Air Quality Designations for the 2006 24-Hour Fine Particle (PM2.5

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

This rule establishes the initial air quality designations for most areas in the United States (U.S.), including Indian Country, for the 2006 24-hour fine particle (PM_2.5) National Ambient Air Quality Standards (NAAQS). Through these designations, EPA is identifying areas that meet or violate these NAAQS. In particular, EPA is identifying the geographic boundaries of areas that violate, or contribute to violations of, the 2006 24-hour PM_2.5 NAAQS. This is an important step toward providing the public health and welfare protections of the 2006 24-hour PM_2.5 NAAQS. The Clean Air Act (CAA) requires states with areas designated nonattainment to undertake certain planning and pollution control activities within these areas in order to attain the standards as quickly as reasonably possible. Designating areas also helps citizens know whether the air quality where they live and work is healthful or unhealthful. Health studies have shown significant associations between exposure to PM_2.5 and premature death from heart and lung disease. PM_2.5 can also aggravate heart and lung diseases and has been linked to effects such as cardiovascular symptoms, cardiac arrhythmias, heart attacks, respiratory symptoms, asthma attacks, and bronchitis. These effects can result in increased hospital admissions, emergency room visits, absences from school or work, and restricted activity days. Individuals that may be particularly sensitive to PM_2.5 exposure include people with heart or lung disease, older adults, and children.

DATES:

Effective Date: The effective date of this rule is December 14, 2009.

ADDRESSES:

The EPA has established a docket for this action under Docket ID NO. EPA-HQ-OAR-2007-0562. All documents in the docket are listed in the index at http://www.regulations.gov . Although listed in the index, some information is not publicly available, i.e., Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically in the docket or in hard copy at the Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m. Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the Office of Air and Radiation Docket and Information Center is (202) 566-1742.

In addition, EPA has established a Web Site for this rulemaking at: http://www.epa.gov/pmdesignations/2006standards/index.htm . The Web site includes EPA's final state and tribal designations, as well as state initial recommendation letters, EPA modification letters, technical support documents, responses to comments and other related technical information.

FOR FURTHER INFORMATION CONTACT:

Amy Vasu, Office of Air Quality Planning and Standards, U. S. Environmental Protection Agency, Mail Code C539-01, Research Triangle Park, NC, 27711, phone number (919) 541-0107 or by e-mail at: vasu.amy@epa.gov or Rich Damberg, Office of Air Quality Planning and Standards, U. S. Environmental Protection Agency, Mail Code C539-01, Research Triangle Park, NC, 27711, phone number (919) 541-5592 or by e-mail at: damberg.rich@epa.gov.

Regional Office Contacts:

Region I—Alison Simcox (617) 918-1684,

Region II—Kenneth Fradkin (212) 637-3702,

Region III—Maria Pino (215) 814-2181,

Region IV—Steve Scofield (404) 562-9034,

Region V—John Summerhays (312) 886-6067,

Region VI—Joe Kordzi (214) 665-7186,

Region VII—Tracey Casburn (913) 551-7016,

Region VIII—Catherine Roberts (303) 312-6025,

Region IX—Eleanor Kaplan (415) 744-1286,

Region X—Krishna Viswanathan (206) 553-2684.

SUPPLEMENTARY INFORMATION:

The public may inspect the rule and the technical support information at the following locations:

Table of Contents

The following is an outline of the Preamble.

I. Preamble Glossary of Terms and Acronyms

II. What Is the Purpose of This Document?

III. What Are Fine Particles and the Health Concerns Associated With Fine Particles?

IV. What Air Quality Standards Has EPA Established To Address Fine Particles?

V. What Are the Clean Air Act (CAA) Requirements for Air Quality Designations?

VI. How Did EPA Comply With the Clean Air Act (CAA) Requirements for Air Quality Designations?

VII. How Did EPA Apply the Statutory Requirements and Applicable Guidance To Determine Nonattainment Area Designations and Boundaries for the 2006 24-Hour PM_2.5 NAAQS?

VIII. What Areas Is EPA Designating Nonattainment for the 2006 24-Hour PM_2.5 NAAQS?

IX. How Has EPA Used 2008 Air Quality Data?

X. How Do Designations Affect Indian Country?

XI. Where Can I Find Information Forming the Basis for This Rule and Exchanges Between EPA, States, and Tribes Related to This Rule?

XII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

B. Paperwork Reduction Act

C. Regulatory Flexibility Act

D. Unfunded Mandates Reform Act

E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

G. Executive Order 13045: Protection of Children From Environmental Health and Safety Risks

H. Executive Order 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use

I. National Technology Transfer Advancement Act (NTTAA)

J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations

K. Congressional Review Act

L. Judicial Review

I. Preamble Glossary of Terms and Acronyms

The following are abbreviations of terms used in the preamble.

APA Administrative Procedure Act

CAA Clean Air Act

CBSA Core Based Statistical Area

CES Contributing Emissions Score

CFR Code of Federal Regulations

CSA Combined Statistical Area

DC District of Columbia

EO Executive Order

EPA Environmental Protection Agency

FR Federal Register

FRM Federal Reference Method

MPO Metropolitan Planning Organizations

NAAQS National Ambient Air Quality Standards

NO₃ Nitrate

NO_X Nitrogen Oxides

NTTAA National Technology Transfer Advancement Act

OMB Office of Management and Budget

RFA Regulatory Flexibility Act

SIP State Implementation Plan

SO₂ Sulfur Dioxide

SO₄ Sulfate

μg/m³ micrograms per cubic meter

UMRA Unfunded Mandate Reform Act of 1995

TAR Tribal Authority Rule

TSD Technical Support Document

U.S. United States

VCS Voluntary Consensus Standards

VOC Volatile Organic Compounds

II. What Is the Purpose of This Document?

The purpose of this document is to announce and promulgate initial designations and boundaries for areas across the country with respect to the 2006 24-hour PM_2.5 NAAQS, in accordance with the requirements of CAA section 107(d). The list of areas in each state and in Indian Country, and the designation for each area, appear in the table at the end of this final rule (amendments to 40 CFR 81.300-356). For those areas designated nonattainment, states must develop a State Implementation Plan (SIP) and tribes may develop a Tribal Implementation Plan that provides for attainment of the NAAQS as expeditiously as practicable, in accordance with the requirements of the CAA and applicable EPA regulations. Pursuant to section 172(b), EPA is announcing that states and tribes must submit these plans no later than three years from the effective date of these designations. Such plans must meet the requirements of section 172(c). EPA's current implementation regulations for PM_2.5 at 40 CFR section 51.1000-1012 apply expressly only to the 1997 PM_2.5 NAAQS. EPA is considering amending those regulations explicitly to encompass the 2006 PM_2.5 NAAQS, and whether any other revisions to the regulations are necessary for these new standards. The Agency anticipates that the SIP requirements for the 2006 PM_2.5 NAAQS should be comparable to those for the 1997 PM_2.5 NAAQS, so that the regulations at sections 51.1000-1012 can be used as a guide to SIP planning for the 2006 NAAQS pending any revisions to the regulations. For those areas designated unclassifiable or attainment, states must meet other statutory and regulatory requirements to prevent significant deterioration of air quality in those areas.

This notice identifies the 31 areas, listed in Table 1 below, comprised of one or more whole or partial counties, as nonattainment areas for the 2006 24-hour PM_2.5 NAAQS. The basis for establishing these areas as “nonattainment” is monitored air quality data for 2006-2008 indicating a violation of the NAAQS. EPA has also identified three additional areas with monitoring data now indicating potential violations of the 2006 24-hour PM_2.5 NAAQS, and we are in the process of working with affected states and tribes in accordance with CAA section 107(d) to establish nonattainment boundaries for these areas. Accordingly, EPA is deferring the designations for these areas until EPA and the states and tribes can develop sufficient information to determine the appropriate boundaries for these nonattainment areas. Table 3 below identifies these areas.

EPA completed initial designations for the annual PM_2.5 NAAQS in 2005 (70 FR 944). EPA's review of 2006-2008 monitoring data indicates that two areas initially designated as “unclassifiable/attainment” for the annual PM_2.5 NAAQS are now violating that NAAQS. For these two areas, EPA intends to initiate the process to redesignate these currently violating areas to nonattainment in accordance with the procedures of CAA section 107(d)(3). The outcome of the redesignation process will be announced in a separate future notice.

This rule also lists the current designations for the 1997 24-hour PM_2.5 NAAQS designations, which remain in place. EPA has not previously, and is not by this action, revoking the 1997 annual or 24-hour PM_2.5 NAAQS. Areas currently designated nonattainment for the 1997 annual or 24-hour NAAQS remain so after this action, and remain obligated to comply with the statutory and regulatory requirements applicable to such areas. EPA is not by this action promulgating any designations for the 1997 PM_2.5 NAAQS, but is announcing its intention to initiate the redesignation process under CAA section 107(d)(3) by a later action.

III. What Are Fine Particles and the Health Concerns Associated With Fine Particles?

Fine particles are extremely small airborne particles. Airborne particles with a nominal aerodynamic diameter of 2.5 micrometers or less (a micrometer is one-millionth of a meter; 2.5 micrometers is less than about one-thirtieth the thickness of a human hair) are considered to be “fine particles” and are also known as PM_2.5. Due to their small size, they can penetrate deeply into the lungs of people who inhale them, where they can accumulate, react, or be absorbed into the body. Epidemiological studies have shown a significant association between elevated PM_2.5 levels and a number of serious health effects, including premature mortality, aggravation of respiratory and cardiovascular disease (as indicated by increased hospital admissions, emergency room visits, absences from school or work, and restricted activity days), lung disease, decreased lung function, asthma attacks, and certain cardiovascular problems such as heart attacks and cardiac arrhythmia. Individuals particularly sensitive to PM_2.5 exposure include older adults, people with heart and lung disease, and children.

Fine particles in the atmosphere are made up of a complex mixture of components, both liquid and solid. Common constituents of ambient PM_2.5 include: Sulfate (SO₄); nitrate (NO₃); ammonium (NH₄); elemental carbon; a great variety of organic compounds; and inorganic material (including metals, dust, sea salt, and other trace elements), which often is referred to as “crustal” material. Ambient PM_2.5 is typically comprised of a mixture of primary and secondary particles. “Primary” particles are emitted directly into the air as a solid or liquid particle (e.g., elemental carbon and organic particles from diesel engines or burning activities). “Secondary” particles (e.g., SO₄ and NO₃) form in the atmosphere as a result of various chemical transformations of gaseous precursors such as sulfur dioxide (SO₂) and oxides of nitrogen (NO_X). These primary and secondary particles result from a broad variety of sources and emissions activities. Chemical precursors to secondary particles include SO_2, NO_X, volatile organic compounds (VOCs), and ammonia.

Fine particles are emitted by, and formed from emissions of, a wide range of sources. For example, SO₄ particles usually result from reactions of SO₂ emissions (from sources like power plants and industrial boilers) with ammonia emissions (from sources like animal feeding operations and fertilizer production, and to a lesser extent from mobile sources and power plants). Nitrate particles usually result from reactions of NO_X emissions (from such as mobile sources, power plants, or other industrial sources) with ammonia emissions. Crustal particles typically result from sources or activities that cause suspension of soils or metals in the air, such as re-entrained road dust, agriculture, or mining. Carbonaceous particles result from emissions from a wide range of sources or activities that cause the suspension of soil or metals in the air, such as re-entrained road dust, agriculture, or mining. Carbonaceous particles emanate directly from diesel and gasoline powered engines in mobile sources and heavy equipment, wildfires, waste burning, power generation, and other industrial sources. They also result from secondary reactions of VOCs in the atmosphere. Speciated data for PM_2.5 can provide information useful in identifying contributing emission sources and areas.

The relative proportion of primary and secondary particles, and the relative proportions of different species of particles found in a given geographic area, can vary widely, depending upon factors such as the mix of sources in the area, the mix of PM_2.5 precursors, and meteorology. The sources of PM_2.5 and PM_2.5 precursors in any area also vary by type, amount, and number. Thus, the ambient PM_2.5 in areas results from complex interaction of emissions that, in the aggregate, comprise the total ambient PM_2.5 level.

Additionally, PM_2.5 and its precursors can transport hundreds or thousands of miles suspended in the atmosphere. The extent and direction of transport are affected by meteorological conditions and winds. Wind direction, speed, and strength all vary over the course of a single day, as well as by season, and, thus, over the entire year. Consequently, ambient PM_2.5 in an area may be the combination of primary and secondary PM_2.5 particles that result from the emissions of sources in that area, nearby areas, and areas much farther away.

Given the complex nature of PM_2.5, including its serious adverse health impacts, multiple precursors, numerous sources, meteorological considerations, and the need to distinguish between impacts of local and non-local sources at any violating monitor, EPA has developed a case-by-case approach to determining designations for PM_2.5. In particular, to determine which areas are violating, and which nearby areas are contributing to those violations, EPA considers the specific facts and circumstances of each area.

IV. What Air Quality Standards Has EPA Established To Address Fine Particles?

On July 18, 1997, EPA revised the NAAQS for particulate matter to add new standards for fine particle pollution, using PM_2.5 as the indicator. EPA established annual and 24-hour standards for PM_2.5 (62 FR 38652). The primary and secondary annual PM_2.5 standards were set at a level of 15 micrograms per cubic meter (μg/m), based on a 3-year average of annual mean PM_2.5 concentrations. The primary and secondary 24-hour PM_2.5 standards were set at a level of 65 μg/m, based on a 3-year average of the 98th percentile of 24-hour PM_2.5 concentrations. The 1997 annual and 24-hour PM_2.5 NAAQS are codified at 40 CFR section 50.7. EPA promulgated the designations for the 1997 PM_2.5 NAAQS on January 5, 2005, and these designations became effective on April 5, 2005 (70 FR 944). The U.S. Court of Appeals for the District of Columbia has recently upheld EPA's designations for the 1997 PM_2.5 NAAQS for all but one area.

In 2006, EPA strengthened the primary and secondary 24-hour PM_2.5 NAAQS from 65 μg/m³ to 35 μg/m³, and retained the current primary and secondary annual PM_2.5 NAAQS at 15 μg/m³. The revised 24-hour PM_2.5 standards were published on October 17, 2006 (71 FR 61144) and became effective on December 18, 2006. The 2006 annual and 24-hour PM_2.5 NAAQS are codified at 40 CFR 50.13. The more stringent 2006 24-hour PM_2.5 standards are based on significant evidence and numerous health studies demonstrating that serious health effects are associated with short-term exposures to PM_2.5 at this level.

Many petitioners challenged EPA's 2006 annual PM_2.5 standards but not the 2006 24-hour PM_2.5 standards. As a result of that challenge, the U.S. Court of Appeals for the District of Columbia has remanded the 2006 annual PM_2.5 standards to EPA for further proceedings. Though remanded, the standards remain in effect while EPA determines how to respond to the concerns raised in the court's opinion. EPA is currently evaluating a petition concerning the designations for the 2006 annual PM_2.5 standards and is not promulgating them at this time. Because the 2006 24-hour PM_2.5 NAAQS are in effect and the court did not remand them, EPA is proceeding to promulgate the designations for these standards in this rulemaking action.

V. What Are the Clean Air Act (CAA) Requirements for Air Quality Designations?

This section summarizes the provisions of section 107(d) of the CAA, which governs the process that the states and EPA must follow in order to promulgate designations. Section 107(d)(1) provides that, after EPA promulgates any new or revised NAAQS, EPA must promulgate designations for all areas nationwide through a specific administrative process governed by the terms of section 107(d). The designations process is explicitly exempt from the usual notice and comment procedures required by the Administrative Procedures Act (APA) pursuant to section 107(d)(2)(B). The process is likewise exempt from the procedural requirements of section 307(d), unless EPA invokes it, by virtue of the fact that designations are not included in the statutory list of actions in section 307(d)(1).

The designation process begins with initial recommendations for designations from the states and tribes for areas within their jurisdictions. Section 107(d)(1)(A) provides that, by not later than one year after promulgation of a new or revised standard, each state is required to submit its recommendations for air quality designations for all areas under its jurisdiction to EPA, including the appropriate boundaries for nonattainment areas. Within section 107(d)(1)(A), the CAA establishes three types of designations: (i) Attainment areas that meet the NAAQS; (ii) unclassifiable areas, for which there is insufficient information to determine whether or not the area meets the NAAQS; and (iii) nonattainment areas that either do not meet the NAAQS, or that contribute to violations in a nearby area that does not meet the NAAQS. With respect to nonattainment areas, it should be noted that the statute does not define what constitutes a violation of the NAAQS. Nor does the statute define the terms “area,” “contributes,” or “nearby” for purposes of designations for any NAAQS.

EPA reviews state recommendations and, under section 107(d)(1)(B), is authorized to make any modifications to those recommendations that the Administrator deems necessary. The statute does not define the term “necessary,” but EPA interprets this to authorize the Administrator to modify designations that did not meet the statutory requirements or were otherwise inconsistent with the facts or analysis deemed appropriate by EPA. If EPA is considering modifications to a state's initial recommendation, EPA is required to notify the state of any such intended modifications to its recommendation not less than 120 days prior to EPA's promulgation of the final designation. If the state does not agree with EPA's modification, it then has an opportunity to respond to EPA and to demonstrate why it believes the modification proposed by EPA is inappropriate, as contemplated by section 107(d)(1)(B)(ii). Even if a state fails to provide any recommendation for an area, in whole or in part, EPA still must promulgate a designation that the Administrator deems appropriate, pursuant to section 107(d)(1)(B)(ii).

Section 107(d)(1)(B)(i) directs EPA to promulgate the designations as expeditiously as practicable, but not later than two years from the date of promulgation of new or revised air quality standards. However, in the event that EPA has insufficient information to promulgate the designation for an area, EPA may extend the period for up to one additional year.

EPA believes that section 107(d) provides the Agency with discretion to determine how best to interpret the terms in the definition of a nonattainment area (e.g., “contributes to” and “nearby”) for a new or revised NAAQS, given considerations such as the nature of a specific pollutant, the types of sources that may contribute to violations, the form of the standards for the pollutant, and other relevant information. In particular, EPA believes that the statute does not require the Agency to establish bright line tests or thresholds for what constitutes contribution or nearby for purposes of designations.

Similarly, EPA believes that the statute permits EPA to evaluate the appropriate application of the term “area” to include geographic areas based upon full or partial county boundaries, and contiguous or non-contiguous areas, as may be appropriate for a particular NAAQS. For example, section 107(d)(1)(B)(ii) explicitly provides that EPA can make modifications to designation recommendations for an area “or portions thereof,” and under section 107(d)(1)(B)(iv), a designation remains in effect for an area “or portion thereof” until EPA redesignates it. See footnote 4.

Section 107(d) contains additional specific provisions applicable to other NAAQS, such as ozone or lead in section 107(d)(4) and (5). The designations for the 2006 24-hour PM_2.5 NAAQS are governed by the general provisions of section 107(d)(1) and (2). However, EPA has concluded that it has discretion to look to other provisions of section 107(d) by analogy, as appropriate, to inform the process for designations for the 2006 24-hour PM_2.5 NAAQS. See footnote 4. For example, EPA recommended that states assess boundaries for nonattainment areas using information related to various factors similar to those that EPA had previously recommended for the 1997 annual PM_2.5 NAAQS designations, and which, in turn, relate to similar types of information that Congress provided for consideration in designations for ozone in section 107(d)(4)(A)(v). See footnote 4.

Another key distinction of section 107(d) is that it directs EPA to identify areas that violate the NAAQS, and nearby areas that “contribute” to those violations. Some have asserted that this term should be controlled by EPA's interpretation of comparable terms in section 110(a)(2)(D) and section 126. In other actions, such as the Clean Air Interstate Rule, EPA has relied on the term “contribute significantly to nonattainment” to support regulatory efforts to address regional interstate transport of pollutants, such as SO₂ and NO_X, that exacerbate nonattainment of the PM_2.5 NAAQS in downwind areas. In these actions, EPA has, through regulation, evaluated amounts of emissions that occur on a statewide basis, and EPA has used this information to develop a threshold to determine which states should be considered to contribute significantly to nonattainment in another state, at a level sufficient to require inclusion within a regional control strategy.

EPA believes that the explicit wording of section 107(d) and section 110(a)(2)(D) differs markedly, and that the purposes of the two provisions are likewise distinct. For example, EPA believes that section 110(a)(2)(D) requires some quantification of the amount of transport from a state, because the provision directs EPA to insure that there are provisions to prevent emissions “in amounts” that would “significantly” contribute to violations of a NAAQS in another state. By comparison, section 107(d) includes no such explicit requirement for any quantification of emissions or contribution and does not use the term “significant” to modify the word “contributes.” Moreover, section 107(d) is intended to accomplish a distinctly different purpose from section 110(a)(2)(D). Section 107(d) directs EPA to identify those areas that are violating, and those nearby areas that are contributing to the violations, as the geographic areas within which states must address local emission sources for purposes of local attainment needs, in accordance with the requirements of section 172 and applicable regulations. By contrast, section 110(a)(2)(D) authorizes EPA to take action to address interstate transport of pollutants from one or more states that affect other states. To be sure, these provisions can work in concert to address the local and regional components of nonattainment for a given NAAQS. They are not, however, identical in wording or purpose.

Designation activities for federally-recognized tribes are covered under the authority of section 301(d) of the CAA. This provision of the CAA authorizes EPA to treat eligible tribes in a similar manner as states. Pursuant to section 301(d)(2), EPA promulgated regulations, known as the Tribal Authority Rule (TAR) (63 FR 7254). The TAR is codified at 40 CFR part 49. That rule specifies those provisions of the CAA for which it is appropriate to treat tribes in a similar manner as states. Under the TAR, tribes may choose to develop and implement their own CAA programs, but are not required to do so. The TAR also establishes procedures and criteria by which tribes may request from EPA a determination of eligibility for such treatment.

The designations process contained in section 107(d) of the CAA is included among those provisions determined to be appropriate by EPA for treatment of tribes in the same manner as states. Under the TAR, tribes generally are not subject to the same submission schedules imposed by the CAA on states. However, EPA itself is required to meet statutory deadlines for promulgation of designations and must observe those deadlines, notwithstanding the discretion EPA has to adjust schedules for tribes. As authorized by the TAR, tribes may seek eligibility to submit designation recommendations to EPA. In addition, CAA section 301(d)(4) gives EPA discretionary authority, in cases where it determines that treatment of tribes as identical to states is “inappropriate or administratively infeasible,” to provide for direct administration by regulation to achieve the appropriate purpose.

To date, one tribe has applied for eligibility under the TAR to submit its own initial designation recommendations under section 107(d)(1). Nonetheless, EPA invites all tribes to submit designation recommendations for new NAAQS. EPA works closely with tribes that request an opportunity to submit designation recommendations and supporting documentation. EPA reviews and acts on recommended designations in consultation with the tribes, and as with states, makes modifications to tribal recommendations as EPA deems necessary.

VI. How Did EPA Comply With the Clean Air Act (CAA) Requirements for Air Quality Designations?

Following the December 18, 2006 effective date of the 2006 PM_2.5 NAAQS, EPA invited all states and tribes to submit area and boundary recommendations within one year. On June 8, 2007, EPA provided guidance making recommendations concerning various aspects of the designations, including timing, process, and factors reflecting the types of information that could be relevant to the evaluation of a specific area.

Most states, and those tribes who elected to do so, submitted initial designation recommendations and supporting documentation to EPA by December 18, 2007. In general, state and tribal area recommendations were based on Federal Reference Method pair quality monitoring data from the 2004-2006 time period. After reviewing and evaluating each of these recommendations, EPA provided responses to the states and tribes on August 19-20, 2008. In these letters, EPA indicated whether or not EPA intended to make modifications to the initial state or tribal recommendations and explained EPA's reasons for suggesting any such modifications. As part of this process, EPA incorporated consideration of the most recent air quality data then available, for the 2005-2007 time period. EPA requested that states and tribes respond to any proposed EPA modifications to their initial recommendations by October 20, 2008.

Although not required by section 107(d) of the CAA, EPA also provided an opportunity for comment by members of the public in order to gather additional information for EPA to consider before making final designations. EPA published a notice on September 2, 2008 (73 FR 51259) which invited the public to comment on EPA's intended designations. In this notice, EPA offered a 30-day comment period to all interested parties, other than states and tribes, as they already have statutorily provided opportunities to participate in the designations process. EPA posted the state and tribal initial recommendations and EPA's responses, including suggested modifications, on a Web site which was accessible to the public to provide information to inform their comments: ( http://www.epa.gov/pmdesignations/2006standards/index.htm ). Timely comments from the public, and EPA's responses to significant public comments, are in the docket for this action.

The Agency received letters from many states and tribes suggesting changes to EPA's proposed modifications and providing additional information. EPA evaluated each letter and all of the timely technical support information that was provided before arriving at the final designation decisions. Some of the final designations reflect EPA's modifications to the initial state and tribal recommendations. Some reflect changes to EPA's suggested modifications, based upon information that states and tribes subsequently provided in response. Through this iterative process, EPA developed the information necessary to inform the final designations decisions.

On December 22, 2008, then EPA Administrator Johnson signed a notice concerning the designations for the 2006 24-hour PM_2.5 NAAQS, and the notice was made available to the public on the EPA Web site at that time. However, that signed notice was never published in the Federal Register and, therefore, designations were not officially promulgated. Section 107(d)(2)(A) requires EPA to publish the notice in the Federal Register in order to promulgate designations. The December 2008 notice was awaiting publication in January 2009 when the newly-elected Administration identified the notice as one that should receive additional review before publication.

Since January 2009, EPA has thus been reviewing the designation decisions for the 2006 24-hour PM_2.5 NAAQS. Three significant events have occurred in the interim that relate to the designations. First, the U.S. Court of Appeals for the District of Columbia issued its opinion in the litigation challenging EPA's 2006 annual PM_2.5 NAAQS. This decision resulted in, among other things, a remand of the annual standards to EPA for further consideration, but did not affect the 2006 24-hour PM_2.5 NAAQS. Second, monitoring data for 2008 has now become available for areas across the U.S. Accordingly, EPA has had the opportunity to evaluate whether data from 2006-2008 would result in previously violating areas now attaining the NAAQS, or previously attaining areas now violating the NAAQS. Third, the U.S. Court of Appeals for the District of Columbia issued its opinion in the litigation challenging EPA's 2005 designations for the 1997 annual PM_2.5 NAAQS. In that decision, the court has affirmed EPA's interpretation of section 107(d) and general approach to promulgating designations for that NAAQS. The final designations that EPA will promulgate through publication of this rule have been informed by these more recent events.

EPA has already received a number of petitions concerning the designations for the 2006 24-hour PM_2.5 NAAQS. Of these, two in particular require specific discussion because of the significant issues they raise. The first petition, from the American Lung Association and other groups, requests that EPA take action to promulgate designations for the 2006 annual PM_2.5 NAAQS. EPA is currently evaluating that petition and will determine later whether to grant or deny it. In the meantime, however, EPA's review of the 2006-2008 monitoring data indicates that two areas currently designated as “unclassifiable/attainment” for the 1997 annual PM_2.5 NAAQS are now violating that NAAQS. For these two areas, EPA intends to initiate the process to redesignate these areas, including both violating and contributing areas, to nonattainment in accordance with the procedures of CAA section 107(d)(3), as appropriate.

The second petition, from the Environmental Defense Fund and other groups, requests that EPA delay or reconsider designations for attainment areas that contain heavily travelled roadways because the monitoring network in such areas may not adequately reflect near-roadway exposure to PM_2.5. EPA will respond to this petition separately in more detail, but believes that it is not appropriate to delay designations for the 2006 24-hour PM_2.5 NAAQS further, based on the concerns raised by these petitioners. EPA intends to evaluate the issues raised by these petitioners in the context of the ongoing review of the PM_2.5 NAAQS and the associated monitoring regulations.

VII. How Did EPA Apply the Statutory Requirements and Applicable Guidance To Determine Nonattainment Area Designations and Boundaries for the 2006 24-Hour PM_2.5 NAAQS?

Section 107(d)(1)(A)(i) of the CAA defines a nonattainment area as any area that does not meet an ambient air quality standard, or that contributes to ambient air quality in a nearby area that does not meet the standard. If an area meets either prong of this definition, then EPA is required to designate the area as “nonattainment.” In June 2007, EPA issued guidance concerning how to determine boundaries for nonattainment areas for the 2006 24-hour PM_2.5 NAAQS (the 2007 Guidance). As part of the 2007 Guidance, EPA recommended that the three most recent calendar years of air quality monitoring data for PM_2.5 be used to identify a violation of the 2006 24-hour PM_2.5 NAAQS. This is appropriate because the form of the 24-hour PM_2.5 NAAQS is calculated over a 3-year period. For the final designations, EPA has identified violating monitors based on air quality monitoring data from Federal Reference Method (FRM) monitors for calendar years 2006-2008.

By definition, areas may need to be designated nonattainment because they contribute to violations in another nearby area, even if they do not themselves have a monitor with violating data, or even if they do not have any monitor at all. As a result, states, tribes, and EPA need to consider additional relevant information in order to assess contributing areas as part of identifying the appropriate boundaries for nonattainment areas. Thus, in the 2007 Guidance, EPA recommended nine factors that pertained to types of information that EPA considered relevant for designations, and indicated that it would evaluate these factors along with any other relevant information or circumstances specific to a particular area, in determining appropriate nonattainment area boundaries.

EPA also noted in the 2007 Guidance that, in making boundary recommendations for nonattainment areas, states and tribes should evaluate each area on a case-by-case basis. EPA intentionally did not attempt to create any bright line test or threshold for any factor or form of information. EPA believes that section 107(d) does not require any such bright lines or thresholds to determine contribution, and that to create one could result in over-inclusion or under-inclusion of areas in nonattainment areas, as compared to a more robust and fact-specific analysis of each area on its merits. This approach is especially appropriate for PM_2.5, given the multiple precursors, numerous sources, meteorological considerations, and need to distinguish between impacts of local and non-local sources at any given violating monitor.

Finally, EPA indicated that it would promulgate nonattainment area boundaries that cover a sufficiently large area to include both the area that violates the standard and the nearby areas that contribute to the violations, as required by section 107, to assure that nonattainment area plans developed for these areas would attain the NAAQS as expeditiously as practicable. Unlike the guidance for the 1997 PM_2.5 NAAQS designations, EPA did not recommend the metropolitan area boundaries established by the U.S. Office of Management and Budget (OMB) as a rebuttable presumption for designations for the 2006 24-hour PM_2.5 NAAQS in the 2007 Guidance. Given the differences in the form of the standards between a 24-hour and an annual standard, EPA was less certain that such a presumption would be appropriate for all areas. For existing PM_2.5 nonattainment areas, based on early technical analyses of PM_2.5 composition and contributing source types, combined with an understanding of the existing PM_2.5 nonattainment areas, EPA noted its anticipation that the same boundaries established for implementing the 1997 annual PM_2.5 NAAQS might also be appropriate for implementing the 2006 24-hour PM_2.5 NAAQS in areas where both standards are violated. EPA also observed that maintaining the same nonattainment area boundaries for both the 1997 annual standards and the 2006 24-hour standards could more easily facilitate overall air quality planning for attaining the suite of PM_2.5 standards.

Section 107(d)(1)(A)(i) of the CAA requires EPA to designate as nonattainment not only violating areas, but also nearby areas that contribute to those violations. As noted above, the statute does not, however, define key terms such are “area,” “contributes,” or “nearby.”

With respect to the term “contributes,” EPA believes that this term does not mean “cause.” The term “contributes” indicates that those areas with emissions that add to the aggregate ambient pollution recorded by a given monitor might be appropriate for inclusion in a nonattainment area. To interpret the term contribute to mean “cause” would be to require a degree of certainty and precision that is inherently unreasonable for evaluating violations that result from the impact of emissions from many different sources of PM_2.5 and PM_2.5 precursors, and would simultaneously undermine the purpose of designations by excluding every area with emissions that added to the aggregate problem, yet did not individually “cause” the violation. EPA also has concluded that a bright line test or threshold for what would constitute contribution for purposes of designations is not appropriate for the 2006 24-hour PM_2.5 NAAQS. Such an approach could result in over- or under-inclusive areas, compared to robust analysis of the facts and circumstances of each area. Similarly, EPA does not interpret the term “contributes” to mean “significantly contributes,” and does not believe that precise quantification of the contribution to violations in a nearby area is necessary or appropriate for designations. EPA generally agrees that areas with no sources of emissions, or areas that are otherwise demonstrated not to be contributing to violations, need not be included in a designated nonattainment area. However, EPA has concluded that the assessment of the “causation” and “materiality” of contribution to nearby violations is best accomplished through a more careful evaluation of the relevant information on an area-by-area basis.

As to what areas should be considered “nearby,” EPA believes that this term must likewise be viewed in light of the specific pollutant at issue. In the case of the 2006 24-hour PM_2.5 NAAQS, this entails consideration of the relatively long distances across which PM_2.5 and PM_2.5 precursors can be transported, but balanced with a key purpose of designations, which is to identify those nearby or local contributing areas that properly should be included within a designated nonattainment area to ensure the development of an appropriate SIP for the area. Thus, EPA's guidance also does not provide a bright line or threshold or specific geographic distance for what constitutes a “nearby” area. The determination of which areas are nearby, for purposes of designations, requires an evaluation of the facts and circumstances of each area. EPA considered the geography of each area, meteorological data, chemical speciation data, and other relevant information in light of the significant distances across which PM_2.5 and PM_2.5 precursors can be transported. EPA has used this process to identify those nearby areas with emissions that contribute to the violations and to distinguish these emissions from more distant or regional sources that are not appropriate for inclusion within the nonattainment area. In particular, EPA does not believe that the term “nearby” requires that the area be contiguous with the violating area or the remainder of the nonattainment area, if the facts support such a conclusion for a given area.

As to the term “area,” EPA concluded that it also should be interpreted as appropriate to the specific NAAQS at issue. In drawing nonattainment areas boundaries, EPA started with county boundaries as the basic jurisdictional element, consistent with past designation practice. Although EPA determined that county boundaries are a useful starting point, relevant facts and circumstances could support making partial county boundary designations for violating or contributing counties in a given area.

EPA began its technical analyses by first identifying violating monitors. In evaluating areas potentially contributing to a monitored violation, EPA initially examined those counties located in the surrounding metropolitan statistical area (i.e., the core-based statistical area (CBSA)) and those counties one to two adjacent rings beyond the metropolitan area. In its Notice on Standards for Defining Metropolitan and Micropolitan Areas (65 FR 82228, December 27, 2000), the Office of Management and Budget (OMB) notes that the general concept of a metropolitan statistical area is that of “an area containing a recognized population nucleus and adjacent communities that have a high degree of integration with that nucleus.” Further, the metropolitan statistical area serves as a “statistical representation of the social and economic linkages between an urban core and outlying, integrated areas.” Because of the inherent linkage between air pollution and pollution-producing human and economic activity, EPA believes that the CBSA, plus one to two adjacent rings beyond the metropolitan area, is an appropriate starting point for evaluation of contributing areas.

EPA evaluated the types of information recommended in the 2007 Guidance, as well as other relevant information that states or tribes provided or that became available, in determining appropriate nonattainment area boundaries. The nine factors EPA recommended in the 2007 Guidance are: (1) Emissions data, (2) air quality data, (3) population density and degree of urbanization including commercial development in included versus excluded areas, (4) traffic and commuting patterns, (5) expected growth (including extent, pattern and rate of growth), (6) meteorology (weather/transport patterns), (7) geography/topography (e.g., mountain ranges or other air basin boundaries), (8) jurisdictional boundaries (e.g., counties, air districts, Reservations), and (9) level of existing controls on emission sources. This was neither a mandatory nor an exclusive list of types of relevant information, and was intended by EPA only as guidance concerning the types of information that might be appropriate for consideration in a given area. These factors are by their nature general and open ended, and EPA intended them to facilitate analysis of each area on its specific facts. Some factors were more relevant or important in some areas than in others in establishing the boundaries of a given area.

As part of the technical analysis, EPA also used an analytical tool to produce a metric referred to as the “contributing emissions score” (CES). The CES takes into consideration emissions data, meteorological data, and air quality monitoring information to provide a relative ranking of the potential contribution from counties near a specific county with a violating monitor. EPA did not use this metric as the exclusive way of considering data for these three factors, nor as the single deciding factor for determining designations. The CES was merely an additional method for evaluating the potential contribution of nearby counties.

To evaluate an area, EPA also used additional data and analytical tools as appropriate, including speciated PM_2.5 data, area maps, and tools for assessing wind patterns. For purposes of determining appropriate nonattainment area boundaries, EPA examined data from PM_2.5 speciation monitors, where available, in addition to the ambient PM_2.5 concentration data from FRM monitors. The speciated PM_2.5 data indicated the relative proportions of specific types of particles at monitors (e.g., SO₂, NO₃, carbonaceous, or crustal particles). These data provided insights as to likely sources of emissions contributing to the ambient PM_2.5 concentrations at the violating monitor on days with high PM_2.5 levels, thus allowing EPA to better evaluate which, if any, of the nearby areas were contributing to the ambient PM_2.5 concentrations at the violating monitor.

EPA used maps of each area that depicted key geographic information. These maps portrayed relevant information such as the locations of FRM monitors and their design values, jurisdictional boundaries, topographic features, major transportation arteries, major emission sources, and existing nonattainment boundaries for other NAAQS. The maps assisted in the evaluation of basic information such as the directions and distances between monitors and sources and the locations of jurisdictional boundaries.

EPA also assessed wind pattern data through the development and use of “pollution roses” that depict monitoring data and meteorological data for monitors in each area. In some cases, where a more detailed assessment of air movement was thought to provide additional relevant information, EPA also used wind trajectory analyses. These tools for assessing wind movement and pollutant concentrations provided further information on likely emission sources contributing to PM_2.5 levels at monitors on days at or near the level of the 24-hour PM_2.5 NAAQS.

In evaluating emissions in areas under consideration for their contribution, EPA generally relied on the best county-level emissions inventory information available. In some areas, EPA reviewed whether significant pollution controls that would be installed in the near-term and with certainty at a specific source or sources, could be relevant to evaluating whether that area is contributing to violations in an adjacent area. EPA examined this type of information when states provided the requisite data and requested its evaluation as part of the process. EPA considered such information on a case-by-case basis, with attention to whether the controls in question would dramatically reduce the emissions of PM_2.5 and all PM_2.5 precursors, the timing of such controls, and the federal enforceability of such controls. EPA considered only controls that would be in place no later than December 2008 (i.e., controls resulting in emissions reductions during the last year of the period for which air quality monitoring data was relevant).

By contrast, EPA did not rely on planned or potential emissions reduction strategies through measures such as the Clean Air Interstate Rule, in making nonattainment designations, even if those strategies might help an area attain the standards in the future. The Agency recognizes that air quality modeling of future emissions reductions (e.g., from state and/or national programs) may indicate that some areas with a violating monitor based upon 2006-2008 data may come into attainment in the future. However, the present tense formulation of section 107(d) indicates that EPA should make nonattainment designations based on current data. Future potential reductions, especially those that are at this time speculative or uncertain, are not appropriate for consideration in the designations context. Such programs might, however, be an appropriate consideration in the development of SIPs for designated nonattainment areas, if they otherwise meet statutory and regulatory requirements.

In order to identify the appropriate boundaries for nonattainment areas, EPA considered the county boundary as the basic jurisdictional element for determining area boundaries, consistent with past designation practice. The Agency believes that such county boundaries are generally an appropriate boundary because they are easily recognized jurisdictional boundaries with indisputable legal descriptions. County boundaries are often the boundaries for the legal jurisdiction of local governments or air quality planning organizations that are responsible for air quality management.

In most cases, if a PM_2.5 monitor was violating the NAAQS, EPA designated the entire county in which that monitor is located as nonattainment. EPA also often included whole nearby counties that it determined to be contributing to PM_2.5 levels at the violating monitor. In some cases, however, EPA determined that only part of a county (e.g., the part of the county that contained the sources of contributing emissions) was contributing to the violation at the monitor. In those instances, EPA designated only that portion of the county nonattainment and, to the extent possible, relied on recognized governmental boundaries for smaller geographic areas that encompassed the relevant emission sources (e.g., townships).

For example, in some cases, EPA determined that the emissions from a large individual source such as a power plant were contributing to violations in a nearby area. If EPA's assessment identified little or no other emissions or emitting activity elsewhere in the county (based on assessment of factors such as emissions, population, and commuting), EPA concluded that it was appropriate to designate as nonattainment only the portion of the county where the large individual source is located, even if that portion is not contiguous with the remainder of the nonattainment area. The Agency adopted this approach for areas where EPA determined it to be inappropriate to include portions of a county merely because those portions were located between, and contiguous with, the large stationary source and the remainder of the designated nonattainment area. In most cases, EPA selected boundaries for these noncontiguous portions of nonattainment areas by relying on legally recognized governmental boundaries (e.g., townships, tax districts, or census blocks) in which the source is located.

EPA also determined partial county boundaries to be appropriate for some areas where a topographic feature, such as a mountain range, helps to define the airshed in which the violation of PM_2.5 standards occurs, or separates contributing from non-contributing areas. In some areas, EPA determined that only a portion of a county was determined to be contributing, due to such a topographic barrier. In a few cases, especially in the West, an area with a violating monitor was topographically isolated from other portions of a much larger county or borough with few or no sources of emissions. EPA considered a partial county to be appropriate for such areas and selected boundaries based on topography, using recognized governmental boundaries (e.g., township ranges), where possible.

Where topography was not an isolating feature, EPA considered the geographic location of the sources of PM_2.5 and PM_2.5 precursors in the area, and other relevant information, such as chemical speciation data and meteorological data, in determining if a partial county boundary was technically justified and appropriate. EPA also considered a partial county boundary for violating counties in situations where a unique situation is shown to exist, in which the sources encompassed by a partial county boundary could account for nearly all of the total fine particle mass from local sources on days with a monitored exceedance. In such areas, given compelling evidence, EPA considered designations of partial violating counties to be appropriate. These areas are typically in the mountainous portions of the West, where emissions activity in a relatively small and isolated geographic area is surrounded by large areas that are largely unpopulated and otherwise lack sources that could contribute to the monitored violations. EPA notes that the 24-hour averaging period of the 2006 24-hour PM_2.5 NAAQS was an important consideration in these areas. EPA selected the boundaries for these areas by relying on legally recognized governmental boundaries (e.g., townships) in which the contributing sources are located.

EPA analyzed the information provided by each state or tribe in its recommendation letter, subsequently submitted information, and any other pertinent information available to EPA, in order to determine whether a county or part of a county should be designated nonattainment. EPA evaluated each state's or tribe's designation recommendation in light of the recommended nine factors, and any other relevant information, including, for example, the CES, PM_2.5 speciation data, and wind pattern data, bringing to bear our best technical and policy judgment. If, as a result of the evaluation, EPA concluded that a county or part of a county contributes to the violation in a nearby area with a violating monitor, EPA included the county or part of the county in the nonattainment area.

VIII. What Areas is EPA Designating Nonattainment for the 2006 24-Hour PM_2.5 NAAQS?

Following the process described above, EPA is designating the 31 areas in Table 1 below, comprised of one or more entire counties or partial counties, as nonattainment areas for the 2006 24-hour PM_2.5 NAAQS.

EPA's specific analysis of these areas, including the determination of the appropriate nonattainment area boundaries for each of these areas, is described in detail in the TSD, with additional information provided in the Supplemental TSD. Both documents are located in the docket for this action. In addition, the letters containing the initial state or tribal recommendations for each of these areas, any EPA modification to those recommendations, and any additional information provided by the state or tribe in response to EPA modifications, is also located in the docket. The specific area or areas within the boundaries for each of these designated nonattainment areas is described in the amendments to 40 CFR part 81 below, and is graphically portrayed in the maps located in the docket for this action.

IX. How Has EPA Used 2008 Air Quality Data?

In December 2008, EPA identified 58 areas as violating the 2006 24-hour PM_2.5 NAAQS based on air quality monitoring data for the 2005-2007 time period. In the 2007 Guidance, EPA recommended that designation decisions be based on the most recent three years of data available. In the December 2008 notice, which was not published in the Federal Register in order to allow additional Agency review, and in communications with states and tribes, EPA had indicated that it would consider state requests to include consideration of 2008 air quality monitoring data for specific areas prior to the effective date of designations under certain circumstances. Due to the delay in the designations, however, EPA now has received and reviewed quality assured, state-certified 2008 air quality monitoring data for all areas.

EPA continues to believe that inclusion of the most recent air quality monitoring data available is appropriate for designation decisions. Thus, EPA is designating as attainment those areas for which complete, quality assured, certified air quality monitoring data for the 2006-2008 time period show attainment of the 2006 24-hour PM_2.5 NAAQS throughout the area. EPA is not reconsidering the boundaries for the areas identified as nonattainment in December 2008 and for which consideration of 2006-2008 air quality data does not change the overall status of the area. The boundaries EPA identified in December 2008 were based upon thorough consideration of the relevant information by EPA. EPA believes that it is appropriate to rely on the 2008 air quality monitoring data and the extensive information and analyses used in the decision making process that spanned the period from approximately June 2007-December 2008. EPA does not believe that the introduction of additional non-air quality information into the process at this time would yield different designation outcomes; and, in fact doing so would cause unjustified delay in issuing these final designations based upon 2006-2008 air quality monitoring data.

Consideration of 2006-2008 air quality monitoring data reduced the number of areas violating the 2006 24-hour PM_2.5 NAAQS from 58 to 31. Table 2 provides a list of the 26 areas that changed from nonattainment to attainment and their design values for 2005-2007 and 2006-2008. For one area no longer violating the 2006 24-hour PM_2.5 NAAQS based on 2006-2008 data, York County, PA, EPA concluded that it nevertheless contributes to violations in another nearby violating area, Harrisburg-Lebanon-Carlisle, PA, and thus EPA has included York County, PA in that nonattainment area. Five of the areas that changed from a designation status of nonattainment to attainment had one or more monitors with incomplete data for 2006-2008. However, data from the highest design value monitor for the area in 2005-2007, as well as other monitors, are complete and show attainment of the 24-hour PM_2.5 NAAQS for 2006-2008. As explained in detail in the Supplemental TSD, based on the relative values of the various monitors, EPA believes it is reasonable to expect that, if the incomplete site had complete 2006-2008 data, it would have a design value equal to or lower than the other sites with complete data that are attaining the NAAQS based on the 2006-2008 data. The additional technical information to support the change in status for all of the areas, including the supporting evaluation for the inclusion of York County in the Harrisburg-Lebanon-Carlisle, PA nonattainment area and for the five areas noted above, is included in the Supplemental TSD, which is located in the docket for this action.

EPA's evaluation of 2006-2008 air quality monitoring data also indicated that monitors in three areas which had not violated the 2006 24-hour PM_2.5 NAAQS based on 2005-2007 data now violate those standards based on 2006-2008 data. These monitors are located in Pinal County, AZ (2006-2008 24-hour design value of 48); Plumas County, CA (2006-2008 24-hour design value of 49); and, Shasta County, CA (2006-2008 24-hour design value of 48). In this notice, EPA is not finalizing initial designations for these newly violating areas. Because these areas are newly violating the 2006 24-hour PM_2.5 NAAQS, EPA and the states and tribes in these areas need further information in order to determine the appropriate nonattainment area boundaries for these areas, in accordance with the process that EPA has used for other nonattainment area designations, as provided by section 107(d).

Because EPA has information indicating that there is a violation in each of these areas, a designation of “unclassifiable” is not appropriate under section 107(d)(1)(A)(iii). Notwithstanding data indicating violations of the 24-hour PM_2.5 NAAQS, EPA has insufficient information to determine the necessary boundaries for these areas. Accordingly, EPA will use the additional time available to it under section 107(d)(1)(B) to assess these areas, complete evaluation of any pending exceptional event claims, and promulgate initial designations for these areas. Consistent with the approach used to assess other potential nonattainment areas, EPA intends to evaluate relevant technical data for the ring of counties immediately surrounding the violating county to determine whether any of these nearby counties contribute to the violation. EPA is deferring the designations for these counties for the 2006 24-hour PM_2.5 NAAQS so that EPA can collect additional information sufficient to assess these areas before promulgating these designations. We recognize that these are large geographical areas. Including all counties surrounding the county with the violating monitor is only a starting point for the evaluation; it should not be assumed that the final designated nonattainment area will include all of these counties. Table 3 provides a list of the counties with violating monitors and the additional nearby areas that EPA believes should be evaluated for potential contribution to those violations.

EPA will work with the relevant states and tribes to finalize the designations for these counties over the next several months. EPA will send letters notifying the states and tribes in question that EPA believes a modification is now necessary to the initial recommendations they made for these areas. Each state and tribe will thereafter have an opportunity to respond to EPA's proposed designations and boundaries. Pursuant to section 107(d), EPA cannot promulgate the designation for these areas less than 120 days from the date of the EPA modification letter. EPA will promulgate the designations for these areas by a separate final rule.

The quality assured, certified air quality monitoring data for 2006-2008 also indicate that two counties that EPA designated in 2005 as attainment for the 1997 annual PM_2.5 NAAQS now have monitors which are potentially violating that NAAQS. These counties are Pinal County, AZ (2006-2008 annual average design value of 21.6) and Harris County, TX (2006-2008 annual average design value of 15.2). Consequently, EPA intends to initiate the redesignation process under section 107(d)(3) for these areas for the 1997 annual PM_2.5 NAAQS. EPA will work with the relevant states and tribes to evaluate the air quality data and other technical information in order to determine whether these areas should be redesignated to nonattainment, and if so, the appropriate boundaries for those nonattainment areas. EPA will promulgate these redesignations by a later final rule.

X. How Do Designations Affect Indian Country?

All full counties, partial counties or Air Quality Control Regions listed in the Part 81 table at the end of this document are designated as indicated, and include Indian Country geographically located within such areas, except as otherwise indicated in the table.

In general, and consistent with relevant air quality information, EPA intends to include Indian Country encompassed within the nonattainment area, in order to protect public health and welfare. In most cases, relevant air quality information will indicate that areas of Indian Country located within a nonattainment area should have the same designation as the surrounding area. See discussion above about tribal responsibility.

EPA does not recognize state recommendations for area designations as applying to Indian country. However, the conditions that support a state's designation recommendation, such as air quality data at the location of the sources, may indicate the likelihood that similar conditions exist in adjacent Indian Country. States generally have neither the responsibility nor the authority for planning and regulatory activities under the CAA in Indian country.

XI. Where Can I Find Information Forming the Basis for This Rule and Exchanges Between EPA, States, and Tribes Related to This Rule?

Information providing the basis for this action and related decisions are provided in the TSD, response to comments documents, and other information in the docket. The TSD, applicable EPA guidance memoranda, copies of correspondence regarding this process between EPA and the states, tribes, and other parties, and EPA's responses to comments, are available for review at the EPA Docket Center listed above in the addresses section of this document and on our designation Web site at http://www.epa.gov/pmdesignations/2006standards/index.htm . Other related state specific information is available at the EPA Regional Offices.

XII. Statutory and Executive Order Reviews

Upon promulgation of a new or revised NAAQS, the CAA requires EPA to designate areas as attaining or not attaining the NAAQS. The CAA then specifies requirements for areas based on whether such areas are attaining or not attaining the NAAQS. In this final rule, EPA assigns designations to areas as required.

A. Executive Order 12866: Regulatory Planning and Review

This action is not a “significant regulatory action” under the terms of Executive Order (EO) 12866 (58 FR 51735, October 4, 1993) and is therefore not subject to review under the EO.

B. Paperwork Reduction Act

This action does not impose an information collection burden under the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. Burden is defined at 5 CFR 1320.3(b). This rule responds to the requirement to promulgate air quality designations after promulgation of a NAAQS. This requirement is prescribed in the CAA section 107 of title 1. The present final rule does not establish any new information collection apart from that required by law.

C. Regulatory Flexibility Act

This final rule is not subject to the Regulatory Flexibility Act (RFA), which generally requires an agency to prepare a regulatory flexibility analysis for any rule that will have a significant economic impact on a substantial number of small entities. The RFA applies only to rules subject to notice and comment rulemaking requirements under the Administrative Procedure Act (APA) or any other statute. This rule is not subject to notice and comment requirements under the APA or any other statute because the rule is not subject to the APA and is subject to CAA section 107(d)(2)(B), which does not require that the Agency issue a notice of proposed rulemaking before issuing this rule.

D. Unfunded Mandates Reform Act

This action contains no federal mandate under the provisions of Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), 2 U.S.C. 1531-1538 for state, local, or tribal governments or the private sector. The action imposes no enforceable duty on any state, local or tribal governments or the private sector. Therefore, this action is not subject to the requirements of sections 202 and 205 of the UMRA.

This action is also not subject to the requirements of section 203 of UMRA because it contains no regulatory requirements that might significantly or uniquely affect small governments. It does not create any additional requirements beyond those of the PM_2.5 NAAQS (40 CFR 50.13), therefore, no UMRA analysis is needed. This rule establishes the application of the PM_2.5 standard and the designation for each area of the country for the PM_2.5 NAAQS. The CAA requires states to develop plans, including control measures, based on their designations and classifications.

One mandate that may apply as a consequence of this action to all designated nonattainment areas is the requirement under CAA section 176(c) and associated regulations to demonstrate conformity of federal actions to SIPs. These rules apply to federal agencies and Metropolitan Planning Organizations making conformity determinations. The EPA concludes that such conformity determinations will not cost $100 million or more in the aggregate.

The EPA believes that any new controls imposed as a result of this action will not cost in the aggregate $100 million or more annually. Thus, this federal action will not impose mandates that will require expenditures of $100 million or more in the aggregate in any one year.

Nonetheless, EPA carried out consultation with government entities affected by this rule, including states, tribal governments, and local air pollution control agencies.

E. Executive Order 13132: Federalism

Executive Order 13132, entitled “Federalism” (64 FR 43255, August 10, 1999), requires EPA to develop an accountable process to ensure meaningful and timely input by state and local officials in the development of regulatory policies that have federalism implications. “Policies that have federalism implications” is defined in the Executive Order to include regulations that have “substantial direct effects on the states, or the relationship between the national government and the states, or on the distribution of power and responsibilities among the various levels of government.”

This final rule does not have federalism implications. It will not have substantial direct effects on the states, on the relationship between the national government and the states, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132. The CAA establishes the process whereby states take the lead in developing plans to meet the NAAQS. This rule will not modify the relationship of the states and EPA for purposes of developing programs to implement the NAAQS. Thus, Executive Order 13132 does not apply to this rule.

F. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

Executive Order 13175, entitled “Consultation and Coordination with Indian Tribal Governments” (65 FR 67249, November 2, 2000), requires EPA to develop an accountable process to ensure “meaningful and timely input by tribal officials in the development of regulatory policies that have Tribal implications.” This action does not have tribal implications, as specified in Executive Order 13175 (65 FR 67249, November 9, 2000). This rule concerns the designation and classification of areas as attainment and nonattainment for the PM_2.5 national ambient air quality standards. The CAA provides for states and eligible tribes to develop plans to regulate emissions of air pollutants within their areas based on their designations. The TAR provides tribes the opportunity to apply for eligibility to develop and implement CAA programs such as programs to attain and maintain the PM_2.5 NAAQS, but it leaves to the discretion of the tribe the decision of whether to apply to develop these programs and which programs, or appropriate elements of a program, the tribe will seek to adopt. This rule does not have a substantial direct effect on one or more Indian tribes. It does not create any additional requirements beyond those of the PM_2.5 NAAQS (40 CFR 50.13). This rule establishes the application of the PM_2.5 standard and the designation and classification for each area of the country for the PM_2.5 NAAQS. Additionally, no tribe has implemented a CAA program to attain the PM_2.5 NAAQS at this time. Furthermore, this rule does not affect the relationship or distribution of power and responsibilities between the federal government and Indian tribes. The CAA and the TAR establish the relationship of the federal government and tribes in developing plans to attain the NAAQS, and this rule does nothing to modify that relationship. Because this rule does not have tribal implications, Executive Order 13175 does not apply.

Although Executive Order 13175 does not apply to this rule, EPA communicated with tribal leaders and environmental staff regarding the designations process. EPA also sent individualized letters to all federally recognized tribes to explain the designation process for the 2006 24-hour PM_2.5 NAAQS, to provide the EPA designations guidance, and to offer consultation with EPA. EPA provided further information to tribes through presentations at the National Tribal Forum and through participation in National Tribal Air Association conference calls. EPA also sent individualized letters to all federally recognized tribes about EPA's intended area designations for the 24-hour PM_2.5 standards and offered tribal leaders the opportunity for consultation. These communications provided opportunities for tribes to voice concerns to EPA about the general designations process for the 24-hour PM_2.5 NAAQS, as well as concerns specific to a tribe, and informed EPA about key tribal concerns regarding designations as the rule was under development.

G. Executive Order 13045: Protection of Children From Environmental Health and Safety Risks

The action is not subject to Executive Order 13045 (62 FR 19885, April 23, 1997) because it is not economically significant as defined in Executive Order 12866, and because EPA does not have reason to believe that the environmental health risks or safety risks addressed by this rule present a disproportionate risk or safety risk to children. Nonetheless, we have evaluated the environmental health or safety effects of the PM_2.5 NAAQS on children. The results of this risk assessment are contained in the NAAQS for the 2006 24-hour PM_2.5, Final Rule (October 17, 2006, 71 FR 61144).

H. Executive Order 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use

This action is not subject to Executive Order 13211 (66 FR 28355 (May 22, 2001)), because it is not a significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act (NTTAA)

Section 12(d) of the NTTAA of 1995, Public Law No. 104-113, section 12(d) (15 U.S.C. 272 note), directs EPA to use voluntary consensus standards (VCS) in its regulatory activities unless to do so would be inconsistent with applicable law or otherwise impracticable. Voluntary consensus standards are technical standards (e.g., materials specifications, test methods, sampling procedures, and business practices) that are developed or adopted by VCS bodies. The NTTAA directs EPA to provide Congress, through OMB, explanations when the Agency decides not to use available and applicable VCS.

This action does not involve technical standards. Therefore, EPA did not consider the use of any VCS.

J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations

Executive Order 12898 (59 FR 7629 (Feb. 16, 1994)) establishes federal executive policy on environmental justice. Its main provision directs federal agencies, to the greatest extent practicable and permitted by law, to make environmental justice part of their mission by identifying and addressing, as appropriate, disproportionately high and adverse human health or environmental effects of their programs, policies, and activities on minority populations and low-income populations in the U.S.

The EPA has determined that this final rule will not have disproportionately high and adverse human health or environmental effects on minority or low-income populations because this rule does not affect the level of protection provided to human health or the environment.

K. Congressional Review Act

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, to each House of the Congress and to the Comptroller General of the U.S. The EPA will submit a report containing this rule and other required information to the U.S. Senate, the U.S. House of Representatives, and the Comptroller General of the U.S. prior to publication of the rule in the Federal Register. A major rule cannot take effect until 60 days after it is published in the Federal Register. This action is not a “major rule” as defined by 5 U.S.C. 804(2). This rule will be effective December 14, 2009.

L. Judicial Review

Section 307(b)(1) of the CAA indicates which Federal Courts of Appeal have venue for petitions of review of final actions by EPA. This section provides, in part, that petitions for review must be filed in the Court of Appeals for the District of Columbia Circuit: (i) When the agency action consists of “nationally applicable regulations promulgated, or final actions taken, by the Administrator,” or (ii) when such action is locally or regionally applicable, if “such action is based on a determination of nationwide scope or effect and if in taking such action the Administrator finds and publishes that such action is based on such a determination.”

This rule designating areas for the 2006 24-hour PM_2.5 NAAQS is “nationally applicable” within the meaning of section 307(b)(1). This rule establishes designations for areas across the U.S. for the 2006 24-hour PM_2.5 NAAQS. At the core of this rulemaking is EPA's interpretation of the definition of nonattainment under section 107(d)(1) of the CAA. In determining which areas should be designated nonattainment (or conversely, should be designated attainment or unclassifiable), EPA used an analytical approach that it applied consistently across the U.S..

For the same reasons, the Administrator also is determining that the final designations are of nationwide scope and effect for the purposes of section 307(b)(1). This is particularly appropriate because, in the report on the 1977 Amendments that revised section 307(b)(1) of the CAA, Congress noted that the Administrator's determination that an action is of “nationwide scope or effect” would be appropriate for any action that has a scope or effect beyond a single judicial circuit. H.R. Rep. No. 95-294 at 323, 324, reprinted in 1977 U.S.C.C.A.N. 1402-03. Here, the scope and effect of this rulemaking extends to numerous judicial circuits since the designations apply to all areas of the country. In these circumstances, section 307(b)(1) and its legislative history calls for the Administrator to find the rule to be of “nationwide scope or effect” and for venue to be in the DC Circuit.

Thus, any petitions for review of final designations must be filed in the Court of Appeals for the District of Columbia Circuit within 60 days from the date final action is published in the Federal Register.

List of Subjects in 40 CFR Part 81

• Environmental protection
• Air pollution control
• National parks
• Wilderness areas

For the reasons set forth in the preamble, 40 CFR part 81, subpart C is amended as follows:

PART 81—DESIGNATIONS OF AREAS FOR AIR QUALITY PLANNING PURPOSES

1. The authority citation for part 81 continues to read as follows:

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

Subpart C—Section 107 Attainment Status Designations

2. Section 81.300 is amended by revising paragraph (a) to read as follows:

2a. Section 81.301 is amended as follows:

a. By revising the table heading for “Alabama—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Alabama—PM _2.5 (24-Hour NAAQS)” to the end of the section.

3. Section 81.302 is amended as follows:

a. By revising the table heading for “Alaska—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Alaska—PM _2.5 (24-Hour NAAQS)” to the end of the section.

4. Section 81.303 is amended as follows:

a. By revising the table heading for “Arizona—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Arizona—PM _2.5 (24-Hour NAAQS)” to the end of the section.

5. Section 81.304 is amended as follows:

a. By revising the table heading for “Arkansas—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Arkansas—PM _2.5 (24-Hour NAAQS)” to the end of the section.

6. Section 81.305 is amended as follows:

a. By revising the table heading for “California—PM _2.5” to read as set forth below.

b. By adding a new table entitled “California—PM _2.5 (24-Hour NAAQS)” to the end of the section.

7. Section 81.306 is amended as follows:

a. By revising the table heading for “Colorado—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Colorado—PM _2.5 (24-Hour NAAQS)” to the end of the section.

8. Section 81.307 is amended as follows:

a. By revising the table heading for “Connecticut—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Connecticut—PM _2.5 (24-Hour NAAQS)” to the end of the section.

9. Section 81.308 is amended as follows:

a. By revising the table heading for “Delaware—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Delaware—PM _2.5 (24-Hour NAAQS)” to the end of the section.

10. Section 81.309 is amended as follows:

a. By revising the table heading for “District of Columbia—PM _2.5” to read as set forth below.

b. By adding a new table entitled “District of Columbia—PM _2.5 (24-Hour NAAQS)” to the end of the section.

11. Section 81.310 is amended as follows:

a. By revising the table heading for “Florida—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Florida—PM _2.5 (24-Hour NAAQS)” to the end of the section

12. Section 81.311 is amended as follows:

a. By revising the table heading for “Georgia—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Georgia—PM _2.5 (24-Hour NAAQS)” to the end of the section.

13. Section 81.312 is amended as follows:

a. By revising the table heading for “Hawaii—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Hawaii—PM _2.5 (24-Hour NAAQS)” to the end of the section.

14. Section 81.313 is amended as follows:

a. By revising the table heading for “Idaho—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Idaho—PM _2.5 (24-Hour NAAQS)” to the end of the section.

15. Section 81.314 is amended as follows:

a. By revising the table heading for “Illinois—PM _2.5” to read as set forth below.

b. By adding a new table entitled “Illinois—PM _2.5 (24-Hour NAAQS)” to the end of the section.

16. Section 81.315 is amended as follows:

a. By revising the table heading for “Indiana PM _2.5” to read as set forth below.

b. By adding a new table entitled “Indiana PM _2.5 (24-Hour NAAQS)” to the end of the section.

17. Section 81.316 is amended as follows:

a. By revising the table heading for “Iowa PM _2.5” to read as set forth below.

b. By adding a new table entitled “Iowa PM _2.5 (24-Hour NAAQS)” to the end of the section.

18. Section 81.317 is amended as follows:

a. By revising the table heading for “Kansas PM _2.5” to read as set forth below.

b. By adding a new table entitled “Kansas PM _2.5 (24-Hour NAAQS)” to the end of the section.