March 2, 1998

Janet McCabe
Office of Air Management
Indiana Department of Environmental Management
100 North Senate Avenue
P.O. Box 6015
Indianapolis, Indiana 46206-6015

Dear Ms. McCabe:

This letter is in response to the proposed revisions to 326 IAC 5-1-3 and 326 IAC 5-1-7 concerning temporary alternative opacity limitations. The provisions in proposed 326 IAC 5-1-3(c) and (d) allow the commissioner to grant an alternative opacity limit to a source if it cannot meet the limitations required under 326 IAC 5-1-3(a) and (b). If such limits are specified in a Part 70 permit or a federally enforceable state operating permit, the provisions in proposed 326 IAC 5-1-7 allow the alternative opacity limits to become effective without a United States Environmental Protection Agency (USEPA) approval as a State implementation plan (SIP) revision.

It is the position of USEPA that this provision is not approvable because it allows limits to be established which exceed the existing SIP opacity limits without a SIP approval. 40 CFR Part 70 does not contain provisions which allow permits to establish new limits exceeding the existing SIP-approved limits without a new SIP approval. 40 CFR 70.6(a)(iii) states that "if an applicable implementation plan allows a determination of an alternative emission limit at a part 70 source, equivalent to that contained in the plan, to be made in the permit issuance, renewal, or significant modification process, and the State elects to use such process, any permit containing such equivalency determination shall contain provisions to ensure that any resulting emissions limit has been demonstrated to be quantifiable, accountable, enforceable, and based on replicable procedures." The proposed State rule, however, goes beyond what is allowed in Part 70 because the alternative opacity limits would not be "equivalent to that contained in the plan."

In addition, USEPA's March 5, 1996, memorandum titled "White Paper Number 2 for Improved Implementation of The Part 70 Operating Permits Program" provides guidance on issuing permits which contain a proposed revision to the SIP. This memorandum states that a proposed permit containing a local rule which represents a relaxation of a current SIP requirement cannot be issued prior to USEPA approval of the rule. Such a permit could not assure compliance with the applicable SIP requirement, as required by section 504 of the Clean Air Act. Therefore, in order to comply with Part 70 and section 504, alternative opacity limits established pursuant to 326 IAC 5-1-3(c) or (d) cannot become effective until approved as a SIP revision by USEPA.

I hope this information is useful. If you have any further questions, please contact Sam Portanova, of my staff, at (312) 886-3189.

Sincerely yours,


Cheryl L. Newton, Chief
Permits and Grants Section

cc: Roger Letterman
Indiana Department of Environmental Management
Office of Air Management