[Federal Register Volume 62, Number 224 (Thursday, November 20, 1997)]
[Notices]
[Pages 62052-62057]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-30519]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-5924-7]


Retrofit/Rebuild Requirements for 1993 and Earlier Model Year 
Urban Buses; Public Review of a Notification of Intent To Certify 
Equipment

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of agency receipt of a notification of intent to certify 
equipment and initiation of 45-day public review and comment period.

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SUMMARY: NOPEC Corporation has submitted to EPA a notification of 
intent to certify urban bus retrofit/rebuild equipment pursuant to 40 
CFR part 85, subpart O. The notification describes equipment consisting 
of biodiesel fuel additive in combination with a particular exhaust 
system catalyst.
    Pursuant to section 85.1407(a)(7), today's Federal Register 
document summarizes the notification, announces that the notification 
is available for public review and comment, and initiates a 45-day 
period during which comments can be submitted. EPA will review this 
notification of intent to certify, as well any comments it receives, to 
determine whether the equipment described in the notification of intent 
to certify should be certified. If certified, the equipment can be used 
by urban bus operators to reduce the particulate matter of urban bus 
engines as discussed below.
    The candidate equipment is identical to equipment supplied by Twin 
Rivers Technologies, Limited Partnership, and which was previously 
certified as described in the Federal Register on October 22, 1996 (61 
FR 54790).
    The NOPEC notification of intent to certify, as well as other 
materials specifically relevant to it, are contained in category XVIII 
of Public Docket A-93-42, entitled ``Certification of Urban Bus 
Retrofit/Rebuild Equipment''. This docket is located at the address 
listed below.
    Today's document initiates a 45-day period during which EPA will 
accept written comments, as discussed further below, relevant to 
whether or not the equipment described in the NOPEC notification of 
intent to certify should be certified. Comments should be provided in 
writing to Public Docket A-93-42, Category XVIII, at the address below, 
and an identical copy should be submitted to William Rutledge, also at 
the address below.

DATES: Comments must be submitted on or before January 5, 1998.

ADDRESSES: Submit identical copies of comments to each of the two 
following addresses:
    1. U.S. Environmental Protection Agency, Public Docket A-93-42 
(Category XVIII), Room M-1500, 401 M Street S.W., Washington, DC 20460.
    2. William Rutledge, Engine Compliance Group, Engine Programs and 
Compliance Division (6403J), 401 ``M'' Street S.W., Washington, DC 
20460.

[[Page 62053]]

    The NOPEC notification of intent to certify, as well as other 
materials specifically relevant to it, are contained in the public 
docket indicated above. Docket items may be inspected from 8 a.m. until 
5:30 p.m., Monday through Friday. As provided in 40 CFR part 2, a 
reasonable fee may be charged by EPA for copying docket materials.

FOR FURTHER INFORMATION CONTACT: William Rutledge, Engine Programs and 
Compliance Division (6403J), U.S. Environmental Protection Agency, 401 
M Street S.W., Washington, DC 20460. Telephone: (202) 564-9297.

SUPPLEMENTARY INFORMATION:

I. Program Background

    On April 21, 1993, EPA published final Retrofit/Rebuild 
Requirements for 1993 and Earlier Model Year Urban Buses (58 FR 21359). 
The retrofit/rebuild program is intended to reduce the ambient levels 
of particulate matter (PM) in urban areas and is limited to 1993 and 
earlier model year (MY) urban buses operating in metropolitan areas 
with 1980 populations of 750,000 or more, whose engines are rebuilt or 
replaced after January 1, 1995. Operators of the affected buses are 
required to choose between two compliance options: Option 1 establishes 
PM emissions requirements for each urban bus engine in an operator's 
fleet which is rebuilt or replaced. Option 2 is a fleet averaging 
program that establishes specific annual target levels for average PM 
emissions from urban buses in an operator's fleet.
    A key aspect of the program is the certification of retrofit/
rebuild equipment. To meet either of the two compliance options, 
operators of the affected buses must use equipment which has been 
certified by EPA. Emissions requirements under either of the two 
compliance programs depend on the availability of retrofit/rebuild 
equipment certified for each engine model. To be used for Option 1, 
equipment must be certified as meeting a 0.10 g/bhp-hr PM standard or 
as achieving a 25 percent reduction in PM. Equipment used for Option 2 
must be certified as providing some level of PM reduction that would in 
turn be claimed by urban bus operators when calculating their average 
fleet PM levels attained under the program. For Option 1, information 
on life cycle costs must be submitted in the notification of intent to 
certify if certification of the equipment is intended to initiate (or 
trigger) program requirements. To trigger program requirements, the 
certifier must guarantee that the equipment will be available to all 
affected operators for a life cycle cost of $7,940 or less at the 0.10 
g/bhp-hr PM level, or for a life cycle cost of $2,000 or less for the 
25 percent or greater reduction in PM. Both of these values are based 
on 1992 dollars.
    As noted above, operators of affected buses must use equipment 
which has been certified by EPA. An important element of the 
certification process is input from the public based on review of 
notifications of intent to certify. It is expected that engine 
manufacturers, bus manufacturers, transit operators, and industry 
associations will be able to provide valuable information related to 
the installation and use of particular equipment by transit operators. 
Such information will be useful to the Engine Programs and Compliance 
Division in its role of determining whether any specific equipment can 
be certified.

II. Notification of Intent To Certify

    By a notification of intent to certify signed February 6, 1997, 
NOPEC Corporation, with principal place of business at 1248 George 
Jenkins Boulevard, Lakeland, Florida 33815, applied for certification 
of equipment applicable to certain urban bus engines manufactured by 
Detroit Diesel Corporation (DDC).
    The NOPEC notification of intent to certify is unique in that the 
NOPEC candidate equipment conforms to the specifications of equipment 
previously certified by EPA for use in the Urban Bus Retrofit/Rebuild 
program. The specifications for the previously-certified equipment, 
supplied by Twin Rivers Technologies, Limited Partnership, are public 
information and described in a Federal Register document dated October 
22, 1996 (61 FR 54790). The October 1996 document provides complete 
equipment specifications, including specifications of the biodiesel 
component of the certified Twin Rivers' equipment. The NOPEC 
notification relies on the same emissions certification data that is 
the basis of the Twin Rivers' certification. Both the emissions test 
data and biodiesel specification referenced in the NOPEC notification, 
are public information. As just noted, the specifications for the 
biodiesel was published in the October 1996 document. The testing used 
to demonstrate the emissions performance of the Twin Rivers' equipment 
was conducted under the auspices of the National Biodiesel Board, which 
has indicated in a letter to EPA that the data is in the public domain. 
Additionally, as with the Twin Rivers' equipment, the NOPEC equipment 
utilizes the same Engelhard exhaust catalyst and, with some 
configurations, fuel injection retard.
    Today's document will begin a 45-day period during which the public 
can review and comment on the candidate equipment and other aspects of 
the NOPEC notification. The following is a brief description of the 
candidate equipment.

III. Description of Previously-Certified Equipment and Identical 
Candidate Equipment

    The equipment is applicable to petroleum-fueled Detroit Diesel 
Corporation (DDC) two-stroke/cycle engines originally equipped in urban 
buses from model year 1979 to model year 1993, excluding the 1990 model 
year DDC model 6L71TA engines. The two configurations of the equipment, 
described more fully below, are: (1) a biodiesel fuel additive used in 
conjunction with an exhaust system catalytic converter muffler; and, 
(2) the biodiesel additive and catalytic converter used in conjunction 
with a fuel injection timing retard.
    The certification announced in the Federal Register document of 
October 22, 1996, applies to equipment configurations of B20, catalyst, 
and timing retard that comply with specifications described below. 
NOPEC intends to comply with identical specifications.
    The key component of the equipment is a particular oxidation 
catalyst-muffler unit designed to replace the typical noise muffler in 
the exhaust system of applicable recipient engines. The particular 
catalyst is the CMX'' manufactured by the Engelhard Corporation and 
certified for use in the urban bus retrofit/rebuild program on May 31, 
1995 (60 FR 28402). The NOPEC equipment must use CMX'' catalyst muffler 
units supplied by Engelhard and meeting the specifications covered by 
Engelhard's certification of May 31, 1995. EPA requires that use of 
catalysts of any other specification, or supplied by any other catalyst 
supplier, be the subject of a separate notification of intent to 
certify. In a letter to EPA dated February 17, 1997, Engelhard states 
that it will notify EPA and NOPEC if the specifications for its 
catalyst change. Engelhard's letter is in the public docket. The 
technical specifications for the CMX are confidential information 
available to EPA.
    Another component of the equipment is use of biodiesel provided by 
NOPEC as an additive that complies with the specifications below. In 
general, biodiesel is an ester-based fuel oxygenate derived from 
biological

[[Page 62054]]

sources for use in compression-ignition (that is ``diesel'') engines. 
It is the alkyl ester product of the transesterification reaction of 
biological triglycerides, or biologically-derived oils. While many 
biological oil sources can produce esters through this reaction, the 
candidate equipment is limited to the identical specification of the 
certification announced in the Federal Register document of October 22, 
1996. It will comply with the following specification.
    The biodiesel component of the equipment is to be supplied by NOPEC 
and must be blended at a nominal 20 percent volume with federally-
required low sulfur diesel fuel (with a maximum sulfur content of 0.05 
weight percent). This blend is referred to as ``B20''. The B20 blend is 
no less than 19 percent and no more than 21 percent by volume 
biodiesel, with the specified diesel. The use of B20 alone (that is, 
without the catalyst) is not candidate for certification because 
emissions test data is not available which sufficiently demonstrate 
that it will reduce PM. The biodiesel component is limited to mono-
alkyl methyl esters meeting the specifications of Table 1 below.

                                  Table 1.--Biodiesel Component Specifications                                  
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                                 Feedstock: Original-use, plant oil sources only                                
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                        Composition: Methyl esters of the following carbon chain length:                        
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Sum of C16 + C18's....................  90.5 wt % min......................  Determined by GC.                  
Fraction < C16........................  2.0 wt % max.......................  Determined by GC.                  
Fraction > C18........................  7.5 wt % max.......................  Determined by GC.                  
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  Blend Ratio: minimum 19 percent and maximum 21 percent by volume biodiesel complying with the above           
specifications for feedstock and composition, and the balance federally required low sulfur diesel fuel         
complying with 40 CFR Section 80.29.                                                                            
----------------------------------------------------------------------------------------------------------------

    The biodiesel component of the candidate equipment must comply with 
the specifications of Table 1. The biodiesel component of the NOPEC 
notification is limited to a nominal B20 blend, and to biodiesel 
meeting the specified carbon chain-lengths and consisting of esters 
produced from methyl alcohol and feedstocks of original-use plant oil 
sources. Because the certification testing was conducted solely using 
soy methyl ester, EPA believes that compliance with the carbon chain-
length specifications and the specified blend ratio of Table 1 are 
appropriate to provide assurance of the emissions performance. This 
specification, including the feedstock and alcohol limitations, is 
discussed further in the following section. Consistent with the 
previously certified Twin Rivers' equipment, blend ratios less than 19 
percent or greater than 21 percent is not part of the NOPEC 
notification.
    The candidate equipment includes a biodiesel component having a 
relatively limited specification. Biodiesel not complying with the 
specifications of Table 1, and biodiesel provided or produced by 
others, must be certified to be used in compliance with the urban bus 
program. Certification by other parties or involving other biodiesel 
specifications may be appropriate upon satisfactory compliance with the 
requirements of the urban bus program (40 CFR part 85, subpart O).
    EPA understands that industry consensus-based fuel specifications 
of such physical and fuel properties for biodiesel is being developed 
by the American Society for Testing and Materials (ASTM), in 
cooperation with petroleum, engine, and biodiesel industry interests. 
NOPEC states that it will maintain compliance with ASTM specifications 
as they evolve.
    For certain DDC engines equipped with MUI as indicated in Table 2, 
the candidate equipment includes fuel injection timing retard from zero 
to four (4) degrees from stock timing. The emission data indicate that 
PM is reduced 24.5 percent when timing is retarded four (4) degrees. 
While these data do not show 25 percent reduction, EPA believes the 
data support certification of retard from zero to three (3) degrees as 
providing PM reduction of at least 25 percent on MUI engines. Zero to 
three (3) degree range of retard, then, can be used by operators 
electing either compliance program 1 or 2 and otherwise in compliance 
with program requirements. MUI engines retarded four (4) degrees do not 
reduce PM emissions by at least 25 percent and, therefore, can be used 
only by operators electing compliance Option 2. Operators electing 
compliance program 2 and using any retard, must use the PM 
certification level specified in Table 3 for the applicable engine when 
calculating fleet emissions averages.
    Injection retard on MUI engines is accomplished by adjusting fuel 
injector height (for four degrees retard, 0.028 inches is added to the 
stock injector timing height).
    As discussed in the Federal Register document of October 22, 1996, 
analysis indicates that 1990 through 1993 model year Detroit Diesel 
Corporation 6V92TA DDEC engines (when using B20 with catalyst) will 
exceed applicable federal standards for NOx unless timing 
retard is used. Therefore, the only configuration for these engines 
requires retarding the injection timing one (1) degree. The NOPEC 
notification states that one (1) degree retard on these DDEC engines is 
accomplished by relocating the reference timing sensor.

IV. Emissions Test Data and Certification Levels

    Reductions in PM emissions are demonstrated using engine 
dynamometer (transient) testing in accordance with the Federal Test 
Procedure for heavy-duty diesel engines. The engine dynamometer data, 
the same used previously by Twin Rivers, are shown below in Table 2, 
and are the bases for the PM reduction attributed to the candidate 
NOPEC equipment when used on applicable engines. The emissions test 
data are part of NOPEC's notification of intent to certify. A letter 
from the National Biodiesel Board (NBB) states that the emissions data 
are in the public domain. All testing was conducted using soy methyl 
ester (SME) additive blended with #2 low-sulfur diesel fuel. 
Hereinafter, the term B20 is used to mean biodiesel blended at the 
ratio of 20 percent by volume with federally required low-sulfur diesel 
fuel (with a maximum sulfur content of 0.05 weight percent). The letter 
from NBB and NOPEC's notification are available in the public docket 
located at the above-mentioned address.

[[Page 62055]]



                                                    Table 2.--Test Engine Emissions (Transient Tests)                                                   
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                                                 Gaseous and particulate                            Smoke                                               
                                  -----------------------------------------------------------------------------------               Comment             
                                      HC        CO        NOX       PM     PM     ACC       LUG      PEAK                                      
--------------------------------------------------------------------------------------------------------------------------------------------------------
Engine:                                                                                                                                                 
(3)g/bhp-hr                        (percent                                                                                                             
                                       )                                                                                                                
(2)Percent opacity                                                                                                                                      
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                                       1.3      15.5      10.7      0.60   ...........      20        15        50    1988 HDDE Standards.              
Engine Dyno:                                                                                                                                            
1977 6V71N MUI \1\...............      0.86      3.18     11.72     0.282  ...........       1.2       1.8       1.8  Baseline (2D).                    
    Do...........................      0.42      1.64     11.72     0.159        -43.6       1.4       2.1       2.1  2D + cat.                         
    Do...........................      0.38      0.86     12.11     0.166        -41.1       0.9       1.7       1.7  B20 \3\ + cat.\4\                 
    Do...........................      0.53      1.37      8.1      0.247        -12.4       4.6       5.4       5.6  2D, cat + 4 deg. retard.          
    Do...........................      0.42      0.94      8.47     0.213        -24.5       2.2       2.8       2.9  B20, cat + 4 deg. retard.         
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(3)g/bhp-hr                        PM                                                                                                               
                                   (percent                                                                                                             
                                       )                                                                                                                
(2)Percent opacity                                                                                                                                      
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1988 6V92TA DDEC \2\ II..........      0.60      1.60      8.52     0.20   ...........       6.0       5.3       8.7  Baseline (2D).                    
    Do...........................      0.21      0.95      9.06     0.11         -45.0       3.7       1.7       6.9  B20 + cat.                        
    Do...........................      0.29      1.21      8.18     0.14         -30.0       6.5       2.1      11.6  2D, cat + 1 deg. retard.          
    Do...........................      0.25      1.05      8.35     0.12         -40.0       5.1       2.5       8    B20, cat + 1 deg. retard.         
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\1\ MUI = Mechanical Unit Injector.                                                                                                                     
\2\ DDEC = Detroit Diesel Electronic Control.                                                                                                           
\3\ The B20 used is SME blended 20 percent by volume with low-sulfur diesel fuel.                                                                       
\4\ The data include an invalid cold cycle. See the Federal Register document on October 22, 1996 (61 FR 54790) for discussion.                         

    Table 3 below lists PM certification levels for the equipment. 
These levels are determined by applying the PM percentage reductions, 
predicted by the test data of Table 2, to the pre-rebuild PM levels 
provided in the program regulations [section 85.1403(c)]. The test data 
indicate that PM is reduced by 41.1 percent on the MUI engines (24.5 
percent with 4 degrees retard) and 45.0 percent on DDEC engines (40.0 
percent with 1 degree retard). No configuration of the candidate 
equipment is certified for the 6L71TA MUI of model year 1990, because 
the MUI test engine was determined not to be a ``worst-case'' test 
engine as required by the program regulations at section 85.1406(a)(2).

                           Table 3.--Equipment Configurations and PM Emissions Levels                           
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                                                                     Equipment configuration                    
           Engine model             Model year -----------------------------------------------------------------
                                                        B20, Cat + stock timing           B20, Cat + retard \1\ 
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6V92TA MUI.......................        79-87  0.29..................................  0.38 \2\                
6V92TA MUI.......................        88-89  0.18..................................  0.23 \2\                
6V92TA DDEC I....................        86-87  0.16..................................  0.18                    
6V92TA DDEC II...................        88-89  0.17..................................  0.19                    
6V92TA DDEC II...................        90-91  Not certified.........................  0.19                    
6V92TA DDEC II...................        92-93  Not certified.........................  0.15                    
6V71N MUI........................        73-87  0.29..................................  0.38 \2\                
6V71N MUI........................        88-89  0.29..................................  0.38 \2\                
6V71T MUI........................        85-86  0.29..................................  0.38 \2\                
8V71N MUI........................        73-84  0.29..................................  0.38 \2\                
6L71TA MUI.......................           90  Not certified.........................  Not certified           
6L71TA MUI.......................        88-89  0.18..................................  0.23 \2\                
6L71TA DDEC......................        90-91  0.16..................................  0.18                    
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\1\ Up to and including four (4) degrees fuel injection retard for MUI engines, and one (1) degree retard for   
  DDEC engines.                                                                                                 
\2\ Not certified for compliance program 1.                                                                     

    As discussed in the Federal Register document of October 22, 1996, 
the data support a net programmatic benefit from certifying B20 with 
the oxidation catalyst, basically because it shows PM reductions 
compared with the baseline of conventional (low sulfur) diesel fuel 
without an exhaust catalyst. EPA believes that most of the reduction in 
PM emissions from the kit is probably attributable to the exhaust 
catalyst, although some additional PM emissions reduction is expected 
to be realized from addition of biodiesel.
    The Federal Register document of October 22, 1996, discussed 
limited data provided by Twin Rivers which indicate that engine-out 
emissions of unregulated aldehydes may increase when fuel injection 
timing is retarded. As stated in that document, it is uncertain whether 
there would be an increase in ambient levels of aldehydes or, if there 
is an increase, whether it would become irritating to exposed 
populations. Operators concerned with the possibility for increased 
irritation to exposed populations may want to minimize the potential 
for increased ambient levels through management practices. Additional 
discussion is provided in the Federal Register document of October 22, 
1996.
    As stated in the October 1996 Federal Register, EPA is, in general, 
concerned when unregulated emissions increase. While EPA has not 
conducted a formal health risk analysis associated with the

[[Page 62056]]

above-mentioned increase in unregulated aldehyde emissions, it is 
uncertain whether there is any potential for an increased health risk. 
In the judgement of the Director of the Engine Programs and Compliance 
Division, the increase in emissions does not appear to be significant. 
Additionally, EPA believes that certifying the Twin Rivers' 
configurations with retarded timing is beneficial, for several reasons. 
The configuration of B20, catalyst, and timing retard meet the program 
requirement to reduce PM emissions, when compared to the baseline of 
neat diesel fuel without catalyst, plus provide a benefit of reduced 
emissions of NOX. The Twin Rivers' certification made those 
configurations available as options to interested operators.
    In summary, while there are uncertainties, in EPA's judgement, the 
program benefits and above factors offset these uncertainties. 
Therefore, EPA certified the Twin Rivers configurations with retarded 
injection timing and proposes to certify the NOPEC equipment likewise.
    While unregulated aldehyde emissions data from buses using the 
certified Twin Rivers' equipment and the candidate equipment described 
in today's Federal Register document are limited, the data indicate 
that the directional changes in emissions relative to conventional 
diesel are dependent upon the fuel injection timing employed with a 
catalyst. If stock timing is used, aldehyde emissions can be expected 
to decrease relative to a baseline of conventional diesel without a 
catalyst. However, if retarded timing is used, then aldehyde emissions 
can be expected to increase relative to the baseline. Transit operators 
should be aware that with configurations using retarded timing, there 
is a possibility for ambient levels of aldehydes to increase. An 
increase in ambient levels is most likely to occur in micro 
environments having topographic or construction features (e.g., without 
adequate ventilation) that limit ambient dispersion of pollutants, such 
as enclosed bus malls or maintenance bays. If there is an increase in 
ambient levels, then there may be increased respiratory irritation by 
exposed populations. In summary, it is uncertain whether there would be 
an increase in ambient levels or, if there is an increase, whether it 
would become irritating to exposed populations. Operators concerned 
with the possibility may want to minimize the potential for increased 
ambient levels through its management practices, such as bus routing, 
bus scheduling, and/or mix of emission reduction technologies.
    In the October 1996 Federal Register document, EPA stated that it 
is interested in gathering additional information on unregulated 
aldehyde emissions, and requested the public and industry provide 
information with regard to the content of the exhaust of compression-
ignition engines fueled with any blend of biodiesel. Additionally, we 
requested operators using the retarded configuration to provide EPA 
information on related public complaints or comments, and actions taken 
to avert or correct perceived problems. No new information has been 
received since that document.
    All configurations, that is, the biodiesel additive and catalyst, 
are covered by emissions performance and defect warranties offered by 
NOPEC described by the urban bus regulations at section 85.1409.
    Section 211 of the Clean Air Act establishes fuel and fuel additive 
prohibitions, and gives EPA authority to waive certain of those 
prohibitions. EPA, however, does not believe that NOPEC must obtain a 
fuel additive waiver under section 211(f)(4) of the Clean Air Act 
before certifying its additive system for the following reasons.
    The Act prohibits the introduction into commerce of any fuel or 
fuel additive that is not substantially similar to a fuel or fuel 
additive used in the certification of any model year 1975 or later 
vehicle or engine under section 206. The Administrator may waive this 
prohibition, if she determines that certain criteria are met. EPA 
believes that certification of an urban bus retrofit system constitutes 
the certification of an engine under section 206 for the purposes of 
the urban bus retrofit/rebuild program, and, since the additive is used 
in the certification of the system, a waiver is not required to market 
the additive in the limited context of use with the certified retrofit 
system. This determination does not affect whether the additive is 
``substantially similar to any fuel or fuel additive'' outside the 
context of the urban bus retrofit/rebuild program. EPA's position on 
this matter is discussed in additional detail as it relates to use of 
another fuel additive (Lubrizol Corporation) at 60 FR 36139 on July 13, 
1995.
    If EPA certifies the candidate NOPEC equipment, then operators may 
use it immediately, as discussed below. NOPEC's notification indicates 
that the candidate equipment is to be certified for compliance option 
2; however, as discussed below, EPA believes that configurations 
utilizing the catalytic muffler and reducing PM by at least 25 percent 
may also be used in compliance with some option 1 requirements (that 
is, for those particular engines requiring equipment certified to 
reduce PM by at least 25 percent). It cannot be used for engines for 
which the 0.10 g/bhp-hr standard is triggered.
    In a Federal Register document dated May 31, 1995 (60 FR 28402), 
EPA certified the CMXTM exhaust catalyst manufactured by the 
Engelhard Corporation, as a trigger of program requirements. Until the 
0.10 g/bhp-hr PM standard is triggered, that certification means that 
rebuilds and replacements of applicable urban bus engines performed 6 
months or more after that date of certification (that is, rebuilds or 
replacements after December 1, 1995), must be performed using equipment 
certified to reduce PM emissions by 25 percent or more. Under Option 1, 
operators could use the NOPEC equipment if certified to reduce PM by at 
least 25 percent, or other equipment certified to provide at least a 25 
percent reduction, unless equipment is certified which triggers the 
0.10 g/bhp-hr PM standard. The 0.10 g/bhp-hr standard has been 
triggered for 6V92TA MUI engines, such that rebuilds or replacements 
after September 14, 1997 must be performed using equipment certified to 
the 0.10 g/bhp-hr standard. The configuration of B20 blend, Engelhard 
catalyst, and injection retard has been demonstrated to comply with the 
standard to reduce PM by at least 25 percent, but only when used with 
the following engines: 6V92TA DDEC I and DDEC II, and 6L71TA DDEC.
    Operators who choose to comply with Option 2 and install the NOPEC 
equipment, would use the PM emission level(s) established during the 
certification process, in their calculations for target or fleet level 
as specified in the program regulations.
    In accordance with the program requirements of section 85.1404(a), 
operators using the candidate NOPEC equipment would have to maintain 
purchase records of the B20 blend if the operator purchases the 
premixed blend from a fuel supplier, or, of biodiesel and low-sulfur 
diesel fuel if the operator mixes the B20. Such records would be 
subject to review in the event of an audit of an urban bus operator by 
EPA. To be in compliance with program requirements, operators must be 
able to demonstrate that B20 is being used in the proper proportions 
required by the candidate equipment.
    At a minimum, EPA expects to evaluate the NOPEC notification of 
intent to certify, and other materials submitted as applicable, to 
determine whether there is adequate

[[Page 62057]]

demonstration of compliance with: (1) the certification requirements of 
section 85.1406, including whether the testing accurately substantiates 
the claimed emission reduction or emission levels; and, (2) the 
requirements of section 85.1407 for a notification of intent to 
certify.
    EPA requests that those commenting also consider these regulatory 
requirements, plus provide comments on any experience or knowledge 
concerning: (a) problems with installing, maintaining, and/or using the 
candidate equipment on applicable engines; and, (b) whether the 
equipment is compatible with affected vehicles.
    The date of this document initiates a 45-day period during which 
EPA will accept written comments relevant to whether or not the 
equipment described in the NOPEC notification of intent to certify 
should be certified pursuant to the urban bus retrofit/rebuild 
regulations. Interested parties are encouraged to review the 
notification of intent to certify and provide comment during the 45-day 
period. Please send separate copies of your comments to each of the 
above two addresses.
    Additionally, EPA is aware that the biodiesel industry is working 
to address other regulatory issues related to the EPA's fuel and fuel 
additive requirements under 40 CFR part 79. Today's Federal Register 
document applies to the limited context of the urban bus program, and 
is not intended to set precedent as a generic definition of 
``biodiesel.''
    EPA will review this notification of intent to certify, along with 
comments received from interested parties, and attempt to resolve or 
clarify issues as necessary. During the review process, EPA may add 
additional documents to the docket as a result of the review process. 
These documents will also be available for public review and comment 
within the 45-day period.

    Dated: November 13, 1997.
Robert D. Brenner,
Acting Assistant Administrator for Air and Radiation.
[FR Doc. 97-30519 Filed 11-19-97; 8:45 am]
BILLING CODE 6560-50-P