UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

Office of Air Quality Planning and Standards 

Research Triangle Park, North Carolina 2771 1 

1 3AUG 1993 

MEMORANQUM 

TV,~--

SUBJECT: Early Implementation of Contingency Measures for 

Ozone and carbon Monoxide (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 to be implemented. The following discussion 

outlines the·contingency measure requirements for ozone and co 

nonattainment areas and provides 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). These measures 

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 contingency measures to be 

implemented if the area fails to meet any applicable milestone. 

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 are taking 

extra steps to ensure attainment of the NAAQS by having them 

adopt additional contingency measures now. Therefore, in cases 

of early implementation of state contingency measures, 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 attain 1 fails to 

demonstrate RFP, or misses a milestone, then additional 

contingency measures are needed and must be adopted in accordance 

with previous guidance ("General Preamble for Implementation of 

Title I of the Clean Air Act Amendments of 1990," Federal 

Register, April 16, l992). 

We trust that this information will be of help to you as you guide your states through the State implementation plan development process. I suggest that you provide a copy of this 

memo to your affected State and local agencies. If you have 

questions or comments, please contact Kimber Scavo at {9l9) 541-

3354. 

co: William Becker, STAPPA/ALAPCO 

Kent Berry, AQMD 

Gary Dolce, OMS 

carla Oldham, AQMD Rich ossias, OGC 

Sharon Reinders, AQMD 

Kimber Scavo, AQMD 

sara Schneeburq, OGC 

Laurel Schultz, AQMO 

John Silvasi, AQMD 

Jan Tierney, OGC 

SIP Control Strategy sub-Work Group