Page 1 of 77 **6560 -**  **50 -**  **P**

**ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 85, 86 and 1039**  **[EPA -**  **HQ -**  **OAR -**  **2011**

**– 1032; FRL** 

**– 9673**  **- 1]**  **RIN A2060 -**  **AR54** Heav y - 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
co nditions of the emission control sy stem could lead to decreased engine power, speed or torque. The revisions will allow manufacturers to request and EPA to approve modifications to emission control sy stems on emergency vehicles so they

do not interfere wi th the vehicles’ missions. This action is not expected to result in an y 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, unl ess EPA receives adverse comment. I f 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 The provisions that ar e not withdrawn will become effective on **[Insert date 60 days from date of publication in the**  **Federal Register ]**  , notwithstanding adverse comment on an y other provision.Page 2 of 77

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

 www.regulations.gov : Follow the on
- line instructions for submitting comments.

 Email: a - and
- r - docket@epa.gov

 Fax: (202) 566
- 9744

 Mail: Envi ronmental 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 onl y 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 i nstructions on submitting written comments, see the SUPPL EMENTARY IN FORMAT ION 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 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 b y statute. Certain other material, such as cop yri ghted material , will be publicly available only

in hard copy . Publicly

available docket materials are available either electronically in www.regulations.gov or in hard copy at EPA Docket Center, EPA/DC, EPA West, Room 3334, 130 1 Constitution Ave., NW, Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m.,Page 3 of 77

Monday through Friday , excluding legal holiday s. The telephone number for the Public Reading Room is (202) 566
- 1744, and the telephone number for the Ai r 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: 7 34
- 214
- 4788; fax number: 734
- 214
- 4816; email address: steele.lauren (@epa.gov). **SUPPLEMENTARY INFORMATION :**  Wh y 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 an d 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 doc ument 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 setPage 4 of 77

out above, notwithstanding adverse comment on any other provision. We would address all public comments in a subsequent final rul e based on the proposed rule. EPA is publishing this direct final rule to expedite the deploy ment 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 th e action with which you agree and support as written, in addition to any comments regarding suggestions for improvement or provisions with which y ou disagree. In the case of a comment that is otherwise unclear whether it is adverse, EPA would interpret re levant 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 full y supported and most needed today , whi le considering and addressing an y 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 heav y - dut y or nonroad diesel engines that are intended for use in vehicles that serve the emergency response industry , including all t ypes 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 th ese are onl y 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 appl y to you, you may call the person listed in the FOR FURTHER IN FORMAT IO N CONTACT section above.Page 5 of 77 Category NAI CS Code a Examples of Potentially Affected Entities Industry 336111 Motor Vehicle Manufacturers, Engine and Truck Manufacturers 336112 333618 336120 Industry 541514 Commercial Importers of Vehicles and Vehicl e Components 811112 811198 Industry 811310 Engine Repair, Remanufacture, and Maintenance Note: a North American Industry Classification Sy stem (NAICS) **Table of Contents**
I. Overview II. Statutory

Authority

and Regulatory

Background A. Statutory

Authorit y B. Background: 2007 and 2010 NO X and PM Standards (1) On
- Highway

Standards (2) Nonroad Standards III. Emergency

Vehicle Provisions A. Background on Regulation of Emergency Vehicles B. Why is EPA Taking This Action? (1) How Does a DPF Work? (2) Why Are Emergency

Vehicles Having Problems with DPF Regeneration? (3) What Are the Concerns for Emergenc y Vehicles Using SCR? C. What Would Occur if EPA Took No Action? (1) The Industry

Would Continue to Get Smarter (2) The Fleet Would Continue to Migrate to the 2 010 Standards (3) Some Trucks Would Continue to Experience Problems D. Regulatory

Action (1) L iberalized Regeneration Requests ( 2) Engine Recalibration (3) Backpressure Relief E. What Engines and Vehicles Are Affected? (1) Newl y Certified Engines (2) Certi fied Engines and Vehicles In
- UsePage 6 of 77

(3) Labeling Requirements (4) Other Regulatory

Provisions F. Economic Impacts (1) Costs to Manu facturers (2) Operational Costs (3) Societal Costs G. Environmental Impacts H. Health Effects IV . Statutory

and Executive Order Reviews A. Executive Order 12866: Regulatory Planning and Review B. Paperwork Reduction Act C. Regulatory

Flexibility

Act D. Unfunded Mandates Reform Act E. Executive Order 13132: Federalism F. Executive Order 13175: Consultation and Coordination with Indian Tribal Governments G. Executive Order 13045: Protection of Children from Environmental Health and Safety Risks H. Executive Order 13211: Actions that Significantly Affect Energy

Supply , Distribution, or Use I. National Technology

Transfer Advancement Act J. Executive Order 12898: Federal Actions to Address Environmental Justice in Minority Populations and L ow - Income Populations K. Congressional Review Act
**I. Overview**  EPA is adopting amendments to its heavy
- dut y diesel engine programs that will specificall y allow engine manufacturers to request to deploy specific emission controls or settings for new and in
- use engines that are so ld for use only in emergency vehicles. EPA is adopting these revisions to enable fire trucks and ambulances with heav y - dut y diesel engines to perform mission
- critical life
- and propert y - saving work without risk of losing power, speed or torque due to abno rmal conditions of the emission control sy stems.Page 7 of 77 EPA’s current diesel engine requirements have spurred application of emission controls sy stems such as diesel particulate filters (commonly called soot filters or DPF’s) and other after
- treatment sy stems on most new diesel vehicles, including emergency vehicles. Some control sy stem 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 safet y and welfare and the protection of lives and property
. **II. Statutory Authority and Regulatory Background**  **A. 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 contrib utes to air pollution which may reasonably

be anticipated to endanger public health or welfare. Such standards appl y 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, NO X and particulate matter (PM) from heavy
- dut y 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 safet y factors associated with the application of such technology . We may revise such technology
- based standards, taking costs into account, on the basis of informationPage 8 of 77

concerning the effects of air pollution from heav y - 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 s afet y in determining whether an emission control device, sy stem 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 publ ic health, welfare or safety associated with use of such device, sy stem or element of design, as well as the availability of other devices, s ys tems or elements of design which may be used to conform to requirements prescribed by (this subchapter) without c ausing 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 estab lish 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 safet y 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 b y section 213(a)(3)) which “may

reasonabl y be anticipated to endanger public health and welfare.”Page 9 of 77

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. **B. Background: 2007 and 2010 NO**  **X and PM Stand**  **ards (1)**  **On -**  **Highway Standards** On January

18, 2001, EPA published a rule promulgating more stringent standards for NO X and PM for heav y - duty highway engines (“the heavy
- duty highway rule”). 1 The 0.20 gram per brake
- horsepower
- hour (g/bhp
- hr) NO X standard in th e heav y - dut y 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 engine s with NO X emissions greater than 0.20 g/bhp
- hr. The phase
- in provisions ended after MY 2009 so that the 0.20 g/bhp
- hr NO X standard was fully phased
- in for model ye ar 2010. Because of these changes that occurred in MY 2010, the 0.20 g/bhp
- hr NO X emission standard is often referred to as the 2010 NO X emission standard, even though it applied to engines as early as MY 2007. The heav y - duty

highway rule adopted in 2001 also included a PM emissions standard for new heav y - duty diesel engines of 0.01 g/bhp
- hr, e ffective for engines beginning with MY 2007. Due to the flexible nature of the phase
- in schedule described

1 Control of Air Pollution f rom New Motor Vehicles: Heavy
- Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements (66 FR 5001 ).Page 10 of 77

above, manufacturers have had the opportunit y to produce engines that met the PM standard while emitting higher levels of NO X . During the phase
- in ye ars, manufacturers of diesel engines generally produced engines that were tuned so the combustion process inherently

emitted lower engine
- out NO X while relyingon PM after
- treatment to meet the PM standard. The principles of combustion chemistry dictate that conditions yielding lower engine
- out NO X emissions generally result in higher engine
- out PM emissions. This is what we call the NO X - PM trade
- off. For many new low
- NO X diesel engines today , engine
- out PM emissions could be at or above the levels see n 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. **(2) Nonroad Standards**  EPA adopted similar technology
- forcing standards for nonroad diese l engines on June 29, 2004. 2 These are known as the Tier 4 standards. This program includes requirements that will generall y involve the use of NO X 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.

2 Control of Emissions of Air Pollution f rom Nonroad Diesel Engines and Fuel ( 69 FR 38958).Page 11 of 77

**III. Emergency Vehicle Provisions**  **A. Background on Regulation of Emergency Vehicles**  Ty pically , the engines powering our nation’s emergency vehicles belong to the same certified engine families as en gines that are installed in similarly sized vehicles sold for other public and private uses. 3 Historicall y, engine and vehicle manufacturers have sought EPA certification for broad engine families and vehicle test groups that are defined b y similar emissi ons and performance characteristics. Engine families ty picall y only consider the t ype 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 d

uty 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 fi re - fighting apparatus, in the same manner as other engines. In the public comments received on the proposed heav y - dut y highway rule, EPA received some comments about DPF technologies and regeneration cycles on heav y - dut y trucks, including one comment that expressed concerns that the s ys tems may not be

3 In this rule, emergency vehicle is defined as a fire truck or an ambulance for on
- highway applications, and for nonroad applications, w e are defining emergency equipment as specialized vehicles to perform aircraft rescue and firefighting functions at airp orts, or wildland fire apparatus. See Section III.C and revisions at 40 CFR 86.1803
- 01 and 40 CFR 1039.801.Page 12 of 77

failsafe. 4 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 publ ishing the final rule requiring heavy
- dut y 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 i mplementing this new rule, considering that fire departments across the nation have trouble covering basic costs and may not have funds for more expensive trucks. 5 This letter did not raise an y technical feasibility issues, and EPA did not see a need to t ake action. More recentl y 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. 6 Power and speed reduction inducements were new on vehicles equipped with SCR. These were not specificall y mandated b y EPA but designed b y manufacturers to occur if DEF levels became low, to induce operators of the vehicles to perform the required emission
- related maintenance in
u se. More discussion on this, including wh y the emergency response community requested relief and what action EPA took, is found below in Section III.B(3).

4 Heavy
- Duty Highway Final Rule, Dec ember 21, 2000 , Response to Comments, Section 3.2.1 , “ Technical Feasibility of Engine/Vehicle Standards//Diesel Engine Exhaust Standards ,” p age 3
- 58 to 3
- 60, available at http://www.epa.gov/otaq/highway
- diesel/regs/2007
- heavy
- duty
- highway.htm
. 5 Letter dated February 1, 2001 to C. Whitman, EPA Administrator from G. Miller, President, National Association of State F ire Marshalls 6 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
.Page 13 of 77 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. 7 EPA promptly opened a dialogue with the fire chiefs and engine manufacturers to understand the issues. Powe r and speed reductions were occurring on some vehicles with soot filters but without SCR sy stems, in part related to engine protection measures designed by manufacturers. Essentially , these soot filters are supposed to be self
- cleaning b y periodicall y bur

ning off accumulated soot during normal vehicle use. The cleaning process is called regeneration, and when this doesn’t work as designed, the filter graduall y gets more clogged, which can lead to engine problems. EPA has determined that while other pathw ay s are available for resolving some issues related to soot filters on emergency

vehicles, there remains a public safet y issue related to design of engines and emission control sy stems 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 ty pes 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

7 See, for example, letter dated Octob er 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 Ad ministrator Jackson.Page 14 of 77

only applicable to newl y certified engines. They are not applicable to any existing in
- use engines that are alread y deployed in emergency equipment. **B. Why is EPA Taking This Action?**  EPA is amending its regulations to facilitate engine manufacturers’ design and implementati on of reliable and robust emission control sy stems 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 sy stems 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 currentl y a nontrivial number of emergency vehicles that are electronicall y 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 an y problems and some reporting problems that raise public safet y and welfare concerns. EPA’s standards are performance
- based, and reflect the greatest degree of emission reduction achievab le, according to CAA sections 202(a)(3) and 213(a)(3). Our
on - highway

and nonroad PM standards do not specify the ty pe of diesel particulate filter for manufacturers to use, nor do they even mandate the use of such a filter. Our anal ys is of the feasibili ty

of the 2007 on
- highway

PM standard is presented in Chapter III of thePage 15 of 77

final Regulatory

Impact Analy sis (RIA) for that rule. 8 Our anal ys is of the feasibility of the Tier 4 nonroad compression ignition engine standards that will be phasing in through 201 5 is presented in Chapter 4 of that rule’s final RIA. 9 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 b y virtually eliminating harmful PM emissions from the regulated engines. Even so, EPA is required b y sections 202(a)(4)(B) and 213(c) of the Act to, among other things, consider methods for reducing risk to p ublic safety and welfare associated with the use of emission control devices or s ys tems. 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 sy stems when they are deploy ed 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, t orque, 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 vehicl es can perform their emergency

missions without the chance of such consequences.

8 Final Regulatory Impact Analysis for the “ 2007 Heavy
- Duty H ighway 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 9 Final Regulatory Impact Analysis for “ Control of Emissions from Nonroad Diesel Engines ,” EPA420
- R
04
- 007 , May 200 4. Chapter 4, Technologies and Test Procedures for Low
- Emission Engines , is available http://www.epa.gov/nonroad
- diesel/2004fr/420r04007e.pdfPage 16 of 77 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 currentl y a mechanism for manufacturers to deplo y 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 onl y to vehicles that are no longer in product ion. 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 wo uld be remiss if we did not act to ensure that our regulations clearl y offer the needed flexibilities for emergency

vehicles. **(1) 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 ac tion, 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 ph ys ically trap PM and remove it from the exhaust stream. Figure III
- 1 depicts a schematic of a wall
- flow monolith style filter, with th e black arrows indicating exhaust gas laden with particles, and the gray arrows indicating filteredPage 17 of 77

exhaust gas. This style of filter is the most common in today ’s heavy
- dut y diesel engines, and has very

high rates of filtration, in excess of 95 percent. 10

**Figure III**  **- 1**  **Illustration of air flow pattern in a wall -**  **flow monolith style PM filter (Source: Corning)**  To be successful, these devices generall y must be able to accomplish two things: collect PM and cle an away accumulated PM. There are two main t ypes of PM that can accumulate: combustible and non
- combustible, and two very different t ypes of cleaning methods: regeneration and ash cleaning. Regeneration occurs relativel y frequently, and is designed to co mplete the combustion (oxidation) of the trapped combustible PM components, releasing them to the exhaust as gas
- phase compounds (mostly H 2 O and

10 See Final RIA Chapter III, Note 8 , above.Page 18 of 77

CO 2 ). 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 destro yed through regeneration and will alway s 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). 11 , 12 This distinction is made here bec ause 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 ty pe of routine DPF cl eaning that must occur regularl y, 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 involv e extra heat and/or ox ygen or oxygen - containing compounds, this must be done carefully and safel y to avoid uncontrolled burns. The discussion below in Section III.B.(1)(b) describes the three ty pes of routine DPF regeneration: passive regeneration, automatic active regeneration, and manual (parked) active regeneration. Additional discussion is provided in the accompan yi ng Notice of Proposed Rulemaking published elsewhere in today ’s Federal

11 EPA’s regula tions 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. 12 See http://www.arb.ca.gov/diese l/tru/documents/ashguide.pdfPage 19 of 77

Register and in a memorandum to the docket. 13 Below, we discuss th e reason why regeneration is needed at all. (a ) Failure of a DPF When the style of filter installed on a diesel vehicle is the wall
- flow t ype that is predominant in the market today , it phy sicall y traps so much of the PM that the particles accumulate on the i nside 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 st yl es of filter, such as flow
through DPF’s, are less prone to plugging, but do not generall y 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 increasingl y restrictive DPF. However, unle ss the DPF is frequently cleansed of the trapped PM, this increased work demand can lead to reductions in engine performance

13 See me mo dated May 4, 2012, “Diesel Particulate Filter Regeneration,” Docket ID EPA
- HQ
- OAR
2011
- 1032
.Page 20 of 77

and increases in fuel consumption. This loss in performance may be not ic ed by

the vehicle operator in terms of poor acceleration and generall y poor drivability of the vehicle. If a DPF is not regenerated and it becomes plugged, there is a risk of two t ypes of failure. The degree of this risk and which consequence may be experienced will depend on the engine and emission control sy stem 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 i n the filter media to increase beyond its phy sical tole rance, possibl y creating high thermal stresses where the DPF material s could crack or melt. This is an unsafe condition, presenting phy sical danger to occupants as well as to objects and persons near the vehicle. Further, catastrophic failure can allow s ignificant amounts of the diesel PM to pass through the DPF without being captured. That is, the DPF is destro yed and PM emission control is lost. For all these reasons, m ost manufacturers generall y design their emission control sy stems 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.Page 21 of 77 (b ) Types of Regeneration There are three t ypes of routine DPF regeneration. Passive regeneration refers to meth ods 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 sy stems, 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 operat ion 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 ty pes 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 onl y while the vehicle is stationary and out
- of

- service. Vehicles with automatic active regeneration sy stems require operators to be alert to dashboard lamps and indicators. Written instructions are provided to operators to explain what ea ch 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 d ictate an y 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 sy stem. As noted above, it isPage 22 of 77

not uncommon in today ’s heavy
- dut y 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 sy stem protection measures can alert drivers to the need to change driving conditi ons 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 ty picall y all owed 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 regen erations 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 overn ight. 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 sy stems calling for minimal driver interventions, while providing drivers with clear and earl y indicators before an y 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 s ys tems ty pically require suffi cient air flow, temperature and soot accumulation before an automatic active regeneration will be requested b y 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 automaticPage 23 of 77

active regeneration and the extra heat is generated, an ideal DPF s ys tem accomplishes this as a transparent process, with no effects perceivable by the driv er. A variet y 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 th e 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 f ilter 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 catal ys t upstream of the filter or oxidized over a catal yz ed particulate filter to combust accumulated particulate matter.

 Post injection of diesel fuel in the exhaust upstream of an oxidation cataly st and/or catal yz ed particulate filter. This method serves to generate heat used to combustPage 24 of 77 accumulated particulates by oxidizing fuel across a catal ys t present on the filter or on an oxidation cataly st upstream of the filter

 On
- board fuel burners upstream of the filter 14 These are presented here merel y as examples, and are b y 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 heavil y 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 cataly st 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 ty pes of vehicles with engines that use fuel dosing as part of the active regeneration strategy . Estimates of the additi onal fuel use b y a vehicle whose DPF regeneration sy stem employ s 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 a ction 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.

14 MECA Diesel Particulate Filter Maintenance: Current Practices and Experience (June 2005) http://www.meca.org/galleries/default
- file/Filter_Maintenance_White_Paper_605_final.pdfPage 25 of 77 **(2) Why Are Emergency Vehicles Having Problems with DPF Regeneration?**  At the time of promulgation of the heav y - duty highway rule, EPA and the engine manufacturers expected the 2007
- compliant engine emission control sy stems 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 pro blems 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 dut y c ycl e means how it is driven, includi ng 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 whe ther it drives over flat or hilly terrain. Because DPF regeneration requires heat and ox ygen (basic ingredients for combustion), the success of DPF regeneration strategies can also be influenced b y ambient conditions such as extreme cold winter temperatur es 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 NO X and PM emission levels can influe nce how easily

the soot can be oxidized, and how much soot needs to be oxidized and how often.Page 26 of 77 Both the engine’s duty

cycle and the overall control strategy of the engine’s emission control sy stem 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 regul atory action to address these issues. While our approach specificall y targets engine combustion characteristics and emission control sy stem design, we encourage emergency vehicle owners to inquire with their dealers and manufacturers regarding suitable vehicle and engine options that are appropriate for their dut y cycle as well as their demographic and geographic location. (a ) Engine Combustion Characteristics Engine combustion characteristics can be designed to enable continuous passive regeneration or to rel y 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 CO 2 and water, the combustion process needs more heat and ox ygen. Both of these things create NO X because nitrogen (N 2 ) is naturally present in the air and readil y oxidizes at high temperatures. Thus there is a NO X - PM trade
- off of most diesel co mbustion processes (homogeneous charge compression ignition being an exception) where lower combustion temperatures help control NO X but create more PM, and higher temperatures that destro y PM (or prevent it from being created) can generate more NO X .Page 27 of 77 In an engine with a DPF sy stem, combustion settings, or calibrations that enable continuous passive regeneration, tend to be those with higher engine
- out NO X and lower engine
- out PM, partly

because of the higher temperatures that create the NO X , partl y because of the NO X 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 heav y reliance on automatic active regeneration tend to be those with lower engine
- out NO X and higher engine
- out PM, partly because of the lower temperatures, partl y because of a lack of helpful NO X , 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 s ystem that may rel y 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 NO X and relativel y high engine
- out PM. An example of a DPF s ys tem that may rarel y experience automatic active regeneration (and frequently passivel y regenerate), from an engine calibration perspective, would be an engine using SCR t o control NO X, because it could have comparatively high engine
- out NO X and relativel y low engine
- out PM. The SCR after
- treatment would then reduce the high engine
- out NO X to provide very low tailpipe NO X . Thus it is important to note that this NO X - PM trad e - off is a critical design parameter when developing an engine that will be successfull y integrated with a DPF
equipped emission control sy stem. To date, all of the concerns expressed to EPA regarding emergency

vehicles with DPF regeneration issues have b een for vehicles that do not employ

SCR technology , and thus may have higher engine
- out PM. ThePage 28 of 77

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 em ergency vehicle fleet may

experience fewer DPF regeneration troubles as it migrates to engines that use after
- treatment to meet EPA’s 2010 NO X standards. Such a trend may indicate that some engine manufacturers may see a greater need to address in
- use eme rgency vehicles than new vehicles
. (b ) Duty Cycles As noted above, the dut y 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 sy stems 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) t ypically leads to successful passive regeneration of a DPF. An example from a duty
- cycle perspective of a vehicle that frequently experiences automatic passive regenerat ion 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 rarel y that a DPF s ys tem 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
.Page 29 of 77 A detailed discussion of the duty cycles of emergency

vehicles is provided in the Notice of Proposed Rulemaking published elsewhere in Today ’s Feder al Register . The data provided in that discussion indicate that engines on emergency vehicles across the country are commonly

operated over dut y c ycl es that offer very limited opportunities to regenerate DPF’s. It is also important to note that emergency vehicles do not ty picall y get deploy ed on planned duty schedules with predictable blocks of garage time for servicing or maintenance. While some other ty pes of vocational vehicles may have dut y cycles with many

characteristics similar to those shown abov e, emergency vehicles are unique in their need to be ready to deplo y at an y moment for the purpose of protecting public safet y and welfare by saving human lives that may be in immediate danger. When trucks with an engine
- driven PTO are working in a station ary 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 ty

pe of regeneration have been noticed b y operator s. 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 operat ion, 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 s ys tem’s pressure regulation, this may in tur n 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 regu lations alreadyPage 30 of 77

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. Wh ile 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 pro grammed automatic engine start/stop sy stems and hy brids. Automatic start/stop sy stems automaticall y stop and start an engine depending upon whether or not it is needed to suppl y power to the vehicle. This technology is already being implemented on other heav y - duty

vehicles to decrease unnecessary engine idling. Hy

brid drivetrains also decrease engine idling with an integrated alternate power source such as a battery . We are currentl y seeing an increase in the use of h yb rid technologies in heav y - duty die sel vocational vehicles. Garbage trucks, utility company trucks, and other work trucks are using h ybrid technology to power on
- board hydraulic sy stems and cab heating and cooling s ys tems. In conventional vehicles these s ystems are powered b y a main engin e ty picall y 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 i s 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 emergenc y 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 specificPage 31 of 77

action at this time related to decreasing the amount of time eme rgency vehicles operate at light load or at idle, in the accompan yi ng NPRM, we request comment on the potential for application of alternate power sources and idle reduction technologies on emergency vehicles. **(3) What Are the Concerns for Emergency Vehicles U**  **sing SCR?** Selective Catal yt ic Reduction (SCR) is an exhaust after
- treatment s ys tem used to control NO X emissions from heavy
- dut y engines by converting NO X into nitrogen (N 2 ) and water (H 2 O). The technology depends on the use of a catal yt ic 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 chos e to compl y with the 2010 NO X emission standard b y adding SCR to their engine models. In general, the approach with an SCR sy stem has been a sound and cost effective pathway to compl y with EPA’s 2010 emissions standards, and it is the primary path being u sed today
. DEF is injected into the exhaust upstream of the SCR cataly st where it forms ammonia and carbon dioxide. The ammonia then reacts with NO and NO 2 , so that one molecule of urea can reduce two molecules of NO or one molecule of NO 2 . A robust SCR sy stem can achieve about 90 percent reduction in cycle
- weighted NO X emissions. Improvements have been made over the last several y ears to improve the NO X conversion rate and reduce the impact of lower exhaust temperatures on the conversion efficiency
.Page 32 of 77 Bec ause an SCR sy stem 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. Thes e operator inducements generall y 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 b y the vehicle operator, eventuall y ad ditional inducements are t ypicall y 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 increasingl y unacceptable if the initial dashboard lamp illumination inducements are persistentl y i gnored. Similar inducements may

occur in cases where DEF quality does not meet sy stem specifications, or if the SCR sy stem is not functioning correctly for another reason. While decreasing vehicle perf ormance 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 an y moment for the purpose of protecting public safety and welfare b y saving human l ives that may be in immediate danger. We recognized this during the initial implementation of our 2010 NO X standards, and we worked with the Fire Apparatus Manufacturers’ Association (FAMA), the Ambulance Manufacturers Division of the National Truck Equip ment Manufacturers Association, and the International Association of Fire Chiefs to support the publication of a May 18, 2010Page 33 of 77

memo that instructed emergency vehicle manufacturers and engine manufacturers to implement less severe inducement strategies for e mergency vehicles. 15 Inthis rule we are taking additional steps so that emergency vehicle manufacturers and engine manufacturers have the option to further reduce the severit y or eliminate altogether an y performance related inducements that are or could b e 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 sy stem from adversely

affecting the speed, torque, o r power of an emergency vehicle during emergency

situations. **C. What Would Occur if EPA Took No Action?**  **(1) The Industry Would Continue to Get Smarter**  Improving the components of diesel particulate filters is the current subject of research and development activi ties within the automotive and air pollution control industries. Aspects that are being improved include filter ash storage capacity , filter pressure drop, substrate durability , catal ys t activity, as well as other ph ys ical and chemical properties that can optimize the device for heav y - dut y vehicle applications. Engine manufacturers have taken a s ys tems approach, optimizing the engine with its after
- treatment s ys tem to realize the best overall performance possible. Manufacturers can manage the functioning of the emission control sy stem by adjusting parameters such

15 FAMA 2010, Emergency Vehicle SCR and DEF Inducement Guidelines; 2010 Engine Emissions Control RequirementsPage 34 of 77

as the thermal profile of the after
- treatment sy stem, the exhaust gas chemical composition, the rate of consumption of DEF, the rate of particle deposition, and the conditions under which DPF reg enerations (soot cleaning) may occur. In a broad and general sense, the trend is that DPF’s are slowl y becoming even more robust without EPA intervention. Future DPF’s will need fewer total regenerations during the useful life of the engine and control s y stem, 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 electronicall y - c ontrolled 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 exh aust 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 EPAPage 35 of 77

2010, EPA 2007, and EPA 2004 vintage trucks. 16 According to TMC, 72 percent of the survey respondents indicated that driver understanding of the 2007
- vintage after
treatment s ys tem was worse than driver understanding of the 2004
- vintage after
treatment s ys tem, and 33 percent of respondents indicated that driver understanding of the 2010
- vintage after
- treatment sy stem was worse than driver understanding of the 2007
- vintage after
- treatment sy stem. The responses regarding driver understanding of fault codes and d ash 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 graduall y impr ove over time without EPA intervention. **(2) The Fleet Would Continue to Migrate to the 2010 Standards**  Vehicles with 2010
- compliant heavy
- dut y diesel engines tend to place different demands on their DPF s ystems than pre
- 2010 vehicles. With the addition of NO X after
treatment such as SCR, engines may be tuned to emit lower engine
- out PM (recall the NO X - PM trade
- off described above). When an SCR sy stem is integrated, it provides the opportunity

to run an engine at lower soot levels and elevated levels of NO 2 , wh ich 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, particularl y those using SCR, will generall y experience fewer troubles with DPF’s than the e arlier

16 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%20M eeting%20and%2 0Exhibition%20Documents/TMC12A_TECH2.pdfPage 36 of 77

model y ear vehicles, due to the nature of the on
- board technology as well as the many ye ars 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. 17 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 sy stem, using a design that allows for the DPF sy stem to reliabl y oxidize accumulated soot using continuous passive regeneration. 18 **(3) Some Trucks Would Continue to Experience Problems**  Even though such trends would indicate that instances of emergency vehicles experiencing difficult y managing regeneration of DPF’s would decrease, in the absence of this EPA action, some vehicles would be likel y 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 r emain in control of an emergency vehicle even facing risk of catastrophic failure, with the consequences of that failure being less

17 See AT A/TMC, Note 16
. 18 See Volvo 2010 product brochure, “Volvo’s SCR No Regen Engine,” available at http://www.volvotrucks.com/SiteCollectionDocuments/VTNA_Tree/ILF/Pro ducts/2010/09
- VTM075_NoRegen_SS_041609.pdfPage 37 of 77

severe than the consequences of the vehicle prematurely losing power, torque and/or speed while performing emergency service s. Without a clear action from EPA to provide the regulatory flexibility

needed for swift deploy

ment 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. **D. Regulatory Action**  As described above in Section III.C, man y DPF
- equipped vehicles include engine controls and driver alerts that lead to de creases 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 catal yt ic reduction (SCR) sy stems for NO X reduction currentl y 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, et c.), as inducements to take immediate corrective action to allow the SCR to function normally . In most vehicles, these alerts and inducements may be easil y avoided with normal driving and routine maintenance, and if activated, these inducements would not have an y significant effect onPage 38 of 77

public safet y 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 vehicl e, 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 d evice, 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 an y design element of an engine’s emission control sy stem that senses temperature, vehicle speed, engine RPM, transmission gear, manifold vacuum, or an y other parameter for the purpose of activating, modulating, delaying, or deactivating the operation of any part of the emission control sy stem. 19 S ome AECD’s can temporaril y decrease the effectiveness of an emission control sy stem. This ty pe of AECD is only

permitted in very

limited situations, for example, when such

19 See 40 CFR 86.082
- 2Page 39 of 77

excursions are deemed to be necessary in order to protect the vehicle, engine, and o r emission control sy stem during limited modes of operation. A defeat device is a ty

pe 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 devic es are not permitted by the Clean Air Act or EPA. Approvals of AECD’s are made b y 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 sy stem. According to 40 CFR 86.094
- 21(b)(1)(i)(B), EPA may disapprove a request for an AECD based on consideration of currentl y available technology . Use of an unauthorized or disapproved AECD can be considered a violation of section 203 of the Act. 20 In this action, EPA is proposing to revise the definition of defeat device at 40 CFR 86.004
- 2, 86.180 3
- 01, and 40 CFR 1039.115 to exclude AECD’s that appl y 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 emi ssion control sy stem, or in terms of preventing such abnormal conditions from occurring during operation related to emergency response.

20 See 40 CFR 86.094
- 21 and 094
- 22Page 40 of 77 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 L ife specification. 21 EPA is proposing to define fire truck as a vehicle designed to be used under emergency

conditions to transport pe rsonnel 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. 22 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 firefighti ng, 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 especiall y interested in information regarding instances of such vehicles experiencing or risking loss of power, speed or torque due to abnormal

21 U.S. General Services Administration, Federal Specification for the Star
- of
- Life Ambulance, August 1, 2007, http://www.deltaveh.com/f.pdf
. 22 See Nationa l 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=Page 41 of 77

conditions of the emission control sy stem, and how that may inhibit mission
- critical life
and propert y - saving work. E PA 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 cur rentl y 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 s ys tem requests regen eration, the warning lights remain illuminated while the vehicle remains in complete control of the driver. In these cases the manufacturer has likel y 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 imple menting trul y 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 safet y, its DPF would continue to accumulate particles and the ris k 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 sy stems for emergencyPage 42 of 77

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 sy stem.EPA is encouraging manufacturers to appl y for AECD’s that are tailored for engines on emergency

vehicles, considering the duty cycle in formation presented in the accompan yi ng NPRM, along with any other information needed to design failsafe emission control sy stems 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 E PA’s strict NO X 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 appl y 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 sy stems may occur or have occurred. EPA suggests that such AECD’s or field modification s could include, but are not limited to, one or more of the following strategies:Page 43 of 77 **(1) 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 wh y manufacturers do this is related to certificatio n 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 h igher average emissions, since some exhaust emissions increase during regeneration. Particularly for engines not equipped with SCR sy stems, NO X emissions can increase b y an order of magnitude during regeneration, and these temporary

increases in emission are accounted for in EPA’s certification process. See the accompan yi ng NPRM for more information about the emissions impacts of DPF regenerations. In addition, excess regenerations could shorten the useful life of the DPF sy stem since high temperatures p lace 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 s ystems 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 frequ ency of regeneration, the resulting increase in NO X emissions will not be counted against certification levels for applicable engine families or vehicle test groups. Furthermore,Page 44 of 77

emissions certification testing may be conducted with any

approved AECD’s fo r 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 t ypical frequency between three an d seven percent. Those with frequencies near zero rel y al most exclusively

on passive regeneration. 23 **(2) Engine Recalibration**  As mentioned above, in
- cylinder combustion chemistry dictates a NO X - PM trade
off where engines calibrated to reduce in
- cylinder NO X 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 effe ctiveness, and boost reliability of the DPF sy stems. On engines with downstream (i.e., SCR) NO X controls, SCR control could be modulated such that engine recalibration would not significantl y affect NO X emissions. On engines without downstream NO X contro ls, EPA believes that some degree of increased NO X emissions during the conditions justified by the AECD would be approvable for emergency vehicles. As explained below in Section III.E(4), EPA does

23 Frequency in percent refers to the fraction of engine test cycles during which an automatic active regeneration occurs.Page 45 of 77

not expect this provision to affect other aspects of cert ification. When manufacturers calculate the average NO X emissions during a test cycle, they incorporate data regarding both the frequency

of regeneration and the increase in NO X emissions during regeneration. For emergency vehicles with approved AECD’s th at involve recalibration to alter regeneration frequency or average NO X emissions, the resulting increase in NO X emissions will not be counted against certification levels for applicable engine families or vehicle test groups. Furthermore, emissions certi fication 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 Fed eral Register. **(3) 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 und erstands that manufacturers are motivated to seek design solutions that are cost effective and easil y deploy able. However, by focusing solely

on preventive measures such as those described above, manufacturers may not achieve a completely failsafe DPF str ategy

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 mar ket today that could be configured to temporarily relieve excessive engine exhaust backpressure when detected, then return the s ys tem 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 anPage 46 of 77

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 m ajority of DPF operating cy cles would be expected to have continuous PM emission control, while an y temporary backpressure relief that reduced PM control or allowed b ypass of controls would be expected relativel y infrequentl y. **E. 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 heav y - dut y diesel engines on these emergency

vehicles and equipment. **(1) Newly Certified Engines**  Of those new diesel engines covered by EPA’s current heav y - dut y diesel standards, onl y 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 ty pe discussed above i n 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, onl y those sold and built as emergency vehicles will be eligible to obtain an approved AEC D of the t ype discussed above. **(2) 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 FieldPage 47 of 77

Modifications (EVFMs) for on
- hi ghwa y 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 sy stems, 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 informatio n submitted for emergency vehicle or equipment AECD’s. Itis important to emphasize that this action will allow only those approved modifications to be deployed b y m anufacturers and their authorized dealers. Modifications made b y end users are not gener ally approvable; rather the tampering prohibitions would generally appl y to such modifications. EPA has identified three ty pes of field modifications that will be permitted for emergency

vehicles and emergency

equipment under the final regulations, based o n the extent to which the modification is being incorporated into new production vehicles and equipment. The three types are: Ty pe A: Any

field modification that is a change to a certified vehicle (i.e., a vehicle, engine or equipment covered b y a cert ificate of conformit y) that is identical in all respects to a running change that is approved for incorporation in new vehicles b y the manufacturer. Where the running change was approved byPage 48 of 77 EPA for implementation only in conjunction with certain other runn ing changes, the field modification may be considered to be a Ty pe A field modification only if implemented under the same constraints. Ty pe B: An y field modification that is not identical in all respects to, but provides for essentiall y the same purpose as, a running change that is being incorporated in new vehicles b y the manufacturer or that would have been incorporated if the vehicle were still in production. A Ty pe 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. Ty pe C: An y field modification that is made selectively onl y 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 ty pe of modification is being requested. **(3) Labeling Requirements**  Because the engines and vehicles eligible for the AECD’s d escribed 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 otherPage 49 of 77

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: “THI S ENGINE I S FOR I NSTALLATION 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 i nformation label: “THI S VEHICL E HAS A LIM ITED 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 fo llowing statement: “THIS ENGINE IS FOR INSTALLAT ION 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 permanentl y dist inguished 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 po wer due to an y occurrences of abnormal conditions of the emission control sy stem, or prevents such abnormal conditions from occurring. **(4) Other Regulatory Provisions**  Today ’s rule will not alter the tampering prohibition in 40 CFR 1068.101(b)(1). This provisi on describes a general prohibition against anyone from removing or rendering inoperative an engine’s emission controls before or after entering into service,Page 50 of 77

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 prev ent the engine from losing speed, torque, or power due to abnormal conditions of the emission control sy stem, or to prevent such abnormal conditions from occurring during operation related to emergency response. EPA recognizes that there may be cases wher e 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 an y 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 emiss ion control sy stems 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 ma nual active regenerations, engine manufacturers may choose to prevent the abuse of this function by means such as a daily

or weekl y cap on the number of manual active regenerations, or a minimum soot loading for the function to engage. As another example, if an emergencyPage 51 of 77

vehicle alerts a driver to an abnormal condition of its emission control sy stem 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. 24 If an operator disregards such warnings beyond the time needed to respond to the emergency , this may be considered tampering. Itis important to note that if an emergency vehicle is not equipped to ever allow an operator to initiate a manu al active regeneration, this may in practice encourage tampering b y 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 proposin g an y 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 durin g 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 wi th any approved AECD’s for emergency vehicle or equipment deactivated
. Additionally , manufacturers do not need to consider emergency vehicle AECD’s when

24 Although this actio 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 oc curs. 40 CFR 86.004
- 25(b)(6)(ii).Page 52 of 77

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 formerl y approved emissions certific ates. **F. 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. **(1) 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 deplo y upgrades to engines for emergency vehicles, they may voluntarily incur some degree of costs associated with the following:

 Design and te sting to determine effectiveness of potential AECDs

 Education & outreach to intermediate vehicle manufacturers and end users

 Deploy

ment of AECDs onto new and in
- use emergency vehicles

 Labeling costs EPA expects any

fixed costs will be small, and any variab le costs will apply only to the engines sold for installation in emergency vehicles or emergency

equipment, which comprise less than one percent of the heav y - dut y on - road fleet, and an even smaller fraction of the nonroad fleet. As per standard practice, m anufacturers would be free to setPage 53 of 77

a fair market price for any approved AECD they

offer, to offset the costs incurred in its development. **(2) Operational Costs**  Depending on the t ype 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 offs et the cost to owners for obtaining requested AECD’s. Where DPF s ys tems employ fuel dosing to enable active automatic regenerations, it is uncertain whether liberalizing the parameters for initiating regenerations would affect fuel consumption, and whethe r 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 an y pote ntial 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
.Page 54 of 77 **(3) Societal Costs**  Because this rule eases constraints on the development of robust DPF s ys tems, 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. **G. 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 heav y - dut y fleet will not change significantl y. EPA estimates that on
- road emergency vehicles comprise less than one percent of the national heav y - dut y fleet. According to the In ternational Council on Clean Transportation (ICCT), less than one percent of all new heav y - duty truck registrations in 2003 to 2007 were for emergency vehicles (includes class 8 fire trucks plus other class 3
- 8 emergency

vehicles). 25 On average, the IC CT’s data suggest that approximately 5,700 new emergency

vehicles are sold in the U.S. each y ear; 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

25 ICCT, May 2009, “Heavy
- Duty Vehicle Market Analysis: Vehicle Characteristics & Fuel Use , Manufacturer Market Shares .”Page 55 of 77

vehicles. Therefore, we conclude that they contribute less than 1% of the annual air emissions from the heavy
- dut y diesel truck fleet. Due to the optional and voluntary nature of this action, it is difficult to estimate its
ove rall emissions impact accuratel y. The amendments offer man y options to manufacturers, and the emissions impacts will depend on which options and strategies are employ ed, and for how many vehicles. Further discussions of potential NO X and PM emissions impac ts and fuel consumption from dosing are provided in the Notice of Proposed Rulemaking published elsewhere in Today ’s Federal Register
. **H. Health Effects**  EPA’s clean diesel standards are alread y providing substantial benefits to public health and welfare and the environment through significant reductions in emissions of NO X , PM, nonmethane hydrocarbons (NMHC), carbon monoxide, sulfur oxides (SO X ), and air toxics. We project that by 2030, the on
- highway

program alone will reduce annual emissions of NO X , NMHC, an d PM by 2.6 million, 115,000 and 109,000 tons, respectivel y. These emission reductions will prevent 8,300 premature deaths, over 9,500 hospitalizations, and 1.5 million work day s lost. All told, the monetized benefits of the
on - highway

rule plus the nonr oad diesel Tier 4 rule total over $150 billion. A sizeable part of the benefits in the earl y ye ars of these programs has come from large reductions in the amount of direct and secondary PM emitted by

the existing fleet of heavy
- dut y engines and vehicles, b y requiring the use of the higher quality diesel fuel in these vehicles. While this final action may slightly increase some emissions, as explained inPage 56 of 77

the previous section, we do not expect that these small increases will significantly diminish the health benefits of our stringent clean diesel standards. **IV. Statutory and Executive Order Reviews**  **A. 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). **B. Paperwork Reduction Act**  This action does not impose an y new information collection burden. The regulatory

relief for emergency

v ehicles is voluntary

and optional, and the revisions for engine and vehicle maintenance merel y codify existing guidelines. However, the Office of Management and Budget (OMB) has previously approved the information collection requirements contained in the e xisting 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. **C. Regulatory Fl**  **exibility Act** The Regulatory

Flexibility

Act (RFA) generall y requires an agency to prepare a regulatory

flexibility

analy sis of any

rule subject to notice and comment rulemaking requirements under the Administrative Procedure Act or an y other statute unles s thePage 57 of 77

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 i mpacts of this rule on small entities, small entity is defined as: (1) a small business primarily engaged in shipbuilding and repairing as defined b y NA IC S code 336611 with 1,000 or fewer employ ees (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 emplo ye es (based on Small Business Administration size standards); (3) a small business p rimarily engaged in commercial and industrial machinery

and equipment repair and maintenance as defined b y NAI CS code 811310 with annual receipts less than $7 million (based on Small Business Administration size standards); (4) a small governmental jurisdi ction that is a government of a cit y, count y, 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 independentl y 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

anal ys esPage 58 of 77

is to identify

and address regulatory

alternativ es “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 regu latory 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 associate d with this rule. We have concluded that this rule will not increase regulatory burden for affected small entities. **D. 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 flex ibility 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.Page 59 of 77

**E. 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 heav y - duty diesel engines and not to state or local governments . Thus, Executive Order 13132 does not apply to this action. **F. Executive Order 13175: Consultation and Coordination with Indian Tribal**  **Governments** This act ion 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 th e 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. **G. Executive Order 1**  **3045: 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 “econom ically significant” as defined under Executive Order 12866, and (2) concerns an environmental health or safet y risk that EPA has reason to believePage 60 of 77

may have a disproportionate effect on children. If the regulatory action meets both criteria, the agency

mus t evaluate the environmental health or safet y effects of the planned rule on children, and explain why the planned regulation is preferable to other potentially

effective and reasonabl y feasible alternatives considered b y the agency
. EPA interprets Executi ve Order 13045 as appl yi ng only to those regulatory actions that are based on health or safety risks, such that the anal ys is required under section 5
- 501 of the Order has the potential to influence the regulation. This direct final rule is not subject to E xecutive Order 13045 because it does not establish an environmental standard intended to mitigate health or safety risks, and because it is not economicall y significant under Executive Order 12866. **H. 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. **I. 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 applicab le 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 standardsPage 61 of 77

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 an y voluntary

consensus standards. **J. 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 environmenta l justice. Its main provision directs federal agencies, to the greatest extent practicable and permitted b y law, to make environmental justice part of their mission by

identifying and addressing, as appropriate, disproportionately high and adverse human h ealth 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 hea lth or environmental effects on minority or low
- income populations. This action is not expected to have any adverse environmental impacts. **K. Congressional Review Act**  The Congressional Review Act, 5 U.S.C. 801 et seq., as added b y the Small Business Regulatory Enforcement Fairness Act of 1996, generall y provides that before a rule may take effect, the agency

promulgating the rule must submit a rule report, which includes a cop y of the rule, to each House of the Congress and to the Comptroller General of the Un ited States. EPA will submit a report containing this rule and otherPage 62 of 77

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 Ma

jor rule cannot take effect until 60 day s 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 inf ormation, 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 AdministratorPage 63 of 77

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** 1. The authorit y citation for part 85 continues to read as follows: **Authority** : 42 U.S.C. 7401
- 7671q. **Subpart R --**  **[Am ended]**  2. Add §85.1716 to subpart R to read as follows: **§ 85.1716 Approval of an emerge ncy vehicle field modification (EVFM).**  This section describes how y ou may implement design changes for an emergency vehicle that has alread y been placed into service to ensure that the vehicle will perform properl y in emergency

situations. This applies fo r an y light
- duty vehicle, light
- dut y truck, or heav y - dut y vehicle meeting the definition of emergency vehicle in 40 CFR 86.004
- 2 or 86.1803. In this section, “you” refers to the certifyingmanufacturer and “we” refers to the EPA Administrator and any auth orized 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 sect ion. (b) Include in your notification a full description of the EVFM and an y 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 contro l sy stem, 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 e xhaust fluidPage 64 of 77

for engines that rel y on urea - based selective catal ytic 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 famil y currently in production, no approval of the proposed EVFM is necessary . (2) Where the proposed EVFM is for an engine family currentl y in production but the applicable demonstration is based on an AECD we approved under this part for an engine famil y 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 day s after you not ify 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 i nformation. (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 occurri ng, during operation related to emergency response.Page 65 of 77 (iii) Unless we say

otherwise, your proposed EVFM is deemed approved 30 day s 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 N EW AND IN**  **- USE HIGHWAY**  **VEHICLES AND ENGINES** 3. The authorit y citation for part 86 continues to read as follows: **Authority** : 42 U.S.C. 7401
- 7671q. **Subpart A**

**– [Amended]**  4. Section 86.004
- 2 is amended as follows: a. By adding a definition for “Ambulance” in alphabe tical order. b. By revising the definition for “Defeat device”.
c. By a dding definitions for “Diesel exhaust fluid”, “Emergency v ehicle”, 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.Page 66 of 77 Defeat device means an auxiliary emission control device (AECD) that reduces the effectiveness of the emission control sy stem under conditions which may reasonabl y be expected to be encountered in normal vehi cle operation and use, unless: (1) Such conditions are substantially included in the applicable Federal emission test procedure for heav y - duty vehicles and heavy
- dut y engines described in subpart N of this part; (2) The need for the AECD is justified in te rms 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 pre venting 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 con ditions 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 catal yt ic reduction. Diesel exhaust fluid (DEF) has the meaning given in §86.180 3. Emergency vehicle means a vehicle that is an ambulance or a fire truck. Fire truck has the meaning given in §86.1803.
* * * * *

5. Section 86.004
- 28 is amended by revising paragraph (i) introductory text to read as follows:Page 67 of 77

**§ 86.004 -**  **28 Compliance wi th emission standards.** 
* * * * * (i) Emission results from heav y - dut y 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 c ycl e. 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).
* * * * *

6. Section 86.095
- 35 is amended b y revising paragraph (a)(3)(iii)(O) to read as follo ws: **§ 86.095 -**  **35 Labeling.** (a) * * * (3) * * * (iii) * * *Page 68 of 77

(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 INSTAL LATION IN EMERGENCY VEHICLES ONLY.”
* * * * *
**Subpart B**

**– [Amended]**  7. 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 solel y for emerg ency vehicle applications under paragraph (4) of the definition of defeat device. The emission standards do not appl y when an y of these AECDs are active.
**Subpart N**

**– [Amended]**  8. Section 86.1305
- 2010 is amended b y adding paragraph (i) to read as follows: **§ 8 6.1305**  **- 2010 Introduction; structure of subpart.** 
* * * * * (i) You may

disable an y AECDs that have been approved solel y for emergency vehicle applications under paragraph (4) of the definition of “ defeat device ” in § 86.004
- 2 . The emission standards do n ot apply when any

of these AECDs are active.

9. Section 86.1370
- 2007 is amended b y adding paragraph (h) to read as follows: **§ 86.1370 -**  **2007 Not -**  **To -**  **Exceed test procedures.**Page 69 of 77

* * * * * (h) Emergency vehicle AECDs
. If your engine family i ncludes engines with on e or more approved AECDs for emergency v ehicle 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]**  10. 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 a dding definitions for “Diesel exhaust fluid”, “Emergency v ehicle”, 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) Safet y, comfort, and avoidance of aggravation of the patient ’s injury or illness. (5) Two
- way

radio communication.Page 70 of 77

(6) Audible and visual traffic warning devices.
* * * * * Defeat device means an auxiliary emission control device (AECD) that reduces the effectiveness of the emission control sy stem under conditions which may reasonabl y 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 vehicl e 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 a bnormal conditions of the emission control sy stem, 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 o verloaded particulate trap, and running out of diesel exhaust fluid for engines that rel y on urea - based selective catal yt ic reduction.
* * * * * Diesel exhaust fluid (DEF) means a liquid compound used in conjunction with selective catal yt ic reduction to r educe NOx emissions. Diesel exhaust fluid is generall y understood to conform to the specifications of I SO 22241.
* * * * * Emergency vehicle means a vehicle that is an ambulance or a fire truck.
* * * * *Page 71 of 77 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.
* * * * *

11. Section 86.1807
- 01 is amended b y adding paragraphs (h) and (i) to read as follows: **§ 86.1807 -**  **0 1 Vehicle labeling.** 
* * * * * (h) Vehicles powered by m odel ye ar 2007 through 2013 diesel
- fueled engines must include permanent readily v isible labels on the dashboard (or instrument panel) and near all fuel inlets that state “Use Ultra Lo w 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: “THI S VEHICLE HAS A LIMITED EXEMPTION AS AN EMERGENCY VEHICLE.” **§86.1807 -**  **07**

**– [Removed]**  12. Subpart S is amended by removing §86.1807
- 07. 13. Section 86.1840
- 01 is amended b y revising paragraph (c) to read as follows: **§ 86.1840 -**  **01 Special test pr ocedures.** 
* * * * * (c) Manufacturers of vehicles equipped with periodically regenerating aftertreatment devices must propose a procedure for testing and certifying such vehicles, includingPage 72 of 77

SFTP testing, for the review and approval of the Administrator. Th e manufacturer must submit its proposal before it begins an y s ervice 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** 14. The authorit y citation for part 1039 continues to read as follows: **Authority** : 42 U.S.C. 7401
- 7671q.
**Subpart B**

**– [Amended]**  15. Section 1039.115 is amended b y adding paragraphs (g)(4) and (5) to read as follows: **§1039.115 What other requirements apply?**
* * * * * (g) * * * (4) The auxiliary

emission control device applies only for en gines 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 sy stem, 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 overloadedPage 73 of 77 particulate trap, and running out of diesel exhaust fluid for engines that rely on urea
based se lective catal yt ic reduction. The emission standards do not appl y when an y 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 r equirements of that section, and you meet all of the requirements of that section.

16. Section 1039.135 is amended b y adding paragraph (c)(15) to read as follows: **§1039.135 How must I label and identify the engines I produce?**
* * * * * (c) * * * (15) For engines with one or more approved auxiliary emission control devices for emergency

equipment applications under §1039.115(g)(4), the statement: “THI S ENGINE IS FOR INSTALLATION IN EMERGENCY EQUIPMENT ONLY.”
* * * * * **Subpart F**

**– [Amended]**  17. 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 solel y for emergency equipment applications under §1039.115(g)(4).

18. Section 1039.525 is amended by revising the introductory text to read as follows:Page 74 of 77

**§ 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 s ys tem restores aftertreatment performance. For example, exhaust gas temperatures may inc rease temporaril y 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 c ycl e or ramped
- modal cycle, or on average less than once per ty pical mode in a discrete
- mode test. If your engine famil y 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]**  19. A dd §1039.670 to subpart G to read as follows: **§ 1039.670 Approval of an emergency equipment field modificat ion (EEFM).**  This section describes how y ou may implement design changes for emergency equipment that has alread y been placed into service to ensure that the equipment will perform properl y in emergency situations.Page 75 of 77

(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 onl y with our advance approval, as specified in this section. (b) Include in your notification a full description of the E EFM and an y 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 sy stem, 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 rel y on urea - based selectiv e catal yt ic 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 famil y 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 engi ne famil y 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 day s 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 requestPage 76 of 77 additional information to support your determination under paragraph (b) of this section, as follows: (i) If we request additional inf ormation 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 determin e that the EEFM is not necessary to prevent the equipment from losing speed, torque, or power due abnormal conditions of the emission control sy stem, or to prevent such abnormal conditions from occurring, during operation related to emergency response. (ii i) Unless we say

otherwise, your proposed EEFM is deemed approved 30 day s 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]**  20. Section 1039.801 is amended b y adding definitions for “Diesel exhaus t fluid” and “Emergency

equipment” in alphabetical order to read as follows: **§ 1039.801 What definitions apply to this part?**
* * * * *Page 77 of 77 Diesel exhaust fluid (DEF) means a liquid compound used in conjunction with selective catal yt ic reduction to reduce NO x emissions. Diesel exhaust fluid is generall y understood to conform to the specifications of I SO 22241.
* * * * * Emergency equipment means either of the following t ypes of equipment: (1) S pecialized 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.
* * * * *

21. Section 1039.805 is amended b y adding abbreviations for “DEF”, “EEFM”, “ISO”, and “SCR” in alphabetical order to read as follows: **§ 1039.805 What symbols, acro nyms, 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 catal yt ic reduction.
* * * * *