UNITEDSTATES ENVIRONMENTALPROTECTIONAGENCY OfficeofAirQualityPlanningandStandards ResearchTrianglePark,NorthCarolina27711 

## 13AUG

# 1993 MEMORANDUM SUBJECT: Early Implementation of ContingencyMeasures for Ozone and carbon Monoxide (CO) Nonattainment Areas

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## ' FROM: G. T. Helms, Chief..;+-

## :1.14~ ozone/Carbon**Monoxi~e** Programs Branch (MD-15) TO: Air Branch Chief, Regions I-X

Several Regional Offices have indicated that some States are interested in implementing their contingency measures'before they are required to be implemented. The following discussion outlines the contingencymeasure requirements for ozone and co nonattainment areas andprovides a predecisional staff recommendation for the early implementation of contingency measures in certain ozone and CO nonattainment areas. The CleanAir Act requires contingencymeasures inthe following three cases: 1. Section 172(c)(9) requires moderate and above ozone and co nonattainment areas (in addition to other areas) to adopt and submit contingencymeasures by November 15, 1993, as established by the Environmental Protection Agency (EPA). These measures must be implemented if the area fails tomake reasonable further progress (RFP) or to attain the national ambient air quality standards (NAAQS) by the applicable attainment date. 2. Section 182(c)(9) requires serious and above ozone nonattainment areas to adopt contingencymeasures to be implemented if the area fails to meet any applicablemilestone. 3. Section 187(a)(3) requires contingency measures to have been adopted by November 15, 1992 for co nonattainment areas with a design value greater than 12.7 parts permillion. These measures are to be implemented if any estimate of actual vehicle miles traveled (VMT) orupdatedprojections of future VMT in the area which is submitted in an annual report exceeds the number predicted in the most recent prior forecast, When triggered, the contingency measures must be implemented without further action by the'State or EPA.

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### we are aware of several areas that wish to implement their contingency measures early, even though the measures are not needed now for their attainment demonstration or tomeet RFP. It seems illogical to penalize nonattainment areas that are taking extra steps to ensure attainment of the NAAQS by having them adopt additional contingencymeasures now. Therefore, in cases of early implementation of State contingencymeasures, we do not feel that it is necessary now toadopt additional contingency measures to backfill for the early activation of contingency measures. Of course, if an area fails to attain, fails to demonstrate RFP, or misses a milestone, then additional contingency measures are needed and must beadopted in accordance with previous guidance ("General Preamble for Implementation of Title I of the Clean Air ActAmendments of 1990," Federal Register, April 16, 1992). We trust that this informationwill be of help to you as you guide your States through the State implementationplan development process. I suggest that you provide a copy 'of this memo to your affected State and local agencies. Ifyou have questions or comments, please contactKimber Scavo at (919) 541- 3354,

cc: William Becker, STAPPA/ALAPCO Kent Berry, AQMD Gary Dolce, OMS carla oldham, AQMD Rich Ossias, OGC Sharon Reinders, AQMD Kimber Scavo, AQMD sara schneeburg, OGC Laurel Schultz, AQMD John Silvasi, AQMD Jan Tierney, OGC SIP Control Strategy Sub-Work Group