Approval and Promulgation of Air Quality Implementation Plans; Massachusetts; Determination of Attainment of the One-Hour Ozone Standard for the Springfield Area

The EPA is making two separate and independent determinations. First, EPA is determining that the Springfield (Western Massachusetts) serious one-hour ozone nonattainment area did not meet the applicable deadline of December 31, 2003, for attaining the one-hour National Ambient Air Quality Standard (NAAQS) for ozone. This final determination is based upon complete, quality-assured, certified ambient air monitoring data that show the area had an expected ozone exceedance rate above the level of the now revoked one-hour ozone NAAQS for the 2001-2003 monitoring period. Second, EPA is determining that the Springfield (Western Massachusetts) serious one-hour ozone nonattainment area currently attains the now revoked one-hour NAAQS for ozone, based upon complete, quality-assured, certified ambient air monitoring data for 2009- 2011. The area first attained the one-hour NAAQS during the 2007-2009 monitoring period, and continued in attainment during the 2008-2010, and 2009-2011 monitoring periods.