19202 Federal Register / Vol. 60, No. 73 / Monday, April 17, 1995 / Proposed Rules

Although the ozone modeling

guidance generally requires that

modeling results show attainment of the

standard in all grid cells, it does allow

alternative methods for demonstrating

attainment on a case by case basis. EPA

believes that the modeling

demonstration submitted by the State of

North Carolina is sufficiently

conservative so that it is likely that the

O3 NAAQS will continue to be

maintained in the Charlotte area

without the State having to invoke

costly additional measures adopted in

the maintenance standard. That belief is

based on the combination of the

following factors:

(1) North Carolina has five years of air

quality data showing attainment of the

standard.

(2) The maintenance plan contains preadopted measures and a violation would

trigger reduction in emissions by the

following ozone season.

(3) The ozone standard is a statistically

based NAAQS that allows one exceedance

per year.

(4) North Carolina has done extensive

modeling to gain an understanding of the

creation of ozone in the Charlotte area and

has generally made conservative assumptions

in selecting modeling inputs.

(5) The uncertainties in the biogenic

emission inventory and other modeling

inputs are well within the range of the 2–3

ppb needed to reach the .124 ppm in all grid

cells.

(6) The modeling did not account for lower

VOC, NOX and O3 boundary conditions

expected when SIP attainment control

programs have been implemented in many

areas throughout the United States.

Therefore, EPA believes the area is eligible

for redesignation with the existing control

strategy and the contingency plan discussed

below.

The emissions budget for conformity is

contingent upon the control strategy selected

pursuant to the April 19, 1995, public

hearing. That budget will be published in any

notice that takes final action approving this

redesignation request.

C. Verification of Continued Attainment

Continued attainment of the O3

NAAQS in the nonattainment area

depends, in part, on the State of North

Carolina’s efforts toward tracking

indicators of continued attainment

during the maintenance period. The

primary trigger of the contingency plan

will be a violation of the ambient air

quality standard for ozone. The trigger

date will be the date that the State

certifies to EPA that the data is quality

assured, which will occur no later than

30 days after the recorded violation. The

secondary trigger of the contingency

plan will be an exceedance of the ozone

standard that would indicate a violation

could be imminent. This trigger will be

activated within 30 days of the State

finding the exceedance.

Once either the primary or the

secondary trigger is activated, the State

Air Quality Section will commence

analysis, including updated modeling as

necessary, to determine what control

measures will be required to bring the

area back into attainment. By May 1 of

the year following the ozone season in

which the primary trigger has been

activated, the State will complete the

analysis and adopt stationary control

measures indicated by the analysis,

using the emergency rule process as

necessary. The time frame for adopting

measures other than for stationary

sources will be based on the time frames

in section 181(b) of the CAA. Where

only the secondary trigger has been

activated, the State will complete the

analysis and begin the regulatory

adoption process for any measures that

are needed by May 1 of the following

year.

D. Contingency Plan

The level of VOC and NOX emissions

in the nonattainment areas will largely

determine its ability to stay in

compliance with the O3 NAAQS in the

future. Despite the State’s best efforts to

demonstrate continued compliance with

the NAAQS, the ambient air pollutant

concentrations may exceed or violate

the NAAQS. Therefore, the State of

North Carolina has provided

contingency measures with a schedule

for implementation in the event of a

future O3 air quality problem. The

actual measures will be determined

from the analysis process described in

the Verification of Continued

Attainment portion of this notice. The

measures analyzed will include RACT

or greater level control for NOX and

VOC sources, Stage II vapor control for

gasoline dispensing facilities,

enhancements to the I/M program,

transportation control measures, and

any other appropriate measures. EPA

finds that the contingency plan

provided in the State of North Carolina’s

submittal meets the requirements of

section 175A(d) of the CAA.

E. Subsequent Maintenance Plan

Revisions

In accordance with section 175A(b) of

the CAA, the State of North Carolina has

agreed to submit a revised maintenance

SIP eight years after the nonattainment

area is redesignated to attainment. Such

revised SIP will provide for

maintenance for an additional ten years.

6. Proposed Action

EPA proposes approval of the State of

North Carolina’s request to redesignate

to attainment the Charlotte-Gastonia O3

nonattainment area and maintenance

plan contingent upon a full and final

approval of the outstanding

requirements discussed above (emission

statement, RACT catch-ups, emission

inventory and I/M). EPA also proposes

to approve the 1990 baseyear inventory

for the Charlotte-Gastonia

nonattainment area.

The OMB has exempted these actions

from review under Executive Order

12866.

Nothing in this action shall be

construed as permitting or allowing or

establishing a precedent for any future

request for a revision to any state

implementation plan. Each request for

revision to the state implementation

plan shall be considered separately 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., 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, 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.

Redesignation of an area to attainment

under section 107(d)(3)(E) of the CAA

does not impose any new requirements

on small entities. Redesignation is an

action that affects the status of a

geographical area and does not impose

any regulatory requirements on sources.

The Administrator certifies that the

approval of the redesignation request

will not affect a substantial number of

small entities.

List of Subjects

40 CFR Part 52

Air pollution control, Carbon

monoxide, Hydrocarbons, Incorporation

by reference, Intergovernmental

relations, Nitrogen dioxide, Ozone,

Reporting and recordkeeping

requirements.

40 CFR Part 81

Air pollution control, National parks,

Wilderness areas.

Dated: April 5, 1995.

Joe R. Franzmathes,

Acting Regional Administrator.

[FR Doc. 95–9248 Filed 4–14–95; 8:45 am]

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