[Federal Register: January 7, 2008 (Volume 73, Number 4)]
[Proposed Rules]
[Page 1175-1195]
[DOCID:fr07ja08-20]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R09-OAR-2007-0561; FRL-8513-6]

Approval and Promulgation of Implementation Plans and Designation
of Areas for Air Quality Planning Purposes; Nevada; Wintertime
Oxygenated Gasoline Rule; Vehicle Inspection and Maintenance Program;
Redesignation of Truckee Meadows to Attainment for the Carbon Monoxide
Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to approve certain submittals by the State of
Nevada of revisions to the Nevada state implementation plan that are
intended to provide for attainment and maintenance of the carbon
monoxide national ambient air quality standard in the Truckee Meadows
nonattainment area located within Washoe County, Nevada. These
revisions include a local wintertime oxygenated gasoline rule, a
``basic'' vehicle inspection and maintenance program (including a
performance standard evaluation), current statutory provisions and
State rules governing mobile sources, a maintenance plan and related
motor vehicle emissions budgets. EPA is also proposing to approve
Nevada's request to redesignate the Truckee Meadows carbon monoxide
nonattainment area to attainment. Lastly, EPA is proposing to rescind a
provision previously approved in error related to inspection and
maintenance of vehicles operated on Federal installations. EPA proposes
these actions pursuant to those provisions of the Clean Air Act that
obligate the Agency to take action on submittals of revisions to state
implementation plans and requests for redesignation. This proposed
action is intended to make certain State and local measures and
commitments related to attainment and maintenance of the carbon
monoxide standard in Truckee Meadows federally enforceable as part of
the Nevada state implementation plan.

DATE: Any comments on this proposal must arrive by February 6, 2008.

ADDRESSES: Submit comments, identified by docket number EPA-R09-OAR-
2007-0561, by one of the following methods:
    1. Federal eRulemaking Portal: http://www.regulations.gov. Follow

the on-line instructions for submitting comments.
    2. E-mail<EMAIL_ADDRESS>    3. Mail or deliver: Eleanor Kaplan (AIR-2), U.S. Environmental
Protection Agency Region IX, 75 Hawthorne Street, San Francisco, CA
94105-3901.
    Instructions: Direct your comments to Docket ID No. EPA-R09-OAR-
2007-0561. 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 that EPA will not know
your identity or contact information unless you provide it in the body
of your comment. If you send e-mail 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 the 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.
    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 information,
such as copyrighted material, will be publicly available only in hard
copy form. Publicly available docket materials are available either
electronically in http://www.regulations.gov or in hard copy at the

Office of Air Planning, Environmental Protection Agency (EPA), Region
IX, 75 Hawthorne Street, San Francisco, California. To inspect the hard
copy materials, please schedule an appointment during normal business
hours with the contact listed in the FOR FURTHER INFORMATION CONTACT
section.

FOR FURTHER INFORMATION CONTACT: Eleanor Kaplan, EPA Region IX, (415)
947-4147<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: Throughout this document, the terms ``we,''
``us,'' and ``our'' refer to EPA. This supplementary information is
organized as follows:

Table of Contents

I. Summary of Today's Proposed Action
II. Nature, Sources, and Health Effects of Carbon Monoxide
III. Introduction to Truckee Meadows, Washoe County, Nevada
IV. History of Carbon Monoxide Planning in Truckee Meadows
V. Nevada's Procedures for Adoption of these SIP Revisions
VI. Washoe County's Wintertime Oxygenated Fuel Requirements
VII. Nevada's Motor Vehicle Inspection and Maintenance (I/M) Program
in Truckee Meadows
    A. Background Information
    B. Evaluation of the State's I/M Program in Truckee Meadows
VIII. Clean Air Act Requirements for Redesignation to Attainment
IX. Evaluation of the State's Redesignation Request for Truckee
Meadows
    A. The Area Must Have Attained the Applicable NAAQS.
    B. The Area Must Have a Fully Approved SIP Under Section 110(k)
of the CAA.
    C. The Area Must Show the Improvement in Air Quality Is Due to
Permanent and Enforceable Emissions Reductions.
    D. The Area Must Have Met All Applicable Requirements Under
Section 110 and Part D.
    1. Section 110 Requirements
    2. Part D Requirements
    E. The Area Must Have a Fully Approved Maintenance Plan Under
CAA Section 175A.
    1. Attainment Inventory
    2. Maintenance Demonstration
    3. Monitoring Network
    4. Verification of Continued Attainment
    5. Contingency Plan
    6. Subsequent Maintenance Plan Revisions
    7. Motor Vehicle Emissions Budgets
    8. Conclusion
X. Proposed Action and Request for Comment
XI. Administrative Requirements

I. Summary of Today's Proposed Action

    Under section 110(k)(3) of the Clean Air Act, as amended in 1990
(CAA or ``Act''), EPA is proposing to approve certain submittals of
revisions to the Nevada state implementation plan (SIP) by the Nevada
Division of Environmental Protection (NDEP). These revisions are
intended to provide for attainment and maintenance of the carbon
monoxide (CO) national ambient air quality standards (NAAQS) in the
Truckee Meadows nonattainment area located within Washoe County,
Nevada. The specific SIP revision submittals that we are proposing to
approve are listed in the following table:

------------------------------------------------------------------------
                                                        State of Nevada
   Plan, plan element or rule      Adoption date(s)    submittal date(s)
------------------------------------------------------------------------
Washoe County District Board of   Originally adopted  Submitted on Apr.
 Health Regulations Governing      on Dec. 21, 1988    14, 1991;
 Air Quality Management, section   and amended on      resubmitted as
 040.095 (``Oxygen content of      Apr. 18, 1990;      amended on Nov.
 motor vehicle fuel'').            amended on Sept.    13, 1992; re-
                                   23, 1992; amended   submitted as
                                   on Sept. 22, 2005.  amended on Nov.
                                                       4, 2005.
State Implementation Plan for a   Regulations         June 3, 1994.
 Basic Program for the             adopted at
 Inspection and Maintenance of     various times by
 Motor Vehicles for the Truckee    the State
 Meadows Planning Area, Nevada     Environmental
 (June 1994).                      Commission and
                                   Department of
                                   Motor Vehicles
                                   but superseded by
                                   SIP revision
                                   submittal dated
                                   May 11, 2007, as
                                   listed below.
Basic I/M Performance Standard    Sept. 28, 2006....  Nov. 2, 2006.
 Evaluation.
Nevada Mobile Source SIP, Update  Regulations         May 11, 2007.
 of the Regulatory Element (May    adopted at
 11, 2007).                        various times by
                                   State
                                   Environmental
                                   Commission and
                                   Department of
                                   Motor Vehicles.
Redesignation Request and         Sept. 22, 2005....  Nov. 4, 2005.
 Maintenance Plan for the
 Truckee Meadows Carbon Monoxide
 Non-Attainment Area (September
 2005).
------------------------------------------------------------------------

    Specifically, we are proposing to approve NDEP's SIP revision
submittal dated November 4, 2005 of the wintertime oxygenated gasoline
rule as amended on September 22, 2005 by the Washoe County District
Board of Health (``District'') and codified as District Regulations
Governing Air Quality Management section 040.095 (``District rule
040.095''). We are also proposing to approve the SIP revision submittal
dated June 3, 1994 of the State Implementation Plan for a Basic Program
for the Inspection and Maintenance of Motor Vehicles for the Truckee
Meadows Planning Area, Nevada (June 1994) (``Basic I/M SIP''). In
connection with the basic vehicle inspection and maintenance (I/M)
program in Truckee Meadows, we are proposing to approve two subsequent
SIP revision submittals: A ``basic'' I/M performance standard
evaluation (``Basic I/M Performance Standard Evaluation'') submitted on
November 2, 2006 and the Nevada Mobile Source SIP, Update of the
Regulatory Element (May 11, 2007) (``Mobile Source SIP Update'')
submitted on May 11, 2007. NDEP's Mobile Source SIP Update contains
current I/M-related statutory provisions, regulations, and updated
exhaust gas analyzer specifications.\1\ In so doing, we find that the
above submittals fulfill the applicable requirements under section 110
and part D (of title I) of the Act.
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    \1\ The statutory provisions and rules submitted by NDEP on May
11, 2007 represent a comprehensive update to the regulatory portion
of the State's mobile source SIP (excluding the rules establishing
fuels specifications, alternative fuels programs for government
vehicles, and local rules related to mobile sources), including the
regulatory portion of the State's Truckee Meadows I/M SIP, which was
last approved in 1984 (49 FR 44208, November 5, 1984), and the
regulatory portion of the State's Las Vegas Valley I/M SIP, which
was last approved in 2004 (69 FR 56351, September 21, 2004). The
current submitted versions of the I/M-related statutory provisions
and rules are not significantly different than the corresponding
versions of the statutory provisions and rules approved in 2004 for
the State's Las Vegas I/M program, and are consistent with the
underlying assumptions used to develop the Las Vegas Valley 2005 CO
Plan, which was approved by EPA on August 7, 2006 (71 FR 44587).
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    In connection with our proposed approval of the State's Basic I/M
SIP, as supplemented and amended in submittals dated November 2, 2006
and May 11, 2007, we are taking no action on submitted rule NAC
445B.595(2), which extends the State's I/M requirements to motor
vehicles operated on Federal installations located within I/M areas
because the Federal government has not waived sovereign immunity in the
context of vehicle I/M programs. Furthermore, we are proposing, under
CAA section 110(k)(6), to rescind our previous, and erroneous, approval
of NAC 445B.595(2) into the Nevada SIP in 2004, also on the grounds of
sovereign immunity.
    Lastly, we are proposing to approve NDEP's SIP revision submittal
(dated November 4, 2005) of the Redesignation

Request and Maintenance Plan for the Truckee Meadows Carbon Monoxide
Non-Attainment Area (September 2005) (``Truckee Meadows CO Maintenance
Plan''), adopted by the District on September 22, 2005, and to approve
NDEP's request for redesignation of the Truckee Meadows CO
nonattainment area to attainment. In connection with our proposed
approval of the Truckee Meadows CO Maintenance Plan, we are approving
certain commitments by the District, contingency provisions, and CO
motor vehicle emissions budgets for years 2010 and 2016 for the
purposes of transportation conformity. In so doing, we find that the
Truckee Meadows CO Maintenance Plan meets the requirements for
maintenance plans under section 175A of the Act. In connection with our
proposed approval of NDEP's redesignation request, we find that the
State has fulfilled the criteria for redesignation of the Truckee
Meadows CO nonattainment area from nonattainment to attainment as set
forth in section 107(d)(3)(E).\2\
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    \2\ The Truckee Meadows CO Maintenance Plan relies upon three
principal State or local control measures: The District's wintertime
oxygenated gasoline rule, the State's vehicle inspection and
maintenance (I/M) program, and the District's residential wood
combustion rule. We are proposing to approve the first and second of
the three measures in this document. We approved the third measure
(the residential wood combustion rule) in a separate document
earlier this year. See 72 FR 33397 (June 18, 2007). We will not
finalize the proposed approval of the redesignation request until we
take final action approving the oxygenated gasoline rule and the I/M
program. Also, for reasons set forth in this document, we find that
we need not fully approve either the County's nonattainment new
source review rules or the County's transportation conformity rules
as a pre-condition to redesignation of Truckee Meadows to attainment
for the CO NAAQS.
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II. Nature, Sources, and Health Effects of Carbon Monoxide

    Carbon monoxide (CO) is a colorless and odorless gas, formed when
carbon in fuel is not burned completely. It is a component of motor
vehicle exhaust, which contributes about 60 percent of all CO emissions
nationwide. Nonroad vehicles account for the remaining CO emissions
from transportation sources. High concentrations of CO generally occur
in areas with heavy traffic congestion. Peak CO concentrations
typically occur during the colder months of the year when CO automotive
emissions are greater and nighttime inversion conditions (where air
pollutants are trapped near the ground beneath a layer of warm air) are
more frequent.
    CO enters the bloodstream through the lungs and reduces oxygen
delivery to the body's organs and tissues. The health threat from
levels of CO sometimes found in the ambient air is most serious for
those who suffer from cardiovascular disease, such as angina pectoris.
At much higher levels of exposure not commonly found in ambient air, CO
can be poisonous, and even healthy individuals may be affected. Visual
impairment, reduced work capacity, reduced manual dexterity, poor
learning ability, and difficulty in performing complex tasks are all
associated with exposure to elevated CO levels.

III. Introduction to Truckee Meadows, Washoe County, Nevada

    Truckee Meadows lies in the far southern portion of Washoe County.
Washoe County lies in the northwestern portion of the State of Nevada
and is bordered by the State of California to the west and the State of
Oregon to the north. Within the State of Nevada, the counties of
Humboldt, Pershing, Churchill, Lyon, and Storey and the city of Carson
City bound Washoe County to the east and south. Located at an average
elevation of 4,500 feet above sea level, Truckee Meadows lies in the
rain shadow of the Sierra Nevada mountain range located to the west.
The boundaries of Truckee Meadows are defined as equal to the State's
hydrographic area 87, and encompass a land area of
approximately 200 square miles. It is surrounded by mountain ranges,
which can lead to persistent wintertime temperature inversions where a
layer of cold air is trapped in the valley. Warmer air above the
inversion acts as a lid, containing and concentrating air pollutants
emitted at ground-level.
    Truckee Meadows has experienced rapid growth in population, with an
increase in population from approximately 138,000 in 1977 to
approximately 359,000 in 2002, an increase of 160 percent over that 25-
year period. The two major cities are Reno and Sparks.
    Air quality planning and monitoring in Truckee Meadows is the
responsibility of the District, which administers air quality programs
in Washoe County through the District Health Department's Air Quality
Management Division (``District AQMD''). The State Environmental
Commission and the Nevada Department of Motor Vehicles are responsible
for the motor vehicle I/M program in Truckee Meadows.

IV. History of Carbon Monoxide Planning in Truckee Meadows

    On April 30, 1971 (36 FR 8186), pursuant to section 109 of the
Clean Air Act, as amended in 1970, EPA promulgated NAAQS for six
criteria pollutants, including CO. EPA set the NAAQS for CO at 35 parts
per million (ppm), one-hour average, and 9 ppm, eight-hour average. The
CO NAAQS remain the same today.
    Under section 110 of the Clean Air Amendments of 1970, States were
required to adopt and submit plans that provide for implementation,
maintenance, and enforcement of the NAAQS. These original plans,
generally submitted and approved in the early 1970's, are referred to
as state implementation plans (SIPs). Incremental changes to SIPs that
a State submits, such as new or amended rules, attainment plans, and
maintenance plans, are referred to as ``SIP revisions.''
    Generally, SIPs were to provide for attainment of the NAAQS within
three years of EPA approval of the plan. However, many parts of the
country did not attain the NAAQS within the statutory period. In
response, Congress amended the Act in 1977 to establish a new approach,
based on area designations, for attaining the NAAQS, and on March 3,
1978 (43 FR 8962), under paragraph 107(d)(2) of the Act as amended in
1977, EPA promulgated attainment status designations for all States.
EPA designated Truckee Meadows (with boundaries defined by reference to
State hydrographic area 87) as a nonattainment area for the CO
NAAQS. See 43 FR 8962, at 9013 (March 3, 1978).
    The Act, as amended in 1977, required States to revise their SIPs
by January 1979 for all designated nonattainment areas. The CO
attainment plan for Truckee Meadows that was developed in the late
1970's and early 1980's relied upon implementation of such control
measures as a vehicle inspection and maintenance (I/M) program, road
improvements, traffic controls, and areawide ride-sharing programs to
attain the CO NAAQS by the statutory deadline of 1982. In 1981, we
approved most of the elements of the CO plan for Truckee Meadows and
conditionally approved other elements. See 46 FR 21758 (April 14,
1981). In 1982, we revoked the remaining conditions resulting in full
approval of the CO plan. See 47 FR 15790 (April 13, 1982).
    Truckee Meadows did not attain the CO NAAQS by the 1982 attainment
deadline, and thus, the District revised the CO attainment plan and
requested an extension in the attainment date to 1987. In 1984, we
approved parts of the revised CO attainment plan but deferred action on
certain other parts based on our conclusion that the emissions
reduction credit taken in the revised CO

plan for one of the principal control measures relied upon to show
attainment, residential wood burning control, was not sufficiently
documented. See 49 FR 31683 (August 8, 1984).
    Like many other areas of the country, Truckee Meadows did not
attain the CO NAAQS by the 1987 attainment date and remained
nonattainment at the time of the 1990 Clean Air Act Amendments. Under
section 107(d)(1)(C) of the 1990 Amended Act, the CO nonattainment
designation in Truckee Meadows was brought forward by operation of law.
Based on a design value of 9.8 ppm (eight-hour average), we further
classified Truckee Meadows as a ``moderate'' CO nonattainment area for
the CO NAAQS with an attainment date of (no later than) December 31,
1995. See 56 FR 56694, at 56798 (November 6, 1991) and CAA section
186(a)(1). A review of the data collected in 1994 and 1995 provided EPA
with the basis to determine that Truckee Meadows in fact attained the
CO NAAQS by the 1995 attainment date. See 70 FR 22803 (May 3, 2005).
    In addition to extending the deadline for attainment of the CO
NAAQS, the Act, as amended in 1990, also established new requirements
for CO nonattainment areas that vary depending upon the severity of the
problem. The additional requirements for ``moderate'' CO nonattainment
areas are set forth in sections 172, 176, 187, and 211 of the Act, and
include such elements as updated and periodic emission inventories,
upgraded vehicle I/M programs, conformity requirements, and wintertime
oxygenated gasoline requirements. To address these requirements, the
District AQMD developed new plans and adopted new or amended rules, the
State revised the vehicle I/M program, and NDEP submitted the plans,
rules and revised vehicle I/M program to EPA as revisions to the
Truckee Meadows portion of the Nevada SIP. In today's action, we are
proposing to approve a number of elements contained in these
submittals, including the wintertime oxygenated gasoline rule and an
upgraded vehicle I/M program. In a separate action, we approved the
District's residential wood combustion rule. See 72 FR 33397 (June 18,
2007).
    Section 107(d)(3)(D) of the Act allows a State to request
redesignation of an air quality planning area. On November 4, 2005,
NDEP submitted such a request for the Truckee Meadows CO nonattainment
area and submitted the Truckee Meadows CO Maintenance Plan to EPA for
approval as a revision to the Nevada SIP. The purpose of the Truckee
Meadows CO Maintenance Plan is to provide for maintenance of the CO
NAAQS in the Truckee Meadows area for ten years following
redesignation. In this action, we are proposing to approve the Truckee
Meadows CO Maintenance Plan and proposing to approve the request for
redesignation of Truckee Meadows from nonattainment to attainment for
the CO NAAQS.

V. Nevada's Procedures for Adoption of These SIP Revisions

    Section 110(l) of the Act requires States to provide reasonable
notice and public hearing prior to adoption of SIP revisions. In this
action, we are proposing to approve the following SIP revisions: the
wintertime oxygenated gasoline rule (District rule 040.095), submitted
on November 4, 2005; the Basic I/M SIP submitted on June 3, 1994, the
Basic I/M Performance Standard Evaluation submitted on November 2,
2006, and current I/M-related statutory provisions and regulations and
updated exhaust gas analyzer specifications submitted on May 11, 2007;
and the Truckee Meadows CO Maintenance Plan submitted on November 4,
2005.
    Each of the SIP revision submittals cited above contains evidence
that reasonable notice of a public hearing was provided to the public
(via newspaper advertisement) and that a public hearing was conducted
prior to adoption by the District.\3\ Following adoption, the District
forwarded these SIP revisions to NDEP, the Governor of Nevada's
designee for submitting SIP revisions and redesignation requests to
EPA, and NDEP then submitted the SIP revisions to EPA for approval. We
find that each of the SIP revisions cited above satisfies the
procedural requirements of section 110(l) of the Act for revising SIPs.
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    \3\ In the case of the Basic I/M SIP and the May 11, 2007 SIP
submittal of current I/M statutory provisions and regulations, NDEP
provided evidence of reasonable notice and public hearing for the
various recent amendments to the I/M regulations. The submittal of
the current I/M-related statutory provisions and regulations
supersede the corresponding provisions and regulations submitted in
1994 as part of the Basic I/M SIP.
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VI. Washoe County's Wintertime Oxygenated Fuel Requirements

    Under section 211(m) of the Act, as amended in 1990, States with CO
nonattainment areas with design values of 9.5 ppm or greater (eight-
hour average) are required to submit an oxygenated gasoline program as
a SIP revision. The design value for Truckee Meadows based on data
collected during 1988-1989 (and recorded in EPA's Air Quality System
database) was 9.8 ppm, eight-hour average, and thus, the State of
Nevada is required to submit an oxygenated gasoline program for the
Truckee Meadows area as a SIP revision.
    Section 211(m) of the 1990 Amended Act also specifies the minimum
geographic extent for such an oxygenated gasoline program (larger of
the Consolidated Metropolitan Statistical Area (CMSA) or MSA if the
area is not in a CMSA), the minimum oxygen content (2.7% by weight),
and the applicable portion of the year in which the program must be
implemented (as determined by EPA). EPA determined that the applicable
control period for the purposes of an oxygenated gasoline program in
Truckee Meadows area is October 1 through January 31. See 57 FR 47853
(October 20, 1992). EPA labeling requirements for oxygenated gasoline
are found at 40 CFR 80.35.
    The District first adopted an oxygenated gasoline rule (i.e.,
District rule 040.095 ``Oxygen Content of Motor Vehicle Fuel'') on
December 21, 1988, and implementation of the rule began in December
1989. This rule applied throughout Washoe County and required a minimum
gasoline oxygen content of 2% by weight during a control period defined
as December 1 through February 15. The District modified the oxygenated
gasoline rule on April 18, 1990 to extend the control period to
November 1 through the end of February. The April 18, 1990 version of
the District's oxygenated gasoline rule was included in a SIP revision
submittal from the Governor to EPA dated April 15, 1991. Meanwhile,
five months prior to this SIP submittal, the Clean Air Act Amendments
of 1990 were enacted, and the amended Act established new SIP
requirements, discussed above, for oxygenated gasoline rules in CO
nonattainment areas.
    In response to the new requirements, the District again amended the
oxygenated gasoline rule (on September 23, 1992) to increase the
minimum oxygen content requirement to 2.7% and to extend the control
period to October 1 through January 31. NDEP submitted this revised
rule to EPA as a SIP revision on November 13, 1992 thereby superseding
the April 15, 1991 submittal of the previous version of the rule. EPA
did not take action on the November 13, 1992 submittal of the
District's oxygenated gasoline rule. In the intervening years, the
District has twice amended the oxygenated gasoline rule: on October 25,
2000, the District phased-out use of methyl tertiary butyl ether (MTBE)
as the oxygenate to meet the oxygen content requirement, and on

September 22, 2005, the District clarified labeling requirements
consistent with related EPA requirements at 40 CFR 80.35 and made
certain other changes to improve enforceability. The September 22, 2005
version of the wintertime oxygenated gasoline rule was submitted as a
SIP revision by NDEP on November 4, 2005, thereby superseding the
November 13, 1992 submittal of the rule.
    We have evaluated the State's November 4, 2005 submittal of the
wintertime oxygenated gasoline rule (District rule 040.095) and find
that it meets the applicable statutory and regulatory requirements by
establishing the necessary minimum oxygen content requirement (2.7% by
weight) in the applicable geographic area (i.e., Reno MSA, which
consists of Washoe County, Nevada) for the appropriate control period
(October 1 through January 31) and also provides for the necessary
labeling of gasoline dispensers, and for recordkeeping, sampling and
for enforceability. The District AQMD enforces the oxygenated gasoline
rule by obtaining fuel samples from retail gasoline distributors, which
are then analyzed by the State of Nevada, Department of Agriculture.
Each year, the District AQMD publishes a report summarizing the results
of the oxygenated gasoline program for the prior year. A review of
these annual reports reveals near-full compliance with the requirements
of the rule.
    For the above reasons, we find that District rule 040.095 (``Oxygen
Content of Motor Vehicle Fuel''), as amended by the District on
September 22, 2005, and submitted by NDEP to EPA on November 4, 2005,
fulfills the requirements of section 211(m) of the Act and applicable
EPA regulations, and, based on that finding, we propose approval of the
rule as a revision to the Nevada SIP.

VII. Nevada's Motor Vehicle Inspection and Maintenance (I/M) Program in
Truckee Meadows

A. Background Information

    As noted in section IV of this document, EPA promulgated area
designations for all states pursuant to the Act, as amended in 1977.
See 43 FR 8962 (March 3, 1978). The Truckee Meadows area of Nevada was
designated nonattainment for the NAAQS for CO and photochemical
oxidant.\4\
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    \4\ In 1979, EPA established a new NAAQS for ozone to replace
the oxidant standard. In 1981, EPA changed the designation for
Truckee Meadows from nonattainment for oxidant to attainment for
ozone. See 46 FR 37896 (July 23, 1981).
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    During the late 1970's, the Nevada Legislature established the
first motor vehicle I/M program for Truckee Meadows, and the Nevada
Department of Motor Vehicles (DMV) began to implement this initial
program in 1978. Nevada's motor vehicle I/M program is required in two
counties, Washoe and Clark.
    Originally, I/M requirements were triggered only by a change in
vehicle ownership, but by 1983, I/M in Truckee Meadows had been
expanded to apply annually upon vehicle registration or upon
registration renewal. Implementation of a mandatory annual I/M program
in Truckee Meadows was not a requirement of the 1977 amended Act but
was one of the control measures selected by Washoe County and the State
of Nevada to reduce CO emissions in that area.
    The 1980's-era program in Truckee Meadows excluded certain types of
vehicles including, among others, new cars, vehicles over 5,000 pounds
unladen weight, and motorcycles. Waivers were allowed in certain cases
for repairs costing over $100 in labor plus parts. For more information
on this early I/M program in Truckee Meadows and related EPA rulemaking
actions, see 44 FR 26763 (May 7, 1979), 45 FR 59334 (September 9,
1980), 46 FR 21758 (April 14, 1981), 48 FR 5071 (February 3, 1983), 49
FR 6386 (February 21, 1984), and 49 FR 44208 (November 5, 1984).
    As noted in section IV of this document, under the Clean Air Act
Amendments of 1990, EPA classified Truckee Meadows as a ``moderate'' CO
nonattainment area based on a design value of 9.8 ppm. Under section
187(a) of the Act, as amended in 1990, States with ``moderate'' CO
nonattainment areas (with design values less than 12.7 ppm) were
required to continue implementation of existing I/M programs and to
submit I/M SIP revisions to meet the ``basic'' I/M performance standard
and other new related requirements promulgated by EPA subsequent to the
1990 Act Amendments. See CAA section 187(a)(4).\5\ On January 15, 1993,
EPA made a finding of failure to submit the required ``basic'' I/M SIP
revision for Truckee Meadows. On November 15, 1993, the NDEP submitted
a ``basic'' I/M SIP revision for Truckee Meadows, but by letter dated
April 13, 1994, EPA made a finding of incompleteness for the November
15, 1993 SIP revision submittal.
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    \5\ In 1991, all of Washoe County was designated as a
``marginal'' nonattainment area for the 1-hour ozone NAAQS. See 56
FR at 56798 (November 6, 1991). For most such areas, a corrected and
upgraded ``basic'' I/M program was required under CAA section
182(a)(2)(B); however, the Washoe County ``marginal'' ozone
nonattainment area was not subject to the I/M requirement because
the EPA-approved I/M program for Truckee Meadows (at the time of
designation as a marginal ozone nonattainment area) did not include
hydrocarbon emissions testing (but only CO emissions testing), and
thus the I/M program was not part of the applicable ozone SIP. The
State of Nevada deleted hydrocarbon emissions testing from the I/M
program in 1983, and EPA approved the related changes in 1984. See
49 FR 6386 (February 21, 1984) and 49 FR 44208 (November 5, 1984).
Hydrocarbon emissions testing requirements have since been restored
to the program and are a part of the current I/M program that is the
subject of today's proposal.
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    On June 3, 1994, NDEP submitted the State Implementation Plan for a
Basic Program for the Inspection and Maintenance of Motor Vehicles for
the Truckee Meadows Planning Area, Nevada (June 1994) (``Basic I/M
SIP''). By letter dated January 31, 1995, EPA found the Basic I/M SIP
to be complete. The Basic I/M SIP includes I/M-related statutes and
rules, as well as various other documents to satisfy EPA I/M
requirements, but does not include the required performance standard
evaluation.
    On November 2, 2006, NDEP submitted a SIP revision containing a
performance standard evaluation of the basic I/M program for motor
vehicles in the Truckee Meadows planning area (``Basic I/M Performance
Standard Evaluation'') thereby fulfilling a requirement not addressed
in the Basic I/M SIP. The November 2, 2006 SIP revision submittal
contained the performance standard evaluation along with motor vehicle
emissions modeling documentation and evidence of public process and
adoption by the Washoe County District Board of Health on September 28,
2006.
    Since the submittal of the Basic I/M SIP in 1994, the State of
Nevada has revised many of the I/M-related statutory provisions and
regulations and has established new specifications for exhaust gas
analyzers. On May 11, 2007, NDEP submitted a SIP revision entitled
Nevada Mobile Source SIP, Update of the Regulatory Element (May 11,
2007) (``Mobile Source SIP Update''), which includes current I/M-
related statutory provisions and regulations as well as updated exhaust
gas analyzer specifications. The current Nevada I/M statutory
provisions and rules submitted by NDEP on May 11, 2007 are as follows:
     Nevada Revised Statutes (2005), chapter 365: section
365.060; chapter 366, section 366.060; chapter 445B, sections 445B.210,
445B.700-845 (excluding NRS 445B.776, 445B.777, and 445B.778); chapter
481, sections

481.019-481.087; chapter 482, sections 482.029, 482.155-482.290,
482.385, 482.461, and 482.565; and chapter 484, sections 484.101,
484.644 and 484.6441;
     Nevada Administrative Code (NAC), chapter 445B (January
2007 revision by the Legislative Counsel Bureau), sections 445B.400 to
445B.735.\6\
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    \6\ As explained below in the subsection entitled ``Vehicle
coverage (40 CFR 51.356), we are taking no action on subsection (2)
of NAC section 445B.595.
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    The Mobile Source SIP Update supersedes the corresponding materials
included in the Basic I/M SIP submitted in 1994 and represents a
comprehensive update to the regulatory portion of the State's mobile
source SIP (excluding the rules establishing fuels specifications,
alternative fuels programs for government vehicles, and any local rules
related to mobile sources), including the regulatory portion of the
Truckee Meadows I/M SIP, which was last approved in 1984 (see 49 FR
44208, November 5, 1984), and the regulatory portion of the Las Vegas
Valley I/M SIP, which was last approved in 2004 (see 69 FR 56351,
September 21, 2004).

B. Evaluation of the State's I/M Program in Truckee Meadows

    This subsection summarizes the applicable requirements of EPA's I/M
requirements found in 40 CFR part 51, subpart S (``Inspection/
Maintenance Program Requirements''), which is referred to herein as the
``Federal I/M rule,'' and discusses whether the elements of the State's
``basic'' vehicle I/M program for Truckee Meadows as contained in SIP
revisions submitted on June 3, 1994, November 2, 2006, and May 11, 2007
comply with Federal requirements.
Applicability (40 CFR 51.350)
    Under the Federal I/M rule, any area classified as marginal ozone
nonattainment or moderate CO nonattainment with a design value of 12.7
parts per million (ppm) or less shall continue operating I/M programs
that were part of an approved SIP as of November 15, 1990, and shall
update those programs an necessary to meet the basic I/M program
requirements as set forth in part 51, subpart S. See 40 CFR
51.350(a)(3). This requirement applies to Truckee Meadows because the
CO SIP for Truckee Meadows, as of November 15, 1990, included an I/M
program and because, under the Act as amended in 1990, the Truckee
Meadows CO nonattainment area was classified as ``moderate'' (with a
design value of 12.7 ppm or less).
    I/M programs are nominally required to cover at least the entire
urbanized area, based on the 1990 census. See 40 CFR 51.350(b)(2). The
State's legal authority necessary to establish program boundaries is
contained in Nevada Revised Statutes (NRS) 445B.770. The applicable
area for the basic I/M program is the urbanized area within ``Truckee
Meadows,'' which is defined by reference to the State's hydrographic
area 87. Under Nevada Administrative Code (NAC) 445B.594, the
State's basic I/M program applies within all of Washoe County, except
for residents that live outside of the urbanized area and are serviced
by one of the following post offices: (1) Crystal Bay, (2) Empire; (3)
Incline Village, (4) Nixon, (5) Sutcliffe, or (6) Wadsworth. This is
acceptable.
    The Federal I/M rule requires a State I/M program to remain in
operation even if the area is redesignated to attainment until the
State submits and EPA approves a SIP revision which convincingly
demonstrates that the area can maintain the relevant standard without
benefit of the emission reductions attributable to the I/M program. See
40 CFR 51.350(c). The statutory authority for the ``basic'' I/M program
in Truckee Meadows contains no automatic sunset provision and thus is
consistent with EPA requirements.
Basic I/M Performance Standard (40 CFR 51.352)
    ``Basic'' I/M programs must be designed and implemented to meet or
exceed a minimum performance standard, which is expressed as emission
levels achieved from highway mobile sources as a result of the program.
Areas are required to meet the performance standard for the pollutants
which cause them to be subject to I/M requirements. The performance
standard is based on the model I/M program inputs and local
characteristics, such as vehicle mix and local fuel controls, and
emission levels and emission reduction benefits must be calculated
using the most recent version of EPA's mobile source emission factor
model (MOBILE).
    The Federal model ``basic'' I/M program has the following
characteristics: (1) Network type (centralized testing); (2) Start date
(for areas with existing I/M programs, 1983); (3) Test frequency
(annual testing); (4) Model year coverage (testing of model year (MY)
1968 and later vehicles); (5) Vehicle type coverage (light-duty
vehicles (excluding trucks)); (6) Exhaust emission test type (idle
test); (7) Emission standards (no weaker than specified in 40 CFR part
85, subpart W); (8) Emission control device inspections (none); (9)
Stringency (a 20% emission test failure rate among pre-1981 model year
vehicles); (10) Waiver rate (0% waiver rate); (11) Compliance rate (a
100% compliance rate); and (12) Evaluation date (1996 for CO
nonattainment areas). Also, the basic I/M performance standard includes
inspection of all 1996 and later light-duty vehicles equipped with
certified on-board diagnostic (OBD) systems,\7\ and repair of
malfunctions or system deterioration identified by or affecting OBD
systems.
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    \7\ A certified OBD system consists of a computer, which
performs checks of a number of different vehicle systems for
malfunctions or deterioration, which could result in the vehicle
exceeding its emissions standards, and a malfunction indicator
light, which is required to be illuminated when the system detects a
problem.
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    The Nevada basic I/M program within Truckee Meadows has the
following characteristics: (1) Network type (decentralized, test-and-
repair); (2) Start date (1983); (3) Test frequency (annual testing);
(4) Model year coverage (testing of MY 1968 and later vehicles); (5)
Vehicle type coverage [light-duty (i.e., less than 8,500 pounds gross
vehicle weight rating (GVWR)) vehicles (both gasoline- and diesel-
powered) and heavy-duty gasoline-powered vehicles]; (6) Exhaust
emission test type (``two-speed idle'' test (i.e, at 2,500 revolutions
per minute (rpm) and at idle) for light-duty gasoline-powered vehicles
from 1968 through 1995 and heavy-duty gasoline-powered vehicles 1968
and newer; 1968 and newer light-duty diesel-powered vehicles are
inspected for exhaust opacity on a dynamometer (i.e., steady state
using load mode)); (7) Emission standards (based on those specified in
40 CFR part 85, subpart W); (8) Emission control device inspections
(for 1968 and newer vehicles, a gas cap check; for gasoline-powered
vehicles newer than 1980, the anti-tampering program (ATP) checks for
air pump disablement, catalyst removal, fuel inlet restrictor
disablement, exhaust gas recirculation (EGR) system disablement,
evaporative system disablement, and positive crankcase ventilation
(PCV) system disablement; for diesel-powered vehicles, visual tampering
inspection is based on manufacturer's specifications); (9) Stringency
(21% based on 1996 data); (10) Waiver rate (4% for pre-1981 and 3% for
1981 and newer based on 1996 data); (11) Compliance rate (96%); and
(12) Evaluation date (year 1996). The State's basic I/M program
includes inspection of all 1996 and newer light-duty gasoline-powered
vehicles equipped with certified on-board diagnostic (OBD) systems.
Repair of

malfunctions or system deterioration is identified for emission
compliance through the OBD system.
    As noted above, the Basic I/M SIP submitted in 1994 does not
include a performance standard evaluation, but NDEP submitted the
required evaluation (referred to herein as the ``Basic I/M Performance
Standard Evaluation'') to EPA for approval on November 2, 2006.
District AQMD prepared this evaluation using the latest available
version of MOBILE (MOBILE6.2.03). District AQMD used the various inputs
for EPA's ``basic'' model program and the State's basic I/M program for
Truckee Meadows as described above to estimate the composite CO
emission rate in year 1996 of the vehicle fleet in Truckee Meadows
under three scenarios: (1) no I/M program, (2) EPA's basic model
program, and (3) the State's basic I/M program for Truckee Meadows.
District AQMD assumed 50% effectiveness for the State's basic I/M
program in Truckee Meadows to account for the decentralized, test-and-
repair nature of the I/M program.
    A comparison of the MOBILE6.2.03-based CO emissions rates for these
three scenarios shows that EPA's basic model program would have reduced
composite CO emissions by 8.9% (relative to the no I/M scenario) and
that the State's basic I/M program for Truckee Meadows reduced the
emissions rate by 9.5% (once again, relative to the no I/M scenario).
We find that District AQMD used the appropriate model and reasonable
methods and assumptions in developing the CO emission rates for the
performance standard evaluation. Based on this finding and because the
results of the evaluation show that State's basic I/M program achieves
equivalent or greater reductions in the CO emissions rate as compared
to EPA's basic model program, we find that the State's basic I/M
program in Truckee Meadows meets the performance standard requirement
under 40 CFR 51.352.
Network Type and Program Evaluation (40 CFR 51.353)
    State law provides for a decentralized (i.e., privately-owned but
licensed by the State), test-and-repair network for 1968 and newer
gasoline-powered autos and trucks.\8\ The network includes different
types of test-and-repair stations. State law differentiates between two
types of test-and-repair stations: (1) Test stations that are allowed
to do only specific types of repairs (such as oil changes, replacement
of oil or air filters, and servicing of the fuel injection system) but
are generally not allowed to perform repairs that affect exhaust
emissions and (2) test stations that are allowed to do more extensive
repairs. The former are referred to as ``authorized inspection
stations'' and the latter are referred to as ``authorized stations.''
NAC sections 445B.460 through 445B.480 specify requirements for
facilities to obtain licenses as authorized test stations or authorized
stations. For the purposes of the performance standard evaluation,
Washoe County assumed 50% effectiveness for the program based on the
decentralized, test-and-repair nature of the network. The 50%
effectiveness value is the default value in MOBILE for such networks
and is acceptable. We find that the State's I/M testing network for
Truckee Meadows is adequately described in the State's I/M submittals,
that the State has sufficient legal authority to enforce the
requirements that must be met for stations to obtain and retain
licenses as authorized inspection stations or as authorized stations,
and that the network has been adequately modeled for performance
standard purposes, and thus the requirements of 40 CFR 51.353 are
satisfied.
---------------------------------------------------------------------------

    \8\ Under the Nevada I/M program, light-duty diesel-powered
motor vehicles registered in the applicable portions of Washoe
County and Clark County are also subject to annual inspections,
which include a tampering inspection and an opacity test.
---------------------------------------------------------------------------

    We note that the program evaluation required under 40 CFR 51.353(c)
applies to ``enhanced'' I/M programs, and because Truckee Meadows is
subject only to the ``basic'' I/M program requirements, the program
evaluation requirement under 40 CFR 51.353(c) does not apply.
Adequate Tools and Resources (40 CFR 51.354)
    The Federal I/M rule requires the state to demonstrate that there
is adequate funding of the program functions including quality
assurance, data analysis and reporting, the holding of hearings and
adjudication of cases. The state must also demonstrate that sufficient
personnel have been employed to effectively carry out the duties
related to the program and that equipment necessary to achieve the
objectives of the program have been acquired.
    Nevada law establishes annual fees to cover costs associated with
implementation, administration and operation of the I/M program. See
NRS 445B.830. The fees must be paid to the DMV and accounted for in the
pollution control account, which is created in the Nevada general fund.
The 1994 Truckee Meadows I/M SIP notes that the basic I/M program in
Truckee Meadows is an update to existing program whose funding has long
been established. To illustrate how the funds paid to DMV are allocated
to provide for employee salaries, the Basic I/M SIP includes a copy of
the budget for the program, as approved by the 67th Session of the
Nevada Legislature and the Governor, showing provisions for personnel
sufficient to meet the oversight requirements of the program for fiscal
year 1994. See appendix 3 of the Basic I/M SIP. EPA believes
the State's I/M program plan for tools and resources is acceptable.
Test Frequency and Convenience (40 CFR 51.355)
    The performance standards for I/M programs assume an annual test
frequency, but under the Federal I/M rule, other schedules may be
approved if the required emission targets are achieved. Also, under the
Federal I/M rule, the SIP must include the legal authority necessary to
implement and enforce the test frequency requirement and explain how
the test frequency will be integrated with the enforcement process.
    Nevada's motor vehicle I/M program is registration-enforced in the
two affected counties (i.e., Washoe and Clark) and is tracked by
continuing annual vehicle registration. Under NRS 482.206, vehicle
registration must be renewed annually, and under NAC 445B.594, persons
who are registering or reregistering their vehicle in Truckee Meadows
(except for new vehicles) must provide evidence of compliance (with the
emission inspection) as part of the annual registration process. New
vehicles are exempt from testing until the third registration cycle.
See NAC 445B.592.
    The DMV has authority under NRS 445B.798 to require proof of
compliance with the emission standards after a vehicle has been cited
for needing mechanical repair or for a smoking vehicle. Nevada law
thereby provides for out-of-cycle emission testing for high-emitting
vehicles. Under NRS 482.461, cancellation of registration can result if
the vehicle failing a test conducted under NRS 445B.798 has not been
repaired as required.
    On May 11, 2007, NDEP submitted all of the current versions of the
statutory provisions and rules cited above for approval into the Nevada
SIP. EPA believes these elements meet the requirements of the Federal
I/M rule.
Vehicle Coverage (40 CFR 51.356)
    The Federal model ``basic'' I/M program against which State
programs are compared assumes coverage of all

1968 and newer model year (MY) ``light-duty'' vehicles (i.e., up to
8,500 pounds GVWR) and includes vehicles operating on all fuel types.
The Federal ``basic'' I/M program does not assume coverage of light-
duty trucks. Other levels of coverage may be approved if the necessary
emission reductions are achieved.
    Under Nevada's basic I/M program, the term ``light-duty motor
vehicles'' refers to passenger cars and trucks up to 8,500 pounds GVWR;
``heavy-duty motor vehicles'' refers to vehicles of 8,500 pounds GVWR
or more. Nevada's basic I/M program is more inclusive than required
under the Federal I/M rule in some ways and less inclusive in others.
For instance, the program is more inclusive in that, as mentioned
above, it requires all 1968 and newer heavy-duty gasoline-powered
vehicles to be tested annually in addition to light-duty gasoline-
powered vehicles. On the other hand, Nevada's basic I/M program
provides certain exemptions not included in the model program, such as
the exemption for new vehicles, which are not emissions-tested until
the third registration cycle (but still must be registered or re-
registered). Other minor exemptions are set forth in NAC 445B.592 (such
as motorcycles and motor vehicles permanently converted from gasoline
to propane, compressed natural gas, methane or butane as a fuel). The
Basic I/M Performance Standard Evaluation submitted by NDEP as a SIP
revision on November 2, 2006 takes these exemptions into account.
    Under the Nevada program, light-duty diesel-powered vehicles, 1968
and newer, are also subject to annual registration requirements and
certain emissions-related requirements but are not subject to the
emissions testing procedures that apply to gasoline-powered vehicles.
In addition, the emissions evaluation for the State's I/M program takes
no specific credit for inspection and maintenance of diesel-powered
vehicles.
    EPA believes that Nevada's ``basic'' I/M program adequately
identifies and accounts for the vehicles covered by the program and
thereby meets the requirements of the Federal I/M rule under 40 CFR
51.356.
    The Federal I/M rule requires that vehicles operated on Federal
installations located within an I/M program area be tested regardless
of whether the vehicles are registered in the state or local I/M area.
See 40 CFR 51.356(a)(4). However, we are not requiring states to
implement 40 CFR 51.356(a)(4) at this time. The Department of Justice
has recommended to EPA that this Federal regulation be revised since it
appears to grant states authority to regulate Federal installations in
circumstances where the Federal government has not waived sovereign
immunity. It would not be appropriate to require compliance with this
regulation if it is not constitutionally authorized. EPA will be
revising this provision in the future and will review state I/M SIPs
with respect to this issue when this new rule is final. Therefore, for
these reasons, EPA is neither approving nor disapproving the specific
requirements which apply to Federal facilities at this time.
Specifically, we are taking no action on submitted rule NAC
445B.595(2), which extends the State's I/M requirements to motor
vehicles operated on Federal installations located within I/M areas. We
are also proposing under CAA section 110(k)(6), which authorizes EPA to
correct errors in SIP actions, to rescind our previous approval of NAC
445B.595(2) into the Nevada SIP on grounds of sovereign immunity. We
approved NAC 445B.595(2) as part of our 2004 approval of the State of
Nevada's I/M program for Las Vegas and Boulder City.
Test Procedures and Standards (40 CFR 51.357)
    The Federal I/M rule requires that states establish written test
procedures and pass/fail standards to be followed for each model year
and vehicle type included in the program. The required test procedures
are specified in 40 CFR 51.357(a). The Federal I/M rule also requires
that beginning January 1, 2002, inspection of the OBD systems on MY
1996 and newer light-duty vehicles shall be conducted according to the
procedure described in 40 CFR 85.2222, at a minimum. See 40 CFR
51.357(a)(12). The required test standards are specified in 40 CFR
51.357(b).
    EPA's basic I/M performance standard assumes testing in idle mode,
but Nevada's I/M program requires subject vehicles to pass the more
demanding ``two-speed idle'' test (i.e., exhaust emissions are tested
in idle mode and at 2,500 rpm). In this instance, the subject vehicles
include all gasoline-powered motor vehicles (except motorcycles, and
other exempt categories), i.e., light-duty gasoline-powered vehicles MY
1968 through MY 1995, and heavy-duty gasoline-powered vehicles MY 1968
and newer. See NAC 445B.580. Generally, the procedures require use of
an approved exhaust gas analyzer and compliance with the emissions
standards set forth in NAC 445B.596 (unless a waiver is granted). All
light-duty gasoline-powered vehicles MY 1996 and newer are subject to
OBD systems checks. See NAC 445B.5805. The State's procedures for the
two-speed idle test and the OBD system check are consistent with EPA
requirements. Testing procedures and standards for light-duty diesel-
powered vehicles are found in NAC 445B.587 through 445B.589.
    EPA's basic I/M performance standard assumes exhaust emission
testing standards as specified in 40 CFR part 85, subpart W. Consistent
with those standards, the State I/M program establishes, for those
vehicles that are subject to emissions testing, maximum exhaust
emissions for MY 1981 and newer of 1.2% for CO and 220 ppm for
hydrocarbons (HC). For older light-duty gasoline-powered vehicles (MY
1968 through 1980), maximum CO (%) and HC (ppm) standards range from
4.0%-2.0% and 800 ppm-500 ppm, respectively. The standards for heavy-
duty gasoline-powered vehicles MY 1981 and newer are 3.5% for CO and
1,000 ppm for HC; for older heavy-duty gasoline-powered vehicles (MY
1968 through 1980), maximum CO (%) and HC (ppm) range from 7.0%-4.0%
and 1,400 ppm-1,000 ppm, respectively. See NAC 445B.596. In the event
of an emission failure of any kind, all components are retested after
repairs.
    The Federal basic I/M performance standard does not assume that
inspections are made of the emission control devices as part of the I/M
program. Under the Nevada I/M program, however, such inspections are
required. Specifically, inspectors perform visual checks for smoke from
the exhaust system and for blowby gases from the crankcase. See NAC
445B.580. Also, inspectors visually inspect all vehicles to determine
the presence of a properly installed gas cap. For light-duty gasoline-
powered vehicles MY 1981 through MY 1995 (and MY 1996 and newer heavy-
duty gasoline-powered vehicles), inspectors also check for the presence
of an exhaust gas recirculation valve, catalytic converter, air
injection system and fuel inlet restricter, and whether this equipment
appears to be operating in accordance with the specifications of the
manufacturer of the vehicle. See NAC 445B.580. For MY 1996 and newer
light-duty gasoline-powered vehicles, inspection stations administer
OBD systems checks (see NAC 445B.5805) that substitute for the visual
inspections that are part of the program for earlier models. If a
vehicle has missing or malfunctioning emissions control equipment,
Nevada's required I/M test will result in a failed vehicle
notification. Under NAC 445B.582 and 445B.589, necessary

repairs must be completed before a second test can be performed.
    We conclude that the State's test procedures and standards meet the
corresponding Federal I/M rule requirements.
Test Equipment (40 CFR 51.358)
    The Federal I/M rule requires computerized test systems for
performing any measurement on subject vehicles, and the SIP is to
include written technical specifications for all test equipment used in
the program.
    In 1994, when the Basic I/M SIP was submitted, the State's exhaust
gas analyzer was the Nevada 94 analyzer, and the Basic I/M SIP included
the written specifications for that analyzer. Since then, the State has
replaced the Nevada 94 analyzer with the NV2000 analyzer and submitted
the related written specifications to EPA in a SIP submittal dated
January 30, 2002. The January 30, 2002 SIP submittal was made in
connection with our review of the I/M program in Las Vegas and Boulder
City, but we note that the same analyzer (i.e., NV2000) is required for
use in both the Las Vegas/Boulder City area and in the Truckee Meadows
area. On May 11, 2007, NDEP submitted another I/M-related SIP revision
that included, among other items, written specifications for a change
in NV2000 as previously submitted to make emissions testing possible on
motor vehicles containing a certified OBD system which uses controller
area network communication.
    NV2000 emission testing equipment has been used to inspect
gasoline-powered vehicles since April 2001. NV2000 analyzers carry
California Bureau of Automotive Repair (BAR 97) certification. Two-
speed idle and OBD inspection procedures can be performed with NV2000
analyzers. The NV2000 emission analyzer has remained in the same
configuration as when first implemented in April 2001 with one
exception. In late 2004, a revised OBD scan hardware capable of
communication with controller area network systems was approved as an
option. Emissions stations were required to update their NV2000
emission analyzers to include the revised OBD scan hardware by
September 2006.
    NV2000 test equipment features include: Concentration measurements
of CO, HC, carbon dioxide (CO2) and oxygen (O2);
engine RPM; leak checks; anti-tampering checks; automatic test data
recording; and lock-out measures. The test begins with a check of the
vehicle's registration and for any recall notices for that model
vehicle. Adoption or use of alternate test equipment, test procedures
or alternate methods requires prior approval by EPA. The exhaust gas
analyzer specifications describe all the necessary components of the
emission analysis process, test equipment and all necessary EPA
requirements under 40 CFR 51.358. We found NV2000 to be acceptable in
connection with our approval of Nevada's I/M program for Las Vegas and
Boulder City (see 69 FR 56351 (September 21, 2004)) and believe that
NV2000, as updated in NDEP's submittal dated May 11, 2007, is equally
acceptable for the purposes of the basic I/M program in Truckee
Meadows.
Quality Control (40 CFR 51.359)
    The Federal I/M rule requires state programs to include measures to
ensure emission testing equipment is calibrated and maintained
properly. See 40 CFR 51.359. SIPs are to include a description of
quality control and recordkeeping procedures and the procedure manual,
rule, ordinance or law describing and establishing the quality control
procedures and requirements. See 40 CFR 51.359(f). The specifications
for Nevada's NV2000 analyzer include several quality control elements.
Only State-certified analyzers may be used for emission testing
purposes under the I/M program, and to qualify for certification,
manufacturers of analyzers must demonstrate that their model complies
with all NV2000 specifications. NV2000 specifications were submitted by
NDEP as part of its January 30, 2002 SIP submittal to EPA and approved
as a SIP revision on September 21, 2004 (69 FR 56351). NDEP submitted
revisions to NV2000 on May 11, 2007. NV2000 requires that analyzers be
designed to perform automatic two-point gas calibrations for HC, CO and
carbon dioxide; ambient air zero and span check tests; and measurements
of oxygen using ambient air. The specifications call for automatic gas
calibration to be conducted every 72 hours as activated by the
analyzer's internal clock. In addition, to meet NV2000 specifications,
an analyzer must be designed with a system capable of requiring an
automatic leak check of the vacuum side of the analyzer activated by
the internal clock every 24 hours.
    The NV2000 analyzer also includes a number of automated controls to
ensure that the system is tamper-resistant. The inspection certificates
are stored automatically by the exhaust gas emission analyzer. The
analyzers provide security capable of preventing any unauthorized
modifications to the software or test data. The performance of licensed
test and repair stations on repairing vehicles for retest is monitored.
Emission certificates are counterfeit-resistant. Overt and covert
audits are used to help verify the security of documents and emission
test information. The Nevada DMV collects and inspects records from
licensed test stations to detect discrepancies in testing and/or
repairs. EPA believes the State's submitted basic I/M program for
Truckee Meadows meets the quality control requirements of 40 CFR 51.359
and is acceptable.
Waivers and Compliance via Diagnostic Inspection (40 CFR 51.360)
    Under the Federal I/M rule, state I/M programs may allow the
issuance of a waiver, which is a form of compliance with the program
requirements that allows a motorist to comply without meeting the
applicable test standards, as long as certain prescribed criteria are
met. See 40 CFR 51.360. For ``basic'' I/M programs, state I/M programs
must require motorists to make an expenditure of at least $75 for pre-
1981 vehicles and $200 for 1981 and newer vehicles to qualify for a
waiver, but allows motorists to wait to repair a failed vehicle for the
period of one test cycle for ``economic hardship.'' See 40 CFR
51.360(a)(9).
    The State of Nevada has adopted procedures for issuing waivers
after an emission test failure (see NAC 445B.590). First of all, only
Nevada DMV may grant a waiver under the emissions standards tests.
Second, for the basic I/M program in Truckee Meadows, the Nevada
program requires a minimum expenditure of at least $200 at an
authorized station on repair parts (other than a catalytic converter,
fuel inlet restrictor or air injection system) or on labor to qualify
for a waiver. See NAC 445B.590(2)(a). Such labor costs cannot include
emission testing if the repairs evidenced by the receipt were directly
related to the deficiency in emissions. If the vehicle is repaired by
the owner, the waiver application must include receipts or other
evidence that at least $200 has been spent on parts (other than a
catalytic converter, fuel inlet restrictor or air injection system). No
allowance is permitted for labor on vehicles repaired by the owner.
Also, a vehicle that qualifies for repairs under a warranty is not
eligible for a waiver. The performance standard evaluation provided by
the State in the Basic I/M Performance Standard Evaluation SIP
submittal dated November 2, 2006 reflects the actual waiver rate that
occurred during the first quarter of 1996: 4.2% for pre-1981 vehicles
and 3.3% of 1981 and newer vehicles. We

find that Nevada's submitted basic I/M program for Truckee Meadows
meets the requirements for issuing waivers under such programs under 40
CFR 51.360 and adequately accounts for waivers in the performance
standard evaluation for the program.
Motorist Compliance Enforcement (40 CFR 51.361)
    The Federal I/M rule requires the use of registration denial to
ensure compliance with the requirements of the I/M program. However,
the Federal I/M rule allows programs in ``basic'' I/M areas to use an
alternative enforcement mechanism if the State demonstrates that the
alternative will be as effective as registration denial.
    The Nevada program includes a registration denial enforcement
program. See NRS 445B.815 AND NRS 482.280. New residents to Nevada must
register their motor vehicles within 60 days of becoming a resident.
See NRS 482.385. Vehicle owners that do not renew vehicle
registrations, and continue to drive an unregistered vehicle in the
state, are subject to enforcement action by any law enforcement officer
in the state. Local governments are responsible for establishing
policies for the mandatory fines of all traffic violations including
failure to comply with registration requirements.
    Persons purchasing vehicles from used-car dealers must have the
vehicle tested and obtain evidence of compliance from the dealers prior
to sale (NRS 445B.800). All persons purchasing vehicles from
individuals must have the vehicle tested and have a passing certificate
of compliance to obtain registration. If a vehicle is not registered,
it is unlawful to be operated on public highways, and NRS 445B.840
prohibits possession of unauthorized evidence of compliance or the
making, issuance, or use of any imitation or counterfeit evidence of
compliance.
    Government fleets (any number of vehicles) and private fleets
(consisting of 25 or more vehicles) can certify their vehicles in their
own licensed fleet facility (see NAC 445B.461 and NAC 445B.478). I/M
inspection facilities for fleets must also meet the requirements
applicable to a licensed test station except for bonds and signs.
Evidence of I/M compliance for vehicles serviced by a covered fleet
must be submitted annually to Nevada DMV.
    Emission control compliance is tied to vehicle registration or re-
registration. Registration tags are color-coded with the date imprinted
to make it easily visible to local, county or State law enforcement
personnel. EPA believes the submitted basic I/M program for Truckee
Meadows meets the requirements under the Federal rule related to
motorist compliance enforcement and is acceptable.
Motorist Compliance Enforcement Program Oversight (40 CFR 51.362)
    The Federal I/M rule requires the State to audit the enforcement
program on a regular basis and to follow effective program management
practices, including adjustments to improve operation when necessary. A
quality assurance program must be implemented to ensure effective
overall performance of the enforcement system.
    Under Nevada's program, compliance is monitored using computer
records of vehicle registration through the Nevada DMV, in conjunction
with the State, local and county law enforcement agencies. Denial of
vehicle registration or re-registration is the main tool for
compliance. The DMV issues and supplies all emission control documents.
The DMV tracks all certificates of inspection issued, received,
returned or voided by the individual licensed test stations. Licensed
test stations are required to provide the DMV with a report on all
control documents received, issued, or voided (see NAC 445B.472 and
445B.473).
    The DMV is required to develop procedures for personnel engaged in
I/M document management and processing. Periodic audits of test records
and registration files for renewals must be performed. Evaluations of
all personnel are conducted on a regular basis in accordance with the
State Personnel Manual.
    Emission test files are required to be updated periodically at the
DMV. Procedures have been developed for inquiry into the host computer
for specific vehicles, stations, and general program reporting.
Information on complaints, waivers issued, and recall information is
included in the data files. NV2000 specifications require automatic
functions for such items as the following: Pass/fail determinations on
all measurements; a record of all test data and vehicle data to the
central computer; electronic calibration and system integrity checks;
and lockouts for specified quality control.
    The State has developed written procedures for all field auditors
and personnel directly involved in the enforcement of the I/M program.
The procedures include: Methods for performing covert and overt audits,
preparation of enforcement documents, methods for operation of I/M test
equipment, public relation materials and other applicable information.
EPA believes the submitted basic I/M program for Truckee Meadows meets
the requirements under the Federal rule related to oversight of the
motorist compliance enforcement program and is acceptable.
Quality Assurance (40 CFR 51.363)
    The Federal I/M rule requires an ongoing quality assurance program
to discover, correct, and prevent fraud, waste, and abuse and to
determine whether procedures are being followed and are adequate, if
equipment is measuring accurately, and if other problems may exist,
which would impede program performance. The procedures must also be
periodically evaluated to assess their effectiveness and relevance in
achieving program goals. See 40 CFR 51.363.
    The specifications for the NV2000 analyzer incorporate quality
assurance procedures. Among its various software requirements, NV2000
provides the capability for generating station and inspector evaluation
reports. NV2000 also provides for different types of reports generated
for State audit purposes, such as a station performance report and
details regarding analyzer maintenance. Each licensed test station must
maintain records and have them available for collection for DMV
evaluation (see NAC 445B.472).
    The State's rules for inspecting test stations and inspectors are
set forth in NAC 445B.7015-445B.7045. Nevada DMV conducts annual audits
of test stations and may determine that additional inspections are
necessary based on circumstances such as abnormal rates of failure of
motor vehicles on exhaust emissions tests or receipt of complaints
against stations or inspectors. In addition, a minimum of once every
calendar month, DMV performs an audit of all exhaust gas analyzers
located at a test station, and once every calendar quarter, DMV's audit
includes an evaluation of the accuracy of the analyzers using specialty
gas specifically designed for that purpose. See NAC 445B.472.
    DMV has developed written standard operating procedures for quality
assurance that were included as appendix 6 of the Basic I/M SIP
submitted in 1994. These procedures cover such subjects as covert
audits and use of covert vehicles. Nevada DMV auditors receive formal
training in the use of analyzers, basics of air pollution control,
basic engine repair, State administrative procedures, quality assurance
practices, covert procedures and program rules and regulations. EPA

believes the State's submitted basic I/M program for Truckee Meadows
meets the requirements under the Federal rule related to quality
assurance and is acceptable.
Enforcement Against Contractors, Stations and Inspectors (40 CFR
51.364)
    The Federal I/M rule requires the establishment of minimum
penalties for violations of program rules and procedures which can be
imposed against licensed stations or contractors, and inspectors.
Procedures for actions against stations and inspectors are provided for
in NAC sections 445B.463 and 445B.476 (stations) and sections 445B.489
and 445B.491 (inspectors). Violations and penalties are set forth in
NRS section 445B.835 and 445B.845 and NAC sections 445B.7045 and
445B.727. Stations and inspectors are regulated by Nevada DMV with
respect to license denials, suspension, reinstatements, temporary
suspensions, revoked licenses, required bonds, reapplications, and
hearings for reapplication [NAC sections 445B.463 through 445B.468
(stations) and sections 445B.489 through 445B.493 (inspectors)]. EPA
believes the State's submitted basic I/M program for Truckee Meadows
meets the requirements for enforcement against licensed stations or
contractors, and inspectors in the Federal rule and is acceptable.
Data Collection (40 CFR 51.365)
    An effective I/M program requires accurate data collection in order
to manage, evaluate and enforce the program requirements. The Nevada I/
M program contains data gathering provisions that meet all of the
criteria of the EPA regulations. Vehicle test data storage and
retrieval methods are enumerated. Test results are expressed as either
pass or fail. Information related to the calibration check must be
stored automatically by each analysis. EPA believes the State's
submitted basic I/M program for Truckee Meadows meets the requirements
for data collection in the Federal rule and is acceptable.
Data Analysis and Reporting (40 CFR 51.366)
    Data analysis and reporting are required to monitor and evaluate
the program by the State and EPA and must provide information regarding
the types of program activities performed and their final outcomes,
including summary statistics and effectiveness evaluations of the
enforcement mechanism, the quality assurance system, the quality
control program, and the testing element. The Federal I/M rule requires
four annual reports to be submitted to EPA: A test data report, a
quality assurance report, a quality control report, and an enforcement
report. In addition, on a biennial basis, the States must submit a
report that addresses programmatic changes, such as funding or
personnel changes and new regulations, and problems identified in the
program and steps taken to correct those problems.
    Nevada DMV is responsible, in cooperation with NDEP, for data
analysis and reporting. The State of Nevada has consistently submitted
the reports on time (by July of each year), and the reports contain the
required information. Nevada's annual data analysis and reporting
includes: The number of vehicles tested by MY; pass/fail data; basic
statistics on the quality assurance program for the previous year that
include the number of inspection stations operating through the year;
overt and covert audit information; quality control reporting that
includes the number of scheduled station audits that were conducted and
the number of analyzers that failed a calibration audit; enforcement-
related information including the motorist compliance level and the
number of waivers granted; and a description of any changes made to the
I/M program. The most recent report covers calendar year 2006.
    EPA believes that the State's submitted basic I/M program for
Truckee Meadows meets the requirements for data analysis and reporting
in the Federal rule and is acceptable.
Inspector Training and Licensing or Certification (40 CFR 51.367)
    The Federal I/M rule requires all inspectors to receive formal
training and be licensed or certified to conduct inspections. NAC
sections 445B.485 through 445B.502 set forth the procedures for the
required training and licensing of inspectors. Nevada DMV's
requirements for an approved inspector include a verified training
program for ``class 1'' and ``class 2'' inspectors (including a course
approved by DMV), a written and practical testing program, and a
separate certification process. All trainees are required to pass a
comprehensive hands-on and written examination which requires
inspectors to demonstrate an understanding of Nevada's regulations,
test procedures, equipment usage, quality control procedures and safety
and health issues. Certified repair technicians must comply with the
training and licensing requirements of ``class 2'' inspectors in order
to perform service on vehicle exhaust emission components. All test
stations must employ approved inspectors of the appropriate class and
rating. Nevada DMV provides the appropriate inspector training and
licensing to meet the requirements listed in 40 CFR 51.367. EPA
believes that the State's submitted basic I/M program for Truckee
Meadows meets the requirements for inspector training and licensing or
certification in the Federal rule and is acceptable.
Public Information and Consumer Protection (40 CFR 51.368)
    The Federal I/M rule requires that an I/M program include a plan
for informing the public on an ongoing basis throughout the life of the
I/M program of: Local air quality problems, the requirements of Federal
and State law, and the impact of motor vehicles to local air quality
problems. The educational program should also include information on:
The need for and benefits of an inspection program, how to maintain a
vehicle in a low-emission condition, how to find a qualified repair
technician, and the requirements of the I/M program. In addition, the
program must describe procedures and mechanisms to protect the public
from fraud and abuse by inspectors, mechanics, and others involved in
the I/M program.
    Pursuant to NRS 445B.785 and NAC 445B.471, Nevada DMV issues a
pamphlet for the purpose of providing the general public with a
description of the methods of, and reasons for, the I/M program. NDEP
included such a pamphlet in appendix 8 of the Basic I/M SIP submitted
in 1994. In addition, Nevada DMV operates a Web site (http://www.dmvnv.com/emission.htm
) that describes the emissions testing

program. Nevada DMV has developed a public relations program to
disseminate information to the public through the local offices of the
DMV and civic events throughout the year. Information is made available
to the motorist, whose vehicle fails the test, regarding repair
facilities. The consumer is protected through covert audits, regular
inspections and public reports of improprieties. EPA believes the
State's submitted basic I/M program for Truckee Meadows meets the
requirements for public information and consumer protection in the
Federal rule and is acceptable.
Improving Repair Effectiveness (40 CFR 51.369)
    I/M program goals are achieved through effective repairs of
vehicles which have failed the initial test. Under the Federal I/M
rule, the State must provide the repair industry with

information and assistance on vehicle inspection, diagnosis and repair.
Also, the State I/M program must provide feedback, including
statistical and qualitative information to individual repair facilities
on a regular basis regarding their success in repairing failed
vehicles. Lastly, the State must assess the availability of adequate
repair technician training in the I/M area and if such training is not
currently available, shall ensure training is made available to all
interested persons in the community either through private or public
facilities.
    Nevada DMV provides technical assistance to the repair industry by
requiring the manufacturer of NV2000 exhaust gas analyzers to train all
approved inspectors at the time of installation in the proper use,
maintenance and operation of the analyzer and to provide on-site
service calls to address specific issues or problems. See NAC
445B.5075. To provide Nevada DMV with the basis to evaluate the success
in repairing failed vehicles, each authorized station is required to
maintain, and have available for collection, records of all repairs at
the request of Nevada DMV. See NAC 445B.472. Lastly, Nevada DMV's
inspector regulations (NAC 445B.485 through 445B.502) require specific
training and licensing of ``class 2'' inspectors, who are then approved
as repair technicians. The training and certifying of mechanics is
under the auspices of the DMV in cooperation with the Community College
System.
    We find that the State's I/M program for repair technician training
meets the requirements of 40 CFR 51.369 thereby justifying the
technician training credit taken in the Basic I/M Performance Standard
Evaluation SIP submitted on November 2, 2006.
Compliance With Recall Notices (40 CFR 51.370)
    States are required to establish a method to ensure that vehicles
subject to ``enhanced'' I/M and that are included in either a voluntary
emissions recall as defined at 40 CFR 85.1902(d), or in a remedial plan
determination made pursuant to section 207(c) of the Act, receive the
required repairs. ``Basic'' I/M programs, such as the one required for
Truckee Meadows, are not subject to this requirement.
On-Road Testing (40 CFR 51.371)
    On-road testing is required in areas subject to ``enhanced'' I/M
requirements but is an option for areas subject to ``basic'' I/M.
Because Truckee Meadows is subject to the ``basic'' I/M requirements,
no on-road testing is required in that area, and none is being
conducted.
State Implementation Plan Submission (40 CFR 51.372)
    The Federal I/M rule requires State I/M SIP submittals to address
the following elements: (1) Schedule of implementation of the program
including interim milestones leading to mandatory testing; (2) an
analysis of emission level targets for the program showing that the
program meets the performance standard; (3) a description of the
geographic coverage of the program; (4) a detailed discussion of each
of the required design elements; (5) legal authority requiring or
allowing implementation of the I/M program; (6) legal authority for I/M
program operation until such time as it is no longer necessary; (7)
implementing regulations, interagency agreements, and memorandum of
understanding; and (8) evidence of adequate funding and resources to
implement all aspects of the program.
    The State of Nevada has implemented a mandatory I/M program in
Truckee Meadows since 1983. The changes that the State adopted to meet
EPA's ``basic'' I/M program requirements were implemented in 1994. For
MY 1996 and newer light-duty gasoline-powered vehicles, mandatory OBD
system checks replaced the previous two-speed idle test beginning in
2002.
    All of the required SIP I/M elements listed above were included in
the Basic I/M SIP submitted by NDEP on June 3, 1994 except for the
performance standard evaluation, which was contained in the Basic I/M
Performance Standard Evaluation SIP submitted on November 2, 2006.
Also, since 1994, the State has updated certain elements of the Basic
I/M SIP, including the legal authority for the program, the
implementing regulations, and the specifications for the approved
exhaust gas analyzer. On May 11, 2007, NDEP submitted a third related
SIP revision entitled Nevada Mobile Source SIP: Update of the
Regulatory Element (May 11, 2007)(``Mobile Source SIP Update''), which
includes a complete set of current I/M-related statutory provisions and
implementing rules as well as the changes to the specifications for the
NV2000 exhaust gas analyzer made since approval of NV2000 as part of
Nevada's I/M program in Las Vegas and Boulder City in 2004. Thus, NDEP
has submitted all of the required I/M elements. We note also that
Nevada's I/M program does not undergo a sunset review, and thereby has
the legal authority to operate until such time as it is no longer
necessary.
Implementation Deadlines (40 CFR 51.373)
    The Federal I/M rule requires I/M programs to be implemented as
expeditiously as practicable. Decentralized ``basic'' I/M programs were
required to be fully implemented by January 1, 1994. On-board
diagnostic system checks must be implemented in all ``basic'' I/M areas
by January 1, 2002. Nevada's ``basic'' I/M program was implemented in
1994, and Nevada's requirements for OBD checks were implemented in
2002. This is acceptable.

Conclusion

    Based on our review of the various elements of the program as
discussed above, we propose to approve the basic I/M program for
Truckee Meadows as meeting all applicable requirements under the CAA
and our implementing regulations under 40 CFR part 51, including the
requirement that the basic program meets the ``basic'' performance
standard applicable to ``moderate'' CO nonattainment areas with design
values less than 12.7 ppm.

VIII. Clean Air Act Requirements for Redesignation to Attainment

    The CAA establishes the requirements for redesignating a
nonattainment area to attainment. Specifically, section 107(d)(3)(E)
allows for redesignation provided that the following criteria are met:
(1) EPA determines that the area has attained the applicable NAAQS; (2)
EPA has fully approved the applicable implementation plan for the area
under section 110(k); (3) EPA determines that the improvement in air
quality is due to permanent and enforceable reductions in emissions
resulting from implementation of the applicable SIP, applicable Federal
air pollution control regulations, and other permanent and enforceable
reductions; (4) EPA has fully approved a maintenance plan for the area
as meeting the requirements of CAA section 175A; and (5) the State
containing such area has met all requirements applicable to the area
under section 110 and part D of the CAA.
    EPA provided guidance on redesignations in the form of a General
Preamble for the Implementation of Title I of the CAA Amendments of
1990 published in the Federal Register on April 16, 1992 (57 FR 13498),
as supplemented on April 28, 1992 (57 FR 18070). Other relevant EPA
guidance documents include:
     ``Contingency Measures for Ozone and Carbon Monoxide (CO)
Redesignations,'' Memorandum from

G.T. Helms, Chief, Ozone/Carbon Monoxide Programs Branch, Office of Air
Quality Planning and Standards (OAQPS), June 1, 1992 (Helms memo);
     ``Procedures for Processing Requests to Redesignate Areas
to Attainment,'' Memorandum from John Calcagni, Director, Air Quality
Management Division, OAQPS, September 4, 1992 (Calcagni memo 1992a);
     ``Public Hearing Requirements for 1990 Base-Year Emissions
Inventories for Ozone and Carbon Monoxide Nonattainment Areas,''
Memorandum from John Calcagni, Director, Air Quality Management
Division, OAQPS, September 29, 1992 (Calcagni memo 1992b);
     ``State Implementation Plan (SIP) Actions Submitted in
Response to Clean Air Act (ACT) Deadlines,'' Memorandum from John
Calcagni, Director, Air Quality Management Division, OAQPS, October 28,
1992 (Calcagni memo 1992c);
     ``State Implementation Plan (SIP) Requirements for Areas
Submitting Requests for Redesignation to Attainment of the Ozone and
Carbon Monoxide (CO) National Ambient Air Quality Standards (NAAQS) On
or After November 15, 1992,'' Memorandum from Michael H. Shapiro,
Acting Assistant Administrator for Air and Radiation, September 17,
1993 (Shapiro memo);
     ``Use of Actual Emissions in Maintenance Demonstrations
for Ozone and Carbon Monoxide (CO) Nonattainment Areas,'' Memorandum
from D. Kent Berry, Acting Director, Air Quality Management Division,
OAQPS, November 30, 1993 (Berry memo);
     ``Part D New Source Review (part D NSR) Requirements for
Areas Requesting Redesignation to Attainment,'' Memorandum from Mary D.
Nichols, Assistant Administrator for Air and Radiation, October 14,
1994 (Nichols memo).
    For the reasons set forth below in section IX of this document, we
propose to approve NDEP's request for redesignation of the Truckee
Meadows nonattainment area to attainment for the CO NAAQS based on our
conclusion that all of the criteria under CAA section 107(d)(3)(E) have
been satisfied.

IX. Evaluation of the State's Redesignation Request for Truckee Meadows

A. The Area Must Have Attained the Applicable NAAQS

    Section 107(d)(3)(E)(i) of the CAA states that for an area to be
redesignated to attainment EPA must determine that the area has
attained the applicable NAAQS. In this case, the applicable NAAQS is
the CO NAAQS.
    On May 3, 2005 (70 FR 22803), we determined that the Truckee
Meadows ``moderate'' CO nonattainment area attained the CO NAAQS by the
applicable attainment date (1995) and had continued to attain the
standard since that time. As part of that determination, we reviewed
the ambient CO monitoring network operated by the District AQMD and
found that it meets or exceeds our requirements. See 70 FR 3170
(January 21, 2005). For a description of District AQMD's ambient CO
monitoring network in Truckee Meadows and our requirements for such
networks, please see our January 21, 2005 proposed CO attainment
finding (70 FR 3170).
    We based our May 3, 2005 determination of attainment on ambient
monitoring data through year 2004. For the purposes of this proposed
rule, we have reviewed the most recent data input to our Air Quality
System (AQS) database and have found that no exceedances of the CO
NAAQS have been recorded in the 2005-2006 period. (The highest 8-hour
CO concentrations were less than 50% of the NAAQS at all of the
stations over the 2005-2006 period.) Thus, based on the attainment
finding and positive assessment of the District AQMD ambient CO
monitoring network that we made in May 2005 and our current review of
the most recent data in AQS, we find that Truckee Meadows has attained
the CO NAAQS thereby satisfying the criterion for redesignation set
forth in section 107(d)(3)(E)(i).

B. The Area Must Have a Fully Approved SIP Under Section 110(k) of the
CAA

    Section 107(d)(3)(E)(ii) precludes redesignation of a nonattainment
area to attainment until EPA has fully approved the applicable
implementation plan for the area under section 110(k). Pursuant to the
CAA amendments of 1977, the State of Nevada submitted a CO plan for the
Truckee Meadows nonattainment area. In 1981, we approved in part, and
conditionally approved in part, the submitted CO plan, and in 1982, we
found that the conditions imposed on approval of certain elements of
the CO plan for Truckee Meadows had been fulfilled. In 1984, we
approved revisions to many of the elements contained in the CO plan for
Truckee Meadows, and deferred action on other elements. We proposed
disapproval of a subsequent CO plan for Truckee Meadows in 1987, but we
consider the plan elements for which we deferred action or proposed
disapproval in the 1980's to be superseded by the SIP revision
submittals made pursuant to the 1990 Clean Air Act Amendments.
    With respect to post-1990 SIP submittals, upon final approval of
the required plan elements proposed for approval herein (wintertime
oxygenated gasoline rule and ``basic'' I/M program), we will have fully
approved the applicable implementation plan for the Truckee Meadows CO
nonattainment area, and thereby satisfied this criterion for
redesignation.

C. The Area Must Show the Improvement in Air Quality Is Due to
Permanent and Enforceable Emissions Reductions

    Section 107(d)(3)(E)(iii) precludes redesignation of a
nonattainment area to attainment unless EPA determines that the
improvement in air quality is due to permanent and enforceable
reductions in emissions resulting from implementation of the applicable
SIP and applicable Federal air pollution control regulations and other
permanent and enforceable regulations. If EPA makes such a
determination, then the criterion is satisfied.
    The improvement in CO air quality in the Truckee Meadows area is
due to the Federal Motor Vehicle Control Program (40 CFR part 86), the
local wintertime oxygenated gasoline rule, the State's ``basic''
vehicle I/M program, and the local residential wood combustion rule.
The Federal Motor Vehicle Control Program has contributed to improved
air quality through the gradual, continued turnover and replacement of
older vehicle models with newer models manufactured to meet
increasingly stringent Federal tailpipe emissions standards. The
emissions reductions from the Federal Motor Vehicle Control Program are
reflected in the emissions inventories and maintenance demonstration
discussed later in this document through the use of EPA's MOBILE
emission factor model for on-road motor vehicles. The Truckee Meadows
CO Maintenance Plan provides estimates of the emissions reductions
associated with the State and local measures in years 2002, 2010 and
2016 (see page 7 of the Truckee Meadows CO Maintenance Plan). Based on
those estimates, the three State and local control measures together
reduced CO emissions that would otherwise have occurred in Truckee
Meadows by approximately 20 percent in 2002.
    With respect to permanence and enforceability, we are proposing
approval of the wintertime oxygenated gasoline rule and the ``basic''
vehicle I/M program in this action, and upon

their final approval, the local wintertime oxygenated gasoline rule and
basic I/M program will become federally enforceable as part of the
Nevada SIP. (The wintertime oxygenated gasoline rule and basic I/M
program are already enforceable by the District and State,
respectively.) Upon the effective date of our approval of the
residential wood combustion rule, it became federally enforceable. None
of these measures include sunset clauses, and thus, upon approval by
EPA, the measures will become permanent features of the Nevada SIP
until such time as the State submits, and EPA approves, future SIP
revisions that amend or delete them.
    With respect to the connection between the emissions reductions and
the improvement in air quality, the Truckee Meadows CO Maintenance Plan
provides a demonstration that the air quality improvement in Truckee
Meadows, that has resulted in attainment of the CO NAAQS by 1995 and
continued attainment since then, is due to emission reductions from
implementation of the control measures discussed above and is not the
result of a local economic downturn or unusual or extreme weather
patterns. See pages 6 through 11 of the Truckee Meadows CO Maintenance
Plan.
    Thus, we find that the improvement in CO air quality in Truckee
Meadows is the result of permanent and enforceable emissions reductions
from a combination of the Federal Motor Vehicle Control Program and
certain State and local measures. As such, the criterion for
redesignation set forth at CAA section 107(d)(3)(E)(iii) is satisfied.

D. The Area Must Have Met All Applicable Requirements Under Section 110
and Part D

    Section 107(d)(3)(E)(v) requires a State to have met all
requirements applicable to a nonattainment area under section 110 and
part D of the Act as a prerequisite to redesignation of that
nonattainment area to attainment.
1. Section 110 Requirements
    Section 110(a)(2) sets forth the general elements that a SIP must
contain in order to be fully approved. Although section 110(a)(2) was
amended in 1990, a number of the requirements did not change in
substance, and therefore, EPA believes that the pre-amendment EPA-
approved SIP met these requirements in Truckee Meadows with respect to
CO. As to those requirements that were amended, (see 57 FR 27936 and
27939, June 23, 1992), many are duplicative of other requirements of
the Act. EPA has analyzed the SIP and determined that it is consistent
with the requirements of amended section 110(a)(2). The Truckee Meadows
portion of the Nevada SIP contains enforceable emission limitations;
requires monitoring, compiling and analyzing of ambient air quality
data; requires preconstruction review of new or modified stationary
sources; provides for adequate funding, staff, and associated resources
necessary to implement its requirements; and provides the necessary
assurances that the State maintains responsibility for ensuring that
the CAA requirements are satisfied in the event that the District is
unable to meet its CAA obligations.
2. Part D Requirements
    The requirements that apply under part D of title I of the Act to
``moderate'' CO nonattainment areas are set forth in sections 172, 176,
187, and 211. The CAA, as amended in 1990, distinguishes between
moderate CO nonattainment areas with design values of 12.7 ppm (eight-
hour average) or less and those with design values greater than 12.7
ppm at the time of initial classification. Truckee Meadows had a design
value of 9.8 ppm at the time of initial classification and thus is
subject to those specific requirements that apply to ``moderate'' CO
nonattainment areas with a design value of 12.7 ppm or less and is not
subject to the additional requirements of ``moderate'' CO nonattainment
areas with design values greater than 12.7 ppm. We have issued guidance
in a General Preamble \9\ describing how we will review SIPs and SIP
revisions submitted under title I of the Act, including those
containing moderate CO nonattainment area SIP provisions.
---------------------------------------------------------------------------

    \9\ ``General Preamble for the Implementation of Title I of the
Clean Air Act Amendments of 1990'' (57 FR 13498, April 16, 1992, as
supplemented 57 FR 18070, April 28, 1992).
---------------------------------------------------------------------------

    Reasonably Available Control Measures / Reasonably Available
Control Technology (RACM/RACT). Section 172(c)(1) of the Act requires
States to submit a SIP revision for nonattainment areas that provide
for the implementation of all reasonably available control measures
(RACM) as expeditiously as practicable (including such reductions in
emissions from existing sources in the area as may be obtained through
the adoption, at a minimum, of reasonably available control technology
(RACT)) and shall provide for attainment of the NAAQS. RACM is a more
general term that can refer to stationary, area or mobile sources while
RACT is a term that refers to stationary sources.
    Attainment of the CO NAAQS in Truckee Meadows relies upon three
State or local control measures: The State's I/M program, Washoe
County's rule establishing a wintertime oxygenated fuel requirement and
Washoe County's rule establishing requirements for residential wood
combustion. We are proposing to approve the State's I/M program for
Truckee Meadows as well as the District's rule establishing a
wintertime oxygenated fuel requirement as part of this action (see
sections VI and VII of this document). In a separate action, we
approved the District's rule governing residential wood combustion. See
72 FR 33397 (June 18, 2007). Because the area has attained the CO
NAAQS, no additional measures need be submitted to fulfill the RACM/
RACT requirement of CAA section 172(c)(1) in the Truckee Meadows CO
nonattainment area.
    Reasonable Further Progress (RFP). Section 172(c)(2) of the Act
requires States to submit a SIP revision for nonattainment areas that
provide for reasonable further progress (RFP). Reasonable further
progress is defined in CAA section 171(1) as such annual incremental
reductions in emissions of the relevant air pollutant as are required
by this part or may reasonably be required by the Administrator for the
purpose of ensuring attainment of the applicable national ambient air
quality standard by the applicable date.
    EPA interprets the Act such that the requirements for RFP do not
apply in evaluating a request for redesignation to attainment since, at
a minimum, the air quality data for the area must show that the area
has already attained. Showing that the State will make RFP towards
attainment will, therefore, have no meaning at that point. See 57 FR
13498, at 13564 (April 16, 1992). See also our September 4, 1992
memorandum from John Calcagni, entitled ``Procedures for Processing
Requests to Redesignate Areas to Attainment'' (Calcagni memo), p. 6.
Based on our finding above that Truckee Meadows has attained the CO
NAAQS, we find that the requirements for RFP do not apply for the
purposes of our evaluation of the State's request to redesignate the
area to attainment.
    Emissions Inventory. Sections 172(c)(3) and 187(a)(1) of the Act
require States to submit a comprehensive, accurate, current inventory
of actual CO emissions for year 1990 from all sources within the
nonattainment area. The inventory is to address actual CO emissions
during the peak CO season for the area, and all stationary (generally
referring to larger stationary source or ``point'' sources), area
(generally referring to smaller

stationary and fugitive (non-smokestack) sources), and mobile (on-road,
nonroad, locomotive and aircraft) sources are to be included in the
compilation. Under sections 172(c)(3) and 187(a)(5) of the Act, States
are required to submit, no later than September 30, 1995, and no later
than the end of each 3-year period thereafter, until redesignation, an
updated inventory of CO emitted within CO nonattainment areas.
    On November 13, 1992, NDEP submitted a revision to the Truckee
Meadows portion of the Nevada SIP that contained a number of items,
including the 1990 Base Year CO Inventory. The 1990 Base Year CO
Inventory was the responsibility of and complied by the staff of the
District AQMD. In the process of developing this base year inventory,
the District AQMD submitted an Inventory Preparation Plan (IPP), which
was officially accepted and approved by EPA.\10\ In 1993, the District
AQMD revised the 1990 Base Year CO Inventory to reflect, among other
things, an update of EPA's on-road motor vehicle emission factor model
(MOBILE) and updated EPA methods for calculating emissions from nonroad
mobile sources. NDEP submitted the revised inventory (``Revised 1990
Base Year CO Inventory'') to EPA on June 3, 1994 as appendix 4 to
NDEP's ``basic'' vehicle I/M SIP revision submittal for Truckee
Meadows.
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    \10\ See letter from Julia Barrow, Chief, Air Quality Section,
Air Division, EPA-Region IX, to Jack Sheen, Air Pollution Control
Officer, District AQMD, dated February 21, 1992.
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    On January 19, 1996; April 14, 1999; February 5, 2002; and February
3, 2005, NDEP submitted SIP revisions that contained updates of the CO
emissions inventories for Truckee Meadows for years 1993, 1996, 1999,
and 2002, respectively, as required under CAA sections 172(c)(3) and
187(a)(5). Each successive inventory update reflects the changes in
activity levels within each of the various source categories, the
effects of on-going emissions control programs such as the Federal
Motor Vehicle Control Program and the District's residential wood
combustion program, as well as the updates to methods and emissions
factors used to develop emissions inventories, such as updates to EPA's
``MOBILE'' emission factor model.
    We interpret the Act such that the emission inventory requirements
of section 172(a)(3), 187(a)(1), and 187(a)(5) are satisfied by the
inventory requirements of the maintenance plan. See 57 FR 13498, at
13564 (April 16, 1992). Thus, our proposed approval of the submitted
maintenance plan and related base year (2002) CO emission inventory
satisfies the requirements of section 172(a)(3), 187(a)(1), and
187(a)(5) for the purposes of redesignation of Truckee Meadows to
attainment for the CO NAAQS. See section IX.E.1 herein for details
concerning the base year (2002) CO emission inventory. We plan no
further action on the previously submitted CO inventories for years
1990, 1993, 1996, and 1999.\11\
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    \11\ We are also not taking specific action on NDEP's submittal
of the 2002 periodic inventory update. However, because the 2002
inventory was used as the base year inventory in the Truckee Meadows
CO Maintenance Plan, we are relying on the technical documentation
submitted with the 2002 periodic inventory update in our evaluation
of the Truckee Meadows CO Maintenance Plan. See section IX.E.1 of
this document.
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Permits for New and Modified Major Stationary Sources

    Under section 172(c)(5), the CAA requires States to submit SIP
revisions that establish certain requirements for new or modified
stationary sources in nonattainment areas, including provisions to
ensure that major new sources or major modifications of existing
sources of nonattainment pollutants incorporate the highest level of
control, referred to as the Lowest Achievable Emission Rate (LAER), and
that increases in emissions from such stationary sources are offset so
as to provide for reasonable further progress towards attainment in the
nonattainment area. The process for reviewing permit applications and
issuing permits for new or modified stationary sources of air pollution
is referred to as ``New Source Review'' (NSR). With respect to
nonattainment pollutants in nonattainment areas, this process is
referred to as ``nonattainment NSR.''
    Under the Clean Air Act Amendments of 1977, States with designated
nonattainment areas were required to amend their NSR rules to impose
LAER and offsets requirements on new major sources and major
modifications of nonattainment pollutants in nonattainment areas. Under
the 1977 Act Amendments, we designated Truckee Meadows as a CO
nonattainment area. In Washoe County, the District AQMD administers the
NSR program for all stationary sources except for certain fossil-fueled
power plants that are subject under State law to NDEP jurisdiction.
    To address the nonattainment NSR requirements flowing from the 1977
Act Amendments, the District amended its NSR rules; NDEP submitted them
to EPA on July 24, 1979 as a revision to the Truckee Meadows portion of
the Nevada SIP; and we approved them on April 14, 1981. See 21758
(April 14, 1981). In that same April 1981 final rule, we also approved
NDEP's revised nonattainment NSR rules. Under these EPA-approved rules,
LAER and offsets have been requirements for any new major sources or
major modifications of CO in the Truckee Meadows nonattainment area.
    The 1990 Clean Air Act Amendments retained the core nonattainment
NSR elements of LAER and offsets but added additional requirements, and
in response, the District again revised its NSR rules, and NDEP
submitted the revised rules to EPA on April 7, 1994. We have not taken
action on the April 7, 1994 NSR SIP submittal.
    We have determined, however, that areas being redesignated from
nonattainment to attainment do not need to comply with the requirement
that an NSR program be approved prior to redesignation provided that
the area demonstrates maintenance of the standard without nonattainment
NSR in effect. The rationale for this determination is described in the
Nichols memo cited in section VIII of this document.
    The Truckee Meadows CO Maintenance Plan anticipates an increase in
CO emissions that is proportional to expected growth in population in
the Truckee Meadows area from the types of sources potentially subject
to LAER and offsets \12\ rather than assuming that any increases in CO
from such sources would be offset. See pages 18-20 in the Truckee
Meadows CO Maintenance Plan. Thus, we find that the maintenance
demonstration for the Truckee Meadows CO nonattainment area does not
rely on nonattainment NSR, and the State need not have a fully-approved
nonattainment NSR program for Truckee Meadows prior to approval of the
CO redesignation request.
---------------------------------------------------------------------------

    \12\ The source categories with sources potentially subject to
LAER and offsets include stationary source fuel combustion and waste
disposal, treatment and recovery.
---------------------------------------------------------------------------

    Prevention of Significant Deterioration (PSD) is the NSR program
that applies to new major sources or major modifications of attainment
pollutants and is the replacement program for nonattainment NSR after
redesignation to attainment, and part of the obligation under PSD is
for a new source to review increment consumption and maintenance of the
air quality standards. The PSD program requires stationary sources to
undergo preconstruction review before facilities

are constructed or modified, and to apply Best Available Control
Technology (BACT). The PSD program will apply to any major source or
major modification of CO emissions wishing to locate in the Truckee
Meadows area once the area is redesignated to attainment. EPA currently
administers the PSD program in Washoe County except for certain types
of sources for which EPA has delegated PSD authority to NDEP. See 68 FR
19371 (April 21, 2003) and 70 FR 52837 (September 8, 2003).
    Contingency Provisions. Section 172(c)(9) of the Act requires a
State to submit contingency measures that will be implemented if an
area fails to make reasonable further progress \13\ (RFP) or fails to
attain by the applicable attainment date.
---------------------------------------------------------------------------

    \13\ RFP means ``such annual incremental reductions in emissions
of the relevant air pollutant as are required by this part or may
reasonably be required by the Administrator for the purpose of
ensuring attainment of the applicable national ambient air quality
standard by the applicable date.'' See section 171(1) of the Act.
---------------------------------------------------------------------------

    On October 20, 1993, the District adopted a request to the Nevada
State Environmental Commission to require and implement an ``enhanced''
vehicle I/M program in Truckee Meadows, upon the occurrence of future
CO NAAQS exceedances, as the contingency measure intended to fulfill
the requirement of CAA section 172(c)(9). NDEP included this
contingency measure as appendix 7 to the State's ``basic'' vehicle I/M
program for the Truckee Meadows area and submitted the ``basic''
vehicle I/M program for the Truckee Meadows to EPA in a SIP revision
submittal dated June 3, 1994.
    As noted above, the section 172(c)(9) requirement for contingency
measures are directed at ensuring RFP and attainment by the applicable
date. We interpret the Act such that this requirement no longer applies
when an area has attained the standard and is eligible for
redesignation. See 57 FR 13498, at 13564 (April 16, 1992). See also
Calcagni memo 1992a, at page 6. Furthermore, we note that CAA section
175A for maintenance plans provides specific requirements for
contingency measures that effectively supersede the requirements of
section 172(c)(9) for these areas.
    Therefore, based on our finding above that Truckee Meadows has
attained the CO NAAQS, we find that the requirement for contingency
measures under section 172(c)(9) does not apply for the purposes of our
evaluation of the State's request for redesignation, and we consider
the contingency provisions submitted as part of the Truckee Meadows CO
Maintenance Plan to supersede the contingency measure submitted on June
3, 1994 and plan no further action on the latter measure.
    Section 176 Requirements. Under section 176(c) of the Clean Air Act
Amendments of 1990, States were required to establish criteria and
procedures to ensure that Federally supported or funded projects
conform to the air quality planning goals in the applicable SIP.
Section 176(c) further provided that State conformity provisions be
consistent with Federal conformity regulations that the CAA required
EPA to promulgate. EPA's conformity regulations are codified at 40 CFR
part 93, subparts A (``transportation conformity'') and B (``general
conformity''). ``Transportation conformity'' applies to transportation
plans, programs, and projects developed, funded, and approved under
title 23 U.S.C. or the Federal Transit Act, and ``general conformity''
applies to all other Federally-supported or funded projects. SIP
revisions intended to address the conformity requirements are referred
to herein as ``conformity SIPs.''
    To address the statutory and regulatory requirements related to
transportation and general conformity, on July 31, 1995, NDEP submitted
the conformity procedures and criteria that had been adopted by the
District on December 14, 1994 and by the Truckee Meadows Regional
Planning Governing Board on February 9, 1995. We have not taken action
on the July 31, 1995 SIP revision submittal.\14\
---------------------------------------------------------------------------

    \14\ On August 10, 2005, the Safe, Accountable, Flexible,
Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU)
was enacted, and among its provisions, this law amended section
176(c) of the CAA to reduce the content requirements for
transportation conformity SIPs. Under SAFETEA-LU, with respect to
transportation conformity, States are required only to develop
criteria and procedures for interagency consultation and enforcement
(and enforceability) of commitments for certain control measures and
mitigation measures. In response to SAFETEA-LU, NDEP is now free to
request that EPA approve only the three provisions that are required
to be included in transportation conformity SIPs and that EPA take
no action on the remainder of the transportation conformity portion
of the July 31, 1995 SIP submission; however, other options are
available as well. See 72 FR 24472, at 24484-24485 (May 2, 2007).
---------------------------------------------------------------------------

    EPA believes it is reasonable to interpret the conformity
requirements as not applicable for purposes of evaluating a
redesignation request under section 107(d)(3)(E). The rationale for
this is based on a combination of two factors. First, the requirement
to submit a conformity SIP continues to apply to areas after
redesignation to attainment, since such areas would be subject to a
section 175A maintenance plan. See CAA section 176(c)(5)(B). Second,
the EPA's conformity rules require the performance of conformity
analyses in the absence of Federally-approved State rules. See 40 CFR
51.390(b) and 51.851(b). Therefore, because areas are subject to the
conformity requirements regardless of whether they are redesignated to
attainment and must implement conformity under Federal rules if State
rules are not yet approved, EPA believes it is reasonable to view these
requirements as not applicable for purposes of evaluating a
redesignation request. See Wall v. EPA, 265 F.3d 426, 439 (6th Cir.
2001) upholding this interpretation.
    For the reasons stated above, EPA believes the approval of
conformity rules into the State's SIP is not a prerequisite for
redesignation and thus, our inaction on NDEP's July 31, 1995 submittal
is no obstacle to redesignation of Truckee Meadows to attainment for
the CO NAAQS. Federal transportation and general conformity rules will
continue to apply with respect to CO emissions associated with
transportation plans, programs, and projects as well as other
Federally-supported or funded projects within Truckee Meadows.
    Vehicle Inspection and Maintenance Program. Under section
187(a)(4), the CAA requires States with moderate CO nonattainment areas
to submit a SIP revision that provides for a new or amended vehicle I/M
program that meets applicable Federal I/M requirements, including the
``basic'' I/M performance standard. As described in section VII of this
document, we are proposing to approve the State's ``basic'' I/M program
for Truckee Meadows, and if we finalize this action as proposed, the
vehicle I/M requirement for Truckee Meadows under CAA section 187(a)(4)
will be fulfilled.
    Oxygenated Gasoline Program. Under section 211(m), the CAA requires
States with CO nonattainment areas with design values of 9.5 ppm or
greater (based on 1988-1989 data) to submit a SIP revision that
provides for an oxygenated gasoline program. As described in section VI
of this document, we are proposing to approve the District's wintertime
oxygenated gasoline rule, and if we finalize this action as proposed,
the fuel requirement under CAA section 211(m) will be fulfilled.
    Conclusion with respect to Section 110 and Part D Requirements.
Based on our evaluation of the various SIP requirements and submittals
discussed above, we conclude that upon our final approval of the SIP
submittals evaluated in this action, the State will have met all

section 110 and part D requirements that apply to the Truckee Meadows
moderate CO nonattainment area and thereby satisfied the criterion for
redesignation under CAA section 107(d)(3)(E)(v).

E. The Area Must Have a Fully Approved Maintenance Plan Under CAA
Section 175A

    Section 107(d)(3)(E)(iv) of the CAA requires, as a pre-condition to
being redesignated to attainment, that EPA has fully approved a
maintenance plan for the area as meeting the requirements of section
175A of the Act. Section 175A sets forth the elements of a maintenance
plan for areas seeking redesignation from nonattainment to attainment.
We interpret this section of the Act to require, in general, the
following core elements: Attainment inventory, maintenance
demonstration, monitoring network, verification of continued
attainment, and contingency plan. See Calcagni memo 1992a.
    The purpose of a maintenance plan is to provide for the maintenance
of the applicable NAAQS for at least 10 years after redesignation.
Eight years after redesignation, the State must submit a revised
maintenance plan which demonstrates continued maintenance of the
applicable NAAQS for an additional 10 years following the initial ten-
year maintenance period. To address the possibility of future NAAQS
violations, the maintenance plan must contain contingency measures,
with a schedule for implementation adequate to assure prompt correction
of any air quality problems. The Redesignation Request and Maintenance
Plan for the Truckee Meadows Carbon Monoxide Non-Attainment Area
(September 2005) (``Truckee Meadows CO Maintenance Plan''), which was
prepared by the District AQMD and adopted by the District Board of
Health, addresses these core elements, and our evaluation of these
elements follows.
1. Attainment Inventory
    The plan must contain an attainment year emissions inventory to
identify a level of emissions in the area which is sufficient to attain
the CO NAAQS. This inventory is to be consistent with EPA's most recent
guidance on emissions inventories for nonattainment areas available at
the time and should represent emissions during the time period
associated with the monitoring data showing attainment. The inventory
should also be based on actual ``CO season data'' (i.e., wintertime)
emissions for the attainment year.
    The District's Truckee Meadows CO Maintenance Plan presents CO
emissions estimates and projections for years 2002, 2010, and 2016. We
find year 2002 to be an acceptable year for the baseline year because
it represents a year in which the Truckee Meadows was in attainment of
the CO NAAQS. See 70 FR 22803 (May 3, 2005). Based on monitoring data
collected during 2002, the design value for CO in Truckee Meadows in
the attainment year was 4.4 ppm, eight-hour average, which is well
below the NAAQS of 9 ppm. The baseline (2002) inventory in the
maintenance plan is not documented in detail in the Truckee Meadows CO
Maintenance Plan itself but is so documented in a separate SIP
submittal of the same date as the Truckee Meadows CO Maintenance Plan
(November 4, 2005) of the 2002 CO periodic inventory update.
    As shown in table 1 below, the baseline inventory (2002) covers
stationary area sources (including stationary source fuel combustion;
waste disposal, treatment, & recovery; residential wood combustion; and
miscellaneous area sources (such as wildfires, structure fires, and
prescribed burning)), nonroad mobile sources (including aircraft,
nonroad gasoline and diesel vehicles, and railroads), and on-road
mobile sources (i.e., cars, trucks, and motorcycles) and reflects
activity profiles and temperatures characteristic of the CO season
(i.e., Winter). On-road estimates were made based on EPA's MOBILE6
(high altitude) emission factors, vehicle I/M and anti-tampering
programs, the oxygenated gasoline requirement, Regional Transportation
Commission (RTC) transportation activity estimates (VMT, vehicle
speeds, etc.), and demographic data provided by the planning
departments for Washoe County, the City of Reno, and the City of
Sparks. Nonroad mobile source emissions (not including aircraft or
locomotives) were estimated using EPA's NONROAD emissions model. The
baseline emissions estimates reflect the basic control measures relied
upon for attainment and maintenance of the CO NAAQS in Truckee Meadows:
The Federal Motor Vehicle Control Program, The District's oxygenated
gasoline requirement, the State's vehicle I/M program for motor
vehicles, and the District's residential wood combustion program.

              Table 1.--Carbon Monoxide Emissions Inventory, Truckee Meadows, 2002, 2010, and 2016
                                       [Pounds per typical CO season day]
----------------------------------------------------------------------------------------------------------------
                             Source                                    2002            2010            2016
----------------------------------------------------------------------------------------------------------------
Stationary Source Fuel Combustion...............................           2,920           3,321           3,619
Waste Disposal, Treatment & Recovery............................              18              20              22
Residential Wood Combustion.....................................          31,918          35,344          35,344
Miscellaneous Area Sources......................................             613             697             760
Aircraft........................................................           4,175           4,748           5,175
Nonroad Gasoline Vehicles.......................................          68,578          68,712          77,226
Nonroad Diesel Vehicles.........................................           1,645           1,834           1,873
Railroads.......................................................             155             176             192
On-road Vehicles (without safety margin)........................         335,508         263,938         236,754
                                                                 -----------------------------------------------
    Subtotal (excluding safety margins).........................         445,530         378,790         360,965
                                                                 -----------------------------------------------
Safety Margin (assigned to on-road vehicles)....................             N/A          66,740          84,565
                                                                 -----------------------------------------------
        Total (including safety margin).........................         445,530         445,530        445,530
----------------------------------------------------------------------------------------------------------------
Source: District AQMD, Truckee Meadows CO Maintenance Plan, pages 20 and 21.

    The baseline inventory estimates that on-road motor vehicles
accounted for approximately 75%, residential wood combustion accounted
for approximately 7%, and nonroad mobile sources (including locomotives
and

aircraft) accounted for approximately 17% of the daily (wintertime) CO
emissions within Truckee Meadows in 2002.
    The methodologies used by the District AQMD to prepare the baseline
(2002) CO inventory, as described in the appendices to the 2002 CO
periodic inventory update SIP submittal (dated November 4, 2005), are
acceptable, and we find the baseline CO inventory for Truckee Meadows
to be reasonably comprehensive and accurate.
2. Maintenance Demonstration
    A State may generally demonstrate maintenance of the NAAQS by
either showing that future emissions of a pollutant or its precursors
will not exceed the level of the attainment inventory, or by modeling
to show that the future mix of sources and emissions rates will not
cause a violation of the NAAQS. In either case, to satisfy the
demonstration requirement, the State should project emissions for at
least 10 years beyond redesignation.
    Table 1, above, summarizes the baseline (2002) CO emissions
estimates and future year (2010 and 2016) projections from the Truckee
Meadows CO Maintenance Plan. The Truckee Meadows CO Maintenance Plan
projects future year inventories (2010 and 2016) by adjusting the 2002
baseline inventory to account for changes in population, vehicle miles