[Federal Register Volume 61, Number 205 (Tuesday, October 22, 1996)]
[Notices]
[Pages 54790-54798]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-27049]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-5638-3]


Retrofit/Rebuild Requirements for 1993 and Earlier Model Year 
Urban Buses; Certification of Equipment

AGENCY: Environmental Protection Agency.

ACTION: Notice of Certification of Equipment Supplied by Twin Rivers 
Technologies for the Urban Bus Retrofit/Rebuild Program.

-----------------------------------------------------------------------

SUMMARY: The Agency received a notification of intent to certify 
equipment signed August 21, 1995, from Twin Rivers Technologies (TRT) 
with principal place of business at 780 Washington Street, Quincy, 
Massachusetts 02159, for certification of urban bus retrofit/rebuild 
equipment pursuant to 40 CFR 85.1401-85.1415. On December 13, 1995, EPA 
published a notice (60 FR 64051) 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. The Agency has 
completed its review of this notification, and the comments received, 
and the Director of the Engine Programs and Compliance Division has 
determined that certain configurations of the candidate equipment meet 
the requirements for certification. Accordingly, today's Federal 
Register notice announces the Agency's decision to certify this 
equipment, as described below. The effective date of certification is 
established in a letter to TRT from the Director of the Engine Programs 
and Compliance Division, as described below.
    Two configurations of equipment are certified for applicable 
engines: (1) A particular biodiesel fuel additive in combination with a 
particular exhaust system oxidation catalyst; and, (2) the additive and 
the catalyst, plus retarded fuel injection timing. The certified 
equipment is applicable to petroleum-fueled Detroit Diesel Corporation 
(DDC) two-stroke/cycle engines originally installed in urban buses of 
model years 1979 through 1993, excluding 1990 model year DDC 6L71TA 
engines. The oxidation catalyst of this equipment is the CMXTM 
catalyst which has been previously certified under the urban bus 
program by the Engelhard Corporation. Biodiesel is a potentially 
renewable, oxygen-containing fuel. As a component of this equipment, 
biodiesel is produced from original-use plant oil sources and methyl 
alcohol, consists of methyl esters of specified carbon chain-lengths, 
and must be blended at a ratio of 20 percent by volume with the balance 
federally required low-sulfur diesel fuel (having a maximum sulfur 
content of 0.05 weight percent). Some configurations of this equipment 
use retarded fuel injection timing to reduce exhaust emissions of 
NOX.
    Today's Federal Register notice announces certification of 
equipment having a biodiesel component of restricted specification. 
This notice, however, is not meant to preclude other Agency actions or 
considerations with respect to other specifications involving biodiesel 
in the urban bus retrofit/rebuild program or other programs. Use of 
biodiesel of other specifications, or without the specified exhaust 
catalyst, is not part of the equipment described in today's notice.
    Some of the certified configurations do not reduce particulate 
matter (PM) emissions by at least 25 percent and, therefore, cannot be 
used to meet program requirements by bus operators that elect 
compliance option 1. Operators electing to use option 1 must, until 
such time that the 0.10 g/bhp-hr standard is triggered, use equipment 
certified to reduce PM emissions by at least 25 percent, when 
rebuilding or replacing engines.
    Any certified configuration of the equipment may be used by 
operators electing compliance option 2, the fleet averaging option. 
Under option 2, an operator must use sufficient certified equipment so 
that its average fleet emission level complies with a specific annual 
target level.
    Today's notice discusses limited data provided by TRT which 
indicate that engine emissions of unregulated aldehydes may increase 
when fuel injection timing is retarded. 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 for increased irritation to exposed 
populations may want to minimize the potential for increased ambient 
levels through management practices. The Agency concludes that the 
totality of available information support a net programmatic benefit 
from certifying B20 with the oxidation catalyst.
    The specified biodiesel blend, in combination with the specified 
exhaust catalyst, has been demonstrated to reduce PM. This 
certification will make the specified biodiesel acceptable, when used 
in conjunction with the specified catalytic converter, for use by 
operators to comply with the urban bus program requirements. The TRT 
notification, as well as other materials specifically relevant to it, 
are contained in Public Docket A-93-42, category X, 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: Today's Federal Register notice announces the Agency's decision 
to certify equipment, as described below. The effective date of 
certification was established in a letter dated September 20, 1996, to 
TRT from the Director of the Engine Programs and Compliance Division. 
(A copy of the letter is in the public docket, which is located at the 
address noted above.) This certified equipment may be used immediately 
by urban bus operators, as described below.

FOR FURTHER INFORMATION CONTACT: Mr. Bill Rutledge, Engine Programs and 
Compliance Division (6403-J), U.S. Environmental Protection Agency, 401 
M St. SW, Washington, DC 20460. Telephone: (202) 233-9297.

[[Page 54791]]

SUPPLEMENTARY INFORMATION:

I. Background

    By a notification of intent to certify signed August 21, 1995, TRT 
applied for certification of equipment 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 
notification of intent to certify contains two equipment configurations 
described more fully below: (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.
    Using engine dynamometer (transient) testing in accordance with the 
Federal Test Procedure for heavy-duty diesel engines, TRT demonstrated 
reductions in PM emissions. Additional data were provided from chassis 
testing of an urban bus coach equipped with a 1988 model year 6V92TA 
DDEC II. The engine dynamometer data are shown below in Table 1, and 
are the bases for the PM reduction attributed to the equipment and the 
certification approval of the equipment when used on applicable 
engines. The emissions test data is part of TRT's notification of 
intent to certify, which is available in the public docket located at 
the above-mentioned address. 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).

                                                    Table 1.--Test Engine Emissions (Transient Test)                                                    
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Gaseous and particulate                      Smoke                                         
                                               ------------------------------------------------------------------------                                 
                                                                                      PM                                    Comment            
                                                   HC        CO        NOX      PM     (percent)    ACC    LUG    Peak                                  
--------------------------------------------------------------------------------------------------------------------------------------------------------
Engine:                                                                                                                                                 
(3)g/bhp-hr                                                                                                                                             
 (2)percent opacity                                                                                                                                     
                                                                                                                                                        
                                                    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).                  
                                                    0.42      1.64     11.72   0.159      -43.6     1.4    2.1    2.1   2D+cat.                         
                                                    0.38      0.86     12.11   0.166      -41.1     0.9    1.7    1.7   B203+cat4.                      
                                                    0.53      1.37      8.1    0.247      -12.4     4.6    5.4    5.6   2D, cat+4 deg. retard.          
                                                    0.42      0.94      8.47   0.213      -24.5     2.2    2.8    2.9   B20, cat+4 deg. retard.         
    1988 6V92TA DDEC 2........................      0.60      1.60      8.52   0.20                 6.0    5.3    8.7   Baseline (2D).                  
II                                                                                                                                                      
                                                    0.21      0.95      9.06   0.11       -45.0     3.7    1.7    6.9   B20+cat.                        
                                                    0.29      1.21      8.18   0.14       -30.0     6.5    2.1   11.6   2D, cat+1 deg. retard.          
                                                    0.25      1.05      8.35   0.12       -40.0     5.1    2.5    8     B20, cat+1 deg. retard.         
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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 text for discussion.                                                                                

    Initial review of the test data of Table 1 indicated that the B20 
plus catalyst configuration reduced PM by between 40 to 45 percent 
compared to the baseline of neat petroleum diesel. However, the test of 
the 6V71N using B20, catalyst, and stock timing, include data from a 
cold start cycle that is invalid because it does not meet the minimum 
statistic for cycle torque (40 CFR 86.1341-84 requires the coefficient 
of determination for the cold cycle to be at least 0.8500; for the test 
in question it is reported as 0.84815). This statistic is out-of-
specification for the cold cycle indicating that the engine could not 
adequately follow the transient driving schedule, perhaps because 
engines in general are often less responsive during cold operation.
    The cold cycle data of this test, although invalid, is important 
for determining whether a basic configuration of the equipment on 
applicable engines [B20 plus catalyst when used on engines having 
mechanical unit injectors (MUI)] meets the emission standard of 
reducing PM by at least 25 percent, and for determining the 
certification level of those engines having the TRT equipment. The 
certification level is used by operators choosing compliance program 2 
to calculate fleet averages, and will also be used if the Agency 
conducts in-use testing.
    Ideally, Agency decisions concerning certification are based on 
accurate and valid test data. In this situation, however, there are 
several circumstances that mitigate our concern regarding use of this 
data. First, the statistic is only marginally out of specification. 
Second, the impact of the out-of-specification statistic on the 
accuracy of the emissions data is probably minimal--the data of the 
cold start cycle are weighted only one-seventh of the composite test 
results. Third, all other cycle statistics are within the CFR 
specifications, including integrated brake horsepower-hour for the cold 
cycle (i.e., the cycle work), which is within three (3) percent of the 
reference driving cycle. Fourth, reliance on the invalid test in this 
case is not unreasonable due to the extent of other supporting 
emissions data. As shown in Table 1, testing of the same engine shows 
that B20, catalyst, and four (4) degrees of retard provide PM 
reductions of almost 25 percent relative to conventional diesel, which 
is significantly greater than when diesel fuel is used with the 
catalyst and retard. Additionally, engine dynamometer testing of the 
DDEC engine show that PM emissions are reduced roughly 45 percent when 
using B20 plus catalyst. Further, data from testing another DDEC engine 
on a chassis dynamometer (included with TRT's notification) show that 
PM reductions range from 20 to 50 percent, depending upon the driving 
cycle used. Because of the extent of these support data, plus the 
technical argument of the minimal impact on the accuracy of the 
emissions data due to the out-of-specification statistic, we believe 
that it is not unreasonable to use the data from the invalid test.

[[Page 54792]]

    As stated above, we believe that the impact of the out-of-
specification statistic on the accuracy of the emissions data is 
minimal because the data of the cold start cycle are weighted only one-
seventh of the composite test results (per 40 CFR 86.1342 and 86.1343). 
Therefore, the reported PM level of the test in question is used to 
base PM reductions and certification levels for the applicable MUI 
engines equipped with B20, catalyst, and stock timing.
    The testing data submitted by TRT (included with TRT's notification 
as part of the public docket) indicate that use of B20 increases the 
soluble organic fraction (SOF) and possibly decreases the soot fraction 
of the exhaust particulate matter. Engelhard Corporation (the 
manufacturer of the exhaust catalyst), in its comments to the public 
docket, states that the greater SOF associated with biodiesel provides 
greater reductions in total particulates by oxidation of SOF. The 
emissions data provided by Engelhard in support of certification of its 
CMX TM catalyst (60 FR 28402 on May 31, 1995) indicate that the 
catalyst, when using diesel fuel, provides PM reduction of roughly 30 
percent. The 41 percent reduction shown in Table 1 above, along with 
the other emissions data noted above, is supportive of B20 improving PM 
reduction compared with the CMX TM and diesel fuel.
    The data of the TRT notification also indicate that, while use of 
B20 with an exhaust catalyst decreases regulated emissions of 
hydrocarbons (HC) and carbon monoxide (CO), it may increase exhaust 
emissions of oxides of nitrogen (NOx). TRT analyzed the impact of 
the NOx increase to determine whether engines would exceed federal 
emissions standards, and determined that the increase predicted by the 
test data will not cause engines equipped with MUI to exceed the 
applicable federal NOx standards. However, TRT's analysis 
indicates that 6V92TA DDEC engines of model years 1990 through 1993 
(equipped with electronically-controlled fuel injection) exceed 
applicable federal NOx standards. (Federal standards for NOx 
dropped to 6.0 g/bhp-hr for model year 1990 engines and 5.0 g/bhp-hr 
for the 1991 model year engines.) The Agency agrees with this 
conclusion but recognizes that it is based on limited emission test 
data. Based on the analysis, the certification of equipment announced 
in today's Federal Register notice applies to the 6V92TA DDEC engines 
of model year 1990 through 1993 only when the fuel injection timing is 
retarded one (1) degree. TRT's analysis is included in the public 
docket and discussed in the Federal Register notice of December 13, 
1995 (60 FR 64051).
    The Agency concludes that the totality of 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. The 
Agency 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.

II. Equipment Description

    Table 2 provides PM certification levels for TRT's certified 
equipment. These levels are determined by applying the PM percentage 
reductions, predicted by the test data of Table 1, to the pre-rebuild 
PM levels specified in the program regulations [Sec. 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 TRT's 
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 Sec. 85.1406(a)(2). 
This was discussed in the Federal Register of December 13, 1995 (60 FR 
64051).

     Table 2.--Certified Configurations and PM Certification Levels     
------------------------------------------------------------------------
                                                 Equipment configuration
                                               -------------------------
            Engine model               Model       B20,                 
                                        year    Cat+stock       B20,    
                                                  timing     Cat+retard 
----------------------------------------------------------------\1\-----
6V92TA MUI.........................      79-87       0.29     \2\ 0.38  
6V92TA MUI.........................      88-89       0.18     \2\ 0.23  
6V92TA DDEC........................      86-87       0.16         0.18  
6V92TA DDEC II.....................      88-89       0.17         0.19  
6V92TA DDEC II.....................      90-91    ( \3\ )         0.19  
6V92TA DDEC II.....................      92-93    ( \3\ )         0.15  
6V71N MUI..........................      73-87       0.29     \2\ 0.38  
6V71N MUI..........................      88-89       0.29     \2\ 0.38  
6V71T MUI..........................      85-86       0.29     \2\ 0.38  
8V71N MUI..........................      73-84       0.29     \2\ 0.38  
6L71TA MUI.........................         90    ( \3\ )      ( \3\ )  
6L71TA MUI.........................      88-89       0.18     \2\ 0.23  
6L71TA MUI DDEC....................      90-91       0.16         0.18  
------------------------------------------------------------------------
\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.                             
\3\ Not certified.                                                      

    The certification announced in today's Federal Register is provided 
to TRT for equipment configurations of B20, catalyst, and timing retard 
that comply with the following specifications.
    The key component of the certified 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 CMXTM manufactured by the Engelhard 
Corporation and certified for use in the urban bus retrofit/rebuild 
program on May 31, 1995 (60 FR 28402). The Agency limits this 
certification of TRT equipment to use of CMXTM catalyst muffler 
units supplied by Engelhard and meeting the specifications covered by

[[Page 54793]]

Engelhard's certification of May 31, 1995. The Agency 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 the Agency dated August 19, 1995, Engelhard 
states that it will notify the Agency and TRT if the specifications for 
its catalyst change. Engelhard's letter is in the public docket.
    Another component of the certified equipment is use of biodiesel 
provided by TRT as an additive that complies with the specifications 
below. In general, biodiesel is an ester-based fuel oxygenate derived 
from biological 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. TRT indicates that any biological oil 
source, such as vegetable oils, animal fats or used cooking oils and 
fats, can produce esters through this reaction. While TRT has 
registered biodiesel under the Agency's Fuel/Fuel Additive Registration 
Program, which defines TRT biodiesel (marketed as 
``EnviroDieselTM'' and ``EnviroDiesel PlusTM'') as an alkyl 
ester containing C1-C4 alcohols and C6-C24 fatty acids, the 
certification announced in today's Federal Register is limited to 
biodiesel complying with the following specification.
    The biodiesel component of the certified equipment is provided by 
TRT 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'' in this notice. 
The B20 blend is required to be 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 certified because 
certification data is not available which sufficiently demonstrate that 
it will reduce PM. The biodiesel component of this certification is 
limited to mono-alkyl methyl esters meeting the following 
specifications:

              Table 3.--Biodiesel Component Specifications              
------------------------------------------------------------------------
                                                                        
------------------------------------------------------------------------
            Feedstock: Original-use, plant oil sources only.            
                                                                        
------------------------------------------------------------------------
    Composition: Methyl esters of the following carbon chain length:    
                                                                        
------------------------------------------------------------------------
Sum of C16 + C18's..............  90.5 wt% min......  Determined by GC. 
Fraction C18...................  7.5 wt % max......  Determined by GC. 
------------------------------------------------------------------------
    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 certified equipment must comply with 
the specifications of Table 3. The biodiesel component of this 
certification 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, the Agency believes that compliance with the carbon 
chain-length specifications of Table 3 and the blend ratio are 
appropriate to provide assurance of the emissions performance. This 
specification, including the feedstock and alcohol limitations, is 
discussed further in the following section. Blend ratios less than 19 
percent or greater than 21 percent are not covered by this 
certification.
    Based on the data presented by TRT, the certification announced in 
today's Federal Register notice includes a biodiesel component having a 
relatively limited specification. Biodiesel not complying with the 
specifications of Table 3, 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).
    Additionally, we are aware that the biodiesel industry is working 
to address other regulatory issues related to the Agency's fuel and 
fuel additive requirements under 40 CFR Part 79. The certification 
announced in today's notice applies to the limited context of the urban 
bus program, and is not intended to set a precedent as a generic 
definition of ``biodiesel''.
    The initial TRT notification lists ``typical'' physical and fuel 
properties of biodiesel. While such properties may be important with 
respect to the operational characteristics of biodiesel, their effect 
on emissions performance is not clear at this point in time. The Agency 
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. TRT has indicated 
that the ``typical'' properties listed in the initial notification were 
based on earlier proposed ASTM specifications, and that TRT will 
maintain compliance with ASTM specifications as they evolve.
    In addition to the concern for the emissions performance of 
equipment certified under the urban bus program, the Agency has 
concerns that any property of neat biodiesel not cause any B20 blend to 
exceed any standards otherwise established for petroleum diesel (for 
example, 40 CFR 80.29). If the Agency learns that any biodiesel 
property requires further limitation, it may take appropriate action 
using its authority under the decertification provisions of the urban 
bus program (Sec. 85.1413).
    The Agency is certifying certain configurations of the TRT 
equipment which include retarded fuel injection timing to decrease 
NOX emissions. TRT requested certification of these configurations 
because some operators may wish to achieve NOX reductions while 
still reducing PM emissions, and some electronically-controlled engines 
may exceed Federal NOX standards without the timing retard. The 
Agency recognizes that certain configurations with retarded injection 
may be useful for reduction of NOX emissions. However, 
certification of NOX levels is outside the context of the urban 
bus program. Today's Federal Register notice provides certification 
levels only for PM emissions levels.
    For the DDC engines equipped with MUI as indicated in Table 2, the 
Agency is certifying any timing retard from zero to four (4) degrees 
from stock timing. The emission data of TRT's notification indicate 
that PM is reduced 24.5 percent when timing is retarded four (4) 
degrees. While these data do not show 25 percent reduction, the Agency 
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. 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 program 2. Operators electing compliance program 2 and using 
any retard, must use the PM certification level specified in Table 2 
for the

[[Page 54794]]

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). The Agency understands that some engine 
models equipped with MUI should not, or cannot, be retarded the full 
four (4) degrees because the engine manufacturer (DDC) recommended 
maximum injector height is 1.520 inches. As explained above, engines 
having injection retarded more than 3 degrees cannot be used by 
operators for compliance with compliance program 1 because it does not 
reduce PM emissions by at least 25 percent. The Agency is certifying 
MUI engines, having injection retarded up to and including three (3) 
degrees, as reducing PM by at least 25 percent. Information provided 
with the TRT notification indicates that each additional 0.007 inch 
increase in injector height, above stock height, results in one (1) 
degree of retard.
    As discussed in the Federal Register notice of December 13, 1995, 
TRT performed analysis which 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 
certified for these engines requires retarding the injection timing one 
(1) degree. The TRT notification states that one (1) degree retard on 
these DDEC engines is accomplished by relocating the reference timing 
sensor.
    All certified configurations, that is, the biodiesel additive and 
catalyst, are covered by emissions performance and defect warranties 
offered by TRT described by the urban bus regulations at Sec. 85.1409.
    Section 211 of the Clean Air Act establishes fuel and fuel additive 
prohibitions, and gives the Agency authority to waive certain of those 
prohibitions. The Agency, however, does not believe that TRT must 
obtain a fuel additive waiver under Sec. 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 Sec. 206. The Administrator may waive this 
prohibition, if she determines that certain criteria are met. The 
Agency believes that certification of an urban bus retrofit system 
constitutes the certification of an engine under Sec. 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. The 
Agency'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.

III. Summary and Analysis of Comments and Concerns

    The Agency received comments from ten (10) parties. Three transit 
operators, the Bi-State Development Agency, Southwest Ohio Regional 
Transit Authority, and Mass Transit Administration of Maryland provided 
comments that are favorable, indicating support for biodiesel as a 
viable alternative fuel. These agencies have participated in 
demonstrations of biodiesel and have found that biodiesel has an 
excellent operational record, and indicate that biodiesel maintains 
power and mileage without extra infrastructure costs. No difficulties 
with biodiesel were noted.
    A fourth transit, New York City Transit Authority (NYCT), comments 
that it reviewed emissions data provided to it by TRT, and concluded 
that their operation would not realize an emission benefit by using 
biodiesel. The Agency respects the conclusion of NYCT, regarding use of 
biodiesel in its own operation. However, the Agency believes that this 
certified TRT equipment, which includes a catalyst component, will 
provide program benefits and additional options for operators. Further, 
certification is consistent with Agency support for fuels that may be 
renewable. A copy of NYCT's comments are available, as are all 
comments, in the public docket for review.
    While the PM reduction attributable to the B20 component may be of 
general interest, a quantifiable reduction is not a specific necessity 
for the certification announced in today's Federal Register notice. The 
PM reduction attributable to the B20 component of the equipment is 
difficult to quantify because of inconsistent test data. The data do 
not consistently show that, when a catalyst is used, B20 reduces PM 
more than diesel fuel. Test data from the MUI engine indicates that 
using B20 with the catalyst may increase PM by roughly four (4) percent 
when compared with diesel fuel plus the catalyst, which may raise a 
question regarding the contribution of the biodiesel component in the 
ability of the TRT kit to reduce PM. On the other hand, other data (see 
Table 1) from testing the MUI engine with timing retarded four (4) 
degrees, and from testing the DDEC engine with timing retarded one (1) 
degree, both indicate that the use of B20 with catalyst further 
improves PM reduction by roughly 14 percent over diesel fuel with 
catalyst. In summary, the Agency believes that this certified TRT 
equipment, which includes catalyst and B20 components, will provide 
program benefits by reducing PM relative to use of conventional diesel 
fuel without a catalyst.
    Other comments supporting certification were received from the 
National Biodiesel Board (NBB) and the Fats and Proteins Research 
Foundation (FPRF). The NBB, a trade association dedicated to creating 
viable commercial markets for biodiesel, notes a number of benefits or 
advantages of biodiesel. For example, NBB notes that increased use of 
biodiesel within the urban bus program can improve the environment, 
enhance national energy security, and give affected transit systems 
greater flexibility in meeting requirements. NBB further indicates that 
more than 10 million miles of in-service demonstration projects 
involving urban bus transit systems across the nation have been 
conducted to test biodiesel's reliability and performance as a fuel 
technology under actual urban transit working conditions, and reports 
overwhelmingly favorable results. The NBB also states that it is 
coordinating the biodiesel industry's response to the request for 
emissions health effects data under the Agency's fuel and fuel additive 
(FFA) program (pursuant to Sec. 211 of the Clean Air Act).
    The NBB states that it is not aware of any data that would bring 
into question any adverse public health effects from the utilization of 
B20, compared with baseline use of diesel fuel in the same engines. 
Further, NBB does not interpret the Agency's request for comments on 
health effects related to use of B20 (contained in the Federal Register 
notice of December 13, 1995) to require separate and independent health 
effects determinations for urban bus equipment that would duplicate the 
requirements under the FFA program. Also, the NBB believes that the on-
going data submission requirements of Sec. 211 fully address the 
potential health effects issues raised in the Federal Register notice 
of December 13, 1995, unless significant, new health effects related 
data to the contrary is submitted to the

[[Page 54795]]

Agency as a consequence of this rulemaking.
    FPRF is an organization dedicated to the development of new uses 
for and added value of animal by-products for the nation's meat 
producing industry. The FPRF expresses support for TRT's notification 
and believes that TRT has fully met EPA's regulatory requirements under 
the urban bus program regulations. FPRF also notes that, the Energy 
Policy Act of 1992 defines ``alternative fuels'' to include fuels 
derived from biological materials, or any other fuel determined to be 
substantially not petroleum and yielding substantial energy security 
benefits and substantial environmental benefits. FPRF requests that the 
Agency defer its consideration of any health effects under the urban 
bus program, until the full course of data development and collection 
requirements under the FFA program are met by the biodiesel industry.
    The Agency notes the information and expressions of approval for 
certification of biodiesel provided by both NBB and FPRF.
    Section 85.1406(d) of the urban bus regulations states that ``* * * 
installation of any certified * * * equipment shall not cause or 
contribute to an unreasonable risk to public health, welfare or 
safety,'' and this is the basis for the Agency's request in the 
December 13, 1995 notice, for any available information regarding 
health risk. While the general health concern of the urban bus program 
is similar to that of the FFA program, the scopes of the programs are 
different. The urban bus program, in general, does not require 
duplication of the on-going health-effects information and testing 
requirements under the FFA program, which need not be provided until 
May 1997. While emissions data made available by TRT on the use of 
biodiesel has been reviewed by the Agency, it is not an adequate basis 
on which to base a comprehensive health-risk evaluation. However, we 
have determined that it should not impede the certification announced 
in today's notice. (This information is discussed further below). The 
Agency does not propose, or believe that others are suggesting, to 
postpone the certification of today's notice until the testing under 
the FFA program are completed. Whether or not the data submission 
requirements of the FFA program address the issues of the urban bus 
program are not relevant at this point in time, because certification 
under the urban bus program does not guarantee completion, or the 
outcome, of the information or testing requirements under the FFA 
program. However, if information becomes available which indicates 
significant health risk associated with use of biodiesel relative to 
conventional diesel, then the certification announced in today's 
Federal Register notice may be re-evaluated. Section 85.1413 provides 
the Agency authority to decertify equipment.
    As discussed in the December 13, 1995 Federal Register notice (60 
FR 64051), the Agency has reviewed information submitted by TRT related 
to unregulated emissions. Information provided by TRT from testing a 
1988 DDC 6V92TA DDEC II engine using three chassis driving cycles 
indicate that emissions of aldehydes and ketones are increased when the 
timing is retarded 1.5 degrees, compared with a baseline of diesel fuel 
#2 without a catalyst. The data were collected using three chassis 
dynamometer cycles for diesel #2 fuel, B20, B20 plus catalyst with 
stock timing, and B20 plus catalyst with retarded timing. The data 
indicate that aldehyde/ketone emissions increase on average about 40 
percent when timing retard is used with B20 plus catalyst, compared to 
a baseline of diesel #2. The aldehyde/ketone emissions decrease on 
average about 20 percent when stock timing is used with B20 plus 
catalyst, compared to the diesel baseline.
    The Agency, in general, is concerned when unregulated emissions 
increase. While the Agency has not conducted a formal health risk 
analysis associated with the 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, we believe that certifying 
the 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. This certification will make those 
configurations available as options to interested operators.
    The Agency's decision to certify the configuration having retarded 
timing is mitigated by several factors. First, aldehyde emissions from 
diesel engines, in general, are very low. Second, TRT's emissions data 
indicate that engines using the TRT equipment with stock timing will 
reduce emissions of aldehydes and ketones. Third, TRT estimates that 
only one in eight buses using its equipment will use the configuration 
with timing retard. Due to the program restriction to pre-1994 model 
year buses, the number of these buses (using timing retard) will 
decline as older buses are retired from the affected fleet. In summary, 
while there are uncertainties, in our judgement, the program benefits 
and above factors offset these uncertainties. Therefore, the Agency is 
certifying configurations with retarded injection timing.
    While unregulated aldehyde emissions data from buses using the 
certified equipment described in today's Federal Register notice are 
limited, they 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. We believe that 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.
    The Agency is interested in gathering additional information on 
unregulated aldehyde emissions, and requests that 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 request operators using the retarded configuration to 
provide us as well as TRT, information on related public complaints or 
comments, and actions taken to avert or correct perceived problems.
    With regard to FPRF's comment on ``alternative'' fuels, there are 
no specific provisions for designating ``alternative'' fuels under the 
urban bus program. However, the program regulations state

[[Page 54796]]

that urban buses using alternative fuel that ``* * * significantly 
reduces particulate emissions compared to emissions from diesel fuel'' 
can be assumed to be operating at a PM level of 0.10 g/bhp-hr [40 CFR 
85.1403(d)]. Further, the preamble to the final rule (58 FR 21380, 
April 21, 1993), relates alternative fuel to ``* * * dedicated gaseous 
fueled or alcohol fueled * * * buses''. Based on the emissions 
performance demonstrated by the certification data, the B20 component 
of the certified equipment does not appear to fit the depiction of 
``alternative'' fuel that ``significantly reduces particulate 
emissions'' in the context of this program.
    Texaco comments that the Agency erred in the December 13, 1995, 
Federal Register notice when it stated that under compliance program 1, 
operators could use the TRT equipment, because TRT has not provided 
life cycle cost information according to 40 CFR 85.1403(b). Texaco 
indicates that because life cycle costs are not provided by TRT, the 
Agency cannot certify it for use under program compliance option one 
(1).
    Section 85.1403(b)(2) states, in part: ``If no equipment meets the 
provisions of paragraph (b)(1) of this section for a particular model 
of urban bus engine, then any urban bus for which this Subpart is 
applicable shall use equipment that has been certified to achieve at 
least a 25 percent reduction in particulate emissions from the original 
certified particulate emission level of the urban bus engine model 
being rebuilt, if such equipment is available as specified in paragraph 
(b)(2)(i) of this section.'' In general, paragraph (b)(2)(i) defines 
``available'' to mean equipment has been certified to reduce 
particulate emissions by at least 25 percent, has been approved for 
certification for at least 6 months, and has a life cycle cost of 
$2,000 (1992 dollars) or less.
    The Agency believes that Sec. 85.1403(b)(2) is clear--once 
equipment is ``available'' (that is, the PM standard has been 
``triggered'') for particular engines, then an operator can select any 
equipment that is certified to comply with the standard, regardless of 
cost associated with the selected equipment. This provides operators 
with equipment options. The Engelhard CMXTM catalyst was certified 
on May 31, 1995, to reduce PM on all two stroke/cycle engines by at 
least 25 percent for less than the applicable life cycle cost. Until 
equipment is certified to meet the 0.10 g/bhp-hr standard for less than 
the applicable life cycle cost, all two stroke/cycle engine rebuilds or 
replacements by operators using compliance program 1 must use equipment 
certified to reduce PM by at least 25 percent. Some, but not all, 
configurations of the certified TRT equipment, reduce PM by at least 25 
percent and can be used in compliance with the current requirement of 
compliance program 1.
    Detroit Diesel Corporation (DDC), the manufacturer of the engines 
to which the TRT equipment applies, comments that it has experience 
with the fuel blend, the exhaust catalyst, and the timing retard 
technologies. DDC states that the emission data provided by TRT is 
generally consistent with DDC's understanding of the expected effects 
of these technologies and DDC believes that TRT used reasonable 
approaches to extrapolate the emission data to the other engine models, 
and does not question PM certification levels provided in the December 
13, 1995, Federal Register notice. Also, ``While DDC is in fundamental 
agreement with the emission claims made in the notice * * *'' they 
express the following concerns relating to the use of the proposed 
technologies.
    DDC is concerned that there is limited experience with long term 
effects of biodiesel use on engine durability. There are concerns about 
the low temperature behavior of biodiesel and its comparability with 
materials that could be found in some engine and vehicle fuel systems 
(especially relevant for retrofit usage of biodiesel fuels). DDC 
believes that if certified, the upper blend ratio should be clearly 
defined and no more than 20 percent.
    DDC notes several concerns related to the exhaust catalyst and 
injection retard features of the equipment. DDC notes that some users 
may experience degraded engine performance or durability as a result of 
using the timing retard. DDC also notes several other effects that are, 
in general, associated with timing retard, including decreased fuel 
economy, poorer cold starting and white smoke control, increased 
exhaust temperature and reduced exhaust valve durability. DDC states 
that without a case-by-case assessments of each of the engine models, 
it cannot provide specific comments on the effects of the proposed 
levels of timing retard.
    DDC also comments that the procedure provided in the TRT 
notification for checking catalyst backpressure is not adequate. DDC 
states that the backpressure specification (3 inches mercury) provided 
with the check should be conducted at wide open throttle, full engine 
load (not the wide open throttle, no load condition as stated in the 
Engelhard material provided as part of TRT's notification). DDC notes 
that its backpressure limits apply at all engine operating conditions, 
but are most applicable to maximum exhaust flow condition of the 
engine, which is most often at the rated speed, full load condition. If 
the engine backpressure limit is just met at the wide-open-throttle no-
load condition, then the engine will be severely over-backpressured 
when it is operated at or near rated power.
    The Agency appreciates that there may be short-comings, or room for 
improvement, in maintenance procedures of components or various aspects 
of equipment certified under the urban bus program. Such concerns, in 
general, can also occur with procedures relating to new engines. 
Indeed, the current backpressure specification and check procedure may 
not be entirely adequate. Perhaps a positive first step is user 
knowledge of these areas of potential concerns. The Agency encourages 
all certifiers to issue revised check procedures when appropriate. If, 
after review of DDC's concern, Engelhard determines another check 
procedure is more appropriate for purchasers of the CMXTM, it 
should notify the Agency, the purchasers, and TRT. DDC also notes that 
the Engelhard service procedure calls for CMXTM inspection during 
normally scheduled vehicle maintenance, contrary to what was stated in 
the December 13, 1995, Federal Register notice.
    The Agency appreciates the extensive substantive comments submitted 
by DDC, given its experience and expertise as manufacturer of the 
engines to which this certified equipment applies. Users of this 
equipment should be aware of the potential concern expressed by the 
engine manufacturer regarding the use of biodiesel, the exhaust 
catalyst, and injection timing retard. Some users may not be satisfied 
with some configurations of the certified equipment, but must recognize 
that a comprehensive and long-term durability demonstration of all 
possible engines and equipment configurations is not part of the 
certification process under the urban bus program. While the Agency 
recognizes these comments as areas of potential concern, it also 
believes that the data presented by TRT is adequate to justify 
certification. Further, several parties involved with demonstration 
programs of biodiesel have provided positive feedback, as mentioned 
previously. The effects involving the long-term use of biodiesel is 
important, given this certification. The Agency is requiring that the 
biodiesel component of the certified

[[Page 54797]]

equipment comply with the indicated specifications and, as DDC 
recommends, limiting biodiesel use to the nominal maximum 20 percent 
biodiesel blend discussed above. The Agency will continue to monitor 
the performance of equipment certified under the urban bus program, and 
encourages users to provide details of its specific experience with 
this certified equipment. As necessary, the Agency has authority to 
decertify equipment pursuant to program regulations at Sec. 85.1413.
    DDC also comments that the TRT equipment should not be certified 
for use under compliance program 1. The Agency discusses this concern 
above in relation to a comment by Texaco. While the TRT equipment is 
neither ``trigger'' technology nor required to be used, certain 
configurations have been demonstrated to reduce PM by at least 25 
percent and therefore can be used under compliance option 1, until 
equipment is certified to meet the 0.10 g/bhp-hr standard for less than 
the applicable life cycle cost.
    With its comments, DDC provided a copy of a report by the Engine 
Manufacturers Association (EMA) dated August 1995 and entitled 
``Biodiesel Fuels and Their Use in Diesel Engine Applications''. DDC 
indicates that it provides a good discussion of the issues surrounding 
the use of biodiesel fuels in diesel engines, and notes that the report 
suggests some caution in using these fuels. While this report on 
biodiesel does not specifically address TRT's notification of intent to 
certify, several points may be relevant to the notification, and of 
interest to operators interested in biodiesel. Interested parties 
should refer to the EMA report (included with DDC's comments in the 
public docket) for additional information concerning the EMA position 
on biodiesel use.
    The EMA report notes that a wide range of feedstock may be grown 
for fuel use, and states that different feedstocks have different 
relative proportions of specific fatty acids (e.g. oleic or linoleic 
acids) and, as a result, the finished fuel will have different 
characteristics. The report, however, does not elaborate on any 
different characteristics or concerns associated with them. As stated 
elsewhere, the biodiesel component that can be used with the certified 
equipment of today's notice is bounded by a chemical specification, 
which is based on the certification emissions data. Further, TRT has 
indicated that it will adhere to industry developed specifications for 
various fuel and physical properties of biodiesel, as those 
specifications evolve.
    Today's Federal Register notice limits the biodiesel component of 
the certified equipment to the chemically-defined description of Table 
3. This specification was proposed by TRT as one which meets its 
manufacturing needs. The Agency believes it acceptable because, as an 
approximation of esters produced from use of soybean oil, it provides 
assurance that emissions performance will be similar to that 
demonstrated by the certification testing.
    TRT's initial notification proposed a broad specification for 
biodiesel (alkyl esters containing C1 through C4 alcohols and C6 
through C24 fatty acids) to permit its production from a wide variety 
of feedstocks using four different alcohols. While the Agency has not 
seen any information which indicate concern for any particular 
feedstock or esters produced using other than methyl alcohol, the 
effect of these variables on either regulated or unregulated emissions 
is not clear at this time. For this reason, and because all of the 
certification testing was conducted using soy methyl ester, today's 
Federal Register notice limits the biodiesel component to the 
description of Table 3.
    Based on information provided by the U.S. Department of Agriculture 
and on vocal communications with TRT, soybean oil is expected to be the 
predominant feedstock in the production of biodiesel. Methyl esters 
produced from soybean oil are predominantly molecules having carbon 
chain-lengths of C16 and C18. Other plant oil sources (such rape seed 
oil), however, can be used to produce ester molecules of this range 
depending upon factors, such as growing conditions. TRT indicates that 
the chemical structure of methyl esters are the same, regardless of 
feedstock origin, and therefore TRT proposed a specification based on 
chain-length which would allow use of other plant oil feedstocks. The 
carbon chain-length specifications will allow use of plant oil 
feedstocks other than soybean oil to make biodiesel for use in 
compliance with the urban bus program. Additionally, the specifications 
provide assurance that the demonstrated emissions performance will be 
attained in-use by virtue of imitating the primary carbon chain-lengths 
of soy methyl ester.
    While the Agency recognizes that there may be uncertainties 
concerning different feedstocks, the information available do not 
support a need to restrict feedstocks for the biodiesel certified by 
TRT (assuming compliance with the specifications of Table 3). If 
significant information becomes available which indicates concern with 
specifications of today's Federal Register notice, then the Agency has 
authority through the decertification process to further restrict 
biodiesel used in compliance of the urban bus program.
    Section 85.1412 of the program regulations requires that TRT, as 
the certifier, maintain data obtained during testing of the equipment, 
including the biodiesel, and a description of the quality control plan 
used to monitor production and assure compliance of the equipment with 
the certification requirements. This section of the regulations 
requires that the certifier provide this information to the Agency upon 
written request. Section 85.1404 requires urban bus operators maintain 
the purchase records for fuel additives and provide the Agency with 
access to such records. The Agency may conduct audits of operators and 
analyze fuel for compliance with specifications, and to perform in-use 
testing to measure emissions.
    The EMA report states that ``If raw vegetable oil is used as 
feedstock in the esterification process, then the final biodiesel fuel 
may have high phosphorus content. High levels of phosphorus would 
reduce the life of a catalyst used to reduce soluble organic fractions 
of particulates.'' While raw vegetable oil is a common feedstock for 
biodiesel production, TRT has forwarded measured phosphorous levels, 
analyzed by the National Biodiesel Board, of samples of SME collected 
over an 18 month period from three suppliers. The results show the 
phosphorous level is very low (a maximum of 0.0000045 weight percent). 
There is currently no Federal specification for the phosphorous level 
in in-use diesel fuel. However, a comparison can be made with the 
maximum level permitted (40 CFR Part 80) for in-use gasoline (0.005 
grams per gallon). (At an average weight per gallon for gasoline of 6.2 
pounds, 0.005 grams is roughly 0.00018 weight percent.) The data 
supplied by TRT, when compared with the allowable phosphorous level for 
in-use gasoline, do not indicate that phosphorous level is a concern 
when B20 is used with a catalyst.
    The EMA report also notes that ``In the absence of a fuel 
specification, the quality of the biodiesel fuel cannot be controlled. 
Therefore engine and vehicle manufacturers cannot warranty the product 
against failures attributed to the use of such fuels or their blends.'' 
As noted above, the Agency understands that physical and fuel 
specifications for biodiesel are being developed by ASTM, and will 
consider the interests of the engine manufacturers, and the petroleum 
and biofuel industries. The

[[Page 54798]]

Agency expects such a standard to reduce the potential for fuel quality 
to be a problem. Further, TRT has indicated that it will adhere to the 
ASTM specifications for biodiesel as it evolves and is finalized.
    Conversations with DDC indicate that, as a general policy, they 
would not cover under warranty the cost of repairing a problem which 
was caused by use of biodiesel. DDC's instructions to owners state that 
the recommended fuels are diesel #1 and #2. The Agency believes that 
the potential lack of coverage by the original engine manufacturer will 
not be a significant problem under the urban bus program because the 
affected engines are generally out of warranty due to age. There are, 
of course, other warranty provisions applicable to certification of 
retrofit/rebuild equipment under the urban bus program.
    The EMA report also indicates that oil change intervals for 
vehicles operating on biodiesel blends need to be shortened to avoid 
durability problems. Operators using biodiesel may want to monitor oil 
parameters more closely until they determine appropriate change 
intervals.
    The EMA reports concludes that biodiesel blends can improve visible 
smoke and particulate emissions in older diesel engines.
    The California Air Resources Board (CARB) provides comments on a 
number of concerns. Many of these comments apply to the testing 
performed by TRT on an engine calibrated to meet federal standards 
using diesel fuel meeting federal requirements, but not requirements of 
that State. The Agency recognizes the special situations existing in 
California, which are reflected in the unique emissions standards, 
engine calibrations, and fuel specifications of the State. While the 
requirements of the federal urban bus program apply to several 
metropolitan areas in California, the Agency understands CARB's view 
that equipment certified under the urban bus program, to be used in 
California, must be provided with an executive order exempting it from 
the anti-tampering prohibitions of that State. Those interested in 
additional information should contact the Aftermarket Part Section of 
CARB, at (818) 575-6848.
    Engelhard commented on the use of its CMXTM exhaust catalyst 
in conjunction with biodiesel. Engelhard notes that the two 
technologies complement each other--biodiesel increases the SOF of 
particulates while the CMXTM catalyst reduces total particulates 
by oxidation of SOF. The greater the SOF, the greater reductions 
obtained. No concerns were expressed by Engelhard regarding use of 
biodiesel with its catalyst.
    Copies of all comments can be found in the public docket located at 
the above address.

IV. Certification

    The Agency has reviewed the notification of intent to certify and 
other information provided by TRT, along with comments received from 
interested parties, and finds, based on available data, that the 
equipment described above:
    (1) Reduces particulate matter exhaust emissions (some 
configurations 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 85.1401 through 85.1415).
    Therefore, today's Federal Register notice announces certification 
of the above-described TRT equipment for use in the urban bus retrofit/
rebuild program as discussed below in section V. The effective date of 
certification is the date of the letter, as noted above, provided 
earlier from the Director of the Engine Programs and Compliance 
Division to TRT. A copy of the letter can be found in the public docket 
at the address listed above.

V. Operator Requirements and Responsibilities

    As discussed below, the certified TRT equipment announced in 
today's Federal Register notice may be used immediately in compliance 
with the urban bus program. Certain configurations apply only to 
compliance program 1. All configurations apply to compliance program 2.
    In a Federal Register notice dated May 31, 1995 (60 FR 28402), the 
Agency certified an exhaust catalyst manufactured by the Engelhard 
Corporation, as a trigger of the program requirement to reduce PM by at 
least 25 percent. Until such time that the 0.10 g/bhp-hr standard is 
triggered, that certification of the Engelhard catalyst means that 
operators who elect to use compliance program 1 must use equipment 
certified to reduce PM emissions by at least 25 percent, when 
rebuilding or replacing engines. With the following exception, the 
certified TRT equipment may be used by operators in compliance with 
these current program 1 requirements. The configuration of the TRT 
equipment using fuel injection timing retard of four (4) degrees is not 
certified to reduce PM by at least 25 percent and, therefore, cannot be 
used by operators to comply with program 1.
    Operators who choose to comply with compliance program 2 may use 
any configuration of the certified TRT equipment announced in today's 
Federal Register notice. Under option 2, an operator must use 
sufficient certified equipment so that its actual fleet emission level 
complies with the target level for its fleet. These operators must use 
the appropriate PM emission level from Table 2 when calculating their 
fleet level attained (FLA).
    As stated in the program regulations (40 CFR 85.1401 through 
85.1415), operators should maintain records for each engine in their 
fleet to demonstrate that they are in compliance with the requirements 
beginning in January 1, 1995. These records include purchase records, 
receipts, and part numbers for the parts and components used in the 
rebuilding of urban bus engines. In accordance with the program 
requirements of Sec. 85.1404(a), operators using the certified 
equipment of today's notice must maintain purchase or delivery 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. During compliance audits of transit operators, 
the Agency may review fuel purchase records and sample fuel supplies to 
verify blend ratios. To be in compliance with program requirements, 
operators must be able to demonstrate that biodiesel of the proper 
specification is being used in the proper proportions required by this 
certification.

    Dated: October 15, 1996.
Mary D. Nichols,
Assistant Administrator for Air and Radiation.
[FR Doc. 96-27049 Filed 10-21-96; 8:45 am]
BILLING CODE 6560-50-P