SO2 Average Values for 2012-2014 in NC Counties
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 concentrations for the 5 highest reported values by county for 2012-2014.
SO2 levels in North Carolina are low, ranging from 1.3 percent to 28 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 a rotating basis. This monitoring is conducted at five sites operated for 12 months every 3 years. For these sites we do not have continuous 3-year averages. The overall monitoring conducted at those sites show no exceedances of the standard.
![A map of North Carolina design values in counties with sulfur dioxide monitors from 2012 to 2014. These are 99th percentile averages.](https://files.nc.gov/deq/styles/_inline_extra_large_/public/images/2023-04/SO2_99th_12-14.png?VersionId=qphCDd9B5LV0lPbDv8Vp57zovejkZnwo&itok=PtViAnxB)
County | 3-Year Average (99th Percentile) |
---|---|
Beaufort | 21 ppb |
Caldwell | 9 ppb |
Forsyth | 9 ppb |
New Hanover | 17 ppb |
Rockingham | 9 ppb |