Approval and Promulgation of Implementation Plans; Louisiana

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[LA 32-1-7190; FRL-5309-8]

Approval and Promulgation of Implementation Plans; Louisiana

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) proposes to approve

Louisiana's request to grant an exemption for the Baton Rouge ozone

nonattainment area from the applicable oxides of nitrogen (NOX)

transportation conformity requirements. On July 25, 1995, Louisiana

submitted, to the EPA, a State Implementation Plan (SIP) revision

request for an exemption (under section 182(b)(1) of the Clean Air Act

(Act)) from the conformity requirements for NOX for the Baton

Rouge ozone nonattainment area, which is classified as serious. The

State of Louisiana bases its request for Baton Rouge upon a modeling

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 November 6, 1995.

ADDRESSES: Written comments on this action should be addressed to Mr.

Thomas Diggs, Chief, Air Planning Section, at the EPA Regional Office

listed below. Copies of the documents relevant to this proposed action

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, Multimedia Planning and

Permitting Division, 1445 Ross Avenue, Suite 700, Dallas, Texas 75202-

2733.

Louisiana Department of Environmental Quality, H.B. Garlock Building,

7290 Bluebonnet, Baton Rouge, Louisiana 70810.

FOR FURTHER INFORMATION CONTACT:

Ms. Jeanne McDaniels or Mr. Quang Nguyen, Air 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

Clean Air Act section 176(c)(3)(A)(iii) requires, in order to

demonstrate conformity with the applicable SIP, that transportation

plans and transportation improvement programs (TIPs) contribute to

emissions reductions in ozone and carbon monoxide nonattainment areas

during the period before control strategy SIPs are approved by the EPA.

This requirement is implemented in 40 CFR 51.436 through 51.440 (and

93.122 through 93.124), which establishes the so-called ``build/no-

build test.'' This test requires a demonstration that the ``Action''

scenario (representing the implementation of the proposed

transportation plan/TIP) will result in lower motor vehicle emissions

than the ``Baseline'' scenario (representing the implementation of the

current transportation plan/TIP). In addition, the ``Action'' scenario

must result in emissions lower than 1990 levels.

The November 24, 1993, final transportation conformity rule does

not require the build/no-build and less-than-1990 tests for NOX as

an ozone precursor in ozone nonattainment areas where the Administrator

determines that additional reductions of NOX would not contribute

to attainment of the National Ambient Air Quality Standard (NAAQS) for

ozone. Clean Air Act section 176(c)(3)(A)(iii), which is the conformity

provision requiring contributions to emissions reductions before SIPs

with emissions budgets can

[[Page 52349]]

be approved, specifically references Clean Air Act section 182(b)(1).

That section requires submission of State plans that, among other

things, provide for specific annual reductions of volatile organic

compounds (VOCs) and NOX emissions ``as necessary'' to attain the

ozone standard by the applicable attainment date. Section 182(b)(1)

further states that its requirements do not apply in the case of

NOX for those ozone nonattainment areas for which the EPA

determines that additional reductions of NOX would not contribute

to ozone attainment.

For ozone nonattainment areas, the process for submitting waiver

requests and the criteria used to evaluate them are explained in the

December 1993 EPA document ``Guidelines for Determining the

Applicability of Nitrogen Oxides Requirements Under Section 182(f),''

and the May 27, 1994, and February 8, 1995, memoranda from John Seitz,

Director of the Office of Air Quality Planning and Standards, to

Regional Air Directors, titled ``Section 182(f) NOX Exemptions--

Revised Process and Criteria.''

In a petition dated November 17, 1994, and in two follow-up letters

to the petition, the Louisiana Department of Environmental Quality

(LDEQ) requested that the EPA grant an exemption from the requirements

of section 182(f) of the Act to include the reasonably available

control technology (RACT) and new source review (NSR) requirements for

major stationary sources of NOX, inspection and maintenance (I/M)

NOX requirements, and transportation and general conformity

requirements for NOX.

On August 18, 1995, the EPA published a rulemaking proposing

approval of the NOX exemption for the RACT, NSR, I/M, and general

conformity requirements. The Region did not propose approval of the

transportation conformity exemption in that notice, however. The reason

for not including the transportation conformity among the proposed

exemptions stems from an April 1995 agreement by the EPA to change the

procedural mechanism through which a NOX exemption from

transportation conformity exemption would be granted (EDF et al. v.

U.S. E.P.A, No. 94-1044, U.S. Court of Appeals, D.C. Circuit). (The EDF

et al. argued that NOX exemptions are provided for in two separate

parts of the Act in sections 182(b)(1) and 182(f), but that the Act's

transportation conformity provisions in section 176(c)(3) explicitly

reference section 182(b)(1).) Therefore, instead of a petition under

section 182(f), transportation conformity NOX exemptions for ozone

nonattainment areas that are subject to section 182(b)(1) now need to

be submitted as a SIP revision. The Baton Rouge ozone nonattainment

area is classified as serious and, thus, is subject to section

182(b)(1).

The transportation conformity requirements are found at sections

176(c) (2), (3), and (4). The conformity requirements apply on an

areawide basis in all nonattainment and maintenance areas. As

originally promulgated, the EPA's transportation conformity rule 1

and general conformity rule 2 referenced the section 182(f)

exemption process as a means for exempting any nonattainment area from

NOX conformity requirements. On August 29, 1995, the EPA amended

the transportation conformity rule to instead reference section

182(b)(1) as the means for exempting areas subject to section 182(b)(1)

from the transportation conformity NOX requirements.3

\1\ ``Criteria and Procedures for Determining Conformity to

State or Federal Implementation Plans of Transportation Plans,

Programs, and Projects Funded or Approved under Title 23 U.S.C. of

the Federal Transit Act,'' November 24, 1993 (58 FR 62188).

\2\ ``Determining Conformity of General Federal Actions to State

or Federal Implementation Plans; Final Rule,'' November 30, 1993 (58

FR 63214).

\3\ ``Transportation Conformity Rule Amendments: Authority for

Transportation Conformity Nitrogen Oxides Waivers; Interim Final

Rule,'' August 29, 1995 (60 FR 44762).

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The July 25, 1995, SIP revision request from Louisiana has been

submitted to meet the requirements of a formal SIP revision submittal

in accordance with the 182(b)(1) requirements. A public hearing on this

SIP revision request was held on June 29, 1995. The Baton Rouge serious

ozone nonattainment area consists of the following parishes: East Baton

Rouge, West Baton Rouge, Pointe Coupee, Livingston, Iberville, and

Ascension.

Section 182(b)(1) requires submittal of a plan revision that

provides for reasonable further progress (RFP) reductions for moderate

and above ozone nonattainment areas. The plan must provide for specific

annual reductions in emissions from VOCs and NOX, as necessary to

attain the national primary ambient air quality standard for ozone by

the attainment date applicable under the Act. Further, the requirement

shall not apply in the case of NOX for which the Administrator

determines that additional reductions of NOX would not contribute

to attainment. In evaluating the 182(b) SIP revision request, the EPA

considered whether additional NOX reductions would contribute to

attainment of the standard in the Baton Rouge area.

As outlined in the relevant EPA guidance, the use of photochemical

grid modeling is the recommended approach for testing contribution of

NOX emission reductions to attainment of the ozone standard. This

approach simulates conditions over the modeling domain that may be

expected at the attainment deadline for three emission reduction

scenarios: (1) Substantial VOC reductions, (2) substantial NOX

reductions, and (3) both VOC and NOX reductions. If the areawide

predicted maximum one-hour ozone concentration for each day modeled

under scenario (1) is less than or equal to those from scenarios (2)

and (3) for the corresponding days, the test is passed and the section

182(f) NOX emissions reduction requirements would not apply.

The EPA has made a determination under section 182(b)(1) that the

NOX requirements do not apply. The EPA has based its decision on

an urban airshed modeling (UAM) demonstration that additional NOX

reductions would not contribute to attainment in the Baton Rouge area.

State Submittal

On July 25, 1995, the State of Louisiana submitted, as a revision

to the SIP, a request for an exemption from the transportation

conformity NOX requirements. The State bases its request on an

urban airshed modeling (UAM) demonstration that additional NOX

reductions would not contribute to attainment in the area. The modeling

demonstrates, consistent with the EPA's December 1993 section 182(f)

guidance, that decreases in ozone concentrations resulting from VOC

reductions alone are equal to or greater than decreases obtained from

NOX reductions or a combination of VOC and NOX reductions.

The State's submission includes a letter dated July 17, 1995, from the

Governor of Louisiana requesting the exemption to the NOX

transportation conformity requirements and a summary of the UAM

modeling results. The State of Louisiana also provided supplemental

technical reports based on the modeling demonstration in the Baton

Rouge post-1996 rate-of-progress (ROP) plan submitted to the EPA on

November 15, 1994, pursuant to the requirements of section 182(c)(2)(B)

of the Act. These reports contained the following: base case model

inputs, base case performance evaluation, 1999 emissions report, and

attainment modeling report. These additional technical reports provided

supplemental detail and

[[Page 52350]]

documentation on the modeling information provided to the EPA in the

State's petition.

Analysis of State Submission

In evaluating the section 182(b)(1) transportation conformity

NOX exemption, the EPA applied the same criteria/guidance used for

evaluating section 182(f) NOX waiver requests. The following items

are the basis for the EPA's action proposing to approve the State of

Louisiana's section 182(b)(1) NOX exemption request for the Baton

Rouge 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 NOX Exemption Guidance

Chapter 4 of the EPA's December 1993 section 182(f) guidance

requires that photochemical grid modeling be used 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 would not contribute to attainment, the areawide 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 Regulator Application

of the UAM (July 1991).'' In addition, Chapter 8 of the EPA's December

1993 section 182(f) guidance requires that the modeling simulating

conditions from the NOX emission reduction scenarios include

NOX emission increases after November 15, 1992, due to new or

modified stationary sources of NOX. (Many of these sources would

be subject to the best available control technology requirement through

the prevention of significant deterioration program, but not to NSR

offsets.) 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 LDEQ used UAM version IV, an EPA-approved photochemical grid

model, to develop the attainment demonstration for the Baton Rouge

area. 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 of 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 Baton Rouge

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. Three episodes were selected for the UAM

analysis for the area.

2. Model Domain and Meteorological Input

The LDEQ used a sufficiently large modeling domain for Baton Rouge

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 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.

3. Emissions Inventory

The Baton Rouge 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 State followed the EPA's procedures for developing

episode-specific emission inventories.

The EPA's section 182(f) guidance explains that, in general, the

purpose of the section 182(f) requirements for NOX is related to

attainment of the ozone standard, which suggests that an analysis be

focussed on the time that attainment of that standard is required. For

the purpose of a section 182(f) modeling demonstration, this means that

the projected emissions inventory for the attainment year should be

used.

For Baton Rouge, the 1999 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 1999, which, in turn, were used to develop a projected

emissions inventory for 1999. The State then applied the VOC emission

reductions that are projected to be realized through 1996 from the

control regulations contained in the Baton Rouge 15 percent ROP SIP

submitted to the EPA on November 15, 1994, and the NOX controls

implemented between 1990 and 1994 due to facilities' voluntary

participation in the early NOX reduction program. (The 1999

inventories did not incorporate any additional NOX emission

reductions that would have been achieved through implementation of the

NOX RACT, NSR, general and transportation conformity, or NOX-

related I/M provisions.)

4. Model Performance

For Baton Rouge, 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 indicated that, overall, the model

performed satisfactorily for the three episodes used for the UAM

demonstration.

5. Modeling Demonstration

The EPA's section 182(f) guidance requires the State to model three

emission reduction scenarios to evaluate the benefits of NOX

reductions: (1) Substantial VOC reductions; (2) substantial NOX

reductions; and (3) both VOC and NOX reductions. For the section

182(b)(1) exemption, the LDEQ modeled the three emission reduction

scenarios for all three episodes using the 1999 projected emission

inventory, which includes the voluntary early (1990-1994) point source

NOX reductions and the VOC emission controls to be implemented

through 1996 (i.e., 15 percent ROP). The LDEQ modeled the scenarios

using across-the-board reductions in the projected VOC and NOX

point source emission inventories. The State first modeled substantial

NOX and VOC emission reductions as follows: A 100 percent

reduction in point source VOC emissions alone; a 100 percent reduction

in point source NOX emissions alone; and a 100 percent reduction

in both VOC and NOX emissions combined. This reduction

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represents approximately 46 percent of the total projected

anthropogenic VOC emissions and approximately 57% of the total

projected NOX emissions. The State also modeled smaller across-

the-board reductions in the projected VOC and NOX point source

emissions of 25%, 50%, and 75% separately and then combined in order to

more accurately characterize near-term VOC and NOX control

scenarios.

As explained in the EPA's section 182(f) guidance, the EPA believes

it is appropriate to focus this analysis on the areawide maximum 1-hour

predicted ozone concentration, since this value is critical for the

attainment demonstration. For all three episodes, the controlling day

showed that the domain-wide predicted maximum ozone concentrations are

lowest when only VOC reductions are modeled. In contrast, further

NOX reductions increase the domain-wide maximum ozone

concentrations. Please refer to the EPA's Technical Support Document

for more detailed information.

The EPA believes that all NOX 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.

If the EPA later determines that additional NOX reductions

from transportation sources 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 implement the NOX

provisions of the transportation conformity rule except to the extent

that modeling shows NOX reductions to be ``excess reductions.''

In summary, the UAM modeling results for the Baton Rouge

nonattainment area indicate that additional NOX reductions as well

as NSR control of any NOX increases related to expected growth

would not contribute to attainment of the ozone standard by 1999. The

EPA therefore proposes to approve the transportation conformity

NOX exemption for the Baton Rouge area. This exemption will remain

effective for only as long as modeling continues to show that NOX

control of transportation sources would not contribute to attainment in

the Baton Rouge nonattainment area.

Proposed Rulemaking Action and Solicitation of Comments

Based on the State's SIP revision request and associated

documentation, the EPA proposes to approve Louisiana's request for an

exemption from the transportation conformity NOX requirements.

Public comments are solicited on the requested SIP revision and on

EPA's proposed rulemaking action. Comments received by November 6,

1995, will be considered in the development of the EPA's final rule.

This action has been classified as a Table 3 action for signature

by the Regional Administrator under the procedures published in the

Federal Register on January 19, 1989 (54 FR 2214-2225), as revised by a

July 10, 1995, memorandum from Mary Nichols, Assistant Administrator

for Air and Radiation. The Office of Management and Budget has exempted

this regulatory action from Executive Order 12866 review.

Nothing in this action should be construed as permitting, allowing,

or establishing a precedent for any future request for revision to any

SIP. The EPA shall consider each request for revision to the SIP in

light of specific technical, economic, and environmental factors and in

relation to relevant statutory and regulatory requirements.

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 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.

This approval does not create any new requirements. Therefore, I

certify that this action does not have a significant impact on any

small entities affected. Moreover, due to the nature of the Federal-

State relationship under the Act, preparation of the regulatory

flexibility analysis would constitute Federal inquiry into the economic

reasonableness of the State action. The Act 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 (1976).

Under section 202 of the Unfunded Mandates Reform Act of 1995,

(``Unfunded Mandates Act''), signed into law on March 22, 1995, the EPA

must prepare a budgetary impact statement to accompany any proposed or

final rule that includes a Federal mandate that may result in estimated

costs to State, local, or tribal governments in the aggregate; or to

the private sector, of $100 million or more. Under section 205, the EPA

must select the most cost-effective and least burdensome alternative

that achieves the objectives of the rule and is consistent with

statutory requirements. Section 203 requires the EPA to establish a

plan for informing and advising any small governments that may be

significantly or uniquely impacted by the rule. The EPA has determined

that this action does not include a Federal mandate that may result in

estimated costs of $100 million or more to either State, local, or

tribal governments in the aggregate, or to the private sector.

This Federal action will relieve requirements otherwise imposed

under the Act, and hence does not impose any Federal intergovernmental

mandate, as defined in section 101 of the Unfunded Mandates Act.

Accordingly, no additional costs to State, local, or tribal

governments, or the private sector, result from this action.

List of Subjects in 40 CFR Part 52

Environmental protection, Air pollution control, Conformity,

Intergovernmental relations, Oxides of nitrogen, Ozone, Transportation

conformity.

Authority: 42 U.S.C. 7401-7671q.

Dated: September 29, 1995.

Samuel Coleman,

Acting Regional Administrator.

[FR Doc. 95-24939 Filed 10-5-95; 8:45 am]

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