Final Statement of Reasons for Rulemaking

Including Summary of Comments and Agency Responses

PUBLIC HEARING TO CONSIDER

THE ADOPTION OF THE PROPOSED AIRBORNE TOXIC

CONTROL MEASURE FOR DIESEL PARTICULATE MATTER

FROM PORTABLE ENGINES GREATER OR EQUAL THAN 50

HORSEPOWER

Public Hearing Date: February 26, 2004

Agenda Item Number: 04-2-2
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State of California

AIR RESOURCES BOARD

Final Statement of Reasons for Rulemaking,

Including Summary of Comments and Agency Responses

PUBLIC HEARING TO CONSIDER THE ADOPTION OF THE

PROPOSED AIRBORNE TOXIC CONTROL MEASURE FOR

DIESEL PARTICULATE MATTER FROM PORTABLE ENGINES

GREATER OR EQUAL THAN 50 HORSEPOWER

Public Hearing Date: February 26, 2004

Agenda Item No.: 04-2-2

I. GENERAL

A. Description of Board Item

On February 26, 2004, the Air Resources Board (ARB or Board) conducted a

public hearing to consider adopting an airborne toxic control measure (ATCM) to

reduce public exposure to diesel particulate matter (PM) emitted from portable

diesel-fueled engines (proposed ATCM). The proposed ATCM was developed

to fulfill the requirements in the Diesel Risk Reduction Program to reduce diesel

PM emissions and associated risk from the use of diesel-fueled portable engines

in California. The proposed ATCM will add sections 93116-93116.5 to Title 17,

California Code of Regulations (CCR).

At the February 26, 2004, hearing, the Board approved the proposed regulation

with modifications. The modifications were made available for a public comment

period from May 13, 2004, to June 1, 2004. This Final Statement of Reasons for

Rulemaking (FSOR) updates the staff report by identifying and explaining the

modifications that were made to the original proposal. The FSOR also

summarizes the written and oral comments received during the 45-day comment

period preceding the February 26, 2004, public hearing, the hearing itself, and

the 15-day comment period for the proposed modifications, and contains the

ARB staff’s responses to those comments.

B. Modifications to the Original Proposal

Various modifications to the original proposal were made to address comments

received during the 45-day public comment period, and to clarify the regulatory

language. A “Notice of Public Availability of Modified Text,” together with a copy
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of the modified proposed language were sent on May 13, 2004, to each of the

individuals described in subsections (a)(1) through (a)(4) of section 44, Title 1,

CCR. Additionally, this notice and the modified proposed language were made

available on ARB’s website and potentially affected industry were notified, via an

email list server, of the website posting.

By these actions, the modified portable diesel-fueled engine ATCM was made

available to the public for a 15-day minimum comment period from May 13, 2004

to June 1, 2004, pursuant to Government Code section 11346.8. Responses to

comments made during the public comment period for these modifications are

presented in Section II of this FSOR. After the close of the public comment

period, the Board’s Executive Officer determined that, with the exception of the

changes described below, no additional modifications should be made to the

portable diesel-fueled engine ATCM. The Executive Officer subsequently issued

Executive Order G-04-080, which adopted the portable diesel-fueled engine

ATCM.

The modifications to the originally proposed regulation are described below:

1. Clarified that the ATCM applies to portable diesel-fueled engines that are

50 horsepower and larger to be consistent with other regulations affecting

portable engines;

2. Revised the “alternative fuel” definition to include liquid petroleum gas

(LPG) and hydrogen;

3. Revised the definitions for “alternative diesel fuel” and “CARB diesel fuel,”

and added a definition for “diesel fuel” to clarify the differences between

these fuels;

4. Added definitions for “engines exclusively used in emergency applications”

and “emergency event” to be consistent with other regulations that affect

stationary and portable engines;

5. Revised the definition of “emergency” to be consistent with other

regulations that affect stationary and portable engines and to include the

breakdown of electric-powered pumping equipment and the pumping of

water to maintain water pressure;

6. Revised the definitions for “fuel additive,” “selective catalytic reduction

system,” and “verified emission control strategy” to be consistent with

other regulations that affect stationary and portable engines;

7. Deleted the definition for “school” because the word is not used in the

regulation;
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8. Clarified that engines manufactured and sold under the flexibility

provisions contained in federal and State regulations are considered

certified engines and would satisfy the “most stringent” requirement;

9. Added provisions to allow the Executive Officer or Air Pollution Control

Officer to exempt portable diesel-fueled engines used in lattice boom

cranes from the 2010 requirement, but require these engines to be

replaced with a Tier 4 engine or achieve equivalent diesel PM reductions

by 2020.

10. Revised the incentive for alternative-fueled engines to provide additional

credit toward satisfying the fleet standards if the alternative-fueled engines

are added to the fleet and operated prior to January 1, 2009, and the

engines are certified to a nonroad engine standard;

11. Added clarification language to test-method requirements;

12. Revised recordkeeping and reporting requirements to include specific

requirements for alternative-fueled engines added to the fleet prior to

January 1, 2009; and

13. Revised the sections’ numbering sequence to conform to regulation order

format and add minor clarification language to other sections of the

regulation.

In addition to the modifications described above, the following non-substantial or

solely grammatical modifications and typographical errors were corrected after

the close of the 15-day comment period. The changes do not materially alter any

requirement, right responsibility, condition, prescription or other regulatory

element of any CCR provisions.

1. Corrected typographical error in Section 93116.1 (a). Section 93116.1 (a)

used “maximum rated capacity,” which is not defined in ATCM. “Maximum

rated capacity” was changed to “maximum rated horsepower,” which is

defined in the ATCM.

2. Corrected typographical error in Section 93316.2(n). The definition name

was revised from “Engines Exclusively Used in Emergency Applications”

to “Engines Used Exclusively in Emergency Applications.” The definition

for the term “Engines Used Exclusively in Emergency Applications” was

not changed.
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3. Typographical error corrected in Section 93116.4(e)(1)(F). To conform to

the outline organization used in the ATCM, reference to section

93116.3(d)(2)(B)(2) was corrected to section 93116.3(d)(2)(B)2.

4. Clarified reporting requirements in Sections 93116.4(c)(3)(B),

93116.4(e)(1)(B), 93116.4(e)(1)(C), 93116.4(e)(1)(D), 93116.4(e)(1)(E),

93116.4(e)(1)(F), 93116.4(e)(3), 93116.4(e)(4), and 93116.4(f) by revising

the term “district permit or State registration number” to “district permit or

State/district registration number.”

5. In the Initial Statement of Reasons (ISOR), there were two references that

contained incorrect dates. The first was reference #4: “CARB, 2001.

California Air Resources Board. Policies and Actions for Environmental

Justice. Sacramento, California. April 2001.” The correct date is

December 2001. The second incorrect date is in reference #6: “CARB

2002b. California Air Resources Board. Public Hearing to Consider

Amendments to the Ambient Air Quality Standards for Particulate Matter

and Sulfates. May 2002.” The date of the report was in May 2002, but the

Board hearing was in June 2002.

C. Incorporated by Reference in Regulation

The ATCM includes the following references to other regulations in order to avoid

an unnecessarily lengthy and repetitious regulatory text:

ß ASTM Standard Specification for Diesel Fuel Oils D975-81.

ß Air Resources Board and district air emission test methods

D. Fiscal Impacts for School Districts and Local Agencies

The Board has determined that this regulatory action will result in a mandate to

school districts and other local agencies that own or operate portable dieselfueled engines. However, the Board found that any costs associated with such

mandates are not reimbursable pursuant to Part 7 (commencing with section

17500), division 4, title 2 of the Government Code because most, if not all, of

these agencies are authorized to collect fees to recoup their costs under this

section of the Government Code. In addition, the regulation applies to all entities

that own or operate portable diesel-fueled engines and, therefore does not

impose unique requirements on local government agencies.
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E. Consideration of Alternatives

Alternatives to this regulatory action were considered in the Staff Report: Initial

Statement of Reasons For Proposed Rulemaking—Airborne Toxic Control

Measure For Diesel-Fueled Portable Engines, in accordance with Government

Code section 11346.2. After responding to the comments received, Staff

concludes that no reasonable alternative considered by the agency, or that has

otherwise been identified and brought to the attention of the agency would be

more effective in carrying out the purpose for which the regulatory action was

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

persons than the action taken by the Board.

II. SUMMARY OF COMMENTS AND AGENCY RESPONSES

The Board received written and oral comments in connection with the 45-day

comment period, the February 26, 2004, hearing, and the 15-day public comment

period for the modified regulatory language. A list of commenters is set forth

below, identifying the date and form of all comments that were timely submitted.

Following the list is a summary of each objection or recommendation made

regarding the proposed action, together with an explanation of how the proposed

action has been changed to accommodate the objection or recommendation or

the reasons for making no change.

A. Responses to Comments Received During the 45-day

Public Comment Period and Board Hearing

Abbreviation Commenter

ALA Bonnie Holmes-Gen

American Lung Association

Written Testimony: February 20, 2004

Oral Testimony: February 26, 2004

ATA Betty L. Hawkins

Air Transport Association of America, Inc.

Written Testimony: February 25, 2004

BJS Doug Van Allen

BJ Services Company USA

Written Testimony: February 18, 2004

Oral Testimony: February 26, 2004
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BP Dave Smith

BP

Written Testimony: February 18, 2004

CAPCOA Larry Green

California Air Pollution Control Officers

Association

Written Testimony: February 24, 2004

Barbara Lee

California Air Pollution Control Officers

Association

Oral Testimony: February 26, 2004

CCEEB Victor Weisser

California Council for Environmental and

Economic Balance

Written Testimony: February 13, 2004

Cindy Tuck

California Council for Environmental and

Economic Balance

Oral Testimony: February 26, 2004

CEE Kathryn Phillips

Center for Energy Efficiency and Renewable

Technologies

Written Testimony: February 20, 2004

CERA Joseph K. Lyou, Ph.D.

California Environmental Rights Alliance

Written Testimony: February 20, 2004

CIAQC Mike Buckantz

Construction Industry Air Quality Coalition

Oral Testimony: February 26, 2004

CSDLA Frank Caponi

County Sanitation Districts of Los Angeles

County

Oral Testimony: February 26, 2004

ED Kate Larsen

Environmental Defense

Written Testimony: February 20, 2004
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EMA Timothy A. French

Engine Manufacturers Association

Written Testimony: February 23, 2004

Oral Testimony: February 26, 2004

EMWD Daniel McGivney

Eastern Municipal Water District

Oral Testimony: February 26, 2004

EXXONMOBIL Stan Holm

ExxonMobil

Written Testimony: February 17, 2004

EYC Angelo Logan

East Yard Communities for Environmental

Justice

Written Testimony: February 20, 2004

KJC David M. Rib

KJC Operating Company

Written Testimony: February 18, 2004

LADWP Mark J. Sedlacek

Los Angeles Department of Water and Power

Written Testimony: February 25, 2004

LCAQMD Robert L. Reynolds

Lake County Air Quality Management District

Written Testimony: February 23, 2004

MECA Dale McKinnon

Manufacturers of Emission Controls

Association

Written Testimony: February 25, 2004

Bruce Bertelsen

Manufacturers of Emission Controls

Association

Oral Testimony: February 26, 2004

MPAA Melissa Patack

Motion Picture Association of America

(California Group)

Written Testimony: February 18, 2004
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MYA Sharon Fuller

Ma’at Youth Academy

Written Testimony: February 20, 2004

NRDC Janet Hathaway

Natural Resource Defense Council

Written Testimony: February 20, 2004

Oral Testimony: February 26, 2004

NSM Larie K. Richardson

North Star Minerals, Inc.

Written Testimony: January 13, 2004

RAM Anne Kelsey Lamb, MPH

Regional Asthma Management and

Prevention Initiative

Written Testimony: February 20, 2004

PCL Tim McRae

Planning and Conservation League

Written Testimony: February 20, 2004

PISD Meena Palaniappan

Pacific Institute for Studies in Development,

Environment and Security

Written Testimony: February 20, 2004

PGE Sven Thesen

Pacific Gas and Electric

Written Testimony: February 18, 2004

Oral Testimony: February 26, 2004

PWS James Thomas

Pool Well Services Company

Written Testimony: February 4, 2004

Oral Testimony: February 26, 2004

SCC V. John White

Sierra Club California

Written Testimony: February 20, 2004

UCS Don Anair

Union of Concerned Scientists

Written Testimony: February 20, 2004
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USNAVY A.J. Gonzales

U.S. Navy, representing Regional

Environmental Coordinator in California for the

Department of Defense

Written Testimony: February 24, 2004

Comments and Responses

1. General

1.1 Comment: The definitions of facility, location, portable, and stationary

source, as defined in the portable and stationary ATCMs, are contradictory

and are inconsistent between the two ATCMs. These definitions should

be clarified between the two ATCMs such that it is clear whether

equipment is classified as portable or stationary. (KJC)

Agency Response: ARB staff believes these definitions are clear and not

contradictory. The definition for “portable” contained in the Portable

Engine ATCM and the definition for “stationary CI engine” contained in the

Stationary Engine ATCM are intended to compliment each other.

Generally, an engine that is placed at a location for less than 12

consecutive months is considered portable—see Section 93116.2 (bb) in

the Portable Engine ATCM and Section 93115(b)(50) in the Stationary

Engine ATCM. Conversely, an engine that is placed at a location for more

than 12 consecutive months is considered stationary—see Section

93115(b)(63) in the Stationary Engine ATCM. Location refers to any

single site at a building, structure, facility, or installation.

1.2 Comment: The regulation is duplicative because federal regulations

already apply to portable engines. (NSM)

Agency Response: ARB staff disagrees. The only federal regulations that

apply to portable engines are contained in 40 CFR Part 89 and apply to

newly manufactured off-road engines. The new engines built by the

manufacturers must satisfy the applicable emission standards contained in

40 CFR Part 89. The federal regulations do not affect in-use portable

engines.

2. Applicability and Authority

2.1 Comment: The ATCM applies to all types of portable engines, including

diesel-fueled turbines. The ATCM should be clarified such that the ATCM

applies to piston-type internal combustion engines only. (LADWP)
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Agency Response: ARB staff believes the applicability of the ATCM is

clear. Section 93116.1(a) under “Applicability” indicates that all portable

engines having a maximum rated horsepower of 50 brake horsepower

(bhp) and greater and fueled with diesel are subject to this regulation.

Section 93116.2(m) defines an “engine” as any piston-driven internal

combustion engine.

2.2 Comment: The Federal Aviation Act and the Airline Deregulation Act

preempts the applicability of the ATCM to airport ground support

equipment. (ATA)

Agency Response: The Commenter relies on broad, conditional language

in its assertion that the ATCM is preempted by the Federal Aviation Act

and the Airline Deregulation Act. Commenter has cited no specific

authority expressly preempting air pollution control by either law. ARB

agrees that no such express preemption exists.

ARB does not agree that either law implicitly preempts the ATCM and the

case authority cited by Commenter does not suggest otherwise. The City

of Burbank case cited by Commenter, a 5-4 decision, really focused more

on the federal Noise Control Act and the City's efforts to reduce noise from

nighttime air traffic, than it did on the Federal Aviation Act. In any event,

the Supreme Court made it clear that the primary focus of the Federal

Aviation Act was the regulation of the navigable airspace, which was,

according to the majority, the precise issue in that case. It is difficult to

relate any aspect this case to the regulation at issue.

Regarding Commenter's claim that, at least in the Fifth Circuit, regulation

of air pollution associated with ground support equipment is preempted,

misstates the conclusions made in the City of Houston case. That case

dealt with the Port Preference Clause of the U.S. Constitution and limiting

nonstop flights. It does not even mention ground support equipment.

Again, gleaning any relevance of that case to the instant issue is difficult.

Nor does the Airline Deregulation Act serve to preempt the ATCM. As

noted by Commenter, the Airline Deregulation Act addresses the pricing,

routing and service of an air carrier. Contrary to Commenter's statement,

the ATCM does not restrict or limit carrier services or operations in any

way.

Commenter cites to the FedEx case for support. In that case, the 9th

Circuit clearly pointed out that it will not give such literal interpretation to

broadly stated preemption language so as to preclude state regulation in

any way, shape or form. The PUC in the FedEx case attempted to
12

regulate pricing. The ARB in no way attempts to regulate in this area

through the adoption of the ATCM.

In sum, ARB disagrees that the regulatory action is preempted in any way.

2.3 Comment: The ATCM conflicts with Section 209(e)(1) of the Clean Air Act

(CAA), which preempts states from adopting or attempting to enforce

emission standards for new engines smaller than 175 horsepower and

used in farm and construction equipment. An engine is considered “new”

for preemption purposes until the equipment is rebuilt or after the

expiration of its useful life. Consequently, ARB cannot adopt or enforce

any emission control requirements for portable farm and construction

equipment less than 175 horsepower until such equipment is rebuilt or

after the expiration of its useful life. (EMA)

Agency Response: Commenter claims that the regulation is "inherently

unlawful and invalid" because it violates §209(e)(1)(A) of the Clean Air

Act. This provision preempts state regulation of new engines smaller than

175 horsepower used in farm or construction equipment or vehicles. Staff

disagrees with this claim. The regulation, in §93116.1(b)(6), specifically

provides that portable engines coming under 209(e)(1) are not covered.

2.4 Comment: The ATCM conflicts with Section 209(e) of the CAA, which

preempts states from adopting or attempting to enforce emission

standards for new and existing nonroad engines. In addition, U.S. EPA

has expressly concluded that fleet standards are preempted emission

standards. (ATA)

Agency Response: ARB disagrees with Commenter's analysis of section

209(e) of the Clean Air Act; both as to its scope and effect. Outside of the

express limitations contained in 209(e)(1), the Clean Air Act provides

California a means of receiving the authority to adopt and enforce

standards and other requirements relating to the control of emissions from

new nonroad engines. California has availed itself of this right many times

in its ongoing efforts to attain the national ambient air quality standards

and provide a healthy environment for all Californians.

With respect to Commenter's claim that 40 CFR §85.1603(c)(2) precludes

ARB from adopting the ATCM, that regulation applies to locomotives, not

portable equipment. Locomotives present a unique situation and have

very little, if anything, in common with portable equipment.

2.5 Comment: The ATCM should be modified to exempt portable equipment

covered by the South Coast Ground Service Equipment Memorandum of

Understanding (MOU) for the useful life of the equipment that is subject to

the MOU, or the reductions achieved from implementing the MOU should
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be considered equivalent to the reductions achieved with the ATCM.

(ATA)

Agency Response: ARB staff does not believe that the diesel PM

emissions reductions from the MOU are de facto equivalent to those

achieved by the ATCM. The ATCM allows the Executive Officer to

exempt this equipment from the ATCM if the affected air carriers can

demonstrate such equivalency.

2.6 Comment: The equivalency determination for the MOU should be based

upon the collective fleet of the MOU participants, not upon each air

carrier’s individual fleet. (ATA)

Agency Response: ARB staff agrees and has incorporated ATA’s

recommendations into the ATCM.

2.7 Comment: The ATCM should be revised to exempt generator sets

equipped with sound-proofing technology. Add-on pollution controls may

not work in conjunction with sound-proofing technology. (MPAA)

Agency Response: ARB staff believes that it is premature to consider this

proposed exemption. The ATCM requires all portable diesel-fueled

engines of 50 brake-horsepower or greater to be certified to a U.S. EPA or

ARB off-road emissions standard by 2010. Add-on controls for portable

diesel-fueled engines will not be necessary until at least 2013, when the

fleet-average emission standards take effect.

Currently, no technology for reducing diesel PM from portable dieselfueled engines has completed the ARB Verification Procedure for In-Use

Strategies to Control Emissions from Diesel Engines (Verification

Procedure), as required by the ATCM. With this in mind, ARB staff, when

developing the ATCM, included sufficient time for the development of

these technologies. At the direction of the Board, staff will monitor the

development and applicability of diesel PM retrofit technologies for

portable applications, including those utilizing sound-proofing technology,

and provide a report to the Board no later than 2008. Revisions to the

ATCM will be considered at that time and based upon the findings of the

technology review.

3. Alternative Fuel and Fuel Additives

3.1 Comment: Only alternative fuels meeting applicable state and federal

requirements, including California Department of Measurement Standards

(DMS), should be considered “alternative fuels,” as defined in the ATCM.

(BP)
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Agency Response: ARB staff agrees and believes that the ATCM

addresses this point. Section 93116.2(b) specifically lists the fuels defined

as “alternative fuels.” These specific fuels are subject to applicable state

and federal requirements, including regulations promulgated by DMS.

3.2 Comment: The definition for “alternative diesel fuel” should be

harmonized between the following regulations: Verification Procedures,

Warranty and In-Use Compliance Regulation; the Stationary Diesel

Engine ATCM; and the Portable Diesel Engine ATCM. Furthermore, the

definition should be clarified to indicate that mixtures of alternative diesel

fuel and diesel fuel are considered “alternative diesel fuels.” Finally, only

alternative diesel fuels satisfying standards adopted by DMS or receiving

an exemption from DMS should be allowed for use in diesel-fueled

engines. (BP)

Agency Response: ARB staff agrees and has revised the definition for

“alternative diesel fuel” in the ATCM to be consistent with the definition for

“alternative diesel fuel” in the Verification Procedures, Warranty and InUse Compliance Regulation and the Stationary Diesel Engine ATCM. In

addition, the definition was clarified to indicate that mixtures of an

alternative diesel fuel with diesel fuel are considered alternative diesel

fuels. Alternative diesel fuels used in portable engines will continue to be

subject to applicable State and federal requirements, including those

under the jurisdiction of DMS.

3.3 Comment: BP supports the requirement that diesel fuel blends must be

verified through the Verification Procedure to receive emissions credit, and

has provided recommendations to clarify the applicability of the

requirement. (BP)

Agency Response: ARB staff incorporated BP’s recommendations into

the ATCM.

3.4 Comment: The regulation as written would preclude the use of fuel

additives as an alternative to reduce diesel PM emissions from portable

diesel-fueled engines. (BJS)

Agency Response: It is not the intent of the ARB staff to preclude the use

of any technology or technique that can reduce the emissions of diesel

PM, as long as the technology or technique satisfies the requirements of

the Verification Procedure for In-Use Strategies to Control Emissions from

Diesel Engines. The ATCM’s definition for both “alternative diesel fuel”

and “fuel additive” are consistent with the definitions in the Verification

Procedure. For example, if a fuel additive is used in conjunction with

diesel fuel, the combination may be treated as an “alternative diesel fuel.”
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As a fuel, the additive/fuel mixture must also meet CARB fuel

requirements, which includes a more rigorous analysis on the impacts of

the fuel mixture on the engine system.

If the fuel additive is not considered an “alternative diesel fuel” because of

the manner or extent to which it is added, then the fuel requirements do

not apply. What does apply to such a fuel additive, however, is the

requirement in the Verification Procedure for a multimedia evaluation of

the potential effects of the additive, making sure that it does not cause a

significant adverse impact on the public health and the environment.

Either way, the ATCM allows the use of fuel additives, as long as they are

CARB-verified.

3.5 Comment: To encourage the use of clean technologies such as fuel cells,

the definition for “alternative fuel” should be revised to include hydrogen.

(PGE)

Agency Response: ARB staff agrees and has incorporated the comment

into the ATCM.

3.6 Comment: The ATCM contains incentives for replacing portable dieselfueled engines with portable engines utilizing alternative fuels. This

incentive should be modified to encourage earlier conversion to alternative

fuels by giving double credit for these engines when calculating the fleet

emissions average if such conversions are completed prior to January 1,

2009. (PGE)

Agency Response: Staff agrees and has incorporated the comment into

the ATCM.

4. Emergency, Emergency Event, and Low-Use Engine

4.1 Comment: The ATCM contains references to the term “engines used

exclusively in emergency applications,” but does not define this term. To

clarify what are considered emergency applications, a definition for

“emergency use engine” should be added to the ATCM as follows: a

portable engine that is: (1) operated to provide electrical power or

mechanical work during the failure of normal electrical power, the pumping

of water or sewage to prevent or mitigate a flood or sewage overflow, or

the pumping of water for fire suppression or protection; and (2) is operated

under limited circumstances for maintenance and testing, emissions

testing, or initial startup testing, not to exceed 26 hours per year.

(USNAVY)
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Agency Response: In response to the USNAVY comment, ARB staff

added a definition for “engines used exclusively in emergency

applications“ to the ATCM. As defined in Section 93116.2(n), “engines

used exclusively in emergency applications“ are engines “that are used

only during an emergency or emergency event, and includes appropriate

maintenance and testing.” (Emphasis added.) “Emergency” and

“emergency event” are defined in Sections 93116.2(k) and 93116.2(l),

respectively. The types of activities described by USNAVY for

“emergency use engine” were incorporated into the term “emergency.”

4.2 Comment: The definition of “emergency” in the ATCM should be

consistent with the definition for “emergency” in the Portable Equipment

Registration Program (PERP) regulation. (BJS, PWS)

Agency Response: ARB staff agrees that the term “emergency” should be

consistent between the Portable Diesel Engine ATCM, the PERP

regulation, and the Stationary Diesel Engine ATCM. Unfortunately, the

term “emergency” is significantly different in the PERP regulation than in

the Stationary Diesel Engine ATCM, as the term is used for completely

different purposes. Consequently, ARB staff introduced the term “engines

used exclusively in emergency applications“ in the Portable Diesel Engine

ATCM to utilize both of these two other definitions.

As defined in Section 93116.2(n), “engines used exclusively in emergency

applications“ are engines “that are used only during an emergency or

emergency event (emphasis added), and includes appropriate

maintenance and testing.” “Emergency” is defined in Section 93116.2(k)

and is similar to the definition for “emergency” in the Stationary Diesel

Engine ATCM. “Emergency event” is defined in Section 93116.2(l) and is

similar to the definition of “emergency” in the PERP regulation. In this

manner, the intent of the term “emergency” in these other two regulations

is maintained in the ATCM.

4.3 Comment: The ATCM defines a “low-use engine” as an engine that

operates 80 hours or less annually. However, if the low-use engine is

pressed into service for an “emergency event,” those hours do not count

toward the 80 hours. There is no such exemption if the engine is used in

an “emergency.”

In the ATCM, the definition of “emergency event” reflects catastrophic

emergencies, such as large wildlife fires or earthquakes, while the

definition of “emergency” lists specific events considered localized

emergencies, such as loss of grid power. The definitions of “emergency”

and “emergency event” should be combined into one definition, and the

hours used in any of these emergency situations should be exempt from

the 80-hour limit for “low-use engines. (EMWD)
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Agency Response: ARB staff disagrees with the proposal of combining

the definitions for “emergency event” and “emergency.” These definitions

are distinct for a reason. The definition of “emergency event”—the

widespread, catastrophic occurrence—is based on the definition of

“emergency” in the Portable Equipment Registration Program (PERP).

PERP recognizes that during such an event, engines may be pressed into

service that are neither registered with the program nor permitted by the

local air districts (e.g., brought in from other states), and there is no time

for the appropriate regulatory process; therefore, these engines receive a

temporary exemption from registration and permitting. Similarly, the

ATCM recognizes that “low-use” engines may be pressed into service

during a catastrophic event, and ARB staff believes that these hours of

service should not count against the 80-hour limit for low-use engines.

The definition of “emergency” in the ATCM—the more specific, local

occurrence—is similar to the definition of “emergency” in the Stationary

Diesel Engine ATCM. ARB staff included this definition to identify other

specific emergencies without compromising the intent behind the

exclusion of hours for “low-use” engines during catastrophic “emergency

events.”

Ultimately, the ATCM provides the same relief from some provisions of the

ATCM to “low-use” engines and “engines used exclusively in emergency

applications,” which entails both “emergency events” and “emergencies.”

The intent of exempting these engines from some provisions of the ATCM

is to recognize that replacing or retrofitting infrequently used engines is not

particularly cost-effective. ARB staff believes that the engine owner

should identify the exemption category of his engines (e.g., exclusively

used for emergency applications or infrequently used), and that the

engines should not switch between these categories. Otherwise, there

exists a possibility that some low-use engines could be used for a

significant number of hours, circumventing the intent behind the

designation of “low-use” and increasing diesel PM emissions.

Furthermore, recordkeeping and enforcement would be more difficult for

engines switching categories.

4.4 Comment: The definition of emergency should be expanded to include

the pumping of water to maintain pressure in the water distribution system

in the event of a pipe break, high demand on the system due to use of fire

hydrants, or breakdown of electric-powered pumping equipment.

(LADWP)

Agency Response: ARB staff agrees and has incorporated the comment

into the definition of “emergency” in the ATCM.
18

4.5 Comment: The definition of emergency should be clarified to include

using portable engines in fire training exercises. (EXXONMOBIL)

Agency Response: ARB staff agrees and has incorporated the comment

into the definition of “emergency” in the ATCM.

4.6 Comment: The definition of low-use engine should be expanded to

include portable diesel-fueled engines with a maximum horsepower rating

of less than 175 horsepower and operated less than 250 hours per

calendar year. (PGE)

Agency Response: ARB staff disagrees. This proposal would result in a

significant increase in both emissions and recordkeeping.

The categories of “low-use engine” and “engines used exclusively in

emergency applications” were developed to recognize that subjecting

these engines to the full requirements of the ATCM would not be costeffective due to low annual usage. Consequently, these engines are not

subject to the fleet-average emission standards of the ATCM in 2013 and

2017.

ARB staff estimates that there are currently about 3,300 engines that

could be considered low-use engines or engines used exclusively in

emergency applications. These 3,300 engines represent 10 percent of the

total engines and emit 3 percent of the total diesel PM emissions from

portable diesel-fueled engines. Expanding this group of portable engines

to include engines with a maximum horsepower rating of less than 175

horsepower and operated less than 250 hours per calendar year would

allow an additional 5,000 or more engines to be exempt from the fleet

standards. This would increase the percentage of engines exempt from

the fleet standards to 25 percent of the total engines, and would more than

triple the emissions from these exempt categories from 3 percent of the

total diesel PM emissions from portable diesel-fueled engines to 10

percent. These emissions increases are unwarranted.

In addition, adding these engines into these fleet-average-exempt

categories would subject these portable engine owners to increased

recordkeeping and reporting requirements, subsequently increasing the

enforcement load on local air districts and ARB staff.

5. Emission Standards and Technology Review

5.1 Comment: MECA supports the proposed air toxic control measure

strategies for reducing diesel PM emissions from in-use diesel-fueled

portable engines. MECA specifically commented that verified Level-3
19

products, while not available today, are expected be available in the 2013

to 2017 timeframe when the fleet PM requirements begin to tighten. In

addition, MECA supports the staff proposal to provide operators with an

early compliance incentive for Tier 4 engines. (MECA)

Agency Response: ARB staff developed the ATCM with the expectation

that Level-3 products will be commercially available when the fleet PM

requirements take effect in 2013.

5.2 Comment: The Stationary and Portable ATCMs have different emission

standards and the timeline for complying with these emission standards

are also different. The requirements of these ATCMs should be

harmonized as expeditiously as possible, such that any engine, regardless

of the engine being used in a stationary or portable application, operating

more than 200 hours, would be subject to the same emissions standards

and time frames of implementation. CAPCOA requests that ARB work

with control product manufacturers and district staff to promote the

expeditious development of diesel PM control devices for portable

equipment. (LCAQMD, CAPCOA)

Agency Response: ARB staff disagrees that the ATCMs can be

harmonized due to the significant operating differences between the two

applications of diesel-fueled engines.

The emissions of diesel PM from stationary diesel-fueled engines are

more amenable to the technologies available to reduce these emissions.

Stationary diesel-fueled engines used in prime applications typically

operate at high loads. The high exhaust temperature from these engines

is sufficient for the proper operation of a passive diesel particulate filter

(DPF). In addition, one technology has been verified to achieve 85%

reduction in diesel PM emissions from stationary engines used in

emergency standby applications.

In contrast, portable engines are used in a wider variety of applications

and with a wider range of engine loads. Some of the businesses and

public agencies that use portable engines in their activities include motion

picture studios, agriculture, air transportation, public and investor-owned

utilities (providing electricity, water, and waste treatment/disposal),

construction services, marine construction and dredging services, oil and

gas well service companies, and rental services. Engine size can vary

from 50 to 3,000 brake-horsepower. This diversity in uses of portable

engines makes it a challenge to develop an effective control technology.

To better understand the exhaust-temperature issue for portable dieselfueled engines, ARB staff and UC Riverside measured the exhaust

temperatures on over 100 different engines representing the range of
20

different portable applications. This information indicated that in many

cases the exhaust gas from portable engines did not attain the necessary

temperature for the proper operation of a passive DPF. Therefore, the

passive DPF is not a good candidate for many portable engine

applications.

Currently, no technology has completed the ARB Verification Process,

which is required by the portable diesel-fueled ATCM. The only available

options in the short term to reduce diesel PM from portable engines is

either to require the replacement of older engines with newer, cleaner

engines or provide incentives to switch to alternative fuels. The ATCM

was crafted to allow sufficient time to develop technologies to reduce

diesel PM emissions from portable diesel-fueled engines. ARB staff will

monitor the development, effectiveness, and availability of retrofit

technologies for portable engines and will report to the Board no later than

2008. Based on the results of this technology review, ARB staff may

recommend revisions to the ATCM.

5.3 Comment: In lieu of purchasing an engine that is certified to an off-road

engine standard by 2010, owners of portable diesel-fueled engines used

exclusively in emergency applications or that qualify as low-use engines

may commit to replacing these engines with Tier 4 engines. The

replacement, for the applicable class and category, must be made within

two years of the first engine being offered for sale. The two-year period

should begin when a Tier 4 engine for that specific application is available

for sale. (BJS)

Agency Response: ARB staff understands that some portable diesel

engine applications make repowering more of a challenge due to technical

and design reasons. However, neither the local air districts nor ARB could

reasonably determine when a specific engine becomes available for a

specific application. The proposed revision would be difficult to enforce

and could significantly delay the replacement of older engines with Tier 4

engines. ARB staff believes that customers can work with the engine

manufacturers to address this issue.

5.4 Comment: The Construction Industry Air Quality Coalition supports

inclusion of a provision that allows either the Executive Officer or the Air

Pollution Control Officer to determine, on a case-by-case basis, that

portable diesel-fueled engines in lattice boom cranes can be exempted

from the 2010 requirement. (CIAQC)

Agency Response: ARB staff worked with the crane industry and CIAQC

on this issue and included the lattice boom exemption in the ATCM.
21

5.5 Comment: The ATCM should be revised to be aligned with the federal

regulatory flexibility provisions for nonroad equipment and vehicle

manufacturers. These provisions were added to the federal regulation as

part of the Tier 2/Tier 3 Nonroad Emission Regulations to avoid

unnecessary hardships for nonroad equipment manufacturers. The

flexibility provisions consists of four elements: 1) a percent-of-production

allowance, 2) small-volume allowance, 3) hardship relief, and 4)

continuance of the allowance to use up existing inventories of engines.

(EMA)

Agency Response: Staff has revised the ATCM to accommodate the

flexibility provisions for nonroad equipment and vehicle manufacturers that

are contained in both the federal and State programs for newlymanufactured nonroad engines. Engines that are certified to Tier 1, 2 or 3

nonroad engine standards and considered compliant with the applicable

nonroad engine standards pursuant to the flexibility provisions for nonroad

equipment and vehicle manufacturers are considered compliant with

sections 9116.3(b)(1)(A) and 9116.3(b)(2)(A) of the ATCM. Consistent

with the effort to replace all portable diesel-fueled engines with engines

that are certified to Tier 1,2, or 3 nonroad engine standards, equipment

that uses noncertified engines pursuant to the flexibility provisions for

nonroad equipment would not comply with sections 9116.3(b)(1)(A) and

9116.3(b)(2)(A) of the ATCM.

5.6 Comment: The initial requirement for the ATCM does not become

effective until 2010. Six years is too long to wait for reductions in diesel

PM from such a large source of diesel exhaust. Consequently, the ARB

should consider moving up the initial implementation date. Fleets with 15

or more portable engines should be required to replace one third of their

uncertified portable engines with certified Tier 3 engines each year in the

2008 to 2010 timeframe. (ALA, CEE, CERA, ED, EYC, MYA, NRDC,

PCL, PISD, RAM, SCC, UCS)

Agency Response: ARB staff did not include this proposed revision in the

ATCM because it would disrupt an existing regulatory schedule for

portable diesel-fueled engine replacement and would not result in

significant emissions reductions. ARB staff chose 2010 as the date to

replace noncertified engines because an existing ARB program affecting

portable engines, the Portable Equipment Registration Program (PERP),

already has a similar requirement that takes effect in 2010. The PERP,

adopted by the Board in 1997, is a voluntary program in which operators

of portable equipment can register portable equipment with the State in

lieu of obtaining permits from local air districts. By January 1, 2010, all

engines registered under PERP must be certified to a U.S. EPA/ARB offroad engine standard. Currently, about 1,400 businesses owning 16,000

engines—nearly half of the total diesel-fueled portable engines in
22

California—are registered with PERP. Most companies registered with

the PERP have factored into their business plans how the fleets will need

to be modified to satisfy the 2010 requirement. ARB staff chose to

harmonize with this existing engine-replacement schedule.

The diesel PM reductions achieved through the proposed revision would

be minimal. Currently, Tier 2 engines are available for most classes and

categories of nonroad engines. Tier 3 engines, which emit less oxides of

nitrogen (NOx), will be commercially available in the 2007-2010

timeframe. Diesel PM emissions reductions achieved by expediting

engine replacement would be temporary—disappearing by 2013, when

the fleet average emissions standards take effect. The minimal impact on

emissions is insufficient to disrupt the existing PERP engine replacement

schedule.

5.7 Comment: The proposed fleet standards are too aggressive in that they

will require the replacement of newly purchased Tier I engines with Tier 4

engines well before the end of the engines’ useful life. This will be

especially costly, as the company has recently purchased 18 engines

rated at 750 horsepower and more. The fleet standards should be

modified as follows:

2013 2017 2020

<175 hp 0.5 0.2 0.04

>175 hp 0.4 0.16 0.02

(BJS)

Agency Response: ARB staff did not make this revision. The fleet

averages in the ATCM provide a reasonable rate of progress between

2010, when portable engines must be certified to an off-road standard,

and 2020, when the ATCM is fully implemented, resulting in diesel PM

emissions reductions of 95 percent.

With the exception of the emission standards that apply to engines rated

at 750 horsepower and larger, the 2013 fleet-average standards will

essentially remove most Tier 1 portable diesel-fueled engines from

California, just as the 2010 requirements removed noncertified engines.

The 2017 fleet-average standards represent fleets that are about half

Tier 2/3 engines and half either Tier 4 engines or engines retrofitted with

control technology that achieves 85 percent reduction in diesel PM

emissions. There are other methods and techniques to achieve these

fleet-average standards—alternative fuels, fuel additives, electrification

credit, early Tier 4 engine purchase credit, etc.—but in general the fleetaverage standards represent reasonable progress toward the 2020 goal.
23

Nevertheless, because of the uncertainty associated with the development

of retrofit technology and of the rollout schedule for Tier 4 engines,

especially for the larger classes and categories of engines, ARB staff will

complete, by no later than 2008, a technology review to determine the

feasibility of satisfying the ATCM’s interim fleet standards. ARB staff

believes it is premature to revise the fleet-average standards in the ATCM

at this time.

5.8 Comment: Engines typically operate with varying power settings or load;

some applications may require an engine to be operated near maximum

capacity for the majority of the time, while other applications may result in

the engine idling for a significant portion of its operating time. Since the

load affects the amount of diesel PM that may be emitted, the fleet

average calculation should consider the different loads an engine would

operate at under different applications. (BJS)

Agency Response: ARB staff believes the fleet-average calculation

accounts for the effect of engine load on emissions. The fleet-average

calculation considers the horsepower and the emission factor for each

portable diesel-fueled engine in the fleet. The emission factors for the

engines are determined through testing by the engine manufacturers for

the purpose of demonstrating compliance with applicable off-road engine

emissions standards. The testing protocol requires emissions testing at

variable loads; therefore, the variable-load effect is taken into account

through the emission factors used in the fleet-average calculation.

5.9 Comment: CSDLA and CCEEB support the commitment for a technology

review before 2008. As part of this technology review, the Board and staff

should consider additional options that provide flexibility, such as in cases

where hardship can be demonstrated. (CSDLA, CCEEB)

Agency Response: ARB staff included flexibility provisions in the ATCM

through incentives, credits, exemptions, and deferrals. As mentioned

earlier, no technologies have presently been verified to reduce diesel PM

from off-road applications of portable diesel-fueled engines. The ATCM

allows the necessary time for the development of such technologies. The

2008 technology review will be an essential step in determining if

additional flexibility needs to be considered. Additional flexibility

provisions in the ATCM will largely depend upon the availability and cost

of installing these diesel PM emissions control technologies.

6. Recordkeeping and Reporting

6.1 Comment: The recordkeeping and reporting requirements of the ATCM

are overly burdensome. In addition, the requirement of a signed
24

statement of compliance by a responsible official provides no real value.

(NSM)

Agency Response: ARB staff disagrees. The recordkeeping and

reporting requirements contained in the ATCM are necessary to ensure

the enforceability of the ATCM. For the most part, recordkeeping is

required if the engine owners choose to utilize the credits built into the

ATCM that concern annual hours of operation (e.g., electrification credit,

use of alternative fuels, the determination of low-use engines). ARB staff

rejected other approaches to the ATCM, such as limiting hours of

operation per project location, because they required burdensome

recordkeeping.

The reporting requirements of the ATCM are necessary to determine if the

engine fleets are meeting the fleet-average standards. Because fleets can

be distributed throughout the State and managed by different personnel

within a company, the ATCM requires a Responsible Official for a

business or government entity to supply the necessary information to

ARB. This minimizes reporting requirements. The statement of

compliance is based on a self-monitoring, self-reporting approach that is

common with many air pollution regulations, including federal Title V

permits for stationary sources.

6.2 Comment: If ARB staff incorporates the proposal to provide additional

credit for early conversion to alternative-fueled engines (Comment 3.6),

additional reporting and recordkeeping requirements pertaining to this

credit will also have to be incorporated into the ATCM. (PGE)

Agency Response: ARB staff has incorporated the comment into the

ATCM.

7. Enforcement of Fleet Requirements

7.1 Comment: The ATCM allows both the ARB and districts to take

enforcement action against companies that violate the fleet emission

standards of the ATCM. The ATCM should be revised to restrict the

enforcement of the ATCM’s fleet emission standards to the ARB.

(USNAVY)

Agency Response: ARB staff believes most fleets operate exclusively

within a specific district’s boundaries. However, because some fleets

operate in multiple air districts throughout the year, it would be difficult for

any specific local air district to enforce the fleet-average standards. In

these cases, ARB may have to act as the primary enforcement agency.
25

8. Schools

8.1 Comment: The Motion Picture Association of America supports the

proposal to continue to study the use of portable engines near schools.

The Association requests that any restrictions for portable engines

operated near schools recognize the mobile and unpredictable nature of

making motion pictures. In addition, the Association requested that the

definition of school be clarified to not include parking lots and to exclude

employer-sponsored schools from requirements that affect the use of

portable engines near schools. (MPAA)

Agency Response: As directed by the Board, ARB staff is assessing the

feasibility of requiring additional diesel PM emissions reductions from

portable diesel-fueled engines that operate near schools. Staff will

provide a report to the Board on this issue. As part of this assessment,

staff will consider the issues raised by MPAA.

8.2 Comment: It is not necessary to include additional requirements to further

limit the emissions from portable diesel-fueled engines operating near

schools. (CCEEB)

Agency Response: As indicated above, ARB staff is assessing the

feasibility of requiring additional diesel PM emissions reductions from

portable diesel-fueled engines that operate near schools. Staff will

provide a report to the Board on this issue.

8.3 Comment: There should be additional requirements to further limit the

emissions from portable diesel-fueled engines operating near schools.

(ALA, CEE, CERA, ED, EYC, MYA, NRDC, PCL, PISD, RAM, SCC, UCS,

MPAA)

Agency Response: As indicated above, ARB staff is assessing the

feasibility of requiring additional diesel PM emissions reductions from

portable diesel-fueled engines that operate near schools. Staff will

provide a report to the Board on this issue.

8.4 Comment: To reduce diesel PM exposure near schools, only clean

engines should be allowed to operate near schools. (ALA).

Agency Response: ARB staff considered a clean-engine requirement for

portable engines operating near schools in an earlier draft of the ATCM,

but ultimately did not include such a requirement. Specifically, the

provision would have required engines operating near schools to be

cleaner than the general population of portable engines in the State. For

example, certified engines would have been required near schools several

years prior to requiring all portable engines to be certified. Staff
26

determined that this approach might result in an economic disadvantage

to small-fleet owners, as they would be compelled to replace a larger

portion, if not all, of their fleet sooner than otherwise necessary if they

occasionally worked near schools. Large-fleet owners would have more

flexibility dispatching their fleets, although many times not without

substantial coordination. Finally, field enforcement of a clean-engine

provision would be difficult and resource-intensive.

ARB staff will re-evaluate this approach as well as other options as it

assesses the feasibility of requiring additional diesel PM emissions

reductions from portable diesel-fueled engines that operate near schools.

Staff will provide a report to the Board on this issue.

9. Economic Impact

9.1 Comment: The cost analysis evaluates the economic impact of each

ATCM on an individual basis only. In addition to the individual economic

impact of this ATCM, the ARB should evaluate the economic impacts from

all measures identified in the Diesel Risk Reduction Plan. The California

Environmental Quality Act (CEQA) requires the project to be evaluated in

its entirely and prevents segmenting a project to minimize the impacts.

(LADWP, EMA)

Agency Response: The Diesel Risk Reduction Plan (Plan), approved by

the Board in 2000, represents ARB staff’s comprehensive approach to

significantly reduce diesel PM emissions from a wide variety of sources,

both on-road and off-road. In the Plan, ARB staff provided an estimate of

the costs associated with several possible emissions control technologies,

especially diesel particulate filters (DPFs). As ARB staff has developed

specific regulations based on the Plan, the installation of DPFs has proved

problematic for some categories of diesel engines, including portable

diesel-fueled engines; therefore, some of the costs of the regulations

outlined in the Plan have been different than what was originally

estimated. Nevertheless, ARB staff committed in the Plan to provide

detailed cost and cost-effectiveness analyses during the preparation of

each control measure.

Staff believes that ARB has fully complied with the requirements of CEQA

at all times.

9.2 Comment: The cost for complying with the PERP is not included as part

of the cost for satisfying the requirements of the ATCM; therefore, the cost

of complying with the requirements of the ATCM is underreported. (PWS)
27

Agency Response: ARB staff disagrees that the cost of complying with

the ATCM is underreported. Staff recognizes that businesses registered

with PERP will have an additional economic impact as a result of

complying with the PERP requirements. However, State law requires that

the focus of the economic analysis be on the regulation, in this case the

ATCM.

9.3 Comment: The assumptions used in the economic impact analysis result

in the underreporting of the total economic impact of the ATCM.

Assumptions that should be reevaluated include the useful life of portable

diesel-fueled engines, the cost for particulate filters, and the cost for

replacing or repowering portable equipment. The cost analysis is based

upon a diesel engine life of 25 years. An engine’s typical useful life in the

oil service industry is considerably longer, and therefore, a longer useful

life should be used for the economic analysis. The economic analysis

also underestimated the cost for diesel particulate filters (DPFs), the cost

of replacing or repowering portable engines, and the maintenance cost

associated with the use of DPFs. (PWS)

Agency Response: ARB staff disagrees that the cost of complying with

the ATCM is underreported. The economic impact analysis reflects the

average costs of the ATCM for the 33,000 portable diesel-fueled engines

operating in California. Over 80 percent of the diesel-fueled engines

registered with the PERP are characterized as generators, pumps, and

compressors. For this type of equipment, the estimated cost for

replacement and repowering is well within the range of $135 to $220 per

horsepower estimated by staff. For certain types and applications of

equipment, such as drill rigs used in the oil well services industry, the

specific cost may be somewhat higher.

Regarding engine replacement or repower, ARB staff assumed that an

existing engine would eventually be replaced at the end of its useful life

and took into account the remaining value of the existing engine at the

time the proposed ATCM requires the engine to be replaced with a new,

cleaner engine. Furthermore, based on the age of the engines registered

with PERP, staff estimated that the useful life of a portable diesel-fueled

engine is typically 25 years, although many times it may be less than that.

While PWS indicated the useful life of engines within its industry can be

between 40 to 60 years, less than one percent of the 16,000 engines

registered with PERP are more than 30 years old.

PWS also commented that the cost use for catalyzed diesel PM filters was

too low. To evaluate the economic impact for the ATCM, the costs for

catalyzed diesel PM filters was estimated to be $40/hp and assumed to

stay at this level until the ATCM is fully implemented. We believe this is a

conservative assumption given that U.S. EPA projected, in the Preamble
28

for the Control of Emissions of Air Pollution from Nonroad Diesel Engines

and Fuel (2003), the cost of catalyzed diesel PM filters would fall to about

$5-8/hp when Tier 4 engines become initially available in 2011-2012.

Finally, PWS commented that the maintenance cost for DPFs might be

underestimated. The maintenance cost used in the economic impact

analysis is based upon DPF manufacturers’ recommendations for on-road

applications. When DPFs are verified for off-road applications, ARB will

review those estimated maintenance costs as part of the 2008 technology

review and revise ATCM costs as necessary.

9.4 Comment: The ATCM will impact the ability of California’s business to

compete for jobs in California with companies that are located outside the

State. (PWS)

Agency Response: ARB staff expects the ATCM to minimally impact the

ability of businesses based in California to complete with businesses

based outside of California. For a business based outside of California to

operate its equipment within California, the company’s portable dieselfueled engines will need to satisfy the applicable requirements of the

ATCM.

9.5 Comment: The economic impact for the ATCM is understated because

the economic analysis does not consider that two engines may need to be

purchased to satisfy the requirements of the ATCM. (EMA)

Agency Response: ARB staff disagrees that the economic impact of the

ATCM is understated. The ATCM is based on a two-phase approach:

replace older engines with newer, cleaner engines, then retrofit those

engines with verified control equipment to reach the ultimate diesel PM

emissions reductions in 2020. Some businesses, such as rental

companies, turn over their fleets of portable engines more frequently and

may wish to replace engines again; however, it was never the intent of the

ATCM to require multiple engine replacements.

Because technologies have not been verified for reducing diesel PM

emissions from off-road applications, the regulation allows for sufficient

time for the development of these technologies. The first fleet-average

standards do not take effect until 2013. In the meantime, because of the

uncertainly of the availability of verified control technologies within the

necessary timeframes, ARB staff is committed to conducting a technology

review and reporting to the Board no later than 2008. If verified control

technologies are not developed and made commercially available and the

only option available to satisfy the standards in the timeframe provided in

the ATCM is to replace engines with cleaner engines, then ARB staff

would revisit the implementation schedule of the ATCM as part of the
29

technical review. Furthermore, ARB staff would also revisit the economic

impact analysis and revise the analysis to be consistent with proposed

revisions to the ATCM.

9.6 Comment: It is incorrect that the ATCM will not have a significant adverse

economic impact on affected business or that affected businesses will be

able to absorb the cost of the proposed regulation without significant

adverse impact on profitability. (NSM, PWS)

Agency Response: ARB staff, in the Initial Statement of Reasons,

estimated the economic impact on businesses of complying with the

ATCM in accordance with state law. Based upon ARB staff’s evaluation,

ARB staff believes that most businesses will be able to absorb the costs of

complying with the ATCM with no significant adverse impact on

profitability.

Furthermore, the overall estimated cost effectiveness of the ATCM is

between $16/lb and $19/lb—consistent with other diesel ATCMs adopted

by the Board. The cost effectiveness of these ATCMs ranges between

$10/lb to $67/lb.

10. Environmental Impacts

10.1 Comment: The staff report should identify the reduction in emissions of

NOx, ROG, CO, and SOx associated with the replacement of existing

diesel-fueled engines with cleaner engines certified to either the Tier 2 or

Tier 3 emission standards for off-road engine. (PWS)

Agency Response: ARB staff, in the Staff Report: Initial Statement of

Reasons for the Proposed Airborne Toxic Control Measure for DieselFueled Portable Engines, estimated the reductions in diesel PM, NOx, and

ROG resulting from the full implementation of the ATCM. As indicated in

the staff report, diesel PM will be reduced by 95 percent, and both NOx

and ROG emissions will be reduced by nearly 80 percent.

The staff report did not provide estimates for reductions of CO or SOx

emissions resulting from the ATCM. While the replacement of older

engines with newer engines would result in a significant reduction of CO,

ARB staff did not quantify the expected reductions because most areas of

the State are in attainment with federal and State ambient CO standards.

In addition, SOx emissions from portable diesel-fueled engines are directly

related to the fuel used in the engine. Consequently, any reduction in SOx

emissions would be the result of regulations requiring the reduction of

sulfur compounds in the fuel and not a result of replacing older engines

with newer, cleaner engines.
30

10.2 Comment: Because of the potential that ash from PM filters may be

considered a hazardous waste, the ARB should consider funding research

to determine if the waste from diesel PM filters would be considered

hazardous waste. In addition, the ATCM should include the cost of

hazardous waste disposal, training of employees for the removal of the

ash, and personal protective equipment. (PWS)

Agency Response: As discussed above, the control technologies and

techniques that will be used to reduce diesel PM from off-road engine

applications are still being developed. Consequently, while staff

suggested in the ISOR that the ash collected from diesel PM filters may be

considered hazardous waste, it is premature to determine the extent of

this issue until the technologies that will be used to reduce diesel PM

emissions from portable diesel-fueled engines have been commercialized.

As part of the technology review, ARB staff will monitor this issue.

10.3 Comment: The health benefits resulting from implementing the ATCM are

based upon unproven methods and invalid assumptions. Consequently,

the whole discussion on health benefits should be deleted from the ISOR.

(EMA)

Agency Response: ARB staff disagrees. As discussed in Chapter VII of the

Staff Report: Initial Statement of Reasons for the Proposed Airborne Toxic

Control Measure for Diesel-Fueled Portable Engines, ARB staff based its

health benefits discussion on the reduction in ambient diesel PM

concentrations when the ATCM is fully implemented. The reduction in

diesel PM concentration would result in corresponding lower exposure to

primary and secondary PM. One of the key health effects associated with

ambient particulate matter, of which diesel PM is a component, is premature

mortality. As discussed in the Staff Report, we based our premature

mortality analysis on sound, peer-reviewed, and defensible methodological

elements from Krewski et al. (Reanalysis of the Harvard Six Cities Study

and American Cancer Society Study of Particulate Air Pollution and

Mortality, Health Effects Institute, Cambridge, MA; 2000) Furthermore, the

U.S. EPA has been using the Krewski’s study for its regulatory impact

analysis since 2000.

10.4 Comment: The ATCM should be modified to allow districts to suspend

PERP registrations and bring the equipment under temporary local air

district jurisdiction to ensure that appropriate measures are taken to avoid

significant health or nuisance impacts. In addition, ARB should work with

CAPCOA to develop a method to evaluate health risks from portable

equipment when multi-day operations will occur near sensitive receptors.

(CAPCOA)
31

Agency Response: The Board adopted revisions to PERP on the same

day it adopted the ATCM. Section 2453(l)(5) was added that states a

district permit may be required if “any engine or equipment unit...has

been determined to cause a public nuisance as defined in Health and

Safety Code Section 41700.” In other words, a local air district can require

a permit if a specific PERP-registered piece of equipment is deemed to be

a public nuisance. The ATCM does not need to be modified to allow

districts to suspend PERP registrations for certain types of projects.

As discussed in Staff Report: Initial Statement of Reasons for the

Proposed Airborne Toxic Control Measure for Diesel-Fueled Portable

Engines, portable diesel-fueled engines are used in a variety of

applications. The majority of applications using portable diesel-fueled

engines are completed in a short period of time. Because of the variability

in the use of portable diesel-fueled equipment and the mobile nature of

portable equipment, it is difficult to quantify the potential health risk

resulting from the operation of a portable diesel-fueled engine on any

specific receptor. The current risk assessment methodology

recommended by the Office of Environmental Health Hazard Assessment

(OEHHA) and used by ARB staff in evaluating potential cancer risk is

based upon exposure to the emissions of a source for 70 years—by

nature very unlikely with portable engines. ARB staff will continue to work

with CAPCOA on this issue.

B. Responses to Comments Received During the 15-Day

Public Comment Period for the Modified Regulatory

Language

Abbreviation Commenter

ATA Betty L. Hawkins

Air Transport Association of America, Inc.

Written Testimony: June 1, 2004

PGE Sven Thesen

Pacific Gas and Electric

Written Testimony: June 1, 2004
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Comments and Responses

1. Alternative Fueled Engines

1.1 Comment: The operating requirements for alternative-fueled engines and

low use engines should have the same operating limit of 80 hours per

calendar year. (PGE)

Agency Response: ARB staff disagrees. The annual operating

requirements in the ATCM for alternative-fueled engines and low-use

engines address completely separate issues. The 100-hour minimum

annual operating requirement for alternative-fueled engines is intended to

encourage owners of alternative-fueled engines to operate these engines

in lieu of diesel-fueled engines. Fleet-average credit is given when these

engines are operated at least 100 hours per year. Credit should not be

given for merely owning these engines.

ARB staff recognizes that portable diesel-fueled engines used infrequently

(i.e., low-use engines) should be exempt from some of the provisions of

the ATCM because of higher cost-effectiveness estimates. To that end,

ARB staff developed an alternative compliance path in the ATCM for lowuse engines based on 80 hours maximum annual use. The two hourly

requirements for alternative-fueled engines and low-use engines are

unrelated; therefore, there is no reason to make the hour target the same.

2. Applicability

2.1 Comment: The emission reductions resulting from implementing the MOU

are equivalent to the reductions achieved by the ATCM, and therefore

portable equipment that are regulated by the MOU are exempted from the

requirements of the ATCM for the life of the engine. (ATA)

Agency Response: The ATCM allows portable equipment that is subject

to the South Coast Ground Service Equipment MOU to be exempt from

the requirements of the ATCM if the participating airlines demonstrate to

the satisfaction of the Executive Officer that the diesel PM reductions

achieved by satisfying the requirements of the MOU are equivalent to the

reductions achieved by the ATCM. ARB staff will evaluate any proposal

submitted by the air carriers or their representatives seeking such an

equivalency determination.
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2.2 Comment: ATA supports the revisions that recognize the collective fleet

of all carriers subject to the MOU would be subject to the requirements of

the ATCM instead of each individual air carrier’s fleet being subject to the

requirements of the ATCM. (ATA)

Agency Comment: The ATCM reflects this comment.