Control of Emissions from Nonroad Large Spark Ignition Engines
and Recreational Engines (Marine and Land-based); Extension of Comment
Period
[Federal Register: May 1, 2002 (Volume 67, Number 84)]
[Proposed Rules]
[Page 21613-21617]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01my02-23]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 89, 90, 91, 94, 1048, 1051, 1065, and 1068
[AMS-FRL-7204-7]
RIN 2060-AI11
Control of Emissions from Nonroad Large Spark Ignition Engines
and Recreational Engines (Marine and Land-based); Extension of Comment
Period
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule; reopening of comment period.
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SUMMARY: The Environmental Protection Agency published in the Federal
Register of October 5, 2001, a notice of proposed rulemaking proposing
new emission standards for large spark-ignition engines, recreational
vehicles using spark-ignition engines, and recreational marine diesel
engines. The Agency received a number of comments noting considerable
information on strategies to reduce permeation emissions and suggesting
that requirements controlling such emissions be proposed for land-based
recreational vehicles. As a result, EPA is requesting comment on
whether it should finalize an emission standard controlling permeation
emissions from fuel tanks and hoses for land-based recreational
vehicles. This document provides a detailed discussion regarding this
issue and discusses what form a final standard regulating these
permeation emissions would take. This document extends the period for
written comments on that notice of proposed rulemaking to May 31, 2002.
The extension only applies to comments on whether EPA should finalize
emission standards regulating permeation emissions from land-based
recreational vehicles, and, if so, the form such standards would take.
DATES: Comments: Send written comments on this notice by May 31, 2002.
ADDRESSES: You may send written comments in paper form to Margaret
Borushko, U.S. EPA, National Vehicle and Fuels Emission Laboratory,
2000 Traverwood, Ann Arbor, MI 48105. We must receive them by the date
indicated under DATES above. You may also submit comments via e-mail to
``NRANPRM@epa.gov.'' In your correspondence, refer to Docket
A-2000-01.
FOR FURTHER INFORMATION CONTACT: Margaret Borushko, U.S. EPA, National
Vehicle and Fuels Emission Laboratory, 2000 Traverwood, Ann Arbor, MI
48105; Telephone (734) 214-4334; FAX: (734) 214-4816; E-mail:
borushko.margaret@epa.gov. EPA hearings and comments hotline:
734-214-4370.
SUPPLEMENTARY INFORMATION: On October 5, 2001, we published a Notice of
Proposed Rulemaking (NPRM) for the Control of Emissions from Nonroad
Large Spark Ignition Engines and Recreational Engines (Marine and Land-
Based) (66 FR 51098). The comment period for the NPRM was originally
scheduled to end on December 17, 2001; however, the comment period was
extended to January 18, 2002 as a result of several requests for
additional time. During this comment period, we received many comments
from a wide range of commenters covering a broad range of issues. One
of the issues that was raised by several commenters \1\ was the
information related to the control of evaporative emissions related to
permeation from fuel tanks and fuel hoses, and the lack of any proposed
emission standards regulating these emissions from land-based
recreational vehicles.
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\1\ See public docket A-2000-1 IV-D-186, items IV-D-198, and IV-
D-202.
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We have conducted our initial review and assessment of the issues
and data raised in these comments, and believe that they have merit and
should be presented to the public for further consideration. Therefore,
we are asking for comment on the possibility of finalizing standards
regulating permeation emissions from land-based recreational vehicles.
Our work on evaporative emissions from marine applications indicates
that the permeation emissions from tanks and hoses are a large part of
the total emissions from these applications. Additionally, commenters
stated that work done by the California Air Resources Board (ARB) on
permeation emissions from plastic fuel tanks and rubber fuel line hoses
for various types of nonroad equipment as well as portable plastic fuel
containers indicated that these permeation emissions are a concern. Our
own investigation into the hydrocarbon emissions related to permeation
of fuel tanks and fuel hoses with respect to marine applications
supports the concerns raised by the commenters. Given this, we are
assessing the possibility of regulating permeation emissions from other
vehicle types, including, off-highway motorcycles (OHM), all-terrain
vehicles (ATVs) (including utility work and specialty
[[Page 21614]]
vehicles), and snowmobiles that may use fuel tanks or hoses with less-
than-optimal control of permeation emissions.
I. Description of Regulatory Concept
We are reopening the comment period for land-based recreational
vehicles to request comment on whether we should finalize standards
that would require low permeability fuel tanks and hoses on off-highway
motorcycles, ATVs, and snowmobiles starting with the 2006 model year.
The requirements would phase-in beginning for all three types of
recreational vehicle at 50 percent in 2006 and 100 percent in 2007.
This is the same start year as was proposed in the October 5, 2001 NPRM
for exhaust emission control for these three types of recreational
vehicle. We believe cost-effective technologies exist to significantly
reduce permeation emissions. Because all of these vehicles use high
density polyethylene (HDPE) tanks, manufacturers would in all
likelihood have to employ one of the barrier technologies (e.g., a
fluorination or sulfonation treatment) described below to meet the
standards. The use of metal fuel tanks would also meet the standards,
since metal tanks do not experience any permeation losses. Fuel tanks
built with permeation resistant barrier layers would also be possible,
but could likely be more expensive and employ production practices not
used on HDPE tanks in these applications. We also request comment on
promulgating standards that would also require the use of low
permeability fuel hoses on all land-base recreational vehicles,
starting with 50 percent implementation in the 2006 model year and 100
percent in 2007.
Even though snowmobiles do not usually experience year around use,
as is the case with ATVs, off-highway motorcycles, etc., we are
including snowmobiles in this request for comment because it is common
practice among snowmobile owners to store their snowmobiles in the off-
season with fuel in the tank (typically half full to full tank). A fuel
stabilizer is typically added to the fuel to prevent gum, varnish, and
rust from occurring in the engine as a result of the fuel sitting in
the fuel tank and fuel system for an extended period of time, but this
does not reduce permeation. Thus, snowmobiles experience fuel
permeation losses just like off-highway motorcycles and ATVs. We
request comment on the fuel storage practices of snowmobile operators.
EPA requests comments in several areas with regard to the way in
which requirement might be implemented. First, we request comment on
the form these standards would take (e.g., whether there should be
absolute numerical limits on a gram per gallon basis or if the standard
should be expressed as a grams per square meter per day of tank surface
area). Given differences in wall thickness, tank geometry, material
quality, and pigment, we also ask comment on whether an emission credit
averaging, banking, and trading (ABT) scheme would be helpful and
necessary for the fuel tank permeation requirements. If we do adopt ABT
provisions, we would envision an ABT program similar in nature to that
used for heavy-duty engines (see 40 CFR 86.004-15) but substituting
fuel tank volume for transient conversion factor.
Information indicates that permeation emissions can essentially be
eliminated at minimal cost. We are interested in comments on provisions
that would require near zero permeation levels, with a small factor to
address issues such as measurement accuracy or repeatability. Available
data indicate that 95 percent reductions are achievable. Achieving
reductions at this level repeatedly would require tanks with consistent
material quality, amount, and composition including pigments and any
additive packages. This would enable process and efficiency
optimization and consistency in the effectiveness of surface treatment
processes. These reductions imply a tank permeability standard of 0.04
grams per gallon per day at 30 deg.C or about 0.4 to 0.5 grams per
square meter per day. We are also requesting comments on the estimates
for emissions reductions and costs presented in this notice.
Certification with these fuel tank requirements would require
testing such as that described in 49 CFR 173 appendix B, California ARB
test method 513, or equivalent, as laid out in the docket. Normally
five tests would be required and the average value used. This test is
based on a change in filled tank mass over a period of time. We would
consider a temperature of 28 deg.C ± 28 deg.C to be an
appropriate range for our testing requirement. Vehicle manufacturers or
tank manufacturers could certify and either could contract with a party
providing barrier treatment or another source to do the required
testing.
With regard to fuel hoses, the requirement would apply to any line
normally containing liquid gasoline in storage or operation. These fuel
hoses could be certified as being manufactured in compliance with
certain accepted SAE specifications. These certification statements
could be done on a family basis, or possibly a blanket statement could
cover a manufacturer's entire product line. Similarly, near zero
permeation emissions from hoses are feasible. Assuming a factor to
address testing concerns, EPA expects that 95 percent reductions over
uncontrolled emission levels for permeation are achievable for rubber
hoses. For fuel hoses, we would consider a standard of 5 grams per
square meter per day at 23 deg.C, as would be measured using the
recommended test procedure in SAE J1527.
We also request comment on implementing requirements such as those
described above by allowing the manufacturer to submit a statement at
the time of certification that the fuel tanks and hoses used on their
products meet standards, specified materials, or construction
requirements based on testing results. For example, a manufacturer
using plastic fuel tanks could state that the family at issue is
equipped with a fuel tank with a low permeability barrier treatment
such as fluorination and provide EPA the supporting test information as
described above for the worst case configuration in the family. Key
parameters could include tank geometry, wall thickness, pigment,
additive package, and amount of material in the tank. All tanks in the
family would require the same level or type of treatment in production.
We request comment on these and other options that would enable
regulation and enforcement of low permeability requirements. Most
notably we are interested in provisions that would allow the
certificate holder assurance that the treated tanks and fuel hoses
provided by suppliers/vendors consistently meet the performance
specifications laid out in the certificate and provisions regarding
liability.
Information concerning potential draft regulations covering these
implementation provisions as discussed above can be found in the public
docket (A-2000-1).
Another important element of the test requirements is fuel quality.
Permeation testing generally involves a gasoline or hydrocarbon mixture
and may involve alcohol as well. There are at least four possible test
fuels for consideration. These include: (1) Neat gasoline such as
current EPA certification fuel, (2) certification quality gasoline with
a 10% ethanol blend as is prescribed for the Tier 2 automobile
evaporative standards, (3) ASTM D471 test fuel C (50% iso-octane/50%
toluene) and, (4) ASTM D471 test fuel I (test fuel C with 15%
methanol). Permeation is greater with alcohol-blend fuels and since
there
[[Page 21615]]
is a significant amount of ethanol and other alcohols used in gasohol
and other summer and winter gasolines Tier 2 type evaporative test fuel
is of special interest. We are requesting comments on the test fuel.
II. Technological Feasibility
EPA believes there are available technologies that can reduce
permeation emissions to near-zero levels. For example, fluorinated fuel
tanks and low permeability hoses, which are already available for small
additional costs, could reduce permeation of tanks and hoses by 95
percent or more. The application of these technologies to land-based
recreational vehicles appears to be relatively straightforward, with
little cost and no adverse performance or aesthetic impacts. In
addition, the control technology would generally pay for itself over
time by conserving fuel that would otherwise evaporate.
A recent regulation in California requires a change from untreated
high-density polyethylene (HDPE) plastic to fluorinated or sulfonated
HDPE portable gasoline cans. Fuel tanks used by land-based recreational
vehicles are all made of HDPE. Comments from California ARB suggest
that the same technology used for small portable HDPE gasoline fuel
cans could be readily applied to the fuel tanks of recreational
vehicles.
As discussed above, there are two types of fuel tank barrier
processes that can be employed to reduce or eliminate permeation in
HDPE plastic tanks. The fluorination process causes a chemical reaction
where exposed hydrogen atoms are replaced by larger fluorine atoms
which form a barrier on the surface of the fuel tank. In this process,
fuel tanks are stacked in a steel basket and placed in a sealed
reactor. All of the air in the reactor is removed and replaced with
fluorine gas. By pulling a vacuum in the reactor, the fluorine gas is
forced into every crevice in the fuel tanks. As a result of this
process, both the inside and outside surfaces of the fuel tank are
treated. As an alternative, for tanks that are blow molded, the inside
surface of the fuel tank can be exposed to fluorine during the blow
molding process. In a similar barrier strategy, called sulfonation,
sulfur trioxide is used to create the barrier by reacting with the
exposed polyethylene to form sulfonic acid groups on the surface.
Either of these processes can be used to reduce gasoline permeation by
more than 95 percent.\2\
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\2\ Kathios, D., Ziff, R., Petrulis, A., Bonczyk, J.,
``Permeation of Gasoline and Gasoline-alcohol Fuel Blends Through
High-Density Polyethylene Fuel Tanks with Different Barrier
Technologies,'' SAE Paper 920164, 1992, Air Docket A-2000-01,
Document No. II-A-60.
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The majority of fuel hoses used in recreational vehicles today are
made of nitrile rubber which has a high rate of fuel permeation.\3\
However, low permeation hoses are available that could be used in these
applications. Low permeability hoses produced today are generally
constructed in one of two ways: using a low permeability material or a
low permeability barrier layer. One hose design, already used in some
marine applications, uses a thermoplastic layer between two rubber
layers to control permeation. This thermoplastic barrier may either be
nylon or ethyl vinyl alcohol. In automotive applications, other barrier
materials are used such as fluoroelastomers and fluoroplastics which
are two to three orders of magnitude less permeable than hoses
currently on recreational vehicles.\4\ By replacing rubber hoses with
low permeability hoses, permeation emissions through the fuel hoses can
be reduced by more than 95 percent. An added benefit of low
permeability lines is that some fluoropolymers can be made to conduct
electricity and therefore can prevent the buildup of static charges.
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\3\ Stahl, W., Stevens, R., ``Fuel-Alcohol Permeation Rates of
Fluoroelastomers, Fluoroplastics, and other Fuel Resisitant
Materials,'' SAE 920163, 1992.
\4\ Denbow, R., Browning, L., Coleman, D., ``Report Submitted
for WA 2-9, Evaluation of the Costs and Capabilities of Vehicle
Evaporative Emission Control Technologies,'' ICF, ARCADIS Geraghty &
Miller, March 22, 1999.
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III. Projected Impacts
A. Economic Impact
Off-highway motorcycle fuel tanks range in capacity from
approximately one gallon on some smaller youth models to about three
gallons on some enduro motorcycles. For ATVs, fuel tanks range from one
gallon for the smaller youth models to five gallons for the larger
utility models. Finally, snowmobile fuel tanks range from 10 gallons to
about 12 gallons. We estimate that fluorination of the fuel tanks would
cost about $0.50 per gallon of capacity. Cost is related to fuel tank
size because the cost of the treatment to any given level of
effectiveness depends on how many fuel tanks can be fit into the
fluorination chamber and the amount of polymer to be treated. It is
estimated that shipping, handling, and overhead costs would be an
additional $0.22 to $0.81 per fuel tank depending on tank volume. Table
1 presents estimated costs of fuel tank permeation control using
fluorination.
EPA's examination of land-based recreational vehicles indicated
that none of these vehicles are equipped with fuel hoses that
significantly reduce or eliminate permeation. The incremental cost of a
fuel line with low permeation properties for recreational vehicles is
estimated to be about $1.00 per foot. For off-highway motorcycles, it
is estimated that they use approximately one to two feet of fuel line
on average. For ATVs, we estimate one foot of fuel line on average.
Snowmobiles are a little more complex since they use multi-cylinder
engines (either two or three cylinders). For two cylinder engines we
estimate two to three feet of fuel line and for three cylinder engines
we estimate three to four feet of fuel line. We are interested in
collecting more information regarding fuel hoses currently used on
land-based recreational vehicles, in particular regarding the typical
length, the material, and the permeation properties. Table 1 also
presents estimated costs of hose permeation control. Fuel savings due
to reducing permeation, which are discussed later, are not included in
this table. The costs in Table 1 include a 30 percent manufacturer
markup from the vehicle manufacturer.
Table 1.--Average Cost of Permeation Control per Vehicle
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OHM ATVs Snowmobiles
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Average fuel tank capacity [gallons]....... 3 4 11
Fluorination cost (includes shipping/ $2.19 $2.93 $5.43
handling/overhead)........................
Average hose length [feet]................. 1.5 1 3.5
Increased Hose Cost........................ 1.95 1.30 4.55
Total Cost Increase........................ 4.14 4.23 9.98
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B. Environmental Impact
As was discussed earlier, EPA as well as California ARB, have
conducted permeation testing with regard to permeation emissions from
HDPE plastic tanks. Permeation rates varied from 0.2 to1.0 grams per
gallon per day with an average value of 0.76 g/gal/day. This data was
based on tests with an average temperature of about 29 deg.C.
Temperature has a first-order effect on the rate of permeation.
Roughly, permeation doubles with every 10 deg.C increase in
temperature. For example, we estimate that at 23 deg.C, the average
value for these fuel tanks would be about 0.50 g/gal/day. This test
data can be found in the docket
[[Page 21616]]
Fuel hoses on recreational vehicles generally have an inside
diameter of about 6 mm (1/4 inch) and a permeation rate of 550 grams
per square meter per day for uncontrolled hoses at 23 deg.C. We base
this permeation rate on the SAE J30 requirement for R7 fuel hose.\5\
For 1 foot of fuel hose, this yields an emission rate of 5.0 g/day at
23 deg.C.
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\5\ SAE J30, ``Fuel and Oil Hoses,'' Surface Vehicle Standard,
Society of Automotive Engineer Revised June 1998.
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Table 2 presents national totals for permeation emissions from
recreational vehicles. These permeation estimates are based on the
emission rates discussed above and population and turnover estimates
used in our draft NONROAD emissions model.\6\ The daily temperatures by
region (6 regions are used) are based on a report which summarizes a
survey of dispensed fuel and ambient temperatures in the United
States.\7\
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\6\ This information is also available in Chapter 6 of the
Regulatory Support Document for the NPRM. For more detailed
information on the draft NONROAD model, see our Web site at
www.epa.gov/otaq/nonrdmdl.htm.
\7\ API Publication No. 4278, ``Summary and Analysis of Data
from Gasoline Temperature Survey Conducted at Service Stations by
American Petroleum Institute,'' Prepared by Radian Corporation for
American Petroleum Institute, November 11, 1976, Docket A-2000-01,
Document II-A-16.
Table 2.--Potential Permeation Emission Control Reductions
[tons/yr]
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Category Scenario 2005 2010 2020 2030
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Off-highway motorcycles............. baseline.............. 6,203 6,434 6,903 6,847
control............... 6,203 3,258 188 651
reduction............. 0 246 519 563
ATVs................................ baseline.............. 24,891 33,136 38,856 36,777
control............... 24,891 21,574 4,139 7,046
reduction............. 0 11,562 34,716 29,731
Snowmobiles......................... baseline.............. 16,083 16,681 17,899 17,679
control............... 16,083 8,462 517 2,320
reduction............. 0 8,219 17,382 15,359
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Total........................... baseline.............. 47,178 56,251 63,658 61,303
control............... 41,178 33,294 4,845 10,018
reduction............. 0 22,957 58,813 51,286
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C. Cost per Ton of Emissions Reduced
The average lifetimes of typical recreational vehicles are
estimated to be about 9 years for off-highway motorcycle and
snowmobiles and 13 years for ATVs. Permeation control techniques can
reduce emissions by about 95 percent for plastic fuel tanks and more
than 99 percent for rubber hoses. Multiplying this efficiency and these
emission rates by the life of the vehicles and discounting at 7 percent
gives us lifetime per vehicle emission reductions. Using the cost
estimates above, we have also determined cost per ton of hydrocarbons
reduced. These estimates are presented Table 3.
Table 3.--Estimated Cost Per Ton of HC Reduced Without Fuel Savings
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Discounted
Lifetime cost per
Category Source Cost (NPV) reductions ton ($/
(NPV, tons) ton)
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Off-highway motorcycles................... fuel tank.................... $2.19 0.0026 $828
fuel hose.................... $1.95 0.0315 $62
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Total................................. ............................. $4.14 0.0342 $121
ATVs...................................... fuel tank.................... $2.93 0.0044 $664
fuel hose.................... $1.30 0.0263 $49
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Total................................. ............................. $4.23 0.0307 $138
Snowmobiles............................... fuel tank.................... $5.43 0.0079 $689
fuel hose.................... $4.55 0.0598 $76
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Total................................. ............................. $9.98 0.0677 $147
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Because these emissions are composed of otherwise useable fuel that
is lost to the atmosphere, measures that reduce permeation emissions
can result in potentially significant fuel savings. Table 4 presents
our estimates of these fuel savings as well as adjusted cost per ton
estimates which consider these fuel savings. The value of the fuel
savings presented are based on a discount rate of 7 percent and an
average nontax gasoline fuel price of $1.10 per gallon. As is shown
below, the fuel savings are generally larger than the cost of using low
permeation technology. To the consumer this is a net cost savings over
the vehicle life of about $8 for off-highway motorcycles, $7 for ATVs,
and $14 for snowmobiles. It is estimated that this technology would
save about 20 million gallons of gasoline per year when fully
implemented.
[[Page 21617]]
Table 4.--Estimated Cost Per Ton of HC Reduced With Fuel Savings
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Value of Discounted
Fuel saved fuel cost per
Category Source (gallons) savings ton ($/
(NPV) ton)
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Off-highway motorcycles................... fuel tank.................... 1.1 $0.96 $465
fuel hose.................... 13.4 11.45 (301)
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ATVs...................................... fuel tank.................... 2.2 1.64 292
fuel hose.................... 12.9 9.79 (323)
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Snowmobiles............................... fuel tank.................... 3.4 2.82 326
fuel hose.................... 25.5 21.71 (287)
Total................................. ............................. 28.8 24.57 (216)
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Dated: April 25, 2002.
Elizabeth Craig,
Acting Assistant Administrator for Air and Radiation.
[FR Doc. 02-10730 Filed 4-30-02; 8:45 am]
BILLING CODE 6560-50-P