Approval and Promulgation of Implementation Plans and Designation
of Areas for Air Quality Planning Purposes; Arizona
[Federal Register: October 8, 2004 (Volume 69, Number 195)]
[Proposed Rules]
[Page 60328-60343]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08oc04-18]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 52 and 81
[AZ104-0069; FRL-7823-6]
Approval and Promulgation of Implementation Plans and Designation
of Areas for Air Quality Planning Purposes; Arizona
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: EPA is proposing to approve the Maricopa Association of
Governments (MAG) serious area carbon monoxide (CO) state
implementation plan (SIP) for the Maricopa County CO nonattainment area
(the metropolitan Phoenix area, Arizona) as meeting the Clean Air Act
(CAA) requirements for serious CO nonattainment areas. We are also
proposing to approve the MAG CO redesignation request and maintenance
plan for the Maricopa County CO nonattainment area as meeting CAA
requirements for redesignation requests and maintenance plans. In
addition, we are proposing to make a boundary change under Section 107
of the CAA to take the Gila River Indian Community (GRIC) out of the
Maricopa County maintenance area. The portion of the Gila River Indian
Community which is currently in the Maricopa County CO nonattainment
area will be ``unclassifiable/attainment'' for CO, and will not be
subject to the MAG CO Redesignation Request and Maintenance Plan.
DATES: Written comments must be received at the address below on or
before November 8, 2004.
ADDRESSES: Formal written comments should be mailed or emailed to
Wienke Tax, Office of Air Planning (AIR-2), U.S. Environmental
Protection Agency, Region 9, 75 Hawthorne Street, San Francisco, CA
94105-3901, tax.wienke@epa.gov. Comments may also be submitted through
the Federal Register Web site at http://www.regulations.gov.
We prefer electronic comments.
You can inspect copies of EPA's Federal Register document and
technical support documents (TSD) at our Region 9 office during normal
business hours (see address above). Due to increased security, we
suggest that you call at least 24 hours prior to visiting the Regional
Office so that we can make arrangements to have someone meet you. The
Federal Register document and TSD are also available as electronic
files on EPA's
[[Page 60329]]
Region 9 Web Page at http://www.epa.gov/region09/air.
You may inspect and copy the rulemaking docket for this notice at
the following location during business hours.
Environmental Protection Agency, Region 9, Air Division, Air
Planning Office (AIR-2), 75 Hawthorne Street, San Francisco, CA 94105.
Copies of the SIP materials are also available for inspection at
the address listed below:
Arizona Department of Environmental Quality, 1110 W. Washington
Street, First Floor, Phoenix, AZ 85007, Phone: (602) 771-4335.
FOR FURTHER INFORMATION CONTACT: Wienke Tax, Office of Air Planning,
U.S. Environmental Protection Agency, Region 9, (520) 622-1622, e-mail:
tax.wienke@epa.gov, or http://www.epa.gov/region09/air.
SUPPLEMENTARY INFORMATION: Throughout this document, the terms ``we,''
``us,'' and ``our'' mean U.S. EPA.
Table of Contents
I. Summary of Today's Proposed Action
II. The Serious Area CO SIP for the Phoenix Area
III. The CAA's Requirements for Serious CO Nonattainment Area Plans
IV. The Revised 1999 CO Plan's Compliance With the CAA's
Requirements for Serious CO Nonattainment Area Plans
A. Completeness of the SIP Submittals and Adequacy of the Motor
Vehicle Emissions Budget
B. Emissions Inventory
C. Adequate Monitoring Network
D. Implementation of Reasonably Available Control Measures
E. Demonstration of Attainment
F. Reasonable Further Progress
G. VMT Tracking and Reporting
H. Transportation Control Measures To Offset Growth in Emissions
I. Contingency Measures
J. Enhanced I/M Program
K. Wintertime Oxygenated Gasoline Program
L. General SIP Requirements
V. The CAA's Requirements for Serious CO Maintenance Plans and
Redesignation Requests
VI. The MAG CO Redesignation Request and Maintenance Plan's
Compliance With the CAA's Requirements for CO Redesignation Requests
and Maintenance Plans
A. General SIP Requirements
B. Attainment of the CO NAAQS
C. Meeting Applicable Requirements of Section 110 and Part D
D. Fully-Approved SIP Under Section 110(k) of the CAA (NSR)
E. Improvement in Air Quality Due to Permanent and Enforceable
Measures
F. Fully-Approved Maintenance Plan Under Section 175A
VII. EPA's Evaluation of the Transportation Conformity Requirements
in the MAG CO Redesignation Request and Maintenance Plan
VIII. GRIC Boundary Change Under CAA Section 107
A. Background
B. EPA Review of the Community's Request
C. Redesignation of the Northern Portion of the Reservation
IX. Proposed Action
X. Statutory and Executive Order Reviews
I. Summary of Today's Proposed Action
We are proposing to approve the MAG serious area SIP for attainment
of the CO air quality standard in the metropolitan Phoenix (Maricopa
County), Arizona area. This action is based on our determination that
this SIP complies with the CAA's requirements for attaining the CO
standard in serious CO nonattainment areas such as the metropolitan
Phoenix area.
We are also proposing to approve the MAG CO redesignation request
and maintenance plan for the Maricopa County CO nonattainment area as
meeting CAA requirements for redesignation requests and maintenance plans.
We are also proposing to make a boundary correction under Section
107 of the CAA for the Gila River Indian Community.
II. The Serious Area CO SIP for the Phoenix Area
We are proposing to approve the Revised MAG 1999 Serious Area
Carbon Monoxide Plan for the Maricopa County Nonattainment Area, March
2001. The plan was developed by MAG, the lead air quality planning
agency in Maricopa County. The Arizona Department of Environmental
Quality (ADEQ) submitted this plan as a revision to the Arizona SIP on
March 30, 2001 and EPA received it on April 2, 2001. We refer to this
plan in this document as the Revised CO Plan or the Revised 1999 CO
plan, or variations of these.
As submitted, the Revised 1999 CO plan consists of the main plan
document, three volumes of technical appendices and three volumes of
commitments from various agencies to implement CO controls. The plan
contains 1993 and 1996 emission inventories, a reasonably available
control measures (RACM) analysis, vehicle miles traveled (VMT) tracking
procedures, annual VMT projections through 2000, and contingency
measures. It uses the Urban Airshed Model (UAM) and CAL3QHC microscale
model to model air quality in 1994 as a base year and in 2000 as the
attainment year and demonstrates both reasonable further progress
towards and attainment of the CO standard by December 31, 2000.
The MAG plan shows that the principal sources contributing to CO
exceedances are gasoline on-road motor vehicles, gasoline non-road
engines, and woodburning. MAG plan, p. ES-1.
In earlier actions, we have already approved revisions to Arizona's
Cleaner Burning Gasoline (CBG) program and to Arizona's Vehicle
Emissions Inspection (VEI) Program as well as the Maricopa County
Woodburning curtailment program. 69 FR 10161 (March 4, 2004), 68 FR
2912 (January 22, 2003), 64 FR 60678 (November 8, 1999) and 67 FR 48718
(July 25, 2002). The revisions to these programs are the principal
controls relied on in the revised MAG CO plan to demonstrate
attainment. We have also previously approved the commitments by the
Phoenix area cities and towns to adopt and/or implement CO control
measures. We approved these commitments as part of the serious area PM-
10 plan approval on July 25, 2002 at 67 FR 48718. See 40 CFR
52.120(c)(100). Many of these commitments by Phoenix area cites and
towns commit to measures which address CO as well as PM-10 emissions
reductions.
For a complete history of the CO planning efforts in the Phoenix
area as well as the history of the development of the CO plan, please
see Section 1 in EPA's TSD.
III. The CAA's Requirements for Serious CO Nonattainment Area Plans
The Phoenix area was reclassified from moderate to serious for CO
on July 29, 1996 (61 FR 39343) because the area had not attained the CO
standard by the moderate area deadline of December 31, 1995. As a
result of this reclassification, Arizona was required to submit by
February 28, 1998, a revision to its SIP for the Phoenix area that met
the CAA requirements for serious CO nonattainment areas found in
section 187(a) and section 172(c)(1). This SIP revision needed to show
attainment of the CO standard by December 31, 2000. In summary, these
requirements are:
(a) Implementation of all reasonably available control measures
(RACM), including reasonably available control technology (RACT) for
stationary sources (CAA section 172(c)(1));
(b) Provisions for attainment, and a demonstration that the plan
will provide for attainment by no later than December 31, 2000 (CAA
section 187(b)(7));
(c) Provisions for such specific annual emission reductions as are
necessary to attain by December 31, 2000 (CAA sections 172(c)(2) and
187(b)(7));
[[Page 60330]]
(d) Forecasts of vehicle miles traveled (VMT) in the nonattainment
area for each year before the year in which the plan projects
attainment (CAA section 187(a)(2)(A));
(e) An enhanced vehicle inspection and maintenance program (CAA
section 187(a)(6));
(f) An oxygenated gasoline program (CAA sections 187(b)(3) and 211(m));
(g) Transportation control strategies and measures to offset any
growth in emissions from vehicle miles traveled or numbers of vehicle
trips (CAA section 187(b)(2));
(h) Contingency measures that will be implemented if the area fails
to attain by its applicable deadline, fails to make reasonable further
progress, or vehicle mile traveled estimates exceed those forecasted
(CAA sections 172(c)(9) and 187(a)(3));
(i) A comprehensive, accurate, current inventory of actual
emissions from all sources of CO (CAA sections 172(c)(3) and
187(a)(5)); and
(j) A transportation conformity budget (CAA section 176(c)).
Serious area CO SIPs must also meet the general requirements
applicable to all SIPs including reasonable notice and public hearing
under section 110(a), necessary assurances that the implementing
agencies have adequate personnel, funding and authority under section
110(a)(2)(E)(i) and 40 CFR 51.280; and the description of enforcement
methods as required by 40 CFR 51.111.\1\
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\1\ Serious area SIPs must also include new source review (NSR)
permitting rules that meet the requirements of sections 172(c)(5)
and 173. In practice, NSR rules are submitted and reviewed
separately from the rest of the serious area CO plan. Maricopa
County has submitted a complete NSR rule.
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We have issued a General Preamble \2\ describing our preliminary
views on how the Agency intends to review SIPs submitted to meet the
Clean Air Act's requirements for CO SIPs. We have also issued other
guidance documents related to CO SIPs or provisions of those SIPs,
including the ``Technical Support Document to Aid States with the
Development of Carbon Monoxide State Implementation Plans,'' Office of
Air Quality Planning and Standards (OAQPS), U.S. EPA, EPA-452/R-92-003
(July 1992).
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\2\ ``State Implementation Plans; General Preamble for the
Implementation of Title I of the Clean Air Act Amendments of 1990,''
57 FR 13498 (April 16, 1992) and 57 FR 18070 (April 28, 1992).
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On July 8, 1999, ADEQ submitted the MAG 1999 Serious Area CO Plan
(``1999 CO Plan'') to EPA. We found the submittal complete on September
9, 1999. The 1999 CO Plan was revised because the Arizona legislature
passed House Bill (HB) 2104 during the 2000 regular session, which
repealed the remote sensing portion of the VEI program. We indicated
that the 1999 CO Plan would need to be revised to reflect the change in
the VEI program. MAG conducted new air quality modeling and revised the
1999 CO Plan. On April 2, 2001, ADEQ submitted the Revised 1999 MAG
Serious Area CO Plan (``Revised 1999 CO Plan'') to EPA.
IV. The Revised 1999 CO Plan's Compliance With the CAA's Requirements
for Serious CO Nonattainment Area Plans
The following sections present a summary of our evaluation of the
Revised 1999 CO Plan's compliance with the applicable CAA requirements
for serious area SIPs for CO. Our complete evaluation is found in the
EPA TSD for this action.\3\ A copy of the EPA TSD can be obtained by
calling or writing the contact person listed above.
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\3\ See ``Technical Support Document for the Notice of Proposed
Rulemaking on the Carbon Monoxide Serious Area Planning Requirements
for the Maricopa County, Arizona Nonattainment Area,'' June 2004,
Air Division, USEPA Region 9.
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A. Completeness of the SIP Submittals and Adequacy of the Motor Vehicle
Emissions Budget
The first step we take after receiving a SIP submittal is to
determine if it is complete. CAA section 110(k)(1)(B) requires that we
review all SIPs and SIP revisions for completeness within 60 days of
receipt. The completeness review allows us to quickly determine if the
submittal includes all the necessary items and information we need to
take action on it. We make completeness determinations using criteria
we have established in 40 CFR part 51, Appendix V.
We found ADEQ's March 30, 2001 submittal (received on April 2,
2001) of the Revised 1999 CO Plan complete and notified the State on
October 9, 2001. See Letter, Jack P. Broadbent, EPA, to Jacqueline
Schafer, ADEQ. Our completeness determination is documented in Section
2 of the EPA TSD.
Section 176(c) of the Clean Air Act requires that federally funded
or approved transportation plans, programs, and projects in
nonattainment areas ``conform'' to the area's air quality SIPs.
Conformity ensures that federal transportation actions do not worsen an
area's air quality or interfere with its meeting the air quality
standards. We have issued a conformity rule that establishes the
criteria and procedures for determining whether or not transportation
plans, programs, and projects conform. See 40 CFR part 93, subpart A.
One of the primary tests for conformity is to show that
transportation plans and improvement programs will not cause motor
vehicle emissions to increase above levels needed to make progress
toward and to meet the air quality standards. The motor vehicle
emissions levels needed to make progress toward and to meet the air
quality standards are set forth in the area's air quality SIPs as an
``emissions budget for motor vehicles.'' The conformity rule's
requirements and EPA's policy on emissions budgets are found in the
preamble to the November 24, 1993 transportation conformity rule (58 FR
62193-96), in the sections of the rule referenced above, and in
subsequent revisions to the conformity rule (69 FR 40004, July 1, 2004).
Before an emissions budget in a submitted SIP revision may be used
in a conformity determination, we must first determine that it is
adequate. The criteria by which we determine adequacy of submitted
emission budgets are outlined in conformity rules in 40 CFR 93.118(e)(4).
The Revised 1999 CO Plan, submitted on March 30, 2001, established
a revised mobile source emissions budget of 412.2 metric tons per day
(mtpd). Revised 1999 CO Plan, p. 9-11. We found this budget adequate
for transportation conformity purposes on September 28, 2001. See
letter, Jack Broadbent, EPA Region 9 to Jacqueline Schafer, ADEQ, and
James Bourey, MAG. Our finding was published in the Federal Register on
October 17, 2001 (66 FR 52761) and became effective 15 days later on
November 1, 2001.
B. Emissions Inventory
CAA section 172(c)(3) requires all serious area CO SIP submittals
to include a comprehensive, accurate, and current inventory of actual
emissions from all sources in the base year inventory to forecast and
backcast other years. Maricopa County chose the year 1993 as the base
year for its serious area CO SIP since it was the most complete
emission inventory available at the time MAG started its modeling for
the 1999 CO Plan. MAG developed a 1994 modeling inventory based on the
1993 annual CO inventory. The base year and forecasted 1996 emission
inventories described all the sources of CO for the nonattainment area.
In 1998, Maricopa County completed the draft 1996 CO emissions
inventory. In response to public comments on the Draft MAG 1998 CO
Plan, a comparison of the 1993 and 1996 periodic inventories and an
evaluation of the 1994 base case
[[Page 60331]]
modeling inventory were conducted. MAG subsequently revised the nonroad
equipment modeling assumptions to be more consistent with the 1996 CO
inventory. The comparison concluded that the 1994 modeling inventory
contained the most recent and valid assumptions.
The emission inventory is divided into source categories and
subcategories. The main source categories are stationary sources (both
point and aggregated), area sources, on-road mobile sources, and off-
road mobile sources. Source categories provide a convenient way to
organize the emission inventory and to determine the significance of
particular sources. Seasonal inventories are provided to account for
the differences in emissions occurring during the times of year when
Maricopa County used to exceed the 8-hour CO standard. We are approving
the emission inventories of the Maricopa County CO nonattainment area
as meeting the requirements of section 172(c)(3) of the CAA.
On September 18, 1996, we proposed approval of the 1990 base year
CO emissions inventory for Maricopa County (see 61 FR 49087). When we
finalize today's proposed action, we will also finalize approval of the
1990 base year emissions inventory proposed on September 18, 1996.
C. Adequate Monitoring Network
The CAA requires states to establish and operate air monitoring
networks to compile data on ambient air quality for all criteria
pollutants. Section 110(a)(2)(B)(i). Our regulations in 40 CFR part 58
establish specific regulatory requirements for operating air quality
surveillance networks to measure ambient concentrations of CO,
including measurement method requirements, network design, quality
assurance procedures, and in the case of large urban areas, the minimum
number of monitoring sites designated as National Air Monitoring
Stations (NAMS).
Ambient networks, however, do not need to meet all our regulations
to be found adequate to support air quality modeling. A good spatial
distribution of sites, correct siting, and quality-assured and quality-
controlled data are the most important factors for air quality
modeling. Nonattainment area plans developed under title I, part D of
the Clean Air Act are not generally required to address how the area's
air quality network meets our monitoring regulations. These plans are
submitted too infrequently to serve as the vehicle for assuring that
monitoring networks remain current.
For this action, we are discussing the adequacy of the Phoenix area
monitoring network solely to support our finding that the Revised 1999
CO Plan appropriately evaluates the CO problem in the Phoenix area.
Reliable ambient data is necessary to validate the base year air
quality modeling which in turn is necessary to assure a sound
attainment demonstration.
There are fourteen CO monitoring sites in the metropolitan Phoenix
area; thirteen are operated by the Maricopa County Environmental
Services Department and one by ADEQ. Figure 4-3 on page 4-7 in the
Revised 1999 CO Plan lists the names of the sites and their locations
in the Phoenix area. These sites all use EPA reference methods, are
sited according to our regulations, meet the applicable monitoring
objections in our regulations, and are operated according to our
regulations. We therefore find that the monitoring network operated by
the MCESD and ADEQ is adequate to support the technical evaluation of
CO nonattainment problem in the Revised 1999 CO Plan. See also EPA TSD
section ``Ambient Air Quality Surveillance''.
D. Implementation of Reasonably Available Control Measures
CAA section 172(c)(1) requires that nonattainment plans provide for
the implementation of all reasonably available control measures (RACM)
as expeditiously as practicable. We interpret this requirement to
require a state to consider available measures for controlling CO and
to adopt and implement those measures that are reasonably available for
implementation in the area as components of the area's attainment
demonstration. In general, we do not consider a measure to be
reasonably available if it is economically or technologically
infeasible for the area, would not advance attainment of the relevant
standard in the area, or is absurd, unenforceable or impracticable.
General Preamble at 13560.
As described above, the principal sources of CO in the metropolitan
Phoenix area are (in order of importance) on-road motor vehicles, non-
road engines, and residential woodburning, which collectively account
for 99 percent of the 1996 seasonal inventory. Revised 1999 CO Plan,
Figure ES-2. The Revised 1999 CO Plan evaluates a broad range of
controls for each of these sources categories. See Revised 1999 CO
Plan, Chapter 6.
For on-road motor vehicles, adopted controls include the State's
enhanced vehicle emission inspection program, cleaner burning gasoline
program including a 3.5 percent oxygen content and 9 psi volatility
standard, requirements and incentives for the use of alternative fueled
vehicles, and numerous transportation control measures (TCMs). See
Revised 1999 CO Plan, Chapter 8. We find that these measures along with
the federal motor vehicle tailpipe standards provide a comprehensive
control strategy for attaining the CO standard and provide for the
implementation of RACM in the on-road motor vehicle category as
required by CAA section 172(c)(1). See EPA TSD section ``Implementation
of RACM for On-Road Motor Vehicle Controls--Technology.''
CAA section 187(b)(2) requires a State with a serious CO
nonattainment area to consider the TCMs in section 108(f) and choose to
implement such measures as necessary to demonstrate attainment. The
Phoenix area has a long history of adopting TCMs, including those in
section 108(f), for controlling CO. The Revised 1999 CO Plan implements
the section 108(f) TCMs and includes additional measures in support of
the attainment demonstration. See Revised 1999 CO Plan, Table 7-2 and
Chapter 8. We therefore find that the Revised 1999 CO Plan complies
with CAA section 187(b)(2) and 172(c)(1). See EPA TSD section
``Implementation of RACM for On-Road Motor Vehicle Controls--
Transportation Control Measures.''
The nonroad (mobile) engine category covers a diverse collection of
engines, equipment and vehicles fueled by gasoline, diesel, and other
fuels and includes outdoor power equipment, recreational equipment,
farm equipment, construction equipment, lawn and garden equipment,
aircraft, locomotives, and marine vessels. Although diesel engines
dominate the market for nonroad engines, ninety percent of CO emissions
from the nonroad category come from gasoline-powered nonroad engines.
Starting in the mid-1990s, EPA promulgated national emission
standards for a broad range of nonroad engines. See EPA TSD section
``Implementation of RACM for Nonroad Engines.'' Nonroad engines sold in
Arizona are required to comply with these national standards which
constitutes a RACM-level program for controlling emissions from nonroad
engines.
In addition, Arizona's CBG program regulates gasoline used in
nonroad engines. The Revised 1999 CO Plan also includes a number of
other nonroad engine measures. See EPA TSD section ``Implementation of
RACM for Nonroad Engines.'' With the national emission standards and
the additional State
[[Page 60332]]
measures, we find that the Revised 1999 CO Plan provides for the
implementation of RACM for nonroad engines.
The residential wood combustion (RWC) category includes emissions
from the burning of solid fuel in residential fireplaces and woodstoves
as well as barbecues and fire pits. Measures to control CO from
residential woodburning include a public education program, woodburning
curtailment programs, retrofit requirements and restrictions or bans on
the installation of woodburning stoves and/or fireplaces.
The Maricopa County Environmental Services Department's Rule 318,
Approval of Residential Woodburning Devices, establishes standards for
the approval of residential woodburning devices that can be used during
restricted-burn periods. Maricopa County's Residential Woodburning
Restriction Ordinance provides that restricted-burn periods are
declared by the Control Officer when the Control Officer determines
that air pollution levels could exceed the CO standard and/or the PM
standard (150 [mu]g/m3). We approved Rule 318 and an earlier
version of the ordinance (revised April 21, 1999) as providing for the
implementation of RACM. See 64 FR 60678 (November 8, 1999).
The Revised 1999 CO Plan includes a number of other woodburning
measures. We find that these measures along with Maricopa County's
woodburning rules provide for the implementation of RACM for
residential wood combustion. See EPA TSD section ``Implementation of
RACM for Residential Wood Combustion.''
E. Demonstration of Attainment
CAA section 187(a)(7) requires serious area plans to provide for
attainment of the CO NAAQS by December 31, 2000 and to contain a
demonstration that the plan will provide for attainment. Under our
guidance, an attainment demonstration may be made using EPA-approved
air quality models and must include the control strategy. General
Preamble at 13533.
There are two parts to reviewing a modeled attainment
demonstration: (1) Evaluating the technical adequacy of the modeling
itself, and (2) evaluating the control measures that are relied on to
demonstrate attainment. We discuss each part below.
1. Air Quality Modeling
MAG used the Urban Airshed Model (UAM), the standard model for
carbon monoxide attainment demonstrations, consistent with EPA
guidance, to predict the effect of control measures in its attainment
demonstration. UAM requires meteorological inputs, such as temperature
and wind speeds, as well as initial and boundary conditions for CO
concentrations, and CO emissions. These must be allocated in time and
space; every hour of the simulation and every one square mile grid cell
requires these inputs. Diagnostic testing is performed to ensure the
model is performing well for a chosen CO episode, which in this case
was December 17, 1994, which at 10.5 ppm had the highest CO peak and
most widespread high CO readings observed during 1994. Once the model
predicts observed CO concentrations for this chosen CO episode
adequately, post-control measure emissions are input to the model to
project future air quality. Separate predictions are also made ``hot
spots'', intersections with high traffic and congested conditions,
using the CAL3QHC model. This ``microscale'' component is then combined
with the UAM results. The total prediction is then compared to the
level of the NAAQS, 9.0 ppm, to demonstrate attainment.
As detailed in the TSD, MAG followed accepted procedures in
developing the model inputs, performing diagnostic testing of the
results, and showing adequate model performance. Model performance
statistics met EPA-recommended goals. The observed spatial and temporal
patterns of CO were replicated fairly well by the model. While there
were some discrepancies, these were attributed to lack of observations
at some locations, and by slight shifts in wind patterns. That is, if
the wind field input to the model had been slightly different, some
high CO locations in the model predictions would have better matched
the monitor locations. But since the magnitude, spatial extent, and
timing of elevated CO concentrations is very similar between the model
and observations, EPA determines the model performed adequately for
attainment demonstration purposes.
Overall, the modeling done by MAG meets EPA guidelines and performs
well enough to be relied upon as the basis for the CO attainment
demonstration. EPA therefore proposes to approve the CO attainment
demonstration.
2. Control Measures Relied on for Attainment
For demonstrating attainment of the CO standard, the Revised 1999
CO Plan relies primarily on reductions from the VEI and CBG programs as
well as much smaller reductions from three other measures, traffic
synchronization, intelligent transportation systems, and deferring
emissions associated with government activities. See Revised 1999 CO
Plan, Figure 9-1. We have previously approved all of these measures.
See 68 FR 2912, 69 FR 10161, 64 FR 60678, and 67 FR 48718.
As part of these approvals, we have evaluated each of these
measures to ensure that they meet our SIP enforceability criteria.
These criteria ensure that the measure's compliance requirements--
applicability, performance standards, compliance schedule, and
monitoring methods--are clear.
We have also evaluated the CO emissions reductions credited to each
measure in the attainment demonstration to ensure they are reasonable.
We found that the emission reduction estimates for each source category
are consistent with research on the applicable control methods and are
appropriately applied in the attainment demonstrations. Finally, we
have determined that the measures relied on for attainment are being
expeditiously implemented. See EPA TSD, section ``Attainment
Demonstration''.
F. Reasonable Further Progress
CAA section 172(c)(2) requires nonattainment plans to provide for
reasonable further progress (RFP), which is defined in section 171(1)
as ``such annual incremental reductions in emissions of the relevant
air pollutant as are required by this part [part D of title I] or may
reasonably be required by the Administrator for the purpose of ensuring
attainment of the applicable national ambient air quality standard by
the applicable date.'' For serious CO nonattainment areas, CAA section
187(a)(7) also requires the plans to provide for such specific annual
emission reductions as are necessary to attain the standard by the
applicable attainment date.
We find that the Revised 1999 CO Plan provides for RFP and for such
specific annual emission reductions as are necessary to attain the
standard by the December 31, 2000 as required by the Act.\4\ The
Revised 1999 CO Plan includes an RFP demonstration for the years 1994,
1999, and 2000. 1994 is the base year, 1999 is the year before the two
largest measures in the Revised 1999 CO Plan (revisions to the VEI and
CBG programs) were implemented, and 2000 is the attainment year. Total
design day CO emissions drop from 687 mtpd
[[Page 60333]]
in 1994 to 686 mtpd in 1999 to 640 mtpd in 2000. Revised 1999 CO Plan,
Figure 9-4. Total CO emissions drop very little from 1994 to 1999
primarily because a large increase in emissions from non-road engines
offsets the decreases in on-road emissions. See MAG TSD, Table II-4.
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\4\ This finding is further supported by our finding that the
area attained the CO standard by December 31, 2000. (68 FR 55008,
effective November 21, 2003).
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G. VMT Tracking and Reporting
CAA section 187(a)(2)(A) requires each State with a serious CO
nonattainment area to forecast VMT in the nonattainment area for each
year before the attainment year. These forecasts must be developed
following guidance issued by EPA in consultation with the U.S.
Department of Transportation. This section also requires the plan to
provide for annual updates of the forecasts to be submitted along with
a report containing estimates of actual VMT for the year. We provided
detailed guidance to States regarding the VMT tracking and reporting
requirement in ``Section 187 VMT Forecasting and Tracking Guidance,''
USEPA, January 1992.
We find that the Revised 1999 CO Plan fully complies with CAA
section 187(a)(2)(A) and our guidance implementing that section.
Specifically, the VMT forecasts in the Revised 1999 CO Plan were
developed consistent with applicable EPA guidance including (1)
forecasting VMT using a validated network-based travel demand model;
(2) clearly identifying a VMT tracking area; (3) estimating actual VMT
on Highway Performance Monitoring System (HPMS) traffic counts adjusted
in a reasonable manner to cover the entire VMT tracking area; and (4)
committing to submitting annual reports meeting EPA requirements.
MAG has submitted VMT tracking reports for the years 1999, 2000,
and 2001. These reports follow EPA guidance regarding content and
procedures for determining actual VMT. All three reports show that VMT
levels in the metropolitan Phoenix CO nonattainment area remain within
the levels projected in the Revised 1999 CO Plan. See ``1999 Vehicle
Miles Travel Forecasting and Tracking Report,'' MAG, September 22, 1999
(submitted September 23, 1999); ``2000 Vehicle Miles Travel Forecasting
and Tracking Report,'' MAG, September 11, 2000 (submitted September 21,
2000); and ``2001 Vehicle Miles Travel Forecasting and Tracking
Report,'' MAG, October 23, 2001 (submitted November 14, 2001).
H. Transportation Control Measures To Offset Growth in Emissions
CAA section 187(b)(2) requires serious area CO plans to identify
and adopt ``specific and enforceable transportation control strategies
and TCMs to offset any growth in emissions from growth in VMT and
numbers of trips'' and to achieve reductions in mobile source emissions
as necessary in conjunction with other measures to comply with the
applicable periodic emission reduction and attainment requirements.
We interpret this provision to require that sufficient measures be
adopted so that projected motor vehicle CO emissions will never be
higher during the CO season in one year than during the CO season in
the year before. Where growth in VMT and trips would otherwise cause a
motor vehicle emissions upturn, this upturn must be prevented. General
Preamble at 13521.
The Revised 1999 CO Plan provides sufficient information for us to
conclude that on-road mobile source emissions will decrease from the
base year of 1994 until the attainment year of 2000 and this decrease
will occur even before we take into account the additional controls in
the Revised 1999 CO Plan. Moreover, the Revised 1999 CO Plan provides
for expeditious attainment of the CO standard. Therefore, we propose to
find that the Revised 1999 CO Plan meets CAA section 187(b)(2).
I. Contingency Measures
CAA section 172(c)(9) requires that nonattainment area SIPs provide
for the implementation of specific measures to be undertaken if the
area fails to make RFP or attain by its attainment deadline. CAA
section 187(a)(7) requires that serious CO nonattainment area plans
also contain contingency measures that would be implemented if the area
exceeds its vehicle mile traveled (VMT) projections. Both sections
require that these contingency measures are to take effect without
further action by the State or the Administrator. The Act does not
specify how many contingency measures are necessary nor does it specify
the magnitude of the emission reductions (or VMT reductions) they must
produce. In policy and in previous rulemaking we have suggested that
one appropriate choice of contingency measures would be to provide for
the implementation of sufficient VMT reductions or emissions reductions
to counteract the effect of one year's growth in VMT in order to ensure
continued progress while the plan was being revised to correct any
deficiencies that resulted in a failure to attain, make RFP, or keep
within VMT forecasts. General Preamble at 13532.
Under applicable Agency policy, states may use already adopted and
implemented measures as contingency measures, provided that those
measures' emission reductions are not needed to demonstrate expeditious
attainment and/or RFP and are not included in either the attainment or
RFP demonstrations. This approach effectively allows for the early
implementation of contingency measures.\5\
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\5\ See memorandum, G. T. Helms, Chief, Ozone/Carbon Monoxide
Programs Brand, OAQPS to Air Branch Chiefs, Regions I-X, ``Early
Implementation of Contingency Measures for Ozone and Carbon Monoxide
(CO) Nonattainment Areas,'' August 13, 1993 (``Helms memo'').
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The Revised 1999 CO Plan includes 9 contingency measures, all of
which have already been adopted and implemented. See Table Con-1 in the
EPA TSD. Collectively these measures result in approximately a 4.1
percent reduction in total CO emissions in 2001 and provide emission
reductions from each of the largest categories of CO emissions in the
Phoenix area: woodburning, gasoline on-road vehicles, and gasoline
nonroad engines. See Revised 1999 CO Plan, p. 9-12.
The annualized VMT growth in the Phoenix area from 2000 to 2005 is
projected to be 2.6 percent. On-road mobile source account for 67
percent of the 2000 base case (e.g., prior to control) CO inventory of
714.9 mtpd. Revised 1999 CO Plan, p. 8-12. Therefore, one year's growth
in VMT is equivalent to 0.67 x 2.6 percent or 1.7 percent (12.2 mptd)
of the 2000 base case inventory.
One of the eight contingency measures listed in the Revised 1999 CO
Plan is no longer applicable. Funding for the lawn mower reduction
program ended in FY 2001. Prior to 2001, the program resulted in the
retirement of a large number of gasoline-powered commercial and
residential lawn mowers and other hand-held gasoline-powered
equipment.\6\ However, because these lawnmowers have been presumably
replaced with cleaner units earlier then they would otherwise have been
replaced, the program will have continuing effects for several years
after 2000.
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\6\ In 1998/99, the program retired 1780 old, polluting gas
mowers and 563 other pieces of garden equipment. See ``Current
Status of Carbon Monoxide,'' Maricopa County Environmental Services
Department, (January 2000).
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The use of an adopted and implemented federal program, the national
LEV program, as a contingency measure is acceptable. The purpose of
contingency measures is to assure continued progress towards attainment
[[Page 60334]]
in an area while its SIP is being revised to correct for a failure to
attain or to make RFP or to deal with higher than expected VMT growth.
To the extent that federal programs provide for this continued progress
and the State has not otherwise relied on the program to demonstrate
attainment or RFP, the State may rely on that measure.\7\
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\7\ However, if the federal program is delayed or does not
generate the expected emission reductions, the State would have to
revise its contingency measures to assure adequate emission
reductions or face a finding of SIP inadequacy.
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We have approved the other seven contingency measures into the
Arizona SIP in earlier rulemakings. See 67 FR 48718 (July 25, 2002) and
68 FR 2912 (January 22, 2003).
Because the contingency measures collectively provide for emission
reductions consistent with EPA policy and meet the statutory
requirement that they ``take effect without further action by the State
or the Administrator,'' we propose to find that the Revised 1999 CO
Plan meets the CAA sections 172(c)(9) and 187(a)(7) requirement for
contingency measures. We also propose to find that the emissions
reductions resulting from these contingency measures are not already
accounted for in the Phoenix CO nonattainment area's RFP or attainment
demonstrations.
J. Enhanced I/M Program
CAA section 187(b)(6) requires that all serious CO nonattainment
areas implement an enhanced I/M program which complies with EPA
guidance. We issued our initial rule containing the requirements for
enhanced I/M programs in 1992 and have amended those rules several
times since. For more information on the requirements for enhanced I/M
programs, see 60 FR 22518 (May 8, 1995) (initial approval of Arizona's
enhanced and basic I/M program) and 67 FR 52433 (August 12, 2002)
(proposed approval of revisions to Arizona's enhanced and basic I/M
program).
Arizona first submitted the legislation and regulations for the
Maricopa County enhanced vehicle emission inspection program in 1994 as
part of its moderate area plans for CO and ozone. Subsequently, Arizona
made a number of modifications to its program including revising the
testing protocol, requiring on-board diagnostic system testing,
expanding the exemption to the latest five model years, changing the
waiver provisions, and removing the remote sensing element of the
program. The State resubmitted the program for approval in 2001. See
2001 I/M submittal.
In a separate action, we approved Arizona's vehicle emission
inspection program for the Phoenix area as meeting the enhanced I/M
program requirements of CAA section 187(b)(6) and our regulations. See
68 FR 2912 (January 22, 2003).
K. Wintertime Oxygenated Gasoline Program
CAA section 211(m) requires states with CO nonattainment areas with
design values of 9.5 ppm or higher to implement a wintertime oxygenated
gasoline program requiring that gasoline contain not less than 2.7
percent oxygen by weight. All serious CO nonattainment areas, which by
definition have design values exceeding the 211(m) thresholds, must
include an oxygenated gasoline program in their SIPs. See also CAA
Sec. 187(b)(3). Under both 211(m) and 187(b)(3), the program is to
apply to all gasoline sold, supplied, offered for sale or supply,
dispensed, transported or introduced into commerce in the consolidated
metropolitan statistical area (CMSA) or, if no CMSA exists, the
metropolitan statistical area (MSA).
1. History of State Program
Arizona first adopted a wintertime oxygenated gasoline program in
1988, before sections 187(b) and 211(m) were added to the Act as part
of the 1990 Clean Air Act Amendments. The original State wintertime
oxygenated gasoline program applied throughout Maricopa County and
established a fairly complicated scheme of shifting averages and
exemptions. In general, however, it required leaded gasoline to contain
between 2.4 and 3.7 percent oxygen by weight and unleaded gasoline to
contain between 1.9 and 3.7 percent oxygen by weight. The program
applied from September 30 through March 31 of each year. EPA approved
this program into the SIP finding the fuel control measure was not
preempted under CAA section 211(c)(4) and would, in any event, provide
necessary CO emission reductions. See 53 FR 30224 (Aug. 10, 1988).
The August 10, 1988 SIP approval, however, was vacated by the Ninth
Circuit Court of Appeals in Delaney v. EPA, 898 F.2d 687 (9th Cir.
1990). In 1991, in response to an order from the court, EPA disapproved
the Maricopa CO SIP including the State's wintertime oxygenated
gasoline requirement. 56 FR 5458 (Feb. 11, 1991). In its place, EPA
adopted a FIP with an oxygenated gasoline program. EPA modeled the FIP
program on the then newly adopted requirements in 211(m). It required
all gasoline sold in the Maricopa nonattainment area to contain a
minimum oxygen content of 2.7 percent by weight from October 1 to March
31 of each year. In the FIP notice, we noted that section 211(m) added
by the 1990 Clean Air Amendments would require Maricopa to adopt a
similar state requirement beginning in 1992. As a result, we
anticipated that the oxygenated gasoline requirement in the FIP would
only be in effect for one year.
Arizona adopted new oxygenated gasoline requirements on June 11,
1991 in Arizona House Bill 2181. On March 9, 1992, EPA approved
Arizona's revised wintertime oxygenated gasoline program into the SIP.
57 FR 8268. The revised program required that all gasoline in the
Maricopa nonattainment area contain no less than 2.7 percent oxygen by
weight from September 30 to March 31 of each year. In that approval,
EPA noted that the area covered by the program did not include the
entire MSA as required under section 211(m). Instead, the program
applied only to the Maricopa CO nonattainment area, which was then
defined as the MAG urban planning area. As a result, we found the State
program could be approved into the SIP as an equivalent substitution
for the FIP program but concluded that Arizona would need to modify the
program further by November 1, 1992 in order to meet all the
requirements of 211(m). Id.
Since our March 1992 approval, Arizona has made a number of changes
to the wintertime oxygenated gasoline program. In 1998, EPA approved
changes to the wintertime program as part of our approval of the
State's new Cleaner Burning Gasoline (CBG) program. 63 FR 6653 (Feb.
10, 1998). The wintertime program approved at that time continued to
require that gasoline supplied or sold in the Maricopa CO nonattainment
area \8\ contain a minimum 2.7 percent oxygen by weight, but changed
the control period to November 1 through March 31. In our approval, we
did not address compliance with 211(m), instead finding the revisions
necessary for attainment of the ozone and PM-10 NAAQS.
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\8\ The revised rules established new defined ``areas'' for
specifying the applicability of their requirements. The wintertime
oxygenated gasoline requirements apply to ``Area A'', which was
originally defined as the Maricopa County CO nonattainment area. As
explained below, Arizona has made a number of changes to the
definition of Area A to affect the applicability of the fuel requirements.
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On March 4, 2004, we approved into the SIP further revisions to the
State CBG program, including changes to the wintertime oxygenated gasoline
[[Page 60335]]
requirements. 69 FR 10161. The current SIP-approved wintertime program
requires all gasoline sold in Maricopa County and in parts of Pinal and
Yavapai Counties from November 1 to March 31 to contain a minimum of
3.5 percent oxygen by weight. Although Arizona's wintertime CBG program
adopted by the State on July 18, 1988 covered the MSA, as required by
211(m), subsequent changes to the covered area that have been approved
into the SIP (i.e., the inclusion of portions of Yavapai and Pinal
Counties) do not correspond to the entire MSA, which itself has been
subsequently modified by the Census Bureau.\9\
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\9\ All of Pinal County was added to the definition of the
Phoenix-Mesa MSA by the 1990 census.
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2. Compliance With 211(m)
The State's wintertime oxygenated gasoline program approved in the
SIP has provided significant CO emissions reductions in the Maricopa CO
nonattainment area and has helped the area attain the CO NAAQS, as
evidenced by the Phoenix area's lack of violations of the CO standard
since 1997, when the program was initiated. As a result, we are
proposing to find that further changes to the program to meet the
specific requirements of 211(m), including the requirement that the
program apply to the entire MSA, are not required under the Act.
Section 211(m)(6) provides:
Nothing in this subsection shall be interpreted as requiring an
oxygenated gasoline program in an area which is in attainment for
carbon monoxide, except that in a carbon monoxide nonattainment area
which is redesignated as attainment for carbon monoxide, the
requirements of this subsection shall remain in effect to the extent
such program is necessary to maintain such standard thereafter in
the area.
See also CAA section 187(b)(3)(B) (providing that a wintertime
oxygenated program is not required for an area if the State
demonstrates that the revision is not necessary for attainment and
maintenance of the CO NAAQS). We have interpreted this language to mean
that once EPA determines that a CO nonattainment area is actually
attaining the CO NAAQS and the area demonstrates it does not need a
program meeting 211(m), section 211(m) no longer requires submittal of
a SIP revision so long as the area continues to maintain the standard.
See, e.g., 60 FR 62741 (Dec. 7, 1995) (waiving 211(m) requirements for
portions of the Camden, New Jersey area).
Today's finding that the State need not submit a program complying
with section 211(m) does not mean the State can abandon its wintertime
oxygenated gasoline program. The program remains approved in the SIP.
Any revision to remove these requirements from the SP would be subject
to the requirements of section 110(l).
L. General SIP Requirements
CAA section 110(a)(2)(C) requires SIPs to include a program to
provide for the enforcement of SIP measures. Section 110(a)(2)(E)(i)
requires that SIPs provide necessary assurances that the State (or the
general purpose local government) will have adequate personnel, funding
and authority under State law to implement the submitted SIP. Finally,
section 110(a)(2)(E)(iii) requires SIPs to include necessary assurances
that where a State has relied on a local or regional government, agency
or instrumentality for the implementation of any plan provision, the
State has responsibility for ensuring adequate implementation of the
plan provision.
The principal control measures in the Revised 1999 CO Plan are
Arizona's VEI program, the wintertime CBG program, and Maricopa
County's woodburning restrictions program. We approved these programs
at 68 FR 2912 (January 12, 2003), 69 FR 10161 (March 4, 2004), 64 FR
60678, and 67 FR 48718 (July 25, 2002) respectively. As part of our
approval actions, we found that Arizona had adequate personnel, funding
and authority to implement these programs and had adequately provided
for the enforcement of these programs.
We have previously found that Arizona law includes the necessary
assurances that where a State has relied on a local or regional
government agency or instrumentality for the implementation of any plan
provision, the State has responsibility for ensuring adequate
implementation of the plan provision. 60 FR 18010, 18019 (April 10, 1995).
V. The CAA's Requirements for Serious CO Maintenance Plans and
Redesignation Requests
Under the Clean Air Act, we can change designations if acceptable
data are available and if certain other requirements are met. See CAA
Section 107(d)(3)(D). Section 107(d)(3)(E) of the CAA provides that the
Administrator may promulgate a redesignation of a nonattainment area to
attainment if the following five criteria are met:
(i) The Administrator determines that the area has attained the
national ambient air quality standard;
(ii) The Administrator has fully approved the applicable
implementation plan for the area under CAA section 110(k);
(iii) The Administrator determines that the improvement in air
quality is due to permanent and enforceable reductions in emissions
resulting from implementation of the applicable implementation plan and
the applicable Federal air pollutant control regulations and other
permanent and enforceable reductions;
(iv) The Administrator has fully approved a maintenance plan for
the area as meeting the requirements of CAA section 175A; and
(v) The State containing the area has met all requirements
applicable to the area under section 110 and part D of the CAA.
Before we can approve the redesignation request, we must determine
that all applicable SIP elements have been fully approved. Approval of
the applicable SIP elements may occur simultaneously with the final
approval of the redesignation request.
VI. The MAG CO Redesignation Request and Maintenance Plan's Compliance
With the CAA's Requirements for CO Redesignation Requests and
Maintenance Plans
We are proposing to approve the MAG Carbon Monoxide Redesignation
Request and Maintenance Plan for the Maricopa County Nonattainment
Area, May 2003 (``MAG CO Redesignation Request and Maintenance Plan'').
The MAG CO Redesignation Request and Maintenance Plan was developed by
the Maricopa Association of Governments (MAG), the lead air quality
planning agency in Maricopa County. The Arizona Department of
Environmental Quality (ADEQ) submitted this plan as a revision to the
Arizona SIP on June 16, 2003 and EPA received it on June 24, 2003. We
refer to this plan in this document as the MAG CO redesignation request
and maintenance plan, the MAG maintenance plan, or variations of these.
As submitted, the MAG CO Redesignation Request and Maintenance Plan
consists of the main plan document and one volume of technical
appendices. The MAG CO Redesignation Request and Maintenance Plan
contains 1994 and 1999 emission inventories and projected inventories
for 2006 and 2015, a modeling demonstration showing maintenance of the
CO standard through 2015, a list of committed control measures, mobile
source emissions budgets for 2006 and 2015, and contingency measures.
It uses UAM and the CAL3QHC microscale model to model air quality in
1994 as a base year and in 2006 as an interim year and 2015 as the
maintenance year
[[Page 60336]]
and demonstrates maintenance of the CO standard through 2015.
The MAG CO Redesignation Request and Maintenance Plan shows that
the principal sources contributing to past CO exceedances are gasoline
on-road motor vehicles, gasoline non-road engines, and woodburning. MAG
CO Redesignation Request and Maintenance Plan, p. ES-5.
In earlier actions, we have already approved revisions to Arizona's
CBG program and to Arizona's VEI program as well as the Maricopa County
Woodburning curtailment program. 69 FR 10161 (March 4, 2004), 68 FR
2912 (January 22, 2003), 64 FR 60678 (November 8, 1999) and 67 FR 48718
(July 25, 2002). The revisions to these programs are the principal
controls relied on in the MAG CO Redesignation Request and Maintenance
Plan to demonstrate attainment. We have also previously approved the
commitments by the Phoenix area cities and towns to adopt and/or
implement CO control measures. We approved these commitments as part of
the serious area PM-10 plan approval on July 25, 2002 at 67 FR 48718.
See 40 CFR 52.120(c)(100).
We have reviewed the MAG CO Redesignation Request and Maintenance
Plan and believe that proposing to approve the request is warranted,
consistent with the requirements of CAA section 107(d)(3)(E). The
following sections of this notice describe how the requirements of
section 107(d)(3)(E) are addressed by the MAG submittal.
A. General SIP Requirements
Section 110(k) of the CAA addresses our actions on submissions of
revisions to a SIP. The CAA requires States to observe certain
procedural requirements in developing SIP revisions for submittal to
us. Section 110(a)(2) of the CAA requires that each SIP revision be
adopted after reasonable notice and public hearing. This must occur
prior to the revision being submitted by a State to us.
MAG held a public hearing for the MAG CO Redesignation Request and
Maintenance Plan on May 5, 2003. The MAG Regional Council adopted the
MAG CO Redesignation Request and Maintenance Plan on May 28, 2003.
These SIP revisions were adopted and submitted by ADEQ to us on June
16, 2003. We received the submittal on June 24, 2003.
We have evaluated MAG's submittal and have determined that the
State met the requirements for reasonable notice and public hearing
under section 110(a)(2) of the CAA. The MAG CO Redesignation Request
and Maintenance Plan was deemed complete by operation of law six months
after the submittal date.
B. Attainment of the CO NAAQS
Section 107(d)(3)(E)(i) of the CAA states that for an area to be
redesignated to attainment, the Administrator must determine that the
area has attained the applicable NAAQS. As described in 40 CFR part
50.8, the national primary ambient air quality standard for carbon
monoxide is 9 parts per million (10 milligrams per cubic meter) for an
8-hour average concentration not to be exceeded more than once per
year. 40 CFR part 50.8 continues by stating that the levels of CO in
the ambient air shall be measured by a reference method based on 40 CFR
part 50, Appendix C and designated in accordance with 40 CFR part 53.
We consider an area to be in attainment if each of the CO ambient air
quality monitors in the area does not have more than one exceedance of
the CO standard over a one-year period. See 40 CFR part 50.8 and 40 CFR
part 50, Appendix C. If any monitor in the area's CO monitoring network
records more than one exceedance of the CO standard during a one-year
calendar period, then the area is in violation of the CO NAAQS.
In addition, our interpretation of the CAA and EPA national policy
has been that an area seeking redesignation to attainment must show
attainment of the CO NAAQS for at least a continuous two-year calendar
period. In addition, the area must also continue to show attainment
through the date that we promulgate the redesignation in the Federal
Register.
December 31, 2000 was the attainment date for the Maricopa County
serious CO nonattainment area. We published a finding of attainment of
the CO standard for the Maricopa County nonattainment area on September
22, 2003 (see 68 FR 55008). In our finding, we noted that not only did
Maricopa County have the required clean data for the two years
preceding the attainment date, but also that the Maricopa County
nonattainment area has been in attainment for the national standards
for CO since 1997. Further information on CO monitoring is presented in
Chapter 3, page 3-15 of the MAG CO Redesignation Request and
Maintenance Plan, and in our finding of attainment (see 68 FR 55008,
September 22, 2003).
Therefore, we believe the Maricopa County area has met the first
component for redesignation: demonstration of attainment of the CO
NAAQS. We note too that MAG has indicated in the MAG CO Redesignation
Request and Maintenance Plan that ADEQ and MCESD will continue to
operate an appropriate air quality monitoring network of National
Ambient Monitoring Stations (NAMS) and State and Local Air Monitoring
Stations (SLAMS) monitors in accordance with 40 CFR Part 58 to verify
the continued attainment of the CO standard.
C. Meeting Applicable Requirements of Section 110 and Part D
To be redesignated to attainment, section 107(d)(3)(E)(v) requires
that an area must meet all applicable requirements under section 110
and part D of the CAA. We interpret section 107(d)(3)(E)(v) to mean
that for a redesignation to be approved by us, the State must meet all
requirements that applied to the subject area prior to or at the time
of submission of a complete redesignation request.
1. CAA Section 110 Requirements
The Maricopa County nonattainment area was initially classified as
moderate for CO. MAG submitted the 1993 Carbon Monoxide Plan by
November 15, 1993 in order to meet the moderate area requirements. An
addendum to this plan was submitted in March 1994. On July 29, 1996,
the nonattainment area was reclassified to serious effective August 28,
1996 due to failure to attain the CO standard by December 31, 1995. The
new attainment date was December 31, 2000.
On July 8, 1999, ADEQ submitted the 1999 CO Plan to EPA. This
submittal contained an attainment demonstration for December 2000. The
submittal was found complete on September 9, 1999.
During the 2000 legislative session, the Arizona Legislature passed
House Bill (HB) 2104, which repealed the Random Onroad Testing
Requirements (Remote Sensing Program) from the Vehicle Emissions
Inspection (VEI) program. EPA indicated that the 1999 CO Plan would
have to be revised to reflect this legislative change. MAG conducted
new air quality modeling and documented the impact of the repeal of the
remote sensing program in the Revised 1999 CO Plan, dated March 2001.
On March 30, 2001, ADEQ submitted the Revised 1999 CO Plan to EPA.
We found the submittal complete on October 9, 2001. We have analyzed
the SIP elements in the Revised 1999 CO Plan that we are proposing for
approval as part our action today, and have determined that they comply
with the relevant requirements of section 110(a)(2).
On June 16, 2003, ADEQ submitted the MAG Carbon Monoxide
Redesignation Request and
[[Page 60337]]
Maintenance Plan for the Maricopa County Nonattainment Area, May 2003.
The submittal was deemed complete by operation of law six months after
receipt by EPA.
2. Part D Requirements
Before the Maricopa County serious CO nonattainment area may be
redesignated to attainment, the State must have fulfilled the
applicable requirements of part D. Under part D, an area's
classification indicates the requirements to which it was subject.
Subpart 1 of part D sets forth the basic nonattainment requirements
applicable to all nonattainment areas. Subpart 3 of part D contains
specific provisions for serious CO nonattainment areas.
The relevant subpart 1 requirements are contained in sections
172(c) and 176. Our General Preamble (see 57 FR 13529, 13533, April 16,
1992) provides EPA's interpretation of the CAA requirements for serious
CO nonattainment areas.
The General Preamble provides that the applicable requirements of
CAA section 172 are 172(c)(3) [emissions inventory], 172(c)(5) [the
section 110(a)(2) air quality monitoring requirements], and 172(c)(9)
[contingency measures]. It is also worth noting that we interpret the
requirements of sections 172(c)(2) [reasonable further progress--RFP]
and 172(c)(6) [other measures] as being irrelevant to a redesignation
request because they only have meaning for an area that is not
attaining the standard.\10\ Finally, the State has not sought to
exercise the options that would trigger sections 172(c)(4)
[identification of certain emissions increases] and 172(c)(8)
[equivalent techniques]. Thus, these provisions are also not relevant
to the redesignation request.
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\10\ See EPA's September 4, 1992 John Calcagni memorandum
entitled ``Procedures for Processing Requests to Redesignate Areas
to Attainment'', and the General Preamble, 57 FR at 13564, dated
April 16, 1992.
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Regarding the requirements of sections 172(c)(3) [emissions
inventory] and 172(c)(9) [contingency measures], please refer to our
discussion below of sections 187(a)(1) and 187(a)(3), which are
provisions of subpart 3 of part D of the CAA that address the same
requirements as sections 172(c)(3) and 172(c)(9).
For the section 172(c)(5) New Source Review (NSR) requirements, the
CAA requires all nonattainment areas to meet several requirements
regarding NSR, including provisions to ensure that increased emissions
will not result from any new or modified major stationary sources and a
general offset rule. We have determined that areas being redesignated
from nonattainment to attainment do not need to comply with the
requirement that an NSR program be approved prior to redesignation
provided that the area demonstrates maintenance of the standard without
part D nonattainment NSR in effect. The rationale for this decision is
described in a memorandum from Mary Nichols dated October 12, 1994
(``Part D New Source Review (part D NSR) Requirements for Areas
Requesting Redesignation to Attainment''). We have determined that the
maintenance demonstration for Maricopa County does not rely on
nonattainment NSR. Therefore, the State need not have a fully-approved
nonattainment NSR program prior to approval of the redesignation request.
Prevention of Significant Deterioration (PSD) is the replacement
for NSR, and part of the obligation under PSD is for a new source to
review increment consumption and maintenance of the air quality
standards. The PSD program requires stationary sources to undergo
preconstruction review before facilities are constructed or modified,
and to apply Best Available Control Technology (BACT). This program
will apply to any major source wishing to locate in the Maricopa County
area once the area is redesignated to attainment. Effective November
22, 1993, we delegated PSD authority to Maricopa County via a PSD
Delegation Agreement (59 FR 1730, January 12, 1994).
For the CAA section 172(c)(7) provisions [compliance with the CAA
section 110(a)(2) air quality monitoring requirements], our
interpretations are presented in the General Preamble (57 FR 13535). CO
nonattainment areas are to meet the applicable air quality monitoring
requirements of section 110(a)(2) of the CAA.
Information concerning CO monitoring in the Maricopa County
nonattainment area is included in the Monitoring Network Review (MNR)
prepared by MCESD and submitted to EPA. In Chapter 3, page 3-15 of the
MAG CO Redesignation Request and Maintenance Plan, MAG commits to the
continued operation of the existing NAMS and SLAMS CO monitors run by
ADEQ and MCESD, according to all applicable Federal regulations and
guidelines, even after the Maricopa County area is redesignated to
attainment for CO. Annual review of the NAMS/SLAMS air quality
surveillance system will be conducted in accordance with 40 CFR
58.20(d) to determine whether the system continues to meet the
monitoring objectives presented in Appendix D of 40 CFR Part 58.
Section 176 of the CAA contains requirements related to conformity.
Although EPA's regulations (see 40 CFR 51.396) require that states
adopt transportation conformity provisions in their SIPs for areas
designated nonattainment or subject to an EPA-approved maintenance
plan, we have decided that a transportation conformity SIP is not an
applicable requirement for purposes of evaluating a redesignation
request under section 107(d) of the CAA. This decision is reflected in
EPA's 1996 approval of the Boston carbon monoxide redesignation (See 61
FR 2918, January 30, 1996).
The relevant subpart 3 provisions were created when the CAA was
amended on November 15, 1990. The new CAA requirements for serious CO
areas, such as Maricopa County, required that the SIP be revised to
include a 1990 base year emissions inventory (CAA section 187(a)(1)),
vehicle miles traveled tracking (CAA section 187(a)(2)(A)), contingency
provisions (CAA section 187(a)(3)), corrections to existing motor
vehicle inspection and maintenance (I/M) programs (CAA section
187(a)(4)), periodic emissions inventories (CAA section 187(a)(5)),
enhanced motor vehicle I/M program (CAA section 187(a)(6)), a modeled
attainment demonstration with specific annual emissions reductions (CAA
section 187(a)(7)) and the implementation of an oxygenated fuels
program (CAA section 211(m)). How the State met these requirements and
our approvals are described earlier in this notice.
Regarding section 187(a)(1) of the CAA (base year emissions
inventory), the State submitted a SIP revision for a 1990 base year
inventory (annual and average daily emissions) as well as projected
1995 and 2005 inventories for the entire Maricopa County nonattainment
area on November 15, 1993 as part of the MAG 1993 Carbon Monoxide Plan
for the Maricopa County Area (``CO Plan''). On April 4, 1994, ADEQ
submitted updated and improved inventories as part of MAG's 1993 Carbon
Monoxide Plan for the Maricopa County Area Addendum (``Addendum'').\11\
These revised
[[Page 60338]]
inventories reflected adjustments to growth factors and the impact of
measures in Arizona House Bill 2001. Both submittals became complete by
operation of law under CAA section 110(k)(1)(B) on May 15, 1994 and
October 8, 1994, respectively.
---------------------------------------------------------------------------
\11\ On August 9, 1993, EPA had issued a SIP call under section
110(k)(5) of the CAA that required Arizona to submit a plan to EPA
that demonstrated attainment of the CO NAAQS in the Phoenix area by
December 31, 1995. As an area with a design value less than 12.7
ppm, the State would not otherwise have been required to submit an
attainment plan for the Phoenix area. See section 187(a). CAA
section 187(a)(1) requires the submittal of a comprehensive,
accurate, current inventory of actual emissions for all CO
nonattainment areas whether or not they have a separate requirement
to submit an attainment demonstration.
---------------------------------------------------------------------------
We proposed approval of the 1990 base year inventory on September
18, 1996 (61 FR 49087), and did not receive any comments on our
proposed action. We will finalize that proposed action in our final
rulemaking on today's proposed rule.
Regarding section 187(a)(5) of the CAA (periodic emissions
inventories), see Section IV.B. ``Emission Inventory'' of this Federal
Register notice for information on the 1993 and 1996 emissions
inventories for Maricopa County for CO. We are proposing to approve
these inventories in our action today.
D. Fully-Approved SIP Under Section 110(k) of the CAA
Section 107(d)(3)(E)(ii) of the CAA states that for an area to be
redesignated to attainment, it must be determined that the
Administrator has fully approved the applicable implementation plan for
the area under section 110(k).
As noted above, in today's action EPA is approving the SIP revision
demonstrating attainment for the Maricopa County serious CO
nonattainment area that was required by the CAA. The bump-up of the
Maricopa County CO nonattainment area from moderate to serious for CO
superceded the remaining moderate CO nonattainment area requirements
for the area. Thus, with a final rule to approve the Maricopa County
attainment demonstration, redesignation request, and maintenance plan,
we will have fully approved the Maricopa County CO element of the SIP
under section 110(k) of the CAA.
E. Improvement in Air Quality Due to Permanent and Enforceable Measures
Section 107(d)(3)(E)(iii) of the CAA provides that for an area to
be redesignated to attainment, the Administrator must determine that
the improvement in air quality is due to permanent and enforceable
reductions in emissions resulting from implementation of the applicable
implementation plan, implementation of applicable Federal air pollutant
control regulations, and other permanent and enforceable reductions.
As part of our action today, we are approving the Revised 1999 CO
Plan. This plan is primarily based on emissions reductions from the
wintertime oxygenated fuels program, the VEI program, traffic
synchronization, and intelligent transportation systems (ITS) measures.
These programs are further described in Chapter Five of the Revised
1999 CO Plan.
As described in Chapter Two, pages 2-11 to 2-15 of the MAG CO
Redesignation Request and Maintenance Plan, significant additional
emissions reductions were realized from Maricopa County's basic
inspection and maintenance program (applicable to vehicles 1966 and
newer), and beginning in 2000, the enhanced I/M program (applicable to
vehicles 1966 and newer, with an exemption for vehicles of the five
most recent model years).
Oxygenated fuels are gasolines that are blended with additives that
increase the level of oxygen in the fuel and consequently reduce CO
tailpipe emissions. Arizona's Cleaner Burning Gasoline (CBG) rule
contains the oxygenated fuels provisions for the Maricopa CO
nonattainment area. As approved by EPA on March 4, 2004 (see 69 FR
10161), Arizona's CBG program requires all Maricopa County-area gas
stations in Area A \12\ to sell fuels containing a 3.5 percent minimum
oxygen content (by weight) during the wintertime season, which runs
from November 2 to March 31 of each year.
---------------------------------------------------------------------------
\12\ Area A includes the urbanized portion of Maricopa County, a
small portion of southern Yavapai County, and the western portions
of Pinal County.
---------------------------------------------------------------------------
Maricopa County has also been implementing the requirements of its
clean burning fireplace ordinances. The Arizona legislature passed SB
1427 in 1998 which required cities, towns, and counties in Area A to
adopt, implement, and enforce an ordinance that complies with MAG's
clean burning fireplace standards by December 31, 1998. The ordinance
allows only the use of permanently-installed gas or electric log
inserts, fireplaces, woodstoves, or other appliances that are certified
by EPA, tested and listed by a nationally recognized testing agency to
meet federal performance standards, or determined by the Maricopa
County Control Officer to meet federal performance standards.
We have evaluated the various State and Federal control measures,
the original 1990 base year emission inventory, and the 1993, and 1996
periodic emissions inventories, and believe that the improvement in air
quality in the Maricopa County nonattainment area has resulted from
emissions reductions that are permanent and enforceable.
F. Fully-Approved Maintenance Plan Under Section 175A
Section 107(d)(3)(E)(iv) of the CAA provides that for an area to be
redesignated to attainment, the Administrator must have fully approved
a maintenance plan for the area meeting the requirements of section
175A of the CAA.
Section 175A of the CAA sets forth the elements of a maintenance
plan for areas seeking redesignation from nonattainment to attainment.
The maintenance plan must demonstrate continued attainment of the
applicable NAAQS for at least ten years after the Administrator
approves a redesignation to attainment. Eight years after the
promulgation of the 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 contingency measures, with a schedule for
adoption and implementation, that are adequate to assure prompt
correction of a violation. In addition, we issued further maintenance
plan interpretations in the ``General Preamble for the Implementation
of Title I of the Clean Air Act Amendments of 1990'' (57 FR 13498,
April 16, 1992), ``General Preamble for the Implementation of Title I
of the Clean Air Act Amendments of 1990: Supplemental'' (57 FR 18070,
April 28, 1992), and the EPA guidance memorandum entitled ``Procedures
for Processing Requests to Redesignate Areas to Attainment'' from John
Calcagni, Director, Air Quality Management Division, Office of Air
Quality Planning and Standards, to Regional Air Division Directors,
dated September 4, 1992 (hereafter referred to as the ``Calcagni
memo''). In this Federal Register action, EPA is proposing approval of
the maintenance plan for the Maricopa County CO nonattainment area
because we believe, as detailed below, that MAG's CO Redesignation
Request and Maintenance Plan submittal meets the requirements of
section 175A and is consistent with the documents referenced above. Our
analysis of the pertinent maintenance plan requirements, with reference
to MAG's CO Redesignation Request and Maintenance Plan, is provided below.
[[Page 60339]]
1. Emissions Inventories--Attainment Year and Projections
EPA's interpretation of the CAA section 175A maintenance plan
requirements are generally provided in the General Preamble (see 57 FR
13498, April 16, 1992) and the Calcagni memo referenced above. Under
our interpretations, areas seeking to redesignate to attainment for CO
may demonstrate future maintenance of the CO NAAQS either by showing
that future CO emissions will be equal to or less than the attainment
year emissions or by providing a modeling demonstration. However, under
the CAA, many areas (such as Maricopa County) were required to submit a
modeled attainment demonstration to show that reductions in emissions
would be sufficient to attain the applicable NAAQS. For these areas,
the maintenance demonstration is to be based on the same level of
modeling (see the ``Calcagni memo''). For the Maricopa County area,
this involved the use of EPA's Urban Airshed Model (UAM) in conjunction
with intersection hotspot modeling using the CAL3QHC model.
The MAG CO Redesignation Request and Maintenance Plan submitted by
ADEQ on June 16, 2003 included comprehensive emissions inventories of
CO emissions for the Maricopa County area. These inventories include
emissions from stationary point sources, area sources, non-road mobile
sources, and on-road mobile sources. MAG used the 1994 base year
inventory, from the Revised 1999 CO Plan received by EPA on April 2,
2001, and included an interim-year projection for 2006 along with the
final maintenance year of 2015. More detailed descriptions of the 1994
base year inventory from the Revised 1999 CO Plan, the 2006 projected
inventory, and the 2015 projected inventory are documented in the MAG
redesignation request and maintenance plan on page 3-8, and in the
State's TSD in Appendix A, Exhibit 1. The State's submittal contains
detailed emission inventory information that was prepared in accordance
with EPA guidance. Summary emissions figures from the 1994 base year,
the 2015 maintenance year and the interim projected year 2006 are
provided in Table 2 below.
Table 2.--Summary of CO Emissions in Tons per Day for Maricopa County
[For a Friday in December]
------------------------------------------------------------------------
1994 2006 2015
------------------------------------------------------------------------
Point sources.................... 2.5 21.9 32.2
Area sources..................... 21.0 29.7 36.2
Non-road mobile sources.......... 155.1 161.0 169.9
On-road mobile sources........... 869.6 699.7 662.9
--------------
Total *...................... 1048.2 912.3 901.2
------------------------------------------------------------------------
* Total may not equal 100% due to rounding.
We note that based on the information in Table 2, minor increases
are projected in years 2006 and 2015 for point sources and area
sources. The most significant reductions in the emissions inventory
come from the on-road mobile sources category. Since two of the MAG CO
Redesignation Request and Maintenance Plan's most significant measures
reduce on-road vehicle emissions, namely the cleaner burning gasoline
and vehicle emissions inspection programs, these projected emissions
reductions are reasonable. MAG's approach follows EPA guidance on
projected emissions, and we believe it is acceptable. Further
information on these projected inventories may also be found on page 3-
9 of the MAG CO Redesignation Request and Maintenance Plan and in
Appendix A, Exhibit 2, Section III-1 of the TSD.
2. Demonstration of Maintenance
The Calcagni memo states that where modeling was relied on to
demonstrate maintenance, the plan is to contain a summary of the air
quality concentrations expected to result from the application of the
control strategies. Also, the plan is to identify and describe the
dispersion model or other air quality model used to project ambient
concentrations.
For the MAG CO maintenance demonstration, MAG used UAM, the
standard model for 1-hour CO attainment demonstrations, consistent with
EPA guidance in Guideline for Regulatory Application of the Urban
Airshed Model for Areawide Carbon Monoxide (EPA-450/4-92-011a and b,
June 1992; hereafter ``Guideline''). Most of the inputs for the
modeling in the MAG CO Redesignation Request and Maintenance Plan were
identical to those in the Revised 1999 CO Plan. The main differences
were in mixing height and in the emissions inputs.
In the MAG CO Redesignation Request and Maintenance Plan, the UAM
model's maximum model height was increased slightly to accommodate
plume rise from growth in peaking power plants. This adjustment has a
relatively small effect on ground-level CO concentrations. Diagnostic
and sensitivity testing showed reasonable agreement with observations
after adjustment of the DIFFBREAK parameter, which in UAM is similar to
mixing height, the height above ground through which substantial mixing
occurs. Adjustment of minimum mixing heights is not ideal, but may be
unavoidable in the absence of specific measured data on mixing heights,
and has been accepted in other CO plans. Since CO is chemically inert,
it is not unreasonable to adjust the air volume available for CO
dilution, and thereby adjust CO concentration. This assumes diagnostic
testing for other model inputs has been done, as is the case here.
MAG's emission input development process used EPA's MOBILE6 model
to estimate on-road mobile source emission factors instead of MOBILE5,
per EPA guidance, and newer traffic data were used. Total estimated CO
emissions are substantially larger due to the changes in MOBILE model
and various traffic and other inputs. On-road emissions for the 1994
episode increased 73%; total emissions from all sources increased 52%.
However, modeled peak CO concentrations increased only slightly.
Several factors account for the apparent discrepancy between input
emissions and output model peak.
First, per EPA guidance, MOBILE6 was used to estimate on-road
emissions instead of the older MOBILE5a. One effect mitigating the
higher MAG CO maintenance plan emissions is that while the base case
(1994) on-road emissions are higher, they decline faster than in the
Revised 1999 CO Plan because of the enhanced effects of vehicle fleet
turnover incorporated in MOBILE6. So higher initial emissions in
[[Page 60340]]
the MAG CO Redesignation Request and Maintenance Plan are still
consistent with maintenance of the CO NAAQS later.
Second, the higher emissions in the MAG CO Redesignation Request
and Maintenance Plan do not translate into increased peak CO
concentrations. Mainly, the higher emissions in the MAG CO
Redesignation Request and Maintenance Plan are shifted in time, and
spread over a large area and volume; these mitigate the peak-increasing
effect of the increased emissions. Revised traffic counts show that
more of the emissions occur during the morning commute than during the
evening. As a result, the increased emissions occur earlier in the day,
farther from the peak in the 8-hour average, which occurs at 3 a.m. The
assumed spatial distribution of cold start emissions was also different
than in the Revised 1999 CO Plan. In the MAG CO Redesignation Request
and Maintenance Plan, cold start emissions were distributed to local
and arterial roads, but not to freeways; in the Revised 1999 CO Plan,
the emissions were distributed to all three facility types. The method
used in the MAG CO Redesignation Request and Maintenance Plan is more
realistic because cold start emissions occur relatively close to the
beginning of trips, when commuting cars are more likely to be on local
roads than on freeways. Another effect of this different spatial
allocation of emissions is that they are more dispersed. Because of
this and because of changes in various other model inputs, CO emissions
are more widely distributed in the MAG CO Redesignation Request and
Maintenance Plan.
Finally, as mentioned above, mixing height was increased to improve
model performance. This provided a greater volume for dilution of CO
emissions, and thus a lower ambient concentration.
A third factor in reconciling higher emissions with a relatively
unchanged peak concentration is that, the MAG CO Redesignation Request
and Maintenance Plan base case had less error and less negative bias
than the Revised 1999 CO Plan's, i.e., it underpredicted by a smaller
amount. The highest CO at any monitor in the MAG CO Redesignation
Request and Maintenance Plan was about 2% above the peak observation,
whereas in the Revised 1999 CO Plan, it was 10% or more below. In
summary, the increased emissions in the MAG CO Redesignation Request
and Maintenance Plan did in fact show up in the modeling results, but
the effect was not to increase the highest peak, but rather to increase
concentrations more generally, distributed in time and space.
For microscale modeling with CAL3QHC, the same intersections as in
the Revised 1999 CO Plan were used, 27th Ave./Grand/Thomas Rd. and 35th
Ave./Grand/Indian School Road. For the attainment demonstration, the
results of the CAL3QHC modeling were combined with that from UAM for
the cell containing the intersection, per EPA guidance. CAL3QHC
contributions to peak concentrations was generally lower than was
modeled for the Revised 1999 CO Plan. As discussed below, the decrease
is partly due to updated traffic data. A shift in peak traffic to the
morning occurred, which is further from the late-night CO peak. But the
main reason for decreased CAL3QHC predictions was the exclusion of cold
start emissions from idling emissions at intersections, in accordance
with EPA guidance. Most cold start emissions occur within a few minutes
of trip starts, so they have little affect on intersection emissions.
Despite generally higher UAM predictions in the MAG CO Redesignation
Request and Maintenance Plan, at the hotspot intersection locations,
overall hotspot predictions are slightly lower. Table 3 lists the
maximum combined dispersion modeling (UAM) and intersection modeling
(CAL3QHC) results for the maintenance demonstration modeling at the
West Indian School Road and Grand Avenue intersections (from MAG CO
Redesignation Request and Maintenance Plan, page 3-13).
Table 3.--Maximum Dispersion Modeling and Intersection Modeling Results
[In parts per million]
-----------------------------------------------------------------------
Intersection 2006 2015
UAM CAL3QHC Total UAM CAL3QHC Total
-----------------------------------------------------------------------
WISR\1\....... 7.17 1.08 8.25 6.23 1.81 8.04
Grand Ave..... 7.74 0.50 8.24 7.16 0.65 7.81
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\1\ West Indian School Road monitor.
The target CO concentration for the maintenance demonstration
modeling is 9.0 ppm. MAG therefore needed to show that combined UAM and
CAL3QHC concentrations remain below 9 ppm in 2006 and 2015, despite the
metropolitan area's growth. The MAG modeling shows a maximum CO
concentration of 8.92 ppm in 2006, and 8.06 ppm in 2015; these meet the
maintenance goal of 9.0 ppm.
For episode selection, modeling domain, wind fields, initial and
boundary conditions, sensitivity testing was essentially identical
between the two episodes (see the EPA TSD for the Revised 1999 CO
Plan). The tests done showed that the model was responding reasonably.
MAG's modeling also meets EPA's performance goals on peak level, peak
timing, and absolute error. Model predictions in the MAG CO
Redesignation Request and Maintenance Plan are closer to observations
than in the Revised 1999 CO Plan modeling.
Since the peak values and general spatial patterns match well and
EPA's model performance goals were met, overall the model appears to be
replicating the episode fairly well, and forms an acceptable basis for
a demonstration of maintenance. Overall, the modeling done by MAG for
the CO maintenance demonstration performed adequately and meets EPA
guidelines. EPA proposes to find the maintenance demonstration
approvable.
3. Monitoring Network and Verification of Continued Attainment
Continued attainment of the CO NAAQS in the Maricopa County area
depends, in part, on the State's efforts to track indicators throughout
the maintenance period. This requirement is met in two sections of the
MAG CO Redesignation Request and Maintenance Plan. On page 3-15 of the
MAG CO Redesignation Request and Maintenance Plan, MAG commits to
continue the operation of the CO monitors in the Maricopa County area
and to annually review this monitoring network and make changes as
appropriate.
Also, on page 3-15 of the MAG CO Redesignation Request and
Maintenance Plan, MAG commits to track mobile sources CO emissions
(which are the
[[Page 60341]]
largest component of the inventories) through the ongoing submittal of
periodic emissions inventories every three years in accordance with
section 187(a)(5) of the CAA. MCESD will coordinate and compile the
inventory with input and assistance from ADEQ, the Arizona Department
of Transportation, and MAG, as described in the 1992 Air Quality
Memorandum of Agreement. Changes in the inventory will be reviewed and
evaluated through the regional air quality planning process to
determine if additional measures should be considered.
Based on the information above, we are proposing approval of these
commitments as satisfying the relevant requirements of the CAA for
maintenance plans. We note that a final rulemaking approval will render
the State's commitments federally enforceable.
4. Contingency Plan
Section 175A(d) of the CAA requires that a maintenance plan include
contingency provisions. To meet this requirement, the State has
identified appropriate contingency measures along with a schedule for
the development and implementation of such measures.
As stated on page 3-15 of the MAG CO Redesignation Request and
Maintenance Plan, implementation of the contingency measures for the
Maricopa County area will be triggered by two verified readings
exceeding 9.0 ppm at one monitor during a single CO season (i.e.,
October 1 through March 31st). Since a violation of the NAAQS for 8-
hour CO occurs when the second highest reading at the same monitor over
two consecutive years is greater than or equal to 9.5 ppm, this trigger
is more stringent than the standard, and will serve to prevent the
occurrence of future violations.
When the contingency measure trigger is activated, MAG will
consider additional measures on the following schedule: (a)
Verification of the monitoring data to be completed three months after
activation of the trigger; (b) applicable measure to be considered for
adoption six months after the date established in (a) above; and (c)
the resultant measure to be implemented within six to twelve months,
depending on the time needed to put the measure in place.
5. Commitment To Submit Subsequent Maintenance Plan Revisions
In accordance with section 175A(b) of the CAA, as the designated
regional air quality planning agency for the Maricopa County area, MAG
has committed to submit a revised maintenance plan eight years after
redesignation. This provision for revising the maintenance plan is
contained in Chapter 3, pages 3-16 to 3-17 of the Maricopa County CO
maintenance plan.
VII. EPA's Evaluation of the Transportation Conformity Requirements in
the MAG CO Redesignation Request and Maintenance Plan
One of the primary tests for conformity is to show that
transportation plans and transportation improvement programs will not
cause motor vehicle emissions to increase above levels needed to make
progress towards and to meet air quality standards. The motor vehicle
emissions levels needed to make progress toward and to meet the air
quality standards are set in the area's air quality plans as
``emissions budgets for motor vehicles''. More details about conformity
tests are described in section IV.A of this notice. EPA has been using
a process and specific criteria for determining the adequacy of
emissions budgets in control strategy SIPs since a 1999 court ruling.
This process is now codified in a recent revision to the conformity
rule (see 69 FR 40004, July 1, 2004).
The MAG CO Redesignation Request and Maintenance Plan defines the
CO motor vehicle emissions budgets in the Maricopa County area as 699.7
tons per day for 2006 and 662.9 tons per day for 2015 and beyond. The
budget for 2015 is equal to the maintenance year (2015) mobile source
emissions inventory for CO for the attainment/maintenance area. The MAG
CO Redesignation Request and Maintenance Plan and supporting
documentation indicate that the 662.9 budget for 2015 is consistent
with maintenance of the CO NAAQS throughout the maintenance period.
Therefore, we are proposing to approve the 699.7 tons per day CO
emissions budget for 2006 and the 662.9 tons per day CO emissions
budget for 2015 for the Maricopa County nonattainment area.
EPA's adequacy determination on the MAG CO budgets for 2006 and
2015 was made in a letter to ADEQ and MAG on September 9, 2003 and was
announced in the Federal Register on September 29, 2003 (68 FR 55950).
As a result of this adequacy finding, the 699.7 ton per day budget for
2006 and the 662.9 budget for 2015 took effect for the conformity
determinations in the Maricopa County nonattainment area on October 14,
2003. However, we are not bound by that determination in acting on the
maintenance plan.
VIII. GRIC Boundary Change Under CAA Section 107
EPA is proposing to change the boundary of the Maricopa County CO
nonattainment/maintenance area to exclude the Gila River Indian
Reservation (``Reservation'').
A. Background
1. Current Area Boundary, Designation, and Classification
Areas of the country were originally designated as attainment,
nonattainment or unclassifiable following enactment of the 1977
Amendments to the CAA. See 43 FR 8962 (March 3, 1978). These
designations were generally based on monitored air quality values
compared to the applicable NAAQS. The Maricopa County nonattainment
area was designated a nonattainment area for CO in April 1977. The
boundary for the Maricopa County CO nonattainment area was first
established following the CAA Amendments of 1977. See 43 FR 8962 (March
3, 1978)
Under the 1990 Clean Air Act Amendments, the Maricopa County CO
nonattainment area was again classified as a nonattainment area for CO.
The nonattainment area boundary remained the same. 56 FR 6335 (November
6, 1991). On August 28, 1996, the Maricopa County CO nonattainment area
was reclassified to serious due to a failure to attain the 8-hour CO
standard by December 31, 1995. 61 FR 39345 (July 29, 1996)
Area boundaries and area classifications have been amended over the
years under the applicable CAA provisions, either by request of a
state, by operation of law, or by EPA initiative. For the State of
Arizona, the current area designations and classifications are codified
at 40 CFR 81.303.
2. GRIC's Request for a Boundary Change
On July 14, 2004, the Gila River Indian Community (``Community''),
a federally-recognized tribal government,\15\ submitted a formal
request to EPA to revise the boundary of the Maricopa County CO
nonattainment area to exclude the Reservation.\16\ The Community's
analysis of air quality data existing at the time of and subsequent to
the designation in 1978 as well as the nature of the CO sources on the
Reservation demonstrated that the Reservation has not had a monitored or
[[Page 60342]]
predicted violation of the CO NAAQS since, and that no significant
sources of CO exist on the Reservation.
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\15\ 67 FR 46329 (July 12, 2002).
\16\ The Maricopa County CO nonattainment area includes the
portion of the Reservation that lies within Maricopa County,
approximately the northern 25% of the Reservation.
---------------------------------------------------------------------------
B. EPA Review of the Community's Request
1. EPA's Authority to Change Boundaries
Under section 107(d)(3)(A), EPA has the authority to revise the
boundary of a nonattainment area on the basis of air quality data,
planning and control considerations, or any other air quality-related
considerations the Administrator deems appropriate.
2. The Gila River Indian Reservation Airshed
The Gila River Indian Reservation consists of approximately 374,000
acres in south central Arizona, south of the Phoenix metropolitan area.
Currently, the Maricopa County (Phoenix area) CO nonattainment area
includes the northern 92,000 acres of the Reservation. The Reservation
is physically separated from the Phoenix metropolitan area by the
Sierra Estrella and South Mountain Ranges. The Sierra Estrella Mountain
Range runs north and south along the western edge of the Reservation.
The South Mountain Range runs diagonally in a northeasterly direction,
between one and five miles beyond the northern Reservation boundary.
The mountain ranges act as a physical barrier between the two airsheds.
A segment of the northern border of the Reservation adjacent to
Chandler does not have a topographical barrier to air pollution
transport. However, the prevailing winds flow to the northeast, sending
CO emissions from Chandler away from the Reservation. Along the
northeastern border of the Reservation, the Santan Mountain Range
separates the Reservation from Gilbert and Apache Junction.
The Reservation has a population of approximately 11,250 people,
with a population density of approximately 20 people per square mile.
There are no major population centers within the Reservation. By
comparison, Maricopa County (including vast rural areas west of the
urban area which are not part of the nonattainment area) has a
population of 2,122,101, with a population density of over 230 people
per square mile.
3. CO and the Reservation
In general, ambient CO concentrations are caused by onroad and
nonroad mobile emissions sources. The level of mobile source emissions
can be directly correlated to population density and land use patterns.
The Community population density of 20 people per square mile is minor
compared to all of Maricopa County, which has a density of over 230
people per square mile. Commuting patterns on the Reservation are
virtually nonexistent. Approximately 2200 cars, trucks and vans commute
to work within the Reservation, compared to 1,250,000 in Maricopa
County. There is little economic integration with commercial
development in metropolitan Phoenix, and the Reservation remains
largely rural and agricultural. The Community plans to expand its
agricultural base by investing millions of dollars in agricultural
infrastructure.
Total annual emissions of CO on the Reservation are less than one
percent of those in the MAG serious CO nonattainment area. High CO
concentrations in the MAG nonattainment area are associated almost
exclusively with areas of high traffic congestion, which do not exist
on the Reservation. Therefore, there is substantial basis for
concluding that the Reservation is an insignificant generator of CO
emissions.
4. CO Planning Issues
Attainment of the CO NAAQS in the Phoenix metropolitan area was
achieved by Arizona through the SIP planning process. It is important
to note that, under the Clean Air Act, the state and local air
pollution control authorities are not administering EPA-approved air
regulatory programs over the Reservation; consequently, the SIP rules
that were applied to the metropolitan area and resulted in attainment
of the NAAQS did not apply to the Reservation. Furthermore, due to the
Reservation's lack of CO sources, it was never considered necessary to
apply CO limits to sources in the Reservation.\17\
---------------------------------------------------------------------------
\17\ EPA could have applied CO limits to sources on the
Reservation, as it has authority under CAA 301(d) to promulgate
regulations for Indian country as necessary or appropriate ``to
achieve the appropriate purpose'' of the Act.
---------------------------------------------------------------------------
Just as it was clear that it was not necessary for an attainment
plan to be applicable to the Reservation for the Phoenix area to attain
the CO NAAQS, it is clear to EPA that it will not be necessary for a
maintenance plan to be applicable to the Reservation for the Phoenix
area to maintain attainment of the NAAQS.
C. Redesignation of the Northern Portion of the Reservation
In view of the above considerations, and because no CO air quality
data exists for the Reservation, EPA believes ``nonclassifiable/
attainment'' is the appropriate designation for the entire Reservation,
including that portion heretofore included in the nonattainment area.
Therefore, EPA proposes to redesignate to ``nonclassifiable/
attainment'' the portion of the Reservation that is now within the
nonattainment area, and make it part of the surrounding
nonclassifiable/attainment area.
IX. Proposed Action
We are soliciting public comment on all aspects of this proposed
SIP rulemaking action. We will consider your comments in deciding our
final action if your comments are received by November 8, 2004.
We propose to approve the following elements of the Revised 1999 CO
Plan for the metropolitan Phoenix area and the MAG CO Redesignation
Request and Maintenance Plan:
1. 1990 base year and 1993 and 1996 periodic emission inventories
as required by sections 172(c)(3) and 187(a)(5).
2. Demonstration that the plan provides for the implementation of
reasonably available control measures including transportation control
measures under sections 172(c)(1) and 187(b)(2);
3. Demonstration of attainment by December 31, 2000 under section
187(a)(7);
4. Demonstration of reasonable further progress under sections
172(c)(2) and 187(a)(7);
5. Contingency measures under sections 172(c)(9) and 187(a)(3);
6. Forecasts of vehicle miles traveled and provisions for annual
tracking and reporting under section 187(a)(2)(A);
7. Transportation control measures as necessary to offset growth in
emissions under section 187(b)(2);
8. Attainment year and projected emissions inventories under
section 175A;
9. Air quality monitoring requirements under section 110(a)(2) and
section 172(c)(7);
10. CO motor vehicle emissions budgets for transportation
conformity under section 176(c) for the attainment demonstration and
the maintenance plan for the years 2000, 2006 and 2015 under the
transportation conformity rule, 40 CFR Part 93, subpart A;
11. Demonstration of maintenance under section 175A(a) and a fully-
approved maintenance plan under section 175A;
12. Maintenance plan contingency measures under section 175A(d);
13. Commitment for subsequent maintenance plan revisions under
section 175A(b);
[[Page 60343]]
14. Redesignation of that portion of the Gila River Indian
Reservation that is now within the nonattainment area to
``nonclassifiable/attainment'; and
15. A determination that the improvement in air quality in the
Maricopa County nonattainment area is due to permanent and enforceable
reductions in emissions resulting from the implementation of the
applicable implementation plan, implementation of applicable Federal
air pollution control regulations, and other permanent and enforceable
reductions.
We have previously approved all control measures relied on for
attainment and contingency measures in the Revised 1999 CO Plan,
including the area's enhanced inspection and maintenance program
(required by section 187(a)(6)), oxygenated gasoline program (required
by sections 187(b)(3) and 211(m)), and woodburning curtailment
regulations. See 68 FR 2912, 69 FR 10161, 64 FR 60678 and 67 FR 52416.
As stated above, we are proposing approval of MAG's June 16, 2003
request to redesignate the Maricopa County CO nonattainment area to
attainment and proposing approval of the maintenance plan for the
Maricopa County CO nonattainment area.
We are also proposing to change the designation of the portion of
the Gila River Indian Community which is in the Maricopa County CO
nonattainment area to ``unclassifiable/attainment'' for CO.
X. Statutory and Executive Order Reviews
Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
proposed action is not a ``significant regulatory action'' and
therefore is not subject to review by the Office of Management and
Budget. For this reason, this action is also not subject to Executive
Order 13211, ``Actions Concerning Regulations That Significantly Affect
Energy Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001). This
proposed action merely proposes to approve state law as meeting Federal
requirements and imposes no additional requirements beyond those
imposed by state law. Accordingly, the Administrator certifies that
this proposed rule will not have a significant economic impact on a
substantial number of small entities under the Regulatory Flexibility
Act (5 U.S.C. 601 et seq.). Because this rule proposes to approve pre-
existing requirements under state law and does not impose any
additional enforceable duty beyond that required by state law, it does
not contain any unfunded mandate or significantly or uniquely affect
small governments, as described in the Unfunded Mandates Reform Act of
1995 (Public Law 104-4).
Executive Order 13175, entitled ``Consultation and Coordination
with Indian Tribal Governments'' (59 FR 22951, November 6, 2000),
requires EPA to develop an accountable process to ensure ``meaningful
and timely input by tribal officials in the development of regulatory
policies that have tribal implications.'' ``Policies that have tribal
implications'' is defined in the Executive Order to include regulations
that have ``substantial direct effects on one or more Indian tribes, on
the relationship between the Federal government and the Indian tribes,
or on the distribution of power and responsibilities between the
Federal government and Indian tribes.''
Under section 5(b) of Executive Order 13175, EPA may not issue a
regulation that has tribal implications, that imposes substantial
direct compliance costs, and that is not required by statute, unless
the Federal government provides the funds necessary to pay the direct
compliance costs incurred by tribal governments, or EPA consults with
tribal officials early in the process of developing the proposed
regulation. Under section 5(c) of Executive Order 13175, EPA may not
issue a regulation that has tribal implications and that preempts
tribal law, unless the Agency consults with tribal officials early in
the process of developing the proposed regulation.
EPA has concluded that this proposed rule may have tribal
implications. EPA's action will remove the Gila River Indian Community
from the Phoenix CO maintenance area. However, it will neither impose
substantial direct compliance costs on tribal governments, nor preempt
State law. Thus, the requirements of sections 5(b) and 5(c) of the
Executive Order do not apply to this rule.
Consistent with EPA policy, EPA nonetheless consulted with
representatives of tribal governments early in the process of
developing this regulation to permit them to have meaningful and timely
input into its development. Representatives of tribal governments
approached EPA two years ago and requested that EPA make this boundary
change. We agree with the technical and policy rationale the tribe
provided, and believe that all tribal concerns have been met.
In the spirit of Executive Order 13175, and consistent with EPA
policy to promote communications between EPA and tribal governments,
EPA specifically solicits additional comment on this proposed rule from
tribal officials.
This action also does not have Federalism implications because it
does not have substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132 (64 FR 43255, August
10, 1999). This action merely proposes to approve a state rule
implementing a Federal standard, and does not alter the relationship or
the distribution of power and responsibilities established in the Clean
Air Act. This proposed rule also is not subject to Executive Order
13045 ``Protection of Children from Environmental Health Risks and
Safety Risks'' (62 FR 19885, April 23, 1997), because it is not
economically significant.
In reviewing SIP submissions, EPA's role is to approve state
choices, provided that they meet the criteria of the Clean Air Act. In
this context, in the absence of a prior existing requirement for the
State to use voluntary consensus standards (VCS), EPA has no authority
to disapprove a SIP submission for failure to use VCS. It would thus be
inconsistent with applicable law for EPA, when it reviews a SIP
submission, to use VCS in place of a SIP submission that otherwise
satisfies the provisions of the Clean Air Act. Thus, the requirements
of section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (15 U.S.C. 272 note) do not apply. This proposed rule does
not impose an information collection burden under the provisions of the
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).
List of Subjects
40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Reporting and recordkeeping
requirements, Carbon monoxide.
40 CFR Part 81
Air pollution control, National parks, Wilderness areas.
Dated: September 21, 2004.
Laura Yoshii,
Acting Regional Administrator, Region 9.
[FR Doc. 04-22485 Filed 10-7-04; 8:45 am]
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