19292 Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 

have determined that it does not have 

implications for federalism. 

Unfunded Mandates Reform Act 

The Unfunded Mandates Reform Act 

of 1995 (2 U.S.C. 1531–1538) requires 

Federal agencies to assess the effects of 

their discretionary regulatory actions. In 

particular, the Act addresses actions 

that may result in the expenditure by a 

State, local, or tribal government, in the 

aggregate, or by the private sector of 

$100,000,000 (adjusted for inflation) or 

more in any one year. Though this 

proposed rule would not result in such 

an expenditure, we do discuss the 

effects of this rule elsewhere in this 

preamble. 

Taking of Private Property 

This proposed rule would not cause a 

taking of private property or otherwise 

have taking implications under 

Executive Order 12630, Governmental 

Actions and Interference with 

Constitutionally Protected Property 

Rights. 

Civil Justice Reform 

This proposed rule meets applicable 

standards in sections 3(a) and 3(b)(2) of 

Executive Order 12988, Civil Justice 

Reform, to minimize litigation, 

eliminate ambiguity, and reduce 

burden. 

Protection of Children 

We have analyzed this proposed rule 

under Executive Order 13045, 

Protection of Children from 

Environmental Health Risks and Safety 

Risks. This rule is not an economically 

significant rule and would not create an 

environmental risk to health or risk to 

safety that might disproportionately 

affect children. 

Indian Tribal Governments 

This proposed rule does not have 

tribal implications under Executive 

Order 13175, Consultation and 

Coordination with Indian Tribal 

Governments, because it would not have 

a substantial direct effect on one or 

more Indian tribes, on the relationship 

between the Federal Government and 

Indian tribes, or on the distribution of 

power and responsibilities between the 

Federal Government and Indian tribes. 

Energy Effects 

We have analyzed this proposed rule 

under Executive Order 13211, Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use. We have 

determined that it is not a ‘‘significant 

energy action’’ under that order because 

it is not a ‘‘significant regulatory action’’ 

under Executive Order 12866 and is not 

likely to have a significant adverse effect 

on the supply, distribution, or use of 

energy. The Administrator of the Office 

of Information and Regulatory Affairs 

has not designated it as a significant 

energy action. Therefore, it does not 

require a Statement of Energy Effects 

under Executive Order 13211. 

Technical Standards 

The National Technology Transfer 

and Advancement Act (NTTAA) (15 

U.S.C. 272 note) directs agencies to use 

voluntary consensus standards in their 

regulatory activities unless the agency 

provides Congress, through the Office of 

Management and Budget, with an 

explanation of why using these 

standards would be inconsistent with 

applicable law or otherwise impractical. 

Voluntary consensus standards are 

technical standards (e.g., specifications 

of materials, performance, design, or 

operation; test methods; sampling 

procedures; and related management 

systems practices) that are developed or 

adopted by voluntary consensus 

standards bodies. 

This proposed rule does not use 

technical standards. Therefore, we did 

not consider the use of voluntary 

consensus standards. 

Environment 

We have analyzed this proposed rule 

under Department of Homeland 

Security Management Directive 023–01 

and Commandant Instruction 

M16475.lD, which guide the Coast 

Guard in complying with the National 

Environmental Policy Act of 1969 

(NEPA) (42 U.S.C. 4321–4370f), and 

have made a preliminary determination 

that this action is one of a category of 

actions which do not individually or 

cumulatively have a significant effect on 

the human environment. A preliminary 

environmental analysis checklist 

supporting this determination will be 

made available in the docket where 

indicated under ADDRESSES. This 

proposed rule involves the 

establishment of a safety zone. We seek 

any comments or information that may 

lead to the discovery of a significant 

environmental impact from this 

proposed rule. 

List of Subjects in 33 CFR Part 165 

Harbors, Marine safety, Navigation 

(water), Reporting and recordkeeping 

requirements, Security measures, 

Waterways. 

For the reasons discussed in the 

preamble, the Coast Guard proposes to 

amend 33 CFR part 165, as follows: 

PART 165—REGULATED NAVIGATION 

AREAS AND LIMITED ACCESS AREAS 

1. The authority citation for Part 165 

continues to read as follows: 

Authority: 33 U.S.C. 1231; 46 U.S.C. 

Chapter 701, 3306, 3703; 50 U.S.C. 191, 195; 

33 CFR 1.05–1(g), 6.04–1, 6.04–6, 160.5; Pub. 

L. 107–295, 116 Stat. 2064; Department of 

Homeland Security Delegation No. 0170.1. 

2. The Coast Guard proposes to 

amend § 165.1305 by revising paragraph 

(a) to read as follows: 

§ 165.1305 Commencement Bay, Tacoma, 

WA. 

(a) Location. The following area is a 

safety zone for the Tacoma Freedom 

Fair Air Show: All portions of 

Commencement Bay bounded by the 

following coordinates: Latitude 

47°17′38′′ N, Longitude 122°28′43′′ W; 

thence south easterly to Latitude 

47°17′4′′ N, Longitude 122°27′32′′ W; 

thence south westerly to Latitude 

47°16′35′′ N, Longitude 122°28′1′′ W; 

thence north westerly along the 

shoreline to Latitude 47°17′10′′ N, 

Longitude 122°29′14′′ W; thence 

returning to the origin. This safety zone 

resembles a rectangle protruding from 

the shoreline along Ruston Way. 

Floating markers will be placed by the 

sponsor of the event to delineate the 

boundaries of the safety zone. 

* * * * * 

Dated: March 24, 2011. 

S. J. Ferguson, 

Captain, U.S. Coast Guard, Captain of the 

Port, Puget Sound. 

[FR Doc. 2011–8370 Filed 4–6–11; 8:45 am] 

BILLING CODE 9110–04–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R10–OAR–2011–0003; FRL–9291–4] 

Approval and Promulgation of 

Implementation Plans; Oregon; 

Interstate Transport of Pollution; 

Significant Contribution to 

Nonattainment and Interference With 

Maintenance Requirements 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: EPA is proposing to approve 

a portion of the State Implementation 

Plan (SIP) revision submitted by the 

State of Oregon for the purpose of 

addressing the interstate transport 

provisions of Clean Air Act (CAA) 

section 110(a)(2)(D)(i)(I) for the 1997 8- 

hour ozone National Ambient Air 


srobinson on DSKHWCL6B1PROD with PROPOSALS
Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 19293 

1See transmittal letters dated June 23, 2010, from 

Joni Hammond, Deputy Director, ODEQ, and 

December 23, 2010, from Dick Pedersen, Director, 

ODEQ, to Dennis McLerran, Regional 

Administrator, EPA Region 10. 

2On March 8, 2011, EPA proposed to approve the 

Oregon interstate transport SIP provisions 

addressing interference with any other state’s 

required measures to protect visibility. See 76 FR 

12651 (March 8, 2011). 

Quality Standards (NAAQS or 

standards) and the 1997 fine particulate 

matter (PM2.5) NAAQS. Section 

110(a)(2)(D)(i) of the CAA requires that 

each State have adequate provisions to 

prohibit air emissions from adversely 

affecting air quality in other States 

through interstate transport. EPA is 

proposing to approve Oregon’s SIP 

revision for the 1997 8-hour ozone and 

1997 PM2.5 NAAQS as meeting the 

requirements of CAA section 

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

that will contribute significantly to 

nonattainment of the these standards in 

any other State and to prohibit 

emissions that will interfere with 

maintenance of these standards by any 

other State. 

DATES: Written comments must be 

received on or before May 9, 2011. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–R10– 

OAR–2011–0003, by one of the 

following methods: 

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

the on-line instructions for submitting 

comments. 

B. E–Mail: R10- 

Public_Comments@epa.gov. 

C. Mail: Donna Deneen, U.S. 

Environmental Protection Agency, 

Region 10, 1200 Sixth Avenue, Suite 

900, Mail Stop: AWT–107, Seattle, WA 

98101. 

D. Hand Delivery: U.S. Environmental 

Protection Agency, Region 10, Attn: 

Donna Deneen (AWT–107), 1200 Sixth 

Avenue, Suite 900, Seattle, Washington 

98101, 9th Floor. Such deliveries are 

only accepted during normal hours of 

operation, and special arrangements 

should be made for deliveries of boxed 

information. 

Instructions: Direct your comments to 

Docket ID No. EPA–R10–OAR–2011– 

0003. EPA’s policy is that all comments 

received 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 information 

claimed to be Confidential Business 

Information (CBI) or other information 

whose disclosure is restricted by statute. 

Do not submit information that you 

consider to be CBI or otherwise 

protected through http:// 

www.regulations.gov or e-mail. The 

http://www.regulations.gov Web site is 

an ‘‘anonymous access’’ system, which 

means EPA will not know your identity 

or contact information unless you 

provide it in the body of your comment. 

If you send an e-mail comment directly 

to EPA without going through http:// 

www.regulations.gov, your e-mail 

address will be automatically captured 

and included as part of the comment 

that is placed in the public docket and 

made available on the Internet. If you 

submit an electronic comment, EPA 

recommends that you include your 

name and other contact information in 

the body of you comment and with any 

disk or CD–ROM you submit. 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. 

Electronic files should avoid the use of 

special characters, any form of 

encryption, and be free of any defects or 

viruses. 

Docket: All documents in the 

electronic docket are listed in the 

www.regulations.gov index. Although 

listed in the index, some information, 

i.e., CBI or other information whose 

disclosure is restricted by statute, is not 

publicly available. Certain other 

material, such as copyrighted material, 

is not placed on the Internet and will be 

publicly available only in hard copy 

form. Publicly available docket 

materials are available either 

electronically in http:// 

www.regulations.gov or in hard copy 

during normal business hours at the 

Office of Air, Waste and Toxics, U.S. 

Environmental Protection Agency, 

Region 10, 1200 Sixth Avenue, Suite 

900, Seattle, Washington 98101. 

FOR FURTHER INFORMATION CONTACT: 

Donna Deneen, (206) 553–6706 or 

deneen.donna@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Throughout this notice, the words ‘‘we’’, 

‘‘us’’, or ‘‘our’’ means the Environmental 

Protection Agency (EPA). 

Table of Contents 

I. What proposed action is EPA taking? 

II. What is a SIP? 

III. What is the background for this proposed 

action? 

IV. What is the state process to submit these 

materials to EPA? 

V. What is EPA’s evaluation of the state’s 

submission? 

A. EPA’s Evaluation of Significant 

Contribution to Nonattainment 

1. Significant Contribution to 

Nonattainment Evaluation for the 1997 

8-Hour Ozone NAAQS 

2. Significant Contribution to 

Nonattainment Evaluation for the 1997 

PM2.5 NAAQS 

3. Conclusion Regarding Significant 

Contribution to Nonattainment 

B. EPA’s Evaluation of Interference With 

Maintenance 

1. Oregon’s 2010 Interstate Transport SIP 

2. Interference With Maintenance 

Evaluation for the 8-Hour Ozone NAAQS 

3. Interference With Maintenance 

Evaluation for the 1997 PM2.5 NAAQS 

4. Conclusion Regarding Interference With 

Maintenance 

VI. Proposed Action 

VII. Statutory and Executive Order Reviews 

I. What proposed action is EPA taking? 

EPA is proposing to approve a portion 

of Oregon’s Interstate Transport State 

Implementation Plan (SIP) revision for 

the 1997 8-hour ozone and 1997 PM2.5

NAAQS submitted by the Oregon 

Department of Environmental Quality 

(ODEQ) on June 23, 2010.1 Specifically, 

we are proposing to approve the portion 

of the interstate transport SIP revision 

that addresses the following elements of 

CAA section 110(a)(2)(D)(i): (1) 

Significant contribution to 

nonattainment of these NAAQS in any 

other state; and (2) interference with 

maintenance of these NAAQS by any 

other state. EPA will address element 

(3), interference with any other state’s 

required measures to prevent significant 

deterioration (PSD) of its air quality; and 

element (4), interference with any other 

state’s required measures to protect 

visibility, in a separate action.2 This 

proposed action does not address the 

requirements of the 2006 PM2.5 NAAQS 

or the 2008 8-hour ozone NAAQS; those 

standards will be addressed in future 

actions. 

II. What is a SIP? 

Section 110(a) of the CAA requires 

each state to develop a plan that 

provides for the implementation, 

maintenance, and enforcement of the 

NAAQS. EPA establishes NAAQS under 

section 109 of the CAA. Currently, the 

NAAQS address six criteria pollutants: 

Carbon monoxide, nitrogen dioxide, 

ozone, lead, particulate matter, and 

sulfur dioxide. 

The plan developed by a state is 

referred to as the SIP. The content of the 

SIP is specified in section 110 of the 

CAA, other provisions of the CAA, and 

applicable regulations. SIPs can be 

extensive, containing state regulations 

or other enforceable measures and 

various types of supporting information, 

such as emissions inventories, 

monitoring networks, and modeling 

demonstrations. 

A primary purpose of the SIP is to 

provide the air pollution regulations, 

control strategies, and other means or 

techniques developed by the state to 


srobinson on DSKHWCL6B1PROD with PROPOSALS
19294 Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 

3See 62 FR 38856. The level of the 1997 8-hour 

ozone NAAQS is 0.08 parts per million (ppm). 40 

CFR part 50.10. The 8-hour ozone standard is met 

when the 3-year average of the annual 4th highest 

daily maximum 8-hour ozone concentrations is 0.08 

ppm or less (i.e., less than 0.085 ppm based on the 

rounding convention in 40 CFR part 50 Appendix 

I). This 3-year average is referred to as the ‘‘design 

value.’’ 

4See 62 FR 38652. The level of the 1997 PM2.5

NAAQS are 15.0 μg/m3 (annual arithmetic mean 

concentration) and 65 μg/m3 (24-hour average 

concentration). 40 CFR part 50.7. The annual 

standard is met when the 3-year average of the 

annual mean concentrations is 15.0 μg/m3 or less 

(i.e., less than 15.05 μg/m3 based on the rounding 

convention in 40 CFR part 50 Appendix N Section 

4.3). The 24-hour standard is met when the 3-year 

average annual 98th percentile of 24-hour 

concentrations is 65 μg/m3 or less (i.e., less than 

65.5 μg/m3 based on the rounding convention in 40 

CFR part 40 Appendix N Section 4.3). Id. These 3- 

year averages are referred to as the annual PM2.5 and 

24-hour PM2.5 ‘‘design values,’’ respectively. 

5Memorandum from William T. Harnett entitled 

‘‘Guidance for State Implementation Plan (SIP) 

Submissions 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. 

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 (DC 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 (DC Cir. 2008). 

7See ‘‘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; Final Rule,’’ at 70 FR 25162 at 

25263–69 (May 12, 2005). 

ensure that the ambient air within that 

state meets the NAAQS. However, 

another important aspect of the SIP is to 

ensure that emissions from within the 

state do not have certain prohibited 

impacts upon the ambient air in other 

states through interstate transport of 

pollutants. This SIP requirement is 

specified in section 110(a)(2)(D). 

Pursuant to that provision, each state’s 

SIP must contain provisions adequate to 

prevent emissions that significantly 

contribute to violations of the NAAQS 

in any other state, interfere with 

maintenance in any other state, interfere 

with any other state’s required measures 

to prevent significant deterioration of its 

air quality, and interfere with any other 

state’s required measures to protect 

visibility. 

States are required to update or revise 

SIPs under certain circumstances. One 

such circumstance is EPA’s 

promulgation of a new or revised 

NAAQS. Each state must submit these 

revisions to EPA for approval and 

incorporation into the federallyenforceable SIP. 

III. What is the background for this 

proposed action? 

On July 18, 1997, EPA promulgated 

new standards for 8-hour ozone 3 and 

fine particulate matter 4 (PM2.5). This 

proposed action is in response to the 

promulgation of these standards (the 

1997 8-hour ozone NAAQS and 1997 

PM2.5 NAAQS). 

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

states to submit SIPs to address a new 

or revised NAAQS within three years 

after promulgation of such standards, or 

within such shorter period as EPA may 

prescribe. Section 110(a)(2) lists the 

elements that such new SIPs must 

address, as applicable, including section 

110(a)(2)(D)(i) which pertains to 

interstate transport of certain emissions. 

On August 15, 2006, EPA issued a 

guidance memorandum that provides 

recommendations to states for making 

submissions to meet the requirements of 

section 110(a)(2)(D)(i) for the 1997 8- 

hour ozone and 1997 PM2.5 standards 

(2006 Guidance).5

The interstate 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 

rulemaking EPA is addressing the first 

two elements of this subsection. 

The first element of section 

110(a)(2)(D)(i)(I) requires that a state’s 

SIP for a new or revised NAAQS must 

contain adequate measures to prohibit 

emissions from sources within the state 

that ‘‘contribute significantly’’ to 

nonattainment of the NAAQS in another 

state. The second element of CAA 

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

state’s SIP must 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. 

The CAA does not specifically 

mandate how to determine significant 

contribution to nonattainment or 

interference with maintenance. 

Therefore, EPA has interpreted these 

terms in past regulatory actions, such as 

the 1998 NOX SIP Call, in which 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 The NOX SIP Call was 

the mechanism through which EPA 

evaluated whether or not the NOX

emissions from sources in certain states 

had such 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. 

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 the 2005 Clean 

Air Interstate Rule (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.7 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 

determined would either be in violation 

of the NAAQS, or would be in jeopardy 

of violating the NAAQS, in a modeled 

future year unless action 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. 

EPA’s 2006 Guidance addressed CAA 

section 110(a)(2)(D)(i) requirements for 

the 1997 8-hour ozone NAAQS and 

1997 PM2.5 NAAQS. For those states 

subject to CAIR, EPA indicated that 

compliance with CAIR would meet the 

two requirements of section 

110(a)(2)(D)(i)(I) for these NAAQS. For 

states outside of the CAIR region, the 

2006 Guidance recommended various 

methods by which states might evaluate 

whether or not their emissions 

significantly contribute to 

nonattainment of the 1997 8-hour ozone 

or the 1997 PM2.5 NAAQS in another 

state. Among other methods, EPA 

recommended consideration of available 

EPA modeling conducted in 

conjunction with the CAIR, or in the 

absence of such EPA modeling, 

consideration of other information such 

as the amount of emissions, the 

geographic location of violating areas, 

meteorological data, or various other 

forms of information that would be 

relevant to assessing the likelihood of 

significant contribution to violations of 

the NAAQS in another state. 

The assessment of significant 

contribution to nonattainment is not 

restricted to impacts upon areas that are 

formally designated nonattainment. 

Consistent with EPA’s approach in 

CAIR and recently in the Transport Rule 


srobinson on DSKHWCL6B1PROD with PROPOSALS
Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 19295 

8See 63 FR 57371 (October 27, 1998), NOX SIP 

Call; 70 FR 25172 (May 12, 2005), CAIR; and 75 FR 

45210 (August 2, 2010), Transport Rule Proposal. 

9 2006 Guidance at 5. 

10See North Carolina v. EPA, 531 F.3d 896 (DC 

Circuit 2008). 

11 531 F.3d at 909. 

12 Ibid. 13See 75 FR 45210 (August 2, 2010). 

14A memorandum in the docket for this action 

provides the information EPA used to identify 

monitors that are receptors for evaluation of 

significant contribution or interference with 

maintenance for certain states in the western United 

States. See Memorandum from Brian Timin, EPA 

Office of Air Quality Planning and Standards, 

‘‘Documentation of Future Year Ozone and Annual 

PM2.5 Design Values for Monitors in Western 

States,’’ August 23, 2010 (Timin Memo). 

15To begin this analysis, EPA first identifies all 

monitors projected to be in nonattainment or, based 

on historic variability in air quality, projected to 

have maintenance problems in 2012. Monitors 

projected to be in nonattainment are those with 

future year design values that violate the standard, 

based on the projection of 5-year weighted average 

concentrations. Monitors projected to have 

maintenance problems are those at risk of not 

staying in attainment because the air quality data 

is close enough to the level of the 1997 8-hour 

ozone and PM2.5 NAAQS that minor variations in 

weather or emissions could result in violations of 

the NAAQS in 2012. 

Proposal, as discussed further below, 

this impact must be evaluated with 

respect to monitors showing a violation 

of the NAAQS.8 Furthermore, although 

relevant information other than 

modeling may be considered in 

assessing the likelihood of significant 

contribution to nonattainment of the 8- 

hour ozone or PM2.5 NAAQS in another 

state, 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 

violations of the 1997 8-hour ozone or 

1997 PM2.5 NAAQS in another state. 

As to the second element of section 

110(a)(2)(D)(i), for states not within the 

CAIR region, EPA recommended that 

states evaluate whether or not emissions 

from their sources would ‘‘interfere with 

maintenance’’ in other states following 

the conceptual approach adopted by 

EPA in CAIR. After recommending 

various types of information that could 

be relevant for the technical analysis to 

support the SIP submission, such as the 

amount of emissions and meteorological 

conditions in the state, EPA further 

indicated that it would be appropriate 

for the state to assess impacts of its 

emissions on other states using 

considerations comparable to those used 

by EPA ‘‘in evaluating significant 

contribution to nonattainment in the 

CAIR.’’ 9 EPA did not make specific 

recommendations for how states should 

assess interference with maintenance 

separately, and discussed the first two 

elements of section 110(a)(2)(D)(i) 

together without explicitly 

differentiating between them. 

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.10 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.’’ 11 EPA’s 

approach, the court reasoned, would 

leave areas that are ‘‘barely meeting 

attainment’’ with ‘‘no recourse’’ to 

address upwind emissions sources.12

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. In 

addition to affecting CAIR directly, the 

court’s decision in the North Carolina 

case indirectly affects EPA’s 

recommendations to states in the 2006 

Guidance with respect to the interfere 

with maintenance element of section 

110(a)(2)(D)(i) because the agency’s 

guidance suggested that states use an 

approach comparable to that used by 

EPA in CAIR. 

To address the judicial remand of 

CAIR, EPA has recently proposed a new 

rule to address interstate transport of air 

pollution pursuant to section 

110(a)(2)(D)(i), the ‘‘Federal 

Implementation Plans to Reduce 

Interstate Transport of Fine Particulate 

Matter and Ozone’’ (Transport Rule 

Proposal).13 As part of the Transport 

Rule Proposal, EPA specifically 

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

requirements that emissions from 

sources in a state must not ‘‘contribute 

significantly to nonattainment’’ or 

‘‘interfere with maintenance’’ of the 1997 

8-hour ozone NAAQS and 1997 PM2.5

NAAQS in other states. In the proposal, 

EPA developed an approach to identify 

areas that it predicts to be violating the 

1997 8-hour ozone and PM2.5 NAAQS in 

the future, and areas that it predicts to 

be close to the level of these NAAQS in 

the future 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. 

As described in more detail below, 

EPA evaluated data from existing 

monitors over three overlapping 3-year 

periods (i.e., 2003–2005, 2004–2006, 

and 2005–2007), as well as air quality 

modeling data, in order to determine 

which areas are predicted to be violating 

the 1997 8-hour ozone and PM2.5

NAAQS in 2012, and which areas are 

predicted potentially to have difficulty 

maintaining attainment as of that date. 

In essence, if an area’s projected data for 

2012 indicates that it would be violating 

the NAAQS based on the average of 

these three overlapping periods, then 

this monitor location is appropriate for 

comparison for purposes of the 

significant contribution to 

nonattainment element of section 

110(a)(2)(D)(i). If, however, an area’s 

projected data indicate that it would be 

violating the NAAQS based on the 

highest single period, but not over the 

average of the three periods, then this 

monitor location is appropriate for 

comparison for purposes of the interfere 

with maintenance element of the 

statute.14

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 or to 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.15 EPA’s 2006 Guidance 

did not provide this specific 

recommendation to states, but in light of 

the court’s decision on CAIR, EPA will 

itself follow this approach in evaluating 

the Oregon submission. 

As explained in the 2006 Guidance, 

EPA does not believe that section 

110(a)(2)(D)(i) SIP submissions from all 

states necessarily need to follow 

precisely the same analytical approach 

of CAIR. In the 2006 Guidance, EPA 

stated that: ‘‘EPA believes that the 

contents of the SIP submission required 

by section 110(a)(2)(D) may vary, 

depending upon the facts and 

circumstances related to the specific 

NAAQS. In particular, the data and 

analytical tools available at the time the 

State develops and submits a SIP for a 

new or revised NAAQS necessarily 


srobinson on DSKHWCL6B1PROD with PROPOSALS
19296 Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 

16 2006 Guidance at 4. 

17 Ibid. at 5. 

18See Transport Rule Proposal, 75 FR 45210 at 

45227 (August 2, 2010). 

19Oregon’s submission addresses the interstate 

transport requirements of the 1997 PM2.5 NAAQS, 

the 1997 8-hour ozone NAAQS, the 2006 PM2.5

NAAQS, and the 2008 8-hour ozone NAAQS. In 

this action, EPA is only taking action with respect 

to CAA section 110(a)(2)(D)(i)(I) for the 1997 PM2.5

and 1997 8-hour ozone NAAQS. 

20Oregon’s submission makes this conclusion 

with respect to not only the 1997 PM 2.5 NAAQS 

and 1997 8-hour ozone NAAQS, but also the 2006 

PM 2.5 NAAQS and the 2008 8-hour ozone 

NAAQS. 

21This north/northwest prevailing wind direction 

was derived from surface level winds and airport 

data and is not necessarily indicative of the 

prevailing wind direction of typical weather 

systems in the west. 

22Note that there are currently no ozone 

nonattainment areas in Oregon or Washington. 

affects the contents of the required 

submission.’’ 16 EPA also indicated in 

the 2006 Guidance that it did not 

anticipate that sources in states outside 

the geographic area covered by CAIR 

were significantly contributing to 

nonattainment, or interfering with 

maintenance, in other states.17 As noted 

in the Transport Rule Proposal, EPA 

continues to believe that the more 

widespread and serious transport 

problems in the eastern United States 

are analytically distinct.18 For the 1997 

8-hour ozone and 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 Proposal, EPA did not calculate the 

portion of predicted ozone or PM 

concentrations in any downwind state 

that would result from emissions from 

individual western states, such as 

Oregon. 

Accordingly, EPA believes that 

section 110(a)(2)(D)(i) SIP submissions 

for states outside the geographic area of 

the Transport Rule Proposal may be 

evaluated using a ‘‘weight of the 

evidence’’ approach that takes into 

account the available relevant 

information, such as that recommended 

by EPA in the 2006 Guidance for states 

outside the area affected by CAIR. 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 significantly contribute to 

nonattainment or interfere with 

maintenance of the 1997 8-hour ozone 

and 1997 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. What is the state process to submit 

these materials to EPA? 

CAA sections 110(a)(1) and (2) and 

section 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 June 23, 2010, and December 23, 

2010, the Oregon Department of 

Environmental Quality (ODEQ) 

submitted a SIP revision to update 

Oregon’s infrastructure SIP for ozone 

and PM2.5. Included in this submittal 

was a SIP revision entitled ‘‘Oregon SIP 

Infrastructure for Addressing the 

Interstate Transport of Ozone and Fine 

Particulate Matter’’ to address the 

interstate transport SIP requirements of 

CAA section 110(a)(2)(D)(i) for the 1997 

8-hour ozone and 1997 PM2.5 NAAQS 

(2010 interstate transport SIP).19

ODEQ’s June 23, 2010, submittal 

includes public process documentation 

for the 2010 interstate transport SIP 

submittal. In addition, the SIP revision 

includes documentation of a duly 

noticed public hearing held on 

December 22, 2009. 

We find that the process followed by 

ODEQ in adopting the 2010 interstate 

transport SIP complies with the 

procedural requirements for SIP 

revisions under CAA section 110 and 

EPA’s implementing regulations. 

V. What is EPA’s evaluation of the 

state’s submission? 

A. EPA’s Evaluation of Significant 

Contribution to Nonattainment 

This proposed approval evaluates the 

significant contribution to 

nonattainment element of section 

110(a)(2)(D)(i)(I) for the 1997 8-hour 

ozone and 1997 PM2.5 NAAQS in 

several ways. It takes into account 

Oregon’s 2010 interstate transport SIP, 

in which the State explains that based 

on meteorological and other 

characteristics in Oregon and in the 

surrounding areas, PM2.5 and ozone 

precursor emissions from Oregon 

sources do not significantly contribute 

to violations of the PM2.5 or ozone 

NAAQS in other states.20 In addition, 

EPA has supplemented the State’s 

analysis with its own evaluation of the 

evidence, including a review of the 

nearest monitors in other states that are 

appropriate nonattainment receptors, in 

order to assess whether emissions 

sources in Oregon contribute 

significantly to nonattainment of the 

1997 8-hour ozone and PM2.5 NAAQS in 

other states. 

Finally, EPA has also reviewed recent 

ozone and PM2.5 monitoring data for the 

states bordering Oregon to consider 

whether Oregon emissions could 

significantly contribute to violations of 

the 1997 8-hour ozone or PM2.5 NAAQS 

in those states. 

1. Significant Contribution to 

Nonattainment Evaluation for the 1997 

8-Hour Ozone NAAQS 

To address whether emissions from 

Oregon sources significantly contribute 

to nonattainment of the 8-hour ozone 

NAAQS in another state, the State 

argued in the 2010 interstate transport 

SIP that meteorological and other 

characteristics of the Pacific Northwest 

support a finding that emissions from 

Oregon sources do not significantly 

contribute to violations of the PM2.5 or 

ozone NAAQS in other states. Oregon 

pointed out that, in the Pacific 

Northwest, exceedances of the 8-hour 

ozone standard occur in the summer 

months, and during that season the 

prevailing winds 21 are predominantly 

from the north to northwest and, 

consequently, preclude any significant 

influence from Oregon on Washington 

ozone nonattainment areas.22 While 

acknowledging the possibility that 

prevailing summer winds could result 

in some interstate transport of ozone 

forming emissions to western Idaho, 

Nevada and northern California, the 

State asserted in the 2010 interstate 

transport SIP that significant distances 

and topography (such as major 

mountain ranges that separate Oregon 

from California, Idaho and Nevada) 

would likely minimize the significance 

of these impacts on other states. Oregon 

gave as an example the largest major 

urban center in Oregon (the greater 

Portland area), which it estimated is 400 

to 700 miles away from urban areas in 

western Idaho, Nevada, and northern 

California, and is separated by at least 

one major mountain range (the 

Cascades). 

Oregon also pointed to its section 110 

infrastructure SIP to show that ODEQ 


srobinson on DSKHWCL6B1PROD with PROPOSALS
Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 19297 

23Transport Rule Proposal, 75 FR 45210 at 

45253–45273. 

24See Transport Rule Proposal, Table IV.C–11, 75 

FR 45210 at 45252. 

25See Timin Memo at Appendix B (‘‘Base year 

2003–2007 and Future Year 2012 8-Hour Average 

Ozone Design Values—Western States’’). 

has the ability to participate as needed 

in future studies on regional air 

pollution issues, or collaborate with 

other states if air quality concerns are 

identified that require a case-specific 

evaluation of interstate transport, and 

also ensures the legal mechanism for 

ODEQ to take action as needed to 

reduce emissions to help attain 

compliance with Federal NAAQS. 

Finally, the State explained that it 

consulted with air agencies in 

Washington, Idaho, Nevada, and 

California and other agencies to evaluate 

case-specific air quality problems that 

may involve regional transport of air 

pollution. These staff-level 

communications indicated no impacts 

on ozone concentrations in other states 

caused by transport from the State of 

Oregon. The State added that if any 

future violations of ozone standards 

occur, Oregon would work with other 

air agencies and EPA as necessary to 

evaluate the role of interstate air 

pollution transport. This consultation 

provided additional support for the 

state’s view that emissions from Oregon 

sources do not significantly contribute 

to violations of the 1997 8-hour ozone 

NAAQS in other states. 

Based on the information provided in 

its 2010 interstate transport SIP, ODEQ 

concluded that emissions from air 

pollution sources in Oregon do not 

significantly contribute to 

nonattainment of the 1997 8-hour ozone 

NAAQS in other states. 

EPA does not necessarily agree that 

Oregon’s methodology is adequate for 

purposes of a section 110(a)(2)(D)(i) 

analysis. Therefore, EPA is 

supplementing the State’s submission 

with additional, and more recent, 

information in order to assess this issue 

more fully. As noted above, EPA is 

evaluating the State’s 2010 interstate 

transport SIP taking into account 

methodologies and analyses for the 

identification of receptor monitors that 

was developed in the Transport Rule 

Proposal, as well as EPA’s projections of 

future air quality at monitors in western 

states in the Timin Memo, and 

preliminary air quality data from 

monitors in the states bordering Oregon. 

Although each of the factors considered 

in the following analysis are not in and 

of themselves determinative, 

consideration of these factors together 

provides a reliable qualitative 

conclusion that emissions from Oregon 

do not contribute significantly to 

nonattainment of the 1997 8-hour ozone 

NAAQS at monitors in other states. 

The Transport Rule Proposal includes 

an approach to determining whether 

emissions from a state contribute 

significantly to nonattainment of the 

1997 8-hour ozone NAAQS in other 

states. Specifically, EPA used existing 

monitoring data to project future 

concentrations of ozone at monitors to 

identify areas that are expected to be 

violating the 1997 8-hour ozone NAAQS 

in 2012, based on the 5-year weighted 

average design value. We call these 

monitors ‘‘nonattainment receptors.’’ To 

identify the states with emissions that 

may contribute significantly to ozone 

nonattainment in other states, the 

Transport Rule Proposal models the 

states’ contributions to ambient ozone 

levels at these nonattainment 

receptors.23 Because the Transport Rule 

Proposal does not model the 

contribution of emissions from Oregon 

(nor other western states not fully inside 

the Transport Rule Proposal’s modeling 

domain) to 8-hour ozone nonattainment 

receptors in other states, our assessment 

in this proposed action relies on a 

weight of evidence approach that 

considers relevant information from the 

Transport Rule Proposal pertaining to 

states within its modeling domain, and 

additional material such as geographical 

and meteorological factors, EPA’s 

projections of future air quality at 

monitors in western states in the Timin 

Memo, and AQS monitoring data. 

Our analysis begins by assessing 

Oregon’s contribution to the closest 

nonattainment receptors for the 1997 8- 

hour ozone standard. The Transport 

Rule Proposal identifies within its 

modeling domain (consisting of 37 

states east of the Rocky Mountains, and 

the District of Columbia) 11 

nonattainment receptors for the 1997 8- 

hour ozone standard. Of these, the 

nonattainment receptors closest to 

Oregon are seven receptors in the 

Dallas-Fort Worth and HoustonGalveston-Brazoria 8-hour ozone 

nonattainment areas in eastern Texas. 

The remaining four nonattainment 

receptors for the 1997 8-hour ozone 

NAAQS are in Louisiana, New York, 

and Pennsylvania.24

The nonattainment receptors in 

Dallas-Fort Worth and Houston areas are 

over 1200 miles from the closest point 

on Oregon’s border, and the receptors in 

Louisiana, New York, and Pennsylvania 

are significantly further away. Although 

distance alone is not determinative in 

the analysis of potential ozone 

transport, with increasing distance there 

are greater opportunities for ozone and 

NOX dispersion and/or removal from 

the atmosphere due to the effect of 

winds or chemical sink processes. 

Moreover, the intervening Rocky 

Mountains act as a natural barrier to air 

pollution transport. These factors 

together support a conclusion that 

Oregon sources do not contribute 

significantly to nonattainment of the 

1997 8-hour ozone NAAQS in the 

nearest areas with nonattainment 

receptors identified in the Transport 

Rule Proposal. 

To assist in the evaluation of the 

potential for ozone transport among 

western states, EPA also developed an 

additional analysis in the Timin Memo 

identifying monitors projected to record 

violations of the 1997 8-hour ozone 

NAAQS in the western U.S. The Timin 

Memo identified predicted future 

nonattainment receptors for the 1997 8- 

hour ozone NAAQS in southern and 

central California. This analysis did not, 

however, identify any projected 

nonattainment receptors for the 1997 8- 

hour ozone NAAQS in any other 

western state.25 The nonattainment 

receptor nearest to Oregon for the 1997 

8-hour ozone NAAQS was identified as 

Nevada County, California. Nevada 

County is approximately 170 miles 

south/southeast of the closest point on 

Oregon’s border and on the other side of 

intervening mountain ranges that act as 

a natural barrier to air pollution 

transport. Although not determinative 

by themselves, distance and topography 

are not favorable to 8-hour ozone 

transport from Oregon to central 

California. In addition, prevailing winds 

in the west generally move from southwesterly, westerly, or north-westerly 

directions, as indicated by the typical 

movement of weather systems. Hence 

central and southern California are not 

in the predominant direction of winds 

from Oregon. Given the distance 

between Oregon’s border and central 

and southern California nonattainment 

receptors, the intervening mountainous 

topography, and the general direction of 

transport winds in the Western U.S., it 

is reasonable to conclude that Oregon 

sources do not contribute significantly 

to nonattainment of the 1997 8-hour 

ozone NAAQS in Nevada County or to 

any more distant nonattainment 

receptors in California. EPA’s analysis 

for western states therefore supports our 

proposal to conclude that Oregon 

sources do not contribute significantly 

to nonattainment of the 1997 8-hour 

ozone NAAQS in any other state. 

In addition to the information in the 

2010 interstate transport SIP and EPA’s 

projections of future air quality in the 

Transport Rule Proposal and in the 


srobinson on DSKHWCL6B1PROD with PROPOSALS
19298 Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 

26See EPA AQS, ‘‘Preliminary Design Value 

Report,’’ 2007–2009, for Washington, Idaho, 

Nevada, and California. 27 Id. 

28Although the 2010 Interstate transport SIP 

identified these areas as PM2.5 nonattainment areas, 

they are all 2006 24-hour PM2.5 nonattainment 

areas. There are no 1997 PM2.5 nonattainment areas 

in Washington or Idaho, and the closest 1997 PM2.5

nonattainment area to Oregon is in California (San 

Joaquin County). Oregon asserts that its evaluation 

of more stringent 2006 24-hour PM2.5 NAAQS 

nonattainment areas is indicative of potential 

contribution to nonattainment of the less stringent 

1997 PM2.5 NAAQS. 

Timin Memo, EPA also evaluated 

preliminary air quality monitoring data 

for the areas in states bordering Oregon 

that are designated nonattainment for 

the 1997 8-hour ozone NAAQS. While 

significant contribution must be 

measured not just against designated 

nonattainment areas but also against 

areas with monitors showing violations 

of the NAAQS, nonattainment areas are 

a convenient point of analysis. Two 

states bordering Oregon—California and 

Nevada—have areas currently 

designated nonattainment for the 1997 

8-hour ozone standard. In California, the 

closest nonattainment area is Butte 

County, and in Nevada, the closest 

nonattainment area is the Las Vegas area 

in Clark County. EPA designated both of 

these areas as nonattainment for the 

1997 8-hour ozone standard in 2004. 

See 69 FR 23858 (April 30, 2004); 40 

CFR 81.305 and 81.329. Both of these 

areas, however, have current design 

values indicating attainment of the 1997 

8-hour ozone NAAQS. Our review of 

preliminary monitoring data for the 

2007–2009 period available in EPA’s Air 

Quality System (AQS) database 

indicates that the 8-hour ozone design 

values for Butte County and Las Vegas 

during this period were 82 and 74 ppb, 

respectively.26 We therefore believe it is 

reasonable to conclude that Oregon 

sources are not contributing 

significantly to nonattainment of the 

1997 8-hour ozone NAAQS in Butte 

County, California or Clark County, 

Nevada. The closest nonattainment area 

to the Oregon border that had a design 

value above the 1997 8-hour ozone 

NAAQS for the 2007–2009 period was 

Nevada County, California. As noted 

above, given the distance between the 

Oregon border and Nevada County, the 

intervening mountainous topography, 

and the general direction of transport 

winds in the Western U.S., it is 

reasonable to conclude that Oregon 

sources do not contribute significantly 

to nonattainment in Nevada County or 

to any more distant central or southern 

California 1997 8-hour ozone 

nonattainment areas. There are no 

designated nonattainment areas in Idaho 

and Washington for the 1997 8-hour 

ozone NAAQS. This is further support 

that Oregon sources do not contribute 

significantly to nonattainment of the 

1997 8-hour ozone NAAQS in any other 

state. 

We also evaluated ozone monitoring 

data from the 2007–2009 period from 

each of the ozone monitoring sites in 

Washington, Idaho, Nevada and 

California, to determine whether the 

ozone levels in any of these states 

violate the 1997 8-hour ozone 

NAAQS.27 We have identified no design 

values above the 1997 8-hour ozone 

NAAQS at any of the monitors in 

Washington, Idaho, or Nevada, nor any 

indication that emissions from Oregon 

sources contribute significantly to 

nonattainment of the 1997 8-hour ozone 

NAAQS in these adjacent states. 

Although AQS data for California show 

8-hour ozone design values above the 

1997 NAAQS during the 2007–2009 

period, the closest monitor to Oregon 

that has a 2007–2009 8-hour ozone 

design value above the 1997 NAAQS is 

located in Nevada County. As noted 

above, given the distance between the 

Oregon border and Nevada County, the 

intervening mountainous topography, 

and the general direction of transport 

winds in the Western U.S., it is 

reasonable to conclude that Oregon 

sources do not contribute significantly 

to nonattainment in Nevada County or 

to any more distant central or southern 

California monitors. This is further 

support that Oregon sources do not 

contribute significantly to 

nonattainment of the 1997 8-hour ozone 

NAAQS in any other state. 

Finally, none of the ozone monitors in 

Oregon have themselves indicated a 

violation of the 1997 8-hour ozone 

NAAQS. The absence of violations in 

Oregon itself does not rule out the 

possibility of transport, but taken in 

conjunction with other relevant 

information, including the distance 

from Oregon to areas with design values 

above the 1997 8-hour ozone NAAQS 

and Pacific Northwest meteorology and 

topography, this fact helps to support 

the conclusion that there is no transport 

from Oregon resulting in significant 

contribution to nonattainment in 

another state. Distance per se is also not 

an obstacle to long range transport of 

ozone and its precursors, as discussed 

above. However, with increasing 

distance there are greater opportunities 

for ozone and NOX dispersion and 

removal from the atmosphere due to the 

effects of winds and chemical sink 

processes. In this context, the distance 

between Oregon sources and areas not 

meeting the 8-hour ozone standard 

reduces, but does not exclude, the 

possibility of significant contribution to 

nonattainment. Nevertheless, the 

absence of violations in Oregon 

combined with the total weight of all of 

the factors discussed above supports a 

conclusion that emissions from its 

sources do not significantly contribute 

to nonattainment in other states, in 

accordance with section 110(a)(2)(D)(i). 

2. Significant Contribution to 

Nonattainment Evaluation for the 1997 

PM2.5 NAAQS 

To address whether emissions from 

sources in Oregon significantly 

contribute to nonattainment of the 1997 

PM2.5 NAAQS in another state, the State 

argued in its 2010 interstate transport 

SIP that meteorological and other 

characteristics of any areas designated 

nonattainment for the 1997 PM2.5

NAAQS in the surrounding states of 

Washington, Idaho, Nevada, and 

California support a finding that 

emissions from Oregon sources do not 

significantly contribute to violations of 

the PM2.5 NAAQS or ozone NAAQS in 

other states. Oregon explained that the 

closest nonattainment areas in 

neighboring states are the Tacoma area 

(Pierce County) in Washington; the 

Chico area (portions of Butte County) in 

California, and the Cache Valley area in 

Southeast Idaho (portions of Cache 

County, Utah and Franklin County, 

Idaho).28 Oregon argues that the area of 

highest Oregon emission densities 

(Portland Metro area) is separated from 

these PM2.5 nonattainment areas by 

significant distances and major 

mountain ranges up to approximately 

7000 feet. Oregon identifies one 

exception—the Portland-Vancouver 

metro area, which shares a common air 

shed between Oregon and Washington. 

Oregon, however, notes that both 

Portland and Vancouver are in 

attainment with the PM2.5 NAAQS. 

Oregon described typical seasonal 

wind patterns during the winter when 

PM2.5 levels are the highest. It noted that 

wind speeds are typically variable with 

the majority of wind speeds occurring at 

less than 8 miles per hour, and a 

significant portion of low winds at less 

than 5 miles per hour. Oregon explained 

that these low wind speeds and air 

stagnation conditions do not lend 

themselves to long distance air 

pollution transport, and noted that the 

Portland area can experience high wind 

speeds in the winter travelling through 

the Columbia River Gorge east of 

Portland that are not conducive to the 

buildup of air pollution. Oregon 

concluded that general meteorology 


srobinson on DSKHWCL6B1PROD with PROPOSALS
Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 19299 

29For PM2.5, the Transport Rule Proposal 

identified nonattainment receptors for the 1997 

annual PM2.5 NAAQS and the 2006 24-hour PM2.5

NAAQS. See 75 FR 45210 at 45212. Because our 

proposal on Oregon’s 2010 Interstate transport SIP 

addresses requirements of CAA section 

110(a)(2)(D)(i) only for purposes of the 1997 ozone 

and PM2.5 NAAQS, for PM2.5 purposes we consider 

only the nonattainment receptors for the 1997 

annual PM2.5 NAAQS identified in the Transport 

Rule Proposal. 

30Specifically, the nonattainment receptors for 

the 1997 annual PM2.5 standard are located in 

Alabama, Georgia, Illinois, Indiana, Kentucky, 

Michigan, Ohio, Pennsylvania, and West Virginia. 

See Transport Rule Proposal, 75 FR 45210 at 

45247–45248 (August 2, 2010). 

31See Timin Memo at Appendix B (‘‘Base year 

2003–2007 and Future Year 2012 8-Hour Average 

Ozone Design Values—Western States’’). 

32 75 FR 45210 at 45249–45251 (August 2, 2010). 

33These values were recorded at monitors in 

Liberty-Clairton, Pennsylvania and Provo, Utah. See 

http://epa.gov/airtrends/pdfs/PM2.5%202007– 

2009%20design%20value%20update.pdf. Data 

from EPA’s Air Quality System can be viewed at 

http://www.epa.gov/ttn/airs/airsaqs/. 

supports the conclusion that high 

winter time PM2.5 levels in Pacific 

Northwest communities are typically 

dominated by local emission sources. 

Oregon also pointed to its section 110 

infrastructure SIP to show that ODEQ 

has the ability to participate as needed 

in future studies on regional air 

pollution issues, or collaborate with 

other states if air quality concerns are 

identified that require a case-specific 

evaluation of interstate transport, and 

also ensures the legal mechanism for 

ODEQ to take action as needed to 

reduce emissions to help attain 

compliance with Federal NAAQS. 

Oregon stated that that high PM2.5 levels 

that threaten the NAAQS are 

investigated as needed to identify 

contributing sources, including any 

potential role of interstate transport. 

Finally, the state explained that it had 

consulted with air agencies in 

Washington, Idaho, Nevada, and 

California and other agencies to evaluate 

case-specific air quality problems that 

may involve regional transport of air 

pollution. These staff-level 

communications indicated no impacts 

on PM2.5 concentrations in other states 

caused by transport from the state of 

Oregon, providing additional support 

for the state’s view that emissions from 

Oregon sources do not significantly 

contribute to violations of the 1997 

PM2.5 NAAQS in other states. 

Based on this and other information 

provided in its 2010 interstate transport 

SIP, ODEQ concluded that emissions 

from air pollution sources in Oregon do 

not significantly contribute to 

nonattainment of the 1997 PM2.5

NAAQS in other states. 

EPA does not necessarily agree that 

Oregon’s methodology is adequate for 

purposes of a section 110(a)(2)(D)(i) 

analysis. Therefore, EPA is 

supplementing the State’s submission 

with additional, and more recent, 

information in order to assess this issue 

more fully. As noted above, EPA is 

evaluating the 2010 interstate transport 

SIP taking into account methodologies 

and analyses for the identification of the 

receptor monitors that was developed in 

the Transport Rule Proposal, as well as 

EPA’s projections of future air quality at 

monitors in western states in the Timin 

Memo, and air quality data from 

monitors in the states bordering Oregon. 

Although each of the factors considered 

in the following analysis are not in and 

of themselves determinative, 

consideration of these factors together 

provides a reliable qualitative 

conclusion that emissions from Oregon 

do not contribute significantly to 

nonattainment of the PM2.5 NAAQS at 

monitors in other states. 

Specifically, we identified the 

nonattainment receptors for the 1997 

annual PM2.5 NAAQS closest to Oregon 

to evaluate whether emissions from 

Oregon sources contribute significantly 

to nonattainment of the 1997 PM2.5

NAAQS in any other state.29 For the 

1997 annual PM2.5 NAAQS, the 

projected nonattainment receptors 

closest to Oregon that EPA identified 

from the modeling analyses conducted 

for the Transport Rule Proposal are all 

east of the Mississippi River.30 Given 

the significant distance between Oregon 

and these nonattainment receptors and 

the intervening mountainous terrain, we 

believe it is reasonable to conclude that 

Oregon sources do not significantly 

contribute to nonattainment of the 1997 

annual PM2.5 NAAQS in any of these 

areas. 

To address the potential for PM2.5

transport among western states, EPA 

also relied on the additional analysis in 

the Timin Memo identifying monitors 

projected to record violations of the 

1997 annual PM2.5 NAAQS. The Timin 

Memo identified predicted future 

nonattainment receptors for the 1997 

annual PM2.5 NAAQS in southern and 

central California but did not identify 

predicted future nonattainment 

receptors for the 1997 annual PM2.5

NAAQS in any other western state.31

For Oregon, the closest nonattainment 

receptor in California for the 1997 

annual PM2.5 NAAQS was Fresno 

County. Fresno County is over 300 miles 

south of the closest point on Oregon’s 

border and is on the other side of 

intervening mountain ranges that act as 

a natural barrier to air pollution 

transport. Although not determinative 

by themselves, distance and topography 

are not favorable to PM2.5 transport from 

Oregon to central California. In 

addition, prevailing winds in the west 

generally move from south-westerly, 

westerly, or north-westerly directions, 

as indicated by the typical movement of 

weather systems. Hence central and 

southern California are not in the 

predominant direction of winds from 

Oregon. Given the distance between the 

Oregon border and central and southern 

California nonattainment receptors, the 

intervening mountainous topography, 

and the general westerly direction of 

transport winds in the Western U.S., 

EPA concludes that Oregon sources do 

not contribute significantly to 

nonattainment of the 1997 annual PM2.5

NAAQS in Fresno County or to any 

more distant nonattainment receptors in 

California. EPA’s analysis for western 

states therefore supports our proposal to 

conclude that Oregon sources do not 

contribute significantly to 

nonattainment of the 1997 annual PM2.5

NAAQS in any other state. 

The analysis for the Transport Rule 

Proposal did not identify any 

nonattainment receptors for the 1997 

24-hour PM2.5 NAAQS in the portions of 

the U.S. covered by the Transport Rule 

Proposal modeling domain (i.e., the 12 

km grid covering the continental U.S. 

east of the Rockies).32 Recent 

monitoring data in EPA’s Air Quality 

System (2007–2009 design values) 

indicate that the highest 24-hour PM2.5

design value in the 47 states of the 

continental U.S. (excluding California) 

is 50 μg/m3,33 which is well below the 

level of the 1997 24-hour PM2.5 NAAQS 

of 65 μg/m3. In California, 2007–2009 

AQS data indicate that only one area, 

Kern County, has a design value above 

the level of the 1997 24-hour PM2.5

NAAQS. As discussed above, EPA 

believes that given the relatively long 

distance between the Oregon border and 

Kern County, the intervening 

mountainous topography, and the 

generally westerly direction of transport 

winds in the Western U.S., emissions 

from Oregon sources do not interfere 

with maintenance of the 1997 24-hour 

PM2.5 NAAQS in Kern County. These 

data and factors further support our 

proposed finding that Oregon sources 

do not significantly contribute to 

nonattainment of the 1997 24-hour 

PM2.5 NAAQS in any other state. 

In addition to the information in the 

2010 interstate transport SIP and our 

review of the nearest nonattainment 

receptors identified from the modeling 

analyses conducted for the Transport 

Rule Proposal, EPA evaluated air quality 

data for the areas in states bordering 

Oregon that are designated 

nonattainment for the 1997 PM2.5


srobinson on DSKHWCL6B1PROD with PROPOSALS
19300 Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 

34 In 2005, EPA designated this area 

nonattainment for violations of the 1997 and annual 

PM2.5 NAAQS. 70 FR 944 (January 5, 2005), and 40 

CFR 81.305. 

35Libby is in a narrow valley surrounded by 

mountains 4,000 feet higher than the town. The 

Rocky Mountain Range to the west of Libby (and 

east of the Idaho border) reaches summit elevations 

of 12,000 feet with most summit elevations between 

6000 and 7000 feet that act as a barrier to air 

movement between Idaho and Montana. 

36 ‘‘Technical Support for State and Tribal Air 

Quality Fine Particle (PM2.5) Designations,’’ (for 

Montana) Chapter 6, pp. 347–352, December 2004. 

37 ‘‘Technical Support for State and Tribal Air 

Quality Fine Particle (PM2.5) Designations,’’ (for 

Montana) Chapter 4.8.1, pp. 1–15, December 2008. 

38 In 2001, 2002 and 2006, design values for two 

monitors in Missoula County were 11.1, 11.4 and 

11.8 μg/m3. Computed from AQS monitoring data. 

75 FR 16028 (March 31, 2010). 

39State of Montana, Department of 

Environmental Quality, ‘‘State Implementation 

Plan-Libby Annual PM2.5 Control Plan,’’ submitted 

to EPA April 1, 2008. 

40See Timin Memo at Appendix A (‘‘Base year 

2003–20007 and Future Year 2012 Annual Average 

PM2.5 Design Values—Western States’’). 

NAAQS. Although significant 

contribution must be measured not just 

against nonattainment areas but also 

against areas with monitors showing 

violations of the NAAQS, 

nonattainment areas are a convenient 

point of analysis. 

The closest 1997 PM2.5 nonattainment 

area in any state bordering Oregon is the 

San Joaquin Valley in California.34 This 

nonattainment area is located in central 

California and is over 250 miles from 

the closest point on Oregon’s border and 

on the other side of intervening 

mountain ranges that act as a natural 

barrier to air pollution transport. In 

addition, prevailing winds in the 

western U.S. generally move from 

south-westerly, westerly, or northwesterly directions, as indicated by the 

typical movement of weather systems. 

Hence, Joaquin Valley, California, is not 

in the predominant direction of winds 

from Oregon. Given the relatively long 

distance between Oregon and the San 

Joaquin Valley, the intervening 

mountainous topography, and the 

general direction of transport winds in 

the Western U.S., EPA believes that 

Oregon sources do not significantly 

contribute to nonattainment of the 1997 

PM2.5 NAAQS in the San Joaquin Valley 

nonattainment area or to any more 

distant California 1997 PM2.5

nonattainment areas. There are no areas 

in Idaho and Washington currently 

designated nonattainment for the 1997 

PM2.5 NAAQS. This is further support 

that Oregon sources do not contribute 

significantly to nonattainment of the 

1997 PM2.5 NAAQS in any other state. 

Although not located in a state 

bordering Oregon, the closest designated 

nonattainment area to Oregon for the 

1997 PM2.5 NAAQS is Libby, in Lincoln 

County, Montana.35 In 2005, EPA 

designated this area nonattainment for 

the 1997 annual PM2.5 NAAQS. 70 FR 

944 (January 5, 2005) and 40 CFR 

81.327. A number of factors provide 

evidence that Oregon emissions do not 

significantly contribute to past 

violations of the 1997 annual PM2.5

standards in Libby, Montana. 

First, in the process of designating 

Libby nonattainment for both the 1997 

PM2.5 NAAQS and the 2006 24-hour 

PM2.5 NAAQS, EPA noted the 

predominantly local origins of PM2.5

nonattainment in Libby.36 37 Residential 

wood-burning stoves during the wintertime, when frequent and persistent 

temperature inversions occurred, were 

specifically identified as a key source of 

PM emissions. The fact that 

nonattainment in a given area is 

primarily the result of local emissions 

sources does not, however, exclude the 

possibility of significant contribution to 

nonattainment from interstate transport. 

EPA believes that other evidence 

supports the conclusion that emissions 

from Oregon sources are not 

significantly contributing to violations 

in Libby, Montana. 

Second, monitoring data from 1999 

through 2009 from areas outside of 

Libby in Montana support a 

determination that Oregon does not 

significantly contribute to 

nonattainment in Libby. At all other 

sites in Montana, annual PM2.5 design 

value levels have remained below the 15 

μg/m3 nonattainment threshold. Annual 

PM2.5 design values for this period for 

most of these monitors remained at 

levels equal to, or less than, two-thirds 

of the 1997 annual PM2.5 NAAQS. Even 

the three highest design values at these 

monitors were 20 percent below the 

level of the annual standard.38 The 

lower PM2.5 levels elsewhere in 

Montana are evidence that local sources, 

and not interstate transport, are key 

contributors to past nonattainment in 

Libby. 

Third, for 2007–2009, AQS data show 

that the annual PM2.5 design values for 

the Libby nonattainment area 

themselves fell below the levels of the 

NAAQS. This reduction has been 

attributed to an effective wood stove 

replacement program that decreased 

PM2.5 emissions by approximately 59 

percent.39 In other words, even if 

emissions from Oregon sources were 

reaching Libby, they would not 

significantly contribute to violations of 

the 1997 annual PM2.5 NAAQS because 

monitoring data demonstrate that Libby 

is not violating the 1997 annual PM2.5

NAAQS. 

Finally, EPA’s conclusion that 

emissions from Oregon do not 

significantly contribute to 

nonattainment in Libby, Montana, is 

further supported by the analysis of 

monitors in the western United States.40

This analysis concludes that in 2012 the 

average annual PM2.5 design values in 

Lincoln County, Montana will be below 

the threshold for consideration as a 

nonattainment receptor. These factors 

together support a conclusion that 

Oregon sources do not contribute 

significantly to nonattainment of the 

1997 annual PM2.5 NAAQS in the Libby 

1997 PM2.5 nonattainment area. 

As mentioned above, EPA considers 

not only significant contribution to 

designated nonattainment areas, but 

also significant contribution to areas 

with monitors showing violations of the 

NAAQS. A review of the most recent 

three years (2007–2009) of monitoring 

data in AQS for the bordering states of 

Washington, Idaho, Nevada, and 

California shows that the only monitors 

with design values above the 1997 

annual PM2.5 NAAQS are located in 

central and southern California. The 

county closest to the Oregon border that 

has a design value above the 1997 

annual PM2.5 NAAQS is Kern County, 

California. Kern County is more than 

400 miles from the closest point on 

Oregon’s border and is on the other side 

of intervening mountain ranges that act 

as a natural barrier to air pollution 

transport. Although not determinative 

by themselves, distance and topography 

are not favorable to PM2.5 transport from 

Oregon to central California. In 

addition, prevailing winds in the west 

generally move from south-westerly, 

westerly, or north-westerly directions, 

as indicated by the typical movement of 

weather systems. Hence Kern County, 

California is not in the predominant 

direction of winds from Oregon. Given 

the relatively long distance between the 

Oregon border and Kern County, the 

intervening mountainous topography, 

and the generally westerly direction of 

transport winds in the Western U.S., it 

is reasonable to conclude that Oregon 

sources do not significantly contribute 

to nonattainment of the 1997 PM2.5

NAAQS in Kern County or to any more 

distant monitors in California. 

As noted above no monitors in 

Washington, Idaho and Nevada or 

Northern California had design values 

above the 1997 annual PM2.5 NAAQS for 

the 2007–2009 period. The fact that 

monitors in these areas are not 

registering violations of the 1997 PM2.5

NAAQS does not in itself conclusively 

establish that emissions from Oregon 

could not contribute in the aggregate to 


srobinson on DSKHWCL6B1PROD with PROPOSALS
Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 19301 

41Oregon’s submission makes this conclusion 

with respect to not only the 1997 PM2.5 NAAQS and 

1997 8-hour ozone NAAQS, but also the 2006 PM2.5

NAAQS and the 2008 8-hour ozone NAAQS. 42This north/northwest prevailing wind direction 

was derived from surface level winds and airport 

data and is not necessarily indicative of the 

prevailing wind direction of typical weather 

systems in the west. 43There are currently no 1997 8-hour ozone 

nonattainment areas in Oregon or Washington. 

violations in these areas. But this fact 

combined with our above evaluation of 

the nearest nonattainment receptors, 

nearest nonattainment areas, and 

nearest monitors with design values 

above the 1997 annual PM2.5 NAAQS, 

supports a conclusion that Oregon 

sources do not significantly contribute 

to nonattainment of the 1997 PM2.5

NAAQS in other states. 

Finally, none of the PM2.5 monitors in 

Oregon have themselves indicated a 

violation of the 1997 annual PM2.5

NAAQS. The absence of violations in 

Oregon itself does not rule out the 

possibility of transport, but taken in 

conjunction with other relevant 

information, including the distance 

from Oregon to areas with design values 

above the 1997 annual PM2.5 NAAQS 

and Pacific Northwest meteorology and 

topography, this fact helps to support 

the conclusion that there is no transport 

from Oregon resulting in significant 

contribution to nonattainment in 

another state. Taking into account the 

total weight of all of the factors 

discussed above, EPA concludes that 

Oregon does not significantly contribute 

to the 1997 annual PM2.5 NAAQS 

nonattainment in any other state. 

3. Conclusion Regarding Significant 

Contribution to Nonattainment 

Based on the weight of evidence 

discussed above, including the location 

of the nearest projected nonattainment 

receptors, distance to the nearest 

designated PM2.5 nonattainment area, 

meteorology, topography, and recent air 

quality monitoring data, we propose to 

determine that Oregon’s 2010 interstate 

transport SIP is adequate to ensure that 

emissions from Oregon do not 

significantly contribute to 

nonattainment in any other state for the 

1997 8-hour ozone or 1997 PM2.5

NAAQS, consistent with the 

requirements of CAA section 

110(a)(2)(D)(i)(I). Thus, we propose to 

determine that Oregon’s SIP includes 

the measures necessary to prevent such 

prohibited interstate transport impacts 

for these NAAQS. 

B. EPA’s Evaluation of Interference With 

Maintenance 

This proposed approval evaluates the 

interfere with maintenance element of 

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

the 1997 8-hour ozone and 1997 PM2.5

NAAQS in several ways. It takes into 

account Oregon’s 2010 interstate 

transport SIP, in which the State 

explains that based on meteorological 

and other characteristics in Oregon and 

in the surrounding areas, PM2.5 and 

ozone precursor emissions do not 

interfere with maintenance of the 1997 

8-hour ozone or 1997 PM2.5 NAAQS in 

other states.41 In addition, EPA has 

supplemented the State’s analysis with 

its own evaluation of the evidence, 

including a review of the nearest 

monitors in other states that are 

appropriate maintenance receptors, 

consistent with EPA’s approach in the 

Transport Rule Proposal, in order to 

assess whether emissions sources in 

Oregon interfere with maintenance of 

the 1997 8-hour ozone and PM2.5

NAAQS in other states. 

1. Oregon’s 2010 Interstate Transport 

SIP 

To show that Oregon emissions, as 

controlled under its SIP, do not interfere 

with maintenance of the 1997 8-hour 

ozone NAAQS and 1997 PM2.5 NAAQS 

in another state, Oregon’s 2010 

interstate transport SIP analyzed several 

types of factors to support its assertion. 

First, the State pointed to topography 

and meteorology for its evaluation, 

maintaining that high PM2.5

concentrations in adjacent states 

typically occur under winter conditions 

when air speeds are low and/or 

localized air inversions occur. 

Describing wind direction as being 

typically variable with the majority of 

wind speeds less than 8 miles per hour, 

and a significant portion of low winds 

less than 5 miles per hour, the state 

noted that these low wind speeds and 

air stagnation conditions do not lend 

them to long distance air pollution 

transport. The State indicated that there 

are occasional high 8-hour ozone levels 

that occur in the summer months, but 

maintained that prevailing winds42 in 

Oregon are predominantly from the 

north to northwest.43 The state 

indicated that prevailing summer winds 

could theoretically result in some 

interstate transport of ozone forming 

emission from Oregon to western Idaho, 

Nevada and northern California. It also 

noted, however, that significant 

distances and topography (such as major 

mountain ranges that separate Oregon 

from California, Idaho, and Nevada) 

would likely minimize the significance 

of these impacts on other states. It 

pointed to, for example, the 

approximately 400 to 700 miles distance 

between the largest major urban center 

in Oregon (the greater Portland area) 

and urban areas in western Idaho, 

Nevada, and northern California and at 

least one major mountain range between 

those areas. 

Second, Oregon used AQS monitoring 

data for 2006–2008 from other states in 

its analysis. Oregon pointed out that 

both PM2.5 and ozone design values in 

all counties adjacent to Oregon are 

below the PM2.5 and 8-hour ozone 

NAAQS. Oregon also consulted with 

each of the state air agencies for 

Washington, Idaho, Nevada, and 

California to get a sense of what the 

local air agencies believe are the likely 

causes of any air quality concerns for 

maintaining compliance with the PM2.5

and ozone NAAQS. Based on these 

consultations and the other information 

above, Oregon concluded that emissions 

from air pollution sources in Oregon do 

not interfere with the maintenance of 

the 8-hour ozone or PM2.5 NAAQS in 

other states. 

Oregon also relied on information 

about air stagnation conditions in other 

states to support its assertions that 

Oregon sources do not interfere with 

maintenance of the 1997 8-hour ozone 

NAAQS and 1997 PM2.5 NAAQS in 

other states. Oregon noted that stagnant 

air conditions are associated with weak 

transport and that high PM2.5

concentrations in adjacent states 

typically occur under winter conditions 

when air speeds are low and/or 

localized air inversions occur. Oregon 

also pointed to examples of where it has 

collaborated with other states to 

demonstrate its ability and willingness 

to address problems involving interstate 

transport. Examples included the 

Portland-Vancouver 1-hour ozone 

attainment and maintenance plans, and 

Oregon’s regional haze plan. Oregon 

described how in the mid-1990s and 

again in 2007, ODEQ collaborated with 

the Southwest Clean Air Agency (i.e., 

the State of Washington air agency with 

jurisdiction over Vancouver) to develop 

bi-state ozone attainment and 

maintenance plans with emission 

reduction strategies needed to attain and 

maintain compliance with federal ozone 

standards. In 2008–09, ODEQ worked 

with the states of Washington, Idaho 

and California, as well as Federal Land 

Managers in developing Oregon’s 

Regional Haze plan. Oregon described 

how under that plan ODEQ adopted 

several emission reduction strategies, 

including emission control 

requirements to reduce the interstate 

transport of haze forming emissions. 

Finally, Oregon pointed to its section 

110 infrastructure SIP to show that 

ODEQ has the ability to participate as 

needed in future studies on regional air 

pollution issues, or collaborate with 


srobinson on DSKHWCL6B1PROD with PROPOSALS
19302 Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 

44See Transport Rule Proposal, 75 FR 45210 at 

45253–45273. 

45See Transport Rule Proposal, Table IV.C–12, 75 

FR 45210 at 45252–45253. 

46See Timin Memo at Appendix B (‘‘Base year 

2003–2007 and Future Year 2012 8-Hour Average 

Ozone Design Values—Western States’’). 

other states if air quality concerns are 

identified that require a case-specific 

evaluation of interstate transport. 

Oregon added that its infrastructure SIP 

also ensures the legal mechanism for 

ODEQ to take action as needed to 

reduce emissions to help maintain 

compliance with federal NAAQS. 

EPA does not necessarily agree that 

Oregon’s methodology is adequate for 

purposes of a section 110(a)(2)(D)(i) 

analysis. Therefore, EPA is 

supplementing the State’s submission 

with additional, and more recent, 

information in order to assess this issue 

more fully. As noted above, EPA is 

evaluating the 2010 interstate transport 

SIP taking into account methodologies 

and analyses for the identification of the 

receptor monitors that was developed in 

the Transport Rule Proposal, as well as 

EPA’s projections of future air quality at 

monitors in western states in the Timin 

Memo and preliminary air quality data 

from monitors in the states bordering 

Oregon. Although each of the factors 

considered in the following analysis are 

not in and of themselves determinative, 

consideration of these factors together 

provides a reliable qualitative 

conclusion that emissions from Oregon 

do not interfere with maintenance of the 

1997 8-hour ozone and PM2.5 NAAQS at 

monitors in other states. 

2. Interfere With Maintenance 

Evaluation for the 8-Hour Ozone 

NAAQS 

As discussed above, in the Transport 

Rule Proposal, EPA projected future 

concentrations of ozone at monitors to 

identify areas that are expected to be 

violating the NAAQS or to have 

difficulty maintaining compliance with 

the NAAQS in 2012. For purposes of the 

interference with maintenance 

evaluation, EPA projected future 

concentrations of ozone at monitors to 

identify areas that are expected to have 

a maximum design value (based on a 

single 3-year period) that exceeds the 

1997 8-hour ozone NAAQS, and EPA 

anticipates that by 2012 these 

maintenance receptors will have 

difficulty in maintaining attainment of 

the NAAQS if there are adverse 

variations in meteorology or emissions. 

To identify the states with emissions 

that may cause interference with 

maintenance of the NAAQS at 

maintenance receptors, the Transport 

Rule Proposal modeled the states’ 

contributions to ambient ozone levels at 

these maintenance receptors.44 Because 

the Transport Rule Proposal did not 

identify the contribution of emissions 

from Oregon (and other western states 

not fully inside the Transport Rule 

Proposal’s modeling domain) to 8-hour 

ozone maintenance receptors in other 

states, our assessment relies on a weight 

of evidence approach that considers 

relevant information from the Transport 

Rule Proposal pertaining to states 

within its modeling domain, and 

additional information such as 

geographical and meteorological factors, 

EPA’s projections of future air quality at 

monitors in western states in the Timin 

Memo, and AQS monitoring data. 

Although each of the factors considered 

in the following analysis is not in and 

of itself determinative, consideration of 

these factors together supports a reliable 

qualitative conclusion that emissions 

from Oregon do not interfere with 

maintenance of the 1997 8-hour ozone 

NAAQS at monitors in other states. 

Our analysis begins by assessing 

Oregon’s contribution to the closest 

maintenance receptors for the 1997 8- 

hour ozone standard. The Transport 

Rule Proposal identifies 16 maintenance 

receptors for the 1997 8-hour ozone 

standard within its modeling domain 

(consisting of 37 states east of the Rocky 

Mountains, and the District of 

Columbia). Of these, the receptors 

closest to Oregon are eight receptors in 

the Dallas-Fort Worth and HoustonGalveston-Brazoria 8-hour ozone 

nonattainment areas in eastern Texas. 

The remaining eight maintenance 

receptors are located in Connecticut, 

Georgia, New York and Pennsylvania.45

As discussed above in section V.A.1, 

the Dallas-Fort Worth and Houston 

areas are over 1200 miles from the 

closest point on Oregon’s border. The 

maintenance receptor monitors located 

in Connecticut, Georgia, New York and 

Pennsylvania are significantly further 

away. Although distance alone is not 

determinative in the analysis of 

potential ozone transport, with 

increasing distance there are greater 

opportunities for ozone and NOX

dispersion and/or removal from the 

atmosphere. Moreover, the intervening 

Rocky Mountains act as a natural barrier 

to air pollution transport. These factors 

together support a conclusion that 

emissions from Oregon sources do not 

interfere with maintenance of the 1997 

8-hour ozone NAAQS in the nearest 

areas with monitors projected to violate 

the 1997 8-hour ozone NAAQS as part 

of the Transport Rule Proposal. 

EPA’s analysis in the Timin Memo 

identified four maintenance receptors 

for the 1997 8-hour ozone NAAQS in 

southern and central California.46 The 

closest 8-hour ozone maintenance 

receptor to Oregon was in Placer 

County, California. Placer County is 

approximately 185 miles south of the 

closest point on Oregon’s border and is 

not in the predominant direction of 

transport winds. As noted earlier, 

prevailing winds generally move from 

south-westerly, westerly, or 

northwesterly directions, as indicated 

by the typical movement of weather 

systems. Given the relatively long 

distance between Oregon and central 

California, the intervening mountainous 

topography, and the general direction of 

west-to-east transport winds across 

Oregon, it is reasonable to conclude that 

Oregon sources do not interfere with 

maintenance of the 1997 8-hour ozone 

NAAQS in Placer County, California. It 

is also reasonable to conclude that 

emissions from sources in Oregon 

would not have such impacts at other 

identified maintenance receptor sites 

that are in central or southern California 

that are in the same direction and 

further away from the Oregon border. 

All of these factors taken together 

supports a conclusion that emissions 

from Oregon sources do not interfere 

with maintenance of the 1997 8-hour 

ozone NAAQS in any other state. 

Finally, none of the ozone monitors in 

Oregon have themselves indicated a 

violation of the 1997 8-hour ozone 

NAAQS. The absence of violations in 

Oregon itself does not rule out the 

possibility of transport, but taken in 

conjunction with other relevant 

information, including the distance 

from Oregon to areas with design values 

above the 1997 8-hour ozone NAAQS 

and Pacific Northwest meteorology and 

topography, this fact helps to support a 

conclusion that there is no transport 

from Oregon resulting in interference 

with maintenance in another state. 

Taking into account the total weight of 

all of the factors discussed above, EPA 

concludes that Oregon does not interfere 

with maintenance of the 1997 8-hour 

ozone NAAQS in any other state. 

3. Interference With Maintenance 

Evaluation for the 1997 PM2.5 NAAQS 

The Transport Rule Proposal 

identifies within its modeling domain 

16 predicted future maintenance 

receptors for the 1997 annual PM2.5

NAAQS. Of these, the closest to Oregon 

are receptors located in Harris County, 

Texas. Harris County, Texas, is over 

1,400 miles from the closest point on 

Oregon’s border and on the other side of 


srobinson on DSKHWCL6B1PROD with PROPOSALS
Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 19303 

47Specifically, the remaining 15 maintenance 

sites for the 1997 annual PM2.5 NAAQS are located 

in Kentucky, New York, Ohio, Pennsylvania, and 

West Virginia. 48 75 FR 45210 at 45249–45251 (August 2, 2010). 

See also fn. 39 and fn. 47. 

49 Data from EPA’s Air Quality System can be 

viewed at http://www.epa.gov/ttn/airs/airsaqs/. 

the Rocky Mountains. Given the long 

distance and intervening mountainous 

topography between Oregon and this 

area, it is reasonable to conclude that 

there is a very low probability that 

Oregon sources interfere with 

maintenance in that area or at the other 

identified maintenance sites east of 

Harris County, Texas.47 EPA, therefore, 

concludes that Oregon sources do not 

interfere with maintenance of the 1997 

annual PM2.5 NAAQS in other states 

within the geographic region covered by 

the Transport Rule Proposal. 

EPA’s analysis in the Timin Memo 

identified Los Angeles County, 

California, as the closest projected 

maintenance receptor to Oregon’s 

border. Los Angeles County is located 

almost 500 miles south of the closest 

point on Oregon’s border and is on the 

other side of intervening mountain 

ranges that act as a natural barrier to air 

pollution transport. Although not 

determinative by themselves, distance 

and topography are not favorable to 

PM2.5 transport from Oregon to central 

California. In addition, prevailing winds 

in the west generally move from southwesterly, westerly, or north-westerly 

directions, as indicated by the typical 

movement of weather systems. Given 

the relatively long distance between 

Oregon and Los Angeles County, the 

intervening mountainous topography, 

and the general westerly direction of 

transport winds in the Western U.S., it 

is reasonable to conclude that Oregon 

sources do not interfere with 

maintenance of the 1997 annual PM2.5

NAAQS in Los Angeles County or to 

any more distant maintenance receptors 

in central or southern California. EPA’s 

analysis for the western states therefore 

supports our proposal to conclude that 

Oregon sources do not interfere with 

maintenance of the 1997 annual PM2.5

NAAQS in any other states. Based on all 

of these factors taken together, EPA 

further believes it is reasonable to 

conclude that Oregon emissions under 

the SIP do not interfere with 

maintenance of the 1997 PM2.5 NAAQS 

in any other state. 

The analysis for the Transport Rule 

Proposal did not identify any 

maintenance receptors for the 1997 24- 

hour PM2.5 NAAQS in the portions of 

the U.S. covered by the Transport Rule 

Proposal modeling domain.48 Recent 

monitoring data in EPA’s AQS Database 

(2007–2009 design values that are under 

final EPA review) indicate that the 

highest 24-hour PM2.5 design value in 

the 47 states of the continental U.S. 

(excluding California) is 50 μg/m3, 

which is well below the level of the 

1997 24-hour PM2.5 NAAQS of 65 μg/ 

m3.49 For California, AQS data indicate 

that only Kern County has a 24-hour 

design value above the level of the 1997 

24-hour PM2.5 NAAQS. As discussed 

above, EPA believes that, based on the 

relatively long distance between the 

Oregon border and Kern County, the 

intervening mountainous topography, 

and the generally westerly direction of 

transport winds in the Western U.S., 

emissions from Oregon sources do not 

interfere with maintenance of the 1997 

24-hour PM2.5 NAAQS in Kern County. 

4. Conclusion Regarding Interference 

With Maintenance 

Based on the weight of evidence, 

including the location of the nearest 

projected maintenance sites, taking into 

account distance, meteorology, 

topography, and recent air quality 

monitoring data, as discussed above, we 

propose to determine that Oregon’s 2010 

interstate transport SIP is adequate and 

that emissions from Oregon do not 

interfere with maintenance in any other 

state for the 1997 8-hour ozone or 1997 

PM2.5 NAAQS, consistent with the 

requirements of element (2) of CAA 

section 110(a)(2)(D)(i)(I). Thus, we 

propose to determine that Oregon’s SIP 

contains adequate provisions necessary 

to prevent such prohibited interstate 

transport impacts for these NAAQS and 

does not require any additional 

measures for this purpose at this time. 

VI. Proposed Action 

In light of the data and the weight of 

evidence analysis presented above, EPA 

is proposing to approve revisions to the 

Oregon SIP, submitted on June 23, 2010, 

and December 23, 2010, and concludes 

that for the 1997 8-hour ozone and 1997 

PM2.5 NAAQS, air pollutant emissions 

from sources within Oregon do not 

either (1) significantly contribute to 

nonattainment of the NAAQS in any 

other state; or (2) interfere with 

maintenance of the NAAQS by any 

other state. 

As noted previously, EPA will 

address element (3) interference with 

any other state’s required measures to 

prevent significant deterioration of its 

air quality and element (4), interference 

with any other state’s required measures 

to protect visibility, in a separate action. 

EPA will also take action on the portion 

of Oregon’s SIP that addresses the 2006 

PM2.5 and 2008 8-hour ozone NAAQS in 

a separate action. 

VII. 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 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 


srobinson on DSKHWCL6B1PROD with PROPOSALS
19304 Federal Register / Vol. 76, No. 67 / Thursday, April 7, 2011 / Proposed Rules 

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, Incorporation by 

reference, Intergovernmental relations, 

Ozone, Particulate matter, Reporting 

and recordkeeping requirements, 

Volatile organic compounds. 

Dated: March 30, 2011. 

Dennis J. McLerran, 

Regional Administrator, Region 10. 

[FR Doc. 2011–8330 Filed 4–6–11; 8:45 am] 

BILLING CODE 6560–50–P 

DEPARTMENT OF THE INTERIOR 

Fish and Wildlife Service 

50 CFR Part 17 

[Docket No. FWS–R2–ES–2010–0041;MO 

92210–0–0008] 

RIN 1018–AV97 

Endangered and Threatened Wildlife 

and Plants; Endangered Status for 

Dunes Sagebrush Lizard 

AGENCY: Fish and Wildlife Service, 

Interior. 

ACTION: Proposed rule; reopening of 

comment period and announcement of 

public hearings. 

SUMMARY: We, the U.S. Fish and 

Wildlife Service, announce the 

reopening of the public comment period 

on the December 14, 2010, proposed 

rule to list the dunes sagebrush lizard 

(Sceloporus arenicolus) under the 

Endangered Species Act of 1973, as 

amended (Act). We are reopening the 

comment period to allow all interested 

parties another opportunity to comment 

on the proposed rule. Comments 

previously submitted need not be 

resubmitted and will be fully 

considered in preparation of the final 

rule. We will also hold two public 

informational sessions and hearings (see 

DATES and ADDRESSES sections). 

DATES: We will consider comments 

received on or before May 9, 2011. 

Comments must be received by 11:59 

p.m. Eastern Time on the closing date. 

Any comments that we receive after the 

closing date may not be fully considered 

in the final decision on this action. 

We will hold a public informational 

session from 3:30 p.m. to 5 p.m., 

followed by a public hearing from 6:30 

p.m. to 8 p.m., on each of the following 

dates: 

1. April 27, 2011: Midland, Texas. 

2. April 28, 2011: Roswell, New 

Mexico. 

ADDRESSES: You may submit comments 

by one of the following methods: 

• Federal eRulemaking Portal: http:// 

www.regulations.gov. Follow the 

instructions for submitting comments to 

Docket No. FWS–R2–ES–2010–0041. 

• U.S. mail or hand-delivery: Public 

Comments Processing, Attn: FWS–R2– 

ES–2010–0041; Division of Policy and 

Directives Management; U.S. Fish and 

Wildlife Service; 4401 N. Fairfax Drive, 

Suite 222; Arlington, VA 22203. 

We will post all comments on 

http://www.regulations.gov. This 

generally means that we will post any 

personal information you provide us 

(see the Public Comments section below 

for more information). 

Information Sessions and Hearings 

The public informational sessions and 

hearings will be held at the following 

locations: 

1. Midland, Texas: Midland Center & 

Centennial Plaza, 105 N. Main Street, 

Midland, Texas 79701. 

2. Roswell, New Mexico: ENMU— 

Roswell, Performing Arts Center, 64 

University Blvd., Roswell, New Mexico 

88202. 

People needing reasonable 

accommodations in order to attend and 

participate in the public hearings 

should contact Wally ‘‘J’’ Murphy, New 

Mexico Ecological Services Field Office, 

at 505–761–4718 as soon as possible 

(see FOR FURTHER INFORMATION CONTACT). 

In order to allow sufficient time to 

process requests, please call no later 

than one week before the hearing date. 

FOR FURTHER INFORMATION CONTACT: 

Wally ‘‘J’’ Murphy, Field Supervisor, 

New Mexico Ecological Services Field 

Office, 2105 Osuna NE., Albuquerque, 

NM 87113; by telephone 505–761–4781 

or by facsimile 505–346–2542. Persons 

who use a telecommunications device 

for the deaf (TDD) may call the Federal 

Information Relay Service (FIRS) at 

800–877–8339. 

SUPPLEMENTARY INFORMATION: 

Public Comments 

We will accept written comments and 

information during this reopened 

comment period for the proposed rule to 

list the dunes sagebrush lizard 

(Sceloporus arenicolus) that was 

published in the Federal Register on 

December 14, 2010 (75 FR 77801). We 

intend that any final action resulting 

from this proposed rule will be based on 

the best scientific and commercial data 

available and be as accurate and as 

effective as possible. Therefore, we 

request comments or information from 

the public, other concerned government 

agencies, the scientific community, 

industry, or other interested parties 

concerning this proposed rule. Verbal 

testimony or written comments may 

also be presented during the public 

hearing. We will consider information 

and recommendations from all 

interested parties. We are particularly 

interested in comments concerning: 

(1) Information on the dunes 

sagebrush lizard relevant to the factors 

that are the basis for making a listing 

determination for a species under 

section 4(a) of the Endangered Species 

Act of 1973, as amended (Act) (16 

U.S.C. 1531 et seq.). These factors are: 

(a) The present or threatened 

destruction, modification, or 

curtailment of its habitat or range; 

(b) Overutilization for commercial, 

recreational, scientific, or educational 

purposes; 

(c) Disease or predation; 

(d) The inadequacy of existing 

regulatory mechanisms; or 

(e) Other natural or manmade factors 

affecting its continued existence. 

(2) Additional information concerning 

the range, distribution, and population 

size of this species, including the 

locations of any additional populations 

of this species. 

(3) Any information on the biological 

or ecological requirements of the 

species. 

If you submitted comments or 

information on the proposed rule (75 FR 

77801, December 14, 2010) during the 

initial comment period from December 

14, 2010, to February 14, 2011, please 

do not resubmit them. We will 

incorporate them into the public record 

as part of this comment period, and we 

will fully consider them in the 

preparation of our final determination. 

Our final determination will take into 

consideration all written comments and 

any additional information we receive 

during both comment periods. 

You may submit your comments and 

materials concerning the proposed rule 

by one of the methods listed in the 

ADDRESSES section. 

We will post your entire comment— 

including your personal identifying 

information—on http:// 

www.regulations.gov. If you provide 

personal identifying information, such 

as your street address, phone number, or 

e-mail address, you may request at the 

top of your document that we withhold 

this information from public review. 

However, we cannot guarantee that we 

will be able to do so. 

Comments and materials we receive, 

as well as supporting documentation we 

used in preparing the proposed rule, 


srobinson on DSKHWCL6B1PROD with PROPOSALS