1. 1 Update on National Ambient Air Quality Standards (NAAQS) National Air Quality Conference March 16, 2010 Lydia Wegman US Environmental Protection Agency Office of Air Quality Planning and Standards

2. 2 Integrated Review Plan timeline and key policy-relevant scientific questions Integrated Science Assessment : concise evaluation and synthesis of most policy-relevant studies Risk/Exposure Assessment: concise quantitative assessment focused on key results, observations and uncertainties Workshop on science-policy issues Public hearings and comments on proposal EPA final decision on standards Interagency review Agency decision- making and draft proposal notice Agency decision- making and draft final notice CASAC review and public comment Policy Assessment staff analysis of policy options based on integration and interpretation of information in ISA and REA EPA proposed decision on standards Peer-reviewed scientific studies Current NAAQS Review Process

3. 3 NAAQS in 2010 NO 2 – Final in Jan 2010 SO 2 – Final in June 2010 O 3 Reconsideration – Final in Aug 2010 CO – Proposal in Oct 2010 PM – Proposal in Nov 2010

4. 4 Current Schedule for Ongoing NAAQS Reviews MILESTONE POLLUTANT LeadNO 2 PrimarySO 2 Primary Ozone Reconsideration COPM NO 2 /SO 2 Secondary NPR New schedule being developed Jun 26, 2009Nov 16, 2009Jan 6, 2010 Oct 28, 2010 Nov 2010July 12, 2011 NFROct 15, 2008Jan 22, 2010Jun 2, 2010Aug 31, 2010 May 13, 2011 July 2011Mar 20, 2012 NOTE: Underlined dates indicate court-ordered or settlement agreement deadlines Next Ozone Review: Proposal in May 2013 and Final in Feb 2014

5. 5 NO 2 NAAQS On January 22, 2010 EPA strengthened the primary national ambient air quality standard (NAAQS) for nitrogen dioxide (NO 2 ) to increase protection of public health by: –adding a 1-hour NO 2 standard at 100 parts per billion (ppb); and –retaining the annual average NO 2 standard at a level of 53 ppb Revised NO2 standard reflects the maximum allowable NO2 concentrations anywhere in an area. In many locations, these maximum concentrations are likely to occur around roads Some monitors will be located to focus on vulnerable and susceptible groups Under a separate review, EPA is considering the need for changes to the secondary NO 2 standard For more information go to http://www.epa.gov/air/nitrogenoxideshttp://www.epa.gov/air/nitrogenoxides

6. 6 Utilities (22%) Mobile Sources (58%) Other (8%) Industrial/commercial/residential combustion (12%) Sources of NO x Pollution Based on 2002 National Emissions Inventory data

7. 7 NO 2 NAAQS Implementation Schedule MilestoneDate State Designation Recommendations to EPA January 2011: One year following promulgation (Based on existing network data) Designations January 2012: EPA designates all/most areas as “unclassifiable” (because near road monitors not in place) New NO 2 Monitoring Network January 1, 2013: All monitors operating Next NO 2 NAAQS Review Completed January 2015: Anticipated time frame Nonattainment Re- Designations (discretionary) January 2016/2017 (depending on date that sites become operational) Attainment Date January 2021/2022 (5 years after date of nonattainment designations)

8. 8 SO 2 NAAQS November 16, 2009: EPA proposed to strengthen primary standards for sulfur dioxide (SO 2 ) to improve public health protection EPA proposed: –A new 1-hour SO 2 standard to better protect public health by reducing people’s exposure to high short-term concentrations of SO 2 –Level between 50 - 100 ppb –Would replace annual and 24-hour primary SO 2 standards Current standards were established in 1971 –In the last review of the SO 2 standards, completed in 1996, EPA considered, but did not set, a 5- minute primary standard to protect asthmatics –In 1998, the U.S. Court of Appeals for the District of Columbia Circuit remanded this decision back to EPA for further explanation –Evaluation of scientific evidence indicates that a 1-hr standard would better protect public health by reducing people’s exposure to high short term concentrations of SO2 EPA’s proposal is consistent with the recommendations of the Clean Air Scientific Advisory Committee The final rule will be signed no later than June 2, 2010 EPA is reviewing secondary SO 2 standard separately –Part of a joint review with NO 2 secondary standards -- to be completed in 2012 –For more information, go to http://www.epa.gov/air/urbanair/so2http://www.epa.gov/air/urbanair/so2

9. 9 Sources of SO 2 Pollution Fossil fuel combustion at power plants (66%) and other industrial facilities (29%) are the main sources of SO 2 emissions Other sources include industrial processes such as extracting metal from ore, and the burning of high sulfur fuels by locomotives, large ships, and non-road equipment

10. 10 SO 2 NAAQS Implementation Timeline MilestoneDate Signature – Final RuleJune 2, 2010 State Designation Recommendations to EPA June 2011 Final DesignationsJune 2012 SIPs DueWinter 2014 Attainment DateSummer 2017

11. 11 CO NAAQS Proposal Oct 28, 2010 Final May 13, 2011 March 22-23 CASAC review of the 2 nd draft Risk and Exposure Assessment and draft Policy Assessment

12. 12 Ozone NAAQS Reconsideration Proposal signed on January 6, 2010. Public comment period of 60 days closes on March 22, 2010 3 Public hearings Final Rule to be signed by August 31, 2010.

13. 13 The proposal reconsiders the 2008 decision on the ground-level ozone standards based on the scientific and technical record used in the March 2008 review, which included more than 1,700 scientific studies. In this reconsideration, EPA is not relying on studies about the health and ecological effects of ozone that have been published since the science assessment to support the 2008 review was completed in 2006. However, EPA’s Office of Research and Development conducted a provisional assessment of these newer studies and found they do not materially change the conclusions of the Agency's earlier science assessment. The proposed range is within the range recommended by CASAC. –The ozone standards set in 2008 were not as protective as recommended by EPA’s panel of science advisors, the Clean Air Scientific Advisory Committee (CASAC). Reconsidering the Ground-Level Ozone Standards

14. 14 Ozone Health Impacts: “ Pyramid of Effects ” At-risk groups include: –People with lung disease such as asthma or chronic obstructive pulmonary disease (COPD). –Children. –Older adults. –People who are more likely to be exposed, such as people who are active outdoors, including children and outdoor workers. Proportion of Population Affected Severity of Effects

15. 15 Ozone and the Environment Ground-level ozone is absorbed by the leaves of plants, where it can: –Interfere with the ability of sensitive plants to produce and store food. This can lead to reduced growth, biomass production and yields. –Make sensitive plants more susceptible to certain diseases, insects, harsh weather, other pollutants, and competition. –Reduce or change plant species diversity in associated ecosystems. This can lead to damage to ecosystems dependent on those species. –Visibly injure the leaves of plants, affecting the appearance of vegetation in national parks, recreation areas and cities.

16. 16 EPA is proposing to strengthen the level of the 8-hour primary ozone standard to a level within the range of 0.060-0.070 parts per million (ppm). The proposal to set a primary standard within this range places additional weight on key pieces of scientific evidence, including: –evidence from clinical studies showing effects in healthy adults at 0.060 ppm, including decreased lung function and respiratory symptoms; –evidence from clinical and epidemiological studies indicating that people with asthma are likely to experience larger and more serious effects than healthy people; –epidemiological evidence indicating associations for a wide range of serious health effects, including respiratory-related emergency department visits and hospital admissions and risk of premature mortality, that extend below the current standard level of 0.075 ppm; and –estimates from the risk and exposure assessment indicating that important improvements in public health could be achieved by a standard more stringent than 0.075 ppm. Proposed Revisions to Primary Ozone Standard

17. 17 The proposed secondary standard, called W126, is designed to account for the cumulative effects of repeated ozone exposures on sensitive vegetation during the three months of the year when ozone concentrations are highest EPA is proposing a cumulative, seasonal secondary standard at a level in the range of 7-15 ppm-hours. –This cumulative standard would add weighted hourly ozone concentrations across all days in a three-month period. The Administrator proposed that a seasonal secondary standard identical to the primary standard, as was set in 2008, is inadequate to provide the requisite level of protection for vegetation and ecosystems. More details about the W126 standard in next slide and at breakout session on Communicating the NAAQS Revisions – Roundtable Discussion Proposed Revisions to Secondary Ozone Standard

18. 18 Daily value = Sum of values over 12 daylight hours Steps in calculating W126 value for a particular site: 1.Measure hourly ozone (O 3 ) concentrations for each hour within the 12 hour daylight period (8am-8pm). 2.Assign a weight to each hourly value based on concentration: lower concentrations receive less weight than higher concentrations. 3.Sum the 12 weighted hourly values to calculate a daily W126 value. 4.Repeat steps 1-3 for each day within the ozone season and then sum the daily values to calculate the monthly W126 value. 5.Identify the consecutive 3-month period whose monthly W126 values produce the highest total. This total becomes the seasonal W126 for this site. 6.Average three years of maximum W126 values and compare to standard. Hourly O 3 (ppm) WeightW126 (ppm-hrs) 0.030.010.00 0.050.110.01 0.060.300.02 0.080.840.07 0.101.00.10 SUM:0.20 weight Understanding the W126 Proposed Secondary Standard Example of weighting over 5-hour period:

19. 19 Implementation Considerations For Proposed Ozone Standards Designations –EPA proposed an accelerated schedule for designating areas for the primary ozone standard. –EPA is taking comment on whether to designate areas for a seasonal secondary standard on an accelerated schedule or a 2-year schedule. –EPA is reviewing existing designations guidance and will be communicating with States and Tribes if additional guidance is needed. Previous Ozone Standards –The 2008 8-hour ozone NAAQS and the 1997 8-hour ozone NAAQS remain in place. –Implementation for the 2008 8-hour ozone NAAQS is delayed during the reconsideration. EPA has extended the deadline for area designations for the 2008 ozone standards by one year (until 2011). Any new ozone standards would replace the 2008 ozone standards. Implementation requirements for the 2008 ozone standards, including designations, would no longer apply. –The 1997 NAAQS remain in effect and implementation of that standard should continue.

20. 20 MilestoneDate Signature—Final RuleAugust 31, 2010 State Designation Recommendations to EPA January 2011 Final DesignationsEffective no later than August 2011 Attainment Demonstration SIPs Due December 2013 Attainment Dates2014-2031 (depends on severity of problem) Proposed Accelerated Implementation Timeline EPA is planning to propose an implementation rule in spring 2010 and issue a final rule as quickly as possible after the final ozone NAAQS.

21. 21 Estimated Number of Adverse Health Effects Avoided under Alternate Standard Levels in 2020* 0.070 parts per million0.060 parts per million Chronic bronchitis8802,200 Nonfatal heart attacks2,2005,300 Hospital and emergency room visits6,70021,000 Acute bronchitis2,1005,300 Upper and lower respiratory symptoms44,000111,000 Aggravated asthma23,00058,000 Days when people miss work or school770,0002.5 million Days when people must restrict their activities 2.6 million8.1 million Avoided premature mortality1,500 to 4,3004,000 to 12,000 *Includes benefits of reduced fine particle concentrations associated with illustrative ozone controls applied to meet a primary ozone standard in the proposed range

22. 22 Counties With Monitors Violating the March 2008 Ground-Level Ozone Standards 0.075 parts per million (Based on 2006 – 2008 Air Quality Data) 322 of 675 1 monitored counties violate the standard Notes: 1.Counties with at least one monitor with complete data for 2006 – 2008 2.To determine compliance with the March 2008 ozone standards, the 3-year average is truncated to three decimal places.

23. 23 Counties With Monitors Violating Proposed Primary 8-hour Ground- level Ozone Standards 0.060 - 0.070 parts per million (Based on 2006 – 2008 Air Quality Data) EPA will not designate areas as nonattainment on these data, but likely on 2008 – 2010 data which are expected to show improved air quality. 515 counties violate 0.070 ppm 93 additional counties violate 0.065 ppm for a total of 608 42 additional counties violate 0.060 ppm for a total of 650 Notes: 1. No monitored counties outside the continental U.S. violate. 2. EPA is proposing to determine compliance with a revised primary ozone standard by rounding the 3-year average to three decimal places.

24. 24 196 counties violate 15 ppm-hours 383 additional counties violate 7 ppm- hours for a total of 579 Counties With Monitors Violating Proposed Secondary Seasonal Ground-Level Ozone Standards 7 – 15 parts per million – hours (Based on 2006 – 2008 Air Quality Data) EPA will not designate areas as nonattainment on these data, but likely on 2008 – 2010 data which are expected to show improved air quality. No monitored counties outside the continental U.S. violate.

25. 25 99 counties projected to violate 0.070 ppm 149 additional counties projected to violate 0.065 ppm for a total of 248 203 additional counties projected to violate 0.060 ppm for a total of 451 Notes: 1.The modeled emissions in 2020 reflect the expected emissions reductions from federal programs by 2020 including: the Clean Air Interstate Rule, the Clean Air Mercury Rule, the Clean Air Visibility Rule, the Clean Air Nonroad Diesel Rule, the Light-Duty Vehicle Tier 2 Rule, the Heavy Duty Diesel Rule, the proposed rules for Locomotive and Marine Vessels and for Small Spark-Ignition Engines, and an estimate of State-level mobile and stationary source controls that were projected to be needed to attain pre-existing PM 2.5 and ozone standards. 2.Controls applied are illustrative. States may choose to apply different control strategies for implementation. 3.EPA did not model future violations outside the continental U.S. 4.EPA is proposing to determine compliance with a revised primary ozone standard by rounding the 3-year average to three decimal places. Counties With Monitors Projected to Violate the Proposed Primary 8-hour Ground-Level Ozone Standards in 2020 0.060 - 0.070 parts per million

26. 26 27 counties violate 15 ppm-hours 167 additional counties violate 7 ppm-hours for a total of 194 Counties With Monitors Projected to Violate the Proposed Secondary Seasonal Ground-level Ozone Standards in 2020 7 – 15 parts per million - hours Notes: 1.The modeled emissions in 2020 reflect the expected emissions reductions from federal programs by 2020 including: the Clean Air Interstate Rule, the Clean Air Mercury Rule, the Clean Air Visibility Rule, the Clean Air Nonroad Diesel Rule, the Light-Duty Vehicle Tier 2 Rule, the Heavy Duty Diesel Rule, the proposed rules for Locomotive and Marine Vessels and for Small Spark-Ignition Engines, and an estimate of State-level mobile and stationary source controls that were projected to be needed to attain pre-existing PM 2.5 and ozone standards. 2.Controls applied are illustrative. States may choose to apply different control strategies for implementation. 3.EPA did not model future violations outside the continental U.S.

27. 27 PM NAAQS 2006 Revised 24-hour PM 2.5 standard by lowering level from 65 to 35 µg/m 3 Retained annual PM 2.5 standard at 15 µg/m 3 Retained 24-hour PM 10 standard to address coarse particles (PM 10-2.5 ) Continued to set secondary standards identical to primary standards Did not adjust the PM AQI, intended to issue a separate rule Following final rule, CASAC expressed serious concerns with decisions that were not consistent with CASAC advice

28. 28 Remand of Primary and Secondary Annual PM 2.5 Standard In Feb 2009, D.C. Circuit Court remanded some portions of the final rule Court concluded EPA failed to adequately explain why annual standard is sufficient to protect public health with an adequate margin of safety Annual primary standard remanded for further consideration of whether it provides an adequate margin of safety from the risk of short-term exposure to PM 2.5, and whether it provides an adequate margin of safety against morbidity in children and other vulnerable subpopulations Court concluded decision to set secondary standards identical to primary standards was unreasonable and contrary to the law Secondary standards remanded for reconsideration

29. 29 PM NAAQS Review Integrated Science Assessment –Finalized December 2009 Risk and Exposure Assessments –Second draft assessment documents (quantitative health risk assessment and urban-focused visibility assessment) released for CASAC and public review on March 10-11 Policy Assessment –First draft released for CASAC and public review in March 2010 –Will discuss CASAC comments at teleconference scheduled for April 8 Proposed rulemaking – November 2010 Final rulemaking – July 2011 For more information: http://www.epa.gov/ttn/naaqs/standards/pm/s_pm_index.html

30. 30 Key Issues for Primary and Secondary Standards Extensive new health evidence available on PM 2.5, including epidemiological studies of short- and long-term exposures To what extent are associations causally related to PM? –For PM 2.5, ISA infers associations are causal for short- and long-term exposures and cardiovascular effects and mortality; likely causal for respiratory effects; and suggestive for cancer, developmental effects –For PM 10-2.5, associations for short-term exposures are suggestive for cardiovascular and respiratory effects and mortality –For UFPs, associations for short-term exposures are suggestive for cardiovascular and respiratory effects To what extent do reported associations extend to air quality levels lower than had previously been observed or that are observed in areas that would meet the current suite of PM 2.5 standards? –Associations extend to lower concentrations than observed in previous review –Include consideration of impacts on at-risk populations To what extent are associations due to specific components or sources? –Emerging information on relative toxicity of some components or sources, but evidence insufficient to infer causality Focus on urban visibility for secondary standards –Assessment of different indicators of PM pollution that are more directly related to visibility impairment as basis for distinct secondary standard

31. 31 PM 2.5 AQI EPA plans to propose revisions to the AQI when we issue a PM NAAQS proposal (currently slated for November) In the interim, we are using 35 µg/m 3 as the AQI value of 100 (the breakpoint between codes yellow and orange) –We have made this change on the AIRNow Web site Guidance issued in Sept 2009 recommended that States consider using alert, warning, emergency and significant harm levels consistent with the AQI levels presented in the February 2007 issue paper –AQI 200 = Alert Level = 140.5 - 210.4 µg/m 3 –AQI 300 = Warning Level = 210.5 – 280.4 µg/m 3 –AQI 400 = Emergency Level = 280.5 – 350.4 µg/m 3 –AQI 500 = Significant Harm Level (SHL) = 350.5 µg/m 3 For those with authority to do so, EPA will accept the use of AQI breakpoints that are consistent this guidance