Approval and Promulgation of Implementation Plans; Indiana

On September 20, 1996, Indiana submitted a request to incorporate revisions to the definitions of ``nonphotochemically reactive hydrocarbon'' and ``volatile organic compounds'' (VOC) into the Indiana State Implementation Plan (SIP). The term ``VOC'' denotes chemical compounds which react with nitrogen dioxide (NO<INF>2) and sunlight to form ozone. The term ``nonphotochemically reactive hydrocarbon'' refers to chemical compounds which USEPA has determined will not react with NO<INF>2 and sunlight to form ozone. In this action, USEPA is approving the State's request to incorporate into the SIP the revisions to these definitions through a ``direct final'' rulemaking; the rationale for this approval is set forth below. Part of this submittal is in response to USEPA's May 4, 1995 conditional approval of the State's VOC definition. Among other things, in this rulemaking, USEPA is finding that the condition identified in USEPA's May 4, 1995 action have been satisfied; therefore, USEPA is converting the conditional approval to a full approval. Elsewhere in this Federal Register, USEPA is proposing approval and soliciting comment on these direct final actions; if adverse comments are received, USEPA will withdraw the direct final rule and address the comments received in a new final rule; otherwise, no further rulemaking will occur on the State's request to incorporate revisions to these definitions into the Indiana SIP.