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Approval and Promulgation of Implementation Plans; Alabama; Attainment Demonstration of the Birmingham 1-hour Ozone Nonattainment Area
Related Material
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: September 11, 2001 (Volume 66, Number 176)]
[Proposed Rules]
[Page 47145-47153]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr11se01-31]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[AL-056-200110; FRL-7053-1]
Approval and Promulgation of Implementation Plans; Alabama;
Attainment Demonstration of the Birmingham 1-hour Ozone Nonattainment
Area
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The EPA is proposing to approve the additions to Alabama's Air
Quality Regulations and the ground-level 1-hour ozone attainment
demonstration State Implementation Plan (SIP) for the Birmingham
nonattainment area submitted by the Alabama Department of Environmental
Management (ADEM) on November 1, 2000. This proposed rule is based on
the requirements of the Clean Air Act as amended in 1990 (CAA) related
to 1-hour ozone attainment demonstrations. EPA will be proposing
approval of the fuel control measure in a separate Federal Register
action.
DATES: Written comments must be received on or before October 11, 2001.
ADDRESSES: All comments should be addressed to: Sean Lakeman at the
EPA, Region 4 Air Planning Branch, 61 Forsyth Street, SW., Atlanta,
Georgia 30303-8960.
Copies of documents relative to this action are available at the
following addresses for inspection during normal business hours:
[[Page 47146]]
Environmental Protection Agency, Region 4, Air Planning Branch, 61
Forsyth Street, SW., Atlanta, Georgia 30303-8960.
Alabama Department of Environmental Management, 400 Coliseum Boulevard,
Montgomery, Alabama 36110-2059.
FOR FURTHER INFORMATION CONTACT: Sean Lakeman, Regulatory Planning
Section, Air Planning Branch, 61 Forsyth Street, SW., Atlanta, Georgia
30303-8960. The telephone number is (404) 562-9043. Mr. Lakeman can
also be reached via electronic mail at lakeman.sean@epa.gov.
SUPPLEMENTARY INFORMATION: This section provides background information
on attainment demonstration SIPs for the 1-hour ozone national ambient
air quality standard (NAAQS) and an analysis of the 1-hour ozone
attainment demonstration SIP submittal for the Birmingham nonattainment
area.
Table of Contents
I. Requirements for Marginal Ozone Nonattainment Areas
II. Background on Birmingham
III. Relevant Policy and Guidance Documents
IV. Description of Revisions to Regulations
V. Framework for Proposing Action on the Attainment Demonstration
SIPs
A. Control Measures Relied on in the Modeled Attainment
Demonstration SIP
B. Description of Controls and Reductions Projected
C. Motor Vehicle Emissions Budget (MVEB)
D. Additional Measures To Further Reduce Emissions
VI. Requirements of a Modeled Attainment Demonstration
VII. Technical Analysis of the Attainment Demonstration
VIII. Reasonably Available Control Measures (RACM)
IX. Proposed Action
X. Administrative Requirements
I. Requirements for Marginal Ozone Nonattainment Areas
The CAA requires EPA to establish NAAQS for certain pollutants that
cause or contribute to air pollution that is reasonably anticipated to
endanger public health or welfare (CAA sections 108 and 109). In 1979,
EPA promulgated the 1-hour 0.12 parts per million (ppm) ground-level
ozone NAAQS (44 FR 8202 (Feb. 8, 1979)). Ground-level ozone is not
emitted directly by sources. Rather, emissions of nitrogen oxides (
NOX) and volatile organic compounds (VOC) react in the
presence of sunlight to form ground-level ozone. NOX and VOC
are referred to as precursors of ozone.
An area exceeds the 1-hour ozone NAAQS each time an ambient air
quality monitor records a 1-hour average ozone concentration above
0.124 ppm. An area is violating the NAAQS when the average of expected
exceedances during a consecutive three-year period is greater than 1 at
any one monitor (40 CFR Part 50, Appendix H). The CAA required EPA to
designate as nonattainment any area that was violating the 1-hour ozone
NAAQS, generally based on air quality monitoring data from the three-
year period from 1987-1989, or any area contributing to a violation
(CAA section 107(d)(4); 56 FR 56694 (Nov. 6, 1991)). The CAA further
classified these areas, based on the area's design value (i.e., the 4th
highest ozone value during the relevant 3 year period at the violating
monitor with the highest ozone levels), as marginal, moderate, serious,
severe or extreme (CAA section 181(a)). Marginal areas were suffering
the least significant air pollution problems.
The control requirements and dates by which attainment needs to be
achieved vary with the area's classification. Marginal areas were
subject to the fewest mandated control requirements and had the
earliest attainment date. Marginal areas were required to attain the 1-
hour NAAQS by November 15, 1993.
Table 1 presents a summary of the CAA requirements for a marginal
ozone nonattainment area for the 1-hour ozone NAAQS. These requirements
are specified in sections 182(b) and 182(f) of the CAA.
Table 1.--CAA Requirements for Marginal Nonattainment Areas
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Submit emissions inventory for VOC and NOX.
Corrections to the Reasonably Available Control Technology (RACT) for
VOC sources.
Reasonably Available Control Measures
Submit Permit Programs.
Submit periodic emissions inventory.
Submit Emissions Statement Rule.
Submit Emissions Offset of at least 1.1 to 1 for VOC and NOX.
------------------------------------------------------------------------
II. Background on Birmingham
The Birmingham area was originally classified as a 1-hour ozone
nonattainment area by EPA on March 3, 1978 (43 FR 8962). The Birmingham
nonattainment area at that time, was geographically defined as
Jefferson County, Alabama. On November 6, 1991, by operation of law
under section 181(a) of the CAA, EPA classified the Birmingham
nonattainment area as a marginal nonattainment area for ozone and added
Shelby County to the nonattainment area (56 FR 56693). The
nonattainment classification for the Birmingham marginal ozone area was
based on ambient air sampling measurements for ozone made during 1987-
1989. The area was required to attain the 1-hour ozone NAAQS by
November 15, 1993, (i.e. three years from the enactment of the CAA)
which is the date set forth in section 181(a)(1).
After the 1993 ozone season the area had three years of quality
assured air monitoring data (1991, 1992 and 1993) which demonstrated
that the 1-hour ozone NAAQS was attained, making the nonattainment area
eligible for redesignation to attainment. The State submitted a final
redesignation request on March 16, 1995, that was deemed
administratively complete by EPA on April 11, 1995. A direct final rule
proposing approval of the redesignation request was signed by the
Regional Administrator and forwarded to the Office of the Federal
Register on August 15, 1995, for publication. Prior to publication of
the document, a violation of the 1-hour ozone NAAQS occurred on August
18, 1995. Because of the violations of the 1-hour ozone NAAQS, EPA
directed the Office of the Federal Register to recall the proposed
direct final rule from publication. EPA began the process to disapprove
the redesignation request. The final action disapproving the
redesignation request was published in the Federal Register on
September 19, 1997, (62 FR 49154). Although exceedances of the 1-hour
ozone NAAQS continued through 1998, the design values for the
Birmingham nonattainment area for the three-year periods 1994-1996,
1995-1997, and 1996-1998 have remained within the range of marginal
classification.
Because of these continuing violations, in a letter dated September
10, 1997, EPA requested that ADEM submit an enforceable commitment to
develop an attainment demonstration SIP to attain the 1-hour ozone
NAAQS. The enforceable commitment submitted by ADEM included a schedule
that required them to submit a new attainment demonstration by July
1999. On August 10, 1998, the State submitted an enforceable commitment
without Board adoption, preventing EPA from approving it into the
federally enforceable SIP. Therefore, Region 4 informed the State that
a SIP call would be initiated (to assure that the SIP provides for the
attainment and maintenance of the 1-hour ozone NAAQS, pursuant to
section 110(k)(5) of the CAA which authorizes EPA to find that a SIP is
substantially inadequate to attain or maintain a NAAQS, and to require
(``call for'') the State to submit, within a specified period, a SIP
revision to correct the inadequacy). EPA
[[Page 47147]]
published a proposal in the Federal Register on December 16, 1999 (64
FR 70205) to require the State to submit an attainment SIP for
Birmingham within six months after final action is taken on the SIP
call and to implement controls by May 1, 2003. The final rulemaking on
the SIP call was published October 28, 2000, with an effective date of
November 27, 2000, (65 FR 64352). ADEM submitted the 1-hour ozone
attainment demonstration to EPA on November 1, 2000.
Alabama has met all the regulatory requirements for a marginal
nonattainment area as specified in sections 182(b) and 182(f) of the
CAA and has elected to develop a control strategy for the SIP revision
based on photochemical grid modeling. Although, the model simulation
for the proposed control strategy was performed for the year 2004, all
control strategies proposed by the attainment demonstration will be in
place by May 1, 2003, and attainment is projected in 2003 (ADEM
responded to comments received during the comment period concerning the
projection that Birmingham will achieve attainment in 2003).
The modeling of 2004 for the attainment year was completed prior to
agreement with EPA on the appropriate attainment year. However, since
the modeling was completed for 2004 and the time and resources to redo
the modeling for 2003 were not available, EPA agreed that attainment
for 2003 could be demonstrated with the submittal of a 2003 emissions
inventory as a supplement to the 2004 demonstration provided that the
2003 emissions inventory emissions are less than or equal to the level
of emissions used in the modeling. It could then be concluded that
emissions concentration for 2003, if modeled, would be less than or
equal to the 2004 1-hour ozone concentrations, which were modeled.
The year 2003 was determined to be the most ``expeditious as
practicable'' based on the control strategies that are needed to bring
Birmingham into attainment and can be implemented in a timely manner.
Due to the large amount of NOX reductions required, a
vehicle inspection and maintenance program would not provide the
reductions required to attain the standard. Additionally there is no
current authority for such a program. Even if such authority existed,
development of a regulation, selection of a contractor and completion
of the testing sites could not be achieved by 2003. The RACM analysis
and fuel waiver request (which will be published in a separate Federal
Register notice) show that other programs would not provide the
reductions required to attain the standard by 2003. Implementing
NOX controls on the Gorgas and Miller Power Plants in the
area will achieve the needed reductions by 2003. Its not possible to
have three years of clean air quality data prior to 2003, based on
monitored violations that occurred in 2000.
EPA conducted a detailed examination of the feasibility of
installing the NOX controls and based on these findings, the
EPA believes that the compliance date of May 1, 2003, for installing
NOX controls (Selective Catalytic Reduction (SCR)) on Gorgas
and Miller is a feasible and reasonable deadline.
There are three basic considerations related to implementation of
post-combustion controls SCR and Selective Non-Catalytic Reduction
(SNCR) by the compliance date: (1) Availability of materials and labor,
(2) the time needed to implement controls at plants with single or
multiple retrofit requirements, and (3) the potential for interruptions
in power supply resulting from outages needed to complete
installations. The EPA examined each of these considerations. An
adequate supply of off-the-shelf hardware (such as steel, piping,
nozzles, pumps, soot blowers, fans, and related equipment), reagent
(ammonia and urea), and labor would be available to complete
implementation of post-combustion controls projected under the assumed
control strategy. However, the catalyst used in the SCR process is not
an off-the-shelf item and, therefore, requires additional
consideration. EPA conservatively concludes that adequate catalyst
supply should be available if SCR installations were to occur over a
period of two years or more.
Implementation of a NOX control technology on a
combustion unit involves conducting facility engineering review,
developing control technology specifications, awarding a procurement
contract, obtaining a construction permit, completing control
technology design, installation, testing, and obtaining an operating
permit. The EPA evaluated the amount of time potentially needed to
complete these activities for a single unit retrofit and found that
about 21 months would be needed to implement SCR while about 19 months
would be needed to implement SNCR.
Based on the estimated timelines for implementing NOX
controls at a plant and availability of materials and labor, the EPA
estimates that the NOX controls in the assumed control
strategy could be readily implemented by September 2002, without
causing an adverse impact on the electricity supply or on the cost of
compliance. Taking this into consideration NOX controls on
Gorgas and Miller could be readily implemented by May 2003 but not in
time to affect ozone level in 2002.
III. Relevant Policy and Guidance Documents
This proposal cites several policy and guidance memoranda. The EPA
has also developed several technical documents related to the
rulemaking action in this proposal. Some of the documents have been
referenced. The documents and their location on EPA's web site are
listed below.
Recent Documents
1. ``Guidance for Improving Weight of Evidence Through
Identification of Additional Emission Reductions, Not Modeled.'' U.S.
Environmental Protection Agency, Office of Air Quality Planning and
Standards, Emissions, Monitoring, and Analysis Division, Air Quality
Modeling Group, Research Triangle Park, NC 27711. November 1999. Web
site: http://www.epa.gov/ttn/scram/ (file name: ``ADDWOE1H'').
2. ``Serious and Severe Ozone Nonattainment Areas: Information on
Emissions, Control Measures Adopted or Planned and Other Available
Control Measures.'' Draft Report. November 3, 1999. Ozone Policy and
Strategies Group. U.S. EPA, RTP, NC. Web site: www.epa.gov/ttn/oarpg/
t1main.html.
3. Memorandum ``Guidance on Motor Vehicle Emissions Budgets in One-
Hour Attainment Demonstrations,'' from Merrylin Zaw-Mon, Office of
Mobile Sources, to Air Division Directors, Regions I-VI. November 3,
1999. Web site: http://www.epa.gov/oms/transp/traqconf.htm
Previous Documents
1. U.S. EPA, (1991), Guideline for Regulatory Application of the
Urban Airshed Model, EPA-450/4-91-013, (July 1991). Web site: http://
www.epa.gov/ttn/scram/ (file name: ``UAMREG'').
2. U.S. EPA, (1996), Guidance on Use of Modeled Results to
Demonstrate Attainment of the Ozone NAAQS, EPA-454/B-95-007, (June
1996). Web site: http://www.epa.gov/ttn/scram/ (file name: ``O3TEST'')
3. Memorandum ``Guidance on Use of Opt-in to RFG and Low-RVP
Requirements,'' from Gay McGregor, Office of Mobile Sources, to Air
Division Directors, Regions I-X. August 21, 1997.
[[Page 47148]]
IV. Description of Revisions to Regulations
The November 1, 2000, submittal included two regulations that will
reduce emissions of NOX and VOC in the Birmingham modeling
domain. Rule 335-3-8-.03 requires utility NOX emission
reduction controls on Alabama Power Company plants Gorgas and Miller
for the period May 1 through September 30, beginning in 2003. This rule
includes specific NOX emission reduction requirements as
well as testing, recordkeeping and reporting requirements. Rule 335-3-
20 regulates the sulfur level in gasoline sold in Jefferson and Shelby
Counties (will be addressed in the fuel waiver request) which will
reduce emissions of NOX and VOC.
V. Framework for Proposing Action on the Attainment Demonstration
SIPs
In general, an attainment demonstration SIP includes a modeling
analysis component showing how the area will achieve the NAAQS by its
attainment date and the control measures necessary to achieve those
reductions.
A. Control Measures Relied on in the Modeled Attainment Demonstration
SIP
To receive final approval of the attainment demonstration SIP, the
State must have adopted the emission control measures required under
the CAA for the area's classification or must have established negative
source declarations for the source categories for which the area has no
sources that are subject to the CAA area's classification requirements
for such sources.
The attainment demonstration must incorporate the emission impacts
of, and the SIP submittal must address the rule development for, any
additional emission control measures needed to achieve attainment. The
rules for the emission controls relied upon in the attainment
demonstration must also have been adopted by the State and approved by
EPA at the time of or prior to final approval of the attainment
demonstration SIP. The emission controls for these sources must be
implemented as expeditiously as practicable but no later than the
beginning of the ozone control season in the attainment year.
B. Description of Controls and Reductions Projected
The demonstration shows that 71.5 tons per day (TPD) of
NOX emission reductions and 7.0 TPD of VOC emission
reductions are needed to achieve attainment of the 1-hour NAAQS for
ozone in 2003. In order to achieve attainment in 2003, the following
modeled controls are being implemented in addition to the controls
mandated and already implemented for marginal nonattainment areas.
(1) During every ozone season (between June 1 and September 15),
gasoline sold in Jefferson and Shelby Counties will be required to have
a volume-weighted average sulfur content no greater than 150 ppm and a
Reid Vapor Pressure (RVP) no greater than 7.0 pounds per square inch.
This will provide 3.3 TPD reduction of NOX emissions and 7.0
TPD reduction of VOC emissions. A separate Federal Register notice will
be published to approve the fuel rule and the waiver (CAA section
211(c)(4)(C)).
(2) Beginning in 2003, utility NOX controls on Alabama
Power Company plants Gorgas and Miller will commence for the period May
1 to September 30 each year beginning in 2003. These controls will
provide for 68.2 TPD reduction of NOX emissions. The
corresponding NOX emission rates for each of the Gorgas and
Miller units are provided in the following table.
------------------------------------------------------------------------
NOX Emission Rate
pounds/million
Plant/Unit British thermal
unit (lb/mmBtu)
------------------------------------------------------------------------
Gorgas Unit 6....................................... 0.35
Gorgas Unit 7....................................... 0.35
Gorgas Unit 8....................................... 0.23
Gorgas Unit 9....................................... 0.24
Gorgas Unit 10...................................... 0.24
Miller Unit 1....................................... 0.20
Miller Unit 2....................................... 0.20
Miller Unit 3....................................... 0.20
Miller Unit 4....................................... 0.20
------------------------------------------------------------------------
These emission limitations will be enforced by establishing a 0.21
lb/mmBtu NOX emission limit for the two plants based on a
rolling 30 day average from May 1 through September 30 of each year.
The limit is based on a two plant average and the rolling 30 day
averages are based on a heat input-weighted average of NOX
emissions from all units at the two plants.
(3) National VOC and NOX control measures on-road
mobile, off-road mobile, and area sources, including the national low
emission vehicle (NLEV) program, locomotive engine standards, phase 2
requirements for VOC consumer and commercial products, marine engine
standards, and phase 2 and 3 non-road diesel engine standards will be
in place and were assumed in the model.
C. Motor Vehicle Emissions Budget (MVEB)
Another component of the attainment demonstration SIP is a motor
vehicle emissions budget for transportation conformity purposes.
Transportation conformity is identification of a process for ensuring
that states consider the effects of emissions associated with the
transportation plan for the nonattainment area on attainment of the
NAAQS. As described in section 176(c)(2)(A), attainment demonstrations
necessarily include the estimates of motor vehicle emissions that are
consistent with attainment, which then act as a budget or ceiling for
the purposes of determining whether transportation plans, programs, and
projects conform to the attainment SIP.
States must include in their attainment demonstration SIP the level
of the motor vehicle emissions that will be produced in the attainment
year, and demonstrate that this emissions level, when considered with
emissions from all other sources, is consistent with attainment. This
level of motor vehicle emissions is used to determine the conformity of
transportation plans and programs to the SIP, as described by CAA
section 176(c)(2)(A). A state cannot effectively demonstrate attainment
through its SIP unless they identify the level of motor vehicle
emissions that can be produced while still achieving attainment. The
motor vehicle emissions budgets must meet certain criteria which are
listed in the Transportation Conformity Rule (40 CFR 93.118) before the
budget can be determined adequate and approved as part of the
attainment demonstration SIP. When a motor vehicle emissions budget is
found to be adequate, it is used to determine the conformity of the
transportation plans and programs to the SIP, as required by section
176(c) of the CAA. EPA's adequacy process as outlined in a May 14,
1999, guidance document, provides the public a 30 day comment period
upon EPA's receipt of a SIP submittal containing a MVEB. Comments were
provided by the Southern Environmental Law Center. EPA considered these
comments in its determination of adequacy and provided responses. These
responses are posted on the EPA MVEB web site: http://www.epa.gov/otaq/
transp/conform/adequacy.htm.
On June 7, 2001, EPA published a finding of adequacy of the motor
vehicle emissions budget for transportation conformity purposes (66 FR
30737). The budgets identified in the attainment demonstration are 52
TPD of VOC and 65 TPD of NOX emissions.
D. Additional Measures To Further Reduce Emissions
If the modeling analysis indicates that emission reductions are
needed beyond
[[Page 47149]]
those in the modeled control strategy, the SIP must include adopted
rules to achieve that additional level of control. The analysis for
Birmingham indicates no further emission reductions are needed (see
section V.A. of this document for further discussion).
VI. Requirements of a Modeled Attainment Demonstration
States may rely on a modeled attainment demonstration supplemented
with additional evidence to demonstrate attainment.\1\ In order to have
a complete modeling demonstration submission, states should submit the
required modeling analysis and identify any additional evidence that
EPA should consider in evaluating whether the area will attain the
NAAQS.
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\1\ The EPA issued guidance on the air quality modeling that is
used to demonstrate attainment with the 1-hour ozone NAAQS. See U.S.
EPA, (1991), Guideline for Regulatory Application of the Urban
Airshed Model, EPA-450/4-91-013, (July 1991). A copy may be found on
EPA's web site at http://www.epa.gov/ttn/scram/ (file name:
``UAMREG''). See also U.S. EPA, (1996), Guidance on Use of Modeled
Results to Demonstrate Attainment of the Ozone NAAQS, EPA-454/B-95-
007, (June 1996). A copy may be found on EPA's web site at http://
www.epa.gov/ttn/scram/ (file name: ``O3TEST'').
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The EPA guidance identifies the following six features of a
modeling analysis that are essential to obtain credible results:
1. The state must develop and implement a modeling protocol. The
modeling protocol describes the methods and procedures used in
conducting the modeling analyses and provides for policy oversight and
technical review by individuals responsible for developing or assessing
the attainment demonstration (state and local agencies, EPA Regional
offices, the regulated community, and public interest groups).
2. For purposes of developing the information to put into the
model, the state must select air pollution days, i.e., days in the past
with bad air quality, that are representative of the ozone pollution
problem for the nonattainment area.
3. The state needs to identify the appropriate dimensions of the
area to be modeled, i.e., the domain size. The domain should be larger
than the designated nonattainment area to reduce uncertainty in the
boundary conditions and should include large upwind sources just
outside the nonattainment area. In general, the domain is considered
the local area where control measures are most beneficial to bring the
area into attainment.
4. The state needs to determine the horizontal and vertical grid
cell resolution (i.e., size) of the receptor network. The grid cell
size is the size of one edge of a grid cell in both the X and Y
directions. The units for the cell size are the same as the coordinate
units (e.g., kilometers). The horizontal and vertical resolutions in
the model affect the dispersion and transport of emission plumes.
Artificially large grid cells (too few vertical layers and horizontal
grids) may dilute concentrations and may not properly consider impacts
of complex terrain, complex meteorology, and land/water interfaces.
5. The state needs to generate meteorological data that describe
atmospheric conditions and emissions inputs.
6. The state needs to perform a model performance evaluation to
verify that the model is properly simulating the chemistry and
atmospheric conditions through diagnostic analyses and model
performance tests. Once these steps are satisfactorily completed, the
model is ready to be used to generate air quality estimates to support
an attainment demonstration.
The modeled attainment test compares model predicted 1-hour ozone
daily maximum concentrations in all grid cells for the attainment year
to the level of the NAAQS. A predicted concentration above 0.124 ppm
ozone indicates that the area is expected to exceed the NAAQS in the
attainment year and a prediction at or below 0.124 ppm indicates that
the area is expected to attain the NAAQS. This type of test is often
referred to as an exceedance test. The EPA's guidance recommends that
states use either of two modeled attainment or exceedance tests for the
1-hour ozone NAAQS: A deterministic test or a statistical test.
The deterministic test requires the State to compare predicted 1-
hour daily maximum ozone concentrations for each modeled day \2\ to the
attainment level of 0.124 ppm. If none of the predictions exceed 0.124
ppm, the test is passed. The statistical test takes into account the
fact that the form of the 1-hour ozone NAAQS allows exceedances. If,
over a three-year period, the area has an average of one or fewer
exceedances per year, the area is not violating the NAAQS. Thus, if the
state models a very extreme day, the statistical test provides that a
prediction above 0.124 ppm up to a certain upper limit may be
consistent with attainment of the NAAQS. (The form of the 1-hour NAAQS
allows for up to three readings above the NAAQS over a three-year
period before an area is considered to be in violation.) A complete
discussion of how to determine the acceptable upper exceedance limit is
included in the Technical Support Document (TSD).
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\2\ The initial, ``ramp-up'' days for each episode are excluded
from this determination.
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When the modeling does not conclusively demonstrate attainment,
additional analyses may be presented to help determine whether the area
will attain the NAAQS. As with other predictive tools, there are
inherent uncertainties associated with modeling and its results. For
example, there are uncertainties in some of the modeling inputs, such
as the meteorological and emissions data bases for individual days and
in the methodology used to assess the severity of an exceedance at
individual sites. The EPA's guidance recognizes these limitations, and
provides a means for considering other evidence to help assess whether
attainment of the NAAQS is likely. The process by which this is done is
called a weight of evidence (WOE) determination (ADEM responded to
several comments received during the comment period concerning the use
of WOE, modeling technique and the models ability to provide a clear
demonstration of attainment).
Under a WOE determination, the state can rely on and EPA will
consider factors such as other modeled attainment tests (e.g., a
rollback analysis), other modeled outputs (e.g., changes in the
predicted frequency and pervasiveness of exceedances and predicted
changes in the design value), actual observed air quality trends,
estimated emissions trends, analyses of monitored air quality data, the
responsiveness of the model predictions to further controls, and
whether there are additional control measures that are or will be
approved into the SIP but were not included in the modeling analysis.
This list is not an exclusive list of factors that may be considered
and these factors could vary for a particular area. The EPA's guidance
contains no limit on how close a modeled attainment test must be to
passing to conclude that other evidence besides an attainment test is
sufficiently compelling to suggest attainment. However, the further a
modeled attainment test is from being passed, the more compelling the
WOE needs to be.
VII. Technical Analysis of the Attainment Demonstration
The Urban Airshed Model, Variable Grid Version (UAM-V) was approved
for use in the attainment modeling demonstration by EPA. The UAM-V
model is suitable for evaluating the air quality effects of emission
control scenarios because it accounts for the spacial and temporal
variations in
[[Page 47150]]
emissions and emission reactivity. The UAM-V modeling domain consists
of three nested grids with approximately 36-, 12- and 4-kilometer (km)
grid cell resolution (i.e. grid cell size), respectively. The 4-km fine
grid, in the Birmingham urban area, encompasses north central Alabama.
A modeling protocol was not developed, but, a modeling scope of work
was developed for obtaining contractor assistance. This scope of work
described the major steps that were used in the modeling project and
reviewed and approved by the Regional Office.
One multi-day ozone episode for the July 7-15, 1995, period was
modeled for the attainment demonstration. The modeling simulation
period included two start-up days (to limit the influence of the
initial conditions on the simulation results). The primary episode days
used to develop the control strategy include the July 9-15, 1995,
period. The July 1995 episode can be generally characterized as an
extended period during which high pressure was a dominant
meteorological feature over the eastern United States. Local
meteorological conditions (high pressure, light winds, high
temperatures) are typical of those associated with high ozone
concentrations in the Birmingham area. The period encompasses a range
of summertime meteorological conditions. It includes days with a range
of maximum ozone concentrations so that the response of the modeling
system to emissions reductions can be examined for low, moderate and
high ozone days. Exceedances of the 1-hour ozone NAAQS were observed on
three days of the episode period.
Emission inventories were developed for the base case year (i.e.,
1995 ) for the model performance evaluation and the future year control
strategy assessment (i.e., 2004). The modeling emission inventories
included five emission source classes: (1) Point, (2) area, (3) on-road
mobile, (4) non-road mobile, and (5) biogenic. The1995 base case
inventory used in the OTAG modeling was used to develop the various
inventories used in the modeling. This inventory was supplemented with
local point source inventories from ADEM, emissions used in the Atlanta
1-hour ozone SIP attainment modeling, and day-specific emissions from a
local utility. Bureau of Economic Analysis growth factors were used to
project the 1995 inventory to 2004 for the Birmingham 4-km domain. For
the outer nested grids in the remainder of the modeling domain, the
2007 OTAG base1C point source inventory was used as the 2004. Biogenic
emissions used in this modeling application were generated using the
EPA's Biogenic Emissions Inventory System (BEIS2). BEIS2 provides
county-level area coverage of different vegetation classes that include
agricultural crop types as well as individual tree genus types, and
uses it along with surface temperature and solar energy to calculate
emissions from biogenic sources.
The model performance evaluation involves a statistical and
graphical assessment. Acceptable model performance is achieved if
spatial and temporal concentrations from the model match well with
observed (i.e., ambient air quality) spatial and temporal patterns, and
the model performance statistics are within EPA's established ranges.
The spatial patterns of simulated ozone concentrations are generally
well replicated in the Birmingham area. In general the model
performance is within EPA's ranges on most days for the statistical
analysis. EPA has determined that the model performance is acceptable
and that the days modeled can be used to evaluate future control
strategies and therefore, are suitable for use in the attainment
demonstration. More information on the model performance evaluation is
included in the TSD.
The 2004 modeling of the Birmingham control strategy contains
regulations that will be implemented by 2003 within the nonattainment
area. The UAM-V 2004 simulation of the control strategy predicts
modeled ozone peaks of 135, 128, 141, 132, 115, 149, and 130 parts per
billion (ppb) for the July 9-15, 1995, episode days, respectively. The
deterministic modeled attainment test is not passed since all but one
of the episode days have predicted 1-hour ozone daily maximum
concentrations above 124 ppb. ADEM applied the statistical attainment
test per the EPA guidance, ``On Use of Modeled Results to Demonstrate
Attainment of the Ozone NAAQS (EPA, 1996).'' A full explanation of this
test is found in the TSD. Of the three benchmarks comprising the
statistical test, only benchmark one was passed, because less than
three exceedances of 124 ppb occurred in any subregion of the modeling
grid. Benchmark two failed because the predicted (modeled) daily
maximum ozone concentration for one of the three severe episode days
exceeded the maximum exceedance limit (i.e., 133 ppb) allowed by the
statistical test. On July 11, 1995, the model predicted concentration
is 141 ppb which is close to the allowed exceedances of 133 ppb (within
8 ppb of passing this attainment test). Benchmark three requires that
the number of daytime grid cell hours exceeding 124 ppb for the days
allowed an exceedance and on which the model under predicts by 5
percent or more reduced by at least 80 percent, as compared to the
base-case simulation. This benchmark is not required for the Birmingham
attainment demonstration because the peak ozone concentrations are not
underestimated. Nevertheless, the simulation results show significant
reductions; the number of exceedance grid cell hours is reduced by 67
percent. According to the EPA guidance, if one or more of the
statistical test's benchmarks is failed, a WOE analysis may be
performed using corroborative information to determine if the strategy
will likely provide for attainment.
The 2004 control strategy simulations indicate that ozone levels in
the Birmingham area will be reduced if the currently proposed controls
are implemented. The demonstration shows that 71.5 TPD of
NOX emission reductions and 7.0 TPD of VOC emission
reductions are needed to achieve attainment of the 1-hour NAAQS for
ozone in 2003. Even though both modeled attainment tests (the
statistical test and the deterministic test) are not satisfied, there
are several reasons to believe that Birmingham will attain the NAAQS.
Additional analyses considered includes: (1) An estimate of additional
reductions needed for attainment through application of EPA's,
``Guidance for Improving Weight of Evidence Through Identification of
Additional Emission Reductions, Not Modeled'' which included an
estimate of the future design value, (2) estimates of future design
values at each monitor using the Relative Reduction Factor (RRF)
analysis recommended in the DRAFT 8-hour modeling guidance, (3)
estimates of additional emissions reductions to be implemented that
were not modeled, (4) statistical test benchmark 3, and (5) normalized
air quality and emissions trends data.
The first analysis involves the use of information from the
photochemical grid modeling and ambient air quality monitoring to
estimate additional levels of emission reductions needed for attainment
of the 1-hour NAAQS for ozone. ADEM used EPA's guidance to identify the
additional percentage reduction in NOX and VOC from the 1995
emissions, needed for attainment. This analysis strengthens the WOE and
accounts for high modeled peaks by estimating the additional measures
that at a minimum bring the model estimated future ozone design value
to 124 ppb or below. The method is based on the assumption that the
relationship between ozone and its precursors (VOC
[[Page 47151]]
and NOX) can be calculated. A detailed discussion of the
steps to calculate the additional emission reductions needed for
attainment is provided in the TSD which can be obtained from the
Regional Office staff contact. ADEM's application of this procedure
estimates a future design value of 124 ppb which indicates additional
reductions NOX and VOC are not needed, in accordance with
EPA guidance.
The second analysis uses air quality modeling results to estimate a
design value in 2003 at each ozone monitor and EPA's draft 8-hour ozone
modeling guidance (``Use of Models and Other Analyses In Attainment
Demonstrations for the 8-Hour Ozone NAAQS, EPA-454/R-99-004 (1999)'')
to develop a local relative reduction factor (RRF). A 2004 ozone design
value that is less than 124 ppb is estimated at almost all monitors in
the Birmingham nonattainment area. The future design value at the
McAdory monitoring site was 128 ppb and the design value resulting from
using the domain wide max base case design value and average of domain
wide model predicted peaks was 127 ppb. This indicates that substantial
progress will be made towards attainment, because design values are
expected to be reduced by as much as 5 ppb.
The third analysis involves consideration of the additional VOC and
NOX reductions from three programs that were not modeled in
the 2004 control strategy but are subject to an emission reduction
regulation or a voluntary program (i.e., Stage 1 Vapor Recovery,
Birmingham NOZONER program and open burning ban in Jefferson and Shelby
counties). The Stage 1 Vapor Recovery regulations were initiated in the
early nineties. Continued implementation of this program has resulted
and will continue to result in reductions in VOC emission reductions
from bulk gasoline plants and retail outlets. The NOZONER program
focuses on collective and individual actions to reduce emissions from
the mobile and area source categories. These actions include changes in
vehicle volumes and traffic patterns by promoting alternative commuting
options, and other actions that involve operational and maintenance
activities. A ban on open burning during the ozone season has been
instituted in Shelby County since 1998 and an open burning ban in
Jefferson County has been in effect since 1998. These emission
reductions are difficult to quantify; however it is believed that these
programs will provide future emissions reductions for VOC and
NOX.
The fourth analysis uses statistical test benchmark 3. Benchmark 3
assesses the improvement in ozone exposure (i.e., reduction in grid
cell hours of 124 ppb or greater). Although, benchmark 3 was not
applicable in the statistical test for the Birmingham area (see
previous discussion), a 67 percent reduction in the number of ozone
exceedance exposure occurrences is predicted by the model. This is a
significant reduction in the extent of the predicted ozone exceedances
over the domain.
The last analysis considers normalized trends data for air quality
and NOX point source emissions. The changes in
NOX point source emissions from 1995 until 1998 for
Birmingham nonattainment area indicate a large increase from 1995 to
1996 and a slight increase from 1996 until 1998. The normalized air
quality trends analysis for the period from 1988 to 1998 indicates a
decrease in the design values from 1996 (i.e., 132 ppb) until 1998
(i.e., 128 ppb) and projects a continued decrease below the 124 ppb
level in the future. Air quality monitoring data in the 1998 to 2000
period indicated a 137 ppb design value which appears to temporarily
deflect the projected downward trend indicated in the SIP. However, it
is expected that the point source controls in the attainment strategy
will support the projected downward trend in the air quality analysis.
Although, the model simulation for the proposed control strategy
that demonstrates attainment was performed for the year 2004, all
control strategies proposed by the attainment demonstration will be in
place by the year 2003 and attainment is projected in 2003. A 2003
emissions inventory, representative of emissions expected in the
attainment year was developed. The 2003 inventory represents future
levels of VOC and NOX that are less than that used in the
modeling due to growth between 2003 and 2004 as well as control
programs being implemented. The levels of anthropogenic NOX
and VOC that are modeled in 2004 strategy in the Birmingham
nonattainment area are 249.9 TPD and 157.3 TPD, respectively. The
levels of anthropogenic NOX and VOC expected in 2003 in the
Birmingham nonattainment area are 246.8 TPD and 155.6 TPD,
respectively. The controls modeled in the 2004 strategy are included in
the 2003 inventory. Since the VOC and NOX emissions
projected for 2003 are less than the levels modeled for 2004, it is
expected that if modeled, attainment would also be projected for 2003.
The SIP included several modeled sensitivity simulations to support
this statement (i.e., lower VOC and NOX emissions than that
modeled in the 2004 attainment strategy can result in lower ozone
concentrations). Therefore, EPA believes the area will attain the NAAQS
in 2003.
VIII. Reasonably Available Control Measures (RACM)
Section 172(c)(1) of the CAA requires that SIPs provide for the
implementation of all RACM as expeditiously as practicable. EPA has
previously provided guidance interpreting the RACM requirements of
172(c)(1) (See 57 FR 13498, 13560). In that guidance, EPA indicated its
interpretation that potentially available measures that would not
advance the attainment date for an area would not be considered RACM.
States must consider all potentially available measures to determine
whether they were reasonably available for implementation in the area
prior to the attainment date and whether they will advance attainment.
If measures are deemed reasonably available and they will advance the
attainment date, they must be adopted as control measures in the SIP.
Finally, states can reject potential RACM measures either because
they would not advance the attainment date, would cause substantial
widespread and long-term adverse impacts, or for various reasons
related to local conditions, such as economics or implementation
issues. EPA issued a recent memorandum on this topic confirming its
earlier guidance, ``Guidance on the Reasonably Available Control
Measures (RACM) Requirement and Attainment Demonstration Submissions
for Ozone Nonattainment Areas,'' John S. Seitz, Director, Office of Air
Quality Planning and Standards, November 30, 1999. Web site: http://
www.epa.gov/ttn/oarpg/t1pgm.html.
Pursuant to section 172(b) of the Clean Air Act as amended in 1977
(now section 172(c)(1)), Alabama conducted a RACM analysis for
Jefferson County in 1985 that underwent public notice and comment.
Since 1990, Birmingham's design value has not exceeded the marginal
ozone concentrations, which may be attributed to improved vehicle
emission technology and previously implemented control measures in the
Birmingham nonattainment area to reduce NOX and VOC
emissions. This continued marginal level has occurred despite dramatic
increases in the level of construction and economic activity and
substantial growth in the mobile fleet.
[[Page 47152]]
The 1985 RACM analysis evaluated the following 19 measures for the
purpose of reducing vehicle emissions:
--Inspection and Maintenance Program
--Vapor Recovery Program
--Improved Public Transit
--Exclusive Bus and Carpool Lanes
--Areawide Carpool Programs
--Private Car Restrictions
--Long-Range Transit Improvements
--On-Street Parking Controls
--Park-and-Ride and Fringe Parking Lots
--Pedestrian Malls and Vehicle Restricted Zones
--Employer Participation in Carpools, Vanpools, etc.
--Bicycle Lanes and Storage Facilities
--Staggered Work Hours
--Road Pricing to Discourage Single Occupancy Vehicles
--Controls on Extended Vehicle Idling
--Traffic Flow Improvements
--Conversion to Cleaner Fuels
--Emission Control Retrofit
--Reducing Extreme Cold Start Emissions
Some examples of control measures that were implemented include
rideshare/carpool program, vanpool subsidy, park and ride lots, bicyle
and pedestrian program, ClasTran public paratransit, incident/
congestion response team, commute smart program, and ozone awareness
program. Programs that are scheduled to be implemented include adding
high occupancy vehicle lanes (September 2001), expanding downtown
shuttle service (October 2001) and installing bicycle racks on all area
buses.
As a part of this submittal ADEM evaluated the feasibility of
implementing non-fuel control measures to show necessity for a fuel
control measure as required by section 211(c)(4)(C) of the 1990 CAA.
Under section 211(c)(4)(C), EPA may approve such a fuel control measure
into a SIP if it is concluded that this fuel control is ``necessary''
to achieve a NAAQS. A fuel control is ``necessary'' if no other
measures that would bring about timely attainment exist, or if other
measures exist and are technically feasible, but are unreasonable or
impracticable. The EPA guidance used to review a state's submittal for
a fuel waiver is the August 21, 1997, Guidance on Use of Opt-in to RFG
and Low-RVP Requirements. The guidance on SIP approvals of fuel
controls sets out four issues to be analyzed:
1. The quantity of emissions reductions needed to achieve the
NAAQS;
2. Other possible control measures and the reductions each would
achieve;
3. The explanation for rejecting alternatives as unreasonable or
impracticable; and
4. A demonstration that reductions are needed even after
implementation of reasonable and practicable alternatives, and that the
fuel control will provide some or all of the needed reductions.
Although the information provided in Appendix II for the fuel waiver
was not specifically identified by ADEM as a RACM analysis for this
submittal, the information provided meets the intent of a RACM
analysis. As part of this submittal, the fuel waiver request went
through public review and comment. EPA will be proposing approval of
the fuel control measure in a separate Federal Register action.
EPA acknowledges that the 1985 RACM analysis did not include Shelby
County. However, given the large reductions (68.2 TPD reduction of
NOX emissions) from the Gorgas and Miller power plants which
will begin in 2003, and the small reductions from the potential RACM
measures, EPA believes that even if ADEM had conducted a new RACM
analysis for both counties, they still would not have identified
sufficient additional measures that would achieve enough emission
reductions to advance attainment prior to 2003.
Furthermore, the process of taking additional measures through a
public hearing, board approval, funding, and time needed to implement
would severely limit the feasibility of obtaining emission reductions
that could accelerate the attainment date. Alabama plans to continue
reviewing and implementing new technologies as appropriate for the
Birmingham area. The area will also benefit from EPA's requirements for
cleaner vehicles and fuels in the future.
IX. Proposed Action
The EPA believes that the Birmingham attainment demonstration SIP
meets the requirements of the CAA. Therefore, EPA is proposing to grant
an attainment date of 2003 and approve the State's demonstration that
Birmingham will attain the 1-hour ozone NAAQS by November 15, 2003. The
modeling and WOE analyses of ozone and ozone precursor emissions from
sources in the Birmingham area, demonstrate that the modeled control
strategy will provide for attainment of the 1-hour ozone NAAQS by
November 2003.
X. Administrative Requirements
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 approves 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 (Pub. L. 104-4).
This proposed rule also does not have a substantial direct effect on
one or more Indian tribes, on the relationship between the Federal
Government and Indian tribes, or on the distribution of power and
responsibilities between the Federal Government and Indian tribes, as
specified by Executive Order 13175 (59 FR 22951, November 9, 2000), nor
will it 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), because it 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 CAA.
This proposed rule also is not subject to Executive Order 13045 (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 CAA. 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 CAA. 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. As required by section 3 of
[[Page 47153]]
Executive Order 12988 (61 FR 4729, February 7, 1996), in issuing this
proposed rule, EPA has taken the necessary steps to eliminate drafting
errors and ambiguity, minimize potential litigation, and provide a
clear legal standard for affected conduct. EPA has complied with
Executive Order 12630 (53 FR 8859, March 15, 1988) by examining the
takings implications of the rule in accordance with the ``Attorney
General's Supplemental Guidelines for the Evaluation of Risk and
Avoidance of Unanticipated Takings' issued under the executive order.
This proposed approval of the Birmingham attainment demonstration
SIP 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 in 40 CFR Part 52
Environmental protection, Air pollution control, Nitrogen dioxide,
Ozone, Volatile Organic Compounds, Reporting and recordkeeping
requirements.
Dated: August 24, 2001.
A. Stanley Meiburg,
Acting Regional Administrator, Region 4.
[FR Doc. 01-22734 Filed 9-10-01; 8:45 am]
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