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Area Designations for 1997 Ground-level Ozone Standards

Sample Nonattainment Requirements

Ozone Classification Sample of Requirements1
    Classified (Subpart 2)
Requirement Basic
(Subpart 1)
Marginal Moderate Serious Severe
Attainment Dates up to 2009. May extend up to 2014 up to
June 15, 2007
up to
June 15, 2010
up to
June 15, 2013
up to
June 15, 2021
States submit plans no later than 2007 not required June 15, 2007 20072 20072
Conformity (transportation and general) required required required required required
Emission inventory required required required required required
Amount of emissions that trigger New Source Review and technology requirements for large sources of emissions (known as Reasonably Available Control Technology) 100 tons per year (TPY) 100 tons TPY

(Except 50 TPY for VOC in the Ozone Transport Region3)
100 TPY

(Except 50 TPY in the Ozone Transport Region3)
50 TPY 25 TPY
Inspection and Maintenance nothing specified nothing specified Basic I&M Enhanced I&M Enhanced I&M
NSR offsets at least 1 to 1 1.1 to 1 1.15 to 1 1.2 to 1 1.3 to 1
Reformulated Gas nothing specified nothing specified nothing specified nothing specified required
Reasonable Further Progress - the amount of improvement an area must make annually "annual incremental emissions reductions" nothing specified 15% VOC reduction from baseline by no later than 2008

Option proposed: Annual incremental reductions for certain areas that have already achieved 15% reduction previously
Moderate req't plus 9% VOC/NOx reductions for years 7-9 after CAA Amendments enactment Serious req't plus 9% VOC/NOx for years 9-15 after CAA Amendments enactment
Moving an area to a higher classification -- this "bump up" is only after EPA finds that the area fails to attain by the attainment date. not applicable required to bump-up to higher required to bump-up to higher required to bump-up to higher  

Other Requirements

  • NOx control for RACT
  • NOx control for NSRRACM/RACT
  • Stage II vapor recovery (VOC)
  • Consequences of failure to attain
  • Milestone Compliance Determination
  • Contingency measure
  • Enhanced (ambient) monitoring (PAMS)
  • VMT demonstration and transportation control measures (TCMs) if needed
  • Transportation Control Measure to offset growth in Vehicle Miles Traveled (VMT) emissions
  • Clean Fuels for Boilers
  • Transportation Control Measures (TCM) during heavy traffic hours)
  • New Technologies


1This summary is a convenient overview of the rule. Additional details can be found in the official Federal Register notice.

2Proposed in June 2003, and final phase 2 ozone implementation rule expected August 2004.

3Ozone Transport Region is defined by the Clean Air Act section 184(a). It is comprised of DC, CT, DE, ME, MD, MA, NH, NJ, NY, PA, RI, VT, and portion of Virginia that is part of the DC CMSA.

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