[Federal Register Volume 77, Number 3 (Thursday, January 5, 2012)]
[Notices]
[Pages 497-499]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-33840]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL-9615-9]


Control of Emissions From New Nonroad Compression-Ignition 
Engines: Approval of New Scheduled Maintenance for Selective Catalytic 
Reduction Technologies

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice.

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SUMMARY: This notice announces that EPA has granted manufacturers new 
emission-related scheduled maintenance and maintenance intervals for 
the replenishment of the nitrogen-containing reducing agent for 
selective catalytic reduction (SCR) technologies used with nonroad 
compression-ignition (NRCI) engines for 2011 and later model years. 
Replenishment of reducing agent for SCR technologies is considered 
critical emission-related maintenance.

FOR FURTHER INFORMATION CONTACT: David Dickinson, Compliance Division, 
U.S. Environmental Protection Agency, 1200 Pennsylvania Ave. NW., 
(405J), Washington, DC 20460. Telephone: (202) 343-9256. Email address: 
[email protected].

SUPPLEMENTARY INFORMATION:

I. Background

    EPA adopted new emission standards for NRCI engines on June 29, 
2004.\1\ We expect that many manufacturers will use SCR systems to meet 
the final Tier IV NOX reduction requirements for their 
diesel engines. SCR systems use a nitrogen-containing reducing agent 
that usually contains urea and is known as diesel exhaust fluid (DEF). 
The DEF is injected into the exhaust gas upstream of a catalyst and 
requires periodic replenishment (maintenance) by refilling the DEF 
tank.
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    \1\ 69 FR 38958 (June 29, 2004).
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    NRCI engine manufacturers are required to provide written 
instructions for properly maintaining and using the engine, including 
the emission control system, to purchasers of new engines. These 
maintenance instructions, including the hours associated with the 
maintenance intervals, also apply to the engine during its service 
accumulation for emission testing purposes.
    Maintenance performed on NRCI engines is classified as critical 
emission-related maintenance if it includes any adjustment, cleaning, 
repair, or replacement of critical emission-related components. As set 
forth at 40 CFR 1039.125(a)(1), 1039.125(a)(2), and 1039.125(a)(3), a 
manufacturer may schedule critical emission-related maintenance on 
these types of components if certain conditions are met, including a 
demonstration that the maintenance is reasonably likely to be done at 
the recommended intervals, and depending upon the size of the engine 
and the type of emission-related component, an EPA-prescribed minimum 
hour maintenance interval. For example, a manufacturer of engines below 
130 kW may not schedule maintenance more frequently than 3,000 hours 
for catalytic converters and if the engines are at or above 130 kW then 
a manufacturer may not schedule the catalytic converter maintenance 
more frequently than 4,500 hours.
    In addition, should a manufacturer desire a new or shorter 
scheduled maintenance interval (that it wishes to recommend to 
purchasers and perform during service accumulation on emission-data 
engines) not found under Sec.  1039.125(a)(2) and 1039.125(a)(3), and 
instead utilize Sec.  1039.125(a)(5), then the manufacturer must submit 
a request to EPA for approval. A request for a shorter maintenance 
interval includes new scheduled maintenance on emission-related 
components that were not in widespread use with NRCI engines before 
2011. Requests from manufacturers for new scheduled maintenance 
intervals must include: (1) A description of the proposed maintenance 
step, (2) the recommended maximum feasible interval for this 
maintenance, (3) the rationale with supporting evidence to support the 
need for the maintenance at the recommended interval, and (4) a 
demonstration that the maintenance will be done at the recommended 
interval on in-use engines.
    In considering requests for new scheduled maintenance EPA will 
evaluate the information provided to EPA and any other available 
information to establish alternate specifications for maintenance 
intervals as deemed appropriate.
    EPA believes the existing allowable scheduled maintenance hour 
intervals applicable to catalytic converters are generally applicable 
to SCR systems which contain a catalyst, but that SCR systems are a new 
type of technology and that DEF refills are a new type of

[[Page 498]]

maintenance uniquely associated with SCR systems. Therefore, the 3,000 
hour (engines below 130 kW) and 4,500 hour (engines at or above 130 kW) 
intervals are generally applicable to SCR systems, but are not 
controlling in determining the appropriate DEF refill interval. As 
noted, the SCR systems are a new type of technology designed to meet 
the newest emission standards and the DEF refill intervals represent a 
new type of scheduled maintenance; therefore, EPA believes that 
manufacturers may request from EPA the ability to perform the new 
scheduled maintenance of DEF refills.

II. Current Requests

    EPA has received information from the Engine Manufacturers 
Association,\2\ as well as AGCO, Caterpillar, and IVECO supporting 
their requests for new recommended scheduled maintenance intervals for 
their SCR systems.
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    \2\ The EMA members participating in nonroad diesel engine 
activities include: Caterpillar Inc., Cummins Inc., Deere & Company, 
Daimler Trucks North America LLC, Deutz Corporation, Fiat Powertrain 
Technologies S.p.A., Hino Motors, Ltd., Isuzu Manufacturing Services 
of America, Inc., Komatsu Ltd., Kubota Engine America Corporation, 
MTU Detroit Diesel Corporation, AB Volvo, and Yanmar America 
Corporation.
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    Several of the requests noted that the DEF is essential for the 
proper functioning of the SCR system, and thereby constitutes a 
``critical'' maintenance component.\3\
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    \3\ 40 CFR 1039.801 defines a critical emission-related 
component to include, in part, any component whose primary purpose 
is to reduce emissions.
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    The requests primarily seek EPA's approval of a DEF tank that 
provides a range of operation that is equal to the engine or 
equipment's fuel capacity--this is known as a 1:1 ratio--for 2011 and 
later model year nonroad engines.\4\ In determining the recommended DEF 
refill intervals, several of the requestors applied ``good engineering 
judgment'' as described in the March 27, 2007 SCR certification 
guidance for on-highway engines.\5\ Some noted that since SCR systems 
may consume DEF at a rate of approximately 2% to 4% of the rate of 
diesel fuel consumption (consumption rates could be even higher as one 
requestor noted), it would be technically infeasible to equip a nonroad 
engine or piece of equipment with a DEF tank large enough to operate 
for the standard 3,000- or 4,500-hour maintenance interval without DEF 
refill. For example, considering a representative range of construction 
and agricultural equipment, to meet the 3,000- to 4,500-hour 
maintenance requirements:
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    \4\ Several of the requests also seek a 2:1 DEF refill ratio if 
there is no DEF level indicator. However, because EPA has already 
made clear that such DEF level indicator is otherwise necessary (see 
footnote 8) the Agency is not evaluating the 2:1 ratio request at 
this time. Separately, a couple of the requests seek a DEF tank size 
that is capable of sustaining a minimum of 120 hours of operation 
for engines used in part-time and full-time stationary applications 
when the engine is provided with a very large, and possibly 
unlimited fuel supply. One of those requests has been withdrawn. The 
other does not provide sufficient evidence to support why the 
recommended interval is the appropriate maintenance interval for 
these particular applications. Thus, the Agency is not taking action 
to approve the requests at this time, but may act in the future if 
more detailed information on this issue is provided to EPA.
    \5\ See CISD-07-07, p. 2.
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     A skid steer loader with a 50 kilowatt (kW) engine, that 
normally carries a maximum of 25 gallons of fuel, would require a DEF 
capacity of approximately 150 gallons, weighing over 1,400 pounds and 
requiring more than 20 cubic feet (ft\3\) of space.
     A bulldozer with a 150 kW engine, that normally carries a 
maximum of 110 gallons of fuel, would require a DEF capacity of 
approximately 900 gallons, weighing over 8,000 pounds and requiring 
more than 120 ft\3\ of space.
     A combine harvester with a 250 kW engine, that normally 
carries a maximum of 250 gallons of fuel, would require a DEF capacity 
of approximately 900 gallons, weighing over 8,000 pounds--almost half 
as much as the combine's grain tank capacity--and requiring more than 
120 ft\3\ of space.
     A large off-highway mining truck with a 900 kW engine, 
that normally carries a maximum of 500 gallons of fuel, would require a 
DEF capacity of approximately 5,500 gallons, weighing over 50,000 
pounds and requiring more than 735 ft\3\ of space.
    Several of the requests suggested that in order to apply good 
engineering judgment EPA must strike the proper balance between the 
dictates of operating nonroad equipment (which requires DEF tanks of 
small enough weight and size so as not to hinder the engine's or 
equipment's function while also not causing too frequent stops or 
downtime) and what the requestors suggest is EPA's need to ensure 
emission compliance in use. The requestors suggest that mobile nonroad 
engines and equipment are directly analogous to ``vocational'' on-
highway vehicles, in that they typically are refueled on a daily basis 
from a central location and so are well-suited to the refilling of 
their DEF tanks on the same daily basis.\6\
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    \6\ In EPA's November 9, 2009 approval of new scheduled 
maintenance for SCR-equipped on-highway engines and vehicles, the 
Agency found that for vocational vehicles the DEF refill interval 
should equal the range of the vehicle operation that is no less than 
the vehicle's fuel capacity (i.e. a 1:1 ratio). 74 FR 57671.
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    The requestors also suggest that their recommended DEF refill 
intervals are the maximum intervals since longer intervals would 
require larger and heavier tanks, which may jeopardize the engine or 
equipment's mission or functionality. One of the requestors noted, by 
way of example, that its average engines used in modern agriculture and 
construction machines would consume as much as 1,000 to 2,200 gallons 
of DEF in order to meet the 4,500-hour regulated interval. Such tanks 
(weighing 9,000/20,000 pounds) would be essentially impossible to 
install given the limitations in available space and visibility for 
operators on machines, with impacts on safety, along with massive 
increases of machine weight which would pose serious problems in 
operability in agricultural lands along with worsening machine fuel 
consumption resulting in higher CO2 emissions. Such 
constraints include the need to work and pass in very narrow openings 
in orchards, safety and visibility concerns, and the operability of 
other components on the equipment (including clearance between the DEF 
tank on tires). This requestor also asks EPA to consider the shelf-life 
of DEF at normal ambient temperatures as 18 months, much less than the 
3- to 5-year period which roughly corresponds to the interval of 4,500 
hours.
    A separate request noted the important relationship between DEF and 
fuel volume, packaging and serviceability concerns, along with tilt 
capability and weight concerns in support of its recommended 1:1 DEF 
refill ratio. A 1:1 ratio develops the correct machine operating habit 
to fill the DEF at each fuel fill interval, and from a vehicle design 
standpoint many of its applications are taking away fuel tank volume to 
create space for the DEF tank and provide instances where the DEF tank 
is nestled in the fuel tank area. In terms of serviceability, the 
optimal placement of the DEF tank is close to the fuel tank so both can 
be refueled conveniently at the same time. As the filler neck on the 
fuel tank is already accessible from ground level, placing the DEF tank 
nearby ensures that it is also accessible. Providing such accessibility 
increases the limitations on the design and placement of the DEF tank. 
Tanks sized for a 1:1 ratio are much more likely to fit within the 
allowable space on a piece of equipment than a larger tank. Examples 
were provided by the requestor noting where 2:1 tanks would not fit. 
This requestor also noted that a 2:1 DEF tank would add 65 to 220 
pounds to machines and would negatively affect the ability to

[[Page 499]]

carry payload, which is one of the primary functions of the majority of 
construction machines. Lastly, construction machines must operate in a 
variety of conditions and operate often on steep slopes. Equipment with 
1:1 DEF tanks of the correct design creates a lower risk of losing DEF 
fluid suction pickup when operating on extreme tilt as compared to 
larger tanks.
    In order to fulfill the obligation to demonstrate that the 
maintenance will be done at the recommended interval on in-use engines, 
requestors noted that manufacturers will deploy warnings and 
inducements should the DEF level become too low. In addition to these 
initial inducements, should the operator ignore them, then the 
requestors noted that manufacturers will employ ``severe inducement'' 
intended to disable the functionality of the engine or equipment.\7\
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    \7\ EMA suggests that a severe inducement would reduce the 
engine to 60% of the rated speed and 50% rated torque.
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    Furthermore, EPA notes that several current SCR systems include the 
final inducement of either having the engine shut down or idle only 
(with no power) when no DEF is present in the DEF tank (or the system 
is no longer able to dose with DEF), and such SCR systems meet EPA's 
expectations of what is required for nonroad SCR systems.\8\ As an 
example, one manufacturer noted that ``To provide the necessary 
assurance that the DEF tank will be refilled, each vehicle will be 
equipped with a constant viewable DEF level indicator included in the 
vehicle dashboard display. * * * the operator display system includes a 
visible warning signal that indicates when the level of DEF in the tank 
is low and will need refilling. As a final inducement, the system also 
includes programmed engine derates that limit engine performance once 
the DEF level drops below certain levels, thereby limiting vehicle 
performance.'' EMA, in its request, noted that should operators fail to 
notice audible or visible warning signals indicating low DEF, then the 
manufacturers may also use a reduction in engine power or equipment 
utility to provide more dramatic notice that the DEF tank needs 
refilling. This ``severe inducement'' is intended to disable the 
functionality of the engine or equipment, and to substantially limit 
the likelihood that the engine or equipment could perform any useful 
work, but is not intended to prohibit the engine or equipment's 
mobility or ability to idle. EMA also notes that it expects EPA to 
provide guidance on an appropriate final inducement once the SCR system 
runs out of DEF.
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    \8\ EPA held a public webinar on July 26, 2011. Copies of the 
presentation used at this webinar can be found at: www.epa.gov/otaq/cert/documents/nrci-scr-web-conf.2011-07-25.pdf.
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III. Discussion

    EPA believes that SCR systems are a new technology and are properly 
considered a critical emission-related component since their primary 
purpose is to control emissions. In addition, the replenishment of DEF 
as part of maintaining the SCR system's functionality is considered to 
be critical emission-related maintenance under 1039.125(a).
    EPA believes it appropriate to evaluate the DEF refill rates by 
taking into consideration the space and weight constraints typically 
involved with the range of NRCI engines using SCR systems, including 
safety and impacts of weight and dosing rates on greenhouse gas 
emissions and fuel efficiency. EPA believes it must also take into 
consideration the likelihood that the maintenance of DEF refills will 
be performed by the owner or operator.\9\
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    \9\ 40 CFR 1039.125(a)(5).
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    In our 2009 Federal Register notice regarding heavy-duty on-highway 
engines and vehicles using SCR systems, we concluded that the requested 
intervals were appropriate because we determined that manufacturer-
recommended DEF refill intervals approximated the maximum feasible 
maintenance intervals associated with reasonable DEF tank sizes. We 
also concluded that the maintenance intervals recommended ensure that 
the functions and operational efficiency of such vehicles are not 
overly compromised.\10\ EPA knows of no SCR technology for NRCI engines 
that is yet capable of attaining longer operation (generally beyond one 
tank full of diesel) without a DEF refill. As noted by the requests, 
there are significant space and weight constraints associated with 
increasing the DEF tank size in order to accommodate a 2:1 refill 
ratio. EPA believes it appropriate to take into consideration the need 
for locating the DEF tank in close proximity to the fuel tank and the 
remainder of the SCR system, as well as the increased likelihood that 
the DEF tank will be refilled if it becomes standard operating practice 
to refill the DEF tank at the same time as the fuel tank. EPA believes 
that such nonroad equipment is similar to centrally-fueled heavy-duty 
on-highway vehicles and that there is a sufficient basis and a 
reasonable expectation that DEF tank refills will occur on a timely 
basis.
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    \10\ 74 FR 57561 (November 9, 2009).
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    EPA notes that the regulations allow any manufacturer to petition 
EPA under the ``paragraph (a)(5) process'' for a new maintenance 
interval for a particular engine family or application than that 
approved for the industry if the manufacturer can show that a certain 
interval is the appropriate maintenance interval for the particular 
engine configuration being certified.
    EPA also notes that all critical emission-related maintenance must 
have a reasonable likelihood of being done at the recommended intervals 
on in-use engines. Paragraph 1039.125(a)(1) sets forth several methods 
by which such demonstration can be made, including data showing that if 
a lack of maintenance increases emissions, it also unacceptably 
degrades the engine's performance. In the context of SCR systems and 
the potential of an empty DEF tank and an inoperable SCR system, EPA 
notes that equipment under such operating conditions are expected to 
shut down or idle only. Engine manufacturers employing such final 
inducements meet the requirements of (a)(1) and furthermore meet the 
requirement under (a)(5) for DEF refill intervals based on a 1:1 ratio.
    For the reasons set forth above, EPA approves a new scheduled 
maintenance interval for DEF refill that shall be no less than the 
equipment's fuel capacity (i.e., a 1:1 ratio of DEF refill to fuel 
refill) for 2011 and later model year nonroad engines.

IV. Procedures for Objections

    Anyone may request a hearing on this determination. The request 
must be in writing and include a description of your objection and any 
supporting data. The request must be made by February 6, 2012. If, 
after review of any objection and supporting data, we find that the 
request raises a substantial factual issue, we will hold a hearing in 
accordance with 40 CFR Part 1068 Subpart G.

    Dated: December 23, 2011.
Gina McCarthy,
Assistant Administrator, Office of Air and Radiation.
[FR Doc. 2011-33840 Filed 1-4-12; 8:45 am]
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