UNITEDSTATESENVIRONMENTALPROTECTIONAGENCY OfficeofAirQualityPlanningandStandards ResearchTrianglePark, NorthCarolina27711 

## 13AUG

# 1993 MEMORANQUM

### TV,~--

SUBJECT: Early Implementation of Contingency Measures for Ozone and carbonMonoxide (CO) Nonattainment Areas FROM: G. T. Helms,

# Chief;W-:114~ ozone/Carbon Monoxitie 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 tobe implemented. The following discussion outlines the·contingency measure 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**C~ean** Air Act requires contingency measures in the 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 contingency measures by November 15, 1993, as established by the Environmental Protection Agency (EPA). Thesemeasures must be implemented 

### if the area fails to make 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 per million. These measures are to be implemented if any estimate of actual vehicle miles traveled (VMT) or updated projections 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.

### 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 to meet RFP. It seems illogical to penalize nonattainment areas that aretaking extra steps to ensure attainment of the NAAQS 

### by having them adopt additional contingencymeasures now. Therefore, in cases of 

### early implementation of statecontingencymeasures, we do 

### not feel that it is necessary 

### now to adopt additional contingency measures to backfill for the early activation of contingency measures. Of 

### course, if an area fails to attain1 

### fails to demonstrate RFP, 

### ormisses a milestone, then additional contingency measures are needed and must be adopted in accordance withprevious guidance ("General Preamble for Implementation of Title 

### I of the CleanAir 

### Act Amendments of 1990," Federal Register, April 16, l992). We trustthat this information will beof help to you as you guide your states through the State implementationplan development process. I suggest that you provide a copyof this memo to your affected Stateand local agencies. Ifyou have questions or comments, please contact Kimber Scavo at {9l9) 541- 3354.



### co: William Becker, STAPPA/ALAPCO Kent Berry, AQMD Gary Dolce, OMS carlaOldham, AQMD Rich ossias, OGC SharonReinders, AQMD Kimber Scavo, AQMD sara Schneeburq, OGC Laurel Schultz, AQMO John Silvasi, AQMD Jan Tierney, OGC SIP Control Strategy sub-Work Group