In 2010, EPA revised the sulfur dioxide (SO2) standard to a 1-hour standard at a level of 75 parts per billion (ppb). To determine if the standard is met, a continuous 3-year average concentration is calculated from daily measurements and compared to the requirements of the standard. The table below shows the 3-year average SO2 concentration in counties where these sites are located for 2011-2013. SO2 levels in North Carolina are low, ranging from 10 percent to 65 percent of the standard. These values are lower than the previous 3-year period.
Additionally, for many years, SO2. has been measured at several sites across the state on an intermittent basis that does not provide 3-year or longer term averages. This monitoring is conducted at five sites operated for 12 months every 3 years. The overall monitoring conducted at those sites show no exceedances of the standard.
|New Hanover||49 ppb|