Response to Comments on Implementation of the 2008

National Ambient Air Quality Standards for Ozone:

Nonattainment Area Classifications Approach, Attainment

Deadlines, and Revocation of the 1997 Ozone Standards for

Transportation Conformity Purposes.

Associated Docket Number: 

Docket Number EPA-HQ-OAR-2010-0885 

April 2012 
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INTRODUCTION

On February 14, 2012, EPA issued a proposed rule regarding certain issues related to the 

implementation of the 2008 ozone National Ambient Air Quality Standards (NAAQS) 

promulgated by EPA on March 12, 2008. Specifically, the proposed rule (1) presents thresholds 

for classifying nonattainment areas for the 2008 ozone NAAQS, (2) proposes that the approved 

prior voluntary reclassification requests for the 1997 ozone NAAQS would also apply for the 

more stringent 2008 ozone NAAQS unless a state explicitly requests otherwise, (3) presents the 

timing of attainment deadlines for each area classified under Clean Air Act (CAA), Title 1, Part 

D, subpart 2, and (4) proposes revocation of the 1997 ozone NAAQS one year after the effective 

date of designations for the 2008 ozone NAAQS for transportation conformity purposes only. 

1. Establishing thresholds for classifying nonattainment areas. 

The method by which EPA proposed to determine thresholds for classifying nonattainment areas 

for the 2008 ozone NAAQS is the “percent-above-the-standard” approach. For purposes of this 

proposed rulemaking, the “percent-above-the-standard approach” involves setting the 

classification threshold for each classification category at the same percentage above the 2008 

ozone NAAQS as the percentage of the same classification category’s threshold set by Congress 

in 1990 above the NAAQS in place at that time. 

2. Voluntary reclassifications. 

CAA §181(b)(3) allows states to voluntarily request that EPA reclassify the area to a higher 

classification; EPA has no discretion to deny such requests. There are seven areas for which 

states requested a voluntary reclassification with respect to the 1997 ozone NAAQS. EPA is 

further proposing that any approved prior voluntary reclassification requests for the 1997 ozone 

NAAQS also apply for the more stringent 2008 ozone NAAQS, unless a state explicitly requests 

otherwise. 

3. Timing of attainment deadlines. 

EPA is proposing two approaches regarding deadlines for attainment. For ozone nonattainment 

areas, the CAA specifies that the primary NAAQS must be met as expeditiously as practicable, 

but no later than the deadlines provided in the classification table in subpart 2, where such 

deadlines for attainment are specified in terms of a certain number of years from the date of 

enactment of the 1990 Amendments to the CAA. Because these time periods are inappropriate 

for later promulgated standards, EPA has in the past interpreted this portion of the CAA to 

require timeframes with similar time lengths provided in subpart 2, but which run from the date 

that area designations and nonattainment classifications become effective. The first approach 

EPA is proposing is to use the approach EPA used in the past. The second and preferred 

approach EPA is proposing is to use the approach that EPA has used in the past, but with the 

time lengths running from December 31 of the year in which area designations and 

nonattainment classifications become effective. 
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4. Revocation of the 1997 NAAQS for transportation conformity purposes. 

EPA proposed to revoke the 1997 ozone NAAQS one year after the effective date of 

designations for the 2008 ozone NAAQS for transportation conformity purposes only. This 

action is intended to bring certainty to the transportation planning process in ozone 

nonattainment and maintenances areas and to ensure that backsliding does not occur for purposes 

of transportation conformity, as areas designated as nonattainment for the 2008 ozone NAAQS 

would be required to use adequate or approved state implementation plan (SIP) motor vehicle 

emissions budgets for the 1997 ozone NAAQS, if the area has such SIP budgets for one of these 

ozone NAAQS, until SIP budgets are found adequate or are approved for the 2008 ozone 

NAAQS. 

5. Scope of comments requested 

EPA invited public comments on the proposed rule during the comment period, which lasted 

from February 14, 2012 through March 15, 2012. EPA requested comments only on the issues 

addressed by the proposed rule. EPA explained that this rule does not address the following: (1) 

specific SIP requirements associated with different classification categories, (2) revocation of the 

1997 ozone NAAQS for purposes other than transportation conformity, (3) anti-backsliding 

issues. EPA plans to address such issues in a separate rulemaking and does not intend to respond 

in the context of this rulemaking to comments pertaining to implementation issues that will be 

addressed by a future rulemaking. 

6. Summary of commenters. 

EPA received 41 public comments regarding the proposed rule. The comments can be obtained 

online from the Federal Docket Management System at http://www.regulations.gov. The docket 

number for this rulemaking is EPA-HQ-OAR-2010-0885. In this document, commenters are 

identified by the last four digits of their respective Document IDs. A listing of all persons 

submitting comments, their respective affiliations, and their respective Document IDs is 

presented in Table 1. Table 2 explains the acronyms and frequently cited abbreviations used 

throughout this document. 

Table 1. List of Commenters and Respective Affiliations and Document IDs. 

ID Commenter/Affiliation 

0018 Michael L. Krancer, Secretary, Pennsylvania Department of Environmental Protection (DEP)

0019 Michael G. Dowd, Virginia Department of Environmental Quality

0020 James A. Capp, Chief, Air Protection Branch, Environmental Protection Division, Georgia 

Department of Natural Resources

0021 Pamela F. Faggert, Vice President and CEO, Dominion Resources Services, Inc.

0022 G. Vinson Hellwig, Chief, Air Quality Division, Michigan Department of Environmental Quality

0023 Bart Sponseller, Bureau of Air Management Director, Wisconsin Department of Natural 

Resources

0024 John A. Paul, Administrator, Regional Air Pollution Control Agency (RAPCA)

0025 John V. Corra, Director, Wyoming Department of Environmental Quality (WDEQ)

0026 Scott J. Nally, Director, Ohio Environmental Protection Agency
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ID Commenter/Affiliation 

0027 Duplicate of 0026

0028 Jane Hayse, Chief, Transportation Planning Division, Atlanta Regional Commission (ARC)

0029 Russell A. Wozniak, Environmental Health & Safety (EH&S) Operations Regulatory Services, 

The Dow Chemical Company

0030 Michael Villegas, Air Pollution Control Officer, Ventura County Air Pollution Control District, 

California

0031 James N. Goldstene, Executive Officer, California Air Resources Board (CARB)

0032 Anne R. Gobin, Chief, Bureau of Air Management, Connecticut Department of Energy and 

Environmental Protection

0033 Samir Shiek, Director of Strategies and Incentives, San Joaquin Valley Unified Air Pollution 

Control District, California

0034 Arthur N. Marin, Executive Director, Northeast States for Coordinated Air Use Management 

(NESCAUM)

0035 George S. (Tad) Aburn, Jr., Maryland, Co-Chair, and Lynne A. Liddington, Kentucky, 

Tennessee, Co-Chair, National Association of Clear Air Agencies (NACAA)

0036 Donald R. Schregardus, Deputy Assistant Secretary of the Navy (Environment), Department of 

Defense (DoD)

0037 Doug Deason, Environmental Advisor, Downstream and Chemical SH&E, Exxon Mobile 

Corporation (Exxon Mobil)

0038 J. Jared Snyder, Assistant Commissioner, Office of Air Resources, Climate Change and Energy, 

New York State Department of Environmental Conservation (DEC)

0039 Elizabeth Hendler, Project Coordinator, 8-Hour Ozone State Implementation Plan (SIP) 

Coalition, Texas

0040 John Fainter, Jr., President and Chief Executive Officer (CEO), Association of Electric 

Companies of Texas Inc. (AECT)

0041 Catharine Fitzsimmons, Chair, Central State Air Resource Agencies (CenSARA)

0042 Louis P. Pocalujka, Senior Environmental Planner, Policy & Strategies Section, Environmental 

Services Department, Consumers Energy, Michigan

0043 Chuck Hersey, Environmental Program Manager, Southeast Michigan Council of Governments 

(SEMCOG)

0044 F. Gao

0045 Stephen Minick, Vice President of Governmental Affairs, Texas Association of Business (TAB)

0046 Michael J. Nasi, Jackson Walker, LLP, Counsel for the Gulf Coast Lignite Coalition (GCLC), et 

al.

0047 Mark R. Vickery, Executive Director, Texas Commission on Environmental Quality (TCEQ)

0048 Myra C. Reece, Bureau of Air Quality, South Carolina Department of Health and Environmental 

Control (SCDHEC)

0049 George S. (Tad) Aburn, Jr., Director, Air and Radiation Management Administration, Maryland 

Department of the Environment (MDE)

0050 J. Wick Havens, Interim Executive Director, Ozone Transport Commission (OTC), a Multi-state 

Organization 

0051 T. Peter Ruane, President and Chief Executive Officer (CEO), American Road & Transportation 

Builders Association (ARTBA)

0052 Sheila Holman, Director, Division of Air Quality, North Carolina Department of Environment 

and Natural Resources (NCDENR)

0053 Samuel Biscoe, Travis County Judge, Chair, Central Texas Clean Air Coalition (CAC)

0054 David Baron, Attorneys, Earthjustice
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ID Commenter/Affiliation 

0055 Norman W. Fichthorn, Hunton & Williams LLP, on behalf of Utility Air Regulatory Group 

(UARG)

0056 Lake Michigan Air Directors Consortium, Organization of Six Region 5 States

0057 John S. Lyons, Director, Division of Air Quality, Kentucky Department for Environmental 

Protection

0058 Duplicate of 0023

0059 Duplicate of 0019

0060 Ali Mirzakhalili, Director, Division of Air Quality, Delaware Department of Natural Resources

0061 Jungus Jordan, Chair, Regional Transportation Council, Transportation Policy Body of North 

Central Texas Council of Governments

Table 2. Explanation of Acronyms and Frequently Used Abbreviations 

Acronym Long Name 

APA Administrative Procedure Act 

ARB Air Resources Board 

BID Background Information Document 

CAA Clean Air Act 

CAAAC Clean Air Act Advisory Committee 

subpart 1 CAA, title I, part D, subpart 1 

subpart 2 CAA, title I, part D, subpart 2 

CAIR Clean Air Interstate Rule 

CARB California Air Resources Board 

CMAQ Congestion Mitigation and Air Quality 

CO Carbon monoxide 

CSAPR Cross State Air Pollution Rule 

DoD Department of Defense 

EAC Early Action Compact 

EO Executive Order 

EPA Environmental Protection Agency 

FHWA Federal Highway Administration 

MATS Mercury and Air Toxics Standards 

MPO Metropolitan Planning Organization 

MVE Motor vehicle emission 

NAAQS National Ambient Air Quality Standards 

NOx Nitrogen oxides 

PATS Percent-Above-The-Standard 

PPM Parts per million 

RFP Reasonable further progress 

SIP State implementation plan 

TCMs Transportation control measure 

VOC Volatile organic compounds 

	 	
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Table of Contents

I. Establishing Thresholds for Classifying Nonattainment Areas ............................................ 9

Support for the “percent-above-the-standard” approach. ....................................................... 9

Opposition to the “percent-above-the-standard” approach, as proposed................................ 9

EPA Consideration of other Approaches for Classifying Nonattainment Areas...................... 21

Approach of Relying on CAA, Title, I, Part D, Subpart 1 in Some Cases. .............................. 23

Application to areas with design values below 0.09 ppm..................................................... 23

Rural nonattainment areas impacted by upwind contributions should not be classified under 

subpart 2................................................................................................................................ 33

Opposition to relying on subpart 1 and completely ignoring subpart 2 classifications........ 33

Other subpart 2 Approaches for Classifying Areas. ................................................................. 34

II. Voluntary Reclassification .................................................................................................... 36

Support for EPA’s voluntary bump-up approach. ................................................................ 36

Opposition to EPA’s voluntary bump-up approach.............................................................. 37

Recommendations to expand EPA’s voluntary bump-up approach. .................................... 38

III. Attainment Deadlines for Nonattainment Areas ............................................................... 39

Support for adopting Option 1 (attainment date running from the effective date of 

designation) and Opposition to Option 2 (attainment date running from December 31)..... 39

Support for Option 2 and Opposition to adopting Option 1 ................................................. 44

Opposition to delaying the start of the attainment clock. ..................................................... 47

Appropriateness of Deadlines due to Upwind Contributions................................................... 48

IV. Revocation of 1997 NAAQS ................................................................................................. 49

Revocation of 1997 Ozone NAAQS for Purposes of Transportation Conformity ................... 49

Support for revocation of 1997 NAAQS with respect to transportation conformity............ 49

Opposition to revocation of 1997 NAAQS with respect to transportation conformity. ....... 51

Effect of revocation of transportation conformity requirements on other programs............ 61

Implementation of transportation control measures. ............................................................ 63

Revocation of the 1997 Ozone NAAQS for General Conformity............................................ 64

Support for revocation of 1997 NAAQS with respect to General Conformity. ................... 64

Revocation of the 1997 Ozone NAAQS for Other Purposes.................................................... 65

Support for revocation of 1997 NAAQS for other purposes. ............................................... 65

V. Transport Emissions .............................................................................................................. 65

Effect of upwind emissions on downwind nonattainment areas........................................... 65

The NAAQS Implementation Process and SIP Requirements................................................. 68
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Generally............................................................................................................................... 68

Timeliness............................................................................................................................. 70

SIP Implementation Requirements for the 2008 Ozone NAAQS. ........................................... 72

Demonstrating Attainment.................................................................................................... 72

Demonstrating reasonable further progress (RFP) ............................................................... 72

Miscellaneous Comments......................................................................................................... 74

Executive Order (EO) Discussion......................................................................................... 74

Future Commitments and New Technologies....................................................................... 74

Rewarding programs for accelerated attainment of the NAAQS. ........................................ 75

Additional funding for states. ............................................................................................... 76

The conformity process......................................................................................................... 77

 
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I. Establishing Thresholds for Classifying Nonattainment Areas 

 Support for the “percent-above-the-standard” approach. 

1. Comment –EPA should adopt the percent-above-the standard (PATS) approach for establishing 

thresholds for classifying nonattainment areas with respect to the 2008 ozone NAAQS. 

Many commenters (0018, 0019, 0020, 0023, 0024, 0025, 0026, 0030, 0033, 0037, 0042, 0048, 

0056, 0057) generally supported the adoption of the percent-above-the-standard (PATS) 

approach for determining thresholds for classifying nonattainment areas with respect to the 2008 

ozone NAAQS. One commenter (0019) further stated that by allowing as many areas as possible 

to be designated as Marginal nonattainment areas, EPA will alleviate resource-intensive SIP 

development processes for many states. 

Several commenters (0018, 0024, 0037, 0057) further stated that the PATS approach appears to 

be consistent with the requirements of CAA, title I, part D, subpart 2 (subpart 2) for classifying 

nonattainment areas. One commenter (0037) further stated that the use of the PATS approach is 

within EPA’s legal discretion as determined by U.S. Court of Appeals for the District of 

Columbia in South Coast Air Quality Management District vs. Environmental Protection 

Agency. 

Several commenters (0030, 0056) stated that this approach is consistent with that used for the 

previous ozone standards and would provide air agencies and the regulated community with 

much needed programmatic continuity. 

1. EPA Response. 

EPA appreciates the support of the commenters. 

 Opposition to the “percent-above-the-standard” approach, as proposed. 

2. Comment –The fact that the 2008 ozone NAAQS is more heavily influenced by 

background/transport ozone precursors presents a flaw in applying the PATS approach to the 

2008 NAAQS implementation because such transport ozone precursors will prevent a 

nonattainment area’s compliance with subpart 2 from resulting in attainment with the 2008 

NAAQS. 

Several commenters (0044, 0049) claimed that the 8-hour ozone NAAQS is more heavily 

influenced by background/transport ozone precursors than the 1-hour ozone standard. They also 

claim this presents a flaw in applying the PATS approach to the 2008 NAAQS implementation 

because transported ozone precursors will prevent a nonattainment area from attaining the 2008 

NAAQS based on its compliance with subpart 2. 

One commenter (0044) specifically stated that the major flaw of EPA’s proposed classification 

method is to simply apply the previous above-the-standard percentages under the 1-hour standard 

to the current 8-hour standard, without careful consideration of the fundamental differences of 
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the two standards; i.e., while the former 1-hour standard reflected peak ozone values within a 

short time frame, the 2008 8-hour NAAQS represents average ozone values over a much longer 

time frame. The commenter (0044) reasoned that this resulted in the former 1-hour standard 

being more influenced by spikes in ozone concentrations while the 2008 NAAQS is more 

influenced by eight-hour averages. Consequently, the commenter (0044) reasoned that the 2008 

NAAQS is more influenced by background transported ozone precursors, and stated that this has 

been supported by modeling studies performed pursuant to the Clean Air Interstate Rule (CAIR) 

and the Cross-State Air Pollution Rule (CSAPR). The commenter (0044) reasoned that applying 

the PATS approach to the 2008 is flawed because such transport ozone precursors will prevent a 

nonattainment area from attaining the 2008 NAAQS based on its compliance with subpart 2. 

Another commenter (0049) specifically noted the differences between the 1-hour NAAQS and 

the 8-hour NAAQS: (1) the 1-hour ozone design values record spikes in ozone concentrations; 

the 8-hour ozone records rolling averages in ozone concentrations, and (2) the 1-hour ozone 

design values are often associated with local phenomena while the 8-hour ozone design values 

are more heavily influenced by background or long-range transport. The commenter (0049) 

believes that these differences mean that the PATS approach should not be adopted for the 2008 

ozone NAAQS. 

2. EPA Response. 

EPA disagrees with the assumption that the 1-hour and 8-hour standards are fundamentally 

different. As an initial matter, EPA first adopted this approach for the 1997 ozone NAAQS, 

which is also an 8-hour standard and in the context of determining how to translate the table in 

section 181(a) considered the issues referenced by the commenter.1 Moreover, data analyses over 

the period 2006-2010 indicate that daily maximum 8-hour concentrations and daily maximum 1-

hour concentrations are highly correlated on average nationally. While the longer averaging time 

for an 8-hour ozone NAAQS, such as the 2008 NAAQS, may slightly extend the geographic 

region contributing to the violations, as compared with a 1-hour ozone NAAQS, EPA disagrees 

 

1

 EPA considered for the 1997 ozone NAAQS options for the translation of the classification table in the CAA. 

These options are discussed in a separate document available in the 1997 8-hour ozone docket - Additional Options 

Considered for Proposed Rule to Implement the 8-Hour Ozone National Ambient Air Quality Standard (OAR-2003-

0079-0376). These other possible ways of translating the classification table, in our opinion, did not have the same 

degree of consonance with the intent of Congress when it enacted subpart 2 as those proposed for the 1997 8-hour 

ozone NAAQS. In the October 21, 2003 notice that reopened the comment period, EPA solicited comment on an 

approach for different percent ranges than Table 1 to account for 1-hour to 8-hour differences and included it as part 

of Alternative A. A number of commenters opposed the idea of regulatorily creating a relationship between the 8-

hour and 1-hour standards and were also concerned about the way in which the relationship was established. They 

claim that the relationship is not scientifically supported. While we agree that in theory this type of approach could 

be consistent with the CAA as interpreted by the Supreme Court, we have rejected it, in part, because we also have 

concerns about establishing such a relationship between the 1-hour and 8-hour standards. In the 2004 Phase I rule, 

EPA stated the preference for using the percentage ranges above the standard concentration for the classification 

thresholds as an appropriate manner of classifying areas based on the relative magnitude of their problem. We chose 

those percentages for the 8-hour standard that Congress chose for the 1-hour standard, since it would result in the 

same relative degree of problem magnitude for each classification that Congress selected in 1990. EPA-HQ-OAR2003-0079-0685 provides additional analysis for comparing 1980 to 2002 1-hour to 8-hour ozone trends. 

 
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that the PATS approach is not appropriate for this NAAQS. We further note that it is unclear 

what the commenter is suggesting as an alternative approach. The commenter does not suggest a 

specific alternative to interpreting the design values in subpart 2 in a way that would better 

address its stated concern regarding transport. To the extent the commenter is suggesting that 

areas should instead be placed under subpart 1, we note that the Court in South Coast found that 

the statute is clear on its face that subpart 2 must apply to certain areas designated nonattainment 

for any ozone NAAQS. Furthermore, although the court recognized limited authority for EPA to 

rely solely on subpart 1 for those areas that the statute is not clear must be subject to subpart 2, 

the court rejected EPA’s reliance on ozone transport as a basis for choosing to place areas solely 

under subpart 1. South Coast, 472 Fed.3d at 894. Finally, we note that the structure of the Act 

provides for transport to be addressed even for those areas subject to subpart 2. The primary 

purpose of the implementation requirements in subpart 2 is to address localized pollution 

problems within a nonattainment area, not transported emissions between two or more areas. 

Section 110(a)(2)(D) of the Act requires all states to address transported emissions and EPA has 

required most states in the eastern portion of the country to reduce NOx emissions to address the 

significant transport of ozone and the precursor NOx to downwind areas for purposes of the 1997 

ozone NAAQS. While States are independently obligated to address transport, EPA notes that it 

has previously issued three regulations addressing the long-range transport of ozone. See 63 FR 

57356 (NOx SIP Call); 70 FR 25162 (2005 Clean Air Interstate Rule); and 76 FR 48208 (CrossState Air Pollution Rule).2

 EPA will continue to assist States to ensure that the long-range 

transport of ozone and ozone precursors is adequately addressed. 

3. Comment –Application of the PATS approach to the 2008 ozone NAAQS is flawed because 

such application results in almost all nonattainment areas being classified as Marginal, and 

associated control program requirements will be inadequate to bring areas into attainment 

Several commenters (0029, 0038, 0044, 0049, 0060, 0049) stated that application of the PATS 

approach to the 2008 ozone NAAQS is flawed because such application results in almost all 

nonattainment areas being placed in the Marginal classification, resulting in no or very limited 

control measure requirements that will not be adequate for bringing the nonattainment area into 

attainment as expeditiously as practicable. 

One commenter (0044) specifically stated that an application of the PATS approach would result 

in more than 80% of the country’s nonattainment areas being classified as Marginal, which 

contrasts to the wider spread of nonattainment area classifications under the 1997 ozone 

NAAQS. The commenter (0044) stated that the Marginal areas would be subject to very limited 

requirements with respect to emission controls, and as a result, implementation of new or 

additional controls in such nonattainment areas would be unlikely. 

One commenter (0060) noted that the application of the PATS approach for the 2008 Ozone 

NAAQS will result in placing most nonattainment areas in the Marginal classification (i.e., 43 

Marginal, 6 Moderate, 3 Serious, and 0 Severe or Extreme). The commenter (0060) further stated 

 

2

 On December 30, 2012, the D.C. Circuit stayed CSAPR pending the court’s resolution of the petitions for review 

of that rule in EME Homer Generation, L.P. v. EPA (No. 11-1302 and consolidated cases). The court also indicated 

that EPA is expected to continue to administer the CAIR in the interim until the court rules on the petitions for 

review of CSAPR. 
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that in the 2004 Phase 1 ozone implementation rule for the 1997 Ozone NAAQS, EPA rejected a 

similar methodology for the reason that it would have produced a similar outcome, reasoning 

that Marginal areas are not subject to the requirement to submit an attainment plan to ensure that 

the area identifies and adopts the controls necessary for attainment within 3 years of 

designation.3 The commenter disagrees with the PATS approach, claiming that classifying most 

areas as Marginal would delay mitigation of the upwind emissions that are the cause of air 

quality problems in many downwind areas. The commenter (0060) states that EPA is now 

indicating that the PATS approach does make sense because EPA believes that many Marginal 

areas are expected to attain the 2008 NAAQS within 3 years of attainment due to reductions of 

ozone precursors resulting from a number of federal and state emission reduction programs that 

have been adopted. 

One commenter (0049) stated that the original intent of the 1990 CAA classification approach 

was to distribute the areas into all six classifications, providing areas with worst problems 

reasonable periods of time to reach attainment. The commenter (0049) stated that the PATS 

approach is straightforward but has an unfortunate effect of placing nearly all areas into the 

lowest two classifications, which require almost no control measures at all, and is, therefore, not 

congruent with Congress’ intent. 

3. EPA Response. 

We believe that application of the PATS methodology for the 2008 NAAQS is a reasonable 

translation of Table 1 in section 181 of the Act. We disagree with the commenters who suggest 

that Congress had some specific intent that areas need to be placed in all five of the 

classifications.4 Rather, we believe that at the time Congress enacted the 1990 Amendments 

establishing the subpart 2 classification approach, they were addressing the specific factual 

situation as it existed at that time, where there were areas with greatly divergent air quality and 

areas with significant air quality problems needed longer to attain the NAAQS than was provided 

under the generic provisions in section 172 of the CAA. Thus, Congress established an approach 

where the time to attain and the mandatory control measures for areas were linked to the 

significance of the air quality problem for the area. Over the past 20 years, areas have made 

tremendous strides in addressing air quality problems and many areas, while violating the 

NAAQS, are doing so to a much less significant degree. We believe that the overarching intent 

of the Act as amended in 1990 is to ensure that most areas are placed in a classification that 

provides sufficient time to attain the NAAQS, and to link more stringent requirements to those 

areas that need more time to attain. Congress also included provisions in the Act allowing 

reclassification of an area if it is unable to attain the NAAQS by the maximum date associated 

with its classification. 

Our analyses indicate that a majority of the areas should attain by the attainment date associated 

with their classification under the PATS approach (see response 5 below). For areas that may 

not be able to attain by their attainment date, the Act provides mechanisms by which a state can 

 

3

 The commenter (0060) quotes text from the preamble of the Final Rule to Implement the 8-Hour Ozone National 

Ambient Air Quality Standard – Phase 1 (84 FR 23962-23964). 

4

 The commenter refers to six classifications. We note that there are five classifications, but in 1990, Congress 

provided that severe areas with the highest design values would have a maximum attainment date of 17 years. 
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request a higher classification. First, section 181(a)(4) provides that the Administrator may 

reclassify an area to a higher or lower classification if the area’s design value used for the initial 

classification is within 5 percent of a classification threshold value for a higher or lower 

classification. This adjustment must be made within 90 days of the initial classification. A State 

may request this adjustment or the Administrator may make the adjustment based on her own 

initiative. Second, section 181(b)(3) provides that a State may request at any time a higher 

classification and EPA must grant such a request. 

The claims by one commenter (0060) misrepresents that the PATS approach was rejected in the 

previous 8-hour ozone classification rule. In the Phase 1 Rule, EPA determined that certain 

areas would be subject only to the planning provisions of subpart 1. EPA did note that for those 

areas (most of which would otherwise have been classified as Marginal if placed under subpart 

2) subpart 1 would require submission of an attainment demonstration – a requirement that does 

not apply to areas classified as Marginal. This formed part of the basis for EPA’s decision to 

place certain areas under the planning provisions of subpart 1; it was not, as the commenter 

suggests, a rejection by EPA of the PATS approach. In fact, EPA adopted the PATS approach in 

the Phase 1 Rule for all areas classified under subpart 2. We address the commenter’s concerns 

regarding transport of emissions in Response 4. 

4. Comment –Application of the PATS approach to the 2008 ozone NAAQS is flawed because 

such application results in almost all nonattainment areas being classified as Marginal, and 

results in delays to address interstate transport of ozone 

 

Several commenters (0032, 0034, 0038, 0050, 0060) claim that EPA’s analysis referred to in 

footnote 18 of the proposed rule regarding the likelihood that nonattainment areas will 

demonstrate attainment by the deadlines is fundamentally flawed. One commenter (0038) stated 

that the predominant use of the Marginal classification will result in the delay in implementation 

of control measures needed to reduce the interstate transport of ozone. The commenter (0038) 

explained that under CAA § 110(a)(2)(D) states are required to submit transport SIPs to prohibit 

the emissions of pollutants that contribute significantly to nonattainment or interfere with 

maintenance of a NAAQS in any other states. The commenter (0038) explained that levels of 

pollution entering New York make it impossible to attain the NAAQS without substantial 

upwind reductions. The commenter (0038) stated that EPA’s classification approach which 

places most areas in the Marginal classification belies the seriousness of the ozone problem and 

will lead to further delays as states upwind of New York are not likely to act to control 

emissions. 

Another commenter (0049) stated that EPA’s PATS approach would result in establishment of 

mostly Marginal nonattainment areas in Maryland, which would mean that Maryland monitors 

would need to begin monitoring attaining air quality levels in 2013. The commenter (0049) 

stated that Maryland research on transported ozone shows that incoming transported ozone often 

exceeds the current standard, and that air quality modeling shows that current control efforts to 

reduce transport will not provide enough reductions to meet the attainment dates. 

The commenter (0049) believes that, because of insufficient controls to reduce transported 

ozone, it will be impossible for Maryland's monitors to achieve clean data starting in 2013 for 
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"Marginal" areas. The commenter (0049) states that Marginal areas will not be required to 

establish budgets for the 2015 attainment year, which is not fair when an upwind Marginal area 

is significantly impacting a downwind Moderate area. The commenter (0049) stated that this is 

the case with Baltimore and Washington DC; i.e., because mobile emissions in Washington DC 

are about 50% greater than emissions in Baltimore, and without strong controls on mobile 

sources in both Baltimore and Washington DC, Baltimore will never attain the standard. 

Several commenters (0029, 0038) specifically stated that EPA’s PATS approach results in 43 out 

of 52 nonattainment areas being classified as Marginal and 6 more being classified as Moderate. 

The commenters (0029, 0038) stated that these classifications create the false impression that 

many areas of the United States will be able to attain the ozone standard based on air quality 

from 2013-2015, when in reality the process will take longer and will be more complex in certain 

areas of the United States. 

4. EPA Response. 

EPA acknowledges that a large part of the ozone problem for eastern states like Maryland, 

Delaware, and others is due to long range transport of ozone that comes from upwind states in 

the mid-west and south. The Cross State Air Pollution Rule is a federal program that will reduce 

ozone and PM precursors regionally, and provide air quality benefits to downwind states. Other 

national rules that address NOx will provide additional benefits. EPA recognizes that these 

states have aggressively pursued control measures for sources within their states. In the case of 

Baltimore, for example, while there are certainly local contributions to the ozone problem, EPA 

recognizes that a significant portion of the air quality problems come from outside the urban 

area. 

The commenters claim that if areas are designated as Marginal for the 2008 standard, these areas 

will not adopt any controls and therefore will not help downwind states attain the standard. As 

noted by the commenters, the Clean Air Act includes separate provisions for addressing 

interstate transport of air pollution and for addressing local nonattainment area problems. The 

states have separate and distinct obligations to address their contributions to downwind 

nonattainment areas while also meeting nonattainment requirements to adopt measures needed to 

attain the standard as expeditiously as practicable. To address the issue of long-range transport, 

section 110 requires States to mitigate pollution from all areas of the State (not just those areas 

designated nonattainment) that to “contribute significantly to nonattainment in, or interfere with 

maintenance by, and other State.” For areas such as New York and Baltimore, the long range 

transport of emissions has been greatly reduced by the NOx SIP Call, 63 FR 57356 (October 27, 

1998) and the Clean Air Interstate Rule, 70 FR 25162 (May 12, 2005).5

 In an “upwind” area that 

is designated nonattainment, the control requirements under subpart 2 would primarily address 

the local air pollution problem and may or may not provide substantial benefit to downwind 

areas. In most cases, it would be expected that controls would be needed from sources 

throughout the state (i.e. those located within nonattainment areas and those located outside of 

nonattainment areas) to eliminate a state’s significant contribution to a downwind area in another 

state. 

 

5

 More recently, EPA promulgated the Cross-State Air Pollution Rule, 76 FR 48208 (August 8, 2011), but the 

United States Court of Appeals for the D.C. Circuit has stayed the CSAPR pending judicial review. 
15

To the extent “local” control measures may provide benefits to a downwind area, it is important 

to note that States have the obligation to ensure that Marginal areas and all other areas attain the 

standard as expeditiously as practicable. Thus, in some Marginal areas, it may be appropriate for 

the state to adopt control measures even though an attainment demonstration is not specifically 

required. We understand it can be challenging for states to address concurrent obligations for 

interstate transport and nonattainment area planning. We will continue to work with States to 

ensure that the interstate transport of emissions is addressed. 

The commenter is correct that Marginal areas are not required to establish motor vehicle 

emissions budgets for their attainment year. This is because Marginal areas are not required by 

the Clean Air Act to submit reasonable further progress plans or attainment demonstrations. 

Motor vehicle emissions budgets are the portion of total allowable emissions defined in the 

submitted or approved control strategy implementation plan revision or maintenance plan for a 

certain date for the purpose of meeting reasonable further progress milestones or demonstrating 

attainment or maintenance of the NAAQS that is allocated highway and transit vehicle use and 

emissions. (40 CFR 93.101) While Marginal areas are not required to submit attainment year 

budgets for the 2008 ozone NAAQS, many areas including Washington, DC have adequate or 

approved or approved budgets for the 1997 ozone NAAQS. Those budgets are required to be 

used in conformity determinations for the 2008 ozone NAAQS. (40 CFR 93.109(c)(2)) With 

regard to the need for strong mobile source controls in the Washington, DC area, as stated above, 

Marginal areas have the obligation to attain the standard as expeditiously as practicable. Thus, in 

some Marginal areas, it may be appropriate for the state to adopt additional mobile source 

control measures that would help to bring such an area into attainment. If additional mobile 

control measures were adopted in the Washington area, they would likely provide benefits to the 

Baltimore area as both areas are part of the same CSA. 

5. Comment –EPA’s analysis cited in footnote 18 in the proposed rule is flawed in concluding that 

most Marginal areas will be able to attain the 2008 NAAQS by 2015, and therefore the PATS 

approach is not an appropriate classification approach. 

Several commenters (0032, 0034) took issue with an EPA analysis which concluded that many 

Marginal areas are expected to attain the 2008 NAAQS within 3 years of designation (in 2015) 

due to reductions including more stringent emission standards for onroad and nonroad vehicles 

and equipment, regional reductions in power plant emission to address interstate transport, and 

future implementation of programs such as the boiler maximum achievable control technology 

standards. The commenters (0032, 0034) note that EPA estimated that in about half of the 

Marginal areas, these reductions in conjunction with ongoing states and federal controls should 

be sufficient to bring about attainment. Several commenters (0032, 0034, 0050, 0060) claim that 

EPA’s analysis was flawed for three main reasons: (1) EPA’s projections do not account for 

differences in ozone season meteorology; (2) EPA projections do not account for reductions 

driven by the economic downturn that occurred during that period; and (3) EPA’s linear 

approach assumes the reduction of ozone precursor emissions on a proportionately comparable 

basis from 2005 to 2015, while not providing adequate analyses of other efforts that may directly 

or indirectly reduce ozone precursor emissions such as the Mercury and Air Toxics Standards 

(MATS) rule. 
16

First, several commenters (0032, 0034) claim EPA’s analysis uses a design value centered 

around 2009, which is a meteorologically unique year in the Northeast. Specifically, the 

commenters (0032, 0034) noted that 2009 included some of the lowest 4th maximum 8-hour 

ozone averages recorded since ambient air monitoring began in the region. They claim that this 

decrease is not solely attributable to ozone precursor emission reductions, as the Northeast 

experienced an unusually mild ozone season in 2009 due to relatively cool ozone season 

temperatures. Consequently, the commenters (0032, 0034) stated that the use of a design value 

incorporating 2009 without normalizing for meteorological differences may underestimate future 

ozone conditions in 2015. Another commenter (0060) specifically stated that EPA’s analysis 

does not account for differences in ozone season meteorology, specifically between the relatively 

warm ozone season of 2005 and the unusually mild ozone season of 2009. 

Second, several commenters (0032, 0034, 0038, 0060) claim that EPA’s analysis uses a design 

value centered around 2009, which does not adequately take into account the economic downturn 

that occurred during the three-year span between 2008 to 2010. The commenters (0032, 0034) 

reasoned that as the state of the economy diminished during this time, ozone precursor emissions 

declined in conjunction with economic activity, and therefore, emission reductions are not 

completely attributable to air pollution control programs. The commenters (0032, 0034) noted 

that EPA’s new projections do not adjust for these emission reductions and therefore do not 

accurately project ozone through 2015. As the economy becomes more stable, emissions 

increases attributable to economic recovery activity are almost certain. 

Third, several commenters (0032, 0034, 0038, 0060) stated that emissions reductions will not be 

linear because the emission reductions from CAIR and CSAPR were front-end loaded and 

largely occurred by 2010. Consequently, the commenters (0032, 0034) believe that EPA’s 

assumption about linearized benefits is flawed, and will overstate emission reductions in the 

years of 2010-2015. 

One commenter (0060) further stated that the analysis is not robust enough to reasonably predict 

that most of these areas would attain by 2015, as the information and calculations provided in the 

analysis selectively emphasize methods or data that support the claim that the Marginal 

nonattainment areas could attain by the 2015 deadline, while ignoring equally legitimate 

methods that would not tend to predict attainment. The commenter (0060) stated that EPA has 

been privy to preliminary modeling done by the ozone transport commission that shows that 

deep reductions beyond those achieved by current control requirements are needed to achieve 

widespread attainment of the 75 ppm standard, and that EPA’s own CSAPR modeling shows 

many areas fall short of attainment with the currently adopted suite of reduction strategies. 

One commenter (0034) further noted the modeling issues for the differences in ozone season 

meteorology, the economic downturn and concerns comparing post-2010 projections to pre-2010 

control programs are issues that are not unknown to EPA. Specifically, the commenter (0034) 

stated that EPA stated in a March 1, 2012 response brief that the extent to which a downward 

ozone trend could be discerned from monitoring data during the 2007-2010 time period, it could 

largely be explained by temporary factors such as CAIR requirements, reduced emissions 

resulting from the severe economic recession, and by the extremely low concentrations of ozone 
17

in 2009 due to meteorological variability. 6 The commentor (0034) states that EPA emphasized 

that, “by 2010, many States were already meeting their 2012 [CSAPR] budgets.” 7

 While EPA’s 

discussion in its response brief caveated the use of these years as end points in elucidating ozone 

trends, those same caveats are equally applicable to the use of these years as starting points for 

projecting future trends. 

One commenter (0050) stated that it has completed several screening model runs showing 

potential pathways to attainment for the 2008 ozone NAAQS, and in contrast to the EPA 

analysis, these results demonstrate that substantial reductions in NOx and VOCs are needed 

throughout the eastern half of the United States in order for it to achieve levels of ozone that 

meet the NAAQS by 2015 and beyond. The commenter (0050) stated that its more robust 

analysis indicates that EPA’s proposed classification approach for the vast majority of the 

nonattainment areas is likely to fail to ensure attainment because neither those areas, nor 

contributing upwind areas, will be required to reduce their emissions beyond any measures that 

are already on the books. 

One commenter (0038) specifically stated that recent Ozone Transport Commission modeling 

suggested that emission reductions on the order of 65% for NOx and 25% for VOCs through the 

eastern United States will be needed for areas along the Eastern Seaboard to attain the 2008 

NAAQS. 

5. EPA Response. 

The analysis included in the proposed rule was intended to demonstrate the number of potential 

Marginal nonattainment areas that might be able to attain by 2015. Numerous Federal rules will 

continue to provide considerable additional emissions reductions between now and 2015 and our 

analysis indicates that these reductions would be sufficient to bring many of the areas we 

predicted would be classified as Marginal into attainment by 2015. The proposed rule modeling 

analysis showed that 33 out of 43 hypothetical Marginal nonattainment areas (at the time of 

proposal) were expected to attain the ozone NAAQS by their 2015 attainment date. 

There continues to be a strong downward trend in NOx and VOC emissions due to rules such as 

the Tier-2 motor vehicle engine standards, heavy duty engine standards, and the locomotive and 

marine diesel engine rule. These rules provide large annual emissions reductions from the 

transportation sector. Since these engine rules are implemented through “fleet turnover,” the 

emissions reductions occur on a steady basis over a large number of years and tend to be roughly 

linear until the rules are completely implemented (e.g. the fleet has been completely replaced). 

The total modeled reduction in summer season NOx emissions between 2005 and 2014 (for 

states in the Transport Rule ozone program) was about 2.5 million tons per ozone season.8

 Of 

that total, 84% of the NOx reductions were from sources other than electric generating units 

(EGUs). In general, the vast majority of those non-EGU reductions are from mobile sources. 

Therefore, rules which are implemented through fleet turnover account for the majority of the 

 

6 U.S. EPA Brief for the Respondents, in EME Homer City Generation, L.P, et al. v. EPA, D.C. Circuit, No. 11-

1302 and consolidated cases (filed March 1, 2012), at pp. 75-76.

7

 U.S. EPA Brief for the Respondents, at p. 92 (see also footnote 53 in Brief). 8

 The ozone season is defined as May-September. 
18

summer NOx emissions reductions in the 2005-2014 period. It was therefore reasonable to 

assume that modeled ozone reductions over the 2005-2014 period (from the final Transport 

Rule) provide a relatively linear ozone reduction during this period. 

There are several ways that ambient data can be projected to future years. Because the ozone 

designations will be based on current (2008-2010) data, we chose to use these ambient data as 

the anchor point for the analysis. Using the 2008-2010 data provided a consistent set of data for 

both the current years (which will be used to designate areas) and future years. The 2008-2010 

design values were projected to 2015 using the average percent per year ozone reductions based 

on modeling from the final Transport Rule. Because the 2008-2010 data was used as the starting 

point for the analysis, any unusual meteorological or emissions patterns that influenced the 2008-

2010 data are also reflected in the 2015 estimates. We agree that the meteorology in 2009 was 

not particularly conducive to ozone formation in the Northeast, and we agree that the economic 

recession likely has affected the amount of emissions of ozone precursors during this time 

period. In response to comments on the issues raised by commenters about using 2009 ambient 

data in our analysis, we compared the final Transport Rule 2014 design values,9

 to the values that 

were projected for the 2015 analysis used to support the proposed rule. The 2014 Transport Rule 

design values were projected using 2003-2007 ambient data as the anchor point. Therefore, 

these projections are not influenced by the recent recession and 2009 meteorology. 

Based on the 2014 final Transport Rule design values, 22 out of 40 hypothetical Marginal areas 

at proposal10 would be expected to attain by 2014. Additionally, there are 3 areas that are within 

0.5 ppb of attaining in 2014. Since the actual Marginal area attainment date will be 2015, we 

also expect these 3 areas would to attain by 2015, given an additional year of emissions 

reductions.11 

Based on the most recent 2009-2011 ambient data, 10 of these 43 Marginal areas have already 

attained the NAAQS and are expected to be designated as attainment areas. This is further 

evidence that Marginal areas are in most cases able to quickly attain the ozone NAAQS with 

existing Federal and state controls. 

Due to the updated ambient data and changes in the expected boundaries of several potential 

nonattainment areas, EPA now expects there to be 37 Marginal nonattainment areas when 

designations are finalized. We are able to project future design values for 36 of these areas using 

the 2008-2010 data analysis12 and 33 of these areas using the Transport Rule 2003-2007 ambient 

 

9

 The 2014 Transport Rule design values were also included in the spreadsheet that documented the analysis 

completed for the proposal. The ozone design value projection methodology is documented in the final Transport 

Rule Air Quality Modeling TSD, available at: http://www.epa.gov/airtransport/pdfs/AQModeling.pdf 10 There were 43 hypothetical Marginal nonattainment areas that were included in the proposal analysis. However, 

due to incomplete data in the 2003-2007 base period, we were not able to project design values for 3 of these areas 

using the Transport Rule methodology. Those areas are Reading PA, San Luis Obispo CA, and Sublette County 

WY. 

11 All 3 of these areas have annualized modeled ozone reductions of greater than 1.3 percent per year and would 

therefore easily achieve more than a 0.5 ppb ozone reduction in one year. 12 One potential Marginal area is the Pechanga tribal area in California does not have valid ambient data to use for 

the projection analysis. 
19

data analysis13. The modeling analysis using 2008-2010 ambient data as the anchor point 

predicts that 27 out of these 36 Marginal nonattainment areas will be able to attain by 2015 

relying solely on measures that are already in place. The modeling analysis using the 2014 

Transport Rule design values (which are anchored by the 2003-2007 ambient data) predicts that 

16 out of 33 hypothetical Marginal nonattainment areas will be able to attain by 2015.14 The 16 

out of 33 area prediction does not include the 10 hypothetical Marginal areas that have already 

attained the NAAQS. The fact that 10 areas that were violating based on 2008-2010 data but now 

are attaining based on 2009-2011 data is evidence that Marginal areas will be able to attain in 3 

years. This fact combined with the updated 2008-2010 projections to 2015 and the results of the 

Transport Rule 2014/2015 analysis further supports EPA’s conclusion that the majority of 

Marginal nonattainment areas will be able to attain the NAAQS within 3 years or would likely be 

eligible for an attainment date extension in 2015. 

The commenters also assert that preliminary OTC modeling indicates that many more areas than 

indicated by the EPA analysis will not be able to attain the 75 ppb NAAQS by their attainment 

date. However the OTC modeling uses a 2020 attainment date, and therefore cannot estimate 

design values for the Marginal area 2015 attainment deadline or even for the Moderate area 2018 

attainment deadline. The only conclusion regarding attainment that can be drawn from the OTC 

modeling is that all areas in the Northeast corridor except Philadelphia and New York will attain 

the ozone NAAQs by 2020. As to all areas in the Northeast other than New York and 

Philadelphia, the OTC modeling does not indicate when those areas are likely to attain other than 

to show that they will attain by 2020; therefore contrary to the commenter's conclusion, the OTC 

modeling does not show that any of those areas will be unable to attain the 2008 NAAQS by the 

attainment date for Marginal or even for Moderate areas. Thus, it does not contradict EPA's 

analysis showing that the majority of Marginal areas across the country are predicted to attain by 

their attainment date. The OTC modeling is qualitatively consistent with EPA's modeling 

regarding the New York and Philadelphia areas. The EPA modeling predicts these two areas 

would have difficulty attaining the NAAQS by the 2015 Marginal area attainment date. 

The transport related comments included with the comments on the Marginal area modeling 

projections are addressed in comment 6 and in Section V. 

If a state believes it will not be able to meet its attainment date, the Act provides mechanisms by 

which a state can request a higher classification. First, section 181(a)(4) provides that the 

Administrator may reclassify an area to a higher or lower classification if the area’s design value 

used for the initial classification is within 5 percent of a classification threshold value for a 

higher or lower classification. This adjustment must be made within 90 days of the initial 

classification. A State may request this adjustment or the Administrator may make the 

adjustment based on her own initiative. Second, section 181(b)(3) provides that a State may 

request at any time a higher classification and EPA must grant such a request. 

 

13 There are 3 additional areas that don’t have valid ambient data for the 2003-2007 data. These are the same 3 areas 

that were identified earlier; Reading PA, San Luis Obispo CA, and Sublette County WY. 14 Similar to the results using the original 43 hypothetical areas, there are 3 areas that do not attain based on the 2014 

Transport Rule results, but are expected to attain by 2015 with an extra year of emissions reductions. 
20

6. Comment: Research shows incoming transported ozone often exceeds the current standard 

 Another commenter (0049) stated that Maryland transport research shows that incoming 

transported ozone often exceeds the current standard, and that its modeling shows that current 

control efforts to reduce transport will not provide enough reductions to meet the attainment 

dates. The commenter (0049) believes that, because of insufficient controls to reduce transport, it 

will be impossible for Maryland's monitors to achieve clean data starting in 2013 for "Marginal" 

areas. 

6. EPA Response

The transport of ozone in the Eastern U.S. has been significantly reduced through previously 

issued rules addressing the transport of ozone and ozone precursors; see 63 FR 57356 (NOx SIP 

Call); 70 FR 25162 (2005 Clean Air Interstate Rule); and 76 FR 48208 (Cross-State Air 

Pollution Rule).15 Additionally, other Federal rules have reduced the transport of NOx from low 

level sources such as cars and trucks, and these reductions are ongoing due to fleet turnover. 

Section 110(a)(2)(D) of the Act requires all states to address transported emissions and states are 

required to submit SIPs for the 2008 ozone NAAQS which show how they will eliminate any 

significant contribution to downwind nonattainment. EPA will continue to assist States to ensure 

that the long-range transport of ozone and ozone precursors is adequately addressed. 

With these ongoing reductions in ozone and ozone precursors, EPA’s modeling analysis 

indicates that the majority of Marginal areas will be able to attain by their attainment date. 

However, if a state believes they will not be able to meet their attainment date, the Act provides 

mechanisms by which a state can request a higher classification. First, section 181(a)(4) 

provides that the Administrator may reclassify an area to a higher or lower classification if the 

area’s design value used for the initial classification is within 5 percent of a classification 

threshold value for a higher or lower classification. This adjustment must be made within 90 

days of the initial classification. A State may request this adjustment or the Administrator may 

make the adjustment based on her own initiative. Second, section 181(b)(3) provides that a State 

may request at any time a higher classification and EPA must grant such a request. 

We disagree with the commenter (0049) who stated that Marginal areas would need to begin 

monitoring attainment in 2013. We note that attainment with the 8-hour ozone standard is 

determined based on the average of the 4th high exceedance at a monitor for each of three 

consecutive three years. Thus, an area could have three exceedances of the 8-hour standard in 

each of the three years and still demonstrate attainment of the NAAQS, or could attain based on 

the average even if it has four or more exceedances of the NAAQS in one or two of the three 

years. We further note that CAA sections 172(a)(2)(C)(ii) and 181(a)(5)(B), which allow for 

EPA to grant one or two 1-year extensions of the area’s attainment date if the area has clean data 

in the attainment year. 

 

15 On December 30, 2012, the D.C. Circuit stayed CSAPR pending the court’s resolution of the petitions for review 

of that rule in EME Homer Generation, L.P. v. EPA (No. 11-1302 and consolidated cases). The court also indicated 

that EPA is expected to continue to administer the CAIR in the interim until the court rules on the petitions for 

review of CSAPR. 
21

EPA Consideration of other Approaches for Classifying Nonattainment Areas 

7. Comment – EPA is attempting to prevent stakeholders from presenting ideas for alternative 

classification approaches. 

One commenter (0020) noted that EPA indicated that many interested parties recommended 

other options for the classification of ozone nonattainment areas, and that EPA has evaluated 

many other methods but is not proposing them or soliciting comment on them because it did not 

find them as compelling as the PATS approach. The commenter (0020) further noted that EPA 

stated that it included in the docket all written recommendations it had received in recent years 

regarding classification approaches. The commenter (0020) stated that it appears that EPA is 

attempting to prevent stakeholders from presenting ideas for alternative classification approaches 

that could be more efficient and effective, and by specifically telling the public that they do not 

want any input on alternative classification approaches, EPA could suggest in their final, or in a 

subsequent legal challenge, that their approach is best because they received little, if any, 

alternative suggestions. The commenter (0020) stated that for EPA to suggest that their own 

analysis, without any review or critique from those most impacted by it, would lead them to a 

single option that would not be swayed by informed comments is arbitrary and capricious on its 

face. 

7. EPA Response. 

In issuing the proposed classifications rule, EPA did consider multiple classification approaches 

which have been suggested by interested parties previously, and these approaches were included 

in a background information document (BID) in the docket for this rulemaking. EPA was not 

attempting to dissuade public comment on classification approaches, but was noting that it has 

seriously considered in the rulemaking to implement the 1997 ozone NAAQS and more recently 

a variety of approaches and had not been persuaded that any other approach was as compelling 

as the approach we proposed. During the commenter period for this rule, we received a number 

of comments on the approaches listed in the background information document as well as the 

proposed PATS approach, and we are responding to all of those comments in this response to 

comments document. 

8. Comment – EPA’s assertion is not accurate that they have included in the docket all 

recommendations raised to EPA regarding classification approaches. 

One commenter (0020) noted that EPA stated that many interested parties have recommended to 

EPA other options for the classification of ozone nonattainment areas, and that EPA has 

evaluated many other methods but is not proposing them or soliciting comment on them because 

it did not find them as compelling as the PATS approach. The commenter (0020) further noted 

that EPA stated that it included in the docket all written recommendations it had received in 

recent years regarding classification approaches. The commenter (0020) stated that it is 

inconceivable that EPA failed to even consider as an alternative to its proposal, the option of 

relying on subpart 1 for the specification of SIP requirements and deadlines, and that EPA’s 

assertion that they have included in the docket all written recommendations received in recent 
22

years regarding classification approaches cannot possibly be accurate. The commenter (0020) 

stated that only a few months ago, a small state/local workshop requested in writing that EPA 

consider relying on subpart 1 for specifying SIP requirements and deadlines, and that EPA 

responded that it would do so. However, the commenter (0020) stated that this option is not in 

the docket. 

8. EPA Response. 

EPA’s statement in the proposed rule referred to classification approaches regarding how to 

interpret the section 181 Table 1 classifications for areas subject to subpart 2. We recognize that 

parties have expressed an interest to the Agency of not placing all or certain areas under the 

subpart 2 classifications and instead having all or some areas subject only to the planning 

requirements of subpart 1. Most recently, the issue was raised at a State/EPA Workgroup on 

Work Prioritization in January 2012. The goal of the workgroup was to discuss opportunities for 

greater efficiency or reduced burden without compromising public health. A subpart 1 

implementation approach was raised as an opportunity to streamline and simplify the 

requirements for implementing the 2008 ozone NAAQS, on the basis that subpart 1 provides 

more flexibility and avoids some mandatory measures that are not as effective as when they were 

first included in the Act in 1990. At the workgroup meeting, EPA noted that it did not anticipate 

providing for any areas to be subject solely to the implementation requirements of subpart 1 for 

the 2008 NAAQS. We agreed to explore ways to continue to streamline and simplify 

implementation policies. EPA documented its response in its March 2012 EPA/ECOS/NACAA 

Priorities Workgroup Update, stating that EPA did not intend to pursue implementation of the 

2008 ozone NAAQS under subpart 1 in the classifications rule. 

9. Comment – EPA’s assertion that they have included in the docket all written recommendations it 

has received in recent years regarding classification approaches is not accurate. 

One commenter (0053) specifically stated that it sent a letter to EPA staff requesting that it 

consider including subpart 1 implementation for areas with design values less than 0.09 ppm, 

and, while EPA staff responded that it would consider such request, EPA did not provide such a 

discussion as part of the proposed rule. The commenter (0053) asked EPA to re-propose an 

approach for the 2008 ozone NAAQS for design values of 0.09 ppm or less and seek comment. 

The commenter (0053) is concerned that since EPA did not include such a discussion in its initial 

proposal, it could be limited in its ability to include any subpart 1 implementation in a final rule 

due to Administrative Procedure Act (APA) requirements. 

9. EPA Response. 

As noted in the previous response, the purpose of the document in the docket was to identify 

alternatives for interpreting the classification approach in Table 1 in section 181(a). We consider 

how to interpret the table for those areas classified under it to be a separate issue from whether 

any areas should be subject solely to the planning requirements of subpart 1. Thus, the “subpart 

1” approach was not addressed as part of that document. For the reasons discussed in responses 
23

10 to 14, EPA determined not to propose applying solely subpart 1 to any areas designated 

nonattainment for the 2008 ozone NAAQS. 

We note that the letter referenced by the commenter was sent to the Agency in February 2011 

when EPA anticipated issuing a proposed implementation rule for a tighter ozone standard in the 

range of 0.060 - 0.070 ppm. The letter applied to the 2011 reconsidered ozone NAAQS but will 

be added to the 2008 ozone NAAQS classification docket for information. 

Approach of Relying on CAA, Title, I, Part D, Subpart 1 in Some Cases. 

 Application to areas with design values below 0.09 ppm. 

10. Comment – EPA should require (or at least consider requiring) only compliance with subpart 1 

for nonattainment areas with design values below 0.09 ppm because subpart 1 will provide a 

more effective approach in bringing such areas into attainment, while subpart 2 largely will be 

ineffective. 

Several commenters (0020, 0024, 0053) stated that EPA should require (or at least consider 

requiring) only compliance with subpart 1 for areas with design values below 0.09 ppm because 

subpart 1 will provide a more effective approach in bringing such areas into attainment, while 

subpart 2 will largely be ineffective. 

One commenter (0024) specifically stated that the additional SIP requirements specified by 

subpart 2 are outdated and ineffective. Specifically, the commenter (0024) stated that the 15% 

reduction in volatile organic compounds (VOC) emissions, the requirement for Stage II vapor 

control, and the requirement for inspection and maintenance programs in Moderate and above 

nonattainment areas are all questionable with regard to feasibility and effectiveness; yet they 

apparently will be applicable under EPA’s proposed classification approach. 

Another commenter (0053) stated that an implementation rule that relies on subpart 2 will 

require a number of measures to address VOC emission without having much of an ozone 

benefit locally. The commenter (0053) stated that these include a mandatory 15% cut in VOC 

emissions for reasonable further progress (RFP), mandatory vehicle inspection and maintenance 

programs, stage II vapor recovery programs, clean fuel fleet programs, reasonably available 

control technologies, and specific tiered new source review offset requirements. The commenter 

(0053) does not believe that requiring the states, with their limited staff resources, to develop a 

suite of unnecessary VOC controls would be an effective way to expeditiously bring an area into 

attainment. 

One commenter (0053) specifically stated that EPA is missing an opportunity to implement the 

2008 ozone NAAQS in a way that would be far more effective in bringing an area with a design 

value of 0.09 ppm or less into attainment. The commenter (0053) stated that the subpart 2 

classifications and accompanying requirements are not needed for many areas. The commenter 

(0053) provided the example of the Austin, Texas, area, whose ozone levels have been steadily 

decreasing over the past several years but are still very close to the 2008 ozone NAAQS. The 
24

commenter (0053) reasoned that since its ozone levels are continuing to decrease, the subpart 2 

requirements are not needed to ensure the area achieves attainment. 

One commenter (0020) specifically stated that in previous Federal Register notices, EPA 

acknowledged that relying on subpart 1 would provide the states and tribes with greater 

discretion in determining the mix of controls needed to expeditiously attain the 2008 ozone 

NAAQS, and that subpart 1 does not mandate the implementation of certain VOC control 

measures that are known to be ineffective at reducing ozone in some parts of the country. 

Another commenter (0052) further stated that based on the types of controls needed in the 

Southeast to reduce ozone formation (i.e., NOx rather than VOC controls), North Carolina will be 

able to attain the 2008 NAAQS more expeditiously under subpart 1 than under subpart 2. 

One commenter (0053) provided a list of reasons why EPA should require only compliance with 

subpart 1 nonattainment areas with design values below the 0.09 ppm, rather than additionally 

classifying under subpart 2: 

• Subpart 1 would enable synchronized attainment deadlines for areas throughout a state that 

could be adjusted to account for availability of control measures and the regional nature of 

ozone pollution, rather than the system of classifications and attainment deadlines under 

subpart 2 that does not allow for consideration of ozone transport, 

• Subpart 1 would eliminate 15-year, 17-year, and 20-year attainment deadlines for areas that 

would otherwise be classified as Severe or Extreme, requiring them to attain in no more than 

10 years, 

• While some areas that might otherwise be classified as Marginal, Moderate, or Serious under 

subpart 2 and would have no more than 3, 6, and 9 years to attain the standard might now be 

eligible for up to 10 years to attain, all areas would still have to attain as expeditiously as 

practicable under subpart 1, which is also true for areas subject to subpart 2, and given what 

we know about ozone transport, those areas might not have been able to attain within those 

time frames anyhow without getting “bumped up.” And since areas that would be classified 

as Severe and Extreme under subpart 2 would need to attain in no more than 10 years, 

subpart 1 implementation would accelerate attainment for those areas and all of the areas 

they might be affecting. 

• Subpart 1’s possibility of synchronized attainment deadlines will significantly reduce the 

amount of time and resources needed for technical preparation for attainment demonstrations, 

since states could model a single base year and single future year for all areas-or two years, 

maximum, rather than for four or five different future years, and additional years of 

emissions estimates for RFP milestones, 

• Subpart 1 allows many more areas to get the full emission reduction benefits of the transport 

SIPs that are due three years after the new ozone standards are finalized and the full benefits 

of federal engine standards and fleet turnover that will occur over the years following 

finalization of the standards, 

• Because of the possibility of ten-year attainment deadlines, subpart 1 enables consideration 

of the co-benefits of longer-term measures such as transportation planning, land use 

planning, and energy efficiency, that will both reduce ozone and have many other social and 
25

environmental benefits, but which would not be able to implemented in only three or six 

years if an area was classified as Marginal or Moderate under subpart 2, 

• Subpart 1 contains less prescriptive requirements for control measures, which will enable 

states more flexibility in designing control strategies that are appropriate for their 

jurisdictions and enable them to optimize their planning and enforcement staff resources and 

financial resources to focus on the rules and strategies that will have the most impact on local 

ozone levels. 

• Subpart 1 would require attainment demonstrations and contingency measures for all 

nonattainment areas, unlike subpart 2, which would exempt areas classified as Marginal from 

these requirements and any local control measures other than new source review permitting, 

• Offset requirements under subpart 1 just require that new or modified sources offset their 

emissions by more than 100%, without setting specific offset ratios of 110% up to 150% 

under subpart 2; since local ozone may be mainly a problem of pollution transport, this 

avoids over regulating local sources without any clear benefit for local ozone levels, 

• Subpart 1 has higher mandatory major source threshold of 100 tons per year than the 50 tons 

per year, 25 tons per year, and 10 tons per year for areas that would be classified as Serious, 

Severe, or Extreme under subpart 2, which enables states the ability to focus most of its 

resources on those sources contributing the most to local ozone pollution; if EPA wanted to 

adjust these, it could do so through an implementation rule, rather than being forced into a 

specific method by statute; 

• Subpart 1 does not include specific mandatory control measures like stage II vapor recovery 

or clean fuel fleet, which may have been appropriate for reducing peak ozone levels in urban 

areas in 1990 but have become obsolete because of technology and are ineffective at 

reducing regional ozone levels, or for expensive mandatory inspection and maintenance 

programs that would provide very few emission reductions in some areas, 

• Subpart 1 does not contain specific requirements for RACT rules for every source covered by 

a Control Technique Guideline, which can consume staff resources at state agencies with 

little to no benefit on local ozone levels, and 

• Since subpart 1 does not contain all of the same onerous provisions for each county in a 

nonattainment area (RFP requirements, mandatory control measures that may have no local 

ozone benefit, specific new source review offsets), states might be encouraged to look more 

at the regional pollution problems and make designation recommendations that are more 

precautionary than they would under subpart 2, where most states seek to keep the 

nonattainment area as small as possible. 

• Subpart 1 offers EPA the opportunity to require areas it would have otherwise classified as 

Serious or Moderate to attain in no later than five years, rather than the six or nine years they 

would have had under subpart 2.. 

One commenter (0053) noted that President Obama, in an op-ed in the Wall Street Journal on 

January 18, 2011 stated that “we are seeking more affordable, less intrusive means to achieve the 

same ends – giving careful consideration to benefits and costs.” The commenter (0053) stated 

that relying on subpart 1 would be exactly the kind of more affordable, less intrusive means to 

achieve the same ends that the President was referring to. 
26

10. EPA Response. 

While EPA did consider placing some areas only under the planning requirements of subpart 1, 

EPA ultimately determined that such an approach was not its preferred approach for the 2008 

ozone NAAQS. Instead, EPA determined that classifying all areas under subpart 2 and using the 

PATS approach to translate Table 1 in section 181(a) was the most appropriate option for 

addressing nonattainment for the 2008 ozone NAAQS. Under this approach, a majority of areas 

would be classified as Marginal and most of those areas are anticipated to attain the 2008 

standard by the Marginal area attainment date. The Marginal classification provides as much, if 

not more, flexibility for areas than would subpart 1. For example, a Marginal area is not required 

to submit an attainment demonstration while subpart 1 requires such a plan. For areas that are 

close to the standard and likely to attain within three years, an attainment demonstration could be 

a costly and likely unnecessary burden. We further note that the planning and control 

requirements that the commenters believed were not flexible do not apply in Marginal areas. 

Further, all of the areas that will be classified as Moderate or higher for the 2008 ozone standard 

are already subject to those requirements for purposes of the 1997 ozone NAAQS. For a future 

ozone NAAQS, EPA may consider placing some areas designated nonattainment solely under 

the planning provisions of subpart 1. 

Furthermore, we disagree with the commenters who suggest that areas would be able to attain the 

standard more expeditiously under subpart 1. As an initial matter, under both subparts, states are 

required to ensure that areas attain the NAAQS as expeditiously as practicable. Furthermore, the 

initial maximum statutory attainment date under subpart 1 is five years, while for Marginal areas, 

which will be the classification for most areas for the 2008 ozone NAAQS, it is three years. 

Regardless, under both subparts, states are required to ensure that areas attain the NAAQS as 

expeditiously as practicable. 

For areas classified as Moderate or Serious, with a maximum attainment date under subpart 2 of 

6 or 9 years respectively, again subpart 1 does not necessarily set a shorter maximum attainment 

date. We note that the five year limit under subpart 1 is only binding if EPA determines it is 

consistent with expeditious attainment. Subpart 1 allows the EPA to approve attainment 

deadlines up to 10 years from designation based on a demonstration by the state that a deadline 

longer than five years is as expeditious as practical considering the severity of nonattainment and 

availability and feasibility of pollution control measures. 

While it is true that subpart 1 would provide a shorter maximum attainment date for areas 

classified as Severe or Extreme, we note that under the court’s decision in South Coast, EPA’s 

ability to place such areas solely under the planning provisions of subpart 1 is untested. The 

lowest design value for an area classified as Severe is 0.113 ppm, which is well above the 0.090 

level that the Court in South Coast indicated was the line between where EPA had discretion to 

place areas in subpart 1 and where it did not have such discretion.16 Subpart 2 provides areas 

classified Severe or Extreme more than the 10 years maximum attainment date which, may be 

more appropriate for these areas given the severity of their ozone nonattainment problem. 

 

16 The same is true for all areas classified as Serious as the lowest design value for such an area is 0.0100 ppm and 

for many areas classified as Moderate, which includes areas with a design value no lower than 0.086 ppm and less 

than 0.100 ppm. 
27

With regard to comments that classification under subpart 1 would allow for coordinated 

planning and/or synchronized attainment dates where there are multiple nonattainment areas in 

the State, we note that under subpart 1 (as under subpart 2) areas are required to attain the 

NAAQS as expeditiously as practicable. Thus, subpart 1 does not allow a State to synchronize 

the attainment date for multiple areas unless the State could show that date is as expeditiously as 

practicable for each individual area. That means that the State would not be able to provide a 

longer attainment date for an area in order to take advantage of measures that would be 

implemented over a longer period if there are short-term emission reductions that are practicable 

and would result in an earlier attainment date. Moreover, we note that subpart 2 does not prevent 

the State from considering synchronization. The State could request a voluntary reclassification 

for an area, particularly if the area cannot practicably attain by the attainment date for its initial 

classification. Similarly, since all areas are required to attain as expeditiously as practicable, a 

State should consider whether areas with a “higher” classification might be able to attain more 

quickly. These provisions allow a State to synchronize attainment dates to the extent the date 

selected for areas is “as expeditiously as practicable.” 

To the extent the bulleted list of points is not responded to above, we note the following: 

To the extent that the commenter is urging that areas be placed solely under subpart 1 because 

subpart 1 provides more flexibility, we note that the Court in South Coast rejected EPA’s 

approach to placing areas under subpart 1 in the Phase 1 Rule on the basis that the Act does not 

allow the requirements of subpart 2 “to be stripped away” on the basis that other provisions 

would allow attainment to be achieved more efficiently. 472 F.3d at 894. 

It is true that under subpart 1, the offset ratio applicable to sources subject to nonattainment new 

source review is lower than under subpart 2. And, it is also true that the major source threshold 

is lower for areas classified under subpart 2 than for those areas subject solely to subpart 1. As 

noted above, EPA’s ability to place areas solely under subpart 1 for areas classified as Marginal 

and areas classified as Moderate with a design value less than 0.090 ppm is untested. 

Nonetheless, for those areas the major source threshold is the same as under subpart 1 – 100 tpy. 

The offset ratio is not significantly different – 1.1 to 1 in Marginal areas and 1.15 to 1 in 

Moderate areas. We do not believe that difference alone is a sufficient justification for placing 

areas solely under the planning provisions of subpart 1, particularly in light of the court’s holding 

in South Coast. 

The commenter also raises several points regarding transport. We have addressed the issue of the 

relationship between transport and the nonattainment area planning provisions in response 4 and 

Section V. 

 

11. Comment – EPA should not adopt the PATS approach under subpart 2 for areas that are in 

attainment with the 1997 ozone NAAQS but are in nonattainment with the 2008 NAAQS. 

One commenter (0020) noted that the history that EPA provided regarding nonattainment area 

classification systems for the ozone NAAQS alleged in part that the PATS approach only was 

adopted for translating the 1979 NAAQS classification threshold values to the 1997 ozone 
28

NAAQS classification threshold values, and that this approach was challenged in litigation and 

was upheld by the court. However, the commenter (0020) stated that EPA is attempting to adopt 

the PATS approach in a different way now than it did in 1997. Specifically, the commenter 

(0020) explained that when EPA adopted the PATS approach for the 1997 NAAQS, it applied 

only to areas that were in nonattainment with both the 1979 and 1997 ozone NAAQS. EPA here 

is attempting to also apply the PATS approach to areas that are in attainment with the 1997 

NAAQS but will be in nonattainment with the 2008 NAAQS. The commenter (0020) does not 

support applying the PATS approach in this way, disagrees with EPA that it has used the PATS 

approach in this way in the past, and states that EPA’s claim that the approach was challenged 

and upheld in previous litigation is misleading. 

11. EPA Response. 

While the commenter is correct that the regulation at issue in South Coast did not place all areas 

in subpart 2 and those areas not placed in subpart 2 were not classified under the PATS 

approach, there is nothing in the Court’s opinion to suggest that it would have reached a different 

result if additional areas had been classified under subpart 2. In South Coast, industry 

petitioners challenged the PATS approach, claiming that it resulted in unrealistic attainment 

dates for areas and that EPA recognized in the preamble to its rule that some areas may be unable 

to attain the standard by the maximum date allowed by the area’s classification. The Court 

rejected those claims and upheld the classification approach as a reasonable approach to 

interpreting the gaps in Table 1 of section 181 of the CAA, as recognized by the Supreme Court 

in Whitman v. ATA. South Coast, 472 at 896-98. EPA is adopting the approach used for the 1997 

NAAQS for purposes of the 2008 NAAQS for the same reasons and believes that the rationale 

used by the court to reject industry claims on the classification approach for the 1997 NAAQS 

applies equally here. 

12. Comment – EPA should require (or at least consider requiring) only compliance with subpart 1 

for nonattainment areas with design values below 0.09 ppm, as the CAA, as interpreted by recent 

case law, gives it such authority. In addition, EPA must address the issue, provide adequate 

public notice of its rationale regarding this issue, and therefore, must withdraw the current 

proposal and re-propose it with a proper explanation 

Many commenters (0037, 0052, 0053, 0055) stated that EPA should require (or at least consider 

requiring) only compliance with subpart 1 for nonattainment areas with design values below 0.09 

ppm, as the CAA, as interpreted by recent case law, gives it such authority. All such commenters 

(0037), 0052, 0053, 0055) relied, at least in part, on Whitman v. American Trucking Association, 

531 U.S. 457, 482-486 (2001) and South Coast Air Quality Management District v. EPA, 472 

F.3d 882, as modified on rehearing 489 F.3d 1245 (D.C. Cir. 2006) to support this contention. 

One commenter (0055) stated that EPA should, at a minimum, provide some explanation for its 

apparent proposed decision to apply the requirements of subpart 2 to areas with design values 

falling between 0.075ppm and 0.09 ppm. The commenter (0055) stated that in proposing 

classification thresholds for nonattainment areas under the 2008 ozone NAAQS, EPA failed to 

address “gap areas,” which are those areas not expressly covered by the table in subpart 2. The 

commenter (0055) assumed that through EPA’s silence, it proposes that such areas will be 
29

governed by subpart 2. The commenter (0055) stated that EPA is obligated to provide at this 

state of the rulemaking a reasoned explanation for its position on this issue. See Shell Oil Co. v. 

EPA, 950 F.2d 741, 751 (D.C. Cir. 1991) (“Interested parties cannot be expected to divine the 

EPA’s unspoken thoughts.”) (citing Small Refiner Lead Phase-Down Task Force v. EPA, 705 

F.2d 506, 548-49 (D.C. Cir. 1983)). The commenter (0055) stated that EPA has failed to provide 

adequate notice for comment on this issue, as required under the APA as well as CAA § 

307(d)(3). See Small Refiner Lead Phase-Down Task Force, 705 F.2d at 548 (an “agency must 

‘make its views known to the public in a concrete and focused form so as to make criticism or 

formulation of alternatives possible’”)(quoting Home Box Office, Inc. v. FCC, 567 F.2d 9, 36 

(D.C. Cir. 1977)). The commenter (0055) further stated that application of subpart 2 to gap areas 

is not mandated by the CAA or court decisions, and is even contrary to the plain language of the 

CAA and Whitman and South Coast. The commenter (0055) interprets Whitman as stating that 

the CAA at a minimum extends to EPA the authority to implement the NAAQS in gaps areas 

under subpart 1, if the reasonable exercise of discretion of EPA were to conclude that doing so is 

appropriate. The commenter (0055) stated that the D.C. Circuit Court acknowledged as much in 

South Coast I, finding that, where EPA had made the ozone NAAQS more stringent, “the gap 

identified in Whitman affords EPA discretion” to implement the revised NAAQS under subpart 1 

in those areas that, while not attaining the revised, more stringent standard, have “air quality 

[that] is not as dangerous as the level addressed by the 1990 [CAA] Amendments, which now 

translates to 0.09 ppm on the eight-hour scale.” 472 F.3d at 893. Consequently, the commenter 

(0055) stated that any conclusions by EPA that gap areas must be subject to subpart 2 is 

untenable and unsupported. The commenter (0055) stated that the fact that classification of all 

ozone attainment areas under subpart 2 is not mandatory creates an obligation for EPA to 

provide a lawful and reasonable justification for any proposal to classify all areas under subpart 

2, but that EPA has provided no such justification in the proposed rule; and indeed, EPA has 

failed even to acknowledge the issue. Consequently, the commenter (0055) stated that consistent 

with its obligation to provide adequate public notice of its proposal and its underling rationale, 

EPA must withdraw the current proposal and re-propose it with a proper explanation or issue a 

notice of supplemental rulemaking containing such an explanation. 

One commenter (0053) specifically stated that Whitman v. American Trucking Association, 531 

U.S. 457, 482-486 (2001) stood for the proposition that EPA can rely solely on subpart 1 for the 

specification of SIP requirements so long as EPA provided a reasonable explanation for doing 

so. The commenter (0053) noted that that after this court decision, the EPA finalized the first 

phase of the ozone implementation rule on April 30, 2004 (69 FR 23951), and stated that it 

would not classify all areas under subpart 2 since subpart 2 provides significantly less flexibility 

than subpart 1 for areas affected by transport pollution. 

The commenter (0053) listed some points to keep in mind regarding the decision in South Coast 

Air Quality Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006): 

• The South Coast Court’s ruling that “EPA’s interpretation of the Act in manner to maximize 

its own discretion is unreasonable” was specifically tied to its ruling that “the 2004 Rule 

violates the Act insofar as it subjects areas with eight-hour ozone in excess of 0.09 ppm to 

subpart 1” (page 895). 
30

• The South Coast Court explicitly expressed its interpretation of the Whitman ruling as 

allowing EPA to implement an eight-hour ozone standard under subpart 1 (page 893). 

• In its ruling on a rehearing petition on June 8, 2007, the Court clarified that “this court 

concluded that EPA had misconstrued the extent of the gaps to exercise its interpretive 

discretion more broadly than the Supreme Court had authorized,” which should make it clear 

that its ruling on EPA’s unreasonable interpretation of the Clean Air Act related its 

application of subpart 1 to areas with eight-hour ozone levels in excess of 0.09 ppm, not to its 

application of subpart 1 to legitimate “gap” areas. 

• The Court further clarified that “The court merely recognized that under Chevron agency 

action that does not constitute a reasonable interpretation of the statute must be vacated. 

Because Congress sought to reduce EPA discretion by enacting subpart 2 as part of the 1990 

amendments to the CAA, EPA could not reasonably rely upon its preference for regulatory 

flexibility in setting the boundary between subpart 1 and subpart 2. EPA’s claim that the 

court nullified the discretion recognized by the Supreme Court in Whitman is meritless.” The 

court did not rule that the EPA did not have the discretion to set the boundary between 

subpart 1 and subpart 2, just that it had to be based on a reasonable interpretation of the 

statute. EPA stated as much in its April 2010 stakeholder presentation, stating, “In South 

Coast the Court determined that Congress did not mandate that areas with an 8-hour DV of 

less than 0.09 ppm be classified under subpart 2. Thus, assuming EPA had a reasonable 

rationale for classifying such areas under subpart 1, it could do so.” 

• A reasonable interpretation of the statute that would allow for subpart 1 implementation 

could rely on the stated purposes of title I: 

o to protect and enhance the quality of the Nation’s air resources so as to as to promote 

the public health and welfare and the productive capacity of its population 

(§101(b)(1)) 

o to encourage and assist the development and operation of regional air pollution 

prevention and control programs (§101(b)(4)) 

o Relying on the features of subpart 1 that would enable more expeditious attainment of 

an ozone NAAQS (such as eliminating the Marginal classification and reducing 

attainment deadlines for areas that would otherwise be classified as severe or higher 

from 15, 17, or 20 years to no more than 10) and that would facilitate a regional 

approach to pollution prevention (such as the ability to classify areas and adjust 

attainment deadlines to take pollution transport into account) would avoid running 

afoul of the restrictions imposed by the South Coast court. 

12. EPA Response. 

 

EPA recognizes that the South Coast court did leave open the possibility that EPA could 

develop a reasonable basis to subject only to subpart 1 all or certain areas with an 8-hour design 

value below 0.09 ppm. EPA determined not to pursue such an approach for purposes of 

implementing the 2008 ozone NAAQS. Doing so, however, does not preclude EPA from 

pursuing such an approach for any future ozone NAAQS. 

We disagree with the commenter who claims that EPA failed to address areas with a design 

value falling between 0.075 ppm and 0.09 ppm. Our proposed rule is clear that areas with these 

design values would be classified as Marginal (i.e., those with a design value of 0.076 ppm and 
31

less than 0.086) or as Moderate (i.e., those with a design value of 0.086 ppm and less than 0.100 

ppm). See 77 FR at 8201, Table 1; see also Background Information Document: Hypothetical 

Nonattainment Areas for Purposes of Understanding the EPA Proposed Rule for Implementing a 

2008 8-Hour Ozone National Ambient Air Quality Standard--Illustrative Analysis Based on 

2010 Design Values. December 2011 (placing all hypothetical areas that would be designated 

nonattainment for the 2008 ozone standard in one of the subpart 2 classifications). We further 

disagree with the comment that EPA is obligated to provide an explanation for its choice to 

classify all areas under subpart 2 rather than to make certain areas subject only to the provisions 

of subpart 1. We read the court's decision in South Coast as interpreting Congressional intent 

such that all areas must be classified under subpart 2 in the absence of a "reasonable 

interpretation" for choosing to place certain areas under subpart 1. Thus, where EPA has chosen 

to follow the presumptive statutory approach of placing all areas under subpart 2, EPA is not 

obligated to explain or justify why it has chosen not to explore other approaches. 

 The court in South Coast did leave open the possibility to implement the ozone NAAQS under 

subpart 1. For the 2008 NAAQS we are choosing not to explore the subpart 1 option. For a 

future ozone NAAQS, EPA may consider an approach under subpart 1. For the 2008 ozone 

NAAQS, most of the areas designated nonattainment have design values close to the level of the 

NAAQS and under the subpart 2 classification approach EPA is promulgating most of the areas 

will be classified as Marginal. The Marginal classification establishes minimal mandatory 

requirements, providing flexibility for areas to develop and adopt additional measures if needed 

to attain the NAAQS. Furthermore, our analysis at the time of the proposal indicated that most 

of the areas that we anticipated would be classified as Marginal had been designated 

nonattainment for the 1997 NAAQS nonattainment areas and are already subject to subpart 2. 

Thus, these areas already have experience meeting the obligations of subpart 2. 

To the extent the bulleted list of comments are not responded to above, we have the following 

response: 

• We disagree with the comments that the South Coast Court’s ruling regarding the 

reasonableness of EPA’s decision to place certain areas only under subpart 1 was limited to 

EPA’s placement of areas with an eight-hour design value in excess of 0.09 ppm. Rather, the 

court clearly states that this section of its opinion is reviewing EPA’s decision to place areas 

with a design value between 0.08 and 0.09 ppm in subpart 1. South Coast, 472 F.3d at 894 

(“For areas with ozone levels between 0.08 and 0.09 ppm, the 2004 Rule overlaps with the 

gap recognized in Whitman. To this extent, the question under Chevron Step 2 is whether 

EPA’s interpretation, while not required to ‘represent the best interpretation of the statute, is 

reasonable.”). 

• We agree that the Court in South Coast determined that in order to place areas with an 8-hour 

design value less than 0.09 ppm in subpart 1, EPA must set forth a reasonable basis. 

However, we disagree with the commenter that the purposes of the statute as set forth in 

section 101 of the Act (and which apply equally to subpart 2) provide a basis for choosing 

subpart 1 over subpart 2. Furthermore, we do not believe that there are features in subpart 1 

that would enable more expeditious attainment of the 2008 ozone NAAQS. Under subpart 1 

or subpart 2, all areas are required to attain the NAAQS as expeditiously as practicable, 

regardless of the maximum attainment date associated with the area’s classification. To the 
32

extent an area that would have a maximum attainment date later than 10 years if placed under 

subpart 2 (i.e., would be classified as Severe or Extreme), it is still required to attain within 

10 years if it is practicable to do so. And, if it is not practicable to do so, then arguably 

subpart 1 would not be a reasonable implementation approach for such areas. As to using 

subpart 1 as more reasonable way to address transport of ozone and its precursors, we note 

that the court rejected that rationale in South Coast, 472 at 894. 

13. Comment – EPA should require (or at least consider requiring) only compliance with subpart 1 

for nonattainment areas with design values below the 0.09 ppm because adoption of subpart 2 

will result in delays in attainment. 

One commenter (0053) stated that the practical effect of classifying areas as Marginal that cannot 

attain the NAAQS would be to delay development of plans for improving air quality, which is 

inconsistent with the CAA’s intent to attain air quality standards as expeditiously as practicable. 

13. EPA Response. 

Our analyses indicate that most areas classified as Marginal will be able to attain the 2008 Ozone 

NAAQS by 2015. Based on our past experience with the 1-hour and 1997 8-hour ozone 

NAAQS, it is likely that there are some areas that will be classified as Marginal that will either 

request reclassification to a higher classification or will be reclassified to a higher classification 

by operation of law because they fail to attain the 2008 by the Marginal area attainment date. 

For areas that are reclassified based on a failure to attain or for which a State requests a voluntary 

bump-up close to the Marginal area attainment date, we agree that planning may occur slightly 

later than for areas that are initially classified as Moderate or higher. The later such an area is 

reclassified, the more the planning time will need to be compressed in order for the area to attain 

by the attainment date for the higher classification. Hopefully this will act as strong incentive for 

states to request a reclassification as early as possible where evidence indicates that area is 

unlikely to attain. While subpart 1 does have the advantage from a planning perspective of 

requiring an attainment plan for all areas, we believe that most of the areas that are classified as 

Marginal will not need such a plan as they are expected to attain the 2008 ozone NAAQS 

without additional local measures. We do not believe that imposing that time and resource cost 

on all areas is justified based on the fact that a few areas may not be able to attain by the 

Marginal area attainment date. Moreover, we do not believe that the choice of placing areas in 

subpart 1 only or in subpart 2 will likely affect when any particular areas attains the 2008 

NAAQS. To the extent that States are motivated to ensure clean air for their citizens, they will 

take timely action regardless of which subpart applies. Similarly, if political, economic or other 

pressures prevent a State from taking action to improve air quality, we do not believe that 

whether an area is placed under subpart 1 or under subpart 2 will counter those pressures. We 

note that under both subparts, areas are required to attain the NAAQS “as expeditiously as 

practicable” regardless of the maximum attainment date. 

 
33

Rural nonattainment areas impacted by upwind contributions should not be classified 

under subpart 2. 

14. Comment – EPA should allow that rural, downwind areas be subject only to the planning 

provisions of subpart 1 and not subject to the requirements of subpart 2. 

One commenter (0031) stated that rural, downwind areas should be subject only to the provisions 

of subpart 1 and not subject to the requirements of subpart 2. The commenter (0031) explained 

that there are several rural, downwind nonattainment areas that are overwhelmingly dominated 

by urban upwind transport, and that these rural downwind nonattainment areas could face 

potentially insurmountable difficulties demonstrating reasonable further progress (RFP) required 

by subpart 2. The commenter (0031) stated that the necessary emissions reductions for 

attainment must come from upwind nonattainment areas subject to subpart 2. The commenter 

(0031) believes that South Coast Air Quality Management District v. EPA, 489 F.3d 1245 (D.C. 

Cir. 2006) left the door open for EPA to make use of subpart 1 in the future under certain 

circumstances. 

14. EPA Response. 

EPA appreciates the concerns of the commenter about nonattainment areas located in rural areas 

with few emissions sources. Section 182(h) contains specific provisions providing relief to 

“rural transport areas” under subpart 2. Specifically, any area that qualifies as a rural transport 

area is deemed to meet the requirements of subpart 2 if it meets the requirements applicable to 

Marginal areas. We note, however, our analyses at the time of proposal indicates that there are 

no rural areas that would be classified higher than Marginal under the classification approach we 

are adopting (and we believe the final designation rule will also reflect this result) 

Opposition to relying on subpart 1 and completely ignoring subpart 2 classifications. 

15. Comment – EPA should require that all nonattainment areas be classified under subpart 2. 

One commenter (0054) stated that it supported subpart 2 classifications for all areas that are in 

nonattainment for the 2008 NAAQS, as this approach is consistent with the CAA and the Court’s 

decision South Coast Air Quality Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006). 

The commenter (0054) stated that there is no lawful or rational basis for EPA to follow the 

approach taken in its 2004 implementation rule of classifying only some nonattainment areas 

under subpart 2 and regulating the remainder exclusively under subpart1. 

15. EPA Response. 

EPA acknowledges the commenter’s support of the proposed approach for classifying areas for 

the 2008 ozone NAAQS only under subpart 2. To the extent the commenter is suggesting that 

the Court in South Coast held that there is no lawful approach to placing certain areas solely 

under the planning provisions of subpart 1, we disagree. The court in South Coast specifically 

noted that the statute is not clear on its face that areas with a design value between 0.08 and 0.09 
34

for the 1997 8-hour standard must be classified under subpart 2 and left open the door for the 

Agency to develop a reasonable basis for placing some or all of such areas solely under the 

planning obligations of subpart 1. While EPA has chosen not to adopt such an approach for the 

2008 ozone NAAQS, it could choose to do so for a future ozone NAAQS. 

Other subpart 2 Approaches for Classifying Areas. 

16. Comment – EPA should propose and solicit comment on at least two other options listed in one 

of its background information documents for classification of ozone nonattainment areas. 

One commenter (0029) noted that EPA stated it evaluated many other methods but is not 

proposing them or soliciting comment on them because it did not find them as compelling for 

application to the 2008 ozone NAAQS as the PATS approach. The commenter (0029) stated that 

EPA should have solicited comments on at least two other options contained in the EPA 

document: “Background Information Document: Additional Options Considered for 

Classification of Nonattainment Areas under the Proposed 2008 Ozone NAAQS (January 

2012).” The commenter (0029) stated that EPA should have solicited comments on Option #1 

(Ratio of Thresholds Method) and Option #6 (Method that would rely on the same proportion of 

areas in each classification as in the original 1991 classifications) because both options are 

reasonable for classifying areas under the 2008 ozone NAAQS and set forth a reasonable 

timetable for attaining the standard for most areas of the United States. 

16. EPA Response. 

After evaluating the various classification options, EPA determined that the PATS approach was 

the appropriate one to propose for adoption for purposes of the 2008 ozone NAAQS. However, 

we did include in a Background Information Document the various other approaches considered 

and while we did not specifically seek comment on those approaches, they were available in the 

record for the public to comment on them. 

Concerning the Ratio of Thresholds approach, as explained in the Background Information 

Document, this approach the design value thresholds for the different classifications would vary 

depending on the years of data used. This is because the threshold for the extreme area 

classification would be based on the highest design value at the time of designation and 

classification of areas and the thresholds for the other classifications would be adjusted from that 

value. The analysis of the hypothetical areas demonstrated that the classification of a significant 

number of areas could change based on the years of data used for designating areas. The 

classification change for an area was not dependent on that area’s design value but on the design 

value of the one or two areas with the highest design value for the three-year period relied on. 

We believed that this approach provided too much uncertainty in light of the quick timeline we 

had for designating and classifying areas for the 2008 ozone NAAQS. 

Option #6 in the BID would rely on the same proportion of areas in each classification as in the 

original 1991 classifications. We believed that this approach was complicated by the fact that so 

many areas had design values close to the level of the NAAQS and, significantly, that many 
35

areas had the same design value. Thus, it would have been difficult to include the same 

percentage of areas in each classification as were included in 1991 unless some areas with the 

same design value were placed in different classifications. For example, this approach would 

require 42% of the areas to be classified Marginal to match the 42 of 101 areas designated 

nonattainment for the 1-hour ozone NAAQS at the time the CAA Amendments of 1990 were 

enacted. Using that same percentage, 22 of the hypothetical 52 areas would need to be classified 

as Marginal. The hypothetical areas were ranked in ascending design values. The 2008-10 

design value had 11 areas with a 0.076 ppm design value, 8 with a 0.077 ppm design value and 6 

with a 0.078 ppm design value. Thus, for the six areas with a design value of 0.078 ppm, EPA 

would have to make a judgment call on whether to include all six as Marginal, which would 

result in 25 Marginal areas; include all as Moderate, which would result in 19 Marginal areas; or 

to determine which three of the six to include as Marginal and which three to include as 

Moderate. We believe that this method to determine threshold cut points would require more 

judgment in setting the classification than the CAA contemplated. 

17. Comment – EPA should adopt a modified Ratio of Threshold approach recommended by the 

commenter (0044). 

Some commenters (0044, 0049) suggested adopting a modified Ratio of Threshold approach. 

The commenters (0044, 0049) presented extensive formulas to use, which, when applied, would 

result in the classification areas being more evenly distributed among the classification 

categories. The commenter’s version of the Ratio of Thresholds approach would set the 

extreme threshold at 0.110 ppm instead of based on the highest design value for an area at the 

time of designation. Both the Ratio of Threshold and the modified version suggested would 

result in one extreme area. 

17. EPA Response. 

As explained in the Background Information Document, we anticipated that under the Ratio of 

Threshold method the extreme threshold would be 0.112 ppm, which is the highest design value 

in 2008-2010. The rationale for this approach was to use the actual design value for an area that 

would ensure that one area is placed in the highest classification provided under Table 1 in 

section 181(a). Thus, the design value for the area with the highest design value at the time of 

designations would be the threshold that would serve as the basis for then calculating thresholds 

for the other classifications. The commenter does not explain the basis for selecting 0.110 ppm 

as opposed to a different level that might also result in one area being classified as extreme. 

Because the design value selected would have a significant effect on the lower classification 

thresholds, we believe that there should be some basis for the level selected. While we would 

not rule out using the Ratio of Thresholds method as provided in the BID or the modified version 

as suggested by the commenter for a future ozone NAAQS, we believe that we would need to 

give more consideration as to how the extreme area threshold is set in order to ensure it is not 

perceived as arbitrary. 

18. Comment – EPA should reconsider and seek comment on the “ratio-of-thresholds” approach. 
36

One commenter (0044) noted that EPA considered the “ratio of thresholds” approach, which is 

identified as Option 1 in the EPA document: “Background Information Document: Additional 

Options Considered for Classification of Nonattainment Areas under the Proposed 2008 Ozone 

NAAQS (January 2012).” The commenter (0044) noted that EPA explained that it considered the 

option because a number of commenters on the implementation rule for the 1997 ozone NAAQS 

recommended that EPA consider a classification approach that would place more areas in higher 

classifications in order to provide maximum timeframes for areas to attain. However, the 

commenter noted that EPA decided not to propose the method, in part, because the result would 

vary depending on the years of data used for the design values in calculating the ratios for the 

2008 ozone NAAQS. The commenter (0044) stated that it did not agree with EPA’s reasoning, 

as the ozone situation has changed and the use of the ratio of thresholds would result in more 

control programs across the country including upwind States that impact Delaware. 

The commenter (044) is expressing a preference for the Ratio of Thresholds or a similar 

classification method. The commenter prefers having more areas classified in higher 

classification categories, as compared to the PATS method. The commenter believes that 

classifying areas in higher classifications will result in more areas being subject to mandatory 

control programs in areas upwind of Delaware. 

18. EPA Response. 

We have explained in previous responses out concerns about using the Ratio of Threshold 

approach for the 2008 ozone NAAQS. We have also addressed in previous responses concerns 

from some commenters that more areas should be subject to more stringent controls in order to 

provide ozone reductions that will help downwind areas. As we noted previously, the structure 

of the Act provides for States to address interstate transport independent of whether areas in the 

state are designated nonattainment or, if designated nonattainment, what nonattainment planning 

provisions apply to the area. 

II. Voluntary Reclassification 

Support for EPA’s voluntary bump-up approach. 

19. Comment – EPA should allow areas’ requests for voluntary nonattainment reclassifications to 

higher classifications (bump-ups) under the 1997 ozone NAAQS to automatically apply to the 

2008 NAAQS unless otherwise requested by a state. 

Many commenters (0022, 0030, 0031, 0033, 0039) stated that they supported EPA’s proposal to 

allow areas that requested voluntary reclassifications to higher classifications (bump-ups) under 

the 1997 ozone NAAQS to automatically apply the bump-up to the 2008 NAAQS unless 

otherwise requested by a state. 

One commenter (0022) specifically stated that for those areas that requested a voluntary bumpup in classification for the 1997 ozone NAAQS, it is preferable to grant these areas an automatic 
37

bump-up at the outset of the designation process rather than to adjust the thresholds to place all 

nonattainment areas in higher classifications. 

One commenter (0030) specifically explained that in 2008, it requested that EPA reclassify its 

county up one level from a Moderate nonattainment area to a serious nonattainment area. The 

commenter (0030) explained that it made this request because it was obvious that more time 

would be required to attain the 1997 ozone NAAQS. The commenter (0030) reasoned that it will 

also need the time afforded by a serious classification to meet the more stringent 2008 ozone 

NAAQS and that EPA’s proposal regarding voluntary bump ups would give it that time. 

One commenter (0033) specifically reasoned that if EPA were to set initial classifications for the 

2008 NAAQS based on design values levels alone, then areas that voluntarily reclassified under 

the 1997 8-hour standard could end up with an earlier attainment date for a more stringent 

standard; this situation of repeated voluntary reclassification requests, and any resulting 

contradictions in classification-based CAA requirements would be difficult to communicate to 

the public. 

One commenter (0039) stated the Houston-Galveston-Brazoria area requested a voluntary bumpup on the 1997 ozone NAAQS, but will not want to be in a higher classification under the 2008 

ozone NAAQS. The commenter (0039) supported EPA’s approach inasmuch as it gives state the 

ability to opt out of the automatic bump-ups. Another commenter (0047) stated that EPA ‘s 

voluntarily bump-up approach is appropriate in that requests for voluntarily bump-ups granted 

under the 1997 ozone NAAQS do not automatically apply to the 2008 ozone NAAQS when a 

state requests otherwise, and specifically stated this aspect of the proposal makes sense for the 

Houston-Galveston-Brazoria area. 

19. EPA Response. 

We appreciate the support of the commenters. 

 Opposition to EPA’s voluntary bump-up approach. 

20. Comment – EPA should clearly articulate the CAA authority for EPA’s voluntary bump-up 

approach. 

One commenter (0037) stated that EPA had correctly identified the three legal mechanisms the 

CAA provides for changing the classification (i.e., CAA §184(a)(4), CAA §181(b)(2), CAA 

§181(b)(3)). The commenter (0037) further noted that EPA provided another option, which 

consisted of allowing areas that requested voluntary nonattainment reclassifications to higher 

classifications (bump-ups) under the 1997 ozone NAAQS to automatically apply to the 2008 

NAAQS unless otherwise requested by a state. The commenter (0037) stated that EPA should 

clearly articulate the CAA authority for this new method. The commenter (0037) noted that 

states could always prepare another CAA 181(b)(3) voluntary re-classification request. The 

commenter (0037) further noted that some areas such as the Houston-Galveston-Brazoria 

nonattainment area have indicated they do not wish for the voluntary re-classification requests 
38

for the 1997 ozone NAAQS to apply to the 2008 ozone NAAQS, as control measures 

implemented improved air quality much faster than anticipated. 

20. EPA Response. 

CAA section 181(b)(3) allows a state to voluntarily request that the EPA reclassify a 

nonattainment area to a higher classification. A number of areas requested voluntary 

reclassifications under the 1997 NAAQS. Several of the areas that requested, and received, a 

voluntary reclassification would initially have been classified with a lower classification with an 

earlier maximum attainment date for the more stringent 2008 NAAQS than the area had for the 

1997 NAAQS. We believe it likely that these areas would as a result have requested a similar 

reclassification for the 2008 NAAQS. The EPA is obligated to approve such voluntary 

reclassification requests if made. EPA therefore proposed to treat prior requests as also being 

requests with respect to the 2008 NAAQS unless a state indicated that EPA should not take that 

interpretation. This approach reduces the burden on states by obviating the need to go through a 

separate process to request bump-up for the 2008 NAAQS but also allows them to opt out of this 

approach by requesting during the comment period on this proposed rule that EPA not interpret 

their previous request to apply for purposes of the 2008 ozone NAAQS. We note that Texas has 

requested that we not interpret the voluntary bump-up request for Houston for the 1997 ozone 

NAAQS to apply for purposes of the 2008 ozone NAAQS, while California has commented that 

it supports this approach. Thus, we are treating the previous bump-up request for areas in 

California to apply for purposes of the 2008 ozone NAAQS, and interpreting the previous 

request by Texas for Houston to not apply, consistent with both the proposal and the states’ 

requests. 

Recommendations to expand EPA’s voluntary bump-up approach. 

21. Comment – EPA should also allow nonattainment areas to opt into a previous classification 

allowed under the previous 1997 ozone NAAQS classification , provided that the classification 

is higher than the classification suggested for the area by the 2008 ozone NAAQS. 

One commenter (0031) noted that EPA proposed to bring forward previous, voluntary bump-ups 

from the 1997 NAAQS, and stated that the nonattainment areas in California include Ventura 

County, South Coast, San Joaquin Valley, Riverside, and Sacramento Metropolitan. The 

commenter (0031) stated that it supported this proposal but recognized that it did not address all 

areas that may need to request that they be put in a higher classification than suggested by the 

proposed PATS approach. Consequently, the commenter (0031) suggested that nonattainment 

areas be allowed to opt into a classification that the area could have bumped into under the 1997 

ozone NAAQS, provided that the classification is higher than the classification suggested for the 

area by the 2008 ozone NAAQS PATS approach. The commenter (0031) stated that it makes 

sense that if an area previously held a high classification for a less stringent standard, that 

classification should be available to the area, on an opt-in basis for a more stringent standard. 

The commenter (0031) stated that this would allow the former Southeast Desert areas (Antelope 

Valley, Western Mojave Desert, and Coachella Valley) access to the severe classification. The 

commenter (0031) reasoned that this avoids a quirk in the law that precludes these districts from 
39

requesting a bump-up to severe, which is the classification they had under the 1997 ozone 

NAAQS. 

21. EPA Response. 

Any area that concludes it cannot attain a standard by the attainment date corresponding to its 

classification can request a voluntary reclassification under section 181(b)(3) which EPA would 

have to approve. Thus, the three California southeast desert areas could request a bump-up to 

severe under this provision of the Act. 

 

III. Attainment Deadlines for Nonattainment Areas 

Support for adopting Option 1 (attainment date running from the effective date of 

designation) and Opposition to Option 2 (attainment date running from December 31) 

22. Comment –EPA should adopt Option 1 for determining the timing of attainment deadlines for 

classified areas. 

A few commenters (0032, 0038, 0050) stated that EPA should adopt Option 1 for determining 

the timing of attainment deadlines for classified areas. 

Commenters (0032, 0034, 0050) stated that a plain reading of the CAA, section 181 presupposes 

an attainment deadline precisely 3 years, or consecutive 365-day periods, after the designations 

become effective, and EPA established the 1997 NAAQS attainment deadlines using this 

identical approach. One commenter (0032) does not support delays for meeting the ozone 

standard beyond the statutory requirements set out in the CAA. One commenter (0034) stated 

that EPA previously stated in a rulemaking to implement the 1997 ozone NAAQS, “We do not 

believe we have authority to change the [ozone NAAQS] attainment dates to November or 

December [from June 15] of the attainment year as several commenters requested.” 

Commenters (0032, 0038) suggested adopting Option 1 because adopting Option 2 would result 

in further delays in areas being required to attain the 2008 ozone NAAQS. 

22. EPA Response. 

As written, Table 1 in section 181(a) would produce an absurd result if applied for purposes of 

the 2008 ozone NAAQS since the attainment dates for all classifications under that Table have 

now passed. Where application of the statute, as written, would produce an absurd result, EPA 

has discretion to develop a reasonable interpretation. We believe Option 2, which assures each 

nonattainment area will be afforded 3, 6, 9, 15, or 20 full ozone seasons after the date of 

designation to attain the NAAQS, is a reasonable approach. It adopts the time periods in the 

statute (3, 6, 9, 15 or 20 years for each of the five classifications) and instead of running such 

timeframes from the date of enactment of the CAA Amendments of 1990 as provided in the 

statutory table, runs those dates from the end of the calendar year of the year in which the 

designations occur. We believe this approach is appropriate for several reasons. First, we believe 
40

that option 2 is consistent with the intent of Congress at the time the CAA Amendments of 1990 

were enacted. Since ozone seasons for most areas run during the spring, summer and fall,17 the 

Act, as amended in 1990 allowed marginal areas three full ozone seasons to attain and maintain 

the NAAQS (and six full ozone seasons for moderate etc.) after the time that areas were 

designated and classified by operation of law at the time of enactment of the CAA Amendments. 

This approach also is consistent with the regulatory provisions specifying how to determine 

whether an area has attained the 2008 ozone NAAQS, which require an evaluation of monitoring 

data from 3 consecutive calendar years running from January 1 to December 31 of each year. 

In addition, some states with Marginal areas may need to adopt measures beyond federal or state 

measures already in place in order to attain within 3 years (based on 2012-2014 air quality data). 

Under the option 1 approach (attainment date running from the effective date of 

designation),these states would have 18 to 21 months18 to adopt and implement such measures 

by no later than the beginning of the 2014 ozone season. This is less time than such areas had 

for purposes of the 1-hour ozone standard under the CAA as amended in 1990. At that time, 

States with Marginal areas had over two years to adopt and implement such measures prior to the 

final ozone season used for purposes of determining attainment.19 The option 2 approach would 

provide more time for states with Marginal areas to complete the rulemaking process to adopt 

and implement additional local measures if needed, and it would thus be consistent with the 1990 

CAA amendments in providing 3 full ozone seasons for Marginal areas to attain the NAAQS. 

We recognize, as stated by the commenters, that at the time we interpreted the section 181(a) 

Table for purposes of the 1997 ozone NAAQS that we established attainment dates consistent 

with Option 1 in this proposal. At that time, we did not focus on the fact that by running the 

attainment date from the effective date of designations areas would essentially be required to 

attain the standard six months earlier than the “attainment date” since attainment is based on 

three full calendar years of data. Thus, for the 1997 ozone NAAQS, the marginal area 

attainment date was effectively December 31, 2006 and we determined whether marginal areas 

attained the 1997 ozone NAAQS based on air quality data from calendar years 2004, 2005 and 

2006. Based on experience with implementing the 1997 ozone NAAQS, we proposed two 

options for attainment dates for the 2008 ozone NAAQS – neither of which truly gives an area 

 

17 A few of the most southern areas in the country do have a year-round ozone season. For purposes of the 1-hour 

NAAQS, EPA effectively interpreted the November 15 attainment date as the end of the calendar year (i.e., the end 

of calendar years 1993, 1996, 1999, 2005, 2007 and 2010) for these areas. 

18 The ozone season for all areas of California, Nevada, Arizona, Southern Texas, and Southern Louisiana starts in 

January, which would provide 18 months for areas classified as marginal in such states to adopt and implement any 

additional measures needed for attainment. The ozone season for all areas of Colorado, Northern Texas, Northern 

Louisiana, Alabama, Mississippi, Georgia, Florida, Tennessee, and Kentucky starts in March, which would provide 

20 months for areas classified as marginal in such states to adopt and implement any additional measures needed for 

attainment. The ozone season for all other areas designated nonattainment for the 2008 NAAQS begins in April, 

which would provide 21 months for areas classified as marginal in such states to adopt and implement any 

additional measures needed for attainment. 

19 The same is true for the higher classifications. For example, under Option 1, moderate areas would have 

approximately 4 1⁄2 years to adopt and implement measures necessary to attain the 2008 ozone NAAQS (i.e., no 

later than the beginning of the 2017 ozone season, which would be the final ozone season relied on for attainment), 

whereas at the time of the CAA Amendments of 1990, Moderate areas had approximately 5 years to adopt and 

implement measures prior to the beginning of the 2006 ozone season, which was the final ozone season considered 

for determining whether an area attained by the November 2006 Moderate area attainment date.
41

three 365-day periods from the effective date of designations to attain the NAAQS. Option 1 

would effectively give areas 2 1⁄2 years (i.e., from mid-2012 until December 2014) and Option 2 

would give areas effectively 3 1⁄2 years to attain the NAAQS (i.e., from mid 2012 until December 

2015). In light of the fact that at the time the CAA Amendments of 1990 were enacted, Congress 

believed that marginal areas would have three full ozone seasons in which to achieve reductions 

to attain the NAAQS, we believe Option 2 is a reasonable interpretation as it gives areas three 

full ozone seasons in which to attain. Similarly, Option 1, which is the approach that we adopted 

for the 1997 ozone NAAQS, is also a reasonable interpretation because it is consistent with other 

statutory provisions that run the attainment date from the time of designation (see 69 FR 23951, 

April 30, 2004). Here, EPA concludes that providing areas three full ozone seasons to attain is a 

reasonable interpretation because it gives effect to the time periods established by Congress and 

applies them in a manner consistent with how those periods functionally applied at the time of 

enactment of the 1990 Amendments. We note that areas are still required to attain as 

expeditiously as practicable. 

To the extent the commenters are suggesting that in the Phase 1 rule establishing classifications 

for the 2004 ozone NAAQS that EPA concluded that Option 2 is unsupportable under the Act, 

we disagree. EPA made general statements that we could not extend the attainment period 

simply to allow areas to take credit for federal or regional measures expected in the future, but 

we did not address the narrow issue of whether the time periods for attainment could run from 

the end of the year in which designations occurred. We continue to believe (as we did for 

purposes of the Phase 1 Rule) that although the statutory provision as applied would produce an 

absurd result, that does not give EPA broad discretion to establish different attainment periods 

than specified in Table 1. In other words, EPA cannot establish attainment periods outside of 

those contemplated by Congress in enacting section 181(a) simply in order to allow areas to take 

advantage of federal and regional controls that will achieve continuing ozone reductions over 

many years. 

We acknowledge for each classification that Option 2 results in data from one later calendar year 

being used to determine compliance with the maximum attainment deadline than Option 1(for 

example, calendar year 2015 for Marginal areas). However, areas are required to attain the 

standard “as expeditiously as practicable,” so an area that can attain sooner than the maximum 

deadline is required to do so. 

23. Comment – EPA should not adopt Option 2 for determining the timing of attainment deadlines 

for classified areas because it will result in delays in areas reaching attainment with the 2008 

ozone NAAQS and endanger public health. 

A few commenters (0038, 0054, 0060) stated that EPA should not adopt Option 2 for 

determining the timing of attainment deadlines because it would result in further delays in areas 

being required to attain the 2008 ozone NAAQS. 

One commenter (0038) stated that adopting Option 2 would further delay the initial expedited 

implementation schedule proposed back on June 20, 2007 that would have resulted in 

designations in March 2010 , and consequently, there is already an effective delay of two years. 
42

The commenter stated that reducing that delay by using Option 1 will provide greater protection 

of public health. 

Another commenter (0060) stated that designations were due in March 2011 and attainment 

according to the CAA for Marginal areas would follow in three years (i.e., March 2014). The 

commenter (0060) explained that that scenario would have meant that attainment decisions 

would have been made on the basis of 2011-2013 ozone data. However, the commenter (0060) 

stated that EPA’s new schedule of finalizing designations by August 2012 means that there 

would be one full year delay from the mandatory CAA requirement. The commenter (0060) 

further reasoned that Option 2 would be based on ozone season data of 2013-2015 or an 

additional year delay beyond the prior one. The commenter (0060) stated that this is an 

unacceptable outcome and contrary to the CAA notion of meeting the NAAQS as expeditiously 

as practicable. 

Another commenter (0054) stated that EPA’s proposed approach also arbitrarily endangers 

public health. The commenter stated that one effect of extending the attainment date to the end 

of the calendar year is to delay reclassification of areas that fail to attain by the deadline, thereby 

also delaying the stronger anti-pollution protections that come with reclassification. The 

commenter (0054) stated that, in areas that continue to violate the standard, a delay of attainment 

from August to December will mean a delay of at least four months in the enhanced health 

protections mandated by the CAA, and there is no possible justification for this delay. The 

commenter (0054) stated that EPA needs to focus on expediting protection of people’s health, 

not on providing maximum leeway to the states. 

The commenter (0054) stated that EPA’s preferred approach would further violate the CAA by 

illegally delaying reclassification of areas that fail to attain within the outside timeframes 

specified in the Act, and that EPA’s approach would forestall the required reclassification by up 

to one year beyond the deadlines specified in the statute. 

23. EPA Response. 

As noted in response 22, EPA finds that option 2 (end of calendar year) is a reasonable approach 

because it provides areas with the same number of ozone seasons for attainment as provided for 

areas at the time of the 1990 CAA amendments. We also note that the CAA still requires all 

areas to attain the NAAQS “as expeditiously as practicable.” 

To the extent that commenters raise concerns about when designations should have been 

promulgated, we do not believe that is relevant for purposes of interpreting the maximum 

attainment dates Table 1 in section 181(a) for the subpart 2 classifications. In order to attain the 

NAAQS, areas classified as Moderate and higher will need to adopt additional local controls and 

will need sufficient time to adopt and implement such measures. We do not believe that we have 

the authority to shorten the time Congress intended to provide States for those activities because 

we did not issue designations within the time contemplated by the Act. We note that even 

though designations were delayed beyond the statutory timeframe, areas designated 

nonattainment for the 2008 ozone NAAQS continue to see reductions in ambient ozone 

concentrations due to benefits of federal and regional programs. Moreover, many of these areas 
43

are also designated nonattainment for the 1997 8-hour ozone NAAQS and are continuing to 

implement measures to meet that standard as expeditiously as practicable. Thus, it is unlikely 

that such areas could adopt and implement additional “practicable” measures to address ambient 

ozone concentrations in the short term. For these reasons, we do not agree that public health is 

not being adequately protected or that setting the maximum attainment date at the end of the 

calendar year will delay public health protection. To the extent any area fails to attain the 

standard by the maximum date for its initial classification for the 2008 ozone NAAQS, such area 

would be reclassified to a higher classification. Again, even after reclassification, areas remain 

obligated to attain as expeditiously as practicable. 

24. Comment – EPA should not adopt Option 2 for determining the timing of attainment deadlines 

for classified areas because EPA has no legal authority under the CAA to adopt Option 2. 

One commenter (0054) stated that EPA should not adopt Option 2 for determining the timing of 

attainment deadlines for classified areas because EPA has no legal authority to adopt Option 2. 

The commenter (0054) stated that the statute explicitly sets out attainment dates in terms of fixed 

time frames from enactment of the 1990 amendments, and from designation and classification of 

nonattainment areas. The commenter (0054) stated that the CAA does not allow EPA to extend 

these time frames by deferring the start of the statutory clocks to the end of the calendar year in 

which designation and classification occur. 

One commenter (0054) noted that EPA suggested that its approach is consistent with the 1990 

CAA amendments because those amendments made designations and classifications on the 

enactment date, November 15, 1990, thereby giving states a full ozone season in the attainment 

year before the attainment deadline. The commenter (0054) stated that the plain language of the 

statute, however, should control over EPA’s groundless attempt to infer meaning into the 

happenstance that the 1990 amendments were enacted in November instead of some other 

month. The commenter (0054) reasoned that Congress most certainly did not mean to stall the 

attainment deadlines to the end of the calendar years is further shown by the fact that (1) the 

attainment deadlines are “as expeditiously as practicable,” showing that Congress plainly 

contemplated that states would have to attain sooner than the outside dates in some cases and (2) 

Congress expressly provided in CAA§181(b) that areas initially designated “attainment” that 

were later redesignated “nonattainment” would have outside attainment dates stated as fixed 

numbers of years after their redesignation – regardless of when in the year that redesignation 

happened to occur. 

The commenter (0054) further stated that EPA’s rationale is further flawed because not all areas 

have a summertime ozone season. The commenter (0054) further explained that Wyoming, for 

example, suffers ozone violations in the winter, and EPA has also found evidence of wintertime 

ozone violations in Utah. The commenter (0054) stated that high ozone levels sometimes occur 

in Spring and Fall in Blount County, Tennessee, in the Great Smoky Mountains National Park, as 

shown in an attached data chart. The commenter (0054) further stated that, even in states where 

ozone is mostly a summertime problem, the ozone monitoring season often runs until October, or 

in some cases December. The commenter (0054) further stated that California and Arizona have 

year-round ozone monitoring requirements. The commenter (0054) concluded that for areas that 

experience ozone violations in January, February or March (or October, November or 
44

December), EPA’s rationale that an August attainment would be near the end of the ozone 

season is wholly unsupportable. 

24. EPA Response. 

We agree with the commenter that other provisions of the CAA, such as section 172(a)(2)(A) 

and 181(b) link the attainment date to the time of designation or reclassification. However, those 

provisions are not directly applicable here and thus are not controlling. As provided in previous 

responses, direct application of the attainment dates in Table 1 would produce an absurd result. 

Because direct application of the statute would produce an absurd result, EPA must interpret this 

provision for purposes of the 2008 ozone NAAQS. We do not believe that this gives the Agency 

broad discretion to establish attainment periods de novo. Instead, we must look to the statute and 

Congressional intent to discern a reasonable interpretation. For the reasons provided in 

Response 22, above, we believe it is reasonable to run the statutory periods for the 2008 ozone 

NAAQS from the end of calendar year 2012, which is the year in which the designations occur. 

We also recognize that not all areas have a summertime ozone season and some areas can have 

high ozone levels in early spring, late fall or even the winter. We believe that this further 

supports having the attainment date fall at the end of the calendar year. This will ensure that all 

areas will have three (or six, etc for Moderate and above) full ozone seasons after designation to 

achieve reductions necessary to attain the NAAQS, assuming that one or more areas cannot 

attain more expeditiously. 

We note that in making determinations of whether areas have actually attained under the 1-hour 

NAAQS for areas with year-round monitoring seasons, EPA did use December 31 of the 

attainment year (rather than the year prior to the deadline year) as the operative deadline. One 

example is Phoenix, AZ. In February 2000, the State of Arizona requested that EPA make a 

finding that the Phoenix metropolitan nonattainment area had attained the 1-hour ozone NAAQS 

by the applicable ‘‘Serious’’ area attainment date of November 15, 1999 based on 1997–1999 

ozone monitoring data. In May of 2000, we proposed such a finding (see 65 FR 31859, May 19, 

2000) and approximately one year later, we published a final attainment determination for the 1-

hour ozone NAAQS. See 66 FR 29230 (May 30, 2001). Similarly, EPA approved attainment 

demonstration SIPs for areas with year-round ozone seasons where such demonstrations 

supported attainment in the attainment year. See 62 FR 1150, January 8, 1997 and 65 FR 18903, 

April 10, 2000 for the approval and amended approval, respectively, of the SIP demonstrating 1-

hour ozone attainment for South Coast, San Diego, San Joaquin, Sacramento, Ventura and the 

Southeast Desert. 

Support for Option 2 and Opposition to adopting Option 1 

25. Comment – EPA should adopt Option 2 for determining the timing of attainment deadlines for 

classified areas. 

Many commenters (0018, 0019, 0020, 0021, 0022, 0023, 0024, 0025, 0026, 0028, 0029, 0030, 

0031, 0033, 0035, 0037, 0039, 0040, 0041, 0042, 0043, 0045, 0046, 0047, 0048, 0052. 0056, 
45

0057, 0055, 0061) supported adopting Option 2 for determining the timing of attainment 

deadlines for areas designated nonattainment and classified under subpart 2. 

Many commenters (0022, 0025, 0026, 0028, 0029, 0030, 0031, 0033, 0035, 0039, 0040, 0042, 

0043, 0045, 0046, 0047, 0056, 0057, 0061) stated that adopting Option 2 would ensure that 

there would be data for three full ozone seasons for Marginal areas (or 6 for Moderate, etc.) to 

utilize for attaining the standard. 

Many commenters (0018, 0019, 0023, 0028, 0039, 0040, 0041, 0043, 0045, 0046, 0057, 0061) 

stated that by providing the extra year of ozone data, EPA allows the full amount of time 

allocated in the CAA for implemented strategies and programs to impact ambient ozone 

concentrations. One commenter (0019) stated that allowing Marginal areas three full years after 

designation, and Moderate areas six full years after designation, to attain the standard will allow 

areas an additional year to benefit from rules already in place such as the Tier 2 Vehicle and 

Gasoline Sulfur Program and 2007 Heavy-Duty Highway Rule. One commenter (0018) 

specifically stated that Option 2 would provide a little more time for the emission reductions 

expected from CAIR and CSAPR to be considered. One commenter (0041) stated that it makes 

sense that ozone attainment deadlines account for emission reductions from the newest, cleanest, 

mobile sources purchased throughout the year as EPA continues to pursue cleaner emission 

standards for vehicles, trucks, and non-road mobile equipment, and it makes sense that 

monitored readings account for air quality improvements from such programs for as long as 

possible prior to attainment deadlines. 

Several commenters (0018, 0021, 0022, 0026, 0031, 0037, 0040, 0045, 0046, 0061) stated that 

the deadlines specified by Option 2 are most consistent with subpart 2 because it allows (for 

Marginal areas) three full ozone seasons after designation for attaining the NAAQS. One 

commenter (0055) further stated that Option 2 is consistent with the time periods provided for 

attainment of the 1-hour ozone NAAQS at the time the CAA was amended insofar as the 1990 

Amendments were enacted after the end of the ozone season for virtually all areas. The 

commenter (0055) further stated that subpart 2 does not limit EPA’s discretion in this regard by, 

for example, specifying that attainment deadlines for areas classified under subpart 2 always 

must be based on a “time period running from the effective date of designation.” With the datecertain attainment deadlines specified in Table 1 of subpart 2 no longer applicable, it cannot be 

said that “Congress has directly spoken to the precise question at issue” here (i.e., what are the 

attainment deadlines for the 2008 Ozone NAAQS?) or that the provisions of CAA §181 reflect 

“the unambiguously expressed intent of Congress” on that precise question. Chevron, U.S.A., 

Inc. v. Natural Res. Def. Council, Inc., 467 U.S. 837, 842-43 (1984). Thus, the commenter 

(0055) believes that EPA at a minimum has discretion to adopt its preferred option if that option 

“is a reasonable policy choice for the agency to make.” For the reasons discussed in the proposed 

rule, the commenter (0055) stated that EPA-preferred option is an eminently reasonable – 

indeed, the most reasonable – policy choice and should be adopted for any 2008 Ozone NAAQS 

nonattainment area. 
46

25. EPA Response. 

 EPA finds that option 2 (end of calendar year) is a reasonable approach because it provides 

areas with the same number of ozone seasons for attainment as provided for areas at the time of 

the 1990 CAA amendments. We also note that the CAA still requires all areas to attain the 

NAAQS “as expeditiously as practicable.” EPA acknowledges the commenters who believe that 

EPA should adopt Option 2 for determining the attainment deadlines for areas classified under 

CAA, Title I, Part 2, subpart 2. For the reasons explained in the prior responses EPA agrees that 

option 2 is reasonable and is adopting that approach. 

26. Comment –EPA should not adopt Option 1 for determining the timing of attainment deadlines 

for areas classified under CAA, title I, part D, subpart 2. 

Several commenters (0018, 0020, 0026, 0030, 0035, 0039, 0056) stated that they did not support 

the adoption of Option 1 for determining the attainment deadlines for areas classified under 

subpart 2. 

Commenters (0030, 0035, 0039) specifically stated that adopting Option 1 may disqualify air 

quality data from an area’s anticipated attainment year from being considered because ozone 

seasons often extend well beyond the month of August, and thus, the attainment determination 

for the area would have to be based on the prior three full years of air quality data, which might 

result in a finding of continued nonattainment when in fact the area has attained the standards. 

Commenters (0018, 0026, 0056) stated that adopting Option 1 would result in the scenario where 

Marginal areas would only have 2 full ozone seasons to reach attainment rather than the 3 years 

intended under the original classification approach outlined in the CAA. One commenter (0021) 

further stated that, for example, a Marginal nonattainment area with an August 15, 2015 

attainment deadline would need to use air quality data from 2012, 2013, 2014 ozone seasons to 

demonstrate attainment of the standard and would not be able to consider any air quality 

improvements that would occur after the 2014 ozone season and during 2015. 

One commenter (0039) further stated that significant new federal on-road emission reduction 

measures will take effect in 2014 and yield ozone reductions in 2015, and Marginal areas will 

not be able to take advantage of the impact of these reductions under the first option, which is 

particularly significant because EPA estimates that the vast majority of all nonattainment areas 

(43 out of 52) will be classified as Marginal. 

26. EPA Response. 

EPA acknowledges the concerns of the commenters who believe that EPA should not adopt 

Option 1 for determining the attainment deadlines for areas classified under CAA, Title I, Part 2, 

subpart 2. For the reasons explained in the prior response EPA agrees that option 2 is reasonable 

and is adopting that approach. 

While it is true that Option 2 would allow States to take credit for federal programs, such as 

federal on-road emission reductions, for one more year than would option 1 as provided in 
47

Response 22 above, we do not believe that this is a basis for adopting Option 2. Measures such 

as the on-road emission reduction program will get continuing emission reductions for many 

years to come and setting attainment deadlines to allow areas to rely on credit for such programs 

would result in deadlines significantly extended beyond the periods contemplated by Congress 

when it enacted Table 1 in Section 181. Thus, we do not think that relying on reductions from 

programs that are phased in over time would result in reasonable attainment dates in light of the 

general intent of Table 1 and the requirement that areas attain as expeditiously as practicable. 

 

Opposition to delaying the start of the attainment clock. 

27. Comment –EPA should not delay the start of the attainment clock until the “effective date” of the 

nonattainment designation. 

One commenter (0054) noted that adopting Option 1 would provide that the attainment date 

would be set as expeditiously as practicable, but not later than the applicable number of years 

after the “effective date” of the nonattainment designation of the area. The commenter (0054) 

stated that while Option 1 comes closer to complying with the statute than Option 2, Option 1 is 

unlawful because it delays the start of the attainment clock until the “effective date” of the 

nonattainment designation. The commenter (0054) stated that the CAA sets out attainment dates 

when areas are first designated nonattainment in terms of fixed time frames after “designation” 

or “classification,” not after the “effective date” of designation or classification. Moreover, the 

commenter (0054) stated that CAA §107 mandates that EPA “promulgate” designations within 

specified timeframes (all of which have passed for the 2008 ozone NAAQS, but does not allow 

EPA to “defer” such promulgations via the artifice of a “deferred” effective date. The 

commenter (0054) noted that the term “promulgate” means “to put into operation (e.g. a law, 

decree of court, etc.) by formal proclamation, and thus, Congress plainly contemplated that 

designations would become operative on the date that they were due. Further, the commenter 

(0054) stated that Congress expressly provide that ozone attainment clocks would start at the 

instant of enactment of the 1990 CAA amendments, and therefore, the time frames in Table 1 of 

subpart 2 were meant to start at the time that states were put on notice of the designations and 

classification. Consequently, the commenter (0054) stated that EPA has no legal authority to 

lengthen the time periods specified in Table 1 of subpart 2 by some additional time period 

equaling the time by which the agency has “deferred” the effective date of designations or 

classifications. 

27. EPA Response. 

We disagree with the commenter that the CAA mandates that attainment dates in subpart 2 must 

run from the date the designations are signed. As an initial matter, the attainment dates in 

subpart 2, as set forth in section 181(a), run a period of years from November 15, 1990, the date 

of enactment of the CAA Amendments of 1990. Thus, the language that the commenter relies on 

to support their position is not relevant. The language the commenter relies on is that in section 

172(a)(2)(A) in subpart 1, which specifies that the attainment date for areas subject only to the 

planning provisions of subpart 1 runs “from the date such area was designated nonattainment.” 

Although that provision is not applicable here, where all areas are classified under subpart 2, we 

note that this provision is not clear whether the attainment date must run from the date the 
48

designation is signed or is promulgated (i.e., signed and widely disseminated) or whether it runs 

from the effective date of the designations. This section uses neither the word “promulgate” nor 

the term “effective date,” leaving open for interpretation what the appropriate starting point is. 

We believe that provision can be reasonably interpreted to mean the effective date of the 

designations. And, we have historically interpreted it as such. See, 40 CFR 51.902, Table 1 

(specifying that the attainment periods in the Table for the 1997 ozone NAAQS are “years after 

the effective date of nonattainment designation”) see also 75 FR 71033 and 76 FR 72097 

(establishing the effective date of the designations for the lead NAAQS, which were signed on 

November 16, 2010 and November 8, 2011, as December 31, 2010 and specifying that the 

attainment date is December 31, 2015). 

However, in this case, the issue posed by the commenter is not raised since the ambiguous phrase 

“designated nonattainment” is not used in section 181(a) which instead specifies a precise date as 

the starting point. As provided in Response 22 above, direct application of that date for purposes 

of the 2008 ozone NAAQS would produce absurd results and we believe we have discretion to 

interpret the starting date for attainment periods specified in Table 1 in section 181(a) and have 

done so in a reasonable manner. 

Appropriateness of Deadlines due to Upwind Contributions 

28. Comment –The deadlines that EPA proposes for meeting the 2008 ozone NAAQS are not 

attainable due to upwind contributions to downwind nonattainment areas. 

One commenter (0020) specifically stated that it is not legal or equitable for EPA to require 

downwind areas to meet an attainment deadline when it is still being subjected to significant 

contributions from upwind, out-of-state sources. The commenter (0020) supported its position 

with a ruling from a 2008 case in the U.S. Court of Appeals for the D.C. Circuit20, which held 

that EPA must require the elimination of upwind emissions that contribute significantly to 

downwind nonattainment areas and that this elimination of emissions must be consistent with the 

attainment deadline established under Title I of the CAA. The commenter (0020) stated that 

EPA’s use of subpart 2 to make ozone classifications coupled with their proposal to classify most 

areas as “Marginal,” even when EPA has conducted analyses projecting that about half of these 

areas will not attain by the attainment deadline, clearly does not comply with the ruling because 

EPA has not proposed any methodology for determining significant contribution to 

nonattainment or interference with maintenance for the 2008 ozone NAAQS and it is impossible 

for prohibitions on upwind contributions to downwind nonattainment to occur consistent with the 

deadlines of Title I. 

The commenter (0020) stated that EPA should re-propose this classification rule, propose 

alternatives, and take comments on ways that EPA could ensure the requirement that prohibitions 

on upwind contributions to downwind nonattainment is consistent with the attainment deadlines 

that it is proposing in this action. 

 

20 The commenter did not cite the decision, but we presume the commenter was referring to a decision on EPA’s 

Clean Air Interstate Rule (CAIR) based on a suit filed by the State of North Carolina. North Carolina v. EPA, 531 

F. 3d 896 (DC Cir. 2008). 
49

28. EPA Response. 

We disagree with the commenter that the requirements in section 110(a)(2)(D), which require 

States to address the significant contribution of ozone and ozone precursor emissions to 

downwind states should drive the attainment dates, which are separately addressed in the statute. 

The North Carolina case to which the commenter refers held that in developing transport rules 

EPA must consider downwind attainment dates, not that in setting attainment dates EPA must 

consider upwind transport. EPA has revised its transport rules consistent with the court decision 

and considering the attainment dates for the NAAQS addressed in those rules. 

With regard to the comment that “about half” of the areas classified as Marginal will not attain 

the standard by the Marginal area attainment date, EPA notes that based on updated analyses, 

this estimate is more appropriately expressed as a range; 30-50% of Marginal areas may not 

attain based on emission reductions through 2015 (see response 5 above). Past history 

demonstrates that areas with design values close to the standards are able to attain in a short 

period due to a steady downward trend in NOx and VOC emissions due to ongoing emission 

reductions resulting from federal, regional, and state measures (e.g. emissions standards and fuel 

requirements on cars, trucks, and nonroad engines; NOx reductions from electric utilities and 

industrial sources). Congress recognized this in 1990 by providing Marginal areas three years to 

attain the standard and by not requiring significant additional planning or controls. However, 

Marginal areas must still ensure that they will attain as expeditiously as practicable. 

IV. Revocation of 1997 NAAQS 

Revocation of 1997 Ozone NAAQS for Purposes of Transportation Conformity 

Support for revocation of 1997 NAAQS with respect to transportation conformity. 

29. Comment –EPA should revoke the 1997 NAAQS for purposes of transportation conformity. 

Many commenters (0018, 0019, 0020, 0022, 0023, 0026, 0028, 0030, 0031, 0033, 0035, 0038, 

0043, 0047, 0049, 0052, 0056, 0061) supported revoking the 1997 NAAQS for purposes of 

transportation conformity. 

Several commenters (0018, 0026, 0028, 0030, 0038, 0043, 0047, 0061) stated that it was most 

logical to only have one ozone NAAQS, the more protective NAAQS, apply in situations 

because the confusion and complexity that may result from determining conformity with two 

ozone NAAQS is an unnecessary burden to place on these agencies performing conformity 

determinations. One commenter (0028) further stated that leaving two concurrent ozone 

standards in place would require it to prepare conformity determinations for two standards for 

the same pollutant across difference geographical boundaries since it expects a reduction in the 

total nonattainment area for the 2008 ozone standards, and it concurs with any EPA decision to 

remove conformity requirements for older, less stringent standards when new standards are 

designated. One commenter (0043) further stated this was consistent with Executive Order (EO) 

13563: Improving Regulation and Regulatory Review, aimed at the President’s belief that the 

U.S. regulatory system “must promote predictability and reduce uncertainty.” 
50

Several commenters (0018, 0019, 0043, 0061) stated that revoking the 1997 NAAQS for 

purposes of transportation purposes would reduce needless expense of state agency and local 

planning organization time and resources, and would allow states/local agencies to use scarce 

resources on other vital transportation needs. 

One commenter (0048) believes the proposal to revoke the 1997 ozone NAAQS for 

transportation conformity purposes only, may be beneficial but is incomplete and does not 

provide certainty for planning purposes. The commenter (0048) states that EPA’s position on 

whether to also revoke the 1997 NAAQS for other purposes should have been fully contained in 

this proposal and that this piecemeal approach is inefficient and counterproductive. 

One commenter (0033) added that enforcement of one NAAQS for transportation conformity is 

beneficial because it simplifies compliance and utilizes a more health protective standard. 

Some commenters (0035, 0049) stated that they supported ensuring against any backsliding 

relative to transportation conformity during the transition to the 2008 ozone NAAQS and 

supported the requirement that “areas designated nonattainment for the 2008 ozone NAAQS that 

have adequate or approved SIP budgets for either the 1997 ozone NAAQS or the 1-hour ozone 

NAAQS must continue to use such budgets in transportation conformity determinations until 

budgets for the 2008 ozone NAAQS are found adequate or approved. Another commenter (0030) 

stated they would be using the motor vehicle emission (MVE) budgets in their Early Progress 

Plan until the MVE budgets in their SIP for either the 1997 or 2008 standards are found adequate 

or the SIP is approved. 

29. EPA Response. 

EPA thanks the commenters for their support of this proposal. 

EPA understands the commenter’s concerns; however as stated in the proposal EPA did not 

include a broad proposal addressing revocation and anti-backsliding requirements for purposes 

besides transportation conformity because of the need to quickly finalize a rule that addresses 

nonattainment area classifications. The classification requirements must be finalized by the time 

that EPA designates nonattainment areas in order for areas to know their classification, the 

requirements that result from those classifications and their attainment date. EPA was able to 

move forward with this rulemaking concerning the revocation of the 1997 ozone NAAQS for 

transportation conformity purposes because the anti-backsliding requirements have already been 

clearly established, by the Clean Air Act, the transportation conformity rule and by the D.C. 

Circuit Court. (CAA section 176(c)(1), 40 CFR 93.109(c)(2), South Coast Air Quality 

Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006), and Environmental Defense v. 

EPA, 467 F3.d at 1329) EPA continues to anticipate that we will propose a separate rule in the 

spring of 2012 that will address how anti-backsliding requirements would apply if the 1997 

ozone NAAQS is revoked for other purposes. 
51

Opposition to revocation of 1997 NAAQS with respect to transportation conformity. 

30. Comment – EPA should not revoke the 1997 ozone NAAQS for purposes of transportation 

conformity for areas designated attainment for the 2008 NAAQS to prevent backsliding. 

One commenter (0032) recommended that EPA not drop current conformity requirements for 

areas that will be designated attainment for the 2008 NAAQS as this amounts to backsliding and 

could lead to greater levels of transported emissions. The commenter (0032) stated that in order 

to prevent backsliding, EPA should retain the existing requirements for those areas to 

demonstrate conformity with the 1997 ozone NAAQS for attainment areas. For areas that will be 

designated nonattainment with the 2008 ozone NAAQS, the commenter (0032) agreed with 

EPA’s proposal to require a conformity SIP budget for only one NAAQS, either the 1997 

NAAQS or a new budget for the 2008 NAAQS. 

Two commenters (0035, 0049) stated that they were concerned about the results regarding areas 

that were nonattainment under the 1997 ozone NAAQS but will be attainment under the 2008 

ozone NAAQS based on 2008 through 2010 data. The commenters (0035, 0049) stated that when 

the 1997 ozone NAAQS is revoked, attainment areas will not be required to do transportation 

conformity or have maintenance plans or mobile budgets. Both commenters (0035, 0049) stated 

that for areas likely to become nonattainment under the 2008 ozone NAAQS once 2011 or 2012 

data are considered, the transportation conformity requirement will not be reinstated until the 

area is redesignated nonattainment and required to develop its attainment SIP. The commenters 

(0035, 0049) stated that backsliding that could occur in the interim could adversely affect not 

only the area itself, but also downwind areas and recommended that EPA consider and address 

this issue. One of these commenters (0049) also stated that areas that are designated 

nonattainment for the 2008 ozone NAAQS and classified as Marginal would not be subject to 

transportation conformity. 

30. EPA Response. 

EPA disagrees with the comments recommending that the 1997 8-hour ozone NAAQS should 

not be revoked in areas that are designated attainment for the 2008 8-hour ozone NAAQS. We 

promulgated the 2008 8-hour ozone NAAQS in response to the latest data and science regarding 

ozone; the 2008 8-hour ozone NAAQS of 0.075 ppm is more protective of public health than the 

1997 8-hour ozone NAAQS which can be met if an area’s air quality is at 0.084 ppm. It is clear 

that any area that is designated attainment for the 2008 8-hour ozone NAAQS must also be 

attaining the less stringent 1997 8-hour ozone NAAQS because all attainment areas for the 2008 

8-hour ozone NAAQS must have design values of 0.075 ppm or less, even if they were not 

previously redesignated for the 1997 ozone NAAQS. Therefore, there will be no areas that are 

not attaining the 1997 8-hour ozone NAAQS but are attaining the 2008 8-hour NAAQS, as may 

have been the case when prior standards were revoked. Areas that are designated attainment for 

the 2008 8-hour ozone NAAQS would not be subject to transportation conformity because 

section 176(c)(5) of the Clean Air Act explicitly limits the applicability of conformity to 

designated nonattainment and maintenance areas. However, areas designated attainment still 

have an incentive to monitor the growth of emissions from the transportation sector; because if 

these areas violate the 2008 8-hour NAAQS, EPA could use its discretionary authority to 
52

redesignate them as nonattainment for the 2008 8-hour NAAQS and conformity would then 

apply one year after the effective date of that nonattainment designation. 

The EPA notes that although states could not implement transportation conformity for attainment 

areas as a matter of federal law, these areas could still work with their Metropolitan Planning 

Organizations (MPOs) to estimate regional emissions that would be generated by the planned 

transportation system to see whether a violation could occur and to address motor vehicle 

emissions growth in advance of any such violation.21 These types of state activities may be done 

under state law, when possible, or on a voluntary basis. EPA also notes that the continued 

implementation of motor vehicle emissions standards that apply to both light-duty and heavyduty vehicles would continue to reduce on-road emissions in future years and any revisions to 

state or local control programs, including controls that reduce emissions from on-road sources, 

that have previously been approved in an area’s ozone SIP would require EPA approval and 

must address the Clean Air act’s anti-backsliding requirements. 

Two commenters described concerns regarding attainment areas that may be redesignated as 

nonattainment for the 2008 8-hour ozone NAAQS if high concentrations occurred in 2011 or 

occur in 2012 and one of these commenters also expressed concerns with areas that are 

designated nonattainment for the 2008 8-hour ozone NAAQS, but are classified as Marginal. 

The commenters believe that there may be long delays before such areas would be required to 

demonstrate conformity and backsliding may occur in the areas and downwind of those areas. 

The commenters appear to be under the impression that Marginal nonattainment areas for the 

2008 ozone NAAS are not subject to transportation conformity requirements. This is incorrect. 

Marginal ozone areas are required to determine conformity for the 2008 ozone NAAQS. Such 

areas are required to make an initial transportation conformity determination for the 2008 ozone 

NAAQS within one year after the effective date of their nonattainment designation. That 

conformity determination must be based on the applicable conformity test (i.e., adequate or 

approved motor vehicle emissions budgets for the 1997 ozone NAAQS or one-hour ozone 

NAAQS if the area has such budgets or the applicable interim emissions test(s). (40 CFR 

93.109(c)(2) and (3)) With regard to attainment areas that are redesignated as nonattainment 

areas, such areas would be required to demonstrate conformity within one year after the effective 

date of the redesignation to nonattainment as opposed to when such an area develops its 

attainment SIP. Because a transportation conformity determination is required within one year 

of the redesignation rather than when the attainment SIP is developed it would minimize any 

 

21 Clean Air Act section 176(c)(5) restricts conformity to nonattainment areas and areas that are 

required to submit maintenance plans under section 175A; in these areas, the Federal 

government’s sovereign immunity is waived so that DOT can be required to make conformity 

determinations. The concept of sovereign immunity specifies that the federal government can 

only be subjected to regulation to the extent it voluntarily agrees to become subject. With respect 

to conformity, in the Clean Air Act, Congress has agreed that the federal government should be 

subject only one year after designation in areas designated nonattainment or previously 

designated nonattainment and redesignated to attainment subject to a 175A maintenance plan. 

Thus, sovereign immunity prevents the mandatory application of conformity requirements either 

prior to a year after designation or after revocation with respect to a given air quality standard.
53

potential for backsliding. Such areas would also have to use any prior budgets if they exist or 

use the interim emission tests. 

31. Comment – EPA should not revoke the 1997 ozone NAAQS for purposes of transportation 

conformity for the 2008 NAAQS to prevent backsliding. 

Several commenters (0050, 0060) stated that EPA should not revoke the 1997 ozone NAAQS for 

purposes of transportation conformity in order to prevent backsliding. 

Some commenters (0050, 0060) stated they are interested in ensuring against any backsliding 

related to transportation conformity during the transition to the 2008 ozone NAAQS, but that 

without a complete implementation rule it is not certain what backsliding provisions EPA intends 

to put in place to allay its concerns. Consequently, the commenters (0050, 0060) believe that 

EPA’s proposal to revoke the 1997 standard is premature and should not yet be done, and 

recommend EPA delay this proposed rule and instead re-propose it in the near future with the 

implementation rule, so that the transportation conformity issues can be evaluated carefully with 

through consideration of all related issues, in particular the necessary anti-backsliding 

provisions. 

31. EPA Response. 

EPA disagrees with the commenters’ recommendation that EPA should re-propose the 

revocation of the 1997 8-hour ozone NAAQS for transportation conformity purposes so that they 

can better determine if their concerns over the potential for backsliding are addressed in the 

context of a proposal that addresses all facets of the implementation of the 2008 8-hour ozone 

NAAQS. EPA continues to believe that the anti-backsliding requirements that apply to the 

transition from the 1997 8-hour ozone NAAQS to the 2008 8-hour ozone NAAQS are well 

established in the Clean Air Act, the transportation conformity rule and recent court decisions. 

(CAA section 176(c)(1), 40 CFR 93.109(c)(2), South Coast Air Quality Management District v. 

EPA, 472 F.3d 882 (D.C. Cir. 2006), and Environmental Defense v. EPA, 467 F3.d at 1329) 

Specifically, areas that are designated nonattainment for the 2008 ozone NAAQS are required to 

demonstrate conformity for that NAAQS using adequate or approved motor vehicle emissions 

budgets for the 1997 8-hour ozone NAAQS, or, if an area does not have budgets for the 1997 8-

hour ozone NAAQS, it would use adequate or approved budgets for the 1-hour ozone NAAQS, 

if available, until such time that motor vehicle emissions budgets for the 2008 ozone NAAQS are 

found adequate or are approved. If no such budgets exist the area would demonstrate conformity 

using the interim emissions tests. EPA intends to propose a broader implementation rule for the 

2008 8-hour ozone NAAQS in the spring of 2012. That proposal will address the revocation of 

the 1997 ozone NAAQS for other purposes and applicable anti-backsliding requirements for 

those purposes, but will not further address transportation conformity anti-backsliding issues as 

they are settled as discussed above. Those anti-backsliding requirements must be consistent with 

the Clean Air Act and Court decision in the South Coast case (South Coast Air Quality 

Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006)). 
54

32. Comment – EPA revocation of the 1997 ozone NAAQS for purposes of transportation 

conformity for the 2008 NAAQS is unlawful. 

One commenter (0054) stated that EPA’s proposed revocation of the 1997 ozone NAAQS for 

transportation conformity purposes is unlawful. The commenter (0054) stated that adoption of 

the 1997 standard triggered statutory attainment deadlines and control requirements (including 

transportation conformity requirements) for meeting that standard, and EPA has no authority to 

suspend those deadlines and requirements by fiat, and thus, EPA must hold states to meeting the 

1997 8-hour standard by the earlier attainment deadlines for that standard and require that 

transportation plans conform to attainment by those earlier deadlines (and related progress 

requirements). 

32. EPA Response. 

We disagree with the commenter’s assertions that the revocation of the 1997 ozone NAAQS is 

unlawful and that it relieves states of control measure, SIP or attainment obligations for the 1997 

8-hour ozone NAAQS. 

In this action EPA is revoking the 1997 ozone NAAQS for the purposes of transportation 

conformity only one year after the effective date of designations for the 2008 ozone NAAQS. 

This means that any areas that are currently designated as nonattainment or maintenance for the 

1997 8-hour ozone NAAQS will not be required to demonstrate conformity for that NAAQS 

beginning one year after the effective date of designations for the more health protective 2008 8-

hour ozone NAAQS. However, all of those areas which are designated nonattainment for the 

2008 8-hour ozone NAAQS will be required to make a conformity determination for that 

NAAQS by the effective date of the revocation or the area will enter a conformity lapse. The 

Clean Air Act, the transportation conformity rule and the South Coast and Environmental 

Defense court decisions all require that any area designated nonattainment for the 2008 8-hour 

ozone NAAQS that has either (1) approved or adequate motor vehicle emissions budgets for the 

1997 8-hour ozone NAAQS or (2) approved or adequate motor vehicle emissions budgets for 

the 1-hour ozone NAAQS (if the area has those but does not have adequate or approved budgets 

for the 1997 8-hour ozone NAAQS) must use those budgets in transportation conformity 

determinations until the state submits a SIP revision for the 2008 ozone NAAQS and EPA either 

finds the budgets in that SIP revision to be adequate for use in transportation conformity or 

approves the budgets as part of the SIP. (CAA section 176(c)(1), 40 CFR 93.109(c)(2), South 

Coast Air Quality Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006), and 

Environmental Defense v. EPA, 467 F3.d at 1329) When areas demonstrate conformity for the 

2008 8-hour ozone NAAQS using the motor vehicle emissions budgets from a SIP for the 1997 

8-hour or 1-hour ozone NAAQS, that determination must include an analysis that shows that the 

area conforms to all of the relevant motor vehicle emissions budgets. For example, if an area is 

classified as Severe for the 1997-hour ozone NAAQS with an attainment year of 2018 it would 

have adequate or approved rate of progress budgets for 2014 and 2017 and attainment budgets 

for 2018. A conformity determination for the 2008 8-hour ozone NAAQS would have to 

demonstrate that the area conforms to the budgets for each of those years as well as any years 

that would be required for the area based on its classification for the 2008 ozone NAAQS. If the 

area was also classified as Severe for the 2008 ozone NAAQS with an attainment year of 2027, 
55

conformity would have to be demonstrated for emissions in the attainment year by comparing 

emissions in that year with the area’s adequate or approved budget for 2018. The area would also 

at least have to demonstrate conformity for the last year of its transportation plan which could be 

a year such as 2035. A determination for that year would also use the adequate or approved 

budgets for 2018 from the area’s SIP for the 1997 8-hour ozone NAAQS. By determining 

conformity for each of the existing budgets for the 1997 8-hour ozone NAAQS the area not only 

demonstrates progress toward attainment of the more health protective 2008-hour ozone NAAQS 

until such time that it submits a SIP for that NAAQS, but it also demonstrates that motor vehicle 

emissions remain consistent with those necessary to make progress toward and attain the less 

protective1997 8-hour ozone NAAQS. 

Areas that are currently designated as nonattainment or maintenance for the 1997 8-hour ozone 

NAAQS, and are designated as attainment areas for the 2008 8-hour ozone NAAQS would not 

be required to demonstrate conformity for ozone beginning one year after the effective date of 

designations for the 2008 8-hour ozone NAAQS. These areas would have air quality data 

showing that they attain both the 1997 and 2008 8-hour ozone NAAQS. Revoking the 1997 8-

hour ozone NAAQS in these areas does not relieve these areas of any statutory obligations for 

attaining the 1997 8-hour ozone NAAQS because such areas would have already attained that 

NAAQS. 

This action addresses revocation for transportation conformity purposes only. No requirements 

of an area’s SIP nor obligations related to attainment of the 1997 8-hour ozone NAAQS will be 

altered by revocation of the 1997 NAAQS for transportation conformity purpose only. EPA 

intends to propose a separate implementation rule this spring which will address all other 

requirements for implementing the 2008 8-hour ozone NAAQs and making the transition from 

the 1997 8-hour ozone NAAQS to the 2008 8-hour ozone NAAQS. This proposal would address 

revocation of the 1997 8-hour ozone NAAQS for other purposes, anti-backsliding requirements 

for the transition from the 1997 to 2008 8-hour ozone NAAQS and any SIP obligations for the 

1997 8-hour ozone NAAQS. This future rulemaking would be consistent with Clean Air Act 

requirements and the decision in the South Coast lawsuit. (South Coast Air Quality Management 

District v. EPA, 472 F.3d 882 (D.C. Cir. 2006)) 

33. Comment – EPA’s revocation of the 1997 ozone NAAQS for purposes of transportation 

conformity for the 2008 NAAQS is arbitrary and irrational. 

One commenter (0054) stated that EPA’s proposed revocation of the 1997 ozone NAAQS for 

purposes of transportation conformity for the 2008 NAAQS is arbitrary and irrational. The 

commenter (0054) reasoned that having determined that ozone is even more dangerous than was 

thought in 1997, EPA cannot plausibly claim that states should be allowed to do less than was 

required to meet the 1997 ozone NAAQS, or be allowed more time to limit transportation-related 

pollution than is necessary to timely achieve that standard. The commenter (0054) noted that 

EPA asserts that the proposal is justified to provide transportation and air quality agencies with 

certainty as to what conformity requirements will apply after designations for the 2008 standard, 

but that is hardly a rational ground for revoking the 2008 standard. The commenter (0054) stated 

that equal or greater certainty would be achieved by telling those agencies that they must assure 
56

conformity with both standards within the relevant time frames for progress toward and 

attainment of each. Further, the commenter (0054) stated that also groundless is EPA’s claim that 

requiring conformity determinations for both standards would lead to “unnecessary complexity,” 

as there is no reason transportation and air agencies cannot perform conformity analyses for two 

ozone standards: Indeed, such agencies routinely perform conformity analyses for multiple 

pollutants with differing progress schedules and attainment dates. The commenter (0054) further 

stated that there is no reason that planning agencies cannot line up attainment dates by working 

to meet all standards by the earlier deadlines. 

33. EPA Response. 

EPA disagrees with the commenter’s assertion that EPA is giving states more time to reduce 

transportation related emissions to attain the less protective 1997-hour ozone NAAQS and that it 

is allowing states to do less to attain that NAAQS. EPA is revoking the 1997 8-hour ozone 

NAAQS for transportation conformity related purposes only in this action. This revocation does 

not relieve the states of any obligation to implement their SIPs for the 1997 8-hour ozone 

NAAQS. It simply means that areas will not have to determine conformity for the 1997 8-hour 

ozone NAAQS beginning one year after the effective date of designations for the more protective 

2008 8-hour ozone NAAQS. If an area is designated as nonattainment for the 2008 8-hour ozone 

NAAQS and has adequate or SIP approved motor vehicle emissions budgets for the 1997 8-hour 

ozone NAAQS those areas are required by the Clean Air Act, the transportation conformity rule 

and recent D.C. Circuit decisions to use those budgets in conformity determinations for the 2008 

8-hour ozone NAAQS until a SIP is submitted for the 2008 8-hour ozone NAAQS and motor 

vehicle emissions budgets are found to be adequate for transportation conformity purposes or are 

approved into the SIP. (CAA section 176(c)(1), 40 CFR 93.109(c)(2), South Coast Air Quality 

Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006), and Environmental Defense v. 

EPA, 467 F3.d at 1329) 

If an area is designated as attainment for the 2008 8-hour ozone NAAQS, it would have also by 

definition attained the less health protective 1997 8-hour ozone NAAQS. Therefore, revocation 

would have the effect of relieving these areas of the obligation to demonstrate conformity for any 

ozone NAAQS. However this is because the Clean Air Act bars EPA from requiring that 

attainment areas demonstrate conformity. (Clean Air Act section 176(c)(5)) Therefore, EPA 

cannot require that areas designated attainment demonstrate conformity for the more protective 

2008 8-hour ozone NAAQS. With regard to the 1997 8-hour ozone NAAQS, such areas would 

have attained that NAAQS by a fairly wide margin because in order to be designated as an 

attainment area for the 2008 8-hour ozone NAAQS the area must have a design value of 75 ppb 

or less and the 1997 8-hour ozone NAAQS can be met with air quality at 84 ppb. Moreover, 

while these areas would no longer have to demonstrate conformity for the 1997 ozone NAAQS 

and cannot be required to demonstrate conformity for the 2008 8-hour ozone NAAQS, nothing in 

this action relieves them of any statutory obligation to implement their approved SIPs for the 

1997 8-hour ozone NAAQS. Any revisions to those SIPs would have to comply with Clean Air 

Act requirements that prevent backsliding. EPA intends to issue a notice of proposed 

rulemaking (NPRM) in the spring of 2012 that addresses all other implementation requirements 

for the 2008 8-hour ozone NAAQS. This would include revocation for other purposes, 
57

associated anti-backsliding requirements and any remaining obligations for the 1997 8-hour 

ozone NAAQS. 

With regard to the commenter’s statement that EPA justifies the revocation of the 1997 8-hour 

ozone NAAQS based on it bringing more certainty to the transportation and air quality planning 

process, this was not EPA’s only reason for proposing to revoke the less health protective 1997 

8-hour ozone NAAQS. EPA maintains and a number of commenters agree that the proposed 

revocation does bring more certainty to the transportation planning process because it allows 

areas to be aware of the specific transportation conformity requirements that will apply at the 

earliest possible time. The commenter implies that this was EPA’s sole justification for the 

revocation; however, as explained in the proposed rule, it was not. EPA also proposed the 

revocation because the anti-backsliding requirements that apply to transportation conformity are 

well established as described elsewhere in this response to comments document. Furthermore, 

areas that are designated nonattainment for the 2008 ozone NAAQS will be required to 

determine conformity for that NAAQS and will be required to use adequate or approve motor 

vehicle emissions budgets for the 1997 ozone NAAQS until they have adequate or SIP approved 

budgets for the 2008 8-hour ozone NAAQS according to the existing transportation conformity 

regulation. We maintain and the DC Circuit has agreed that this is the most appropriate test to be 

used in determining conformity for a revised NAAQS until budgets for the new NAAQS are 

available. (South Coast Air Quality Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006), 

and Environmental Defense v. EPA, 467 F3.d at 1329) As stated in the proposal, determining 

conformity for the more health protective 2008 8-hour ozone NAAQS both fulfills the Clean Air 

Act requirements to prevent new violations of the NAAQS, to avoid making existing violations 

worse and to avoid delaying timely attainment of the ozone NAAQS and any required interim 

milestones. (Clean Air Act section 176(c)(1)(B)(i)-(iii)) As for commenters that support the 

revocation of the 1997 ozone NAAQS for transportation conformity purposes indicate it also 

serves to make the most efficient use of state and local resources in fulfilling those requirements. 

The commenter states that equal or greater certainty could be achieved by determining 

conformity for both the 1997 and 2008 8-hour ozone NAAQS. As described in the example 

provided above in response to one of this commenter’s other comments, for an area that is 

designated nonattainment for the 1997 ozone NAAQS and has a nonattainment date in the future 

the conformity rule’s requirements for using budgets for the 1997 8-hour ozone NAAQS until 

adequate or approved budgets for the more protective 2008 8-hour ozone NAAQS are available 

shows that emissions in the area remain consistent with those needed for rate of progress and 

attainment purposes established in the area’s SIP for the 1997 8-hour ozone NAAQS. Such an 

area as shown in the example has to use all of its future year budgets (i.e., rate of progress and 

attainment) until the area has adequate or approved budgets for the 2008 8-hour ozone NAAQS. 

Once budgets for the more protective 2008 8-hour ozone NAAQS are available, the budgets for 

the prior NAAQS no longer apply, as the area has established its plan for how to come into 

attainment for the more protective NAAQS. 

The commenter further asserts that areas can continue to determine conformity for the 1997 

ozone NAAQS because MPOs already determine conformity for multiple pollutants with 

differing requirements and attainment dates. EPA agrees that some MPOs are located in 

nonattainment or maintenance areas for multiple pollutants and each may have unique attainment 
58

or maintenance years and differing boundaries. However, EPA disagrees that this is a reason for 

continuing to determine conformity for two ozone NAAQS. The commenter should recognize 

that where MPOs are determining conformity for different NAAQS, each of those NAAQS 

provides its own independent health protection and it is important to demonstrate conformity for 

each to ensure that the SIP for each of these pollutants achieves its purpose. However, EPA does 

not agree that this is a justification for requiring conformity determinations for two ozone 

NAAQS after the end of the one-year grace period, particularly considering that the 2008 8-hour 

ozone NAAQS is more protective. EPA does not believe that areas should be required to 

continue to determine conformity for the less health protective 1997 ozone NAAQS as well as 

the now applicable standard. 

Finally, the commenter suggests that areas could line up attainment dates so that they could 

attain both standards by the earlier deadline. However, this is neither required by the Clean Air 

Act nor is it feasible. First, the majority of areas that are nonattainment or maintenance for the 

1997 8-hour ozone NAAQS have attainment dates that are in the past. (A number of areas that 

are still officially designated as nonattainment for the 1997 8-hour ozone NAAQS have clean 

data but have either elected not to seek redesignation or are in the process of doing so. Two 

areas that missed their attainment dates, Dallas and Baltimore, have been bumped up to a higher 

classification.) It would be impossible for these areas to line up attainment dates for the 1997 

and 2008 ozone NAAQS due to the unique air quality challenges in each of these areas. While 

areas are required to attain the NAAQS as expeditiously as practicable, EPA cannot compel an 

area to attain a more stringent NAAQS by an earlier deadline for a less stringent NAAQS. 

34. Comment – EPA should not revoke the 1997 ozone NAAQS for purposes of transportation 

conformity because the 1997 ozone NAAQS requires compliance with NAAQS in ways not yet 

required by the 2008 ozone NAAQS. 

One commenter (0054) stated that EPA should not revoke the 1997 ozone NAAQS for purposes 

of transportation conformity because the 1997 ozone NAAQS requires compliance with the 

NAAQS in ways not required by the 2008 ozone NAAQS. Specifically, the commenter (0054) 

stated that EPA’s proposal does not in fact ensure conformity with the 2008 ozone NAAQS with 

anything like the accuracy or certainty required at this juncture for the 1997 ozone NAAQS. The 

commenter (0054) explained that EPA is apparently planning to allow states to claim conformity 

with the 2008 ozone NAAQS based on an “adequacy” showing (due one year after 

nonattainment designation) that does not require full attainment or rate-of-progress 

demonstrations and that does not require actual motor vehicle emission budgets for the 2008 

standard. The commenter (0054) explained that, in contrast, by now, the CAA requires motor 

vehicle emission budgets – based on approved rate-of-progress and attainment demonstrations - 

to be in place for any area that is nonattainment or maintenance for the 1997 ozone NAAQS, and 

to be sufficient to assure attainment by the applicable attainment date for the 1997 ozone 

NAAQS. In addition, the commenter (0054) stated that it appears that EPA is proposing to allow 

areas that are nonattainment or maintenance for the 1997 standards and that lack fully approved 

and sufficient motor vehicle emission budgets (based on the progress and attainment deadlines 

for their relevant classification for the 1997 standard) to be relieved of any requirement to 

prepare and secure approval for such budgets once the 1997 standard is revoked. The commenter 

(0054) reasoned that, as a result of all the foregoing, EPA’s proposal will weaken protections 
59

required under the 1997 ozone NAAQS for residents of areas that are nonattainment or 

maintenance for the 1997 ozone NAAQS, flouting both the anti-backsliding directives of 

CAA§172(e). 

34. EPA Response. 

The commenter alleges that the proposal will not ensure conformity for the 2008 8-hour ozone 

NAAQS because the proposal will allow conformity determinations for the 2008 8-hour ozone 

to be based on an “adequacy” showing which is due one year after the effective date of the 

area’s designation rather than on a SIP for the 2008 ozone NAAQS. EPA does not understand 

what the commenter is referring to as an “adequacy” showing. We reiterate that areas that are 

designated nonattainment for the 2008 ozone NAAQS are required by the Clean Air Act, the 

transportation conformity rule and the recent DC Circuit court decisions to determine conformity 

for the 2008 ozone NAAQS by using adequate or SIP approved budgets for the 1997 8-hour 

ozone NAAQS (or 1-hour ozone NAAQS if the area has those but not budgets for the 1997 8-

hour ozone NAAQS) until such time as the area has adequate or SIP approved budgets for the 

2008 8-hour ozone NAAQS. (CAA section 176(c)(1), 40 CFR 93.109(c)(2), South Coast Air 

Quality Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006), and Environmental 

Defense v. EPA, 467 F3.d at 1329)This was the outcome of the DC Circuit court decision in the 

South Coast case and the DC Circuit case on the transportation conformity rule. (South Coast Air 

Quality Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006) and Environmental Defense 

v. EPA, 467 F3.d at 1329)). This has been judged to be the best test of conformity for these 

areas until a SIP for the revised NAAQS is submitted and motor vehicle emissions budgets are 

found adequate or are approved. If an area does not have any existing motor vehicle emissions 

budgets for any ozone NAAQS, the area would be required to demonstrate conformity using the 

applicable interim emissions test(s). (40 CFR 93.109(c)(3)) In addition, areas are required to 

determine conformity for the new NAAQS within one year after they are designated 

nonattainment or they enter a conformity lapse which greatly restricts the types of transportation 

projects they can fund. EPA maintains and the DC Circuit court agrees that the best test of 

conformity before an area has budgets for a revised NAAQS is to use budgets for the prior 

NAAQS if an area has such budgets. 

The commenter states nonattainment areas for the 1997 8-hour ozone NAAQS are already 

required to have approved motor vehicle emissions budgets from rate of progress plans and 

attainment demonstrations, and that EPA is not requiring that motor vehicle emissions budgets 

for the 2008 8-hour ozone NAAQS be used in the initial conformity determinations for the 2008 

8-hour ozone NAAQS. EPA agrees that many areas that are still designated nonattainment for 

the 1997 8-hour ozone NAAQS have adequate or approved motor vehicle emissions budgets for 

the 1997 8-hour ozone NAAQS which must continue to be used for conformity determinations 

for the 2008 NAAQS as described above. There are reasons that some remaining nonattainment 

areas do not yet have adequate or approved budgets. Some areas received clean data 

determinations and under that rule the requirement for these areas to submit plans such as rate of 

progress plans or attainment demonstrations is suspended as long as the area continues to have 

clean data. Areas that are classified as Marginal are not required to submit rate of progress or 

attainment demonstrations. 
60

In addition, as already described in the responses to this commenter’s comments these budgets 

for the 1997 8-hour ozone NAAQS must be used in transportation conformity determinations for 

the 2008 8-hour ozone NAAQS until a SIP is submitted for the 2008 8-hour ozone NAAQS and 

EPA finds the budgets in that SIP to be adequate for use in transportation conformity 

determinations or approves those budgets. The initial conformity determination for the 2008 

ozone NAAQS is due within one year after the effective date of an area’s designation. SIPs that 

would establish motor vehicle emissions budgets for the 2008 ozone NAAQS are generally due 

three years after the effective date of an area’s designation and conformity for the 1997 8-hour 

ozone NAAQS continues to apply until the end of the one-year grace period in areas that are 

currently nonattainment or maintenance for the 1997 8-hour ozone NAAQS. Therefore, it would 

not be possible to demonstrate conformity for the 2008 8-hour ozone NAAQS by the end of the 

Clean Air Act’s one year grace by using motor vehicle emissions budgets for the 2008 8-hour 

ozone NAAQS. As stated previously in the response to these comments using the budgets for 

the prior ozone NAAQS is, until budgets for the current ozone NAAQS are available, is the best 

test of conformity and is consistent with the Clean Air Act, transportation conformity rule and 

decisions from the DC Circuit Court. (CAA section 176(c)(1), 40 CFR 93.109(c)(2), South Coast 

Air Quality Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006), and Environmental 

Defense v. EPA, 467 F3.d at 1329) 

The commenter also stated that it appears that EPA is proposing to allow areas that are 

nonattainment or maintenance for the 1997 8-hour ozone NAAQS and that lack fully approved 

and sufficient motor vehicle emission budgets (based on the progress and attainment deadlines 

for their relevant classification for the 1997 8-hour ozone NAAQS ) to be relieved of any 

requirement to prepare and secure approval for such budgets once the 1997 8-hour ozone 

NAAQS is revoked. EPA must point out that maintenance areas for the 1997 8-hour ozone 

NAAQS have attained that NAAQS otherwise they could not have been redesignated. These 

areas all have approved motor vehicle emissions budgets that are consistent with their approved 

maintenance plans. With regard to nonattainment areas for the 1997 8-hour ozone NAAQS, this 

rulemaking does not address whether or not these areas would have to submit SIPs for the 1997 

8-hour ozone NAAQS or whether EPA would have to act on submitted SIPs for the 1997 8-hour 

ozone NAAQS after that NAAQS is revoked. The requirements with regard to the submittal of 

outstanding SIPs for the 1997 8-hour ozone NAAQS will be addressed in the upcoming proposal 

for the remainder of the implementation requirements for the 2008 8-hour ozone NAAQS. 

Requirements for EPA to act on submitted SIPs are governed by the Clean Air Act and this 

rulemaking does not alter those requirements. 

EPA disagrees with the assertion that EPA’s proposal will weaken protections required under the 

1997 ozone NAAQS for residents of areas that are nonattainment or maintenance for the 1997 

ozone NAAQS. The revocation of the 1997 ozone NAAQS for transportation conformity 

purposes will not weaken the protection provided to residents of areas that are either 

nonattainment or maintenance for the 1997 ozone NAAQS precisely because it is consistent with 

Clean Air Act anti-backsliding requirements. This was the subject of two court cases decided by 

the DC Circuit court and these affirmed that EPA can revoke a NAAQS if it provides adequate 

anti-backsliding requirements and that those requirements for transportation conformity purposes 

are that budgets for the prior NAAQS be used in transportation conformity determinations until 

budgets for the new NAAQS are submitted and are found adequate or are approved, and that 
61

conformity for a revoked standard is not required after revocation. (South Coast Air Quality 

Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006), and Environmental Defense v. 

EPA, 467 F3.d at 1329) With regard to the remaining anti-backsliding requirements for the 2008 

ozone NAAQS, EPA intends to address those in a proposal that will be issued this spring. Those 

requirements must be consistent with the Clean Air Act and the DC Circuit court’s decision in 

the South Coast litigation. (South Coast Air Quality Management District v. EPA, 472 F.3d 882 

(D.C. Cir. 2006)) 

Effect of revocation of transportation conformity requirements on other programs. 

35. Comment –EPA should consider the effect of revoking transportation conformity requirements 

on potential future year Congestion Mitigation and Air Quality fund allocations. 

Several commenters (0019, 0022, 0048) expressed concern on the effect of the revocation of the 

1997 NAAQS for purposes of transportation conformity on Congestion Mitigation and Air 

Quality (CMAQ) fund allocations. 

One commenter (0019) specifically urged EPA, in collaboration with the Federal Highway 

Administration (FHWA), to consider the effect of the revocation on potential future year CMAQ 

fund allocations for areas that were designated nonattainment or maintenance under the 1997 

Ozone NAAQS, but will be designated attainment under the 2008 ozone NAAQS. The 

commenter (0019) stated that funding is an integral part of many jurisdictions’ future year 

transportation plans and funds a wide array of very beneficial programs. The commenter (0019) 

further stated that if such areas cannot continue to receive CMAQ funds, EPA should work with 

FHWA to ensure that jurisdictions are eligible to receive allotments at least three to five years 

into the future. The commenter (0019) stated that this transitional period would allow 

Metropolitan Planning Organizations (MPOs) time to determine which projects and programs 

must be continued and to determine alternative funding sources for those projects and programs. 

The commenter (0019) stated that in these difficult fiscal times where many MPOs have less 

money with which they need to do more, making such decisions about which programs to keep 

and which to fund as well as finding new funding mechanisms will require a great deal of 

planning and analysis. 

One commenter (0048) explained that CMAQ funds are apportioned annually to each state 

according to the severity of its ozone and carbon monoxide (CO) problem, where the population 

of each county that is in a nonattainment or maintenance area for ozone and/or CO is weighted 

by multiplying by the appropriate factor, but that PM nonattainment and maintenance areas and 

former 1-hour areas are not included in the apportionments, except for areas participating in 

Early Action Compacts (EACs).” The commenter (0048) stated that given that South Carolina 

led the nation in forming EACs in 45 of the state’s 46 counties, it is concerned with the issue of 

how classification designations and/or revocation of previous NAAQS may affect the 

distribution of CMAQ funds in the future. 

One commenter (0022) specifically stated that while the potential loss of CMAQ funds is a 

looming concern for maintenance areas that will be in attainment under the new standard, the 
62

CMAQ funding effects of a full revocation of the 1997 ozone standard will not be understood 

until after the reauthorization of the federal transportation bill by Congress. 

35. EPA Response. 

Revocation of the transportation conformity requirements will not affect the amount of CMAQ 

funds apportioned to the States. The eligibility requirements and the apportionment formula for 

distributing CMAQ funds to the States is established by the Safe, Accountable, Flexible, 

Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU).22 Funds for the 

CMAQ program are appropriated yearly, and apportioned to the States according to the statutory 

formula, which includes the population of counties in CO and ozone nonattainment and 

maintenance areas, and weighting factors for the severity of CO and ozone air pollution in those 

areas. Since this action revokes only the conformity requirements for the 1997 ozone 

nonattainment and maintenance areas, and does not change the designation and classification of 

areas, this action has no effect on the apportionment of CMAQ funds to the States. 

CMAQ apportionment may be changed by a full revocation of the 1997 ozone standard and 

designation and classification under the 2008 ozone standard. Any such impact is unknown at 

this time due in part to the fact that SAFETEA-LU reauthorization is being considered by 

Congress at this time and changes could be made to the CMAQ program which could further 

affect the amount of funds received by the States. 

36. Comment – If the proposed rule is finalized the CMAQ fund should not be continued to areas 

that are in attainment or to Ozone Advance areas. 

One commenter (0049) stated that under the proposed PATS approach, the Baltimore area will 

become one of only a handful of areas classified as Moderate and will need to find additional 

local reductions to incorporate into a SIP. The commenter (0049) stated that since transportation 

emissions remain a significant portion of the emissions causing the problem, it will need 

additional emission reductions from this sector. The commenter (0049) stated that without 

additional controls expected in the near term and considering the expense of travel demand 

measures, it does not support continuation of CMAQ funds to areas that become attainment or to 

Ozone Advance areas. The commenter (0049) reasoned that since these areas are not 

nonattainment or maintenance, the limited pool of CMAQ dollars should not be stretched to 

include them, and that areas with continuing problems or more severe problems should receive 

additional funds if they are available. 

36. EPA Response. 

This issue is not related to Clean Air Act transportation conformity requirements. The eligibility 

requirements and the apportionment formula for distributing CMAQ funds to the States is 

established by the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy 

for Users (SAFETEA-LU). CMAQ eligibility and CMAQ apportionments are two different 

things. CMAQ apportionments of funds to the States are calculated based on the population and 

severity of air pollution in the nonattainment and maintenance areas that exist at the time of 

 

22 Pub. L. 109-59, 119 Stat. 1144 (Aug. 10, 2005 
63

apportionment. Areas that are no longer designated and classified because the 1997 8-hour ozone 

NAAQS is revoked are not included in the apportionment formula. However, States have 

flexibility in how they direct the CMAQ funds they receive to eligible areas. The former 

nonattainment and maintenance areas are eligible under SAFETEA-LU and therefore could 

receive CMAQ funds from the State, but the State is under no obligation to do so. If the State 

decided to do so, it could invest its CMAQ funds entirely in areas designated and classified 

under the 2008 ozone standard. 

CMAQ apportionment may be changed by a full revocation of the 1997 ozone standard and 

designation and classification under the 2008 ozone standard. Any such impact is unknown at 

this time due in part to the fact that SAFETEA-LU reauthorization is being considered by 

Congress at this time and changes could be made which could affect the apportionment formula 

and the geographic eligibility criteria for CMAQ funds. 

Implementation of transportation control measures. 

37. Comment –EPA should address timely implementation of transportation control measures 

(TCMs). 

One commenter (0030) stated that timely implementation of transportation control measures 

(TCMs), a part of the transportation conformity process, is not addressed in the proposed rule. 

The commenter (0030) stated that this requirement should be clarified with respect to revocation 

of the 1997 ozone standards, especially when the revocation occurs before ozone SIPs for the 

2008 are approved. The commenter (0030) questioned whether the TCMs in an approved SIP 

for the 1997 ozone standards are subject to timely implementation after the 1997 ozone standards 

are revoked for conformity purposes, and sought clarification from EPA on this issued to be 

provided in future rulemaking or guidance documents. 

37. EPA Response. 

Timely implementation of transportation control measures is required by the Clean Air Act as 

part of an area’s transportation conformity determination and as a matter of SIP implementation 

requirements. (Clean Air Act section 176(c)(2)(B)) The transportation conformity rule contains 

specific requirements for demonstrating that TCMs are being implemented on a timely basis for 

transportation conformity purposes. (40 CFR 93.113) However, these requirements also apply to 

TCMs that are contained in approved SIPs as a matter of Clean Air Act SIP requirements. 

Therefore, any TCMs that are approved as part of an area’s SIP for the 1997 8-hour ozone 

NAAQS remain subject to timely implementation requirements even after the 1997 ozone 

NAAQS is revoked. Revocation of the NAAQS does not change any of the elements of an 

area’s approved SIP for the NAAQS that is being revoked. If an area wishes to remove an 

approved TCM from its SIP and replace it with a TCM or TCMs that provide equal emissions 

reductions it could make use of the Clean Air Act’s TCM substitution mechanism. (Clean Air 

Act section 176(c)(8)) However, if an area wishes to remove a TCM from an approved SIP and 

not replace it, the area must go through a SIP revision process and demonstrate that backsliding 

does not occur. 
64

Revocation of the 1997 Ozone NAAQS for General Conformity. 

Support for revocation of 1997 NAAQS with respect to General Conformity. 

38. Comment – EPA should clearly indicate that in a separate action that EPA propose a rule to 

address the revocation of the 1997 ozone NAAQS for general conformity purposes. 

One commenter (0036) stated that the proposed rulemaking addresses the revocation of the 1997 

ozone NAAQS for transportation conformity purposes but does not propose to revoke the 1997 

ozone NAAQS for general conformity purposes. The commenter (0036) explained that all 

Department of Defense (DoD) conformity analyses have been done under the general conformity 

rule and not under transportation conformity, and if the implementation of the 2008 ozone 

NAAQS does not include revocation of the 1997 ozone NAAQS for general conformity 

purposes, then DoD and other federal agencies would be subject to satisfying general conformity 

requirements for both the 1997 and 2008 ozone NAAQS. The commenter (0036) stated that 

while EPA is likely to address revocation of the 1997 ozone NAAQS for general conformity 

purposes in its follow-up rulemaking to complete the implementation of the 2008 ozone 

NAAQS, the commenter (0036) believes that it is necessary that it be explicitly mentioned in the 

preamble of this final rule due to the importance of this issue to DoD. 

38. EPA Response. 

The 1997 ozone NAAQS is being revoked for transportation conformity due to the fact that 

implementation of the 2008 NAAQS triggers a requirement for a new transportation conformity 

requirement within one year, unlike for general conformity. There are no new requirements for 

demonstrating general conformity of a federal action that is nonattainment or maintenance under 

the 1997 ozone NAAQS when it is designated under the 2008 ozone NAAQS. For ozone, 

general conformity cannot be demonstrated using modeling. Generally, an emissions test 

offsetting or mitigating net emissions increases to zero would be no different under either 

standard. EPA does not anticipate that two conformity determinations would be needed. Only 

one demonstration to the applicable SIP is required. The 2008 ozone classification may be lower 

than the 1997 ozone classification for some areas, in these cases the applicability thresholds are 

higher and a general conformity determination may not be required. Revocation of the 1997 

ozone NAAQS for purposes other than transportation conformity will be addressed in a 

subsequent rulemaking and the EPA plans to address any relevant comments in that action. 
65

Revocation of the 1997 Ozone NAAQS for Other Purposes. 

 Support for revocation of 1997 NAAQS for other purposes. 

39. Comment –EPA should revoke the 1997 ozone NAAQS for other purposes. 

One commenter (0048) stated that EPA’s proposal to revoke the 1997 ozone NAAQS for 

transportation conformity purposes only may be beneficial but is incomplete and does not 

provide certainty for planning purposes. 

39. EPA Response. 

EPA understands the commenter’s concerns; however as stated in the proposal EPA did not 

include a broad proposal addressing revocation and anti-backsliding requirements for purposes 

besides transportation conformity because of the need to quickly finalize a rule that addresses 

nonattainment area classifications. The classification requirements must be finalized by the time 

that EPA designates nonattainment areas in order for areas to know their classification, the 

requirements that result from those classifications and their attainment date. EPA was able to 

move forward with this rulemaking concerning the revocation of the 1997 ozone NAAQS for 

transportation conformity purposes because the anti-backsliding requirements have already been 

clearly established, by the Clean Air Act, the transportation conformity rule and by the D.C. 

Circuit Court. (CAA section 176(c)(1), 40 CFR 93.109(c)(2), South Coast Air Quality 

Management District v. EPA, 472 F.3d 882 (D.C. Cir. 2006), and Environmental Defense v. 

EPA, 467 F3.d at 1329) EPA continues to anticipate that we will propose a separate rule in the 

spring of 2012 that will address how anti-backsliding requirements would apply if the 1997 

ozone NAAQS is revoked for other purposes. 

V. Transport Emissions

Effect of upwind emissions on downwind nonattainment areas. 

40. Comment – EPA should address the effect of upwind emissions on downwind nonattainment 

areas, which is the true challenge faced by many nonattainment areas. 

Many commenters (0020, 0031, 0034, 0035. 0038, 0050, 0053, 0060) stated that EPA should 

address the effect of upwind emissions on downwind nonattainment areas. Many commenters 

(0031, 0034, 0038, 0049, 0050) stated that upwind emissions would prevent some nonattainment 

areas from attaining the 2008 ozone NAAQS. 

Several commenters (0031, 0034, 0050) stated that the proposed rule does not address the true 

challenge to nonattainment areas, which is transported pollution out of control of the 

nonattainment area. One commenter (0031) specifically stated that EPA is proposing that areas 

meet the required progress without reflecting out-of-area emissions, and that downwind areas 

failing to demonstrate the required progress must meet prohibitive requirements applicable to 
66

those for Extreme areas. The commenter (0031) stated that applying these subpart 2 requirements 

to downwind sources not responsible for the nonattainment problem would do little to reduce 

downwind ozone levels. The commenter (0031) stated that while one possible approach is to 

incorporate these rural areas into larger nonattainment areas along with their upwind 

metropolitan neighbors, doing so is not necessarily appropriate or cost-effective because it would 

require that complex controls developed for more populated areas be applied to rural, distant, 

less populated areas. Another commenter (0034) stated that EPA should pursue strategies to 

address the challenges faced by many nonattainment areas for which a vast majority of 

contributing pollution comes from sources outside the nonattainment areas, or from sources 

within the nonattainment areas over which the state air agencies have no regulatory authority, or 

for which federal regulation is far more cost-effective than state action, because such strategies 

would greatly assist in ensuring further progress towards clean air. The commenter (0034) stated 

that EPA should ensure that states submit and implement CAA §110(a)(2)(D) SIP revisions to 

provide the reductions in transported air pollution necessary to enable downwind states to attain 

and maintain the 2008 ozone NAAQS in the timeframes established by the CAA. One 

commenter (0050) explained that a Marginal area in the upper end of the proposed range will 

require about 10 ppb reduction in 8-hour ozone levels in less than three years. The commenter 

(0050) stated that this is a tremendous challenge that cannot be possible to meet unless 

reductions in transported ozone into the area are addressed adequately. Consequently, the 

commenter (0050) stated that EPA consider fully such impacts by considering a classification 

approach that would require the implementation of appropriate measures in a timeframe designed 

to bring healthy air to nonattainment areas as expeditiously as practicable. 

One commenter (0038) stated that nonattainment is still predicted in 2015 in Baltimore, New 

York, and Philadelphia and also possibly Pittsburgh and Washington D.C., and that the New 

York City metropolitan area will continue to bear the burden of this transported pollution, 

leaving it at a distinct environmental and economic disadvantage. 

One commenter further stated that classification approach based on subpart 2 is flawed in that it 

does not address transport pollution for Marginal areas. The commenter (0053) stated that the 

Austin, Texas area, for example, is impacted by transported emissions, and under subpart 2, the 

only way to account for transported emissions would be to bump-up an area, which would 

impose more stringent local controls without directly addressing the regional transport emissions 

that are the problem. However, the commenter (0053) stated that under subpart 1, EPA could 

take this relationship into account in setting Austin’s attainment deadline and determining 

control requirements if the region were to be designated nonattainment. 

40. EPA Response 

The EPA understands the commenters’ concern about the potential impact of ozone precursor 

emissions from upwind states on the ability of downwind states to attain the 2008 NAAQS, and 

acknowledges the potential role for federal measures to help achieve these reductions. The EPA 

also knowledges the requirements that states have an obligation to submit and implement CAA 

§110(a)(2)(D) SIP revisions to address significant contribution to violations of the NAAQS in 

areas other States. The EPA will address the CAA §110(a)(2)(D)(i) interstate transport 

requirements for the 2008 ozone NAAQS in a separate rulemaking and/or guidance. 
67

41. Comment – EPA should move forward to adopt federal rules to address significant source 

categories that are the largest upwind contributors to downwind nonattainment areas. 

Commenters (0031, 0035, 0048) stated that, in order to address the effect of upwind emissions 

on downwind nonattainment areas, EPA should move forward to adopt federal rules to address 

significant source categories. 

One commenter (0035) stated that it cannot overstate the critical need for EPA to move forward 

without delay to adopt federal rules to address significant source categories. The commenter 

(0035) noted that in October, 2010, the commenter (0035) adopted a resolution highlighting the 

need for EPA to develop and promulgate strong national strategies and controls for seven source 

categories (electric generating units; industrial, commercial, and institutional boilers; cement 

kilns; light-duty vehicles; locomotive engines; oceangoing marine engines; and aircraft). The 

commenter (0035) reiterated its recommendations since such source categories represent a large 

portion of contributing emissions. 

One commenter (0031) stated that EPA should move as fast as possible to tighten standards for 

sources (ships, locomotives, harbor craft, aircraft, off-road equipment) under its authority, 

keeping in mind California’s air quality challenge and attainment deadlines. The commenter 

(0031) noted that it has the authority to regulate operational controls on these sources at the state 

level, and the ability to regulate such sources in markets outside of California when they operate 

within California, but for these sources and for other sources under exclusive or concurrent 

federal jurisdiction, federal regulation would enable greater and faster emission reductions than 

otherwise would be possible with only State action. The commenter (0031) reasoned that not 

only would federal action lower emissions for new sources, but it would allow state and local 

actions to lower emissions from existing sources by setting in-use rules and speed up the 

integration of the cleaner engines and technology into California fleets. 

The commenter (0048) further stated that it relies on EPA to promulgate national measures, such 

as stricter controls on mobile sources and major source categories, in a timely manner to address 

ozone and ozone precursors. Consequently, the commenter (0048) stated that EPA must 

complete a rulemaking and align schedules to provide the necessary reductions on which states 

are dependent for attaining the ozone NAAQS. However, the commenter (0048) stated that such 

reliance on federal rules in SIPs is problematic, because often the entire validity of a SIP can be 

compromised by the vacatur of any one rule, which is what happened with CAIR and CSAPR. 

41. EPA Response 

 The EPA acknowledges that federal rules can be very effective at reducing ozone precursor 

emissions. The EPA has promulgated a number of regulations over the past decade to reduce 

emissions from many types of mobile sources (e.g., Tier 2 on-road vehicle and standards; the 

2007 heavy duty highway vehicle, engine and on-road diesel fuel rule; various non-road engine, 

vehicle and equipment regulations; the locomotive and marine engine rule; and the ocean-going 

vessel rule). All of these regulations, in addition to federal stationary source controls on electric 

generating units, will provide emission reductions over a broad region, which are expected to 
68

help many Marginal nonattainment areas attain the NAAQS. The EPA intends to continue 

evaluating the appropriateness of additional federal emissions control measures to satisfy CAA 

requirements imposed on EPA and state governments. 

42. Comment – Upwind states contributing to the nonattainment of downwind states should be 

required to follow the requirements for Moderate classifications. 

One commenter (0049) stated that the classification of most areas as Marginal does nothing to 

help states within the Ozone Transport Region (OTR) attain the standard, and ignores accepted 

meteorological science transport. The commenter (0049) explained that OTR states are required 

to implement Reasonably Available Control Technology (RACT) and follow the requirements of 

areas classified as Moderate, where such requirements were established by Congress as the 

“standard” for transport areas before the scope of transport was understood. The commenter 

(0049) believes that now the broader scope of transport is known, all contributing areas should 

be required to follow the requirements of Moderate areas. 

42. EPA Response 

We disagree with the commenter that the classification of nonattainment areas should be a means 

of addressing ozone transport. Section 110(a)(2)(D) of the CAA provides for all States to 

address transported emissions that significantly impact areas in downwind states regardless of 

the designation or classification of areas in the State. The classification of areas under subpart 2 

is primarily for the purpose of addressing local impacts of air pollution. The commenter is 

correct that Congress established through CAA section 184 the Ozone Transport Region (OTR) 

in the northeast and required all areas within the OTR to implement certain requirements 

applicable in nonattainment areas. Furthermore, this section does provide for the creation of 

additional ozone transport regions, though none have been created to date. To the extent the 

commenter is suggesting that EPA create one or more additional transport regions, the 

commenter should make such a recommendation to EPA in a separate request and identify and 

support the areas that should be included in each requested region. If additional transport regions 

are created, they would be subject to the same requirements that apply under section 184 to the 

northeast OTR. 

VI. Additional Comments

The NAAQS Implementation Process and SIP Requirements 

 Generally. 

43. Comment – Compliance with the CAA SIP requirements and with the NAAQS implementation 

process in general is burdensome, complicated, costly, and unnecessary. 

Commenters (0048, 0051) stated that compliance with the CAA SIP requirements and with the 

NAAQS process, in general, is burdensome, complicated, costly and unnecessary. 

One commenter (0048) specifically stated that no air quality improvements were gained from 

complying with the SIP requirements for the 1997 ozone NAAQS, despite the fact that the state 
69

spent significant time and resources on modeling, SIP preparations, and then EPA requested the 

commenter state (0048) to withdraw these submissions for various reasons. The commenter 

(0048) believes that a paradigm shift is needed away from a process that favors paperwork and 

procrastination and a process that favors pollution reduction and public health. 

Another commenter (0051) stated that the NAAQS process should be reexamined in light of 

President Obama’s recent Executive Order (EO) noting that all regulatory efforts must “protect 

public welfare, safety and our environment while promoting economic growth, innovation 

competitiveness and job creation” and “be based upon the best available science” and the “use 

the best, most innovative and least burdensome tools for achieving regulatory ends” and to 

“impose the least burden on society.” The commenter (0051) stated that the NAAQS 

implementation process is inconsistent with such EO on all accounts. The commenter (0051) 

stated that regulations should not operate in vacuum. The commenter (0051) further stated that 

many counties are focused on addressing existing ozone standards and any further changes will 

undermine these efforts. The commenter (0051) stated that local officials need some sense of 

predictability in order to develop and implement long-range transportation plans to achieve 

ozone reductions. The commenter (0051) reasoned that if counties are to effectively comply 

with current standards, additional requirements will only serve to hamper these efforts by 

opening the door to possible litigation and sanctions potentially resulting in the loss of federal 

funding for transportation improvement projects, many of which ultimately improve air quality 

by reducing congestion. 

43. EPA Response. 

We disagree that plans to implement the 1997 ozone NAAQS have not resulted in emission 

reductions and air quality improvement. Over the past 8 years, since areas were designated for 

the 1997 ozone NAAQS approximately 62% of the areas designated nonattainment have been 

redesignated as attainment. In addition, many more areas have achieved significant reductions in 

ambient ozone levels, as evidenced by the fact that 36 of the 46 areas designated nonattainment 

for the 2008 NAAQS have a design value indicating the area is attaining the 1997 ozone 

NAAQS. We also disagree that promulgation of a more stringent standard will undermine 

efforts to comply with the 1997 NAAQS. Existing efforts to address the 1997 standard should 

also provide air quality improvements that move toward meeting the more stringent 2008 ozone 

standard. The EPA is concerned about reducing the burden of transportation planning when 

multiple ozone standards are in effect, which is why this final rule revokes transportation 

conformity for the 1997 NAAQS so that future plans only need to address the more stringent 

2008 NAAQS. To the extent that a state’s failure to submit a required plan would result in a 

highway funding sanction, we note that the sanction does not cut off federal highway funding; 

rather such funds can only be spent on an enumerated list of highway projects, including “such 

other transportation-related programs as the Administrator, in consultation with the Secretary of 

Transportation, finds would improve air quality and would not encourage single occupancy 

vehicle capacity.” 

The NAAQS and SIP planning processes are specified in the CAA and the President’s Executive 

Order does not modify those statutory requirements. EPA has been considering the Executive 

Order as it develops the proposed rule to implement the 2008 ozone NAAQS and is considering 
70

how it can best meet the goals stated in the Executive Order in a manner consistent with the 

requirements of the CAA. 

Timeliness. 

44. Comment –EPA should address other implementation issues as soon as possible. 

Many commenters (0020, 0022, 0024, 0026, 0028, 0033, 0034, 0041, 0042, 0048, 0049, 0052) 

urged EPA to issue further implementation guidance in a timely manner. 

Several commenters (0022, 0028, 0033) stated that having an implementation rule finalized well 

before plans are due will provide a better tool to guide local processes, which will ultimately 

result in better plans, and plans that EPA will be able to approve within CAA deadlines. One 

commenter (0028) stated that by providing the entire implementation rule as soon as possible, 

including information on what to do about changes in geography and timing requirements, EPA 

can ensure that redundancies in work can be avoided and local and state money can be used as 

efficiently as possible. One commenter (0022) further stated that states should have a full 

understanding of the requirements for nonattainment areas prior to making nonattainment 

recommendations, and should be provided with the entire attainment planning period for 

developing the most technically appropriate SIP submittals, and adopting the necessary state 

laws and regulations to fully comply with the CAA. 

One commenter (0041) stated that states must know now what EPA’s expectations are for the 

SIPs required under CAA §110(a)(2)(D), but that planning is difficult when states are told by 

EPA that the requirements will be similar to those for the 1997 ozone NAAQS, but EPA 

continues to delay confirmation of that through a proposed rule. The commenter (0041) urged 

EPA to share the 2008 ozone NAAQS implementation rule with states as soon as possible. 

One commenter (0048) further emphasized how important it is for EPA to provide timely, 

complete and appropriate guidance for this and revisions to all NAAQS. The commenter (0048) 

stated that it is difficult to have meaningful public participation when it cannot answer important 

questions due to lack of guidance and requirements needed to implement the standards. 

One commenter (0049) stated that EPA has indicated that the proposed rule does not address 

specific SIP requirements associated with different classification categories, broader revocation 

(for purposes beyond transportation conformity) of the 1997 ozone NAAQS and any related antibacksliding issues, and EPA states, "[t]he remaining implementation requirements for the 2008 

ozone NAAQS will be addressed in a separate rulemaking. The commenter (0049) stated that 

the ozone implementation rule is essential to state and local air agencies and urged EPA to 

propose and promulgate that rule as quickly as possible. 

Several commenters (0020, 0028, 0049) stated that EPA should consider providing the entire 

implementation rule at once in the future instead of breaking it into two or more separate rules, 

and for the implementation rules be concurrent with the final NAAQS. 

One commenter (0020) specifically stated that it understood that EPA does not intend to respond 

to any comments related to other issues regarding the implementation of the 2008 ozone 
71

NAAQS, but that many states, including Georgia, have consistently stated in many forums that it 

is imperative that these kinds of rules be finalized concurrent with the final NAAQS. The 

commenter (0020) stated that since these rules have not yet been proposed, it was concerned that 

EPA will not be able to finalize them in time for effective implementation of the standard. The 

commenter (0020) stated that delays in promulgation of the implementation rules result in 

uncertainty on the part of the states, regulated sources, and the public, which leads to wasted 

effort on the part of states that are forced to implement the NAAQS without knowing what 

regulatory path to follow, and also leads to delays in emission reductions, which is the key 

element needed for protection of public health and the environment. The commenter (0020) 

stated that in a memorandum dated March 25, 2010 from Assistant Administrator Gina 

McCarthy, she stated that “EPA headquarters plans to issue implementation rules and related 

guidance with NAAQS promulgation or as promptly thereafter as possible.” It has now been 

more than four years since the 2008 ozone NAAQS was promulgated and EPA has not proposed 

any implementation rules (other than the classifications and conformity matters in this proposal) 

or issued any substantive implementation guidance (other than for assessing nonattainment 

boundaries). The commenter (0020) stated that of particular importance is that EPA has not 

proposed any rulemaking or issued any implementation guidance for the purpose of determining 

significant contribution to nonattainment or interference. 

44. EPA Response. 

The CAA sets out in detail the requirements that apply to areas designated nonattainment for 

ozone and classified under subpart 2. While EPA intends to issue shortly a proposed 

implementation rule that would provide some additional guidance to States, we believe that the 

Act, in conjunction with EPA’s interpretation of those provisions for more than 20 years, 

provides sufficient overall guidance for States to begin their planning efforts. To the extent that 

States have questions or concerns as they develop SIPs to implement the 2008 ozone NAAQS, as 

always, they should consult with the relevant regional EPA office. 

One commenter is correct that in a memorandum issued two years after EPA promulgated the 

2008 ozone NAAQS, Gina McCarthy indicated EPA’s intention in the future to at the time of 

NAAQS promulgation or soon thereafter to issue implementation rules and related guidance. 

With respect to the 2008 ozone NAAQS, EPA initially delayed implementation efforts based on 

a decision to reconsider that standard. Late last summer, EPA determined that it must move 

forward to implement the 2008 NAAQS and has been acting quickly to do so, prioritizing first its 

statutory obligation to designate areas, which entailed issuing a rule regarding how areas would 

be classified under subpart 2. Concurrently, but on a slightly later schedule, EPA is developing a 

proposed rule addressing implementation issues for the 2008 ozone NAAQS, revocation of the 

1997 ozone NAAQS for purposes other than transportation conformity, and anti-backsliding 

requirements for the 1997 ozone NAAQS. EPA expects to issue that proposal in the next several 

months. 
72

SIP Implementation Requirements for the 2008 Ozone NAAQS. 

 Demonstrating Attainment. 

45. EPA should simplify attainment demonstrations by requiring a weight-of-the-evidence method 

for demonstrating attainment rather than the use of photochemical modeling. 

One commenter (0031) stated that demonstrating attainment through photochemical grid 

modeling in Moderate areas under subpart 2 or under subpart 1 nonattainment areas would 

require a great level of resources at the state and local level; and alternatively, EPA should 

require a weight-of-the-evidence method for demonstrating attainment. The commenter (0031) 

stated that in California photochemical modeling for demonstrating attainment is better reserved 

for upwind, major, urbanized regions. The commenter (0031) stated other areas should be 

allowed to use weight-of-evidence methods including air quality trends, emission assessments, 

and photochemical modeling done by upwind areas to demonstrate attainment. The commenter 

(0031) further stated that in many of California’s areas, the mountainous terrain causes 

unpredictable weather patterns within the model’s grid cells making it difficult to predict air 

quality. Consequently, the commenter (0031) stated that photochemical modeling is unavailable 

or unsuitable as a stand-alone tool for demonstrating attainment for many areas. 

45. EPA Response. 

The CAA requires that attainment demonstrations for Serious and higher classified areas be 

based on photochemical modeling or another analytical method that the Administrator 

determines is at least as effective. For purposed of the 1997 ozone NAAQS, EPA guidance 

specified that States should perform a weight-of-evidence analysis as part of the attainment 

demonstration for all areas required to have such a plan. EPA will be addressing attainment 

demonstration requirements for the 2008 ozone NAAQS in a separate proposed implementation 

rule that we expect to issue in the next several months. 

Demonstrating reasonable further progress (RFP) 

46. Comment –EPA should provide for the treatment of nitrogen oxides (NOx) emissions in RFP 

determinations that accommodate the current scientific understanding that volatile organic 

compounds (VOC) reductions alone may be relatively ineffective in reducing ozone levels. 

One commenter (0031) stated that EPA should provide for the treatment of NOx emissions in 

RFP determinations to accommodate the current scientific understanding that VOC reductions 

alone may be relatively ineffective in reducing ozone levels, particularly in downwind, transportimpact areas in California. First, the commenter (0031) suggested that EPA allow a longer time 

frame for showing a 15 percent VOC-only reduction for RFP instead of the current six year 

period from 1990 to 1996, where the longer period could be from 1990 up to the baseline year of 

the RFP demonstration. The commenter (0031) reasoned that while the current requirement 

reflects the emphasis on the role of VOC in ozone formation at the time of the CAA, this change 

would continue to secure the necessary VOC reductions while enabling these areas to take full 

credit for more beneficial NOx reductions. Second, the commenter (0031) suggested that EPA 
73

should use a weighting approach in RFP determinations that is more consistent with the CAA 

and current science. The commenter (0031) noted that CAA §182(c)(2)(C) allows for the use of 

NOx reductions in RFP demonstrations on an equivalent ozone forming basis, but existing 

guidance for RFP is more limiting, only allowing for the substitution of NOx reductions on a 

one-for-one percent basis. 

46. EPA Response. 

The EPA intends to address the statutory RFP requirements as they apply for the 2008 ozone 

NAAQS in a separate proposed implementation rule that we expect to issue in the next several 

months. 

47. Comment –EPA should allow downwind subpart 1 areas to use out-of-area emissions in their 

RFP plans. 

One commenter (0031) who supported placing areas solely under the planning provisions of 

subpart 1 further stated that EPA should allow downwind subpart 1 areas to use out-of-area 

emissions in their RFP plans since the subpart 1 language governing RFP allows for tailoring 

RFP requirements to each planning area. 

47. EPA Response. 

We are placing all nonattainment areas under the classifications provided in subpart 2 and thus 

we are not addressing subpart 1 RFP requirements in the implementation rules for the 2008 

ozone NAAQS. 

48. Comment –EPA should allow for base year flexibility for RFP purposes. 

One commenter (0031) stated that EPA should allow states to select a year other than 2011 as the 

baseline year for RFP demonstrations. The commenter (0031) stated that this will enable states 

to select the most technically robust and quality assured base year inventory upon which to 

develop its plans, and if EPA proposes use of either 2008 or 2011 as the baseline year for RFP 

demonstrations, all emission reductions targets in such plans would be calculated from either of 

these two years. The commenter (0031) reasoned that emission levels in both years are expected 

to be lower due to the economic recession, and RFP emission targets will be set at artificially low 

levels that will be difficult to meet as the economy rebounds and activity increases. 

48. EPA Response. 

The EPA intends to address the baseline year requirement as it applies for the 2008 ozone 

NAAQS in a separate proposed implementation rule that we expect to issue in the next several 

months. 
74

Miscellaneous Comments 

 Executive Order (EO) Discussion. 

49. Comment –EPA’s cite to EO 13121 is erroneous. 

One commenter (0020) noted that in the preamble, EPA makes the statement, “In the spirit of EO 

13121 and consistent with EPA policy to promote communications between the EPA and state 

and local governments, the EPA is soliciting comments on this proposal from state and local 

officials.” The commenter (0020) stated that it assumes that the reference to EO 13121 is a 

typographical error, since this order pertains to Blocking Property of the Governments of the 

Federal Republic of Yugoslavia (Serbia and Montenegro), the Republic of Serbia, and the 

Republic of Montenegro, and Prohibiting Trade Transactions Involving the Federal Republic of 

Yugoslavia. 

49. EPA Response. 

The commenter is correct that this was a typographical error. EPA meant to refer to EO 13132 --

the EO issued for Federalism. 

50. Comment –EPA should consider commenter input as the “consultation” contemplated by EO 

13132, Section 3(d)(3). 

One commenter (0020) stated that EO 13132, section 3(d)(3) states the following: “in 

determining whether to establish uniform national standards, consult with appropriate State and 

local officials as to the need for national standards and any alternatives that would limit the scope 

of national standards or otherwise preserve State prerogatives and authority; and (4) where 

national standards are required by Federal statutes, consult with appropriate State and local 

officials in developing those standards.” The commenter (0020) asked EPA to consider the 

correspondence from the commenter (0020) as such “consultation.” 

50. EPA Response. 

We appreciate the comment. However, in the context of EO 13132 the EPA is not establishing 

any national standards in the rule being finalized today. The three issues addressed in this final 

rule are not ones for which “standards” are set. Rather, EPA is establishing how to classify areas 

for the 2008 ozone NAAQS, attainment dates for each classification of areas, and when the 1997 

ozone standard is revoked for purposes of transportation conformity. 

Future Commitments and New Technologies 

51. Comment –EPA should approve SIPs with greater dependence on future commitments based on 

developing new, green technologies. 

One commenter (0031) stated that EPA should approve SIPs with greater dependence on future 

commitments based on developing new, green technologies. The commenter (0031) stated that 
75

with more stringent ozone standards on the horizon and a transition towards an economy based 

on clean energy, EPA should reconsider old policies about future commitments. The commenter 

(0031) noted that in the past EPA expressed unease with SIPs that contain emission reductions 

from new technologies and maintains that it cannot approve SIPs until many of the new 

measures in the SIP are adopted by the districts and the Air Resources Board (ARB), submitted 

to EPA, and federally approved. The commenter (0031) believes that a SIP that emphasizes 

previously-approved measures is not a roadmap for future efforts, but rather an accounting of 

actions taken to date. 

51. EPA Response. 

While this issue is not relevant for purposes of the issues being addressed in this final rule, we 

note that section 182(e) of the CAA addresses this issue specifically, but only for areas classified 

as Extreme. In addition, we note that for all areas EPA interprets the Act to allow approval of 

commitments in place of adopted measures in limited circumstances. See our approval of the 

SJV PM10 Plan at 69 FR 30005 (May 26,2004), the SJV 1-hour ozone plan at 75 FR 10420 

(March 8, 2010), the Houston-Galveston 1-hour ozone plan at 66 FR 57160 (November 14, 

2001), proposed approval of the SJV 2007 PM2.5 SIP at 76 FR 41338 (July 13, 2011), proposed 

approval of the South Coast PM2.5 SIP at 76 FR 41562 (July 14, 2011), the South Coast 8-hour 

ozone plan at 77 FR 12674 (March 1, 2012), and the SJV 8-hour ozone plan at 77 FR 12652 

(March 1, 2012) The U.S. Court of Appeals for the Fifth Circuit upheld EPA’s interpretation of 

CAA sections 110(a)(2)(A) and 172(c)(6) and the EPA’s approval of enforceable commitments 

in the 1-hour ozone SIP for Houston-Galveston. (BCCA Appeal Group et al. v. EPA et al., 355 

F.3d 817 (5th Cir. 2003)). Although there are these limited tools that allow States additional 

time to adopt cutting edge measures, we note that we do not believe that the Act allows for broad 

deferral of measures that will achieve reductions in the short term where such measures are 

reasonably available. 

Rewarding programs for accelerated attainment of the NAAQS. 

52. EPA should reward programs for accelerated attainment of the ozone NAAQS. 

One commenter (0048) stated that the goal should be attainment of the ozone NAAQS as soon as 

practical to provide public health protection as expeditiously as possible. Consequently, the 

commenter (0048) stated that that process should reward and provide maximum flexibility to 

programs that that can attain the standard on an accelerated basis. The commenter (0048) stated 

that EPA should consider providing an incentive for areas to attain the NAAQS sooner than 

would be required, especially as it considers comments on its Ozone Advance program. The 

commenter (0048) noted that 13 out of 14 areas across the nation were successful in 

implementing the 8-hour Ozone Early Action Compact (EAC) for the 1997 ozone NAAQS, and 

these areas were provided the incentive of a deferred effective data of a nonattainment 

designation as long as the requirements of the EAC were followed, including the implementation 

of measures earlier than required and essentially avoided a nonattainment designation altogether. 
76

52. EPA Response. 

We agree that the goal of the Act is to provide health protection as expeditiously as practicable. 

We have introduced the Ozone Advance program as a collaborative effort between EPA, states, 

tribes, and local governments to encourage expeditious emission reductions in ozone attainment 

areas to help these areas continue to meet the NAAQS for ground-level ozone. For those areas 

designated nonattainment, Congress enacted a more rigorous program for attainment of the 

NAAQS because of the past failure of areas to adopt plans and meet attainment deadlines under 

more flexible provisions. The EPA does not have authority to modify statutory mandates. We 

do not believe that the EAC approach is not a viable approach but are open to exploring 

incentive programs that are consistent with the Act. 

Additional funding for states. 

53. EPA should provide additional funding to states to implement new federal requirements. 

One commenter (0048) stated that it is imperative that states and local air programs receive 

additional funding to implement new federal requirements, and to help ease the financial burden, 

EPA should immediately implement the funding allocation formula that was finalized in late 

2008 by the EPA funding allocation formula workgroup. The commenter (0048) further stated 

that EPA should recognize the value in the regional process and financially support this technical 

work, as significant financial resources have been conserved by states working together 

regionally on the technical work required to develop inventories and conduct the modeling 

necessary for the SIPs that must be submitted to the EPA to demonstrate how standards will be 

met. 

53. EPA Response. 

EPA agrees that additional funds are needed by state, local and tribal air programs for basic CAA 

implementation and the EPA has again requested a significant increase in funds for these core air 

program operations for FY 2013. However, the uncertain budget climate notwithstanding, EPA 

and its partners must still address the realignment of state grant funds in order to target resources 

to the most pressing air quality problems while still maintaining the integrity of state/local air 

program operations. In April 2011, the EPA Assistant Administrator for the Office of Air and 

Radiation (OAR) indicated that, despite uncertain funding levels, the EPA would need to move 

towards a reallocation consistent with its guiding principles and would work with states/locals in 

implementing a reasonable, equitable approach beginning in FY 2013. 

 

EPA agrees that there is value in states working together to address regional air quality issues, 

but Congress is no longer targeting dedicated funding for the Regional Planning Organizations 

(RPOs). The RPOs, originally formed from existing multi-jurisdictional organizations, were 

created to assist states in characterizing their regional haze problem and in developing their state 

implementation plans to address it. The EPA is working with state, local, and tribal agencies that 

still find it advantageous to continue to support key RPO activities. 
77

The conformity process. 

54. The conformity process is flawed. 

One commenter (0051) opined that the transportation conformity process is flawed. The 

commenter (0051) suggested that conformity lapses occur due to missed deadlines and not 

because of air quality problems. The commenter (0051) believes that conformity does not 

emphasize true transportation planning that is good for the environment and the mobility of the 

region’s population. The commenter (0051) is also concerned transportation plans having long 

planning horizons requiring frequent updates, and most air quality plans having short planning 

horizons and being updated infrequently. 

Another commenter (0049) stated that the conformity process suffers from budgets that exert no 

downward pressure on transportation emissions and a lack of requirements for future budgets. 

The commenter included an example to illustrate his views. The commenter (0049) believes that 

incentives to reduce emissions in the transportation process by smart growth and travel demand 

strategies no longer exist. 

54. EPA Response. 

All of these are comments are outside of the scope of today’s rulemaking. EPA did not propose 

any changes to the transportation conformity regulations. EPA merely proposed and is finalizing 

a revocation of the 1997 8-hour ozone NAAQS for transportation conformity purposes effective 

one year after the effective date of designations for the 2008 8-hour ozone NAAQS. 

With regard to comments made by the first commenter, the conformity rule’s requirements that 

address the frequency of conformity determinations and the timeframe over which transportation 

conformity is determined are based on specific requirements contained in Clean Air Act section 

176(c)(3)(E), (4)(D)(ii), and (7). The commenter should also be aware that Clean Air Act 

section 176(c)(9) establishes a 12-month grace period before the consequences of a conformity 

lapse are applied; therefore, giving an area the opportunity to make a conformity determination 

before a lapse is put in place. 

The second commenter appears to be under the misimpression that a SIP’s motor vehicle 

emissions budgets are control measures. The budgets that the commenter refers to are contained 

in an area’s implementation plan and those budgets must be consistent with the purpose of an 

area’s implementation plan (i.e., reasonable further progress, attainment or maintenance) and the 

control measures contained in that implementation plan, and must be based on the most recent 

planning information available when the SIP is developed. Therefore, it is not budgets that exert 

downward pressure on transportation emissions, but rather the control measures in an area’s SIP. 

Additionally, an area’s SIP may contain budgets for later years (e.g., a year or years after the 

area’s attainment date); however, those must be consistent with the area’s SIP and have a basis in 

fact for planning assumptions concerning expected growth in the area. Some strategies such as 

smart growth are longer term strategies and are not well aligned with short term attainment dates.