| | 1: |  | Title:   |  |   |  |   | Volume/Number:   | 2009  |   |  |   | Issuing Agency:   |  |   |  |   | Description:   | This document describes Illinois Maintenance Plan for the Illinois portion of the Chicago ozone nonattainment area. A Maintenance Plan is required before the area can be redesignated from nonattainment to attainment of the 8-hour ozone National Ambient Air Quality Standard (NAAQS) promulgated in 1997. This document also provides technical information required to support a redesignation request. |   |  |   | Date Created:   | 05-12-2009 |   |  |   | Agency ID:   | AQPSTR 09-04 |   |  |   | ISL ID:   | 000000056836   Original UID: 177798 FIRST WORD: Maintenance |   |  
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