[Federal Register Volume 59, Number 166 (Monday, August 29, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-21253]
[[Page Unknown]]
[Federal Register: August 29, 1994]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[TX-45-1-6566; FRL-5060-2]
Conditional Approval and Promulgation of Section 182(f) Exemption
to the Nitrogen Oxides (NOx) Control Requirements for the Dallas-
Fort Worth and El Paso Ozone Nonattainment Areas; Texas
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rulemaking.
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SUMMARY: The EPA proposes to conditionally approve two petitions from
the State of Texas requesting that the Dallas-Fort Worth (DFW) and El
Paso ozone nonattainment areas be exempt from NOx control
requirements of section 182(f) of the Clean Air Act (CAA) as amended in
1990. The State of Texas bases its request for DFW upon a demonstration
that the DFW nonattainment area would attain the National Ambient Air
Quality Standards (NAAQS) for ozone by the CAA mandated deadline
without the implementation of the additional NOx controls required
under section 182(f). Similarly, the State bases its exemption request
for El Paso on a demonstration that the El Paso nonattainment area
would attain the ozone NAAQS by the CAA mandated deadline without
implementing the additional NOx controls required under section
182(f), but for emissions emanating from Mexico. These exemptions are
being requested under authority similarly granted under section 182(f)
of the CAA.
DATES: Comments on these proposed actions must be received in writing
on or before September 28, 1994.
ADDRESSES: Written comments on these actions should be addressed to Mr.
Thomas Diggs, Chief, Planning Section, at the EPA Regional Office
listed below. Copies of the documents relevant to these proposed
actions are available for public inspection during normal business
hours at the following locations. The interested persons wanting to
examine these documents should make an appointment with the appropriate
office at least 24 hours before the visiting day.
U.S. Environmental Protection Agency, Region 6, Air Programs Branch
(6T-A), 1445 Ross Avenue, suite 700, Dallas, Texas 75202-2733.
Texas Natural Resource Conservation Commission, P. O. Box 13087,
Austin, Texas 78711-3087.
FOR FURTHER INFORMATION CONTACT: Ms. Leila Yim Surratt or Mr. Matthew
Witosky, Planning Section (6T-AP), Air Programs Branch, USEPA Region 6,
1445 Ross Avenue, Dallas, Texas 75202-2733, telephone (214) 665-7214.
SUPPLEMENTARY INFORMATION:
Background
NOx are precursors to ground level (tropospheric) ozone, or
urban ``smog.'' When released into the atmosphere, NOx will react
with volatile organic compounds (VOC) in the presence of sunlight to
form ozone. Tropospheric ozone is an important factor in the Nation's
urban air pollution problem.
The 1990 Clean Air Act Amendments (CAAA) made significant changes
to the air quality planning requirements for areas that do not meet the
ozone NAAQS. Subparts 1 and 2 of part D, title I of the CAA as amended
in 1990 contain the air quality planning requirements for ozone
nonattainment areas. Title I includes new requirements to control
NOx emissions in certain ozone nonattainment areas and ozone
transport regions. Section 182(f) requires States to apply the same
requirements to major stationary sources of NOx as are applied to
major stationary sources of VOC. The new NOx requirements are
reasonably available control technology (RACT) and new source review
(NSR). These provisions are explained more fully in the EPA's NOx
Supplement to the General Preamble published in the Federal Register
(FR) on November 25, 1992 (see 57 FR 55620). In addition, the general
and transportation conformity rules (conformity) required by section
176(c) contain new NOx requirements (see 58 FR 63214 and 58 FR
62188).
El Paso, Texas, was designated nonattainment for ozone and
classified as serious pursuant to sections 107(d)(4) and 181(a) of the
CAA. The El Paso nonattainment area consists of El Paso County and
shares a common airshed with Juarez, Mexico. Under section 181(a),
serious areas must attain the ozone NAAQS by 1999. DFW was classified
as moderate with an attainment deadline of 1996. The DFW nonattainment
area consists of Dallas, Tarrant, Denton, and Collin Counties. Please
reference 56 FR 56694 (November 6, 1991, codified for Texas at title 40
of the Code of Federal Regulations in Sec. 81.344).
Applicable EPA Guidance
The CAA specifies in section 182(f) that if one of the conditions
listed below is met, the new NOx requirements would not apply:
1. In any area, the net air quality benefits are greater without
NOx reductions from the sources concerned;
2. In a nontransport region, additional NOx reductions would
not contribute to ozone attainment in the nonattainment area; or
3. In a transport region, additional NOx reductions would not
produce net ozone benefits in the transport region.
In addition, section 182(f)(2) states that the application of the
new NOx requirements may be limited to the extent that any portion
of those reductions are demonstrated to result in ``excess reductions''
of NOx. The NOx provisions of the conformity requirements
would also not apply in an area that is granted a section 182(f)
exemption (see 58 FR 63214 and 58 FR 62188).
The EPA's Guideline for Determining the Applicability of Nitrogen
Oxides Requirements under Section 182(f) (December 1993) describes how
the EPA will interpret the NOx exemption provisions of section
182(f). In addition, a memorandum signed by John S. Seitz, Director of
the EPA Office of Air Quality Planning and Standards, dated May 27,
1994, describes certain revisions to the process the EPA currently
intends to follow for granting exemptions from NOx control
requirements.
As described more fully in the Seitz memorandum, petitions
submitted under section 182(f)(3) are not required to be submitted as
State Implementation Plan (SIP) revisions. Consequently, the State is
not required under the CAA to hold a public hearing in order to
petition for an areawide NOx exemption determination. Similarly,
it is not necessary to have the Governor submit the petition.
International Border Area
Section 818 of the 1990 CAAA incorporates a new section 179B into
the CAA which contains special provisions for nonattainment areas that
are affected by emissions emanating from outside the United States. The
section 818 provisions are hereinafter referred to as section 179B.
Because the El Paso nonattainment area shares a common airshed with
Juarez, Mexico, the section 179B provisions apply to El Paso.
Under section 179B, the EPA will approve a SIP if the area meets
all other CAA requirements and establishes that implementation of the
plan would achieve attainment of the ozone standard by the CAA
statutory deadline ``but for emissions emanating from outside the
United States.'' Customarily, an area must demonstrate, using EPA
guideline models, that it would attain the relevant NAAQS. Since El
Paso and Juarez, Mexico, share an airshed and data are not available
for a Juarez emission inventory, modeling of the entire airshed is not
possible at this time. Current EPA policy allows an area subject to
section 179B, such as El Paso, to perform modeling using only U.S. air
emission data. Such modeling may form an acceptable basis for
demonstrating attainment for analysis purposes required under section
179B. As applied under EPA guidance, for areas that demonstrate
attainment, ``but for emissions emanating from a foreign country,'' the
provisions of section 179B will keep an area on an international border
from being subject to the ``bump up'' provisions of section 181(b)(2)
requiring reclassification to the next higher ozone nonattainment
classification if the area fails to attain the relevant NAAQS by the
applicable attainment date. See 57 FR 13498, 57 FR 13569-13570 (April
16, 1992).
The State of Texas performed Urban Airshed Modeling (UAM) using
only El Paso emissions data, which demonstrates that El Paso would
attain the ozone standard by 1996 ``but for emissions emanating from
Mexico.'' The El Paso UAM ozone modeling analysis will be referred to
in this document as the ``attainment demonstration'' for El Paso.
Although the EPA allows an area such as El Paso to demonstrate
attainment on a basis of U.S.-only modeling, it is understood that
ultimately basin-wide modeling must occur in order to develop a control
strategy in El Paso that will achieve the NAAQS. The United States
entered into the Agreement for Environmental Cooperation along the
U.S.-Mexico Border, referred to as the La Paz Agreement, with Mexico in
1983 to address environmental concerns along the border between the two
countries. Annex V of the Agreement, negotiated in 1989, calls for
basin-wide modeling to be accomplished for the El Paso/Juarez airshed.
The EPA has been working with Mexico and with the Texas Natural
Resource Conservation Commission (TNRCC) to accomplish the basin-wide
modeling. Since the statutory attainment date for serious ozone
nonattainment areas such as El Paso is 1999, concerned agencies intend
to complete such modeling by 1999.
State Submittal
On June 17, 1994, the TNRCC submitted to the EPA two petitions
pursuant to section 182(f) which request that the DFW and El Paso
nonattainment areas be exempted by the EPA from the NOx control
requirements of section 182(f) of the CAA.
The State bases its petitions on a demonstration that NOx
reductions would not contribute to attainment in either area, as
allowed for under the test (2) listed above, because such NOx
reductions would be in excess of the reductions necessary for
attainment. Consistent with the EPA's December 1993 section 182(f)
guidance, the State's excess emissions reductions demonstration is tied
to the attainment demonstration SIP required under section 182(c)(2)(A)
of the CAA.
The State's submission for each petition includes: (1) A letter
from Anthony C. Grigsby, Executive Director of the TNRCC, to Jane N.
Saginaw, Regional Administrator of the EPA Region 6, transmitting the
NOx exemption petition; (2) the petition from the TNRCC
summarizing the State's UAM attainment demonstration results; and (3)
technical reports documenting the State's base case UAM inputs. The
State has also previously submitted to the EPA the 15 percent
Reasonable Further Progress (RFP) SIPs for the DFW and El Paso areas,
as required by section 182(b)(1) of the CAA. The 15 percent RFP SIPs
contain regulations that are estimated to reduce VOC emissions in each
area by 15 percent from 1990 levels, net of any growth that may occur.
The State of Texas supplemented its petitions by submitting to the EPA
in July 1994, two additional technical reports on the UAM for each
area, which contained the following: base case performance evaluation,
attainment year emissions report, and attainment year modeling report.
These additional technical reports provided supplemental detail and
documentation on the modeling information already provided to the EPA
in the State's petitions. Finally, in the petitions, the State commits
to taking its attainment demonstration SIPs through public hearing,
adopting them, and submitting them to the EPA by November 15, 1994, as
required by section 182(c)(2)(A) of the CAA.
Analysis of State Submission
The following items are the basis for the EPA's action proposing to
conditionally approve the State of Texas section 182(f) NOx
exemption petitions for the DFW and El Paso ozone nonattainment areas.
Please refer to the EPA's Technical Support Document and the State's
submittal for more detailed information.
A. Consistency with EPA Section 182(f) Guidance
Chapter 6 of the EPA's December 1993 section 182(f) guidance
requires that the excess reductions demonstration for the ``contribute
to attainment'' test, i.e., test (2) listed above, must be tied to the
area's attainment demonstration SIP. This test must show that the
excess reductions are reductions in excess of those specified in the
attainment demonstration required by section 182, and either contained
in the approved SIP or as adopted by the State to meet the section 182
attainment demonstration requirement, and submitted to the EPA for
approval. The EPA believes that the more precise modeling analysis
contained in the State's attainment demonstration SIP is required for
the excess reduction test because the demonstration must show that a
specific portion of the total areawide NOx emissions is not
beneficial under one of the three tests listed above. The tie to the
attainment demonstration assures that an excess reductions petition
would not arbitrarily be based on small emissions and would not
undermine the State's control strategy.
The State has completed its modeling demonstrating attainment in
both areas and has committed to taking the attainment demonstrations
through public hearing, adopting them and submitting them to the EPA by
November 15, 1994. Because the attainment demonstrations rely on VOC
regulations contained in the 15 percent RFP SIPs which have been
adopted by the State and submitted to the EPA, the EPA does not
anticipate that the content of the final attainment demonstration SIPs
will differ from what has already been submitted to the EPA by the
TNRCC in the section 182(f) exemption petitions.
Chapter 7 of the EPA section 182(f) guidance requires that
photochemical grid modeling be used to demonstrate that NOx
reductions would be excess reductions for attainment. The guidance also
specifies that application of UAM should be consistent with the
techniques specified in the EPA ``Guideline on Air quality Models
(Revised),'' and ``Guideline for Regulatory Application of the UAM,''
(July 1991). As discussed in the next section, the State has met these
requirements by using the UAM consistent with the EPA's guidance.
B. UAM Modeling Analysis
The TNRCC used UAM version IV, an EPA-approved photochemical grid
model, to develop the attainment demonstration for the DFW and El Paso
areas. The State's modeling activities were performed as outlined in
the UAM modeling protocols, according to the EPA's ``Guideline for
Regulatory Application of the Urban Airshed Model.'' A specific
modeling protocol was developed by the State for its modeling
activities. The State's modeling protocol was reviewed and approved by
the EPA. The discussion below summarizes the EPA's analysis on how the
State's modeling demonstrations complied with the EPA's guidance.
Please refer to the EPA's Technical Support Document for more detailed
information.
1. Episode Selection
The State used the EPA ``Guideline For Regulatory Application of
The Urban Airshed Model'' to select episodes for use in the DFW and El
Paso UAM modeling exercises. Data from 1987 through 1991 were examined
for episodes which cover at least 48 consecutive hours and the worst-
case meteorological conditions. Four episodes were selected for the UAM
analysis for each area.
2. Model Domain and Meteorological Input
The TNRCC used sufficiently large modeling domains for DFW and El
Paso to ensure that the model captures the movement of ozone episodes
as a result of the VOC and NOx emissions emitted from the surface
sources. Meteorological data were collected from numerous monitoring
stations in both areas. The TNRCC followed the methods described in the
UAM User's Guides to develop model inputs for wind field data, mixing
heights, temperature, and meteorological scalars for both areas.
3. Emissions Inventory
The DFW and El Paso modeling exercises were conducted using VOC and
NOx emission inventories compiled by survey and direct measurement
by the TNRCC. The modeling emissions inventories are composed of point
source, area, on-road mobile, off-road mobile, and biogenic emissions.
Where applicable, emissions were adjusted for pertinent conditions
related to the episode day to be modeled, thus producing day-specific
emissions. The EPA procedures for developing episode-specific emission
inventories were followed.
For El Paso, as discussed above, the modeling exercise was
conducted based on an emission inventory consisting of the U.S. sources
only. Using this limited data set, the TNRCC was able to demonstrate
attainment for the El Paso side of the airshed using the 1996 emissions
inventory. Therefore, the State plans to submit an attainment
demonstration SIP that reflects an attainment year of 1996, three years
earlier than the CAA mandated deadline of 1999. Although a basin-wide
emissions inventory that includes Juarez, Mexico, emissions is
necessary to conduct reliable basin-wide modeling, such an inventory is
not presently available due to the lack of data on Juarez sources.
Therefore, the modeling for El Paso is based on a limited set of
emissions data. As discussed above, however, pursuant to Annex V of the
La Paz Agreement, basin-wide modeling will be performed once a complete
emissions inventory is available and the question of whether more
permanent improvements in air quality are achievable in El Paso will be
revisited at that time.
For both DFW and El Paso, the 1996 attainment year modeling
inventory was developed from the 1990 base year emission inventory and
adjusted to reflect the projected conditions for the attainment year.
Demographic and econometric forecasting methods were employed to
project activities levels to 1996, which in turn were used to develop a
projected emissions inventory for 1996. The State then applied the VOC
emission reductions that are projected to be realized from the control
regulations contained in the 15 percent RFP SIPs for each area. The
1996 inventories did not incorporate any NOx emission reductions
that would have been achieved through implementation of the NOx
RACT, NSR, or conformity provisions.
4. Model Performance
For DFW, both graphical and statistical performance measures were
used to evaluate the model. Using these analyses, the predicted results
from the model were compared to the observed results for each episode.
These analyses demonstrated that the model performed satisfactorily for
three of the episodes that were used for the attainment demonstration.
For El Paso, neither graphical nor statistical performance measures
could be used for the performance evaluation, because it is impossible
to estimate ozone formation in the atmosphere without complete
emissions data for the airshed. As described more fully in the EPA's
Technical Support Document, the State developed several alternative
diagnostic tests to evaluate the model's performance. Based on these
tests, the model exhibited satisfactory performance on two of the
episodes that were used for the attainment demonstration.
5. Demonstration of Attainment Without NOx Reductions
For the DFW attainment demonstration, all three episodes that
provided adequate performance with the base case inventory were used
with the DFW 1996 modeling inventory to model attainment of the ozone
NAAQS. The DFW 1996 modeling inventory incorporates approximately 75
percent of the emission reductions that are projected to be achieved
from the State's 15 percent RPF SIP. In each case, the predicted
domain-wide maximum ozone concentration was less than the NAAQS of 120
parts per billion (ppb). Sensitivity studies performed during the model
performance evaluation demonstrated that when all the reductions from
the 15 percent RFP SIP are included, the modeling demonstration results
in even lower predicted ozone concentrations.
For the El Paso attainment demonstration, TNRCC repeated UAM using
the El Paso 1996 modeling inventory, which incorporated the 15 percent
RFP SIP reductions, for the two 1987 summer episodes that exhibited
satisfactory performance as described above. In each case, the
predicted domain-wide maximum ozone concentration for 1996 was
significantly below the NAAQS of 120 ppb.
Proposed Rulemaking Action
In this action, the EPA proposes to conditionally approve1 the
182(f) NOx exemption petitions submitted by the State of Texas for
the DFW and El Paso ozone nonattainment areas. The EPA will not take
final action to conditionally approve the petitions for each area
unless and until the State submits the attainment demonstration SIPs to
the EPA in accordance with section 182(c)(2)(A) of the CAA. If the
attainment SIPs are not submitted in accordance with section
182(c)(2)(A), the EPA will issue a final disapproval of the State's
exemption petitions.
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\1\This conditional approval is distinct from the conditional
approval authority granted under section 110(k)(4), which pertains
to SIP actions. As discussed in the previously cited John S. Seitz
memorandum dated May 27, 1994, concerning the EPA's processing of
section 182(f) petitions, these NOx exemptions petitions are
not revisions to the SIP.
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If the State submits the attainment demonstration SIPs for DFW and
El Paso in accordance with section 182(c)(2)(A) of the CAA, the EPA
will issue a final conditional approval of the section 182(f) NOx
exemption petitions for each area, conditioned upon the EPA approving
the modeling portion of the attainment demonstration SIPs. If the EPA
proposes to disapprove the modeling portion of the SIPs, the EPA will
also propose disapproval of the section 182(f) NOx exemption
petitions, based on the fact that the technical basis for the exemption
is no longer valid. Upon final disapproval of the modeling portion of
the attainment SIPs, the EPA will issue a final disapproval of the
section 182(f) NOx exemption petitions as well.
There are several consequences if the EPA disapproves the section
182(f) NOx exemption petitions based on the conclusion that either
the attainment SIPs were not submitted by the State of Texas or they
were submitted but not approved by the EPA. The State would be required
to submit NOx RACT and NSR rules and implement the NOx
conformity requirements for the DFW and El Paso areas. The EPA would
issue a finding of nonsubmittal of the NOx RACT and NSR rules. As
provided under section 179(a) of the CAA, if the State did not make a
complete submittal within 18 months after the finding of failure to
submit, the EPA would be required to impose the requirement to provide
two-to-one NSR offsets. If the State had not corrected its deficiency
within six months after imposing the offset sanction, the EPA would
impose a second sanction, on highway funding. Any sanction the EPA
imposes must remain in place until the EPA determines that the State
has corrected the deficiency. In addition, the finding of failure to
submit would trigger the 24-month clock for the EPA to impose a Federal
Implementation Plan as provided under section 110(c)(1) of the CAA.
The EPA believes that all section 182(f) exemptions that are
approved, should be approved only on a contingent basis. As described
in the EPA's NOx Supplement to the General Preamble (57 FR 55628,
November 25, 1992), the EPA would rescind a NOx exemption in cases
where NOx reductions were later found to be beneficial in the
area's attainment plan. That is, a modeling based exemption would last
for only as long as the area's modeling continued to demonstrate
attainment without the additional NOx reductions required by
section 182(f).
If the EPA later determines that NOx reductions are beneficial
based on new photochemical grid modeling in an area initially exempted,
the area would be removed from exempt status and would be required to
adopt the NOx RACT and NSR rules, except to the extent that
modeling shows NOx reductions to be ``excess reductions.'' In the
rulemaking action which removes the exempt status, the EPA would
specify a schedule for States to adopt the NOx RACT and NSR rules
and for sources to comply with the NOx RACT emission limits.
The subsequent modeling analyses mentioned above need not be
limited to the purpose of demonstrating attainment in the 1994 SIP
revisions without the need for NOx RACT and NSR. For example,
future modeling might also be initiated to resolve issues related to
transport of ozone and ozone precursors into downwind nonattainment
areas. An area might want to consider a strategy that phases-in
NOx reductions only after certain VOC reductions are implemented.
As improved emission inventories and ambient data become available,
areas may choose to remodel. In addition, alternative control strategy
scenarios might be considered in subsequent modeling analyses in order
to improve the cost-effectiveness of the attainment plan.
In summary, the EPA proposes to approve exemptions for the DFW and
El Paso areas conditioned upon EPA approval of the modeling portion of
the attainment demonstrations for these areas. These exemptions will
remain effective for only as long as modeling in each nonattainment
area continues to show that NOx control activities would not be
beneficial in the DFW or El Paso nonattainment areas.
In addition, the State of Texas and EPA have committed to data-
gathering and modeling throughout the El Paso-Juarez air basin in
accordance with Annex V of the La Paz Agreement for Environmental
Cooperation on the U.S.-Mexico Border. Once the data are collected and
basin-wide modeling is concluded, the EPA, the State of Texas, and the
Republic of Mexico can develop a binational control strategy that will
result in improved air quality throughout the airshed. If EPA review of
modeling and air quality data confirms that NOx control
requirements on local U.S. sources would not be beneficial, the
exemption would be sustained. In contrast, if the EPA determines that
NOx control requirements would be beneficial, the exemption would
be rescinded.
Request for Public Comments
The EPA requests comments on all aspects of this proposal. As
indicated at the outset of this action, the EPA will consider any
comments received by September 28, 1994.
Regulatory Process
Under the Regulatory Flexibility Act, 5 U.S.C. 600 et seq., the EPA
must prepare a regulatory flexibility analysis assessing the impact of
any proposed or final rule on small entities (5 U.S.C. 603 and 604).
Alternatively, the EPA may certify that the rule will not have a
significant economic impact on a substantial number of small entities.
Small entities include small businesses, small not-for-profit
enterprises, and government entities with jurisdiction over populations
of less than 50,000.
Approvals of NOx exemption petitions under section 182(f) of
the CAA do not create any new requirements. Therefore, because the
Federal approval of the petition does not impose any new requirements,
the EPA certifies that it does not have a significant impact on
affected small entities. Moreover, due to the nature of the Federal-
State relationship under the CAA, preparation of a regulatory
flexibility analysis would constitute Federal inquiry into the economic
reasonableness of State action. The CAA forbids the EPA to base its
actions concerning SIPs on such grounds (Union Electric Co. v. U.S.
E.P.A. , 427 U.S. 246, 256-66 (S. Ct. 1976); 42 U.S.C. 7410 (a)(2)).
If the conditional approval is converted to a disapproval based on
the State's failure to meet the condition upon which the approval is
granted, it will not affect any existing State requirements applicable
to small entities. Federal disapproval of the State submittal does not
affect its State-enforceability. Moreover, the EPA's disapproval of the
submittal does not impose a new Federal requirement. Therefore, the EPA
certifies that this disapproval action would not have a significant
impact on a substantial number of small entities because such
disapproval would not remove existing State requirements, nor does it
substitute a new Federal requirement.
Executive Order 12866
Under Executive Order 12866, (58 FR 51735 (October 4, 1993)), the
EPA must determine whether the regulatory action is ``significant'',
and therefore subject to Office of Management and Budget (OMB) review
and the requirements of the Executive Order. It has been determined
that this rule is not a ``significant regulatory action'' under the
terms of Executive Order 12866, and is therefore not subject to OMB
review.
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Hydrocarbons,
Intergovernmental relations, Nitrogen dioxide, Ozone, Volatile organic
compounds.
Authority: 42 U.S.C. 7401-7671q.
Dated: August 22, 1994.
Carol M. Browner,
Administrator.
[FR Doc. 94-21253 Filed 8-26-94; 8:45 am]
BILLING CODE 6560-50-F
