Federal Register / Vol. 77, No. 146 / Monday, July 30, 2012 / Proposed Rules 44551 

1The rule establishing the revised PM2.5 NAAQS 

was signed by the Administrator and publically 

disseminated on September 21, 2006. Because EPA 

did not prescribe a shorter period for section 110(a) 

‘‘infrastructure’’ SIP submittals for these NAAQS, 

these submittals were due on September 21, 2009, 

three years from the September 21, 2006 signature 

date pursuant to section 110(a)(1) of the CAA. See 

42 U.S.C. 7410(a)(1). 

2This proposed action does not address the 

remaining two elements of the transport SIP 

provision (in CAA section 110(a)(2)(D)(i)(II)) 

regarding interference with measures required to 

prevent significant deterioration of air quality or to 

protect visibility in another state. We intend to 

evaluate and act upon Arizona’s SIP submissions 

addressing these additional requirements of CAA 

section 110(a)(2)(D)(i) in separate rulemakings. We 

proposed action on Arizona’s provisions regarding 

interference with other states’ measures to prevent 

significant deterioration of air quality on June 27, 

2012. See 77 FR 38239. 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R09–OAR–2012–0398; FRL–9707–4] 

Approval of Air Quality Implementation 

Plans; Arizona; Interstate Transport of 

Fine Particulate Matter 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: EPA is proposing to approve 

a State Implementation Plan (SIP) 

revision submitted by the State of 

Arizona on October 14, 2009 and to 

determine that the existing SIP is 

adequate to address the requirements of 

section 110(a)(2)(D)(i)(I) of the Clean Air 

Act (CAA) for the 2006 National 

Ambient Air Quality Standard (NAAQS 

or standard) for fine particulate matter 

(PM2.5). Section 110(a)(2)(D)(i)(I) of the 

CAA requires that each SIP contain 

adequate provisions to prohibit air 

emissions from adversely affecting air 

quality in other states through interstate 

transport. EPA is proposing to approve 

the SIP revision submitted by Arizona 

and to conclude that additional control 

measures in Arizona are not necessary 

under CAA section 110(a)(2)(D)(i)(I) 

because emissions from Arizona sources 

do not contribute significantly to 

nonattainment or interfere with 

maintenance of the 2006 24-hour PM2.5

NAAQS in any other state. We are 

taking comments on this proposal and 

plan to follow with a final action. 

DATES: Written comments must be 

received on or before August 29, 2012. 

ADDRESSES: Submit your comments, 

identified by Docket ID Number EPA– 

R09–OAR–2012–0398, by one of the 

following methods: 

1. http://www.regulations.gov: Follow 

the on-line instructions for submitting 

comments. 

2. Email: vagenas.ginger@epa.gov. 

3. Fax: 415–942–3964. 

4. Mail or deliver: Ginger Vagenas 

(AIR–2), U.S. Environmental Protection 

Agency, Region IX, 75 Hawthorne 

Street, San Francisco, CA 94105–3901. 

Deliveries are only accepted during the 

Regional Office’s normal hours of 

operation. 

Instructions: All comments will be 

included in the public docket without 

change and may be made available 

online at http://www.regulations.gov, 

including any personal information 

provided, unless the comment includes 

Confidential Business Information (CBI) 

or other information whose disclosure is 

restricted by statute. Information that 

you consider CBI or otherwise protected 

should be clearly identified as such and 

should not be submitted through 

http://www.regulations.gov or email. 

http://www.regulations.gov is an 

anonymous access system, and EPA will 

not know your identity or contact 

information unless you provide it in the 

body of your comment. If you send 

email directly to EPA, your email 

address will be automatically captured 

and included as part of the public 

comment. If EPA cannot read your 

comment due to technical difficulties 

and cannot contact you for clarification, 

EPA may not be able to consider your 

comment. 

Docket: Generally, documents in the 

docket for this action are available 

electronically at www.regulations.gov 

and in hard copy at EPA Region IX, 75 

Hawthorne Street, San Francisco, 

California. While all documents in the 

docket are listed at 

www.regulations.gov, some information 

may be publicly available only at the 

hard copy location (e.g., copyrighted 

material, large maps), and some may not 

be publicly available in either location 

(e.g., CBI). To inspect the hard copy 

materials, please schedule an 

appointment during normal business 

hours with the contact listed in the FOR

FURTHER INFORMATION CONTACT section. 

FOR FURTHER INFORMATION CONTACT: 

Ginger Vagenas, Air Planning Office 

(AIR–2), U.S. Environmental Protection 

Agency, Region IX, (415) 972–3964 

vagenas.ginger@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Throughout this document, the terms 

‘‘we,’’ ‘‘us,’’ and ‘‘our’’ refer to EPA. 

Table of Contents 

I. Background 

II. The State’s Submittal 

III. EPA’s Evaluation 

IV. Proposed Action 

V. Statutory and Executive Order Reviews 

I. Background 

A. 2006 24-Hour PM2.5 NAAQS 

Infrastructure Requirements 

On September 21, 2006, EPA 

promulgated a final rule revising the 

1997 24-hour primary and secondary 

NAAQS for PM2.5 from 65 micrograms 

per cubic meter (mg/m3) to 35 mg/m3. 71 

FR 61144 (October 17, 2006). 

Section 110(a)(1) of the CAA requires 

each state to submit to EPA, within 3 

years (or such shorter period as the 

Administrator may prescribe) after the 

promulgation of a primary or secondary 

NAAQS or any revision thereof, a SIP 

that provides for the ‘‘implementation, 

maintenance, and enforcement’’ of such 

NAAQS. EPA refers to these specific 

submissions as ‘‘infrastructure’’ SIPs 

because they are intended to address 

basic structural SIP requirements for 

new or revised NAAQS. For the 2006 

24-hour PM2.5 NAAQS, these 

infrastructure SIPs were due on 

September 21, 2009.1 Section 110(a)(2) 

includes a list of specific elements that 

each such plan submission must meet, 

including section 110(a)(2)(D)(i), which 

pertains to interstate transport of certain 

emissions. 

The transport SIP provisions in 

section 110(a)(2)(D)(i) (also called ‘‘good 

neighbor’’ provisions) require each state 

to submit a SIP that prohibits emissions 

that adversely affect another state in the 

ways contemplated in the statute. 

Section 110(a)(2)(D)(i) identifies four 

distinct elements related to the 

evaluation of impacts of interstate 

transport of air pollutants. In this action, 

EPA is addressing the first two elements 

of this section (i.e., the requirements in 

section 110(a)(2)(D)(i)(I) to prohibit 

emissions activity within a state that 

will significantly contribute to 

nonattainment or interfere with 

maintenance of the NAAQS in any other 

state) for the 2006 24-hour PM2.5

NAAQS.2

The first element of section 

110(a)(2)(D)(i) requires that each SIP for 

a new or revised NAAQS contain 

adequate measures to prohibit any 

source or other type of emissions 

activity within the state from emitting 

air pollutants that will ‘‘contribute 

significantly to nonattainment’’ of the 

NAAQS in another state. The second 

element of CAA section 110(a)(2)(D)(i) 

requires that each SIP prohibit any 

source or other type of emissions 

activity in the state from emitting 

pollutants that will ‘‘interfere with 

maintenance’’ of the applicable NAAQS 

in any other state. 


srobinson on DSK4SPTVN1PROD with PROPOSALS
44552 Federal Register / Vol. 77, No. 146 / Monday, July 30, 2012 / Proposed Rules 

3See ‘‘Finding of Significant Contribution and 

Rulemaking for Certain States in the Ozone 

Transport Assessment Group Region for Purposes of 

Reducing Regional Transport of Ozone,’’ 63 FR 

57356 (October 27, 1998) (‘‘NOX SIP Call’’). 

4See ‘‘Rule to Reduce Interstate Transport of Fine 

Particulate Matter and Ozone (Clean Air Interstate 

Rule); Revisions to Acid Rain Program; Revisions to 

the NOX SIP Call,’’ 70 FR 25162 (May 12, 2005) 

(‘‘CAIR’’). 

5See ‘‘Federal Implementation Plans: Interstate 

Transport of Fine Particulate Matter and Ozone and 

Correction of SIP Approvals; Final Rule,’’ 76 FR 

48208 (August 8, 2011) (‘‘Transport Rule’’). 

6See 63 FR 57356 (October 27, 1998). EPA’s 

general approach to section 110(a)(2)(D) in the NOX

SIP Call was upheld in Michigan v. EPA, 213 F.3d 

663 (D.C. Cir. 2000), cert denied, 532 U.S. 904 

(2001). However, EPA’s approach to interference 

with maintenance in the NOX SIP Call was not 

explicitly reviewed by the court. See North Carolina 

v. EPA, 531 F.3d 896, 907–09 (D.C. Cir. 2008). 

7 Ibid. 

8See 70 FR 25162 at 25263–69 (May 12, 2005). 

9CAIR did not address the 2006 24-hour PM2.5

NAAQS. 

10See Order dated December 30, 2011, EME 

Homer City Generation, L.P. v. EPA (No. 11–1302 

and consolidated cases) (D.C. Circuit). 

11See Memorandum from William T. Harnett 

entitled ‘‘Guidance on SIP Elements Required 

Under Sections 110(a)(1) and (2) for the 2006 

24-Hour Fine Particle (PM2.5) National Ambient Air 

Quality Standards (NAAQS),’’ September 25, 2009. 

12See Memorandum from William T. Harnett 

entitled ‘‘Guidance for State Implementation Plan 

(SIP) Submission to Meet Current Outstanding 

Obligations Under Section 110(a)(2)(D)(i) for the 

8-hour ozone and PM2.5 National Ambient Air 

Quality Standards,’’ August 15, 2006. 

B. NOX SIP Call, Clean Air Interstate 

Rule (CAIR) and the Transport Rule 

EPA has previously addressed the 

requirements of section 110(a)(2)(D)(i)(I) 

in past regulatory actions such as the 

1998 NOX SIP call,3 the 2005 Clean Air 

Interstate Rule (‘‘CAIR’’),4 and the 2011 

Transport Rule (also known as the 

‘‘Cross-State Air Pollution Rule’’ or 

‘‘CSAPR’’).5 In the NOX SIP call, EPA 

took action to remediate emissions of 

nitrogen oxides (NOX) that significantly 

contributed to nonattainment of, or 

interfered with maintenance of, the then 

applicable ozone NAAQS through 

interstate transport of NOX and the 

resulting ozone.6 Through this rule, EPA 

evaluated whether or not the ozoneseason NOX emissions in certain states 

had prohibited interstate impacts, and if 

they had such impacts, required the 

states to adopt substantive SIP revisions 

to eliminate the NOX emissions, 

whether through participation in a 

regional cap and trade program or by 

other means.7

After promulgation of the 1997 8-hour 

ozone NAAQS and the 1997 PM2.5

NAAQS, EPA again recognized that 

regional transport was a serious concern 

throughout the eastern United States 

and therefore developed CAIR to 

address emissions of sulfur dioxide 

(SO2) and NOX that exacerbate ambient 

ozone and PM2.5 levels in many 

downwind areas through interstate 

transport.8 Within CAIR, EPA 

interpreted the term ‘‘interfere with 

maintenance’’ as part of the evaluation 

of whether or not the emissions of 

sources in certain states had such 

impacts on areas that EPA projected 

would be in violation of the NAAQS 

unless actions were taken by upwind 

states to reduce SO2 and NOX emissions. 

Through CAIR, EPA again required 

states that had such interstate impacts to 

adopt substantive SIP revisions to 

eliminate the SO2 and NOX emissions, 

whether through participation in a 

regional cap and trade program or by 

other means. 

In 2008, the U.S. Court of Appeals for 

the D.C. Circuit found that CAIR and the 

related CAIR federal implementation 

plans were unlawful. North Carolina v. 

EPA, 531 F.3d 896 (D.C. Cir. 2008), 

modified on rehearing, North Carolina 

v. EPA, 550 F.3d 1176, 1178 (D.C. Cir. 

2008). Among other issues, the court 

held that EPA had not correctly 

addressed the second element of section 

110(a)(2)(D)(i)(I) in CAIR and noted that 

‘‘EPA gave no independent significance 

to the ‘interfere with maintenance’ 

prong of section 110(a)(2)(D)(i)(I) to 

separately identify upwind sources 

interfering with downwind 

maintenance.’’ 531 F.3d at 909. EPA’s 

approach, the court reasoned, would 

leave areas that are ‘‘barely meeting 

attainment’’ with ‘‘no recourse’’ to 

address upwind emissions sources. Id. 

The court therefore concluded that a 

plain language reading of the statute 

requires EPA to give independent 

meaning to the interfere with 

maintenance requirement of section 

110(a)(2)(D)(i) and that the approach 

used by EPA in CAIR failed to do so. 

To address the judicial remand of 

CAIR and to replace it, on August 8, 

2011, EPA published the final Transport 

Rule. 76 FR 48208. The Transport Rule 

addresses interstate transport pursuant 

to CAA section 110(a)(2)(D)(i)(I) in the 

eastern United States with respect to the 

1997 8-hour ozone NAAQS, the 1997 

PM2.5 NAAQS, and the 2006 24-hour 

PM2.5 NAAQS.9 As part of this 

rulemaking, EPA specifically 

reexamined the section 110(a)(2)(D)(i)(I) 

requirements to prohibit emissions from 

sources in a state that ‘‘contribute 

significantly to nonattainment’’ or 

‘‘interfere with maintenance’’ of the 

NAAQS in other states and developed 

an approach to identify (1) areas that it 

predicts to be violating the NAAQS, and 

(2) areas that it predicts to be close to 

the level of these NAAQS and therefore 

at risk to become nonattainment unless 

emissions from sources in other states 

are appropriately controlled. This 

approach starts by identifying those 

specific geographic areas for which 

further evaluation is appropriate and 

differentiates between areas where the 

concern is significant contribution to 

nonattainment as opposed to 

interference with maintenance. EPA 

then conducts state-specific analyses of 

multiple factors related to pollution 

levels at the identified ‘‘receptors’’ 

(monitoring sites) of concern to evaluate 

significant contribution to 

nonattainment and interference with 

maintenance of the NAAQS in other 

states. 

On December 30, 2011, the U.S. Court 

of Appeals for the D.C. Circuit issued an 

order addressing the status of the 

Transport Rule and CAIR in response to 

motions filed by numerous parties 

seeking a stay of the Transport Rule 

pending judicial review.10 In that order, 

the court stayed the Transport Rule 

pending resolution of these petitions for 

review of the rule. The court also stated 

that EPA is expected to continue to 

administer CAIR in the interim until the 

court rules on these petitions for review 

of the Transport Rule. 

C. EPA Guidance 

On September 25, 2009, after the 

court remanded CAIR and while EPA 

was working on its replacement, EPA 

issued a guidance memorandum that 

provides recommendations to states for 

making submissions to meet the 

requirements of CAA section 

110(a)(2)(D)(i) for the 2006 PM2.5

standards (‘‘2006 PM2.5 NAAQS 

Infrastructure Guidance’’ or 

‘‘Guidance’’).11 With respect to the 

requirement in section 110(a)(2)(D)(i)(I) 

to prohibit emissions that would 

contribute significantly to 

nonattainment of the NAAQS in any 

other state, the 2006 PM2.5 NAAQS 

Infrastructure Guidance essentially 

reiterated the recommendations for 

western states made by EPA in previous 

guidance addressing the 110(a)(2)(D)(i) 

requirements for the 1997 8-hour Ozone 

and 1997 PM2.5 NAAQS.12 The 2006 

PM2.5 NAAQS Infrastructure Guidance 

advised states outside of the CAIR 

region to include in their section 

110(a)(2)(D)(i)(I) SIPs adequate technical 

analyses to support their conclusions 

regarding interstate pollution transport, 

e.g., information concerning emissions 

in the state, meteorological conditions 

in the state and in potentially impacted 

states, monitored ambient pollutant 

concentrations in the state and in 

potentially impacted states, distances to 


srobinson on DSK4SPTVN1PROD with PROPOSALS
Federal Register / Vol. 77, No. 146 / Monday, July 30, 2012 / Proposed Rules 44553 

13The 2006 PM2.5 NAAQS Infrastructure 

Guidance stated that EPA was working on a new 

rule to replace CAIR that would address issues 

raised by the court in the North Carolina case and 

that would provide guidance to states in addressing 

the requirements related to interstate transport in 

CAA section 110(a)(2)(D)(i)(I) for the 2006 PM2.5

NAAQS. It also noted that states could not rely on 

the CAIR rule for section 110(a)(2)(D)(i)(I) 

submissions for the 2006 24-hour PM2.5 NAAQS 

because the CAIR rule did not address this NAAQS. 

See 2006 PM2.5 NAAQS Infrastructure Guidance 

at 3. 

14See Transport Rule Proposal, 75 FR 45210 at 

45227 (August 2, 2010). 

15ADEQ intended for this SIP submittal to also 

address all other requirements of CAA section 

110(a), excepting section 110(a)(2)(G), for the 1997 

8-hour ozone and PM2.5 NAAQS and the 2006 PM2.5

NAAQS. See letter dated October 14, 2009, from 

Eric C. Massey, Air Quality Director, ADEQ, to 

Laura Yoshii, Acting Regional Administrator, EPA 

Region 9, with enclosures. EPA has proposed to act 

on this submittal for purposes of addressing the 

other ‘‘infrastructure’’ requirements of CAA section 

110(a) in a separate proposed rule published on 

June 27, 2012 (77 FR 38239). 

the nearest areas not attaining the 

NAAQS in other states, and air quality 

modeling. See 2006 PM2.5 NAAQS 

Infrastructure Guidance at 3.13 With 

respect to the requirement in section 

110(a)(2)(D)(i)(I) to prohibit emissions 

that would interfere with maintenance 

of the NAAQS by any other state, the 

Guidance stated that SIP submissions 

must address this independent 

requirement of the statute and provide 

technical information appropriate to 

support the state’s conclusions, such as 

information concerning emissions in the 

state, meteorological conditions in the 

state and in potentially impacted states, 

monitored ambient concentrations in 

the state and in potentially impacted 

states, and air quality modeling. See 

2006 PM2.5 NAAQS Infrastructure 

Guidance at 3, 4. 

In this action, EPA is maintaining the 

conceptual approach to evaluating 

interstate pollution transport under 

CAA section 110(a)(2)(D)(i)(I) that the 

Agency provided in the 2006 PM2.5

NAAQS Infrastructure Guidance and the 

Transport Rule. 

As described more fully in our 

Technical Support Document (TSD), 

EPA evaluated data from existing 

monitors over three overlapping 3-year 

periods (i.e., 2006–2008, 2007–2009, 

and 2008–2010) to determine which 

areas are expected to be violating the 

2006 24-hour PM2.5 NAAQS and which 

areas are predicted to potentially have 

difficulty maintaining attainment. In 

essence, if a monitoring site shows a 

violation of the 2006 24-hour PM2.5

NAAQS during the most recent 3-year 

period (2008–2010), then this monitor 

location is appropriate for evaluation for 

purposes of the significant contribution 

to nonattainment element of section 

110(a)(2)(D)(i)(I). If, on the other hand, 

a monitoring site shows attainment of 

the 2006 24-hour PM2.5 NAAQS during 

the most recent 3-year period (2008– 

2010) but a violation in at least one of 

the previous two 3-year periods (2006– 

2008 or 2007–2009), then this monitor 

location is appropriate for evaluation for 

purposes of the interfere with 

maintenance element of the statute. 

By this method, EPA has identified 

those areas with monitors that are 

appropriate ‘‘nonattainment receptors’’ 

or ‘‘maintenance receptors’’ for 

evaluating whether the emissions from 

sources in another state could 

significantly contribute to 

nonattainment in, or interfere with 

maintenance in, that particular area. 

EPA believes that this approach for 

identifying areas that are predicted to be 

nonattainment and significantly 

impacted by other states, or have 

difficulty maintaining the NAAQS, is 

appropriate to evaluate a state’s 

submission in relation to the elements 

of CAA section 110(a)(2)(D)(i)(I) 

pertaining to significant contribution to 

nonattainment and interference with 

maintenance. 

EPA continues to believe that the 

more widespread and serious transport 

problems in the eastern United States 

are analytically distinct.14 For the 2006 

PM2.5 NAAQS, EPA believes that 

nonattainment and maintenance 

problems in the western United States 

are relatively local in nature with only 

limited impacts from interstate 

transport. In the Transport Rule, EPA 

did not calculate the portion of any 

downwind state’s predicted PM2.5

concentrations that would result from 

emissions from individual western 

states, such as Arizona. Accordingly, 

EPA believes that section 

110(a)(2)(D)(i)(I) SIP submissions for 

states outside the geographic area 

analyzed to develop the Transport Rule 

may be evaluated using a ‘‘weight of the 

evidence’’ approach that takes into 

account available relevant information, 

such as that recommended by EPA in 

the 2006 PM2.5 NAAQS Infrastructure 

Guidance. Such information may 

include, but is not limited to, the 

amount of emissions in the state 

relevant to the NAAQS in question, the 

meteorological conditions in the area, 

the distance from the state to the nearest 

monitors in other states that are 

appropriate receptors, or such other 

information as may be probative to 

consider whether sources in the state 

may contribute significantly to 

nonattainment or interfere with 

maintenance of the 2006 24-hour PM2.5

NAAQS in other states. These 

submissions can rely on modeling when 

acceptable modeling technical analyses 

are available, but EPA does not believe 

that modeling is necessarily required if 

other available information is sufficient 

to evaluate the presence or degree of 

interstate transport in a given situation. 

II. The State’s Submittal 

CAA sections 110(a) and 110(l) 

require that revisions to a SIP be 

adopted by the State after reasonable 

notice and public hearing. EPA has 

promulgated specific procedural 

requirements for SIP revisions in 40 

CFR part 51, subpart F. These 

requirements include publication of 

notices, by prominent advertisement in 

the relevant geographic area, of a public 

hearing on the proposed revisions, a 

public comment period of at least 30 

days, and an opportunity for a public 

hearing. 

On October 14, 2009, the Arizona 

Department of Environmental Quality 

(ADEQ) submitted the ‘‘Arizona State 

Implementation Plan Revision under 

Clean Air Act Section 110(a)(1) and (2); 

2006 PM2.5 NAAQS, 1997 PM2.5 NAAQS 

and 1997 8-hour Ozone NAAQS,’’ to 

address the requirements of CAA 

section 110(a)(2)(D)(i)(I) for the 2006 

PM2.5 NAAQS, among other 

requirements (‘‘2009 Infrastructure 

Analysis’’).15 Within that submittal, 

Appendix B, ‘‘Clean Air Act Section 

110(a)(2)(D)(i)—Interstate Transport 

Analysis for the 2006 PM2.5 National 

Ambient Air Quality Standards’’ 

(referred to herein as ‘‘PM2.5 Transport 

Analysis’’) addresses the CAA section 

110(a)(2)(D)(i)(I) interstate transport 

requirements that are the subject of this 

proposed rule. 

ADEQ’s October 14, 2009 submittal 

includes public process documentation 

for the 2009 Infrastructure Analysis, 

including the PM2.5 Transport Analysis. 

In addition, the SIP revision includes 

documentation of a duly noticed public 

hearing held on September 16, 2009, on 

the proposed 2009 Infrastructure 

Analysis. 

We find that the process followed by 

ADEQ in adopting the PM2.5 Transport 

Analysis complies with the procedural 

requirements for SIP revisions under 

CAA section 110 and EPA’s 

implementing regulations. 

III. EPA’s Evaluation 

To determine whether the CAA 

section 110(a)(2)(D)(i)(I) requirement is 

satisfied, EPA must determine whether 

a state’s emissions contribute 

significantly to nonattainment or 


srobinson on DSK4SPTVN1PROD with PROPOSALS
44554 Federal Register / Vol. 77, No. 146 / Monday, July 30, 2012 / Proposed Rules 

16See NOX SIP Call, 63 FR 57371 (October 27, 

1998); CAIR, 70 FR 25172 (May 12, 2005); and 

Transport Rule or Cross-State Air Pollution Rule, 76 

FR 48208 (August 8, 2011). 

17EPA has also considered potential PM2.5

transport from Arizona to the nearest nonattainment 

and maintenance receptors located in the eastern, 

midwestern and southern states covered by the 

Transport Rule and believes it is reasonable to 

conclude that, given the significant distance from 

Arizona to the nearest such receptor (in Illinois) 

and the relatively insignificant amount of emissions 

from Arizona that could potentially be transported 

such a distance, emissions from Arizona sources do 

not significantly contribute to nonattainment or 

interfere with maintenance of the 2006 24-hour 

PM2.5 NAAQS at this location. These same factors 

also support a finding that emissions from Arizona 

sources neither contribute significantly to 

nonattainment nor interfere with maintenance of 

the 2006 24-hour PM2.5 NAAQS at any location 

further east. See TSD at Section I.B.3. 

18Because CAIR did not cover states in the 

western United States, these data are not 

significantly impacted by the remanded CAIR and 

thus could be considered in this analysis. In 

contrast, recent air quality data in the eastern, 

midwestern and southern states are significantly 

impacted by reductions associated with CAIR and 

because the Transport Rule was developed to 

replace CAIR, EPA could not consider reductions 

associated with the CAIR in the base case transport 

analysis for those states. See 76 FR at 48223–24. 

19EPA did not identify any nonattainment 

receptors in New Mexico or Colorado. 

20EPA did not identify any nonattainment 

receptors in Wyoming. 

interfere with maintenance in 

downwind areas. If this factual finding 

is in the negative, then section 

110(a)(2)(D)(i)(I) does not require any 

changes to a state’s SIP. If, however, the 

evaluation reveals that emissions from 

sources within the state do contribute 

significantly to nonattainment or 

interfere with maintenance in other 

states, then the state must adopt 

substantive provisions to eliminate 

those emissions. The state could achieve 

any required reductions through 

traditional command and control 

programs, or at its own election, through 

participation in a cap and trade 

program. Consistent with EPA’s 

approach in the 1998 NOX SIP call, the 

2005 CAIR, and the 2011 Transport 

Rule,16 EPA is evaluating these impacts 

with respect to specific monitors 

identified as having nonattainment and/ 

or maintenance problems, which we 

refer to as ‘‘receptors.’’ EPA notes that 

no single piece of information is by 

itself dispositive of the issue. Instead, 

the total weight of all the evidence taken 

together is used to evaluate significant 

contributions to nonattainment or 

interference with maintenance of the 

2006 24-hour PM2.5 NAAQS in another 

state. 

This proposed approval addresses the 

requirements of CAA section 

110(a)(2)(D)(i)(I) for the 2006 24-hour 

PM2.5 NAAQS in several ways. It takes 

into account Arizona’s PM2.5 Transport 

Analysis, which explains that 

meteorological and other characteristics 

in Arizona and in the surrounding areas 

reduce the likelihood that Arizona’s 

emissions contribute significantly to 

nonattainment or interfere with 

maintenance of the 2006 24-hour PM2.5

NAAQS in any downwind state. In 

addition, EPA has supplemented its 

evaluation of Arizona’s submittal with a 

review of the monitors in other states 

that are appropriate ‘‘nonattainment 

receptors’’ or ‘‘maintenance receptors,’’ 

consistent with EPA’s approach in the 

Transport Rule, and additional technical 

information to consider whether sources 

in Arizona contribute significantly to 

nonattainment or interfere with 

maintenance of the 2006 24-hour PM2.5

NAAQS in other states. 

Our Technical Support Document 

(TSD) contains a more detailed 

evaluation and is available in the public 

docket for this rulemaking, which may 

be accessed online at http:// 

www.regulations.gov, docket number 

EPA–R09–OAR–2012–0398. We provide 

below a summary of our analysis. 

A. Evaluation of Significant 

Contribution to Nonattainment 

EPA reviewed the State of Arizona’s 

PM2.5 Transport Analysis and additional 

technical information to evaluate the 

potential for Arizona emissions to 

contribute significantly to 

nonattainment of the 2006 PM2.5

NAAQS at specified monitoring sites in 

the western United States.17 EPA first 

identified as ‘‘nonattainment receptors’’ 

all monitoring sites in the western states 

that had recorded PM2.5 design values 

above the level of the 2006 24-hour 

PM2.5 NAAQS (35 mg/m3) during the 

years 2008–2010.18 See Section III of the 

TSD for more a more detailed 

description of EPA’s methodology for 

selection of nonattainment receptors. 

Because geographic distance is a 

relevant factor in the assessment of 

potential pollution transport, EPA 

focused its review on information 

related to potential transport of PM2.5

pollution from Arizona to 

nonattainment receptors in the states 

bordering Arizona: Utah, Nevada, and 

California.19 With respect to Utah and 

Nevada, as detailed in the TSD, EPA 

believes that the following factors 

support a finding that emissions from 

Arizona do not significantly contribute 

to nonattainment of the 2006 24-hour 

PM2.5 NAAQS in either of these states: 

(1) Technical information indicating 

that elevated PM2.5 levels at 

nonattainment receptors are 

predominantly caused by local emission 

sources, (2) air quality data indicating 

that regional background levels of PM2.5

are generally low during the time 

periods of elevated PM2.5 at these 

receptors, and (3) the presence of 

significant terrain, which creates a 

physical impediment to pollution 

transport. Similarly and again as 

detailed in the TSD, with respect to 

California, technical information 

indicating that elevated PM2.5 levels at 

the nonattainment receptors are 

predominantly caused by local emission 

sources and that the dominant air flows 

across California are from the west to 

the east support a finding that emissions 

from the state of Arizona do not 

significantly contribute to 

nonattainment of the 2006 24-hour 

PM2.5 standards in California. 

EPA also evaluated potential PM2.5

transport to nonattainment receptors in 

the more distant western states of 

Oregon, Washington, Idaho, and 

Montana.20 EPA believes that the 

following factors support a finding that 

emissions from Arizona do not 

significantly contribute to 

nonattainment of the 2006 24-hour 

PM2.5 NAAQS in any of these states: (1) 

The significant distance from the State 

of Arizona to the nonattainment 

receptors in these states, (2) technical 

information indicating that elevated 

PM2.5 levels at nonattainment receptors 

in these states are predominantly caused 

by local emission sources, (3) air quality 

data indicating that regional background 

levels of PM2.5 are generally low during 

the time periods of elevated PM2.5 at 

these receptors, and (4) the presence of 

significant terrain, which creates a 

physical impediment to pollution 

transport. 

Based on this evaluation of Arizona’s 

PM2.5 Transport Analysis and additional 

technical information, EPA proposes to 

conclude that emissions of direct PM2.5

and PM2.5 precursors from sources in 

the State of Arizona do not significantly 

contribute to nonattainment of the 2006 

24-hour PM2.5 standards in any other 

state and that CAA section 

110(a)(2)(D)(i)(I) therefore does not 

require Arizona to adopt additional 

controls for purposes of implementing 

the 2006 24-hour PM2.5 standards. 

B. Evaluation of Interference With 

Maintenance 

EPA reviewed the State of Arizona’s 

PM2.5 Transport Analysis and additional 

technical information to evaluate the 

potential for Arizona emissions to 

interfere with maintenance of the 2006 

24-hour PM2.5 standards at specified 

monitoring sites in the western U.S. 

EPA first identified as ‘‘maintenance 


srobinson on DSK4SPTVN1PROD with PROPOSALS
Federal Register / Vol. 77, No. 146 / Monday, July 30, 2012 / Proposed Rules 44555 

21As this analysis focused on interstate transport, 

EPA did not evaluate the impact of Arizona 

emissions on maintenance receptors within 

Arizona. (EPA has not identified any nonattainment 

receptors in Arizona.) 

receptors’’ all monitoring sites in the 

western states that had recorded PM2.5

design values above the level of the 

2006 24-hour PM2.5 NAAQS (35 mg/m3) 

during the 2006–2008 and/or 2007–2009 

periods but below this standard during 

the 2008–2010 period. See section IV of 

the TSD for more information regarding 

EPA’s methodology for selection of 

maintenance receptors. All of the 

maintenance receptors in the western 

states are located in California, Utah, 

and Arizona. EPA therefore evaluated 

the potential for transport of Arizona 

emissions to the maintenance receptors 

located in California and Utah.21 As 

detailed in the TSD, EPA believes that 

the following factors support a finding 

that emissions from Arizona do not 

interfere with maintenance of the 2006 

24-hour PM2.5 NAAQS in either state: 

(1) Technical information indicating 

that elevated PM2.5 levels at these 

maintenance receptors are 

predominantly caused by local emission 

sources, and (2) technical information 

indicating that the dominant air flows 

across California are from the west to 

the east. 

Based on this evaluation of Arizona’s 

PM2.5 Transport Analysis and additional 

technical information, EPA proposes to 

conclude that emissions of direct PM2.5

and PM2.5 precursors from sources in 

the State of Arizona do not interfere 

with maintenance of the 2006 24-hour 

PM2.5 standards in any other state and 

that CAA section 110(a)(2)(D)(i)(I) 

therefore does not require Arizona to 

adopt additional controls for purposes 

of implementing the 2006 24-hour PM2.5

standards. 

C. Section 110(l) of the Act 

Section 110(l) of the Act prohibits 

EPA from approving any SIP revision 

that would interfere with any applicable 

requirement concerning attainment and 

reasonable further progress (RFP) or any 

other applicable requirement of the Act. 

The PM2.5 Transport Analysis contains 

no regulatory provisions and does not 

affect any requirement in Arizona’s 

applicable implementation plan. We 

propose to determine that our approval 

of the PM2.5 Transport Analysis would 

comply with CAA section 110(l) 

because the proposed SIP revision 

would not interfere with the on-going 

process for ensuring that requirements 

for RFP and attainment of the NAAQS 

are met. The SIP revision does not alter 

any provisions in the SIP as EPA has 

concluded, based on its supplemental 

analysis, that the existing SIP is 

sufficient to meet the requirements of 

110(a)(2)(D)(i)(I). Our TSD contains a 

more detailed discussion of our 

evaluation. 

IV. Proposed Action 

Under section 110(k) of the Clean Air 

Act, EPA is proposing to approve a SIP 

revision submitted by the State of 

Arizona on October 14, 2009 and to 

determine, based on that submission 

and additional EPA analysis, that 

emissions from Arizona sources do not 

contribute significantly to 

nonattainment of the 2006 24-hour 

PM2.5 NAAQS in any other state or 

interfere with maintenance of the 2006 

24-hour PM2.5 NAAQS by any other 

state. Accordingly, we propose to 

conclude that the existing SIP is 

adequate to address the requirements of 

section 110(a)(2)(D)(i)(I) of the Clean Air 

Act (CAA) for the 2006 National 

Ambient Air Quality Standard (NAAQS 

or standard) for fine particulate matter 

(PM2.5) and that additional control 

measures in Arizona are not necessary 

for this purpose. 

EPA is soliciting public comments on 

this proposal and will accept comments 

until the date noted in the DATES section 

above. 

V. Statutory and Executive Order 

Reviews 

Under the Clean Air Act, the 

Administrator is required to approve a 

SIP submission that complies with the 

provisions of the Act and applicable 

Federal regulations. 42 U.S.C. 7410(k); 

40 CFR 52.02(a). Thus, in reviewing SIP 

submissions, EPA’s role is to approve 

state choices, provided that they meet 

the criteria of the Clean Air Act. 

Accordingly, this action merely 

proposes to approve state law as 

meeting Federal requirements and does 

not impose additional requirements 

beyond those imposed by state law. For 

that reason, this proposed action: 

• Is not a ‘‘significant regulatory 

action’’ subject to review by the Office 

of Management and Budget under 

Executive Order 12866 (58 FR 51735, 

October 4, 1993); 

• Does not impose an information 

collection burden under the provisions 

of the Paperwork Reduction Act (44 

U.S.C. 3501 et seq.); 

• Is certified as not having a 

significant economic impact on a 

substantial number of small entities 

under the Regulatory Flexibility Act 

(5 U.S.C. 601 et seq.); 

• Does not contain any unfunded 

mandate or significantly or uniquely 

affect small governments, as described 

in the Unfunded Mandates Reform Act 

of 1995 (Pub. L. 104–4); 

• Does not have Federalism 

implications as specified in Executive 

Order 13132 (64 FR 43255, August 10, 

1999); 

• Is not an economically significant 

regulatory action based on health or 

safety risks subject to Executive Order 

13045 (62 FR 19885, April 23, 1997); 

• Is not a significant regulatory action 

subject to Executive Order 13211 (66 FR 

28355, May 22, 2001); 

• Is not subject to requirements of 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (15 U.S.C. 272 note) because 

application of those requirements would 

be inconsistent with the Clean Air Act; 

and 

• Does not provide EPA with the 

discretionary authority to address, as 

appropriate, disproportionate human 

health or environmental effects, using 

practicable and legally permissible 

methods, under Executive Order 12898 

(59 FR 7629, February 16, 1994). 

In addition, this proposed rule does not 

have tribal implications as specified by 

Executive Order 13175 (65 FR 67249, 

November 9, 2000), because the SIP is 

not approved to apply in Indian country 

located in the state, and EPA notes that 

it will not impose substantial direct 

costs on tribal governments or preempt 

tribal law. 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Intergovernmental 

relations, Nitrogen dioxide, Ozone, 

Reporting and recordkeeping 

requirements, Volatile organic 

compounds. 

Authority: 42 U.S.C. 7401 et seq. 

Dated: July 20, 2012. 

Jared Blumenfeld, 

Regional Administrator, Region IX. 

[FR Doc. 2012–18545 Filed 7–27–12; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R09–OAR–2012–0398; FRL–9707–5] 

Partial Approval and Disapproval of Air 

Quality Implementation Plans; Arizona; 

State Board Requirements for Ozone 

and Fine Particulate Matter 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: EPA is proposing to partially 

approve and partially disapprove a State 


srobinson on DSK4SPTVN1PROD with PROPOSALS