State of California

AIR RESOURCES BOARD

Addendum to the Final Statement of Reasons for Rulemaking,

Including Summary of Comments and Agency Response

RULEMAKING TO CONSIDER THE ADOPTION OF PROPOSED AMENDMENTS TO THE 

REGULATION TO REDUCE EMISSIONS OF DIESEL PARTICULATE MATTER 

(Truck and Bus)

Public Hearing Date: December 16, 2010

Agenda Item No.: 10-11-3

Addendum Prepared: December 12, 2011

As part of the Office of Administrative Law’s (OAL) review of the Regulation to Reduce 

Emissions of Diesel Particulate Matter, Oxides of Nitrogen and Other Criteria Pollutants, 

from In-Use Heavy-Duty Vehicles (Truck and Bus Regulation), title 13, California Code 

of Regulations section 2025, OAL requested further explanation from the Air Resources 

Board (ARB) of several changes made to the Final Regulation Order as non-substantive 

changes. Specifically, OAL requested additional explanation of changes to the following 

sections: 2025(j)(1)(B); 2025(n)(1) and (2); 2025(p)(1); and 2025(p)(2)(D). The 

following identify the changes made to the Final Regulation Order that were not shown 

in the 15-Day Modifications to the Original Proposal and ARB staff’s further explanation 

of why the final changes are not substantive. Additions to the text are marked in BOLD 

and deletions to the text are indicated by BOLD STRIKEOUT.

Section 2025(j)(1)(B). Form 400 Text, pg. 25. 

(j) Credits for Fleets that have Downsized, Early PM Retrofits, Hybrid Vehicles, 

Alternative Fueled Vehicles, Vehicles with Heavy-Duty Pilot Ignition Engines, and 

Early Addition of Newer Vehicles

Fleets can take advantage of credits that reduce the number of vehicles with a GVWR 

greater than 26,000 lbs that must meet the PM BACT requirements in the phase-in 

option of section 2025(i) as described in items (1) to (3) below, and does not apply to 

school buses. 

(1) Credit for Fleets that have Downsized

Until January 1, 2016, a fleet that has fewer vehicles with a GVWR greater than 26,000 

lbs operating in the compliance year than in the 2006 baseline fleet may claim a credit 

towards compliance with the phase-in option of section 2025(i) for that year. 

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(B) A vehicle that is not operated in the compliance year may be excluded from 

the existing fleet in determining the credit if:

1. The vehicle is not driven for the entire compliance year and
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a. Either a certificate of non-operation has been issued by the DMV 

or a request for a non-operation certificate has been filed with

DMV prior to the beginning of the compliance year; or

b. An equivalent certificate has been issued by another state or a 

request for such a certificate has been filed with the state prior 

to the beginning of the compliance year; or

c. The vehicle is not operated for any purpose during the compliance 

year except to demonstrate functionality of the vehicle to potential 

buyers, to move the vehicle short distances for maintenance, or to 

a storage facility while awaiting sale.

ARB Explanation:

The intent of the 15-day modifications was to allow fleets to exclude 

vehicles that are not being operated in a compliance year by a covered 

fleet. For purposes of documentation, ARB would accept either a notice of 

non-operation that has been received from the California Department of 

Motor Vehicles (DMV) or a request from the fleet that has been filed with 

the DMV but has not been acted upon. ARB would similarly accept 

comparable documentation sent to or issued by equivalent out-of-state 

agencies for vehicles that are registered outside of California. Upon 

review of the 15-day language, ARB thought that its intent could be 

expressed more clearly and consistently, which are the reasons for the 

changes to the final regulation order.

Section 2025(n)(1) and (2). Form 400 Text, pp. 44-45. 

(n) Requirements for Single-Engine and Two-Engine Sweepers

(1) Two-engine sweepers with auxiliary engines 50 hp or greater must comply with 

section 2025(e). The propulsion engine is required to meet PM BACT and to 

upgrade to a 2010 model year emissions equivalent engine like other vehicles, 

and the auxiliary engines must meet PM BACT as follows:

(A) The auxiliary engine is required to meet PM BACT when the propulsion 

engine is first required to meet PM BACT or to be upgraded to a 2010 model 

year emissions equivalent. The auxiliary engine is not required to be 

replaced or upgraded if it meets PM BACT. The reporting requirements of 

2025(r)(17) must be met unless the fleet complies with the model year 

schedules of 2025(f) or 2025(g).

(2) Regardless of fleet size, two-engine sweepers may not operate any with Tier 0 

auxiliary engines, 50 hp or greater, may not operate more than 450 hours per 

year starting January 1, 2010 until January 1, 2014 and no more than 100 hours 

per year thereafter. The fleet owner must meet the reporting requirements in 

2025(r)(17) for sweepers with Tier 0 auxiliary engines.
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ARB Explanation:

Section (r)(17) requires all owners of two engine sweepers to report 

specific information to ARB. However, sections 2025(f) and (g) state that 

propulsion engines meeting the model-year schedules for those sections 

do not need to meet the reporting requirements of section (r). The change 

to section (n)(1) was intended to clarify the requirements of the section 

(n)(1) consistent with sections 2025(f), (g), and (r)(17). 

The exemption from the reporting requirements in sections 2025(f) and (g) 

was not intended to apply to the auxiliary engine of a two-engine sweeper. 

Thus the change to (n)(2) was intended to make it clear that owners must 

report information on the auxiliary engine consistent with section 

2025(r)(17). 

Section 2025(p)(1). Form 400 Text, pg. 47

(p) Exemptions, Delays, and Extensions Exemptions, Compliance Extensions, and 

Credits

(1) Vehicles used Exclusively in NOx Exempt Areas

This section applies to vehicles that are used exclusively in NOx exempt areas as 

defined in section 2025(d)(46) when operating in California. The fleet owner must 

meet the record keeping requirements of section 2025(s) and meet the reporting 

requirements as specified below. 

(A) Any vehicle with a GVWR greater than 14,000 lbs that is used exclusively in 

NOx exempt areas shall meet PM BACT but may be exempt from meeting 

the 2010 model year emissions equivalent requirements of section 2025(f) or 

2025(g) if the vehicle meets PM BACT by the compliance date that the 

engine would otherwise be required to be upgraded to a 2010 model year 

emissions equivalent engine.

ARB Explanation

Sections 2025(f) and (g) require all heavy-duty vehicles to comply with the 

model-year schedules set forth in Tables 1 and 2, which require PM BACT 

and turnover to 2010 model-year or emissions-equivalent engines. 

Section 2025(p)(1) provides an exemption from the turnover requirements 

for vehicles that operate exclusively in NOx exempt areas. The language 

“meet PM BACT but” was added to make it clear that the exemption only 

applies to the turnover requirement. The initially submitted Final 

Regulation Order incorrectly inserted “may” after “meet PM BACT but” (the 

term was not part of the 15-Day Notice). The term has been deleted from 
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the revised Final Regulation Order, making it clear that if the conditions of 

the section are met the vehicle will be exempt. 

Section 2025(p)(2)(D). Form 400 Text, pg. 50. 

(p) Exemptions, Delays, and Extensions Exemptions, Compliance Extensions, and 

Credits

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(2) Extension for Low-Mileage Construction Trucks

Beginning January 1, 2012, fleets with low-mileage construction trucks as defined 

in section 2025(d)(40) may opt to have a limited number of low-mileage 

construction trucks in the fleet comply by meeting all of the requirements as set 

forth below and do not need to include such vehicles in meeting the fleet 

requirements of sections 2025(g) through (i).

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(D) Alternately, fFleets that have low-mileage construction trucks and other

vehicles with a GVWR greater than 26,000 lbs that comply with section 

2025(e), except low-use vehicles, may must, except low-use vehicles, 

must demonstrate that the combined fleet meets the phase-in schedule of 

Table 9 and, if so, the low-mileage construction vehicles in the fleet qualifying 

for the extension under sections 2025(p)(2)(A) and (C) above may delay 

having to comply with PM BACT until as late as 2016.

ARB Explanation

“Alternately,” was deleted as its use was confusing given the structure of 

section 2025(p)(2). The word “other” was added to make it clear that the 

reference to “greater than 26,000 lbs refers to construction vehicles as 

well as other vehicles in the fleet. The reference to “that comply with 

section 2025(e)” was deleted and the reference to “for low-use vehicles,” 

was added to make it clearer as to exactly what types of vehicles must be 

included when calculating the combined fleet and what vehicles must be 

excluded. Consistent with those changes the term “may” was replaced 

with “must.” The changes are consistent with the requirements of section 

2025(e), which requires that unless otherwise provided, all vehicles 

26,000 lbs. or greater must meet the PM BACT and 2010 model-year or 

emissions-equivalent engines by specified dates, and the exemption from

those requirements in section 2025(p)(4).