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State of California

AIR RESOURCES BOARD

Final Statement of Reasons for Rulemaking,

Including Summary of Comments and Agency Response

PUBLIC HEARING TO CONSIDER THE ADOPTION OF THE PROPOSED

Modifications to the Exhaust Emission Standards and Test Procedures - 1985 and

Subsequent Model Heavy-Duty Urban Bus Engines and Vehicles, the Fleet Rule for Transit

Agencies, and the Zero-Emission Bus (ZEB) Demonstration Project

Public Hearing Date: June 24, 2004

Agenda Item No.: 04-6-4

I. INTRODUCTION

On May 7, 2004 the Air Resource Board (ARB or the Board) published a Notice of Public

Hearing that described the proposed modifications to the regulations described therein and

invited public comment on the proposal. The Staff Report: Initial Statement of Reasons for

Rulemaking ("Staff Report"), titled "Proposed Modifications to the Exhaust Emission

Standards and Test Procedures - 1985 and Subsequent Model Heavy-Duty Urban Bus

Engines and Vehicles, the Fleet Rule for Transit Agencies, and the Zero-Emission Bus

Demonstration Project," was released on May 7, 2004. This document included an

underline/strikeout version of the regulatory text and was made available to the public upon

request as required by Government Code §11346.2, and is incorporated by reference

herein.

At the public hearing held on June 24, 2004, the Board considered the proposed regulations

and received written or oral comments on the regulatory proposal. At the conclusion of the

hearing, the Board adopted the regulation as initially proposed by staff without further

modifications.

Background. At the public hearing in February 2000, the Board confirmed its continued

commitment toward improving emissions from public transportation by establishing a new

fleet rule for transit agencies and more stringent emission standards for manufacturers of

new urban bus engines and vehicles. The multi-faceted regulations were designed to

reduce oxides of nitrogen, or NOx, an ozone precursor, and particulate matter, or PM, by

setting fleet emission reduction requirements that encouraged transit agencies to purchase

cleaner buses and retrofit their existing buses. The rule promoted advanced technologies

by adopting a zero-emission bus (ZEB) demonstration project and ZEB acquisition

requirements applicable to larger transit agencies.

Hybrid-Electric Buses

On January 1, 2004, the California diesel urban bus engine exhaust emission standard

dropped to 0.5 grams per brake horsepower-hour (g/bhp-hr) NOx and no diesel engine

manufacturer has certified or plans to certify an engine to this engine standard. Thus, no

diesel hybrid-electric system manufacturer can certify its product for California and no transit

agency can purchase new diesel buses to replace older buses or augment its fleet. Hybrid-
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electric buses (HEB) are technologically able to achieve lower emissions and better fuel

economy than an equivalently-sized diesel bus. Since ARB’s adoption of the interim

certification procedure for hybrid-electric vehicles in the urban bus and heavy-duty vehicle

classes in October 2002, only one 2004 model year HEB, which is gasoline-fueled, has

been California-certified for sale and purchase.

With only a single gasoline HEB certified for purchase in California, the transit agencies on

the diesel path cannot purchase new buses without converting to alternative fuels. Most of

the transit agencies on the diesel path are limited by a lack of infrastructure and are not able

to purchase alternative fuel buses without investing in a fueling station. In an effort to

promote the turnover of the oldest, dirtiest diesel engines with newer, cleaner buses, the

Board agreed that transit agencies on the diesel path should be provided with the cleanest,

most aggressive diesel choice available, which currently is diesel HEB technology.

The current diesel HEBs do not meet the 0.5 g/bhp-hr NOx standard; therefore, they are

prohibited for sale in California. A standard for diesel HEBs for the 2004-2006 MYs is

needed to bring innovative technology, at the lowest technically feasible emission standard,

to California’s marketplace. From 2004 through 2006 transit agencies on the diesel path will

be allowed to purchase diesel HEBs certified to 1.8 g/bhp-hr NOx, provided they offset the

difference between 1.8 g/bhp-hr NOx and the current diesel urban bus engine standard of

0.5 g/bhp-hr NOx. Offsets can be obtained through installing a retrofit device that reduces

NOx emissions or repowering to a lower emitting diesel or alternative-fuel engine. Thus, the

Board maintains a fuel neutral position while requiring that all transit agencies, regardless of

fuel path, comply with the 0.5 g/bhp-hr NOx standard.

Zero-Emission Bus Demonstration

In the original rulemaking imposing the zero-emission bus (ZEB) requirements, the Board

anticipated that fuel cells would be developed and deployed in transit buses initially;

however, light duty vehicle applications have been the focus of fuel cell providers, resulting

in heavy-duty fuel cells that are both more expensive and behind schedule. Transit

agencies have been diligent in attempting to comply with the original fuel cell bus

demonstration project requirements and timetable; however, the projects are behind

schedule, and the transit agencies will not have the number of concurrent, in-use fuel cell

buses in revenue service in time to meet the regulatory deadline. In order to reflect the cost

and expected availability of the advanced technology required for the delivery of fuel-cell

buses, a revised start date and a reduction in the number of buses required for the ZEB

demonstration project are needed.

A complete description of the proposed modifications and their rationale is contained in the

Staff Report. This document and the May 7, 2004, Notice are incorporated herein by

reference. This Final Statement of Reasons summarizes the Staff Report by identifying and

explaining the regulatory amendments. This Final Statement of Reasons also contains a

summary of the comments the Board received on the proposed modifications during the

formal rulemaking process and ARB’s responses to those comments.

The proposed modifications will appear in title 13, California Code of Regulations (CCR),

sections 1956.1, 1956.2, 1956.3, and 1956.4.

Economic And Fiscal Impacts. In developing the proposed modifications, ARB staff

evaluated the potential economic impacts on private persons and businesses. The Board

has determined that the proposed modifications would not impose any costs on

government-contracted (publicly-contracted) and government (publicly-owned) transit

agencies. Furthermore, Staff believes there will be no business elimination, and believes
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there will be no or minimal business creation or expansion, as a result of the adoption of the

proposed modifications. Staff does not expect any negative impacts from this proposal.

The estimated cost-effectiveness of the original transit agency regulation was detailed in the

December 1999 Initial Statement of Reasons (ARB 1999). Staff determined the costeffectiveness of the engine emission standards and zero-emission bus purchase

requirements to be about $1.80/lb of NOx in 2010 and $1.50/lb in 2020. This proposal does

not change the expected cost-effectiveness determined at that time. As explained in the

Staff Report, these proposed amendments provide transit agencies with the option to

purchase diesel HEBs in 2004 through 2006. These rules are not a mandate to purchase

and thus impose no additional cost on transit agencies. In addition, staff’s proposal cuts the

number of ZEBs demonstrated by one-half and extends the time for compliance, thus

spreading out the cost over a longer time period.

Consideration Of Alternatives. For reasons set forth in the Staff Report, in staff’s

comments and responses at the hearing, and in this Final Statement of Reasons, the Board

has determined that no alternative considered by the agency, or that has otherwise been

identified and brought to the attention of the agency, would be more effective in carrying out

the purposes 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.

Non-Substantial Changes. Staff made changes to the final regulation order to correct

clerical errors deemed non-substantial. The changes are described below:

1956.3 (b) (2) (C): the referenced section should be 1956.4, not 1956.3

1956.3 (b) (2) (D): the referenced section should be (e)(4), not (e)(3)

1956.2 (d) (9) (A): deadline is by January 31, not January 1

II. SUMMARY OF PUBLIC COMMENTS AND AGENCY RESPONSES

At the June 24, 2004, hearing, oral testimony was received from:

Joshua Shaw, California Transit Association (Cal Transit)*

Jose Cisneros, San Francisco MUNI (MUNI)

Gene Walker, California Transit Association (Cal Transit)* and Golden Gate Bridge Highway

& Transportation District (GGT)*

David Olmeda, San Mateo County Transit District (Samtrans)

Robert F. Babik, General Motors (GM)*

Thomas Webb, BAE Systems (BAE)*

Doug Quetin, California Air Pollution Control Officers Association (CAPCOA)

Barry Wallerstein, South Coast Air Quality Management District (SCAQMD)*

Chung Liu, South Coast Air Quality Management District (SCAQMD)

Michael Eaves, California Natural Gas Vehicle Coalition (CNGVC)*

Julie Masters, Natural Resources Defense Council (NRDC)

Michael C. Simon, ISE Corp (ISE)*

Dawn Friest, Engine Manufacturer's Association (EMA)*

Nidia Bautista, Coalition for Clean Air (CCA)

Marty Mellera, San Francisco MUNI (MUNI)

The people listed above with asterisks also submitted written comments. In addition, written

comments were received by the hearing date from the following persons:

Paul Scott, ISE Corp (ISE)

Andrew J. Littlefair, Clean Energy
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Steve Heminger, Metropolitan Transportation Commission (MTC)

Jeffrey Noonan-Day, John Deere (Deere)

Gavin Newsom, City & County of San Francisco (SF)

Gabriel Metcalf, San Francisco Planning and Urban Research Association (SPUR)

Jared Blumenfeld, San Francisco Department of the Environment (SF Environment)

Michael Burns, Municipal Transportation Agency, San Francisco (SF MTA)

Andrew Sullivan, Rescue MUNI

Tom K. Koutsoulis, private citizen

Jack P. Broadbent, Bay Area Air Quality Management District (BAAQMD)

Larry Greene, California Air Pollution Control Officers Association (CAPCOA)

Peter M. Cipolla, Santa Clara Valley Transportation Authority (VTA)

Gary B. Heston, Long Beach Transit (LBT)

Chris Ferrara, Chuck Hammond, Rick Ruvolo, Bay Area Regional Clean Cities Coalition

(BARCCC)

William Craycraft, California Natural Gas Vehicle Partnership (CNGVP)

Daniel Murphy, Municipal Transportation Agency, Citizen's Advisory Council, San Francisco

(MTA CAC SF)

Diane Bailey, Natural Resources Defense Council (Enviro Coalition)

Bonnie Holmes-Gen, American Lung Association of California (Enviro Coalition)

Todd Campbell, Coalition for Clean Air (Enviro Coalition)

Joseph K. Lyou, California Environmental Rights Alliance (Enviro Coalition)

Don Anair, Union of Concerned Scientists (Enviro Coalition)

V. John White, Sierra Club California (Enviro Coalition)

Kathryn Phillips, Center for Energy Efficiency and Renewable Technologies (Enviro

Coalition)

Meena Palaniappan, Pacific Institute for Studies in Development, Environment, and Security

(Enviro Coalition)

Jesse N. Marquez, Coalition for a Safe Environment (Enviro Coalition)

Tiffany Schauer, Our Children's Earth (Enviro Coalition)

Martha Dina Arguello, Physician's for Social Responsibility-Los Angeles (Enviro Coalition)

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

regarding the specific regulatory action proposed, together with the ARB response to each

objection or recommendation, and the reasons for making no change. The comments have

been grouped by topic wherever possible. Comments not involving objections or

recommendations specifically directed towards the rulemaking or to the procedures followed

by ARB in this rulemaking are not summarized below, although some non-responsive

comments are summarized and discussed.

SUPPORT

1. Comment (MTC, SF, Cal Transit, SPUR, SF Environment, MTA SF, Rescue MUNI,

GGT, Koutsoulis, GM, BAAQMD, VTA, MTA CAC SF, BAE, MUNI, Samtrans, CCA):

Staff received several comments in support of the proposed amendments (some made

supporting comments relating to specific amendments; others offered general support).

Agency Response: Staff appreciates these comments and looks forward to continuing

to work with industry and environmental leaders to promote the overall improvement of

air quality in the state of California.

HYBRID-ELECTRIC BUS (HEB) AMENDMENTS

2. Comment (Clean Energy): Staff is proposing to use a 0.75 multiplier to reduce

emissions of the diesel hybrid electric bus from 2.5 g/bhp-hr to 1.8 g/bhp-hr. "I do not
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recall any public hearings to debate the validity of this factor." "I strongly urge . . . the

Board members to ask for staff to both clarify and justify this methodology."

Agency Response: The diesel hybrid-electric urban bus emission standard is based on

staff’s comprehensive assessment of hybrid-electric technology and emissions test data,

and is not based on applying a multiplier to an existing emission standard. Staff

concluded that an exhaust emission standard of 1.8 g/bhp-hr NOx and 0.01 g/bhp-hr PM

is feasible for state of the art diesel hybrid-electric drive systems. In fact, a 0.75

multiplier applied to 2.5 g/bhp-hr results in 1.875 g/bhp-hr, which is greater than the

diesel hybrid-electric urban bus NOx standard of 1.8 g/bhp-hr.

3. Comment (Clean Energy): Diesel HEBs have an incremental cost over traditional diesel

buses of $140,000 to $150,000 per bus, plus the requirement to repower or retrofit will

add $40,000 to the total cost per bus. If cost is a consideration in rule making decisions,

how can the staff's proposed modification be justified?

Agency Response: This amendment provides transit agencies on the diesel path with

an additional option when making decisions about bus purchases but does not mandate

any transit agency to purchase a diesel HEB. A voluntary provision, such as this one,

does not impose additional costs on transit agencies.

4. Comment (SCAQMD): Retain the 2004-2006 MY emissions standard of 0.5 g/bhp-hr

NOx for diesel path properties, along with all provisions of the existing Transit [Agency]

Fleet Rule. Hybrid gasoline buses should be considered the benchmark for interim rule

compliance, since they have been certified at less than the 0.5 gram NOx level.

Agency Response: The Board acknowledges the recent advance in gasoline hybrid bus

engine technology, including lower emissions and better fuel economy, but this

technology is in the early stages of commercialization and does not yet have proven

durability and reliability. The advances are very promising; however, there is still more

work to be done. The Board recognizes the various applications in the field and

supports all levels of technological advancement in order to best serve the public while

promoting air quality. Gasoline hybrid-electric buses are the current benchmark

technology available for those transit agencies on the alternative fuel path. Many transit

agencies on the diesel path, however, are limited by the lack of fueling infrastructure and

are therefore not able to purchase alternative fuel buses.

Diesel HEB technology offers transit agencies on the diesel path an alternative that

allows them to maintain a single fuel and maintenance program geared towards diesel

engines, while at the same time offering them a bus with lower emissions and better fuel

economy than a conventional diesel bus. Retaining the 0.5 g/bhp-hr NOX emission

standard for the 2004 – 2006 MY would continue to prevent the sale of diesel HEBs in

California during a time period when there very few urban buses, diesel- or alternativefueled, for sale. Preventing replacement of the oldest diesel buses with cleaner-emitting

urban buses for this three-year period would result in higher net. Therefore, to promote

innovative technological advances, the Board approved a 1.8 g/bhp-hr NOx standard for

diesel HEBs, but included an offset requirement to ensure that all transit agencies,

regardless of fuel path, comply with the 0.5 g/bhp-hr NOx standard. By doing so, the

Board maintains a fuel neutral position while promoting innovative technology to improve

air quality.

5. Comment (SCAQMD, CAPCOA): The Board should require that manufacturers pull

forward [to require in 2004] the use of diesel engines certified to 1.2 g NOx/bhp-hr or

less for the HEBs.
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Agency Response: Staff solicited comments from diesel engine manufacturers during

the informal workshop process and no manufacturer stated that it could or would bring a

1.2 g NOx/bhp-hr engine into California prior to 2007. California represents a small

portion of the overall urban bus market share and therefore cannot compel engine

manufacturers to meet this stricter standard. The commenters' proposal therefore would

have no effect on the availability of diesel engines certified in California for urban buses.

6. Comment (SCAQMD): The existing 0.4 g NOx gasoline hybrid bus certification should

be considered by CARB to represent full compliance with the interim urban bus emission

standard of 0.5 grams NOx.

Agency Response: Staff agrees and the Board has defined gasoline, when used in a

HEB, as an alternative fuel. Thus any transit agency is able to purchase a gasoline

HEB, including those on the alternative-fuel path.

7. Comment (BAAQMD): CARB should require that the proposed mitigation plan for transit

districts purchasing diesel-electric hybrid buses offset the emissions difference between

the proposed 1.8 g/bhp-hr standard and the 2007 emission standard of 0.2 g/bhp-hr.

Agency Response: This would require a much more stringent standard beyond the

proposed regulation. The additional costs associated with a more stringent standard

could hinder the replacement of dirtier buses; thus, result in higher emissions because

older, higher emitting diesel buses would not be replaced with newer, cleaner diesel

buses. Staff’s assessment of the proposed regulation found the standard to be

technologically and economically feasible, given the current available technology, while

providing emissions benefits by introducing new and cleaner technology to the state.

8. Comment (CAPCOA): The proposed changes are unjustified in light of the need to

achieve maximum emission control effectiveness from this source category and the

availability of gasoline HEB technology. Between 2004-2006, transit agencies on the

diesel path should be encouraged to purchase gasoline hybrid buses or diesel buses

certified to 1.2 g NOx/bhp-hr.

Agency Response: The Staff Report (pages 13 - 18) details the justification for the

proposed regulation. Transit agencies on the alternative-fuel path are able to purchase

gasoline hybrid buses; however, there are no diesel buses certified to 1.2 g/bhp-hr NOx.

Therefore, to maintain integrity of the dual-fuel path regulation as adopted by the Board

in 2000, and to encourage the turnover the dirtiest diesel buses, staff believes that

transit agencies on the diesel path should be provided with the most aggressive diesel

choice available, which currently is diesel HEB technology.

9. Comment (LBT): The proposed restriction that NOx offsets be surplus to emission

reductions accruing from the retirement of a diesel bus replaced by an HEB is overly

restrictive and should be removed so that emission reductions gained by retiring a diesel

bus and replacing it with a diesel HEB would count as an offset. ARB should allow both

types of certified HEBs (diesel and gasoline) without requiring the offset to be made

solely with NOx emission control devices.

Agency Response: The Board is requiring that NOx offsets be surplus to emission

reductions accruing from the retirement of a replaced diesel bus to ensure that the NOx

offsets are greater than those achieved by a simple replacement program. This

regulation offers NOx reduction offsets for either installing aftertreatment technology or

repowering an older bus because neither are required purchases under the fleet rule for
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transit agencies. These emission savings would be surplus to other requirements and

thus available to offset any NOx increases from the purchase of diesel HEBs. Staff is

proposing the need for NOx reduction offsets for transit agencies on the diesel path, as

there is an alternative-fueled HEB already certified and available to transit agencies on

the alternative fuel path.

10. Comment (CNGVC): The emission [standard] target for diesel HEBs seems to be a

technical modification of the rule that is a circumvention of CARB standards and a major

concession to engine manufacturers.

Agency Response: Staff disagrees with the comment that these emission standards

circumvent the current diesel engine standards. The Notice of Public Hearing clearly

described the amendment to the standards to accommodate HEBs, so ARB standards

are not being “circumvented”. Staff’s assessment, described in detail in the Staff Report,

provides the rationale for the Board’s decision to approve the proposed regulation. The

Board is committed to bringing innovative technology at the lowest technically feasible

emission standard and cost-effectiveness. To achieve this goal, staff assessed available

technology and emission data and determined the necessary standards to promote air

quality and state-of-the-art technology.

11. Comment (ISE): Raising the current NOx emissions standard to a higher level as

proposed would open up California's market to diesel hybrid systems produced outside

our state, but none of these is any more proven than ISE's [gasoline] hybrid system.

Agency Response: The diesel HEB option is only being made available to transit

agencies on the diesel path. Diesel path transit agencies can purchase a gasoline HEB

without having to provide offsets, which may serve as an incentive to purchase these

buses instead of a diesel HEB. The transit agencies on the alternative-fuel path will not

be able to purchase any diesel HEBs, thus preserving ISE's ability to sell its gasoline

HEBs to approximately 40 percent of the transit agencies on the alternative-fuel path

plus those diesel path agencies operating in the South Coast AQMD, most of which are

prohibited from purchasing diesel urban buses.

12. Comment (Enviro Coalition): We do not take a position on the diesel hybrid-electric

proposal so long as it includes NOx offset requirements.

Agency Response: Staff thanks the commenters and appreciates their input.

13. Comment (NRDC): We strongly support advancement of hybrid technology but ARB

should require the purchase of the cleanest hybrid rather than allowing the dirtier diesel

hybrids into the rule.

Agency Response: Under the commenter's proposal, only the manufacturer that "wins"

(i.e., has the cleanest engine), after a long and very costly research and development

program, could sell its engine in California. Such a regulation that restricts purchases to

the "cleanest" hybrid available would hinder technology research and development. This

would also remove competition from the marketplace and could therefore result in

increased costs to transit agencies as the "winner" would have no competition to reduce

costs. The current regulation-setting system of establishing a standard and allowing all

manufacturers to meet or even beat the standard has been very successful in

encouraging technological advancement, competition, and emission reductions.

While they do have higher emissions than the gasoline HEB, ARB is allowing diesel

HEBs to enter the California market to encourage development of this technology and
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allow transit agencies on the diesel path to replace their oldest, dirtiest diesel buses with

cleaner HEBs. One type of bus does not fit all situations in all transit agencies and thus

ARB is providing transit agencies with more than one type of HEB. A transit agency that

purchases a diesel HEB will still have to reduce its NOx emissions to as low as if the

transit agency had purchased the cleaner gasoline HEB.

ZERO EMISSION BUS (ZEB) AMENDMENTS

14. Comment (ISE): The proposed modification to the ZEB rule should reflect advances in

hydrogen internal combustion engine and hybrid hydrogen drive-trains, and the possible

attainment of ZEB goals by use of larger numbers of less expensive hydrogen hybrid

internal combustion engines (HHICE). Staff's analysis should include the HHICE option

as an acceptable alternative to the fuel cell path to ZEB goals.

Agency Response: The changes to the ZEB regulation, proposed by staff at the June

Board hearing, were limited to the ZEB demonstration project. Staff has been

monitoring the progress of the ZEB demonstration and determined that despite due

diligence by the transit agencies they would not be able to comply with the regulation.

While transit agencies did request a review of the compliance target dates in the

regulation, they did not request a change of the technology eligible for the ZEB

demonstration. The transit agencies subject to the ZEB demonstration project have

initiated development of fuel cell based ZEB demonstrations and have entered into

contracts for fuel cell powered buses. In addition, a limited technology review did not

suggest that changing the type of technology used in the ZEB demonstrations was

needed at this time.

In addition, a ZEB is defined, in section 1956.3, as producing zero exhaust emissions of

any criteria pollutant (or precursor pollutant) under any and all possible operational

modes and conditions. While HHICE have the potential of being very low emitting, they

do not meet the criteria of this definition.

15. Comments (ISE): Appropriate credit should be allowed to fuel suppliers and transit

properties that choose low-carbon or zero carbon sustainable fuel path choices.

Agency Response: The carbon content of fuel or fuel specifications is not directly

regulated through the transit bus regulations. However, the transit bus regulations

provide incentives to transit agencies choosing to use alternative or low-carbon fuels.

Transit agencies using alternative fuels were given additional time to comply with

particulate matter retrofit requirements and may purchase new alternatively fueled

engines with relatively higher oxides of nitrogen emission through model year 2006.

16. Comment (Cal Transit, GGT): The current test and reporting dates for the ZEB

[demonstration] program have not been addressed; while staff has recognized the delay

in the demonstration project, the reporting dates have not been changed to reflect those

delays.

Agency Response: The proposed regulations modify the start and reporting dates of

the ZEB demonstration project to allow the participating transit agencies to attain

compliance. The regulation was modified to require that the buses be deployed by

February 28, 2006, and the final project report is due to the ARB July 31, 2007.

17. Comment (LBT): ARB should amend the ZEB purchase requirement timeline and

extend the deadline by which transit agencies on the diesel path must replace 15

percent of their fleet from 2008 to 2010.
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Agency Response: ARB staff will be researching and presenting a zero-emission bus

technology review that will include an assessment on the feasibility of implementing the

ZEB purchase requirements to the Board in early 2006. The 2006 date will allow ARB to

include information from the current ZEB demonstration projects in the review and still

allow time for transit agencies to develop purchase plans.

HARMONIZATION WITH 2007 EPA STANDARDS

18. Comment (Cal Transit, EMA, GGT, MTC, Samtrans): ARB should align urban bus

engine standard with the 2007 federal heavy-duty on-highway engine requirements.

Comment (Enviro Coalition, CCA, NRDC): ARB should not align urban bus engine

standards with the 2007 federal heavy-duty on-highway engine requirements.

Agency Response: The 2007 exhaust emission standards for urban bus engines were

not the focus of these proposed modifications; therefore, these comments are nonresponsive to the proposal set forth in the hearing notice. However, the Board will

consider this issue in 2005.

FUEL PATH

19. Comment (Clean Energy, CNGVC, CNGVP): ARB should eliminate the diesel fuel path

in favor of the alternative fuel path.

Comment (CNGVC): On the basis of economics, natural gas buses are far and away

the best choice over diesel or gasoline hybrid electric buses.

Comment (BARCCC): CARB should not compromise the rule for non-compliant diesel

engines to be sold in California; diesel path transit agencies should begin using natural

gas buses

Agency Response: Amending the choice of fuel path was not the focus of this proposed

regulation; therefore, these comments are non-responsive. It is important to note,

however, that the dual-path system was established to provide flexibility to transit

agencies in choosing diesel or alternative-fueled buses while ensuring maximum

emission benefits by encouraging a turnover of the oldest, dirtiest diesel engines.

EMISSION BENEFITS

20. Comment (CNGVC): Modeling will show under certain circumstances there are

insufficient emission offsets to be gained by retrofitting a fleet with aftermarket NOx

control systems to allow a six-year purchase of diesel hybrid buses. And while offsets

lower the near term fleet NOx average, in the out years (2014-2025), [NOx] fleet

averages will be higher than where fleets would be had CARB compliant engines been

purchased as specified under the rule. If you take a look at the modeling, it takes more

than a one-to-one offset to make the system whole.

Agency Response: Staff conducted a comprehensive assessment of the emission data

and believes its assumptions used in establishing the standards accurately reflect the

emission benefits gained from the adoption of the proposed regulations. Further, the

commenter did not provide staff with its modeling or analysis and so we cannot evaluate

the commenter's claims. Staff is requiring that each transit agency incorporate the

expected life of the NOx reduction system in developing its offset program to ensure that
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the offsets last for the twelve year life of an urban bus. ARB's modeling did not show

that more than a one-to-one offset is required to make the system whole.

REQUESTS FOR FURTHER NOX REDUCTION

21. Comment (SCAQMD): CARB's proposal allows those transit agencies on the diesel

path to demonstrate equivalency to a 0.5 g/bhp-hr NOx standard by requiring retrofit

requirements of the existing diesel transit bus fleet. The South Coast AQMD staff urges

CARB to consider amendments to this regulation to require retrofit requirements which

achieve additional NOx reductions from existing transit bus fleets.

Comment (BAAQMD): CARB should also adopt a lower fleet-wide NOx average for all

transit fleets to accelerate fleet turnover, installation of after-treatment technology, and

repowering with certified cleaner engines.

Comment (CAPCOA): Transit agencies should be required to retrofit all diesel buses

with NOx controls to achieve at least a 25 percent reduction from baseline such that the

fleet average NOx is reduced to 3.6 g/bhp-hr.

Agency Response: These proposals are beyond the scope of the rulemaking notice

and thus are non-responsive to the proposal. Nevertheless, staff will provide an analysis

of NOx fleet averages in California transit agencies and the state of NOx aftertreatment

technology in a future report to the Board. Staff does know that fleet-wide NOx emission

from transit agencies have been dropping since the NOx fleet average of 4.8 g/bhp-hr

was mandated by the Board on Oct 1, 2002, at the same time that transit agencies have

been reducing their fleet PM emissions.

OTHER COMMENTS

22. Comment (ISE): "Well-to-wheels" and health and air quality cost benefit analyses

should be rigorously applied to all public transportation entities, such that the basis for

total cost is used in governmental analyses.

Agency Response: ARB's methodology for calculating the cost effectiveness of a

proposed regulation, or amendments to an existing regulation, includes costs associated

with compliance and the value of avoided deaths as a result of emission reductions. As

such, health benefits are incorporated into the analysis. In addition, no project that may

have a significant adverse environmental impact may be adopted as originally proposed

if feasible alternatives or mitigation measures are available to reduce or eliminate such

impacts. The Board has considered the impact of this proposed regulatory action on the

economy of the state and a detailed cost benefit analysis is provided in the Staff Report.

While a "well-to-wheels" cost analysis, which incorporates all of the costs (and benefits)

from the extraction of the oil or gas through to the development and building of the bus,

could be a useful additional analysis to consider, this analysis is very difficult and timeconsuming to conduct, has many uncertainties because the data are often proprietary or

otherwise unavailable, and has not been widely applied or accepted in determining costs

and benefits from regulatory programs.

23. Comment (Deere): Incentive funding for the purchase of natural gas school, transit, and

refuse truck fleet operators needs to continue to support the sale of low-emissions

engines.
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Agency Response: This comment is non-responsive to staff's proposal. Incentive

funding is more properly addressed through the Carl Moyer Program and comments

should be addressed to Carl Moyer Program staff.

24. Comment (BAAQMD): We encourage CARB to expedite as reasonably as practical its

review and certification of biodiesel as a valid emission control strategy.

Agency Response: The verification of biodiesel as a diesel emission control strategy is

not within the scope of the proposed regulation; therefore, this comment is nonresponsive. However, it is important to note that use by a transit agency of any biodiesel

fuel that meets the requirements of title 13, CCR, section 1956.2 (f)(6) is permitted at

this time. In other words, the fuel must have less than 15 parts per million sulfur content

and otherwise meet the requirements of a diesel fuel in California. The conflict with the

use of biodiesel in an urban bus, or in any engine, arises in two situations: the engine

manufacturer may void the engine warranty if it does not recognize biodiesel as an

acceptable fuel and use of biodiesel may invalidate the verified diesel particulate matter

reductions of an installed diesel emission control strategy, such as a diesel particulate

filter. Currently, no diesel particulate filter is verified for use with biodiesel fuel, although

that could change in the future.