[Federal Register Volume 61, Number 115 (Thursday, June 13, 1996)]
[Proposed Rules]
[Pages 30024-30028]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-15034]



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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52

[LA-22-1-6870; FRL-5520-4]


Approval and Promulgation of Section 182(f) Exemption to the 
Nitrogen Oxides (NOX) Control Requirements for the Calcasieu 
Parish Ozone Nonattainment Area; Louisiana

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rulemaking.

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SUMMARY: The EPA proposes to approve a petition from the State of 
Louisiana requesting that the Calcasieu Parish marginal ozone 
nonattainment area be exempt from applicable NOX control 
requirements of section 182(f) of the Clean Air Act (Act). The section 
182(f) NOX requirement from which the area will be exempt is 
NOX new source review (NSR). In addition, approval of the section 
182(f) petition would remove the NOX general conformity provisions 
and the NOX build/no build provisions of the transportation 
conformity rule (for conformity provisions, see the November 24, 1993 
and November 30, 1993 Federal Register). The exemption for conformity 
NOX requirements is found, generally, in 40 CFR part 93, subparts 
T and W. The section 182(f) NOX provisions are explained fully in 
the EPA's NOX Supplement to the General Preamble, published in the 
Federal Register (FR) on November 25, 1992. The State of Louisiana made 
the request for Calcasieu Parish based on a demonstration that 
additional NOX reductions would not contribute to ozone attainment 
in the nonattainment area.

DATES: Comments on this proposed action must be received in writing on 
or before July 15, 1996.

ADDRESSEES: 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 Planning (6PD-L), 
1445 Ross Avenue, Suite 700, Dallas, Texas 75202-2733.
Louisiana Department of Environmental Quality, N.B. Garlock Building, 
7290 Bluebonnet, Baton Rouge, Louisiana 70810.

FOR FURTHER INFORMATION CONTACT:
Mr. Matthew Witosky or Mr. Quang Nguyen, Planning Section (6PD-L), 
Multimedia Planning and Permitting Division, U.S. EPA 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.
    Calcasieu Parish, Louisiana, was designated nonattainment for ozone 
and classified as marginal pursuant to sections 107(d)(4) and 181(a) of 
the Act. Under section 181(a), marginal areas must attain the National 
Ambient Air Quality Standard for ozone (the ozone standard) by November 
15, 1993. Please reference 56 FR 56694 (November 6, 1991, codified for 
Louisiana at 40 CFR 81.319).
    The Amendments to the Act (1990 Amendments) made significant 
changes to the air quality planning requirements for areas that do not 
meet the ozone standard. Subparts 1 and 2 of part D, title I of the Act 
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 control requirements 
to major stationary sources of NOX as are applied to major 
stationary sources of VOC. For marginal areas, the NOX requirement 
is to provide for nonattainment new source review (NSR). In addition, 
there are new NOX requirements under the general and 
transportation conformity provisions of section 176(c). This approval 
exempts the area from the section 182(f) NSR NOX requirements (see 
the NOX Supplement to the General Preamble 57 FR 55620), and from 
the NOX requirements of the general, as well as the NOX 
requirements of the build/no build provisions of the transportation, 
conformity rules (see also 58 FR 63214 published on November 24, 1993 
and 58 FR 62188 published on November 30, 1993, as amended, 
particularly at 60 FR 44790, 44794, of August 29, 1995).

Applicable EPA Guidance

    The Act 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 previously-described NOX provisions of the 
conformity rules would also not apply in certain areas that are granted 
a section 182(f) exemption (see amendment to transportation conformity 
rule and associated explanation at 60 FR 44794). In addition, certain 
NOX provisions of the I/M rule would not apply in an area that is 
granted a section 182(f) exemption (see 57 FR 52989).
    The EPA's Guideline for Determining the Applicability of Nitrogen 
Oxides

[[Page 30025]]

Requirements Under Section 182(f) (December 1993), and 2 revisionary 
memoranda signed by John S. Seitz, Director of the EPA Office of Air 
Quality Planning and Standards, dated May 27, 1994 and February 8, 
1995, describe how the EPA will interpret the NOX exemption 
provisions of section 182(f). As described more fully in the Seitz 
memoranda, 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 Act to hold a public 
hearing in order to petition for an area-wide NOX exemption 
determination. Similarly, it is not necessary to have the Governor 
submit the petition.
    It should be noted with respect to the application of section 
182(f) NOX waivers to certain NOx requirements of the 
transportation conformity rule that the EPA has revised the 
transportation conformity rule to ensure consistency with section 
176(c) (see especially 60 FR 44790, 44794). This rule revision requires 
areas subject to section 182(b)(1) (moderate and above, but not 
marginal ozone nonattainment areas) to submit transportation conformity 
NOX exemption requests as revisions to the SIP. Because Calcasieu 
is classified as marginal, the revision addressing 182(b)(1) is not 
applicable.

State Submittal

    On October 28, 1994, the Louisiana Department of Environmental 
Quality (LDEQ) submitted to the EPA a petition pursuant to section 
182(f) which requests that the Calcasieu Parish nonattainment area be 
exempted by the EPA from the NOX control requirements of section 
182(f) of the Act. On December 21, 1995, the Governor of Louisiana 
submitted a request for redesignation of the area to attainment which 
contained additional information relevant to the State's NOX 
exemption petition. The request for redesignation is currently under 
review and will be addressed in a separate rulemaking action.
    The State's NOX waiver petition was based on urban airshed 
modeling (UAM). Subsequently, an analysis of ambient air quality data 
(``clean air data'') indicates that the area is currently in attainment 
of the ozone standard, prompting the state to submit a request that the 
area be redesignated as attainment. The state's modeling and monitoring 
data together demonstrate that additional NOX reductions would not 
contribute to attainment of the ozone standard in the area. Overall, 
this demonstration is consistent with the EPA's section 182(f) 
guidance. The State's submission includes a letter from Gustave Von 
Bodungen, Assistant Secretary of the LDEQ, to Jane N. Saginaw, Regional 
Administrator of the EPA Region 6, and LDEQ's summary of the State's 
photochemical grid modeling results. Further, the State's submission 
requesting redesignation to attainment for Calcasieu Parish contains 
quality-assured and quality-controlled data showing attainment of the 
ozone standard. This data is for the three-year time period of 1993 to 
1995.

Analysis of State Submission

    The following items are the basis for the EPA's action proposing to 
approve the State of Louisiana's section 182(f) NOX exemption 
petition for the Calcasieu Parish ozone nonattainment area. 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 4 of the EPA's December 1993 section 182(f) guidance states 
that the typical procedure for demonstrating that additional NOX 
reductions would not contribute to ozone attainment is to utilize 
photochemical grid modeling, such as UAM, to simulate conditions 
resulting from three emission reduction scenarios: (1) Substantial VOC 
reductions; (2) substantial NOX reductions; and (3) both VOC and 
NOX reductions. To demonstrate that NOX reductions are not 
beneficial to attainment, the area-wide predicted maximum 1-hour ozone 
concentration for each day modeled under scenario (1) must be less than 
or equal to that from scenarios (2) and (3) for the same day. Chapter 7 
specifies that the 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).'' This guidance specifically applies to moderate and 
higher classification ozone nonattainment areas. As discussed in the 
following sections, the EPA believes that the State's UAM demonstration 
together with the ambient air quality data showing that the area is 
attaining the ozone standard support the granting of an exemption from 
the NOX requirements of section 182(f) of the CAA.

B. UAM Modeling Analysis

    Although many ozone nonattainment areas used photochemical grid 
modeling that was required by the Act for their attainment 
demonstrations to apply for a NOX exemption as a marginal 
nonattainment area, the Act did not require Calcasieu Parish to perform 
such modeling for the purpose of an attainment demonstration. Thus, 
where such an area can make an adequate showing of the effects of 
NOX reductions with respect to attainment through alternative 
means that are otherwise consistent with relevant guidance, EPA could 
approve the area's demonstration.
    The LDEQ submitted the results of a photochemical grid modeling 
exercise that was carried out, in conjunction with Calcasieu's 
attainment efforts, to determine if the Calcasieu area was the object 
of ozone and precursor transport. Although the modeling utilized for 
this exercise does not precisely replicate the procedures EPA guidance 
suggests be used to support a 182(f) exemption petition. However, the 
EPA believes the modeling analysis that was performed by LDEQ when 
combined with the area's clean air data is comprehensive enough to use 
in determining if the area should receive an exemption.
    The LDEQ used UAM version IV, an EPA-approved photochemical grid 
model, to develop the attainment demonstration for Calcasieu Parish. 
The State's modeling activities were performed in accordance with the 
EPA's ``Guideline for Regulatory Application of the Urban Airshed 
Model.'' 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 Calcasieu 
Parish UAM modeling exercises. Data from 1991 and 1992 were examined 
for episodes which cover at least 48 consecutive hours and the worst-
case meteorological conditions. Three episodes from 1992 were selected 
for the UAM analysis for the area.
    Episodes selected for the Lake Charles modeling represent three 
different meteorological regimes which can be characterized as 
exhibiting potential for transport of pollutants from source areas near 
Baton Rouge to the Lake Charles area, absence of transport potential, 
and potential for transport from areas in Texas.
2. Model Domain and Meteorological Input
    The LDEQ used a large modeling domain for Calcasieu Parish to 
ensure that the model captured the movement

[[Page 30026]]

of VOC and NOX emissions generated by the surface sources. The 
domain covers all or part of seven counties in Texas and eight parishes 
in Louisiana. The domain modeled encompassed 32,000 square kilometers 
of surface area. Meteorological data were collected from numerous 
monitoring stations in the area. The LDEQ 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 
the areas. Data was obtained from the Aerometric Information and 
Retrieval System (AIRS), LDEQ data gathering activities, the Texas 
Natural Resource Conservation Commission (TNRCC), and other direct 
measurement techniques.
3. Boundary and Initial Conditions
    LDEQ used the air quality data collected at monitoring stations 
throughout the domain to construct the initial conditions of the model 
exercise. Some default values were used where actual measurements were 
not available. The applied boundary conditions were developed to 
measure possible transport into the area from the east and west.
4. Emissions Inventory
    The Calcasieu Parish modeling exercises were conducted using VOC 
and NOX emission inventories compiled by survey and direct 
measurement by the LDEQ. 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 Calcasieu Parish, the LDEQ developed three emission inventories 
for all three episodes modeled. Although the projected inventory does 
not reflect the attainment year for the area, the inventory projected 
for 1993 does not differ significantly from 1991 and 1992 inventories. 
Hence, the EPA believes the State's analysis still provides a valid 
technical basis to evaluate the NOX contributions.
5. Model Performance
    For all UAM activities, model performance is measured 
quantitatively and qualitatively. The EPA has issued guidelines to 
statistically measure accuracy. In addition, the EPA strongly 
recommends that agencies submit graphical analysis, as a complement to 
statistical analysis. While the EPA has recommended ranges for 
statistical accuracy, there are no rigid criterion to accept or reject 
a model exercise. Similarly, qualitative characterizations such as 
good, satisfactory, fair, or poor describe the EPA's best professional 
judgment about graphed model performance, but are not used to grade the 
model exercise as acceptable or unacceptable.
    Based on the above criteria, the Calcasieu model performance was 
satisfactory. Both graphical and statistical performance measures were 
employed for all meteorological episodes and monitoring networks. 
Sensitivity analysis was also conducted to assess the stability of the 
models across a range of possible input parameters.
    For the August 20-21, 1991 episode, two of the three EPA-criterion 
statistical measures obtained for the area are well within the EPA's 
recommended ranges for good model performance (see Table 2 of the 
technical support document). For the April 7-8, 1992 episode, the 
statistical analysis for the primary day, April 8, indicates fair model 
performance. The statistical measures were well within the EPA-
recommended ranges for the primary episode day. However, simulated 
maximum concentrations are, in general, lower than observed peak 
concentrations. For the April 20-21, 1992 episode, the model 
performance is good. The statistical measures all fall within the EPA-
recommended ranges, and the temporal profiles of many sites were fairly 
well simulated.
    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 indicate that the model performed satisfactorily for the three 
episodes used for the UAM demonstration.
6. Section 182(f) Demonstration
    As noted previously, Calcasieu Parish is a marginal ozone 
nonattainment area and EPA's NOX exemption guidance does not fully 
address the requirements for less than moderate nonattainment areas 
that were not required to utilize photochemical grid modeling for their 
attainment demonstrations. For purposes of their 182(f) demonstration, 
the LDEQ modeled the three episodes discussed above under a substantial 
NOX reduction strategy only. The VOC-only and VOC plus NOX 
reduction modeling strategies listed in EPA guidance were not 
performed. EPA nonetheless feels that the State's UAM demonstration in 
combination with the area's ambient air quality data provide adequate 
justification for proposing approval of the NOX exemption 
petition. The justification related to clean air quality data is 
discussed in Section C of this notice.
    The LDEQ's modeling considered across-the-board reductions in the 
projected NOX point source emission inventories. The State modeled 
50 and 25 percent emission reductions in the NOX point sources 
inventory for each of the three episode-days. This generated six 
different sensitivity tests to gauge the direction and intensity of the 
atmospheric reaction to NOX reductions. The State modeled 25 
percent NOX reductions to characterize the effect of NOX 
control strategies that could have a more immediate impact. For all 
three episodes at 25 and 50 percent reductions, the results for the 
controlling day show that domain-wide predicted maximum ozone 
concentrations increase as the NOX reductions are applied.
    As explained in the EPA's 182(f) guidance, the EPA believes it is 
appropriate to focus this analysis on the area-wide maximum 1-hour 
predicted ozone concentration, since this value is critical for the 
typical attainment demonstration. For all three episodes, the 
controlling day showed that the domain-wide predicted maximum ozone 
concentrations are lower without NOX reductions. The model results 
lead to the conclusion that NOX reductions would increase the 
domain-wide maximum ozone concentrations. Please refer to the EPA's 
Technical Support Document for more detailed information.

C. Clean Data Eligibility for NOX Exemption

    On December 21, 1995, the EPA received a request from the State to 
redesignate the Calcasieu area to attainment. The request for 
redesignation is based upon three years of quality-assured monitoring 
data that show no violations of the ozone standard. The data that 
constitute the substance of the redesignation request is available to 
the EPA through the Aerometric Information and Retrieval System (AIRS). 
Since the data were not available when the State initially requested a 
NOX exemption, the State chose to base its waiver request on 
modeling data. Now that monitoring data are available, the EPA believes 
it is appropriate to consider the air quality data in conjunction with 
the modeling information contained in the State's NOX exemption 
petition in determining whether to approve the State's NOX 
exemption request. Moreover, since the

[[Page 30027]]

EPA's NOX guidance provides for granting NOX exemptions based 
solely on clean air data, the State could have resubmitted a request 
for a NOX waiver based only on clean data. However, rather than 
having the state resubmit an additional petition, the EPA decided that 
the air quality data and modeling information already before the 
Agency, when analyzed in combination, constituted an adequate basis to 
propose approval of the waiver request. The EPA will act upon the 
State's request for redesignation in a subsequent notice.
    An EPA review of the AIRS ambient air quality data concluded that 
no violations of the ozone standard occurred in the area from 1993 
through 1995. Since the absence of such violations over a 3-year period 
indicates that an area is in attainment of the ozone standard, this 
data provides further support for the conclusion that the section 
182(f) test is met. This is true because for an area, like Calcasieu, 
that is already attaining it is clear that additional reductions of 
oxides of nitrogen would not contribute to ozone attainment in that 
area. ``Guideline for Determining the Applicability of Nitrogen Oxide 
Requirements Under section 182(f)'' December 1993. See the TSD for 
additional information regarding the area's air quality data.

Proposed Rulemaking Action

    In this action, the EPA proposes to approve the 182(f) NOX 
exemption petition submitted by the State of Louisiana for the 
Calcasieu Parish ozone nonattainment area. 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). Similarly, if an area 
that received an exemption based on clean air quality data which shows 
that the area is attaining the ozone standard experiences a violation 
prior to redesignation of the area to attainment, the exemption would 
no longer be applicable.
    If the EPA later determines, based on new photochemical grid 
modeling that NOX reductions would be beneficial in Calcasieu 
Parish, or because of an ozone violation, the area would be removed 
from exempt status and would be required to adopt the applicable 
NOX provisions of the NSR and conformity rules except to the 
extent that NOX reductions are shown to be ``excess reductions.'' 
In the rulemaking action which removes the exempt status, the EPA would 
provide specific information regarding the reapplication of the NSR 
rules and the conformity rules.
    The subsequent modeling analyses mentioned above need not be 
limited to the purpose of demonstrating attainment as required by 
section 182(c)(2)(A). For example, 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 UAM modeling results together with ambient air 
quality data showing no violations of the ozone standard during the 
last 3 years in Calcasieu Parish support the conclusion that additional 
NOX reductions would not contribute to attainment of the ozone 
standard in this area. The EPA therefore proposes to approve a NOX 
exemption for the Calcasieu Parish area. Approval of this petition 
means that the area is exempt from new source review for sources of 
NOX, the NOX requirements of the general conformity rule, and 
the NOX ``build/no build'' provisions of the transportation 
conformity rule (see 58 FR 63214 and 58 FR 62188). This exemption will 
remain effective for only as long as modeling continues to show that 
NOX control activities would not be beneficial in the Calcasieu 
Parish nonattainment area, and/or so long as, prior to redesignation to 
attainment, the area does not violate the ozone standard.

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 July 15, 1996.

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 SIP's 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)]. 
The Office of Management and Budget has exempted this action from 
review under Executive Order 12866.

Unfunded Mandates

    Under sections 202, 203, and 205 of the Unfunded Mandates Reform 
Act of 1995 (``Unfunded Mandates Act''), signed into law on March 22, 
1995, EPA must undertake various actions in association with proposed 
or final rules that include a Federal mandate that may result in 
estimated costs of $100 million or more to the private sector, or to 
State, local, or tribal governments in the aggregate.
    Through submission of this state implementation plan or plan 
revision, the State and any affected local or tribal governments have 
elected to adopt the program provided for under section 110 of the 
Clean Air Act. These rules may bind State, local and tribal governments 
to perform certain actions and also require the private sector to 
perform certain duties. To the extent that the rules being approved by 
this action will impose no new requirements, such sources are already 
subject to these regulations under State law. Accordingly, no 
additional costs to State, local, or tribal governments, or to the 
private sector, result from this action. EPA has also determined that 
this action does not include a mandate that may result in estimated 
costs of $100 million or more to State, local, or tribal governments in 
the aggregate or to the private sector.

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.


[[Page 30028]]


    Dated: June 7, 1996.
Carol M. Browner,
Administrator.
[FR Doc. 96-15034 Filed 6-12-96; 8:45 am]
BILLING CODE 6560-50-P