How Ozone is Regulated under the Clean Air Act

Darcy J. AndersonAZ Dept. of Environmental Quality

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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

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• 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

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8-Hour Ozone Standard – Background / Timeline

• 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 http://www.epa.gov/ttn/naaqs/ozone/ozonetech/#newstd and http://www.epa.gov/airprogm/oar/tribal/tribe8hd.html

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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. 99-1257, 99-1426, February 27, 2001)

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Comparison of Ozone Standards

Standard Level Averaging Time Form(attainment test)

One-Hour 0.12 ppm 1 hour

Three exceedances at a monitor allowed in a three year period; fourth exceedance is a violation

Eight-Hour 0.08 ppm 8 hours

Three-year average of the annual fourth highest 8-hour concentration, calculated for each monitor*

*Because of rounding convention, 0.085 ppm considered level of violation

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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 http://www.epa.gov/ttn/naaqs/ozone/ozonetech/

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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 http://www.epa.gov/ttn/naaqs/ozone/ozonetech/

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8-Hour Ozone Standard - Designation Process (cont.)

• June 2003: EPA proposes rule for implementing 8-hour NAAQS

• See text of proposed rule at http://www.epa.gov/airlinks/airlinks4.html

• Final rule for implementing 8-hour NAAQS expected early 2004

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8-Hour Ozone Standard - Designation Process (cont.)

• July 15, 2003: State recommendations for area designations submitted to EPA

• see www.epa.gov/oar/oaqps/glo/designations/index.htm

• Tribes could also submit recommendations by this date

• Options: attainment / unclassifiable or nonattainment

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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

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Arizona Designation Process – Examples

• Monitoring data – exceedances, violations

• Location of emission sources• Meteorology, geography, and

jurisdictional boundaries• Population• Traffic and commuting patterns

Annual Fourth Highest 8-Hour Ozone Concentration in Parts per Billion (PPB) Monitor Site Abbreviation 1995 1996 1997 1998 1999 2000 2001 2002

Maricopa CountyBlue Point BP 83 89 87 87 80 86Cave Creek CC 83 86Central Phoenix CP 85 76 77 79 78 76 75 76Falcon Field FF 81 83 82 75 81 84Fountain Hills FH 88 86 86 85 83 86Glendale GL 80 72 76 70 81 81 78 83Humboldt Mountain HM 81 90 86 82 85 90Lake Pleasant LP 82 81 82 73Maryvale MA 78 86 77 80 73 84Mesa ME 92 90 84 80 83 75 74 72Mt. Ord MO 84 88 87 90 77North Phoenix NP 92 95 91 89 84 86 86 85Palo Verde PAVE 71 77 80 80 80 74 78Emergency Management EM 85 81 86 70 63Super Site PXSS 87 79 79 76 79 76Pinnacle Peak PP 91 91 82 86 83 86 85 84Rio Verde RV 85 79 86 86 83 85Roosevelt RO 84Salt River Pima SRPI 92 92 82 87 82South Phoenix SP 84 91 75 80 75 83 76 81South Scottsdale SS 89 87 76 78 72 80 79 77Surprise SU 71 79Tempe TE 78 79 80Vehicle Emissions VE 92 80West Chandler WC 77 74 69 74 78 83West Phoenix WP 84 81 78 86 91 81 75 84

Gila CountyRye RY 56 65 80Tonto N.M. TONO 87

Pinal CountyApache Junction AJ 91 85 82 82 80 82 78 80Casa Grande CG 71 79 72 68 78 75 74 78Queen Valley QUAZ 79 83

Yavapai CountyHillside HISD 85 76 83 84 83 76 89Values in blue indicate an exceedance of the 8-hour ozone standard

Three-Year Average of the Annual Fourth Highest 8-Hour Ozone Concentration in Parts per Billion (PPB) Monitor Site Abbreviation 1995-1997 1996-1998 1997-1999 1998-2000 1999-2001 2000-2002

Maricopa County Blue Point BP 86 87 84 84 Cave Creek CC Central Phoenix CP 79 77 78 77 76 75 Falcon Field FF 82 80 79 80 Fountain Hills FH 86 85 84 84 Glendale GL 76 72 75 77 80 80 Humboldt Mountain HM 85 86 84 85 Lake Pleasant LP 81 78 Maryvale MA 80 81 76 79 Mesa ME 88 84 82 79 77 73 Mt. Ord MO 86 88 84 North Phoenix NP 92 91 88 86 85 85 Palo Verde PAVE 76 79 80 78 77 Emergency Management EM 84 79 73 Super Site PXSS 81 68 67 67 77 Pinnacle Peak PP 88 86 83 85 84 85 Rio Verde RV 83 83 85 84 Roosevelt RO Salt River Pima SRPI 88 87 83 South Phoenix SP 83 82 76 74 80 South Scottsdale SS 84 80 75 76 77 78 Surprise SU 75 Tempe TE 79 Vehicle Emissions VE West Chandler WC 73 72 79 West Phoenix WP 81 81 85 86 82 80

Gila County Rye RY 67 Tonto N.M. TONO

Pinal County Apache Junction AJ 86 83 81 81 80 80 Casa Grande CG 74 73 72 77 79 79 Queen Valley QUAZ

Yavapai County Hillside HISD 81 81 83 81 82 Values in red indicate a violation of the 8-hour ozone standard

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8-hour Average Ozone Exceedances and Concentrations Maricopa County, 1995 - 2003

62

27

68

39

57

42

84

0

20

40

60

80

100

1995 1996 1997 1998 1999 2000 2001 2002 2003**

Num

bers

of E

xcee

danc

es*

0.00

0.02

0.04

0.06

0.08

0.10

Max

4th

Hig

h C

once

ntra

tion

(ppm

)

Exceedances Fourth Hi

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Meteorology, Geography and Jurisdictional Boundaries

0 20 4010Miles¹

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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

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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)

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Next Steps in 8-Hour Ozone Process: Ozone Implementation Plan

• June 2, 2003 - EPA proposed rule to implement 8-hour NAAQS (68 FR 32802)– August 6, 2003 - 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)

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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

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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