BEFORE THE 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

In the Matter of California’s Request for 

Confirmation that its Requirements to 

Reduce Idling Emissions from New and 

In-Use Trucks, Beginning in 2008, are 

Either Not Preempted or Within the Scope 

of Previous Waivers of Preemption Issued 

Pursuant to Section 209(b) and 209(e) of 

the Clean Air Act, and Request for New 

Authorization Under Clean Air Act Section 

209(e)(2) 

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WAIVER AND AUTHORIZATION ACTION SUPPORT DOCUMENT 

 SUBMITTED BY THE 

 CALIFORNIA AIR RESOURCES BOARD

Submitted May 9, 2008 

I. INTRODUCTION AND OVERVIEW 

The California Air Resources Board (CARB or Board) requests that the Administrator of 

the U.S. Environmental Protection Agency (EPA) take the Clean Air Act (CAA) 

section 209(b) and (e)(2) waiver and authorization actions described below for CARB’s 

regulatory amendments adding requirements to reduce idling emissions from new and 

in-use trucks beginning in 2008 (the 2008 Truck Idling Requirements). The remaining 

paragraphs of this Section I summarize the specific actions we are requesting. Section 

II describes the process by which CARB adopted the amendments. Section III 

describes the 2008 Truck Idling Requirements. Section IV describes the pertinent 

California standards, test procedures, and related requirements for which waivers and 

authorizations have previously been issued. Section V describes the criteria and 

principles for granting CAA section 209 waivers, authorizations, and related 

determinations for California regulatory activities. Sections VI through IX demonstrate 

that the 2008 Truck Idling Requirements meet the criteria for waiver and authorization 

actions CARB is requesting. 

 

The 2008 Truck Idling Requirements consist of three elements. The first element, 

referred to as the “new engine requirements,” requires that new California-certified 2008 

and subsequent model-year on-road diesel engines in trucks with a gross vehicle weight 

rating (GVWR) greater than 14,000 pounds (heavy-duty diesel vehicles or HDDVs) be 

equipped with a system that automatically shuts down the engine after five minutes of 

continuous idling. In lieu of the engine shutdown system, manufacturers may optionally 

certify their engines to an oxides of nitrogen (NOx) idling emission standard of 30 grams 
per hour under loaded, low and high idle operating conditions. Since the engine 

shutdown system requirement is akin to an operational control limiting extended idling, 

CARB requests that EPA confirm that the requirement is not preempted by section 

209(a). Alternatively, the engine shutdown requirements are “other conditions 

precedent” required prior to the initial sale of new heavy-duty diesel engines; since a 

waiver has been issued for California’s 2007 and subsequent model-year standards for 

these engines, no further waiver action is necessary. Should EPA conclude that the 

engine shutdown requirement is an “emission standard,” CARB requests that the 

Administrator confirm that the requirement is within the scope of the waiver for 2007 and 

later heavy-duty diesel engines. No waiver action is necessary for the optional NOx 

idling emission standard as it is solely an option to the engine shutdown provision. A 

requirement that engines certified to the idling emissions standard carry a “clean idle” 

label is an additional condition precedent that is not preempted. 

The second element is designed to reduce idling emissions in California from the 

existing fleet of sleeper trucks, whether they are registered in California or another 

state. A preexisting CARB Air Toxic Control Measure (ATCM) requires that the operator 

of a commercial vehicle with a GVWR greater than 10,000 pounds manually shut off the 

engine before an idling time limit of five minutes is reached. The 2008 Truck Idling 

Requirements eliminated the provision that exempted sleeper-berth equipped trucks 

when the operator is resting in the sleeper berth and the engine is idling for climate 

control or to power on-board accessories. As a result, the operator of a sleeper truck is 

required to manually shut down the engine after five minutes of continuous idling 

starting January 1, 2008. This requirement – referred to as the “in-use idling ATCM 

requirement” – is a purely operational control that is not preempted by CAA 

section 209(a) and thus needs no waiver action by EPA. 

The third element was developed because of the expectation that the new idling 

restrictions could result in many HDDV operators using alternative technologies to 

supply power for truck cab or sleeper berth climate control and/or other on-board 

accessories that would otherwise have been generated by the continuous idling of the 

truck’s main engine. These technologies include, but are not limited to, internal 

combustion engine driven alternative power supplies (APSs) and fuel-fired heaters. To 

insure that such technologies do not undermine or reduce the emission benefits of the 

2008 Truck Idling Requirements, CARB established in-use performance requirements 

referred to as the “alternative technology requirements” that apply starting January 1, 

2008 to diesel-fueled commercial vehicles with a GVWR greater than 10,000 pounds 

operated in California. Those requirements, and the authorization action sought (if any), 

are summarized as follows. 

• The driver may not operate an APS using an internal combustion engine unless 

that engine has been certified to applicable California off-road and/or federal 

nonroad emissions standards and test procedures for its fuel type and power 

category. Any new APS engine acquired since the 2000 model year is already 

required to meet the California or federal nonroad engine standards. EPA should 

confirm that the in-use performance requirements are within the scope of the 

2
authorization for the new nonroad engine standards to be issued by EPA 

pursuant to CAA section 209(e)(2). 

• The driver may not operate a diesel-fueled APS engine on a vehicle with a 

primary engine certified to the 2007 and subsequent model-year heavy-duty 

diesel engine standards unless the APS is certified to the applicable California or 

federal non-road engine emission standard and either: 

o The exhaust is routed into the truck’s exhaust system and PM trap; 

o The engine is equipped with a level 3 verified PM control strategy 

(i.e. achieves at least an 85 percent PM reduction efficiency); or 

o The engine uses other procedures to demonstrate an equivalent level of 

emissions compliance. 

CARB seeks an authorization for this requirement pursuant to CAA 

section 209(e). A requirement that a complying APS carry a “verified clean APS” 

label is an accompanying enforcement procedure that should be included in the 

authorization action. 

• There are also requirements pertaining to fuel-fired heaters and to other idle 

reduction technologies such as the use of batteries, fuel cells, power 

inverter/chargers for on-shore power, and truck electrification. The provisions on 

fuel-fired heaters do not impose requirements on motor vehicle engines or 

nonroad engines and accordingly are not preempted by section 209. The 

provisions on other idle reduction technologies either fall within the scope of an 

authorization being sought by CARB or meet the criteria for a new authorization. 

II. ADOPTION OF THE 2008 TRUCK IDLING REQUIREMENTS 

The Board considered the 2008 Truck Idling Requirements at an October 20, 2005 

hearing. At the hearing, the Board approved the requirements by Resolution 05-55 

(Reference 5) subject to a supplemental comment process. In accordance with the 

Board’s direction, after making modifications to the regulation available for supplemental 

public comment, ARB’s Executive Officer formally adopted the 2008 Truck Idling 

Requirements by issuing Executive Order R-06-003 on September 1, 2006 

(Reference 6). The 2008 Truck Idling Requirements were submitted to California’s 

Office of Administrative Law (OAL) for review on September 1, 2006, and were 

approved by OAL and filed with California’s Secretary of State on October 16, 2006. 

The 2008 Truck Idling Requirements became effective under state law November 15, 

2006. 

The specific regulatory text amended by the 2008 Truck Idling Requirements is set forth 

in title 13, California Code of Regulations (CCR), sections 1956.8, 2404, 2424, 2425, 

and 2485 (see Reference 9). Those sections incorporate the amended test procedure 

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document: "California Exhaust Emission Standards and Test Procedures for 2004 and 

Subsequent Model Heavy-Duty Diesel Engines and Vehicles.” (See Reference 10.) 

III. SUMMARY OF THE 2008 TRUCK IDLING REQUIREMENTS 

A. Background 

In California, emissions generated from idling HDDVs pose a significant air quality 

problem. By 2010, HDDVs are estimated to account for as much as 28 percent, or 

559 tons per day (tpd), of the statewide mobile source NOx emission inventory and 

9 percent, or 12 tpd, of the statewide mobile source PM emission inventory. This is 

especially significant since these estimates already take into account the stringent 2007 

on-road heavy-duty diesel engine (HDDE) exhaust emission standards recently adopted 

by CARB and EPA. 

Operators of HDDVs generally idle vehicle engines at truck stops and at rest areas 

during layover hours to provide heat or cooling to the sleeper berth, to operate on-board 

electrical accessories, to maintain battery charge, and to warm the engine for easy 

start-up during cold weather. HDDV idling is also significant at warehouse/distribution 

centers and port terminals where loading and unloading freight require long waiting 

periods. The high density of idling trucks at such locations for extended periods of time 

can produce highly localized and concentrated emissions which adversely affect the 

health of the drivers and the neighboring communities. The health concerns become 

more serious when these idling centers are located in low income communities that are 

already disproportionately impacted by air pollution. HDDV idling also consumes fuel 

and increases engine maintenance costs. 

California’s plan for reducing the reactive organic gases (ROG) and NOx that contribute 

to both ozone and particulate matter (PM) formation is set forth in the 2003 State and 

Federal Strategy for the California State Implementation Plan (2003 SIP). Mobile 

sources produce the majority of the state’s ozone precursor emissions and diesel PM 

inventory. Controlling mobile source emissions is therefore an important element of 

California’s strategy for attaining air quality standards and constitutes a significant part 

of the 2003 SIP. The 2008 Truck Idling Requirements are designed to reduce 

emissions generated from idling on-road HDDEs, and are part of the 2003 SIP’s 

proposed on-road heavy-duty vehicle control measure “ON-RD HVY DUTY 3.” 

On December 12, 2002, CARB adopted an ATCM that required operators of school 

buses, transit buses, and other commercial vehicles to manually shut off their engines 

upon arriving at a school. Restarting the engines is limited to no more than 30 seconds 

before departing.1

 CARB subsequently adopted at its July 22, 2004 public hearing 

more general requirements to limit emissions from in-use diesel-fueled commercial 

vehicles with a GVWR greater than 10,000 pounds. Operators of commercial trucks 

and buses are required to manually shut off their engines before an idling time limit of 

 

1

 Title 13, CCR section 2480. 

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five minutes is reached. However, this requirement does not apply to idling 

sleeper-berth equipped trucks unless they are located within 100 feet from residential 

homes or schools.2

 

B. The 2008 Truck Idling Requirements

1. The New Engine Requirements for New 2008 and Subsequent 

Model-Year California-Certified HDDE Requirements (Amendments to 

title 13, CCR section 1956.8) 

The new engine requirements provide two compliance options for new California 

certified 2008 and subsequent model-year HDDEs installed in trucks with a GVWR 

greater than 14,000 pounds. Gasoline engines and diesel engines produced for use in 

buses (commercial buses as well as school buses), recreational vehicles, medium-duty 

vehicles, military tactical vehicles or authorized emergency vehicles are exempted from 

the new engine requirements. 

 

 a. Idle Shutdown System

The first compliance option requires engine manufacturers to install in new California 

certified 2008 and subsequent model-year HDDEs a system that automatically shuts 

down the engine after five minutes of continuous idle operation. The engine shutdown 

system must be tamper resistant and non-programmable. 

 

(i) Shutdown Conditions 

The engine shutdown system must automatically shut down the engine after five 

minutes of continuous engine operation at idle when the truck comes to a stop, the 

transmission is set in the “neutral” or “park” position, and the parking brake is engaged. 

If the parking brake is not engaged, the engine shutdown system must shut down the 

engine after 15 minutes of continuous idling if the truck is stopped and the transmission 

is set in the “neutral” or “park” position. 

 (ii) Shutdown Timer Reset Provisions 

A truck operator is allowed to reset the engine shutdown system timer before the engine 

shuts down. A warning signal, such as a light or sound indicator inside the truck’s cab, 

may be used to alert the operator up to 30 seconds prior to engine shutdown. The 

operator can then reset the engine shutdown system by momentarily changing the 

position of the accelerator, clutch, or brake pedal or any other mechanism only during 

the last 30 seconds of the five-minute shutdown time limit (or the last 30 seconds of the 

15 minute shutdown limit when the parking brake is not engaged). This will allow the 

truck operator to continue operating the engine at idle as long as the truck is being 

driven. 

 

2

 Title 13, CCR section 2485. 

5
 (iii) Override Provisions 

The engine shutdown system may be overridden if the engine is operating power 

take-off (PTO) equipment such as that associated with trash trucks, cement mixers, 

mobile cranes, dump trucks, and vehicles with conveyors or other loading or unloading 

devices. Equipment associated with a truck’s air conditioning system and on-board 

accessories (e.g., a television, microwave, etc.) do not qualify as PTO equipment. The 

engine shutdown system may also be overridden to warm up the engine if the engine 

coolant temperature is below 60°F. The engine coolant temperature must be measured 

using the engine’s existing engine coolant temperature sensor designed for engine 

protection. However, a manufacturer may request the Executive Officer’s approval to 

use other methods of measuring the engine coolant temperature. Finally, the engine 

shutdown system may be overridden during exhaust emission control device 

regeneration or maintenance periods, of if engine servicing or maintenance requires 

extended idling. 

(iv) Technical Feasibility of Engine Shutdown Systems 

As discussed in Section V.A. of the Staff Report: Initial Statement of Reasons (ISOR, 

Reference 2), engine shutdown systems are software-based controls that are presently 

available as standard features in most commercially available on-road heavy-duty 

engines. Engine manufacturers including Detroit Diesel Corporation, Cummins, and 

Caterpillar presently build engine shutdown systems into their engines’ electronic 

control software and make those engine shutdown systems available as standard 

features, but most fleet owners and operators do not activate such engine shutdown 

systems. CARB staff found that only minor modifications to the programming of 

currently available HDDE electronic control software would be needed to comply with 

this new engine requirement compliance option. Staff also estimated that the 

compliance costs associated with this option would be minimal – $100 per engine to 

cover additional administrative costs and minimal reprogramming costs. 

 b. Optional NOx Idling Emission Standard

 (i) Description of Standard 

During the development of the 2008 Truck Idling Requirements, several engine 

manufacturers indicated that NOx aftertreatment devices may reduce NOx idling 

emissions to some extent, and requested an option to certify engines to a new NOx 

idling emission standard as an alternative to complying with the engine shutdown 

system requirements. Another method suggested by the manufacturers was utilize 

other strategies, such as advanced combustion processes or operational controls such 

as cylinder deactivation, to reduce NOx emissions during idling. 

To accommodate the engine manufacturers’ requests, CARB staff developed an 

optional NOx idling emission standard and test procedure as an alternative to the 

engine shutdown system requirement. Staff determined that an emission standard of 

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30 grams of NOx per hour (without also increasing emissions of other criteria pollutants) 

was equivalent to the emissions of a 5 to 19 kW diesel-fueled off-road APS, and that 

this standard would provide significant NOx emissions benefits compared to the 

average NOx idling emissions from late model HDDEs. 

Staff also developed a test procedure to account for the varied operation of truck 

engines at idle. Typically, truck operators elevate the idle speed to provide more power 

for cab comfort and accessory devices. Higher engine speed also reduces truck 

vibration when idling and thus provides more comfort for the operator during rest 

periods. The test procedure requires engine testing at “curb idle” and at 1100 

revolutions per minute (rpm) idle speed, under loaded and unloaded conditions using an 

engine dynamometer operated under a 2-mode steady-state test cycle. 

 (ii) Technical Feasibility of the Optional NOx Idling Emission Standard 

In the ISOR, staff acknowledged that although NOx aftertreatment devices such as NOx 

adsorbers or NOx catalysts could be used to reduce NOx emissions from idling engines, 

these devices generally operate most efficiently at exhaust temperatures higher than 

200oC, and exhaust temperatures during extended idling typically are no higher than 

150oC. Several engine manufacturers, however, indicated that sufficient temperatures 

could be achieved by using supplemental heat sources in conjunction with NOx 

aftertreatment devices. Staff indicated in Section V.B of the ISOR that it did not expect 

manufacturers would certify engines under this compliance option until 2010. 

Although several commenters stated that the optional NOx idling emission standard was 

not technically feasible by the January 1, 2008 compliance date, since NOx 

aftertreatment devices were not anticipated to be feasible until the year 2010, CARB 

staff disagreed in the Final Statement of Reasons (FSOR), stating that although it had 

anticipated in the ISOR that it did not expect this option to be widely available until 

2010, it did not believe that the NOx idling emission standard was technically infeasible. 

As discussed above, several engine manufacturers have indicated that existing NOx 

aftertreatment devices demonstrate the potential to reduce NOx emissions during idling 

(if supplemental heat sources are also used). Furthermore, contrary to CARB’s early 

predictions, manufacturers have certified significantly more 2008 model-year engines to 

this option than staff previously anticipated. 

2. The In-Use Idling ATCM for Sleeper-Berth Equipped HDDVs 

(Amendments to title 13, CCR section 2485) 

The 2008 Truck Idling Requirements also amend the existing idling ATCM to include 

in-use sleeper trucks, whether they are registered in California or another state. The 

idling ATCM in title 13 CCR section 2485 requires truck operators to manually shut off 

engines after five minutes of continuous idling, but previously exempted sleeper-berth 

equipped trucks when the operator was resting in the sleeper berth and idling the main 

engine for climate control or to power on-board accessories. The 2008 Truck Idling 

Requirements removed this exemption for sleeper-berth equipped trucks and now 

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requires sleeper truck operators to manually shut down the engine after five minutes of 

continuous idling starting January 1, 2008. 

No comments were submitted regarding the technical feasibility of these requirements. 

It is readily apparent that a sleeper berth truck operator can readily comply with this 

requirement by manually shutting off the truck’s engine after five minutes of continuous 

idling. 

3. Alternative Technology Requirements (Amendments to title 13, CCR 

sections 2485(c)(3), 2404, 2424, and 2425) 

Many HDDV operators will likely utilize truck-mounted alternative technologies to supply 

power for truck cab or sleeper berth climate control purposes and/or other 

on-board accessories that would otherwise have been generated by the continuous 

idling of the truck’s main engine. These technologies include internal combustion 

engine driven APSs and fuel-fired heaters. Currently, the most widely used on-board 

auxiliary devices on sleeper trucks are APSs powered by small diesel-fueled internal 

combustion engines equipped with generators/alternators to provide climate control, 

heat to the engine for cold weather starting, 12-volt DC electrical power to charge the 

batteries and 110-volt AC power for on-board accessories. These APSs are subject to 

existing CARB off-road engine emission standards because they are not used to propel 

motor vehicles.3

 The vast majority of off-road engines used in APS applications are 

rated at less than 19 kW (26.03 hp). 

A primary consideration in developing the alternative technology emission requirements 

was to ensure that the requirements would not undermine California’s new 2007 

on-road HDDE emission standards. Specifically, starting in 2007, new on-road 

California-certified diesel engines are subject to aftertreatment-based diesel particulate 

matter (PM) standards that are more stringent than the recently adopted Tier 4 off-road 

PM standards applicable to diesel-fueled APSs.4 Therefore, unless safeguards were 

incorporated into the alternative technology requirements, PM emissions from 

diesel-fueled APSs would overwhelm the PM emissions benefits of the 2008 Truck 

Idling Requirements. CARB accordingly established APS emission requirements that 

are dependent on the model year of the truck engine utilizing the APS. Alternative 

technologies that comply with the performance requirements may be used on both new 

and in-use HDDEs and HDDVs. The requirements apply starting January 1, 2008 to all 

diesel-fueled commercial motor vehicles with a GVWR greater than 10,000 pounds 

when operated in California. 

 

3

 In this request the term “off-road” is used intrerchangeably with the federal term “nonroad.” 

4 At a public hearing on December 9, 2004, CARB approved amendments to its off-road CI regulations to 

harmonize ARB’s standards and test procedures with the federal standards and test procedures specified 

in its Tier 4 rulemaking (40 CFR Part 89) and the subsequent Omnibus Technical Amendments 

(70 Fed.Reg. 40240 (July 13, 2005)), while still maintaining the emission benefits of the current California 

program. The ARB Tier 4 exhaust emission standards for new off-road CI engines rated less than 19 kW 

are implemented starting with the 2008 model year. 

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 a. General Emission Requirements for APSs 

Internal combustion engines used in APSs must be certified to the California or federal 

non-road emission standards and test procedures applicable to their fuel type and 

horsepower category of the engines. 

 b. Specific Requirements for Diesel-Fueled APSs 

 (i) 2007 and Subsequent Model-Year Trucks 

Diesel-fueled APSs installed on trucks equipped with 2007 and subsequent model year 

HDDEs must comply with the California or federal non-road emission standards and test 

procedures applicable to the horsepower category of the engines and additionally must 

either: 

• route their exhaust into the truck’s exhaust system so that the APS’s PM 

emissions are controlled by the truck’s PM trap; or 

• be equipped with a level 3 verified PM control strategy (i.e., achieve an 

85 percent PM reduction efficiency).5

 CARB’s verification procedures involve a 

thorough evaluation of the emission reduction capability of a trap and of its 

durability. The verification process ensures that the emission reductions 

achieved by the trap are both real and durable, and that production units in the 

field are achieving emission reductions that are consistent with the verification. It 

also requires the manufacturer to warrant that its PM trap is free from defects in 

design, materials, workmanship, and that operation of the trap achieves the 

emission reduction levels it was verified to; or 

• subject to advance Executive Officer approval, use other procedures to 

demonstrate an equivalent level of emissions compliance (compared to a level 3 

verified PM control strategy). 

 

 (ii) 2006 and Older Model-Year Trucks 

Diesel-fueled APS engines installed on trucks equipped with 2006 or older model-year 

diesel engines need only comply with the California or federal non-road emission 

standards and test procedures applicable to the horsepower category of the engines. 

This requirement is in effect subsumed by the requirement described above for all 

internal combustion engines used in APSs. 2006 and older model year HDDEs are not 

equipped with PM aftertreatment systems and therefore PM emissions from a certified 

diesel APSs will not be greater than the PM emissions from idling main engines. 

 (iii) Technical Feasibility of Diesel-Fueled APS Emission Requirements 

 

5

 The PM trap verification procedure and in particular, the level 3 verification level, are specified in title 13, 

CCR sections 2700 to 2710. 

9
CARB did not receive any comments questioning the technical feasibility of routing a 

diesel APS’ exhaust upstream of the main engine’s diesel particulate trap. It did receive 

two comments questioning whether this compliance option might jeopardize the 

warranty provided by the main engine’s manufacturer (FSOR, Comments 35 and 36 

and Agency response thereto, pp. 38-39). 

The level 3 verified PM control strategy option is technically feasible within the specified 

timeframes, and particulate filters for diesel fueled APSs should be available before the 

implementation date of the 2008 Truck Idling Requirements. In fact, Cummins and 

Caterpillar were developing integrated main engine/APS systems that they expected to 

offer as factory options in 2006. During the development of CARB’s Tier 4 off-road 

emission standards, aftertreatment technology was not commercially available for small 

diesel engines, such as the engines powering diesel APSs, and staff therefore could not 

specifically elaborate on the feasibility of applying PM aftertreatment to these smaller 

diesel engines. However, there is no inherent PM emission characteristic that would 

prevent a manufacturer from applying a PM filter system used on larger diesel engines 

to smaller diesel engines. The lower exhaust temperatures from smaller engines will 

likely require an active regeneration strategy to prevent the PM filter from clogging, but 

PM aftertreatment strategies being developed for 2007 and newer on-road HDDEs will 

also employ active regeneration strategies to prevent the possibility of PM filter failure 

under certain low exhaust temperature operations. Therefore, on-road diesel PM filter 

technologies that will be deployed on HDDEs beginning in 2007 can be applied to diesel 

fueled APSs with only modifications to active regeneration strategies and to 

accommodate the smaller PM filter sizes. Furthermore, PM traps and regeneration 

strategies designed for use in transport refrigeration units (TRUs) and TRU generator 

sets can be readily adapted to APSs, since these applications use the same categories 

of small diesel engines that are operated under similar engine speeds and loads. 

Moreover, if in fact no level 3 verified PM control strategy is available in 2008, truck 

operators may elect to simply route the APS’ exhaust upstream of the truck’s particulate 

trap or to utilize other available cab comfort technologies, such as battery electric APS 

and thermal energy storage systems. 

 c. APS Labeling Requirements

A truck equipped with an APS that complies with the emission requirements outlined 

above must display a label on its hood area to aid enforcement staff in quickly 

identifying which diesel engines and trucks are equipped with compliant APSs. 

 

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 d. Emission Requirements for Fuel-Fired Heaters

Fuel-fired heaters are used to provide heat to truck cabs or sleeper berths and/or to 

preheat the engine block during cold weather. Beginning January 1, 2008, 2007 and 

subsequent model-year trucks in California may only operate fuel-fired heaters that 

comply with the requirements specified in California’s second generation Low Emissions 

Vehicle (LEV II) regulations.6

 The LEV II regulations require fuel-fired heaters to meet 

the Ultra Low Emission Vehicle exhaust emission standards for light duty vehicles. 

However, unlike the LEV II program requirement that limits the operation of fuel-fired 

heaters to ambient temperatures of 40oF or less, the alternative technology 

requirements allow fuel-fired heaters to be operated at any ambient temperature. 

Several manufacturers currently produce fuel-fired heaters for heavy-duty trucks that 

meet the proposed requirement. 

 e. Other Idle Reduction Devices/Strategies

Alternative technologies that do not directly produce emissions, such as battery electric 

APSs, fuel cell APSs, thermal energy storage devices, or power inverter chargers for 

use with battery and grid-supplied electricity are also allowed. Technologies not 

otherwise specifically identified in the 2008 Truck Idling Requirements may also be 

used, subject to the approval of CARB’s Executive Officer. 

 (i) Battery Electric APS 

Battery electric APSs typically consist of an independent electrically driven heating and 

air-conditioning system and an inverter to provide 120 Volt AC electrical power for 

on-board accessories, and are capable of providing more than ten hours of continuous 

cab comfort between charges. Depending on the number of batteries installed and 

alternator capacity, such systems typically require two to six hours of charging time. 

Commercially available battery systems cost between $4,000 to $10,000 per unit. 

Examples of commercially available battery electric APS systems include Idling 

Solutions’ Idling Solutions 9000 and Bergstrom’s Nite System. 

 (ii) Fuel Cell APS 

Fuel cell APSs offer the potential of supplying power to heat or cool a cab/sleeper 

compartment and run on-board electrical equipment without producing any associated 

emissions. However, technical and economic issues, such as availability and 

infrastructure of a suitable fuel, the production costs of the units, and integration of the 

units with other on-board truck systems need to be resolved before such systems can 

become cost-effective for commercial truck operators. 

 

6

 The standards are specified in title 13, CCR, section 1961(a)(15) and (d), or in Part I.E.1.13 of the 

incorporated “California Exhaust Emission Standards and Test Procedures for 2001 and Subsequent 

Model Passenger Cars, Light-Duty Trucks and Medium-Duty Vehicles.” 

11
 (iii) Cold Storage Systems 

Cold storage systems utilize the truck’s air conditioning system to store cooling energy 

when the truck is operated that is retained and later used to cool the sleeper berth when 

the truck is stopped and the driver is resting. Some aftermarket cold storage systems 

are currently commercially available and may be used in conjunction with a fuel-fired 

heater to provide both heating and cooling. An example of a cold storage system that is 

currently commercially available is Webasto’s BlueCool Truck system. Including 

installation, this system costs $3,600 per unit ($4,600 including a heater). 

(iv) On-Shore Electrical Power 

The development of an electrical power infrastructure at truck stops and other locations 

is another option to reduce engine idling emissions. On-shore electrical power involves 

the electrification of truck parking spaces to provide power for heating, cooling and 

on-board accessories. While it provides significant emissions benefits at the truck stop 

area or the site where it is installed, it is not widely available. Even if such systems 

become widely available in the future, truck operators located away from such 

installations may still need an alternative cab comfort technology that is portable with 

the truck. There are currently two methods of using on-shore electrical power. One 

method allows the truck to “plug-in” to the electrical power grid to power on-board air 

conditioning and heating systems, referred to as “on-board power infrastructure.” The 

other method relies on heating and air conditioning provided at the location where the 

infrastructure is installed, referred to as “off-board power infrastructure.” 

[1] On-Board Power Infrastructure 

This technology provides trucks with 110-volt AC electrical power at truck stops or other 

locations to run the air conditioning, heating and on-board accessories. This requires 

truck stops to be equipped with electrical outlets throughout the parking spaces and 

trucks need to be equipped or retrofitted with inverter/chargers, electrical power 

connections and electrically driven heating and air conditioning units. The 

inverter/chargers are used to charge the truck batteries from grid supplied electricity and 

to convert the truck batteries' 12-volt DC to 120-volt AC power for all on-board 

accessories. The drawbacks of this system include the high initial infrastructure cost, 

cost for equipment add-ons to trucks, and its availability, which is limited to where the 

infrastructure is installed. 

[2] Off-Board Power Infrastructure 

IdleAire Technologies recently introduced an off-board infrastructure system that 

provides 110-volt AC electrical power for on-board accessories, an externally installed 

heating and air conditioning unit, and hook-ups for basic telephone, internet and 

television (access to cable/satellite) services at each truck parking space. The unit is 

connected to the truck through a console installed to the truck window using a template 

insert. The console contains all the necessary connections and controls, including a 

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card reader for the billing system. Basic services currently cost about $1.25 to $1.50 

per hour. The drawbacks are the high infrastructure installation and maintenance costs 

and availability, which is limited to where the infrastructure is installed. 

4. Labeling Requirements (Amendments to title 13, CCR sections 1956.8, 

2404, 2424, and 2425) 

Because the 2008 Truck Idling Requirements allow diesel-powered trucks certified to 

the optional NOx idling emission standard to idle continuously longer than five minutes 

(except when located within 100 feet of a restricted area), and also allow compliant 

alternative idling technologies to continually operate (again, except when located within 

100 feet of a restricted area), engine manufacturers, original vehicle equipment 

manufacturers (OEMs), or internal combustion engine APS manufacturers, as 

applicable, are required to produce and affix standardized permanent labels to the hood 

of the truck to assist enforcement staff in clearly and easily identifying those diesel 

trucks that comply with the 2008 Truck Idling requirements. 

For new engines certified to the optional NOx idling emission standard or engines 

equipped with an integrated engine-APS exhaust system for which the engine 

manufacturer is responsible, the engine manufacturer will be responsible for producing 

the labels and supplying them to the OEM. The OEM is then required to affix the label 

to the hood of the truck. Aftermarket manufacturers of internal combustion engine 

APSs that meet California requirements and who install APSs on trucks are responsible 

for producing the label and affixing it to the hood of the truck. If the APS manufacturer 

does not install the APS, the APS manufacturer must supply the label to the party that 

installs the APS (OEM or any other APS installer), and that party must affix the label. 

IV. PREEXISTING CALIFORNIA ON-ROAD HEAVY-DUTY DIESEL EMISSION 

STANDARDS, TEST PROCEDURES AND VEHICLE LABELING PROVISIONS 

FOR WHICH A WAIVER HAS BEEN GRANTED, AND OFF-ROAD EMISSION 

STANDARDS AND TEST PROCEDURES FOR WHICH AN AUTHORIZATION 

HAS BEEN GRANTED (OR IS PENDING) 

A. On-Road Heavy-Duty Diesel Emission Standards

On August 26, 2005, the EPA Administrator granted California a waiver of preemption 

pursuant to section 209(b) of the CAA for CARB’s adoption of amendments to its 

heavy-duty diesel engine standards for 2007 and subsequent model-year vehicles and 

engines and related test procedures, including the not-to-exceed (NTE) and 

supplemental steady-state tests (supplemental test procedures) to determine 

compliance with applicable standards.7

 These standards apply to all heavy-duty diesel 

engines, except those in urban buses, and align California’s standards and test 

 

7

 70 Fed.Reg. 50322 (August 26, 2005). 

13
procedures with existing federal standards and test procedures applicable to 2007 and 

subsequent model-year heavy-duty diesel engines and vehicles.8

 CARB’s amendments 

Increased the stringency of the California emission standards for NOx, non-methane 

hydrocarbons (NMHC) and PM compared to the previously applicable California 

standards. The PM standard applicable to 2007 and subsequent model-year 

heavy-duty diesel engines is 0.01 grams per brake horsepower-hour (g/bhp-hr). 

B. Small Off-Road Engine Emission Standards

As previously mentioned, most off-road engines used in APS applications are rated at 

less than 19 kW (26.03 hp). Therefore, the following discussion will be limited to 

authorizations either granted or being sought for engines less than 19 kW. 

 1. Utility, Garden and Lawn Engine/Small Off-Road Engine Standards 

Since the enactment of the California Clean Air Act in 1988 – which authorizes CARB to 

adopt emission standards and other regulations for off-road vehicles and nonvehicular 

engine categories – CARB has adopted numerous regulations applicable to off-road 

engines rated at or less than 19 kW. 

CARB first adopted standards and test procedures applicable to utility and lawn and 

garden engines (ULGEs Rule, subsequently renamed in a later rulemaking as the 

“Small Off-Road Engine (SORE) Regulation”9

) on March 20, 1992, which OAL approved 

on May 1, 1992. In April 1993, in response to a petition from industry, CARB amended 

these regulations to delay initial implementation until January 1, 1995. CARB requested 

that EPA grant authorization for the SORE regulation as required by section 209(e)(2) of 

the federal CAA.10 The Administrator granted authorization to CARB on July 5, 1995.11

The authorized SORE regulation established exhaust emission standards for all 

gasoline, diesel, and other fueled spark-ignited (SI) and compression-ignited (CI) 

engines and equipment under 25hp (19kW) that were found not to be otherwise 

 

8 See p. 3, Decision Document accompanying waiver determination in 70 Fed.Reg. 50322 (August 26, 

2005) 

9

 For purposes of consistency, the regulation will be referred to as the SORE regulation. 

10 Section 209(e) provides in pertinent part: 

(1) No state or any political subdivision thereof shall adopt or attempt to enforce any standard or 

other requirement relating to the control of emissions from either of the following new 

nonroad engines or nonroad vehicles subject to regulation under this Act– 

(A) New engines which are used in construction equipment or vehicles or used in farm 

equipment or vehicles and which are smaller than 175 hp. 

(B) New locomotives or new engines used in locomotives 

* * * * * 

(2) (A) In the case of any nonroad vehicles or engines other than those referred to in 

subparagraph [(e)(1)], the Administrator shall, after notice and public hearing, authorize 

California to adopt and enforce standards and other requirements relating to the control 

of emissions from such vehicles and engines if [certain specified conditions are met]. 

See infra. 

11 60 Fed.Reg. 37440 (July 20, 1995). 

14
preempted. The regulation established two tiers of exhaust emission standards for new 

engines. Tier I standards applied to 1995 through 1998 model-year engines, while the 

Tier II standards applied to 1999 and newer engines. Emission standards were 

established for hydrocarbon (HC), NOx, carbon monoxide (CO), and PM, the last of 

which applied only to diesel-powered and two-stroke engines. The SORE regulation 

also included test procedures and provisions for warranty and production engine 

compliance programs. The SORE regulation applied to two categories of small off-road 

engines – handheld and non-handheld. Engines in handheld applications, such as 

chainsaws and trimmers, were required to comply with less stringent emission 

standards than non-hand-held equipment and engines. 

CARB amended the SORE regulation in 1994, 1995, and 1996 to clarify certification 

and implementation procedures of the Tier 1 standards, exempt military tactical 

equipment, and relax the Tier 1 CO emission standard on class 1 and 2 engines and the 

HC and NOx standards for engines used in certain “wintertime” equipment. CARB 

requested and received EPA’s confirmation that these amendments fell within the scope 

of the initially granted SORE authorization on November 9, 2000.12 

2. 1998 SORE Amendments 

In 1998, CARB amended the SORE regulation to apply to all engines rated less than 

25 hp that are used in off-road applications (i.e., not just utility and lawn and garden 

engines), including specialty vehicles and golf cart engines; revised the regulation to be 

based on engine displacement instead of whether the engine is used in a handheld or 

non-handheld application; and delayed implementation of the 1999 Tier 2 standards for 

at least one year. For CI engines, the Board extended application of the authorized 

Tier 1 emission standards one year and adopted the new emission standards for new 

engines under 19 kW, consistent with the “Compression-Ignition Engine Statement of 

Principles” (SOP) jointly entered into by CARB, EPA, and engine manufacturers in 

August 1996. The adopted emission standards were to be phased in, starting with the 

2000 model year.13 Finally, CARB adopted new durability requirements that were also 

to be phased in for new engines starting in the 2000 model year. 

EPA subsequently determined that, except for the above-mentioned durability 

requirements, California’s 1998 amendments to the SORE regulation were within the 

scope of the previously granted 1995 authorization.14 EPA issued CARB a new 

authorization for the durability requirements on November 21, 2003.15 

 

12 65 Fed.Reg. 69763 (November 20, 2000). 13 These emission standards were subsequently also adopted by EPA in its final rule for “Control of 

Emissions of Air Pollution from Nonroad Diesel Engines,” 62 Fed.Reg. 200 (January 2, 1997). 14 65 Fed.Reg. 69767 (November 20, 2000). 15 68 Fed.Reg. 65702 (November 21, 2003). 

15
3. 2004 SI SORE Amendments 

In 2004, CARB amended the exhaust emission standards and associated test 

procedures for SI small off-road engines, and adopted evaporative emission standards 

and associated test procedures for SI small off-road engines rated at or below 19 kW or 

equipment utilizing such engines. These amendments: aligned CARB’s HC + NOx 

exhaust emission standards with federal exhaust standards for engines less than 50 

cubic centimeters (cc) starting with the 2005 model year; extended the exhaust 

emission standards for 50 to 65 cc engines up to 80 cc engines, beginning in the 2005 

model year; adopted catalyst-based standards for engines between 80 to less than 225 

cc and 225 cc and larger engines; and more closely aligned CARB and federal exhaust 

emission test procedures. These amendments also established, for the first time, 

permeation and diurnal evaporative emission standards and associated test procedures 

for small off-road engines and fuel tanks on equipment powered by small off-road 

engines beginning in the 2007 model year. EPA issued CARB a full authorization for 

the 2004 SI SORE amendments on December 15, 2006.16

 

 4. 2000 and 2004 Off-Road CI Amendments 

On January 28, 2000, CARB adopted amendments to regulations applicable to 2000 

and subsequent model-year off-road CI engines. These amendments did not 

substantively amend the Tier I and Tier 2 requirements applicable to new CI engines 

rated at or less than 19 kW, but merely moved the regulations for new CI engines less 

than 19 kW from the SORE regulation (title 13 CCR section 2400 et seq.) to a new 

regulatory section in title 13 CCR section 2400 et seq. that includes all off-road CI 

engines. With this change all off-road CI engine categories are contained in the same 

regulatory section, which conforms to the federal regulatory program. The 2000 

amendments therefore recodify the emission standards adopted in 1998 for CI SORE 

engines. 

At a public hearing on December 9, 2004, CARB approved amendments to its off-road 

CI regulations to harmonize CARB’s standards and test procedures with the federal 

standards and test procedures specified in its Tier 4 rulemaking (40 CFR Part 89) and 

the subsequent Omnibus Technical Amendments (70 Fed.Reg. 40240 (July 13, 2005)), 

while still maintaining the emission benefits of the current California program. CARB 

Tier 4 exhaust emission standards for new off-road CI engines rated less than 19 kW 

are scheduled to be implemented starting with the 2008 model year. California’s OAL 

approved the 2004 amendments on December 7, 2005, and CARB will soon file a 

request for authorization that covers both the 2000 and 2004 amendments to the 

standards for new off-road CI engines. 

 

16 71 Fed.Reg. 75536 (December 15, 2006). 

16
V. WAIVER AND AUTHORIZATION CRITERIA AND PRINCIPLES 

A. Criteria for Granting Waivers of Preemption Under CAA Section 209(b) 

and Confirmations that Amendments are Within the Scope of Previous 

Waivers or Constitute Other Conditions Precedent That Do Not 

Necessitate an Additional Waiver Action

Section 209(a) of the CAA provides: 

No State or any political subdivision thereof shall adopt or attempt to 

enforce any standard relating to the control of emissions from new motor 

vehicles or any new motor vehicle engines subject to this part. No State 

shall require certification, inspection, or any other approval relating to the 

control of emissions from any new motor vehicle or new motor vehicle 

engine as condition precedent to the initial sale, titling (if any), or 

registration of such motor vehicle, motor vehicle engine, or equipment. 

Section 209(b) of the CAA sets forth the mechanism for granting California17 a waiver 

from the general preemption of section 209(a). Under section 209(b), the Administrator 

must grant a waiver to California if the state has determined that its standards will be, in 

the aggregate, at least as protective of public health and welfare as applicable federal 

standards, unless the Administrator finds that (1) the state’s protectiveness 

determination is arbitrary and capricious, (2) California does not need separate state 

standards to meet compelling and extraordinary conditions, or (3) the state’s standards 

and accompanying enforcement procedures are not consistent with section 202(a) of 

the CAA. 

In considering whether to grant waivers for accompanying enforcement procedures tied 

to standards for which a waiver has already been granted, the Administrator has long 

held that he will only address questions as to (1) whether the enforcement procedures 

are so lax that they threaten the validity of California’s determination that its standards 

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

(2) whether the enforcement procedures are consistent with section 202(a).18

The Administrator has applied a similar analysis in finding that amendments to a 

standard or regulation are within the scope of a previously granted waiver: 

If California acts to amend a previously waived standard or accompanying 

enforcement procedure, the amendments may be considered within the 

scope of a previous previously granted waiver provided that they (a) do 

 

17 CAA section 209(b) provides for granting a waiver to “any State that has adopted standards (other than 

crankcase emission standards) for the control of emissions from new motor vehicles or new motor vehicle 

engines prior to March 30, 1966.” California is the only State that meets this eligibility criterion for 

granting waivers. See, e.g., S. Rep. No. 90-403, at 632 (1967) and Motor and Equipment Manufacturers 

Association v. EPA (MEMA I) (D.C. Cir. 1979) 627 F.2d 1095, 1101 fn. 1. 18 See MEMA I, supra, 627 F.2d. at 1111, 1113. 

17
not undermine California’s determination that its standards are, in the 

aggregate, as protective of public health and welfare as applicable Federal 

standards; (b) do not affect the consistency of California’s requirements 

with section 202(a) of the [CAA]; and raise no new issues affecting EPA’s 

previous waiver determination.19

In addition, the Administrator has stated: 

After California has received a waiver of Federal preemption for its 

standards and enforcement procedures for a class of vehicles, it may 

adopt other conditions precedent to initial retail sale, titling or registration 

of the subject class of vehicles without the necessity of receiving an 

additional waiver of preemption.20

B. Criteria for Granting Authorizations Under CAA Section 209(e) and 

Confirmations that Amendments are Within the Scope of Previously 

Granted Authorizations

Section 209(e)(2) of the CAA sets forth the protocol for the Administrator to grant 

California authorization to adopt and enforce standards and other requirements relating 

to controlling emissions from new and in-use nonroad engines that are not conclusively 

preempted by section 209(e)(1) – new engines less than 175 hp used in farm and 

construction equipment and vehicles and new engines used in new locomotives and 

locomotive engines. Closely tracking the new motor vehicle waiver process, section 

209(e)(2) directs the Administrator to grant the authorization to California for standards 

and requirements for all other nonroad engines if California determines that the state’s 

standards will be, in the aggregate, at least as protective of public health and welfare as 

applicable federal standards, unless he finds that: (1) the protectiveness finding of the 

state is arbitrary and capricious; (2) California does not need separate state standards 

to meet compelling and extraordinary conditions; or (3) the state standards and 

accompanying enforcement procedures are not consistent with CAA section 209.

The criteria for reviewing a California request for authorization under section 209(e)(2) 

are nearly identical to the criteria that the Administrator must consider under section 

209(b). In light of these almost identical protocols, EPA has confirmed that it would 

similarly interpret sections 209(b) and (e) where the language is similar.21 

 

19 Decision Document accompanying within-the-scope determination in 69 Fed.Reg. 59920 (October 6, 

2004), at pp. 2-3; see also Decision Document accompanying within-the-scope determination in 

51 Fed.Reg. 12391 (April 10, 1986), at p. 2 and 46 Fed.Reg. 36742 (July 15, 1981). 20 Decision Document accompanying within-the-scope determination in 69 Fed.Reg. 59920 (October 6, 

2004), at p. 2, citing 43 Fed.Reg. 36679 (August 18, 1978), 54 Fed.Reg. 13427 (April 3, 1989), and 

55 Fed.Reg. 28824 (July 13, 1990).

21 Air Pollution Control; Preemption of State Regulation for Nonroad Engine and Vehicle Standards (Final 

209(e) Rule), 59 Fed.Reg. 36969, 36981 (July 20, 1994); see also Utility Authorization, Decision 

Document, at p. 11; see also 65 Fed.Reg. 69763, 69763-69764 (November 20, 2000). 

18
One deviation in language is that CAA section 209(e)(2) requires the Administrator to 

consider not only consistency with CAA section 202(a) – as required under section 

209(b)(1)(C) – but also other subsections of section 209. In its 209(e) Final Rule, EPA 

interpreted this provision to require that California’s standards and accompanying 

enforcement provisions must also be consistent with sections 209(a) and 209(e)(1).22 

As the Administrator stated in a recent authorization: 

In [o]rder to be consistent with section 209(a), California’s [nonroad] 

standards and enforcement procedures must not apply to new motor 

vehicles or new motor vehicle engines. Secondly, California’s nonroad 

standards and enforcement procedures must be consistent with section 

209(e)(1), which identifies the categories permanently preempted from 

state regulation. California’s nonroad standards and enforcement 

procedures would be considered inconsistent with section 209 if they 

applied to the categories of engines or vehicles identified and preempted 

from State regulation in section 209(e)(1). Finally, and most importantly in 

terms of application to nonroad [authorization requests], California’s 

nonroad standards and enforcement procedures must be consistent with 

section 209(b)(1)(C). EPA will review nonroad authorization requests 

under the same “consistency” criteria that are applied to motor vehicle 

waiver requests. Under section 209(b)(1)(C), the Administrator shall not 

grant California’s motor vehicle waiver if she finds that California 

standards and accompanying enforcement procedures are not consistent 

with section 202(a)” of the [CAA].23 

 

The Administrator has applied a similar analysis in finding that amendments to a 

nonroad standard or regulation are within the scope of a previously granted 

authorization.”24 

C. Principles Followed in Granting CAA Section 209(b) Waivers and 209(e) 

Authorizations

1. The Burden Is on Those Who Challenge the Request

In considering a waiver, authorization, or a within-the-scope request, California’s 

regulations and protectiveness determination are presumed to satisfy the criteria for 

granting a waiver or authorization, and the burden to show otherwise is on those 

persons challenging the waiver request.25 As held by the court in MEMA I and long 

followed by EPA: 

The language of the statute and its legislative history indicate that 

California’s regulations and California’s determination that they comply 

 

22 59 Fed.Reg. 36969, 36983 (July 20, 1994). 23 65 Fed.Reg. 69763, 69764 fn. 5 (November 20, 2000). 24 Id., 69763-69764. 25 MEMA I, 627 F.2d 1095, 1121. 

19
with the statute, when presented to the Administrator are presumed to 

satisfy the waiver requirements and that the burden of proving otherwise is 

on whoever attacks them. [It is they who] bear the burden of persuading 

the Administrator that the waiver request should be denied.26

Given the identical structure and near identical language of sections 209(b) and 

209(e)(2), the opponents of an authorization request should bear a similar burden of 

proof when arguing that authorization should be denied. EPA has so stated in all 

off-road authorization decisions to date.27

2. The Scope of the Waiver/Authorization Hearing Should Be Limited 

As indicated above, the scope of the Administrator’s inquiry in determining whether to 

deny a waiver or authorization request is limited by the express terms of CAA 

sections 209(b)(1) and (e)(1). Once California determines that its standards are, in the 

aggregate, at least as protective of public health and welfare as applicable federal 

standards, the Administrator must grant the waiver or authorization unless one of the 

three specified findings can be made. 

This reading of the statute is consistent with the decision in MEMA I and prior EPA 

waiver decisions interpreting CAA section 209(b), which hold that the review of 

California’s decision to adopt separate standards is a narrow one.28 In granting the 

waiver for the OBD II regulation in 1996, Administrator Carol Browner concluded that 

she must grant a waiver if she could not find sufficient evidence in the record to support 

any of the above listed criteria that would dictate not granting the waiver.29 Much earlier 

Administrator William D. Ruckleshaus stated: 

The law makes it clear that the waiver request cannot be denied unless the 

specific findings designated in the statute can properly be made. The issue of 

whether a proposed California requirement is likely to result in only marginal 

improvement in air quality not commensurate with its cost or is otherwise an 

arguably unwise exercise of regulatory power is not legally pertinent to my 

decision under section 209 . . . . 30

 

26 Id.; See also Decision Document accompanying OBD II Waiver Determination (61 Fed.Reg. 53371), at 

p. 15-16. 

27 OHRV Authorization, Decision Document, at pp. 16-17; Utility Authorization, Decision Document, at 

p. 14; 60 Fed.Reg. 48981 (September 21, 1995) (HDOR Authorization), Decision Document, at p. 13. 

See also Waiver of Federal Preemption California Low-Emission Vehicle Standards, 58 Fed.Reg. 4166 

(January 7, 1993) (LEV Waiver), Decision Document, at p. 21. 28 See 40 Fed.Reg. 23102, 23103 (May 28, 1975). 29 61 Fed.Reg. 53371 (October 11, 1996). 30 36 Fed.Reg. 17158 (August 31, 1971). See also 40 Fed.Reg. 23102, 23104; 58 Fed.Reg. 4166 

(January 7, 1993), Decision Document, at p. 20. 

20
3. Deference Must Be Given to California’s Policy Judgments 

As indicated in the waiver decisions cited above, in granting waivers to California’s 

motor vehicle program, EPA has routinely deferred to the policy judgments of 

California’s decision-makers. EPA has recognized that the intent of Congress in 

creating a limited review of California’s determinations regarding its need for separate 

standards was to ensure that the federal government did not second-guess the wisdom 

of state policy.31 Administrators have recognized that the deference is wide-ranging: 

The structure and history of the California waiver provision clearly indicate 

both a Congressional intent and an EPA practice of leaving the decision 

on ambiguous and controversial matters of public policy to California’s 

judgment. 

* * * * * * 

It is worth noting . . . I would feel constrained to approve a California 

approach to the problem which I might also feel unable to adopt at the 

federal level in my own capacity as a regulator. The whole approach of 

the Clean Air Act is to force the development of new types of emission 

control technology where that is needed by compelling the industry to 

“catch up” to some degree with newly promulgated standards. Such an 

approach . . . may be attended with costs, in the shape of a reduced 

product offering, or price or fuel economy penalties, and by risks that a 

wider number of vehicle classes may not be able to complete their 

development work in time. Since a balancing of these risks and costs 

against the potential benefits from reduced emissions is a central policy 

decision for any regulatory agency under the statutory scheme outlined 

above, I believe I am required to give very substantial deference to 

California’s judgments on this score.32

By authorizing California to adopt its own emission standards for nonroad vehicles and 

engines and by establishing almost identical requirements for EPA review of authorizing 

requests under section 209(e)(2) as it requires for waiver decisions under section 

209(b), Congress unmistakably intended that the EPA accord similar deference to 

California’s decisions under 209(e)(2).33

 

31 40 Fed.Reg. 23102, 23103. 32 40 Fed.Reg. 23102, 23104 (emphasis added). See also 58 Fed.Reg. 4166, Decision Document, at 

p. 64. 

33 See discussion in Engine Manufacturers Association v. U.S. EPA (EMA), 88 F.3d 1075, 1090 (D.C. 

Cir. 1996), wherein the court recognized California's leadership in emission control regulation in both new 

motor vehicles and new and in-use nonroad engines. 

21
VI. THE NEW ENGINE REQUIREMENTS 

A. The New Engine Requirements Are Akin to an Operational Control on 

In-Use Vehicles and Accordingly Are Not Preempted By CAA 

Section 209(a) 

The new engine requirements are akin to an in-use operational control of motor vehicles 

and accordingly are not preempted by CAA section 209(a). CAA section 209(d) 

provides that California and other states are not precluded from controlling, regulating or 

restricting the “use, operation, or movement of registered or licensed motor vehicles,” 

and since the states are expressly authorized to impose these categories of controls, 

California does not need a waiver of preemption pursuant to section 209(b). 

In the EMA case, EPA and the Court of Appeals for the D.C. Circuit recognized that 

states are not precluded from regulating the extending idling of on-road vehicles: 

[A]s the EPA points out, the longstanding scheme of motor vehicle 

emissions control has always permitted the states to adopt in-use 

regulations – such as carpool lanes, restrictions on car use in downtown 

areas, and programs to control extended idling of vehicles – that are 

expressly intended to control emissions. ... Section 209(d) does, 

therefore, protect the power of the states to adopt such in-use 

regulations.34 

As discussed in Section VII., infra, CARB’s in-use idling ATCM that requires operators 

of commercial heavy-duty diesel vehicles – including those with 2008 and subsequent 

model engines – to manually shut off engines after five minutes of continuous idling 

clearly constitutes an in-use operational control under section 209(d) that is not 

preempted by section 209(a). EPA itself utilized this reasoning in approving Texas’ SIP 

revision that incorporated idling limits on vehicles over 14,000 pounds.35 Texas’ 

measure is analogous to ARB’s new engine requirements in that it prohibits extended 

idling beyond five minutes when the vehicle is not in motion,36 and EPA stated it was 

approving the measure in part because it was consistent with CARB’s 2008 truck idling 

regulation37; EPA also stated that the Texas measure “does not alter the relationship or 

the distribution of power and responsibilities established in the Clean Air Act.”38 

The new engine requirements differ from the in-use idling ATCM in that they place the 

compliance burden of shutting off the engine onto the engine computers rather than the 

vehicle operators, but this is a distinction without significance. The new engine 

requirements essentially present a more technically advanced means of enforcing a 

vehicular anti-idling measure of the type that CAA section 209(d) explicitly authorizes 

 

34 EMA, supra, 88 F.3d 1075, 1094. Emphasis supplied. 35 70 Fed. Reg. 18308 (April 11, 2005). 36 Id. at 18309. 

37 Ibid. 38 Id. at 18310. 

22
states to adopt and enforce. CARB is aware that the new engine measures could be 

alleged to violate the principles set forth in Allway Taxi, Inc. v. City of New York39 and 

therefore be preempted by CAA section 209(a) because the measures effectively 

regulate the design of new engines and place the burden of compliance on engine 

manufacturers, but this allegation disregards the findings in the rulemaking record that 

engine shutdown systems are software-based controls that have been and are 

presently available as standard features in most commercially available on-road 

heavy-duty engines, so that nearly all engines already incorporate all the software and 

hardware needed to comply with the new engine requirements.

40 Furthermore, the new 

engine requirements apply to either engine manufacturers or original equipment 

manufacturers, but the nature of the heavy-duty diesel vehicle marketplace virtually 

ensures that heavy-duty vehicle manufacturers rather than engine manufacturers will be 

primarily responsible for complying with the new engine requirements (i.e., vehicle 

manufacturers know which applications will be powered by any given engine, so they 

can order the applicable engine from the engine manufacturers). This is consistent with 

CARB staff’s findings that engine manufacturers (including Detroit Diesel Corporation, 

Cummins, and Caterpillar) presently make engine shutdown systems available as 

standard features, but most fleet owners and operators do not activate such engine 

shutdown systems. These factors sufficiently demonstrate that the new engine 

requirements avoid the concerns articulated by the Allway Taxi court in that they do not 

require changes to or redesign of the engine, and thus do not place an impermissible 

burden on the manufacturer to incorporate new changes or designs on future engines. 

The new engine requirements are consequently not subject to any preemption under 

section 209(a). 

CARB therefore requests that EPA confirm that the new engine requirements are akin 

to in-use operational controls of motor vehicles, and accordingly are not preempted by 

CAA section 209(a) and are enforceable by California without further action by the 

Administrator. 

B. Alternatively, the New Engine Requirements Are “Other Conditions 

Precedent” to Initial Sale, Titling Or Registration that Fall Within the 

Scope of the Waiver Of Preemption Issued for California’s 2007 and 

Newer Heavy-Duty Diesel Engine Standards 

The new engine requirements provide manufacturers with two compliance options – 

either install a system that automatically shuts down an engine after five minutes of 

continuous idling, or certify the engine to an optional NOx idling standard of 30 grams 

per hour. These requirements constitute neither a standard nor an accompanying 

enforcement procedure because the primary automatic shut-down requirement does not 

pertain to a manufacturer’s ability to certify and produce engines that comply with 

applicable emission standards.41 They are instead a condition precedent to the initial 

 

39 340 F.Supp. 1120 (S.D.N.Y) aff’d 468 F.2d 624 (2d Cir. 1972). 40 ISOR Section V.A. To date, CARB has certified 46 2008 model year HDDE engine families. See 

section VI.C.2 of this document. 

41 See 54 Fed.Reg. 13427 (April 3, 1989) and 43 Fed.Reg. 36679 (August 18, 1978). 

23
retail sale of new engines and vehicles in California; since California has received a 

waiver of preemption for its standards and enforcement standards for 2008 and 

subsequent heavy-duty diesel engines, no further waiver action is necessary for the 

new engine requirements. 

1. The New Engine Requirements Are Not Standards Relating to the 

Control of Emissions 

In Engine Manufacturers Ass’n. v. South Coast Air Quality Management District, 541 

U.S. 246 (2004), the U.S. Supreme Court interpreted the phrase “standard relating to 

the control of emissions from new motor vehicles or new motor vehicle engines” in CAA 

section 209(a) as describing a requirement that a vehicle or engine “not emit more than 

a certain amount of a given pollutant,” be “equipped with a certain type of 

pollution-control device,” or “have some other design feature related to the control of 

emissions.”42 The Court noted this interpretation was consistent with the use of the 

term “standard” throughout Title II of the CAA “to denote requirements such as 

numerical emission levels with which vehicles or engines must comply . . . or 

emission-control technology with which they must be equipped, e.g. [section 202(a)(6), 

which requires the Administrator to promulgate regulations requiring that new light-duty 

motor vehicles be equipped with onboard vapor recovery systems].”43

a. The Primary Compliance Option for the New Engine Requirements Neither 

Limits Levels of Pollutants Nor Requires Engines to Incorporate Specified 

Pollution Control Devices or Design Features Related to the Control of 

Emissions 

The primary compliance option of the new engine requirements requires new 2008 and 

later model-year heavy-duty diesel engines to be equipped with idling shutdown 

systems. This option overlays the previously adopted and waived emission standards 

and other requirements applicable to the certification of such engines, but does not 

independently establish numerical limits on the emissions from those engines. 

The primary compliance option also does not require that new heavy-duty diesel 

engines be equipped with pollution control devices or incorporate design features 

related to the control of emissions. An engine shutdown system shuts off the engine 

after five minutes of continuous idling, but does not otherwise reduce or control engine 

or vehicle emissions. In fact, if an engine shutdown system was to catastrophically fail, 

the engine would likely still be able to demonstrate compliance with current certification 

and in-use standards because, as previously mentioned, compliance with those 

standards is determined in accordance with test procedures that do not include 

extended operation at idling modes. It is notable that an engine shutdown system does 

not even fall within the definition of an “emission related part” as defined in EPA’s 

aftermarket program.44 

 

42 Id. at 253. 

43 Id. 

44 40 CFR section 85.2102 and 45 Fed.Reg. 78448, 78450 (Nov. 25, 1980) (Final Rule for EPA’s 

voluntary aftermarket part self-certification program that limits eligibility to parts affecting emissions; EPA 

24
b. The Optional NOx Idling Standard Does Not Constitute an Emission Standard 

Requiring a Waiver of Preemption

The new engine requirements also provide manufacturers the option of certifying new 

engines to an optional NOx idling emission standard and accompanying test procedure. 

Although this compliance option might initially appear to be a “standard relating to the 

control of emissions from new motor vehicles or new motor vehicle engines” because it 

specifies a quantified limit of NOx emissions as measured over a specific test cycle, it is 

important to note that this secondary option was only proposed in conjunction with a 

primary compliance option that is clearly both technically feasible and cost effective (see 

Section III.B.1.a.(iv) above). Moreover, because manufacturers are not compelled to 

certify engines to the optional NOx standard but only do so on a voluntary basis, this 

compliance option cannot be construed as a mandated emissions standard relating to 

the control of emissions from new motor vehicle engines.45 

2. The New Engine Requirements Are Not Accompanying Enforcement 

Procedures 

Neither the primary nor the optional compliance options of the new engine requirements 

are “accompanying enforcement procedures” because neither establishes criteria by 

which CARB will determine whether 2008 and newer HDDEs in trucks with a GVWR 

greater than 14,000 pounds comply with the existing, previously waived standards 

applicable to those engines.46 As discussed above, the existing 2007 and subsequent 

model-year HDDE standards do not specify quantifiable limits on emissions generated 

during operational modes involving extended idling over five continuous minutes; 

therefore, ARB cannot use either option to determine if a new 2008 or newer engine 

complies with non-existent criteria. 

 

explains that only parts, “that could fail in a manner that would cause a vehicle to exceed applicable 

emission standards ... should be eligible for certification.”) Under this criterion, an engine shutdown 

system would not be a system affecting emissions since if it catastrophically failed, the engine would still 

likely be able to demonstrate compliance with its certification and in-use standards because compliance 

with those standards is determined in accordance with test procedures that do not include operations at 

extended idling. 

45 See Motor and Equipment Mfrs. Ass’n, Inc. v. Environmental Protection Agency (MEMA II), 627 F.2d 

1128, 1132 (D.C. Cir. 1979) (a regulatory compliance option constitutes a mandate only if the regulation 

does not specify another compliance option.) 

46 MEMA I, supra, 627 F.2d 1095, 1111-1113, American Automobile Manufacturers Association v. Cahill

(2nd Cir. (N.Y.) 1998) 152 F.3d 196, 200. 

25
3. Since the New Engine Requirements are Neither Standards nor 

Accompanying Enforcement Procedures, They Must Constitute “Other 

Conditions Precedent” That do not Necessitate an Additional Waiver 

Action 

Since the new engine requirements constitute neither standards nor accompanying 

enforcement procedures, they must fall within the remaining “catch-all” category of 

restrictions in CAA section 209(a) – other requirements relating to the control of 

emissions that are imposed as a “condition precedent to the initial retail sale, titling (if 

any), or registration of such motor vehicle, motor vehicle engine, or equipment.” As 

discussed in Section V.A. above, once EPA has granted a waiver for a class of vehicles, 

California may adopt other conditions precedent without the need for additional waiver 

action. EPA has granted CARB a waiver of federal preemption for emission standards 

and associated test procedures applicable to the categories of engines subject to the 

new engine requirements of the 2008 truck idling requirements, and the new engine 

requirements are neither new motor vehicle emission standards nor accompanying 

enforcement procedures. Accordingly, CARB requests EPA’s confirmation that the 

previous section 209(b) waiver issued for CARB’s 2007 and subsequent model-year 

HDDE emission standards and test procedures relieves CARB of the need to 

demonstrate that the specifications independently meet the waiver criteria, and that the 

new engine requirements may be enforced in California without further action by the 

Administrator. 

C. Should EPA Determine that the New Engine Requirements Constitute 

“Emission Standards Relating to the Control of Emissions from New 

Motor Vehicle Engines,” Such Requirements Fall Within the Scope of 

Previous Waivers of Preemption 

If EPA declines to accept either of CARB’s preceding characterizations of the new 

engine requirements, CARB then requests that EPA confirm that the requirements 

fall within the scope of the waiver of preemption published on August 26, 2005 for 

California’s amendments to the 2007 HDDE standards and related test procedures.47 

In adopting the 2008 Truck Idling Requirements in Resolution 05-55, the Board 

expressly found that the requirements fell within the scope of previous waivers in that 

the amendments do not undermine the Board’s previous determinations that its 

emission standards, in the aggregate, are at least as protective of public health and 

welfare as comparable federal standards, do not affect the consistency of California’s 

requirements with section 202(a) of the CAA, and raise no new issues affecting the 

Administrator’s previous waiver determinations. (Reference 5, Resolution 05-55, p. 9). 

The new engine requirements accordingly fall within the scope of the waiver for 

amendments to CARB’s 2007 HDDE standards and accompanying test procedures. 

Application of each of the scope-of-the-waiver criteria is discussed below. 

 

47 70 Fed.Reg. 50322 (August 26, 2005). 

26
1. The New Engine Requirements Do Not Undermine California’s 

Protectiveness Determination Regarding its 2007 HDDE Standards and 

Test Procedures 

The 2008 Truck Idling Requirements do not undermine the Board’s previous 

determinations that the new motor vehicle engine emission standards established by 

the amendments to its heavy-duty diesel engine standards for 2007 and subsequent 

model-year vehicles and engines and related test procedures, are, in the aggregate, at 

least as protective of public health and welfare as applicable federal standards. The 

Board based its previous protectiveness determinations upon a comparison of the 

amended standards and test procedures to the applicable federal standards. This 

comparison indicated that CARB’s amendments would make California’s emission 

standards and test procedures virtually identical to the federal requirements. In granting 

California a waiver of preemption for the 2007 HDDE amendments, the Assistant 

Administrator of EPA stated that he could not find that “CARB’s determination, that its 

2007 California Heavy-duty Diesel Engine Standards are, in the aggregate, at least as 

protective of public health and welfare, is arbitrary and capricious.”48 The new engine 

requirements at issue in this request in no way reduce the stringency of either the 

underlying exhaust emission standards or the associated test procedures; instead EPA 

may find that they impose additional requirements that are not reflected in EPA’s 

regulations. 

2. The New Engine Requirements Do Not Affect the Consistency of CARB’s 

Heavy-Duty Engine Requirements with CAA Section 202(a) 

The Administrator has stated that California’s standards and accompanying test 

procedures are inconsistent with section 202(a) if: (1) there is inadequate lead time to 

implement the new procedures, giving appropriate consideration to the cost of 

compliance within the applicable time frame, or (2) the federal and California test 

procedures impose inconsistent certification requirements so as to make manufacturers 

unable to meet both sets of requirements with the same vehicle.49

a. Technical Feasibility of the New Engine Requirements 

The CARB staff set forth its bases for determining that the engine shutdown system and 

the optional NOx idling standard compliance options are technically feasible in the ISOR 

and the FSOR. Sections III.B.1.a. and b. of this document provide a brief summary of 

the compliance options that staff believes engine and original equipment manufacturers 

will likely utilize to comply with these options. 

 

48 70 Fed.Reg. 50322 (August 26, 2005). See also Decision Document accompanying 2007 HDDE 

Waiver Determination, at pp. 7-8. 

49 See, e.g., 46 Fed.Reg. 26371, 26371 (May 12, 1981). Even where there is incompatibility between the 

California and federal test procedures, EPA has granted a waiver under circumstances where EPA 

accepts a demonstration of federal compliance based on California test results, thus obviating the need 

for two separate tests. (43 Fed.Reg. 1829, 1830 (January 12, 1978); 40 Fed.Reg. 30311, 30314 (July 18, 

1975).) 

27
 (i) Engine Shutdown Compliance Option

 

The technology needed to comply with the new engine shutdown system option 

presently exists, and in fact has been widely available as a standard feature in most 

commercially available on-road heavy-duty engines. Engine manufacturers including 

Detroit Diesel Corporation, Cummins, and Caterpillar presently build engine shutdown 

systems into their engines’ electronic control software and make those engine shutdown 

systems available as standard features, but most fleet owners and operators have 

elected not to activate these capabilities. CARB staff further found that only minor 

modifications to the programming of currently available HDDE electronic control 

software would be needed to comply with the new engine shutdown system 

requirement. CARB has currently certified 46 2008 model year HDDE engine families; 

22 of these families incorporate an engine shutdown system.50

The cost of compliance within the lead time provided was also appropriately considered. 

As stated in Section VII.C of the ISOR, staff estimated that the compliance costs 

associated with this option would be minimal – $100 per engine to cover additional 

administrative costs and minimal reprogramming costs. Although one commenter 

suggested that the engine shutdown requirement might require hardware changes to a 

vehicle’s electronic control module (ECM) as well as software changes, CARB staff 

disagrees that hardware changes would be required.51 

These considerations demonstrate that the new engine shutdown system compliance 

option is technologically feasible considering the cost of compliance within the lead time 

provided. 

Several commenters asserted that the new engine shutdown timer requirement 

fails to comply with the lead-time and stability requirements of section 202(a)(3)(C) 

of the CAA, which specifies that no new emission standard may take effect earlier than 

four model years after it is promulgated (“lead-time” requirement), or before the prior 

emission standard has been in effect for at least three model years (“stability” 

requirement). The commenters asserted that the engine shutdown requirement 

violates the lead-time requirement because it takes effect in the 2008 model year, less 

than two model years from its date of adoption. The commenters also alleged that the 

engine shutdown requirement violates the stability requirement because heavy-duty 

on-highway engines are already subject to emission control requirements applicable to 

2007 through 2010 model-year engines. Therefore, the CAA’s stability requirement 

prevents CARB from imposing any new emission control requirements until 2013. 

As CARB stated in the FSOR,52 even if a waiver under section 209(a) is required for the 

engine shutdown timer requirement, the lead-time and stability provisions of CAA 

section 202(a)(3)(C) do not apply to this requirement. First, section 202(a)(3)(C) only 

 

50 These engine families are manufactured by Caterpillar, Detroit Diesel Corporation, International Truck 

and Engine Corporation, General Motors, and Isuzu. Data current as of March 8, 2008. 

51 FSOR, Section III (Comment 8 and Agency Response thereto; pp. 21-22). 52 FSOR, response to Comment 70, pp. 56-58. 

28
applies to standards “promulgated or revised under this paragraph [section 202(a) of the 

CAA],” that is, to standards promulgated by the Administrator of EPA. Because CARB 

adopted the new engine requirement pursuant to authority of California state law and 

the waiver provisions of section 209(b) of the CAA, the lead-time and stability 

requirements are simply inapplicable. 

Second, EPA has historically only applied a “two-pronged” test of whether California 

standards are consistent with CAA section 202(a) as required by section 209(b)(1)(C). 

The standards must be: (1) technologically feasible in the lead time provided 

considering the cost of compliance, and (2) compatible with the federal test procedures 

so that a single vehicle could be subjected to both tests. No more should be required.53 

This is in accord with the legislative history of section 209. When the California waiver 

provisions and the “consistent with section 202(a)” language were first placed in the 

CAA in 1965, section 202(a) consisted of just one sentence requiring adequate lead 

time in consideration of technological feasibility and economic costs. In the 1977 CAA 

amendments, Congress amended section 209 “to afford California the broadest 

possible discretion in selecting the best means to protect the health of its citizens and 

the public welfare.”54 At the same time, Congress expanded section 202(a) to add 

several directives to EPA regarding its adoption of emission standards, including the 

four-year lead time requirement for heavy-duty vehicles. Given Congress’s expressed 

intent to strengthen the waiver provisions, it is unlikely Congress intended to apply the 

specific 4-year requirement to California. 

Finally, even if the engine shutdown requirement were to be deemed a “standard” for 

purposes of CAA section 209(a), it still should not be considered to be a standard for 

purposes of the four-year lead-time requirement CAA section 202(a)(3)(C). The 

four-year lead-time requirement was designed to assure that manufacturers have 

sufficient time to redesign and employ emission control hardware. As stated above in 

Section VI.A, the new engine requirements do not necessitate redesign of current 

engines. Similarly, the lead-time and stability requirements of section 202(a)(3)(C) were 

not intended to encompass a software change that does not affect the emissions 

monitored under the applicable test procedures or engine design. The software 

changes needed to comply with the engine shutdown requirement are much more 

limited than those needed to implement on-board diagnostic requirements which 

Congress itself has determined do not necessitate four years lead time.55 

CARB also believes that the commentators are misreading the stability requirement in 

CAA section 202(a)(3)(C). That section simply states that any standard promulgated 

under 202(a) shall apply “for a period of no less than 3 model years,” and does not 

support an interpretation that limits the EPA’s authority to regulate heavy-duty vehicles 

or engines to once every three model years. 

 

53 “Neither the court nor the agency has ever interpreted compliance with section 202(a) to require more.” 

Motor & Equipment Mfrs Assoc. v. Nichols, 142 F.3d 449, 463 (D.C. Cir. 1998). 54 H. R. Rep. No. 294, 95th Cong., 1st Sess. 301 (1977), reprinted in 4 Leg. Hist. at 2768. 55 The 1990 amendments to the CAA mandated EPA to adopt by November 1991 OBD requirements that 

take effect for model-year 1994. 

29
 (ii) Optional NOx Idling Emission Standard 

If the Administrator grants California a waiver of preemption for a primary motor vehicle 

emission standard (which necessarily requires the Administrator to find that the 

standard is technically feasible), the Administrator may also waive an optional 

compliance procedure associated with the primary compliance option. In MEMA II, 

supra, petitioners challenged EPA’s issuance of a waiver for California’s optional 

100,000 mile certification procedures. These procedures provided manufacturers an 

alternative to certifying vehicles to a 50,000 mile certification procedure, for which EPA 

had previously issued California a waiver from preemption. The MEMA II court held 

EPA properly granted the waiver, even if the waiver decision did not include any 

evidence that the optional procedure was technically feasible for gasoline fueled 

vehicles. “The [optional] certification procedure is an option, and only if it is one among 

several technologically infeasible options is the California program in peril. ... No 

manufacturer is being required to choose between two impossible options.”56

In this case, CARB only included the optional NOx idling emission standard to 

accommodate engine manufacturers’ requests for an alternative compliance option to 

the new engine shutdown timer requirement. As demonstrated above, the shutdown 

timer requirement is technologically feasible within the lead time provided, and under 

the reasoning of the MEMA II court, EPA should find that the optional NOx idling 

compliance option also falls within the scope of the previously granted waiver for 

CARB’s 2007 HDDE standards and accompanying test procedures. As in the MEMA II

case, no manufacturer is compelled to follow two technologically infeasible options. 

CARB acknowledges that staff did not anticipate manufacturers would widely utilize the 

optional NOx idling emission standard option until the 2010 model year because “NOx 

aftertreatment devices are not anticipated to be employed and other engine idling 

controls/strategies have not been fully demonstrated” and because it is unlikely that 

engine manufacturers will equip their engines with NOx aftertreatment devices capable 

of complying with the NOx emission standard before the 2010 model year.57 However, 

as discussed in Section IV.A.iii of the ISOR, several manufacturers indicated that 

existing NOx aftertreatment devices (such as NOx adsorbers) did demonstrate the 

potential to reduce NOx emissions during idling.58 Most significantly, substantially more 

manufacturers have certified 2008 model-year engines to this option than staff 

previously anticipated.59 In fact, Cummins, Volvo, Hino, and Mitsubishi have certified 

their entire line of 2008 HDDEs to the optional NOx idling standard, and manufacturers 

that currently utilize the engine shutdown system option have indicated they may later 

certify their engines to this option via running changes. The strategies utilized by 

manufacturers to comply with the optional NOx idling standard largely do not require 

any additional hardware or modifications to emission control systems or components, 

 

56 MEMA II, 627 F.2d 1128, 1132 (D.C. Cir. 1979). 57 ISOR, pp. 13 and 28. 58 Id., p.11 59 These manufacturers include Cummins, Hino, Mitsubishi, and Volvo. As of March 2008, 24 of the 46 

HDDE engine families certified by CARB in 2008 are certified to the optional NOx idling standard. 

30
but only involve modifications to existing software (e.g., modifying exhaust gas 

recirculation rates and/or the pulse widths of the fuel injectors during idle operating 

modes. 

b. The New Engine Requirements Do Not Impose Inconsistent Certification 

Requirements 

Neither the new engine shutdown system nor the optional NOx idling emission standard 

option present any issues of test procedure inconsistency because there are no 

analogous federal requirements. The federal heavy-duty diesel standards for 2007 and 

newer model-year engines do not require engines to shut off after five or fifteen minutes 

of continuous idling or require engines to not exceed 30 grams of NOx per hour as 

measured over a prescribed test cycle (either the idle mode of the supplemental 

steady-state test, the idle portion of the transient test cycle, or another test procedure, 

subject to advance Executive Officer approval). In fact, the optional NOX idling 

emission standard test procedures expressly provide they can be performed 

immediately after any testing conducted using the Federal Test Procedure or 

supplemental emissions tests.60 Therefore, engine manufacturers are not precluded 

from conducting one set of tests on 2008 and newer model-year heavy-duty diesel 

engines to determine compliance with both California and federal procedures. 

3. The New Engine Requirements Do Not Raise New Issues Affecting the 

Waiver Determination for CARB’s Amendments to its 2007 HDDE 

Standards and Test Procedures 

No new issues are presented by the new engine requirements that affect the waiver 

determination for amendments to California’s 2007 heavy-duty diesel standards and 

associated test procedures. The requirements do not extend the previously waived 

standards to a previously unregulated class of vehicles, establish significantly more 

stringent standards, or require significant new technological efforts to comply with the 

new engine requirements. The primary compliance option (engine shutdown system) 

will only require manufacturers to perform minor reprogramming of the software 

incorporated in existing engine or vehicle computers, and will not require any 

modifications to hardware. Engine shutdown systems are software based controls that 

are presently available as standard features in most commercially available on-road 

heavy-duty engines. In fact, because commercially available engines already 

incorporate engine shutdown capability in their software, any reprogramming will only 

require minimal effort to activate the idling shutdown capabilities of new engines. 

Manufacturers will not need to develop new technologies or to produce and install 

mechanical components or systems into new engines beyond those already present in 

existing engines. 

 

60 California Exhaust Emission Standards and Test Procedures for 2004 and Subsequent Model heavyDuty Diesel Engines and Vehicles, Part II, section 86.1360-2007.B.4.2.1(a). 

31
VII. THE IN-USE IDLING ATCM REQUIREMENT IS AN OPERATIONAL CONTROL 

ON IN-USE VEHICLES THAT IS NOT PREEMPTED BY CAA SECTION 209(a) 

AND ACCORDINGLY DOES NOT NEED A SECTION 209(b) WAIVER 

The 2008 truck idling requirement that extends the idling ATCM requirements to sleeper 

trucks as of January 1, 2008 constitutes an in-use operational control of motor vehicles 

and does not require a waiver. CAA Section 209(a) only preempts states from adopting 

or attempting to enforce standards related to the control of emissions from new motor 

vehicles or new motor vehicle engines and the amendments to title 13 CCR 

section 2485 only apply to in-use motor vehicles. Moreover, CAA section 209(d) 

provides that: 

Nothing in this part shall preclude or deny to any State or political 

subdivision thereof the right otherwise to control, regulate, or restrict the 

use, operation, or movement of registered vehicles. 

Taken together, CAA sections 209(a) and (d) make clear that the idling limits imposed 

on sleeper truck operators are not preempted and accordingly need no CAA 

section 209(b) waiver action. 

 

VIII. THE ALTERNATIVE TECHNOLOGY REQUIREMENTS 

As a threshold matter, it should be noted that the alternative technology requirements 

merely establish performance requirements for technologies used to supply power for 

truck cab or sleeper berth climate control purposes and/or for other on-board 

accessories that would otherwise have been generated by the continuous idling of the 

truck’s main engine. The decision to utilize such alternative technologies is entirely 

optional. 

As previously described, the alternative technology requirements are dependent upon 

the model year of the truck engine utilizing the APS, and alternative technologies that 

comply with the performance requirements may be used on both new and in-use 

HDDEs and HDDVs. 

Currently, the most widely used on-board auxiliary devices on sleeper trucks are APSs 

powered by small diesel-fueled internal combustion engines equipped with 

generators/alternators. These APSs are subject to existing CARB off-road emission 

standards because they are not used to propel motor vehicles. The vast majority of 

off-road engines used in APS applications are rated at less than 19 kW (26.03 hp), and 

therefore the following discussion of APS engines is limited to off-road engines rated at 

or below this power rating. 

32
A. The Performance Requirements for Non-Diesel Fueled APS Engines and 

for Diesel-Fueled APS Engines Used on HDDVs Equipped with 2006 and 

Older HDDEs are Within the Scope of Previously Granted Authorizations 

As noted in Section IV., since 1995 all new 1995 through 2007 model-year nonroad CI 

APS engines sold in California have been required to meet the applicable California Tier 

1 or Tier 2 nonroad engine standards. EPA has administered largely identical federal 

standards for these engines since the 1997 model year. The California standards for 

new 1995 through 2007 model-year engines are covered by an outstanding 

authorization and subsequent within-the-scope confirmations.61 California’s Tier 4 

standards applicable to 2008 and subsequent model year engines are identical to EPA’s 

standards, and will be covered by the nonroad engine Tier 4 authorization that CARB 

will soon submit. California’s standards for the SI engines that could be used in an APS 

are also covered by a granted authorization.62 

As discussed in Section III.B.3.a. and b., the 2008 Truck Idling Requirements add a 

requirement that starting January 1, 2008, a diesel-fueled APS engine on an HDDV 

equipped with a 2006 or older model-year HDDE may be operated in California only if 

the APS engine is certified to the applicable California or federal non-road emission 

standards. This requirement is effectively subsumed by the broader requirement that in 

order to be operated in California starting January 1, 2008, an APS using any kind of 

internal combustion engine on an HDDV must be certified to applicable California or 

federal nonroad engine emission standards for its fuel type and power category. These 

provisions largely ensure that the preexisting standards for new nonroad engines are 

enforced while APSs are operated. The engine in any new APS acquired by the truck 

operator in response to the new in-use idling restrictions will be directly subject to the 

preexisting off-road engine standards and certification requirements. By requiring that 

APSs operating in California be California or federally certified, the requirement 

effectively prohibits the use of uncertified pre-1995 model year engines. Because of the 

links to the preexisting standards and certification requirements, the new requirements 

fall within the scope of prior authorizations for these engines. Consideration of each of 

the within-the-scope criteria demonstrates this conclusion. 

1. Protectiveness 

In adopting the 2008 Truck Idling Requirements, the Board approved Resolution 05-55 

(Reference 5), in which it expressly declared: 

BE IT FURTHER RESOLVED that the Board hereby determines, 

pursuant section 209(e)(2) of the federal Clean Air Act, that the emission 

standards and other requirements related to the control of emissions 

adopted as part of this Airborne Toxic Control Measure are, in the 

aggregate, at least as protective of public health and welfare as applicable 

 

61 60 Fed.Reg. 37440 (July 20, 1995); 65 Fed.Reg. 69763 (November 20, 2000); 65 Fed.Reg. 69767 

(November 20, 2000); 68 Fed.Reg. 65702 (November 21, 2003). 62 71 Fed.Reg. 75536 (December 15, 2006). 

33
federal standards, that California needs the adopted standards to meet 

compelling and extraordinary conditions, and that the amended standards 

and accompanying enforcement procedures are consistent with the 

provisions of section 209. 

The CAA only authorizes EPA to adopt standards and other requirements for new 

nonroad engines, vehicles, and equipment,63 and only California may adopt emission 

standards and other emission-related requirements for in-use nonroad engines.64 

Accordingly, EPA has not adopted any standards or requirements for in-use APS 

engines and there is no question that the alternative technology requirements applicable 

to non-diesel fueled APS engines and diesel-fueled engines used on HDDVs equipped 

with 2006 and older model-year HDDEs are at least as protective of public health and 

welfare as applicable federal standards.65 

2. Consistency with CAA Section 209 

As previously stated, section 209(e)(2) requires consistency with the several 

subsections of section 209; that is the Administrator must consider not only consistency 

with section 202(a) – as required under section 209(b)(1)(C) – but also other 

subsections of section 209.66 In its 209(e) Final Rule, EPA interpreted this provision to 

require that California’s standards and accompanying enforcement provisions must also 

be consistent with sections 209(a) and 209(e)(1).67 

a. Consistent with CAA Section 209(a)

The APS requirements are consistent with CAA section 209(a) which preempts states 

and political subdivisions from adopting or attempting to enforce any standard relating to 

the control of emissions from new motor vehicles or new motor vehicle engines. APSs 

are not subject to section 209(a) preemption because they are not new motor vehicles 

or new motor vehicle engines. Although APSs may be installed on heavy-duty diesel 

vehicles, they do not propel the vehicles and therefore cannot be considered a motor 

vehicle engine.68 APS engines clearly fall within the definition of nonroad engine 

established by Congress. 

 

63 CAA section 213, which provides in relevant part: 

If the Administrator makes an affirmative determination under paragraph (2) the 

Administrator shall, within 12 months after completion of the study under paragraph (1), 

promulgate and from time to time revise regulations containing standards applicable to 

emissions from those classes or categories of new nonroad engines and new nonroad 

vehicles.... 

64 EMA v. U.S. EPA, 88 F.3d 1075 at 1089-1090. 

65 Id., at 1089. 

66 Air Pollution Control; Preemption of State Regulation for Nonroad Engine and Vehicle Standards 

(“Section 209(e) Rule”), 59 Fed.Reg. 36969, 36983 (July 20, 1994). 67 Id.

68 See CAA section 216(2). 

34
In the Section 209(e) Rule, EPA defined “nonroad engine” to mean: 

(1) Except as discussed in (2) below, a nonroad engine is any internal 

combustion engine: 

(i) in or on a piece of equipment that is self-propelled or serves a dual 

purpose by both propelling itself and performing another function 

(such as garden tractors, off-highway mobile cranes and 

bulldozers); or 

(ii) in or on a piece of equipment that is intended to be propelled while 

performing its function (such as lawnmowers and string trimmers); 

or 

(iii) that by itself or in or on a piece of equipment, is portable or 

transportable, meaning designed to be and capable of being carried 

or moved from one location to another. Indicia of transportability 

include, but are not limited to wheels, skids, carrying handles, dolly, 

trailer, or platform. 

(2) An internal combustion engine is not a nonroad engine if: 

(i) the engine is used to propel a motor vehicle or a vehicle used solely for 

competition, or is subject to standards promulgated under section 202 of 

the [CAA]; or 

(ii) the engine is regulated by the New Source Performance Standard 

promulgated under section 111 of the [CAA]; or 

(iii) the engine otherwise included in (1)(iii) remains or will remain at a location 

for more than 12 consecutive months or a shorter period of time for an 

engine located at a seasonal source....69 

APS engines fall within the scope of section (1)(iii) of this definition, as they are engines 

incorporated in systems that are designed to be and capable of being transported by 

motor vehicles and do not meet any of the conditions for exclusion under paragraph (2). 

As stated, they are not used to propel a motor vehicle or vehicle used solely in 

competition; they are also not subject to section 111 of the CAA, and are not stationary 

sources in that they are constantly being transported from one location to another. 

 

69 59 Fed.Reg. 36969, 36971 (July 20, 1994). 

35
b. Consistent with CAA Section 209(e)(1)

The APS requirements are not inconsistent with section 209(e)(1). That section 

establishes the federal preemption prohibiting states and local subdivisions from 

adopting or enforcing any standard or other requirement relating to the control of 

emissions of new engines used in farm and construction equipment that are smaller 

than 175 hp or engines used in new locomotives. APS engines are not used in 

locomotives and are not primarily used in farm and construction equipment and 

vehicles. 

In the Section 209(e) Rule, EPA established a “Primary Use Test” to determine whether 

equipment using nonroad engines are preempted under section 209(e)(1).70 Under that 

test, if the universe of a specific type of equipment or vehicle is used more than a 

majority of time in farm or construction uses than it would be considered a farm or 

construction piece of equipment or vehicle for purposes of section 209(e)(1).71 EPA 

defined “construction equipment or vehicle” and “farm equipment or vehicle” as follows: 

Construction equipment or vehicle means any internal combustion 

engine-powered machine primarily used in construction and located on 

commercial construction sites. 

Farm equipment or vehicle means any internal combustion 

engine-powered machine primarily used in the commercial production 

and/or commercial harvesting of food, fiber, wood, or commercial organic 

products or for the processing of such products for further use on the 

farm.72

APSs are not primarily used in construction vehicles or equipment and are seldom, if 

ever, found on construction sites. Similarly, APSs systems are not primarily used in 

vehicles or equipment engaged in the commercial production or harvesting of food, 

fiber, wood, etc. and are seldom found on farms or agricultural lands. 

c. Consistent with CAA Section 209(b)(1)(C)

 (i) General 

CAA section 209(b)(1)(C) provides that no waiver shall be granted if the Administrator 

finds that the state standards and accompanying enforcement procedures are not 

consistent with section 202(a) of the CAA. EPA has historically interpreted consistency 

with section 202(a) using a two-prong test: (1) that there is sufficient lead time to permit 

the development of technology necessary to meet the standards and other 

requirements, giving appropriate consideration to the cost of compliance in the time 

 

70 Id., at 36977. 

71 Id., at 36978, 36986. 

72 Id., at 36986. 

36
frame provided and (2) that the California and federal test procedures are sufficiently 

compatible to permit manufacturers to meet both the state and federal test requirements 

with one test vehicle or engine.73 

 (ii) Technical Feasibility of APS Requirements 

As described above, the alternative technology requirements specify different 

requirements that are dependent on the model year, fuel type, and the horsepower 

category of the APS engines, and for diesel fueled APSs, the model year of the engine 

in the HDDV. 

In evaluating technical feasibility under section 202(a) of the CAA, the Administrator 

considers the factors previously discussed in Section VI.C.2 of this document. In 

applying these factors, it is readily apparent that the APS requirements are 

technologically feasible within the applicable time frame, because the requirements 

simply require that any internal combustion off-road engine used in an APS comply with 

the California off-road and/or federal non-road emission standards and test procedures 

applicable for its fuel type and power category. The technological feasibility of these 

requirements has already been fully considered by EPA in granting California 

authorizations under section 209(e) for its small off-road engine and off-road CI engine 

standards and test procedures.74 The only substantive authorization request still 

pending EPA’s review is for California’s 2004 amendments to new off-road CI engines, 

but given that these most recent amendments harmonize CARB’s standards and test 

procedures with the federal standards and test procedures specified in its Tier 4 

rulemaking (40 CFR Part 89) and the subsequent Omnibus Technical Amendments,75

CARB is confident that EPA will find that these amendments satisfy the technical 

feasibility requirements of section 202(a). 

Moreover, since EPA has also established emissions standards and test procedures 

applicable to small nonroad engines since the 1997 model year,76 it has fully explored 

the same issues relating to technical feasibility in promulgating federal standards and 

requirements relating to smaller nonroad engines. These engines have been produced 

and used in APSs for years, and no commenter raised any issue regarding the 

feasibility of using a certified California or federal off-road engine on a HDDV equipped 

with a 2006 or older HDDE. The fact that the APS requirements apply to operators and 

owners of heavy-duty diesel vehicles and not to off-road engine manufacturers should 

not affect this analysis. Traditional lead-time assumptions that apply to manufacturers 

of new engines as opposed to the time that end-users may elect to install in-use 

 

73 See 61 Fed.Reg. 53371, 53372 (October 11, 1996); Decision Document at p.2 (OBD II Waiver 

Decision). 74 See Section IV of this waiver support document, which provides a brief overview of California’s 

regulations and authorization requests for off-road engines rated at or less than 19 kW. 

75 70 Fed.Reg. 40240 (July 13, 2005). 

76 “Control of Air Pollution; Emission for New Nonroad Spark-ignition Engines At or Below 19 Kilowatts; 

Final Rule; 60 Fed.Reg. 34581-34657 (July 3, 1995). 

37
engines and equipment do not apply when considering in-use performance standards.77 

There is no lead time required for tooling a production line and there is no clear end 

date for beginning the base time of production.78 In this case what matters is whether 

the APSs needed for compliance will be commercially available in time for 

owners/operators to comply with the January 1, 2008 effective date, and no commenter 

disputed such availability. Indeed, the lack of comments from engine manufacturers 

effectively confirms that Tier 4 engines should be available in the time provided for 

compliance by end users. 

The APS requirements do not modify the test procedures specified for certifying a 

California or federal off-road engine, and accordingly, the Administrator’s prior 

determinations of test procedure consistency still remain in effect. 

d. No New Issues 

Finally, the APS requirements do not raise any new issues affecting the Administrator’s 

previous authorization determinations. 

B. THE PERFORMANCE REQUIREMENTS FOR DIESEL-FUELED APS 

ENGINES OPERATED ON HDDVs EQUIPPED WITH 2007 AND NEWER 

HDDEs EITHER FALL WITHIN THE SCOPE OF PREVIOUSLY GRANTED 

AND PENDING AUTHORIZATIONS OR QUALIFY FOR A NEW 

AUTHORIZATION 

The APS requirements specify that, starting January 1, 2008, diesel APS engines that 

are operated in California on HDDVs equipped with 2007 and subsequent model-year 

HDDEs must comply with the California or federal non-road emission standards and test 

procedures applicable to the horsepower category of the engines and must additionally 

either:

(i) have their exhaust routed into the truck’s exhaust system so that the APS PM 

emissions are controlled by the truck’s PM trap, (title 13, CCR section 

2485(c)(3)(A)1.b), or 

(ii) be equipped with a level 3 verified PM control strategy (i.e., achieve an 

85 percent or greater PM reduction efficiency).79 (Title 13, CCR section 

2485(c)(3)(A)1.a.) CARB’s verification procedures involve a thorough evaluation of 

the emission reduction capability of a trap and of its durability to ensure that the 

emission reductions achieved by the trap are both real and durable, and that 

production units in the field are achieving emission reductions that are consistent 

 

77 Cf., International Harvester v. Ruckelshaus (D.C. Cir. 1973) 478 F.2d 615 and Natural Resources 

Defense Council v. U.S. EPA (D.C. Cir 1981) 655 F.2d 318. 78 Id. 

79 The PM trap verification procedure and in particular, the level 3 verification level, are specified in 

title 13, CCR sections 2700 to 2710. 

38
with the verification. They also require the manufacturer to warrant that its PM trap 

is free from defects in design, materials, workmanship, and that operation of the 

trap achieves the emission reduction levels it was verified to, or 

(iii) subject to advance Executive Officer approval, use other procedures to 

demonstrate an equivalent level of emissions compliance (compared to routing the 

exhaust or using a level 3 verified PM control strategy). (Title 13, CCR section 

2485(c)(3)(A)2.) 

1. Option 1 of the Performance Requirements for Diesel APSs is Within the 

Scope of California’s Pending Authorization Request for CARB’s 2000 

and 2004 Amendments to California’s Off-Road CI Regulations 

CARB will soon be filing a request for authorization for its 2000 and 2004 amendments 

applicable to new California off-road CI engines that harmonize CARB’s standards and 

test procedures with the federal standards and test procedures specified in EPA’s Tier 4 

rulemaking and the subsequent Omnibus Technical Amendments.80 These 

amendments establish CARB Tier 4 exhaust emission standards for new off-road CI 

engines rated less than 19 kW that will be implemented starting with the 2008 model 

year. CARB is confident that once EPA approves this authorization request, it will also 

determine that Option 1 of the performance requirements applicable to diesel-fueled 

APSs falls within the scope of the authorization request for CARB’s 2000 and 2004 

amendments to California’s off-road CI engines. 

The first compliance option of the Alternative Technology Requirements specifies that 

owners or operators electing to operate a diesel-fueled APS on a HDDV equipped with 

a 2007 or newer model-year HDDE must route the APS’ exhaust into the HDDV’s 

exhaust system upstream of the vehicle’s particulate matter trap. 

This option satisfies the protectiveness criterion of CAA section 209(e)(2) for the 

reasons set forth above under Section VIII.A.1 – viz., only California may adopt 

emission standards and other emission-related requirements for in-use nonroad 

engines, and EPA has not adopted any requirements applicable to this category of 

in-use APS engines. There is no question that this option’s requirements are at least as 

protective of public health and welfare as applicable federal standards. New 2008 

diesel-fueled APSs will be certified to either CARB or federal Tier 4 standards. As 

stated, in CARB’s 2004 rulemaking, California merely harmonized its regulations with 

those already adopted by EPA. In Resolution 04-43 (Reference 12), the Board found 

that the amended emission standards and test procedures do not undermine its 

previous determinations that California’s emission standards for off-road CI engines 

under 19 kW are at least as protective of public health and welfare as applicable federal 

standards. 

 

80 40 CFR Part 89 and 70 Fed.Reg. 40240 (July 13, 2005). 

39
This option is also not inconsistent with CAA section 209. It neither applies to motor 

vehicles and motor vehicle engines that are preempted under section 209(a) nor to 

nonroad engines that are specifically preempted under section 209(e)(1). 

Finally, this option is consistent with section 209(b)(1)(C) in that it is technically feasible 

within the specified lead time. CARB did not receive any comments questioning the 

technical feasibility of routing a diesel APS’ exhaust upstream of the main engine’s 

diesel particulate trap81 and at least one major engine manufacturer has submitted an 

application for certification for its fully integrated APS and truck exhaust system for the 

2008 model-year. The option also raises no issues of test procedure inconsistency 

because it does not alter the test procedures specified for certifying a California or 

federal off-road engine. Option 1 also does not raise any new issues affecting the 

Administrator’s previous authorization determinations or the pending authorization 

request for 2000 and 2004 CI engines. Accordingly, the first option falls within the 

scope of CARB’s authorization request for its 2000 and 2004 amendments applicable to 

new California off-road CI engines. 

2. Options 2 and 3 of the Performance Requirements for Diesel APSs Meet 

the Criteria for a New Authorization 

The second compliance option specifies that owners or operators electing to operate a 

diesel-fueled APS on a HDDV equipped with a 2007 or newer model-year HDDE must 

equip the APS with a level 3 verified PM control strategy, to reduce baseline PM 

emissions an additional 85 percent. The third compliance option allows the use of a 

diesel-fueled APS that utilizes an alternative control measure that has demonstrated an 

equivalent level of emissions compliance compared to either routing the exhaust to the 

HDDV’s main PM trap or using a level 3 verified PM control strategy. Because these 

requirements subject in-use off-road engines to much more stringent particulate matter 

emission standards than those established in California’s Tier 4 standards for new 

off-road CI engines,82 CARB requests that the Administrator grant a new authorization 

for options 2 and 3. No basis exists for the Administrator to deny this request. 

 a. Protectiveness

In adopting Resolution 05-55 (Reference 5), the Board found that to the extent the 

Alternative Technology Requirements component of the 2008 Truck Idling 

Requirements affects off-road engines, the emission standards and other requirements 

related to the control of emissions are, in the aggregate, at least as protective of public 

health and welfare as applicable federal standards. California and federal Tier 4 

emission standards for off-road CI engines are identical, and because options 2 and 3 

now require these off-road CI engines to comply with more stringent PM emission 

 

81 However, commenters did raise issues regarding the effect such a modification would have on a 

HDDV’s warranty. See FSOR, comments 35 and 36 and Agency Responses thereto. 

82 The PM standard for new off-road CI engines rated at or less than 19 kW is 0.40 g/kw-hr; Options 2 

and 3 would require Tier 4 engines to emit no more than 0.06 g/kw-hr. 

40
standards, it follows that these options are more stringent than applicable federal 

regulations, which do not require level 3 verified PM strategies (or their equivalent). 

b. The Requirements are Needed to Meet Compelling and Extraordinary 

Circumstances

In adopting Resolution 05-55, the Board also confirmed CARB’s longstanding position 

that California continues to need its own nonroad engine and vehicle program to meet 

serious air pollution problems. The Administrator has previously and consistently 

recognized that California meets the compelling and extraordinary criterion when 

granting waivers for motor vehicles under section 209(b) and authorization for 

California’s nonroad regulations under section 209(e) of the CAA. 

The relevant inquiry under section 209(e)(2)(A)(ii) is whether California needs its own 

emission control program to meet compelling and extraordinary conditions, not whether 

any given standard is necessary to meet such conditions.83 In approving waivers under 

section 209(b), the Administrator has determined that: 

“[C]ompelling and extraordinary conditions” does not refer to levels of 

pollution directly, but primarily to the factors that tend to produce them: 

geographical and climatic conditions that, when combined with large 

numbers and high concentrations of automobiles, create serious air 

pollution problems.84

California and the South Coast and San Joaquin Valley air basins in particular continue 

to experience some of the worst air quality in the nation.85 The geographical and 

climatic conditions, and the tremendous growth in vehicle population and use that 

moved Congress to authorize California to establish separate vehicle standards in 1967, 

still exist today. EPA recently confirmed the ARB’s judgment, on behalf of the State of 

California, on this matter.86

In the California Clean Air Act of 1988, the California Legislature found that: 

[D]espite the significant reductions in vehicle emissions which have been 

achieved in recent years, continued growth in population and vehicle miles 

traveled throughout California have the potential not only to prevent 

 

83 Final 209(e) Rule, 59 Fed.Reg. at 36982. The Administrator has recognized that even if such a 

standard by standard test were applied to California, it "would not be applicable to its fullest stringency 

due to the degree of discretion given to California in dealing with its mobile source pollution problems." 

(41 Fed.Reg. 44209, 44213, (October 7, 1976); 49 Fed.Reg. 18887, 18892 (May 3, 1984).) 

84 49 Fed.Reg. at 18890. There the Administrator found that California need not demonstrate its 

particulate problem (or diesel vehicles’ contribution to it) is the worst in the country in order to adopt a 

particulate matter standard affecting diesel vehicles. Id. at 18891-92.

85 See e.g. Approval and Promulgation of State Implementation Plans; California – South Coast, 

64 Fed.Reg.1770, 1771 (January 12, 1999). 

86 California State Motor Vehicle Pollution Control Standards; Waiver of Federal Preemption – Notice of 

Decision, 68 Fed.Reg.19811, 19812 (April 22, 2003). 

41
attainment of the state standards, but in some cases, to result in 

worsening of air quality.87

In response to the undisputed severe air quality problems in California, the California 

Legislature authorized CARB to consider adopting, inter alia, standards and regulations 

for nonroad engines.88 Given the serious air pollution problems California faces and the 

resultant need to achieve the maximum reductions in emissions, the California 

Legislature and CARB believe it is necessary to develop emission controls for nonroad 

sources as well as for motor vehicles.89 CARB continues to find such previously 

uncontrolled nonroad engines to be significant emission sources for which controls are 

necessary to meet federal and state air quality standards.90 

By adding federal and state authority to regulate nonroad engines, Congress and 

California’s Legislature, respectively, acknowledged the increasing importance of 

reducing emissions from all mobile sources, including nonroad engines. The 

Administrator has repeatedly agreed with CARB that California’s continuing 

extraordinary conditions justify separate California nonroad programs.91 Nothing in 

these conditions has changed to warrant a change in this determination. Accordingly, 

for all the aforementioned reasons, there can be no doubt of the continuing existence of 

compelling and extraordinary conditions justifying California’s need for its own nonroad 

vehicle and engine emissions control program. 

 c. The Requirements Are Consistent with CAA Section 209

The requirements of title 13, CCR sections 2485(c)(3)(A)1 and 2485(c)(3)(A)2 are 

consistent with CAA section 209. First, by their terms, the requirements apply only to 

off-road sources, and not motor vehicles as defined by 40 CFR section 85.1703. 

Second, the options do not apply to new nonroad engines under 175 hp used in farm 

and construction vehicles or to locomotives.92 The options are also fully consistent with 

CAA section 202(a). 

 

(i) Technology Required to Comply with Option 2 Is Feasible Given the Lead 

Time Provided and the Costs of Compliance 

Option 2 is consistent with section 202(a) in that the required technology is feasible 

within the lead time provided and considering the costs of compliance. CARB has not 

yet issued a verification for any level 3 particulate matter control strategies for diesel 

APS applications, but several APS manufacturers have submitted applications to verify 

level 3 particulate matter devices for APS applications for idling trucks that are presently 

being reviewed and processed by staff. Also, major engine manufacturers (Cummins 

 

87 California Health and Safety Code section 43000.5. 88 California Health and Safety Code sections 43013 and 43018. 89 See California Health and Safety Code sections 41750, 41754, 43000.5, 43013 and 43018. 90 Resolution 03-37. See also ISOR at Chapter II. 91 Utility Authorization, Decision Document, at p. 33; OHRV Authorization, Decision Document, at 

pp. 27-29; and HDOR Authorization, Decision Document, at pp. 16-18. 92 CAA section 209(e)(1). 

42
and Caterpillar) are developing integrated main engine/APS systems that they expect to 

offer as factory options. 

During the development of CARB’s Tier 4 off-road emission standards, aftertreatment 

technology was not commercially available for smaller diesel engines, such as the 

engines powering diesel APSs, and staff therefore could not specifically elaborate on 

the feasibility of applying PM aftertreatment to these smaller diesel engines. However, 

there is no inherent PM emission characteristic that would prevent a manufacturer from 

applying a PM filter system used on larger diesel engines to smaller diesel engines. 

The lower exhaust temperatures from smaller engines will likely require an active 

regeneration strategy to prevent the PM filter from clogging, but PM aftertreatment 

strategies being developed for 2007 and newer on-road HDDEs will also employ active 

regeneration strategies to prevent the possibility of PM filter failure under certain low 

exhaust temperature operations. Therefore, on-road diesel PM filter technologies that 

will be deployed on HDDEs beginning in 2007 can be applied to diesel fueled APSs with 

only modifications to active regeneration strategies and to accommodate the smaller 

PM filter sizes. Furthermore, PM traps and regeneration strategies designed for use in 

transportable refrigeration units (TRUs) and TRU generator sets can be readily adapted 

to APSs, since these applications use the same categories of small diesel engines that 

are operated under similar engine speeds and loads. The technological feasibility 

discussion for Option 2 is set forth in greater detail the ISOR at pp. 28-29. 

The cost of compliance within the lead time provided was also given appropriate 

consideration. CARB staff estimated that businesses that purchase new 2007 and 

subsequent model-year sleeper trucks will incur a cost of approximately $7,000 to 

$10,100 (cost of an APS with additional PM control and, for California certified trucks, 

an engine shutdown system for 2008 and subsequent model-year engines). However, 

staff also concluded that these additional costs could be recovered within 2.5 years 

through reduced fuel consumption and maintenance requirements. Therefore, overall, 

the proposed requirements would benefit HDDV owners because they will realize a net 

savings from improved operating costs.93

Moreover, Option 2 constitutes only one of several alternatives available to owners or 

operators. It bears repeating that the 2008 Truck Idling Requirements were deliberately 

designed to be “technology neutral.” Specifically, the regulation provides regulated 

entities a wide range of compliance options, and does not mandate or compel regulated 

entities to utilize any one specific technology or strategy. For example, heavy-duty 

diesel vehicles using 2008 and newer engines certified to the optional NOx idling 

emission standard94 are exempted from the in-use idling ATCM, provided they are 

located beyond 100 feet of a restricted area (title 13 CCR section 2485(d)(1)(A)).95 As 

 

93 Staff’s analysis in the ISOR was based on a diesel fuel price of $2.40 a gallon. Diesel prices are now 

significantly higher ($3.44/gallon). Diesel Jumps to a Record High at the Pump, Los Angeles Times 

(November 27, 2007) (Reference 13). 

94 Title 13 CCR section 1956.8(a)(6)(C) 95 Title 13 CCR section 2485(d)(1)(B)provides that the HDDV must also labeled in accordance with title 

13 CCR section 1956.8(b). 

43
stated, during the rulemaking, CARB staff did not anticipate that manufacturers would 

widely utilize this compliance option before 201096, but staff now indicates that 

substantially more manufacturers will be certifying 2008 model-year engines to this 

option than it previously anticipated.97 Other options include Option 1 (routing the APS 

exhaust), utilizing a non-diesel fueled APS, Option 3 (using an emissions control 

strategy that is equivalent to Option 1 or 2 on a diesel APS), or another idle reduction 

technology (discussed in greater detail below). 

 (ii) Technology to Comply with Option 3 Is Presently Available 

The Alternative Technology Requirements also allow the use of any compliance 

strategy provided it is at least as effective in reducing idling emissions as the emission 

requirements applicable to internal combustion engine powered APSs or the optional 

NOx idling emission standard98. Such alternatives include, without limitation, battery 

powered APSs, thermal energy storage systems, truck stop electrification, and off-board 

power infrastructure such as that developed by IdleAire Technologies. These 

technologies are described in greater detail in Section V of the ISOR, and 

representatives from companies producing such alternative technologies testified at the 

October 20, 2005 public hearing that their products were presently commercially 

available and had payback periods of less than a year, which is comparable to staff’s 

projected payback period of 1.5 to 2.5 years.99 

The anticipated compliance costs associated with these alternatives are set forth in 

Section V of the ISOR. As expected, these costs are generally higher than those 

associated with more proven technologies, but have costs with payback periods 

comparable to those projected for Option 2. 

It should also be noted that many if not most of the technologies that could be used to 

comply with Option 3 could also be used to comply with the Other Idle Reduction 

Technology compliance provision described below. 

 (iii) Options 2 and 3 Are Consistent with Federal Test Procedures 

Options 2 and 3 present no issue regarding incompatibility between California and 

federal test procedures that would prevent manufacturers from meeting both California 

and federal test requirements with one test engine. Specifically with respect to the 

Level 3 verified PM control strategy and equivalent compliance levels, no incompatibility 

 

96 ISOR, p. 13; FSOR, pp. 23-24. 97 These manufacturers include Caterpillar, Cummins, Detroit Diesel Corporation, Ford, and Hino. 98 Title 13 CCR section 2485(c)(3)(C). 99 Specifically, Webasto’s Blue Cool Truck parking cooler (thermal energy storage system) has a payback 

period of 30 weeks or less [Transcript of October 20, 2005 Public Hearing in the 2008 Truck Idling 

Requirements rulemaking, hereinafter “Transcript,” 221:23 to 224:5; (Reference 8)]; IdleAire stated that it 

intended to expand its truck stop electrification services in California to approximately three to four times 

the amount of its current levels [Transcript 225:21-23]; Idling Solutions and Coval Partners discussed its 

battery powered system that is currently available and has a projected payback period of less than one 

year [Transcript, 234:5 to 235:20]. 

44
issue arises because EPA does not have any comparable in-use standards and lacks 

the authority to adopt such requirements.100 

For the foregoing reasons, CARB requests that the Administrator grant a new 

authorization for Options 2 and 3 to the Performance Requirements for Diesel APSs. 

C. The “Other Idle Reduction Technologies” Option Either Falls Within the 

Scope of Previously Granted Authorizations and Waivers or Meets the 

Criteria for a New Authorization 

Title 13 CCR section 2485(c)(3)(C) allows the use of technologies that will reduce idling 

emissions provided they are at least as effective in reducing emissions as the 

requirements applicable to APSs as described above, or the optional NOx idling 

emission standard. These technologies include batteries, fuel cells, power 

inverter/chargers for on-shore electrical power, on-shore electric power infrastructure 

(truck stop electrification) and other technologies that produce minimal or no emissions. 

To the extent this alternative establishes requirements equivalent to those applicable to 

non-diesel and diesel fueled APSs operated on HDDVs equipped with 2006 and older 

HDDEs, it falls within the scope of previously granted authorizations for the reasons 

specified in Section VIII.A. of this document. 

To the extent this alternative establishes requirements equivalent to those applicable to 

diesel fueled APSs operated on HDDVs equipped with 2007 and newer HDDEs and to 

the performance requirements of Option 1 (routing APS exhaust into the main PM trap), 

it falls within the scope of authorization for the reasons specified in Section VIII.B.1 of 

this document. 

To the extent this alternative establishes requirements equivalent to those applicable to 

diesel fueled APSs operated on HDDVs equipped with 2007 and newer HDDEs and to 

the performance requirements of Options 2 and 3 (requiring a level 3 verified PM control 

strategy or equivalent), it qualifies for a new authorization for the reasons specified in 

Section VIII.B.2 of this document. 

Finally, to the extent this alternative establishes requirements equivalent to the optional 

NOx idling emission standard, it falls within the scope of the previously granted waiver 

for CARB’s 2007 HDDE standards and accompanying test procedures for the reasons 

specified in Section VI.C. of this document. 

D. The Fuel-Fired Heater Requirements Are Not Preempted and 

Accordingly Do Not Require an Authorization 

Title 13 section 2485(c)(3)(B) states that fuel-fired heaters must generally comply with 

the emission limits contained in California’s Low Emission Vehicle program 

requirements. This requirement does not require an authorization because CAA 

 

100 See CAA section 213; EMA v. U.S. EPA, supra, 88 F.3d 1075. 

45
section 209(e) only preempts states from adopting or attempting to enforce standards 

related to the control of emissions from nonroad engines or nonroad vehicles. 

Fuel-fired heaters are neither nonroad engines nor vehicles. 

IX. LABELING REQUIREMENTS 

 

The 2008 Truck Idling Requirements contain engine and vehicle labeling provisions. 

The engine labeling requirement requires that new 2008 and subsequent model-year 

California certified HDDEs be equipped with a label containing an unconditional 

statement of compliance with appropriate model-year California regulations (subsection 

35.A.1.3 of the “California Exhaust Emission Standards and Test Procedures for 2004 

and Subsequent Model heavy-Duty Diesel Engines and Vehicles”). 

The vehicle labels will aid enforcement personnel in clearly and easily identifying those 

HDDVs that are either equipped with HDDEs certified to the optional NOx idling 

emission standard or are equipped with APSs that comply with the proposed 

performance requirements. The first vehicle labeling provision requires engine 

manufacturers that elect to certify 2008 and later model-year HDDES to the optional 

NOx idling emission standard to produce a vehicle label to identify the vehicle as being 

equipped with a “Clean Idle” engine.101 The second vehicle labeling provision requires 

that a 2007 or newer model-year HDDV equipped with an APS complying with 

applicable performance specifications have a label affixed to the vehicle hood that 

identifies the vehicle uses a “Verified Clean APS.”102 

A. The Engine and Optional NOx Idling Labeling Requirements Constitute 

“Other Conditions Precedent” That Do Not Require Further Waiver 

Action

Because the engine and optional NOx idling labeling requirements do not pertain to a 

manufacturer’s ability to certify and produce motor vehicles or motor vehicle engines 

that comply with applicable emission standards, the requirements are not standards or 

accompanying enforcement procedures.103 The specifications are, however, subject to 

federal preemption pursuant to Clean Air Act Section 209(a) because they are a 

condition precedent to the initial retail sale of new vehicles in California.104

EPA has stated with respect to the application of Section 209 of the Clean Air Act: 

 

101 Title 13, CCR section 1956.8(a)(6)(C) and subsection 35.B.4 of the “California Exhaust Emission 

Standards and Test Procedures for 2004 and Subsequent Model heavy-Duty Diesel Engines and 

Vehicles”. 

102 Title 13, CCR sections 2404, 2424 and 2485(c)(3)(D) and subsection 35.B.4 of the “California Exhaust 

Emission Standards and Test Procedures for 2004 and Subsequent Model heavy-Duty Diesel Engines 

and Vehicles”. 

103 54 Fed.Reg. 13427 (April 3, 1989); 43 Fed.Reg. 36679 (August 18, 1978). 104 See, e.g., 49 Fed.Reg. 18887 (May 5, 1984); 47 Fed.Reg. 1015 (January 8, 1982); 46 Fed.Reg. 

36237 (July 14, 1981). 

46
Once California has received a waiver of federal preemption for its 

standards and enforcement procedures for a class of vehicles, it may 

adopt other conditions precedent to initial retail sale, titling or registration 

of the subject class of vehicles without the necessity of receiving a further 

waiver of Federal preemption.105

EPA has also stated in a prior determination regarding emission control labeling: 

EPA’s prior issuance of waivers for the affected classes of vehicles and 

engines, based on California’s standards and/or accompanying 

enforcement procedures, removes the prohibitions of section 209(a) 

regarding such conditions precedent for these classes. Hence no waiver 

under section 209(b) is required for California to enforce the amended 

[Emission Control] Label Specifications.106

As discussed in Section IV.A. above, CARB has previously received a section 209(b) 

waiver for the amendments to its heavy-duty diesel engine standards for 2007 and 

subsequent model-year engines and related test procedures. Therefore, with respect to 

these amendments, CARB requests confirmation that the previous section 209(b) 

waiver relieves CARB of the need to demonstrate that the specifications independently 

meet the waiver criteria and that the amended specifications may be enforced in 

California without further action by the Administrator. 

B. The Auxiliary Power System Labeling Requirement Is an Accompanying 

Enforcement Provision

The APS labeling requirement is intended to ensure effective enforcement of the 

underlying APS performance standards by requiring manufacturers certifying a 

compliant APS to produce label to be affixed to the HDDV, and is therefore an 

accompanying enforcement provision. In adopting the Alternative Technology 

Requirements, the Board determined that these requirements, in the aggregate, are as 

protective of public health and welfare as applicable federal standards, and that the 

requirements are necessary to meet compelling and extraordinary conditions.107 No 

issues regarding consistency of the APS labeling requirement with section 202(a) were 

raised during the rulemaking process. 

To the extent that the APS labeling requirements help enforce elements for which 

CARB is seeking confirmation that the elements are within the scope of previous 

authorizations or waivers, CARB is requesting that the confirmation decision include the 

APS labeling requirements. To the extent that the APS labeling requirements help 

enforce elements for which CARB seeks a new authorization, it similarly requests that 

the authorization include the APS labeling requirement. 

 

105 46 Fed.Reg. 36742 (July 15, 1981), footnotes omitted; 45 Fed.Reg. 54131 (August 14, 1980); 43 

Fed.Reg. 36579 (August 18, 1978). 

106 54 Fed.Reg. 13427 (April 3, 1989). 107 Resolution 05-55. 

47
X. CONCLUSION 

Based on the foregoing, CARB respectfully requests that the Administrator grant 

California’s requests for the waiver and authorization actions as described in this 

document pursuant to CAA section 209. To assist you in reviewing the requests, CARB 

is enclosing two CD-ROMs, each containing the following referenced documents to be 

included in the record of this waiver proceeding. 

Reference Materials from the 2008 Truck Idling Requirements Rulemaking 

1. Public Hearing Notice, dated August 23, 2005. 

2. Staff Report: Initial Statement of Reasons for Proposed Rulemaking, with 

Appendices A and B. 

3. Copy of Slides for Staff Presentation. 

4. Notice of Availability of Modified Text, with Attachments 1 and 2, issued June 28, 

2006. 

5. Resolution 05-55, dated October 20, 20005, with Attachment C. 

6. Executive Order R-06-003, dated September 1, 2006. 

7. Final Statement of Reasons for Rulemaking, Including Summary of Comments 

and Agency Response. 

8. Transcript of October 20, 2005 Public Hearing in the 2008 Truck Idling 

Requirements rulemaking 

9. Fully endorsed STD 400 face sheet and Final Regulation Order as approved by 

OAL and filed with the Secretary of State January 18, 2007, for amendments to 

title 13, California Code of Regulations, sections 1956.8, 2404, 2424, 2425, 2485 

and incorporated test procedures. 

10. The final version of the document incorporated by reference in the regulations 

 contained in the Final Regulation Order: 

California Exhaust Emission Standards and Test Procedures for 2004 and 

Subsequent Model Heavy-Duty Diesel Engines and Vehicles, as amended 

September 1, 2006, incorporated by reference in § 1956.8, title 13, CCR. 

11. Office of Administrative Law Approval Notice, dated October 16, 2006. 

48
49

Other Relevant Materials 

12. Resolution 04-43 

13. Diesel Jumps to a Record High at the Pump, Los Angeles Times (November 27, 

 2007). 

CARB Contacts

Technical questions or requests for additional technical information on this item should 

be directed to Stephan Lemieux, Manager of CARB’s On-Road Heavy-duty Diesel 

Section, at (626) 450-6162. Legal questions should be directed to Alex Wang, Senior 

Staff Counsel, at (916) 323-9610.