State of California 

AIR RESOURCES BOARD 

Resolution 05-61 

October 27, 2005 

Agenda Item No.: 05-10-2 

WHEREAS, sections 39600 and 39601 of the Health and Safety Code authorize the Air 

Resources Board (ARB or Board) to adopt standards, rules, and regulations and to do 

such acts as may be necessary for the proper execution of the powers and duties 

granted to and imposed upon the Board by law; 

WHEREAS, on October 20, 2005, the Board adopted Resolution 05-53, which approved 

amendments to sections 1956.1 and/or 1956.8, title 13, California Code of Regulations 

with the modifications described in Attachment C to the Resolution; these amendments 

retain the urban bus engine standard for oxides of nitrogen (NOx) in model years 2007 

through 2009, but allow transit agencies to purchase model year 2007 through 2009 

diesel urban bus engines not certified to the 0.2 gram per brake horsepower-hour 

(g/bhp-hr) NOx standard for urban bus engines, but meeting the California heavy-duty 

truck engine standards for model years 2007 through 2009, as long as any diesel path 

transit agency with 30 or more urban buses satisfies the conditions described in 

Attachment C to Resolution 05-53 in order to maximize NOx emission reductions; 

WHEREAS, at the public hearing on October 20, 2005, the Board further directed staff 

to report to the Board at its public meeting on October 27, 2005, on the effect of the 

retention of the urban bus engine NOx standard at 0.2 g/bhp-hr for model years 2007 to 

2009 on transit agencies’ access to external funding sources, and most specifically to 

report on the effect of the anticipated loss of funding under the Carl Moyer Program; 

WHEREAS, the staff has presented its report to the Board as directed; 

WHEREAS, based on the staff’s October 27, 2005, report to the Board, the Board finds 

that aligning California’s urban bus engine standards in the 2007 and subsequent model 

years with California’s heavy-duty truck engine standards – coupled with a requirement 

that transit agencies districts purchasing 2007 through 2009 model-year urban buses or 

engines certified to a NOx emission level greater than 0.2 g/bhp-hr must meet all of the 

applicable conditions identified in Attachment C to Resolution 05-53 in order to 

maximize the NOx emission reductions – would lessen any potential loss of funding 

under the Carl Moyer Program (Health and Safety Code section 44275 et seq.); and 

Attachment A hereto sets forth regulatory modifications consistent with this finding; and 
Resolution 05-61 2

WHEREAS, the Board finds that no alternatives considered by the Board would be 

more effective in carrying out the purposes of the regulations as noticed on July 29, 

2005, and modified by the Board as specified in Attachment A hereto, have been 

proposed, nor are there alternatives that would be as effective and less burdensome to 

affected private persons. 

NOW, THEREFORE, BE IT RESOLVED that the Board hereby incorporates by 

reference Resolution 05-53 and its attachments, amends Resolution 05-53 by approving 

the modifications set forth in Attachment A hereto in place of the modifications set forth 

in Attachment C to Resolution 05-53, and reaffirms Resolution 05-53 in all other 

respects. 

I hereby certify that the above is a true 

and correct copy of Resolution 05-61, as 

adopted by the Air Resources Board. 

_______________________________ 

Lori Andreoni, Clerk of the Board 
Resolution 05-61 

Attachment A 

Approved Modifications to the Original Proposal 

(concepts) 

1. Align the California urban bus engine standards for the 2007 and subsequent 

model years with the standards for heavy-duty truck engines as set forth in 

title 13, California Code of Regulations (CCR), section 1956.8. 

 

2. Allow transit agencies to purchase urban buses containing model-year 2007 

through 2009 diesel engines not certified to the 0.2 gram per brake 

horsepower-hour (g/bhp-hr) oxides of nitrogen (NOx) emission standard, but 

meeting the California heavy-duty truck engine emission standards for model 

years 2007 through 2009, as long as they meet the following conditions, as 

applicable, in order to maximize NOx emission reductions: 

• Any diesel path transit agency with 30 or more urban buses must retrofit an 

existing urban bus or transit fleet vehicle in its fleet with a level 3 particulate 

matter (PM) verified diesel emission control strategy that achieves a minimum 

NOx emission reduction of 40 percent or more, if available, for each new 

model year 2007 through 2009 diesel urban bus purchased with an engine 

that does not meet the 0.2 g/bhp-hr NOx standard. 

• If a level 3 PM diesel emission control strategy with a minimum of 40 percent 

NOx reduction is not available then an existing engine must be retrofitted with 

a level 3 PM diesel emission control strategy that achieves a minimum of 

25 percent NOx reduction, if available. 

• The retrofit requirement applies on a one-to-one basis for each new modelyear 2007 through 2009 diesel urban bus or diesel urban bus engine 

purchased that does not meet the 0.2 g/bhp-hr NOx standard until all diesel 

urban buses and transit fleet vehicles within the transit agency’s fleet are 

either retrofitted or are unable to be retrofitted, subject to Executive Officer 

verification that all available retrofitting has been accomplished.