Approval and Promulgation of Implementation Plans; Indiana

On August 26, 1996, the State of Indiana submitted rule 326 IAC 10-1 as a requested revision to the State Implementation Plan (SIP) for ozone. This rule requires oxides of nitrogen (NO<INF>X</INF>) Reasonably Available Control Technology (RACT) for portland cement kilns, electric utility boilers, and industrial, commercial, or institutional (ICI) boilers in Clark and Floyd Counties. In addition, on April 30, 1997, Indiana submitted a negative declaration certifying that, to the best of the State's knowledge, there are no remaining major sources of NO<INF>X</INF> in Clark and Floyd Counties which need RACT rules. NO<INF>X</INF> emissions are a precursor of ground-level ozone, an air pollutant which can cause inflammation of lung tissue and decrease lung function. NO<INF>X</INF> emissions also contribute to acid rain, eutrophication of estuaries, and the formation of secondary nitrate particulate matter. Indiana expects this NO<INF>X</INF> RACT SIP revision will reduce NO<INF>X</INF> emissions by 44 percent (%), or 6352 tons per year, in Clark and Floyd Counties. In this action, EPA is approving the NO<INF>X</INF> RACT rule and negative declaration as revisions to the SIP through a ``direct final'' rulemaking; the rationale for this approval is set forth below.