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State of California

AIR RESOURCES BOARD

Final Statement of Reasons for Rulemaking,

Including Summary of Comments and Agency Responses

PUBLIC HEARING TO CONSIDER THE ADOPTION OF A PUBLIC TRANSIT BUS

FLEET RULE AND EMISSION STANDARDS FOR NEW URBAN BUSES

First Public Hearing Date: January 27, 2000

Continued to: February 24, 2000

Agenda Item No.: 00-1-2

I. GENERAL

This rulemaking was initiated by a Notice of Public Hearing to consider the

adoption of a public transit bus fleet rule and emission standards for new urban buses

released and made available to the public on December 10, 1999. A Staff Report (Initial

Statement of Reasons for the proposed regulation) was also made available for public

inspection on December 10, 1999. The Staff Report, which is incorporated by reference

herein, contained the text of the regulation as initially proposed by the staff, along with

an extensive description of the rationale for the regulation. The regulation as originally

proposed added sections 1956.1, 1956.2, 1956.3, and 1956.4 to the California Code of

Regulations (CCR), title 13. It also included amendments to section 1956.8, title 13,

CCR, and to the “California Exhaust Emission Standards and Test Procedures for 1985

and Subsequent Model Heavy-Duty Engines and Vehicles” (hereinafter “Standards and

Test Procedures”), which is incorporated by reference in sections 1956.1 and 1956.8.

At a public hearing conducted on January 27, 2000, the Air Resources Board

(the “Board” or “ARB”) considered the adoption of a regulation for a public transit bus

fleet rule and emission standards for new urban buses. At this hearing, the staff

presented modifications to the regulation originally proposed in the Staff Report

released on December 10, 1999, in response to comments received subsequent to

publication of the Staff Report. After extensive public testimony, the Board Chairman

closed the public record for the proposed regulation and continued the hearing until

February 24, 2000.

At the February 24 hearing, the staff presented additional modifications to the

regulation originally proposed in response to public testimony and Board direction at the

January 27 hearing. At the conclusion of the hearing, the Board approved the staff’s

proposal with the modifications presented at both the January and February hearings,

with minor changes. In accordance with section 11346.8 of the Government Code, the

Board directed the Executive Officer, through Resolution 00-2, to make the text of the

modified amendments available to the public for a supplemental written comment period

of 15 days. The Executive Officer was then directed either to adopt the amendments
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with such additional modifications as may be appropriate in light of comments received,

or to present the regulation to the ARB for further consideration if warranted in light of

the comments.

The text of the ARB-approved modifications, with the modifications clearly

identified, was made available for a supplemental 15-day comment period by issuance

of a Notice of Public Availability of Modified Text and Supporting Documents on August

16, 2000. The Notice, which is incorporated by reference herein, contained the text of

the modified regulation with additions shown by double underline and deletions shown

by double underline strikeout. The Notice also contained descriptions of the significant

modifications by section number, subdivision, and when applicable, by paragraph.

While three written comment letters relevant to the modifications were received during

the supplemental 15-day comment period, only two of the letters contained specific

objections or recommendations regarding the regulatory modifications.

After considering the comments received during the supplemental 15-day

comment period, the Executive Officer issued Executive Order G-00-060, adopting the

regulation as modified, described in the Notice of Public Availability of Modified Text and

Supporting Documents,” into sections 1956.1, 1956.2, 1956.3, 1956.4, 1956.8, 1965,

and to three documents incorporated by reference: 1) the amended Standards and

Test Procedures document incorporated by reference in sections 1956.1(b) and

1956.8(b), title 13, CCR; 2) the amended “California Motor Vehicle Emission Control

and Smog Index Label Specifications” incorporated by reference in section 1965, title

13, CCR; and 3) the newly adopted “California Certification Procedures for PM Retrofit

Devices for Heavy-Duty Diesel Engines” incorporated by reference in section

1956.2(f)(7),

title 13, CCR.

Modifications to the original proposal

There were a number of modifications presented by the ARB staff at the January

and February hearings and approved by the Board to revise sections 1956.1, 1956.2,

1956.3, 1956.4, and 1956.8, title 13, CCR, and the Standards and Test Procedures

document. In addition, other modifications were made and included in the Notice of

Public Availability of Modified Text and Supporting Documents that were not presented

at either the January or February hearing. These changes were sufficiently related to

the original text of the regulation such that the public was placed on notice that the

changes could result from the originally proposed regulatory action. All the significant

modifications included in the regulation are described below. Other modifications were

made to correct typographical errors, provide conformity throughout the regulation, and

to improve its clarity.
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Section 1956.1, Title 13, CCR: Exhaust Emission Standards and

Test Procedures – 1985 and Subsequent Model Heavy-Duty Urban Bus Engines

and Vehicles

Paragraph (a)(7) was added to require that diesel-fueled, dual-fuel, and bi-fuel

urban bus engines shall meet a 0.01 grams per brake horsepower-hour

(g/bhp-hr) particulate matter (PM) standard beginning with 2002 and subsequent

model year engines produced beginning October 1, 2002. This modification was

drafted in response to a commitment by the Engine Manufacturers Association

(EMA) to produce such engines meeting a 0.01 g/bhp-hr PM standard, made

subsequent to the publication of the originally proposed regulation in the Staff

Report released on December 10, 1999.

Paragraphs (a)(8) and (a)(9) were modified to provide clarity in the applicability of

the ARB’s optional, reduced emission standards for 2002 and subsequent model

year urban bus engines, produced beginning October 1, 2002.

Paragraph (a)(11) was modified to include bi-fuel urban bus engines, to provide

clarity with respect to proposed emission standards for non-methane

hydrocarbons, carbon monoxide, and formaldehyde, and to provide specificity

regarding the ability of engine manufacturers to sell bus engines certified to

emission standards other than those required by paragraph (a)(11).

Paragraph (a)(12) was modified to delete restrictions on averaging, banking, and

trading provisions for engine manufacturers based on comments made by the

EMA subsequent to the publication of the originally proposed regulation in the

Staff Report released on December 10, 1999.

Subdivision (b) was added to incorporate by reference the document entitled

“California Exhaust Emission Standards and Test Procedures for 1985 and

Subsequent Model Heavy-Duty Diesel Engines and Vehicles,” adopted April 8,

1985, and last amended on February 26, 1999.

Section 1956.2, Title 13, CCR: Fleet Rule for Urban Transit Bus Operators

Subdivision (a) was modified to require transit agencies choosing the fleet rule’s

diesel path to notify the ARB of this action.

Subdivision (b) was added to define, for the purpose of the fleet rule described in

section 1956.2, the following terms: “alternative fuel”; “active fleet”; “transit

agency”; and “urban bus.”

Paragraph (c)(5) was added to clarify requirements for diesel-fueled, dual-fuel, or

bi-fuel new bus purchases made by transit agencies on the alternative-fuel path.
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Paragraph (d)(4) was modified to clarify requirements for diesel-fueled, dual-fuel,

bi-fuel, or alternative-fuel new bus purchases made by transit agencies on the

diesel path.

Paragraph (d)(7) was added to allow urban bus fleets, upon approval by the

Executive Officer, to implement an alternative emission reduction strategy to

achieve emission reductions greater than those that would be achieved through

implementation of the staff’s originally proposed emission standards for model

year 2004 through 2006 diesel-fueled and dual-fuel urban bus engines.

Paragraph (e)(1) was modified to allow zero-emission buses not defined as an

urban bus to be used in calculating a transit agency’s oxides of nitrogen (NOx)

fleet average standard.

Subdivision (f), pertaining to PM retrofit requirements, was modified for clarity

based on comments from the EMA made subsequent to the publication of the

originally proposed regulation in the Staff Report released on December 10,

1999. It was also modified to accelerate the PM retrofit schedule for transit

agencies on the diesel path based on comments from environmental groups at

the January hearing.

Paragraph (f)(7) was added to incorporate, by reference, a certification procedure

for use by retrofit device manufacturers in certifying retrofit devices to reduce PM

emissions from diesel-fueled, dual-fuel, bi-fuel, and diesel hybrid electric urban

transit buses. While the PM retrofit requirements were included in the notice of

public hearing issued on December 10, 1999, the entire certification procedure is

a modification recommended by staff at the January hearing and approved by the

Board at the February hearing. As presented at the January hearing, the

certification procedure was originally included in section 1956.2, title 13, CCR.

To provide clarity and specificity, the staff removed the procedure from section

1956.2 subsequent to the February hearing, added more detail to the certification

requirements, and incorporated the procedure within a new, separate document

entitled “California Certification Procedures for PM Retrofit Devices for HeavyDuty Diesel Engines.”

The legal authorities and references cited for section 1956.2, title 13, CCR, were

modified to include Health and Safety Code section 43701(b) pertaining to the

ARB’s authority to require retrofits for heavy-duty diesel vehicles.

Section 1956.3, Title 13, CCR: Zero-Emission Bus Requirements

Paragraphs (c)(4)(A) and (c)(4)(B) were added to allow transit agencies to earn

credits for placing zero-emission buses, other than zero-emission buses used in

required demonstration projects, in service earlier than required by the

purchase/lease requirements specified in subdivision (c).
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Section 1956.4, Title 13, CCR: Reporting Requirements for all Urban Bus Transit

Agencies

The term “leasing companies” was deleted from the title of section 1956.4

because the reporting requirements described therein only apply to urban bus

transit agencies.

The reporting requirements were modified in subdivisions (a), (d), and (f) to

reflect that urban bus transit agencies must submit annual reports regarding bus

purchases and leases, and compliance with required PM retrofit requirements,

rather than just maintain records for inspection upon request.

Paragraph (a)(2) was modified to specify requirements for a transit agency that is

requesting a deviation from the 85 percent alternative-fuel bus purchase/lease

requirement for transit agencies on the fleet rule’s alternative-fuel path.

Subdivision (b) was added to specify that urban bus transit agencies on the fleet

rule’s diesel path must submit an initial report stating an agency’s intent to follow

the diesel path and annual reports regarding new bus purchases and leases.

Subdivision (d) was modified to conform the reporting requirements for PM

retrofits to the modified PM retrofit requirements for transit agencies on the fleet

rule’s diesel path.

Paragraph (f)(2) was modified to specify requirements for a transit agency that is

requesting a deviation from the 15 percent zero-emission purchase/lease

requirement for large transit agencies on the fleet rule’s diesel and alternativefuel paths.

Subdivision (g) was added to include reporting requirements for transit agencies

exempted from the requirements for new purchases of 2004 through 2006 model

year diesel-fueled, dual-fuel, bi-fuel, or alternative-fuel urban buses.

Section 1956.8, Title 13, CCR: Exhaust Emission Standards and

Test Procedures – 1985 and Subsequent Model Heavy-Duty Engines and Vehicles

The language in paragraph (a)(1) was modified to accurately reflect the contents

of the modified table contained therein.

Footnote G in paragraph (a)(1) is new language in the regulation originally

proposed in the Staff Report released on December 10, 1999, that was not

shown as a proposed amendment. Hence, it was included in the Notice of Public

Availability of Modified Text and Supporting Documents as modified text for

which public comment was invited.
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The table in paragraph (a)(2) was modified in response to comments made by

International Truck and Engine Corporation (formerly known as Navistar)

subsequent to publication of the originally proposed regulation in the Staff Report

released on December 10, 1999. The modifications to the table and the addition

of new footnote H are intended to clarify that each heavy-duty engine

manufacturer is subject to its respective requirements in settlement agreements

reached with the ARB and the United States Environmental Protection Agency

(U.S. EPA) in an enforcement action concerning violations of emission

standards. In addition, the table was retitled to more accurately reflect its

contents.

Paragraphs (a)(4)(A) and (a)(4)(B) were modified to conform with footnote

modifications in paragraphs (a)(1) and (a)(2), pertaining to the dual fueling mode

certification process.

Footnote A in subdivision (h) was modified to include reference to

section 1961, title 13, CCR – Exhaust Emission Standards and Test Procedures

– 2004 and Subsequent Model Passenger Cars, Light-Duty Trucks, and MediumDuty Vehicles.

Section 1965, Title 13, CCR: Emission Control and Smog Index Labels – 1979 and

Subsequent Model Year Motor Vehicles

Section 1965 in title 13 incorporates by reference the document entitled

“California Motor Vehicle Emission Control and Smog Index Label

Specifications.” These specifications for tune-up labels, vehicle/engine emission

configuration bar-code labels, and vehicle identification number bar-code labels

apply to all new 1979 and subsequent model-year heavy-duty engines, as well as

other categories of motor vehicles. Minor conforming amendments to section

1965 were inadvertently omitted from the regulatory text as originally proposed in

the Staff Report released on December 10, 1999. Hence, section 1965, as

amended, was noticed for the 15-day supplemental public comment period and is

now included in the modified regulation, along with conforming modifications to

the incorporated document “California Motor Vehicle Emission Control and Smog

Index Label Specifications.”

California Exhaust Emission Standards and Test Procedures for 1985 and

Subsequent Model Heavy-Duty Diesel Engines and Vehicles

The Standards and Test Procedures document is incorporated by reference in

sections 1956.1 and 1956.8, title 13, CCR. The ARB and the U.S. EPA work

closely together in regulating motor vehicles, including heavy-duty diesel

vehicles. Hence, this document contains various sections of the Code of Federal

Regulations (CFR) promulgated by the U.S. EPA pertaining to heavy-duty diesel

vehicles, including urban transit buses. Some of the CFR provisions in the

Standards and Test Procedures Document remain the same as those for the
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federal motor vehicle control program, while others have been modified to

conform to the unique requirements of California’s motor vehicle control program.

Various sections of the CFR with proposed amendments were inadvertently

omitted from the regulatory text as originally proposed in the Staff Report

released on December 10, 1999. The omitted CFR sections, sections 86.098-15

and 86.004-15, title 40, were noticed for the 15-day supplemental public

comment period, and are now included in the regulation with conforming

amendments based on modifications to sections 1956.8 and 1956.1, title 13,

CCR.

In addition, CFR sections 86.098-11 and 86.004-11, title 40, which were included

in the regulation as originally proposed, contain additional amendments to

conform them to the modifications to CCR sections 1956.1 and 1956.8. For CFR

section 86.098-11, the additional amendments include clarification of the PM

standard for 2002 and subsequent model year diesel-fueled, dual-fuel, and bifuel urban bus engines produced beginning October 1, 2002, and further

clarification of the optional, reduced emission standards for urban bus engines

and heavy-duty truck engines. For CFR section 86.004-11, the additional

amendments include clarification of the emission standards for all 2004 and

subsequent model year urban bus engines, and language included in the

regulation as originally proposed in the Staff Report released on

December 10, 1999, that was not shown in underline/strikeout format as

proposed amendments.

Incorporated Documents

The regulation contains three documents incorporated by reference. They are:

1) the amended Standards and Test Procedures document incorporated by reference in

sections 1956.1(b) and 1956.8(b), title 13, CCR; 2) the amended “California Motor

Vehicle Emission Control and Smog Index Label Specifications” incorporated by

reference in section 1965, title 13, CCR; and 3) the newly adopted “California

Certification Procedures for PM Retrofit Devices for Heavy-Duty Diesel Engines”

incorporated by reference in section 1956.2(f)(7), title 13, CCR. These documents are

available upon request from the ARB in accordance with section 1902, title 13, CCR.

These documents are incorporated by reference because it would cumbersome, unduly

expensive, and otherwise impractical to publish them in the CCR. It has been a

longstanding and accepted practice for the ARB to incorporate ARB test methods and

other similar documents by reference because the interested audience is small.

Mandates

The Board has determined that this regulatory action will result in a mandate for

transportation planning agencies and commissions (the entities that fund transit

agencies), and for transit agencies statewide. However, the Board finds that these

costs are not reimbursable pursuant to part 7 (commencing with section 17500), division

4, title 2 of the Government Code, because transportation planning agencies,
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commissions, and transit agencies may recover their additional costs through existing

federal, state, and local funding transportation funding mechanisms, and/or through

increased user fees (i.e., trip fares).

Alternatives and Reports

The Staff Report released and made available to the public on

December 10, 1999, did not include any proposed alternatives designed specifically to

lessen the adverse economic impact on small businesses, nor were any identified and

proposed by the public during the 45-day comment period prior to the January hearing.

The Board has further determined that no alternative considered by the agency

would be more effective in carrying out the purpose for which the regulatory action was

proposed or would be as effective and less burdensome to affected private persons

than the action taken by the Board.

Finally, in accordance with section 11346.3(c) of the Government Code, the

Board has determined that the reporting requirements applicable to the transit agencies

are necessary for public health, safety, and welfare.

II. SUMMARY OF COMMENTS AND AGENCY RESPONSES

The ARB received over 5,900 written comment letters during the 45-day

comment period (over 5,800 were form-type letters), and received additional comments

by way of oral testimony taken over a period of nearly eight hours during the public

hearing on January 27, 2000. On August 16, 2000, the Notice of Public Availability of

Modified Text and Supporting Documents, which contains the modified text of the

regulation and an explanation of the proposed modifications, was made available to the

public for a supplemental comment period of 15 days. During the 15-day comment

period, the ARB received three written comment letters. Set forth below is a summary

of all individuals and organizations that provided written comments during the 45-day

comment period, oral testimony at the public hearing on January 27, 2000, and written

comments during the 15-day supplemental comment period.

45-day Comment Submittals

The following 27 transit-related organizations, industry groups, environmental

organizations, local air districts, and concerned individuals submitted written comments

during the 45-day comment period:

American Lung Association of California; California League of Conservation

Voters; California League of Conservation Voters Education Fund; Coalition for

Clean Air; Environmental Health Coalition; Natural Resources Defense Council;

Sierra Club of California; Union of Concerned Scientists (ENVIRONMENTAL

GROUP JOINT LETTER)

ARCO Products (ARCO)
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California Natural Gas Vehicle Coalition (CNGVC)

Children’s Health Environmental Coalition (CHEC)

City of Fresno

Mike Cluster

Cummins Engine Company (Cummins)

John Dunlap

Engine Manufacturers Association (EMA)

The Honorable Tom Hayden, Senator, California Legislature

Lockheed Martin

Manufacturers of Emission Controls Association (MECA)

Metropolitan Transit Development Board (MTDB)

Metropolitan Transportation Commission (MTC)

NALEO Educational Fund (NALEO)

Northern Sierra Air Quality Management District (NSAQMD)

Nova BUS

Pacific, Gas, and Electric (PG&E)

Physicians for Social Responsibility (PhSR)

Pickens Fuel Corporation (PFC)

Jeffrey M. Reid, City of Fresno

Sacramento Metropolitan Air Quality Management District (SMAQMD)

Santa Barbara Metropolitan Transit District (SBMTD)

Sempra Energy

Tosco Corporation

Western States Petroleum Association (WSPA)

Amanda Westervelt

Twelve members of the concerned public submitted form-type letters urging the

Board to strengthen the proposed regulation to achieve more reductions in diesel bus

emissions. These letters, referred to in total as “FL1,” came from the following

individuals:

Amanda Johnson

Brian J. Johnson

Edward Mainland

Hannah Nielsen

Malcolm Ponder

Zack Sarconi

Gerald Scherba

Owen Siegel

M. Ruth Viswander

Joe Weichman

Stacy A. Wolf

Letter from unidentifiable individual

In addition, 245 more members of the concerned public submitted, through
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e-mail to the ARB, the same type of form letter identified above. These comments are

also referred to in total as FL1. A complete list of these individuals is incorporated

herein as Attachment A. In total, the ARB received 257 comment letters urging the

Board to strengthen the proposed regulation.

An additional 5,634 members of the concerned public submitted form-type letters

urging the Board to replace diesel transit buses with cleaner alternatives. These

comments are referred to in total as “FL2.” Of these letters, 5,624 were submitted by a

service company, Working Assets®, on behalf of its clients. A complete list of these

5,624 individuals is incorporated herein as Attachment B. The remaining ten letters

referred to as FL2 came from the following individuals:

Charles Cirino

Carla Dimondstein

K. Dosif

Pattie Gardiner

Jan Kalyani

Craig Markson

Beth Olson

Linda M. Robertshaw

Earle Spanger

Letter from unidentifiable individual

Finally, nine additional members of the concerned public, listed below, submitted

comments to the ARB through e-mail. While each expressed an individual opinion,

these commenters generally expressed the need for the ARB to do more to reduce

emissions from diesel buses.

Jeanne and Lou Aceto

Jane Enrietto

Nancy Koke

Mary Matvy

Jon McHugh

F. Michael Montgomery

Jill North

James H. Prescott

Megan Ritchie

Oral Testimony at the January Hearing

Representatives of the following forty transit-related organizations, industry

groups, environmental organizations, local air districts, and concerned members of the

public presented oral testimony at the hearing on January 27, 2000. Organizations

identified with an asterisk (*) also submitted written comments during the 45-day

comment period, as indicated above.
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AC Transit

American Lung Association* (ALA)

ARCO Products* (ARCO)

Bay Area Air Quality Management District (BAAQMD)

California Chamber of Commerce (CCC)

California Electric Transportation Coalition (CETC)

California Natural Gas Vehicle Coalition* (CNGVC)

California Transit Association (CTranA)

California Trucking Association (CTA)

City of Fresno

Clean Air Now (CAN)

Coalition for Clean Air* (CCA)

Communities for a Better Environment (CBE)

Cummins Engine Company (Cummins)

dbb Fuel Cell Engines

Detroit Diesel Corporation (DDC)

Engine Manufacturers Association (EMA)

Judy Fogel

Goal Line Environmental Technologies

Golden Bear Oil Specialties

Labor/Community Strategy Center

Manufacturers of Emission Controls Association* (MECA)

Metropolitan Transportation Commission* (MTC)

Natural Resources Defense Council* (NRDC)

Neisi Farmers League and CAGI

Nova Bus*

Pickens Fuel Corporation*

San Mateo County Transit District (SMCTD)

San Joaquin Valley Air Pollution Air Pollution Control District (SJVAPCD)

Santa Barbara Electric Transportation Institute (SBETI)

Santa Clara Valley Transportation Authority (SCVTA)

Santa Clarita Transit District (SCTD)

Sempra Energy*

Sierra Club*

South Coast Air Quality Management District (SCAQMD)

Sunline Transit Agency

SUVA/LA CAUSA – Maggie Perales

SUVA/LA CAUSA – Joseph Perales

Union of Concerned Scientists* (UCS)

Western States Petroleum Association* (WSPA)

15-day Comment Submittals

The three organizations identified below submitted written comments during the

supplemental 15-day comment period. Only the Santa Barbara Metropolitan Transit
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District perceived all the modifications as favorable and did not provide any additional

objections or recommendations; hence, its comments are not summarized.

California Transit Association (CTranA)

Engine Manufacturers Association (EMA)

Santa Barbara Metropolitan Transit District (SBMTD)

Comment Summary and Agency Responses

Set forth below is a summary of each objection or recommendation made

regarding the specific regulatory actions proposed, together with an explanation of how

the proposed action was changed to accommodate each objection or recommendation

or the reasons for making no change. To the extent possible, the comments have been

grouped by issue. In cases where a specific comment applies to multiple but related

issues, the comment is only discussed in one issue category. Comments not involving

objections or recommendations specifically directed towards the rulemaking or to the

procedures followed by the ARB in this rulemaking are not summarized below.

1. 45-DAY COMMENT SUMMARY AND AGENCY RESPONSES

A. 2004 through 2006 Emission Standards for

Diesel-Fueled Engines

1. Comment: The future availability of NOx emission control technology under the

diesel path is uncertain. (SCAQMD, CTranA)

Agency Response: The ARB believes the technology to meet the 2004 through

2006 emission standards for diesel-fueled urban bus engines will be available.

Compliance with these standards could be achieved through engine modifications,

or through the use of aftertreatment devices to reduce emissions. As proposed by

staff, the 2004 through 2006 emission standards originally required significant

reductions in both NOx and PM. However, EMA committed to producing dieselfueled urban bus engines meeting the proposed 2004 PM standard (0.01 g/bhp-hr)

in October 2002; therefore, the engine manufacturers’ challenge for 2004 is to

further reduce NOx while maintaining low PM levels. The regulation provides

flexibility to engine manufacturers by providing two methods for compliance with the

2004 through 2006 emission standards for diesel-fueled urban bus engines. In

conjunction with low-sulfur diesel fuel, engine manufacturers may rely on engine

modifications to certify a new engine to the standards, or they may certify a new

engine by reducing the emissions from an engine meeting existing 2002

requirements with the use of aftertreatment devices.

If engine manufacturers choose to use aftertreatment devices, NOx adsorbers and

selective catalytic reduction systems are expected to be commercially available to

reduce NOx emissions. For PM control and compliance with the 0.01 g/bhp-hr PM

standard to take effect for 2002 model year urban bus engines produced on or after
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October 1, 2002, aftertreatment devices – particulate traps—are already

commercially available and will soon be undergoing certification for use in California.

2. Comment: It is uncertain whether transit fleets will want to meet their 2004 through

2006 engine needs with technology that is unproven, costly, possibly unavailable,

and which may be orphaned; that is, which may not have the long-term future

applicability that the staff is assuming. (EMA)

Agency Response: As indicated in response to Comment 1, the ARB expects that

the technology to meet the 2004 through 2006 emission standards will be available.

In some cases, this technology is a refinement of current technologies; in other

cases, it is new (e.g., NOx adsorbers). In either case, certified engines are

warranted by engine manufacturers for emissions performance and durability to

ensure their customers (transit agencies) of product effectiveness and reliability and

to protect their own business interests. As with any new technology, there are often

incremental costs. The Staff Report (page 44) contains a discussion of the expected

incremental costs associated with the 2004 through 2006 emission standards.

Nevertheless, transit agencies may use an alternative compliance option—an

alternative NOx strategy—if they choose not to purchase buses with diesel-fueled

engines meeting the 2004 through 2006 standards. There will be costs associated

with this option as well, and transit agencies should evaluate these costs compared

to the costs of standard compliance (i.e., purchasing engines meeting the 2004

through 2006 standards).

Regarding the long-term applicability of the 2004 through 2006 emission standards,

the ARB disagrees that the technology used to meet these standards will be

“orphaned.” To the contrary, the ARB expects the technologies to meet these

standards will pave the way for compliance with the 2007 emission standards, and

with further refinements, the 2004 technologies will enable engines to achieve nearzero-emission levels in 2007. (Please also see Agency Response to Comment 1.)

3. Comment: The ARB is now proposing to undo the heavy-duty on-highway

Statement of Principles (described in response, below) by proposing separate and

unique emission standards for heavy-duty on-highway transit buses and bus engines

in 2004. (EMA)

Agency Response: With the approval of the regulation in February, the Board did, in

fact, approve California emission standards for diesel-fueled urban bus engines for

the 2004 through 2006 model years. However, the ARB disagrees that this

represents an effort to undo the on-road Statement of Principles (SOP; see below).

The ARB believes these interim standards are essential for partially mitigating

excess in-use NOx emissions resulting from the engine manufacturers’ illegal use of

defeat devices, as well as demonstrating the effectiveness of diesel aftertreatment

systems that will be used in heavy-duty trucks and buses in the 2007 timeframe.
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In June 1995, the ARB, the U.S. EPA, and the heavy-duty engine manufacturers

signed an SOP calling for harmonization of ARB and U.S. EPA heavy-duty vehicle

emission standards. The end result of this agreement was the U.S. EPA’s adoption

of new emission standards in October 1997, and the ARB’s adoption of standards

aligned with the new federal standards in March 1998. However, subsequent to the

signing of the SOP and the adoption of the new federal and California emission

standards for heavy-duty vehicles and engines, federal investigations revealed that

seven of the largest heavy-duty diesel engine manufacturers had violated engine

certification regulations by programming engines to turn off emission control devices,

used to comply with the Federal Test Procedure (FTP), during in-use driving. These

violations, in direct conflict with the intent of SOP, have resulted in significant

increases of in-use NOx emissions, beyond what would be expected from heavyduty engines that comply with emission standards during the FTP cycle. The seven

heavy-duty engine manufacturers have settled with both the federal government and

the ARB by signing legally enforceable federal Consent Decrees and Californiaspecific Heavy-Duty Diesel Engine Settlement Agreements requiring the

manufacturers to reduce emissions. The legal authority of the ARB to adopt urban

bus standards is not in question, nor is this the proper forum for alleging violations of

the SOP. The EMA comment is disingenuous given the NOx emission violations of

the engine manufacturers through the use of electronic defeat devices.

4. Comment: The anticipated emission benefits from the 2004 through 2006 emission

standards for diesel-fueled urban bus engines will only be realized if transit fleets

purchase and operate a substantial number of buses and engines complying with

the standards. (DDC, Cummins)

Agency Response: It is true that the emission benefits of the 2004 through 2006

emission standards for diesel-fueled engines will only be realized if transit agencies

that would normally purchase new diesel-fueled buses in the 2004 through 2006

timeframe do so, and do not attempt to circumvent the regulation by pre-buying

buses or delaying bus purchases. To ensure that full emission benefits are realized,

the regulation incorporates two strategies to achieve full compliance. First, the 2004

through 2006 emission standards are in force for engine manufacturers and will

affect transit agencies purchasing buses with 2004 though 2006 model year dieselfueled engines. New diesel-fueled buses with these model year engines will emit 75

percent less NOx than the previous model year engines. Second, transit agencies

that would normally purchase new diesel-fueled buses in 2004 through 2006 may

choose to implement an alternative NOx strategy, in lieu of purchasing new buses,

provided that the strategy achieves greater NOx reductions than what would be

achieved through the 2004 through 2006 emission standards. (Please also see

Agency Response to Comment 5.)

5. Comment: The regulation should include, as a compliance option for transit

agencies, an optional fleet average NOx requirement to achieve emission benefits

equivalent to the 2004 through 2006 emission standards. This optional fleet

average, combined with low sulfur fuel, and a pull ahead of the 0.01 g/bhp-hr PM
15

standard to October 2002, will provide NOx and PM reductions that are superior to

those under the staff’s proposal. (EMA, DDC, Cummins)

Agency Response: At the February hearing, the Board approved a modification to

the originally proposed regulation that allows transit agencies to implement an

optional compliance strategy for achieving the emission reductions attributable to the

emission standards for 2004 though 2006 model year diesel-fueled bus engines.

 At the January hearing, the EMA proposed an optional fleet average NOx provision

(alternative NOx strategy) to achieve NOx emission reductions equivalent to those

that would be achieved through implementation of proposed emission standards for

2004 though 2006 model year diesel-fueled engines. This optional fleet average

NOx standard, which offers transit agencies compliance flexibility, would be in

addition to the required 4.8 g/bhp-hr fleet average NOx standard applicable to all

transit agencies in California. The staff did not support EMA’s original proposal

because it did not achieve NOx reductions superior to those of the staff’s proposed

2004 though 2006 emission standards; in fact, it achieved less NOx reductions.

Subsequent to the January hearing, EMA revised its proposal to provide NOx

reductions equivalent to the proposed 2004 though 2006 emission standards for

diesel-fueled engines. In addition, EMA’s revised proposal retained its original

commitment to provide more PM reductions than the 2004 through 2006 standards

by producing diesel-fueled engines meeting a 0.01 g/bhp-hr standard beginning in

October 2002 --a full 15 months ahead of when the standard was originally proposed

to take effect.

At the February hearing, the Board approved EMA’s revised proposal as a

regulatory modification, while directing the staff to make one significant change –

any transit agency opting to conduct an alternative NOx strategy must achieve

greater emission reductions, not merely equivalent emission reductions, to those

achievable through implementation of the 2004 through 2006 emission standards.

The Board’s direction for greater NOx reductions was to account for the inherent

uncertainty associated with an alternative NOx strategy and to send a clear

message to the engine manufacturers to do everything feasible to accelerate

development in advanced NOx control technology.

6. Comment: The regulation should include a fleet average standard as an option for

transit agencies to comply with the 2004 through 2006 emission standards for

diesel-fueled engines. A fleet average rule would ensure more certain emission

reductions when compared to an emission standard that would only affect new bus

purchases. It also ensures emission reductions even if technology cannot costeffectively achieve the required 2004 through 2006 standards. (MTC)

Agency Response: While the ARB believes the technology will be available to costeffectively meet the 2004 through 2006 emission standards, the Board directed the

staff to modify the regulation, in response to public comments, to include an optional
16

fleet average NOx requirement (alternative NOx strategy) as a compliance option for

transit agencies. Transit agencies purchasing 2004 through 2006 model year dieselfueled, dual-fuel, or bi-fuel urban buses must either purchase buses meeting the

2004 through 2006 model year standards, or, as a compliance option, they may

implement an alternative NOx strategy to achieve NOx reductions greater than those

that would be achieved through the 2004 through 2006 standards. As a condition of

the Board approving the alternative NOx strategy option, the EMA committed to

producing diesel-fueled urban bus engines meeting a 0.01 g/bhp-hr PM standard in

October 2002 – over a year ahead of when required, and, in conjunction with transit

agencies, to implement a demonstration program of buses equipped with control

technology designed to meet the 2004 through 2006 emission standards. (Please

also see Agency Response to Comment 5.)

7. Comment: The regulation should be modified to include a NOx fleet average

requirement to supplement the 2004 through 2006 diesel-fueled engine emission

standards in case the technology to meet the standards is not yet available.

(CTranA)

Agency Response: The ARB believes the technology to meet the 2004 through

2006 emission standards for diesel-fueled engines will be available. Nevertheless,

the Board directed the staff to modify the regulation, in response to public

comments, to include an optional compliance option (alternative NOx strategy) for

achieving the emission reductions attributable to the emission standards for 2004

though 2006 model year diesel-fueled bus engines. Transit agencies may

implement an alternative NOx strategy if they choose not to purchase diesel-fueled

engines meeting the 2004 through 2006 emission standards. (Please also see

Agency Responses to Comments 1, 5, and 6.)

8. Comment: For both engine manufactures and bus builders, the 2004 through 2006

emission standards for diesel-fueled engines represent a significant workload.

Given the significant resources necessary for compliance with general heavy-duty

emission standards, and given the small number of diesel-fueled engines that the

California transit bus market represents, it’s questionable as to whether or not it will

be practical to carry out the regulation as proposed. (Cummins)

Agency Response: The ARB acknowledges the significant workload posed to

engine manufacturers and bus builders by the implementation of the 2004 through

2006 emission standards for diesel-fueled engines. However, NOx reductions are

vital in California, and the ARB believes the standards are technologically feasible

and are necessary to pave the way for advanced technology required to meet the

2007 standards for urban buses and 2007 standards to be proposed for heavy-duty

trucks. As such, the ARB does not believe it prudent to relax the 2004 through 2006

emission standards for diesel-fueled engines.

9. Comment: The requirement for engine manufacturers to meet a 0.5 g/bhp-hr NOx

standard in 2004 should be moved up to 2002/2003. This would speed the
17

introduction of low-NOx technologies into transit vehicle applications and also

facilitate the availability of commercial aftertreatment technologies for other heavyduty vehicles. (SMAQMD)

Agency Response: The ARB did not modify the regulation to accelerate the

implementation of the 0.5 g/bhp-hr NOx standard because it does not believe the

technology necessary to meet the standard will be sufficiently developed in the

2002/2003 timeframe. Furthermore, most engine manufacturers are required to

meet a 2.5 g/bhp-hr NOx + NMHC standard in October 2002 (15 months ahead of

when required by federal and state regulations) to comply with the requirements of

the federal Consent Decrees and the California-specific Heavy-Duty Diesel Engine

Settlement Agreements. Requiring manufacturers to meet a lower NOx standard in

the 2002/2003 timeframe would violate legally-binding terms of the federal and

California agreements.

B. Harmonization with U.S. EPA’s 2007 Emission Standards

10.Comment: Once the federal emission standards for 2007 and subsequent model

year heavy-duty engines and vehicles are finalized, California’s urban bus standards

should be aligned with the federal standards. (Cummins)

Agency Response: The emission standards proposed by staff and approved by the

Board for 2007 and subsequent model year urban bus engines are essential to

achieving crucial reductions in ozone-precursor NOx emissions and toxic PM

emissions in California. Throughout the course of this rulemaking, the ARB stated

its intent to harmonize, to the extent possible, California’s 2007 and subsequent

model year urban bus engine standards with the heavy-duty engine standards

ultimately adopted by the U.S. EPA for the same timeframe. The U.S. EPA recently

issued its Notice of Proposed Rulemaking for Heavy-Duty Engines and Vehicle

Standards and Highway Diesel Fuel Sulfur Control Requirements (Federal Register,

Vol. 65, No. 107, June 2, 2000, pp. 35430 - 35545). Once the U.S. EPA’s

rulemaking is finalized, the ARB staff will consider modifications to California’s 2007

standards for urban bus engines, if necessary.

C. PM Retrofit Requirements

11.Comment: The ARB should do more to reduce PM emissions from new diesel

buses, thereby limiting the emissions gap between the diesel and alternative-fuel

paths. This can be achieved through a combination of more stringent PM emission

standards for diesel bus engines and a more aggressive PM retrofit program for the

diesel path. Specifically, the ARB should adopt a 0.005 g/bhp-hr PM standard for

diesel bus engines beginning with the 2004 model year and should accelerate the

PM retrofit requirements on the diesel path for 1996 through 2003 model year buses

(Tier 3) and for 1991 through 1995 model year buses (Tier 2). (ENVIRONMENTAL

GROUP JOINT LETTER)
18

Agency Response: The Board did approve modifications to the regulation as

originally proposed that accelerate the PM retrofit requirements on the diesel path.

Specifically, Tier 2 retrofits, applicable to buses with 1991 through 1995 model year

diesel-fueled engines, must now be completed by the year 2004 – one year ahead of

the schedule originally proposed in the regulation. Next, Tier 3 retrofits, applicable

to buses with 1996 through 2002 model year diesel-fueled engines produced before

October 1, 2002, must be completed by the year 2007 – two years ahead of the

schedule originally proposed in the regulation. (The engine model year range for

Tier 3 retrofits changed based on the EMA’s commitment to pull ahead from 2004 to

October 1, 2002, the production of diesel-fueled engines meeting a 0.01 g/bhp-hr

PM standard.) Additional changes were also made to the applicability of exemptions

for buses nearing retirement. Accelerating the retrofit requirements on the diesel

path will reduce the PM emissions gap between the diesel and alternative-fuel paths,

and will reduce the public’s exposure to toxic PM emissions from buses operated by

transit agencies choosing the diesel path.

The ARB did not propose a 0.005 g/bhp-hr PM standard for diesel-fueled bus

engines beginning with the 2004 model year because it did not believe PM control

technology would be able to achieve such low PM levels in conjunction with the

stringent NOx standard for diesel-fueled engines taking effect at the same time.

However, during the course of this rulemaking, the EMA agreed to start production

of diesel-fueled engines meeting a 0.01 g/bhp-hr PM standard on October 1, 2002, --

fifteen months ahead of when originally proposed. This regulatory modification,

approved by the Board on February 24, 2000, will limit the emissions gap between

the diesel and alternative-fuel paths.

12.Comment: The regulation should accelerate the PM retrofit requirements on the

diesel path, while relaxing the retrofit requirements on the alternative-fuel path.

(CNGVC)

Agency Response: As discussed in the response to Comment 11, the Board

approved modifications to the regulation accelerating the PM retrofit requirements on

the diesel path. The ARB did not relax the retrofit requirements on the alternativefuel path because transit agencies choosing this path could still have a significant

presence of buses in their existing fleets with diesel-fueled engines, many of these

being the oldest, most-polluting model years. It is only appropriate that these fleets

also implement measures to reduce toxic PM exposure for the public they serve.

D. Low-Sulfur Diesel Fuel

13.Comment: There are concerns about the availability of low-sulfur diesel fuel and

whether it will be available to all transit operators. The Board should continue to

monitor the availability of this fuel. (CTranA)

Agency Response: While the ARB expects that transit operators will not experience

difficulties obtaining low-sulfur diesel fuel, the ARB is committed to monitoring its
19

availability and reporting back to the Board, should availability issues arise. One

California oil refinery is capable of producing low-sulfur diesel fuel now, and at least

two more California oil refineries have committed to producing low-sulfur diesel fuel

by mid-2002 --- the date the regulation requires most transit agencies with dieselfueled buses to begin using low-sulfur diesel fuel. These three California oil

refineries account for over 70 percent of California’s current diesel production.

To provide compliance flexibility to small transit agencies in rural areas, areas that

may experience some difficulty in obtaining low-sulfur diesel fuel due to the higher

cost of securing delivery in outlying rural areas, the regulation allows transit

agencies operating in federal one-hour ozone attainment areas with active fleets of

less than 20 urban buses to delay using low-sulfur diesel fuel until mid-2006. The

ARB expects that a national low-sulfur diesel fuel requirement will be in effect by that

time, thus minimizing price and supply disruptions in California and enabling the

small transit agencies in ozone attainment areas to meet their compliance deadline.

To coincide with the delayed requirement to use low-sulfur diesel fuel, these smaller

transit agencies are permitted to delay compliance with Tier 1 and Tier 2 PM retrofit

requirements until 2007.

The U.S. EPA’s Notice of Proposed Rulemaking for Heavy-Duty Engines and

Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements (Federal

Register, Vol. 65, No. 107, June 2, 2000, pp. 35430 - 35545) includes a proposal to

limit the sulfur content in diesel fuel to 15 parts per million (ppm) by weight , the

same requirement contained in this rulemaking, by 2006. Board Resolution 00-2

directs the Executive Officer to work closely with the U.S. EPA in its development of

a new national diesel fuel specification, and to reevaluate the low-sulfur diesel fuel

requirement in this regulation, if necessary, soon after the U.S. EPA adopts its

national fuel specification.

14.Comment: While we agree with the requirement to use low-sulfur diesel fuel, are we

to infer that the ARB is guaranteeing the availability of such fuel by mid-2002? If not,

will there be a relaxation of the diesel emission requirements that are dependent on

the use of low-sulfur diesel fuel? (Nova BUS)

Agency Response: The ARB believes that sufficient amounts of low-sulfur diesel

fuel will be available for transit agencies to comply with the regulation’s

requirements. One California oil refinery is capable of producing low-sulfur diesel

fuel now, and at least two more California oil refineries have committed to producing

low-sulfur diesel fuel by mid-2002 --- the date the regulation requires most transit

agencies with diesel-fueled buses to begin using low-sulfur diesel fuel. These three

California oil refineries account for over 70 percent of California’s current diesel

production. Nonetheless, the ARB staff is committed to monitoring the availability of

low-sulfur diesel fuel and reporting back to the Board, should availability issues

arise.
20

Another consideration affecting the near-term availability of low-sulfur diesel fuel is

the Board’s September 28, 2000, approval of the “Diesel Risk Reduction Plan to

Reduce Particulate Matter Emissions from Diesel-Fueled Engines and Vehicles.”

This comprehensive plan to significantly reduce diesel PM emissions recommends

expanding the use of low-sulfur diesel fuel to other diesel-fueled vehicles and

equipment. Regulations and programs resulting from this plan will increase the

market penetration of low-sulfur diesel fuel, thus reducing fuel availability concerns.

15.Comment: The ARB has been overly conservative in selecting the 15 ppm by

weight sulfur content for diesel fuel, particularly due to the lack of demonstration that

15 ppm is required for the urban bus technology under consideration in this

rulemaking. (WSPA)

Agency Response: During regulatory development, the ARB staff worked closely

with affected stakeholders on all issues related to the urban bus regulation, including

the sulfur content of diesel fuel. After discussions and workshops with interested

parties, the ARB staff proposed, and the Board approved, a maximum sulfur content

of 15 ppm by weight. The ARB believes a cap of 15 ppm sulfur by weight is the

appropriate level to ensure that PM retrofit devices are effective and durable, and to

allow engine manufacturers to consider the full range of exhaust control

technologies to meet the regulation’s more stringent emission standards for dieselfueled engines.

The U.S. EPA’s Notice of Proposed Rulemaking for Heavy-Duty Engines and

Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements (Federal

Register, Vol. 65, No. 107, June 2, 2000, pp. 35430-35545) also includes a proposal

to limit the sulfur content in diesel fuel to 15 ppm by weight. The ARB supports this

nationwide sulfur standard for diesel fuel.

16.Comment: We support a national diesel fuel standard. Our members our concerned

that the regulation includes a sulfur standard that may be different than what is

proposed by the federal government. (CTA)

Agency Response: The U.S. EPA had not yet proposed a sulfur requirement for

diesel fuel when the ARB’s proposed regulation was released to the public on

December 10, 1999, or when it was presented to the Board at the January and

February hearings. However, subsequent to the Board approving the regulation on

February 24, 2000, the U.S. EPA released its Notice of Proposed Rulemaking for

Heavy-Duty Engines and Vehicle Standards and Highway Diesel Fuel Sulfur Control

Requirements (Federal Register, Vol. 65, No. 107, June 2, 2000, pp. 35430-35545).

The proposal includes a requirement to limit the sulfur content in diesel fuel to 15

ppm by weight, the same sulfur limit contained in the urban bus regulation. As

directed in Board Resolution 00-2 , the ARB is committed to working closely with the

U.S. EPA in its development of a new national diesel fuel specification, and to

reevaluating its own low-sulfur diesel fuel requirement, if necessary, soon after the

U.S. EPA adopts its national fuel specification.
21

17.Comment: The ARB supports a uniform national sulfur standard for broad statewide

application in California, however, a national sulfur standard has not yet been

promulgated. (WSPA)

Agency Response: Subsequent to the Board approving the regulation on

February 24, 2000, the U.S. EPA released its Notice of Proposed Rulemaking for

Heavy-Duty Engines and Vehicle Standards and Highway Diesel Fuel Sulfur Control

Requirements (Federal Register, Vol. 65, No. 107, June 2, 2000, pp. 35430-35545).

It includes a proposal to limit the sulfur content in diesel fuel to 15 ppm by weight,

the same sulfur limit contained in the urban bus regulation. (Please also see Agency

Response to Comment 16.)

18.Comment: The requirement for transit agencies to use low-sulfur diesel fuel should

be strengthened to include a fuel specification similar to the EC-Diesel currently

being demonstrated by ARCO. This fuel has the added benefit of reducing NOx

emissions. (SMAQMD)

Agency Response: The ARB acknowledges the air quality challenges facing this

commenter, the Sacramento Air Quality Management District, and its specific need

to reduce NOx emissions in order to comply with its federal ozone attainment and

transportation conformity deadlines. The fuel formula that the SMAQMD

recommends for inclusion in the regulation contains changes to ARB’s diesel fuel

specifications other than just the sulfur content. When developing its regulation, the

ARB had to weigh the impact that creating a California “fuel island” would have on

the price and availability of diesel fuel, and balance this with the need to achieve

significant emission reductions. Ultimately, the staff proposed, and the Board

approved, the use of a diesel fuel that differs from the ARB’s existing diesel fuel

specifications only in its sulfur content. This was done with the expectation that the

U.S. EPA would soon propose a nationwide diesel fuel specification with the same

sulfur content as contained in the urban bus regulation. Subsequent to the

regulation’s approval by the Board, the U.S. EPA released its Notice of Proposed

Rulemaking for Heavy-Duty Engines and Vehicle Standards and Highway Diesel

Fuel Sulfur Control Requirements (Federal Register, Vol. 65, No. 107, June 2, 2000,

pp. 35430-35545). This proposal includes a requirement to limit the sulfur content in

diesel fuel to 15 ppm by weight, the same sulfur limit contained in the urban bus

regulation. This nationwide fuel specification, when adopted, will eliminate any price

and supply disruptions throughout California.

E. Hybrid-Electric Urban Bus Technology

19.Comment: The regulation makes no provision for the consideration of the actual

emissions of a transit bus with a diesel hybrid-electric powertrain, and instead only

considers the certification emissions of the diesel internal combustion engine. The

Board should direct the ARB staff to investigate certifying hybrid transit buses on the

basis of their per-mile emissions. (SBMTD, SMCTD, Fresno Area Express)
22

Agency Response: The Board recognizes that diesel hybrid-electric buses offer the

potential for significant emission benefits, and did acknowledge at the January and

February hearings the lack of a test procedure to adequately characterize the true

emission benefits of this technology. Current California and federal certification test

procedures are engine-based and therefore are not able to adequately represent the

emissions benefits of the hybrid technology. To help resolve this, the Board, in

Resolution 00-2, directed the staff to develop a test procedure to accurately evaluate

hybrid-electric bus emissions and to report back to the Board by mid-2001 on the

status of its development. As a member of the Northeast Advanced Vehicle

Consortium’s Heavy-Duty Hybrid Bus Certification Working Group, a cooperative

effort involving the hybrid bus industry, the U.S. EPA, and other governmental

organizations, the ARB is actively working to develop an appropriate certification test

procedure for hybrid-electric buses.

20.Comment: The exclusion of diesel hybrid-electric buses from the alternative-fuel

path, in the absence of any substantive or credible technical rationale, flies in the

face of federal law as provided for in the Transportation Equity Act for the 21st

Century (TEA-21), Federal Transit Administration (FTA) grant rules, and much of the

research and development work of the Department of Energy and the FTA. The

ARB should allow diesel-fueled hybrid-electric buses to qualify for the alternative-fuel

path, provided that the correlated emissions performance on the Central Business

District chassis test cycle meets the grams per brake horsepower-hour requirements

of that path. (Nova BUS)

Agency Response: Diesel hybrid-electric buses are not excluded from the

alternative-fuel path, as the commenter states. Diesel hybrid-electric buses are

allowed to participate on the alternative-fuel path through a provision that allows up

to 15 percent of new bus purchases on that path to be diesel-fueled (this is in

addition to full participation on the diesel path). This provision was included in the

regulation to provide transit agencies with compliance flexibility.

Regarding the commenter’s specific recommendation, emissions testing performed

on the Central Business District, New York Bus, and Manhattan Drive Cycles for the

Northeast Advanced Vehicle Consortium’s Hybrid-Electric Drive Heavy-Duty Vehicle

Testing Project (final report dated February 15, 2000; Agreement No.: NAVC1098-

PG009837) indicate that state-of-the-art diesel hybrid buses with a particulate filter

and low-sulfur fuel have PM emissions as low as compressed natural gas (CNG)

buses without a particulate filter, but they still emit NOx at higher levels than CNG

buses. Thus, the ARB believes it is premature to allow diesel hybrid-electric buses

to fully participate on the alternative-fuel path at this time.

21.Comment: If the Board adopts the dual compliance path as the only viable

regulatory option, the ‘alternative fuel” path should be renamed the “clean fuel” path,

and the regulation should incorporate a definition of clean fuel consistent with

current federal regulations in the TEA-21. This modification would allow diesel
23

hybrid electric buses to qualify for the clean fuel path based on reduced fuel

consumption and significantly lower emissions than a diesel transit bus. (Lockheed

Martin)

Agency Response: Renaming the alternative-fuel path to the clean fuel path to allow

diesel hybrid technology to fully participate on that path contradicts the intent of the

regulation – to encourage public agencies to voluntarily purchase low-emission,

alternative-fuel urban buses to achieve emission reductions and reduce the public's

exposure risk to particulate matter. The Board adopted a dual-path approach to

encourage further alternative-fuel use, yet still provide transit agencies with

compliance flexibility by allowing them to choose between one of two distinct

strategies for reducing emissions. Allowing diesel hybrids to qualify for the 85

percent alternative-fuel bus purchase requirement on the alternative-fuel path would

effectively meld the dual-path compliance approach into just one path – a diesel

path. Furthermore, state-of-the-art diesel hybrid buses are not yet able to achieve

low NOx emission levels comparable to CNG buses. (Please also see Agency

Response to Comment 20.)

22.Comment: The diesel path should be renamed the standard path, thus requiring

compliance from all transit agencies. The alternative-fuel path should then be

renamed the low-emissions path. This path could then provide for additional funding

incentives for any technology and/or fuel combination meeting the required emission

levels in g/bhp-hr or equivalent g/mi. (Nova BUS)

Agency Response: Taken out of context, this is a general comment. However, this

commenter, a leading proponent of diesel hybrid-bus technology, has provided other

comments (to which the Agency has responded) seeking recognition for the

emission reducing potential of diesel hybrid technology. Therefore, the ARB

believes this is the impetus for this comment as well and will respond accordingly.

While the Board recognizes that diesel hybrid-electric buses offer the potential for

significant emission benefits, renaming the regulation’s compliance paths as this

commenter recommends would still not enable diesel hybrid-electric buses to fully

participate on the “low-emissions path.” Current California and federal certification

test procedures are engine-based and therefore are not yet able to adequately

represent the emissions benefits of the hybrid technology. Emissions testing

performed on the Central Business District, New York Bus, and Manhattan Drive

Cycles (which are not certification test procedures) for the Northeast Advanced

Vehicle Consortium’s Hybrid-Electric Drive Heavy-Duty Vehicle Testing Project (final

report dated February 15, 2000; Agreement No.: NAVC1098-PG009837) indicate

that state-of-the-art diesel hybrid buses with a particulate filter and low-sulfur fuel

have PM emissions as low as CNG buses without a particulate filter, but they still

emit NOx at higher levels than CNG buses. Thus, the ARB believes it is premature

to allow diesel hybrid-electric buses to fully participate on a “low-emissions path” at

this time. (Please also see Agency Responses to Comments 19, 20, and 21.)
24

23.Comment: The regulation could delay the introduction of low emission, diesel

hybrid-electric buses in California. (Lockheed Martin)

Agency Response: The regulation was designed to promote competition and

innovative technology development through its dual-path approach, not hinder it.

Opportunities for diesel hybrid technology exist on both the diesel and the

alternative-fuel paths (up to 15 percent of new bus purchases on the alternative-fuel

path may be diesel-fueled purchases). Together, this combined market could

account for about 400 bus purchases each year in California. The ARB believes this

market is significant enough to encourage further development of diesel hybridelectric buses, thus reducing costs and enabling them to cost-effectively compete

with conventional diesel buses.

24.Comment: If the regulation’s intent is to test the feasibility and cost-effectiveness of

low-emission vehicles, the staff should consider incorporating a percentage of

hybrid-electric buses into the required zero-emission bus demonstration. This would

allow a side-by-side comparison of both technologies and allow the staff to make an

informed decision about hybrid vehicles versus zero-emission vehicles. (SMCTD)

Agency Response: One of the regulation’s goals is to advance heavy-duty

technology development to achieve near-zero, and ultimately, zero-emissions.

Hybrid bus technology has the potential to be a significant contributor in achieving

the near-zero goal. The ARB acknowledges the potential value of a side-by-side

comparison of hybrid and zero-emission technology. However, the ARB believes

that such an approach could prematurely preclude one technology over the other,

and could unduly burden transit agencies by requiring them to demonstrate two new

technologies simultaneously. Neither is the regulation’s intent.

The regulation seeks to foster innovative technology development in both hybrid and

zero-emission bus technology; both are critical to achieving California’s long-term

emission reduction goals. The result of the regulation’s zero-emission bus

demonstration requirements, independent of the status of hybrid technology

development, will determine the feasibility of implementing zero-emission bus

purchase requirements. It is important to note that significant hybrid technology

demonstrations are already underway. For example, the Northeast Advanced

Vehicle Consortium’s Hybrid-Electric Drive Heavy-Duty Vehicle Testing Project final

report (dated February 15, 2000; Agreement No.: NAVC1098-PG009837)

demonstrates heavy-duty hybrid technology’s potential to provide significant

emission benefits and improved fuel economy over that of conventional diesel

buses.

25.Comment: The regulation should include a partial zero-emission credit (similar to

the manner in which partial credits are given in the light-duty vehicle sector) for

hybrid- electric buses that run on alternative fuel and have some electric range.

(CETC)
25

Agency Response: Under the regulation, a hybrid-electric bus that uses an

alternative-fuel to power its internal combustion engine could be eligible for incentive

funding (e.g., Carl Moyer Program funds or other incentive funds) if the engine is

certified to one of the optional, low-emission standards specified in section 1956.1,

title 13, CCR. This incentive mechanism, albeit different than a partial zero-emission

credit, could encourage further market penetration of alternative-fuel hybrid buses.

Because the ARB currently lacks a test procedure to accurately characterize the true

emission benefits of hybrid urban buses, including the emission benefits associated

with electric range, it is not possible at this time to include the concept of partial

zero-emission credit for alternative-fuel hybrids with some electric range in the

regulation. As the staff works to develop a heavy-duty hybrid test procedure, it is

possible that partial credit applicable to the zero-emission bus purchase

requirements could be allowed in the future.

F. Zero-Emission Urban Bus Technology

26.Comment: The exclusion of reformer-based fuel cell buses from the regulation’s

zero-emission bus requirements is clearly an exclusionary and anti-competitive

practice. Instead, the regulation should establish scientifically derived emission

requirements for zero-emission buses based on “vehicle system emissions” so that a

broad range of fuel cell technology is included under the zero-emission bus definition

for the purpose of stimulating competition and innovation. (Nova BUS)

Agency Response: The ARB disagrees that excluding reformer-based fuel cell

buses from the regulation’s zero-emission bus requirements is exclusionary and

anti-competitive. Fuel cell technologies that reform fuels such as natural gas,

methanol, diesel, or gasoline onboard a bus to produce hydrogen for the fuel cell

produce some emissions, although at lower levels than produced by internal

combustion engines. Hence, they do not have truly zero-emission exhaust levels.

The regulation’s intent is to foster significant advances in zero-emission technology,

as well as near zero-emission technologies. The 2007 emission standards will

require the use of technologies able to achieve these near zero-emission levels; we

expect that reformer-based fuel cell buses will be able to meet that challenge and

will have a role on both the diesel and alternative-fuel paths in the 2007 and beyond

timeframe.

27.Comment: Hybrid technology is an enabling technology for fuel cell buses to be

commercialized for the future. If diesel hybrid-elective drive technologies are

eliminated from the alternative-fuel path, the future viability of fuel cell transit buses

will be harmed. (Nova Bus)

Agency Response: The ARB recognizes the role of hybrid technology in developing

fuel cell bus technology. However, diesel hybrid-electric buses are not excluded

from the alternative-fuel path. The alternative-fuel path provides flexibility to transit

agencies by allowing up to 15 percent of annual new bus purchases to be dieselfueled – this would include diesel hybrid-electric buses. Furthermore, diesel hybrid
26

technology can have a significant role on the diesel path. As such, the ARB believes

the regulation provides sufficient opportunities for hybrid technology as a “stand

alone” technology and as an enabling technology for fuel cell buses.

G. Zero-Emission Bus Demonstration/Purchase Requirements

28.Comment: The ARB should increase the zero-emission bus requirements on the

diesel path either by increasing the size and duration of the demonstration program,

accelerating the date of the new purchase requirements, or increasing the required

new purchase percentage on the diesel path beginning in 2008. The ARB should

also consider increasing the required new purchase percentage on the alternativefuel path beginning in 2010, when the zero-emission purchase requirement on this

path will help increase sales volume and ensure lower zero-emission bus costs.

(ENVIRONMENTAL GROUP JOINT LETTER)

Agency Response: The ARB did not modify the regulation as this commenter

recommended. The regulation requires transit agencies that continue to purchase

primarily diesel-fueled buses to be the first to implement future aggressive emission

standards and the first to introduce zero-emission bus technology. This is a

“tradeoff” of sorts for those transit agencies. That said, it is not the Board’s intent to

force transit agencies onto a compliance path, in this case, the alternative-fuel path,

by including unrealistic or extremely onerous requirements on the diesel path. The

regulation was truly designed to provide transit agencies with compliance flexibility to

best meet their service requirements. In proposing the regulation, the ARB staff had

to balance the need to “push” transit agencies to achieve significant emission

reductions with the need to design a workable, effective regulation. Therefore, the

ARB believes it is not prudent, at this time, to increase or accelerate zero-emission

bus demonstration/purchase requirements on either path. The results of the

regulation’s 2006 feasibility review for zero-emission bus technology will assist the

staff and the Board in determining whether modifications are necessary for the zeroemission bus purchase requirements beginning in 2008 and 2010.

29.Comment: The zero-emission bus demonstration projects should require more zeroemission buses than currently included in the regulation. The demonstration

requirement should be tied to fleet size. For example, one demonstration should be

required for every 200 diesel buses in a fleet in 2003, followed by one demonstration

for every 100 diesel buses in 2004, and then one demonstration for every 50 diesel

buses in 2005. (PG&E)

Agency Response: The ARB did not modify the regulation as this commenter

recommended. It is not the Board’s intent to force transit agencies onto a

compliance path, in this case, the alternative-fuel path, by including unrealistic or

extremely onerous requirements on the diesel path. The regulation was truly

designed to provide transit agencies with compliance flexibility to best meet their

service requirements. In proposing the regulation, the ARB staff had to balance the

need to “push” transit agencies to achieve significant emission reductions with the
27

need to design a workable, effective regulation. Thus, the ARB believes it is not

prudent, at this time, to increase zero-emission bus demonstration requirements.

(Please also see Agency Response to Comment 28.)

30.Comment: It would be more equitable to implement the zero-emission purchase

requirements for the alternative-fuel path seven years after their implementation on

the diesel path (since they are first required on the diesel path seven years after

initial regulation implementation). (PG&E)

Agency Response: The ARB did not modify the regulation as this commenter

recommended. Zero-emission bus purchase requirements begin on the diesel path

in 2008. The fact that it is seven years after initial regulation implementation is

irrelevant and should not bear significance on when the purchase requirements

begin on the alternative-fuel path. The ARB approved the 2008 date because it

allows for completion of the zero-emission bus demonstration projects, the 2006

technical feasibility review, and any resulting regulatory modifications to the zeroemission bus purchase requirements that may be warranted. The ARB believes that

the 2010 date for implementing the zero-emission bus purchase requirements on the

alternative-fuel path is justified in order to advance further technological

improvements and increase market penetration. As a result of increased market

penetration, the incremental cost of a zero-emission bus over the cost of an

advanced diesel bus will decrease; in fact, the incremental cost of a zero-emission

bus in 2010 is expected to be nominal.

31.Comment: The ARB could more effectively reduce PM emissions simply by

specifying that the zero-emission bus purchase requirements would not apply to bus

fleets on the alternative-fuel path that purchase exclusively CNG buses after

January 2010. (PG&E)

Agency Response: The ARB did not modify the regulation as this commenter

recommended. One of the goals of the zero-emission bus purchase requirements is

to stimulate advances in zero-emission bus technology. The ARB believes that

eliminating one of the markets for this technology would only serve to hinder its

development.

32.Comment: It is unnecessary at this time for the ARB to establish a calendar date for

alternative-fuel path fleets to introduce zero-emission buses. It is unreasonable to

expect bus fleets to shift to 100 percent CNG in 2000 when they will be expected to

face a second shift to zero-emission technology in 2010. (PG&E)

Agency Response: The ARB believes that it is necessary to include an introduction

date for zero-emission bus technology on the alternative-fuel path. The Board

adopted the 2010 introduction date to create a larger market demand for zeroemission bus technology, which, in turn, will foster innovative technological

advances. The Board will use the results of the 2006 zero-emission bus technology

review to determine the feasibility of retaining this requirement as is, or modifying it.
28

It appears that the commenter’s second concern is based on the belief that CNG

technology will be an “orphaned” technology as fleets begin zero-emission bus

purchases. The ARB encourages and supports the purchase of clean, natural gas

buses and believes this technology has long-term viability for zero-emission

hydrogen fuel cell buses. One option for producing hydrogen is to reform CNG on

site at a fueling facility. In this case, existing natural gas infrastructure will be

transferable to the operation of fuel cell buses and could substantially reduce the

associated infrastructure costs. Finally, it is important to correct the commenter’s

misconception that fleets are expected to shift to 100 percent CNG (or other

alternative-fuel) in 2000. The ARB believes that many fleets will ultimately purchase

exclusively alternative-fuel fleets; the regulation, however, provides flexibility to

transit fleets by allowing up to 15 percent of annual new bus purchases to be dieselfueled

33.Comment: The regulation should allow for light-rail extensions to be applicable to

the zero-emission bus purchase requirement if, in fact, they are replacing diesel

urban buses. (CETC)

Agency Response: The ARB recognizes the significant air quality and congestion

mitigation benefits light rail provides, and acknowledges that, in some cases, light

rail extensions can replace urban bus service. However, the ARB chose to focus its

efforts, at this time, on urban bus fleets, as they are the backbone of the public

transportation system in the vast majority of the state. The zero-emission bus

purchase requirements are intended to stimulate advanced technology development

for urban bus fleets that, with the exception of electric trolley buses, are an

uncharted transportation sector for electrification.

H. Incentives for Low-Emission/Zero-Emission Technologies

34.Comment: Market-based incentives are critical to offsetting the costs of converting

from diesel to alternative-fuel fleets. We support the Carl Moyer Program in helping

to defray the incremental capital costs associated with alternative-fuel and

recommend adding additional funds to the program. (CCC)

Agency Response: The ARB agrees that monetary incentive programs, such as the

Carl Moyer Program, are critical to encouraging the shift to alternative-fuel urban bus

fleets. While the ARB and the Carl Moyer Program Advisory Board can develop

recommendations for the Governor and the Legislature regarding appropriate

funding levels for the Carl Moyer Program, including increases in funding, funds for

the program are allocated to the ARB’s budget through the state budget process.

Historically, Carl Moyer Program funds have been allocated on an annual basis. For

the 2000/2001 fiscal year, $50 million dollars is available to fund the program. Of

this amount, the California Energy Commission (CEC) receives $5 million dollars to

fund the Advanced Technology and the Infrastructure Demonstration portions of the

program. Previously, $25 million in ARB's 1998/1999 fiscal year budget and
29

$19 million in ARB's 1999/2000 fiscal year budget were allotted for Carl Moyer

Program incentive grants.

For clarification, it must be pointed out that Carl Moyer Program grant funds are only

available to cover the incremental cost of an urban bus if the engine is certified to

one of the ARB’s optional, reduced-emission standards (section 1956.1, title 13,

CCR). The grant funds cannot be used to purchase an alternative-fuel urban bus

with an engine that is certified to existing, mandatory standards. From a practical

standpoint, however, this is not an issue since engine manufacturers already certify

their alternative-fuel urban bus engines to the optional, reduced-emission standards.

35.Comment: The ARB should use the regulation to provide regulatory incentives for

the early introduction of zero-emission buses, thereby helping to build the market in

preparation for the 2008 requirement and achieving critical early emission benefits.

Regulatory incentives could include the use of multiple credits for the early

introduction of zero-emission buses that could be applied against the 15 percent

new purchase requirement in later years. (ENVIRONMENTAL GROUP JOINT

LETTER)

Agency Response: The ARB did modify the regulation to provide transit agencies

multiple credits for placing zero-emission buses into service prior to the regulatory

purchase requirements. Credits earned for early introduction can be applied to the

15 percent zero-emission bus purchase requirements that begin in 2008 for transit

agencies on the diesel path and in 2010 for transit agencies on the alternative-fuel

path. Because the regulation also requires zero-emission bus demonstration

projects, buses placed in service in the 2003 timeframe to satisfy demonstration

requirements are not permitted to earn credits applicable to the future purchase

requirements.

36.Comment: The regulation embodies market disincentives for natural gas buses.

Most notable among these is the lack of recognition and credit for PM reductions

based on certification levels and in-use levels, which the Staff Report acknowledges

are substantial. (PFC)

Agency Response: The ARB disagrees with this comment. In proposing the

regulation, the ARB staff had to balance the need to “push” transit agencies to

achieve significant emission reductions with the need to design a workable, effective

regulation. The Board acknowledged that natural gas buses have inherently lower

PM emissions than their diesel counterparts and approved modifications to the

originally proposed regulation to help address this inequity in PM emissions. First,

the Board approved an accelerated PM retrofit schedule for transit agencies on the

diesel path that will help limit the PM emissions gap between the diesel and

alternative-fuel paths. Next, during the course of this rulemaking, the EMA agreed to

start production of diesel-fueled engines meeting a 0.01 g/bhp-hr PM standard on

October 1, 2002, -- fifteen months ahead of when originally proposed by the ARB

staff, and over four hears ahead of when alternative-fuel engines are required to
30

meet the same PM standard. The ARB believes the regulation is designed to

encourage transit agencies to shift to alternative-fuels while providing compliance

flexibility so transit agencies can best meet the needs of their respective regions.

37.Comment: The Board should consider postponing adoption of the regulation until

either meaningful incentives for natural gas buses can be incorporated into the

regulation, or until the loss of in-use PM reductions from pursuit of the diesel path

can be accounted for and quantified. (PFC, CNGVC, PG&E)

Agency Response: The Board did not postpone adoption of the regulation; it was

approved by the Board on February 24, 2000. The ARB staff and the Board

acknowledged that diesel-fueled buses have inherently greater in-use PM emissions

than natural gas buses; hence the regulation’s PM retrofit requirements for dieselfueled buses. To reduce the PM emissions gap between the diesel and alternativefuel paths, the Board approved an accelerated PM retrofit schedule for transit

agencies on the diesel path. Furthermore, during the course of this rulemaking, the

EMA agreed to start production of diesel-fueled engines meeting a 0.01 g/bhp-hr PM

standard on October 1, 2002, -- fifteen months ahead of when originally proposed by

the ARB staff, and over four hears ahead of when alternative-fuel engines are

required to meet the same PM standard. This regulatory modification approved by

the Board will also limit the emissions gap between the regulation’s two compliance

paths.

38.Comment: To meet the emission standards in the regulation, diesel engine

manufacturers must make a significant investment in diesel engine research and

development in the next few years. Conversely, the regulation does not encourage

a corresponding investment in natural gas engine technology development that

would further reduce its emissions and improve its efficiency and performance.

(CNGVC)

Agency Response: Natural gas heavy-duty engines for on-road applications are

already capable of certifying to the ARB’s existing optional, reduced-emission NOx

standards, which start at approximately 40 percent below the current mandatory

NOx standard. Diesel engines are not yet able to achieve these low emission levels,

thus the ARB’s focus on stimulating development in conventional diesel technology.

Nonetheless, the advanced engine and aftertreatment technologies that will enable

diesel engines to emit at significantly lower levels in the future can generally be used

in natural gas engines to reduce emissions as well. Because natural gas engines

operate at higher temperatures, which can improve aftertreatment efficiency,

aftertreatment technologies may be able to achieve an even higher level of emission

reductions in natural gas engines than in comparable diesel engines.

39.Comment: The regulation should be modified to shift the burden of PM retrofits and

zero-emission bus purchase requirements from the alternative-fuel path to the diesel

path. For example, a better strategy for the commercialization of zero-emission
31

buses is to accelerate their introduction on the diesel path, while eliminating the

purchase requirement on the alternative-fuel path. (CNGVC)

Agency Response: The regulation includes PM retrofit requirements for dieselfueled buses and purchase requirements for zero-emission buses for all transit

agencies, regardless of whether they participate on the diesel path or the alternativefuel path. In response to public comment, however, the ARB did modify the

regulation to accelerate the PM retrofit requirements on the diesel path thereby

reducing the PM emissions gap between the diesel and alternative-fuel paths. The

ARB did not eliminate PM retrofit requirements on the alternative-fuel path because

transit agencies choosing this path could still have a significant presence of buses

with diesel-fueled engines in their existing fleets, many of these being the oldest,

most-polluting model years. It is only appropriate that these fleets also implement

measures to reduce toxic PM exposure for the public they serve.

The ARB did not modify the zero-emission bus purchase requirements as this

commenter recommended. The ARB approved 2008 as the start date for

implementation of the zero-emission bus purchase requirements on the diesel path

because it allows for completion of the zero-emission bus demonstration projects,

the 2006 technical feasibility review, and any resulting regulatory modifications to the

zero-emission bus purchase requirements that may be warranted. Furthermore, the

regulation was truly designed to provide transit agencies with compliance flexibility to

best meet their service requirements. In proposing the regulation, the ARB staff had

to balance the need to “push” transit agencies to achieve significant emission

reductions with the need to design a workable, effective regulation. Therefore, the

ARB believes it is not prudent, at this time, to accelerate zero-emission bus

purchase requirements. The results of the regulation’s 2006 feasibility review for

zero-emission bus technology will assist the staff and the Board in determining

whether modifications are necessary for the zero-emission bus purchase

requirements beginning in 2008 and 2010. Finally, the ARB did not eliminate the

zero-emission bus purchase requirements on the alternative-fuel path because it

believes that eliminating one of the markets for this technology would only serve to

hinder its development.

40.Comment: To encourage the shift to the alternative-fuel path, the ARB should relax

the PM retrofit requirements for fleets choosing that path. One way to accomplish

this would be to exempt alternative-fuel path fleets from all retrofit requirements.

Another way would be to accelerate Tier 3 retrofits for fleets selecting the diesel

path. The optimal approach would be to tie all retrofit requirements to mileage

weighted fleet average in-use PM emission targets that decline annually. (PG&E)

Agency Response: The ARB did modify the regulation to accelerate the schedule

for PM retrofit requirements on the diesel path. The accelerated schedule applies to

Tier 2 retrofits (applicable to buses with 1991 through 1995 model year diesel-fueled

engines) and Tier 3 retrofits (applicable to buses with 1996 through 2002 model year

diesel-fueled engines produced before October 1, 2002). However, the ARB did not
32

exempt transit fleets on the alternative-fuel path from any of the PM retrofit

requirements for buses with diesel-fueled engines. Transit agencies on the

alternative-fuel path may still have a significant presence of buses with diesel-fueled

engines in their existing fleets, many of these being the oldest, most-polluting model

years. It is only appropriate that these fleets also implement measures to reduce

toxic PM exposure for the public that they serve.

I. Dual-Path Compliance Approach

41.Comment: The ARB’s approach to the regulation is fundamentally flawed. A sound

regulation sets performance requirements and then fosters innovation and

competition inherent within the free-market system to determine how to best

accomplish the given requirement. As such, the ARB’s regulation should set

common fuel and technology neutral emission standards that foster innovation and

competition, and refrain from specifying or directing fuel type and technology. (Nova

BUS)

Agency Response: Innovation and competition are important elements within the

free market system and within this regulation; the regulation’s focus on lower

emission standards recognizes this element. The regulation provides many

opportunities for development of new technology, particularly zero-emission engine

technology. However, emission reductions leading to air quality improvements are

the primary goal of the ARB. Thus, the regulation contains two components to

reduce emissions from urban buses: 1) a multi-component transit bus fleet rule

applicable to transit agencies; and 2) more stringent emission standards for engines

used in urban buses applicable to engine manufacturers. The regulation is

structured to encourage transit agencies to voluntarily purchase cleaner alternative

fuel buses in order to reduce emissions of NOx and PM. However, to provide transit

agencies with flexibility in determining their optimal fleet mix, the regulation allows

transit agencies to choose between two compliance paths, either the diesel path or

the alternative-fuel path.

42.Comment: The regulation should not mandate the method by which the proposed

emission standards for transit buses are met (i.e., separate emission standards for

different fuel types and/or technologies). Instead, the regulation should allow transit

agencies to purchase buses that meet a single emission standard, regardless of fuel

type or technology. The dual path compliance approach penalizes transit agencies

that choose the diesel path despite the air quality improvements they are providing.

(Lockheed Martin)

Agency Response: The regulation does not prescribe the technology to meet the

regulation’s emission standards. It does, however, include a flexible dual pathapproach that allows transit agencies to choose the fuel and buses that best meet

the needs of their respective regions. Engine manufacturers have the flexibility to

design engines operating on one or more different fuels. Over the life of the

regulation, the engine standards on both paths will provide nearly comparable NOx
33

reductions, although the alternative-path will provide greater PM emission benefits

due to inherently low in-use PM emissions from alternative-fuel buses.

43.Comment: The regulation should be modified to eliminate the diesel path.

(SUVA/La Causa, Joe Perales, Labor/Community Strategy Center)

Agency Response: During regulatory development, the staff’s initial proposal did

require transit agencies to purchase only alternative-fuel buses. However, the staff

discovered that some transit agencies would face significant barriers to using

alternative fuels, either due to the demands of their service needs or due to the

difficulties in securing alternative fuel in some regions. In its efforts to develop an

effective and workable regulation, the staff ultimately proposed, and the Board

adopted, a dual path approach that will reduce emissions from urban bus fleets, yet

provide compliance flexibility to transit agencies. The regulation is designed to

encourage transit agencies to voluntarily purchase cleaner alternative-fuel buses in

order to reduce emissions of NOx and toxic PM. Funding from air district and state

air quality incentive programs is available throughout the state for transit agencies

that purchase urban buses with engines certified to the ARB’s optional, reducedemission standards. Alternative-fuel urban bus engines are all currently certified to

these reduced-emission standards; diesel-fueled engines are yet unable to achieve

these low-emission levels. The ability to access this incentive money has

encouraged some transit agencies to switch to alternative-fuel transit systems.

44.Comment: California’s diesel transit buses should be replaced with cleaner

alternatives like natural gas or electric-powered buses. (FL2, Enrietto, Koke)

Agency Response: The regulation encourages transit agencies to purchase new

alternative-fuel buses, thus initiating the process of replacing diesel bus fleets with

alternative-fuel fleets. In addition, the regulation requires the demonstration and

commercialization of zero-emission urban buses, powered by electricity or by

hydrogen fuel cells. (Please also see Agency Response to Comment 45.)

45.Comment: The number of diesel buses on the road of California should be reduced.

The ARB should not let diesel engine manufacturers keep California from a cleaner,

healthier future. (Westervelt, Montgomery)

Agency Response: The number of diesel buses on the road will be reduced as a

result of this regulation. The regulation is designed to encourage transit agencies to

purchase new alternative-fuel buses, and some large transit agencies have already

committed to purchasing primarily alternative-fuel buses in lieu of diesel buses.

Other transit agencies are in the process of choosing either the diesel path or

alternative-fuel path; the regulation’s deadline for choosing a compliance path is

January 31, 2001. Each transit agency must weigh the pros and cons of a particular

compliance path, and thus fuel choice, in a public forum. Transit agencies not yet

committed to a compliance path are currently making that effort, and there are

indications that several more large transit agencies will choose the alternative-fuel
34

path. Those transit agencies choosing the diesel path will also be purchasing loweremitting buses as a result of the regulation’s more stringent emission standards for

diesel-fueled urban bus engines that take effect in the 2002 model year, the 2004

model year, and again in the 2007 model year.

46.Comment: The ARB should take strong action against diesel and outlaw diesel

buses. (Aceto)

Agency Response: It would be inappropriate for the ARB to retroactively and

arbitrarily remove existing diesel buses from service. Diesel technology still has a

vital role in California’s economy and public transportation system. One of the

ARB’s goals, however, is to significantly reduce emissions from existing and new

diesel vehicles, and encourage the use of alternative-fuel technology whenever

appropriate. The regulation encourages the use of alternative-fuel buses and

includes other strategies to reduce emissions from diesel buses. These strategies

include: 1) a requirement for each transit agency, regardless of compliance path, to

attain and maintain a 4.8 g/bhp-hr NOx fleet average standard; 2) requirements for

transit agencies on both compliance paths to retrofit their existing diesel buses to

reduce PM emissions, with an accelerated compliance schedule on the diesel path,

and 3) requirements for zero-emission bus demonstration projects (diesel path only)

and zero-emission bus purchases (diesel and alternative-fuel paths). Most

importantly, the regulation requires engine manufacturers to produce lower-emitting

diesel-fueled urban bus engines beginning in 2002, and then requires further

emission reductions from diesel-fueled urban bus engines in 2004 and 2007.

47.Comment: There is no excuse for transit agencies to continue to buy and run dirty

diesel buses. (FL1)

Agency Response: Please see Agency Response to Comments 45 and 46.

48.Comment: The ARB should strengthen the transit bus regulation by: 1) requiring

more stringent emission standards for transit bus engines; and 2) providing strong

incentives for transit fleets to choose cleaner alternatives to diesel transit buses.

(FL1, NALEO, CHEC, PhSR)

Agency Response: The regulation already requires engine manufacturers to

produce urban bus engines meeting more stringent emission standards for both NOx

and PM. By prior legal agreement (the federal Consent Decrees and the Californiaspecific Heavy-Duty Diesel Engine Settlement Agreements), most engine

manufacturers are required to produce heavy-duty engines, including urban bus

engines, that reduce NOx by 50 percent from the current NOx standard beginning

October 1, 2002. However, the regulation further reduces the NOx emission

standard for diesel-fueled engines in 2004 and again in 2007. The regulation also

reduces the PM emission standard for urban bus engines in 2002 and 2007. The

2002 PM standard approved by the Board is a regulatory modification that requires

diesel-fueled engines to meet a 0.01 g/bhp-hr PM standard 15 months ahead of
35

when originally proposed in the Staff Report. While the 2002 emission standards

and the 2004 emission standards are only applicable to diesel-fueled engines, the

2007 emission standards also apply to alternative-fuel engines. These new

standards for diesel-fueled and alternative-fuel engines are significant and

technology-forcing.

Furthermore, funding from air district and state air quality incentive programs is

available throughout the state for transit agencies that purchase urban buses with

engines certified to the ARB’s optional, reduced-emission standards. Alternativefuel urban bus engines are all currently certified to these reduced-emission

standards; diesel-fueled engines are yet unable to achieve these low-emission

levels. The ability to access this incentive money has encouraged some transit

agencies to switch to alternative-fuel transit systems.

49.Comment: The ARB should require transit agencies to either buy only alternative

fuel buses, or instead, adopt emission standards for diesel buses at the emissions

level of natural gas buses. (Matvy, North)

Agency Response: During regulatory development, the ARB staff originally

considered requiring transit agencies to purchase only alternative-fuel buses.

However, the staff found that this was not a practical option for some transit

agencies, either based on the demands of their service needs or the difficulties in

securing alternative fuel in some regions. However, beginning October 1, 2002,

diesel engines must meet a PM standard that is lower than that required for

alternative-fuel buses. Additionally, the regulation requires diesel-fueled engines to

meet a NOx emission standard in 2004 that is lower than what will be in effect for

alternative-fuel buses at that time. In 2007, all urban bus engines, regardless of fuel

type, will be required to meet the same stringent emission standards.

50.Comment: The transit bus regulation is not strong enough to encourage transit

agencies to shift to cleaner, alternative-fueled buses, such as natural gas or electricpowered buses. At a minimum, the final regulation should be tightened to achieve

larger reductions in pollution from diesel exhaust. (FL1, NALEO, McHugh)

Agency Response: The ARB believes the regulation will be effective in encouraging

transit agencies to shift to alternative-fuel urban buses. Funding from air district and

state air quality incentive programs is available throughout the state for transit

agencies that purchase urban buses with engines certified to the ARB’s optional,

reduced-emission standards. Alternative-fuel urban bus engines are all currently

certified to these reduced-emission standards; diesel-fueled engines are yet unable

to achieve these low-emission levels. Additionally, transit agencies on the diesel

path are required to purchase buses with engines meeting lower PM and NOx

standards than alternative-fuel buses in the early years of the regulation, forego

access to air quality incentive funding, accelerate the PM retrofits for their diesel

buses, demonstrate zero-emission buses in 2003, and purchase zero-emission

buses earlier than required on the alternative-fuel path. A number of transit
36

agencies are buying alternative-fuel buses now, and the ARB expects other

agencies to choose the alternative-fuel path as well.

51.Comment: Allowing clean diesel technology to compete is in the best interest of the

environment, consumers, and the California economy, and should be state policy as

well as implemented uniformly in every situation. (WSPA)

Agency Response: The regulation does provide significant opportunities for diesel

technology through the regulation’s dual-path compliance approach. Even the

alternative-fuel path provides opportunities for diesel technology through a provision

that allows up to 15 percent of new bus purchases to be diesel-fueled purchases.

The ARB staff initially considered requiring transit agencies to exclusively purchase

alternative-fuel buses when making new purchases. However, in response to transit

agencies concerns, the regulation proposed and ultimately adopted provides transit

agencies the flexibility to choose either the diesel or alternative-fuel compliance

path.

52.Comment: Diesel proponents in the transit industry indicate that they expect no

appreciable impact from the alternative-fuel path on the dominance of diesel engines

in the California transit market. This is bad news for the transit industry; it sets a

poor precedent for at least the next 14 -15 years during which the ARB will forego 50

percent reductions in NOx and more reductions in PM. (CNGVC)

Agency Response: The ARB disagrees with this comment. Even before the Board

approved this regulation, at least 20 medium-to-large transit agencies committed to

operating alternative-fuel buses. Subsequent to regulation approval, about eight

other transit agencies have stated their intent to comply with the alternative-fuel

path. Governing boards of other transit agencies are now actively considering

choosing the alternative-fuel path based on the availability of air quality incentive

funds and a commitment to improving air quality in the regions they serve. This, in

conjunction with the regulation’s more stringent emission standards for diesel-fueled

engines, will provide significant reduction in NOx and PM from the public transit bus

sector. As a result, the ARB does not believe it will not forego significant reductions

in NOx and PM.

53.Comment: The diesel path discourages an early investment in proven advanced

NOx reduction technology, such as natural gas technologies. Instead, it relies on

strategies that don’t yet exist in the marketplace. (CNGVC)

Agency Response: The implied assumption behind this comment made by

proponents of natural gas and natural gas technologies is that the dual-path

compliance approach will not have the desired result of incentivizing fleet transitions

to alternative-fuels. The ARB disagrees with this comment. Instead, the ARB

believes the regulation effectively in encourages transit agencies to shift to

alternative-fuel urban buses. Funding from air district and state air quality incentive

programs is available throughout the state for transit agencies that purchase urban
37

buses with engines certified to the ARB’s optional, reduced-emission standards.

Alternative-fuel urban bus engines are all currently certified to these reducedemission standards; diesel-fueled engines are yet unable to achieve these lowemission levels. Additionally, transit agencies on the diesel path are required to

purchase buses with engines meeting lower PM and NOx standards than

alternative-fuel buses in the early years of the regulation, forego access to air quality

incentive funding, accelerate the PM retrofits for their diesel buses, demonstrate

zero-emission buses in 2003, and purchase zero-emission buses earlier than

required on the alternative-fuel path.

J. Transit Agency Issues

54.Comment: The regulation allows for no more than three transit operators to

consolidate their zero-emission bus demonstrations at one property to allow for cost

savings from infrastructure sharing. Since the Bay Area transit system consists of

four transit operators subject to the zero-emission bus demonstration requirement,

the regulation should allow four transit operators to consolidate for purposes of

meeting the requirement. (MTC)

Agency Response: The commenter’s statement that the regulation allows no more

than three transit agencies in the same air basin to conduct a joint demonstration

project is correct. However, the fact that a particular region has more than three

transit agencies subject to the demonstration project requirements does not

necessarily warrant expanding the number of agencies that may participate in a joint

project.

Under a joint demonstration, all participating agencies would be required to fund the

demonstration, yet only one agency could act as the onsite “host”. The purpose of a

joint demonstration is to allow transit agencies opportunities for infrastructure cost

savings. Still, the joint demonstration must provide each participating agency with

broad-based mechanic and driver training, significant experience with and public

visibility of zero-emission bus technology, revenue service over a wide area, and

sufficient evaluation of passenger reaction. The ARB believes all transit agencies

participating in a joint demonstration may not reap the necessary experience and

knowledge to be gained through a demonstration project if too many transit agencies

consolidate to conduct one.

55.Comment: The fleet rule component of the regulation should include an option for

several transit fleets in a metropolitan area to combine into one regional bus fleet.

(MTDB)

Agency Response: The ARB reviewed this option and did not modify the regulation

as this commenter recommended. The ARB does not believe the modification would

provide the fleets in the San Diego region (the MTDB is the transit development

board for the San Diego region) with any significant advantage. By its own

admission, the MTDB stated that the consequences of such an option had not been
38

fully evaluated and further analysis was necessary to determine those

consequences. While combining fleets could provide some flexibility in meeting the

required NOx fleet average standard, it could also impose zero-emission bus

demonstration and/or purchase requirements that might not take effect for transit

agencies operating separately.

56.Comment: Districts that choose to replace a full-sized transit bus with a zeroemission shuttle-sized bus should get credit for that in the NOx fleet average

requirement. (CETC)

Agency Response: The ARB has modified the regulation to allow transit agencies to

count zero-emission buses that do not qualify as standard urban buses, as defined

in section 1956.2 (a)(4), title 13, CCR, in calculating an agency’s NOx fleet average.

(Please also see Agency Response to Comment 57.)

57.Comment: The Santa Barbara MTD is concerned that it may be penalized for using

smaller zero-emission buses -- buses that don’t meet the definition of an urban bus.

Currently, the only zero-emission buses available are smaller than a typical urban

bus. (SBMTD)

Agency Response: It is the ARB’s intent to encourage the use of zero-emission

technology; not discourage its use in appropriate situations. As such, the ARB has

modified the regulation to allow transit agencies to count zero-emission buses that

do not qualify as standard urban buses, as defined in section 1956.2 (a)(4), title 13,

CCR, in calculating an agency’s NOx fleet average. This provision will benefit those

transit agencies that have been proactive in efforts to reduce fleet emissions and

that already service some routes with smaller, battery-electric buses. Nonetheless,

the regulation is designed to foster advances in zero-emission technology for urban

bus applications; therefore, zero-emission buses not meeting the definition of an

urban bus cannot be used to meet the regulation’s zero-emission bus demonstration

requirements.

58.Comment: The zero-emission bus purchase requirements specifying that 15 percent

of annual new bus purchases shall be zero-emission (beginning in 2008 for transit

agencies on the diesel path and in 2010 for transit agencies on the alternative-fuel

path) should allow zero-emission bus purchases to be applied over a five-year rolling

period. This would allow transit operators to alternate between CNG bus purchases

one year and zero-emission bus purchases the next year. (MTDB)

Agency Response: The regulation already provides flexibility in meeting the zeroemission bus purchase requirements by allowing transit agencies to deviate from the

purchase requirements on a case-by case basis, upon prior approval from the

Executive Officer. This option is intended to accommodate transit agencies’ bus

purchase cycles; it is not intended as an option to delay compliance.
39

K. Technology Reviews

59.Comment: The regulation should be modified to include a technology review in 2003

to evaluate the feasibility of the 2004 through 2006 emission standards for dieselfueled engines. If the emission standards are not technologically feasible, some

other emission level, one that is technologically feasible, yet still achieves emission

reductions, should be considered. (SMCTD)

Agency Response: Technological feasibility reviews, whether specified or not within

an ARB regulation, are a standard component of ongoing regulatory development.

The ARB staff is committed to periodically reporting back to the Board on the status

of all new technologies used to meet the emission standards set forth in the

regulation, and will consider regulatory modification, if warranted. It is also important

to note that while the ARB believes the 2004 through 2006 emission standards are

technologically feasible, transit agencies may use an alternative compliance option

(alternative NOx strategy) if they choose not to purchase urban buses with dieselfueled engines meeting the 2004 through 2006 emission standards. This alternative

compliance option ensures that the emission benefits attributable to the 2004

through 2006 standards will be realized. (Please also See Agency Response to

Comment 61.)

60.Comment: The Board should give consideration in the future to technological

solutions that have been fully tested and service proven. Therefore, the fuel-cell bus

technology review required by January 2006 should be broadened to include a

review of all the technologies required to meet the emission standards in the transit

bus regulation. (MTDB)

Agency Response: The regulation and Board Resolution 00-2 include a specific

provision for the review of zero-emission bus technology by no later than January

2006. This review is not limited to fuel cell technology, as the commenter states, but

could include the review of other zero-emission technologies as well. While the

regulatory text limits this review to zero-emission bus technology, the ARB staff is by

no means closed to reviewing new technologies that may be used to meet other

requirements in the regulation. In fact, the ARB staff is committed to periodically

reporting back to the Board on the status of all new technologies used to meet the

emission standards set forth in the regulation, and will consider regulatory

modification, if warranted.

61.Comment: WSPA does not support the inclusion of a new purchase/lease

percentage requirement for zero-emission buses on either compliance path. WSPA

requests that the two following revisions be made to the regulation:

a) The regulation should include a future technical review(s) to be completed by

ARB regarding the viability of zero-emission buses, including their costeffectiveness. The review should be bracketed around the required demonstration

programs in order to assist transit agencies in their bus purchase decisions.
40

b) The regulation should not restrict the definition of a zero-emission bus in a

fashion that is not fuel neutral. The proposal should be revised to be fuel neutral

and should include, for example, a diesel or distillate powered fuel cell. (WSPA)

Agency Response: Regarding the commenter’s first recommendation, the regulation

already includes an explicit requirement for the ARB to conduct a zero-emission bus

technology review, by no later than January 2006, for the purpose of assessing the

feasibility of implementing the regulation’s zero-emission bus purchase/lease

requirements applicable on both compliance paths. The ARB’s technology review is

bracketed around the demonstration programs; the 2006 date was chosen to allow

transit agencies sufficient time to complete their required reports to the ARB, and to

allow the ARB staff sufficient time to analyze the reports and, based on the their

contents, develop recommendations for the Board’s consideration.

Regarding the commenter’s second concern, the ARB did not include fuel cells

powered by fuels other than hydrogen in the definition of a zero-emission bus

because such fuel cell technologies do not produce zero-emission exhaust levels.

Fuel cell technologies that reform fuels such as natural gas, methanol, diesel, or

gasoline onboard a bus to produce hydrogen for the fuel cell produce some

emissions, although at lower levels than produced by internal combustion engines.

The regulation’s intent is to foster significant advances in zero-emission bus

technology, as well as near zero-emission technologies. The 2007 emission

standards will require the use of technologies able to achieve these near zeroemission levels; we expect that reformer-based fuel cell buses will be able to meet

that challenge and will have a role on both the diesel and alternative-fuel paths in the

2007 and beyond timeframe.

62.Comment: Many of the technologies required for transit operators to comply with the

regulation are currently experimental. The regulation should include future feasibility

reviews of regulation components such as the 2004 through 2006 emission

standards for diesel-fueled engines, the low-sulfur diesel fuel requirement, and the

retrofit requirements to reduce PM emissions by 85 percent. (MTC)

Agency Response: Technological feasibility reviews, whether specified or not within

an ARB regulation, are a standard component of ongoing regulatory development.

The ARB staff is committed to periodically reporting back to the Board on the status

of all new technologies used to meet the requirements set forth in the regulation, and

will consider regulatory modification, if warranted. Regarding the low-sulfur diesel

fuel requirement, Board Resolution 00-2 specifically directs the ARB to work closely

with the U.S. EPA in its development of a new national diesel fuel specification, and

to reevaluate its own low-sulfur diesel fuel requirement, if necessary, soon after the

U.S. EPA adopts its national fuel specification.

L. Funding Sources
41

63.Comment: WSPA supports fuel neutral existing programs that encourage the

accelerated replacement or retrofit of old diesel engine technology with new modern

low emission technologies. To that end, we recommend that existing incentive

programs be modified, as necessary, to help underwrite the diesel retrofit

requirements in the rule. (WSPA)

Agency Response: The Carl Moyer Program is a voluntary incentive program

specifically charged with providing grants for the purchase of new, low-emission

heavy-duty engines and equipment, or for the retrofit or repower of existing heavyduty engines to lower-emitting configurations. However, Health and Safety Code

section 44281(b), as part of the legislative authority for the Carl Moyer Program,

specifically states that “no new purchase, retrofit, repower, or add-on equipment

shall be funded under this chapter if it is required by any local, state, or federal

statute, rule, regulation, memoranda of agreement or understanding, or other legally

binding document.” Thus, California statute prohibits the ARB from modifying its

Carl Moyer Program Guidelines to allow grants to be used for compliance with the

regulation’s retrofit requirements. It is general ARB policy that regulatory

compliance cannot be funded through state incentive programs.

64.Comment: The federal funding highlighted as the basis for complying with the

regulation is extremely limited; further stretching of these funds directly impacts

service on the street. (AC Transit)

Agency Response: The ARB acknowledges in the Staff Report that some transit

agencies could experience service cut-backs or fare increases if transportation

planning agencies do not allocate federal transportation funding to public transit

projects. Multiple transportation projects affecting streets and highways, bridges,

pedestrian and bicycle facilities, and ferries, just to name a few, compete for federal

funding; it is the responsibility of transportation planning agencies to prioritize the

allocation of that available funding. In general, the ARB has identified adequate

funds from transportation, air quality, and energy-related sources available to

subsidize the incremental cost of alternative-fuel buses in urban areas, assuming a

normal bus turnover rate. Unfortunately, adequate funds to cover the entire cost of

infrastructure necessary for alternative-fuel bus purchases have not yet been

identified. Therefore, Board Resolution 00-2 directs the ARB to work with transit

agencies to identify potential sources of funding for the capital costs and

infrastructure for future lower-emission bus technology, as well as encourage

transportation planning agencies to provide more funding for transit agencies to

cover retrofit costs, infrastructure costs, and new bus purchase costs not already

funded by federal funds or state incentive program funds.

65.Comment: The regulation should be strengthened so that areas classified as

extreme or severe nonattainment for the federal one-hour ozone standard receive

TEA-21 funding for air quality goals, and not for roads or stop signs. (Neisi Farmers

League and CAGI )
42

Agency Response: The United States Congress is responsible for allocating

TEA-21 funds to various transportation-related programs. In turn, local

transportation planning agencies receiving TEA-21 funding are responsible for

prioritizing transportation project categories in their respective regions and allocating

funding to each category. This means that multiple transportation-related projects

compete for available funding. The ARB does not have the authority to regulate how

the TEA-21 funds may be used. However, Board Resolution 00-2 directs the ARB to

encourage transportation planning agencies to make funding for urban bus projects

a priority in order to assist them in meeting the regulation’s air quality goals.

66.Comment: The regulation will increase the cost of public transportation. If sufficient

government funding is not available to defray the increased costs, fleet sizes may be

reduced and/or fares will be increased, thus negatively impacting transit bus

ridership and the ARB’s goal to achieve emission reductions. (Lockheed Martin)

Agency Response: Please see Agency Response to Comment 64.

67.Comment: Additional funding should be provided for the incremental cost of

alternative-fuel buses and the associated fueling station infrastructure, or the ARB’s

Carl Moyer Program Guidelines should be amended to provide for 100 percent of

the incremental costs. (MTDB)

Agency Response: The ARB is committed to working with transportation planning

agencies and transit agencies to identify and secure additional funding from federal,

state, and local sources for the incremental capital and infrastructure costs

associated with alternative-fuel technology. Regarding the Carl Moyer Program, the

ARB’s current guidelines allow funding for the full incremental cost of alternative-fuel

bus projects, provided the bus projects are cost-effective, meet the guidelines’

criteria, and include documentation clearly indicating that federal funding is not

available to purchase the alternative-fuel buses. Additional infrastructure funding is

available from the Advanced Technology Development and Infrastructure

Demonstration Program, which is administered by the CEC. (Please also see

Agency Response to Comment 64.)

68.Comment: The ARB and air districts should allow existing funding sources (i.e., Carl

Moyer and AB 434 programs) to be used for any and all technology and equipment

purchased to comply with the regulation, including PM retrofits, diesel engine repowers, zero-emission bus demonstrations and purchases and supporting

infrastructure, and diesel hybrid-electric bus purchases. (MTC)

Agency Response: As discussed in the response to Comment 63, Health and

Safety Code section 44281(b) specifically prohibits Carl Moyer funds to be used in

complying with state, federal, or local regulatory requirements. Therefore, these

funds cannot be use to meet the requirements of the urban bus regulation. They

can, however, be used to purchase urban buses certified to the ARB’s optional,

reduced-emission standards (section 1956.1, title 13, CCR). The regulation does
43

not require transit agencies to purchase urban buses certified to the optional

standards. Thus, Carl Moyer funds can be used by transit agencies purchasing

alternative-fuel urban buses with engines certified to the optional emission standards

(only alternative-fuel engines are currently able to certify to these low levels).

Regarding infrastructure funding, Carl Moyer funding for alternative-fuel

infrastructure is already available from the CEC, which administers the advanced

technology development and infrastructure portions of the program.

The urban bus regulation does not contain requirements for diesel hybrid-electric

bus purchases, nor can Carl Moyer funds be used for these purchases at this time.

Current California and federal certification test procedures are engine-based and

therefore are not able to adequately represent the emission benefits of diesel hybridelectric technology. Additionally, current data indicate that state-of-the-art diesel

hybrid buses with a particulate filter and low-sulfur fuel have PM emissions as low as

CNG buses without a particulate filter, but they still emit NOx at higher levels than

CNG buses. The ARB, in conjunction with the Northeast Advanced Vehicle

Consortium, the U.S. EPA, and the engine and hybrid bus manufacturers, is working

to develop a certification procedure for heavy-duty vehicle hybrids. Until that occurs,

however, the reduced emission levels of diesel hybrids cannot be easily validated.

The ARB staff is scheduled to propose modifications to the Carl Moyer Program

Guidelines for the Board’s consideration in November 2000. One of the proposed

modifications is to allow diesel hybrids to qualify for program funding on a case-bycase basis until a heavy-duty hybrid vehicle certification procedure is developed. It

is important to note that alternative-fuel hybrid-electric buses with engines certified to

one of the ARB’s optional, reduced-emission standards are already eligible for Carl

Moyer Program funding.

Regarding Assembly Bill 434 (AB 434; Stats. 1990, Ch. 1705, Sec.1) programs,

funds for these programs are generated by a surcharge levied within the Bay Area

Air Quality Management District (BAAQMD) on all motor vehicle registrations in that

area. Health and Safety Code section 44241, the provision of the legislation that

determines the allocation of fee revenues within the BAAQMD, specifically limits the

transportation and congestion management programs that can be funded with these

fees [see Health and Safety Code section 44241(b)]. While clean fuel buses may be

purchased with AB 434 funds (i.e., alternative-fuel buses certified to one of the

ARB’s optional, reduced-emission standards specified in section 1956.1, title 13,

CCR), the fees cannot be used to fund compliance with mandatory emission

standards or other mandatory requirements in the regulation.

69.Comment: The best way to meet the goals of regulation is to request funds from the

Governor and Legislature to meet some of the additional costs that transit agencies

may incur as a result of the regulation. (CTranA)

Agency Response: The ARB is committed to working with this commenter, the

California Transit Association, in securing additional funds from the Legislature and
44

the Governor to assist transit agencies with low-emission bus purchases and

associated alternative-fuel infrastructure.

It is important to point out, however, that the existing Carl Moyer Program, funded

each year through the state budget process, is a significant source for funding the

incremental cost of urban buses certified to the ARB’s optional, reduced-emission

standards (which only alternative-fuel buses can currently meet) and associated

alternative-fuel infrastructure. The $50 million funding level for the 2000/2001 fiscal

year is the highest in the Carl Moyer Program’s three year history.

Additionally, the recent enactment of Assembly Bill 2511 (Steinberg; Stats. 2000,

Ch. 532) provides $50 million to the Sacramento region and $25 million to the San

Joaquin Valley region to fund incentive programs for reducing emissions from heavyduty diesel vehicles. These funds could be used by transit agencies in these regions

to purchase low-emission urban buses certified to the ARB’s optional, reducedemission standards. The recent enactment of Senate Bill 1662 (Burton; Stats. 2000,

Chapter 656) also provides additional funds to select transit agencies throughout the

state to purchase low-emission urban buses.

M. Articulated Buses

70.Comment: It is unclear how the regulation applies to articulated buses since there

are currently limited options for alternative-fuel technologies and other emissionreducing technologies for articulated buses. (MTC)

Agency Response: The engines used in articulated buses must meet the

regulation’s applicable emission standards, specified in section 1956.1, title 13,

CCR, and must comply with the fleet rule components specified in section 1956.2,

title 13, CCR. However, the ARB acknowledges the unique operating parameters of

articulated buses that can now only be met with diesel-fueled urban bus engines,

and that some transit agencies on the alternative-fuel path have service needs best

met through the use of articulated buses. Therefore, the regulation was designed to

provide flexibility to these transit agencies by allowing up to15 percent of new bus

purchases on the alternative-fuel path to be diesel buses.

N. Compliance and Enforcement

71.Comment: The ARB should expand its in-use compliance program to ensure

compliance with the new emission standards for urban bus engines and the retrofit

requirements set forth in the regulation. The provisions outlined by the Consent

Decree offer a template for including on-board diagnostics and not-to-exceed

provisions that should be formally adopted by the ARB in the transit bus regulation.

(ENVIRONMENTAL GROUP JOINT LETTER)

Agency Response: Board Resolution 00-2 directs the Executive Officer to evaluate

the viability of test procedures to measure in-use emissions from urban buses for the
45

purpose of determining compliance with all the regulation’s requirements. As

discussed at the February hearing, evaluating the feasibility of an expanded in-use

compliance program is a complex task that could take two to three years to

complete. After an extensive evaluation, the staff will report its findings to the Board

and present any recommendations for addressing compliance concerns, should they

exist.

72.Comment: The ARB should establish strong noncompliance penalties, whether in

the form of sanctions, fines, loss of funding, or other mechanisms, to send a clear

signal to transit agencies that compliance with the ARB’s fleet rule requirements is a

priority. Additionally, the ARB must establish a program by which transit agencies

make up for lost emission benefits if they fail to comply with the regulation.

(ENVIRONMENTAL GROUP JOINT LETTER)

Agency Response: The ARB is committed to ensuring compliance with the

regulation’s fleet rule requirements and will actively work with transit agencies to

monitor the status of its implementation. The Health and Safety Code, commencing

with section 42400, specifies legal procedures and penalties for addressing criminal

and civil noncompliance with the ARB’s regulations and for administering

noncompliance penalties. In addition to fines and penalties up to $50,000 per day

for intentional noncompliance with regulatory requirements, injunctive orders to

enable the ARB to recoup lost emission benefits and other appropriate equitable

relief are available through a court order directed to any transit agency that fails to

comply with the regulation.

73.Comment: The ARB should undertake a research effort to develop a more

representative test cycle so that future standards and in-use compliance programs

will be more representative of real-world gains. Such a program might appropriately

be part of a larger effort to develop more representative test cycles for all dieselcycle engines, including those certified as on-road heavy-duty and non-road

engines. (ENVIRONMENTAL GROUP JOINT LETTER)

Agency Response: The ARB is evaluating the feasibility of in-use testing and

compliance as part of its efforts to expand the current Heavy-Duty Vehicle Inspection

Program and to develop measure M-17, Additional Reductions from Heavy-Duty

Vehicles, in the 1994 State Implementation Plan for Ozone. This effort could include

developing a compliance test procedure more representative of urban bus drive

cycles. Additionally, such efforts may ultimately be the basis for developing new test

cycles for other categories of diesel engines.
46

O. Regulatory Compliance Costs

74.Comment: The regulation should include a cost cap on the PM retrofit requirements

because the Tier 2 and Tier 3 PM requirements are very aggressive and may cost

more than estimated in the Staff Report. (CTranA)

Agency Response: The costs to comply with the PM retrofit requirements, as

presented in the Staff Report, are based on information obtained from industry and

trade groups. However, as a matter of course, some level of uncertainty is inherent

in all cost projections. Nevertheless, the ARB believes that the level of uncertainty

for PM retrofit technology is not as great as what would be expected for

undeveloped or unproven technologies. Particulate trap technology has been well

demonstrated and the manufacturing process is relatively straightforward and well

established. The per unit cost of PM trap technology is expected to be reduced from

the cost projected for Tier 1 requirements due to increased manufacturing efficiency

and economy of scale associated with mass production. As such, the ARB believes

that it is not necessary to include a cost cap in the regulation.

75.Comment: The regulation should include cost caps on the PM retrofit requirements.

The U.S. EPA, in its urban bus retrofit/rebuild regulation, has an excellent protocol

that establishes how to implement a cost cap. The concept is to set a cap on what

that technology is worth, and then let industry compete for that technology.

(SMCTD)

Agency Response: The cost caps contained in U.S. EPA’s urban bus retrofit/rebuild

regulation (sections 85.1401 - 85.1415, title 40, CFR) were established to provide

maximum costs levels that the U.S. EPA considered to be reasonable in requiring

transit agencies to comply with provisions of its regulation. At the time the

U.S. EPA’s regulation was promulgated, the technologies that could be used to

reduce PM emissions from urban buses were still relatively immature and there was

limited knowledge regarding what technologies would be effective and would

ultimately prevail in the market place. Because of this uncertainty, the costs of these

technologies remained largely unknown. The situation is now different; particulate

traps are expected to be the technology used for compliance with the ARB’s PM

retrofit requirements. Since PM traps have been installed in buses for a number of

years, the expected costs are much better understood. With increased production

and market competition from various PM trap manufacturers, the ARB expects the

cost of PM traps to decline over time from the current price. Therefore, the ARB

believes that it is unnecessary to specify a cost cap in the regulation. In fact,

including a cost cap in the regulation could prevent the expected cost reduction

associated with economy of scale production as a cost cap could alter the

competitive market pricing of the technology. A cost cap provision could interfere

with the equilibrium pricing that would result from free-market forces and could

artificially inflate PM trap costs.
47

76.Comment: As with the U.S. EPA’s urban bus retrofit/rebuild regulation, lower

outyear emission levels should only be triggered if technology is available at or

below responsible dollar thresholds established by the ARB, corrected to calendar

year 2000 dollars. For example, the ARB should only require transit agencies to

place into service three zero-emission buses by mid-2003, if the fuel cell bus

incremental cost of $275,000, as estimated by the ARB, is accurate. Without such

limits, the requirement could become overly burdensome. (Nova BUS)

Agency Response: The primary goal of the regulation is to reduce emissions from

both existing and new buses. Another goal of the regulation is to promote the

development of advanced technology, such as zero-emission buses. It is to be

expected that the cost of any new, advanced technology is likely high, particularly

when first introduced. It is also as likely that the cost of advanced technology will

decrease, substantially in most cases, as the technology becomes more mature and

its use becomes more prevalent. The regulation requires larger transit agencies on

the diesel path to participate in a zero-emission bus demonstration program.

However, a transit agency has the choice of electing which compliance path to

follow; either the diesel path or alternative-fuel path. If a transit agency elects to

follow the alternative-fuel path, it will not be required to purchase zero-emission

buses as part of the zero-emission bus demonstration program. By electing to go

with the diesel path, a transit agency has chosen not to expend current capital

resources to purchase alternative-fuel buses, but, in so doing, will not be contributing

to any immediate emission reductions. To preserve financial equity and to ensure

that emission reduction obligations are equally distributed between both compliance

paths, the regulation requires larger transit agencies on the diesel path to participate

in a zero-emission bus demonstration program, as well as being the first to purchase

zero-emission buses. The ARB believes that zero-emission technology will play a

vital role in reducing emissions from urban buses. As such, that ARB believes that

the emission benefits of zero-emission buses justify the efforts and costs in

promoting its development and commercialization.

77.Comment: With the federal urban bus retrofit/rebuild regulation as a precedent, the

ARB’s urban bus regulation should include incremental cost caps for each regulation

requirement, based on the ARB’s estimates of those costs. If the cost per bus,

including infrastructure and fuel, should exceed the cost caps, the ARB should

redefine the requirements in order to allow transit operators the ability to comply

within the cost caps. (MTC)

Agency Response: The ARB's regulations typically do not include cost caps as a

way to control costs. Rather, ARB's regulations make use of cost-effectiveness

criteria as a means to gauge the economic feasibility of the regulations. A regulation

is deemed economically reasonable if the cost-effectiveness of the proposed

requirements is below a certain threshold, typically less than $6.00 per pound of

NOx reduced for mobile source regulations. For the urban bus regulation, ARB

estimated that the cost-effectiveness of the NOx requirements to range from $1.50
48

to $1.80 per pound of NOx reduced. This cost-effectiveness level is well below the

$6.00 per pound cost-effectiveness threshold.

Because PM reductions are much more expensive to achieve than NOx reductions

and because they involve health benefits associated with a reduction in exposure to

a toxic air contaminant, it is not possible to base the feasibility of the regulation’s PM

control requirements on straight cost-effectiveness criteria. The cost-effectiveness

of the regulation’s PM retrofit requirements averages $17.90 per pound of PM

reduced annually from 2003 to 2009. This cost-effectiveness includes the cost

associated with the requirement to purchase low-sulfur diesel fuel. However, the

cost-effectiveness of the PM retrofit requirements does not include the value of

health benefits associated with a reduction in exposure to a toxic air contaminant

(which PM is). The risk management process for the control of toxic PM emissions

from diesel-fueled engines is ongoing. Any PM control measures resulting from the

risk management process will produce additional PM reductions and health benefits

that are not part of this cost-effectiveness determination.

78.Comment: The regulation balances the necessary research and development on

the backs of a small market segment. Instead, the regulation should be modified to

focus on a larger heavy-duty engine market segment, which would allow technology

to advance that can then be applied to urban buses. (CTranA)

Agency Response: The regulation focuses on diesel buses for several reasons.

First, diesel urban buses are ideally suited for improved controls due to relatively

high NOx and PM emissions on a per bus basis. Many of these buses operate in

the most heavily congested urban areas where air quality is critical and direct

exposure to toxic diesel particulates occurs for a large number of people, thus

making toxic particulate emissions an even greater public health concern. In

addition, they are centrally-fueled with known, fixed routes, which allow for

alternative-fuel or low-sulfur diesel fuel to be utilized more effectively. Next, the

entire cost of a new bus is not borne by the local transit agency, but is funded with

government subsidies. Furthermore, cost-effective emission reductions can be

immediately achieved as cleaner alternative-fuel engine technology is already

available. Finally, technologies to reduce PM emissions have already been

demonstrated on urban buses and are expected to become more widely available at

lower costs in the near future. The technologies used to meet the requirements of

this regulation will pave the way for more stringent federal and California emission

standards for other classes of heavy-duty vehicles to take effect in the 2007

timeframe.

79.Comment: The regulation’s impact on the state’s business community and economy

has not been fully explored. While the proposed regulation will provide substantial

economic benefits to some energy providers, no effort has been made to assess the

impact on petroleum-based fuel producers. (Lockheed Martin)
49

Agency Response: The ARB has evaluated the potential impacts of the regulation

on California businesses and individuals. The potential economic impact on

petroleum-based producers is expected to be modest since the regulation does not

require the elimination of diesel fuel for urban bus applications. Although the

regulation does require that the diesel fuel used must not exceed a 15 ppm by

weight sulfur content, diesel fuel will continue to be in demand from transit agencies

that operate diesel buses. Most, if not all, of the additional costs associated with

producing low-sulfur diesel fuel are expected to be passed onto the end users.

While ARB expects that some transit agencies will be switching to alternative-fuel

buses, the ARB estimated the overall effect on petroleum-based producers to be

small.

80.Comment: The regulation is biased against diesel fuel by understating the costs to

implement the regulation while overstating the funding available for its

implementation. Prior to making a decision on the proposed regulation, the Board

should have at its disposal a complete benefits analysis that includes the true

unsubsidized costs of compliance, including the infrastructure costs for all fuel types,

safety issues associated with alternative fuels, transit agencies’ experiences with

alternative fuels, and all actual funding sources available to transit agencies.

(Lockheed Martin)

Agency Response: The ARB does not believe the regulation to be biased against

diesel fuel. The goal of the bus regulation is to reduce emissions from both new

and existing buses. Regulatory requirements were designed to cost-effectively

achieve that goal and to provide equity between the two compliance paths. The

ARB’s primary method for estimating the cost of a regulation is by determining the

cost-effectiveness of the various requirements of the regulation. Using this

approach, the ARB estimates the cost for complying with the various requirements

and divides that cost by the emission reductions expected from implementation of

the requirements. As such, the ARB calculated the cost-effectiveness for

complying with the PM retrofit requirements and the new engine emission

standards, including the low-sulfur diesel fuel and zero-emission bus purchase

requirements. All new urban bus purchases, both diesel and alternative fuel, are

subsidized by public funds, regardless of the ARB regulation. A large portion of

these funds comes from the FTA. Thus, in determining the cost-effectiveness of

the regulation, the ARB believes that it is appropriate to include the FTA

contribution toward the cost of new bus purchases in the cost-effectiveness

calculation.

Because the alternative-fuel path is an optional path and because the ARB expects

that incentive funding will be available from existing programs to offset most of the

incremental cost of alternative-fuel buses, the cost of purchasing alternative-fuel

buses is not included as part of the cost of the regulation. Nevertheless, the ARB

estimated that the total incremental alternative-fuel bus purchase cost to transit

agencies is about $2,200,000 per year. This cost is based on current purchasing

trends from transit agencies that already have a significant number of alternative-
50

fuel buses in their fleets. These transit agencies would be expected to continue to

purchase alternative-fuel buses even in the absence of this proposed regulation.

Since the regulation requires transit agencies choosing the alternative-fuel path to

have at least 85 percent of their new bus purchases be alternative-fuel buses, some

transit agencies could be required to buy more alternative-fuel buses than they

were planning to buy in absence of the regulation. However, the additional costs

for alternative-fuel bus purchases are expected to be offset through incentive

programs available for the purchase of low-emission buses. The ARB is currently

administering the Carl Moyer program, in conjunction with local air districts

statewide, that provides grants for the purchase of low-emission technologies, such

as alternative-fuel urban buses certified to the ARB’s optional, reduced-emission

standards. Some local air districts also have additional incentive-based programs

to encourage fleet operators to switch to cleaner alternatives to diesel.

81.Comment: The Board should not adopt a regulation that suggests it is “cheaper to

be dirtier.” The ARB has underestimated the zero-emission bus costs. The ARB

should either correct its cost estimates, or shift zero-emission bus and PM retrofit

requirements as needed to better equalize costs under both paths. At a minimum,

the regulation should ensure that the path with higher emissions [the diesel path] is

not perceived as the path with the lowest cost. (PG&E)

Agency Response: The ARB’s policy is to adopt regulations that provide the most

cost-effective emission reductions. With the urban bus regulation, that policy was

coupled with the desire to provide compliance flexibility through the dual-path

approach. The ARB addressed equity issues in proposing the two compliance

paths. Transit agencies electing to be on the alternative-fuel path will provide early

and immediate emission benefits through their purchase and operation of

alternative-fuel buses. In so doing, these transit agencies could potentially incur

some additional capital costs associated with alternative-fuel bus purchases and

infrastructure installations. To balance this situation, the regulation requires transit

agencies that choose the diesel path to comply with more stringent requirements

such as an accelerated PM retrofit schedule, more stringent emission standards for

diesel-fueled engines in the 2004 to 2006 timeframe, and, for larger transit agencies,

zero-emission bus demonstration programs, and early phase-in of zero-emission

bus purchases. These additional requirements are intended to provide equity, in

both emission benefits and financial considerations, such that the diesel path will not

be perceived as the path with the lowest cost. The true cost of zero-emission bus

requirements cannot be resolved at this time with existing information. If the cost of

zero-emission buses are higher than that estimated by the ARB, transit agencies on

the diesel path would have to absorb the higher cost as a result of the zero-emission

bus demonstration program and the early purchase requirement. Because of the

uncertainty associated with zero-emission buses and the more stringent requirement

for transit agencies on the diesel path to incorporate zero-emission buses into their

fleets, it is not necessarily true that the diesel path will be the lower cost path.
51

82.Comment: The costs of compliance with the 2004 through 2006 emission standards

for diesel-fueled urban engines, the PM retrofit requirements, and the zero-emission

bus demonstration requirements are significantly understated. (Nova BUS)

Agency Response: The ARB disagrees with this comment. The costs of the

regulation’s requirements were derived from the ARB’s evaluation of information

provided by industry and the public, both privately and through a number of public

forums. For the 2004 through 2006 emission standards for diesel-fueled urban bus

engines, the costs are based on the cost of aftertreatment technology applied to a

base engine manufactured on or after October 1, 2002. For the PM retrofit

requirements, the ARB projected that the actual compliance costs will likely be lower

than the initial costs estimated for Tier 1 retrofits due to economy of scale and

increased competition among PM trap manufacturers. There is more uncertainty

associated with estimating the cost of zero-emission buses than for PM traps since

the technology for zero-emission buses is much less mature than that of PM trap

technology. However, based on the ARB’s experiences with other technological

innovations, the ARB expects that the cost of zero-emission buses will ultimately be

less than current projections once the technology is fully developed and

commercialized. It should be pointed out that the regulation also allows transit

agencies the option of complying with the 2004 through 2006 emission standards for

diesel-fueled urban bus engines by implementing an alternative NOx strategy in lieu

of purchasing bus with engines certified to the 2004 through 2006 emission

standards. The ARB anticipates that this alternative compliance option will drive

down compliance costs since transit agencies will be able to choose a potentially

lower cost option.

83.Comment: The ARB completely ignores the significant operating costs and

infrastructure increases associated with the use of CNG. (Nova BUS)

Agency Response: The ARB disagrees with this comment. During regulatory

development, the ARB extensively investigated the costs associated with operating

a fleet of alternative-fuel buses. In fact, prior to proposing the regulation, ARB staff

conducted site visits to a number of transit agencies throughout the country to obtain

information on capital and operating costs, including infrastructure costs, associated

with alternative-fuel urban bus fleets. The ARB staff visited the following transit

agencies: the Los Angeles County Metropolitan Transit Authority; Sacramento

Regional Transit District; Pierce Transit in Tacoma, Washington; Greater Cleveland

Regional Transit District; New York City Metropolitan Transit Authority; Dallas Rapid

Transit District; and Houston Metropolitan Transit Authority. These transit agencies,

which vary in size, have significant experience operating CNG and/or liquefied

natural gas urban buses. In addition to these site visits, the ARB conducted

telephone surveys with other transit agencies, fuel providers, and equipment

suppliers to obtain additional information on costs associated with alternative-fuel

buses and its associated infrastructure. Through these efforts, the ARB found that

the combined capital costs of alternative-fuel buses, fueling infrastructure, and
52

maintenance facilities could be significant if these costs were not offset with

incentive funding.

However, the situation is different when comparing operating costs between diesel

and alternative-fuel fleets. While several transit agencies have indicated that CNG

bus operating costs are higher than diesel bus operating costs, some transit

agencies have reported lower operating costs for CNG buses than for diesel buses.

Operating costs include both maintenance and fuel costs. While, in some cases,

maintaining diesel fleets can currently cost less than maintaining CNG fleets, the

requirements for diesel engines to meet more stringent emission standards, along

with the availability of more reliable natural gas engines, should equalize the cost

gap. Fuel costs per mile for natural gas buses, including compression or

liquefaction, is less than for diesel buses. The increased price of low-sulfur diesel

fuel needed in the future should increase this difference. After considering all the

available information, not just information from one or two specific transit agencies,

the ARB expects future operating costs for natural gas fleets and diesel fleets to be

comparable.

84.Comment: The incremental costs of zero-emission buses are likely to be extremely

high due to low production volumes, high development costs, and uncertain

infrastructure requirements. Given the cost uncertainty, it is unrealistic that bus

manufacturers and transit agencies will be more likely to embrace zero-emission

buses in 2007 than they are to accept low-emission, alternative-fuel buses today.

(CNGVC)

Agency Response: The requirements in the ARB’s regulation are intended to

reduce emissions from urban transit buses as expeditiously as possible, and to push

the development of advanced urban bus technologies toward zero or near zeroemission levels. The ARB acknowledges that there will be research, development,

and commercialization costs associated with bringing zero-emission buses into the

market. It is normal to anticipate that there will be higher costs associated with the

introduction of new products, especially if the product results in a shift away from

established technologies. The ARB believes that the emission benefits warrant the

continued focus on developing and commercializing zero-emission urban bus

technology. The ARB is working with several technology providers toward this end

and believes that zero-emission buses will be available in the timeframe specified in

the regulation. Thus, ARB believes that the zero-emission bus demonstration

program and purchase requirements are an effective way to introduce zero-emission

buses into the public transit sector.

85.Comment: Public transit is a solution to pollution and other environmental problems,

rather than a problem itself. Therefore, public transit should not suffer undue burden

that could reduce existing service, or prevent improvements in service necessary to

reduce automobile traffic. The regulation should provide more flexibility based on

the availability of reasonably priced fuel and engines. (Cluster)
53

Agency Response: The ARB concurs that public transit provides vital services to the

community it serves, including transportation to transit-dependent users and traffic

congestion relief. In certain situations, transit buses could also reduce emissions

compared to passenger car trips. But because emissions from passenger cars have

been reduced to very low levels, the previous statement is true only if the emissions

from buses are much lower than required by existing emission standards. Currently,

only natural gas buses have been certified to a level that is about one-half of the

existing mandatory NOx emission standard. In order to fully realize the societal

benefits that could be provided by transit buses, emissions from these buses must

be further reduced. The ARB believes that the regulation strikes a balance between

the need to achieve that goal and the desire to provide flexibility to transit agencies.

As such, the regulation does not force any transit agency to use a specific fuel or

engine type. The regulation only specifies emission requirements and allows transit

agencies to choose between two distinct compliance paths -- the alternative-fuel

path or the diesel path. Each transit agency is allowed to choose the path that best

meets its needs, yet, at the same time, provides direct air quality benefits to bus

riders and the community it serves.

P. Legal and Procedural Issues

86.Comment: The ARB’s Staff Report singles out only one of many fuel cell

manufacturers and specifies its basic fuel cell system. The Notice of Public Hearing

similarly singles out only one fuel cell manufacturer. It is improper and exclusionary

for government to endorse a specific manufacturer of any good or service; hence,

the laws which provide for free and open competition and anti-trust. (Nova BUS)

Agency Response: The reference to the fuel cell manufacturer and, in the case of

the Staff Report, a description of the specific fuel cell system, was included as an

example of fuel cell development for transit applications. The ARB’s regulations are

highly technical and dependent upon the underpinning of sound science and the

availability of required control technology. The Staff Report, released to the public

on December 10, 1999, clearly states on its cover that its contents do not

necessarily reflect the views and policies of the ARB, nor does the mention of trade

names or commercial products constitute an endorsement or recommendation for

use. The ARB acknowledges that other manufacturers may meet the regulatory

performance standards and would welcome robust and open competition to provide

low-emission technology.

87.Comment: The ARB would not accept oral comments, only written comments,

during the 45-day comment period prior to adoption of the proposed regulation.

(Individual comment within an FL2 letter)

Agency Response: The California Administrative Procedure Act, title 2, division 3,

part 1, chapter 3.5 of the Government Code, sections 11340 through 11356,

prescribes the requirements and procedures to which public agencies must adhere

during the public rulemaking process. In accordance with sections 11346.5(a)(9)
54

and 11346.8(a) of the Government Code, the ARB specified in the Notice of Public

Hearing the date by which written comments on the proposed regulation had to be

submitted in order to be considered by the ARB prior to regulation adoption. In

addition to this written comment period, the ARB invited oral testimony at the

January hearing in the same Notice of Public Hearing. The hearing was conducted

in accordance with the requirements of section 11346.8(a) of the Government Code,

and both written and oral statements were permitted. All comments, oral and

written, were considered, and the ARB is responding, in writing, to each comment in

the public record through this Final Statement of Reasons. This process benefits the

public by providing full and accessible disclosure of all issues raised by the public

during the formal comment period, as well as the manner in which they were

addressed by the public agency.

Q. Local Air Quality Management and Air Pollution Control District Issues

88.Comment: The regulation should not permit exceptions for individual air districts to

require transit agencies to implement the alternative-fuel path. A statewide rule

should remain in force to provide uniformity. (CCC, WSPA)

Agency Response: The Health and Safety Code, not the ARB regulation, provides

local air quality management and air pollution control districts the authority to require

transit agencies to implement the alternative-fuel path. Thus, the ARB’s legal

counsel has concluded that the South Coast Air Quality Management District, the

Sacramento Metropolitan Air Quality Management District, and the Mojave Desert

Air Quality Management District all have specific legislative authority to implement

measures requiring transit operators to purchase and operate low-emission vehicles.

This authority is provided in sections 40447.5(a), 41011, and 41231 of the Health

and Safety Code. Furthermore, the ARB’s legal counsel has also concluded that

other air districts with “serious,” “severe,” or “extreme” air pollution have the legal

authority to regulate vehicle fleets (see sections 40919(a)(4), 40920(a), and

40920.5(a) of the Health and Safety Code), and thus can require transit agencies to

implement only the alternative-fuel path. As such, the ARB cannot modify the

regulation to include a provision that would directly conflict with these statutes, nor

as a policy matter, does the ARB believe this would be beneficial to air quality.

89.Comment: The regulation should allow air districts the flexibility to protect the health

of their communities by requiring transit agencies in their respective regions to follow

a single path – the alternative-fuel path. (CBE, PFC, SJVAPCD)

Agency Response: Just as the regulation does not explicitly provide air districts the

authority to require transit agencies to implement the alternative-fuel path, it does

not explicitly prohibit them from exercising their existing legal authority to do so. The

ARB’s legal counsel has concluded that the South Coast Air Quality Management

District, the Sacramento Metropolitan Air Quality Management District, and the

Mojave Desert Air Quality Management District have specific legal authority to

implement measures requiring transit operators to purchase and operate low-
55

emission vehicles. This authority is provided in sections 40447.5(a), 41011, and

41231 of the California Health and Safety Code. The ARB’s legal counsel has also

concluded that other air districts with “serious,” “severe,” or “extreme” air pollution

have the legal authority to regulate vehicle fleets (see sections 40919(a)(4),

40920(a), and 40920.5(a) of the Health and Safety Code), and thus can require

transit agencies to implement the alternative-fuel path. As such, the ARB believes

that modifying the regulation to provide air districts with a mechanism to require

transit agencies to implement the alternative-fuel path is both redundant and

unnecessary.

90.Comment: The ARB should specify in the regulation that a local air district

designated (at a minimum) as a serious PM10 nonattainment area may adopt a

resolution that would limit transit agencies in that region to the alternative-fuel path.

(ENVIRONMENTAL GROUP JOINT LETTER)

Agency Response: Please see Agency Response to Comment 89.

91.Comment: The ARB should modify the regulation to enable air districts with an

extreme ozone air quality designation to have the authority to opt out of the diesel

path. The ARB should also consider providing “opt out” authority to all air districts in

the state, regardless of their air quality designations. (Sempra Energy)

Agency Response: The ARB did not modify the regulation as this commenter

recommended. The ARB’s legal counsel has concluded that the South Coast Air

Quality Management District, the Sacramento Metropolitan Air Quality Management

District, and the Mojave Desert Air Quality Management District already have the

specific legal authority to implement measures requiring transit operators to

purchase and operate low-emission vehicles. This authority is provided in sections

40447.5(a), 41011, and 41231 of the California Health and Safety Code. Only the

South Coast region has the distinction of being classified as an “extreme” federal

ozone nonattainment area. The ARB’s legal counsel has also concluded that other

air districts with “serious,” “severe,” or “extreme” air pollution have the legal authority

to regulate vehicle fleets (see sections 40919(a)(4), 40920(a), and 40920.5(a) of the

Health and Safety Code), and thus can require transit agencies to implement the

alternative-fuel path. As such, the ARB believes that modifying the regulation to

provide air districts with a mechanism to require transit agencies to implement the

alternative-fuel path is both redundant and unnecessary.

It is important to note that air districts that exercise their authority to require that

transit agencies comply with the alternative-fuel path would gain little or no overall

NOx emission benefits (NOx contributes to ozone formation) for their respective

regions because the ARB designed both compliance paths to provide equivalent

NOx benefits over the lifetime of the regulation. On the other hand, air districts that

choose to require that transit agencies adhere to the alternative-fuel path would

reduce toxic exposure from diesel PM earlier than transit agencies on the diesel path

due to the inherently low in-use PM emissions of alternative-fuel buses.
56

92.Comment: The diesel path is not in the best interest of the residents in the South

Coast region because the particulate emission reductions are not the same for the

diesel and alternative-fuel paths. Therefore, the regulation should be modified to

allow the South Coast Air Quality Management District to eliminate, either partially or

completely, the diesel path compliance option for new urban bus purchases.

(SCAQMD, Senator Hayden)

Agency Response: As discussed in the agency responses to Comments 89 and 91,

section 40447.5(a) of the Health and Safety Code provides the South Coast Air

Quality Management District with the legal authority to regulate fleets and to require

transit agencies to purchase and operate low-emission vehicles. Therefore, the

ARB believes it is unnecessary and redundant to modify the regulation to include a

specific mechanism to allow the SCAQMD to partially or completely eliminate the

diesel path. Subsequent to the Board’s approval of this regulation, the South Coast

Board approved Rule 1192 on June 16, 2000, requiring transit agencies to purchase

only low-emission, alternative-fuel buses when making new bus purchases. Other

provisions of the ARB’s regulation that are not diesel path-dependent are not

superceded by Rule 1192 and still apply in the South Coast region (i.e., PM retrofit

requirements, NOx fleet average standard requirement, and zero-emission bus

purchases).

93.Comment: The regulation should include special allowances for rural areas that

have no choice but to comply with the diesel path due to the unavailability of natural

gas. For example, the regulation could define a rural county as having less than

100,000 people, and then exempt rural counties that are in attainment with the

California Ambient Air Quality Standards (CAAQS) for ozone and exempt rural public

transit agencies with fewer than 25 buses. Another option for modifying the

regulation would be to allow rural counties on the diesel path to be exempt from

regulation’s requirements until January 1, 2007. (NSAQMD)

Agency Response: The ARB did not modify the regulation as this commenter

recommended because the regulation already provides compliance flexibility to

small transit agencies operating in federal one-hour ozone attainment areas. The

ARB is aware that pipeline natural gas is not available in some rural counties.

Therefore, the ARB expects that transit agencies in these areas will continue to

purchase and/or lease diesel buses, thus participating in the diesel path. Diesel

purchases or leases will be required to meet applicable the emission standards for

diesel-fueled engines, as specified in section 1956.1 title 13, CCR.

However, transit agencies with an active fleet consisting of less than 20 urban buses

operating in federal one-hour ozone attainment areas are permitted to delay

compliance with the Tier 1 (applicable to urban buses with 1990 and earlier model

year diesel-fueled engines) and Tier 2 (applicable to urban buses with 1991 through

1995 model year diesel-fueled engines) PM retrofit requirements until 2007. This

delay is necessary due to the difficulties that these regions, most likely rural areas,
57

may experience in obtaining the low-sulfur diesel fuel (due to price and the logistics

of fuel distribution) necessary to comply with the PM retrofit requirements. The ARB

expects that the U.S. EPA’s low-sulfur diesel fuel requirement will be in effect by

2006, thus minimizing price and supply disruptions in California and enabling the

smaller transit agencies in federal one-hour ozone attainment areas to meet their

compliance deadlines.

R. Emissions from Other Heavy-Duty Vehicles

94.Comment: The ARB needs to address emissions from school buses and other

heavy-duty vehicles. When will the ARB promulgate these regulations? (SCVTA)

Agency Response: During the course of this rulemaking, the ARB stated its intent to

address emissions from school buses and other heavy-duty vehicles. In December

2000, the Board is scheduled to consider guidelines for the implementation of the

Lower Emission School Bus Program. Governor Davis recently allocated $50 million

in the 2000/2001 state budget to fund this voluntary program for the purpose of

reducing school children’s exposure to harmful diesel exhaust emissions. These

guidelines, once approved by the Board, will be used to assist school districts with

funding new school bus purchases and/or retrofits for existing buses.

Additionally, the ARB will be considering new emission standards for the 2007

timeframe for other on-road heavy-duty engines and vehicles. This proposal will be

subject to notice and comment rulemaking procedures pursuant to the

Administrative Procedure Act and will address engines used in school buses and

smaller transit buses, which have historically been regulated through emission

standards for heavy-duty truck engines. The U.S. EPA has already proposed new

emission standards for heavy-duty trucks and buses, to take effect in the 2007

timeframe, in its Notice of Proposed Rulemaking for Heavy-Duty Engines and

Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements (Federal

Register, Vol. 65, No. 107, June 2, 2000, pp. 35430 - 35545). In consultation with

the U.S. EPA, the ARB is committed to harmonizing its 2007 standards with those

ultimately adopted by the U.S. EPA.

Finally, on September 28, 2000, the Board approved the “Diesel Risk Reduction

Plan to Reduce Particulate Matter Emissions from Diesel-Fueled Engines and

Vehicles,” a comprehensive plan to significantly reduce diesel PM emissions from

diesel-fueled engines used in all heavy-duty applications. Regulations to be

developed over the next few years will affect off-road mobile source and stationary

source diesel-fueled engines, in addition to the on-road mobile sources discussed

above.
58

95.Comment: The regulation should be modified to include school buses. (Judy Fogel,

BAAQMD, SUVA/La Causa, CBE)

Agency Response: While developing this regulation, the ARB staff encountered

barriers to including school buses in the fleet rule portion of the regulation.

Specifically, the lack of funding available to school districts to purchase new school

buses, install alternative-fuel infrastructure, and/or fund retrofits for existing school

buses made it impractical to address this transportation sector in this regulation.

However, the ARB committed to specifically address school bus emissions in the

immediate future. Consequently, the ARB staff is now proposing guidelines for the

implementation of the Lower Emission School Bus Program, which will be

considered by the Board at its December 2000 public hearing. Governor Davis

recently allocated $50 million in the 2000/2001 state budget to fund this voluntary

program for the purpose of reducing school children’s exposure to harmful diesel

exhaust emissions. These guidelines, once approved by the Board, will be used to

assist school districts with funding new school bus purchases and/or retrofits for

existing buses. Additionally, the ARB will be proposing new emission standards for

the 2007 timeframe for other on-road heavy-duty engines and vehicles. This

proposal will include emission standards for engines used in school buses and

smaller transit buses, which have historically been regulated as heavy-duty truck

engines. (Please Also See Agency Responses to Comments 94 and 96.)

96.Comment: Despite the fact that the state’s school buses log far fewer miles than

transit buses, their total PM emissions are projected to be over four times higher in

2010. Considerable time has elapsed since the ARB identified both transit and

school buses as a priority for regulation. The ARB should develop a draft school bus

regulation in the year 2000. (ENVIRONMENTAL GROUP JOINT LETTER)

Agency Response: The ARB, in consultation with the CEC, is developing guidelines

for the implementation of the Lower Emission School Bus Program, to which

Governor Davis has allocated $50 million for the 2000/2001 fiscal year. The

purpose of this voluntary program is to reduce school children’s exposure to harmful

diesel exhaust emissions. The guidelines, scheduled to be considered by the Board

in December 2000, will be used to assist school districts with funding new school

bus purchases and/or retrofits for existing buses.

New, mandatory emission standards for engines used in school buses will be

included in emission standards that the ARB will soon be proposing to take effect in

the 2007 timeframe. (Please Also See Agency Responses to Comments 94 and

95.)
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97.Comment: We are concerned that the fleet rule does not capture the smaller 30 to

40 foot transit buses that do not meet a 33,000 Gross Vehicle Weight Rating. The

ARB should evaluate actual Gross Vehicle Weight data for 30-foot transit buses and

establish a means by which these vehicles can be included in the fleet rule.

(ENVIRONMENTAL GROUP JOINT LETTER)

Agency Response: The ARB did not modify the regulation to include smaller transit

buses in the fleet rule portion of the regulation. The regulation only affects full-size

transit buses meeting the federal definition of an urban bus as defined in section

86.094-2, subpart N, part 86, title 40, CFR. Historically, smaller transit buses have

been regulated through emission standards for heavy-duty truck engines, not

through emission standards for urban bus engines. The ARB has continued this

regulatory precedent. The ARB will be considering new emission standards for the

2007 timeframe for other heavy-duty engines and vehicles, including engines used

in smaller transit buses. The U.S. EPA has already proposed new emission

standards for heavy-duty trucks and buses, to take effect in the 2007 timeframe, in

its Notice of Proposed Rulemaking for Heavy-Duty Engines and Vehicle Standards

and Highway Diesel Fuel Sulfur Control Requirements (Federal Register, Vol. 65,

No. 107, June 2, 2000, pp. 35430 - 35545). In consultation with the U.S. EPA, the

ARB is committed to harmonizing its 2007 standards with those ultimately adopted

by the U.S. EPA.

S. Miscellaneous Comments

98.Comment: The regulation should allow diesel fleets to switch to biodiesel as an

interim solution while gradually phasing out diesel buses. Biodiesel, coupled with a

gradual phase out of diesel buses, should provide an economically viable interim

solution, thus easing the transition to alternative fuels. (Dunlap)

Agency Response: The urban bus regulation does not explicitly prohibit the use of

biodiesel as an alternative to diesel fuel use. Biodiesel, made from natural,

renewable sources such as vegetable oils, can be substituted in diesel engines with

essentially no engine modifications. Depending on the test methods used, biodiesel

has demonstrated both increases and decreases in NOx emissions, and decreases

in unburned hydrocarbons, carbon monoxide, and particulate matter. However,

biodiesel’s use in widespread commercial markets in California (and in the rest of

the United States) is relatively unknown, and it is marketed at a premium compared

to petroleum diesel. Thus, fuel costs are greater than petroleum diesel for fleet

managers that use biodiesel or biodiesel blends.

99.Comment: There is a method for converting frying oil into a fuel that could be used

instead of diesel fuel, thus lowering diesel exhaust emissions. (Individual comment

within an FL2 letter)
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Agency Response: Used frying oil is one potential feedstock in producing biodiesel,

a diesel fuel substitute. However, biodiesel’s use in widespread commercial markets

in California (and in the rest of the United States) is relatively unknown, and it is

marketed at a premium compared to petroleum diesel. Thus, fuel costs are greater

than petroleum diesel for fleet managers that use biodiesel or biodiesel blends. The

ARB is unaware of any other viable method for converting frying oil into motor

vehicle fuel for commercial use. (Please also see Agency Response to Comment

98.)

100. Comment: The safety issues regarding CNG fueling and gaseous hydrogen are

grossly understated and clearly not understood by the ARB. (Nova BUS)

Agency Response: The ARB disagrees with this comment and acknowledges the

safety concerns associated with natural gas and gaseous hydrogen. However,

safety concerns are not limited to these specific fuels; diesel, too, has safety issues

associated with its use. All fuels pose potential hazards; these hazards, however,

do not preclude their viability as motor vehicle fuels. Proper training for personnel

who handle fuels, strict adherence to rigorous safety, handling, and manufacturing

procedures, and familiarization with specific fuel properties will reduce the potential

for accidents and help ensure public safety. This tenet holds true for all motor

vehicle fuels.

101. Comment: The ARB should require all urban buses, regardless of fuel type, to

eventually meet a lower NOx emission standard than what is contained in the

proposed regulation. Specifically, the ARB should adopt a 0.1 g/bhp-hr NOx

standard for 2008 and subsequent model year bus engines. There are at least three

potential technical pathways for achieving this level assuming five or more years of

additional aftertreatment development and several years for ramp up to full

production: 1) 2.0 g/bhp-hr NOx engines with 95 percent control; 2) 1.0 g/bhp-hr

NOx engines with 90 percent control; or 3) 0.5 g/bhp-hr engines NOx engines with

80 percent control. (ENVIRONMENTAL GROUP JOINT LETTER)

Agency Response: The ARB did not modify the regulation as this commenter

recommended. The ARB expects that NOx aftertreatment technologies, such as

NOx adsorbers or selective catalytic reduction systems, will be able to reduce NOx

emissions by more than 70 percent from existing standards in the 2004 timeframe.

With additional advances, the ARB expects that perfected aftertreatment

technologies will be able to achieve even more reductions in the future. As such, the

regulation already includes a requirement for a more stringent NOx standard -- a

0.2 g/bhp-hr standard -- for 2007 and subsequent model year urban bus engines. In

addition, the ARB stated its intent during this rulemaking to harmonize, to the extent

possible, California’s heavy-duty vehicle emission standards with federal emission

standards proposed for the 2007 timeframe. The U.S. EPA’s Notice of Proposed

Rulemaking for Heavy-Duty Engines and Vehicle Standards and Highway Diesel

Fuel Sulfur Control Requirements (Federal Register, Vol. 65, No. 107, June 2, 2000,

pp. 35430 - 35545) includes a proposed 0.2 g/bhp-hr NOx standard for 2007 and
61

subsequent model year heavy-duty engines, including urban bus engines. Thus, the

ARB believes the NOx emission standards contained in this regulation are the most

appropriate level at this time.

102. Comment: The current requirement for transit fleets to meet a 4.8 g/bhp-hr NOx

fleet average standard should be strengthened to provide a more aggressive

strategy incorporating a declining fleet average standard (e.g., requirements to meet

4.8 g/bhp-hr in 2002, 3.0 g/bhp-hr in 2003, 2.0 g/bhp-hr in 2004, etc.). This would

not only provide additional emission benefits from existing transit fleets, but would

also drive the creation of aftertreatment devices for the much larger non-transit

heavy-duty vehicle population. (MTDB)

Agency Response: The ARB did not modify the regulation as the commenter

recommended. During regulatory development, the ARB evaluated NOx fleet

average emissions from numerous transit agencies throughout California to

determine the most appropriate NOx fleet average requirement to impose on transit

agencies. While the intent behind the 4.8 g/bhp-hr NOx fleet average standard is to

require transit agencies to reduce emissions from their oldest, most polluting urban

buses, it is not meant to subject transit agencies to an overly onerous requirement.

The ARB determined that most transit agencies could comply with the 4.8 g/bhp-hr

NOx standard by retiring their 1987 and earlier buses and replacing them with new

urban buses meeting more stringent emission standards. Depending on a transit

agency’s actual fleet composition, this could be the most cost-effective way for a

transit agency to comply with the requirement. Transit agencies could also repower

or retrofit existing buses to lower-emitting configurations. While the ARB recognizes

that a more aggressive NOx fleet average standard could result in additional

emission reductions, it also believes such a requirement could be a financial burden

to many transit fleets and jeopardize their ability to comply.

103. Comment: Buses are an integral component in an effective transportation

system for the masses. The ARB should ensure that the regulation promotes both

clean air and the use of public transportation. (Ritchie)

Agency Response: The ARB agrees wholeheartedly that urban buses are an

integral component of an effective public transportation system, and believes that

the regulation promotes clean air through the implementation of multiple strategies

to reduce emissions from urban bus fleets. While the ARB encourages the use of

alternative modes of transportation, including public transportation, to reduce

vehicular emissions, it does not have the authority to require the public to use any

form of public transportation.
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2. 15-DAY COMMENT SUMMARY AND AGENCY RESPONSES

T. Alternative NOx Strategies

104. Comment: In approving the EMA’s recommendation for an alternative NOx

strategy in section 1956.2, title 13, CCR, the Board directed that any transit fleet

conducting such a strategy must demonstrate NOx emission reductions “greater

than” the base requirement (i.e., the 2004 through 2006 emission standards for

diesel-fueled engines), rather than “equivalent” to the base requirement. The Board

provided no justification for why a demonstration of “greater than” must be made,

especially considering that EMA’s recommendation linked the NOx equivalency

option to a clear and demonstrable PM benefit. Nevertheless, if the final regulation

includes the ”greater than” requirement, the language in paragraph (d)(7)(B) in

section 1956.2 should be modified by changing “through 2015” to “an average over

the period from adoption of this rule through 2015” in order to avoid ambiguity in the

duration of time over which the demonstration must be made. (EMA)

Agency Response: The ARB did not modify the regulation as this commenter

recommended. With regard to the commenter’s first point, the ARB believes that the

Board provided ample justification at the February hearing for this requirement. The

Board directed that the optional, alternative NOx strategies must achieve NOx

emission reductions greater than the 2004 through 2006 standards to account for

the inherent uncertainty associated with an alternative strategy and to send a clear

signal to the engine manufacturers to do everything possible to accelerate the

development of advanced NOx control technology. The Board was clear in directing

the staff to make this change to the EMA recommendation in keeping with the

Board’s intent to provide compliance flexibility, while at the same time demonstrating

the Board’s unwavering commitment to achieving critical NOx reductions.

Regarding the commenter’s recommendation for modifying the regulatory language

to allow NOx reductions to be averaged over the life of the regulation, the ARB

believes that such a modification would explicitly allow for NOx increases over a

potentially long period of time from regulation adoption through 2015. This was not

the Board’s intent; rather, it expects appreciable benefits in NOx reductions

throughout the life of the regulation. Nonetheless, the Board will work with transit

agencies to ensure that they are afforded the compliance flexibility needed to meet

their emission reduction goals in consideration of available technology and cost.

(Please also see Agency Response to Comment 105.)

105. Comment: One of the key elements of the modified regulation is the provision

incorporating the EMA’s proposal to provide significant emission reductions by

implementing the 0.01 g/bhp-hr PM standard 15 months ahead of when originally

proposed, in conjunction with providing the Executive Officer discretionary authority

to approve fleet specific, optional, alternative NOx strategies that provide emission

reductions equivalent to the 2004 through 2006 emission standards for diesel-fueled
63

engines. In approving the EMA’s recommendation, the Board also directed the

Executive Officer to present the application of the first transit fleet requesting an

exemption to conduct an optional NOx strategy to the Board for consideration. Such

a process is likely to delay granting any such exemption and to discourage a transit

fleet from being the first to apply. The Board should not impose an unnecessary and

burdensome process and should not unduly constrain the Executive Officer’s

discretion. (EMA)

Agency Response: The ARB declines to change this provision. At the

February 24, 2000, hearing, the Board clearly directed the Executive Officer to

present the application of the first transit fleet requesting an exemption to conduct an

optional NOx strategy to the Board for consideration. This direction is not contained

in the regulation itself, but in Board Resolution 00-2. The purpose of this provision is

to provide a full public forum in which to discuss the status of advanced NOx control

technology and to determine, at that time, a definition of what “greater than” means

in terms of achieving NOx reductions from an alternative NOx strategy, rather than

through the purchase of diesel-fueled engines meeting the 2004 through 2006

standards.

Aftertreatment technology is rapidly developing and the Board did not want to limit

the NOx reductions that could be achieved with an alternative strategy by

constraining the reductions to “equivalent to” what could be achieved through the

2004 through 2006 standards, or by defining “greater than” in the context of current

expectations for advanced technology.

The ARB believes this process could, in fact, encourage, rather than discourage,

transit agencies to be the first to apply because the first to apply will have a more

active role in defining “greater than,” rather than being subject to a precedent, as

subsequent transit agencies to apply may be. (Please also see Agency Response

to Comment 104.)

106. Comment: Paragraph (d)(7)(A) in section 1956.2, title 13, CCR, requires transit

agencies to apply to the Executive Officer by June 30, 2001, for an exemption from

purchasing diesel-fueled engines meeting the 2004 through 2006 emission

standards. This deadline does not provide transit agencies with sufficient time to

evaluate all their options, including whether diesel-fueled engines meeting the

standards would be available. The deadline for applying to the Executive Officer

should be extended to June 30, 2003. Furthermore, the regulation should require

the Executive Officer to respond to the application within a reasonable timeframe, for

example, within 30 days. (CTranA)

Agency Response: The June 30, 2001, deadline for transit agencies to exercise the

alternative NOx strategy compliance option is derived from two factors. First, the

entire process for a transit agency to purchase an urban transit bus takes

approximately 12 to 18 months from the time of order to actual bus delivery.
64

Purchasing decisions for buses to be delivered in 2004 would need to be made as

early as mid-2002.

Second, the ARB staff needs sufficient time to evaluate applications to conduct an

alternative NOx strategy for effectiveness in achieving claimed NOx reductions.

Because each transit agency’s application will be based on its individual fleet

composition and could include a variety of emission reduction strategies, each

application will require an extensive case-by-case review. If the ARB determines

that an alternative NOx strategy would not achieve NOx emission benefits greater

than what would be achieved through the implementation of the 2004 through 2006

emission standards, it wants to ensure that transit agencies will have adequate time

to revise their alternative NOx strategies and resubmit to the ARB for further

evaluation. Changing the application deadline to June 30, 2003, could severely

constrain both the ARB’s review time and transit agencies’ abilities to make

purchasing decisions based on the outcome of the review of their respective

applications.

Finally, the Executive Officer will not impede transit agencies’ compliance with the

regulation and will therefore respond to all applications as expeditiously as is

possible, whether or not specific regulatory language exists directing him to do so,

given the extensive application review that will be required by the ARB.

107. Comment: The requirement that transit agencies apply to the Executive Officer

by June 30, 2001, for an exemption to conduct an alternative NOx reduction strategy

was never considered as part of the rulemaking, nor discussed with interested and

affected parties. Fleets seeking the option to conduct an alternative NOx reduction

strategy should not have an arbitrarily imposed deadline on when they can seek and

obtain the available exemption. The June 30, 2001, deadline should be deleted from

the regulation. (EMA)

Agency Response: This requirement was included in the regulatory language

presented to the Board at the February 24, 2000, hearing, and was made available

to the public for a supplemental 15-day comment period from August 16, 2000,

through August 31, 2000, pursuant to Government Code section 11346.8(c). Due to

the complexity of strategies that may be submitted, the ARB believes this deadline is

necessary to ensure that transit agencies have adequate time to resubmit an

appropriate alternative NOx strategy and make informed purchasing decisions,

should the ARB, after a thorough review, determine that a transit agency’s first

submission for an alternative strategy does not achieve sufficient NOx reductions.

(Please also see Agency Response to Comment 106.)

108. Comment: Paragraph (c)(5) in section 1956.2, title 13, CCR, appears to have

been included as a modification to the regulation without any explicit direction by the

Board. We believe the intent of this paragraph is to conform the sales of dieselfueled engines to transit agencies on the alternative-fuel path to the same emission

standards for 2004 through 2006 model year diesel-fueled engines as sold to transit
65

agencies on the diesel path. If that is the intent, the paragraph should be modified to

include the same alternative NOx strategy option available to transit agencies on the

diesel path. (CTranA).

Agency Response: It is correct that the intent of paragraph (c)(5) in section 1956.2

is to conform the sales of diesel-fueled engines to transit agencies on the

alternative-fuel path to the emission standards for 2004 through 2006 model year

diesel-fueled engines sold to transit agencies on the diesel path. This language was

negotiated at the January 24, 2000, hearing and included in modifications presented

to the Board at that time. Thus, it was clearly approved by the Board.

Regarding the commenter’s recommendation for regulatory modification, the ARB

agrees with the recommendation and has clarified its intent by adding language to

the regulatory text to provide transit fleets on the alternative-fuel path the same

flexibility as transit fleets on the diesel path by allowing such fleets to conduct an

alternative NOx strategy in lieu of purchasing diesel-fueled urban buses with engines

meeting the emission standards for 2004 through 2006 model year diesel-fueled

engines. It was the ARB’s intent to make the alternative NOx strategy provision

equally available to transit agencies on both the diesel and alternative-fuel paths; the

regulation now makes this clear. (Please also see Agency Response to Comment

109.)

109. Comment: While the modified regulation includes the EMA’s recommendation

for an alternative NOx strategy that may be used by transit agencies on the diesel

path in lieu of purchasing diesel-fueled engines meeting the 2004 through 2006

model year standards, it still includes a provision that engine manufacturers produce

diesel-fueled engines meeting those standards for an incredibly small market —

transit agencies on the alternative-fuel path. If engine manufacturers did not or

could not produce such a specialized engine, the regulation penalizes transit

agencies on the alternative-fuel path that need to purchase diesel-fueled engines for

articulated buses or other specialty applications not served by alternative-fuel

engines. The ARB should modify paragraph (c)(5) in section 1956.2, title 13, CCR,

to eliminate the reference to the more stringent emission standards applicable to

2004 through 2006 diesel-fueled engines, thus allowing transit agencies on the

alternative-fuel path to purchase diesel-fueled engines meeting the existing 2.5

g/bhp-hr NOx + NMHC emission standard. (EMA)

Agency Response: The Board made it clear that the 2004 through 2006 standards

for diesel-fueled engines are a crucial element of this regulation and are intended to

stimulate technology advances that, with further refinements, will enable other

heavy-duty vehicles to meet lower emission standards proposed for 2007. When the

Board approved the inclusion of an alternative NOx strategy for transit agencies as a

compliance option at the request of the EMA and the California Transit Association,

it was not the Board’s intent to entirely eliminate the emission standards for 2004

through 2006 model year diesel-fueled engines. These emission standards are still

in force.
66

However, the ARB has always agreed that compliance flexibility is necessary for

transit fleets on the alternative-fuel path that would normally purchase only a small

percentage of diesel-fueled urban buses in the 2004 through 2006 timeframe to

meet special service needs. Therefore, the ARB has explicitly clarified the

regulation to allow transit fleets on the alternative-fuel path to utilize an alternative

NOx strategy, just as transit fleets on the diesel path are allowed to do. Because

this amendment more clearly effectuates the Board’s intent, it is a nonsubstantive

change. (Please also see Agency Response to Comment 108.)

110. Comment: Paragraph (d)(7)(C) in section 1956.2, title 13, CCR, states that the

Executive Officer can only approve a transit agency’s application for the alternative

NOx strategy if transit agencies “have demonstrated, or are contractually committed

to demonstrate, advanced NOx aftertreatment technology.” This is a totally new

concept, and to our recollection, was never discussed by interested parties and the

staff, and certainly not at the Board level. The alternative NOx strategy option

should remain as flexible as possible and should not limit the program to specific

technologies or approaches. This provision should be eliminated. (CTranA)

Agency Response: The provision to require a NOx aftertreatment technology

demonstration as a component of an alternative NOx strategy was a commitment

made by the EMA as a condition of including the alternative NOx strategy in the

regulation. The technology demonstration is a criterion for Executive Officer

approval of a transit agency’s alternative NOx strategy; it is not a prescribed method

for achieving reductions through an alternative NOx strategy. The technology

demonstration concept was included in the staff’s presentation to the Board on

February 24, 2000. The full regulatory text of this specific condition for receiving

approval to conduct an alternative NOx strategy states, “The Executive Officer finds

that transit agencies, after consulting with the EMA, have demonstrated, or are

contractually committed to demonstrate, advanced NOx aftertreatment technology.

It is interesting to note that the EMA did not comment negatively regarding this

specific provision during the supplemental 15-day comment period.

The purpose of this provision is to have transit agencies demonstrate the advanced

NOx aftertreatment devices that are necessary for meeting the 2004 emission

standards for diesel-fueled urban bus engines, and for establishing a technical basis

for more stringent emission standards to be proposed for the 2007 timeframe for

heavy-duty diesel trucks. While the demonstrations are limited to advanced NOx

aftertreatment technology, the alternative NOx strategies that may be implemented

by transit agencies are not limited to a specific technology or approach, such as the

use of aftertreatment. The regulation does not prescribe the technology or approach

that a transit agency must use when implementing an alternative NOx strategy, only

specific criteria that must be met should any transit agency opt to conduct one.

111. Comment: Paragraph (d)(7)(B) in section 1956.2, title 13, CCR, states that the

alternative NOx strategy option must demonstrate “NOx emissions benefits through
67

2015.” The Board’s clear direction was that any optional program must not result in

one more ounce of emissions than the 2004 through 2006 model year emission

standards would otherwise allow, over the entire life of the rule. Therefore, the

paragraph should properly read “NOx emissions benefits by 2015.” (CTranA)

Agency Response: The ARB believes the regulatory language specifying NOx

emission benefits through 2015 is correct. The provisions of the fleet rule contained

in section 1956.2 extend from the effective date of the regulation through 2015, as

stated on page 16 of the Staff Report. Modifying the regulatory language to read

“NOx emissions benefits by 2015” would only provide emission benefits through the

year 2014.

U. PM Retrofit Requirements

112. Comment: The regulation provides an exemption from the PM retrofit

requirements for transit agencies with fewer than 20 buses. However, the

exemption applies only if the fleet is located in an ozone (not PM) attainment area.

Since this provision relates to a potential exemption from a PM retrofit requirement,

the requirement relating to ozone attainment makes no sense and should be

deleted. Small fleets should be afforded PM retrofit flexibility irrespective of whether

they are located in an ozone attainment area. (EMA)

Agency Response: The concept of a compliance delay for small transit agencies in

ozone attainment areas was in the regulation as originally proposed in the Staff

Report on December 10, 1999. This particular comment relates to language that

was added to further clarify the ARB’s intent. The ARB certainly understands the

difference between ozone and PM; the ARB provided PM retrofit flexibility to small

transit agencies in federal one-hour ozone attainment areas because these are most

likely rural regions that may have difficulty obtaining the low-sulfur diesel fuel (due to

price and the logistics of fuel distribution) necessary to comply with the PM retrofit

requirements. It is also important to note that these small transit agencies are not

given an exemption, as the commenter states, but a delay in complying with the

requirements until January 1, 2007. The ARB expects that a national low-sulfur

diesel fuel requirement will be in effect by January 2007, thus minimizing price and

supply disruptions in California and enabling the small transit agencies in ozone

attainment areas to meet their compliance deadlines.

The U.S. EPA’s Notice of Proposed Rulemaking for Heavy-Duty Engines and

Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements (Federal

Register, Vol. 65, No. 107, June 2, 2000, pp. 35430 - 35545) includes a proposal to

limit the sulfur content in diesel fuel to 15 ppm by weight, which is the same

requirement contained in this rulemaking. Board Resolution 00-2 directs the

Executive Officer to work closely with the U.S. EPA in its development of a new

national diesel fuel specification, and to reevaluate the low-sulfur diesel fuel

requirement in this regulation, if necessary, soon after the U.S. EPA adopts its

national fuel specification.
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113. Comment: The regulation specifies the procedures transit agencies must use to

obtain a one-year delay in complying with the PM retrofit requirements when a

retrofit device for a particular engine is not available to perform the retrofit within six

months of the compliance deadlines. If the conditions leading to approval of the

one-year delay should continue beyond the initial year, the Executive Officer should

have the discretion to extend or renew the delay. Paragraph (f)(6) in section 1956.2,

title 13, CCR, should be modified accordingly. (EMA)

Agency Response: The ARB agrees that if the conditions leading to approval of the

one-year delay continue beyond the initial year, the Executive Officer should have

the discretion to extend or renew the delay. The current regulatory language does

not contain any provision that limits the Executive Officer’s authority to perform such

an action; hence, no change to the regulation is necessary.

V. PM Retrofit Certification Procedures

114. Comment: The modified regulation includes a procedure for certifying PM retrofit

devices, incorporated by reference in title 13, section 1956.2 (f)(7), for use in

meeting the regulation’s PM retrofit requirements. However, there has been no

dialogue, workshops, public hearing, or meaningful opportunity to review and

comment on the procedures by engine manufacturers, aftertreatment device

manufacturers, and other interested parties. Indeed, the proposed procedures are

not even limited to transit buses and appear to apply to all on-road heavy-duty diesel

engines. (EMA)

Agency Response: The ARB disagrees with this comment. The Notice of Public

Hearing made available to the public on December 10, 1999, clearly stated that the

proposal required the use of PM retrofit devices with an efficiency of at least 85

percent. The public was clearly on notice that retrofit device certification procedures

would be subject to discussion during the hearing process. The specific procedures

for certifying PM retrofit devices were incorporated into the regulation after the

original proposal contained in the Staff Report was released and made available to

the public on December 10, 1999. Representatives of the EMA, along with

representatives of the aftertreatment industry who will be manufacturing and

certifying the devices, received and discussed the proposed certification procedures

with the ARB staff prior to the January 27, 2000, hearing. At that hearing, the ARB

staff presented the certification procedures to the Board as a regulatory modification

that amplified the previously noticed PM retrofit device requirement. This action was

supported by the EMA, who urged the Board to accept the procedures as part of the

staff’s regulatory modifications. (For EMA’s support testimony, see page 317 of

Hearing Transcript.)

In accordance with section 11346.8(c) of the Government Code, the regulatory

modifications presented to the Board at the January and February public hearings,
69

and subsequently approved at the February hearing, including the PM retrofit

certification procedures, were made available to the public for a supplemental

15-day public comment period beginning August 16, 2000. With the exception of the

EMA’s comments, the ARB did not receive any negative comments concerning the

procedures, and may assume that those who will be manufacturing the devices are

comfortable with the requirement.

Regarding the commenter’s concern that the PM retrofit certification procedures are

not limited to urban buses, the only California regulatory requirements to perform PM

retrofits are those contained in this rulemaking for urban bus engines.

Other classes of heavy-duty diesel engines are not required by any regulation to

undergo retrofits for PM control; therefore, the PM retrofit certification procedures

are limited to urban bus engines. Regulatory retrofit requirements for other heavyduty engines will be addressed through the traditional rulemaking process in the

future and will be subject to full public comment. (Please also see Agency

Responses to Comment 115 and 116.)

115. Comment: The proposed PM retrofit certification procedures are brand new; are

not sufficiently related to the originally proposed rule so as to provide adequate

notice for public comment; were not explicitly directed to be a part of the 15-day

Notice by the Board’s action on February 24, 2000; and, if adopted, would impose

significant costs, create unnecessary hardships, and would likely stifle the use of

effective retrofit technologies. The ARB should revise and re-propose for public

comment an appropriate certification procedure for PM retrofits. (EMA)

Agency Response: The ARB disagrees with this comment. The Notice of Public

Hearing made available to the public on December 10, 1999, clearly stated that the

proposal required the use of PM retrofit devices with an efficiency of at least 85

percent. The proposed PM retrofit certification procedures included in the 15-day

Notice were presented to the Board as a regulatory modification to the originally

proposed text as early as the January hearing, at which time the commenter

provided support testimony urging the Board to adopt the certification procedures.

(For EMA’s support testimony, see page 317 of Hearing Transcript.) In response to

public comments received at the January hearing, the Board Chairman asked the

staff to provide further information at the continuation of the hearing on those issues

that had generated extensive discussion at the January hearing. The PM retrofit

certification procedures were not among the issues that had engendered substantial

comment and on which the Board sought further staff analysis, although EMA and all

of the others who participated in the hearing had been given ample opportunity to

comment and raise their concerns.

The Board’s approval of the regulation at the February hearing included the

modifications that had been previously discussed at the January hearing; among

them were the PM retrofit certification procedures. Pursuant to section 11346.8(c) of

the Government Code, the regulatory modifications, including the PM retrofit

certification procedures, were made available to the public for a supplemental
70

15-day public comment period beginning August 16, 2000. With the exception of the

EMA’s comments, the ARB did not receive any negative comments concerning the

certification procedures. The EMA had sufficient opportunity during the rule

adoption process to address the PM retrofit certification procedures had it chosen to

do so.

Regarding the commenter’s second concern that the retrofit certification procedures

would impose significant costs, create unnecessary hardships, and would likely stifle

the use of effective retrofit technologies, it must be pointed out that the commenter is

not the party that would suffer alleged hardships imposed by the certification

procedures. The aftertreatment industry would develop, manufacturer, and certify

the retrofit devices for sale in California. The leading diesel particulate trap

manufacturers have already stated their intent to certify retrofit devices under the

ARB’s proposed certification procedures. The ARB takes particular exception to the

comment that the proposed procedures would stifle the use of effective PM retrofit

technologies. Effective retrofit technologies are currently available for commercial

use; the ability to use these technologies will be facilitated and enhanced by the

imposition of certification procedures that will ensure that the retrofit devices are

durable, achieve claimed emission reductions, and are warranted for emissions and

mechanical performance. The ARB believes the adoption of the certification

procedures will encourage the use of effective retrofit technologies.

116. Comment: The scope of appropriate PM retrofit device certification procedures

must be addressed. If the scope is limited to urban buses, the provisions that

require a 0.01 g/bhp-hr or 85 percent reduction performance criteria are acceptable.

If, however, the procedures apply to all heavy-duty on-road diesel engines, the ARB

should not require the 0.01 or 85 percent acceptability criteria. There may be robust

retrofit technologies that, while unable to achieve an 85 percent reduction, still

achieve significant reductions in PM. These retrofit technologies should not

automatically be precluded. (EMA)

Agency Response: The only California regulatory requirements, at this time, to

perform PM retrofits are those contained in this rulemaking for urban bus engines.

Therefore, the procedures are currently limited to urban bus engines.

Retrofit devices for use on other heavy-duty vehicle duty applications could be

subject to the retrofit procedures in the future as part of non-regulatory incentive

programs (e.g., the Lower Emission School Bus Program) that provide public monies

to achieve necessary emission reductions. Regulatory retrofit requirements for other

classes of heavy-duty engines will be addressed through the traditional rulemaking

process in the future, and if other heavy-duty engines are made subject to PM

retrofit requirements after full public discussion, appropriate changes could be

incorporated into the procedures at that time. (Please also see Agency Response to

Comment 114.)
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117. Comment: The use of a chassis test should not be included in PM retrofit

certification procedures until there are acceptable, accurate, and repeatable chassis

test procedures that can be correlated with the Federal Test Procedure. (EMA)

Agency Response: The Federal Test Procedure (FTP) is a prescribed set of engine

operation test points conducted in the laboratory intended to represent the typical

operation of a heavy-duty vehicle in-use, and is the standard test cycle for engine

certification. In practice, however, the FTP is not, in all instances, representative of

actual operating parameters, which may vary significantly between different heavyduty vehicle applications (e.g., a line-haul haul truck versus an urban transit bus).

Because a vehicle’s operating parameters (e.g., vehicle speed, engine load, exhaust

temperature) are critical to demonstrating the emissions performance and system

durability for retrofit devices, the aftertreatment manufacturers sought the flexibility to

use a chassis test cycle that may better represent the operating parameters of an

urban transit bus. Hence, the ARB believes it is appropriate for the PM retrofit

procedures to include the option to use a chassis test cycle in lieu of the FTP, if

approved by the Executive Officer.

118. Comment: The PM retrofit certification procedures should not include a

requirement for two emission tests. There is no need for two tests, nor do the

proposed procedures explain what happens if the two tests produce different results.

(EMA)

Agency Response: The purpose of the requirement to perform at least two emission

tests is to demonstrate repeatability in emissions performance. The ARB will

evaluate all test data, and if significant test-to-test variability occurs, may request

that the applicant for retrofit device certification perform additional emission tests.

W. Compliance Issues

119. Comment: Since the Board approval of the regulation in February 2000, several

transit agencies have expressed uncertainty in evaluating the two compliance paths

without the benefit of the final regulatory language that includes all the modifications

made subsequent to the regulation as originally proposed on December 10, 1999.

While the content of the modified regulation is now known and it is acknowledged

that most transit agencies had a fair idea about the contents of the modified

regulation, based on the previously published staff report and the actions of the

Board on February 24, 2000, there is still uncertainty on how the modified regulation

would reflect the Board’s decision to include an alternative NOx strategy provision.

Therefore, the ARB should allow transit agencies a six month delay in the

requirement to choose a compliance path by January 31, 2001. (CTranA, EMA)

Agency Response: The ARB is fully committed to working with the California Transit

Association and its individual member agencies in achieving successful regulation

implementation and compliance. As such, the ARB staff is available to meet with

individual transit agencies to discuss regulation requirements and how their
72

respective fleets may be affected. That said, the ARB does not believe there is

sufficient cause to approve the request for a delay. The regulation’s reporting

requirements, including the requirement to choose a compliance path by

January 31, 2001, were approved by the Board at the February 24, 2000, public

hearing. The ARB staff is required to implement the decisions of the Board; it

cannot modify them at its own discretion. Furthermore, the alternative NOx strategy

provision was added, at the request of the EMA and the California Transit

Association, as a compliance option, not as a requirement, designed to provide

flexibility to transit agencies that purchase diesel-fueled buses in the 2004 through

2006 timeframe. The regulation does not prescribe the strategies that a transit

agency may use when exercising this option, only specific criteria that must be met

should any transit agency opt to conduct an alternative NOx strategy. It is

somewhat ironic that the commenters are basing their request for a delay in

choosing a compliance path on a provision that was included in the modified

regulation at their request.

120. Comment: Paragraph (a)(2) in section 1956.4, title 13, CCR, specifies the

procedures transit agencies on the alternative fuel path must use in requesting a

deviation from the 85 percent purchase requirement. The regulation should also

require the Executive Officer to respond to the request within a reasonable

timeframe, for example, within 30 days. (CTranA, EMA)

Agency Response: The Executive Officer will not impede transit agencies’

compliance with the regulation and will therefore respond to all requests in a timely

manner, whether or not specific regulatory language exists directing him to do so.

121. Comment: Paragraph (f)(2) in section 1956.4, title 13, CCR, specifies the

procedures transit agencies must use in requesting a deviation from the 15 percent

zero-emission bus purchase requirement. The regulation should also require the

Executive Officer to respond to the request within a reasonable timeframe, for

example, within 30 days. (CTranA, EMA)

Agency Response: The Executive Officer will not impede transit agencies’

compliance with the regulation and will therefore respond to all requests in a timely

manner, whether or not specific regulatory language exists directing him to do so.

122. Comment: Paragraphs (d)(2)(A) and (d)(2)(B) in section 1956.4, title 13, CCR

set dates for transit agencies to submit reports on compliance with the regulation’s

PM retrofit requirements. As provided for in paragraphs (f)(1) and (f)(2) of section

1956.2, some small transit agencies are allowed a delay in complying with the PM

retrofit requirements. The reporting dates specified in section 1956.4 do not account

for those transit agencies that are allowed to delay compliance. (EMA)

Agency Response: It is correct that the reporting deadlines to demonstrate

compliance with the PM retrofit requirements are based on a “conventional” retrofit

schedule. The ARB will coordinate with the small transit agencies in ozone
73

attainment areas that are allowed a delay in compliance to determine appropriate

reporting deadlines commensurate with the approved delays.

123. Comment: Paragraph (d)(4) in section 1956.2, title 13, CCR, states that “transit

agencies on the diesel path shall not purchase any diesel-fueled, dual-fuel, bi-fuel,

or alternative-fuel buses with 2004 – 2006 model year engines certified to emissions

levels in excess of those specified in (a)(11) of section 1956.1, title 13, CCR.” For

clarity, the words “unless exempted under the provisions of paragraph (d)(7) of this

section” should be appended to this paragraph. (EMA)

Agency Response: The ARB agrees with this comment and has incorporated the

recommended modification as a change without regulatory effect.

124. Comment: Paragraph (f)(2) in section 1956.2, title 13, CCR, pertains to PM

retrofit requirements for 1991 through 1995 urban bus engines. To improve clarity,

the reference to “interim requirements” should be modified to state “the interim

requirements described in subsections (A) and (B) below.” (EMA)

Agency Response: The ARB agrees with this comment and has incorporated the

recommended modification as a change without regulatory effect.

125. Comment: In paragraph (c)(4)(B) in section 1956.3, title 13, CCR, it appears the

words “in service” have been omitted from the language describing requirements for

earning credits for the early introduction of zero-emission buses. The words “in

service” should be included. (EMA)

Agency Response: The ARB agrees with this comment and has incorporated the

recommended modification as a change without regulatory effect.

X. Articulated Urban Buses

126. Comment: During rule development, the California Transit Association believed

that articulated buses, having extraordinary engine horsepower requirements, would

be exempted from the requirements of the regulation. The ARB should confirm this.

(CTranA)

Agency Response: The regulation does not exempt articulated buses from the

requirements of the regulation, but does provide flexibility to those transit agencies

that have service needs best met through the use of articulated buses. The ARB

acknowledges the unique operating parameters of articulated buses that can now

only be met with diesel-fueled urban bus engines. For this reason, the regulation

was specifically crafted to accommodate transit agencies on the alternative-fuel path

by allowing up to15 percent of new bus purchases on the alternative-fuel path to be

diesel buses. The diesel-fueled engines in those buses, however, must still meet

the applicable emission standards, specified in section 1956.1, title 13, CCR, and

must comply with the fleet rule components specified in section 1956.2.
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Y. Harmonization with U.S. EPA’s 2007 Emission Standards

127. Comment: The ARB’s regulation sets emission standards for 2007 and

subsequent model year urban bus engines. There are some significant differences

between the ARB’s 2007 emission standards and the heavy-duty engine and vehicle

standards proposed by the U.S. EPA for the same timeframe. (Federal Register, Vol.

65, No. 107, June 2, 2000, pp. 35430 – 35545.) Specifically, the standards for

NMHC, CO, and formaldehyde are different. In addition, the U.S. EPA is proposing

to phase in its standards, while the ARB’s standards take full effect in 2007. The

ARB should officially indicate that it will attempt to harmonize its standards with

those in the U.S. EPA’s proposal. (CTranA)

Agency Response: While this comment is not germane to the modifications

contained in the Notice of Public Availability of Modified Text and Supporting

Documents, the ARB will respond.

The emission standards proposed by staff and adopted by the Board for 2007 and

subsequent model year urban bus engines are essential to achieving crucial

reductions in ozone-precursor NOx emissions and toxic PM emissions in California.

Throughout the course of this rulemaking, the ARB stated its intent to harmonize, to

the extent possible, California’s 2007 and subsequent model year urban bus engine

standards with the heavy-duty engine standards ultimately adopted by the U.S. EPA

for the same timeframe. The U.S. EPA only recently issued its Notice of Proposed

Rulemaking for Heavy-Duty Engines and Vehicle Standards and Highway Diesel

Fuel Sulfur Control Requirements (Federal Register, Vol. 65, No. 107, June 2, 2000,

pp. 35430 - 35545). Once the U.S. EPA’s rulemaking is finalized, the ARB staff will

consider modifications to California’s 2007 standards for urban bus engines, if

necessary.

128. Comment: Throughout development of this regulation, the EMA stressed the

need for the ARB’s regulation to harmonize with the U.S. EPA’s emission standards

for 2007 and subsequent model year engines used in trucks and buses. The

U.S. EPA has now published its Notice of Proposed Rulemaking, and its proposed

standards for NMHC, CO, and formaldehyde are somewhat different that the ARB’s

emission standards for 2007 and subsequent model year bus engines. The ARB

must modify the provisions in paragraph (a)(12) of section 1956.1, title 13, CCR, to

assure harmonization with the standards U.S. EPA ultimately finalizes. The ARB

should delete the numerical limits in paragraph (a)(12) and insert a provision

incorporating by reference whatever standards the U.S. EPA ultimately finalizes in

the Code of Federal Regulations. (EMA)

Agency Response: Again, while this comment is not germane to the modifications

contained in the Notice of Public Availability of Modified Text and Supporting

Documents, the ARB will respond.
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In response to the commenter’s specific suggestion for modifying the ARB’s

regulation, the ARB is required by law to include the title and date of issuance of the

document containing another agency’s rule or test procedure referenced within an

ARB regulation; the ARB cannot include an open-ended provision incorporating a

standard not yet adopted by the U.S. EPA. (See title 1, section 20(c)(4), CCR.)

Once the U.S. EPA finalizes its rulemaking for emission standards for 2007 and

subsequent model year heavy-duty vehicles and engines, the ARB staff will consider

modifications to California’s 2007 standards for urban bus engines, if necessary.

(Please also see Agency Response to Comment 127.)

Z. Miscellaneous Comments

129. Comment: To clarify the ARB’s intent and provide consistency with language in

the remainder of the paragraph, paragraph (e) in section 1956.2, title 13, CCR,

should be changed to refer to engines in the “active fleet”, rather than “engines in

use.” (CTranA)

Agency Response: The ARB agrees that this comment represents the Board’s

intent and has modified language in paragraph (e) of section 1956.2, title 13, CCR,

regarding the fleet NOx average requirement to read, “beginning October 1, 2002,

no transit agency shall own, operate, or lease an active fleet of urban buses with

average NOx emissions in excess of 4.8 g/bhp-hr, based on the engine certification

standards of the engines in the active fleet.” This is a change without regulatory

effect.

130. Comment: Since paragraph (b)(2) in section 1956.2, title 13, CCR, defines

“active fleet”, it is redundant to include the language “of the engines in use” in

paragraph (e) referring to the NOx fleet average requirements. This language

should be deleted. In addition, it is likely that the active fleet will contain engines

with improved emission performance from their original certified configuration.

Those upgraded engine emission performance characteristics should also be

included in the fleet average. (EMA)

Agency Response: The ARB has modified the regulatory language to refer to

certification standards of engines in the active fleet, rather than the certification

standards “of the engines in use.” This is a change without regulatory effect. The

ARB intends for the NOx fleet average to be calculated based on either an engine’s

original certification standard, the certification standard of a new engine placed in an

older bus chassis (i.e., a bus repower), or the certification standard of an engine

retrofitted with an ARB-approved NOx retrofit system, whichever is applicable. This

methodology will account for those engines that have improved their emission

performance characteristics from their original certified configuration. (Please also

see Agency Response to Comment 129.)
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THE FOLLOWING COMMENTS ARE NOT GERMANE TO THE MODIFICATIONS

CONTAINED IN THE NOTICE OF PUBLIC AVAILABILITY OF MODIFIED TEXT AND

SUPPORTING DOCUMENTS. THE ARB IS RESPONDING IN ORDER TO PROVIDE

CLARITY AND IMPROVE UNDERSTANDING OF THE REGULATION

131. Comment: Paragraph (e)(2) in section 1956.2, title 13, CCR, states that transit

agencies may use ARB-certified NOx retrofit systems to comply with the NOx fleet

average requirement. There are currently no ARB procedures for certifying NOx

retrofit systems. Therefore, the ARB should propose a procedure and allow transit

agencies and industry to comment. (CTranA, EMA)

Agency Response: The ARB does have retrofit certification procedures applicable

to heavy-duty vehicles, including urban buses, that could be used to certify NOx

retrofit systems. These procedures are contained in the document entitled

“California Certification and Installation Procedures for Alternative Fuel Retrofit

Systems for Motor Vehicles Certified for 1994 and Subsequent Model Years,”

adopted March 11, 1993, and last amended on April 26, 1995. This document is

incorporated by reference in sections 2030 and 2031, title 13, CCR,. The ARB

intends to develop additional procedures more specifically designed for the

certification of NOx aftertreatment devices, a technology relatively new in mobile

source applications. At that time, the procedures for notice and hearing in the

Administrative Procedure Act will be utilized and full public participation will be

encouraged.

132. Comment: Paragraph (f) in section 1956.2, title 13, CCR, includes the

requirement that agencies operate their diesel buses on diesel fuel with a maximum

sulfur content of 15 ppm by weight. We support this requirement and believe it to be

so important that we request the regulation to specifically require the Executive

Officer to report regularly to the Board on the availability and cost of low-sulfur diesel

fuel. (CTranA)

Agency Response: The ARB staff agrees that it is important to regularly update the

Board on implementation issues associated with the regulation’s requirement for

low-sulfur diesel fuel. While the regulation contains no specific provision requiring

updates to the Board on low-sulfur diesel fuel issues, Board Resolution 00-2 directs

the Executive Officer to work with transit agencies during implementation of the

regulation and to report back to the Board on the status of implementation. It is

reasonable to expect that any issues concerning low-sulfur diesel fuel would be

reported to the Board through this process.

133. Comment: Paragraph (a) in section 1956.3, title 13, CCR, defines a zeroemission bus as one that the Executive Officer has certified as a zero-emission bus

based on its ability to meet specific criteria described in the regulatory language.

We are unaware of any procedure for the Executive Officer to certify an urban bus,

as opposed to an urban bus engine. Therefore, the ARB should specify the details

of such a procedure and allow transit agencies and industry to comment; or,
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alternatively, clarify that section 1956.3 applies to a certified engine in a bus.

(CTranA, EMA)

Agency Response: The commenters are correct that conventional certification

procedures apply to urban bus engines, and not the entire bus. The ARB will be

working closely with affected industries, organizations, and individuals to develop an

appropriate certification procedure for zero-emission urban buses in time for the

regulation’s zero-emission purchase requirements beginning in 2008. Any proposed

certification procedure will be subject to the ARB’s traditional rulemaking process

involving full public comment, pursuant to the Administrative Procedure Act.

134. Comment: Paragraph (a) in section 1956.3, title 13, CCR, defines a zeroemission bus as an Executive Officer certified urban bus that produces zero exhaust

emissions of “any” criteria pollutant. To improve clarity, the word “any” should be

replaced by the word “all.” (EMA)

Agency Response: For clarification, the ARB interprets “any” to mean “all” criteria

pollutants.

135. Comment: Paragraph (a) in section 1956.1, title 13, CCR, includes a general

reference that the numerical exhaust emission standards are expressed in units of

g/bhp-hr. However, in some cases the regulatory text includes the units with the

numerical standards, while in other cases it does not. The general reference to

g/bhp-hr should be deleted and the numerical exhaust emission standards should

always be expressed with a specific unit of measurement (g/bhp-hr) attached.

(EMA)

Agency Response: The ARB agrees with this comment and has incorporated the

recommended modification for clarity and specificity. This is a change without

regulatory effect.

136. Comment: Paragraph (b)(3) in section 1956.2, title 13, CCR, defines “transit

agency.” Given that section 1956.2 applies to transit agencies, it would add clarity to

retitle it “Fleet Rule for Transit Agencies.” (EMA)

Agency Response: The ARB agrees with this comment and has incorporated the

recommended modification as a change without regulatory effect.

137. Comment: To be consistent with the regulation’s intent, paragraph (c)(1)

regarding alternative-fuel path requirements in section 1956.2, title 13, CCR, should

state “upon approval of the regulation, and through model year 2015, at least 85

percent of all urban buses purchased or leased each year must be alternative-fuel

buses.” (EMA)

Agency Response: The ARB agrees with this comment and has incorporated the

recommended modification as a change without regulatory effect.
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138. Comment: Paragraph (c)(3) in section 1956.2, title 13, CCR, applies to transit

agencies on the alternative-fuel path and states “beginning October 1, 2000, only

engines certified to an optional PM standard of 0.03 g/bhp-hr or lower shall be

purchased when making new bus purchases.” Paragraph (a)(8) in section 1956.1,

title 13, CCR, outlines the optional, reduced-emission standards applicable for

alternative-fuel engines during the period of October 2002 to 2006. According to

section 1956.1, certification to an optional, reduced-emission PM standard must be

done in conjunction with certification to an optional, reduced-emission NOx + NMHC

standard, while paragraph (c)(3) in section 1956.2 only explicitly imposes a

requirement to certify to a low PM standard (0.03 g/bhp-hr or lower). The ARB

should clarify its intent. (EMA)

Agency Response: Section 1956.1, title 13, CCR, specifies emission standards for

urban bus engines and is applicable to the manufacturers of those engines. This

section includes optional, reduced-emission NOx + NMHC standards to which

engine manufacturers may choose to certify their engines. As part of this

rulemaking, the ARB staff proposed, and the Board approved, that when certifying to

one of the optional, reduced-emission NOx + NMHC standards, an alternative-fuel

engine must also certify to an optional, reduced-emission PM standard of

0.03 g/bhp-hr or lower, beginning with the 2002 model year produced on or after

October 1, 2002. The optional NOx + NMHC standards were existing standards;

only the optional PM standards were proposed in the regulation as contained in the

Staff Report made available to the public on December 10,1999.

Section 1956.2, title 13, CCR, contains fleet rule components and is applicable to

transit agencies. Paragraph (c)(3) in this section specifies, as one of the

requirements of the alternative-fuel path, that transit agencies shall only purchase

urban buses with alternative-fuel engines meeting a 0.03 g/bhp-hr or lower PM

standard when making new bus purchases beginning October 1, 2002. For such

transit agencies, the 0.03 g/bhp-hr PM standard is not optional; it is a requirement.

However, the alternative-fuel path does not require transit agencies to purchase

buses certified to any NOx + NMHC standard other than the base standard in effect

in October 2002 (2.5 g/bhp-hr). In theory, this means that beginning

October 1, 2002, a transit agency could purchase a bus with an alternative-fuel

engine certified to a 2.5 g/bhp-hr NOx + NMHC standard (the existing mandatory

NOx + NMHC standard) and a 0.03 g/bhp-hr PM standard. In practice, however, the

ARB expects that transit agencies will purchase alternative-fuel engines certified to

an optional, reduced-emission NOx + NMHC standard (beginning at 1.8 g/bhp-hr as

specified in paragraph (a)(8) of section 1956.1) and the 0.03 g/bhp-hr or lower PM

standard in order to obtain state incentive funding to pay for the incremental cost of

more expensive alternative-fuel engines.

Attachment A: Form Letter 1 (FL1) E-Mail Commenters

Attachment B: Form Letter 2 (FL2) Commenters