Approval and Promulgation of Implementation Plan; Illinois

In this action USEPA is approving the State Implementation Plan (SIP) revision request submitted by the Illinois Environmental Protection Agency (IEPA) on August 15, 1996. In the August 15 request, IEPA requested that the Marathon Oil Company in Robinson, Illinois be granted a carbon monoxide (CO) variance with specified conditions beginning January 19, 1996, and ending August 4, 1997. This variance exempts the Marathon Oil Company from the emission limits specified in the relevant CO SIP approved May 31, 1972 and revised February 21, 1980, thereby allowing its fluid bed catalytic cracking unit (FCCU) to emit 300 parts per million (ppm) of CO corrected for 50 percent excess air (Corrected) instead of the SIP emission limit of 200 ppm Corrected. The conditions require that the Marathon Oil Company utilize all means possible to minimize emissions and implement a plan of compliance submitted as part of the SIP revision. In this action, USEPA is approving the requested SIP revision through a ``direct final'' rulemaking; the rationale for this approval is set forth below. Elsewhere in this Federal Register, USEPA is proposing approval and soliciting comment on this direct final action; if adverse comments are received, USEPA will withdraw the direct final and address the comments received in a new final rule; otherwise, no further rulemaking will occur on this requested SIP revision. The USEPA is approving this SIP revision request because modeling shows that the emission limits are adequate to protect the CO national ambient air quality standards (NAAQS).