```

[Federal Register Volume 78, Number 142 (Wednesday, July 24, 2013)]
[Proposed Rules]
[Pages 44494-44511]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-17825]

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R09-OAR-2012-0877; FRL-9837-6]

Approval and Promulgation of Implementation Plans; Designation of 
Areas for Air Quality Planning Purposes; State of California; 
PM10; Redesignation of Sacramento to Attainment; Approval of 
PM10 Redesignation Request and Maintenance Plan for 
Sacramento

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: EPA is proposing to approve, as a revision of the California 
state implementation plan, the State's request to redesignate the 
Sacramento nonattainment area to attainment for the 24-hour particulate 
matter of ten microns or less (PM10) National Ambient Air 
Quality Standard (NAAQS). EPA is also proposing to approve the 
PM10 maintenance plan and the associated motor vehicle 
emissions budgets for use in transportation conformity determinations 
necessary for the Sacramento area. Finally, EPA is proposing to approve 
the attainment year emissions inventory. EPA is proposing these actions 
because the SIP revision meets the requirements of the Clean Air Act 
and EPA guidance for such plans and motor vehicle emissions budgets.

DATES: Comments must be received on or before August 23, 2013.

ADDRESSES: Submit your comments, identified by Docket ID Number EPA-
R09-OAR-2012-0877, by one of the following methods:
    1. http://www.regulations.gov: Follow the on-line instructions for 
submitting comments.
    2. Email: ungvarsky.john@epa.gov.
    3. Mail or deliver: John Ungvarsky (AIR-2), U.S. Environmental 
Protection Agency, Region IX, 75 Hawthorne Street, San Francisco, CA 
94105-3901. Deliveries are only accepted during the Regional Office's 
normal hours of operation.
    Instructions: All comments 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 Confidential Business Information (CBI) or 
other information whose disclosure is restricted by statute. 
Information that you consider CBI or otherwise protected should be 
clearly identified as such and

[[Page 44495]]

should not be submitted through http://www.regulations.gov or email. 
http://www.regulations.gov is an anonymous access system, and EPA will 
not know your identity or contact information unless you provide it in 
the body of your comment. If you send email directly to EPA, your email 
address will be automatically captured and included as part of the 
public comment. 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.
    Docket: The index to the docket and documents in the docket for 
this action are generally available electronically at 
www.regulations.gov and in hard copy at EPA Region IX, 75 Hawthorne 
Street, San Francisco, California. While all documents in the docket 
are listed at www.regulations.gov, some information may be publicly 
available only at the hard copy location (e.g., copyrighted material, 
large maps), and some may not be publicly available in either location 
(e.g., CBI). 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: John Ungvarsky, Air Planning Office 
(AIR-2), U.S. Environmental Protection Agency, Region IX, (415) 972-
3963, ungvarsky.john@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document, whenever ``we,'' 
``us,'' or ``our'' is used, we mean EPA. This supplementary information 
section is arranged as follows:

Table of Contents

I. Summary of Today's Proposed Action
II. Background
    A. The PM10 NAAQS
    B. PM10 Planning Requirements
III. Procedural Requirements for Adoption and Submittal of SIP 
Revisions
IV. Substantive Requirements for Redesignation
V. Evaluation of the State's Redesignation Request for the 
Sacramento PM10 Nonattainment Area
    A. Determination That the Area Has Attained the PM10 
NAAQS.
    B. The Area Must Have a Fully-Approved SIP Meeting Requirements 
Applicable for Purposes of Redesignation Under Clean Air Act Section 
110 and Part D
    1. Basic SIP Requirements under Section 110
    2. SIP Requirements under Part D
    C. EPA Has Determined That the Improvement in Air Quality is Due 
to Permanent and Enforceable Reductions in Emissions
    D. The Area Must Have a Fully Approved Maintenance Plan Under 
Clean Air Act Section 175A
    1. Attainment Inventory
    2. Maintenance Demonstration
    3. Verification of Continued Attainment
    4. Contingency Provisions
    5. Subsequent Maintenance Plan Revisions
    6. Transportation Conformity and Motor Vehicle Emissions Budgets
VI. Proposed Action and Request for Public Comment
VII. Statutory and Executive Order Reviews

I. Summary of Today's Proposed Action

    Under Clean Air Act (CAA or ``the Act'') section 107(d)(3)(D), EPA 
is proposing to approve the State's request to redesignate the 
Sacramento PM10 nonattainment area to attainment for the 24-
hour PM10 National Ambient Air Quality Standard (NAAQS or 
``standard''). We are doing so based on our conclusion that the area 
has met the five criteria for redesignation under CAA section 
107(d)(3)(E): (1) That the area has attained the 24-hour 
PM10 NAAQS in the 2010-2012 time period and that the area 
continues to attain the PM10 standard since that time; (2) 
that relevant portions of the California state implementation plan 
(SIP) are fully approved; (3) that the improvement in air quality is 
due to permanent and enforceable reductions in emissions; (4) that 
California has met all requirements applicable to the Sacramento 
PM10 nonattainment area with respect to section 110 and part 
D of the CAA; and (5) that the PM10 Implementation/Maintenance Plan and 
Redesignation Request for Sacramento County (October 28, 2010) 
(``Sacramento PM10 Maintenance Plan'' or ``Plan'') \1\ meets 
the requirements of section 175A of the CAA.
---------------------------------------------------------------------------

    \1\ See letter, James N. Goldstene, Executive Officer, to Jared 
Blumenfeld, Regional Administrator, EPA Region 9, dated December 7, 
2010, with attachments.
---------------------------------------------------------------------------

    In addition, under CAA section 110(k)(3), EPA is proposing to 
approve the maintenance plan including the motor vehicle emissions 
budgets (MVEBs) in the 2008 Sacramento PM10 Plan as a 
revision to the California SIP because we find the MVEBs meet the 
applicable transportation conformity requirements under 40 CFR 
93.118(e). EPA finds that the maintenance demonstration shows how the 
area will continue to attain the 24-hour PM10 NAAQS for at 
least 10 years beyond redesignation (i.e., through 2023) and that the 
contingency provisions describing the actions that the Sacramento 
Metropolitan Air Quality Management District (SMAQMD) will take in the 
event of a future monitored violation meet all applicable requirements 
for maintenance plans and related contingency provisions in CAA section 
175A. Finally, EPA is proposing to approve the attainment year 
emissions inventory under CAA section 172(c)(3).
    EPA is proposing these actions because the SIP revision meets the 
requirements of the CAA and EPA guidance for such plans and budgets.

II. Background

A. The PM10 NAAQS

    EPA sets the NAAQS for certain ambient air pollutants at levels 
required to protect public health and welfare. Particulate matter with 
an aerodynamic diameter less than or equal to a nominal ten 
micrometers, or PM10, is one of these ambient air pollutants 
for which EPA has established health-based standards.
    EPA revised the NAAQS for particulate matter on July 1, 1987 (52 FR 
24633), replacing standards for total suspended particulates (TSP less 
than 30 microns in diameter) with new standards applying only to 
particulate matter up to 10 microns in diameter (PM10). At 
that time, EPA established two PM10 standards, an annual 
standard and a 24-hour standard.
    In an October 17, 2006 p.m. NAAQS revision, the 24-hour 
PM10 standards were retained but the annual standards were 
revoked effective December 18, 2006. 71 FR 61144 (October 17, 2006). On 
January 15, 2013, EPA announced that it was again retaining the 24-hour 
PM10 NAAQS as a 24-hour standard of 150 micrograms per cubic 
meter (ug/m\3\). See 78 FR 3086. This SIP submittal addresses the 24-
hour PM10 standard as originally promulgated in 1987 and 
reaffirmed on January 15, 2013. An area attains the 24-hour 
PM10 standard of 150 micrograms per cubic meter (ug/m\3\) 
when the expected number of days per calendar year with a 24-hour 
concentration in excess of the standard (referred to as an exceedance), 
is equal to or less than one.\2\
---------------------------------------------------------------------------

    \2\ An exceedance is defined as a daily value that is above the 
level of the 24-hour standard, 150 [mu]g/m\3\, after rounding to the 
nearest 10 [mu]g/m\3\ (i.e., values ending in five or greater are to 
be rounded up). Thus, a recorded value of 154 [mu]g/m\3\ would not 
be an exceedance since it would be rounded to 150 [mu]g/m\3\; 
whereas, a recorded value of 155 [mu]g/m\3\ would be an exceedance 
since it would be rounded to 160 [mu]g/m\3\. See 40 CFR part 50, 
Appendix K, section 1.0.
---------------------------------------------------------------------------

B. PM10 Planning Requirements

    Effective January 20, 1994, EPA designated Sacramento County as a 
moderate nonattainment area for the PM10 NAAQS. See 58 FR 
67334 (December, 21, 1993). The designation, classification, and 
boundaries of the Sacramento nonattainment area are codified at 40 CFR 
81.305.

[[Page 44496]]

    Beginning in the 1970's and continuing to the present, the SMAQMD 
\3\ and CARB have adopted a number of rules and prepared a number of 
nonattainment plans to address planning requirements under the CAA, as 
amended in 1977. CARB submitted these rules and plans to EPA at various 
times, and EPA approved a number of them into the California SIP. 
Examples of rules adopted by SMAQMD and approved by EPA as revisions to 
the California SIP as part of the PM10 control strategy in 
the Sacramento PM10 nonattainment area include: Rule 403--
Fugitive Dust; Rule 405--Dust and Condensed Fumes; Rule 412--Stationary 
Source Internal Combustion Engines at Major Stationary Sources of 
NOX; and Rule 414--Natural Gas Fired Water Heaters. Examples 
of rules adopted by CARB and approved by EPA as revisions to the 
California SIP that have reduced PM10 in the Sacramento 
PM10 nonattainment area include: California Code of 
Regulations (CCR) Title 13, Section 1956.8--Heavy Duty Vehicle Exhaust 
Emission Standards; CCR, Section 2262--California Reformulated Gasoline 
Phase 2 and Phase 3 Standards; and CCR, Sections 2420-2427--Heavy Duty 
Diesel Cycle Engines.
---------------------------------------------------------------------------

    \3\ In 1990, the Sacramento County Air Pollution Control 
District changed its name to the Sacramento Metropolitan Air Quality 
Management District.
---------------------------------------------------------------------------

    On February 15, 2002, EPA determined under section 179(c) of the 
CAA that the Sacramento PM10 nonattainment area had attained 
the 24-hour PM10 NAAQS by its December 31, 2000 attainment 
date, based on complete, quality-assured, and certified ambient air 
monitoring data that showed the area monitored attainment of the 24-
hour PM10 NAAQS for 1998-2000. (67 FR 7082). Because EPA 
determined that the Sacramento PM10 nonattainment area met 
its attainment date, no PM10 serious nonattainment area 
requirements apply in the Sacramento PM10 nonattainment 
area. In this action, we are updating the determination of attainment 
to account for PM10 monitoring data since 2001, including 
more recent years consistent with the applicable criterion for 
redesignation under CAA section 107(d)(3)(E)(i).
    On December 7, 2010, CARB submitted the Sacramento PM10 
Maintenance Plan and requested that EPA redesignate the Sacramento 
PM10 nonattainment area to attainment for the 24-hour 
PM10 NAAQS. We are proposing action today on CARB's December 
7, 2010 submittal, including the Sacramento PM10 Maintenance 
Plan and redesignation request.

III. Procedural Requirements for Adoption and Submittal of SIP 
Revisions

    Sections 110(a)(1) and 110(l) of the Act require states to provide 
reasonable notice and public hearing prior to adoption of SIP 
revisions. In this action, we are proposing action on CARB's December 
7, 2010 submittal of the Sacramento PM10 Maintenance Plan, 
dated October 28, 2010, as a revision to the California SIP. The 
submittal documents the public review process followed by SMAQMD and 
CARB in adopting the Sacramento PM10 Maintenance Plan prior 
to submittal to EPA as a revision to the California SIP. The 
documentation provides evidence that reasonable notice of a public 
hearing was provided to the public and that a public hearing was 
conducted prior to adoption.
    CARB's submittal includes a letter dated October 28, 2010 from 
Larry Greene, Executive Director/Air Pollution Control Officer to the 
Board of Directors for the SMAQMD. In addition, Enclosure 1, Attachment 
3 of CARB's submittal includes a copy of the notice to the public 
published on September 27, 2010, announcing a public hearing to be held 
on October 28, 2010. These materials document the public review process 
followed by SMAQMD in adopting the Sacramento PM10 
Maintenance Plan prior to transmittal to CARB and provide evidence that 
reasonable notice of a public hearing was provided to the public and 
that a public hearing was conducted prior to adoption. Specifically, 
the notice for the Board hearing was published in the Sacramento Bee, a 
newspaper of general circulation, on September 27, 2010 and sent to 
over 2000 email addresses. The Sacramento PM10 Maintenance 
Plan was also made available for viewing on the District's Web site and 
at the District office on and after September 27, 2010.
    Enclosure I, Attachment 1 of CARB's submittal documents the 
adoption of the Sacramento PM10 Plan by the SMAQMD Board of 
Directors. On October 28, 2010, the SMAQMD Board of Directors approved 
the Sacramento PM10 Maintenance Plan and directed SMAQMD 
staff to forward the Plan to CARB, the Governor of California's 
designee for SIP matters.
    Enclosure IV of CARB's submittal documents CARB's board resolution 
regarding the Sacramento PM10 Plan. On December 7, 2010, 
CARB submitted the Sacramento PM10 Maintenance Plan to EPA 
for approval as a revision to the California SIP.
    Based on the documentation included in CARB's submittal, we find 
that the submittal of the Sacramento PM10 Maintenance Plan 
as a SIP revision satisfies the procedural requirements of sections 
110(l) of the Act for revising SIPs.
    CAA section 110(k)(1)(B) requires EPA to determine whether a SIP 
submittal is complete within 60 days of receipt. This section also 
provides that any plan that we have not affirmatively determined to be 
complete or incomplete will become complete six months after the day of 
submittal by operation of law. A completeness review allows us to 
determine if the submittal includes all the necessary items and 
information we need to act on it.
    We make completeness determinations using criteria we have 
established in 40 CFR part 51, Appendix V. These criteria fall into two 
categories: administrative information and technical support 
information. The administrative information provides documentation that 
the State has followed basic administrative procedures during the SIP-
adoption process and thus we have a legally-adopted SIP revision in 
front of us. The technical support information provides us the 
information we need to determine the impact of the proposed revision on 
attainment and maintenance of the air quality standards.
    We notify a state of our completeness determination by letter 
unless the submittal becomes complete by operation of law. A finding of 
completeness does not approve the submittal as part of the SIP nor does 
it indicate that the submittal is approvable. It does start a 12-month 
clock for EPA to act on the SIP submittal. See CAA section 110(k)(2). 
The Sacramento PM10 Maintenance Plan became complete by 
operation of law on June 7, 2011.

IV. Substantive Requirements for Redesignation

    The CAA establishes the requirements for redesignation of 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

[[Page 44497]]

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 a document entitled, 
``State Implementation Plans; General Preamble for the Implementation 
of Title I of the Clean Air Act Amendments of 1990,'' published in the 
Federal Register on April 16, 1992 (57 FR 13498), and supplemented on 
April 28, 1992 (57 FR 18070) (referred to herein as the ``General 
Preamble''). Other relevant EPA guidance documents include: 
``Procedures for Processing Requests to Redesignate Areas to 
Attainment,'' Memorandum from John Calcagni, Director, Air Quality 
Management Division, EPA Office of Air Quality Planning and Standards, 
September 4, 1992 (referred to herein as the ``Calcagni memorandum''); 
``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 memorandum); and ``State Implementation Plans for Serious 
PM10 Nonattainment Areas, and Attainment Date Waivers for 
PM10 Nonattainment Areas Generally; Addendum to the General 
Preamble for the Implementation of title I of the Clean Air Act 
Amendments of 1990,'' 59 FR 41998 (August 16, 1994) (PM10 
Addendum).
    In this proposed rulemaking action, EPA applies these policies to 
the Sacramento PM10 Maintenance Plan, taking into 
consideration the specific factual issues presented. For the reasons 
set forth below in section V of this document, we propose to approve 
CARB's request for redesignation of the Sacramento PM10 
nonattainment area to attainment for the 24-hour PM10 NAAQS 
based on our conclusion that all of the criteria under CAA section 
107(d)(3)(E) have been satisfied.

V. Evaluation of the State's Redesignation Request for the Sacramento 
PM10 Nonattainment Area

A. Determination That the Area Has Attained the PM10 NAAQS

    CAA section 107(d)(3)(E)(i) states that for an area to be 
redesignated to attainment, EPA must determine that the area has 
attained the relevant NAAQS. In this case, the relevant NAAQS is the 
24-hour PM10 NAAQS.
    Generally, EPA determines whether an area's air quality is meeting 
the 24-hour PM10 NAAQS based upon complete,\4\ quality-
assured, and certified data gathered at established state and local air 
monitoring stations (SLAMS) in the nonattainment area and entered into 
the EPA Air Quality System (AQS) database. Data from air monitors 
operated by state, local, or tribal agencies in compliance with EPA 
monitoring requirements must be submitted to AQS. These monitoring 
agencies certify annually that these data are accurate to the best of 
their knowledge. Accordingly, EPA relies primarily on data in AQS when 
determining the attainment status of an area. See 40 CFR 50.6; 40 CFR 
part 50, appendices J and K; 40 CFR part 53; and, 40 CFR part 58, 
appendices A, C, D, and E.\5\ EPA will also consider air quality data 
from other air monitoring stations in the nonattainment area provided 
those stations meet the federal monitoring requirements for SLAMS, 
including the quality assurance and quality control criteria in 40 CFR 
part 58, appendix A. See 40 CFR 58.14 (2006) and 58.20 (2007); \6\ 71 
FR 61236, 61242; (October 17, 2006). All valid data are reviewed to 
determine the area's air quality status in accordance with 40 CFR part 
50, appendix K.
---------------------------------------------------------------------------

    \4\ For PM10, a complete set of data includes a 
minimum of 75 percent of the scheduled PM10 samples per 
quarter. See 40 CFR part 50, Appendix K, section 2.3(a).
    \5\ Because the annual PM10 standard was revoked 
effective December 18, 2006, this document discusses only attainment 
of the 24-hour PM10 standard. See 71 FR 61144; (October 
17, 2006).
    \6\ EPA promulgated amendments to the ambient air monitoring 
regulations in 40 CFR parts 53 and 58 on October 17, 2006. (See 71 
FR 61236.) The requirements for Special Purpose Monitors were 
revised and moved from 40 CFR 58.14 to 40 CFR 58.20.
---------------------------------------------------------------------------

    Attainment of the 24-hour PM10 standard is determined by 
calculating the expected number of exceedances of the standard in a 
year. The 24-hour PM10 standard is attained when the 
expected number of exceedances averaged over a three-year period is 
less than or equal to one at each monitoring site within the 
nonattainment area. Generally, three consecutive years of air quality 
data are required to show attainment of the 24-hour PM10 
standard. See 40 CFR part 50 and appendix K.
    To demonstrate attainment of the 24-hour PM10 standard 
at a monitoring site, the monitor must provide sufficient data to 
perform the required calculations in 40 CFR part 50, appendix K. The 
amount of data required varies with the sampling frequency, data 
capture rate, and the number of years of record. For PM10, a 
``complete'' set of data includes a minimum of 75 percent of the 
scheduled PM10 samples per quarter. See 40 CFR part 50, 
appendix K, section 2.3(a). In all cases, three years of representative 
monitoring data that meet the 75 percent criterion should be utilized, 
if available. More than three years may be considered if all additional 
representative years of data meeting the 75 percent criterion are 
utilized. Data not meeting these criteria may also suffice to show 
attainment; however, such exceptions must be approved by the 
appropriate Regional Administrator in accordance with EPA guidance. See 
40 CFR part 50, appendix K, section 2.3.
    In the Sacramento PM10 nonattainment area, the agencies 
responsible for assuring that the area meets air quality monitoring 
requirements include CARB and SMAQMD. Both CARB and SMAQMD submit 
annual monitoring network plans to EPA. SMAQMD network plans describe 
the monitoring network operated by SMAQMD and CARB in Sacramento 
County, and CARB's network plans describe the monitoring sites CARB 
operates. These plans discuss the status of the air monitoring network, 
as required under 40 CFR 58.10.
    EPA regularly reviews these annual plans for compliance with the 
applicable reporting requirements in 40 CFR part 58. With respect to 
PM10, EPA has found that the area's network plans, submitted 
by CARB and SMAQMD, meet the applicable requirements under 40 CFR part 
58. See EPA letters to CARB and SMAQMD approving their annual network 
plans for years 2010, 2011, and 2012.7 8 EPA also concluded 
from its

[[Page 44498]]

Technical System Audit of the CARB Primary Quality Assurance 
Organization (PQAO) (conducted during the summer of 2011), that the 
combined ambient air monitoring network operated by CARB and the local 
air districts in their PQAO (which includes SMAQMD) currently meets or 
exceeds the requirements for the minimum number of SLAMS for 
PM10 in the Sacramento nonattainment area.\9\ CARB annually 
certifies that the data it submits to AQS are complete and quality-
assured.\10\
---------------------------------------------------------------------------

    \7\ Letter from Matthew Lakin, Manager, Air Quality Analysis 
Office, U.S. EPA Region IX, to Karen Magliano, Chief, Air Quality 
Data Branch, Planning and Technical Support Division, CARB (October 
29, 2010) (approving CARB's ``2010 Annual Monitoring Network Plan 
for the Small Districts in California''); Letter from Matthew Lakin, 
Manager, Air Quality Analysis Office, U.S. EPA Region IX, to Karen 
Magliano, Chief, Air Quality Data Branch, Planning and Technical 
Support Division, CARB (November 1, 2011) (approving CARB's ``2011 
Annual Monitoring Network Plan for the Small Districts in 
California''); Letter from Matthew Lakin, Manager, Air Quality 
Analysis Office, U.S. EPA Region IX, to Karen Magliano, Chief, Air 
Quality Data Branch, Planning and Technical Support Division, CARB 
(April 19, 2013) (approving CARB's ``2012 Annual Monitoring Report 
for the Small Districts in California'').
    \8\ Letter from Matthew Lakin, Manager, Air Quality Analysis 
Office, U.S. EPA Region IX, to Larry Greene, Air Pollution Control 
Officer, SMAQMD (November 1, 2010) (approving the ``Sacramento 
Metropolitan Air Quality Management District's 2010 Annual 
Monitoring Network Plan''); Letter from Matthew Lakin, Manager, Air 
Quality Analysis Office, U.S. EPA Region IX, to Larry Greene, Air 
Pollution Control Officer, SMAQMD (October 31, 2011) (approving the 
``Sacramento Metropolitan Air Quality Management District's 2011 
Annual Monitoring Network Plan''); Letter from Matthew Lakin, 
Manager, Air Quality Analysis Office, U.S. EPA Region IX, to Larry 
Greene, Air Pollution Control Officer, SMAQMD (March 1, 2013) 
(approving the ``Sacramento Metropolitan Air Quality Management 
District's 2012 Annual Monitoring Network Plan'').
    \9\ See letter from Deborah Jordan, Director, Air Division, U.S. 
EPA Region IX, to James Goldstene, Executive Officer, CARB, 
transmitting ``System Audit of the Ambient Monitoring Program: 
California Resources Board, June-September: 2011,'' with enclosure, 
October 22, 2012.
    \10\ See, e.g., letter from Sylvia Vanderspek, Chief, Air 
Quality Data Branch, Planning and Technical Support Division, CARB, 
to Jared Blumenfeld, Regional Administrator, U.S. EPA Region IX, 
certifying calendar year 2012 ambient air quality data and quality 
assurance data, May 16, 2013.
---------------------------------------------------------------------------

    There are two types of PM10 monitors used throughout the 
Sacramento PM10 nonattainment area monitoring network: the 
Federal Reference Method (FRM) filter-based high-volume size-selective 
inlet sampler (hi-vols or SSI), and the Federal Equivalent Method (FEM) 
tapered element oscillating microbalance (TEOM), which measures 
PM10 on a continuous basis. The schedule for PM10 
sample collection is one in six days for the FRM filter-based high 
volume samplers, while the FEM TEOM monitors operate on a daily 24-hour 
schedule.
    There were six PM10 monitoring sites within the 
Sacramento PM10 nonattainment area in calendar years 2010, 
2011, and 2012. SMAQMD operates five of the monitoring sites: 
Goldenland Court, North Highlands, Del Paso Manor, Branch Center Rd 
2, and Stockton Blvd. CARB operates the T Street monitoring 
site. FRM filter-based high-volume samplers are located at all of the 
six sites listed above. Del Paso Manor and the Stockton Blvd. utilize 
both the FRM filter-based samplers and FEM TEOM monitors.\11\ EPA 
defines specific monitoring site types and spatial scales of 
representativeness to characterize the nature and location of required 
monitors. For the six sites, the spatial scale is neighborhood scale, 
and the monitoring objective is population exposure, except the T 
Street site, which has a monitoring objective of highest 
concentration.\12\
---------------------------------------------------------------------------

    \11\ A map of the locations of Sacramento County monitoring 
stations is found in Figure 3.2 of the Sacramento PM10 
Plan.
    \12\ See footnotes 7 and 8.
---------------------------------------------------------------------------

    Consistent with the requirements contained in 40 CFR part 50, EPA 
has reviewed the quality-assured, and certified PM10 ambient 
air monitoring data as recorded in AQS for the applicable monitoring 
period collected at the monitoring sites in the Sacramento 
nonattainment area and determined that the data are complete.
    Table 1 summarizes the site-specific highest 24-hour 
PM10 concentrations for the period of 2001-2012. As shown in 
Table 1, only one of the highest concentrations exceeded the 24-hour 
PM10 NAAQS standard of 150 [micro]g/m\3\. Table 2 summarizes 
the expected number of exceedances occurring over three-year periods 
dating back to EPA's previous clean data determination. See 67 FR 7082 
(February 15, 2002). The 24-hour PM10 standard is attained 
when the expected number of exceedances averaged over a three-year 
period is less than or equal to one at each monitoring site within the 
nonattainment area. The highest value in Table 2 is 0.3 exceedances 
over a three-year period, and the Sacramento PM10 
nonattainment area did not violate the 24-hour PM10 NAAQS 
during the 2001-2012 period. Therefore, we are proposing to determine, 
based on the complete, quality-assured data for three most recent years 
(2010-2012) that the Sacramento PM10 nonattainment area has 
attained the 24-hour PM10 standard. There are six 
PM10 monitors currently operating in the nonattainment area. 
Preliminary SLAMS data for 2013 from these monitors are also consistent 
with continued attainment.

 Table 1--Summary of Highest 24-hour PM10 Concentrations ([micro]g/m3) From Ambient Data Collected Within the Sacramento PM10 Nonattainment Area, 2001-
                                                                         2012.a
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                             Highest concentration ([micro]g/m\3\)
                       Site                          AQS Monitor ID  -----------------------------------------------------------------------------------
                                                                       2001   2002   2003   2004   2005   2006   2007   2008   2009   2010   2011   2012
--------------------------------------------------------------------------------------------------------------------------------------------------------
North Highlands-Blackfoot........................      06-067-0002-1     64     53     62     44    110     65     56     97     33     48     65     34
Sacramento-Del Paso Manor........................      06-067-0006-1     68     86     53     38     71     63     70     71     45     44     62     41
                                                       06-067-0006-3     65     43     43    101     49    132     66     92     39     19     NA     NA
Branch Center Road 1 \b\................      06-067-0283-1     78     77     75     45     61     38     NA     NA     NA     NA     NA     NA
Branch Center Road 2 \b\................      06-067-0284-1     NA     NA     NA     NA     NA     81     56     89     76     62     69     60
Sacramento-Airport Road \c\......................      06-067-0013-1     73    144     NA     35     56     90     94     71     NA     NA     NA     NA
                                                       06-067-0013-2     51     73     57     47     NA     NA     NA     NA     NA     NA     NA     NA
Sacramento Health Dept.-Stockton Blvd............      06-067-4001-2     58     85     53     44     64     56     56     88     45     45     60     34
                                                       06-067-4001-3    122    103     73     91     70    159     51     92     44     50     73     37
Sacramento-Goldenland Court \c\..................      06-067-0014-1     NA     NA     NA     NA     NA     NA     NA     56     48     42     63     32
                                                       06-067-0014-3     NA     NA     NA     NA     NA     NA     NA     NA     NA     55     69     76
Sacramento-T Street..............................      06-067-0010-1     89     77     65     58     53    109     53     73     47     53     38     36
                                                       06-067-0010-2     73     86     NA     NA     NA     NA     NA     NA     NA     NA     NA     NA
                                                       06-067-0010-3     48     NA     NA     NA     NA     NA     NA     NA     NA     NA     NA     NA
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The data in this table are from AQS QuickLook Reports dated January 10, 2013 and June 7, 2013.
\b\ The Branch Center Road 1 monitor was replaced by the Branch Center Road 2 monitor, located .25 mi to the north, in early 2006.
\c\ The Airport Road site was relocated to the Goldenland Court site in August 2008.
NA: data are not available.

[[Page 44499]]

                         Table 2--Summary of Expected Exceedances 3-yr Average From Ambient Data Collected within the Sacramento PM10 Nonattainment Area, 2001-2012.\a\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                               Expected Exceedances 3-yr Average
                Site name                  Site (AQS Monitor -----------------------------------------------------------------------------------------------------------------------------------
                                                  ID)         1999-2001  2000-2002  2001-2003  2002-2004  2003-2005  2004-2006  2005-2007  2006-2008  2007-2009  2008-2010  2009-2011  2010-2012
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
North Highlands-Blackfoot................      06-067-0002-1         0          0          0          0          0          0          0          0          0          0          0          0
Sacramento-Del Paso Manor................      06-067-0006-1         0          0          0          0          0          0          0          0          0          0          0          0
                                               06-067-0006-3         0          0          0          0          0          0          0          0          0          0          0          0
Branch Center Road 1 \b\........      06-067-0283-1         0          0          0          0          0          0          0          0         NA         NA         NA         NA
Branch Center Road 2 \b\........      06-067-0284-1        NA         NA         NA         NA         NA         NA          0          0          0          0          0          0
Sacramento-Airport Road \c\..............      06-067-0013-1         0          0          0          0          0          0          0          0          0          0         NA         NA
                                               06-067-0013-2         0          0          0          0          0          0         NA         NA         NA         NA         NA         NA
Sacramento Health Dept.-Stockton Blvd....      06-067-4001-2         0          0          0          0          0          0          0          0          0          0          0          0
                                               06-067-4001-3         0          0          0          0          0        0.3        0.3        0.3          0          0          0          0
Sacramento-Goldenland Court \c\..........      06-067-0014-1        NA         NA         NA         NA         NA         NA         NA          0          0          0          0          0
                                               06-067-0014-3        NA         NA         NA         NA         NA         NA         NA         NA         NA          0          0          0
Sacramento-T Street......................      06-067-0010-1         0          0          0          0          0          0          0          0          0          0          0          0
                                               06-067-0010-2         0          0          0          0          0         NA         NA         NA         NA         NA         NA         NA
                                               06-067-0010-3         0          0          0          0         NA         NA         NA         NA         NA         NA         NA         NA
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ The data in this table are from AQS QuickLook Reports dated January 10, 2013 and June 7, 2013.
\b\ The Branch Center Road 1 monitor was replaced by the Branch Center Road 2 monitor, located .25 mi to the north, in early 2006.
\c\ The Airport Road site was relocated to the Goldenland Court site in August 2008.
NA: data are not available.

B. The Area Must Have a Fully Approved SIP Meeting Requirements 
Applicable for Purposes of Redesignation Under Clean Air Act Section 
110 and Part D

    Section 107(d)(3)(E)(ii) and (v) require EPA to determine that the 
area has a fully approved applicable SIP under section 110(k) that 
meets all applicable requirements under section 110 and part D for the 
purposes of redesignation.
1. Basic SIP Requirements Under Section 110
    The general SIP elements and requirements set forth in section 
110(a)(2) include, but are not limited to, the following: submittal of 
a SIP that has been adopted by the State after reasonable public notice 
and hearing; provisions for establishment and operation of appropriate 
procedures needed to monitor ambient air quality; implementation of a 
source permit program; provision for the implementation of part C 
requirements for prevention of significant deterioration (PSD) 
provisions; provisions for the implementation of part D requirements 
for nonattainment new source review (nonattainment NSR) NSR permit 
programs; provisions for air pollution modeling; and provisions for 
public and local agency participation in planning and emission control 
rule development.
    We note that SIPs must be fully approved only with respect to 
applicable requirements for purposes of redesignation in accordance 
with section 107(d)(3)(E)(ii). The section 110 (and part D) 
requirements that are linked to a particular nonattainment area's 
designation and classification are the relevant measures to evaluate in 
reviewing a redesignation request. Requirements that apply regardless 
of the designation of any particular area on the State are not 
applicable requirements for the purposes of redesignation, and the 
State will remain subject to these requirements after the Sacramento 
PM10 nonattainment area is redesignated to attainment.
    For example, CAA section 110(a)(2)(D) requires that SIPs contain 
certain measures to prevent sources in a state from significantly 
contributing to air quality problems in another state, known as 
``transport SIPs.'' Because the section 110(a)(2)(D) requirements for 
transport SIPs are not linked to a particular nonattainment area's 
designation and classification but rather apply regardless of the 
attainment status, these are not applicable requirements for the 
purposes of redesignation under section 107(d)(3)(E).
    Similarly, EPA believes that other section 110 (and part D) 
requirements that are not linked to nonattainment plan submissions or 
to an area's attainment status are not applicable requirements for 
purposes of redesignation. EPA believes that the section 110 (and part 
D) requirements that relate to a particular nonattainment area's 
designation and classification are the relevant measures to evaluate in 
reviewing a redesignation request. This view is consistent with EPA's 
existing policy on applicability of the conformity SIP requirement for 
redesignations. See discussion in 75 FR 36023, 36026 (June 24, 2010).
    On numerous occasions, CARB and SMAQMD have submitted and we have 
approved provisions addressing the basic CAA section 110 provisions. 
The Sacramento portion of the California SIP \13\ 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,

[[Page 44500]]

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 Sacramento is unable to meet its CAA 
obligations. There are no outstanding or disapproved applicable SIP 
submittals with respect to the Sacramento portion of the SIP that 
prevent redesignation of the Sacramento PM10 nonattainment 
area for the 24-hour PM10 standard. Therefore, we propose to 
conclude that CARB and SMAQMD have met all SIP requirements for 
Sacramento applicable for purposes of redesignation under section 110 
of the CAA (General SIP Requirements).
---------------------------------------------------------------------------

    \13\ Sacramento's portion of the California SIP may be found at 
http://yosemite.epa.gov/r9/r9sips.nsf/Casips?readform&count=100&state=California.
---------------------------------------------------------------------------

2. SIP Requirements Under Part D
    Subparts 1 and 4 of part D, title 1 of the CAA contain air quality 
planning requirements for PM10 nonattainment areas. Subpart 
1 contains general requirements for all nonattainment areas of any 
pollutant, including PM10, governed by a NAAQS. The subpart 
1 requirements include, among other things, provisions for the 
reasonable available control measures (RACM), reasonable further 
progress (RFP), emissions inventories, contingency measures, and 
conformity. Subpart 4 contains specific planning and scheduling 
requirements for PM10 nonattainment areas. Section 189(a), 
(c), and (e) requirements apply specifically to moderate 
PM10 nonattainment areas and include: (1) An approved permit 
program for construction of new and modified major stationary sources; 
(2) provisions for RACM; (3) an attainment demonstration; (4) 
quantitative milestones demonstrating RFP toward attainment by the 
applicable attainment date; and (5) provisions to ensure that the 
control requirements applicable to major stationary sources of 
PM10 also apply to major stationary sources of 
PM10 precursors except where the Administrator has 
determined that such sources do not contribute significantly to 
PM10 levels that exceed the NAAQS in the area.
    As noted above, in 2002, EPA determined that the Sacramento 
PM10 nonattainment area attained the 24-hour PM10 
NAAQS based on 1998-2000 data. (67 FR 7082, February 15, 2002). In 
accordance with EPA's Clean Data Policy, we have determined that the 
following requirements do not apply to the State for so long as 
Sacramento continues to attain the PM10 standard or until 
the area is redesignated to attainment: an attainment demonstration 
under section 189(a)(1)(B); RACM provisions under sections 172(c) and 
189(a)(1)(C); reasonable further progress provisions under section 
189(c)(1); and contingency measures under section 172(c)(9). For other 
rulemaking actions applying the Clean Data Policy in the context of 
PM10, see 77 FR 31271-72 (proposed Determination of 
Attainment for Paul Spur/Douglas, Arizona); 76 FR 10821-22 (proposed 
Determination of Attainment for Truckee Meadows, Nevada); 75 FR 13712-
14 (proposed Determination of Attainment for Coso Junction, 
California); 75 FR 36027 (proposed Redesignation for Coso Junction, 
California); 73 FR 22313 (proposed Redesignation for San Joaquin 
Valley). See also, 40 CFR 51.918.
    Moreover, in the context of evaluating the area's eligibility for 
redesignation, there is a separate and additional justification for 
finding that requirements associated with attainment are not applicable 
for purposes of redesignation. Prior to and independently of the Clean 
Data Policy, and specifically in the context of redesignations, EPA 
interpreted attainment-linked requirements as not applicable for 
purposes of redesignation. In the General Preamble, ``General Preamble 
for the Interpretation of Title I of the Clean Air Act Amendments of 
1990,'' (General Preamble) 57 FR 13498, 13564 (April 16, 1992), EPA 
stated: [t]he section 172(c)(9) requirements are directed at ensuring 
RFP and attainment by the applicable date. These requirements no longer 
apply when an area has attained the standard and is eligible for 
redesignation. Furthermore, section 175A for maintenance plans * * * 
provides specific requirements for contingency measures that 
effectively supersede the requirements of section 172(c)(9) for these 
areas. See also Calcagni memorandum at 6 (``The requirements for 
reasonable further progress and other measures needed for attainment 
will not apply for redesignations because they only have meaning for 
areas not attaining the standard.''). Thus, even if the requirements 
associated with attainment had not previously been suspended, they 
would not apply for purposes of evaluating whether an area that has 
attained the standard qualifies for redesignation. EPA has enunciated 
this position since the General Preamble was published more than twenty 
years ago, and it represents the Agency's interpretation of what 
constitutes applicable requirements under section 107(d)(3)(E). The 
Courts have recognized the scope of EPA's authority to interpret 
``applicable requirements'' in the redesignation context. See Sierra 
Club v. EPA, 375 F.3d 537 (7th Cir.2004).
    The remaining applicable Part D requirements for moderate 
PM10 areas are: (1) An emission inventory under section 
172(c) (3); (2) a permit program for the construction and operation of 
new and modified major stationary sources of PM10 under 
sections 172(c)(5) and 189(a)(1)(A); (3) control requirements for major 
stationary sources of PM10 precursors under section 189(e), 
except where the Administrator determines that such sources do not 
contribute significantly to PM10 levels that exceed the 
standard in the area; (4) requirements under section 172(c)(7) that 
meet the applicable provisions of section 110(a)(2); and (5) provisions 
to ensure that federally supported or funded projects conform to the 
air quality planning goals in the applicable SIP under section 176(c). 
We discuss each of these requirements below.
 Emissions Inventory
    CAA section 172(c)(3) requires states to submit a comprehensive, 
accurate, current inventory of relevant PM10 pollutants for 
the baseline year from all sources within the nonattainment area. The 
inventory is to address direct and secondary PM10 emissions, 
and all stationary (generally referring to larger stationary source or 
``point'' sources), area (generally referring to smaller stationary and 
fugitive sources), and mobile (on-road, nonroad, locomotive and 
aircraft) sources are to be included in the inventory. We interpret the 
Act such that the emission inventory requirements of section 172(c)(3) 
are satisfied by the inventory requirements of the maintenance plan. 
See 57 FR 13498, at 13564 (April 16, 1992). Thus, EPA is proposing to 
approve the attainment inventories submitted as part of the Sacramento 
PM10 Maintenance Plan as satisfying the requirements of 
sections 172(c)(3) for the purposes of redesignation of the Sacramento 
PM10 nonattainment area to attainment for the 24-hour 
PM10 NAAQS. The attainment inventories are described in 
V.D.1 of this notice.
 Permits for New and Modified Major Stationary Sources
    CAA Sections 172(c)(5) and 189(a)(1)(A) require the State 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

[[Page 44501]]

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 in nonattainment 
areas is referred to as ``nonattainment New Source Review'' 
(nonattainment NSR).
    EPA has previously approved SMAQMD Rule 203 (Prevention of 
Significant Deterioration) and partially approved and partially 
disapproved SMAQMD Rule 214 (Federal New Source Review). 76 FR 43183 
(July 20, 2011). Because of the partial disapproval, SMAQMD does not 
currently have a fully-approved nonattainment NSR program.
    The NSR deficiencies identified in EPA's partial approval and 
partial disapproval of Rule 214 are limited to the following issues: 
(1) A small number of definitions: ``begin actual construction,'' 
``federally enforceable,'' and ``necessary preconstruction approvals or 
permits''; (2) the rule is missing adequate public notice requirements 
for minor sources; (3) the rule is missing provisions meeting the 
requirements of 40 CFR 51.165(a)(5)(ii) and 40 CFR 51.307(b)(2); and 
(4) the rule contains a cross reference to Rule 207--Title V--Federal 
Operating Permit Program, which is not SIP approved. The limited 
disapproval triggered an obligation on EPA to promulgate a federal 
implementation plan (FIP) to remedy the NSR deficiencies by August 19, 
2013. See 76 FR 43184 (July 20, 2011). To correct the deficiencies, on 
September 26, 2012, CARB submitted amended SMAQMD Rule 214 for 
inclusion in the SIP. On February 14, 2013, a notice of proposed 
rulemaking to approve revised Rule 214 was published in the Federal 
Register. See 78 FR 10589. On April 25, 2013, Regional Administrator 
Jared Blumenfeld signed a notice of final rulemaking to approve revised 
Rule 214. It is currently awaiting publication in the Federal Register. 
If the final rulemaking for revised Rule 214 becomes effective prior to 
EPA finalizing the area's redesignation to attainment for 
PM10, the 172(c)(5) and 189(a(1)(A) requirements would be 
fulfilled prior to redesignation.
    If EPA does not approve revised Rule 214 prior to EPA finalizing 
the area's redesignation to attainment for PM10, it would 
not affect EPA approval of the redesignation request because upon 
redesignation the requirements of SMAQMD's PSD program would apply to 
PM10 and PM10 precursor emissions of new major 
sources or major modifications. Thus, new major sources with 
significant PM10 emissions and major modifications of 
PM10 at major sources as defined under 40 CFR 51.21 will be 
required to obtain a PSD permit or include PM10 emissions in 
their existing PSD permit. Since PSD requirements \14\ will apply after 
redesignation, an area being redesignated to attainment need not comply 
with the requirement that a nonattainment NSR program be approved prior 
to redesignation as long as the state demonstrates maintenance of the 
NAAQS in the area without implementation of nonattainment NSR. A more 
detailed rationale for this view is described in a memorandum from Mary 
Nichols, Assistant Administrator for Air and Radiation, dated October 
14, 1994, titled ``Part D New Source Review Requirements for Areas 
Requesting Redesignation to Attainment.'' See also, redesignation 
rulemakings for Detroit, Michigan (60 FR 12467-12468, March 7, 1995); 
Cleveland-Akron-Lorain, Ohio (61 FR 20458, 20469-20470, May 7, 1996); 
Louisville, Kentucky (66 FR 53665, October 23, 2001); and, Grand 
Rapids, Michigan (61 FR 31834-31837, June 21, 1996).
---------------------------------------------------------------------------

    \14\ PSD requirements control the growth of new source emissions 
in areas designated as attainment for a NAAQS.
---------------------------------------------------------------------------

    Based on our review of the Sacramento PM10 Maintenance 
Plan, we conclude that the maintenance demonstration does not rely on 
implementation of nonattainment NSR because the Plan applies standard 
growth factors to stationary source emissions and does not rely on NSR 
offsets to reduce the rate of increase in emissions over time from 
point sources.\15\ In addition, the PM10 Maintenance Plan 
adds emission reduction credits (ERCs) for PM10, 
NOX, and SOx to future projected emissions to 
ensure that the use of ERCs will not be inconsistent with the future 
PM10 maintenance goals. Therefore, EPA concludes that a 
fully-approved nonattainment NSR program is not necessary for approval 
of the State's redesignation request for the Sacramento PM10 
nonattainment area.
---------------------------------------------------------------------------

    \15\ See letter, Larry Greene, Executive Officer, SMAQMD, to 
Deborah Jordan, Director, Air Division, US EPA, Region 9, dated June 
28, 2013.
---------------------------------------------------------------------------

    We conclude that Sacramento's portion of the California SIP 
adequately meets the requirements of section 172(c)(5) and 189(a)(1)(A) 
for purposes of this redesignation.
 Control Requirements for PM10 Precursors
    Section 189(e) of the CAA requires that the control requirements 
applicable under the part D SIP for major stationary sources of 
PM10 also apply to major stationary sources of 
PM10 precursors, except where the Administrator determines 
that such sources do not contribute significantly to PM10 
levels which exceed the standard in the area. Sacramento's 
PM10 Maintenance Plan states that NOX is a 
PM10 precursor in the secondary formation of atmospheric 
ammonium nitrates, which are a significant component of PM10 
concentrations in the Sacramento area. SMAQMD also determined, based on 
analyses of inventories \16\ from CARB and Chemical Mass Balance 
modeling, that emissions of sulfur oxides \17\ (SOX) and 
volatile organic compounds (VOCs) from sources in the Sacramento 
nonattainment area are an insignificant contributor to secondary 
particulate formation in the Sacramento PM10 nonattainment 
area. Therefore, SOX and VOC emissions are not included in 
the Sacramento PM10 Maintenance Plan. See pages 4-1 and 5-4 
in the Sacramento PM10 Maintenance Plan. To satisfy ozone 
nonattainment requirements in CAA section 182(b), SMAQMD has adopted 
Reasonably Available Control Technology rules to reduce NOX 
emissions from existing sources. See Rules 411, 412, and 413 in Table 3 
in this action. These rules also address the control requirements in 
CAA section 189(e) because they control NOX emissions from 
major stationary sources. Major stationary sources of NOX 
are also controlled by Rules 202 and 203, which are the District's 
nonattainment NSR and PSD permitting programs.
---------------------------------------------------------------------------

    \16\ California Emission Forecasting System (CEFS) Version 1.06 
Sacramento Metropolitan AQMD, Rf980.
    \17\ The following SMAQMD measures were previously implemented 
to reduce sulfur dioxide emissions: Rule 406--Specific Contaminants 
and Rule 420--Sulfur Content of Fuels. These measures were approved 
into the SIP on December 5, 1984 (49 FR 47490). Adjusting for the 
past decrease in SOX emissions, current ambient ammonium 
sulfate concentrations are estimated to be about 1 [mu]g/m\3\.
---------------------------------------------------------------------------

 Compliance with Section 110(a)(2)
    Section 172(c)(7) requires the SIP to meet the applicable 
provisions of section 110(a)(2). As noted above, we conclude the 
California SIP meets the requirements of section 110(a)(2) applicable 
for purposes of this redesignation.

[[Page 44502]]

 General and Transportation Conformity Requirements
    Under section 176(c) of the Clean Air Act Amendments of 1990, 
states are 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 provides 
that state conformity provisions must be consistent with federal 
conformity regulations that the CAA requires EPA to promulgate. EPA's 
conformity regulations are codified at 40 CFR part 93, subparts A 
(referred to herein as ``transportation conformity'') and B (referred 
to herein as ``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.''
    EPA believes it is reasonable to interpret the conformity SIP 
requirements as not applying for purposes of a redesignation request 
under section 107(d) because state conformity rules are still required 
after redesignation and federal conformity rules apply where state 
rules have not been approved. See Wall v. EPA, 265 F. 3d 426 (6th Cir. 
2001), upholding this interpretation. See also, 60 FR 62748 (December 
7, 1995).
    Thus, EPA proposes to determine that, if EPA later finalizes its 
approval of the Sacramento PM10 Maintenance Plan described 
in today's proposal and also finalizes its approval of the emissions 
inventory and motor vehicle emissions budgets for SMAQMD, the State has 
a fully-approved SIP meeting all requirements applicable under section 
110 and part D for the Sacramento PM10 nonattainment area 
for purposes of redesignation. CAA Section 107(d)(3)(E)(v).

C. EPA Has Determined That the Improvement in Air Quality Is Due to 
Permanent and Enforceable Reductions in Emissions

    Section 107(d)(3)(E)(iii) requires EPA to determine that the 
improvement in air quality is due to emission reductions that are 
permanent and enforceable resulting from the implementation of the 
applicable SIP and applicable Federal air pollution control regulations 
and other permanent and enforceable regulations in order to approve a 
redesignation to attainment. Under this criterion, the State must be 
able to reasonably attribute the improvement in air quality to 
emissions reductions which are permanent and enforceable. Attainment 
resulting from temporary reductions in emissions rates (e.g., reduced 
production or shutdown due to temporary adverse economic conditions) or 
unusually favorable meteorology would not qualify as an air quality 
improvement due to permanent and enforceable emission reductions. 
Calcagni memorandum, p. 4.
    Historically, exceedances of the 24-hour PM10 NAAQS in 
the Sacramento nonattainment area occur in late November and December. 
The Chemical Mass Balance (CMB) model was used to identify source 
contributions for ambient air quality samples collected during the 
winter months (i.e., November through January) for 1991-1996. CMB uses 
known chemical ``fingerprints'' of various source types together with 
measurements of the chemical components of ambient PM10 to 
find the contribution of those sources to PM10 
concentrations. CMB results show the main components of wintertime 
PM10 in the Sacramento nonattainment area were secondary 
ammonium nitrate particles (29%), motor vehicle exhaust from cars, 
trucks, and buses (23%), wood smoke (17%), and fugitive dust (12%).\18\ 
The CMB analysis indicates how reductions in emissions of primary 
PM10 and PM10 precursors (e.g., NOX) 
will reduce ambient PM10 concentrations; each of the ambient 
components can be ``rolled back'' in proportion to the emission changes 
in the corresponding source categories. The Sacramento PM10 
Maintenance Plan credits control measures adopted and implemented by 
SMAQMD and CARB and approved into the SIP by EPA as reducing emissions 
to attain the 24-hour PM10 NAAQS.
---------------------------------------------------------------------------

    \18\ See Sacramento PM10 Maintenance Plan, section 
3.5, page 3-10.
---------------------------------------------------------------------------

    The SMAQMD has jurisdiction over air quality planning requirements 
for Sacramento County. The SMAQMD has adopted numerous plans, rules, 
and revisions for Sacramento County in order to reduce PM10 
and PM10 precursor emissions. The Sacramento PM10 
Maintenance Plan includes a list of control measures adopted and 
implemented by SMAQMD and approved into the SIP by EPA as reducing 
emissions to attain the 24-hour PM10 NAAQS. Table 3 lists 
SMAQMD rules contributing towards attainment and/or continued 
attainment of the 24-hour PM10 NAAQS.

   Table 3--Sacramento Metropolitan AQMD Control Measures and Programs Contributing Towards Attainment and/or
                                 Continued Attainment of the 24-hour PM10 NAAQS.
----------------------------------------------------------------------------------------------------------------
                                                                            Date
                 Rule                                Title                approved             Citation
                                                                          into SIP
----------------------------------------------------------------------------------------------------------------
401...................................  Ringelmann Chart/Opacity......    02/01/1984  49 FR 3987.
403...................................  Fugitive Dust.................    12/05/1984  49 FR 47490.
404...................................  Particulate Matter............    07/13/1987  52 FR 26148.
405...................................  Dust and Condensed Fumes......    12/05/1984  49 FR 47490.
406...................................  Specific Contaminants.........    12/05/1984  49 FR 47490.
407...................................  Open Burn.....................    12/05/1984  49 FR 47490.
417...................................  Wood Burning Appliances.......    04/11/2013  78 FR 21540.
408...................................  Incinerator Burning...........    12/05/1984  49 FR 47490.

[[Page 44503]]

 
409...................................  Orchard Heaters...............    12/05/1984  49 FR 47490.
411...................................  NOX from Boilers, Process         08/01/2007  72 FR 41894.
                                         Heaters, and Steam Generators.
412...................................  Stationary Source Internal        04/30/1996  61 FR 18959.
                                         Combustion Engines at Major
                                         Stationary Sources of NOX.
413...................................  Stationary Gas Turbines.......    02/11/1999  64 FR 6803.
414...................................  Natural Gas Fired Water          04/20/1999,  64 FR 19277
                                         Heaters.                         11/01/2011  76 FR 67366.
420...................................  Sulfur Content of Fuels.......    12/05/1984  49 FR 47490.
501...................................  Agricultural Burning..........    12/05/1984  49 FR 47490.
----------------------------------------------------------------------------------------------------------------
                             Other SMAQMD measures or programs not in the SIP 19 20
----------------------------------------------------------------------------------------------------------------
421...................................  Mandatory Episodic Curtailment   Wood Stove/  Spare The Air.
                                         of Wood and Other Solid Fuel      Fireplace
                                         Burning..                        Change Out
                                                                           Incentive
                                                                            Program.
----------------------------------------------------------------------------------------------------------------
\19\ On September 26, 2012, Rule 421 was submitted to EPA for inclusion in the SIP. The Wood Stove/Fireplace
  Change Out Incentive Program, Spare The Air public education program, and Sacramento Valley Air Basin Smoke
  Management Program have not been submitted for inclusion in the SIP.
\20\ Sacramento County also participates in the State's Sacramento Valley Air Basin Smoke Management Program.
  The program describes the policies and procedures used with hourly and daily measurements of air quality and
  meteorology to determine how much open biomass burning can be allowed in the Sacramento Valley Air Basin. The
  program ensures that agricultural burning is prohibited on days meteorologically conducive to potentially
  elevated PM10 concentrations. The area covered by the program is referred to as the Sacramento Valley Air
  Basin, and includes all or parts of the following counties: Butte, Colusa, Glenn, Placer (portion),
  Sacramento, Shasta, Solano (portion), Sutter, Tehama, Yolo and Yuba. See Title 17 California Code of
  Regulations, Subchapter 2, Section 80100 et. seq. The regulations can be viewed at http://www.arb.ca.gov/smp/regs/RevFinRegwTOC.pdf.

    Source: Categories for which CARB has primary responsibility for 
reducing emissions in California include most new and existing on- and 
off-road engines and vehicles, motor vehicle fuels, and consumer 
products. In addition, California has unique authority under CAA 
section 209 (subject to a waiver by EPA) to adopt and implement new 
emission standards for many categories of on-road vehicles and engines, 
and new and in-use off-road vehicles and engines. California has been a 
leader in the development of some of the most stringent control 
measures nationwide for on-road and off-road mobile sources and the 
fuels that power them. These measures have helped reduce primary 
PM10 and PM10 precursors in the Sacramento 
PM10 nonattainment area and throughout the State.
    CARB's 2007 State Strategy and 2009 and 2011 updates to the State 
Strategy provide a recent summary of the measures adopted and 
implemented by the State.\21\ From 1994 to 2006, the State promulgated 
more than thirty-five rules that have achieved significant emission 
reductions contributing to attainment and continued attainment in the 
Sacramento PM10 nonattainment area. See 2007 State Strategy, 
p.38.22 23 These measures include new emission standards and 
in-use requirements that have resulted in significant reductions in 
emissions of PM10 and PM10 precursors (e.g., 
NOX) from categories such as passenger cars, trucks, buses, 
motorcycles, locomotives, cargo handling equipment, and large off-road 
equipment. EPA has generally approved into the SIP all of the State's 
measures that are not subject to the CAA section 209 waiver process. 
See EPA's final approval of the San Joaquin Valley PM2.5 
Plan at 76 FR 69896 (November 9, 2011) and accompanying Technical 
Support Document and Responses to Comments.\24\ Finally, in addition to 
the local district and State rules discussed above, the Sacramento 
PM10 nonattainment area has also benefitted from emission 
reductions from federal measures. These federal measures include EPA`s 
national emissions standards for heavy-duty diesel trucks (66 FR 5001 
(January 18, 2001)), certain emissions standards for new construction 
and farm equipment (Tier 2 and 3 non-road engines standards, 63 FR 
56968 (October 23, 1998) and Tier 4 diesel non-road engine standards, 
69 FR 38958 (June 29, 2004)), and locomotive engine standards (63 FR 
18978 (April

[[Page 44504]]

16, 1998) and 73 FR 37096 (June 30, 2008)).
---------------------------------------------------------------------------

    \21\ See ``Air Resources Board's Proposed State Strategy for 
California's 2007 State Implementation Plan,'' release date: April 
26, 2007 (2007 State Strategy).
    \22\ The 2007 Proposed State Strategy can be found at: http://arb.ca.gov/planning/sip/2007sip/apr07draft/sipback.pdf. Page 38 of 
the Proposed State Strategy lists forty-five actions; thirty-five of 
these actions provide NOX reductions.
    \23\ On August 12, 2009, CARB submitted the ``Status Report on 
the State Strategy for California's 2007 State Implementation Plan 
(SIP) and Proposed Revision to the SIP Reflecting Implementation of 
the 2007 State Strategy,'' dated March 24, 2009 and adopted April 
24, 2009 (``2009 State Strategy Status Report''). This submittal 
updated the 2007 State Strategy to reflect its implementation during 
2007 and 2008. See CARB Resolution No. 09-34, April 24, 2009 and 
letter, James N. Goldstene, Executive Officer, CARB, to Wayne 
Nastri, Regional Administrator, EPA Region 9, August 12, 2009 with 
enclosures. Only pages 11-27 of the 2009 State Strategy Status 
Report are submitted as a SIP revision. The balance of the report is 
for informational purposes only. See Attachment A to CARB Resolution 
No. 09-34.
    \24\ Technical Support Document and Responses to Comments, Final 
Rule on the San Joaquin Valley 2008 PM2.5 State 
Implementation Plan, September 30, 2011. This document can be found 
at: http://www.regulations.gov/#!documentDetail;D=EPA-R09-OAR-2010-
0516-0175.
---------------------------------------------------------------------------

    The on-road and off-road vehicle and engine standards cited above 
have contributed to improved air quality through the gradual, continued 
turnover and replacement of older vehicle models with newer models 
manufactured to meet increasingly stringent emissions standards.
    We note that many of the control measures cited above and in the 
Sacramento PM10 Maintenance Plan have provided emissions 
reductions since 1990, and thus, the improvement in air quality since 
1990 may reasonably be attributed to them.
    A sense of the effectiveness of the control measures to reduce 
PM10 and PM10 precursor emissions can be gained 
by comparing emissions in 1990 (a nonattainment year), 2000 (the year 
EPA determined the area met its attainment date) and 2008 (an 
attainment year).\25\ In 1990, area-wide PM10 and 
NOX emissions in the Sacramento PM10 
nonattainment area were estimated to be approximately 37 and 133 tons 
per day (winter day), respectively. In 2000, despite an increase in 
population and vehicle-miles-traveled (VMT) of approximately 14% and 
15%, respectively, area-wide emissions of PM10 dropped to 33 
tons per day and NOX declined to 100 tons per day compared. 
Despite increases between 1990 and 2008 in population (29%) and VMT 
(35%), area-wide emissions of direct PM10 decreased slightly 
to 35 tons per day. NOX emissions decreased significantly to 
82 tons per day, a reduction of approximately 38% compared 
to 1990 levels.
---------------------------------------------------------------------------

    \25\ See Appendix A in the Sacramento PM10 
Maintenance Plan.
---------------------------------------------------------------------------

    With respect to the connection between the emissions reductions and 
the improvement in air quality, we also conclude that the air quality 
improvement in the Sacramento PM10 nonattainment area since 
1990 through 2011 is not the result of a local economic downturn or 
unusual or extreme weather patterns. Our conclusion is based on the air 
quality data in Table 1 and recognition that the fluctuation in 
economic and meteorological conditions since 1998 did not result in a 
violation of the 24-hour PM10 standard.\26\ We do recognize 
that a significant economic slowdown occurred nationally starting in 
2008, but we note that the downward PM10 trend had already 
been established before that time (see Figure 3.3 on page 3-7 of the 
Sacramento PM10 Maintenance Plan).
---------------------------------------------------------------------------

    \26\ EPA's February 2002 determination that the Sacramento 
PM10 nonattainment area had attained the 24-hour 
PM10 NAAQS was based on complete, quality-assured, and 
certified ambient air monitoring data for 1998-2000.
---------------------------------------------------------------------------

    Thus, we find that the improvement in air quality in the Sacramento 
PM10 nonattainment area is the result of permanent and 
enforceable emissions reductions from a combination of EPA-approved 
local and State control measures and federal control measures. As such, 
we propose to find that the criterion for redesignation set forth at 
CAA section 107(d)(3)(E)(iii) is satisfied.

D. The Area Must Have a Fully Approved Maintenance Plan Under Clean Air 
Act Section 175A

    Section 175A of the CAA 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 plus a commitment to submit a second maintenance plan 
eight years after redesignation, monitoring network, verification of 
continued attainment, and contingency plan. See Calcagni memorandum, 
pages 8 through 13.
    Under CAA section 175A, a maintenance plan must demonstrate 
continued attainment of the applicable NAAQS for at least ten years 
after EPA approves a redesignation to attainment. Eight years after 
redesignation, the State must submit a revised maintenance plan that 
demonstrates continued attainment for the subsequent ten-year period 
following the initial ten-year maintenance period. To address the 
possibility of future NAAQS violations, the maintenance plan must 
contain such contingency provisions that EPA deems necessary to 
promptly correct any violation of the NAAQS that occurs after 
redesignation of the area. Based on our review and evaluation of the 
plan, as detailed below, we are proposing to approve the Sacramento 
PM10 Maintenance Plan because we believe that it meets the 
requirements of CAA section 175A.
1. Attainment Inventory
    Section 172(c)(3) of the CAA requires plan submittals to include a 
comprehensive, accurate, and current inventory of actual emissions from 
all sources in the nonattainment area. In demonstrating maintenance in 
accordance with CAA section 175A and the Calcagni memorandum, the State 
should provide an attainment emissions inventory to identify the level 
of emissions in the area sufficient to attain the NAAQS. Where the 
State has made an adequate demonstration that air quality has improved 
as a result of the SIP, the attainment inventory will generally be an 
inventory of actual emissions at the time the area attained the 
standard. EPA's primary guidance in evaluating these inventories is the 
document entitled, ``PM-10 Emissions Inventory Requirements,'' EPA, 
OAQPS, EPA-454/R-94-033 (September 1994) which can be found at: http://www.epa.gov/ttn/chief/eidocs/pm10eir.pdf.
    A maintenance plan for the 24-hour PM10 standard must 
include an inventory of emissions of PM10 and its precursors 
(NOX, sulfur oxides, and volatile organic compounds) in the 
area to identify a level of emissions sufficient to attain the 24-hour 
PM10 NAAQS. This inventory must 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 must also be comprehensive, including emissions from 
stationary point sources, area sources, and mobile sources.
    SMAQMD selected year 2008 as the year for the attainment inventory 
in the Sacramento PM10 Maintenance Plan. Year 2008 is a 
current, accurate, and comprehensive inventory during a period which 
the area continued to attain the 24-hour PM10 standard prior 
to adoption and submittal of the redesignation request and maintenance 
plan. The attainment inventory will generally be the actual inventory 
during the time period the area attained the standard. EPA previously 
made an attainment determination for the Sacramento PM10 
nonattainment area. See 67 FR 7082, February 15, 2002. Thus, Sacramento 
Metropolitan's selection of 2008 for the attainment inventory is 
acceptable.
    Based on our review of the Sacramento PM10 Maintenance 
Plan, we find that the emissions inventories in the Plan are 
comprehensive in that they include estimates of PM10 and its 
precursors from all of the relevant source categories, which the Plan 
divides among stationary, area wide, on-road motor vehicles, and other 
mobile.
    The Sacramento PM10 Maintenance Plan includes 
inventories for total primary PM10 and for NOX as 
a PM10 precursor. See tables 4-1 and 4-2 in the Sacramento 
PM10 Maintenance Plan. Appendix A to the PM10 
Maintenance Plan contains additional details of the emission 
inventories for 2008 (and 1990, 1995, 2000, 2012, and 2022). As 
previously described in section V.B.2, SMAQMD determined, based on 
analyses of inventories from CARB and Chemical Mass Balance modeling, 
that

[[Page 44505]]

emissions of SOx and VOCs from sources in the Sacramento 
nonattainment area are an insignificant contributor to secondary 
particulate formation in the Sacramento PM10 nonattainment 
area. Therefore, SOx and VOC emissions are not included in 
the Sacramento PM10 Maintenance Plan.
    The stationary source category includes non-mobile, fixed sources 
of air pollution. Examples of sources included in this category include 
fuel combustion (e.g., electric utilities), waste disposal (e.g., 
landfills), and oil and gas production. SMAQMD's 2008 (and subsequent 
year inventories) for stationary sources were developed using methods 
in CARB's 2009 Almanac \27\ and information reported by emission 
sources to SMAQMD and entered into the California Emission Inventory 
Development and Reporting System (CEIDARS) database.\28\ For area wide 
sources, SMAQMD calculated emissions based on reported data for fuel 
usage, product sales, population, employment data, and other parameters 
covering a wide range of activities.\29\
---------------------------------------------------------------------------

    \27\ The 2009 Almanac contains information about current and 
historical air quality and emissions in California. In addition, 
forecasted emissions are presented. See http://www.arb.ca.gov/aqd/almanac/almanac09/almanac09.htm
    \28\ The CEIDARS database consists of two categories of 
information: source information and utility information. Source 
information includes the basic inventory information generated and 
collected on all point and area sources. Utility information 
generally includes auxiliary data, which helps categorize and 
further define the source information. Used together, CEIDARS is 
capable of generating complex reports based on a multitude of 
category and source selection criteria.
    \29\ For more information on emissions from the area-wide source 
category, see the CARB Web site: http://www.arb.ca.gov/ei/areasrc/areameth.htm.
---------------------------------------------------------------------------

    The on-road mobile source category consists of trucks, automobiles, 
buses, and motorcycles. The on-road emissions inventory estimates in 
the Sacramento PM10 Plan were prepared by CARB using 
EMFAC2007 (version 2.3), a California model for on-road motor vehicle 
emissions.\30\ The vehicle miles traveled were developed from 
Sacramento Area Council of Governments-supplied activity data using 
transportation modeling prepared for the Sacramento region's August 
2009 Metropolitan Transportation Improvement Program.\31\
---------------------------------------------------------------------------

    \30\ EMFAC software and detailed information on the vehicle 
emission model can be found on the CARB Web site at http://www.arb.ca.gov/msei/onroad/on-road.htm.
    \31\ Metropolitan Transportation Improvement Program 2009/12, 
Sacramento Area Council of Governments, August 21, 2008.
---------------------------------------------------------------------------

    With respect to nonroad mobile sources (or other mobile as 
categorized in the PM10 Plan), the category includes 
aircraft, trains, boats, and off-road vehicles and equipment used for 
construction, farming, commercial, industrial, and recreational 
activities. CARB used its OFFROAD2007 to calculate the nonroad 
emissions.\32\ In general, emissions are calculated using equipment 
population, engine size and load, usage activity, and emission factors.
---------------------------------------------------------------------------

    \32\ See http://www.arb.ca.gov/msei/offroad/offroad.htm
---------------------------------------------------------------------------

    Table 4 presents the direct PM10 and PM10 
precursor emissions (i.e., NOX) estimates contained in the 
Sacramento PM10 Maintenance Plan for 2008. Based on the 
estimates in table 4, the area-wide category of emissions accounted for 
86% of the direct PM10, with residential fuel combustion 
making up 28%, construction and demolition 20%, and paved road dust 17% 
of the total direct PM10 inventory for 2008. Mobile source 
emissions accounted for 90% of the NOX emissions generated 
within the PM10 nonattainment area in 2008 with on-road 
motor vehicle emissions comprising approximately 61% and off-road 
equipment 20% of the total NOX inventory for 2008.

  Table 4--2008 Actual PM10 Emissions From Various Source Categories in the Sacramento PM10 Nonattainment Area,
                                              Total Daily Emissions
                                      [Tons per day, average winter day]\a\
----------------------------------------------------------------------------------------------------------------
                                                                                                2008
                    Category                              Emission source          -----------------------------
                                                                                         PM10           NOX
----------------------------------------------------------------------------------------------------------------
Stationary.....................................  Fuel Combustion..................            0.5            3.9
                                                 Industrial Processes.............            1.0            0.1
Area wide......................................  Residential Fuel Combustion......            9.9            4.4
                                                 Farming Operations...............            2.4  .............
                                                 Construction and Demolition......            7.0  .............
                                                 Paved Road Dust..................            6.1  .............
                                                 Unpaved Road Dust................            3.6  .............
                                                 Managed Burning and Disposal.....  .............            0.1
                                                 Other............................            1.2  .............
On-Road Motor Vehicles.........................  On-Road Motor Vehicles...........            2.2           49.6
Other Mobile...................................  Aircraft.........................            0.1            2.0
                                                 Trains...........................            0.1            3.4
                                                 Boats............................            0.1            0.5
                                                 Equipment (Off-Road/Farm)........            1.1           17.8
������������������������������������������������
                     Totals                      .................................           35             82
----------------------------------------------------------------------------------------------------------------
\a\ From Appendix A in the Sacramento PM10 Maintenance Plan.

    Based on our review of the emissions inventories (and related 
documentation) from the Sacramento PM10 Maintenance Plan, we 
find that the inventories for 2008 are comprehensive, that the methods 
and assumptions used by CARB and SMAQMD to develop the emission 
inventories are reasonable, and that the 2008 inventory reasonably 
estimates actual PM10 emissions in the attainment year. 
Therefore, we are proposing to approve the 2008 inventory, which serves 
as the Sacramento PM10 Maintenance Plan's attainment year 
inventory, as satisfying the requirements of section 172(c)(3) of the 
CAA for the purposes of redesignation of the Sacramento PM10 
nonattainment area to attainment of the 24-hour PM10 NAAQS.
2. Maintenance Demonstration
    Section 175A(a) of the CAA requires that the maintenance plan 
``provide for the maintenance of the national primary ambient air 
quality standard for such air pollutant in the area concerned for at

[[Page 44506]]

least 10 years after the redesignation.'' Generally, a state may 
demonstrate maintenance of the 24-hour PM10 NAAQS by 
modeling to show that the future mix of sources and emissions rates 
will not cause a violation of the NAAQS. A showing that future 
emissions will not exceed the level of the attainment year inventory 
can also be used to further support of a maintenance demonstration. For 
areas that are required under the Act to submit modeled attainment 
demonstrations, the maintenance demonstration should use the same type 
of modeling. Calcagni memorandum, page 9.
    In addition to accounting for area-wide growth trends, SMAQMD 
included growth in airport emissions to accommodate future airport 
expansions within the Sacramento County Airport System.\33\ The portion 
of the 2012 and 2022 inventories associated with airports is detailed 
in table 5.
---------------------------------------------------------------------------

    \33\ See Sacramento PM10 Maintenance Plan, section 
4.7, page 4-10.

                  Table 5--Airport Emissions for Sacramento County Only, Total Daily Emissions
                                     [Tons per day, average winter day] \a\
----------------------------------------------------------------------------------------------------------------
                                                        NOX                            PM10
                 Emission source                 ---------------------------------------------------------------
                                                       2012            2022            2012            2022
----------------------------------------------------------------------------------------------------------------
Aircraft Operations Only........................             2.3             3.0             0.1             0.1
Ground Support Equipment........................             0.3             0.2             0.1             0.1
----------------------------------------------------------------------------------------------------------------
\a\ From table 4-4 in the Sacramento PM10 Maintenance Plan.

    SMAQMD also included emissions reduction credits (ERCs) from pre-
2008 ERCs, future bankable rice burning ERCs, and the wood stove/
fireplace change out incentive program in the event that the ERCs are 
used for the purposes of issuing permits for new or modified stationary 
sources in the air quality planning area.\34\
---------------------------------------------------------------------------

    \34\ See Sacramento PM10 Maintenance Plan, section 
4.7, page 4-11.
---------------------------------------------------------------------------

    We have reviewed the methods and assumptions, as described in 
connection with the attainment inventory, that SMAQMD used to project 
emissions to 2012 and 2022 for the various source categories and find 
them to be reasonable. The Sacramento PM10 Maintenance 
Plan's maintenance demonstration is based on the use of Chemical Mass 
Balance (CMB) with proportional rollback (69 FR 5412, 5424-5425 and 69 
FR 30006) to demonstrate maintenance of the 24-hour PM10 
standard until 2022. See Plan, pp. 6-1--6-5. Under proportional 
rollback, changes in source categories' emissions are added in 
proportion to their corresponding component from CMB. In proportional 
rollback, a 1% change in direct PM10 emissions causes a 1% 
change in the direct PM10 ambient component. However, 
because ammonium nitrate is secondary PM, that is, it is formed from 
chemical reactions in the air, it does not necessarily scale one-to-one 
with the precursor NOX emissions. The Plan relied on 
photochemical modeling results showing that a 1% change in 
NOX emission causes only a 0.7% change in ammonium nitrate. 
See Plan, p. 6-3.
    The results of the modeling show that all monitoring sites in the 
Sacramento PM10 nonattainment area will be below the 24-hour 
PM10 NAAQS in 2022, with the projected value of 99 [mu]g/m3 
at the T Street site, which had the peak monitored value from 2006-2008 
in the Sacramento PM10 nonattainment area. See Plan, Table 
6.3.
    In addition to the CMB rollback modeling in the Sacramento 
PM10 Maintenance Plan, it also demonstrates that the 2022 
maintenance year inventory is well below the 2008 attainment year 
inventory for PM10 precursors (i.e., NOX) and 
flat for direct PM10. Thus, even without the rollback 
analysis previously described, the Plan clearly demonstrates 
maintenance of the PM10 NAAQS through 2022. Tables 6, 7 and 
8 compare inventory estimates for direct PM10 and 
PM10 precursor (i.e., NOX) for various years, 
including the 2008 attainment year, 2012, and the 2022 maintenance 
year. Since current ambient concentrations are well below the NAAQS, 
the slight increase in projected direct PM10 emissions is 
consistent with maintenance of the NAAQS. Even if all ambient 
PM10 were directly emitted (i.e., without accounting for the 
benefit of NOx reductions), the 2008 measured ambient level of 109 
[mu]g/m\3\ could increase by 37% and remain below the NAAQS, so direct 
PM10 emissions could also increase by 37% and the area would 
remain in attainment. In fact, direct PM10 is projected to 
increase by only 3% (or 7% considering potential increases in road dust 
allowed for in the Motor Vehicle Emissions Budget). This is a very 
conservative conclusion, because is assumes NOx emissions are constant, 
whereas they are actually projected to decrease by 50%, with an 
accompanying reduction in the ammonium nitrate component of 
PM10. The effects of the declining NOx and slightly 
increasing PM constitute a variant of simple rollback modeling, and can 
be considered a second, supporting maintenance demonstration method in 
addition to the CMB proportional rollback demonstration.

Table 6--Summary of 2008 Actual and 2012 and 2022 Projected PM10 and NOX
           Emissions in the Sacramento PM10 Nonattainment Area
                  [Tons per day, average winter day]\a\
------------------------------------------------------------------------
                     Pollutants                       2008   2012   2022
------------------------------------------------------------------------
PM10...............................................     35     35     36
NOX................................................     82     67     42
------------------------------------------------------------------------
\a\ From Appendix A in the Sacramento PM10 Maintenance Plan; includes
  Emission Reduction Credits in 2012 and 2022 for PM10 and NOX in table
  4-5 of the Sacramento PM10 Maintenance Plan.

    Based on our review of the 2012 and 2022 emissions inventories and 
related documentation from the Sacramento PM10 Maintenance 
Plan, we find that the 2012 and 2022 emissions inventories in the 
PM10 Maintenance Plan reflect the latest planning 
assumptions and emissions models available at the time the Plan was 
developed, and provide a comprehensive and reasonably accurate basis 
upon which to forecast direct PM10 and PM10 
precursor emissions for years 2012 and 2022.\35\ These inventories 
further support maintenance through 2022.
---------------------------------------------------------------------------

    \35\ The 2022 emission inventory includes emissions reductions 
from State measures adopted through 2006. Because the measures in 
Table 3 were adopted after 2006, the 2022 inventory is a 
conservative estimate of the projected emissions. December 27, 2012 
email from Martin Johnson of CARB to John Ungvarsky, EPA.

[[Page 44507]]

Table 7--2008 Actual and 2012 and 2022 Projected PM10 Emissions From Various Source Categories in the Sacramento
                                 PM10 Nonattainment Area, Total Daily Emissions
                                     [Tons per day, average winter day] \a\
----------------------------------------------------------------------------------------------------------------
                                                                                         PM10
                Category                       Emission source      --------------------------------------------
                                                                          2008           2012           2022
----------------------------------------------------------------------------------------------------------------
Stationary.............................  Fuel Combustion...........            0.5            0.5            0.6
                                         Industrial Processes......            1.0            0.9            1.1
Area wide..............................  Residential Fuel                      9.9            9.2           10.2
                                          Combustion.
                                         Farming Operations........            2.4            2.3            2.1
                                         Construction and                      7.0            7.2            7.8
                                          Demolition.
                                         Paved Road Dust...........            6.1            6.2            6.4
                                         Unpaved Road Dust.........            3.6            3.6            3.6
                                         Other.....................            1.2            1.3            1.4
On-Road Motor Vehicles.................  On-Road Motor Vehicles....            2.2            2.1            2.1
Other Mobile...........................  Aircraft..................            0.1            0.1            0.1
                                         Trains....................            0.1            0.1            0.1
                                         Boats.....................            0.1            0.1            0.1
                                         Equipment (Off-Road/Farm).            1.1            1.0            0.4
    Totals.............................  ..........................           35             35             36
----------------------------------------------------------------------------------------------------------------
\a\ From Appendix A in the Sacramento PM10 Maintenance Plan.

  Table 8--2008 and Projected 2012 and 2022 NOX Emissions From Various Source Categories in the Sacramento PM10
                                    Nonattainment Area, Total Daily Emissions
                                     [Tons per day, average winter day] \a\
----------------------------------------------------------------------------------------------------------------
                                                                                         NOX
                Category                       Emission source      --------------------------------------------
                                                                          2008           2012           2022
----------------------------------------------------------------------------------------------------------------
Stationary.............................  Fuel Combustion...........            3.9            4.0            4.2
                                         Industrial Processes......            0.1            0.1            0.1
Areawide...............................  Residential Fuel                      4.4            4.3            4.4
                                          Combustion.
                                         Managed Burning and                   0.1            0.1            0.1
                                          Disposal.
On-Road Motor Vehicles.................  On-Road Motor Vehicles....           49.6           37.6           18.1
Other Mobile...........................  Aircraft..................            2.0            2.3            3.0
                                         Trains....................            3.4            3.3            3.6
                                         Boats.....................            0.5            0.5            0.5
                                         Off-Road Equipment........           16.0           13.6            7.6
                                         Farm Equipment............            1.8            1.4            0.6
    Totals.............................  ..........................           82             67             42
----------------------------------------------------------------------------------------------------------------
\a\ From Appendix A in the Sacramento PM10 Maintenance Plan.

    Taking the CMB results into account gives an even stronger 
conclusion with respect to the acceptability of the slight increase of 
direct PM10 emissions. According to the CMB proportional 
rollback, direct PM10 contributes 81 [mu]g/m\3\ of the 2008 
total. See Plan, Table 6.3, p. 6-5. Considering the measured 109 [mu]g/
m\3\, that component could increase by 41 [mu]g/m\3\, or 50%, and the 
sum would remain below the NAAQS. When combined, the projected slight 
PM10 emissions increase and substantial NOX 
emissions decrease are well below the levels consistent with attainment 
through the 2022 maintenance period and thereby adequately demonstrate 
maintenance through that period.
a. Showing That Maintenance Plan Provides for Ten Years of Maintenance 
Through 2023
    Section 175A requires a state seeking redesignation to attainment 
to submit a SIP revision to provide for the maintenance of the NAAQS in 
the area ``for at least 10 years after the redesignation.'' EPA has 
interpreted this as a showing of maintenance ``for a period of ten 
years following redesignation.'' September 4, 1992 Memorandum from John 
Calcagni, Director, AQMD, ``Procedures for Processing Requests to 
Redesignate Areas to Attainment,'' p. 9.
    As discussed in detail above, the Sacramento PM10 
Maintenance Plan expressly documents that the area's emissions 
inventories will remain below the attainment year inventories through 
2022. In addition, for the reasons set forth below, EPA believes that 
the State's submission, in conjunction with additional supporting 
information, further demonstrates that the area will continue to 
maintain the 24-hour PM10 NAAQS at least through 2023. Thus, 
if EPA finalizes its proposed approval of the redesignation request and 
maintenance plans in 2013, it will be based in part on a showing, in 
accordance with section 175A, that the Sacramento PM10 
Maintenance Plan provides for maintenance for at least ten years after 
redesignation. EPA believes the area will continue to maintain the 24-
hour PM10 NAAQS at least through 2023 for the following 
reasons.
    1. Significant emissions controls remain in place and will continue 
to provide reductions that keep the area in attainment. Because the 
Sacramento area is currently nonattainment for the 1997 and 2008 ozone 
standards and the 2006 24-hour PM2.5 standard, it is 
expected that not only will existing emissions controls remain in 
place, but the Sacramento area may need additional reductions (e.g., 
NOX) to attain the aforementioned standards. In addition, 
the emissions controls that brought the area into attainment cannot be 
removed from the SIP unless the

[[Page 44508]]

State demonstrates that the removal would be consistent with sections 
110(l) and 193 of the CAA.
    2. The 2022 projected emissions inventory for PM10 
precursors is well below the 2008 attainment year level and is expected 
to decline or remain stable during the 2022 to 2023 period. It is 
extremely improbable that emissions would increase between 2022 and 
2023 such that they would exceed the 2008 attainment year levels. As 
shown in table 7, while primary PM10 emissions have remained 
relatively flat, by 2022 NOX emissions are projected to 
decline by approximately 70% and 49% when compared to 1990 and 2008, 
respectively. The majority of these reductions resulted from cleaner 
fuels, tighter emission standards, and fleet turnover in the mobile 
source sector. The 2022 emission inventory is conservative in that it 
does not include reductions from State measures adopted after 2006. 
Because Sacramento is nonattainment for the 1997 and 2008 ozone 
standards and the 2006 24-hour PM2.5 standard, SMAQMD and 
the State may need to adopt additional measures that will further 
reduce emissions between 2013 and 2023. Because fundamental relaxations 
or changes to the existing SIP-approved measures, mobile source fleet, 
and infrastructure cannot be easily made or reversed during the 2022-
2023 period, it is highly unlikely that PM10 and 
PM10 precursor emissions would increase significantly 
between 2022 and 2023 to the extent it would jeopardize a showing of 
maintenance for a 10-year period after redesignation.
    3. Fleet turnover supports a continued gradual decrease in emission 
levels beyond 2025. Specifically, California's Low Emission Vehicle 
(LEV) program sets gasoline and vehicle emissions standards for 
passenger cars, light trucks, and larger passenger vehicles. The 
program was designed to reduce emissions, including NOX, 
responsible for the ozone and particulate matter impacts from these 
vehicles. The LEV 2 standards were phased in between 2004 and 2010, 
have been replaced by the LEV 3 standards adopted in 2012. The LEV 3 
standards represent a further strengthening of the program and are 
planned to be phased in between 2015 and 2025. Consequently, the full 
emission reduction benefits from the LEV 2 and 3 standards will not be 
achieved until after 2022 and continue beyond 2023.\36\ The 
relationship between the LEV standards and fleet turnover is just one 
example of a measure providing continued NOX emissions 
reductions between 2022 and 2023 because of continued fleet turnover.
---------------------------------------------------------------------------

    \36\ 2011 records from CARB's inspection and maintenance program 
indicate approximately 20% of the fleet had not yet turned over 
after 15 years. It is reasonable to assume that because the LEV 2 
standards were not fully implemented until 2009, the reductions from 
the program will continue through 2023, which would represent the 14 
years of turnover affected by the LEV 2 standards. Thus, it is 
reasonable to conclude reductions from fleet turnover would continue 
even beyond 2023. To see the report, go to: http://www.bar.ca.gov/80_BARResources/04_Miscellaneous/USEPA%202010%20Calendar%20Year.pdf.
---------------------------------------------------------------------------

    4. Air quality concentrations are well below the 24-hour 
PM10 NAAQS, and, when coupled with the emissions inventory 
projections through 2022, clearly show it would be very unlikely for a 
PM10 violation to occur in 2023. The Sacramento 
PM10 nonattainment area has not violated the 24-hour 
PM10 NAAQS since 1990. Air quality concentrations for the 
three most recent years (2009-2011) of complete, quality-assured, and 
certified ambient air monitoring data show the highest monitored 
PM10 concentration to be 76 [micro]g/m\3\, approximately 
half of the PM10 NAAQS. The historical trend of the maximum 
24-hour PM10 peak concentrations between 1989 and 2011 
indicates a steady decline.\37\ As shown in table 7, by 2022 
PM10 precursor emissions (NOX) will drop 
significantly compared to 2008, and direct PM10 emissions 
will remain relatively flat. The combination of the air quality 
concentrations well below the standard and the declining inventory as 
described above indicate it is highly unlikely that the Sacramento 
PM10 nonattainment area will violate the 24-hour 
PM10 NAAQS during the 2022 to 2023 period.
---------------------------------------------------------------------------

    \37\ See Sacramento PM10 Maintenance Plan, Figure 
3.3, page 3-7.
---------------------------------------------------------------------------

    For the above reasons, EPA believes the area will continue to 
maintain the 24-hour PM10 NAAQS at least through 2023 and 
that the Sacramento PM10 Maintenance Plan shows maintenance 
for a period of ten years following redesignation. Thus, if EPA 
finalizes its proposed approval of the Sacramento PM10 
Maintenance Plan in 2013, it is based on a showing, in accordance with 
section 175A, that the Sacramento PM10 Maintenance Plan 
provides for maintenance for at least ten years after redesignation.
3. Verification of Continued Attainment
    In demonstrating maintenance, continued attainment of the NAAQS can 
be verified through operation of an appropriate air quality monitoring 
network. The Calcagni memorandum states that the maintenance plan 
should contain provisions for continued operation of air quality 
monitors that will provide such verification. Calcagni memorandum, p. 
11. As discussed in section V.A. of this document, PM10 is 
currently monitored by SMAQMD (five sites) and CARB (one site) within 
the Sacramento PM10 nonattainment area. In the Sacramento 
PM10 Maintenance Plan (see Plan, p. 7-1), SMAQMD indicates 
its intention to continue operation of an air quality monitoring 
network that meets or exceeds the minimum monitoring requirements and 
that ambient PM10 concentrations will be monitored 
appropriately to verify continued attainment of the 24-hour 
PM10 NAAQS. The Sacramento PM10 Maintenance Plan 
also notes that a review of the entire monitoring network will be 
undertaken annually as required by federal regulations.\38\ We find the 
SMAQMD's commitment for continued ambient PM10 monitoring as 
set forth in the Sacramento PM10 Maintenance Plan to be 
acceptable.
---------------------------------------------------------------------------

    \38\ EPA's requirements for annual review of monitoring networks 
are found at 40 CFR 58.10.
---------------------------------------------------------------------------

    Second, the transportation conformity process, which would require 
a comparison of on-road motor vehicle emissions that would occur under 
new or amended regional transportation plans and programs with the 
MVEBs in the PM10 Maintenance Plan, represents another means 
by which to verify continued attainment of the 24-hour PM10 
NAAQS in Sacramento County. See page 8-1 of the Sacramento 
PM10 Maintenance Plan.
    Lastly, while not cited in the Plan, CARB and SMAQMD must inventory 
emissions sources and report to EPA on a periodic basis under 40 CFR 
part 51, subpart A (``Air Emissions Reporting Requirements''). These 
emissions inventory updates will provide a third way to evaluate 
emissions trends in the area and thereby verify continued attainment of 
the NAAQS. These methods are sufficient for the purpose of verifying 
continued attainment.
4. Contingency Provisions
    Section 175A(d) of the Clean Air Act requires that maintenance 
plans include contingency provisions, as EPA deems necessary, to 
promptly correct any violations of the NAAQS that occur after 
redesignation of the area. Such provisions must include a requirement 
that the State will implement all measures with respect to the control 
of the air pollutant concerned that were contained in the SIP for the 
area before redesignation of the area as an attainment area. These 
contingency provisions are distinguished from those

[[Page 44509]]

generally required for nonattainment areas under section 172(c)(9) in 
that they are not required to be fully-adopted measures that will take 
effect without further action by the state in order for the maintenance 
plan to be approved. However, the contingency plan is considered to be 
an enforceable part of the SIP and should ensure that the contingency 
measures are adopted expeditiously once they are triggered by a 
specified event.
    Under section 175A(d), contingency measures identified in the 
contingency plan do not have to be fully adopted at the time of 
redesignation. However, the contingency plan is considered to be an 
enforceable part of the SIP and should ensure that the contingency 
measures are adopted expeditiously once they are triggered by a 
specified event. The maintenance plan should clearly identify the 
measures to be adopted, a schedule and procedure for adoption and 
implementation, and a specific timeline for action by the State. As a 
necessary part of the plan, the State should also identify specific 
indicators or triggers, which will be used to determine when the 
contingency measures need to be implemented.
    As required by section 175A of the CAA, SMAQMD has adopted a 
contingency plan to address possible future PM10 air quality 
problems. The contingency provisions in the Sacramento PM10 
Maintenance Plan are contained in section 7.3 of the Plan and were 
clarified in a subsequent letter from the District.\39\ After 
verification of the 24-hour PM10 NAAQS violation, including 
allowing sufficient time for sample weighing and processing, SMAQMD 
commits to the following steps.
---------------------------------------------------------------------------

    \39\ See letter, Larry Greene, Executive Officer, SMAQMD, to 
Deborah Jordan, Director, Air Division, US EPA, Region 9, dated June 
28, 2013.
---------------------------------------------------------------------------

    (1) Examine the violation to determine if it qualifies as a natural 
or exceptional event.
    (2) If the violation was not a natural or exceptional event, SMAQMD 
will analyze the event to determine its plausible causes. Any 
applicable emission reductions from already adopted rules that have not 
yet been implemented would be evaluated to determine if these new 
emission reductions would be sufficient to prevent future 
PM10 exceedances. These already adopted controls could 
include CARB and SMAQMD PM2.5 and NOX measures to 
address ozone and PM2.5 SIP requirements. In addition, the 
SMAQMD would evaluate applicable reasonably available control measures 
(RACM) that could potentially provide the corrective action needed. 
This evaluation step will take no more than 18 months.
    (3) If the additional emission reductions from already adopted 
rules are insufficient, the SMAQMD would proceed with selecting 
specific RACM measures for adoption and implementation that would be 
applicable to addressing the seasonal PM10 problem. Appendix 
B in the Sacramento PM10 Maintenance Plan contains potential 
RACM measures to be evaluated for future adoption and implementation. 
This adoption and implementation step will take no more than 12 months.
    In their June 28, 2013 letter, SMAQMD clarified that all three of 
the aforementioned steps will be completed, including the 
implementation of additional control measures, within 24 months.
    Upon our review of the Plan, as summarized above, we find that the 
contingency provisions of the Sacramento PM10 Maintenance 
Plan clearly identify specific contingency measures, contain tracking 
and triggering mechanisms to determine when contingency measures are 
needed, contain a description of the process of recommending and 
implementing contingency measures, and contain specific timelines for 
action. Thus, we conclude that the contingency provisions of the 
Sacramento PM10 Maintenance Plan are adequate to ensure 
prompt correction of a violation and therefore comply with section 
175A(d) of the Act. For the reasons set forth above, EPA is proposing 
to find that the Sacramento PM10 Maintenance Plan is 
consistent with the maintenance plan contingency provision requirements 
of the CAA and EPA guidance.
5. Subsequent Maintenance Plan Revisions
    Section 175A(b) of the CAA provides that eight years after 
redesignation, the State must submit a revised maintenance plan that 
demonstrates continued attainment for the subsequent ten-year period 
following the initial ten-year maintenance period. The Sacramento 
PM10 Maintenance Plan includes a SMAQMD commitment to 
prepare and submit a revised maintenance plan in 2020, seven years 
after redesignation to attainment. See page 6-7 of the Sacramento 
PM10 Maintenance Plan.
    In light of the discussion set forth above, EPA is proposing to 
approve the Sacramento PM10 Maintenance Plan as meeting the 
requirements of CAA section 175A.
6. Transportation Conformity and Motor Vehicle Emissions Budgets
a. Requirements for Transportation Conformity and Motor Vehicle 
Emissions Budgets
    Under section 176(c) of the CAA, transportation plans, programs and 
projects in the nonattainment or maintenance areas that are funded or 
approved under title 23 U.S.C. and the Federal Transit Laws (49 U.S.C. 
chapter 53) must conform to the applicable SIP. In short, a 
transportation plan and program are deemed to conform to the applicable 
SIP if the emissions resulting from the implementation of that 
transportation plan and program are less than or equal to the motor 
vehicle emissions budgets (budgets) established in the SIP for the 
attainment year, maintenance year and other years. See, generally, 40 
CFR part 93 for the federal conformity regulations and 40 CFR 93.118 
specifically for how budgets are used in conformity.
    The budgets serve as a ceiling on emissions that would result from 
an area's planned transportation system. The budget concept is further 
explained in the preamble to the November 24, 1993, transportation 
conformity rule (58 FR 62188). Maintenance plan submittals must specify 
the maximum emissions of transportation-related PM10 and 
NOX emissions allowed in the last year of the maintenance 
period, i.e., the motor vehicle emissions budgets (MVEBs). (MVEBs may 
also be specified for additional years during the maintenance period.) 
The submittal must also demonstrate that these emissions levels, when 
considered with emissions from all other sources, are consistent with 
maintenance of the NAAQS.
b. Motor Vehicle Emissions Budgets in the Sacramento PM10 
Maintenance Plan
    The Sacramento PM10 Maintenance Plan contains 
PM10 and NOX MVEBs for the Sacramento 
PM10 nonattainment area for 2008, 2012, and 2022. The MVEBs 
are the on-road mobile source primary PM10 and 
NOX (as a PM10 precursor) emissions for 
Sacramento County for 2008, 2012 and 2022. The MVEBs are compatible 
with the 2008, 2012, and 2022 on-road mobile source PM10 and 
NOX emissions included in SMAQMD's 2008, 2012, and 2022 
p.m.10 and NOX emission inventories, as 
summarized above in tables 6, 7 and 8. The derivation of the MVEBs is 
thoroughly discussed in section 8 of the Sacramento PM10 
Maintenance Plan.\40\

[[Page 44510]]

The motor vehicle emissions budgets for Sacramento are summarized in 
table 9.
---------------------------------------------------------------------------

    \40\ Additional information associated with the motor vehicle 
emission budget calculations is provided in a technical analysis 
accompanying June 2013 letters from ARB and SMAQMD to EPA.
    \41\ See Table 8.1, page 8-4 of the Sacramento PM10 
Maintenance Plan.

   Table 9--Summary of Motor Vehicle Emissions Budgets (Tons per Day,
    Average Winter Day) in the Sacramento PM10 Maintenance Plan \41\
------------------------------------------------------------------------
                       Budget year                         PM10     NOX
------------------------------------------------------------------------
2008....................................................      15      50
2012....................................................      15      38
2022....................................................      17      19
------------------------------------------------------------------------

    The details for each component of the budgets are shown in table 10 
and are comprised of direct on-road mobile source emissions, road 
construction emissions, fugitive emissions from paved and unpaved 
roads, and safety margins. A state may choose to apply a safety margin 
under our transportation conformity rule so long as such margins are 
explicitly quantified in the applicable plan and are shown to be 
consistent with attainment or maintenance of the NAAQS (whichever is 
relevant to the particular plan).\42\ In this instance, the safety 
margin has been explicitly quantified and shown to be consistent with 
continued maintenance of the PM10 NAAQS through the 
applicable maintenance period, through 2023. The MVEBs incorporate: (1) 
On-road motor vehicle emission inventory factors of EMFAC2007 \43\ and 
AP-42; \44\ and (2) updated recent vehicle activity data from 
Sacramento Area Council of Governments' Sacramento Activity-Based 
Travel Demand Simulation Model transportation modeling system.
---------------------------------------------------------------------------

    \42\ See 40 CFR 93.124(a).
    \43\ EMFAC (EMission FACtor) is California's model for 
estimating emissions from on-road vehicles operating in California. 
EPA approved EMFAC2007 on January 18, 2008 (73 FR 3464). CARB's 
latest release is EMFAC 2011 which EPA approved on March 6, 2013 (78 
FR 14533) was not approved when this plan was developed.
    \44\ AP-42, Compilation of Air Pollutant Emission Factors, is a 
document published by EPA as the primary collection of EPA approved 
emission factor information. The emission factors have been 
developed and compiled from source test data, material balance 
studies, and engineering estimates. EPA has publishes supplements 
and updates to the each of the chapters available in Volume I, 
Stationary Point and Area Sources at the following Web site: http://www.epa.gov/ttnchie1/ap42/.
    \45\ Ibid.
    \46\ The Sacramento PM10 Maintenance Plan includes 
PM10 MVEB safety margins of 1.3 tons per day (tpd) for 
2012 and 2.4 tpd for 2022. This additional increase may be needed 
for the Sacramento Area Council of Governments to make a 
transportation conformity determinations, including for a horizon 
year of 2035 or later for transportation planning purposes when 
using the latest year of motor vehicle emissions budgets (2022) in 
the Sacramento PM10 Maintenance Plan. See letter, Larry 
Greene, Executive Officer, SMAQMD, to Deborah Jordan, Director, Air 
Division, US EPA, Region 9, dated June 28, 2013. Also see letter, 
Lynn Terry, Deputy Executive Officer, CARB, to Deborah Jordan, 
Director, Air Division, US EPA, Region 9, dated June 13, 2013.

 Table 10--Source Categories and Emissions Comprising the Motor Vehicle Emissions Budgets (Tons per Day, Average
                            Winter Day) in the Sacramento PM10 Maintenance Plan \45\
----------------------------------------------------------------------------------------------------------------
                                              2008                      2012                      2022
             Category              -----------------------------------------------------------------------------
                                        NOX          PM10         NOX          PM10         NOX          PM10
----------------------------------------------------------------------------------------------------------------
Direct Exhaust \a\................         49.6          2.2         37.6          2.1         18.1          2.1
Paved Road Dust...................  ...........          6.1  ...........          4.9  ...........          5.5
Unpaved Road Dust.................  ...........          3.6  ...........          3.6  ...........          3.6
Road Construction Dust............  ...........          2.7  ...........          2.8  ...........          2.8
Safety Margin \46\................  ...........  ...........  ...........          1.3  ...........          2.5
                                   -----------------------------------------------------------------------------
Totals (rounded up to nearest ton)         50           15           38           15           19           17
----------------------------------------------------------------------------------------------------------------
\a\ Direct Exhaust includes PM10 from tire and brake wear.

c. Initial Adequacy Review of Budgets
    On September 1, 2011, EPA announced the availability of the 
Sacramento PM10 Maintenance Plan with MVEBs and a 30-day 
public comment period on EPA's Adequacy Web site at: http://www.epa.gov/otaq/stateresources/transconf/reg9sips.htm#ca. The comment 
period for this notification ended on October 3, 2011, and EPA received 
no comments from the public. On November 23, 2011, EPA published in the 
Federal Register (76 FR 72404) a finding of adequacy for the 
PM10 MVEBs for the years 2008, 2012, and 2022.
d. Updated Technical Review
    As described earlier, the budgets were developed using emission 
factors generated by CARB's EMFAC2007 model and AP-42. The paved road 
emissions were originally calculated using the 2006 version of AP-42 by 
estimating the 2008 paved road emissions and projecting them to 2012 
and 2022. The calculation relied on a California profile of silt 
loading, weather, and growth in roadway centerline miles.
    EPA released an update to Compilation of Air Pollutant Emission 
Factors (AP-42) in January of 2011, which revised the equation for 
estimating paved road dust emissions based on an updated regression 
that included new emission tests results. CARB staff conducted an 
additional technical analysis of the Sacramento County paved road 
emission projections using the updated AP-42 equation and growth in 
vehicle miles traveled, to ensure that the motor vehicle emission 
budgets were still consistent with the currently approved modeling 
tools and data and the maintenance demonstration. The technical 
analysis showed that the updated paved road emissions provided safety 
margins in 2012 and 2022 as compared to the attainment inventory 
emissions of paved road dust which was used in establishing the MVEBs 
in the Sacramento PM10 Maintenance Plan.\47\ Therefore, the 
total MVEBs are consistent with maintenance of the standard.
---------------------------------------------------------------------------

    \47\ See letter, Lynn Terry, Deputy Executive Officer, CARB, to 
Deborah Jordan, Director, Air Division, US EPA, Region 9, dated June 
13, 2013. See Letter, Larry Greene, Executive Director/Air Pollution 
Control Officer, SMAQMD, to Deborah Jordan, Director Air Division, 
US EPA, Region 9, dated June 28, 2013.
---------------------------------------------------------------------------

e. Proposed Actions on the Budgets
    EPA is proposing to approve the MVEBs for 2008, 2012 and 2022 as 
part of our approval of Sacramento PM10 Maintenance Plan. 
EPA has determined that the MVEB emission targets are consistent with 
emission control measures in the SIP and that Sacramento County can 
maintain attainment of the 24-hour PM10 NAAQS. Because the 
budgets EPA found

[[Page 44511]]

adequate in 2011 are the same budgets EPA is proposing to approve in 
this action, if EPA approves the MVEBs in the final rulemaking action, 
it would not change the budgets currently in use for future 
transportation conformity determinations for Sacramento County. As 
discussed in section V.D.2.a of this notice, EPA is proposing that if 
this approval is finalized in 2013 the area will continue to maintain 
the 24-hour PM10 NAAQS through at least 2023. Consistent 
with this proposal, EPA is proposing to approve the MVEBs submitted by 
the State in the Sacramento PM10 Maintenance Plan. EPA is 
proposing that the submitted budgets, when combined with EPA's 
additional analysis for the 2022-2023 time period, are consistent with 
maintenance of the 24-hour PM10 NAAQS through 2023.

VI. Proposed Action and Request for Public Comment

    Based on our review of the Sacramento PM10 Maintenance 
Plan submitted by the State, air quality monitoring data, and other 
relevant materials, EPA is proposing to find that the State has 
addressed all the necessary requirements for redesignation of the 
Sacramento nonattainment area to attainment of the PM10 
NAAQS, pursuant to CAA sections 107(d)(3)(E) and 175A.
    First, under CAA section 107(d)(3)(D), we are proposing to approve 
CARB's request, which accompanied the submittal of the Sacramento 
PM10 Maintenance Plan, to redesignate the Sacramento 
PM10 nonattainment area to attainment for the 24-hour 
PM10 NAAQS. We are doing so based on our conclusion that the 
area has met the five criteria for redesignation under CAA section 
107(d)(3)(E). Our conclusion is based on our proposed determination 
that the area has attained the 24-hour PM10 NAAQS; that 
relevant portions of the California SIP are fully approved; that the 
improvement in air quality is due to permanent and enforceable 
reductions in emissions; that California has met all requirements 
applicable to the Sacramento PM10 nonattainment area with 
respect to section 110 and part D of the CAA; and is based on our 
proposed approval of the Sacramento PM10 Maintenance Plan as 
part of this action.
    Second, in connection with the Sacramento PM10 
Maintenance Plan and EPA's analysis showing maintenance through 2023, 
EPA finds that the maintenance demonstration showing how the area will 
continue to attain the 24-hour PM10 NAAQS for 10 years 
beyond redesignation (i.e., through 2023) and the contingency 
provisions describing the actions that SMAQMD will take in the event of 
a future monitored violation meet all applicable requirements for 
maintenance plans and related contingency provisions in section 175A of 
the CAA. EPA is also proposing to approve the motor vehicle emissions 
budgets in the Sacramento PM10 Maintenance Plan because we 
find they meet the applicable transportation conformity requirements 
under 40 CFR 93.118(e). Lastly, EPA is proposing to approve the 2008 
inventory, which serves as the Sacramento PM10 Maintenance 
Plan's attainment year inventory, as satisfying the requirements of 
section 172(c)(3) of the CAA.
    We are soliciting comments on these proposed actions. We will 
accept comments from the public on this proposal for 30 days following 
publication of this proposal in the Federal Register. We will consider 
these comments before taking final action.

VII. Statutory and Executive Order Reviews

    Under the CAA, redesignation of an area to attainment and the 
accompanying approval of a maintenance plan under section 107(d)(3)(E) 
are actions that affect the status of a geographical area and do not 
impose any additional regulatory requirements on sources beyond those 
imposed by State law. Redesignation to attainment does not in and of 
itself create any new requirements, but rather results in the 
applicability of requirements contained in the CAA for areas that have 
been redesignated to attainment. Moreover, the Administrator is 
required to approve a SIP submission that complies with the provisions 
of the Act and applicable federal regulations. 42 U.S.C. 7410(k); 40 
CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to 
approve State choices, provided that they meet the criteria of the 
Clean Air Act. Accordingly, these actions merely propose to approve a 
State plan and redesignation request as meeting federal requirements 
and do not impose additional requirements beyond those by State law. 
For these reasons, these proposed actions:
     Are not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Order 
12866 (58 FR 51735, October 4, 1993);
     Do not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Are certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Do not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Do not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Are not an economically significant regulatory action 
based on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Are not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Are not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA; and
     Do not provide EPA with the discretionary authority to 
address disproportionate human health or environmental effects with 
practical, appropriate, and legally permissible methods under Executive 
Order 12898 (59 FR 7629, February 16, 1994).
    In addition, this proposed rule does not have tribal implications 
as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), 
because the SIP is not approved to apply in Indian country located in 
the State, and EPA notes that it will not impose substantial direct 
costs on tribal governments or preempt tribal law. In addition, there 
are no federally recognized tribes located within the Sacramento 
PM10 nonattainment area.

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Nitrogen dioxide, Particulate 
matter, Reporting and recordkeeping requirements, Sulfur dioxide.

40 CFR Part 81

    Environmental protection, Air pollution control, National parks, 
Wilderness areas.

    Dated: July 12, 2013.
Alexis Strauss,
Acting Regional Administrator, Region IX.
[FR Doc. 2013-17825 Filed 7-23-13; 8:45 am]
BILLING CODE 6560-50-P
```