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

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]

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