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U.S. EPA Determines Lake and Porter Counties Meet Ozone Standard


By Jennifer Thompson, Attorney, Bingham Greenebaum Doll LLP

On March 12, 2010 U.S. EPA published its determination in the 75 Federal Register 12087 (March 12, 2010) that the Indiana portion (Lake and Porter Counties) of the Chicago-Gary-Lake County, Illinois-Indiana area has attained the 1997 eight-hour ozone National Ambient Air Quality Standard (“NAAQS”). Additionally, U.S. EPA published its proposed rule to approve Indiana’s request to redesignate Lake and Porter Counties to attainment with the NAAQS. The area was designated as moderate nonattainment for the 1997 ozone NAAQS in April 2004, and was given until June 15, 2020 to attain the NAAQS.

An area is considered to be attainment with the 1997 eight-hour ozone NAAQS if there are no violations of the NAAQS in the most recent consecutive three years of quality-assured air quality monitoring data at all ozone monitoring sites in the area and at any nearby ozone monitor outside of the area with ozone concentrations impacted by Volatile Organic Compound (“VOC”) and Nitrogen Oxides (“NOx”) emissions from the area. The Indiana Department of Environmental Management (“IDEM”) showed that the 2006-2008 ozone design values for all monitoring sites for the area were below the 0.084 ppm ozone attainment level, and U.S. EPA has determined that Lake and Porter Counties and the State of Indiana have met all the State Implementation Plan (“SIP”) requirements for purposes of redesignation under the Clean Air Act (“CAA”).

In connection with the finding, U.S. EPA has: (1) approved Indiana’s request to exempt sources of NOx in Lake and Porter Counties from CAA Reasonably Available Control Technology (“RACT”) requirements; (2) proposed to approve revisions to Indiana’s SIP designed to maintain the eight-hour ozone standard in Lake and Porter Counties and in the Chicago-Gary-Lake County, Illinois-Indiana ozone nonattainment area through 2020; (3) proposed to approve VOC and NOx emission inventories for Lake and Porter Counties as a revision to Indiana’s SIP; and (4) proposed to approve Indiana’s 2010 and 2020 Motor Vehicle Emission Budgets for Lake and Porter Counties.

U.S. EPA’s determination becomes effective on April 12, 2010 and comments on the proposed redesignation and SIP revisions are due on or before April 12, 2010. 


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