Document ID: EPA-HQ-OAR-2010-0142-0002
Agency: epa
Document Type: Proposed Rule
Title: Revisions to In-Use Testing for Heavy-Duty Diesel Engines and Vehicles; Emissions Measurement and Instrumentation; Not-to-Exceed Emission Standards; and Technical Amendments for Off-Highway Engines; Proposed Rule
Posted Date: 2010-11-08T05:00Z

[Federal Register Volume 75, Number 215 (Monday, November 8, 2010)]
[Proposed Rules]
[Pages 68575-68582]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-27894]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 86, 1033, 1039, 1042, 1045, 1054, and 1065

[EPA-HQ-OAR-2010-0142; FRL-9220-7]
RIN 2060-AO69

Revisions To In-Use Testing for Heavy-Duty Diesel Engines and 
Vehicles; Emissions Measurement and Instrumentation; Not-to-Exceed 
Emission Standards; and Technical Amendments for Off-Highway Engines

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of proposed rulemaking.

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SUMMARY: This NPRM proposes to make several revisions to EPA's mobile 
source emission programs and test procedures. EPA believes that each of 
these is minor and non-controversial in nature. Most of the proposed 
changes arise from the results of the collaborative test program and 
related technical work we conducted for the highway heavy-duty diesel 
in-use testing program. Most noteworthy here is the proposal to adopt a 
particulate matter measurement allowance for use with portable emission 
measurement systems. Related to this are two provisions to align the 
in-use program timing requirements with completion of the program as 
required in current regulations and the incorporation of revisions to a 
few technical requirements in the testing regulations based on 
information learned in this and one other test program. Finally, the 
NPRM proposes to modify a few transitional flexibilities for 
locomotive, recreational marine, and Tier 4 nonroad engines and 
incorporates a handful of minor corrections.

DATES: Written comments must be received by December 8, 2010. Request 
for a public hearing must be received by November 23, 2010. If we 
receive a request for a public hearing, we will publish information 
related to the timing and location of the hearing and the timing of a 
new deadline for public comments.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2010-0142, by one of the following methods:
     http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: a-and-r-docket@epa.gov.
     Fax: (202) 566-9744.
     Mail: Environmental Protection Agency, Mail Code: 2822T, 
1200 Pennsylvania Ave., NW., Washington, DC 20460. Please include two 
copies.
     Hand Delivery: U.S. Environmental Protection Agency, EPA 
Headquarters Library, EPA West Building, Room: 3334, 1301 Constitution 
Avenue, NW., Washington, DC. Such deliveries are only accepted during 
the Docket's normal hours of operation, and special arrangements should 
be made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2010-0142. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through http://www.regulations.gov or e-mail. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through http://www.regulations.gov your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket visit the EPA Docket Center homepage at http://www.epa.gov/oar/dockets.html.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in http://www.regulations.gov or in hard copy at the EPA Docket Center, 
EPA West Building, EPA Headquarters Library, Room 3334, 1301 
Constitution Avenue, NW., Washington, DC. The Public Reading Room is 
open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 
legal holidays. The telephone number for the Public Reading Room is 
(202) 566-1744, and the telephone number for the Air Docket is (202) 
566-1742.

FOR FURTHER INFORMATION CONTACT: Rich Wilcox, Assessment and Standards 
Division, Office of Transportation and Air Quality, 2000 Traverwood 
Drive, Ann Arbor, MI 48105; telephone number: (734) 214-4390; fax 
number: (734) 214-4050; email address: laroo.chris@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

    In the ``Rules and Regulations'' section of this Federal Register, 
we are making these revisions as a direct final rule without prior 
proposal because we view these revisions as noncontroversial and 
anticipate no adverse comment.
    The regulatory text for this proposed rule is included in the 
direct final rule and parties should review that rule for the 
regulatory text. If we receive no

[[Page 68576]]

adverse comment, we will not take further action on this proposed rule. 
If we receive adverse comment on the rule or any portions of the rule, 
we will withdraw the direct final rule or the portion of the rule that 
received adverse comment. We will address all public comments in a 
subsequent final rule based on this proposed rule. We will not 
institute a second comment period on this action. Any parties 
interested in commenting must do so at this time.

II. Does this action apply to me?

    This action will affect companies that manufacture and certify 
heavy-duty diesel engines and vehicles for use on the highway.

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                                                                              Examples of potentially affected
                   Category                           NAICS code \a\                      entities
----------------------------------------------------------------------------------------------------------------
Industry......................................                     336112  Engine and Truck Manufacturers.
                                                                   336120
Industry......................................                     333112  Manufacturers of lawn and garden
                                                                            tractors.
Industry......................................                     333618  Manufacturers of new engines.
Industry......................................     482110, 482111, 482112  Railroad owners and operators.
Industry......................................             811112, 811198  Independent commercial importers of
                                                                            vehicles and parts.
----------------------------------------------------------------------------------------------------------------
\a\ North American Industry Classification System (NAICS).

    To determine whether particular activities may be affected by this 
action, you should carefully examine the regulations. You may direct 
questions regarding the applicability of this action as noted in FOR 
FURTHER INFORMATION CONTACT.

III. What should I consider as I prepare my comments for EPA?

    A. Submitting CBI. Do not submit this information to EPA through 
http://www.regulations.gov or e-mail. Clearly mark the part or all of 
the information that you claim to be CBI. For CBI information in a disk 
or CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM 
as CBI and then identify electronically within the disk or CD-ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR Part 2.
    B. Tips for Preparing Your Comments. When submitting comments, 
remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree; suggest alternatives 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     Make sure to submit your comments by the comment period 
deadline identified.

IV. Details of the Proposed Rule

A. Revision of 40 CFR Part 86 Subpart T to Revise the In-Use Testing 
Program for Heavy-Duty Diesel Engines

1. Background
    The manufacturer-run, in-use testing program for heavy-duty diesel 
vehicles that are used on the highway was promulgated in June 2005 to 
monitor the emissions performance of the engines used in 2007 and later 
model year vehicles when operated under a wide range of real world 
driving conditions.\1\ The program is specifically intended to monitor 
compliance with the applicable Not-to-Exceed (NTE) exhaust emission 
standards for non-methane hydrocarbons (NMHC), carbon monoxide (CO), 
oxides of nitrogen (NOX), and particulate matter (PM). It 
requires each manufacturer of heavy-duty highway diesel engines to 
assess the in-use exhaust emissions from their engines using onboard, 
portable emission measurement systems (PEMS) during typical operation 
while on the road. The PEMS unit must meet the requirements of 40 CFR 
1065 Subpart J.
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    \1\ See ``Control of Emissions of Air Pollution From New Motor 
Vehicles: In-Use Testing for Heavy-Duty Diesel Engines and Vehicles, 
70 FR 34594 (June 14, 2005).
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    The program was amended in March 2008 to delay some of the 
implementation dates and reporting deadlines and to adopt final PEMS 
measurement ``accuracy'' margins for gaseous emissions (i.e., NMHC, CO, 
and NOX).\2\ The development of PEMS accuracy margins are 
further described below.
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    \2\ See ``Control of Emissions of Air Pollution From New Motor 
Vehicles; Emission Measurement Accuracy Margins for Portable 
Emission Measurement Systems and Program Revisions, 73 FR 13441 
(March 13, 2008).
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    The in-use testing program began with a mandatory two-year pilot 
program for gaseous emissions in calendar years 2005 and 2006. The 
program also included a pilot program for PM emissions in calendar 
years 2007 and 2008. The programs are fully enforceable after their 
respective pilot program ends, i.e., the 2007 calendar year for gaseous 
emissions and the 2009 calendar year for PM emissions. Fully 
enforceable means that engines found not compliant after this time 
frame could be subject to a compliance action.
    The in-use testing program is based on the NTE emission standards. 
For the purposes of the in-use testing program, EPA established a 
vehicle pass/fail criterion for each pollutant that compares a 
vehicle's measured in-use emissions to a corresponding numerical 
compliance limit, i.e., NTE threshold. The NTE threshold for each 
pollutant is the sum of the NTE standard, any in-use compliance testing 
margin that is already allowed by the regulations, and a new emission 
measurement accuracy margin associated with the use of PEMS. The PEMS 
accuracy margin is the difference between the emission measurement 
``error'' for the portable instrument and the measurement ``error'' for 
``laboratory grade'' instruments that are used to test vehicles or 
engines on a dynamometer in a laboratory setting. This accuracy margin 
is expressed in the same numerical terms as the applicable NTE emission 
standards, i.e., grams of pollutant per brake horsepower-hour (g/bhp-
hr).
    When the in-use testing program was first established in June of 
2005, there was uncertainty regarding what specific

[[Page 68577]]

accuracy margins should be used in the in-use testing program, since 
the portable measurement devices that were expected to be used in the 
program had not been rigorously tested at that time. As a result, we 
originally promulgated interim accuracy margins for use in the pilot 
programs.\3\ These interim values were believed to represent an upper 
bound of the possible instrumentation variability based on our 
experience with portable and laboratory instruments and test methods. 
Subsequently, we adopted final values for gaseous pollutants based on 
the cooperative research program described below.\4\
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    \3\ The interim additive accuracy margins for the pilot programs 
are: NMHC = 0.17 g/bhp-hr, NOX = 0.50 g/bhp-hr, CO = 0.60 
g/bhp-hr, and PM = 0.10 g/bhp-hr.
    \4\ The final additive accuracy margins for the enforceable 
gaseous programs are: NMHC = 0.01 g/bhp-hr, NOX = 0.15 g/
bhp-hr, and CO = 0.25 g/bhp-hr.
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    In May of 2005, shortly before the in-use test program was 
promulgated, EPA entered into a memorandum of agreement (MOA) with the 
California Air Resources Board (CARB) and the manufacturers of heavy-
duty highway diesel engines (through the Engine Manufacturers 
Association (EMA)) to develop ``data driven'' emission measurement 
allowances through a comprehensive research, development, and 
demonstration program for the fully enforceable programs.\5\ The 
overall test program was designed to be completed in two phases. The 
first phase addressed gaseous emission accuracy margins and the second 
phase addressed the PM emission accuracy margin. The remainder of this 
discussion focuses on the final PEMS accuracy measurement for PM, since 
the final margins for gaseous emissions have already been adopted.
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    \5\ See ``Memorandum of Agreement, Program to Develop Emission 
Measurement Accuracy Margins for Heavy-Duty In-Use Testing,'' dated 
May 2005. A copy of the memorandum is available in the public docket 
for this rule and at the EPA/OTAQ Web site (http://www.epa.gov/otaq/hd-hwy.htm).
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    The MOA and the June 2005 final rulemaking addressed the 
consequences of failing to complete the accuracy margin development 
work in time for the scheduled start of the PM enforceable program.\6 
7\ Two provisions in these documents are most relevant to today's rule. 
The first provision addresses short term delays in receiving the final 
accuracy margins. Specifically, for each month the accuracy margins are 
delayed beyond the agreed upon dates, then the affected enforceable 
program would be delayed by the same number of months up to three 
months. The second provision, which is most relevant to today's action, 
addresses delays in excess of three months. In particular, if the final 
accuracy margin and documentation were delayed more than three months 
from November 1, 2008, then the affected PM enforceable program would 
be placed in abeyance for a year and the respective pilot program would 
be continued for calendar year 2009 using the interim allowance. If 
necessary, this programmatic adjustment would be repeated in subsequent 
years until the final PM accuracy margin was identified.
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    \6\ See ``Memorandum of Agreement, Program to Develop Emission 
Measurement Accuracy Margins for Heavy-Duty In-Use Testing,'' dated 
May 2005. A copy of the memorandum is available in the public docket 
for this rule and at the EPA/OTAQ Web site (http://www.epa.gov/otaq/hd-hwy.htm).
    \7\ See ``Control of Emissions of Air Pollution From New Motor 
Vehicles: In-Use Testing for Heavy-Duty Diesel Engines and 
Vehicles,'' 70 FR 34624 (June 14, 2005).
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2. Particulate Matter Emission Measurement Margin for Portable Emission 
Measurement Systems
    The MOA described above called for development of a comprehensive 
test plan for determining the final emission measurement accuracy 
margins for the manufacturer-run, in-use testing program.\8\ Generally, 
the detailed plan included a methodology that called for: (1) 
Comprehensive engine testing in the laboratory to assess the agreed 
upon sources of possible error and the resultant measurement 
variability between the PEMS and laboratory instrumentation and 
measurement methods; (2) the effects of environmental conditions on 
PEMS error and the variability in key engine parameters supplied by the 
engine's electronic controls to the PEMS; (3) the development of a 
statistically-based computer model to simulate effects of all sources 
of error on the final measurement accuracy margin; and (4) validation 
of the simulation model results and resulting accuracy margin against 
data generated through actual in-use field testing using simultaneous 
on-vehicle measurements from a mobile emissions laboratory (i.e., 
laboratory-grade instruments mounted inside a trailer) and a PEMS unit. 
This validation step is important because it provides confidence that 
the simulation model results reflect reasonable accuracy margin. If the 
two methods do not statistically agree, then there may be possible 
errors in the simulation model, the in-use mobile emissions testing 
results, or both. The test plan also contained the statistically-based 
algorithms for calculating the data-driven margin for PM from in-use 
data.
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    \8\ See ``Test Plan to Determine PEMS Measurement Allowance for 
the PM Emissions Regulated under the Manufacturer-Run Heavy-Duty 
Diesel Engine In-Use Testing Program, for the U.S. Environmental 
Protection Agency, California Air Resources Board, and Engine 
Manufacturers Association'', dated November 11, 2008 (published by 
EPA August 2010), EPA report number: EPA-420-B-10-901. A copy of the 
report is available in the public docket for this rule and at the 
EPA/OTAQ Web site (http://www.epa.gov/otaq/hd-hwy.htm).
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    After the simulation modeling results were completed, the test plan 
called for the final accuracy margin to be determined by the following 
generalized process. First, select the PEMS with the lowest or minimum 
positive value. Second, select the calculation method that has the 
lowest or minimum positive value. Third, and finally, use the results 
from that method to determine the final measurement accuracy margin.
    The cooperative test program for PM as described in the MOA is 
complete and a final report has been issued.\9\ Two PEMS units from 
different manufacturers were evaluated in the validation phase. When 
the predicted results from the model simulations for one of the PEMS 
units was compared to the mobile emissions laboratory results, the 
model did not validate for PM. It was determined from analyzing the 
results, that the PEMS exhibited a negative bias that was more 
pronounced during the validation tests when compared to the model 
development tests. The model did validate for the PEMS from the other 
manufacturer. Based on these results for that instrument, EPA, ARB, and 
EMA selected the final measurement allowance value and agreed to 
conclude the test program. We are proposing to adopt the resultant 
final emission measurement accuracy margin of 0.006 g/bhp-hr for PM. 
The derivation of this value is documented in the final report 
referenced above.
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    \9\ See ``PM PEMS Measurement Allowance Determination: Final 
Report,'' U.S. Environmental Protection Agency, June 2010 (published 
by EPA August 2010), EPA report number: EPA-420-R-10-902. A copy of 
the report is available in the public docket for this rule and at 
the EPA/OTAQ Web site (http://www.epa.gov/otaq.hd-hwy.htm).
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3. Delaying the Enforceable PM Program from 2009 to 2011
    As described above, the PM accuracy margin test program has been 
completed. However due to unexpected delays in beginning the test 
program, issues in the development of PM PEMS technology, and other 
challenges in conducting the work, the program took two years longer 
than originally anticipated. Accordingly, in-use test program 
regulations require that the first two years of the previously adopted 
enforceable program, which was originally scheduled for the calendar

[[Page 68578]]

year 2009, be placed into abeyance for two years. Hence, we are 
proposing that the enforceable PM program will now begin in 2011 
calendar year.
    As already noted, the current in-use test program regulations 
require that the PM pilot program, which began in the 2007 calendar 
year, be continued for an additional two years through calendar year 
2010. This would result in four years of pilot testing for PM. However, 
our current assessment shows that such extended pilot program testing 
is unnecessary as described below.
    The intent of the original two-year pilot program for PM was to 
make certain that engine manufacturers had adequate real-world 
operational experience, i.e., from recruiting vehicles to submitting 
test reports to EPA, to ensure a successful start of the subsequent 
fully enforceable program.\10\ Manufacturers have reached the May 31, 
2010 reporting deadline for the 2007 calendar year PM pilot program. 
Also, engine manufacturers have completed a substantial amount of in-
use testing for gaseous pollutants, i.e., NMHC, CO, and NOX. 
More specifically, two years of gaseous emissions pilot testing (2005 
and 2006 calendar years) and two years of the fully enforceable program 
(2007 and 2008 calendar years) for these pollutants have been 
completed. Gaseous pollutant in-use testing is in many ways 
complementary to PM in-use testing because nearly all aspects of the 
test regime are the same. Even certain parts of the portable emission 
measurement system instrumentation are used to measure both types of 
pollutants. Engine manufacturers, therefore, have already had a 
substantial amount of experience conducting all aspects of in-use 
testing. As a result, we have concluded that the original intent for 
conducting the PM pilot program will be achieved by retaining the 
requirement for two years of pilot testing rather than expanding it to 
four years. Therefore, we are proposing not to extend the PM pilot 
testing program beyond its initial requirement of two years of testing.
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    \10\ See ``Control of Emissions of Air Pollution From New Motor 
Vehicles: In-Use Testing for Heavy-Duty Diesel Engines and Vehicles, 
70 FR 34614 (June 14, 2005).
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    As a result of the proposal to delay the enforceable program for PM 
until the 2011 calendar year and the proposal not to extend the two-
year pilot program, we need to reassess the schedule for conducting the 
required tests for the pilot program. Two considerations are especially 
important here. First, there is no apparent advantage to require that 
engine manufacturers conduct testing over a single, consecutive two-
year period, e.g., calendar years 2007 and 2008. Second, there may be a 
benefit to allowing each manufacturer to decide which two years out of 
the four possible years to conduct its PM pilot testing. This is 
because the PM PEMS technology has continued to improve and mature as a 
result of the ongoing cooperative test program for developing the final 
PM accuracy margin. As result, a manufacturer may benefit from an 
additional flexibility in selecting when to complete the PM pilot 
program in order to gain experience with PEMS that will be more like 
the instrumentation they may use for the proposed 2011 enforceable 
program. Therefore, we are proposing to allow each manufacturer to 
report test results in any two out of the potentially four calendar 
years for completing its testing obligations under the PM pilot 
program.
    Finally, we previously designated the engine families for the 2007, 
2008, and 2009 calendar years that each engine manufacturer must test, 
and we have recently designated engine families for the 2010 calendar 
year program. Given the new flexibility in choosing which two of the 
four years to fulfill their testing obligations for the PM pilot 
program, we are proposing that each engine manufacturer must notify EPA 
by letter to the Agency's designated compliance officer to explicitly 
identify both: (1) The designated calendar year(s) where in-use PM 
pilot program testing will be forgone, and (2) the designated calendar 
year(s) when their obligations for PM pilot testing will be completed. 
We are proposing that this notification must be provided to the Agency 
by January 7, 2011 and must be quickly updated if planned testing 
changes for any calendar year.
4. Removing the PM Accuracy Test Program From the Regulations
    We are taking this opportunity to delete the references in Sec.  
86.1935 that pertain to the final report for PM emission accuracy 
margin and the consequences that would ensue if the report was delayed 
beyond certain dates. These provisions are no longer needed because 
accuracy margin for PM pollutants are being promulgated in this Direct 
Final Rule. This will result in removal of Sec.  86.1935 from the 
regulations in its entirety and any references made to Sec.  86.1935 
throughout 40 CFR part 86.

B. Revisions to 40 CFR 1033.150 To Allow the Use of Earlier Model Year 
Switch Engines With Equivalent Emission Controls

    Section 1033.150(e) allows the use of certified 2008 and later 
nonroad engines in switch locomotives. We are proposing to extend the 
allowance to include nonroad engines produced in model years before 
2008 as long as they were certified to the same standards as 2008 
engines. This extension will not have any emissions impact since the 
engines will be required to have the same emission controls with or 
without the revisions.

C. Revision of 40 CFR Part 1065 To Clarify the Requirements for PM PEMS 
Testing

    We are taking this opportunity to propose minor technical 
amendments to 40 CFR part 1065 that are mostly related to the 
requirements for in-use PM instrumentation and that arose from 
knowledge gained during the accuracy margin laboratory and field work 
mentioned in Section A. above. The proposed changes are specified in 
the following paragraph. The reasons for these proposed revisions are 
detailed in a separate document.\11\ The proposed amendments have no 
effect on the stringency of the regulations, but simply improve and 
increase testing efficiency, allow new measurement techniques, or 
otherwise clarify the regulatory requirements.
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    \11\ See ``List of Part 1065 Changes Resulting from HDIUT PM MA 
Program'', dated June 2010. A copy of this list is available in the 
public docket for this rule.
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    The proposed amendments are as follows:
    1. We propose to remove the requirement to control dilution air 
temperature for in-use testing;
    2. We propose adding an in-use filter face velocity specification;
    3. We propose adding an in-use filter face temperature 
specification;
    4. We propose specifying that there is no requirement for control 
of humidity control for in-situ PM analyzers;
    5. We propose allowing the use of a fixed molar mass for the dilute 
exhaust mixture for field testing;
    6. We propose deleting the frequency and rise/fall time specs for 
inertial batch PM analyzers;
    7. We propose adding a statement that field testing applies at any 
ambient temperature, pressure and humidity, unless otherwise specified 
in the standard setting part (e.g., 40 CFR part 86 for heavy-duty 
highway engines);
    8. We propose adding language to state that EPA approves of 
electrostatic

[[Page 68579]]

deposition technique for PM collection and that the technique must meet 
95% collection efficiency, as validated by the manufacturer;
    9. We propose excluding PM PEMS from the system-response and 
updating-recording verification requirements;
    10. We propose clarifying when an HC contamination check of the 
sampling system should take place;
    11. We propose allowing the use of a PM loss correction to account 
for PM loss in the inertial balance, including the sample handling 
system for in-use testing only;
    12. We propose making a clarification on how to handle positive 
displacement pump (PDP) pressure calibrations at maximum pressure;
    13. We propose allowing a restart of the hot portion of the 
transient test if the hot start was void;
    14. We propose making some language changes to make the language 
used more consistent throughout the document; and
    15. We propose correcting typographical errors.

D. Revision of 40 CFR 1065.140 To Allow the Use of Partial Flow 
Dilution Systems for Laboratory Transient Test Cycle PM Measurement

    We are proposing to make changes to 40 CFR part 1065.140(d) to 
allow the use of partial flow sampling systems for measurement of PM 
during transient test cycles for laboratory testing.
    PM measurement has been traditionally performed using a full flow 
dilution tunnel where the entire amount of engine exhaust gas is 
collected and made available for sampling. With this sampling method, 
commonly referred to as a constant volume sampler (CVS), the size of 
the dilution tunnel depends on the exhaust gas volume, thus the greater 
the volume of exhaust gas emitted from the engine, the larger the 
dilution tunnel must be. As an alternative, a partial-flow dilution 
tunnel allows sampling of part of the total exhaust flow, which reduces 
the size of the sampling system. One of the drawbacks to partial flow 
sampling systems in the past was that the flow controllers did not have 
a fast enough response time to accurately respond to the changing 
exhaust flow rates during a transient cycle. Thus partial flow sampling 
systems were only allowed for use during steady-state cycle testing. 
Recent advancements in the development of fast response flow control 
systems, along with the advancement in the understanding of PM 
formation characteristics have made partial flow sampling systems a 
viable technology for use in transient applications when compared to 
the CVS reference method.
    We currently allow the use of partial flow sampling systems for 
measurement of PM for steady-state and ramped modal cycle (RMC) testing 
and have put specifications in place in 40 CFR 1065.140(e) with respect 
to dilution air temperature, minimum dilution ratio, filter face 
temperature, and residence time to control PM formation. These 
specifications have further worked to improve the accuracy of partial 
flow systems when compared to the CVS.
    We initially proposed this allowance in the locomotive and 
compression-ignition marine engines less than 30 liters per cylinder 
NPRM, but did not finalize it due to concerns over the viability of 
partial flow systems in transient applications.12 13 Since 
promulgating that rule, EPA has worked with industry to gain a better 
understanding of partial flow systems and the improvements that have 
been made over the past decade. We have also reviewed additional data 
supplied by engine and partial flow system equipment manufacturers 
showing comparisons between the traditional CVS and partial flow 
systems for PM measurement.\14\ These data have shown that partial flow 
measurement of PM is a viable tool for measurement in transient 
applications and these systems can meet the dilution parameter control 
requirements in 40 CFR 1065.140 as well as the flow rate linearity 
requirements in 40 CFR 1065.307, Table 1, and the validation of 
proportional flow control requirement in 40 CFR 1065.545. Further, 
correlation testing involving partial flow systems and CVS based 
systems has shown that the partial flow method is equivalent to the CVS 
method via t- and f-test analysis. In light of these recent 
disclosures, EPA is proposing to allow the use of this measurement 
technique.\15\
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    \12\ See ``Proposed Rule: Control of Emissions of Air Pollution 
from Locomotives and Marine Compression-Ignition Engines Less than 
30 Liters per Cylinder'', 72 FR 34594 (April 3, 2007).
    \13\ See ``Final Rule: Control of Emissions of Air Pollution 
from Locomotives and Marine Compression-Ignition Engines Less Than 
30 Liters per Cylinder'', 73 FR (May 6, 2008).
    \14\ See ``Sierra Instruments Model BG-3 vs. CVS Multiple Engine 
Correlation Study'', dated November 2009. A copy of this list is 
available in the public docket for this rule.
    \15\ Compliance evaluation when conducted by the Administrator, 
independent of the method for dilution, become the official results. 
Manufacturers should be prepared to demonstrate compliance with the 
full flow CVS even if initial certification was conducted using a 
partial flow dilution system. EPA will continue to use the CVS-based 
PM measurement method for our own compliance testing regardless of 
what method the manufacturer used to certify the engine.
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E. Revision of 40 CFR 86.1370 To Clarify How To Handle NTE Events 
During Regeneration

    We are proposing to further define how to handle regeneration 
events that occur during real world in-use NTE tests. The current text 
as it exists in 40 CFR 86.1370-2007(d)(2) has caused confusion with 
respect to determination of the NTE minimum averaging period.
    This proposed revision would establish a new method to calculate 
the minimum averaging period. The intent here is to minimize the number 
of voided NTE events due to regeneration for systems that undergo 
frequent and/or infrequent regeneration, while ensuring that the NTE 
averaging time is appropriate based on the regeneration time.
    The regeneration duty cycle fraction over the course of the entire 
test day can be determined by dividing the mean time of the complete 
regeneration events (state 2) by the sum of the mean time of the non-
regeneration events (state 0) and the mean time of the complete 
regeneration segments including time in those segments where 
regeneration is pending (states 1 and 2).
    To determine whether an NTE that includes a regeneration event is 
valid, the minimum average time is determined by summing the portion of 
the NTE event that occurs during regeneration and dividing by the 
fraction of time over the entire sampling period, i.e., shift-day, that 
regeneration occurred for complete regeneration events. This latter 
term is referred to as the regeneration fraction. If the duration of 
the NTE is greater than or equal to this minimum average time, then the 
NTE event is valid.\16\ For example, if an NTE event was 125 seconds 
long and contained 25 seconds of regeneration, and regeneration 
fraction was 0.24, the minimum averaging time for this NTE event is 104 
seconds (25/0.24 = 104). In this example, the NTE event would be valid.
---------------------------------------------------------------------------

    \16\ See, Letter from EMA to EPA, ``Treatment of Overlapping NTE 
and Regeneration Events (July 29, 2009). A copy of the report is 
available in the public docket for this rule.
---------------------------------------------------------------------------

F. Revision of 40 CFR 1065.915 To Allow the Use of ECM Fuel Rate To 
Determine NTE Mass Emission Rate

    We are proposing to allow the use of fuel rate data that is 
available from the engine's electronic control module (ECM) along with 
other information, including the CO2, CO, and hydrocarbon 
emissions to calculate the requisite exhaust flow rate for mass 
emission rate determination. We believe that all large horsepower 
nonroad diesel engines will

[[Page 68580]]

be equipped with ECMs that report fuel flow within the time frame 
proposed for implementation of the in-use testing program. The ECM fuel 
flow rate-based methodology currently requires prior EPA approval under 
40 CFR 1065.915(d)(5)(iv). This pre-approval requirement is based on 
past concerns with respect to the accuracy of the ECM broadcast fuel 
flow rate when calculating brake-specific emission results in the 
absence of an exhaust flow measurement. However, more recent 
information from the cooperative in-use emission measurement allowance 
program for PEMS showed that emission calculations incorporating the 
ECM fuel rate yielded results comparable to those using approved 
calculation methodology.\17\ Based on that study and the inclusion of 
ECM derived BSFC in the determination of the accuracy margin, we are 
proposing to eliminate the requirement that a manufacturer must have 
EPA approval to use this method to determine exhaust flow rates via an 
amendment to 40 CFR 1065.915.
---------------------------------------------------------------------------

    \17\ See ``Determination of PEMS Measurement Allowances for 
Gaseous Emissions Regulated under the Heavy-Duty Diesel Engine In-
Use Testing Program, dated April, 2007. A copy of the report is 
available in the public docket for this rule and at the EPA/OTAQ Web 
site (http://www.epa.gov/otaq/hd-hwy.htm).
---------------------------------------------------------------------------

G. Revision of 40 CFR 1045.145 To Extend the Notification Deadline for 
Small-Volume Manufacturers of Marine SI Engines

    Our current regulations for sterndrive/inboard marine SI engines 
allow for delayed implementation of emission standards for small-volume 
manufacturers making sterndrive/inboard marine SI engines (see Sec.  
1045.145(a)). One requirement related to this delay is for the 
manufacturer to notify EPA before the standards take effect. However, 
we have learned that there are some small-volume engine manufacturers 
that have not yet learned about the new emission standards. We believe 
it is appropriate to extend the notification deadline for these 
manufacturers by one year to allow for further communications related 
to the new requirements. To accommodate the proposed later deadline, we 
are also proposing to add language in the regulation to clarify that 
manufacturers need to notify EPA before introducing such engines into 
U.S. commerce for them to have a valid temporary exemption. These 
proposed revisions address the logistical challenges related to 
implementing the new standards without changing the effective 
implementation schedule of the original rule.
    These proposed revisions address the logistical challenges related 
to implementing the new standards without changing the effective 
implementation schedule of the original rule.

H. Revision of 40 CFR 1039.102 To Enable Phase Out of Tier 3 Diesel 
Engines

    When creating 40 CFR 1039.102 (69 FR 39213, June 29, 2004), we 
included provisions intended to allow engine manufacturers to use 
emission credits to continue producing a small number Tier 3 nonroad 
diesel engines after the Tier 4 standards began to apply. However, we 
now realize that the provisions may not work as intended because the 
Tier 4 averaging programs inadvertently do not allow manufacturers to 
show compliance with the applicable 0.19 g/kW-hr NMHC standard using 
credits. In today's rulemaking, we are proposing to amend this section 
to allow manufacturers to use credits to show compliance with alternate 
NOx + HC standards. The alternate NOX + NMHC 
standards for each power category would be equal to the numerical value 
of the applicable alternate NOX standard of Sec.  
1039.102(e)(1) or (2) plus 0.10 g/kW-hr. Engines certified to these 
NOX + NMHC standards may not generate emission credits. 
Since additional 0.10 g/kW-hr for the combined standard is less than 
the otherwise applicable NMHC standard, there would be a small 
environmental benefit when manufacturers choose to certify to the 
alternate standards.

I. Revision of 40 CFR 1039.625 To Revise TPEM Provisions for Special 
High-Altitude Equipment

    We have been made aware of a number of unique challenges involved 
in implementing Tier 4 requirements for certain specialized high-
altitude equipment. In setting the Tier 4 standards in 2004, we 
anticipated that typical engineering challenges would arise in 
redesigning machines to use the new engines, and we restructured our 
transition program for equipment manufacturers, first established in 
the Tier 2/Tier 3 rule, to help manufacturers deal with these 
challenges. This important flexibility program has been highly 
successful. We do feel that a minor adjustment is warranted for the 
specialized high-altitude equipment identified.
    This equipment is designed for use on snow and, for at least some 
of its operating life, at elevations more than 9,000 feet above sea 
level. The applications are ski area snow groomers, both alpine and 
cross-country, and personnel transporters used in search and rescue 
operations, and maintenance of utility lines and towers.
    One manufacturer of this equipment, has identified a number of 
technical issues specific to the equipment, including:\18\
---------------------------------------------------------------------------

    \18\ E-mail from Jean-Claude Perreault, Prinoth Ltd, to Byron 
Bunker, U.S. EPA, ``Prinoth technical information'', June 8, 2010.
---------------------------------------------------------------------------

    1. Reliability: The performance of the new engine and 
aftertreatment components is untested at high altitudes in winter 
conditions. Engine operating temperatures may be elevated at higher 
altitudes with potential impacts on engine performance and reliability;
    2. Cold Starting: Diesel cold starting is aggravated at high 
altitudes due to lower oxygen availability. No-start situations for 
high-altitude equipment may be life threatening;
    3. Engine power: The degree to which a Tier 4 engine's power is 
reduced, i.e., derated, with increasing altitude is unproven. Excessive 
derate would hinder the vehicles' snow grooming function and 
performance;
    4. Particulate filter regeneration: These machines operate for long 
periods traveling downhill with little engine load. Regeneration must 
be validated;
    5. Functioning in extreme conditions: Snow groomers must 
reliability push and grind snow and ice in extreme conditions, 
including while moving up and down steep grades; and
    6. Weight: The added weight of Tier 4 aftertreatment and cooling 
components will directly affect ground pressure, which can hamper a 
snow groomer's essential function.
    In identifying these issues, the manufacturer stated that it 
expects two, possibly three, winters of prototype testing are needed to 
work through these issues and believes that flexibility in the use of 
exemptions provided by the Tier 4 transition program is key to enabling 
this. We have evaluated the technical issues, and have concluded there 
are likely to be some unique challenges in implementing Tier 4 for 
high-altitude equipment of this type.
    In response, to provide modest but meaningful additional 
flexibility, we are proposing to remove the single engine family 
restriction for the use of the small volume provision allowing 700 
exempted units over seven years. This proposed additional flexibility 
would only apply for manufacturers of specialized high-altitude 
equipment (designed to commonly operate above 9,000 feet), and only in 
the first two model years of Tier 4 standards.

[[Page 68581]]

Afterward, the single engine family restriction would apply. In no case 
would the 700 unit maximum over seven years be exceeded.
    We do not expect that this change will result in a significant 
negative impact on any engine or equipment manufacturers. Engine 
manufacturers are already expecting to produce some Tier 4 engines for 
the transition program, and the number of additional exempted engines 
will be relatively small. Equipment manufacturers can either take 
advantage of this change, or are already able to exempt the same number 
of affected machines for several years under the existing transition 
program provisions.
    We also believe the impact of this proposed modification on Tier 4 
environmental benefits will be negligible, given that: (1) It only 
applies to the small volume portion of the transition program, (2) the 
total U.S. annual sales of specialized high-altitude equipment is, at 
most, a few hundred, (3) much of this equipment operates for only a 
part of the year, (4) the modification only applies in the first two 
Tier 4 model years, and does not increase the overall exemption limit 
of 700 over seven years.

J. Revision of 40 CFR 1054.101 To Clarify Prohibitions Related to 
Handheld Small SI Engines Installed in Nonhandheld Equipment

    The existing regulations related to emission standards for nonroad 
spark-ignition engines below 19 kW specifically prohibit the sale of 
nonhandheld equipment equipped with handheld engines. The regulations 
in Sec.  1054.101 state that handheld engines may not be installed in 
nonhandheld equipment, but the regulatory text does not state that this 
is prohibited under Sec.  1068.101 or identify which penalty provisions 
apply. In this rule we are proposing to add a statement to Sec.  
1054.101(e) to describe how this action violates the prohibited acts 
identified in Sec.  1068.101, consistent with the regulations under 40 
CFR part 90.

K. Revision of 40 CFR 1042 Appendix II To Correct Time Weighting at 
Mode for Engines Certifying to the E2 RMC Cycle

    The existing regulations contain an error in the time at mode for 
each steady-state point when certifying an engine to the E2 ramped 
modal cycle (RMC). When the E2 RMC cycle was generated, the times at 
mode were not correct based on the weighting of the discrete-mode 
cycle. In this notice we are proposing to correct the time at mode for 
all four steady-state portions of the E2 RMC cycle to correspond with 
the mode weighting for the discrete-mode test.

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    This proposed 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 the EO. EPA is 
taking direct final action on several revisions to EPA's mobile source 
emission programs standards and test procedures. This proposed rule 
merely contains several minor and noncontroversial technical amendments 
to EPA's mobile source emission programs as described in the Summary 
and Section IV. Details of the Proposed Rule.

B. Paperwork Reduction Act

    This proposed action does not impose an new information collection 
burden under the provisions of the Paperwork Reduction Act, 44 U.S.C. 
3501 et seq. Burden is defined at 5 CFR 1320.3(b). It merely contains 
several minor and noncontroversial technical amendments to EPA's mobile 
source emission programs as described in the Summary and Section IV. 
Details of the Proposed Rule. Therefore, there are no new paperwork 
requirements associated with this proposed rule.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of this proposed rule on 
small entities, a small entity is defined as: (1) A small business that 
meet the definition for business based on SBA size standards at 13 CFR 
121.201; (2) a small governmental jurisdiction that is a government of 
a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise which is independently owned and operated 
and is not dominant in its field.
    After considering the economic impacts of today's proposed rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities. This 
proposed rule will not impose any new requirements on small entities.
    EPA has determined that it is not necessary to prepare a regulatory 
flexibility analysis in connection with this proposed rule. It merely 
contains several minor and noncontroversial technical amendments to 
EPA's mobile source emission programs as described in the Summary and 
Section IV. Details of the Proposed Rule. We have, therefore, concluded 
that today's proposed rule will not affect the regulatory burden for 
all small entities and will not have a significant economic impact on a 
substantial number of small entities.

D. Unfunded Mandates Reform Act

    This proposed rule contains no federal mandates for state, local, 
or tribal governments as defined by the provisions of Title II of the 
UMRA. The proposed rule imposes no enforceable duties on any of these 
governmental entities. Nothing in the proposed rule would significantly 
or uniquely affect small governments. EPA has determined that this 
proposed rule contains no federal mandates that may result in 
expenditures of more than $100 million to the private sector in any 
single year. It merely contains several minor and noncontroversial 
technical amendments to EPA's mobile source emission programs as 
described in the Summary and Section IV. Details of the Proposed Rule. 
We have, therefore, concluded that today's proposed rule will not 
effect the regulatory burden for all small entities and will not have a 
significant economic impact on a substantial number of small entities. 
See the direct final rule EPA has published in the ``Rules and 
Regulations'' section of today's Federal Register for a more extensive 
discussion of UMRA policy.

E. Executive Order 13132: Federalism

    This proposed rule 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 proposed rule merely 
contains several minor and noncontroversial technical amendments to 
EPA's mobile source emission programs as described in the Summary and 
Section IV. Details of the Proposed Rule. We have, therefore, concluded 
that today's proposed rule will not affect

[[Page 68582]]

the regulatory burden for all small entities and will not have a 
significant economic impact on a substantial number of small entities. 
See the direct final rule EPA has published in the ``Rules and 
Regulations'' section of today's Federal Register for a more extensive 
discussion of Executive Order 13132.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This proposed rule does not have tribal implications. It will not 
have substantial direct effects on tribal governments, on the 
relationship between the Federal government and Indian tribes, or on 
the distribution of power and responsibilities between the Federal 
government and Indian tribes, as specified in Executive Order 13175. 
This proposed rule does not uniquely affect the communities of Indian 
Tribal Governments. Further, no circumstances specific to such 
communities exist that would cause an impact on these communities 
beyond those discussed in the other sections of this rule. This 
proposed rule merely contains several minor and noncontroversial 
technical amendments to EPA's mobile source emission programs as 
described in the Summary and Section IV. Details of the Proposed Rule. 
We have, therefore, concluded that today's proposed rule will not 
affect the regulatory burden for all small entities and will not have a 
significant economic impact on a substantial number of small entities. 
Thus, Executive Order 13175 does not apply to this rule. See the direct 
final rule EPA has published in the ``Rules and Regulations'' section 
of today's Federal Register for a more extensive discussion of 
Executive Order 13132.

G. Executive Order 13045: Protection of Children From Environmental 
Health and Safety Risks

    This proposed rule is not subject to the Executive Order because it 
is not economically significant, and does not involve decisions on 
environmental health or safety risks that may disproportionately affect 
children. See the direct final rule EPA has published in the ``Rules 
and Regulations'' section of today's Federal Register for a more 
extensive discussion of Executive Order 13045.

H. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This proposed rule is not a ``significant energy action'' as 
defined in Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 
28355, May 22, 2001) because it is not likely to have a significant 
adverse effect on the supply, distribution or use of energy. This 
proposed rule merely contains several minor and noncontroversial 
technical amendments to EPA's mobile source emission programs as 
described in the Summary and Section IV. Details of the Proposed Rule. 
We have, therefore, concluded that today's proposed rule will not 
affect the regulatory burden for all small entities and will not have a 
significant economic impact on a substantial number of small entities.

I. National Technology Transfer and Advancement Act

    This proposed rule does not involve technical standards. This 
proposed rule merely contains several minor and noncontroversial 
technical amendments to EPA's mobile source emission programs as 
described in the Summary and Section IV. Details of the Proposed Rule. 
We have, therefore, concluded that today's proposed rule will not 
affect the regulatory burden for all small entities and will not have a 
significant economic impact on a substantial number of small entities. 
Thus, we have determined that the requirements of the NTTAA do not 
apply. See the direct final rule EPA has published in the ``Rules and 
Regulations'' section of today's Federal Register for a more extensive 
discussion of NTTAA policy.

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

    EPA has determined that this proposed rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it does not 
affect the level of protection provided to human health or the 
environment. See the direct final rule EPA has published in the ``Rules 
and Regulations'' section of today's Federal Register for a more 
extensive discussion of Executive Order 13045.

K. Statutory Authority

    The statutory authority for this action comes from 42 U.S.C. 7401-
7671q.

List of Subjects

40 CFR Part 86

    Environmental protection, NTE, Administrative practice and 
procedure, Confidential business information, Labeling, Motor vehicle 
pollution, Reporting and recordkeeping requirements.

40 CFR Part 1033

    Environmental protection, Administrative practice and procedure, 
Confidential business information, Incorporation by reference, 
Labeling, Penalties, Railroads, Reporting and recordkeeping 
requirements.

40 CFR Part 1039

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

40 CFR Part 1042

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Confidential business information, Imports, 
Incorporation by reference, Labeling, Penalties, Vessels, Reporting and 
recordkeeping requirements, Warranties.

40 CFR Part 1045

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

40 CFR Part 1054

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

40 CFR Part 1065

    Administrative practice and procedure, Air pollution control, 
Reporting and recordkeeping requirements, Research.

    Dated: October 29, 2010.
Lisa P. Jackson,
Administrator.
[FR Doc. 2010-27894 Filed 11-5-10; 8:45 am]
BILLING CODE 6560-50-P