may want to or need to use emission credits that would allow for fuel
tanks with permeation rates above the applicable standards. Equipment
manufacturers would quantify positive or negative emission credits by
establishing a Family Emission Limit (FEL) to define the applicable
emission level, then factoring in sales volumes and useful life to
calculate a credit total. This FEL could be based on testing done
either by the component manufacturer or the equipment manufacturer.
Through averaging, these emission credits could be used by the same
equipment manufacturer to offset other fuel tanks in the same model
year that do not have control technologies that control emissions to
the level of the standard. Through banking, such an equipment
manufacturer could use the emission credits in later model years to
offset high-emitting fuel tanks. The emission credits could also be
traded to another equipment manufacturer to offset that company's high-
emitting fuel tanks.

    We believe an ABT program is potentially very advantageous for fuel
tanks because of the wide variety of tank designs. The geometry,
materials, production volumes, and market dynamics for some fuel tanks
are well suited to applying emission controls but other fuel tanks pose
a bigger challenge. The proposed emission credit program allows us to
set a single standard that applies broadly without dictating that all
fuel tanks be converted to use low-permeation technology at the same
time.
    We are requesting comment on one particular issue. We are not
proposing to limit the life of evaporative emission credits under the
proposed banking program. However, we are concerned that this could
result in a situation where credits generated by a fuel tank sold in a
model year are not used until many years later when the fuel tanks
generating the credits have been scrapped and are no longer part of the
fleet. EPA believes there may be value to limiting the use of credits
to the period that the credit-generating fuel tanks exist in the fleet.
For this reason, EPA requests comment on limiting the lifetime of the
credits generated under the proposed evaporative emission ABT program
to five years. The five-year period is consistent with the proposed
useful life for fuel tank evaporative emissions.
    We are proposing not to allow manufacturers to generate emission
credits by using metal fuel tanks. These tanks would have permeation
rates well below the standard, but there is extensive use of metal
tanks today, so it would be difficult to allow these emission credits
without undercutting the stringency of the standard and the expected
emission reductions from the standard.
    Emission control technologies and marketing related to portable
marine fuel tanks are quite different than for installed tanks. Since
these fuel tanks are not installed in vessels that are subject to
emission standards, the fuel tank manufacturer would need to take on
the responsibility for certification. As a result, we would treat these
companies as both component manufacturer and equipment manufacturer
with respect to their portable fuel tanks. As described above, we are
proposing that component manufacturers not be responsible for
compliance as part of an emission credit program. We would expect all
portable fuel tank manufacturers to also make nonportable fuel tanks,
which would again lead to a confusing combination of manufacturers
maintaining credit balances to demonstrate compliance. In addition,
most if not all portable fuel tanks are made using high-density
polyethylene in a blow-molding process. The control technologies for
these tanks are relatively straightforward and readily available so we
do not anticipate that these companies will need emission credits to
meet the proposed standards. We are therefore proposing to require
portable marine fuel tanks to meet emission standards without an
emission credit program.
    We are proposing not to allow cross-trading of emission credits
between Small SI equipment and Marine SI vessels. The proposed
standards are intended to be technology-forcing for each equipment
category. We are concerned that cross-trading may allow marginal
credits in one area to hamper technological advances in another area.
We are also proposing not to allow credit exchanges with Small SI
equipment certified in California because California has its own
emission standards for these products. Similarly, if California ARB
adopts different evaporative requirements or separate ABT provisions
for Marine SI vessels, we would not allow credit exchanges with marine
vessels certified in California. These restrictions are consistent with
our existing ABT programs. We also would not allow credit exchanges
between handheld and nonhandheld equipment or between Class I and Class
II equipment. We are concerned that cross trading between these
equipment types could give an unfair competitive advantage to equipment
manufacturers with broader product lines. We request comment regarding
whether the competitive nature of the market warrants such a
restriction in cross-trading between Class I and Class II equipment.
    In the early years of the ABT program we are proposing not to have
an FEL cap. This would give manufacturers additional time to use
uncontrolled fuel tanks, primarily in small-volume applications, until
they could convert their full product lines to having fuel tanks with
permeation control. After an initial period of three years after the
implementation date of the fuel tank standards, we are proposing an FEL
cap of 5.0 g/m2 /day (8.3 g/m2 /day if tested at
40 [deg]C). For Class II equipment, portable marine fuel tanks, and
personal watercraft, the FEL cap would begin in 2014. For Class I
equipment, handheld equipment, and other installed marine fuel tanks,
the FEL cap would begin in 2015. See Sec.  1045.107 and Sec.  1054.110.
For small volume, Small SI equipment families, we are proposing an FEL
cap of 8.0 g/m2 /day (13.3 g/m2 /day if tested at
40 [deg]C). The purpose of the FEL cap would be to prevent the long-
term production of fuel tanks without permeation control, while still
providing regulatory flexibility. We request comment on the level of
the FEL that would be necessary to achieve this goal.
    While the FEL cap is intended to require manufacturers to move
toward widespread use of emission control technologies, we are aware of
technologies that have measured emission levels between the proposed
standard and the proposed FEL cap. As a result, the effect of an FEL
cap may be that there will be little or no use of emission credits as a
compliance strategy once the FEL cap applies. We request comment on the
usefulness of maintaining an ABT program after we implement an FEL cap.
    We are proposing that emission credits under the tank permeation
standards would be calculated using the following equation: Credits
[grams] = (Standard - FEL) x useful life [years] x 365 days/year x
inside surface area [m2]. Both the standard and the FEL are
in units of g/m2 /day based on testing at 28 [deg]C.
    As discussed earlier, we are proposing an alternative standard for
tank permeation testing performed at 40 [deg]C. Because permeation is
higher at this temperature than the primary test temperature, emissions
credits and debits calculated at this test temperature would be
expected to be higher as well. An FEL 10 percent below the standard
would generate 0.15 grams of credit for the primary standard and 0.25
grams of credit for the alternative standard. Therefore, we are
proposing that credits and debits that are calculated based on the
alternative standard be adjusted using a multiplicative factor of 0.6
(1.5/2.5 = 0.6).
    We request comment on the need for averaging, banking and trading
for fuel tanks and on the specific provisions proposed above.
(2) Averaging, Banking, and Trading Program for Handheld Equipment
    We are proposing an ABT program for handheld equipment that would
include fuel tanks and fuel lines. Under this program, a manufacturer
would be able to use credits from fuel tanks to offset debits from fuel
lines, or vice versa. This category of equipment generally involves
very short sections of fuel lines, which are often made using complex,
injection-molded designs. We believe an ABT program would help handheld
equipment manufacturers meet fuel line permeation standards sooner than
would otherwise be possible.

    As discussed earlier, we are proposing a higher standard level of
2.5 g/m2 /day for structurally integrated handheld fuel
tanks. This standard is intended to reflect the measured permeation
rates and characteristics of materials used in these fuel tanks and
manufacturer concerns regarding uncertainty about the permeation rates
from tanks used in the wider range of products and the lack of
definitive control strategies to reduce emissions while meeting other
product requirements. A similar issue exists for cold-weather fuel
lines, for which we are proposing a less stringent permeation standard
of 175 g/m2 /day to address uncertainty associated with the
availability of appropriate low-permeation cold-weather materials in
the time frame of the new standards. We are concerned that windfall
credits that may be generated for these applications if products are
produced that are below the adjusted standards, but do not meet the
primary standards for fuel tanks and fuel lines. To address this issue,
we are proposing that credits would only be earned below 1.5 g/
m2 /day for fuel tanks and below 15 g/m2 /day for
fuel lines on handheld equipment. To promote early introduction of low-
permeation products, we are proposing to allow manufacturers to be able
to earn credits on this basis even before the permeation standards go
into effect. Credit use would be calculated based on the applicable
standards. Emission credits would otherwise be calculated using the
same equation described in Section VI.D.1 above.
    Both the fuel line and fuel tank standards are in units of g/
m2 /day. However, fuel line testing is performed at 23
[deg]C while tank testing is performed at 28 [deg]C. Because permeation
tends to increase with increases in temperature, we request comment
regarding whether the credits should be adjusted to account for
temperature. This adjustment would be smaller than the adjustment
described above for a 28 [deg]C versus 40 [deg]C test.
    For non-structurally integrated fuel tanks, we are proposing to
apply an FEL cap of 5.0 g/m2 /day (8.3 g/m2 /day
if tested at 40[deg]C) beginning in 2015. For structurally integrated
fuel tanks we are proposing an FEL cap of 3.0 g/m2 /day (5.0
g/m2 /day if tested at 40 [deg]C) in 2015. We believe this
cap gives adequate flexibility for manufacturers to address variability
in the permeation rates of these fuel tanks. For small volume, Small SI
equipment families (including handheld and nonhandheld equipment), we
are proposing a long term FEL cap of 8.0 g/m2 /day (13.3 g/
m2 /day if tested at 40[deg]C) to provide additional
regulatory flexibility where costs cannot be spread over high
production volumes. We request comment on the need for continuing an
ABT program once there is an FEL cap, as described for nonhandheld
equipment above.
(3) Other Evaporative Sources
    We are not proposing an emission credit program for other
evaporative sources. We believe technologies are readily available to
meet the applicable standards for fuel line permeation, diurnal
emissions and diffusion emissions (see Section VI.H.). The exception to
this is for fuel lines on handheld equipment as discussed above. In
addition, the diurnal emission standards for portable marine fuel tanks
and PWC fuel tanks are largely based on existing technology so any
meaningful emission credit program with the proposed standards would
result in windfall credits. The running loss standard is not based on
emission measurements and refueling-related requirements are based on
design specifications only, so it is not appropriate or even possible
to calculate emission credits.
(4) Early-Allowance Programs
    Manufacturers may in some cases be able to meet the proposed
emission standards earlier than we would require. We are proposing
provisions for equipment manufacturers using low-emission evaporative
systems early to generate allowances before the standards apply. These
early allowances could be used, for a limited time, after the
implementation date of the standards to sell equipment or fuel tanks
that have emissions above the standards. We are proposing two types of
allowances. The first is for Small SI equipment as a whole where for
every year that a piece of equipment is certified early, another piece
of equipment could delay complying with the proposed standards by an
equal time period beyond the proposed implementation date. The second
is similar but would be just for the fuel tank rather than the whole
equipment (Small SI or Marine SI). Equipment or fuel tanks certified
for the purposes of generating early allowances would be subject to all
applicable requirements. These allowances are similar to the emission
credit program elements described above but they are based on counting
compliant products rather than calculating emission credits.
Establishing appropriate credit calculations would be difficult because
the early compliance is in some cases based on products meeting
different standards using different procedures.
(a) Nonhandheld Small SI Equipment
    Many Small SI equipment manufacturers are currently certifying
products to evaporative emission standards in California. The purpose
of the proposed early-allowance program is to provide an incentive for
manufacturers to begin selling low-emission products nationwide. We are
proposing to give allowances to manufacturers for equipment meeting the
California evaporative emission standards that are sold in the United
States outside of California and are therefore not subject to
California's emission standards. Manufacturers would need to have
California certificates for these equipment types. See Sec.  1054.145.
    Allowances could be earned in any year before 2012 for Class I
equipment and before 2011 for Class II equipment. We are proposing that
the allowances may be used through the 2014 model year for Class I and
through the 2013 model year for Class II equipment. We are proposing
not to allow trading of allowances between Class I and Class II. To
keep this program simpler, we are not proposing to adjust the
allowances based on the anticipated emission rates from the equipment.
Therefore, we believe it is necessary to at least distinguish between
Class I and Class II equipment. We request comment on the early
allowance program described above for nonhandheld Small SI equipment.
(b) Fuel Tanks
    We are also proposing an early-allowance program for nonhandheld
Small SI equipment for fuel tanks (see Sec.  1054.145). This program
would be similar to the program described above for equipment
allowances, except that it would be for fuel tanks only. We would
accept California-certified configurations. Allowances could be earned
prior to 2011 for Class II equipment and prior to 2012 for Class II
equipment; allowances could be used through 2013 for Class II equipment
and through 2014 for Class II equipment. Allowances would not be
exchangeable between Class I and Class II equipment. See Section V.E.3
for a description of how this provision would interact with the
proposed transition program for equipment manufacturers.
    The proposed early-allowance program for marine fuel tanks would be
similar except that there are no California standards for these tanks
(see Sec.  1045.145). Manufacturers certifying early to the proposed
fuel tank permeation standards would be able to earn allowances that
they could use to

offset high-emitting fuel tanks after the proposed standards go into
place. We are proposing not to allow cross-trading of allowances
between portable fuel tanks, personal watercraft, and other installed
fuel tanks. Each of these categories includes significantly different
tank sizes and installed tanks have different implementation dates and
are expected to use different permeation control technology. For
portable fuel tanks and personal watercraft, allowances could be earned
prior to 2011 and used through the 2013 model year. For other installed
tanks, allowances could be earned prior to 2012 and used through the
2014 model year.

E. Testing Requirements

    Compliance with the emission standards is determined by following
specific testing procedures. This section describes the proposed test
procedures for measuring fuel line permeation, fuel tank permeation,
diurnal emissions, and diffusion emissions. We also describe
measurement procedures related to running loss emissions. As discussed
in Section VI.H, we are proposing design-based certification as an
alternative to testing for certain standards.
(1) Fuel Line Permeation Testing Procedures
    We are proposing that fuel line permeation be measured at a
temperature of 23  2 [deg]C using a weight-loss method
similar to that specified in SAE J30 \85\ and J1527 \86\ recommended
practices (see Sec.  1060.515). We are proposing two modifications to
the SAE recommended practice. The first modification is for the test
fuel to contain ethanol; the second modification is to require
preconditioning of the fuel line through a fuel soak. These
modifications are described below and are consistent with our current
requirements for recreational vehicles.
---------------------------------------------------------------------------

    \85\ Society of Automotive Engineers Surface Vehicle Standard,
``Fuel and Oil Hoses,'' SAE J30, June 1998 (Docket EPA-HQ-OAR-2004-
0008-0176).
    \86\ SAE Recommended Practice J1527, ``Marine Fuel Hoses,''
1993, (Docket EPA-HQ-OAR-2004-0008-0195-0177).
---------------------------------------------------------------------------

(a) Test Fuel
    The recommended practice in SAE J30 and J1527 is to use ASTM Fuel C
(defined in ASTM D471-98) as a test fuel. We are proposing to use a
test fuel containing 10 percent ethanol. We believe the test fuel must
contain ethanol because it is commonly blended into in-use gasoline and
because ethanol substantially increases the permeation rates for many
materials.
    Specifically, we are proposing to use a test fuel of ASTM Fuel C
blended with 10 percent ethanol by volume (CE10).\87\ Manufacturers
have expressed support of this test fuel because it is a consistent
test fluid compared to gasoline and because it is widely used today by
industry for permeation testing. In addition, most of the data used to
develop the proposed fuel line permeation standards were collected on
this test fuel. This fuel is allowed today as one of two test fuels for
measuring permeation from fuel lines under the recreational vehicle
standards.
---------------------------------------------------------------------------

    \87\ ASTM Fuel C is a mix of equal parts toluene and isooctane.
We refer to gasoline blended with ethanol as E10.
---------------------------------------------------------------------------

    We request comment on allowing permeation testing using EPA
certification gasoline (known as indolene and specified in 40 CFR
1065.710) blended with 10 percent ethanol as the test fuel (IE10). This
test fuel is also specified in the recreational vehicle standards and
has the advantage of being more similar to in-use fuel than CE10. Based
on data contained in Chapter 5 of the Draft RIA, most materials used in
fuel line constructions have lower permeation rates on IE10 than CE10.
Because the proposed standards are based primarily on data collected
using CE10 as a test fuel, we also request comment on how the level of
the standard would need to be adjusted for testing performed on IE10.
(b) Preconditioning Soak
    The second difference from weight-loss procedures in SAE practices
is in fuel line preconditioning. We believe the fuel line should be
preconditioned with an initial fuel fill followed by a long enough soak
to ensure that the permeation rate has stabilized. We are proposing a
soak period of four to eight weeks at 23  5 [deg]C.
Manufacturers should use the longer soak period as necessary to achieve
a stabilized permeation rate for a given fuel line design, consistent
with good engineering judgment. For instance, thick-walled marine fuel
line may take longer to reach a stable permeation rate than the fuel
line used in Small SI equipment. After this fuel soak, the fuel
reservoir and fuel line would be drained and immediately refilled with
fresh test fuel prior to the weight-loss test. We request comment on
the need to require a longer fuel soak, especially for marine lines.
(c) Alternative Approaches
    We also propose to allow permeation measurements using alternative
equipment and procedures that provide equivalent results (see Sec.
1060.505). To use these alternative methods, manufacturers would first
need to get our approval. Examples of alternative approaches that we
anticipate manufacturers may use are the recirculation technique
described in SAE J1737 or enclosure-type testing such as in 40 CFR part
86.\88\ Note that the proposed test fuel, test temperatures, and
preconditioning soak described above would still apply. Because
permeation increases with temperature we would accept data collected at
higher temperatures (greater than 23 [deg]C) for a demonstration of
compliance.
---------------------------------------------------------------------------

    \88\ SAE Recommended Practice J1737, ``Test Procedure to
Determine the Hydrocarbon Losses from Fuel Tubes, Hoses, Fittings,
and Fuel Line Assemblies by Recirculation,'' 1997, (Docket EPA-HQ-
OAR-2004-0008-0178).
---------------------------------------------------------------------------

    For portable marine fuel tanks, the fuel line assembly from the
engine to the fuel tank typically includes two sections of fuel line
with a primer bulb in-between and quick-connect assemblies on either
end. We are proposing a provision to allow manufacturers to test the
full assembly as a single fuel line to simplify testing for these fuel
line assemblies (see Sec.  1060.102). This gives the manufacturer the
flexibility to use a variety of materials as needed for performance
reasons while meeting the fuel line permeation standard for the fully
assembled product. Measured values would be based on the total measured
permeation divided by the total internal surface area of the fuel line
assembly. However, where it is impractical to calculate the internal
surface area of individual parts of the assembly, such as a primer
bulb, we would allow a simplified calculation that treats the full
assembly as a straight fuel line. This small inaccuracy would cause
reported emission levels (in g/m\2\/day) to be slightly higher so it
would not jeopardize a manufacturer's effort to demonstrate compliance
with the applicable standard.
    We request comment on the above approaches for fuel line permeation
testing and on the proposed test fuel.
(2) Fuel Tank Permeation Testing Procedures
    The proposed test procedure for fuel tank permeation includes
preconditioning, durability simulation, and a weight-loss permeation
test (see Sec.  1060.520). The preconditioning and the durability
testing may be conducted

simultaneously; manufacturers would put the tank through durability
testing while the tank is undergoing its preconditioning fuel soak to
reach a stabilized permeation level. We request comment on the proposed
tank permeation test procedures and options.
(a) Test Fuel
    Similar to the proposed fuel line testing procedures, we are
proposing to use a test fuel containing 10 percent ethanol to help
ensure in-use emission reductions with the full range of in-use fuels.
We are proposing to specify IE10 as the test fuel; this is made up of
90 percent certification gasoline and 10 percent ethanol (see 40 CFR
1065.710). This is the same test fuel specified for testing fuel tanks
for recreational vehicles. In addition, IE10 is representative of in-
use test fuels. We are proposing that Fuel CE10 may be used as an
alternative test fuel. Data in Chapter 5 of the Draft RIA suggest that
permeation tends to be somewhat higher on CE10 than IE10, so testing on
CE10 should be an acceptable demonstration of compliance. We request
comment on the proposed test fuels.
    We included a provision allowing recreational vehicle manufacturers
to perform emission measurements after preconditioning using IE10. This
allowance has created substantial confusion and necessitated including
additional provisions to prevent manufacturers from exercising the test
option in a way that undermines the objective of maintaining a
procedure that accounts for the effect of ethanol. As a result, we
believe it is appropriate to propose a test procedure for Small SI
equipment and Marine SI vessels that maintains a consistent approach by
including ethanol in the test fuel for both preconditioning and
emission measurements. We request comment on this approach.
(b) Preconditioning Fuel Soak
    Before testing fuel tanks for permeation, the fuel tank must be
preconditioned by allowing it to sit with fuel inside until the
hydrocarbon permeation rate has stabilized. Under this step, we are
proposing that the fuel tank be filled with test fuel and soaked--
either for 20 weeks at 28  5 [deg]C or for 10 weeks at 43
 5 [deg]C. The manufacturer may need to use a longer soak
period if necessary to achieve a stabilized permeation rate for a given
fuel tank, consistent with good engineering judgment.
    The tank would have to be sealed during this fuel soak and we are
proposing that any components that are directly mounted to the fuel
tank, such as a fuel cap, must be attached. Other openings, such as
fittings for fuel lines or petcocks, would be sealed with impermeable
plugs. In addition, if there is a vent path through the fuel cap, that
vent path may be sealed. Alternatively, we are proposing that the
opening could be sealed for testing and the fuel cap tested separately
for permeation (discussed below). If the fuel tank is designed to have
a separate fill neck between the fuel cap and the tank that is at least
12 inches long and at least 6 inches above the top of the fuel tank,
the tank may be sealed with something other than a production fuel cap.
    Manufacturers may do the durability testing described below during
the time period specified for preconditioning. The time spent in
durability testing may count as preconditioning time as long as the
fuel tank has fuel inside the entire time. During the slosh testing, a
fuel fill level of 40 percent would be considered acceptable for the
fuel soak. Otherwise, we are proposing to require that the fuel tank be
filled to nominal capacity during the fuel soak.
(c) Durability Tests
    We are proposing three tests to evaluate the durability of fuel
tank permeation controls: (1) Fuel sloshing; (2) pressure-vacuum
cycling; and (3) ultraviolet exposure. The purpose of these
deterioration tests would be to help ensure that the technology is
durable under the wide range of in-use operating conditions. For
sloshing, the fuel tank would be filled to 40 percent capacity with E10
fuel and rocked for one million cycles. The pressure-vacuum testing
would consist of 10,000 cycles from -0.5 to 2.0 psi. These two proposed
durability tests are based on draft recommended SAE practice.\89\ The
third durability test would be intended to assess potential impacts of
ultraviolet sunlight (i.e., light with wavelength ranging from 300 to
400 nanometers) on the durability of surface treatment. In this test,
the tank would be exposed to ultraviolet light with an intensity of at
least 0.40 W-hr/m2/min on the tank surface for 450 hours.
Alternatively, we are proposing the tank could be exposed to direct
natural sunlight for an equivalent period of time.
---------------------------------------------------------------------------

    \89\ Draft SAE Information Report J1769, ``Test Protocol for
Evaluation of Long Term Permeation Barrier Durability on Non-
Metallic Fuel Tanks,'' (Docket EPA-HQ-OAR-2004-0008-0195).
---------------------------------------------------------------------------

    We are proposing to include a provision that would allow
manufacturers to omit one or more of the durability tests if it is not
appropriate for a certain tank design. For example, coextruded plastic
tanks rely on a thin layer of material within the wall of the tank.
This material is never exposed to sunlight or liquid fuel so the
sloshing, pressure, and ultraviolet-exposure tests would not be
necessary. At the same time, we request comment on whether other
durability tests would be necessary to ensure that the fuel tank would
not be compromised for safety due to changes to address permeation.
Examples may be temperature cycling or impact testing.
(d) Weight-Loss Test
    Following the fuel soak, we are proposing that the fuel tank must
be drained and refilled with fresh fuel immediately after to prevent
the fuel tank from drying out. The tank would have to be sealed within
eight hours after refreshing the fuel at the end of the soak period.
The permeation rate from fuel tanks would be measured by comparing mass
measurements of the tank before and after a soaking period of at least
two weeks at a temperature of 28  2 [deg]C. In the case of
fuel tanks with very low permeation, the weight loss of the fuel tank
over two week period could be too small to obtain an accurate
measurement. We are proposing that manufacturers may extend the test
period by two weeks to obtain an accurate measurement for fuel tanks
with low permeation rates, consistent with good engineering judgment.
    A change in atmospheric pressure over the weeks of testing can
affect the accuracy of measured weights for testing due to the buoyancy
of the fuel tank. The buoyancy effect on emission measurements is
proportional to the volume of the fuel tank, so this procedure is
appropriate even for testing very small fuel tanks. To address this we
are proposing a procedure in which a reference fuel tank filled with
sand or some other inert material to the approximate total weight of
the test tank be used to zero the scale used for measuring the test
tank. This would result in measured and reported values representing
the change in mass from permeation losses rather than a comparison of
absolute masses. This is similar to an approach in which weighing would
determine absolute masses with a mathematical correction to account for
the effects of buoyancy. We believe the proposed approach is better
because it minimizes the possibility of introducing or propagating
error.
    We propose to allow permeation measurements for certification using
alternative equipment and procedures that provide equivalent results.
To use these alternative methods, manufacturers would first need to get

our approval. An example of an alternative weight-loss measurement
procedure would be to test the fuel tank in a SHED and determine the
permeation by measuring the concentration of hydrocarbons in the
enclosure.
(e) Fuel Cap Permeation Testing
    As discussed above, we are proposing that manufacturers would have
the option to test the fuel cap separately from the tank and combine
the results to determine the total tank permeation rate. In this case,
the permeation test would be performed as described above except that
the fuel cap would be mounted on an impermeable reservoir such as a
metal or glass tank. The volume of the test reservoir would have to be
at least one liter to ensure sufficient fuel vapor exposure. We are
proposing that the ``tank'' surface area for calculating the results
would be the smallest inside cross sectional area of the opening on
which the cap is mounted. The fuel cap would need to be tested in
conjunction with a representative gasket. In the case where the vent
path is through grooves in the gasket, another gasket of the same
material and dimensions, without the vent grooves, may be used. In the
case where the vent is through the cap, that vent would be sealed for
testing.
(3) Diurnal Emission Testing Procedures
    The proposed test procedure for diurnal emissions from installed
marine fuel tanks involves placing the fuel tank in a SHED, varying the
temperature over a prescribed profile, and measuring the hydrocarbons
escaping from the fuel tank (see Sec.  1060.525). The final result
would be reported in grams per gallon where the grams are the mass of
hydrocarbons escaping from the fuel tank over 24 hours and the gallons
are the nominal fuel tank capacity. The proposed test procedure is
derived from the automotive evaporative emission test with
modifications specific to marine applications.\90\ We request comment
on the proposed diurnal test procedures described below.
---------------------------------------------------------------------------

    \90\ See 40 CFR part 86, subpart B, for the automotive
evaporative emission test procedures.
---------------------------------------------------------------------------

(a) Temperature Profile
    We believe it is appropriate to base diurnal measurements on a
summer day with ambient temperatures ranging from 72 to 96 [deg]F (22.2
to 35.6 [deg]C). This temperature profile, which is also used for
automotive testing, represents a hot summer day when ground-level ozone
formation is most likely. Due to the thermal mass of the fuel and, in
some cases, the inherent insulation provided by the boat hull, the fuel
temperatures would cover a narrower range. Data presented in Chapter 5
of the Draft RIA suggest that the fuel temperature in an installed
marine fuel tank would see a total change of about half the ambient
temperature swing. We are therefore proposing a test temperature range
of 78 to 90 [deg]F (25.6 to 32.2 [deg]C) for installed marine fuel
tanks. This testing would be based on fuel temperature instead of
ambient temperature.
    We are proposing an alternative, narrower temperature range for
fuel tanks installed in nontrailerable boats (>=26 ft.). Data presented
in Chapter 5 of the Draft RIA suggest that the fuel temperature swing
in a boat stored in the water would be about 20 percent of the ambient
temperature swing. Based on this relationship, we are proposing an
alternative temperature cycle for tanks installed in nontrailerable
boats of 81.6 to 86.4 [deg]F (27.6 to 30.2 [deg]C). This alternative
temperature cycle would be associated with an alternative standard as
discussed earlier. See the proposed regulations at Sec.  1060.525 for
further detail. We request comment on the proposed test temperatures,
especially on the appropriateness of the alternative test procedure and
standard for tanks installed in nontrailerable boats.
    The automotive diurnal test procedure includes a three-day
temperature cycle to ensure that the carbon canister can hold at least
three days of diurnal emissions without vapors breaking through to the
atmosphere. For marine vessels using carbon canisters as a strategy for
controlling evaporative emissions, we are proposing a three-day cycle
here for the same reason. In the automotive test, the canister is
loaded and then purged by the engine during a warm-up drive before the
first day of testing. Here, we are proposing a different approach
because we anticipate that canisters on marine applications will be
passively purged. Before the first day of testing, the canister would
be loaded to full working capacity and then run over the diurnal test
temperature cycle, starting and ending at the lowest temperature, to
allow one day of passive purging. The test result would then be based
on the highest recorded value during the following three days.
    For fuel systems using a sealed system (including those that rely
on pressure-relief valves with no canister), we believe a three-day
test would not be necessary. Before the first day of testing, the fuel
would be stabilized at the initial test temperature. Following this
stabilization, the SHED would be purged, followed by a single run
through the diurnal temperature cycle. Because this technology does not
depend on purging or storage capacity of a canister, multiple days of
testing should not be necessary. We are therefore proposing a one-day
test for the following technologies: Sealed systems, sealed systems
with a pressure-relief valve, bladder fuel tanks, and sealed fuel tanks
with a volume-compensating air bag. We request comment on this
simplified approach.
(b) Test Fuel
    Consistent with the automotive test procedures, we are proposing to
specify a gasoline test fuel with a volatility of 9 psi.\91\ We are not
proposing that the fuel used in diurnal emission testing include
ethanol for two reasons. First, we do not believe that ethanol in the
fuel affects the diurnal emissions or control effectiveness other than
the effect that ethanol in the fuel may have on fuel volatility.
Second, in-use fuels containing ethanol are generally blended in such a
way as to control for ethanol effects in order to meet fuel volatility
requirements. We request comment on the proposed test fuel and whether
it would be appropriate to specify a test fuel blended with ethanol
either as the primary test fuel or as an optional test fuel. If so, we
request comment regarding whether the volatility of the test fuel
should be controlled to 9 psi or if ethanol should be blended into
certification gasoline. We also request comment on the effect of
ethanol in the fuel on controlled diurnal emissions and if the standard
would need to be adjusted to account for ethanol in the test fuel.
---------------------------------------------------------------------------

    \91\ Volatility is specified based on a procedure known as Reid
Vapor Pressure (see ASTM D 323-99a).
---------------------------------------------------------------------------

    Diurnal emissions are not only a function of temperature and fuel
volatility, but of the size of the vapor space in the fuel tank.
Consistent with the automotive procedures, we are proposing that the
fill level at the start of the test be 40 percent of the nominal
capacity of the fuel tank. Nominal capacity of the fuel tank would be
defined as the a fuel tank's volume as specified by the fuel tank
manufacturer, using at least two significant figures, based on the
maximum volume of fuel the tank can hold with standard refueling
techniques. The ``permanent'' vapor space above a fuel tank that has
been filled to capacity would not be considered in the nominal capacity
of the fuel tank.

(c) Fuel Tank Configuration
    The majority of marine fuel tanks are made of plastic. Even plastic
fuel tanks designed to meet our proposed standards would be expected to
have some amount of permeation. However, over the length of the diurnal
test, if it were performed on a new tank that had not been previously
exposed to fuel, the effect of permeation on the test results should be
insignificant. For fuel tanks that have reached their stabilized
permeation rate (such as testing on in-use tanks), we believe it would
be appropriate to correct for permeation. In such a case, we propose
that the permeation rate be measured from the fuel tank and subtracted
from the final diurnal test result. The fuel tank permeation rate would
be measured with the established procedure for measuring permeation
emissions, except that the test fuel would be the same as that used for
diurnal emission testing. This test measurement would have to be made
just before the diurnal emission test to ensure that the permeation
rate does not change when measuring diurnal emissions. In no case would
we allow a permeation correction higher than that corresponding to the
applicable permeation standard for a tank with a given inside surface
area. Because not correcting for permeation represents the worst-case
test result, we would accept data from manufacturers in which no
permeation correction was applied. We request comment on this approach.
(4) Diffusion Testing Procedures
    The proposed procedure for measuring diffusion emissions is very
similar to that for diurnal emissions, with three primary differences
(see Sec.  1060.530). First, the fuel tank should be filled to 90
percent of its nominal capacity. Second, the fuel tank is held in a
controlled environment to stabilize at test temperatures. Third, the
test run is proposed to be six hours in length. Testing has shown that
diffusion occurs at a steady rate, so we would want manufacturers to be
able to run a full test in a single day's shift rather than running a
test for a full 24 hours. Measured emissions are then adjusted
mathematically for comparison to the gram-per-day standard.
    There is some concern that fluctuating temperatures during this
test could cause small diurnal effects that would result in higher
measured emissions. Filling the fuel tank to 90 percent would help
minimize the potential for diurnal effects by increasing the thermal
mass of the fuel and by reducing the volume of the vapor space. In
addition, the proposed diffusion standard is based on data collected
from testing in this manner.
    As described above, we are proposing to allow fuel cap
manufacturers to voluntarily certify their fuel caps to diffusion
standard. This would require a separate test with a fuel cap mounted on
a test tank with a representative sealing configuration of production
tanks.
    As described for diurnal measurements, we are proposing that
manufacturers would be able to separately quantify permeation emissions
occurring during the diffusion test and subtract the permeation
contribution so the reported result isolates the test to quantifying
diffusion emissions.
(5) Measurement Procedures Related to Running Loss Emissions
    We do not specify a procedure for measuring running loss emissions,
but we are proposing to allow manufacturers to demonstrate control of
running losses by showing that fuel temperatures will not increase by
more than 8 [deg]C during normal operation (see Sec.  1060.104 and
Sec.  1060.535). This requires testing to measure fuel temperatures on
each equipment configuration. We are proposing a fuel temperature test
that includes filling the fuel tank with commercially available
gasoline and operating the equipment for one hour over a normal in-use
duty cycle with a load factor approximately the same as the specified
test cycle. If the equipment consumes 80 percent of the fuel capacity
in one hour of operation, a shorter period may be used based on time
until the fuel tank is drained to 20 percent capacity. We are proposing
that manufacturers would be required to document a description of the
operation and include grass height or equivalent variables affecting
load.
    We are proposing that the testing must occur outdoors with a
beginning ambient temperature ranging from 20 to 30 [deg]C with no
precipitation and with average wind speeds below fifteen miles per
hour. The ambient temperature would have to be steady or increasing
during the test and it must be during a mostly sunny time period with a
maximum cloud cover of 25 percent as reported by the nearest local
airport making hourly meteorological observations.
    We are proposing that the temperature of the fuel in the tank must
be within 2 [deg]C of (but not exceeding) the ambient temperature at
the beginning of the test. Fuel temperature would be measured with a
thermocouple positioned in the fuel but not touching the inside walls
or bottom of the tank. Ambient temperature would be measured on-site in
the shade. The equipment configuration meets the requirement to control
running losses if measured minimum and maximum fuel temperatures
throughout the period of operation do not differ by more than 8 [deg]C.
In the case were the equipment has multiple fuel tanks, the temperature
would have to be measured on each fuel tank. We request comment on this
procedure for measuring fuel temperatures.
    We are also proposing to allow manufacturers to use an alternative
procedure in a laboratory with prior EPA approval. The alternative test
procedure would need to simulate outdoor conditions and consider engine
operation, solar load, temperature, and wind speed. The manufacturer
would be required to make a demonstration of equivalency.

F. Certification and Compliance Provisions

    Sections VII and VIII describe several general provisions related
to certifying emission families and meeting other regulatory
requirements. This section notes several particulars related to
applying these general provisions to evaporative emissions.
    Marine vessels do not always include installed fuel systems.
Manufacturers of vessels without installed fuel systems do not have the
ability to control engine or fuel system design parameters. We are
therefore proposing that vessels without an installed fuel system would
not be subject to the proposed standards (see Sec.  1045.5). As a
result, it is necessary for us to treat manufacturers of uninstalled
fuel-system components as the equipment manufacturer with respect to
evaporative emission standards. This includes manufacturers of outboard
engines (including any fuel lines or fuel tanks produced with the
engine), portable fuel tanks, and the fuel line system (including fuel
line, primer bulb, and connectors).
    For ease of reference, Small SI equipment manufacturers, Marine SI
boat builders, and manufacturers of portable marine fuel tanks (and
associated fuel-system components) are all referred to as equipment
manufacturers in this section.
(1) Liability for Certification and Compliance
    The proposed standards for fuel lines and fuel tanks apply to any
such components that are used with or intended to be used with Small SI
engines or Marine SI engines (see Sec.  1060.1 and Sec.  1060.601).
Section VI.C

describes for each standard which manufacturer is expected to certify.
Engine manufacturers would describe these fuel-system components in the
same certification application in which they document their compliance
with exhaust emission standards (see Sec.  1045.201 and Sec.
1054.201).
    In most cases, nonroad standards apply to the manufacturer of the
engine or the manufacturer of the nonroad equipment. Here, the products
subject to the standards (fuel lines and fuel tanks) are typically
manufactured by a different manufacturer. In most cases the engine
manufacturers do not produce complete fuel systems and would therefore
not be in a position to do all the testing and certification work
necessary to cover the whole range of products that will be used. We
are therefore proposing an arrangement in which manufacturers of fuel-
system components are in most cases subject to the standards and are
subject to certification and other compliance requirements associated
with the applicable standards. We are proposing to prohibit the
introduction into commerce of noncompliant fuel-system components that
are intended for installation in Small SI equipment or Marine SI
vessels unless the component manufacturer either certifies the
component or has a contractual arrangement for each equipment
manufacturers using their products to certify those components. As a
matter of good practice, any components not intended for installation
in Small SI equipment or Marine SI vessels should be labeled
accordingly to prevent the possibility of improper installation to
prevent confusion in this regard.
    As described in Section VI.D, component manufacturers may certify
with measured emission levels showing that the components meet the
emission standard, or they may certify to an FEL above or below the
standard. If any component manufacturer certifies using an FEL, the FEL
becomes the emission standard for that emission family for all
practical purposes. The component manufacturer however would not be
required to meet any overall average for their products, but would have
the option to certify to an FEL above or below the standard. This is to
facilitate the use of ABT by equipment manufacturers, as discussed
below.
    Equipment manufacturers would be subject to all the proposed
evaporative standards. This applies for the general standards described
above with respect to fuel caps, miscellaneous fuel-system components,
and refueling. These standards generally depend on design
specifications rather than emission measurements, so we believe it is
appropriate to simply deem these products to be certified if they are
designed and produced to meet the standards we specify. The vessel
manufacturer would also need to keep records of the components used
(see Sec.  1060.210). This would allow us, by operation of the
regulation, to have certified products without requiring the paperwork
burden associated with demonstrating compliance with these relatively
straightforward specifications. Manufacturers could optionally apply
for and receive a certificate of conformity with respect to these
general standards, but this would not be necessary and we would expect
this to be a rare occurrence.
    Equipment manufacturers would also be subject to all the proposed
emission standards. Equipment manufacturers may comply with
requirements related to evaporative emission standards in three
different situations. First, equipment manufacturers might install only
components certified by the component manufacturer, without using
emission credits. In this case all the components must meet the
proposed emission standard or have an FEL below the standard. Such an
equipment manufacturer would be subject to the fuel line and fuel tank
standards, but would be able to satisfy their requirements by using
certified components. They would need to apply for certification only
with respect to the remaining emission standards they are subject to,
such as running loss emissions (if applicable). Equipment manufacturers
must also design and produce their equipment to meet the requirements
specified in Sec.  1060.101(f), though this would not necessarily
involve an application for certification. Such an equipment
manufacturer would generally need only to use certified components, add
an emission label, and follow any applicable emission-related
installation instructions to ensure that certified components are
properly installed. This is similar to an equipment manufacturer that
is required to properly install certified engines in its equipment,
except that the equipment manufacturer must meet general design
standards and shares the liability for meeting emission standards.
    Second, equipment manufacturers may be required to certify certain
components based on contractual arrangements with the manufacturer of
those components. In this case, the equipment manufacturer's
certification causes the component manufacturer to no longer be subject
to the standard. This approach might involve the equipment manufacturer
relying on test data from the component manufacturer. The equipment
manufacturer might also be producing its own fuel tanks for
installation in its equipment, in which case it would be subject to the
standards and all requirements related to certification and compliance.
In either case, the equipment manufacturer would take on all the
responsibilities associated with certification and compliance with
respect to those components.
    Third, equipment manufacturers may comply with evaporative emission
requirements by using certified components, some of which are certified
to an FEL above the standard. The equipment manufacturer would then
comply based on emission credits. In this case, the equipment
manufacturer would take on all the certification and compliance
responsibilities with respect to any components that are part of the
equipment manufacturer's emission credit calculations. Equipment
manufacturers would generally use only certified components for meeting
evaporative emission requirements, but they might also hold the
certificate for such components. For purposes of certification,
equipment manufacturers would not need to submit new test data if they
use certified components. Equipment manufacturers would make an annual
accounting to demonstrate a net balance of credits for the model year.
Under this approach, the component manufacturer would continue to be
subject to the standards for its products and be required to meet the
certification and compliance responsibilities related to the standard.
However, as in the first option, the component manufacturer would not
be required to meet any averaging requirements or be required to use
emissions credits. Where equipment manufacturers use ABT with
components that have already been certified by the component
manufacturer, there will be overlapping certifications between the two
parties. We propose to address this by specifying that all parties are
responsible for meeting applicable requirements associated with the
standards to which they have certified, but if any specific requirement
is met by one company, we will consider the requirement to be met for
all companies (see Sec.  1060.5). For example, either the component
manufacturer or the equipment manufacturer could honor warranty claims,
but we may hold both companies responsible for the violation if there
is a failure to meet warranty obligations.
    Similarly, if we find that new equipment is sold without a valid

certificate of conformity for the fuel lines or fuel tanks, then the
equipment manufacturer and all the affected fuel-system manufacturers
subject to the standards would be liable for the noncompliance (see
Sec.  1060.601).
    Liability for recall of noncompliant products would similarly fall
to any manufacturer whose product is subject to the standard, as
described above. If more than one manufacturer is subject to the
standards for a noncompliant product, we would have the discretion to
assign recall liability to any one of those manufacturers. In assigning
this liability, we would generally consider factors such as which
manufacturer has substantial manufacturing responsibility and which
manufacturer holds the certificate (see Sec.  1060.5). However, we may
hold equipment manufacturers liable for recall even if they don't
manufacture or certify the defective product. This would generally be
limited to cases where the component manufacturer is unavailable to
execute any remedial action. For example, if a foreign component
manufacturer discontinues their participation in the U.S. market or a
component manufacturer goes out of business, we would turn to the
equipment manufacturer.
    The proposed running loss standards for nonhandheld Small SI
engines are not geared toward component certification, which
necessitates some special provisions. If engine manufacturers sell
their engines with a complete fuel system, which is typical for Class I
engines, they would also be subject to and need to comply with running
loss standards as part of their overall certification. Of the available
alternatives for demonstrating compliance with the running loss
standard, we would expect the only practical approach for these
companies would be to route vapors from the fuel tank into the engine's
air intake system for combustion. Any engine manufacturer certifying
its engines this way would need to test for exhaust emissions with an
installed running loss vent (see Sec.  1054.501). If equipment
manufacturers use only fuel-system components that have been certified
by component manufacturers (without using emission credits) and engines
that are certified by the engine manufacturer to meet both exhaust and
running loss standards, they would have no responsibility to certify.
However, if the engine manufacturer does not sell its engine with a
complete fuel system that has been certified for running loss control,
the equipment manufacturer would need to certify with respect to the
running loss standard.
    The running loss standard is not a typical standard based on
emission measurements using established procedures. Some of the
available compliance demonstrations involve straightforward design
specifications that involve no measurement at all. The approach of
keeping fuel temperatures from increasing above a specified threshold
involves a test procedure with a performance standard, but does not
involve emission measurements. As described above, it may be possible
to identify design specifications that would replace the need for the
proposed temperature measurements. In this case running loss control
would be a straightforward design standard that we could treat like the
general standards above, in which equipment manufacturers are deemed to
be certified by operation of the regulations, rather than submitting an
application for certification. The regulations would prohibit the sale
of equipment without the specified running loss controls.
(2) Regulatory Requirements Related to Certification
    The established provisions for implementing exhaust emission
standards apply similarly for evaporative emission standards; however,
because the control technologies are very different, these requirements
require further clarification. For example, scheduled maintenance is an
important part of certifying engines to exhaust emission standards.
There is little or no maintenance involved for the expected
technologies for controlling evaporative emissions. The regulations
still require manufacturers to identify specified maintenance