6560-50-P

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 85, 86 and 1039

[EPA-HQ-OAR-2011–1032; FRL–9673-1]

RIN A2060-AR54

Heavy-Duty Highway Program: Revisions for Emergency Vehicles

AGENCY:  Environmental Protection Agency (EPA).

ACTION:  Direct final rule.

SUMMARY:  EPA is taking direct final action on revisions to its
heavy-duty diesel regulations that will enable emergency vehicles, such
as dedicated ambulances and fire trucks, to perform mission-critical
life-saving work without risking that abnormal conditions of the
emission control system could lead to decreased engine power, speed or
torque.  The revisions will allow manufacturers to request and EPA to
approve modifications to emission control systems on emergency vehicles
so they do not interfere with the vehicles’ missions. This action is
not expected to result in any significant changes in regulatory burdens
or costs.

DATES:  This rule is effective on [Insert date 60 days from date of
publication in the Federal Register] without further notice, unless EPA
receives adverse comment.  If we receive relevant adverse comment on
distinct elements of this rule by July 27, 2012, we will publish a
timely withdrawal in the Federal Register indicating which provisions we
are withdrawing. The provisions that are not withdrawn will become
effective on [Insert date 60 days from date of publication in the
Federal Register], notwithstanding adverse comment on any other
provision.

ADDRESSES:  Submit your comments, identified by Docket ID No.
EPA-HQ-OAR-2011-1032, by one of the following methods:

 HYPERLINK "http://www.regulations.gov" www.regulations.gov : Follow the
on-line instructions for submitting comments.

Email:  HYPERLINK "mailto:a-and-r-docket@epa.gov" a-and-r-docket@epa.gov


Fax:  (202) 566-9744

Mail: Environmental Protection Agency, Air Docket, Mail-code 6102T, 1200
Pennsylvania Ave., NW, Washington, DC 20460. 

Hand Delivery: EPA Docket Center (EPA/DC), EPA West, Room 3334, 1301
Constitution Ave., NW., Washington, DC, Attention Docket No. EPA-HQ-
OAR-2010-0162.  Such deliveries are only accepted during the Docket’s
normal hours of operation, and special arrangements should be made for
deliveries of boxed information.

Instructions:  Direct your comments to Docket ID No.
EPA-HQ-OAR-2011-1032. For additional instructions on submitting written
comments, see the SUPPLEMENTARY INFORMATION section on “Public
Participation” in the parallel Notice of Proposed Rulemaking in
today’s Federal Register.

Docket: All documents in the docket are listed in the  HYPERLINK
"http://www.regulations.gov" www.regulations.gov  index.  Although
listed in the index, some information is not publicly available, e.g.,
CBI or other information whose disclosure is restricted by statute. 
Certain other material, such as copyrighted material, will be publicly
available only in hard copy.  Publicly available docket materials are
available either electronically in  HYPERLINK
"http://www.regulations.gov" www.regulations.gov  or in hard copy at EPA
Docket Center, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW,
Washington, DC.  The Public Reading Room is open from 8:30 a.m. to 4:30
p.m., Monday through Friday, excluding legal holidays.  The telephone
number for the Public Reading Room is (202) 566-1744, and the telephone
number for the Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT:  Lauren Steele, Environmental
Protection Agency, Office of Transportation and Air Quality, Assessment
and Standards Division, 2000 Traverwood Drive, Ann Arbor, Michigan
48105; telephone number: 734-214-4788; fax number: 734-214-4816; email
address: steele.lauren (@epa.gov). 

SUPPLEMENTARY INFORMATION:

Why is EPA Using a Direct Final Rule?

EPA is publishing this rule without a prior proposed rule because we
view this as a noncontroversial action and anticipate no adverse
comment.  This is also to expedite the regulatory process to allow
engine and vehicle modifications to occur as soon as possible. However,
in the “Proposed Rules” section of today’s Federal Register, we
are publishing a separate document that will serve as the proposed rule
to adopt these revisions for emergency vehicles if adverse comments are
received on this direct final rule. We will not institute a second
comment period on this action.  Any parties interested in commenting
must do so at this time.  For further information about commenting on
this rule, see the ADDRESSES section of this document.

If EPA receives adverse comment on a distinct provision of this
rulemaking, we will publish a timely withdrawal in the Federal Register
indicating which provisions we are withdrawing.  The provisions that are
not withdrawn will become effective on the date set out above,
notwithstanding adverse comment on any other provision.  We would
address all public comments in a subsequent final rule based on the
proposed rule.

EPA is publishing this direct final rule to expedite the deployment of
solutions that will best ensure the readiness of the nation’s
emergency vehicles.  We request that commenters identify in your
comments any portions of the action with which you agree and support as
written, in addition to any comments regarding suggestions for
improvement or provisions with which you disagree.  In the case of a
comment that is otherwise unclear whether it is adverse, EPA would
interpret relevant comments calling for more flexibility or less
restrictions for emergency vehicles as supportive of the direct final
action.  In this way, the EPA will be able to adopt those elements of
this action that are fully supported and most needed today, while
considering and addressing any adverse comments received on the proposed
rule, in the course of developing the final rule.

Does This Action Apply to Me?

This action may affect you if you produce or import new heavy-duty or
nonroad diesel engines that are intended for use in vehicles that serve
the emergency response industry, including all types of dedicated and
purpose-built fire trucks and ambulances.  The following table gives
some examples of entities that may be affected by this action.  Because
these are only examples, you should carefully examine the existing and
revised regulations in 40 CFR parts 85, 86 and 1039.  If you have
questions regarding how or whether these rules apply to you, you may
call the person listed in the FOR FURTHER INFORMATION CONTACT section
above.

Category	NAICS Codea	Examples of Potentially Affected Entities

Industry	336111	Motor Vehicle Manufacturers, Engine and Truck
Manufacturers

	336112



333618



336120

	Industry	541514	Commercial Importers of Vehicles and Vehicle Components

	811112



811198

	Industry	811310	Engine Repair, Remanufacture, and Maintenance

Note:

a  North American Industry Classification System (NAICS)

Table of Contents

  TOC \o "1-3" \n \h \z \u  

 HYPERLINK \l "_Toc324944235" I. Overview 

 HYPERLINK \l "_Toc324944236" II. Statutory Authority and Regulatory
Background 

 HYPERLINK \l "_Toc324944237" A. Statutory Authority 

 HYPERLINK \l "_Toc324944238" B. Background: 2007 and 2010 NOX and PM
Standards 

 HYPERLINK \l "_Toc324944239" (1) On-Highway Standards 

 HYPERLINK \l "_Toc324944240" (2) Nonroad Standards 

 HYPERLINK \l "_Toc324944241" III. Emergency Vehicle Provisions 

 HYPERLINK \l "_Toc324944242" A. Background on Regulation of Emergency
Vehicles 

 HYPERLINK \l "_Toc324944243" B. Why is EPA Taking This Action? 

 HYPERLINK \l "_Toc324944244" (1) How Does a DPF Work? 

 HYPERLINK \l "_Toc324944245" (2) Why Are Emergency Vehicles Having
Problems with DPF Regeneration? 

 HYPERLINK \l "_Toc324944246" (3) What Are the Concerns for Emergency
Vehicles Using SCR? 

 HYPERLINK \l "_Toc324944247" C. What Would Occur if EPA Took No Action?


 HYPERLINK \l "_Toc324944248" (1) The Industry Would Continue to Get
Smarter 

 HYPERLINK \l "_Toc324944249" (2) The Fleet Would Continue to Migrate to
the 2010 Standards 

 HYPERLINK \l "_Toc324944250" (3) Some Trucks Would Continue to
Experience Problems 

 HYPERLINK \l "_Toc324944251" D. Regulatory Action 

 HYPERLINK \l "_Toc324944252" (1) Liberalized Regeneration Requests 

 HYPERLINK \l "_Toc324944253" (2) Engine Recalibration 

 HYPERLINK \l "_Toc324944254" (3) Backpressure Relief 

 HYPERLINK \l "_Toc324944255" E. What Engines and Vehicles Are Affected?


 HYPERLINK \l "_Toc324944256" (1) Newly Certified Engines 

 HYPERLINK \l "_Toc324944257" (2) Certified Engines and Vehicles In-Use 

 HYPERLINK \l "_Toc324944258" (3) Labeling Requirements 

 HYPERLINK \l "_Toc324944259" (4) Other Regulatory Provisions 

 HYPERLINK \l "_Toc324944260" F. Economic Impacts 

 HYPERLINK \l "_Toc324944261" (1) Costs to Manufacturers 

 HYPERLINK \l "_Toc324944262" (2) Operational Costs 

 HYPERLINK \l "_Toc324944263" (3) Societal Costs 

 HYPERLINK \l "_Toc324944264" G. Environmental Impacts 

 HYPERLINK \l "_Toc324944265" H. Health Effects 

 HYPERLINK \l "_Toc324944266" IV. Statutory and Executive Order Reviews 

 HYPERLINK \l "_Toc324944267" A. Executive Order 12866: Regulatory
Planning and Review 

 HYPERLINK \l "_Toc324944268" B. Paperwork Reduction Act 

 HYPERLINK \l "_Toc324944269" C. Regulatory Flexibility Act 

 HYPERLINK \l "_Toc324944270" D. Unfunded Mandates Reform Act 

 HYPERLINK \l "_Toc324944271" E. Executive Order 13132: Federalism 

 HYPERLINK \l "_Toc324944272" F. Executive Order 13175: Consultation and
Coordination with Indian Tribal Governments 

 HYPERLINK \l "_Toc324944273" G. Executive Order 13045: Protection of
Children from Environmental Health and Safety Risks 

 HYPERLINK \l "_Toc324944274" H. Executive Order 13211: Actions that
Significantly Affect Energy Supply, Distribution, or Use 

 HYPERLINK \l "_Toc324944275" I. National Technology Transfer
Advancement Act 

 HYPERLINK \l "_Toc324944276" J. Executive Order 12898: Federal Actions
to Address Environmental Justice in Minority Populations and Low-Income
Populations 

 HYPERLINK \l "_Toc324944277" K. Congressional Review Act 

 Overview

EPA is adopting amendments to its heavy-duty diesel engine programs that
will specifically allow engine manufacturers to request to deploy
specific emission controls or settings for new and in-use engines that
are sold for use only in emergency vehicles.  EPA is adopting these
revisions to enable fire trucks and ambulances with heavy-duty diesel
engines to perform mission-critical life- and property-saving work
without risk of losing power, speed or torque due to abnormal conditions
of the emission control systems.

EPA’s current diesel engine requirements have spurred application of
emission controls systems such as diesel particulate filters (commonly
called soot filters or DPF’s) and other after-treatment systems on
most new diesel vehicles, including emergency vehicles. Some control
system designs and implementation strategies are more effective in other
segments of the fleet than in emergency vehicles, especially given some
emergency vehicles’ extreme duty cycles.  By this action, EPA intends
to help our nation’s emergency vehicles perform their missions; to
better ensure public safety and welfare and the protection of lives and
property.

Statutory Authority and Regulatory Background

Statutory Authority

Section 202(a)(1) of the Clean Air Act (CAA or the Act) directs EPA to
establish standards regulating the emission of any air pollutant from
any class or classes of new motor vehicles or new motor vehicle engines
that, in the Administrator’s judgment, causes or contributes to air
pollution which may reasonably be anticipated to endanger public health
or welfare.  Such standards apply for the useful life of the vehicles or
engines.  Section 202(a)(3) requires that EPA set standards applicable
to emissions of hydrocarbons, carbon monoxide, NOX and particulate
matter (PM) from heavy-duty trucks that reflect the greatest degree of
emission reduction achievable through the application of technology
which we determine will be available for the model year to which the
standards apply.  We are to give appropriate consideration to cost,
energy, and safety factors associated with the application of such
technology.  We may revise such technology-based standards, taking costs
into account, on the basis of information concerning the effects of air
pollution from heavy-duty vehicles or engines and other sources of
mobile source related pollutants on the public health and welfare.

Section 202(a)(4)(A) of the Act requires the Administrator to consider
risks to public health, welfare or safety in determining whether an
emission control device, system or element of design shall be used in a
new motor vehicle or new motor vehicle engine.  Under section
202(a)(4)(B), the Administrator shall consider available methods for
reducing risk to public health, welfare or safety associated with use of
such device, system or element of design, as well as the availability of
other devices, systems or elements of design which may be used to
conform to requirements prescribed by (this subchapter) without causing
or contributing to such unreasonable risk.

Section 206(a) of the Act requires EPA to test, or require to be tested
in such manner as it deems appropriate, motor vehicles or motor vehicle
engines submitted by a manufacturer to determine whether such vehicle or
engine conforms to the regulations promulgated under section 202. 
Section 206(d) provides that EPA shall by regulation establish methods
and procedures for making tests under section 206. 

Section 213 of the Act gives EPA the authority to establish emissions
standards for nonroad engines and vehicles (42 U.S.C. 7547).  Sections
213(a)(3) and (a)(4) authorize the Administrator to set standards and
require EPA to give appropriate consideration to cost, lead time, noise,
energy, and safety factors associated with the application of
technology. Section 213(a)(4) authorizes the Administrator to establish
standards to control emissions of pollutants (other than those covered
by section 213(a)(3)) which “may reasonably be anticipated to endanger
public health and welfare.” Section 213(d) requires the standards
under section 213 to be subject to sections 206-209 of the Act and to be
enforced in the same manner as standards prescribed under section 202 of
the Act.

Background: 2007 and 2010 NOX and PM Standards

On-Highway Standards

On January 18, 2001, EPA published a rule promulgating more stringent
standards for NOX and PM for heavy-duty highway engines (“the
heavy-duty highway rule”).  The 0.20 gram per brake-horsepower-hour
(g/bhp-hr) NOX standard in the heavy-duty highway rule first applied in
MY 2007.  However, because of phase-in flexibility provisions adopted in
that rule and use of emission credits generated by manufacturers for
early compliance, manufacturers were able to continue to produce engines
with NOX emissions greater than 0.20 g/bhp-hr.  The phase-in provisions
ended after MY 2009 so that the 0.20 g/bhp-hr NOX standard was fully
phased-in for model year 2010.  Because of these changes that occurred
in MY 2010, the 0.20 g/bhp-hr NOX emission standard is often referred to
as the 2010 NOX emission standard, even though it applied to engines as
early as MY 2007.

The heavy-duty highway rule adopted in 2001 also included a PM emissions
standard for new heavy-duty diesel engines of 0.01 g/bhp-hr, effective
for engines beginning with MY 2007.  Due to the flexible nature of the
phase-in schedule described above, manufacturers have had the
opportunity to produce engines that met the PM standard while emitting
higher levels of NOX.  During the phase-in years, manufacturers of
diesel engines generally produced engines that were tuned so the
combustion process inherently emitted lower engine-out NOX while relying
on PM after-treatment to meet the PM standard.  The principles of
combustion chemistry dictate that conditions yielding lower engine-out
NOX emissions generally result in higher engine-out PM emissions.  This
is what we call the NOX-PM trade-off.  For many new low-NOX diesel
engines today, engine-out PM emissions could be at or above the levels
seen with the MY 2004 standards (0.1 g/bhp-hr).  To meet today’s
stringent PM standards, manufacturers rely on diesel particulate filter
after-treatment to clean the exhaust.

Nonroad Standards

EPA adopted similar technology-forcing standards for nonroad diesel
engines on June 29, 2004.  These are known as the Tier 4 standards. 
This program includes requirements that will generally involve the use
of NOX after-treatment for engines above 75 hp and PM after-treatment
(likely soot filters) for engines above 25 hp.  These standards phase in
during the 2011 to 2015 time frame.

Emergency Vehicle Provisions

Background on Regulation of Emergency Vehicles

Typically, the engines powering our nation’s emergency vehicles belong
to the same certified engine families as engines that are installed in
similarly sized vehicles sold for other public and private uses. 
Historically, engine and vehicle manufacturers have sought EPA
certification for broad engine families and vehicle test groups that are
defined by similar emissions and performance characteristics.  Engine
families typically only consider the type of vehicle in which the engine
is intended to be installed to the extent that it fits into a broad
vehicle weight class and, to a lesser extent, the vehicle’s intended
duty cycle (i.e. urban or highway).

Because of the above-described manufacturing practices and the narrow
CAA authority for any exemptions, EPA has historically regulated engines
for emergency vehicles, including ambulances as well as police vehicles
and fire-fighting apparatus, in the same manner as other engines.  

In the public comments received on the proposed heavy-duty highway rule,
EPA received some comments about DPF technologies and regeneration
cycles on heavy-duty trucks, including one comment that expressed
concerns that the systems may not be failsafe.  However, none of the
comments specifically raised technical feasibility with respect to
emergency vehicles, and EPA’s response was based on the best
information available at the time.  After publishing the final rule
requiring heavy-duty highway engines to meet performance standards that
compelled technologies such as DPF’s, EPA received a letter from the
National Association of State Fire Marshals, requesting some provision
for public safety in implementing this new rule, considering that fire
departments across the nation have trouble covering basic costs and may
not have funds for more expensive trucks.  This letter did not raise any
technical feasibility issues, and EPA did not see a need to take action.
 

More recently EPA has received letters from fire apparatus manufacturers
and ambulance companies requesting relief from power or speed
inducements related to low levels of DEF for SCR systems on emergency
vehicles.  Power and speed reduction inducements were new on vehicles
equipped with SCR.  These were not specifically mandated by EPA but
designed by manufacturers to occur if DEF levels became low, to induce
operators of the vehicles to perform the required emission-related
maintenance in use. More discussion on this, including why the emergency
response community requested relief and what action EPA took, is found
below in Section III.B(3).  

Recently, beginning in October 2011, EPA received a series of comment
letters from fire chiefs and other interested stakeholders, requesting
regulatory action to relieve emergency vehicles from the burden of
complying with the 2007 PM standards.  EPA promptly opened a dialogue
with the fire chiefs and engine manufacturers to understand the issues.
Power and speed reductions were occurring on some vehicles with soot
filters but without SCR systems, in part related to engine protection
measures designed by manufacturers.  Essentially, these soot filters are
supposed to be self-cleaning by periodically burning off accumulated
soot during normal vehicle use.  The cleaning process is called
regeneration, and when this doesn’t work as designed, the filter
gradually gets more clogged, which can lead to engine problems.  EPA has
determined that while other pathways are available for resolving some
issues related to soot filters on emergency vehicles, there remains a
public safety issue related to design of engines and emission control
systems on emergency vehicles that should be addressed through this
rulemaking. More discussion of this, including why relief was requested
and what other actions can be taken in addition to EPA regulation, is
found below in Sections III.B and III.C.

There have been some examples of EPA providing limited exemptions for
other types of emergency-use engines and vessels.  Further descriptions
of current and proposed limited exemptions are provided in the Notice of
Proposed Rulemaking published elsewhere in today’s Federal Register. 
These limited exemption provisions are only applicable to newly
certified engines.  They are not applicable to any existing in-use
engines that are already deployed in emergency equipment.

Why is EPA Taking This Action?

EPA is amending its regulations to facilitate engine manufacturers’
design and implementation of reliable and robust emission control
systems with regeneration strategies and other features that do not
interfere with the mission of emergency vehicles.  Through the comments
and letters we have received, as well as our own outreach and
data-gathering efforts, we have learned that some emission control
systems on fire trucks and ambulances today, in particular, certain
applications using diesel particulate filters, are requiring an
unexpected amount of operator interventions, and there are currently a
nontrivial number of emergency vehicles that are electronically
programmed to cut power or speed – even while responding to an
emergency - when certain operational parameters are exceeded in relation
to the emission control system.  As we understand it, the experiences of
operators are mixed, with some not reporting any problems and some
reporting problems that raise public safety and welfare concerns.  

EPA’s standards are performance-based, and reflect the greatest degree
of emission reduction achievable, according to CAA sections 202(a)(3)
and 213(a)(3).  Our on-highway and nonroad PM standards do not specify
the type of diesel particulate filter for manufacturers to use, nor do
they even mandate the use of such a filter.  Our analysis of the
feasibility of the 2007 on-highway PM standard is presented in Chapter
III of the final Regulatory Impact Analysis (RIA) for that rule.  Our
analysis of the feasibility of the Tier 4 nonroad compression ignition
engine standards that will be phasing in through 2015 is presented in
Chapter 4 of that rule’s final RIA.  For most nonroad engines, these
standards are similar in stringency to the 2007 on-highway heavy-duty
engine and vehicle standards.  As described below in Section III.H,
these two rules are providing billions of dollars of annual health
benefits by virtually eliminating harmful PM emissions from the
regulated engines.  Even so, EPA is required by sections 202(a)(4)(B)
and 213(c) of the Act to, among other things, consider methods for
reducing risk to public safety and welfare associated with the use of
emission control devices or systems.  

Based on the information available to us, we have concluded that there
is an indirect risk to public safety and welfare associated with some
examples of emission control systems when they are deployed on emergency
vehicles that experience extreme duty cycles.  This indirect risk is
related to the readiness of emergency vehicles and the risk that they
may not be able to respond during emergencies with the full power,
torque, or speed that the engine is designed to provide. While this risk
is not inherent to the requirement to reduce emissions or to the use of
diesel particulate filters on emergency vehicles, EPA believes it is
appropriate to ensure that emergency vehicles can perform their
emergency missions without the chance of such consequences. 

EPA’s current rules already provide the opportunity for manufacturers
to address many issues through applications for certification of new
engines and new vehicles. There is also currently a mechanism for
manufacturers to deploy field modifications to the in-use fleet,
including those that are substantially similar to approved upgrades for
new vehicles, as well as those that apply only to vehicles that are no
longer in production.  As manufacturers become aware of the need for
upgrades or enhancements, this process occurs within the new and in-use
fleet with various degrees of application.  While that process is
occurring today, EPA views this issue as serious enough that we would be
remiss if we did not act to ensure that our regulations clearly offer
the needed flexibilities for emergency vehicles.

How Does a DPF Work?

To explain more fully the issues that we are addressing with this
action, and hence why we are taking this action, we are providing here
some background information on diesel particulate filters and the
process of DPF regeneration.  DPF’s are exhaust after-treatment
devices that significantly reduce emissions from diesel-fueled vehicles
and equipment.  DPF’s physically trap  HYPERLINK
"http://www.epa.gov/airscience/quick-finder/particulate-matter.htm" PM 
and remove it from the exhaust stream.    REF _Ref322528003 \h  \*
MERGEFORMAT  Figure III-1  depicts a schematic of a wall-flow monolith
style filter, with the black arrows indicating exhaust gas laden with
particles, and the gray arrows indicating filtered exhaust gas. This
style of filter is the most common in today’s heavy-duty diesel
engines, and has very high rates of filtration, in excess of 95 percent.
 

Figure   STYLEREF 1 \s  III -  SEQ Figure \* ARABIC \s 1  1 
Illustration of air flow pattern in a wall-flow monolith style PM filter
(Source: Corning)

To be successful, these devices generally must be able to accomplish two
things:  collect PM and clean away accumulated PM.  There are two main
types of PM that can accumulate: combustible and non-combustible, and
two very different types of cleaning methods: regeneration and ash
cleaning.  Regeneration occurs relatively frequently, and is designed to
complete the combustion (oxidation) of the trapped combustible PM
components, releasing them to the exhaust as gas-phase compounds (mostly
H2O and CO2).  In contrast to the PM that can be oxidized and carried
out the tailpipe as gases, the non-combustible PM such as metallic ash
cannot be destroyed through regeneration and will always remain inside a
DPF.  To clean ash from a DPF, the filter unit is removed from the
vehicle and professionally cleaned with a special machine.  Fortunately,
there is very little ash formation from modern diesels so ash cleaning
and ash disposal occurs very infrequently, generally with at least
150,000 mile service intervals, and the mass of accumulated ash is
generally small (a few teaspoons).,  This distinction is made here
because the ash cleaning process is not a source of concern that has
given rise to this EPA action.  The infrequent cleaning of
noncombustible materials from DPF’s is not part of the scope of this
action.  

  Regeneration, however, is a type of routine DPF cleaning that must
occur regularly, and for which EPA does not specify a minimum interval
in its regulations, in contrast to the ash cleaning process.  At its
very essence, regeneration involves burning off the accumulated soot.
Since this burning can involve extra heat and/or oxygen or
oxygen-containing compounds, this must be done carefully and safely to
avoid uncontrolled burns.  The discussion below in Section III.B.(1)(b)
describes the three types of routine DPF regeneration: passive
regeneration, automatic active regeneration, and manual (parked) active
regeneration.  Additional discussion is provided in the accompanying
Notice of Proposed Rulemaking published elsewhere in today’s Federal
Register and in a memorandum to the docket.  Below, we discuss the
reason why regeneration is needed at all. 

Failure of a DPF

When the style of filter installed on a diesel vehicle is the wall-flow
type that is predominant in the market today, it physically traps so
much of the PM that the particles accumulate on the inside of the filter
and if not burned off, this PM can over time block the passages through
the filtering media, making it more restrictive to exhaust flow.  This
is commonly referred to as “trap plugging.”  Some other styles of
filter, such as flow-through DPF’s, are less prone to plugging, but do
not generally reduce the PM emission rate sufficiently to meet today’s
stringent PM standard.  Any time something gets in the way of free
flowing air through an engine, it creates what we call “exhaust
backpressure.”  Even a clean, new DPF generates a small amount of
exhaust backpressure due to the porous walls through which all of the
exhaust flows.

Engines can tolerate a certain range of exhaust backpressure.  When an
increase in this backpressure, or resistance, is detected, engines can
compensate to a point.  An increase in exhaust backpressure from a DPF
trapping more and more PM represents increased work demanded from the
engine to force the exhaust gas through the increasingly restrictive
DPF.  However, unless the DPF is frequently cleansed of the trapped PM,
this increased work demand can lead to reductions in engine performance
and increases in fuel consumption.  This loss in performance may be
noticed by the vehicle operator in terms of poor acceleration and
generally poor drivability of the vehicle.   

If a DPF is not regenerated and it becomes plugged, there is a risk of
two types of failure. The degree of this risk and which consequence may
be experienced will depend on the engine and emission control system
design.  One consequence is that the lack of air flowing through an
engine will cause an engine to shut down because it can no longer
compensate for the extra work being demanded of it.  The other is a risk
of catastrophic DPF failure when excessive amounts of trapped PM begin
to oxidize at high temperatures (i.e., DPF regeneration temperatures
above 1,000°C) leading to a “runaway” combustion of the PM within
the DPF.  This can cause temperatures in the filter media to increase
beyond its physical tolerance, possibly creating high thermal stresses
where the DPF materials could crack or melt.  This is an unsafe
condition, presenting physical danger to occupants as well as to objects
and persons near the vehicle.  Further, catastrophic failure can allow
significant amounts of the diesel PM to pass through the DPF without
being captured.  That is, the DPF is destroyed and PM emission control
is lost.  For all these reasons, most manufacturers generally design
their emission control systems to prevent uncontrolled shutdown or
runaway DPF regeneration by programming the engine’s electronic
control module (ECM) to limit maximum engine speed, torque and/or power
when excessive backpressures are detected.  This mode of engine
operation at reduced performance may allow a vehicle to “limp home”
to receive service.  In extreme cases the ECM may command the engine to
shut down to prevent a catastrophic failure.

Types of Regeneration

There are three types of routine DPF regeneration. Passive regeneration
refers to methods that rely strictly on the temperatures and
constituents normally available in the vehicle’s exhaust to oxidize PM
from a DPF in a given vehicle application.  Passive regeneration is an
automatic process that occurs without the intervention of an engine’s
on-board diagnostic and control systems, and often without any operator
notice or knowledge.  Passive regeneration is often a continuous
process, because of which, it is sometimes referred to as continuous
regeneration.  In a vehicle whose normal operation does not generate
temperatures needed for passive DPF regeneration, the system needs a
little help to clean itself.  This process is called active
regeneration, and supplemental heat inputs to the exhaust are provided
to initiate soot oxidation. There are two types of active regeneration: 
those that may occur automatically either while the vehicle is in
motion, while idling, or while powering an auxiliary device such as a
pump or ladder (power take-off (PTO) mode)), and those that must be
driver-initiated and occur only while the vehicle is stationary and
out-of-service.  

Vehicles with automatic active regeneration systems require operators to
be alert to dashboard lamps and indicators.  Written instructions are
provided to operators to explain what each lamp means (such as high
temperatures or need for regeneration) and what action is called for
(such as driving at highway speeds or initiating a manual active
regeneration).  Because EPA emissions standards are performance based;
and therefore, do not dictate any required emission control system
technologies or configurations, each manufacturer has the discretion to
program the timing and sequence of lamps as needed to inform drivers of
the condition of the emission control system.  As noted above, it is not
uncommon in today’s heavy-duty fleet for an engine’s ECM to limit
its maximum speed, torque or power when a plugging DPF is detected. 
These engine and emission control system protection measures can alert
drivers to the need to change driving conditions to facilitate automatic
active regeneration or to make plans to allow for a manual active
regeneration.

A manual active regeneration allows the engine’s ECM to increase
engine speed and exhaust temperature to a greater extent than what is
typically allowed during an automatic active regeneration.  Because the
ECM takes full control of an engine during a manual active regeneration,
the vehicle must remain parked and not used for other purposes, such as
pumping water in PTO mode.  Some manual active regenerations may require
towing the vehicle to a special service center, and may occur while the
DPF is on the vehicle, or offline with the DPF removed from the vehicle.
 In such cases, if a spare DPF is not available, the vehicle could be
out of service overnight.  If a driver disregards such warnings, the
risk of uncontrolled engine shutdown or a catastrophic DPF failure may
increase.  EPA encourages the design of robust systems calling for
minimal driver interventions, while providing drivers with clear and
early indicators before any interventions are needed.  EPA also
encourages accurate and thorough operator training to ensure that the
correct remedial action is taken at the earliest available time.

Actively regenerating DPF systems typically require sufficient air flow,
temperature and soot accumulation before an automatic active
regeneration will be requested by the engine’s ECM.  As mentioned
above, this may occur either while the vehicle is in motion or parked,
if pre-set engine operating conditions are met (such as speed and
temperature).  When the engine’s ECM signals the initiation of an
automatic active regeneration and the extra heat is generated, an ideal
DPF system accomplishes this as a transparent process, with no effects
perceivable by the driver.

A variety of manufacturer approaches can be taken to produce the
supplemental heat needed for active regeneration.  Diesel engines of MY
2007 or newer often incorporate one or more of the following approaches:

On-board electrical heaters upstream of the filter.

Air-intake throttling in one or more of the engine cylinders. When
necessary, this device would limit the amount of air entering the
engine, raising the exhaust temperature and facilitating regeneration.

Exhaust brake activation. When necessary, this device would limit the
amount of exhaust exiting the engine, raising the exhaust temperature
and facilitating regeneration.

Engine speed increases.  This approach is sometimes used in combination
with the other approaches to deliver more heat to the filter to
facilitate regeneration.

Post top-dead-center (TDC) fuel injection. Injecting small amounts of
fuel in the cylinders of a diesel engine after pistons have reached TDC
introduces a small amount of unburned fuel in the engine’s exhaust
gases. This unburned fuel can then be oxidized over an oxidation
catalyst upstream of the filter or oxidized over a catalyzed particulate
filter to combust accumulated particulate matter. 

Post injection of diesel fuel in the exhaust upstream of an oxidation
catalyst and/or catalyzed particulate filter. This method serves to
generate heat used to combust accumulated particulates by oxidizing fuel
across a catalyst present on the filter or on an oxidation catalyst
upstream of the filter

On-board fuel burners upstream of the filter 

These are presented here merely as examples, and are by no means a
complete list of the strategies available to manufacturers when
designing engines that use automatic active DPF regeneration, though not
all may be applicable to all engines.  A common approach that gets a lot
of consumer attention is the use of fuel burners or fuel injection
strategies.  This approach is often called “dosing.”  Vehicle owners
may notice an increase in fuel consumption when driving a vehicle that
relies heavily on fuel dosing for its automatic active regenerations. 
In this case, when an engine’s ECM gives the signal, the doser injects
a metered amount of diesel fuel into the exhaust flow (or cylinders),
which reacts with the DPF catalyst to raise the temperature to a point
that enables regeneration.  EPA does not have information about which
manufacturers employ this technique or the number or types of vehicles
with engines that use fuel dosing as part of the active regeneration
strategy.  Estimates of the additional fuel use by a vehicle whose DPF
regeneration system employs fuel dosing are described in the Notice of
Proposed Rulemaking published elsewhere in today’s Federal Register. 
This is also mentioned here because one of the possible outcomes of this
EPA action is that some manufacturers may alter their strategies for
automatic active regenerations on emergency vehicles, which may have a
modest effect on supplemental fuel use due to dosing.

Why Are Emergency Vehicles Having Problems with DPF Regeneration?

At the time of promulgation of the heavy-duty highway rule, EPA and the
engine manufacturers expected the 2007-compliant engine emission control
systems would be integrated with advanced engine controls to ensure DPF
regeneration under all vehicle operating conditions and environments. 
While this is widely true today, the experience of the rule
implementation thus far indicates there are still some exceptions.

Although EPA is aware of a relatively small number of emergency vehicles
that are experiencing problems with DPF regeneration, of those that are
having problems, most of the problems can be related to the vehicle’s
duty cycle, the ambient conditions, and/or the engine’s combustion
characteristics.  A vehicle’s duty cycle means how it is driven,
including its speeds, loads, and distances, as well as time out of
service and time spent idling.  A vehicle’s duty cycle can vary by the
demographic of the service area, including whether the vehicle responds
to emergencies in a rural or urban community, and whether it drives over
flat or hilly terrain.  Because DPF regeneration requires heat and
oxygen (basic ingredients for combustion), the success of DPF
regeneration strategies can also be influenced by ambient conditions
such as extreme cold winter temperatures and whether the vehicle
operates near sea level or at a high elevation.  The engine combustion
and exhaust characteristics can influence the success of a DPF
regeneration strategy since parameters such as engine-out NOX and PM
emission levels can influence how easily the soot can be oxidized, and
how much soot needs to be oxidized and how often.

Both the engine’s duty cycle and the overall control strategy of the
engine’s emission control system play a large role in the success of
integrating a DPF with an engine to control PM emissions.  In this
section we provide additional discussion of how engine combustion
characteristics and vehicle duty cycle can lead to DPF regeneration
problems on emergency vehicles.  In Section III.D, below, we discuss our
regulatory action to address these issues.  While our approach
specifically targets engine combustion characteristics and emission
control system design, we encourage emergency vehicle owners to inquire
with their dealers and manufacturers regarding suitable vehicle and
engine options that are appropriate for their duty cycle as well as
their demographic and geographic location.

Engine Combustion Characteristics

Engine combustion characteristics can be designed to enable continuous
passive regeneration or to rely heavily on automatic active
regeneration.  As mentioned above, regeneration is a combustion process,
burning off the accumulated PM or soot.  The PM is created because the
initial combustion process in the engine was imperfect.  To completely
convert all fuel to CO2 and water, the combustion process needs more
heat and oxygen.  Both of these things create NOX because nitrogen (N2)
is naturally present in the air and readily oxidizes at high
temperatures.  Thus there is a NOX-PM trade-off of most diesel
combustion processes (homogeneous charge compression ignition being an
exception) where lower combustion temperatures help control NOX but
create more PM, and higher temperatures that destroy PM (or prevent it
from being created) can generate more NOX. 

In an engine with a DPF system, combustion settings, or calibrations
that enable continuous passive regeneration, tend to be those with
higher engine-out NOX and lower engine-out PM, partly because of the
higher temperatures that create the NOX, partly because of the NOX
itself that can act as an oxidizer (to burn off soot), and partly
because of the lighter soot loading rate.  In contrast, engine
calibrations that may lead to a heavy reliance on automatic active
regeneration tend to be those with lower engine-out NOX and higher
engine-out PM, partly because of the lower temperatures, partly because
of a lack of helpful NOX, and partly because of a heavier soot loading
rate.  Note that “engine-out” means emissions upstream of any
after-treatment cleaning devices such as DPF or SCR.  An example of a
DPF system that may rely almost exclusively on active regeneration to
maintain a clean PM filter, from an engine calibration perspective,
would be an engine using advanced exhaust gas recirculation, because it
would have very low engine-out NOX and relatively high engine-out PM. 
An example of a DPF system that may rarely experience automatic active
regeneration (and frequently passively regenerate), from an engine
calibration perspective, would be an engine using SCR to control NOX,
because it could have comparatively high engine-out NOX and relatively
low engine-out PM.  The SCR after-treatment would then reduce the high
engine-out NOX to provide very low tailpipe NOX.

Thus it is important to note that this NOX-PM trade-off is a critical
design parameter when developing an engine that will be successfully
integrated with a DPF-equipped emission control system.  To date, all of
the concerns expressed to EPA regarding emergency vehicles with DPF
regeneration issues have been for vehicles that do not employ SCR
technology, and thus may have higher engine-out PM.  The differences in
engine combustion characteristics of the MY 2007 vehicles compared to
those of the majority of MY 2010+ vehicles support the concept that the
emergency vehicle fleet may experience fewer DPF regeneration troubles
as it migrates to engines that use after-treatment to meet EPA’s 2010
NOX standards.  Such a trend may indicate that some engine manufacturers
may see a greater need to address in-use emergency vehicles than new
vehicles.

Duty Cycles

As noted above, the duty cycle of a vehicle is one of the factors that
influences how often the DPF regenerates passively or actively.  It is
important to note that all DPF systems with active regeneration
components also have the capability to passively oxidize soot
accumulated on the filter, though some of the above-described factors
may inhibit successful passive regeneration.  Operation at highway
speeds and high engine loads (high load means demanding more work from
the engine, such as accelerating, driving uphill or carrying heavy
cargo) typically leads to successful passive regeneration of a DPF.  An
example from a duty-cycle perspective of a vehicle that frequently
experiences automatic passive regeneration would be a long-haul
tractor-trailer.  There is also often a threshold of speed or load that
is required for automatic active regeneration strategies as well, though
not as great as for passive regeneration – often at least 5 miles/hour
or parked with a PTO engaged.  In some vehicles, passive regeneration
occurs so rarely that a DPF system relies almost exclusively on active
regenerations to maintain a clean PM filter. An example of this from a
duty-cycle perspective would be a vehicle that operates at idle, low
speed and low load over most of its duty cycle.  Many emergency vehicles
fall into this category.

A detailed discussion of the duty cycles of emergency vehicles is
provided in the Notice of Proposed Rulemaking published elsewhere in
Today’s Federal Register.  The data provided in that discussion
indicate that engines on emergency vehicles across the country are
commonly operated over duty cycles that offer very limited opportunities
to regenerate DPF’s.  It is also important to note that emergency
vehicles do not typically get deployed on planned duty schedules with
predictable blocks of garage time for servicing or maintenance.  While
some other types of vocational vehicles may have duty cycles with many
characteristics similar to those shown above, emergency vehicles are
unique in their need to be ready to deploy at any moment for the purpose
of protecting public safety and welfare by saving human lives that may
be in immediate danger.

When trucks with an engine-driven PTO are working in a stationary PTO
mode, some engines achieve the conditions to enable an automatic active
regeneration during this time.  While this is normally designed to be a
transparent process, in practice some effects of this type of
regeneration have been noticed by operators.  EPA has received
information from fire chiefs indicating that there have been instances
where engine ECM’s took control from the operator during water pumping
operations.  When an automatic active regeneration is initiated during a
water pumping operation, for example, an ECM may be programmed to alter
throttle position or engine speed to achieve the conditions needed to
complete an automatic active regeneration.  Depending on the design of
the water pumping system’s pressure regulation, this may in turn
affect the water pressure in the fire hoses.  EPA has not heard of this
occurring on a widespread basis, and has reason to believe that affected
engine and truck manufacturers have identified and corrected this issue
on some vehicles.  EPA’s current regulations already allow
manufacturers to develop and request EPA approval for certification of
engines with emission control strategies where the process of undergoing
automatic active regeneration would not interfere with safely pumping
fire suppressant.

While not addressed directly in this action, there are technologies that
could be implemented to decrease the amount of time emergency vehicles
spend with their main engines operating at light loads and at idle. 
These technologies include electronically programmed automatic engine
start/stop systems and hybrids.  Automatic start/stop systems
automatically stop and start an engine depending upon whether or not it
is needed to supply power to the vehicle.  This technology is already
being implemented on other heavy-duty vehicles to decrease unnecessary
engine idling.  Hybrid drivetrains also decrease engine idling with an
integrated alternate power source such as a battery.  We are currently
seeing an increase in the use of hybrid technologies in heavy-duty
diesel vocational vehicles.  Garbage trucks, utility company trucks, and
other work trucks are using hybrid technology to power on-board
hydraulic systems and cab heating and cooling systems.  In conventional
vehicles these systems are powered by a main engine typically operating
at light load or at idle.  Because automatic start/stop and hybrid
technologies improve fuel economy and decrease greenhouse gas emissions,
we believe that they will be used in more and more vehicles in the
future.  We believe there is potential for these technologies to be
integrated into future designs of emergency vehicles to decrease their
operation at light loads and at idle.  Such technologies would not only
improve fuel economy and decrease greenhouse gas emissions from
emergency vehicles, they would also help to prevent their diesel
particulate filters from becoming plugged due to excessive operation at
light loads and at idle.  While we are not taking any specific action at
this time related to decreasing the amount of time emergency vehicles
operate at light load or at idle, in the accompanying NPRM, we request
comment on the potential for application of alternate power sources and
idle reduction technologies on emergency vehicles.

What Are the Concerns for Emergency Vehicles Using SCR?

Selective Catalytic Reduction (SCR) is an exhaust after-treatment system
used to control NOX emissions from heavy-duty engines by converting NOX
into nitrogen (N2) and water (H2O).  The technology depends on the use
of a catalytic converter and a chemical reducing agent, which generally
is in an aqueous urea solution, and is often referred to as diesel
exhaust fluid (DEF).  Some trade names for this chemical reductant
include AdBlue,  BlueDef, NOxBlue, and TerraCair.

Most engine manufacturers chose to comply with the 2010 NOX emission
standard by adding SCR to their engine models.  In general, the approach
with an SCR system has been a sound and cost effective pathway to comply
with EPA’s 2010 emissions standards, and it is the primary path being
used today.  

DEF is injected into the exhaust upstream of the SCR catalyst where it
forms ammonia and carbon dioxide. The ammonia then reacts with NO and
NO2, so that one molecule of urea can reduce two molecules of NO or one
molecule of NO2.  A robust SCR system can achieve about 90 percent
reduction in cycle-weighted NOX emissions. Improvements have been made
over the last several years to improve the NOX conversion rate and
reduce the impact of lower exhaust temperatures on the conversion
efficiency.

Because an SCR system is only effective when DEF is injected into the
exhaust, we consider refilling a vehicle’s DEF tank to be a critical
emission-related engine maintenance requirement.  We are proposing to
take action to establish this in our regulations, as described in
Section V of the Notice of Proposed Rulemaking published elsewhere in
today’s Federal Register.  Therefore, manufacturers have implemented a
number of strategies to induce a vehicle operator to refill a
vehicle’s DEF tank when needed.  These operator inducements generally
include first illuminating one or more dashboard lights to warn the
operator that the DEF tank needs to be refilled soon.  However, if such
initial inducements are persistently ignored by the vehicle operator,
eventually additional inducements are typically activated that decrease
the maximum speed or power of the vehicle.  These additional inducements
are intended to create conditions making operational conditions of the
vehicle increasingly unacceptable if the initial dashboard lamp
illumination inducements are persistently ignored.  Similar inducements
may occur in cases where DEF quality does not meet system
specifications, or if the SCR system is not functioning correctly for
another reason.

While decreasing vehicle performance can be an effective inducement
strategy, we believe it may not be appropriate in all situations for
emergency vehicles because of their special need to be ready at any
moment for the purpose of protecting public safety and welfare by saving
human lives that may be in immediate danger.  We recognized this during
the initial implementation of our 2010 NOX standards, and we worked with
the Fire Apparatus Manufacturers’ Association (FAMA), the Ambulance
Manufacturers Division of the National Truck Equipment Manufacturers
Association, and the International Association of Fire Chiefs to support
the publication of a May 18, 2010 memo that instructed emergency vehicle
manufacturers and engine manufacturers to implement less severe
inducement strategies for emergency vehicles.  In this rule we are
taking additional steps so that emergency vehicle manufacturers and
engine manufacturers have the option to further reduce the severity or
eliminate altogether any performance related inducements that are or
could be implemented on emergency vehicles and their engines during
emergency situations.  We believe that this additional flexibility will
help to prevent any abnormal condition of a vehicle’s emission control
system from adversely affecting the speed, torque, or power of an
emergency vehicle during emergency situations.

What Would Occur if EPA Took No Action?

The Industry Would Continue to Get Smarter

Improving the components of diesel particulate filters is the current
subject of research and development activities within the automotive and
air pollution control industries.  Aspects that are being improved
include filter ash storage capacity, filter pressure drop, substrate
durability, catalyst activity, as well as other physical and chemical
properties that can optimize the device for heavy-duty vehicle
applications. 

Engine manufacturers have taken a systems approach, optimizing the
engine with its after-treatment system to realize the best overall
performance possible.  Manufacturers can manage the functioning of the
emission control system by adjusting parameters such as the thermal
profile of the after-treatment system, the exhaust gas chemical
composition, the rate of consumption of DEF, the rate of particle
deposition, and the conditions under which DPF regenerations (soot
cleaning) may occur.

In a broad and general sense, the trend is that DPF’s are slowly
becoming even more robust without EPA intervention.  Future DPF’s will
need fewer total regenerations during the useful life of the engine and
control system, more passive and fewer active regenerations will occur,
and manual regenerations will become rarer. 

In addition, vehicle operators and fleet managers will continue to
become more experienced with this new generation of sophisticated
electronically-controlled vehicles.  Manufacturers across the country
are providing training on actions fleet managers can take to decrease
problems with DPF regenerations. These actions include:

Use low-ash engine oils

Avoid extended idling

Maintain insulation on the exhaust pipe

Maintain the crankcase filter

Periodically operate a vehicle at higher speeds and loads

The Technology & Maintenance Council (TMC) of the American Trucking
Associations conducted a survey in late 2011 to compare user experiences
between EPA 2010, EPA 2007, and EPA 2004 vintage trucks.   According to
TMC, 72 percent of the survey respondents indicated that driver
understanding of the 2007-vintage after-treatment system was worse than
driver understanding of the 2004-vintage after-treatment system, and 33
percent of respondents indicated that driver understanding of the
2010-vintage after-treatment system was worse than driver understanding
of the 2007-vintage after-treatment system.  The responses regarding
driver understanding of fault codes and dash lamps indicated that
drivers have 69 percent poorer understanding of 2007 vs. 2004 fault
codes and dash lamps, and 50 percent poorer understanding of 2010 vs.
2007 fault codes and dash lamps.  We expect that this education
component will gradually improve over time without EPA intervention.

The Fleet Would Continue to Migrate to the 2010 Standards 

Vehicles with 2010-compliant heavy-duty diesel engines tend to place
different demands on their DPF systems than pre-2010 vehicles. With the
addition of NOX after-treatment such as SCR, engines may be tuned to
emit lower engine-out PM (recall the NOX-PM trade-off described above). 
When an SCR system is integrated, it provides the opportunity to run an
engine at lower soot levels and elevated levels of NO2, which is a
chemical species that efficiently oxidizes the soot in the absence of
elevated temperatures.  It is EPA’s expectation that vehicles of MY
2010 and beyond, particularly those using SCR, will generally experience
fewer troubles with DPF’s than the earlier model year vehicles, due to
the nature of the on-board technology as well as the many years of
experience gained by manufacturers since 2007.  The 2011 TMC survey
included an assessment of relative satisfaction levels between EPA 2010,
EPA 2007, and EPA 2004 vintage trucks.  The survey results indicate that
after-treatment durability is better with EPA 2010 trucks compared to
EPA 2007 trucks, with less time out of service.  As an illustration,
according to a Volvo product brochure, the company’s EPA
2010-compliant trucks eliminate the need for active DPF regeneration,
reducing driver involvement with the emission control system, using a
design that allows for the DPF system to reliably oxidize accumulated
soot using continuous passive regeneration. 

Some Trucks Would Continue to Experience Problems

Even though such trends would indicate that instances of emergency
vehicles experiencing difficulty managing regeneration of DPF’s would
decrease, in the absence of this EPA action, some vehicles would be
likely to continue to experience some problems. 

EPA has learned that some engine manufacturers have disabled these
engine protection measures on some emergency vehicles.  In these cases
the manufacturer has reasoned that an operator should be allowed to
remain in control of an emergency vehicle even facing risk of
catastrophic failure, with the consequences of that failure being less
severe than the consequences of the vehicle prematurely losing power,
torque and/or speed while performing emergency services.

Without a clear action from EPA to provide the regulatory flexibility
needed for swift deployment of robust remedies throughout the emergency
vehicle fleet, implementation of best practices could be inconsistent,
insufficient, or even impossible due to regulatory constraints.  Some
vehicles would continue to experience frequent plugging of DPF’s,
frequent forced filter regenerations, and reduced engine power, speed or
torque that diminish the ability of first responders to save lives and
property.  There would also remain a heightened risk that an emergency
vehicle could be taken out of service when it is most needed.

Regulatory Action

As described above in Section III.C, many DPF-equipped vehicles include
engine controls and driver alerts that lead to decreases in maximum
speed, torque, or power when DPF backpressure exceeds normal levels, as
protective measures for either the engine or the DPF, or as inducements
for the operator to immediately conduct DPF regeneration.  Similarly,
vehicles equipped with selective catalytic reduction (SCR) systems for
NOX reduction currently have engine controls and driver alerts that lead
to eventual loss of speed, torque, or power when the SCR controls detect
abnormal conditions (such as a malfunction, low DEF levels, etc.), as
inducements to take immediate corrective action to allow the SCR to
function normally.  In most vehicles, these alerts and inducements may
be easily avoided with normal driving and routine maintenance, and if
activated, these inducements would not have any significant effect on
public safety and welfare.  In emergency vehicles, however, should any
of these limits on maximum speed, torque, or power occur while a vehicle
is responding to an emergency, it could be a matter of life or death. 
To address these issues that could otherwise limit the maximum speed,
torque or power of an emergency vehicle’s engine when it is needed
most, EPA is proposing to amend 40 CFR part 86 to revise the definition
of defeat device; add new definitions of emergency vehicle, ambulance
and fire truck; and add new labeling requirements for new on-highway
engines with approved Auxiliary Emission Control Devices for emergency
vehicles. EPA is also amending its regulations at 40 CFR part 1039 to
revise the definition of defeat device, add a new definition of
emergency equipment, and add a new labeling requirement for nonroad
engines with approved Auxiliary Emission Control Devices for emergency
equipment.

In our current regulations, engine manufacturers may request as part of
an application for new engine or vehicle certification, and EPA may
approve, Auxiliary Emission Control Devices, if they are not determined
to be “defeat devices.”  Auxiliary Emission Control Devices, or
AECD’s, are any design element of an engine’s emission control
system that senses temperature, vehicle speed, engine RPM, transmission
gear, manifold vacuum, or any other parameter for the purpose of
activating, modulating, delaying, or deactivating the operation of any
part of the emission control system.  Some AECD’s can temporarily
decrease the effectiveness of an emission control system. This type of
AECD is only permitted in very limited situations, for example, when
such excursions are deemed to be necessary in order to protect the
vehicle, engine, and or emission control system during limited modes of
operation.

A defeat device is a type of AECD that reduces the effectiveness of
vehicle emission controls in situations when such reduction in
effectiveness is not approved or permitted by EPA.  Defeat devices are
not permitted by the Clean Air Act or EPA.  

Approvals of AECD’s are made by EPA on a case-by-case basis.  In
applications for engine certification, manufacturers must include a
detailed description of each AECD to be installed in or on any vehicle
(or engine) covered by the application, as well as a detailed
justification of each AECD that results in a reduction in effectiveness
of the emission control system.  According to 40 CFR
86.094-21(b)(1)(i)(B), EPA may disapprove a request for an AECD based on
consideration of currently available technology.  Use of an unauthorized
or disapproved AECD can be considered a violation of section 203 of the
Act.

In this action, EPA is proposing to revise the definition of defeat
device at 40 CFR 86.004-2, 86.1803-01, and 40 CFR 1039.115 to exclude
AECD’s that apply only for engines on emergency vehicles, where the
need for an AECD is justified in terms of preventing the vehicle or
equipment from losing speed, torque, or power due to abnormal conditions
of the emission control system, or in terms of preventing such abnormal
conditions from occurring during operation related to emergency
response.

In this action, EPA is proposing to define an emergency vehicle as a
vehicle that is an ambulance or a fire truck.  EPA is proposing to adopt
a definition of ambulance consistent with the current U.S. General
Services Administration Star of Life specification.  EPA is proposing to
define fire truck as a vehicle designed to be used under emergency
conditions to transport personnel and equipment and to support the
suppression of fires and mitigation of other hazardous situations,
consistent with the scope of standards for automotive fire apparatus
issued by the National Fire Protection Association.  We are defining
emergency equipment as specialized vehicles to perform aircraft rescue
and firefighting functions at airports, or wildland fire apparatus. 
With these definitions, it is EPA’s intent to include vehicles that
are purpose-built and exclusively dedicated to firefighting,
emergency/rescue medical transport, and/or performing other rescue or
emergency personnel or equipment transport functions related to saving
lives and reducing injuries coincident with fires and other hazardous
situations.  EPA requests comment on whether we should refine or expand
our definition of emergency vehicle within the scope of this action to
include those equipped with heavy-duty diesel engines that serve other
civilian rescue, law enforcement or emergency response functions.  We
are especially interested in information regarding instances of such
vehicles experiencing or risking loss of power, speed or torque due to
abnormal conditions of the emission control system, and how that may
inhibit mission-critical life- and property-saving work.  

EPA is also adopting an associated engine labeling requirement so that
engines with approved emergency vehicle AECD’s will be clearly
identified and distinguished from other similar engines.

As mentioned above in Section III.B, some engine manufacturers currently
specify that when an engine is sold for installation in an emergency
vehicle, some of the default power, torque or speed inducements be
de-activated or set to alternate, less severe settings.  In such
applications, when the DPF system requests regeneration, the warning
lights remain illuminated while the vehicle remains in complete control
of the driver.  In these cases the manufacturer has likely reasoned that
the consequences of catastrophic failure would be less severe than the
consequences of the vehicle prematurely losing power, torque and/or
speed while performing emergency services.  EPA has granted related
AECD’s in the past.

However, without the optional flexibilities provided by EPA in this
action, manufacturers could be prevented from implementing truly
failsafe solutions for all affected vehicles.  For example, while
current custom solutions may allow an emergency vehicle to continue
pumping water or transporting a person to safety, its DPF would continue
to accumulate particles and the risk of catastrophic failure would
increase.

In this action, EPA is adopting amendments so that manufacturers can
apply for (and EPA can approve) AECD’s that may be justified in terms
of preventing the occurrence of abnormal conditions of the emission
control systems for emergency vehicles or in terms of preventing the
engines from losing speed, torque, or power due to such abnormal
conditions.  In this context, EPA would consider abnormal conditions to
be parameters outside normal ranges for proper operation, such as
excessive exhaust backpressure from high soot loading on a DPF or
insufficient DEF for use with an SCR system. 

EPA is encouraging manufacturers to apply for AECD’s that are tailored
for engines on emergency vehicles, considering the duty cycle
information presented in the accompanying NPRM, along with any other
information needed to design failsafe emission control systems for new 
emergency vehicles. EPA is also encouraging manufacturers to design
field modifications to address these issues on in-use emergency
vehicles, including those whose engines are no longer in production.
Further discussion of field modifications is provided below in Section
III.E(2).

To achieve these goals, EPA understands that increased flexibility will
be needed because EPA’s strict NOX and PM standards present many
design constraints.  Below we describe some solutions that EPA believes
it could approve as part of an emergency vehicle AECD or field
modification, as adopted.  EPA is encouraging engine manufacturers to
apply for emergency vehicle AECD’s and/or field modifications for
in-use emergency vehicles for which service disruptions related to
abnormal conditions of emission control systems may occur or have
occurred.  EPA suggests that such AECD’s or field modifications could
include, but are not limited to, one or more of the following
strategies:

Liberalized Regeneration Requests

It is current practice that most modern diesel engine ECM’s are set to
initiate an automatic active regeneration only above a designated DPF
soot load, and those vehicles equipped with manual regeneration switches
are set to not allow the option of initiating manual active regeneration
until an even greater soot load is detected.  The reason why
manufacturers do this is related to certification of engine families and
vehicle test groups. If manufacturers can limit the frequency of
regenerations by design, then they can be assured that average emissions
will remain below the certified average emission level.  Excess
regenerations could lead to higher average emissions, since some exhaust
emissions increase during regeneration.  Particularly for engines not
equipped with SCR systems, NOX emissions can increase by an order of
magnitude during regeneration, and these temporary increases in emission
are accounted for in EPA’s certification process.  See the
accompanying NPRM for more information about the emissions impacts of
DPF regenerations.  In addition, excess regenerations could shorten the
useful life of the DPF system since high temperatures place stress on
filter substrates.  

EPA believes that emergency vehicle AECD’s that enable more frequent
automatic active and manual active DPF regenerations, associated with a
wider range of soot loads could improve the reliability of DPF systems
without significantly compromising emissions reductions or durability. 
As explained below Section III.E(4), EPA does not expect this provision
to affect other aspects of certification.  For emergency vehicles with
approved AECD’s that involve changes in the frequency of regeneration,
the resulting increase in NOX emissions will not be counted against
certification levels for applicable engine families or vehicle test
groups.  Furthermore, emissions certification testing may be conducted
with any approved AECD’s for emergency vehicle or equipment
deactivated.  According to EPA’s current engine certification data,
engines from MYs 2008 and 2011 have an average maximum automatic active
regeneration frequency near 20 percent, with the typical frequency
between three and seven percent.  Those with frequencies near zero rely
almost exclusively on passive regeneration.  

Engine Recalibration 

As mentioned above, in-cylinder combustion chemistry dictates a NOX-PM
trade-off where engines calibrated to reduce in-cylinder NOX tend to
have higher PM levels. These factors lead to higher rates of particle
accumulation and lower rates of particle oxidation on filters.  EPA
believes that AECD’s that incorporate engine calibration modifications
could enable operation in a “low soot mode” with a reduced rate of
particle deposition that would lead to more frequent and effective
passive regenerations.  Such calibration modifications could also extend
the operating time between all types of regenerations, improve active
regeneration effectiveness, and boost reliability of the DPF systems. 
On engines with downstream (i.e., SCR) NOX controls, SCR control could
be modulated such that engine recalibration would not significantly
affect NOX emissions.  On engines without downstream NOX controls, EPA
believes that some degree of increased NOX emissions during the
conditions justified by the AECD would be approvable for emergency
vehicles.  As explained below in Section III.E(4), EPA does not expect
this provision to affect other aspects of certification.  When
manufacturers calculate the average NOX emissions during a test cycle,
they incorporate data regarding both the frequency of regeneration and
the increase in NOX emissions during regeneration. For emergency
vehicles with approved AECD’s that involve recalibration to alter
regeneration frequency or average NOX emissions, the resulting increase
in NOX emissions will not be counted against certification levels for
applicable engine families or vehicle test groups.  Furthermore,
emissions certification testing may be conducted with any approved
AECD’s for emergency vehicle or equipment deactivated.  A discussion
of the estimated emissions impacts of recalibration is provided in the
Notice of Proposed Rulemaking published elsewhere in today’s Federal
Register.

Backpressure Relief

It is EPA’s objective that all of our clean diesel emissions standards
be implemented with reliable technologies that require a minimum amount
of driver intervention and do not compromise the utility of vehicles. 
EPA understands that manufacturers are motivated to seek design
solutions that are cost effective and easily deployable.  However, by
focusing solely on preventive measures such as those described above,
manufacturers may not achieve a completely failsafe DPF strategy on all
emergency vehicles.  EPA anticipates that some vehicles may benefit from
an additional failsafe measure that relieves engine exhaust backpressure
as a last resort to prevent loss of engine speed, torque or power. 
There are products on the market today that could be configured to
temporarily relieve excessive engine exhaust backpressure when detected,
then return the system to normal at the instant that backpressure
returns to a safe level.  Such a device may be justified as a failsafe
measure, and may be included as part of an overall strategy that also
includes preventive measures, if justified and properly limited, where
excess PM emissions would be expected to be emitted only during a small
fraction of vehicle operation.  That is, the vast majority of DPF
operating cycles would be expected to have continuous PM emission
control, while any temporary backpressure relief that reduced PM control
or allowed bypass of controls would be expected relatively infrequently.

What Engines and Vehicles Are Affected?

Today’s action applies to new and in-use fire trucks and ambulances,
new and in-use airport fire apparatus and wildland fire apparatus, and
heavy-duty diesel engines on these emergency vehicles and equipment.

Newly Certified Engines

Of those new diesel engines covered by EPA’s current heavy-duty diesel
standards, only those installed in vehicles or equipment meeting the
definition of emergency vehicle or emergency equipment will be eligible
to obtain an approved AECD of the type discussed above in Section III.D.
 Where a vehicle is chassis-certified and either sold as an incomplete
vehicle to a truck body manufacturer or built and sold as a complete
vehicle, only those sold and built as emergency vehicles will be
eligible to obtain an approved AECD of the type discussed above. 

Certified Engines and Vehicles In-Use

To address in-use engines and vehicles, EPA plans to allow engine and
vehicle manufacturers to submit requests for EPA approval of Emergency
Vehicle Field Modifications (EVFMs) for on-highway emergency vehicles
and Emergency Equipment Field Modifications (EEFMs) for nonroad
emergency equipment.  EVFMs and EEFMs will be modifications to existing
hardware and software to be installed on in-use vehicles or equipment to
prevent loss of speed, torque, or power due to abnormal conditions of
emission control systems, or to prevent such abnormal conditions from
occurring, during vehicle or equipment operation related to emergency
response.  EPA will use an approval process similar to the process that
is currently utilized to submit modifications to current applications
for certification, also known as “running changes.”  The information
submitted by a manufacturer to EPA as part of this request and approval
process will be similar to the information submitted for emergency
vehicle or equipment AECD’s.

  It is important to emphasize that this action will allow only those
approved modifications to be deployed by manufacturers and their
authorized dealers.  Modifications made by end users are not generally
approvable; rather the tampering prohibitions would generally apply to
such modifications.

EPA has identified three types of field modifications that will be
permitted for emergency vehicles and emergency equipment under the final
regulations, based on the extent to which the modification is being
incorporated into new production vehicles and equipment.  The three
types are: 

	Type A: Any field modification that is a change to a certified
vehicle (i.e., a vehicle, engine or equipment covered by a certificate
of conformity) that is identical in all respects to a running change
that is approved for incorporation in new vehicles by the manufacturer.
Where the running change was approved by EPA for implementation only in
conjunction with certain other
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	Type B: Any field modification that is not identical in all respects
to, but provides for essentially the same purpose as, a running change
that is being incorporated in new vehicles by the manufacturer or that
would have been incorporated if the vehicle were still in production. A
Type B field modification is used when it is not practical to
incorporate the exact running change in vehicles that have left the
assembly line, or when the vehicles are no longer in production.

	Type C: Any field modification that is made selectively only to
vehicles which have left the assembly line and which would not have been
incorporated on the assembly line.  For example, this would apply when
making a field modification to a vehicle that is no longer in production
where there are no similar vehicles in production.

The amount of justification needed for the field modification differs
depending on which type of modification is being requested.

Labeling Requirements

Because the engines and vehicles eligible for the AECD’s described in
this proposal belong to broadly certified engine families and test
groups, when they are sold for installation in an emergency vehicle and
equipped with one or more approved emergency vehicle AECD’s, they must
be labeled as such, to distinguish them from other certified engines. 
EPA is proposing adding a labeling requirement to 40 CFR part 86 subpart
A, such that engines with one or more approved AECD’s for emergency
vehicle applications must be labeled with the statement: “THIS ENGINE
IS FOR INSTALLATION IN EMERGENCY VEHICLES ONLY.”  EPA is also
proposing adding a labeling requirement to 40 CFR part 86 subpart S,
such that vehicles with one or more approved AECD’s for emergency
vehicles, include the following statement on the emission control
information label: “THIS VEHICLE HAS A LIMITED EXEMPTION AS AN
EMERGENCY VEHICLE.”  EPA is also adding a labeling requirement to 40
CFR part 1039, such that nonroad engines with one or more approved
AECD’s for emergency equipment include a label with the following
statement: “THIS ENGINE IS FOR INSTALLATION IN EMERGENCY EQUIPMENT
ONLY.”

EPA requests comment on whether these labeling requirements are
satisfactory to ensure that engines and vehicles operating with approved
emergency AECD’s are permanently distinguished from similar certified
engines.  EPA also requests comment on whether a similar label should be
required for an in-use emergency vehicle or equipment where a field
modification is deployed that prevents the engine from losing speed,
torque, or power due to any occurrences of abnormal conditions of the
emission control system, or prevents such abnormal conditions from
occurring.

Other Regulatory Provisions

Today’s rule will not alter the tampering prohibition in 40 CFR
1068.101(b)(1).  This provision describes a general prohibition against
anyone from removing or rendering inoperative an engine’s emission
controls before or after entering into service, where an exception is
provided in 1068.101(b)(1)(ii) for engine modifications needed to
respond to a temporary emergency, provided that the engine is restored
to proper functioning as soon as possible after the emergency has
passed.  EPA encourages manufacturers to design their emergency vehicle
AECD’s to be engaged only to the extent necessary to prevent the
engine from losing speed, torque, or power due to abnormal conditions of
the emission control system, or to prevent such abnormal conditions from
occurring during operation related to emergency response.  EPA
recognizes that there may be cases where an AECD may need to be engaged
at times other than while actively responding to an emergency, in order
to assure that loss of speed, torque or power does not occur during
operation related to emergency response.  EPA also recognizes that some
AECD’s may involve electronic approaches where the engine’s
functions would be modulated based on exhaust backpressure or other
parameters that are not correlated with any emergency situation.  EPA
may even, in extreme cases, such as at high altitude or with certain
older MY engines allow engagement of AECD’s at all times, if they are
justified as necessary to prevent engine from losing speed, torque, or
power during operation related to emergency response.  

We are also encouraging manufacturers to design their emission control
systems to discourage tampering.  According to EPA’s tampering
prohibition, a vehicle operator who abuses or alters an approved AECD
may be guilty of tampering.  For example, if an AECD includes enabling
an operator to initiate more frequent manual active regenerations,
engine manufacturers may choose to prevent the abuse of this function by
means such as a daily or weekly cap on the number of manual active
regenerations, or a minimum soot loading for the function to engage.  As
another example, if an emergency vehicle alerts a driver to an abnormal
condition of its emission control system by illuminating dash lamps,
alarms or other warnings that do not limit vehicle performance, it is
the operator’s responsibility to take prompt action to remedy the
problem.  If an operator disregards such warnings beyond the time needed
to respond to the emergency, this may be considered tampering.  It is
important to note that if an emergency vehicle is not equipped to ever
allow an operator to initiate a manual active regeneration, this may in
practice encourage tampering by the end user.

Manufacturers of highway and nonroad engines will be required to
describe any emergency vehicle AECD in an application for certification.
 In this action, we are not proposing any revisions to the information
needed to review and approve AECD’s.  It is common practice for
manufacturers, in describing AECD’s, to identify engine parameters
such as those that would operate differently to preserve adequate engine
performance during an emergency, including information about how the
engine would respond under different in-use operating conditions under
the various sets of conditions that would otherwise cause the engine to
operate at less than full performance levels. Other than the requirement
for a manufacturer to describe the emergency vehicle AECD in its
application for certification, we do not expect this provision to be
relevant for other aspects of certification.  For example, emissions
certification testing may be conducted with any approved AECD’s for
emergency vehicle or equipment deactivated.  Additionally, manufacturers
do not need to consider emergency vehicle AECD’s when developing
infrequent regeneration adjustment factors (IRAFs) or when developing
deterioration factors (DFs).  Thus, manufacturers can include emergency
and non-emergency engines and vehicles in the same engine families and
test groups.  Manufacturers may also apply for emergency vehicle
AECD’s for new, existing, and/or formerly approved emissions
certificates.  

Economic Impacts

EPA expects the economic effects of this rule to be small, and to
potentially have benefits that are a natural result of easing
constraints.

Costs to Manufacturers

Due to the optional and voluntary nature of this action, there are no
direct regulatory compliance costs to engine manufacturers.  To the
extent manufacturers elect to develop and deploy upgrades to engines for
emergency vehicles, they may voluntarily incur some degree of costs
associated with the following:

Design and testing to determine effectiveness of potential AECDs

Education & outreach to intermediate vehicle manufacturers and end users

Deployment of AECDs onto new and in-use emergency vehicles

Labeling costs

EPA expects any fixed costs will be small, and any variable costs will
apply only to the engines sold for installation in emergency vehicles or
emergency equipment, which comprise less than one percent of the
heavy-duty on-road fleet, and an even smaller fraction of the nonroad
fleet. As per standard practice, manufacturers would be free to set a
fair market price for any approved AECD they offer, to offset the costs
incurred in its development. 

Operational Costs

Depending on the type of AECD or field modification that a manufacturer
voluntarily elects to deploy, some operational costs could increase and
some could decrease.

When an emergency vehicle is experiencing frequent plugging of its DPF,
this increases maintenance costs for owners and warranty costs for
manufacturers.  These costs are expected to decrease with this action. 
Furthermore, EPA believes that the potential for reduced warranty costs
may help to offset the cost to produce and deploy any optional AECD’s.
 Similarly, EPA believes the potential for reduced maintenance and
operational costs may offset the cost to owners for obtaining requested
AECD’s. 

Where DPF systems employ fuel dosing to enable active automatic
regenerations, it is uncertain whether liberalizing the parameters for
initiating regenerations would affect fuel consumption, and whether fuel
consumption would increase with an increased number of regenerations
during a given operating period.  To the extent regenerations are
enabled with other means besides fuel, or demand for regenerations is
reduced through recalibration, then any potential increase in fuel use
from dosing would be mitigated.  Further discussion of operational costs
including costs of fuel dosing is provided in the Notice of Proposed
Rulemaking published elsewhere in Today’s Federal Register.

Societal Costs

Because this rule eases constraints on the development of robust DPF
systems, the economic impacts can only improve with this action.  It is
presumed that the benefits to society of enabling first responders to
act quickly when needed outweigh the costs to society of the temporary
increase in emissions from this small segment of vehicles.

Environmental Impacts

We expect any environmental impacts from this action will be small. By
promulgating these amendments, it is expected that the emissions from
this segment of the heavy-duty fleet will not change significantly.

EPA estimates that on-road emergency vehicles comprise less than one
percent of the national heavy-duty fleet.  According to the
International Council on Clean Transportation (ICCT), less than one
percent of all new heavy-duty truck registrations in 2003 to 2007 were
for emergency vehicles (includes class 8 fire trucks plus other class
3-8 emergency vehicles).  On average, the ICCT’s data suggest that
approximately 5,700 new emergency vehicles are sold in the U.S. each
year; about 0.8 percent of the 3.4 million new heavy-duty trucks
registered between 2003 and 2007.  The available information indicates
that the emergency vehicles included in the scope of this rulemaking
have lower annual vehicle miles traveled than average non-emergency
vehicles.  Therefore, we conclude that they contribute less than 1% of
the annual air emissions from the heavy-duty diesel truck fleet.

Due to the optional and voluntary nature of this action, it is difficult
to estimate its overall emissions impact accurately. The amendments
offer many options to manufacturers, and the emissions impacts will
depend on which options and strategies are employed, and for how many
vehicles. Further discussions of potential NOX and PM emissions impacts
and fuel consumption from dosing are provided in the Notice of Proposed
Rulemaking published elsewhere in Today’s Federal Register.

Health Effects

EPA’s clean diesel standards are already providing substantial
benefits to public health and welfare and the environment through
significant reductions in emissions of NOX, PM, nonmethane hydrocarbons
(NMHC), carbon monoxide, sulfur oxides (SOX), and air toxics. We project
that by 2030, the on-highway program alone will reduce annual emissions
of NOX, NMHC, and PM by 2.6 million, 115,000 and 109,000 tons,
respectively.  These emission reductions will prevent 8,300 premature
deaths, over 9,500 hospitalizations, and 1.5 million work days lost. 
All told, the monetized benefits of the on-highway rule plus the nonroad
diesel Tier 4 rule total over $150 billion. A sizeable part of the
benefits in the early years of these programs has come from large
reductions in the amount of direct and secondary PM emitted by the
existing fleet of heavy-duty engines and vehicles, by requiring the use
of the higher quality diesel fuel in these vehicles.  While this final
action may slightly increase some emissions, as explained in the
previous section, we do not expect that these small increases will
significantly diminish the health benefits of our stringent clean diesel
standards.

Statutory and Executive Order Reviews

Executive Order 12866: Regulatory Planning and Review 

This action is not a “significant regulatory action” under the terms
of Executive Order (EO) 12866 (58 FR 51735, October 4, 1993) and is
therefore not subject to review under Executive Orders 12866 and 13563
(76 FR 3821, January 21, 2011).

Paperwork Reduction Act

This action does not impose any new information collection burden. The
regulatory relief for emergency vehicles is voluntary and optional, and
the revisions for engine and vehicle maintenance merely codify existing
guidelines. However, the Office of Management and Budget (OMB) has
previously approved the information collection requirements contained in
the existing regulations under the provisions of the Paperwork Reduction
Act, 44 U.S.C. 3501 et seq. and has assigned OMB Control Numbers
2060-0104 and 2060-0287. The OMB control numbers for EPA’s regulations
in 40 CFR are listed in 40 CFR part 9.

Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) generally requires an agency to
prepare a regulatory flexibility analysis of any rule subject to notice
and comment rulemaking requirements under the Administrative Procedure
Act or any other statute unless the agency certifies that the rule will
not have a significant economic impact on a substantial number of small
entities.  Small entities include small businesses, small organizations,
and small governmental jurisdictions.

For purposes of assessing the impacts of this rule on small entities,
small entity is defined as: (1) a small business primarily engaged in
shipbuilding and repairing as defined by NAICS code 336611 with 1,000 or
fewer employees (based on Small Business Administration size standards);
 (2) a small business that is primarily engaged in freight or passenger
transportation on the Great Lakes as defined by NAICS codes 483113 and
483114 with 500 or fewer employees (based on Small Business
Administration size standards); (3) a small business primarily engaged
in commercial and industrial machinery and equipment repair and
maintenance as defined by NAICS code 811310 with annual receipts less
than $7 million (based on Small Business Administration size standards);
(4) a small governmental jurisdiction that is a government of a city,
county, town, school district or special district with a population of
less than 50,000; and (5) a small organization that is any
not-for-profit enterprise which is independently owned and operated and
is not dominant in its field.

After considering the economic impacts of today’s rule on small
entities, I certify that this final rule will not have a significant
economic impact on a substantial number of small entities.  

In determining whether a rule has a significant economic impact on a
substantial number of small entities, the impact of concern is any
significant adverse economic impact on small entities, since the primary
purpose of the regulatory flexibility analyses is to identify and
address regulatory alternatives “which minimize any significant
economic impact of the rule on small entities.” 5 U.S.C. 603 and 604.
Thus, an agency may certify that a rule will not have a significant
economic impact on a substantial number of small entities if the rule
relieves regulatory burden, or otherwise has a positive economic effect
on all of the small entities subject to the rule.  

This rule provides regulatory relief related to emergency vehicles.  As
such, we anticipate no costs and therefore no regulatory burden
associated with this rule. We have concluded that this rule will not
increase regulatory burden for affected small entities.	

Unfunded Mandates Reform Act

This action contains no Federal mandates under the provisions of Title
II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C.
1531-1538 for State, local, or tribal governments or the private sector.
 The action imposes no enforceable duty on any State, local or tribal
governments or the private sector.  This direct final rule offers
manufacturers the flexibility to choose whether to use optional AECD’s
based on their strategies for complying with the applicable emissions
standards.  Therefore, this action is not subject to the requirements of
sections 202 or 205 of the UMRA.

This action is also not subject to the requirements of section 203 of
UMRA because it contains no regulatory requirements that might
significantly or uniquely affect small governments.

Executive Order 13132: Federalism

This action does not have federalism implications.  It will not have
substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government, as
specified in Executive Order 13132.  This direct final rule applies to
manufacturers of heavy-duty diesel engines and not to state or local
governments.  Thus, Executive Order 13132 does not apply to this action.

Executive Order 13175: Consultation and Coordination with Indian Tribal
Governments

This action does not have tribal implications, as specified in Executive
Order 13175 (65 FR 67249, November 9, 2000).  This direct final rule
will be implemented at the Federal level and may result in indirect
costs on affected engine manufacturers depending on the extent to which
they take advantage of the flexibilities offered.  Tribal governments
will be affected only to the extent they purchase and use vehicles with
regulated engines.  Thus, Executive Order 13175 does not apply to this
action.

Executive Order 13045: Protection of Children from Environmental Health
and Safety Risks

Executive Order 13045: “Protection of Children from Environmental
Health Risks and Safety Risks” (62 FR 19885, April 23, 1997) applies
to any rule that: (1) is determined to be “economically significant”
as defined under Executive Order 12866, and (2) concerns an
environmental health or safety risk that EPA has reason to believe may
have a disproportionate effect on children.  If the regulatory action
meets both criteria, the agency must evaluate the environmental health
or safety effects of the planned rule on children, and explain why the
planned regulation is preferable to other potentially effective and
reasonably feasible alternatives considered by the agency.

EPA interprets Executive Order 13045 as applying only to those
regulatory actions that are based on health or safety risks, such that
the analysis required under section 5-501 of the Order has the potential
to influence the regulation. This direct final rule is not subject to
Executive Order 13045 because it does not establish an environmental
standard intended to mitigate health or safety risks, and because it is
not economically significant under Executive Order 12866.  

Executive Order 13211: Actions that Significantly Affect Energy Supply,
Distribution, or Use

This action is not subject to Executive Order 13211 (66 FR 28355 (May
22, 2001)), because it is not a significant regulatory action under
Executive Order 12866.

National Technology Transfer Advancement Act

Section 12(d) of the National Technology Transfer and Advancement Act of
1995 (“NTTAA”), Public Law No. 104-113, 12(d) (15 U.S.C. 272 note)
directs EPA to use voluntary consensus standards in its regulatory
activities unless to do so would be inconsistent with applicable law or
otherwise impractical. Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies.  NTTAA directs EPA to provide
Congress, through OMB, explanations when the Agency decides not to use
available and applicable voluntary consensus standards. 

This action does not involve technical standards. Therefore, EPA did not
consider the use of any voluntary consensus standards.	

Executive Order 12898: Federal Actions to Address Environmental Justice
in Minority Populations and Low-Income Populations

Executive Order (EO) 12898 (59 FR 7629 (Feb. 16, 1994)) establishes
federal executive policy on environmental justice.  Its main provision
directs federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission by
identifying and addressing, as appropriate, disproportionately high and
adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.  

EPA has determined that this direct final rule will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations. This action is not
expected to have any adverse environmental impacts.

Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating the
rule must submit a rule report, which includes a copy of the rule, to
each House of the Congress and to the Comptroller General of the United
States. EPA will submit a report containing this rule and other required
information to the U.S. Senate, the U.S. House of Representatives, and
the Comptroller General of the United States prior to publication of the
rule in the Federal Register. A Major rule cannot take effect until 60
days after it is published in the Federal Register. This action is not a
“major rule” as defined by 5 U.S.C. 804(2). This rule will be
effective on [Insert date 60 days from date of publication in the
Federal Register].

List of Subjects

40 CFR Part 85

Confidential business information, Imports, Labeling, Motor vehicle
pollution, Reporting and recordkeeping requirements, Research,
Warranties.

40 CFR Part 86

Administrative practice and procedure, Confidential business
information, Motor vehicle pollution, Reporting and recordkeeping
requirements.

40 CFR Part 1039

Environmental Protection, Administrative practice and procedure, Air
pollution control, Confidential business information, Imports, Labeling,
Penalties, Reporting and recordkeeping requirements, Warranties.

Dated: May 23, 2012 			Lisa P. Jackson

					Administrator

For the reasons set forth in the preamble, the Environmental Protection
Agency amends title 40, chapter I of the Code of Federal Regulations as
follows:

PART 85--CONTROL OF AIR POLLUTION FROM MOBILE SOURCES

  The authority citation for part 85 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart R--[Amended]

Add §85.1716 to subpart R to read as follows:

§ 85.1716   Approval of an emergency vehicle field modification (EVFM).

This section describes how you may implement design changes for an
emergency vehicle that has already been placed into service to ensure
that the vehicle will perform properly in emergency situations.  This
applies for any light-duty vehicle, light-duty truck, or heavy-duty
vehicle meeting the definition of emergency vehicle in 40 CFR 86.004-2
or 86.1803.  In this section, “you” refers to the certifying
manufacturer and “we” refers to the EPA Administrator and any
authorized representatives. 

(a) You must notify us in writing of your intent to install or
distribute an emergency vehicle field modification (EVFM). In some cases
you may install or distribute an EVFM only with our advance approval, as
specified in this section.

(b) Include in your notification a full description of the EVFM and any
documentation to support your determination that the EVFM is necessary
to prevent the vehicle from losing speed, torque, or power due to
abnormal conditions of its emission control system, or to prevent such
abnormal conditions from occurring during operation related to emergency
response.  Examples of such abnormal conditions may include excessive
exhaust backpressure from an overloaded particulate trap, or running out
of diesel exhaust fluid for engines that rely on urea-based selective
catalytic reduction.  Your determination must be based on an engineering
evaluation or testing or both.

(c) You may need our advance approval for your EVFM, as follows:

(1) Where the proposed EVFM is identical to an AECD we approved under
this part for an engine family currently in production, no approval of
the proposed EVFM is necessary.

(2) Where the proposed EVFM is for an engine family currently in
production but the applicable demonstration is based on an AECD we
approved under this part for an engine family no longer in production,
you must describe to us how your proposed EVFM differs from the approved
AECD.  Unless we say otherwise, your proposed EVFM is deemed approved 30
days after you notify us.

(3) If we have not approved an EVFM comparable to the one you are
proposing, you must get our approval before installing or distributing
it.  In this case, we may request additional information to support your
determination under paragraph (b) of this section, as follows:

(i) If we request additional information and you do not provide it
within 30 days after we ask, we may deem that you have retracted your
request for our approval; however, we may extend this deadline for
submitting the additional information.

(ii) We will deny your request if we determine that the EVFM is not
necessary to prevent the vehicle from losing speed, torque, or power due
abnormal conditions of the emission control system, or to prevent such
abnormal conditions from occurring, during operation related to
emergency response.

(iii) Unless we say otherwise, your proposed EVFM is deemed approved 30
days after we acknowledge that you have provided us with all the
additional information we have specified.

(4) If your proposed EVFM is deemed to be approved under paragraph
(c)(2) or (3) of this section and we find later that your EVFM in fact
does not meet the requirements of this section, we may require you to no
longer install or distribute it.

PART 86--CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND
ENGINES

The authority citation for part 86 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart A– [Amended]

  Section 86.004-2 is amended as follows:

a. By adding a definition for “Ambulance” in alphabetical order.

b. By revising the definition for “Defeat device”.

c. By adding definitions for “Diesel exhaust fluid”, “Emergency
vehicle”, and “Fire truck” in alphabetical order.

The additions and revision read as follows:

§ 86.004–2  Definitions.

*	*	*	*	*

	Ambulance has the meaning given in §86.1803.

	Defeat device means an auxiliary emission control device (AECD) that
reduces the effectiveness of the emission control system under
conditions which may reasonably be expected to be encountered in normal
vehicle operation and use, unless:

(1) Such conditions are substantially included in the applicable Federal
emission test procedure for heavy-duty vehicles and heavy-duty engines
described in subpart N of this part;

(2) The need for the AECD is justified in terms of protecting the
vehicle against damage or accident; 

(3) The AECD does not go beyond the requirements of engine starting; or

(4) The AECD applies only for engines that will be installed in
emergency vehicles, and the need is justified in terms of preventing the
engine from losing speed, torque, or power due abnormal conditions of
the emission control system, or in terms of preventing such abnormal
conditions from occurring, during operation related to emergency
response.  Examples of such abnormal conditions may include excessive
exhaust backpressure from an overloaded particulate trap, and running
out of diesel exhaust fluid for engines that rely on urea-based
selective catalytic reduction. 

	Diesel exhaust fluid (DEF) has the meaning given in §86.1803.

	Emergency vehicle means a vehicle that is an ambulance or a fire truck.


	Fire truck has the meaning given in §86.1803.

*	*	*	*	*

Section 86.004-28 is amended by revising paragraph (i)  introductory
text to read as follows:

§ 86.004-28   Compliance with emission standards.

*	*	*	*	*

(i) Emission results from heavy-duty engines equipped with exhaust
aftertreatment may need to be adjusted to account for regeneration
events. This provision only applies for engines equipped with emission
controls that are regenerated on an infrequent basis. For the purpose of
this paragraph (i), the term “regeneration” means an event during
which emission levels change while the aftertreatment performance is
being restored by design. Examples of regenerations are increasing
exhaust gas temperature to remove sulfur from an adsorber or increasing
exhaust gas temperature to oxidize PM in a trap. For the purpose of this
paragraph (i), the term “infrequent” means having an expected
frequency of less than once per transient test cycle. Calculation and
use of adjustment factors are described in paragraphs (i)(1) through (5)
of this section.  If your engine family includes engines with one or
more AECDs for emergency vehicle applications approved under paragraph
(4) of the definition of defeat device, do not consider additional
regenerations resulting from those AECDs when calculating emission
factors or frequencies under this paragraph (i).

*	*	*	*	*

 Section 86.095-35 is amended by revising paragraph (a)(3)(iii)(O) to
read as follows:

§ 86.095-35  Labeling.

(a)	*	*	*

(3) 	*	*	*

(iii)	*	*	*

(O) For engines with one or more approved AECDs for emergency vehicle
applications under paragraph (4) of the definition of “defeat
device” in § 86.004-2, the statement: “THIS ENGINE IS FOR
INSTALLATION IN EMERGENCY VEHICLES ONLY.”

*	*	*	*	*

Subpart B– [Amended]

Section 86.131-00 is amended by adding paragraph (g) to read as follows:

§ 86.131-00   Vehicle preparation.

*	*	*	*	*

(g) You may disable any AECDs that have been approved solely for
emergency vehicle applications under paragraph (4) of the definition of
defeat device.  The emission standards do not apply when any of these
AECDs are active.

Subpart N– [Amended]

Section 86.1305-2010 is amended by adding paragraph (i) to read as
follows:

§ 86.1305-2010   Introduction; structure of subpart.

*	*	*	*	*

(i) You may disable any AECDs that have been approved solely for
emergency vehicle applications under paragraph (4) of the definition of
“defeat device” in § 86.004-2.  The emission standards do not apply
when any of these AECDs are active.

Section 86.1370-2007 is amended by adding paragraph (h) to read as
follows:

§ 86.1370-2007   Not-To-Exceed test procedures. 

*	*	*	*	*

(h) Emergency vehicle AECDs. If your engine family includes engines with
one or more approved AECDs for emergency vehicle applications under
paragraph (4) of the definition of “defeat device” in § 86.1803,
the NTE emission limits do not apply when any of these AECDs are active.

Subpart S– [Amended]

Section 86.1803-01 is amended as follows:

a. By adding a definition for “Ambulance” in alphabetical order.

b. By revising the definition for “Defeat device”.

c. By adding definitions for “Diesel exhaust fluid”, “Emergency
vehicle”, and “Fire truck” in alphabetical order.

§ 86.1803-01  Definitions.

*	*	*	*	*

	Ambulance means a vehicle used for emergency medical care that provides
all of the following:

(1) A driver’s compartment.

(2) A patient compartment to accommodate an emergency medical services
provider and one patient located on the primary cot so positioned that
the primary patient can be given intensive life-support during transit.

(3) Equipment and supplies for emergency care at the scene as well as
during transport.

(4) Safety, comfort, and avoidance of aggravation of the patient’s
injury or illness.

(5) Two-way radio communication.

(6) Audible and visual traffic warning devices.

*	*	*	*	*

	Defeat device means an auxiliary emission control device (AECD) that
reduces the effectiveness of the emission control system under
conditions which may reasonably be expected to be encountered in normal
vehicle operation and use, unless:

(1) Such conditions are substantially included in the Federal emission
test procedure;

(2) The need for the AECD is justified in terms of protecting the
vehicle against damage or accident;

(3) The AECD does not go beyond the requirements of engine starting; or

(4) The AECD applies only for emergency vehicles and the need is
justified in terms of preventing the vehicle from losing speed, torque,
or power due to abnormal conditions of the emission control system, or
in terms of preventing such abnormal conditions from occurring, during
operation related to emergency response.  Examples of such abnormal
conditions may include excessive exhaust backpressure from an overloaded
particulate trap, and running out of diesel exhaust fluid for engines
that rely on urea-based selective catalytic reduction.

*	*	*	*	*

	Diesel exhaust fluid (DEF) means a liquid compound used in conjunction
with selective catalytic reduction to reduce NOx emissions.  Diesel
exhaust fluid is generally understood to conform to the specifications
of ISO 22241.

*	*	*	*	*

	Emergency vehicle means a vehicle that is an ambulance or a fire truck.

*	*	*	*	*

	Fire truck means a vehicle designed to be used under emergency
conditions to transport personnel and equipment and to support the
suppression of fires and mitigation of other hazardous situations.

*	*	*	*	*

  Section 86.1807-01 is amended by adding paragraphs (h) and (i) to read
as follows:

§ 86.1807-01   Vehicle labeling.

*	*	*	*	*

(h) Vehicles powered by model year 2007 through 2013 diesel-fueled
engines must include permanent readily visible labels on the dashboard
(or instrument panel) and near all fuel inlets that state “Use Ultra
Low Sulfur Diesel Fuel Only” or “Ultra Low Sulfur Diesel Fuel
Only”.

(i) For vehicles with one or more approved AECDs for emergency vehicles
under paragraph (4) of the definition of defeat device in § 86.1803,
include the following statement on the emission control information
label: “THIS VEHICLE HAS A LIMITED EXEMPTION AS AN EMERGENCY
VEHICLE.”

§86.1807-07 – [Removed]

  Subpart S is amended by removing §86.1807-07.

  Section 86.1840-01 is amended by revising paragraph (c) to read as
follows:

§ 86.1840-01   Special test procedures.

*	*	*	*	*

(c) Manufacturers of vehicles equipped with periodically regenerating
aftertreatment devices must propose a procedure for testing and
certifying such vehicles, including SFTP testing, for the review and
approval of the Administrator. The manufacturer must submit its proposal
before it begins any service accumulation or emission testing. The
manufacturer must provide with its submittal sufficient documentation
and data for the Administrator to fully evaluate the operation of the
aftertreatment devices and the proposed certification and testing
procedure.

*	*	*	*	*

PART 1039– CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD
COMPRESSION-IGNITION ENGINES

The authority citation for part 1039 continues to read as follows:

Authority: 42 U.S.C. 7401-7671q.

Subpart B– [Amended]

  Section 1039.115 is amended by adding paragraphs (g)(4) and (5) to
read as follows:

§1039.115  What other requirements apply?  TC \l1 " 

*	*	*	*	*

(g) *	*	* 

 (4) The auxiliary emission control device applies only for engines that
will be installed in emergency equipment and the need is justified in
terms of preventing the equipment from losing speed or power due to
abnormal conditions of the emission control system, or in terms of
preventing such abnormal conditions from occurring, during operation
related to emergency response.  Examples of such abnormal conditions may
include excessive exhaust backpressure from an overloaded particulate
trap, and running out of diesel exhaust fluid for engines that rely on
urea-based selective catalytic reduction.  The emission standards do not
apply when any AECDs approved under this paragraph (g)(4) are active.

(5) The auxiliary emission control device operates only in emergency
situations as defined in §1039.665 and meets all of the requirements of
that section, and you meet all of the requirements of that section.

  Section 1039.135 is amended by adding paragraph (c)(15) to read as
follows:

§1039.135  How must I label and identify the engines I produce?  TC \l1
" 

*	*	*	*	*

(c)	*	*	*

(15) For engines with one or more approved auxiliary emission control
devices for emergency equipment applications under §1039.115(g)(4), the
statement: “THIS ENGINE IS FOR INSTALLATION IN EMERGENCY EQUIPMENT
ONLY.”

*	*	*	*	*

Subpart F– [Amended]

Section 1039.501 is amended by adding paragraph (g) to read as follows:

§ 1039.501   How do I run a valid emission test?

*	*	*	*	*

(g) You may disable any AECDs that have been approved solely for
emergency equipment applications under §1039.115(g)(4).  

Section 1039.525 is amended by revising the introductory text to read as
follows:

§ 1039.525   How do I adjust emission levels to account for
infrequently regenerating aftertreatment devices?

This section describes how to adjust emission results from engines using
aftertreatment technology with infrequent regeneration events. For this
section, “regeneration” means an intended event during which
emission levels change while the system restores aftertreatment
performance. For example, exhaust gas temperatures may increase
temporarily to remove sulfur from adsorbers or to oxidize accumulated
particulate matter in a trap. For this section, “infrequent” refers
to regeneration events that are expected to occur on average less than
once over the applicable transient duty cycle or ramped-modal cycle, or
on average less than once per typical mode in a discrete-mode test.  If
your engine family includes engines with one or more AECDs for emergency
equipment applications approved under §1039.115(g)(4), do not consider
additional regenerations resulting from those AECDs when calculating
emission factors or frequencies under this section.

*	*	*	*	*

Subpart G– [Amended]

  Add §1039.670 to subpart G to read as follows:

§ 1039.670   Approval of an emergency equipment field modification
(EEFM).

This section describes how you may implement design changes for
emergency equipment that has already been placed into service to ensure
that the equipment will perform properly in emergency situations.

(a) You must notify us in writing of your intent to install or
distribute an emergency equipment field modification (EEFM). In some
cases you may install or distribute an EEFM only with our advance
approval, as specified in this section.

(b) Include in your notification a full description of the EEFM and any
documentation to support your determination that the EEFM is necessary
to prevent the equipment from losing speed, torque, or power due to
abnormal conditions of its emission control system, or to prevent such
abnormal conditions from occurring during operation related to emergency
response.  Examples of such abnormal conditions may include excessive
exhaust backpressure from an overloaded particulate trap, or running out
of diesel exhaust fluid (DEF) for engines that rely on urea-based
selective catalytic reduction.  Your determination must be based on an
engineering evaluation or testing or both.

(c) You may need our advance approval for your EEFM, as follows:

(1) Where the proposed EEFM is identical to an AECD we approved under
this part for an engine family currently in production, no approval of
the proposed EEFM is necessary.

(2) Where the proposed EEFM is for an engine family currently in
production but the applicable demonstration is based on an AECD we
approved under this part for an engine family no longer in production,
you must describe to us how your proposed EEFM differs from the approved
AECD.  Unless we say otherwise, your proposed EEFM is deemed approved 30
days after you notify us.

(3) If we have not approved an EEFM comparable to the one you are
proposing, you must get our approval before installing or distributing
it.  In this case, we may request additional information to support your
determination under paragraph (b) of this section, as follows:

(i) If we request additional information and you do not provide it
within 30 days after we ask, we may deem that you have retracted your
request for our approval; however, we may extend this deadline for
submitting the additional information.

(ii) We will deny your request if we determine that the EEFM is not
necessary to prevent the equipment from losing speed, torque, or power
due abnormal conditions of the emission control system, or to prevent
such abnormal conditions from occurring, during operation related to
emergency response.

(iii) Unless we say otherwise, your proposed EEFM is deemed approved 30
days after we acknowledge that you have provided us with all the
additional information we have specified.

(4) If your proposed EEFM is deemed to be approved under paragraph
(c)(2) or (3) of this section and we find later that your EEFM in fact
does not meet the requirements of this section, we may require you to no
longer install or distribute it.

Subpart I– [Amended]

  Section 1039.801 is amended by adding definitions for “Diesel
exhaust fluid” and “Emergency equipment” in alphabetical order to
read as follows:

§ 1039.801   What definitions apply to this part?

*	*	*	*	*

	Diesel exhaust fluid (DEF) means a liquid compound used in conjunction
with selective catalytic reduction to reduce NOx emissions.  Diesel
exhaust fluid is generally understood to conform to the specifications
of ISO 22241.

*	*	*	*	*

	Emergency equipment means either of the following types of equipment:

(1) Specialized vehicles used to perform aircraft rescue and
fire-fighting functions at airports, with particular emphasis on saving
lives and reducing injuries coincident with aircraft fires following
impact or aircraft ground fires.

(2) Wildland fire apparatus, which includes any apparatus equipped with
a slip-on fire-fighting module, designed primarily to support wildland
fire suppression operations.

*	*	*	*	*

  Section 1039.805 is amended by adding abbreviations for “DEF”,
“EEFM”, “ISO”, and “SCR” in alphabetical order to read as
follows:

§ 1039.805   What symbols, acronyms, and abbreviations does this part
use?

*	*	*	*	*

DEF	Diesel exhaust fluid.

EEFM	Emergency equipment field modification.

*	*	*	*	*

ISO	International Organization for Standardization (see www.iso.org).

*	*	*	*	*

SCR	Selective catalytic reduction.

*	*	*	*	*

 Control of Air Pollution from New Motor Vehicles:  Heavy-Duty Engine
and Vehicle Standards and Highway Diesel Fuel Sulfur Control
Requirements (66 FR 5001).

 Control of Emissions of Air Pollution from Nonroad Diesel Engines and
Fuel (69 FR 38958).

 In this rule, emergency vehicle is defined as a fire truck or an
ambulance for on-highway applications, and for nonroad applications, we
are defining emergency equipment as specialized vehicles to perform
aircraft rescue and firefighting functions at airports, or wildland fire
apparatus.  See Section III.C and revisions at 40 CFR 86.1803-01 and 40
CFR 1039.801.

 Heavy-Duty Highway Final Rule, December 21, 2000, Response to Comments,
Section 3.2.1, “Technical Feasibility of Engine/Vehicle
Standards//Diesel Engine Exhaust Standards,” page 3-58 to 3-60,
available at
http://www.epa.gov/otaq/highway-diesel/regs/2007-heavy-duty-highway.htm.

 Letter dated February 1, 2001 to C. Whitman, EPA Administrator from G.
Miller, President, National Association of State Fire Marshalls

 See, for example, letter dated October 22, 2009, from Roger Lackore of
the Fire Apparatus Manufacturers’ Association and Randy Hanson of the
Ambulance Manufacturers Division, to Keisha Jennings of EPA.

 See, for example, letter dated October 4, 2011 from Congressman Filner
to EPA Administrator Jackson, and letter dated October 14, 2011, from
Director Cimini of the Southeast Association of Fire Chiefs to EPA
Administrator Jackson.

 Final Regulatory Impact Analysis for the “2007 Heavy-Duty Highway
Rule,” EPA420-R-00-026, December 2000.  Chapter III, Emissions
Standards Feasibility, is available at
http://www.epa.gov/otaq/highway-diesel/regs/ria-iii.pdf

 Final Regulatory Impact Analysis for “Control of Emissions from
Nonroad Diesel Engines,” EPA420-R-04-007, May 2004.  Chapter 4,
Technologies and Test Procedures for Low-Emission Engines, is available
http://www.epa.gov/nonroad-diesel/2004fr/420r04007e.pdf

 See Final RIA Chapter III, Note   NOTEREF _Ref319314940 \h  8 , above.

  EPA’s regulations at 40 CFR 86.004-25(b)(4) for heavy-duty diesel
engine maintenance specify a minimum interval for DPF ash cleanout from
100,000 to 150,000 mi. Many manufacturers design DPF systems with longer
maintenance intervals.

  See http://www.arb.ca.gov/diesel/tru/documents/ashguide.pdf

  See memo dated May 4, 2012, “Diesel Particulate Filter
Regeneration,” Docket ID EPA-HQ-OAR-2011-1032. 

 MECA Diesel Particulate Filter Maintenance: Current Practices and
Experience (June 2005)  HYPERLINK
"http://www.meca.org/galleries/default-file/Filter_Maintenance_White_Pap
er_605_final.pdf"
http://www.meca.org/galleries/default-file/Filter_Maintenance_White_Pape
r_605_final.pdf  

 FAMA 2010, Emergency Vehicle SCR and DEF Inducement Guidelines; 2010
Engine Emissions Control Requirements

 American Trucking Associations, Technology & Maintenance Council, S3
Engine Study Group. Survey conducted Fall 2011, public slides dated
February 2012 available at
http://www.truckline.com/Federation/Councils/TMC/Documents/2012%20Annual
%20Meeting%20and%20Exhibition%20Documents/TMC12A_TECH2.pdf

 See ATA/TMC, Note   NOTEREF _Ref319070126 \h  16 .

 See Volvo 2010 product brochure, “Volvo’s SCR No Regen Engine,”
available at
http://www.volvotrucks.com/SiteCollectionDocuments/VTNA_Tree/ILF/Product
s/2010/09-VTM075_NoRegen_SS_041609.pdf

 See 40 CFR 86.082-2  

 See 40 CFR 86.094-21 and 094-22

 U.S. General Services Administration, Federal Specification for the
Star-of-Life Ambulance, August 1, 2007,  http://www.deltaveh.com/f.pdf.

 See National Fire Protection Association web page. Accessed April 2012
at
http://www.nfpa.org/catalog/product.asp?title=Code-1901-2009-Automotive-
Fire-Apparatus&category%5Fname=&pid=190109&target%5Fpid=190109&src%5Fpid
=&link%5Ftype=search&icid=

 Frequency in percent refers to the fraction of engine test cycles
during which an automatic active regeneration occurs.

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n will not affect certification of engine families or test groups,
EPA’s regulations do offer options to manufacturers who wish to ensure
that emission-related maintenance will occur in use, including visible
signals that are not reset until maintenance occurs. 40 CFR
86.004-25(b)(6)(ii).

 ICCT, May 2009, “Heavy-Duty Vehicle Market Analysis: Vehicle
Characteristics & Fuel Use, Manufacturer Market Shares.”

DRAFT & DELIBERATIVE

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