19510 Federal Register / Vol. 60, No. 75 / Wednesday, April 19, 1995 / Rules and Regulations

1The section 182(f) exemption provisions center

on the effect on ozone concentrations due to NOX

emission reductions. In the case of new or modified

sources, even after the application of on-site

controls from NSR programs, the source will result

in increases of NOX emissions. Therefore, the

‘‘substantial NOX reductions’’ analysis used to

demonstrate that NOX reductions do not contribute

to attainment should reflect a zero emissions

increase from new or modified stationary sources.

2 ‘‘Scope of Nitrogen Oxides (NOX) Exemptions,’’

from G.T. Helms, Group Leader, Ozone/Carbon

Monoxide Programs Branch (MD–15), to the Air

Branch Chiefs, January 12, 1995. ‘‘I/M

Requirements in NOX RACT Exempt Areas’’, from

Mary T. Smith, Acting Director, Office of Mobile

Sources, to the Air Division Directors, October 14,

1994.

100 above-threshold export transactions

destined for designated countries. This

rule is not a significant regulatory action

and therefore has not been reviewed by

the Office of Management and Budget

pursuant to Executive Order 12866.

This action has been analyzed in

accordance with the principles and

criteria in E.O. 12612, and it has been

determined that the rule does not have

sufficient federalism implications to

warrant the preparation of a Federalism

Assessment.

List of Subjects in 21 CFR Part 1310

Drug traffic control, Reporting and

recordkeeping requirements.

For reasons set out above, 21 CFR part

1310 is amended as follows:

PART 1310—[AMENDED]

1. The authority citation for part 1310

continues to read as follows:

Authority: 21 U.S.C. 802, 830, 871(b).

2. Section 1310.02 is amended by

adding a new paragraph (b)(10) to read

as follows:

§ 1310.02 Substances Covered.

* * * * *

(b) * * *

(10) Methyl Isobutyl Ketone (MIBK)

* * * * *

3. Section 1310.04 is amended by

adding new paragraph (f)(2)(v) to read as

follows:

§ 1310.04 Maintenance of Records.

* * * * *

(f) * * *

(2) * * *

(v) Export and International

Transactions to Designated Countries,

and Importations for Transshipment or

Transfer to Designated Countries

Chemical Threshold

by volume

Threshold by

weight

(A) Methyl

Isobutyl Ketone (MIBK).

500 gallons 1523 kilograms.

(B) Reserved.

4. Section 1310.08 is amended by

adding new paragraphs (c), (d) and (e)

to read as follows:

§ 1310.08 Excluded transactions.

* * * * *

(c) Domestic transactions of Methyl

Isobutyl Ketone (MIBK).

(d) Import transactions of Methyl

Isobutyl Ketone (MIBK) destined for the

United States.

(e) Export transactions, international

transactions, and import transactions for

transshipment or transfer of Methyl

Isobutyl Ketone (MIBK) destined for

Canada or any country outside of the

Western Hemisphere.

Dated: April 12, 1995.

Stephen H. Greene,

Deputy Administrator.

[FR Doc. 95–9589 Filed 4–18–95; 8:45 am]

BILLING CODE 4410–09–M

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 52

[AZ–34–1–6823; FRL–5193–4]

Clean Air Act Section 182(f) NOX

Exemption Petition; Phoenix Ozone

Nonattainment Area

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: The EPA is finalizing the

approval of a petition submitted by the

Arizona Department of Environmental

Quality (ADEQ) requesting that EPA

grant an exemption for the Phoenix

ozone nonattainment area (Phoenix

area) from the requirement to

implement oxides of nitrogen (NOX)

reasonably available control technology

(RACT). EPA published a proposed

action to approve the Phoenix area NOX

exemption in the Federal Register on

November 1, 1994. In accordance with

the requirements of the Clean Air Act,

as amended in 1990 (the Act or CAA),

the EPA has determined that additional

NOX reductions from major stationary

sources in the Phoenix area would not

contribute to attainment of the national

ambient air quality standard (NAAQS)

for ozone. The approval of this action

exempts the Phoenix area from

implementing the NOX requirements for

RACT, new source review (NSR), and

the applicable general and

transportation conformity and

inspection and maintenance (I/M)

requirements of the CAA. The EPA is

finalizing approval of this action under

provisions of the CAA regarding plan

requirements for nonattainment areas.

EFFECTIVE DATE: This action is effective

on April 11, 1995.

ADDRESSES: Copies of the petition and

EPA’s evaluation report is available for

public inspection at EPA’s Region IX

office during normal business hours.

Copies of the submitted petition is

available for inspection at the following

locations:

Rulemaking Section (A–5–3), Air and

Toxics Division, U.S. Environmental

Protection Agency, Region IX, 75

Hawthorne Street, San Francisco, CA

94105

Environmental Protection Agency, Air

Docket (6102), 401 ‘‘M’’ Street, SW.,

Washington, DC 20460

Arizona Department of Environmental

Quality, 3033 North Central Avenue,

Phoenix, Arizona 85012

Maricopa County Air Pollution Control

District, 2406 South 24th Street, Suite

E214, Phoenix, Arizona 85034

FOR FURTHER INFORMATION CONTACT:

Wendy Colombo, Rulemaking Section,

Air and Toxics Division, U.S.

Environmental Protection Agency,

Region IX, 75 Hawthorne Street, San

Francisco, CA 94105, Telephone: (415)

744–1202.

SUPPLEMENTARY INFORMATION:

Background

On November 1, 1994, EPA proposed

to approve the Phoenix area NOX

exemption petition, submitted by the

ADEQ on April 13, 1994. 59 FR 54540.

The exemption petition is based on

urban airshed modeling (UAM) and

makes a demonstration that additional

NOX reductions in the Phoenix area

would not contribute to attainment of

the NAAQS for ozone. A detailed

discussion of the background

concerning the NOX requirements and

the submitted petition is provided in the

notice of proposed rulemaking (NPRM)

cited above.

EPA has evaluated the exemption

petition for consistency with the

requirements of the CAA, EPA

regulations, and EPA interpretation of

these requirements as expressed in the

various EPA policy guidance documents

referenced in the NPRM cited above.

EPA has found that the petition satisfies

the applicable EPA requirements and is

exempting the Phoenix area from

implementing the NOX requirements for

RACT, NSR1, and the applicable general

and transportation conformity and I/M

requirements 2 of the CAA. A detailed

discussion of the petition and EPA’s

evaluation have been provided in the

NPRM and in the technical support

document (TSD), dated October 1994. A

detailed discussion of the scope of the
Federal Register / Vol. 60, No. 75 / Wednesday, April 19, 1995 / Rules and Regulations 19511

3 ‘‘Guideline for Determining the Applicability of

Nitrogen Oxide Requirements under Section

182(f),’’ from John S. Seitz, Director, Office of Air

Quality Planning and Standards, to the Regional

Division Directors, December 16, 1993.

NOX exemption as applicable to the

Phoenix area is discussed in the TSD

dated January 1995 which accompanies

this final action. These documents are

available at EPA’s Region IX office.

Response to Public Comments

A 30-day public comment period was

provided in 59 FR 54540. EPA received

comment letters of support from two

utility companies, the Arizona

transportation authority, and two local

governments in the Phoenix area. Two

adverse comment letters were received

from environmental groups and a local

public interest law office

In August 1994, three environmental

groups submitted joint comments on the

proposed approvals of NOX exemptions

for the Ohio and Michigan ozone

nonattainment areas. The comments

address EPA’s policy regarding NOX

exemptions in general and apply to all

actions EPA takes regarding section

182(f) NOX exemptions. These

comments as well as those received

from the local public interest law office

are addressed below.

Comment: Certain commenters argued

that NOX exemptions are provided for in

two separate parts of the CAA, section

182(b)(1) and section 182(f). Because the

NOX exemption tests in subsections

182(b)(1) and 182(f)(1) include language

indicating that action on such requests

should take place ‘‘when [EPA]

approves a plan or plan revision,’’ these

commenters conclude that all NOX

exemption determinations by the EPA,

including exemption actions taken

under the petition process established

by subsection 182(f)(3), must occur

during consideration of an approvable

attainment or maintenance plan, unless

the area has been redesignated as

attainment. These commenters also

argue that even if the petition

procedures of subsection 182(f)(3) may

be used to relieve areas of certain NOX

requirements, exemptions from the NOX

conformity requirements must follow

the process provided in subsection

182(b)(1), since this is the only

provision explicitly referenced by

section 176(c), the CAA’s conformity

provisions.

Response: Section 182(f) contains

very few details regarding the

administrative procedure for acting on

NOX exemption requests. The absence

of specific guidelines by Congress leaves

EPA with discretion to establish

reasonable procedures, consistent with

the requirements of the Administrative

Procedures Act (APA).

The EPA disagrees with the

commenters regarding the process for

considering exemption requests under

section 182(f), and instead believes that

subsections 182(f)(1) and 182(f)(3)

provide independent procedures by

which the EPA may act on NOX

exemption requests. The language in

subsection 182(f)(1), which indicates

that the EPA should act on NOX

exemptions in conjunction with action

on a plan or plan revision, does not

appear in subsection 182(f)(3). And,

while subsection 182(f)(3) references

subsection 182(f)(1), the EPA believes

that this reference encompasses only the

substantive tests in paragraph (1) [and,

by extension, paragraph (2)], not the

procedural requirement that the EPA act

on exemptions only when acting on

SIPs. Additionally, paragraph (3)

provides that ‘‘person[s]’’ (which

section 302(e) of the CAA defines to

include States) may petition for NOX

exemptions ‘‘at any time,’’ and requires

the EPA to make its determination

within six months of the petition’s

submission. These key differences lead

EPA to believe that Congress intended

the exemption petition process of

paragraph (3) to be distinct and more

expeditious than the longer plan

revision process intended under

paragraph (1).

With respect to major stationary

sources, section 182(f) requires States to

adopt NOX NSR and RACT rules, unless

exempted. These rules were generally

due to be submitted to EPA by

November 15, 1992. Thus, in order to

avoid the CAA sanctions, areas seeking

a NOX exemption would have needed to

submit their exemption request for EPA

review and rulemaking action several

months before November 15, 1992. In

contrast, the CAA specifies that the

attainment demonstrations are not due

until November 1993 or 1994 (and EPA

may take 12–18 months to approve or

disapprove the demonstration). For

marginal ozone nonattainment areas

(subject to NOX NSR), no attainment

demonstration is called for in the CAA.

For maintenance plans, the CAA does

not specify a deadline for submittal of

maintenance demonstrations. Clearly,

the CAA envisions the submittal of and

EPA action on exemption requests, in

some cases, prior to submittal of

attainment or maintenance

demonstrations.

The CAA requires conformity to the

applicable SIP with regard to federallysupported NOX generating activities in

relevant nonattainment and

maintenance areas. However, EPA’s

conformity rules explicitly provide that

these NOX requirements would not

apply if EPA grants an exemption under

section 182(f). In response to the

comment that section 182(b)(1) should

be the appropriate vehicle for dealing

with exemptions from the NOX

requirements of the conformity rule,

EPA notes that this issue has previously

been raised in a formal petition for

reconsideration of EPA’s final

transportation conformity rule and in

litigation pending before the U.S. Court

of Appeals for the District of Columbia

Circuit on the substance of both the

transportation and general conformity

rules. The issue, thus, is under

consideration within EPA, but at this

time remains unresolved. Additionally,

subsection 182(f)(3) requires that NOX

exemption petition determinations be

made by the EPA within six months.

The EPA has stated in previous

guidance that it intends to meet this

statutory deadline as long as doing so is

consistent with the Administrative

Procedures Act. The EPA, therefore,

believes that until a resolution of this

issue is achieved, the applicable rules

governing this issue are those that

appear in EPA’s final conformity

regulations, and EPA remains bound by

their existing terms.

Comment: One commenter contends

that because the Arizona SIP is

inadequate to produce attainment, EPA

cannot approve the waiver under

section 182(f).

Response: The basis for granting the

NOX exemption is that additional NOX

reductions would not contribute to

attainment. How an area demonstrates

that NOX reductions do not contribute

to attainment is outlined in EPA’s

December 1993 exemption guidance.3

The contribute to attainment test is met

by demonstrating through UAM that

substantial reductions of VOC emissions

result in lower ozone levels than would

result from both substantial reductions

of NOX emissions and combined

reductions of VOC and NOX emissions.

The Phoenix petition adequately

demonstrates this through UAM

modeling consistent with EPA’s

guidance. For reasons stated above, EPA

does not agree that the decision to grant

or deny the Phoenix petition under

section 182(f) should depend on the

approvability of the attainment

demonstration under section 182 (b) or

(c).

Comment: Some commenters stated

that the modeling required by EPA

guidance is insufficient to establish that

NOX reductions would not contribute to

attainment since only one level of NOX

control, i.e., ‘‘substantial’’ reductions, is

required to be analyzed. The comments

also contend that the NOX reductions

modeled specifically for the Phoenix
19512 Federal Register / Vol. 60, No. 75 / Wednesday, April 19, 1995 / Rules and Regulations

petition are not sufficient to meet the

requirements of section 182(f), and that

if any level of additional NOX

reductions would contribute to

attainment (as opposed to one test

showing substantial reductions do not

contribute to attainment), then the

waiver must be denied. In addition, the

commenters claim that Arizona did not

model scenarios actually presented in

the SIP.

Response: As described in EPA’s

December 1993 NOX exemption

guidance, photochemical grid modeling

is generally needed to document cases

where NOX reductions are

counterproductive to net air quality, do

not contribute to attainment, do not

show a net ozone benefit, or include

excess reductions. The UAM or, in an

ozone transport region, the Regional

Oxidant Model (ROM) are acceptable

models for these purposes.

EPA’s guidance also states that

application of UAM should be

consistent with techniques specified in

the EPA document, entitled, Guideline

on Air Quality Models, Revised. Further,

application of UAM should also be

consistent with procedures contained in

the EPA document, Guideline for

Regulatory Application of the Urban

Airshed Model, issued July 1991. Thus,

episode selection for the section 182(f)

demonstration should be consistent

with the UAM guidance for SIP

attainment demonstrations.

The section 182(f) contribute to

attainment and net ozone benefit

demonstrations concern unspecified

‘‘additional reductions’’ of NOX. EPA’s

December 1993 exemption guidance

specifies that the analysis should reflect

3 scenarios of ‘‘substantial’’ NOX and

VOC emission reductions. The guidance

states that, in the first scenario, the

demonstration should use the VOC

reductions needed to attain

(demonstrated by EKMA or UAM

analyses). Alternatively, if the

attainment demonstration has not been

completed, the demonstration may use

some other substantial VOC reduction.

In any case, the VOC reductions should

be substantial and documented as

reasonable to expect for the area due to

the CAA requirements. In the second

scenario, NOX reductions should be

modeled without any VOC reductions

above the attainment year baseline. The

level of NOX reductions should reflect

the same percent reduction of

anthropogenic VOC emissions in

scenario (1) above. In the third scenario,

a similar level of NOX reductions would

be modeled along with the level of VOC

reductions chosen. That is, if a 40%

VOC reduction is chosen in scenario (1),

then the model for scenario (3) would

simulate a 40% VOC reduction and

approximately a 40% NOX reduction. It

would be inappropriate to select a high

level of VOC reductions and a low level

of NOX reductions since this could

artificially favor a finding that NOX

reductions are not beneficial; thus, the

scenarios are constrained to avoid an

inappropriate analysis.

The EPA believes that these analyses

are appropriate to determine in a

directional manner whether or not NOX

reductions are expected to be beneficial

with respect to the air quality in the

area/region. These analyses described in

EPA’s December 1993 guidance may be

less precise than an attainment

demonstration required under section

182(c). By contrast, with respect to the

excess reductions provision in section

182(f)(2), EPA believes that more than a

directional analysis is needed (for

reasons described in the December 1993

guidance) and, therefore, requires an

analysis based on the attainment

demonstration.

The EPA does not agree that the

waiver analysis must consider ‘‘any

level’’ of NOX reductions. The EPA

guidance requires analysis of

‘‘substantial’’ reductions because

reductions which are extremely small or

extremely large would bias the model so

that the results could be predetermined.

Analyzing very small changes in NOX

and/or VOC emissions would yield a

result of no change in the ozone

concentrations since the model cannot

assess very small changes. Analysis of

very large NOX emission reductions

might be unrealistic (especially

compared to the adopted attainment

demonstration) and would result in

concluding that NOX reductions reduce

ozone concentrations in all cases. Also,

in developing an attainment

demonstration, an area typically tries to

attain the ozone standard in the least

costly way by starting from current

conditions and reducing emissions from

there. While 100% VOC reduction

alternatives exist, they are not the least

expensive ways to meet the NAAQS,

and may not be feasible. Instead,

alternative combinations of VOC and

NOX reductions are examined. If two

different strategies show the same

ambient ozone concentration, but one

requires greater reductions and cost, the

latter is not considered a preferable

strategy.

EPA believes that the main reason for

the NOX RACT waiver provisions in the

CAA is the recognition by Congress that

under certain conditions NOX emission

reductions can be counterproductive to

ozone attainment, because they could

increase ozone levels and necessitate

additional VOC reductions to

compensate. Although required as

beneficial to ozone attainment unless

demonstrated otherwise, NOX

reductions which achieve the same

ozone levels at a greater cost based on

a strategy using extra counterbalancing

VOC reductions does not make sense

from an ozone regulatory standpoint.

Therefore, EPA’s exemption guidance

reflects this rationale in allowing

petitioners the opportunity to

demonstrate scenarios where substantial

reductions of NOX are

counterproductive to ozone attainment.

In the Arizona petition, both across-theboard NOX reductions and NOX RACT

specific reductions were simulated

which consistently demonstrate that

NOX reductions do not contribute to

attainment of the ozone standard.

The EPA believes that the scenarios

utilized in the Phoenix analysis are

adequate to determine that NOX

reductions that might reasonably be

considered in an attainment strategy

would not contribute to attainment in

the Phoenix area.

Comment: Some commenters

provided a comment that three years of

‘‘clean’’data fail to demonstrate that

NOX reductions would not contribute to

attainment.

Response: The EPA does not believe

that this comment is applicable to the

Phoenix area action because the area’s

section 182(f) petition is based on

modeling rather than ‘‘clean’’

monitoring data.

Comment: Some commenters

provided a comment on all section

182(f) actions that a waiver of NOX

controls is unlawful if such a waiver

will impede attainment and

maintenance of the ozone standard in

separate downwind areas.

Response: The EPA believes that

while this comment may be applicable

to proposed NOX exemption actions in

other areas, it is not applicable to the

Phoenix exemption action because the

EPA is unaware of, and the comment

itself does not specify, any downwind

area for which NOX transport is of

concern.

Comment: Comments were received

regarding exemption of areas from the

NOX requirements of the conformity

rules. They argue that such exemptions

waive only the requirements of section

182(b)(1) to contribute to specific

annual reductions, and do not waive the

requirement that conformity SIPs

contain information showing the

maximum amount of motor vehicle NOX

emissions allowed under the

transportation conformity rules and,

similarly, the maximum allowable

amounts of any such NOX emissions

under the general conformity rules. The
Federal Register / Vol. 60, No. 75 / Wednesday, April 19, 1995 / Rules and Regulations 19513

4 ‘‘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).

5 ‘‘Determining Conformity of General Federal

Actions to State or Federal Implementation Plans;

Final Rule,’’ November 30, 1993 (58 FR 63214).

commenters admit that, in prior

guidance, EPA has acknowledged the

need to amend a drafting error in the

existing transportation conformity rules

to ensure consistency with motor

vehicle emissions budgets for NOX, but

want EPA in actions on NOX

exemptions to explicitly affirm this

obligation and to also avoid granting

waivers until a budget controlling future

NOX increases is in place.

Response: With respect to conformity,

EPA’s conformity rules 4, 5 provide a

NOX waiver if an area receives a section

182(f) exemption. In its ‘‘Conformity;

General Preamble for Exemption From

Nitrogen Oxides Provisions,’’ 59 FR

31238, 31241 (June 17, 1994), EPA

reiterated its view that in order to

conform nonattainment and

maintenance areas must demonstrate

that the transportation plan and TIP are

consistent with the motor vehicle

emissions budget for NOX even where a

conformity NOX waiver has been

granted. Due to a drafting error, that

view is not reflected in the current

transportation conformity rules. As the

commenters correctly note, EPA states

in the June 17th notice that it intends to

remedy the problem by amending the

conformity rule. Although that notice

specifically mentions only requiring

consistency with the approved

maintenance plan’s NOX motor vehicle

emissions budget, EPA also intends to

require consistency with the attainment

demonstration’s NOX motor vehicle

emissions budget. However, the

exemption for the Phoenix area was

submitted pursuant to section 182(f)(3),

and EPA does not believe it is

appropriate to delay the statutory

deadline for acting on this petition until

the conformity rule is amended. As

noted earlier in response to a previous

issue raised by these commenters, this

issue has also been raised in a formal

petition for reconsideration of the

Agency’s final transportation conformity

rule and in litigation pending before the

U.S. Court of Appeals for the District of

Columbia Circuit on the substance of

both the transportation and general

conformity rules. This issue, thus, is

under consideration within the Agency,

but at this time remains unresolved. The

EPA, therefore, believes that until a

resolution of this issue is achieved, the

applicable rules governing this issue are

those that appear in the Agency’s final

conformity regulations, and the Agency

remains bound by their existing terms.

Comment: Some commenters argue

that the CAA does not authorize any

waiver of the NOX reduction

requirements until conclusive evidence

exists that such reductions are counterproductive.

Response: EPA does not agree with

this comment since it ignores

Congressional intent as evidenced by

the plain language of section 182(f), the

structure of the Title I ozone subpart as

a whole, and relevant legislative history.

By contrast, in developing and

implementing its NOX exemption

policies, EPA has sought an approach

that reasonably accords with Congress’

intent. Section 182(f), in addition to

imposing control requirements on major

stationary sources of NOX similar to

those that apply for such sources of

VOC, also provides for an exemption (or

limitation) from application of these

requirements if, under one of several

tests, EPA determines that in certain

areas NOX reductions would generally

not be beneficial. In subsection

182(f)(1), Congress explicitly

conditioned action on NOX exemptions

on the results of an ozone precursor

study required under section 185B.

Because of the possibility that reducing

NOX in a particular area may either not

contribute to ozone attainment or may

cause the ozone problem to worsen,

Congress included attenuating language,

not just in section 182(f) but throughout

the Title I ozone subpart, to avoid

requiring NOX reductions where it

would be nonbeneficial or

counterproductive. In describing these

various ozone provisions (including

section 182(f)), the House Conference

Committee Report states in pertinent

part: ‘‘[T]he Committee included a

separate NOX/VOC study provision in

section [185B] to serve as the basis for

the various findings contemplated in the

NOX provisions. The Committee does

not intend NOX reduction for

reduction’s sake, but rather as a measure

scaled to the value of NOX reductions

for achieving attainment in the

particular ozone nonattainment area.’’

H.R. Rep. No. 490, 101st Cong., 2d Sess.

257–258 (1990). As noted in response to

an earlier comment by these same

commenters, the command in

subsection 182(f)(1) that EPA ‘‘shall

consider’’ the 185B report taken together

with the timeframe the Act provides

both for completion of the report and for

acting on NOX exemption petitions

clearly demonstrate that Congress

believed the information in the

completed section 185B report would

provide a sufficient basis for EPA to act

on NOX exemption requests, even

absent the additional information that

would be included in affected areas’

attainment or maintenance

demonstrations. However, while there is

no specific requirement in the Act that

EPA actions granting NOX exemption

requests must await ‘‘conclusive

evidence’’, as the commenters argue,

there is also nothing in the Act to

prevent EPA from revisiting an

approved NOX exemption if warranted

due to better ambient information.

In addition, the EPA believes (as

described in EPA’s December 1993

guidance) that section 182(f)(1) of the

CAA provides that the new NOX

requirements shall not apply (or may be

limited to the extent necessary to avoid

excess reductions) if the Administrator

determines that any one of the following

tests is met:

(1) In any area, the net air quality

benefits are greater in the absence of

NOX reductions from the sources

concerned;

(2) In nonattainment areas not within

an ozone transport region, additional

NOX reductions would not contribute to

ozone attainment in the area; or

(3) In nonattainment areas within an

ozone transport region, additional NOX

reductions would not produce net ozone

air quality benefits in the transport

region.

Based on the plain language of section

182(f), EPA believes that each test

provides an independent basis for

receiving a full or limited NOX

exemption.

Only the first test listed above is

based on a showing that NOX reductions

are ‘‘counter-productive.’’ If one of the

tests is met (even if another test is

failed), the section 182(f) NOX

requirements would not apply or, under

the excess reductions provision, a

portion of these requirements would not

apply.

Comment: One commenter objected to

the adequacy of the modeling

demonstration in meeting the

fundamental requirements of EPA’s

guidance for applying the UAM,

because the record reflects that the

Phoenix area is not an area with a single

meteorological regime and no intensive

data from a field study was obtained for

modeling purposes. In addition to these

reasons, the commenter claims that

because there was not a field study

conducted with respect to the emissions

inventory and that modeling

performance was not very good at

several sites, the petition should be

denied.

Response: EPA’s Guideline on

Regulatory Application of the Urban
19514 Federal Register / Vol. 60, No. 75 / Wednesday, April 19, 1995 / Rules and Regulations

6 ‘‘Review of Ozone Episodes (1987–1991) in the

Phoenix Area’’, from the Arizona Department of

Environmental Quality to Systems Applications

International, September 17, 1992. This

memorandum is a summary of the characteristics of

the ozone episodes in the Phoenix area, including

annual, seasonal, and spatial distributions of the

exceedances.

Airshed Model (UAM guidance), EPA–

450/91–013, July 1991, describes

procedures for the appropriate use of

UAM, such as for attainment

demonstrations required of all ozone

nonattainment areas. This guidance

generally requires that for attainment

demonstrations, an area with a single

meteorological regime, must model

three episodes of that type of regime.

However, EPA believes that the results

of simulating two episodes with

intensive data from a field study would

be more reliable than simulating three

episodes with merely routine data.

In terms of the meteorological regime

issue, every day has different

meteorology and will yield different

ozone predictions. This does not

necessarily mean that each varying

meteorological day belongs to a different

meteorological regime. Regime refers to

a general pattern responsible for ozone

formation. In the case of Phoenix, as

documented in the Systems

Applications International (SA)

memorandum dated September 17,

1992,6 a single meteorological regime

exists in the Phoenix area which

consists of a low pressure system over

southwestern Arizona, with light

southwesterly flow during the

afternoon, and high temperatures. There

is nothing in the record that is

inconsistent with this description or

conclusion.

EPA guidance for UAM states that

three episodes should be modeled for

each observed meteorological regime.

However, in this case two episodes were

considered sufficient because it was

determined that data beyond that

routinely available would be gathered

and used to simulate ozone episodes. A

field study, documented in ‘‘Summer

1992 Phoenix Ozone Field Study’’

(ADEQ, 1/93), involved the collection of

data beyond that recorded on a routine

basis, such as meteorological and air

quality data aloft, VOC data, and extra

background air quality data. In addition,

because of the desire to use a fuller

database, episodes were selected from

among those that occurred during the

study.

There was not a ‘‘field study’’

conducted in regards to the emissions

inventory as field studies usually do not

refer to emissions inventories. The

emissions inventory in the Phoenix area

was developed using standard EPAapproved methods.

Because modeling performance is

never exact, EPA must evaluate whether

its performance is adequate for

regulatory decision-making. Although

modeling performance was not good at

several sites, and some under-prediction

occurred, the modeling exercise meets

EPA’s performance goals, and appears

overall to perform reasonably. Spatial

plots of the whole modeling domain and

time-series plots of individual stations

show reasonable performance. This is

illustrated by the model’s correct

responses to diagnostic and sensitivity

tests, in which various inputs are

changed in determining if the model

responds consistently with our

scientific understanding of ozone

formation. Therefore, EPA believes that

the overall modeling performance is

reasonable and acceptable.

Comment: One commenter contends

that the Phoenix modeling tests failed

the alternative ‘‘net air quality benefits’’

test because there were no ozone

decreases in some model grid cells on

the initial modeling day.

Response: While there was some

discussion, the ‘‘net air quality benefits’’

test was not relied on by Arizona in

support of the petition. Instead, two sets

of modeling runs were performed for

each modeling episode to meet the

‘‘contribute to attainment’’ test. The two

sets were substantial levels of pollutant

reductions and source-specific NOX

reductions. Together, these runs showed

that the specific reductions that would

occur under NOX RACT, and also levels

of NOX reductions likely to be examined

in an attainment demonstration, would

overall be counterproductive to ozone

attainment.

The effect of decreases in NOX will

always depend on location because a

decrease can increase ozone nearby in

time or space, and decrease it later and

farther away. The fact that various

modeling cells go up and down is far

less significant for regulatory purposes

than the effect on the overall peak.

The initial day of a modeling

simulation is typically not used, per

EPA guidance, because it is deemed too

dependent on uncertain initial

conditions for air quality, which must

be extrapolated in time and space from

relatively few measurements. Thus, the

decreases in ozone for the initial days of

the episodes modeled are not

considered meaningful. Results for the

second and later days of a simulation

are used, since these more closely

reflect the area’s actual emissions.

EPA Action

EPA is finalizing this action to exempt

the Phoenix ozone nonattainment area

from implementing the NOX

requirements for RACT, NSR, and the

applicable general and transportation

conformity and I/M requirements.

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).

Arizona submitted its ozone attainment

demonstration on November 15, 1994,

and EPA is currently in the process of

evaluating it in regards to meeting the

CAA requirements.

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 and implement the

NOX requirements, except to the extent

that modeling shows NOX reductions to

be ‘‘excess reductions’’. A determination

that the NOX exemption no longer

applies would mean that the NOX

general and transportation conformity

provisions would again be applicable

(see 58 FR 63214, 58 FR 62188; 59 FR

31238) to the affected area. In the

rulemaking action which removes the

exempt status, the EPA would specify a

schedule for Arizona to adopt the NOX

requirements and for sources to comply

with the applicable requirements.

The subsequent modeling analyses

mentioned above need not be limited to

those whose main purpose is to

demonstrate attainment in the 1994 SIP

revisions without the need for NOX

controls required under section 182(f).

State or local officials 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,

planning officials 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.

Nothing in this action should be

construed as permitting or allowing or

establishing a precedent for any future
Federal Register / Vol. 60, No. 75 / Wednesday, April 19, 1995 / Rules and Regulations 19515

request for 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.

Regulatory Process

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 action is not a

‘‘significant regulatory action’’ under

the terms of Executive Order 12866, and

is therefore not subject to OMB review.

Under section 307(b)(1) of the CAA,

petitions for judicial review of this

action must be filed in the United States

Court of Appeals for the appropriate

circuit by May 19, 1995. Filing a

petition for reconsideration by the

Administrator of this rule does not

affect the finality of this rule for the

purposes of judicial review nor does it

extend the time within which a petition

for judicial review may be filed, and

shall not postpone the effectiveness of

such a rule. This action may not be

challenged later in proceedings to

enforce its requirements. Section

307(b)(2).

List of Subjects in 40 CFR Part 52

Environmental protection, Air

pollution control, Hydrocarbons,

Incorporation by reference,

Intergovernmental relations, Nitrogen

dioxide, Ozone, Reporting and

recordkeeping requirements, Volatile

organic compounds.

NOTE: Incorporation by reference of

the State Implementation Plan for the

State of Arizona was approved by the

Director of the Federal Register on July

1, 1982.

Dated: April 11, 1995.

Carol M. Browner,

Administrator.

Part 52, chapter I, title 40 of the Code

of Federal Regulations is amended as

follows:

PART 52—[AMENDED]

1. The authority citation for part 52

continues to read as follows:

Authority: 42 U.S.C. 7401–7671q.

Subpart D—Arizona

2. Subpart D is amended by adding

§ 52.136 to read as follows:

§ 52.136 Control strategy for ozone:

Oxides of nitrogen.

EPA is approving an exemption

request submitted by the State of

Arizona on April 13, 1994 for the

Maricopa County ozone nonattainment

area from the NOX RACT requirements

contained in section 182(f) of the Clean

Air Act. This approval exempts the

Phoenix area from implementing the

NOX requirements for RACT, new

source review (NSR), and the applicable

general and transportation conformity

and inspection and maintenance (I/M)

requirements of the CAA. The

exemption is based on Urban Airshed

Modeling as lasts for only as long as the

area’s modeling continues to

demonstrate attainment without NOX

reductions from major stationary

sources.

[FR Doc. 95–9568 Filed 4–18–95; 8:45 am]

BILLING CODE 6560–50–W

40 CFR Part 52

[TX–49–1–6831; FRL–5193–8]

Approval and Promulgation of

Temporary Section 182(f) Exemption to

the Nitrogen Oxides (NOX) Control

Requirements for the Houston and

Beaumont Ozone Nonattainment

Areas; Texas

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: In this action, the EPA is

approving a petition from the State of

Texas requesting that the Houston and

Beaumont ozone nonattainment areas be

temporarily exempted 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 upon preliminary

photochemical grid modeling which

shows that reductions in NOX would be

detrimental to attaining the National

Ambient Air Quality Standards

(NAAQS) for ozone in these areas. This

temporary exemption is being requested

under section 182(f) of the CAA.

EFFECTIVE DATE: This action is effective

as of April 12, 1995.

ADDRESSES: Copies of the documents

relevant to these 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, Dallas, Texas

75202–2733

The Air and Radiation Docket and

Information Center, U.S.

Environmental Protection Agency,

401 M Street, SW., Washington, DC

20460

Texas Natural Resource Conservation

Commission, P.O. Box 13087, Austin,

Texas 78711–3087

FOR FURTHER INFORMATION CONTACT: Ms.

Leila Yim Surratt or Mr. Quang Nguyen,

Planning Section (6T–AP), Air Programs

Branch, EPA Region 6, 1445 Ross

Avenue, Dallas, Texas 75202–2733,

telephone (214) 665–7214.

SUPPLEMENTARY INFORMATION:

I. Background

On August 17, 1994, the Texas

Natural Resource Conservation

Commission (TNRCC) submitted to the

EPA a petition pursuant to section

182(f) of the CAA which requests that

the Houston and Beaumont ozone

nonattainment areas be temporarily

exempted by the EPA from the NOX

control requirements of section 182(f).

The Houston nonattainment area

includes the cities of Houston and

Galveston, and consists of the following

eight counties: Brazoria, Chambers, Fort

Bend, Galveston, Harris, Liberty,

Montgomery, and Waller. The

Beaumont nonattainment area includes

the cities of Beaumont and Port Arthur,

and consists of the following three

counties: Hardin, Jefferson, and Orange.

The State bases its petition on an Urban

Airshed Modeling (UAM)

demonstration showing that NOX

reductions would not contribute to

attainment in either area because the

decrease in ozone concentrations

resulting from volatile organic

compound (VOC) reductions alone is

equal to or greater than the decrease

obtained from NOX reductions or a

combination of VOC and NOX

reductions.

As described in the State’s petition,

the TNRCC plans to complete additional

UAM modeling between November

1995 and May 1996 using the results of

an intensive 1993 field study, the

Coastal Oxidant Assessment for

Southeast Texas (COAST). The data

collected through the COAST study

consist of hourly point source

emissions, gridded typical summer day

on-road mobile source emissions,

hourly air quality data, and detailed

meteorological data for specific ozone

exceedance episodes in the HoustonBeaumont domain. Because it is the

most comprehensive data set available,

it should result in greater accuracy in

the modeling and therefore in the