How Ozone is Regulated under the Clean Air Act Darcy J. Anderson AZ Dept. of Environmental Quality

2 Presentation Outline 8-Hour Ozone Standard – Background / Timeline 8-Hour Ozone Standard – Designation Process Arizona Designation Process – Examples Potential Impacts of 8-Hour Ozone Designations on Tribes Next Steps in 8-Hour Ozone Process

3 July 1997: EPA issued revised 8-hour health- based standard for ozone. –New standard 0.08 ppm averaged over 8 hours. Pre-1997 ozone standard 0.12 ppm averaged over 1 hour (40 CFR §§ 50.9 and 50.10) –Studies show that long-term, low exposure to ozona as harmful to human health as short-term, high exposure. –New standard more protective for longer exposure 8-Hour Ozone Standard – Background / Timeline

4 2000: EPA issues guidance documents “Boundary Guidance on Air Quality Designations for the 8-Hour Ozone National Ambient Air Quality Standards” and “Guidance on 8-Hour Ozone Designations for Indian Tribes” See and

5 8-Hour Ozone Standard – Background / Timeline (cont.) February 2001: Following court challenge, –U.S. Supreme Court upheld 8-hour ozone standard –Directed EPA to develop an implementation approach that blends CAA Title I, Part D, Subpart 1 and 2 requirements (Whitman v. American Trucking Association, U.S. Supreme Court, Nos , , February 27, 2001)

6 Comparison of Ozone Standards StandardLevelAveraging Time Form (attainment test) One-Hour0.12 ppm1 hour Three exceedances at a monitor allowed in a three year period; fourth exceedance is a violation Eight-Hour0.08 ppm8 hours Three-year average of the annual fourth highest 8-hour concentration, calculated for each monitor* *Because of rounding convention, ppm considered level of violation

7 8-Hour Ozone Standard - Designation Process November 2002: As part of lawsuit settlement, EPA and environmental groups agree on schedule for EPA to promulgate 8-hour ozone designations (April 15, 2004–See 67 FR 70070) See

8 8-Hour Ozone Standard - Designation Process (cont.) February 27, 2003: EPA memorandum on 8-hour ozone designations extends deadline for states to submit recommendations for designating areas from April 15, 2003 to July 15, 2003 See

9 8-Hour Ozone Standard - Designation Process (cont.) June 2003: EPA proposes rule for implementing 8-hour NAAQS See text of proposed rule at Final rule for implementing 8-hour NAAQS expected early 2004

10 8-Hour Ozone Standard - Designation Process (cont.) July 15, 2003: State recommendations for area designations submitted to EPA see Tribes could also submit recommendations by this date Options: attainment / unclassifiable or nonattainment

11 8-Hour Ozone Standard - Designation Process(cont.) Governor’s recommendation for Arizona submitted to EPA in July 2003 –Analysis included looking at monitoring data, location of emission sources, meteorology, geography, population, traffic and commuting patterns, jurisdictional boundaries –Recommended all areas of state attainment / unclassifiable for 8-hour standard except Phoenix metro area –No state jurisdiction / recommendation for Indian reservations –Some Arizona tribes submitted their recommendations

12 Arizona Designation Process – Examples Monitoring data – exceedances, violations Location of emission sources Meteorology, geography, and jurisdictional boundaries Population Traffic and commuting patterns

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17 Meteorology, Geography and Jurisdictional Boundaries

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20 Potential Impacts of 8-Hour Ozone Designations on Tribes Boundary / background / transport Tribes can provide valuable ozone data for urban nonattainment areas Tribes can conduct additional ozone and NOx monitoring to assist with model verification Public information / outreach (API) Ozone mapping – AIRNOW

21 Next Steps in 8-Hour Ozone Process February 6, 2004: Revised nonattainment area recommendations due to EPA EPA looking at 2003 ozone monitoring data to determine effect on recommended area designations Designations and classifications published in FR by April 30, 2004 (signed by April 15)

22 Next Steps in 8-Hour Ozone Process: Ozone Implementation Plan June 2, EPA proposed rule to implement 8-hour NAAQS (68 FR 32802) –August 6, Draft rule text made available (68 FR 46536) –Possible options for implementation – CAA Subpart 1 or subpart 2 Option 1: All areas under subpart 2 (Classify 8-hour nonattainment areas based on 8-hour design values) Option 2: Separate areas based on whether they meet the 1-hour standard (Regulate areas generally meeting the 1-hour standard under Subpart 1 and areas generally exceeding the 1-hour standard under Subpart 2) –Subpart 1 - more flexible, minimal mandated controls (max attainment dates 5 or 10 years after designation) –Subpart 2 - proscriptive (attainment dates based on classification [marginal, moderate, serious, etc] consistent with subpart 2 provisions, i.e., 2007, 2010, 2013, 2019)

23 Next Steps in 8-Hour Ozone Process: Ozone Implementation Plan (cont.) –Anticipate implementation of new standard for Phoenix area either under subpart 1 or marginal under subpart 2 Subpart 1 option - Attainment demonstration due 2007; attainment required 2009 Subpart 2 option – Attainment required 2007 New control measures may be necessary to meet proposed attainment date

24 Next Steps in 8-Hour Ozone Process: NOx Waiver Draft rule proposes NOx waiver provisions under CAA Section 182(f) apply to any area designated nonattainment for 8-hour standard; –Requires new analysis to obtain waiver under 8-hour guidance NOx control for RACT required for moderate and above areas under subpart 2 option, unless EPA approves NOx waiver NSR & RACT requirements for major stationary VOC sources also apply to all major NOx sources unless NOx waiver provision implemented