# 52.774 Determination of attainment.
(a) Based upon EPA's review of the air quality data for the 3-year period 2007-2009, EPA determined that the Louisville, Kentucky-Indiana PM<sub>2.5</sub> nonattainment Area attained the 1997 annual PM<sub>2.5</sub> NAAQS by the applicable attainment date of April 5, 2010. Therefore, EPA has met the requirement pursuant to CAA section 179(c) to determine, based on the Area's air quality as of the attainment date, whether the Area attained the standard. EPA also determined that the Louisville PM<sub>2.5</sub> nonattainment Area is not subject to the consequences of failing to attain pursuant to section 179(d).
(b) Based upon EPA's review of the air quality data for the 3-year period 2007-2009, EPA determined that the Cincinnati-Hamilton, Ohio, Kentucky, and Indiana PM<sub>2.5</sub> nonattainment Area attained the 1997 annual PM<sub>2.5</sub> NAAQS by the applicable attainment date of April 5, 2010. Therefore, EPA has met the requirement pursuant to CAA section 179(c) to determine, based on the Area's air quality as of the attainment date, whether the Area attained the standard. EPA also determined that the Cincinnati-Hamilton, Ohio, Kentucky, and Indiana PM<sub>2.5</sub> nonattainment Area is not subject to the consequences of failing to attain pursuant to section 179(d).
(c) Based upon air quality modeling, EPA determined that the Huntington County sulfur dioxide (SO<sub>2</sub>) nonattainment area failed to attain the 2010 SO<sub>2</sub> NAAQS by the applicable attainment date of April 9, 2023. Therefore, EPA has met the requirement pursuant to CAA section 179(c) to determine, based on the Area's air quality as of the attainment date, whether the Area attained the standard. EPA also determined that Indiana has met the requirements resulting from failing to attain pursuant to section 179(d) for the Huntington County SO<sub>2</sub> nonattainment area.
[76 FR 55545, Sept. 7, 2011, as amended at 76 FR 60375, Sept. 29, 2011; 90 FR 39132, Aug. 14, 2025]