National Ambient Air Quality Standards and Implementation

1. National Ambient Air Quality Standards and Implementation National Tribal Forum June 2011

2. What are NAAQS? • Title I of CAA directs EPA to establish National Ambient Air Quality Standards (NAAQS) for commonly occurring air pollutants posing public health threats • NAAQS set national levels for acceptable concentrations of specific pollutants in outdoor air known as “criteria pollutants” • NAAQS consist of pollutant concentrations in air that may not be exceeded • NAAQS are federal standards that apply coast-to-coast, regardless of jurisdiction

3. National Ambient Air Quality Standards • Two types of standards are developed: • “Primary” standards to protect public health with an adequate margin of safety • “Secondary” standards to protect public welfare and the environment • The CAA requires EPA to review the standard set for each criteria pollutant every 5 years with advice from the Clean Air Scientific Advisory Committee (CASAC)

4. National Ambient Air Quality Standards

5. Current Schedule for Ongoing NAAQS Reviews (March 2011) NOTE: Underlined dates indicate court-ordered or settlement agreement deadlines Next Ozone Review: Proposal in Jun 2013 and Final in Mar 2014

6. PM NAAQS Review

7. PM NAAQS Review Process to Date • Current review initiated in 2007; includes review of primary (health-based) and secondary (welfare-based) standards for fine and coarse particles • Review is thorough and extensive, with many opportunities for CASAC and public comment; final documents take into consideration CASAC and public comments on multiple draft documents • Integrated Science Assessment: final document issued December 2009 • Synthesis and assessment of most policy-relevant science • Risk/Exposure Assessments: final documents issued June/July 2010 • Quantitative Health Risk Assessment; Urban-Focused Visibility Assessment • Focus on fine particles and did not assess risks associated with coarse particles • Policy Assessment: final document issued April 2011 • Staff conclusions address adequacy of current standards and potential alternative standards appropriate to consider • Discusses broadest range of policy options supported by the available scientific evidence, quantitative assessments, and air quality analyses • All documents available at: http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_index.html

8. Final Policy Assessment Conclusions and CASAC Advice Primary (health-based) PM2.5 Standards • Staff and CASAC conclude it is appropriate to consider revising the standards to provide increased public health protection • Consider revisingannual standard level within a range of 13-11 µg/m3(current standard is 15 µg/m3) • Staff concludes that evidence most strongly supports range of 12 -11 µg/m3 • Consider retaining or revising 24-hour standard level within a range of 35-30 µg/m3(current standard is 35 µg/m3) Primary (health-based) PM10 standards • Staff concludes scientific evidence and associated uncertainties could provide support for eitherretaining or revising the current primary 24-hour PM10 standard • To the extent consideration is given to revising the standard, staff concludes it would be appropriate to consider a 98th percentile form in conjunction with a level within a range of 85 to 65 µg/m3 • CASAC does not support retaining the current PM10 standard; recommendsrevising form and level in order to increase public health protection • CASAC recommends a 98th percentile form in conjunction with a level within a range of 75 to 65 µg/m3 Secondary (welfare-based) PM standards • Staff and CASAC agree that it is appropriate to consider setting a distinct secondary PM2.5 standard to address visibility impairment primarily in urban areas; considering options for structuring such a secondary standard distinct from the primary PM2.5 standards, in terms of: • Alternative indicators, averaging times, and forms • Selecting alternative standard levels that reflect appropriate degree of public welfare protection No decisions have been made at this time • EPA anticipates issuing a proposal for public review and comment later this year

9. Review of the Secondary NAAQS for Oxides of Nitrogen and Sulfur

10. Overview • Existing secondary NAAQS (for environmental effects): • For NO2: 0.053 ppm (parts per million) averaged over a year; and • For SO2: 0.5 ppm averaged over three hours, not to be exceeded more than once per year • In this review, for the first time, EPA is reviewing the environmental impacts of pollutants separately from the health-based impacts, and considering the effects of multiple pollutants simultaneously. Specifically, EPA’s Integrated Science Assessment covers: • Oxides of nitrogen (N) and sulfur (S) -- the “criteria pollutants” : • SO2 andNO2 – indicators for current secondary standard • Particulate sulfate, SO4, combined with SO2 is defined as SOx • NOy – includes the transformation products from emissions of oxides of nitrogen (e.g., nitric acid and particulate nitrate) • Forms of N which are not criteria pollutants, but that contribute to N deposition, include: • Ammonia gas, NH3 • Ammonium ion, NH4 • EPA is under a court-ordered schedule to sign a proposed rule by July 12, 2011 Together referred to as reduced nitrogen, NHx

11. Key Issues • Existing secondary standards protect against direct effects of gaseous NO2 and SO2 on vegetation • In addition to affecting plants, oxides of nitrogen and sulfur are associated with an array of deposition-related effects, including nutrient enrichment and aquatic acidification • When deposited on land and in lakes and streams, oxides of nitrogen and sulfur affect soils, water quality, and fish and wildlife • In this review, the EPA has been exploring the possibility of developing a multi-pollutant standard to address deposition-related effects, particularly aquatic acidification • Because different ecosystems vary in the amount of acid deposition they can tolerate, the EPA staff has been working to develop a formula called the “Aquatic Acidification Index” (AAI) that could be used to relate ambient levels of oxides of nitrogen and sulfur to water quality • The terms of the equation need to be quantified on an area-specific basis, because ecosystem sensitivity varies across the nation due to variable geologic, hydrologic, and environmental factors • The significant challenge is to translate spatially variable effects into a national standard, including limitations on available monitoring data

12. Conceptual Model of an Aquatic Acidification Standard Ecological effects and ecological indicator (Acid Neutralizing Capacity, ANC) Linking atmospheric deposition to ecological indicator Linking deposition to “allowable” concentrations of oxides of N and S in ambient air • Aquatic effects are not directly related to concentrations of oxides of N and S in the ambient air– major difference from other NAAQS standards • Linkage between ecological effects and deposition of oxides of N and S is characterized by critical load modeling • Linkage between deposition and air concentrations of oxides of N and S is characterized by atmospheric modeling that translates emissions of N and S into estimates of both ambient concentrations and related deposition • Model also takes into account deposition of N from reduced forms of nitrogen (e.g., ammonia) that contribute to the aquatic effects but are not part of the “criteria” pollutants addressed by this standard

13. Illustrating the Complexity: Significant Variation Among Ecoregions • Omernik Ecoregion III classification scheme (developed in the 1980s by EPA) divides the continental U.S. into 84 ecologically relevant regions, based on common vegetation, geology, soils, and hydrological characteristics • A multi-pollutant standard for oxides of nitrogen and sulfur must account for these differences to provide appropriate degree of protection against aquatic acidification in different regions • Remaining complexities and uncertainties will be challenging to address

14. Acid Sensitive and Non-Sensitive Ecoregions • Categorization based on water quality data and land use categories (naturally acidic and managed areas categorized as relatively non-sensitive) • Ecosystem sensitivity varies across the nation, predominantly due to variability of geologic material (bedrock and soils) which buffers acidifying deposition

15. NAAQS Implementation

16. AnticipatedNAAQS 110 SIP Implementation Milestones Updated April 2011 Section 110 plans will be needed for multiple NAAQS in coming years.

17. Ozone Implementation Rules • Revisions to implementation rule for 1997 8-hr ozone NAAQS • Draft 2011 ozone NAAQS implementation rule will address: • Proposed approaches to classifying ozone nonattainment areas • Air quality thresholds for Marginal, Moderate, Serious, Severe, and Extreme • Impact of options will be illustrated using 2008-2010 air quality data • Attainment deadlines for each classification • State Implementation Plan (SIP) schedule and requirements for primary standard nonattainment areas • Planning and control requirements currently required for the 1997 NAAQS that must continue to be implemented (i.e., “anti-backsliding” requirements) • Implementation approach for first-ever separate secondary standard, including classifications and SIP requirements

18. PM 2.5 Implementation • SIP timeline • For the 2006 standards • Designations occurred in Dec. 2009, and SIPs are due Dec. 2012 • For the 2012 standards (assume promulgation in 2012) • Designations would be in 2014, and SIPs would be due in 2017

19. Implementation Guidance for 2006 PM2.5 Standards • Framework of existing implementation rule is appropriate for attainment planning for 2006 PM2.5 standards. Guidance memo (not rule revision) on key issues under development. • Interpretation of existing rule as applied to 2006 standards • Attainment within 5 years based on 2012-2014 air quality data • RFP policy revision: no credit for reductions outside the NA • RFP milestone years if attainment date beyond 5 years: 2014, 2017 • Reminder that PM2.5 attainment planning and control strategies must account for condensable PM2.5 emissions. • Significant local health benefits from direct PM2.5 reductions • Issued “Strategies for Reducing Residential Wood Smoke” (Oct. 2009) • www.epa.gov/ttncaaa1t1/memoranda/strategies-doc-8-11-09.pdf

20. Redesignation Requests • 1997 8-hr Ozone NAAQS • Moderate area requests (June 2011 attainment deadline extensions) are pending for RACT updates of 2006-2007 CTG revisions • Baton Rouge Area, LA; Chicago-Gary-Lake County Area, IL; Milwaukee-Racine Area, WI; Sheboygan Area, WI; St. Louis Area, IL; Phoenix-Mesa Area, AZ (Former Subpart 1) • 1997 PM2.5 NAAQS • Most are pending final Transport Rule • Chicago-Gary-Lake County, IN; Cincinnati-Hamilton, KY; Evansville, IN; Greensboro-Winston Salem-High Point, NC; Hickory-Morganton-Lenoir, NC; Birmingham, AL (also 2006 PM2.5 NAAQS)

21. CO NAAQS Review • Proposed to retain current standard on January 28, 2011 • Public health and environmental organizations in NESCAUM support revision • Industry and 4 state agencies support retention • Proposed ambient air monitoring requirements to co-locate CO monitors with “near-road” NO2 monitors in urban areas having populations of 1 million or more • Approximately 77 CO monitors within 53 urban areas, as part of the overall CO monitoring network • NACAA, NESCAUM, NYSDEC, and public health and environmental groups support new requirements, but states want population threshold raised to 2.5 million • Many also concerned about losing Neighborhood monitors • Industry and several state and local governments do not support near-road monitoring • There are currently no CO nonattainment areas for existing standards (9 ppm 8-hr, 35 ppm 1-hr) • Final rule due by August 12, 2011

22. Exceptional Events Guidance • Flagging Monitoring Data for exclusion for determining nonattainment • Draft Guidance Products Available Now • Overview of draft guidance and 2 attachments • Frequently asked questions (~30 pages) • High Winds Guidance Document (~60 pages) • Deadline for comments is 6/30/11; will work with state/local/tribal stakeholders in developing solutions to identified issues • Finalize guidance in November after broader outreach and comment (longer timeframe if rule revisions are pursued) • Website with example demonstration submittals at http://www.epa.gov/ttn/analysis/exevents.htm • Draft Guidance Products Under Development • Guidance document on wildfire events and ozone – summer 2011 draft for review • Replacement for EPA’s Interim Fire Policy • Currently reconsidering the purpose and approach in light of interagency review comments. • Anticipate components to clarify treatment of agricultural burning and better define “basic smoke management practices” • Will then meet with states and federal agencies to discuss concepts before issuing new draft for public comment

23. Pb Designations • The final Pb NAAQS was signed on October 15, 2008. • Guidance was published in the Federal Register as part of the Pb NAAQS revision on November 12, 2008 • Pb designations is occurring in two rounds: • The first round of designations was signed on November 16, 2010. • Designated 16 areas as nonattainment. • Deferred designations for all other areas to the second round. • Statutory deadline for the second round of designations is October 14, 2011. • 120-day letters are due June 15, 2011. • Anticipating designating 5 areas as nonattainment. • Remaining areas will be designated as unclassifiable/attainment. • No tribal areas were designated nonattainment in the first round, and we don't expect any areas to be designated nonattainment in the second round. • Under section 110 of the Clean Air Act, all states (including those without any nonattainment areas) are required to submit infrastructure SIPs by October 15, 2011 • Among the requirements for an infrastructure SIP is a permit program implementing PSD and nonattainment NSR. • Attainment Demonstrations SIPs, for round one, are due June 30, 2012. For the second round, attainment SIPS are expected to be due June 30, 2013 • The attainment date for the first round is December 31, 2015, and the attainment date for the second round is expected to be December 31, 2016

24. Ozone Designations • EPA is reconsidering the 2008 ozone NAAQS. • Proposed more protective standards in January 2010 • Final decision expected by end of July 2011 • New NAAQS established as a result of the reconsideration would replace the 2008 ozone NAAQS. EPA does not intend to implement the 2008 NAAQS • Final NAAQS rule will provide schedule for designating areas for 2011 ozone NAAQS, including deadline for submitting area designation recommendations • EPA will be providing guidance and training to help tribes participate in the designations process

25. PSD Revisions for Part 52.21(u) • Working on a rule to remove the preclusion of tribes taking delegation of the PSD program • Proposal in September 2011 • Final in January 2012

26. For More Information • Contact • Laura McKelvey • Mckelvey.laura@epa.gov • 919-541-5497 • Angel McCormack • Mccormack.angel@epa.gov • 919-541-3588 • Visit the NAAQS website • http://www.epa.gov/ttnnaaqs