THE ADMINISTRATOR OFTHE ENVIRONMENTAL PROTECTION AGENCY

Mr

.JoshuaStebbins Managing Attorney The Sierra Club 50 F Street, NW, EighthFloor Washington, D.C. 20001
DearMr. Stebbins: WASHINGTON

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## AUG 142014

Onbehalfofthe Sierra Club, you and your colleague SethJohnson, filed onNovember 14, 2013, a petition requesting that the U.S. Envirorunental Protection Agencyredesignate as nonattairunent 57 areas with 2012 designvalues violating the 2008 National AmbientAir Quality Standards for ozone. Furthennore, the Sierra Clubrequested that the EPA set specific boundariesfor the areas as identified in the petition. TheEPA has carefully evaluated the issues andinfonnationin yourpetition as well as infonnation obtained from therespective states with areas listedinyourpetition. Forthe reasons explained inthe enclosure, theEPAisdenying thepetitionusing thediscretionthatthe CleanAirAct affords me as Administrator to not initiate theredesignation process for any oftheareas identified inthe Sierra Club petition.
As an initial matter, 22 areas identified inthe petition are again attaining the ozoneNAAQS based on 2013 designvalues. Astothe remaining areas, the EPA believesit is appropriate to allow time for affected statesto consider appropriate measures toaddress the air-quality problems. TheEPA expects thatreductions inemissions ofoxides ofnitrogen and volatile organiccompounds dueto existingfederal measures, such astheTier3 motor-vehicle standards, and state-ledefforts will assistthese areas in attaining the 2008 ozone NAAQS. TheEPAplans to publish a notice ofthis denial inthe

### Federal Register.
I appreciate the SierraClub andEarthjustice'sinterestinreducing ground-level ozone levels and in providing cleaner, healthier air for all Americans. Sincerely,

Enclosure

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.Enclosure Response to Petition from Sierra Club to Redesignate as Nonattainment 57 Areas with 2012 Design Values Violating the 2008 8-Hom· National Ambient Air Quality Standards for Ozone
By Petition dated November 14,2013, Sierra Club requested that the U.S. Environmental Protection Agency redesignate as nonattainment 57 areas with 2012 design values violating the 2008 national ambient air quality standards (NAAQS) for ozone. Sierra Club further requested that the EPA set specific boundaries for the areas, as identified in the Petition. For the reasons discussed below, the EPA is denying the Petition. Whenever the EPA promulgates a new orrevised NAAQS, the EPA has a mandatory duty under CAA section 107(d)(l) to designate all areas in the country no later than 2 years from promulgation ofthe new or revised NAAQS. (The EPA may extend the deadline by up to I year ifthe EPA has insufficient information to complete the designations in 2 years.) For the 2008 ozone NAAQS, the EPA completed these initial area designations in spring of2012. The EPA based the designations on the most recent cetiified air quality data available at that time (e.g., generally, 2008-2010 data and, in some cases, 2009- 2011 data). For areas designated as attainment that subsequently violate the NAAQS, the CAA provides the EPA with discretion regarding whether and when to redesignate such areas to nonattainment. Section 107(d)(3) ofthe CAA states, "onthe basis ofair quality data, planning and control considerations, or any other air quality-related considerations the Administrator deems appropriate, the Administrator may at any time notify the Governor ofany State that available information indicates that the designation of any area or pottion ofan area within the State or interstate area should be revised." Thus, unlike initial designations, the Administrator does not have a mandatory duty to initiate the redesignation process. Ground-level ozone is not emitted directly into the air, but is created by chemical reactions between ozone precursors, primarily oxides ofnitrogen (NOx) and volatile organic compounds (VOC), in the presence ofsunlight. Therefore, the CAA and the EPA's regulations to control ozone focus on reducing emissions ofNOx and VOC. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some ofthe major sources ofNOx and VOC. Ozone design values are statistics that describe the air quality status ofa given area relative to the level ofa NAAQS. They are based on a 3-year average ofthe annual4111 highest daily maximum 8-hour ozone concentration. Variations in weather conditions play an important role in determining ozone levels and thus design values can fluctuate f!·om year to year. Ozone levels tend to be highest during the summer months, especially during periods ofhot, dry and stagnant weather conditions. The EPA notes that the summer of2012 was characterized by unusually hot, dry, and stagnant weather conditions, while, conversely, the summer of2009 was characterized by cooler and wetter than normal conditions throughout much ofthe United States. These weather conditions contributed to annual4111 highest daily maximum 8-hour ozone concentrations which were 6 parts per billion (ppb) higher on average in 2012 than in 2009. This translates to an average 2 ppb increase in ozone design values from the 2009-2011 period to the 20I0-2012 period.
In evaluating whether the agency should exercise its discretion under CAA section 107(d)(3) to initiate the redesignation process for the areas identified in the Petition, the EPA considered air quality trends and expected emissions reductions in the near term. The EPA tracks the levels ofozone and the other NAAQS pollutants in the air and how much ofeach pollutant (or the pollutants that form them) isemitted from various pollution sources. The agency reviews these values year after year to see how the levels and emissions ofthe pollutants have changed over time. Nationally, ozone levels have shown a notable decline since 2002. (See http://www.epa.govlairtrendslozone.html.) The EPA expects this overall long-term trend to continue as additional emissions reductions are achieved through existing regulations. Based on the 2013 ozone design values, 22 ofthe 57 areas identified in the Petition are again attaining the NAAQS. The EPA notes that ifthe EPA were to grant the Petition to initiate the redesignation process for one or more areas, we would base the redesignations on the most recent, quality assured air quality design values rather than the 2012 design values. Therefore, the EPA would not grant the Petition for any area for which the most current design value shows attainment.
Our expectation that ozone levels will continue to decline is supported by emissions inventories and projected inventories ofNOx and VOC emissions that indicate significant emissions reductions in the coming years. The EPA compiles the National Emissions Inventory (NEI) 1every 3 years. The NEI is a compilation ofemissions data collected from state, local and tribal air agencies as well as from the EPA's emissions collection for emissions trading programs and from EPA emissions estimation tools and models. The 20ll NEI is the most recent emissions inventory. In addition, the EPA has projected emissions for 2018,2 which have been compiled from a variety ofsources and include projected emissions reductions from numerous existing EPA regulations. The 2018 projected emissions are estimated using the EPA models for electric generating utilities, on-road vehicles and nonroad engines, as well as by projecting 20ll emissions to 2018 for other sources. A comparison ofthe 20ll NEI and the projected 2018 emissions inventory provides a prediction ofthe change in NOx and VOC emissions over that several year period.3
Emissions ofNOx in the United States are expected to decline by 29 percent from 2011 through 2018,
even when accounting for increases in some sectors, such as the oil and gas production industry. A comparison ofthe 2011 NEI and the projected 2018 emission inventory predicts a reduction ofNOx emissions from 14.1 million tons in 20II to I0 million tons in 2018, a 4.1 million ton reduction. Existing EPA regulations primarily account for those reductions, which come from a variety ofsources. On-road mobile source emissions reductions of3 million tons are predicted from Tier 2, heavy duty, and other motor vehicle standards implemented years ago, as oldervehicles are replaced with newer cars and trucks meeting better fuel economy and other standards. The 3 million ton estimate also includes early reductions from the recently finalized Tier 3 standards that EPA expects will provide significant NOx emissions reduction benefits from on-road mobile sources in 2018. Approximately 740,000 tons ofNOx reductions come from locomotive and nonroad engine rules. Reductions from electric generation account for about 500,000 tons ofthe projected reductions, resulting from the ongoing EPA NOx trading programs as well as other factors such as increased use ofnatural gas. Expected NOx emissions increases ofabout 140,000 tons for the oil and gas sector and about 30,000 tons for other smaller sectors partly offset the reductions, but the net result is still an overall 29 percent decrease in NOx emissions. Emissions ofVOC in the United States are expected to decline by 10 percent from 2011 through 2018, even when accounting for increases in some sectors such as the oil and gas production industry. A comparison ofthe 20II and 2018 emission inventories predicts a reduction ofVOC from 17.2 million

1 20II National Emissions Inventory Technical Support Document (http:! /www.epa.govlttn/ chieflnet/20IIinvent01y.html#inven/Otydoc). 2 20II and 2018 Emissions Modeling Platform Technical Support Document (http:! /www. epa.gov/1/n/ chief! emch/index.htm/#20I !). 3 The projected 2018 emissions inventory may be used by the Office ofAir and Radiation in several contexts, including the development ofrules related to the transport ofair pollution and the NAAQS. 2tons in 201 I to 15.5 million tons in 2018, a 1.7 million ton reduction. Existing EPA regulations primarily account for those reductions, which come from a variety ofsources. On-road mobile source reductions ofI.2 million tons come from Tier2, heavy duty, and other standards implemented years ago, as older vehicles are replaced with newer cars and trucks meeting better fuel economy and other standards. The I.2 millionton estimate also includes early reductions from the recently finalized Tier 3 standards that the EPA expects will provide VOC emissionreduction benefits from on-road mobile sources in 2018. Another approximately 664,000 tons ofVOC reductions come from nonroad engine rules. Expected VOC increases ofabout 298,000 tons for the oil and gas sector and about 27,000 tons for other smaller sectors partly offset the reductions, but the net result is an overall I0 percent decrease in VOC. The EPA notes that, based on 2013 design values, all but I ofthe areas identified in the Petition would be classified as Marginal ifredesignated to nonattainment. The Marginal classification is for nonattainment areas with ozone levels closest to the level ofthe NAAQS. Under CAA section I82(a), Marginal areas have nominal planning requirements (e.g., submission ofperiodic emissions inventory and establishment ofreasonably available control technology) and are not required to submit attainment demonstrations. Attainment demonstrations, which are required for nonattainment areas with higher classifications, are state plans that describe the local, regional and national control measures to be implemented to reduce emissions in order for the area to demonstrate attainment by the required attainment date. When Congress amended the CAA in I990, it anticipated that nonattainment areas with ozone concentrations close to the level ofthe NAAQS would likely come into attainment within 3 years after designation as nonattainment without any additional local planning. Therefore, redesignating the areas identified in the Petition to nonattainment that would be classified as Marginal would not on its ownresult in additional local attainment planning requirements for the areas. The EPA believes that the NOx and VOC emissions reductions discussed above that are projected in the nearterm from existing regulations will assist the areas identified in the Petition in meeting the ozone NAAQS. Fornewly violating areas, the EPA and states may pursue various options for addressing emerging air qualityproblems. Historically, EPA'srecommended approach has been to assist state and local officials, local stakeholders and tribes to develop collaborative strategies to bring newly-violating areas back into attainment as soon as possible. The EPA Regional Offices address the emerging air quality problems as partofthe annual grant negotiations with their states. The annual EPA grant guidance includes a performance measure to have the EPA Regional Office and the respective state target grant funds to specific actions to bring newly violating designated attainment areas into compliance with the respective NAAQS. (See Performance Measure OAQPSNJO in OAR National Program Guidance Fiscal Year 2014

- http:l/www2.epa.gov/planandbudget/national-program-manager-guidances#fY2014.) The grant agreements have included enforceable and voluntary agreements, such as the EPA's Ozone Advance Program,4 to reduce emissions. Nineteen ofthe 57 areas listed in the Sierra Club Petition have chosen to participate in Ozone Advance, a voluntary program that encourages emissions reductions in ozone attainment areas by providing EPA assistance to help these areas continue to meet the ozone NAAQS. While the program itselfdoes not establish any regulatory requirements, it provides a framework for local action and for closer collaboration with the EPA. The EPA provides technical advice and other support including identifying available tools and resources that may be used to putplans in place to keep ozone levels under control.
Forthe reasons explained above, the EPA is choosing not to exercise its discretion to initiate the redesignation process for the areas identified in the Sierra Club Petition. Furthermore, because the EPA

4See Ozone Advance Program website at http://www.epa.gov/ozonepmadvance/. 

### 3is denying the Petition and is not initiating the process to redesignate any ofthe 57 areas identified in the Petition, the issue ofappropriate nonattainment area boundaries is not triggered. However, the EPA notes that, even ifthe EPA were to grant the Petition to initiate the redesignation process for one or more areas, we would not grant the request to establish specific boundaries for designated nonattainment areas. Section I07(d)(3)(A-C) ofthe CAA establishes the process for redesignating areas to nonattainment, which is an interactive process between states and the EPA. 

### It is only upon completion of that process resulting in a redesignation ofan area to nonattainment that the final boundaries ofthe nonattainment area would be established.

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