Retrofit/Rebuild Requirements for 1993 and Earlier Model Year
Urban Buses; Approval of a Notification of Intent to Certify Equipment
Related Material
[Federal Register: November 26, 1997 (Volume 62, Number 228)]
[Notices]
[Page 63159-63161]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26no97-91]
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ENVIRONMENTAL PROTECTION AGENCY
[FRL-5927-9]
Retrofit/Rebuild Requirements for 1993 and Earlier Model Year
Urban Buses; Approval of a Notification of Intent to Certify Equipment
AGENCY: Environmental Protection Agency.
ACTION: Notice of Agency Certification of Equipment for the Urban Bus
Retrofit/Rebuild Program.
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SUMMARY: The Agency received a notification of intent to certify
equipment signed March 11, 1997 from Nelson Industries, Inc., Nelson
Division (Nelson) with principal place of business at 1801 Highway 51
West, P.O. Box 428, Stoughton, WI, 53589 for certification of urban bus
retrofit/rebuild equipment pursuant to 40 CFR 85.1401 through 85.1415.
The equipment is applicable to petroleum-fueled Detroit Diesel
Corporation (DDC) two-stroke/cycle engines originally installed in
urban buses from model year 1979 to model year 1993, excluding the DDC
6L71TA 1990 model year engines, all alcohol fueled engines, and models
which were manufactured with particulate trap devices. In addition, the
equipment is applicable to engines which have been previously rebuilt
using the certified DDC 6V92TA MUI or DDECII upgrade kits.<SUP>1</SUP>
On July 11, 1997, EPA published a notice in the Federal Register that
the notification had been received and made the notification available
for public review and comment for a period of 45-days (62 FR 37228).
EPA received no comments in response to that Federal Register notice.
Subsequently, EPA has completed its review of this notification, and
the Director of the Engine Programs and Compliance Division has
determined that it meets all the requirements for certification.
Accordingly, EPA certified this equipment in a letter to Nelson
Industries dated October 14, 1997.
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\1\ The DDC 6V92TA MUI upgrade kit was certified by EPA on
October 2, 1995 (60 FR 51472). The DDC 6V92TA DDECII upgrade kit was
certified by EPA on July 19, 1996 (61 FR 37738).
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The certified equipment provides 25 percent or greater reduction in
exhaust emissions of particulate matter (PM) for the engines for which
it is certified. In addition, this equipment is certified as complying
with a life cycle cost limit of $2,000 or less (in 1992 dollars).
The Nelson notification, as well as other materials specifically
relevant to it, are contained in Public Docket A-93-42, category XIX,
entitled ``Certification of Urban Bus Retrofit/Rebuild Equipment''.
This docket is located in room M-1500, Waterside Mall (Ground Floor),
U.S. Environmental Protection Agency, 401 M Street SW, Washington, DC
20460.
Docket items may be inspected from 8:00 a.m. until 5:30 p.m.,
Monday through Friday. As provided in 40 CFR Part 2, a reasonable fee
may be charged by the Agency for copying docket materials.
DATES: The effective date of certification is October 14, 1997,
established in a letter from EPA to Nelson Industries. This certified
equipment may be used immediately by urban bus operators. The impact of
this certification on transit operators is discussed in more detail in
section IV of today's notice.
FOR FURTHER INFORMATION CONTACT: Tom Stricker, Engine Compliance
Programs Group, Engine Program and Compliance Division (6403J), U.S.
Environmental Protection Agency, 401 M St. SW, Washington, D.C. 20460.
Telephone: (202) 564-9322.
SUPPLEMENTARY INFORMATION:
I. Background
By a notification of intent to certify signed March 11, 1997,
Nelson applied for certification of equipment applicable to petroleum-
fueled Detroit Diesel Corporation (DDC) two-cycle engines originally
installed in an urban bus from model year 1979 to model year 1993,
excluding the DDC 6L71TA 1990 model year engines and models which were
manufactured with particulate trap devices or alcohol fueled. In
addition, Nelson requested certification for engines rebuilt using the
certified DDC 6V92TA MUI or DDECII upgrade kits when the CEM is
installed at the same time as the DDC rebuild kit. The notification of
intent to certify states that the equipment being certified is a
catalytic exhaust muffler (Nelson converter), packaged as a direct
replacement for the muffler. The application demonstrates that the
candidate equipment provides a 25 percent or greater reduction in
emissions of particulate matter (PM) for petroleum fueled diesel
engines relative to an original engine configuration with no after
treatment installed. Certification is applicable to engines that are
rebuilt to original specifications, or in-use engines that are not
rebuilt at the time the Nelson converter is installed provided the
engine is calibrated to meet the original manufacturer's specifications
and meets engine oil consumption limits specified by Nelson. According
to Nelson, a 6-cylinder engine that uses more than one-and-a-half
quarts of oil per 10 hours of operation, or an 8-cylinder engine that
uses more than 2.0 quarts of oil per 10 hours of operation, must be
rebuilt. The Nelson Converter is certified for use on engines rebuilt
using new DDC certified rebuild kits only in those instances where the
Nelson converter is installed at the same time the DDC rebuild kit is
installed on the engine.
Using engine dynamometer testing in accordance with the Federal
Test Procedure for heavy-duty diesel engines, Nelson documented a 53%
PM reduction for the test engine retrofit with the Nelson Converter
compared to a standard rebuild. The test engine with the certified
retrofit equipment installed complies with applicable Federal emission
standards for hydrocarbon (HC), carbon monoxide (CO), oxides of
nitrogen (NOX), and smoke emissions in addition to
demonstrating reductions in PM exhaust emissions.
Table A below lists the engine models covered by this
certification, and the PM level to which each model is certified. The
Nelson equipment is certified to reduce PM emissions by 25 percent. The
certification level (shown as ``PM Level with Converter'' in Table A)
represents a 25 percent reduction in PM emissions compared to the pre-
rebuild PM level shown in the table at 40 CFR Section
85.1403(c)(1)(iii)(A).
Table A.--Certification Levels
----------------------------------------------------------------------------------------------------------------
PM level
Engine models Model year with Code Family
converter
----------------------------------------------------------------------------------------------------------------
6V92TA MUI \2\............... 1979-87 0.38 All All.
[[Page 63160]]
1988-1989 0.23 All All.
6V92TA DDEC I................ 1986-89 0.23 All All.
6V92TA DDEC II \3\........... 1988-91 0.23 All All.
1992-93...................... 0.19 All All.
6V71N........................ 1973-87 0.38 All All.
6V71N........................ 1988-89 0.38 All All.
6V71T........................ 1985-86 0.38 All All.
8V71N........................ 1973-84 0.38 All All.
6L71TA....................... 1988-89 0.23 All All.
6L71TA DDEC.................. 1990-91 0.23 All All.
8V92TA....................... 1979-87 0.38 All 8V92TA.
1988 0.29 All
8V92TA.......................
8V92TA-DDEC.................. 1988 0.31 All 8V92TA-DDEC II.
8V92TA....................... 1989 0.35 9E70 KDD0736FWH9.
8V92TA....................... 1989 0.29 9A90 KDD0736FWH9.
8V92TA....................... 1989 0.26 9G85 KDD0736FWH9.
8V92TA DDEC.................. 1989 0.31 1A KDD0736FZH4.
8V92TA....................... 1990 0.35 9E70 LDD0736FAH9.
8V92TA DDEC.................. 1990 0.37 1A LDD0736FZH3.
8V92TA DDEC.................. 1991 0.19 1A or 5A MDD0736FZH2.
8V92TA DDEC.................. 1992-93 0.16 1D NDD0736FZH1 &
PDD0736FZH X.
8V92TA DDEC.................. 1992-93 0.22 6A NDD0736FZH 1 &
PDD0736FZH X.
8V92TA DDEC.................. 1992-93 0.15 5A NDD0736FZH 1 &
PDD0736FZHX.
8V92TA DDEC.................. 1992-93 0.19 1A NDD0736FZH 1 &
PDD0736FZHX.
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\2\ For 6V92TA MUI models that are rebuilt using a certified DDC emissions retrofit kit, Nelson is certifying
the PM engine emissions to a level of 0.22 g/bhp-hr for the 1979 to 1987 models and to a level of 0.17 g/bhp-
hr for the 1988-1989 models provided the Nelson converter is installed at the same time the rebuild with the
DDC upgrade takes place. The DDC 6V92TA MUI upgrade kit certification notification was published in the
Federal Register on October 2, 1995 (60FR51472).
\3\ For the 6V92TA DDECII models that are rebuilt using a certified DDC emissions retrofit kit, Nelson is
certifying the PM engine emissions to a level of 0.17 g/bhp-hr for 1988-1990 models provided the Nelson
converter is installed at the same time the rebuild with the DDC upgrade takes place. The DDC 6V92TA DDECII
upgrade kit certification notification was published in the Federal Register on July 19, 1996 (61 FR 37738).
Note: The original PM certification levels for the 1991 6V92TA DDEC II, 6LV71TA DDEC and 8V92TA DDEC engine
models are based on Federal Emission Limits (FELs)under the averaging, banking and trading program. These
limits are higher than the 1991 PM standard of 0.25 g/bhp-hr. The PM level listed in this table for the
engines that are equipped with the Nelson converter provide at least a 25% reduction from the original
certification levels. The 1992 to 1993 6V92TA DDEC II and 8V92TA DDEC engine models were also certified using
FELs under the trading and banking program and likewise the PM levels for the engines equipped with the Nelson
converter represent at least a 25% reduction from the original certification levels.
In addition to reducing PM emissions by 25% or more, this equipment
is certified to comply with a life cycle cost limit of $2,000 or less
(in 1992 dollars). The maximum purchase price for the Nelson converter
is $2,091 (in August 1997 dollars), and the maximum installation time
is stated to be 5 hours, or $201 (in August 1997 dollars). Nelson
states that no additional maintenance cost is associated with use of
the Nelson converter, and the test data demonstrate no fuel economy
impact. Thus, the maximum total life cycle cost for this equipment is
$2,292 (in August 1997 dollars), or $2,000 (in 1992 dollars). Although
this equipment meets the life cycle cost limit associated with 25%
reduction technology, this certification does not trigger any new
program requirements for applicable engines. The requirement to use
equipment certified to achieve at least a 25% reduction in PM has
previously been triggered for some of these engines and is superseded
by the 0.10 g/bhp-hr PM standard that has been triggered for 1979-89
DDC 6V92TA MUI engines. The impact of this certification on transit
operators is discussed in more detail in section IV of today's notice.
II. Summary and Analysis of Comments
EPA received no comments in response to the July 11, 1997 Federal
Register notice. However, EPA requested clarification from Nelson
regarding several issues discussed below.
The Notification of Intent to Certify (NIC) describes the baseline
rebuilt engine used in emissions testing as having 9G75 fuel injectors
rated at 294 horsepower (HP). However, the NIC also states that the
initial run-in power for the engine was 277 HP. Nelson was asked to
explain this apparent discrepancy in rated HP versus observed HP. In
response, Nelson states that the engine was rebuilt by DDC with 9G75
fuel injectors rated at 294 HP, although the engine only produced 277
HP upon initial run-in. Nelson states that the DDC power rating has a
tolerance of plus/minus 5% (279 to 306 HP for a 294 HP rating). After
additional break-in in the test cell, the engine produced 283 HP
(within the tolerance range) as documented in the laboratory checklist
contained in the NIC.
Nelson requested that certification be granted for the Nelson
converter installed on rebuilt, and non-rebuilt engines. EPA requested
that Nelson provide a rationale to support why the claimed PM
reductions are appropriate for engines which have not been rebuilt. In
response, Nelson states that the installation instructions provide
criteria
[[Page 63161]]
which must be met in order to install the Nelson converter on non-
rebuilt engines. These criteria include maintenance of the engine in
accordance with the original engine manufacturer's specifications,
adjustment of all adjustable parameters in accordance with
manufacturer's specifications, and oil consumption criteria. For 6-
cylinder engines, the oil consumption may be no greater than 1.5 quarts
per 10 hours of service. For 8-cylinder engines, the oil consumption
may be no greater than 2.0 quarts per 10 hours of service. These
criteria are intended to ensure that the engine is operating within the
worse-case PM level of 0.5 g/bhp-hr. In addition, Nelson states that
certification testing demonstrated a PM removal of 0.16 g/bhp-hr on an
engine emitting at 0.30 g/bhp-hr. Nelson states that it is reasonable
to assume that an even greater mass of PM would be removed from an
engine operating at 0.50 g/bhp-hr. Even if this is not the case,
conservatively using a 0.16 g/bhp-hr of PM removal on such an engine
results in a 32% reduction, which is still greater than the 25%
reduction to which the equipment is certified. EPA believes that
Nelson's response is adequate to support certification for applicable
non-rebuilt engines. In addition, Nelson clarified that certification
for use on engines rebuilt with new DDC certified rebuild kits is
limited to instances where the Nelson converter is installed on the
engine at the same time as the DDC rebuild kit.
As discussed in the July 11, 1997 Federal Register notice
requesting public comment, EPA believes that the Nelson test engine
meets the criteria for worse-case test engine, described at
Sec. 85.1406(a), for all two-stroke cycle engines (exclusive of the
1990 model year DDC 6L71TA), including both mechanically and
electronically fuel injected engines. EPA reserves the right to request
additional information showing that PM reduction does not vary
significantly among engine families. However, because the Nelson test
data indicate over a 50 percent PM reduction on the DDC 6V92TA MUI test
engine, EPA believes it reasonable to expect that electronically-
controlled engines, with the Nelson catalyst installed, will be capable
of meeting the 25 percent reduction standard for which Nelson is
requesting certification. EPA received no comments contrary to this
position, and thus approves certification for both mechanically and
electronically fuel injected engines as shown in Table A.
Finally, EPA notes that Nelson is required to provide a 100,000
mile emission defect warranty on the Nelson converter, and a 150,000
mile emission performance warranty per 40 CFR 85.1409. Use of the
Nelson Converter on an engine utilizing a DDC certified upgrade kit
does not in any way relieve Nelson of the required warranty
responsibilities outlined above.
III. Certification
The Agency has reviewed this notification, along with comments
received from interested parties, and finds that the equipment
described in this notification of intent to certify:
(1) Reduces particulate matter exhaust emissions by at least 25
percent, without causing the applicable engine families to exceed other
exhaust emissions standards;
(2) Will not cause an unreasonable risk to the public health,
welfare, or safety;
(3) Will not result in any additional range of parameter
adjustability; and,
(4) Meets other requirements necessary for certification under the
Retrofit/Rebuild Requirements for 1993 and Earlier Model Year Urban
Buses (40 CFR Sections 85.1401 through 85.1415). The Agency therefore
certified this equipment in a letter to Nelson dated October 14, 1997,
for use in the urban bus retrofit/rebuild program as discussed below in
section IV.
IV. Transit Operator Requirements
Based on this certification, no new requirements are placed on
operators and no operator will be required to purchase this equipment.
For the 1979 through 1989 6V92TA MUI engine models, EPA has previously
certified equipment which triggered the requirement to use equipment
certified to the 0.10 g/bhp-hr level beginning September 15, 1997.
Therefore, under Program 1, operators who rebuild or replace 1979
through 1989 model year DDC 6V92TA MUI engines after this date will be
required to use equipment certified to meet the 0.10 g/bhp-hr PM level.
For all other engine models to which this certification applies, EPA
has previously certified equipment which triggered the requirement to
use equipment certified as providing a minimum 25 percent reduction in
PM beginning December 1, 1995. The Nelson converter is certified to
reduce PM by at least 25 percent, and can be used under program 1 to
meet this requirement for these other engine models until such time
that equipment is certified to trigger the 0.10 g/bhp-hr emission
standard for these engines for less than a life cycle cost of $7,940
(in 1992 dollars).
Operators who choose to comply with Program 2 and install the
Nelson equipment, will use the specified PM emission levels in Table A
in their calculation of fleet level attained.
Dated: November 19, 1997.
Robert Brenner,
Acting Assistant Administrator for Air and Radiation.
[FR Doc. 97-31138 Filed 11-25-97; 8:45 am]
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