PROPOSED WITH 15-DAY MODIFICATIONS 

State of California 

AIR RESOURCES BOARD 

Resolution 10-47 

December 17, 2010 

Agenda Item No.: 10-11-3 

WHEREAS, the Air Resources Board (ARB or Board) adopted the Regulation for In-Use 

Off-Road Diesel-Fueled Fleets (Off-Road regulation), California Code of Regulations 

(Cal. Code Regs.), title 13, sections 2449 through 2449.3, and amendments thereto 

pursuant to the authority set forth in Resolutions 07-19, 08-43, 09-3, and 09-50, all of 

which are respectively incorporated by reference herein; 

WHEREAS, in-use off-road diesel vehicles operating in the state, as a class, continue to 

be a significant source of air pollution emissions in California that contribute to 

continuing violations of the national ambient air quality standards (NAAQS) for both 

particulate matter (PM) less than 2.5 microns (PM2.5) and ozone, and to continuing 

localized health risk, including premature death, associated with exposure to PM2.5; 

WHEREAS, California and the nation continue to be in the midst of a serious economic 

recession that was not anticipated when the Board initially approved the regulation on 

July 26, 2007; 

WHEREAS, the recession has had a significant impact on companies that operate 

in-use off-road diesel vehicles in the normal course of business and has reduced overall 

off-road diesel vehicle and engine activity, with concomitant reductions in PM2.5 and 

oxides of nitrogen (NOx) emissions, in the state; 

WHEREAS, ARB staff has undertaken a thorough review and update of its emissions 

inventory for in-use off-road diesel vehicles and engines and determined that emissions 

from off-road vehicles and engines are substantially lower than previously estimated in 

July 2007; 

WHEREAS, ARB staff presented the results of the updated emissions inventory to the 

Board at the November 2010 Board hearing, and the Board took public comment on the 

staff presentation and findings; 

WHEREAS, the recession has also impacted the activity of on-road heavy-duty vehicles 

covered by the Regulation to Reduce Emissions of Diesel Particulate Matter, Oxides of 

Nitrogen and Other Criteria Pollutants, from In-Use Heavy-Duty Diesel-Fueled Vehicles, 

title 13, Cal. Code Regs., section 2025 (Truck and Bus regulation) and that ARB staff 
Resolution 10-47 2

has estimated that emissions from vehicles covered by the Truck and Bus regulation 

are also lower than initially estimated when that regulation was adopted in 2008; 

WHEREAS, the Board directed staff to develop concurrent amendments to the 

Off-Road regulation and the Truck and Bus regulation that would provide economic 

relief to both off-road and on-road diesel fleets while continuing to meet the Board’s 

air quality goals and obligations; 

WHEREAS, on April 23, 2009, the Air Resources Board adopted revisions to 

California’s State Implementation Plan (SIP) reflecting implementation of the 2007 State 

Strategy (State Strategy); 

WHEREAS, the State Strategy identifies NOx and PM2.5 emission reduction targets 

that were expected from each control measure identified in the State Strategy at the 

time the State Strategy was adopted; 

WHEREAS, the commitment in the State Strategy is to achieve aggregate emission 

reductions from all control measures in the State Strategy; there is no commitment to 

achieve the emission reduction target for each individual control measure; 

WHEREAS, if a particular control measure does not achieve its expected emission 

reduction target, the State Strategy specifies that the emission reductions can be 

achieved through additional reductions from other identified measures, or from 

alternative control measures or incentive programs, as long as the aggregate emission 

reductions are achieved; 

WHEREAS, actual emissions from sources impacted by economic conditions will 

continue to change over time, and may increase as the economy recovers; 

WHEREAS, it is ARB’s responsibility to track progress towards achieving the State’s 

aggregate emission reduction commitment in the State Strategy, and if there is a 

shortfall in emissions reductions as the economy recovers, the State remains 

responsible for achieving the aggregate emission reductions commitment identified in 

the State Strategy; 

WHEREAS, between January 2010 and October 2010, ARB staff met and worked with 

affected private and public fleets that operate in-use off-road diesel vehicles and the 

public, in general, and held 20 public workshops statewide to discuss potential changes 

to the Off-Road regulation and updates to the emissions inventories; 

WHEREAS, with the information and comments received at the aforementioned 

meetings, ARB staff prepared a report, entitled “Staff Report: Initial Statement of 

Reasons for Proposed Rulemaking: Proposed Amendments to the Regulation for 

In-Use Off-Road Diesel-Fueled Fleets and the Off-Road Large Spark-Ignition Fleet 

Requirements,” released October 28, 2010 (ISOR); 
Resolution 10-47 3

WHEREAS the ISOR along with the report, “Staff Report: Initial Statement of Reasons 

for Proposed Rulemaking – Proposed Regulation for In-Use Off-road Diesel Vehicles” 

(Staff Report 2007) and an associated technical support document, “Technical Support 

Document – Proposed Regulation for In-Use Off-road Diesel Vehicles,” and the report, 

“Risk Reduction Plan to Reduce Particulate Matter Emissions from Diesel-Fueled 

Engines and Vehicles,” adopted by the Board on September 28, 2000, constitute the 

reports required under Health and Safety Code section 39665; 

WHEREAS, Staff Report 2007 further discussed the results of ARB staff’s evaluations 

of the non-cancer health effects of exposure to primary and secondary PM emissions 

from the vehicles subject to the initially proposed Off-Road regulation, and these 

evaluations indicated that exposure to these emissions can be associated with 

premature deaths and other non-cancer health impacts; 

WHEREAS, the United State Environmental Protection Agency (U.S. EPA) in a recently 

published review of the PM-related health science literature, which is the first part of an 

ongoing review of the national ambient air quality standards for PM, concluded that 

long-term exposure to PM2.5 is causally associated with premature mortality, and that 

premature deaths caused by PM2.5 occur at levels as low as 5.8 micrograms per cubic 

meter, which is considerably lower than the current national standard of 15 micrograms 

per cubic meter; 

WHEREAS, the U.S. EPA risk assessment methodology is the basis for ARB’s estimate 

that 9,200 (7,300 to 11,000, 95 percent confidence interval) premature deaths occur 

annually in California and that reducing emissions to meet the Federal standard would 

result in 2,700 fewer premature deaths annually; 

WHEREAS, the ISOR identified and explained the need to amend the Off-Road 

regulation for the following reasons: 

The global recession has caused a loss in employment and revenue in the 

construction sector and other industries that are affected by the Off-Road 

regulation; this has resulted in a reduction in business activity and has strained 

the financial ability of industry to comply with the regulation; 

Based on the new data available, staff now believes that past and future 

emissions from off-road diesel vehicles are significantly lower than previously 

estimated; staff has determined that it is feasible to provide economic relief to 

fleets, while still achieving the emission reductions necessary to attain the 

NAAQS; 

When the Board approved the Off-Road regulation in July 2007, staff believed 

off-road exhaust retrofit devices would be a widely available and a cost-effective 

solution for compliance for nearly all fleets; as implementation of the Off-Road 

regulation began, it became clear that for some fleets and applications, the 

installation of retrofit devices presented a significant challenge and accelerated 
Resolution 10-47 4

turnover to newer vehicles was a more appropriate compliance option; although 

exhaust retrofit devices remain a viable option for many fleets, staff believes it is 

necessary to restructure the Off-Road regulation to remove a mandatory retrofit 

requirement and instead allow fleets to choose between turnover and retrofitting 

of their vehicles as a compliance strategy; and 

Several areas of the Off-Road regulation need to be modified to make the 

regulation clearer, easier to implement, or correct inconsistencies discovered 

during the beginning stages of regulatory implementation. 

WHEREAS, the ISOR discussed, to the extent data could reasonably be made 

available, the factors specified in Health and Safety Code sections 39665(b), 43013, 

and 43018, including, but not limited to estimates of emissions, exposure, potential 

cancer risk and non-cancer health effects associated with the operation of in-use 

off-road diesel vehicles subject to the proposed amendments, technically feasible 

control options for compliance, potential environmental impacts, cost of compliance for 

all owners and/or operators of in-use off-road diesel vehicles, and cost impacts for ARB 

implementation of the proposed amendments; 

WHEREAS, for the reasons set forth above, staff has proposed the following 

amendments to sections 2449 through 2449.3, as set forth in Attachment A, to address 

the issues identified above: 

Delay the first compliance date for all fleets by approximately four years (i.e. 

compliance for large fleets would be delayed from March 1, 2010 to 

January 1, 2014); 

Place annual requirements on fleets over the following timeline: 

 

 Large fleets: 2014 to 2023;

 Medium fleets: 2017 to 2023; 

 Small fleets: 2019 to 2028;

 

In each compliance year, fleets (of all sizes) would be required to meet a single 

fleet average target, as opposed to separate NOx and PM targets, or complete a 

single set of Best Available Control Technology (BACT) requirements; 

Reduce annual BACT requirements from 8 to 10 percent turnover, and 

20 percent retrofitting, to a single requirement requiring the turnover or retrofitting 

of 8 to 10 percent of the fleet’s horsepower (4.8 percent for large fleets in 2014); 

Extend double credit period for fleets choosing to retrofit their vehicles; 

Define vehicles used 200 hours or less annually (previously 100 hours or less) as 

low-use, which would largely exempt such vehicles from the Off-Road 

regulation’s requirements; 
Resolution 10-47 5

Provide credit for reduced fleet horsepower from 2010 to 2011; 

Provide a simplified compliance option for fleets having a total fleet horsepower 

under 500 horsepower, which would allow the fleets to phase-out the use of Tier 

0 and Tier 1 vehicles between 2019 and 2029; 

Increase turn-over requirements of the Off-Road regulation in 2022 and 2023 so 

that fleets are required to turn over to additional Tier 4i and/or Tier 4 vehicles; 

and 

Make other minor amendments to clarify or streamline the Off-Road regulation. 

WHEREAS, Attachment B hereto contains staff’s suggested modifications to the initially 

proposed amendments set forth in Attachment A, based on staff’s further evaluation on 

the need for additional amendments and on comments received since release of the 

ISOR; 

WHEREAS, the Board has considered the impact of the Off-Road regulation on the 

economy of the State, and the potential adverse economic impacts on California 

business enterprises and individuals; 

WHEREAS, the Board has considered the community impacts of the proposed 

regulation including environmental justice concerns; 

WHEREAS, the California Environmental Quality Act (CEQA), section 21080.5 of the 

Public Resources Code and Board regulations at title 17, Cal. Code Regs., 

section 60006 require that no project that may have significant adverse environmental 

impacts be adopted as originally proposed if feasible alternatives or mitigation 

measures are available to reduce or eliminate such impacts; 

WHEREAS, a public hearing and other administrative proceedings have been held in 

accordance with the provisions of chapter 3.5 (commencing with section 11340), part 1, 

division 3, title 2 of the Government Code; 

WHEREAS, the Board further finds based on its independent judgment and analysis of 

the entire record before it that: 

In-use off-road diesel vehicles and engines that operate in the State – whether 

based in California or not – continue to be significant contributors of diesel PM 

and NOx emissions, which California must reduce to attain the ozone and PM2.5 

NAAQS and to reduce the health risks associated with such pollutants; 

The proposed amendments are necessary to provide economic relief to affected 

fleets while assuring that California continues to meet its air quality obligations 

and health based goals; 
Resolution 10-47 6

Even with the amendments and economic relief proposed, the proposed 

amended regulation would significantly reduce diesel PM and NOx emissions 

and associated cancer, premature mortality, and other adverse health effects 

statewide, such that emission reductions from the proposed amended regulation 

are expected to prevent 470 premature deaths from 2014 to 2029; 

In accordance with Health and Safety Code section 43013(a) and (b), the 

amended in-use emission standards and requirements are necessary, 

cost-effective, and technologically feasible for in-use on-road diesel fleets within 

the time provided for compliance; 

The proposed amendments would provide substantial economic relief for 

affected fleets, while the benefits of the regulation to public health and the 

environment justify the costs of compliance and enforcement; 

The proposed amended regulation would reduce the estimated costs in the first 

five years of the regulation by about 97 percent, from over $1 billion to 

approximately $33 million and the costs over the life of the regulation would be 

reduced by 72 percent, which represents a savings of over $1.5 billion; 

The overall cost effectiveness associated with proposed amended regulation with 

the updated inventory would be $76 per pound of diesel PM reduced and $4.31 

per pound of NOx reduced; 

The reporting requirements of the proposed amended regulation which apply to 

businesses are necessary for the health, safety, and welfare of the people of the 

state. 

WHEREAS, pursuant to the requirements of the California Environmental Quality Act 

(CEQA) and the Board’s regulations under its certified regulatory program, the Board 

further finds that: 

ARB staff has prepared an environmental analysis for the proposed amendments, which 

is contained in Chapter VI of the Initial Statement of Reasons (ISOR); 

Staff’s environmental analysis determined that the proposed amendments would 

substantially reduce both PM and NOx emissions, as compared to the environmental 

conditions that currently exist because the in-use emission requirements in the OffRoad regulation have not yet become effective and have therefore not yet resulted in 

actual emission reductions; 

 

Staff’s environmental analysis determined that the proposed amendments would 

substantially reduce both PM and NOx emissions, as compared to the environmental 

conditions that currently exist; this is because the future-effective standards in ARB’s 

current Off-Road regulation have not yet become effective and have therefore not yet 

resulted in actual emission reductions; 
Resolution 10-47 7

However, staff’s environmental analysis also determined that the emission benefits from 

the proposed amendments would, in the short term, be less than what would have 

occurred under the current regulation with no amendments; these foregone emission 

benefits are quantified in the ISOR; 

 

While the proposed amendments would not result in any adverse environmental 

impacts compared to the environmental conditions that currently exist, the foregone 

emission reductions in future years could be viewed as a significant adverse 

environmental impact; 

 

These potential adverse environmental impacts have been significantly lessened 

because of the recession and its impact on fleet activity, which has resulted in 

emissions being lower today than originally anticipated when the current regulation was 

adopted in 2007; emissions in future years will also be lower than originally anticipated, 

as demonstrated by the updated emissions inventory;

The ISOR describes the benefits of the proposed amendments, which are designed to 

address the serious economic recession and its impact on industry and residents of the 

State; and 

The Executive Officer is the decision maker for the purposes of title 17, California Code 

of Regulations, section 60007, and no final decision will be made until comments on the 

environmental analysis are fully considered and addressed by the decision maker. 

 

WHEREAS, the Board further finds that no alternatives considered or that have 

otherwise been identified and brought to the attention of the ARB would be more 

effective carrying out the purpose for which the amendments to the regulation is 

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

businesses and public agencies than the proposed amended regulation; 

WHEREAS, California is not preempted under section 209(e)(1) of the federal Clean Air 

Act (CAA) from adopting emission standards and other requirements related to the 

control of emissions from in-use off-road diesel engines covered by the regulation; 

WHEREAS, section 209(e)(2) of the CAA requires that California request authorization 

from U.S. EPA prior to enforcing emission standards or other requirements relating to 

the control of emissions from new and in-use nonroad engines (of which off-road diesel 

engines are a subpart) not otherwise preempted by section 209(e)(1); and 

WHEREAS, on August 12, 2008, and February 11, 2010, ARB submitted to the U.S. 

EPA requests for authorization pursuant to CAA section 209(e)(2) for the regulation that 

are currently pending before the U.S. EPA. 

NOW, THEREFORE, BE IT RESOLVED that the Board directs the Executive Officer to 

take the following actions: 
Resolution 10-47 8

Make the modified regulatory language as set forth in Attachment B and as 

directed below, with such other conforming modifications as may be appropriate, 

available for public comment for a period of 15 days, provided that the Executive 

Officer shall consider such written comments as may be submitted during this 

period, shall make such modifications as may be appropriate in light of the 

comments received, and shall present the regulation to the Board for further 

consideration if he determines that this is warranted; 

Evaluate all comments received during the public comment periods, including 

comments raising significant environmental issues, and prepare and approve 

written responses as required by Government Code section 11346.9, Public 

Resource Code section 21080.5(d)(2)(D), and title 17, California Code of 

Regulations section 60007; 

Determine whether there are feasible alternatives or mitigation measures that could be 

implemented to reduce or eliminate any potential adverse environmental impacts, while 

at the same addressing the serious economic recession and its impact on industry and 

residents of the State; 

Make findings as required by Public Resources Code section 21081 if the proposed 

amendments would result in one or more significant adverse environmental effects; 

Take final action to adopt the proposed amendments set forth in Attachment A, with the 

modifications set forth in Attachment B and as directed below, as well as any additional 

conforming modifications that may be appropriate, and any modifications that are 

necessary to ensure that all feasible mitigation measures or feasible alternatives that 

would substantially reduce any significant adverse environmental impacts have been 

incorporated into the final action, or return the proposed amendments and findings to the 

Board for further consideration before taking final action, if he determines that this is 

warranted. 

BE IT FURTHER RESOLVED that the Board directs the Executive Officer to develop 

and incorporate into the Off-Road regulation and Truck and Bus regulation a 

compliance option that would allow on-road and off-road vehicles that have been 

retrofitted consistent with the requirements of the two regulations to count towards the 

compliance requirements of either regulation for a specified period of time, so long as 

the actions taken under this option do not result in the loss of emission benefits in any 

given year, subject to the following conditions: 

 

If the vehicle that is retrofitted is subject to the Off-Road regulation and is not 

needed to demonstrate compliance with the BACT or fleet average requirements, 

the retrofitted vehicle may be used to comply with the Truck and Bus Regulation 

until such time that it is needed for compliance with the Off-Road regulation. 
Resolution 10-47 9

Similarly, if the vehicle is retrofitted and is not needed to demonstrate compliance 

with the Truck and Bus regulation, the retrofitted vehicle may be used to comply 

with the Off-Road regulation until such time that it is needed for compliance with 

the Truck and Bus Road regulation. 

BE IT FURTHER RESOLVED that the Board directs the Executive Officer to return to 

the Board as soon as practicable with a separate rulemaking that will amend other ARB 

regulations affecting two-engine vehicles, as necessary, to be consistent with the 

amendments proposed herein. 

BE IT FURTHER RESOLVED that the Board directs the Executive Officer to provide an 

update to the Board in 2012 on the impact of economic conditions on on-road heavy 

duty truck and off-road equipment emissions. 

BE IT FURTHER RESOLVED that the Board hereby determines, in accordance with 

CAA section 209(e)(2), that the proposed amendments as they affect nonroad vehicles 

or nonroad engines as defined in CAA section 216(10) and (11), do not undermine the 

Board’s previous determination that the regulation’s emission standards, other emission 

related requirements, and associated enforcement procedures are, in the aggregate, at 

least as protective of public health and welfare as applicable federal standards, are 

necessary as part of ARB’s off-road emissions program to meet compelling and 

extraordinary conditions existing in the state, and are consistent with CAA section 209. 

BE IT FURTHER RESOLVED that the Board, pursuant to CAA section 209(e)(2) and 

the determinations set forth in the preceding paragraph, directs the Executive Officer to 

request that if U.S. EPA has granted California authorization to adopt and enforce the 

regulation in response to its previously submitted requests that the Administrator 

confirm that the proposed amendments fall within the scope of the granted authorization 

and that if U.S. EPA has not taken action on California’s previously submitted requests 

by the date that the Executive Officer submits the latest amendments for review that the 

Administrator grant California a full authorization for the regulation as amended herein. 
Resolution 10-47 

December 17, 2010 

Identification of Attachments to the Board Resolution

Attachment A: Proposed amendments to the Regulation for In-use Off-road 

Diesel-Fueled Fleets Cal. Code Regs., title 13, section 2449 

through 2449.3 as set forth in Appendix A to the Initial Statement of 

Reasons, released October 21, 2010. 

Attachment B: Staff’s Suggested Modifications to the Proposed Amendments to 

the Regulation for In-use Off-road Diesel-Fueled Fleets.