Kentucky recommends 1-hour SO2 National Ambient Air Quality Standard designations
As was reported in the 2010 second quarter issue of Greenebaum Air Quality Letter, States were required to submit attainment and nonattainment designations for the new sulfur dioxide (SO2) NAAQS by June 3, 2011. The new 1-hour standard is 75 parts per billion (ppb) based on a three year average of the 99th percentile of the annual distribution of daily maximum 1-hour average concentrations. In Kentucky, measured ambient concentrations were below the standard of 75 ppb at all monitors in all counties except for Jefferson County. Thus, Kentucky has recommended that Jefferson County be designated as nonattainment for the 1-hour SO2 standard. Kentucky recommended that all other areas in the state be designated as attainment/unclassifiable for the 1-hour SO2 standard.
EPA expects to make final attainment designations by June 2012. If EPA expects to modify the attainment designations recommended by the state, it will notify Kentucky 120 days prior to a final designation.
To view a complete PDF of the Second Quarter 2011 issue of the Air Quality Letter, click HERE.