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

ENVIRONMENTAL PROTECTION AGENCY

[FRL-5344-6]

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.

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: Twin Rivers Technologies' (TRT) has submitted to the Agency 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 Sec. 85.1407(a)(7),

today's Federal Register notice 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. The

Agency 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.

The notification of intent to certify, as well as other materials

specifically relevant to it, are contained in category X 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 notice initiates a 45-day period during which the Agency

will accept written comments relevant to whether or not the equipment

included in this notification of intent to certify should be certified.

Comments should be provided in writing to Public Docket A-93-42,

Category X, 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 29, 1996.

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 X), 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.

The TRT 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 8:00 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.

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) 233-9297.

SUPPLEMENTARY INFORMATION:

I. Background

On April 21, 1993, the Agency published final Retrofit/Rebuild

Requirements for 1993 and Earlier Model Year Urban Buses (58 FR 21359).

The retrofit/rebuild program is intended

[[Page 64052]]

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: Program 1 establishes PM emissions requirements for

each urban bus engine in an operator's fleet which is rebuilt or

replaced. Program 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 the Agency. 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 program 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 Program 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 program 1, information

on life cycle costs must be submitted in the notification of intent to

certify in order for certification of the equipment 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 August 18, 1995, and

subsequently modified by letter dated October 5, 1995, Twin Rivers

Technologies, Limited Partnership (TRT), with principal place of

business at 780 Washington Street, Quincy, Massachusetts 02169, applied

for certification of equipment applicable to certain urban bus engines

manufactured by Detroit Diesel Corporation (DDC). The notification

states that the candidate equipment will provide reductions in exhaust

PM, as discussed below, dependent upon the configuration used, from

petroleum-fueled diesel engines that have been properly calibrated or

rebuilt to the original engine manufacturer's specifications.

TRT requests certification for the following two configurations of

equipment: (1) Biodiesel fuel additive blended with diesel fuel (the

blend is referred to as ``B20'') in combination with a particular

exhaust system oxidation catalyst; and, (2) B20 and the catalyst, plus

retarded fuel injection timing. Certification, if approved by the

Agency, would apply to the combination of catalyst and biofuel supplied

by TRT or its licensed distributors. The fuel B20 (alone) is not

candidate for certification under this notification.

One configuration of the candidate equipment, as applied to some

engines, provides PM reductions greater than 25 percent and the other

configuration does not. This is discussed further below. TRT has not

provided life cycle cost information with the notification and has not

requested to be certified as being available for less than the life

cycle cost ceiling.

A key component of both configurations of the candidate equipment

is use of biodiesel as an additive at a 20 percent by volume blend

ratio with diesel fuel. Biodiesel is an ester-based fuel oxygenate

derived from biological sources for use in compression-ignition (that

is ``diesel'') engines. Biodiesel is the alkyl ester product of the

transesterification reaction of biological triglycerides, or

biologically-derived oils. Any biological oil source, such as vegetable

oils, animal fats or used cooking oils and fats, can produce esters

through this reaction. TRT has registered biodiesel under the Agency's

Fuel/Fuel Additive Registration Program, which defines Twin Rivers

biodiesel (marketed as ``EnviroDieselTM'' and ``EnviroDiesel

PlusTM'') as an alkyl ester containing C1-C4 alcohols and C6-C24

acids. The fuel handling procedure differs from that for diesel fuel

only in that it requires mixing by the fuel distributor or bus operator

of 20 percent by volume biodiesel with low-sulfur diesel fuel. TRT is a

company created specifically for the production of biodiesel.

A key component of both configurations of the candidate equipment

is a particular oxidation catalyst-muffler unit (discussed further

below) designed to replace the typical noise muffler in the exhaust

system of applicable recipient engines. In a report included as an

attachment to TRT's notification, it is indicated that the combination

of B20 and the catalyst achieve greater PM reductions than with the

catalyst alone. Improved PM reduction associated with that combination

may be due to an apparent shift in the composition of total exhaust

particulates, when using B20, toward a lower soot fraction and higher

soluble organic fraction (SOF). It is the SOF portion of the exhaust

particulates that an oxidation catalyst is most effective in reducing.

The exhaust catalysts are to be matched to specific urban bus and

engine configurations. Further, the maximum allowable exhaust pipe

length between engine and catalyst is 108 inches. Exhaust system

backpressure is designed to remain within the engine manufacturer's

specified limits. The catalyst unit has no additional maintenance

requirements for the life of the catalyst.

The second configuration of the candidate equipment includes the

retard of fuel injection timing in combination with B20 and the above-

described exhaust catalyst. All applicable engines using this second

configuration and equipped with mechanical unit injection (MUI) would

use a timing retard of four (4) degrees. All applicable engines using

this configuration and equipped with electronically-controlled fuel

injection would use a timing retard of one (1) degree. The notification

states that timing is retarded by a shift of the timing sensor. The

Agency requests comment and information concerning the reasonability of

these timing specifications.

For its certification testing, TRT used catalytic muffler units

that were manufactured by Engelhard Corporation and are the same

formulation and configuration that is certified by the Agency for use

in the urban bus program (see 60 FR 28402, dated May 31, 1995, for that

certification). While an agreement is in place for Engelhard to supply

TRT with catalysts, the physical specifications of the catalyst to be

used in production are neither part of the

[[Page 64053]]

TRT notification of intent to certify nor provided to TRT as part of

that agreement. In general, the Agency has concerns when a certifier is

not aware of the technical specifications of equipment it wants to

certify and when the potential exists for a change in equipment

specifications to adversely affect emissions reduction performance.

Such a change in specifications may occur, for example, with a change

in catalyst production which may not be known to the certifier. In a

letter provided to the Agency, Engelhard states that it will notify

both TRT and the Agency in the event of changes to specifications of

the catalytic converter muffler provided to TRT. The specifications for

the catalyst have been provided to the Agency as a confidential part of

Engelhard's notification of intent to certify its CMXTM catalyst

muffler. A copy of this letter can be found in the public docket at the

address indicated above. This provides the Agency with assurance that

changes to catalyst specifications will be brought to the Agency's

attention, and the Agency proposes to restrict certification for

candidate TRT equipment to use of catalyst muffler units supplied by

Engelhard and covered by Engelhard's certification, and require that

use of catalysts supplied by any other supplier be the subject of a

separate notification of intent to certify.

TRT presents exhaust emission data from testing the candidate

equipment configurations on three engines using the federal engine-

dynamometer test procedures of 40 CFR Part 86, as well as chassis

dynamometer testing. A 1977 model year DDC 6V71N and 1988 model year

DDC 6V92TA DDEC II were tested on engine dynamometers, and another 1988

model year DDC 6V92TA DDEC II was tested on a chassis dynamometer. The

6V71N engine was selected to represent a ``worst case'', with respect

to PM, for most of the engines for which certification of the equipment

is being sought, and also to represent engines equipped with MUI. Based

on a pre-rebuild PM level for the 6V71N of 0.50, from the table in 40

CFR section 85.1403(c)(1)(iii)(A), TRT states that the 6V71N qualities

as ``worst case'' for all two-stroke/cycle engines with the exception

of the 1990 DDC 6L71TA. The 1988 6V92TA DDEC engines were tested to

show the results of the biodiesel fuel on engines having electronic

fuel control, and also to represent the ``worst case'' engine

configuration for such engines, based on their ``pre-rebuild'' level of

0.31 g/bhp-hr. The notification states that the fuel used for testing,

both the biodiesel and diesel, are representative of commercially

available biodiesel and low-sulfur diesel fuels.

Baseline testing was conducted after two of the test engines were

rebuilt to the original engine manufacturer's configurations. A third

engine had not been used prior to testing. Baseline testing was

conducted using low sulfur test fuel having a maximum sulfur level of

0.05 weight percent. Subsequent testing of the engines was done after

the candidate equipment was installed.

Table 1A below summarizes the emission levels from the engine

dynamometer testing. Table 1B summarizes the chassis testing in terms

of range of impact on exhaust emissions of the candidate equipment from

three driving cycles. The driving cycles used for the chassis testing

were the Central Business District, New York Bus Composite Cycle, and

the Arterial Cycle. A report attached to TRT's notification provides

specific emission rates measured for each driving cycle and equipment

configuration. Table 2 summarizes, for each test engine, the changes in

PM and NOX emissions with use of each configuration of the

equipment. The reductions listed for the chassis testing include double

weighting of the emission data from the Arterial Cycle, because TRT

believes the resultant combination of the chassis driving cycles is

more representative of the Agency's Urban Dynamometer Driving Schedule

for Heavy-Duty Vehicles (40 CFR Part 86, Appendix I). Table 3 provides

a summary of all engine models for which TRT intends the equipment to

apply, and the associated percent reductions in PM emissions for these

models, based on the test data. Table 4 summarizes the PM certification

levels for each engine model for which certification is sought, based

on reductions of Table 3 applied to the pre-rebuild levels established

in the program regulations. Additional testing information is provided

in reports from the facilities which conducted the emission testing

(these reports are attachments to the notification).

Table 1A.--Test Engine Emissions

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Gaseous and Particulate Smoke

Engine --------------------------------------------------------------- Comment

HC CO NOX PM ACC LUG Peak

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(3) g/bhp-hr

(2) percent opacity

Engine Dyno................................. 1.3 15.5 10.7 0.60 20 15 50 1988 EPA stds.

1977 6V71N MUI.............................. 0.86 3.18 11.72 0.282 1.2 1.8 1.8 Baseline (low S, 2D).

1977 6V71N MU............................... 0.38 0.86 12.11 0.166 0.9 1.7 1.7 B20 + cat.

1977 6V71N MU............................... 0.42 0.94 8.47 0.213 2.2 2.8 2.9 B20, cat + 4 deg. retard.

1988 6V92TA DDEC II......................... 0.60 1.60 8.52 0.20 6.0 5.3 8.7 Baseline (low S, 2D).

1988 6V92TA DDEC II......................... 0.21 0.95 9.12 0.11 3.7 1.7 6.9 B20 + cat.

1988 6V92TA DDEC II......................... 0.25 1.05 8.35 0.12 5.1 2.5 8 B20, cat + 1 deg. retard.

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Table 1B.--Chassis Testing: Range of Percentage Change \1\ in Emissions From Baseline (Low Sulfur Diesel)

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Pollutant B20 + catalyst B20 + catalyst + 1.5 deg. retard

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HC..................................... -59 to -39................ -33 to +3

CO..................................... -85 to -54................ -38 to -19

NOX.................................... +4 to +8.................. -5 to -2

PM..................................... -56 to -22................ -46 to -7

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\1\ Three different chassis driving cycles were used.

[[Page 64054]]

Table 2.--Emissions Changes From Test Engines

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Configuration Per cent

Test Engine ---------------------------------------- Per cent NoX Test/dyno

B20 CAT Timing retard PM change change

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1977 6V71N...................... None.......... -41 +3 Engine.

MUI............................. 4 deg......... -24.5 -28 ................

1988 6V92TA DDEC................ None.......... -45 +6 Engine.

II.............................. 1 deg......... -40 -2 ................

1988 6V92TA DDEC................ None.......... -40 +4 Chassis.

II.............................. 1.5 deg....... -27 -5 ................

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Table 3.--Applicable Engines and PM Reduction

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

Configuration and per

Cent PM Reduction

Engine model Model year -------------------------

B20, cat +

B20 + cat retard

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

6V92TA MUI....................... 79-87 41.1 24.5

6V92TA MUI....................... 88-89 41.1 24.5

6V92TA DDEC I.................... 86-87 45.0 40.0

6V92TA DDEC II................... 88-91 45.0 40.0

6V92TA DDEC II................... 92-93 45.0 40.0

6V71N MUI........................ 73-87 41.1 24.5

6V71N MUI........................ 88-89 41.1 24.5

6V71T MUI........................ 85-86 41.1 24.5

8V71N MUI........................ 73-84 41.1 24.5

6L71TA MUI....................... 90 41.1 24.5

6L71TA MUI....................... 88-89 41.1 24.5

6L71TA DDEC...................... 90-91 45.0 40.0

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Table 4.--PM Certification Levels

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Equipment Configuration

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

Engine model Model year B20, cat +

B20 + cat retard

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6V92TA MUI....................... 79-87 0.29 0.38

6V92TA MUI....................... 88-89 0.17 0.23

6V92TA DDEC I.................... 86-87 0.17 0.18

6V92TA DDEC II................... 88-91 0.17 0.19

6V92TA DDEC II................... 92-93 0.14 0.15

6V71N MUI........................ 73-87 0.29 0.38

6V71N MUI........................ 88-89 0.29 0.38

6V71T MUI........................ 85-86 0.29 0.38

8V71N MUI........................ 73-84 0.29 0.38

6L71TA MUI....................... 90 0.34 0.44

6L71TA MUI....................... 88-89 0.18 0.23

6L71TA DDEC...................... 90-91 0.17 0.18

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Section 85.1406(a) of the program regulations state ``The test

results must demonstrate that the retrofit/rebuild equipment * * * will

not cause the urban bus engine to fail to meet any applicable Federal

emission requirements set for that engine in the applicable portions of

40 CFR part 86 * * *''. TRT's emission test data indicate that both

configurations of the candidate equipment reduce hydrocarbon (HC) and

carbon monoxide (CO), when compared with baseline (pre-retrofit)

emissions. There is, however, potential for concern with regard to

NOX emissions from other engines with which the candidate

equipment might be certified, because an increase of three percent was

measured for the MUI test engine when equipped with the B20-catalyst

configuration without fuel injection retard, and six percent for the

electronically-timed DDEC II test engine. Because test data is not

available on all engines for which certification of the equipment is

sought, TRT performed analyses to determine whether such increases

would indicate that other engines exceed applicable NOX standards.

The analysis, in general, applies each of the measured increases to the

NOX certification levels established by the engine manufacturer

for engines tested under the Agency's new engine certification program.

(New engine certification testing results are reported yearly by the

Agency in its ``Federal Certification Test Results''.) Three percent

increase in NOX is evaluated for engines equipped with MUI, and

six percent increase is evaluated for engines equipped with

electronically-timed injection. The increased NOX level is

compared with the relevant standard for the particular engine. TRT's

analyses is in the public docket, and discussed below.

[[Page 64055]]

TRT's analysis for MUI engines is broken down by engine model year

to account for two new engine certification test procedures, each

having particular emissions standards. The ``13 mode'' engine

dynamometer test procedure was used for heavy-duty engine testing prior

to the 1985 model year, and the ``transient'' engine dynamometer test

procedure is used for 1985 and later model years. For certification

under the urban bus program, TRT tested the 1977 model year 6V71N MUI

engine using the ``transient'' procedure. While the ``13 mode'' test

was used for new engine certification of the 1977 model year, the

``transient'' test is the current standard test procedure for heavy-

duty engines and is generally recognized as more representative than

the ``13-mode'' test. Therefore, the Agency believes that the NOX

increase measured by TRT using the ``transient'' test data is a

relevant gauge of the impact of the candidate equipment. TRT's analysis

applies the increase to the new engine certification data available for

engines of 1984 and earlier model years. Prior to 1985, there was no

federal emission standard for NOX alone. The relevant emission

standards (for engines that were certified using the ``13-mode''

procedure) are 16 g/bhp-hr for 1974 through 1978 model year engines and

10 g/bhp-hr for 1979 through 1984 model year engines, for the sum of HC

emissions added to NOX emissions. TRT's initial analysis applied

three percent increase to the new engine certification levels for HC +

NOX emissions for 1982 and later model year engines for which such

data is available. This predicts that only one engine (a 325 horsepower

version of 1982 model year 6V92TA engine family CGM0552FWG5) would

exceed its NOX standard. Further analysis for this engine,

applying three percent increase in its NOX emission level added to

50 percent decrease in its reported HC certification level, indicates

that the combined federal emission standard would not be exceeded for

this engine if equipped with the candidate equipment. Based on this

analysis and TRT's emission test data indicating significant reductions

in HC emissions (at least 50 percent), the Agency believes that for any

applicable pre-1985 engine equipped with MUI, an increase in NOX

emissions of the percentage measured on the 1977 6V71N MUI test engine

will be more than offset by a decrease in HC emissions, such that the

HC + NOX standard will not be exceeded.

Another part of TRT's analysis pertains to engines equipped with

MUI and certified using the ``transient'' test procedure (that is, the

engines of model year 1985 and later). TRT's analysis, applying three

percent increase to NOX levels developed during new engine

certification testing, indicates that no 1985 or later engine equipped

with MUI would exceed the applicable federal standard if equipped with

the candidate equipment. TRT also analyzed the impact of six percent

increase in NOX emissions on electronically-controlled engines,

because their data show that NOX emissions for the 1988 model year

6V92TA DDEC II test engine increase roughly six percent when equipped

with the B20-catalyst configuration without injection retard. This

increase in NOX emissions is important, especially because federal

standards for NOX were lowered to 6.0 g/bhp-hr for the 1990 model

year and 5.0 g/bhp-hr for the 1991 model year. Therefore, TRT analyzed

the impact of six percent increase in NOX emission levels

developed during new-engine certification testing on Detroit Diesel

Corporation's DDEC engines. (Under the new engine certification

program, all DDEC engines have been tested using the ``transient''

procedure.) The results indicate that NOX levels for the engine

families in Table 5 would exceed the appropriate federal emission

standard. Therefore, the Agency proposes that use of the candidate

equipment without fuel injection retard on any urban bus engines of the

engine families listed in Table 5 not be covered by certification under

the urban bus program.

Table 5.--Engine Families not Covered by Certification

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Configuration: B20 and Catalyst (without injection retard)

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

Model year Model Engine family

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

1990........................ 6V92TA DDEC II...... LDD0552FZG6

6V92TA DDEC II Coach LDD0552FZL2

1991........................ 6L71TA DDEC ALCC.... MDD0426FZFX

6V92TA DDEC II...... MDD0552FZG5

6V92TA DDEC II...... MDD0552FZL1

1992........................ 6V92TA DDEC II...... NDD0552FZG4

6V92TA DDEC II Coach NDD0552FZL0

1993........................ 6V92TA DDEC II...... PDD0552FZG2

6V92TA DDEC II Coach PDD0552FZL9

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

The Agency requests comment, additional analysis, or additional

emission test data or for engine families to which the equipment is

intended to apply, to determine whether regulatory requirements are met

with urban bus engines using the candidate equipment.

While absolute smoke opacity levels during testing of the 1977

6V71N MUI test engine were well below relevant standards, increases

were measured between the baseline test and testing using B20, catalyst

and retarded timing. This is not of significant concern because the

Agency believes the absolute level of increase is more relevant than

the percentage increase. Further, the absolute level of increase in

opacity is believed not significant in the context of the current smoke

test and opacity standards (in other words, there is probably no real

increase in smoke opacity, given the nature of the smoke test and level

of the standards). Finally, smoke emissions from heavy duty diesel

engines, in general, have declined over the years as engines are

designed to comply with declining federal PM emissions standards. The

Agency believes that even if this test data accurately predicts an

increase in smoke emission opacity with other engines for which the

equipment is intended to apply, it is not a significant increase. The

Agency requests comment regarding the applicability of that data to

other engines having MUI for which the equipment is intended to apply.

Smoke emission measurements for the 1988 engine indicate compliance

with applicable standards.

As indicated in the notification, the 6V71N test engine qualities

as a ``worst case'' for all two-stroke/cycle engines with exception of

the 1990 DDC

[[Page 64056]]

6L71TA. (The 1990 model year DDC 6L71TA has a pre-rebuild PM level of

0.59 g/bhp-hr.) While TRT requests certification coverage for the 1990

DDC 6L71TA and warrants comparable particulate emissions reduction

percentages for it as is demonstrated by the 6V71N test engine, the

requirement of the program regulations have not been met. Therefore,

the Agency believes that the notification lacks sufficient basis for

certification of the candidate equipment with the 1990 DDC 6L71TA.

Section 85.1406(d) of the regulations governing urban bus equipment

certification states, in part, ``* * * installation of any certified

retrofit/rebuild equipment shall not cause or contribute to an

unreasonable risk to the public health, welfare or safety * * *''.

Information for considering whether B20 in this context would affect

any potential human health risks associated with exposure to

conventional diesel emissions has been provided by TRT with its

notification of intent to certify. This information will be reviewed by

the Agency. The Agency has made this information part of the public

docket at the address listed above. Any findings based on this

information, together with any other information that may be

considered, will be made part of the public docket located at the

address noted above, and considered by the Agency in its decision

regarding certification of the candidate equipment. The Agency requests

additional information, including information on combustion by-

products, for considering whether and, if so how, the use of the

subject biodiesel blend, that is, B20, in diesel engines would affect

any potential health risks associated with exposure to conventional

diesel emissions.

Section 211 of the Clean Air Act sets forth 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 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. The

Agency 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. 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.

If the Agency certifies the candidate TRT equipment, operators may

use it immediately, as discussed below. TRT's notification indicates

that the candidate equipment is to be certified for compliance program

2; however, as discussed below, the Agency believes that configurations

utilizing the catalytic muffler and reducing PM by at least 25 percent

may also be used in compliance with current program 1 requirements.

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 program requirements. For urban bus

operators affected by this program and electing to comply with program

1 requirements, that certification means that rebuilds and replacements

of all 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 with equipment certified to reduce

PM emissions by 25 percent or more. Under Program 1, operators could

use the TRT equipment if certified to reduce PM by at least 25 percent,

or other equipment certified to provide at least a 25 percent

reduction, until equipment is certified which triggers the 0.10 g/bhp-

hr PM standard. For Program 1, operators may also use the B20 blend

with the Engelhard catalyst and injection retard only for the following

engines: 6V92TA DDEC I and DDEC II, and 6L71TA DDEC.

Operators who choose to comply with Program 2 and install the TRT

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 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 a urban bus operator by the Agency. 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 this notification of intent

to certify, and other materials submitted as applicable, to determine

whether there is adequate demonstration of compliance with: (1) The

certification requirements of Sec. 85.1406, including whether the

testing accurately substantiates the claimed emission reduction or

emission levels; and, (2) the requirements of Sec. 85.1407 for a

notification of intent to certify.

The Agency 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 notice initiates a 45-day period during which the

Agency will accept written comments relevant to whether or not the

equipment described in the TRT 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.

The Agency 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, the

Agency 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: December 1, 1995.

Mary D. Nichols,

Assistant Administrator for Air and Radiation.

[FR Doc. 95-30405 Filed 12-12-95; 8:45 am]

BILLING CODE 6560-50-P