[Federal Register Volume 63, Number 115 (Tuesday, June 16, 1998)]
[Notices]
[Pages 32878-32880]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-15845]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-6111-1]


Revision to Addendum to Mobile Source Enforcement Memorandum 1A; 
Revised Tampering Enforcement Policy for Alternative Fuel Conversions

A. Purpose

    The purpose of this document is to revise the tampering enforcement 
policy for alternative fuel conversions as currently provided in the 
U.S. Environmental Protection Agency's (EPA) Addendum to Memorandum 1A 
in response to comments and suggestions received by the regulated 
community and other stakeholders.

B. Background

    EPA issued an Addendum to Mobile Source Enforcement Memorandum 1A 
(Addendum) on September 4, 1997, to address emissions increases that 
resulted from the conversion of gasoline powered vehicles and engines 
to operate on compressed natural gas (CNG) and liquefied petroleum 
gasoline (LPG or propane). The background and basis for the issuance of 
the Addendum and the contents of the new policy are fully contained in 
the Addendum. Since issuance of the Addendum, EPA has received a number 
of inquiries and recommendations that certain revisions to the policy 
would be in the public interest while not jeopardizing the

[[Page 32879]]

effectiveness of the Addendum. EPA believes some of those suggestions 
are appropriate and is revising the Addendum as described below.

C. Revised Policy

    Effective June 1, 1998, the Addendum to Memorandum 1A is revised as 
follows:
    1. In lieu of meeting the testing requirements under Options 1, 2 
or 3 of the Addendum for model year 1997 and older motor vehicles and 
engines, compliance with the requirements for demonstrating a 
``reasonable basis'' may be achieved by completing back-to-back I/M 240 
emissions tests as contained in 40 CFR Part 51, Subpart S, for each 
converted vehicle using gasoline in the vehicle or engine's original 
configuration and with each operational fuel after conversion provided:
    (a) All tests are conducted in accordance with the specified 
protocols under 40 CFR Part 51, Subpart S,
    (b) The vehicle as tested in the original configuration with 
gasoline meets the applicable standards under 40 CFR 51.351,
    (c) The exhaust emissions of each regulated pollutant after 
conversion using the alternative fuel are no greater than .90 times the 
emissions levels for each pollutant before conversion, except that no 
hydrocarbon standard shall apply for operation exclusively using CNG,
    (d) If dual fuel operation is retained, the exhaust emissions of 
each regulated pollutant after conversion using the original 
certification fuel are no greater than the emissions levels for each 
pollutant before conversion, and
    (e) No party shall convert more than 25 vehicles or engines of any 
single vehicle/engine family combination in any calendar year under 
this I/M 240 protocol.
    2. The final date for both testing and installations under Option 3 
of the Addendum is extended from April 24, 1998 and December 31, 1998, 
respectively, to June 30, 2000, for up to and including 1999 model year 
vehicles and engines. All alternative fuel conversions of model years 
2000 and later vehicles and engines and conversions of model year 1998 
and 1999 vehicles and engines after June 30, 2000, may only be 
performed in accordance with Options 1 or 2 of the Addendum.
    3. As an alternate to engine dynamometer testing for heavy duty 
engine conversions under Option 3 for a specific heavy duty engine 
family, the manufacturer may demonstrate a ``reasonable basis'' by 
performing back-to-back chassis dynamometer emission tests in 
accordance with the Urban Dynamometer Driving Schedule for Heavy Duty 
Vehicles (UDDS) contained in 40 CFR Part 86 Appendix I, Paragraph (d), 
provided:
    (a) The exhaust emissions results for THC, NO<INF>X</INF> and CO 
measured during the UDDS after conversion and when operated exclusively 
or in combination with the alternative fuel are no greater than .90 
times the baseline emissions for THC and NO<INF>X</INF> and no greater 
than 1.00 times CO before conversion, except that NMHC after conversion 
shall be compared to the baseline THC before conversion in the case of 
operation exclusively with CNG, and
    (b) All tests are performed in accordance with all specified 
protocols in 40 CFR Part 86, Subpart M, including vehicle preparation, 
dynamometer loading, emissions measurements and driving schedule except 
that commercially available fuel may be used for vehicle 
preconditioning and baseline testing.
    4. As an alternate to engine dynamometer testing for heavy duty 
engine conversions under Option 3 for a specific heavy duty engine 
family or the alternate procedures provided in paragraph 3. above or 
the Addendum, any party may propose an alternate heavy duty vehicle or 
engine test procedure which operates the subject test engine through a 
range of engine speed and load conditions reasonably representative of 
both urban and highway driving, measures the exhaust emissions 
specified above on a grams per mile or grams per brake horsepower-hour 
basis and specifies appropriate pass/fail criteria equivalent to 
paragraph 3. above for the purpose of demonstrating a ``reasonable 
basis'' under EPA's tampering enforcement policy. Any such proposed 
procedures shall be submitted to the Director, Air Enforcement Division 
(2242A), Office of Enforcement and Compliance Assurance, U.S. EPA, 401 
M Street, S.W., Washington, D.C. 20460 for consideration and approval, 
if appropriate, under this policy prior to the initiation of any 
vehicle procurement, modification or testing.
    5. The results of federal emissions tests conducted under Option 3 
for a specific engine family may be applied as a ``reasonable basis'' 
for up to a maximum of three additional engine families to that tested 
for demonstrating compliance with the applicable Tier 1 emission 
standards for that class of vehicle or engine as specified in 40 CFR 
Part 86 provided:
    (a) The engine family tested in accordance with 40 CFR Part 86 
meets the applicable Tier 1 standards for that vehicle or engine class 
with the application of the appropriate deterioration factor as 
provided under Option 3,
    (b) The engine family tested above represents the ``worst case'' 
for emissions of the applicable engine families as based on engine or 
vehicle parameters reasonably expected to adversely affect the emission 
results such as maximum gross vehicle weight, maximum engine 
displacement and any other reasonable engineering judgments,
    (c) The determination of ``worst case'' is confirmed by conducting 
I/M 240 emissions tests of one vehicle or engine of each applicable 
engine family after conversion,
    (d) The results of the I/M 240 tests of the three additional engine 
families are no greater than the I/M 240 emission results of the 
original engine family tested,
    (e) The additional engine families meet the criteria specified in 
paragraphs 3.(b)(4)B. through D. of the Addendum, and
    (f) The evaporative emission control system remains as installed by 
the original engine manufacturer if gasoline operation is retained.
    6. For both LEV and Tier 1 vehicles or engines, any additional 
engine families for which emission data would be carried across under 
paragraph 5. above or paragraph 3.(b)(4) under Option 3 of the Addendum 
must be produced by the same vehicle or engine manufacturer as the 
original engine family tested.
    7. Any party responsible for demonstrating compliance, installing, 
converting, selling or marketing alternative fuel conversion systems in 
accordance with the requirements of the Addendum and this revised 
policy shall retain the results of all tests, installations and sales 
of such systems as specified under Option 3 of the Addendum or this 
Revision for inspection by EPA for five (5) years following completion 
of the testing, installing or marketing of such systems.
    8. Any provisions or requirements of the Addendum not extended or 
revised herein remain in effect as provided in the Addendum.

C. Conclusion

    EPA believes the revisions described above will provide additional 
flexibility and streamlining to manufacturers, installers and marketers 
of alternative fuel conversion systems while not jeopardizing the 
emission reduction purposes of the original Addendum. EPA will continue 
to review the progress of the industry in developing and testing of 
alternative fuel systems to

[[Page 32880]]

ensure the emissions benefits are being achieved and to determine if 
any future revisions are necessary. Any questions regarding this 
revised policy should be directed to the Mobile Source Enforcement 
Branch at (202) 564-2255.
Bruce C. Buckheit,
Director, Air Enforcement Division, Office of Enforcement and 
Compliance Assurance.
[FR Doc. 98-15845 Filed 6-15-98; 8:45 am]
BILLING CODE 6560-50-P