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Note: EPA no longer updates this information, but it may be useful as a reference or resource.

Please see www.epa.gov/air/ozonepollution for the latest information on EPA's efforts to reduce ground level ozone pollution.

Basic Information

At the time of the passage of the Clean Air Act Amendments (CAAA) in 1990, there was a total of 157 ozone nonattainment areas (98 Classified, 12 Transitional, and 47 Incomplete or No Data). The designation and classification process for ozone areas was started on November 6, 1991, with the publication of the Air Quality Designations and Classifications final rule (56 FR 56694). Since that time, through September 30, 1997, 41 of the 98 classified areas have been redesignated to attainment. In addition, 15 "unclassifiable" (incomplete data, transitional) nonattainment areas have been redesignated to attainment for ozone. Each of these areas was able to be redesignated due to successful completion of each of the conditions numbered below.

Section 107(d)(3)(E) of the 1990 CAAA states that the following criteria must be met in order for an area to be redesignated from nonattainment to attainment:

  1. The EPA has determined that the national ambient air quality standard (NAAQS) has been attained. This standard is 0.12 ppm for ozone.

  2. The applicable State Implementation Plan (SIP) has been fully approved by the EPA under section 110(k).

  3. The EPA has determined that the improvement in air quality is due to permanent and enforceable reductions in emissions.

  4. The State has met all applicable requirements for the area under section 110 and part D.

  5. The EPA has fully approved a maintenance plan, including a contingency plan, for the area under section 175A.

PURPOSE

This report focuses on the fifth condition, concerning the maintenance plan and the respective contingency measures. In addition, total VOC and NOx emission reductions planned to occur during the ten year maintenance period for each area are examined. The CAAA require a demonstration of maintenance for ten years after redesignation. However, in some cases, modeling can be used to allow for increase/growth in emissions during the maintenance period so long as the NAAQS is not violated. This plan will therefore set a base year of attainment and project maintenance for at least that ten year period. The maintenance plan specifies techniques used by the area in order to continue maintenance and compliance with the NAAQS, as well as the controls the area will use to ensure these levels of emissions.

This plan also includes contingency measures to ensure prompt and effective correction of any violation of the NAAQS that may occur after redesignation, despite the State's best efforts to demonstrate continued compliance. The events that would trigger such measures to be implemented should be clearly identified, as well as an adequate description of the measures to be adopted, a schedule and procedure for implementation, and a specific time limit for action to be taken by the State. At a minimum, the contingency measures must include a requirement that the State will implement measures contained in the nonattainment SIP prior to redesignation. For the purposes of 175A, the State is not required to fully adopt contingency measures prior to redesignation. This contingency plan is, however, considered an enforceable part of the SIP and must ensure that the measures will be adopted and implemented promptly after they are triggered.

SUMMARY

Each of the 41 redesignated areas submitted satisfactory maintenance plans to the EPA. Details of these plans are described in this report, including control measures implemented by each maintenance area, an emissions budget, the triggers used to initiate contingency measures, what these specific contingency measures entail, and a schedule for implementation, as well as a contact for further information.

Since the passage of the CAAA, implementation of Title I has resulted in bringing areas into attainment, reducing emissions of both VOC and NOx for the country. By comparing the actual emissions of each area during its base year of attainment and comparing these emissions to its projected emissions, it is evident that significant reductions will occur because of national measures, permitting, conformity, etc. These reductions can be observed in the graphs included in the maintenance plan summary for each area. Reductions are evident in each area, as well as in the totals for each source category and the entire country. Overall, for areas with base year 1990 and projection year 2005, 2006, or 2007, a total of 1,310 tons VOC and 607 tons NOx will be reduced per day during the ten year maintenance period. A significant difference is seen in the percent emissions from each source category (point, area, and mobile) in 1990 compared to that in 2005, 2006, or 2007. For areas with a base year 1993 and projection year 2008 or 2010, a total of 139 tons VOC and 58 tons NOx will be reduced per day during the next ten year maintenance period. The reductions are graphically presented in the tables and figures in the summaries of maintenance plans, the VOC emissions summary, and the NOx emissions summary.

All information in the maintenance plan summaries was drawn from Federal Register notices containing proposed and final redesignations. The following areas were required to complete only a limited maintenance plan which does not require projections to 2005: Beauregard Parish, LA; Grant Parish, LA; Lafayette Parish, LA; Lafourche Parish, LA; St. Mary Parish, LA; and Victoria County, TX. Therefore, the total VOC and NOx emissions for Region VI in 2005 (and the graphs and charts in the VOC Emissions Summary and the NOx Emissions Summary) do not accurately represent the emissions for that Region.

CONTENTS

The Table of Redesignated Areaslist each redesignated area (including its Region and State), its nonattainment classification, the proposed rule date and FR notice, the final rule date and FR notice, and the effective date of redesignation. The Index to Summary of Maintenance Plans provides a listing of all Regions, States and Areas affected by ozone nonattainment redesignation. An area's maintenance plan summary can be accessed by clicking on the name of the redesignated area. Acronyms contains a list of acronyms found in the summaries of the maintenance plans. The VOC Emissions Summary (1990 Base Year) and VOC Emissions Summary (1993 Base Year) presents summarized VOC emissions for the redesignated areas in tabular and graphical formats. The NOx Emissions Summary (1990 Base Year) and NOx Emissions Summary (1993 Base Year) presents summarized NOx emissions for the redesignated areas. Pending/Other Areas presents maintenance plan summaries for those areas that are either proposed for redesignation or have unique redesignation status.

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