On June 2, 2011 the NC Division of Air Quality (NCDAQ) made a recommendation to the EPA that they postpone designation of the Wilmington area (New Hanover County) as nonattainment for SO2 until after 2012.
In June 2010, the EPA adopted a more stringent SO2 standard of 75 parts per billion (ppb) averaged over one hour where as there previously had been three SO2 standards: 500 ppb averaged over 3 hours, 140 ppb averaged over 24 hours, and 30 ppb averaged over a year.
The NCDAQ made this recommendation due to the fact that several sources that are large emitters of SO2 have actually closed their sites which has dropped the SO2 levels significantly. Southern States Chemical & WASTEC have closed their sites near the monitor and Progress Energy is in the process of converting its Sutton plant from coal to natural gas which is predicted to substantially reduce ambient SO2 concentrations in the area near an air quality monitor in the area.
If EPA does not allow a postponement of the nonattainment decision for the Wilmington area, NCDAQ has recommended that they designate the northwest corner of New Hanover as nonattainment. Industries that emit SO2 may face more stringent requirements if they are designated as nonattainment because the state would be required to develop a plan for bringing such areas back into compliance in order to meet air quality standards.