[Federal Register: March 13, 2008 (Volume 73, Number 50)]
[Rules and Regulations]
[Page 13441-13452]
[DOCID:fr13mr08-6]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 86

[EPA-HQ-OAR-2004-0072; FRL-8539-3]
RIN 2060-A-069

In-Use Testing for Heavy-Duty Diesel Engines and Vehicles;
Emission Measurement Accuracy Margins for Portable Emission Measurement
Systems and Program Revisions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Direct final rule.

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SUMMARY: In a rule published on June 14, 2005, EPA established a
manufacturer-run, in-use testing program for heavy-duty diesel
vehicles. The program requires engine manufacturers to measure exhaust
emissions from their diesel engines using portable emissions
measurement systems during real-world operation. At the time the rule
was promulgated, EPA established interim emission measurement
``accuracy'' margins for the requisite portable emission measurement
devices pending the development of final accuracy margins through a
comprehensive research program. This Direct Final Rule adopts the
resulting final accuracy margins for gaseous pollutants. Also, this
rule makes several changes to the program in the early years of in-use
testing. First, we are eliminating the first calendar year, i.e., 2006,
of the two-year pilot program for particulate emissions (PM) in
response to engine manufacturers' concerns, which primarily relate to
the availability and efficacy of the requisite portable measurement
systems (PEMS) for that pollutant. Second, due to a delay in developing
the final accuracy margin for PM under the aforementioned comprehensive
research program, we are delaying the first year of the fully
enforceable PM test program from the 2008 calendar year to the 2009
calendar year. During the 2008 calendar year, there will be another
year of pilot program testing for that pollutant. Third, and finally,
we are extending the normal period for reporting in-use test results
during the initial years of the program and allowing certain short-term
changes in how vehicles are recruited and tested. These revisions are
primarily intended to address delays in initiating the gaseous emission
and PM pilot programs, manufacuturers' concerns regarding the schedule
for initial purchases of PM measurement systems, and manufacturers'
concerns regarding potential difficulties of initially instrumenting
vehicles with these units.

DATES: This is effective on May 12, 2008 without further notice, unless
EPA receives adverse comment by April 14, 2008. If EPA receives adverse
comment, we will publish a timely withdrawal of the Direct Final Rule
in the Federal Register informing the public that the rule will not
take effect.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2004-0072, by one of the following methods:
     www.regulations.gov: Follow the on-line instructions for
submitting comments.
     E-mail<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     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-
2004-0072. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
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 www.regulations.gov or e-mail.
The 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 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
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 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<PHONE_NUMBER>, and the telephone
number for the Air Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Richard 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:<PHONE_NUMBER>; e-mail address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. Why Is EPA Using a Direct Final Rule?

    EPA is publishing this rule without a prior proposal because we
view this action as noncontroversial and anticipate no adverse comment.
However, in the ``Proposed Rules'' section of today's Federal Register
publication, we are publishing a separate document that will serve as
the proposal to adopt the provisions in this Direct Final Rule if
adverse comments are received on this rule. We will not institute a
second comment period on this action, however. 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 or a request for public hearing, we
will publish a timely withdrawal in the Federal Register informing the
public that this direct final rule will not take effect. We would
address all public comments in any subsequent final rule based on the
proposed rule.

II. Does This Action Apply to Me?

    This action will affect companies that manufacture and certify all-
terrain vehicles for sale in the United States.

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                                                        Examples of
           Category              NAICS code \a\     potentially affected
                                                          entities
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Industry.....................      336112; 336120  Engine and Truck
                                                    Manufacturers.
Industry.....................      811112; 811198  Independent
                                                    commercial importers
                                                    of vehicles and
                                                    parts.
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\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
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. 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 those 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.
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    \1\ See ``Control of Emissions of Air Pollution From New York
Motor Vehicles: In-Use Testing for Heavy-Duty Diesel Engines and
Vehicles, 70 FR 34594 (June 14, 2005).''
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    The in-use testing program begins with a two-year pilot (i.e.,
demonstration) program for gaseous emissions (i.e., NMHC, CO, and
NOX) in calendar years 2005 and 2006. As originally adopted,
the program also includes a pilot program for PM emissions in calendar
years 2006 and 2007. The one-year offset acknowledged that the portable
measurement system technology for PM emissions was lagging that for
measuring gaseous emissions. The programs are fully enforceable after
their respective pilot program ends, i.e., the 2007 calendar year for
gaseous emissions and the 2008 calendar year for PM emissions. The
enforceable program applies to 2007 and later model year diesel
engines. Each manufacturer generally has 18 months to report all
required test results for the engine families that EPA selects for
testing in any calendar year.
    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. The accuracy
allowances are 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 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 promulgated
interim accuracy allowances for use in the pilot programs.\2\ 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.
    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, i.e.,
beginning in the 2007 calendar year for gaseous emissions and the 2008
calendar year for PM.\3\ 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 PM emission accuracy
margins. The program was to be managed by EPA, in close cooperation
with CARB and the involved engine manufacturers.
    The MOA also addressed the consequences of failing to complete the
accuracy margin development work in time for the scheduled start of
either the gaseous or PM enforceable programs. Two of these provisions
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 affected gaseous emissions or PM enforceable program, i.e.,
either gaseous emissions or PM, would be delayed by the same number of
months up to three months. The second provision addresses delays in
excess of three months. In particular, if the accuracy allowances were
delayed beyond three months of the agreed upon dates, then the affected
gaseous or PM enforceable program would be placed in abeyance for a
year and the respective pilot program would be extended to include that
year using the interim allowance(s).
    Finally, the MOA acknowledged that if fundamental, irresolvable
technical problems were identified relative to PM PEMS, the PM portion
of the in-use testing program would be placed into abeyance until such
time as suitable devices were identified and available, or the problems
otherwise resolved.

V. Details of the Rule

    This Direct Final Rule establishes new, final gaseous emission
measurement margins that are required for the manufacturer-run, in-use
test program for heavy-duty diesel vehicles and engines. This Direct
Final Rule also makes several changes to the in-use test program in the
early years of testing. First, it places the fully enforceable PM
program, which would have begun in 2008, into abeyance for one year due
to delays in the accuracy margin development program. In its place, the
pilot program for PM will be extended into 2008. Second, it grants a
request by EMA and its member companies to place the 2006 PM pilot
program into abeyance to accommodate their concerns regarding the
availability and efficacy of PM PEMS. Third, it provides engine
manufacturers with additional time to conduct in-use testing and report
the results to EPA because of delays in developing the requisite
electronic reporting guidance, additional short-term delays in the PM
accuracy margin development program, and to grant a request from some
engine manufacturers to delay PM PEMS purchasing decisions until they
could evaluate the initial results of the PM accuracy margin. That will
allow them to make more refined purchasing decisions and to have the
resulting PM PEMS include any instrumentation upgrades that may be
forthcoming. Fourth, it grants a request from engine manufacturers for
the flexibility to recruit and test separate vehicles for the 2007 and
2008 gaseous emissions and PM test programs, and to recruit test
vehicles from their internal fleets and test them while being operated
by company employees for the 2007 PM pilot program. This addresses the
manufacturers' concerns that procuring and instrumenting test vehicles
with PM PEMS could, in some instances, be more complex and time
consuming than for gaseous emissions testing. Finally, this rulemaking
removes references in the applicable regulations to the development of
final accuracy margins for measuring gaseous emissions with portable
systems because that program has been completed. Each of these changes
is further described separately below.

A. Gaseous Emission Measurement Margins for Manufacturer-Run, In-Use
Testing

1. Results of the Test Program Under the Memorandum of Agreement (MOA)
    The MOA (described in section IV.) called for development of a
comprehensive test plan for determining the final emission measurement
accuracy margins for the manufacturer-run, in-use testing program. The
test plan for the gaseous pollutants was subsequently agreed upon on
May 20, 2005.\4\ 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 margins; and (4) validation
of the simulation model results and resulting accuracy margins 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 measurement allowances.
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.
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    \2\ 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.
    \3\ 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).
    \4\ See ``Test Plan to Determine PEMS Measurement Allowances for
the Gaseous Emissions Regulated Under the Manufacturer-Run Heavy-
Duty Diesel In-Use Testing Program,'' for the U.S. Environmental
Protection Agency, California Air Resources Board, and Engine
Manufacturers Association, dated May 20, 2005. 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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    The test plan also contained the statistically-based algorithms for
calculating the data-driven margins for

the gaseous pollutants in addition to three different brake-specific
calculation methods for determining emission results (i.e., grams/bhp-
hr) from in-use data. The first two of these methods (Methods 1 and 2
below) are described in 40 CFR 1065.650(a)(1) and (3). The third method
has been suggested by the engine manufacturers and would require prior
approval of the Administrator before it could be used as provided for
in 40 CFR 1065.915(d)(5)(iv). The basic calculation is similar for each
of the three methods and is shown generically in the following
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equation:

Brake-Specific Emissions = Mass of Pollutant/Work Performed

Where:
    Mass of Pollutant = Exhaust Pollutant Concentration x Exhaust
Flow Rate

    The three methods differ primarily in how the exhaust flow rate or
the work portion (i.e., brake horsepower-hours) of the calculation is
determined. The methods are also more fully described in the test plan.
    After the simulation modeling results for the three calculation
methods were completed, the test plan called for the final set of
accuracy margins (i.e., NMHC, CO, and NOX) to be determined
by the following generalized process. First, identify the maximum
percentage measurement error associated with any of the three
pollutants, i.e., without regard to the pollutant species, for each of
the three calculation methods.\5\ Second, from these three maximum
values, select the method with the lowest or minimum value. Third, and
finally, use the results from that method to determine the measurement
accuracy margins for all of the pollutants.
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    \5\ The percentage error for each pollutant and calculation
method was found by dividing the associated numerical result from
the simulation model by an NTE limit. EPA determined the NTE limit
by multiplying an assumed in-use emission rate from future heavy-
duty diesel engines in the 2010 model year timeframe by the
multiplier that is used to calculate the NTE standard. In this case
the multiplier is 1.5. See 40 CFR 86.007-11(a)(4) for more
information on the NTE multiplier.
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    The cooperative test program for gaseous pollutants as described in
the MOA was completed and a final report issued.\6\ \7\ When the
predicted results from the model simulations were compared to the
mobile emissions laboratory results, only Method 1 could be validated
for NMHC and NOX. Methods 2 and 3 could only be validated
for NMHC. None of the methods validated for CO. While unexpected, the
lack of overall validation for the three methods is not necessarily
surprising given the enormous amount of laboratory-based and on-vehicle
testing, the number of possible errors and the model simulations (i.e.,
thousands of simulation runs), and complexity of the overall
cooperative test program.
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    \6\ See ``Gaseous Emission Measurement Accuracy Margins for
Portable Emission Measurement Systems Used in the Heavy-Duty Diesel
Engine In-Use Testing Program: Revised Final Report,'' U.S.
Environmental Protection Agency, February 2008, EPA report number:
EPA420-R-08-005. 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).
    \7\ The estimated cost of the gaseous emission measurement
accuracy margin test program is $2.2 million.
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    The emission test data, simulation model, and in-use validation
data were investigated further to determine if there were any errors
that could be remedied to resolve the validation problems. While this
investigation identified some reasons for the lack of validation and
potential additional work that might lead to fully validated results,
none of additional work was judged to be possible under the schedule
for determining the final set of gaseous emission accuracy allowances
as required by the MOA.
    In order to ensure that the fully enforceable program for gaseous
emissions started on schedule and to provide an orderly transition for
engines designed and produced during the early years of the program,
the emission measurement accuracy margins from Method 1 were chosen for
use in the fully enforceable program for 2007 through 2009 model year
engine families regardless of the calendar year in which they may be
selected for testing.\8\ Therefore, the accuracy margins based on the
completed test program only apply to the emission results calculated
using Method 1 for these initial three model years.\9\ The resultant
emission measurement accuracy margins are: 0.02 for NMHC; 0.5 for CO;
and 0.45 for NOX.
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    \8\ Method 1 was chosen because it was the only method that was
validated for the two most environmentally important pollutants from
heavy-duty diesel truck engines, i.e., NMHC and NOX.
    \9\ The test program results led to no accuracy allowances for
either of the other two calculation methods from 2007 through 2009
model year engine families.
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    At the time Method 1 was selected, it was anticipated that EPA
would continue to develop validated results for the remaining methods,
although it was unknown how long that work might take. It was also
anticipated that if the work was successful, new accuracy margins could
be established through rulemaking, although the above accuracy margins
for Method 1 would be retained for 2007 through 2009 model year engine
families, as described above.
2. Results of Additional Gaseous Measurement Margin Analysis
    At the end of the cooperative test program that eventually led to
using the accuracy margins for Method 1 testing for 2007 through 2009
model year engine families, EPA expressed its intent to continue work
to develop more robust gaseous emission measurement accuracy margins,
especially for NOX, as originally anticipated in the test
program plan. We envisioned this work would primarily focus on the
reasons for the lack of validation and potential additional work that
was identified at the end of the original test program, as previously
discussed.
    In our follow-on work we corrected an error in the previous test
data, included additional valid engine test data that was not used in
the original work, and eliminated or corrected some error biases or
data outliers in the data set based on engineering judgment. A total of
four different modified data sets or scenarios were constructed for
combinations of the changes described above for each of the three
calculation methods.\10\ After rerunning the simulation model for the
various combinations, we found that each of the four modifications
validated for all three methods and all the gaseous pollutants.
Furthermore, we found that the results from the various methods for
each pollutant were numerically quite close to each other.
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    \10\ See ``Additional Analyses of the Monte Carlo Model
Developed for the Determination of PEMS Measurement Allowances for
Gaseous Emissions Regulated Under the Heavy-Duty Diesel Engine In-
Use Testing Program,'' August 2007, EPA report number: EPA420-R-07-
010. 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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    In order to select final accuracy margins from the validated
results described above, we evaluated each of the modified data sets to
identify the most appropriate and reasonable revision from an
engineering science perspective (or based on good engineering
practice). Based on this evaluation, we selected the modification
scenario where some data from three test points (emission results at
specific engine speed and load combinations) from one of the test
engines were excluded from the data set. These data reflected
atypically elevated levels of NOX with large and
inconsistent measurement errors. The other modification scenarios,
while justifiable, were judged to represent somewhat more extreme or
difficult to

defend manipulations of the data on a relative basis.
    After selecting the most appropriate modified data set, we
determined the final accuracy margins by applying the ``minimum of the
maximums'' selection criteria from the original test plan to the three
calculation methods. This showed that the largest percentage errors
were associated with NOX and that Method 2 had the lowest
error for that pollutant of the three methods.\11\ Therefore, pursuant
to the results of the original test plan, the subsequent validation
work performed by EPA, and after discussions with the other parties to
the MOA, we are promulgating the final emission measurement accuracy
margins shown in Table 1 for all the calculation methodologies
beginning with 2010 model year engine families. Also as shown in the
table, we are adopting these same numerical values for Methods 2 and 3
for 2007 through 2009 model year engines, at the discretion of the
engine manufacturers, in order to provide a full compliment of
calculation methods and accuracy margins for those engines.
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    \11\ ``Selection of Final Gaseous Emission Measurement Accuracy
Margins for Portable Emission Measurement Systems,'' memorandum from
Richard S. Wilcox, U.S. Environmental Protection Agency, to Docket
No. EPA-HQ-OAR-2004-0072, dated November 4, 2007. A copy of the
document is available in the public docket for this rule.

    Table 1.--Final Measurement Accuracy Margins for the Enforceable Gaseous Emissions In-Use Testing Program
----------------------------------------------------------------------------------------------------------------
                                                                       Accuracy margins (g/bhp-hr)
                                                       ---------------------------------------------------------
                                                             2007-2009 model year engines        2010 and later
                       Pollutant                       ---------------------------------------     model year
                                                                                engines
                                                           Method 1 only     Methods 2 and 3  ------------------
                                                                                All methods
----------------------------------------------------------------------------------------------------------------
NMHC..................................................                0.02               0.01               0.01
CO....................................................                0.5                0.25               0.25
NOX...................................................                0.45               0.15               0.15
----------------------------------------------------------------------------------------------------------------

B. NMHC Plus NOX In-Use Testing Accuracy Margins

    The June 2005 final rule that implemented the in-use testing
program addressed accuracy margins for each of the gaseous pollutants
and their associated individual standards, i.e., NMHC, CO, and
NOX. The MOA and subsequent gaseous emissions test program
also focused on identifying the final accuracy margins for these
individual pollutants. In developing the original rule and subsequent
test program, however, we failed to recognize that 2004 through 2006
model year diesel engine families may be certified to a combined
NOX plus NMHC standard under Sec.  86.004-11(a)(1) of the
applicable regulations. Furthermore, under the ``phase-in options'' of
Sec.  86.007-11(g)(1) an engine manufacturer may optionally certify
some of its production in model years 2007 through 2009 to the combined
NOX plus NMHC standard for 2006 model year engines under
Sec.  86.2004-11, rather than the otherwise applicable individual
NOX and NMHC standards. Therefore, we are correcting this
oversight by promulgating in-use testing accuracy margins for 2004-2009
model year engines that may be certified to the combined NOX
plus NMHC standard.
    The methodology for determining an accuracy margin for the combined
NOX plus NMHC emission standard is the same as that used to
determine the numerical value of the combined standard itself.
Specifically, the individual NOX and NMHC accuracy margins
are simply added together to provide a single value. Therefore, for
2004-2007 model year engines that may be tested under the gaseous
emission pilot program for the 2006 and 2007 calendar years, the
combined accuracy margin is the sum of the individual NOX
and NMHC values already contained in Sec.  86.1912, or 0.67 g/bhp-hr.
For engines tested in the enforceable program that begins in the 2007
calendar year and applies to 2007 and later model year diesel engines,
the combined NOX plus NMHC accuracy margins, using the
individual values from Table 1, are shown in Table 2.

 Table 2.--Final Combined NOX Plus NMHC Measurement Accuracy Margins for
        the Enforceable Gaseous Emissions In-Use Testing Program
------------------------------------------------------------------------
                                   Accuracy margins for 2007-2009 model
                                         year engines  (g/bhp-hr)
            Pollutant            ---------------------------------------
                                     Method 1 only      Methods 2 and 3
------------------------------------------------------------------------
NOX + NMHC......................               0.47                0.16
------------------------------------------------------------------------

C. Delaying the Enforceable PM Program From 2008 to 2009

    The MOA described in section IV. acknowledged that in order to
promulgate new measurement accuracy margins with adequate lead time to
begin the 2008 enforceable PM program, certain key milestone dates in
the test program had to be achieved. For example, all the parties
agreed that the final accuracy margins and documentation were needed by
November 1, 2007. That meant the final test plan would have to be
agreed upon by September 2006, given the time needed to complete the
testing and analysis. Contingencies for missing the final delivery date
were specified in the MOA and in the June 2005 final rulemaking.\12\
Most relevant to this action was that if the final values and

documentation were delayed more than three months from November 1,
2007, then the PM pilot program would continue for calendar year 2008
in place of the fully enforceable program for that year.
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    \12\ See 40 CFR 86.1935.
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    Completing the PM test program on schedule required that the
initial work be conducted in parallel with the ongoing gaseous emission
test program using the same contractors and personnel from EPA, CARB,
and the engine manufacturers. Due to unexpected issues in the gaseous
emission test program and the lack of other resources, all work on the
PM test plan and subsequent test program had to be postponed. The end
result of this postponement is that the final accuracy margin for PM
will be delayed by approximately one year. Accordingly, the MOA and in-
use test program regulations require that the first year of the
previously adopted enforceable program (calendar year 2008) be placed
into abeyance and the PM pilot program continued for that year. Hence,
the enforceable PM program will now begin in 2009 calendar year.
    In isolation, delaying the start of the enforceable PM program by
one year and continuing the PM pilot program for that year would result
in a three-year pilot, i.e., 2006 through 2008, as described above.
However, as explained in the next section, we also believe it is
appropriate to eliminate the first year of the original two-year pilot
program. As a result, a two-year PM pilot will still occur as
originally envisioned beginning with the 2007 calendar year.

D. Suspending the 2006 PM Pilot Program

    The in-use testing program, as originally adopted in June 2005,
included a two-year pilot (i.e., demonstration) program for PM
emissions in calendar years 2006 and 2007. In establishing this
requirement, EPA noted that the onboard measurement of PM emissions was
significantly more challenging than for gaseous emissions, and that
further development of the requisite portable measurement systems would
be needed. We also stated that our technical assessment indicated that
these systems would be available in time to start the in-use testing
program. More specifically with regard to the PM pilot program, we
noted our expectation that engine manufacturers would use ``best
available'' prototype systems that were capable of measuring these
emissions as required. Nonetheless, in recognition of the then
remaining technical uncertainties, we added a provision to the
regulations that would suspend the in-use test program as it applied to
PM measurement if we discovered fundamental technical problems with
portable in-use PM measurement systems that could not be resolvable in
a reasonable time.
    In a letter dated January 4, 2007, EMA requested that the first
year of the two-year PM pilot program be held in abeyance.\13\ The
principle reasons were summarized as follows: (1) Suitable portable
measurement systems are not commercially available; (2) fundamental
technical issues remain to be resolved; (3) the joint program to
develop a data-driven PM accuracy margin for these devices has been
delayed at least one year; and (4) the final in-use testing regulation
and the MOA require the one-year delay. The third issue relates to the
delay of the first year of the fully enforceable PM test program from
2008 until 2009 as discussed in the previous section. The last issue
relates to regulatory requirement to delay the PM measurement program
if fundamental technical problems were discovered as described in the
preceding paragraph.
---------------------------------------------------------------------------

    \13\ See letter from Timothy A. French, Engine Manufacturers
Association, to Khesha Jennings, U.S. Environmental Protection
Agency, dated January 4, 2007. A copy of the letter is available in
the public docket for this rule.
---------------------------------------------------------------------------

    Focusing on the first two points, we reminded EMA at the time that
although some parties may interpret the term ``commercially available''
differently, the original rulemaking clearly stated the expectation
that prototype portable measurement systems would be used in the PM
pilot program if they could accurately and reliably measure PM
emissions. This was acceptable because the pilot is designed for the
engine manufacturers and EPA to gain experience in implementing the in-
use testing program and using the portable measurement systems. Also,
we noted that both EPA and some engine manufacturers had already
purchased prototype portable PM measurement systems meeting these
requirements. Finally, we described how we had successfully used the
same prototype system to measure PM emissions over NTE events while
traveling cross-country in a particulate trap-equipped truck using
ultra-low sulfur diesel fuel.\14\ Therefore, we concluded that
acceptable measurement systems were available and no fundamental,
irresolvable issues had been identified that would justify a delay in
the pilot program. Nonetheless, we invited EMA to further elaborate on
their technical concerns with the currently available measurement
systems.
---------------------------------------------------------------------------

    \14\ ``Road Test of an On-board Particulate Matter Mass
Measurement System,'' D. R. Booker, Sensors, Inc., R. A. Giannelli
and J. Hu, U.S. Environmental Protection Agency, March 2007, SAE
paper number 2007-01-1116.
---------------------------------------------------------------------------

    In a subsequent letter dated April 11, 2007, EMA more specifically
detailed its technical concerns with currently available portable PM
measurement systems.\15\ Specifically, EMA listed fourteen technical
considerations. These generally can be summarized as follows: (1) The
devices had not been demonstrated as meeting the technical requirements
of EPA's 40 CFR 1065; (2) the engine manufacturers' have no current
experience with the measurement device because the current version is
relatively new, the instrument manufacturer does not offer all the
accessories needed to install and operate the system; (3) mounting the
units on some trucks presents installation issues; (4) the sampling
technology will not work properly with dirtier pre-2007 engines; (5) no
training from the instrument manufacturer was available; and (6) a
number of issues with accuracy and repeatability remain to be resolved.
They also argued that it would be better to take the time now to focus
on developing better portable PM measurement devices and, thereby,
helping to ensure a successful launch of the fully enforceable program
in 2009, especially since we would still have a full two years of the
PM pilot program as originally called for by the regulations.
---------------------------------------------------------------------------

    \15\ See letter from Timothy A. French, Engine Manufacturers
Association, to Khesha Jennings, U.S. Environmental Protection
Agency, dated April 11, 2007. A copy of the letter is available in
the public docket for this rule.
---------------------------------------------------------------------------

    After carefully considering EMA's more explicit concerns, we
concluded that: (1) A number of the issues were only relevant to the
future fully enforceable program, not the pilot demonstration program;
(2) EPA and EMA could work to resolve some issues such as only testing
existing or prototype lower emitting buses or trucks; and (3) the
remaining items simply did not by themselves reach a level that would
justify delaying the pilot program. At the same time, we agreed with
EMA that it is more important to continue to work cooperatively for a
successful launch of the enforceable PM in-use testing program,
especially since we will still have a two-year pilot. Therefore, at
that point in time, we decided it was in the best interests of all
parties to eliminate the 2006 calendar year pilot program and focus our
collective efforts to improve the current portable PM measurement
systems and conduct the cooperative research and development program
for this pollutant.

E. Revised Schedules and Testing Flexibilities for the 2005 Through
2009 In-Use Test Programs

    The June 2005 final rule that established the heavy-duty in-use
test program stated that EPA would typically select engine families for
testing in June of each calendar year. Further, the regulations allowed
18 months from the time engine families were designated for engine
manufacturers to complete all testing and report the results to EPA.
Subsequent to the final rule, we found that certain adjustments to the
test schedules were necessary in the early years of the program for the
reasons given below. The adjustments for engine family designation and
reporting dates are summarized in Table 3.

                       Table 3.--Revised Engine Family Designation and Reporting Schedules
----------------------------------------------------------------------------------------------------------------
                                              Designate families                         Report due
              Program              -----------------------------------------------------------------------------
                                       Original            Revised            Original            Revised
----------------------------------------------------------------------------------------------------------------
2005 Gaseous Pilot *..............         06/2005  Unchanged............         11/2006  11/2007.
2006 Gaseous Pilot................         06/2006  12/2006..............         11/2007  11/2008.
2007 Gaseous Enforceable..........         06/2007  12/2007..............         11/2008  11/2009.
2007 PM Pilot.....................         06/2007  12/2007..............         11/2008  05/2010.
2008 Gaseous Enforceable..........         06/2008  09/2008..............         11/2009  03/2010.
2008 PM Pilot.....................         06/2008  09/2008..............         11/2009  09/2010.
2009 Gaseous Enforceable..........         06/2009  Unchanged............         11/2010  04/2011.
2009 PM Enforceable...............         06/2009  Unchanged............         11/2010  04/2011.
2010 Gaseous Enforceable **.......         06/2010  Unchanged............         11/2011  Unchanged.
2010 PM Enforceable **............         06/2010  Unchanged............         11/2011  Unchanged.
----------------------------------------------------------------------------------------------------------------
* The 2005 Gaseous Pilot Program has been completed.
** For illustration only. The 2010 program dates are as originally promulgated.

    When the final rule was promulgated, EPA was working with ARB and
the engine manufacturers to create a standardized, electronic reporting
format which precisely specified each of the numerous reporting data
elements and enabled the test results from the portable emission
measurement systems to be reported into EPA's computerized database. We
had envisioned that this work would be completed in a timely manner so
that the 2005 gaseous emissions pilot program could be conducted as
scheduled. However, despite the diligent work of all parties, creating
the electronic reporting guidance for this all new test program proved
more complex and time consuming than expected. By September 2005 it
became obvious that the lack of the reporting guidance document had
become an impediment to efficiently conducting the in-use test program.
As a result, EPA agreed with the engine manufacturers, and ARB
concurred, that the start of the 18-month reporting period should be
delayed until a reporting guidance document was issued.\16\
---------------------------------------------------------------------------

    \16\ See letter from Merrylin Zaw-Mon, U.S. Environmental
Protection Agency, to John Duerr, Detroit Diesel Corporation, dated
November 15, 2005. A copy of the letter is available in the public
docket for this rule.
---------------------------------------------------------------------------

    In late May 2006 the reporting guidance was released and the 18-
month reporting period began in June of that year and ended in November
2007.\17\ To accommodate this delay without unduly compressing or
overlapping the testing in subsequent years, we are delaying engine
family designations, and sometimes extending the reporting period, for
the 2006 through 2008 gaseous emissions testing programs. Specifically
as shown in Table 3, we are delaying engine family designations for
2006 until December of that year and extending the reporting period to
24 months. For 2007, we are similarly delaying engine family
designations and extending the reporting period. Further, we are
shortening the delay in selecting engine families for the 2008 gaseous
emissions enforceable program to four months, i.e., September of that
year, and subsequently returning to the normal 18-month reporting
period. Finally, we are aligning the engine family designation dates
for the 2007 and 2008 PM pilot programs with the revised gaseous
emissions program dates to keep the program start dates the same.
---------------------------------------------------------------------------

    \17\ All manufacturers successfully reported the 2005 gaseous
emission test results according to that modified schedule.
---------------------------------------------------------------------------

    We have more recently reevaluated the schedules for the in-use PM
test program. Our reassessment was based on the progress that is being
made to develop ``data driven'' emission measurement allowances as part
of the comprehensive research, development, and demonstration program
outlined in the MOA,\18\ as previously described in section IV. The
reassessment was also made in the context that successfully measuring
PM emissions onboard a vehicle and deploying this technology in revenue
service represents the fundamental next step in emission measurement
technology and environmental protection. On balance, we have concluded
that additional time and added flexibility in the early years of the
in-use PM test program is required now to help ensure that this
important programmatic advancement is successful.
---------------------------------------------------------------------------

    \18\ 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).
---------------------------------------------------------------------------

    More specifically, last summer EPA and the other contributors to
the PM accuracy margin development program decided to do some pre-
testing of a PM PEMS prior to initiating the full test program in order
to further demonstrate and refine the test protocol and
instrumentation. This led to some technical changes to the PM PEMS
themselves. It also caused the full accuracy margin development program
to be delayed. At nearly the same time, some engine manufacturers
stated that they would like to use the initial results from the full
test program on the various PM PEMS devices in order to make more
refined purchasing decisions and to include any resulting upgrades to
the instruments. Given the importance of the program and expense
involved, we believe it is reasonable to accommodate the delay in
initiating the full PM accuracy margin development program and to allow
manufacturers to use the initial test results for purchasing decisions.
Therefore, as shown in Table 3, we are adding a total of six months to
the testing period to the 2007 PM pilot program. As with the gaseous
emissions program described above, we are also extending the PM
reporting

periods for the 2008 pilot and the 2009 enforceable PM programs to
avoid compression effects. Further, we are extending the reporting
period for the 2009 enforceable gaseous emissions program to match the
revised period for the 2009 enforceable PM program to couple and
realign the programs as originally intended. Finally, we want to make
it clear that any month-to-month delay (up to three months) in
initiating the 2009 enforceable PM program, as outlined in the accuracy
margin development MOA \19\ and described in section IV, will have no
effect on the reporting dates described above, i.e., no additional
time.
---------------------------------------------------------------------------

    \19\ 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).
---------------------------------------------------------------------------

    Most recently engine manufacturers have expressed concerns that
procuring and instrumenting test vehicles with PM PEMS could, in some
instances, be more complex and time consuming than for gaseous
emissions testing. For example, they claim that mounting the
instruments and running sampling lines with current generation PM PEMS
might require drilling holes in a truck's cab or creating special
mounting hardware. In such cases, the manufacturers argue that it might
be difficult to obtain vehicles from independent owners as required by
the current regulations. Engine manufacturers have requested that they
be given the flexibility to recruit and test vehicles from their
captive fleets for the 2007 PM pilot program based on these concerns.
In considering the engine manufacturers appeal, we note that the
gaseous emissions enforceable and PM pilot programs for that year would
have to be ``decoupled'' so that the gaseous emissions program would
continue to be conducted according to the applicable testing protocols,
e.g., obtaining vehicles from independent owners and testing them in
normal revenue service.
    While we are not convinced that current PM PEMS will cause these
unique challenges, we also can not conclusively rule out some
instrumentation and recruiting issues in the early part of the PM
program. Again, given the importance of successfully launching this
program, EPA is granting the engine manufacturers' request to modify
the PM pilot program test protocols. Therefore, we are allowing
manufacturers to recruit vehicles from their captive fleet and to test
them while being driven by a company employee. However, manufacturers
must ensure that the vehicles are screened, prepared, operated, and
tested in accordance with all other applicable requirements.
Furthermore, the vehicle must be tested by being driven on a route that
reasonably replicates normal, in-use revenue service for that type of
vehicle. The requirements for the enforceable gaseous emissions test
program for 2007 and 2008 are unchanged.

F. Removing the Gaseous 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 gaseous emission accuracy
margins and the consequences that would ensue if the report was delayed
beyond certain dates. These provisions are no longer needed because
accuracy margins for gaseous pollutants are being promulgated in this
Direct Final Rule. The revised section, therefore, appropriately
focuses on the ongoing development of accuracy margins for PM
emissions.

VI. 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 the EO. This Direct Final Rule
merely replaces the interim gaseous emission measurement accuracy
allowances for portable emission measurement systems with final values
and delays the in-use testing implementation dates for the fully
enforceable PM test program as either envisioned or allowed for in the
original final rule. This rule also grants a request from the affected
engine manufacturers for a one year delay in the start of the pilot
testing program for PM. Further, there are no costs associated with
this rule beyond those envisioned in the original rule.

B. Paperwork Reduction Act

    This direct final rule does not include any new collection
requirements, as it acts to replace interim gaseous emission
measurement accuracy allowances for portable emission measurement
systems with final values and delays the implementation schedule for
the in-use PM testing program. Therefore, there are no new paperwork
requirements associated with this rule.
    Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of information;
and transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required
to respond to a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations in 40 CFR are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

    EPA has determined that it is not necessary to prepare a regulatory
flexibility analysis in connection with this direct final rule.
    For purposes of assessing the impacts of this final rule on small
entities, a small entity is defined as: (1) A small business that meets
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 final rule on
small entities, EPA has concluded that this action will not have a
significant economic impact on a substantial number of small entities.
In determining whether a rule has a significant economic impact on a
substantial number of small entities, the impact of concern is any
significant adverse economic impact on small entities, since the
primary purpose of the regulatory flexibility analyses is to identify
and address regulatory alternatives ``which minimize any significant
economic impact of the proposed rule on small entities.'' 5 U.S.C. 603
and 604. Thus, an agency may conclude that a rule will not have a
significant economic impact on a substantial number of small entities
if the rule relieves regulatory burden, or otherwise has a positive
economic effect on all of the small entities subject to the rule.
    This direct final rule acts to replace interim gaseous emission
measurement

accuracy allowances for portable emission measurement systems with
final values and delays the implementation schedule for the in-use PM
testing program. We have, therefore, concluded that today's final rule
will relieve 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

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for federal agencies to assess the
effects of their regulatory actions on state, local, and tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``federal mandates'' that
may result in expenditures to state, local, and tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
one year. Before promulgating an EPA rule for which a written statement
is needed, section 205 of the UMRA generally requires EPA to identify
and consider a reasonable number of regulatory alternatives and adopt
the least costly, most cost-effective, or least burdensome alternative
that achieves the objectives of the rule. The provisions of section 205
do not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective, or least burdensome alternative if the
Administrator publishes with the final rule an explanation of why such
an alternative was adopted.
    Before EPA establishes any regulatory requirements that may
significantly or uniquely affect small governments, including tribal
governments, it must have developed under section 203 of the UMRA a
small government agency plan. The plan must provide for notifying
potentially affected small governments, enabling officials of affected
small governments to have meaningful and timely input in the
development of EPA regulatory proposals with significant federal
intergovernmental mandates, and informing, educating, and advising
small governments on compliance with the regulatory requirements.
    This rule contains no federal mandates for state, local, or tribal
governments as defined by the provisions of Title II of the UMRA. The
rule imposes no enforceable duties on any of these governmental
entities. Nothing in the rule would significantly or uniquely affect
small governments. EPA has determined that this rule contains no
federal mandates that may result in expenditures of more than $100
million to the private sector in any single year. This direct final
rule acts to replace interim gaseous emission measurement accuracy
allowances for portable emission measurement systems with final values
and delays the implementation schedule for the in-use PM testing
program. The requirements of UMRA, therefore, do not apply to this
action.

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August
10, 1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' are defined in the
Executive Order to include regulations that 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.''
    Under section 6 of Executive Order 13132, EPA may not issue a
regulation that has federalism implications, that imposes substantial
direct compliance costs, and that is not required by statute, unless
the Federal government provides the funds necessary to pay the direct
compliance costs incurred by State and local governments, or EPA
consults with State and local officials early in the process of
developing the regulation. EPA also may not issue a regulation that has
federalism implications and that preempts State law, unless the Agency
consults with State and local officials early in the process of
developing the regulation.
    Section 4 of the Executive Order contains additional requirements
for rules that preempt State or local law, even if those rules do not
have federalism implications (i.e., the rules 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). Those
requirements include providing all affected State and local officials
notice and an opportunity for appropriate participation in the
development of the regulation. If the preemption is not based on
express or implied statutory authority, EPA also must consult, to the
extent practicable, with appropriate State and local officials
regarding the conflict between State law and Federally protected
interests within the agency's area of regulatory responsibility.
    This 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 direct final rule merely
replaces interim gaseous emission measurement accuracy allowances for
portable emission measurement systems with final values and delays the
implementation schedule for the in-use PM testing program.

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

    Executive Order 13175, entitled ``Consultation and Coordination
With Indian Tribal Governments'' (59 FR 22951, November 6, 2000),
requires EPA to develop an accountable process to ensure ``meaningful
and timely input by tribal officials in the development of regulatory
policies that have tribal implications.'' ``Policies that have tribal
implications'' is defined in the Executive Order to include regulations
that have ``substantial direct effects on one or more Indian tribes, on
the relationship between the Federal government and the Indian tribes,
or on the distribution of power and responsibilities between the
Federal government and Indian tribes.''
    This 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 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 direct final rule
merely replaces interim gaseous emission measurement accuracy
allowances for portable emission measurement systems with final values
and delays the implementation schedule for the in-use PM testing
program. Thus, Executive Order 13175 does not apply to this rule.

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

    Executive Order 13045, ``Protection of Children From Environmental
Health

Risks and Safety Risks'' (62 FR 19885, April 23, 1997) applies to any
rule that (1) is determined to be ``economically significant'' as
defined under Executive Order 12866, and (2) concerns an environmental
health or safety risk that EPA has reason to believe may have a
disproportionate effect on children. If the regulatory action meets
both criteria, section 5-501 of the Order directs the Agency to
evaluate the environmental health or safety effects of the planned rule
on children, and explain why the planned regulation is preferable to
other potentially effective and reasonably feasible alternatives
considered by the Agency.
    This rule is not subject to the Executive Order because it is not
economically significant as defined in EO 12866, and because the Agency
does not have reason to believe the environmental health or safety
risks addressed by this action present a disproportionate risk to
children. This direct final rule merely replaces the interim gaseous
emission measurement accuracy allowances for portable emission
measurement systems with final values and delays the implementation
schedule for the in-use PM testing program.

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

    This 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
direct final rule merely replaces the interim gaseous emission
measurement accuracy allowances for portable emission measurement
systems with final values and delays the implementation schedule for
the in-use PM testing program.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104-113, section 12(d) (15 U.S.C.
272 note) directs EPA to use voluntary consensus standards in its
regulatory activities unless doing so would be inconsistent with
applicable law or otherwise impractical. Voluntary consensus standards
are technical standards (such as materials specifications, test
methods, sampling procedures, and business practices) that are
developed or adopted by voluntary consensus standards bodies. NTTAA
directs EPA to provide Congress, through OMB, explanations when the
Agency decides not to use available and applicable voluntary consensus
standards.
    This direct final rule does not involve technical standards. This
direct final rule merely replaces the interim gaseous emission
measurement accuracy allowances for portable emission measurement
systems with final values and delays the implementation schedule for
the in-use PM testing program. Thus, we have determined that the
requirements of the NTTAA do not apply.

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 environmental justice. Its main provision
directs federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.
    EPA has determined that this 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. This direct
final rule merely replaces the interim gaseous emission measurement
accuracy allowances for portable emission measurement systems with
final values and delays the implementation schedule for the in-use PM
testing program.

K. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as amended by
the Small Business Regulatory Enforcement Fairness Act of 1996,
generally provides that before a rule may take effect, the agency
promulgating the rule must submit a rule report, which includes a copy
of the rule, to Congress and the Comptroller General of the United
States. We will submit a report containing this rule and other required
information to the U.S. Senate, the U.S. House of Representatives, and
the Comptroller General of the United States before publication of the
rule in the Federal Register. A major rule cannot take effect until 60
days after it is published in the Federal Register. This action is not
a ``major rule'' as defined by 5 U.S.C. 804(2). This direct final rule
is effective on May 12, 2008.

L. Statutory Authority

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

List of Subjects in 40 CFR Part 86

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

    Dated: February 28, 2008.
Stephen L. Johnson,
Administrator.

0
For the reasons set out in the preamble, title 40, chapter I of the
Code of Federal Regulations is amended as follows:

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

0
1. The authority citation for part 86 continues to read as follows:

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

0
2. Section 86.1905 is amended by revising paragraph (c)(2) to read as
follows:

Sec.  86.1905  How does this program work?

* * * * *
    (c) * * *
    (2) 2009 for PM testing.
* * * * *
0
3. Section 86.1912 is amended by adding new paragraphs (a)(3)(v) and
(a)(5) and revising paragraph (a)(4) to read as follows:

Sec.  86.1912  How do I determine whether an engine meets the vehicle-
pass criteria?

* * * * *
    (a) * * *
    (3) * * *
    (v) NOX + NMHC: 0.67 grams per brake horsepower-hour.
    (4) Accuracy margins for portable in-use equipment when testing is
not performed under the special provisions of Sec.  86.1930 for 2007
through 2009 model year engine families that are selected for testing
in any calendar year as follows:
    (i) NMHC using the emission calculation method specified in 40 CFR
1065.650(a)(1): 0.02 grams per brake horsepower-hour.
    (ii) NMHC using the emission calculation method specified in 40 CFR
1065.650(a)(3): 0.01 grams per brake horsepower-hour.
    (iii) NMHC using an alternative emission calculation method as

approved by the Administrator under 40 CFR 1065.915(d)(5)(iv): 0.01
grams per brake horsepower-hour.
    (iv) CO using the emission calculation method specified in 40 CFR
1065.650(a)(1): 0.5 grams per brake horsepower-hour.
    (v) CO using the emission calculation method specified in 40 CFR
1065.650(a)(3): 0.25 grams per brake horsepower-hour.
    (vi) CO using an alternative emission calculation method as
approved by the Administrator under 40 CFR 1065.915(d)(5)(iv): 0.25
grams per brake horsepower-hour.
    (vii) NOX using the emission calculation method
specified in 40 CFR 1065.650(a)(1): 0.45 grams per brake horsepower-
hour.
    (viii) NOX using the emission calculation method
specified in 40 CFR 1065.650(a)(3): 0.15 grams per brake horsepower-
hour.
    (ix) NOX using an alternative emission calculation
method as approved by the Administrator under 40 CFR
1065.915(d)(5)(iv): 0.15 grams per brake horsepower-hour.
    (x) NOX + NMHC using the emission calculation method
specified in 40 CFR 1065.650(a)(1): 0.47 grams per brake horsepower-
hour.
    (xi) NOX + NMHC using the emission calculation method
specified in 40 CFR 1065.650(a)(3): 0.16 grams per brake horsepower-
hour.
    (xii) NOX + NMHC using an alternative emission
calculation method as approved by the Administrator under 40 CFR
1065.915(d)(5)(iv): 0.16 grams per brake horsepower-hour.
    (xiii) PM: To be determined by rulemaking as indicated in Sec.
86.1935.
    (5) Accuracy margins for portable in-use equipment when testing is
not performed under the special provisions of Sec.  86.1930 for 2010 or
later model year engines families that are selected for testing in any
calendar year as follows:
    (i) NMHC using any emission calculation method specified in 40 CFR
1065.650(a) or an alternative emission calculation method as approved
by the Administrator under 40 CFR 1065.915(d)(5)(iv): 0.01 grams per
brake horsepower-hour.
    (ii) CO using any emission calculation method specified in 40 CFR
1065.650(a) or an alternative emission calculation method as approved
by the Administrator under 40 CFR 1065.915(d)(5)(iv): 0.25 grams per
brake horsepower-hour.
    (iii) NOX using any emission calculation method
specified in 40 CFR 1065.650(a) or an alternative emission calculation
method as approved by the Administrator under 40 CFR
1065.915(d)(5)(iv): 0.15 grams per brake horsepower-hour.
    (iv) PM: To be determined by rulemaking as indicated in Sec.
86.1935.
* * * * *

0
4. Section 86.1930 is amended as follows:
0
a. By revising the section heading.
0
b. By redesignating paragraphs (a) through (f) as paragraphs (a)(1)
through (a)(6).
0
c. By redesignating the introductory text as paragraph (a) introductory
text.
0
d. By revising newly designated paragraph (a) introductory text.
0
e. By redesignating newly designated paragraphs (a)(4)(1) and (2) as
paragraphs (a)(4)(i) and (ii).
0
f. By adding new paragraphs (a)(7) and (b).

Sec.  86.1930  What special provisions apply from 2005 through 2009?

    (a) We may direct you to test engines under this subpart for
emissions other than PM in 2005 and 2006, and for PM emissions in 2007
and 2008. In those interim periods, all the provisions of this subpart
apply, with the following exceptions:
* * * * *
    (7) You must complete all the required testing and reporting under
this subpart by the following dates:
    (i) November 30, 2007 for engine families that we designate for
non-PM testing in 2005.
    (ii) November 30, 2008 for engine families that we designate for
non-PM testing in 2006.
    (iii) May 31, 2010 for engine families that we designate for PM
testing in 2007.
    (iv) September 30, 2010 for engine families we designate for PM
testing in 2008.
    (b) For 2007 through 2009 all the provisions of this subpart and
paragraph (a) of this section apply, with the following additional
exceptions:
    (1) You must complete all the required testing and reporting under
this subpart by the following dates:
    (i) November 30, 2009 for engine families that we designate for
non-PM testing in 2007.
    (ii) March 31, 2010 for engine families that we designate for non-
PM testing in 2008.
    (iii) April 30, 2011 for engine families that we designate for non-
PM and PM testing in 2009.
    (2) You may conduct non-PM and PM testing on different vehicles for
engine families that we designate in 2007 and 2008.
    (3) You may conduct PM testing as follows for 2007:
    (i) Test vehicles may be selected from a vehicle fleet that you own
or otherwise directly control.
    (ii) Test vehicles may be operated by a driver that you employ.
    (iii) Each test vehicle must be operated on a route and under
operating conditions that reasonably replicate the use of the selected
vehicle type when operated in typical revenue service, unless otherwise
approved by us.

0
5. Section 86.1935 is revised to read as follows:

Sec.  86.1935  What special provisions may apply as a consequence of a
delay in the particulate matter accuracy margin report for portable
emission measurement systems?

    (a) A memorandum entitled, ``Memorandum of Agreement, Program to
Develop Emission Measurement Accuracy Margins for Heavy-Duty In-Use
Testing'' describes a test program for establishing measurement
accuracy margins related to testing under Sec.  86.1912(a)(4) which
will be used for testing under this subpart. This document is available
at http://www.epa.gov/otaq/hd-hwy.htm or at the mailing address
specified in Sec.  86.1905(g).
    (b) If there is a delay in receiving the written final report for
PM emissions described in the agreement referenced in paragraph (a) of
this section, and that delay is not attributable to engine
manufacturers failing to meet their commitments under that agreement,
the following provisions apply:
    (1) If the delay is 3 months or less, we will delay the designation
of engine families for testing in the applicable calendar year, as
described in Sec.  86.1905(d), by the same number of additional whole
months (rounded up) needed to complete the report.
    (2) If the delay is more than 3 months but less than 12 months, we
may continue to designate engine families for testing under the special
provisions described in Sec.  86.1930 for an additional year.
    (3) If the delay is longer than 12 months, the following approach
is established for the applicable calendar year:
    (i) If the delay is longer than 12 months but less than 15 months,
we will follow the steps described in paragraph (b)(1) of this section.
    (ii) If the delay is longer than 15 months, but, less than 24
months, we will follow the steps described in paragraph (b)(2) of this
section, for the applicable calendar year.
    (iii) If the delay is longer than 24 months, the emission testing
program will go into abeyance.

    (c) If one or more engine manufacturers fail to meet commitments
under the agreement described in paragraph (a) of this section and such
a failure results in a delay in the final written report for PM
emissions described in the agreement, the following provisions apply:
    (1) If the delay is 3 months or less, we will delay the designation
of engine families for testing in the applicable calendar year, as
described in Sec.  86.1905(d), by the same number of additional whole
months (rounded up) needed to complete the report.
    (2) If the delay is more than 3 months but less than 12 months, the
provisions of this subpart will not apply for the otherwise applicable
calendar year, subject to the following provisions:
    (i) We may identify the number of engine families that would
otherwise have been designated for testing in that calendar year for
the delayed pollutant type and direct manufacturers to test that number
of engine families under the special provisions described in Sec.
86.1930 and additionally in any later calendar year once the provisions
of this subpart begin for that pollutant type, without counting those
accumulated engine families toward the allowable annual cap on the
number of engine families specified in Sec.  86.1905.
    (ii) The normal 18-month period for testing and reporting results
specified in Sec.  86.1905(d) is extended to 24 months for any
accumulated engine-family designation described in paragraph (c)(2)(i)
of this section. The additional time extensions for testing and
reporting results as specified in Sec.  86.1905(d) also apply.
    (3) If the delay is longer than 12 months, the following approach
is established for the applicable calendar year.
    (i) If the delay is longer than 12 months but less than 15 months,
we will follow the steps described in paragraph (c)(1) of this section.
    (ii) If the delay is longer than 15 months, but less than 24
months, we will follow the steps described in paragraph (c)(2) of this
section for the applicable calendar year.
    (iii) If the delay is longer than 24 months, we will continue to
follow the steps described in paragraphs (c)(1) and (c)(2) of this
section, including the accumulation of engine families for testing
until the report is received and the fully implemented program
commences.
    (d) We may determine that any individual manufacturer's failure
under paragraph (c) of this section constitutes a failure by all engine
manufacturers.
    (e) Nothing in this section affects our ability to select engines
from any model year beginning with model year 2007, or for gaseous
emission testing.
    (f) If we determine that fundamental technical problems with
portable in-use PM measurement systems are not resolvable in a
reasonable time, the provisions of this subpart, as they apply to PM,
will go into abeyance until we determine that suitable emission-
measurement devices are available for in-use testing.
    (g) Engine manufacturers contributing to the test programs
described in the agreement referenced in paragraph (a) of this section
may limit their testing under the special provisions described in Sec.
86.1930 to five engines in each selected engine family.

[FR Doc. E8-4388 Filed 3-12-08; 8:45 am]

BILLING CODE 6560-50-P