UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Office of Air Quality Planning and Standards Research Triangle Park, North Carolina 27711

01 DEC 1988

MEMORANDUM

SUBJECT: RACT Requirements in Ozone Nonattainment Areas

FROM: Gerald A. Emison, Director Office of Air Quality Planning and Standards (MD-l0)

TO: William A. Spratlin, Director Air and Toxics Division, Region VII

This is in response to your memorandum of October 12, 1988 concerning reasonably available control technology (RACT) requirements for automobile assembly plants in ozone nonattainment areas.

We agree that automobile assembly plants in ozone nonattainment areas should have volatile organic compound emission requirements that are at least as stringent as RACT. As described below, the requirements for new source performance standards (NSPS) or lowest available emission rate (LAER) (as determined at the time of permit issuance) for two plants in the St. Louis area may not be as stringent as RACT. Therefore, the St. Louis State implementation plan should contain RACT requirements for these plants.

There are important differences in the format and compliance demonstration methodology for automobile coating RACT and NSPS. Topcoat and surfacer RACT require daily averaging and actual transfer efficiency, while the NSPS allows monthly averaging and table transfer efficiency values. These differences may result in RACT being more stringent than NSPS. The OAQPS recommends that the June 1988 protocol be used as the basis for determining compliance with the RACT limit.

The Ford Hazelwood plant is subject to NSPS and RACT. The State has proposed to delete the RACT requirements for Ford Hazelwood on the basis that the NSPS is more stringent. This claim is not correct. Therefore, the RACT requirements for Ford Hazelwood should not be deleted, rather they should be maintained and the June 1988 protocol adopted as

________________ (footnote-1)-For this discussion, RACT for topcoat means an appropriate emission limit for which compliance is demonstrated on a daily basis using the June 1988 protocol. For surfacer, the RACT requirements should also specify daily compliance and actual transfer efficiency.2

the compliance determination procedure.

The GM Wentzville plant was permitted as a new source in the early 1980's. This source is subject to NSPS and LAER, which was set equal to NSPS for topcoat and surfacer. Since the St. Louis RACT requirements for automobile coating were source specific and the GM Wentzville plant did not exist when the RACT requirements were first adopted, there are currently no RACT requirements for this plant. The NSPS and LAER requirements for this plant may not be as stringent as RACT. Therefore, RACT requirements should be adopted for GM Wentzville.

Thank you for bringing this situation to our attention. Questions concerning this matter should be addressed to Bill Polglase (629-5246) or Dave Salman (629-5417).

cc: J. Calcagni A. Campbell T. Helms J. Berry D. Salman G. McCutchen D. Crumpler B. Polglase J. Silvasi Director, Air Management Div., Regions I, III, V, IX Director, Air and Waste Management Division, Region II Director, Air, Pesticides, and Toxics Division, Regions IV, VI Director, Air and Toxics Division, Regions VII, VIII, X Chief, Air Branch, Regions IX Chief, Air Compliance Branch, Regions IV, V Chief, Air Enforcement Branch, Region III Chief, Air Operations Branch, Region IX