North Carolina Counties with 8-Hour Ozone Violations 2006-2008

In March 2008, the US EPA promulgated a revision of the ozone standard with a lower nonattainment threshold. We have colored the Design Value map in a novel way so that it can be compared easily to past years with the previous standard and to future years with the new standard. We present the details in four tables. Table 1 and Table 2 refer to the ozone standard that was effective from 1997 through 2007. Table 3 and Table 4 refer to the ozone standard that was effective beginning in 2008.

Table 1. The following table shows two counties with a 3-year average of the annual 4th high value for each year equaling 0.085 ppm level or higher (violation of the 8-hour standard that was in effect from 1997 through 2007). The first column lists the county; the second lists the average value for that county. On the 2006-2008 Design Value Map, these counties are colored red.

County Average value
Mecklenburg 0.094 ppm
Rowan 0.088 ppm

 

 

 

 

Table 2. The following table shows 27 monitored counties that are attaining the 0.085 ppm standard that was in effect from 1997 through 2007. The first column lists the county; the second lists the average value for that county. On the 2006-2008 Design Value Map, these counties are colored orange and green, with orange signifying counties that would not attain the 2008 8-hour standard.

County Average Value
Alexander 0.077 ppm
Avery 0.068 ppm
Buncombe 0.071 ppm
Caldwell 0.075 ppm
Caswell 0.079 ppm
Chatham 0.072 ppm
Cumberland 0.077 ppm
Davie 0.082 ppm
Durham 0.078 ppm
Edgecombe 0.076 ppm
Forsyth 0.081 ppm
Franklin 0.077 ppm
Graham 0.078 ppm
Granville 0.080 ppm
Guilford 0.082 ppm
Haywood 0.078 ppm
Johnston 0.075 ppm
Lenoir 0.074 ppm
Lincoln 0.082 ppm
Martin 0.073 ppm
New Hanover 0.069 ppm
Person 0.077 ppm
Rockingham 0.080 ppm
Swain 0.065 ppm
Union 0.080 ppm
Wake 0.080 ppm
Yancey 0.077 ppm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 3. The following table shows 20 counties with a 3-year average of the annual 4th high value for each year equaling 0.076 ppm level or higher (violation of the 8-hour standard established in 2008). The first column lists the county; the second lists the average value for that county. On the 2006-2008 Design Value Map, these counties are colored red and orange, with red signifying counties that violated the 1997 8-hour standard and orange signifying counties attaining the 1997 8-hour standard.

County Average Value
Alexander 0.077 ppm
Caswell 0.079 ppm
Cumberland 0.077 ppm
Davie 0.082 ppm
Durham 0.078 ppm
Edgecombe 0.076 ppm
Forsyth 0.081 ppm
Franklin 0.077 ppm
Graham 0.078 ppm
Granville 0.080 ppm
Guilford 0.082 ppm
Haywood 0.078 ppm
Lincoln 0.082 ppm
Mecklenburg 0.094 ppm
Person 0.077 ppm
Rockingham 0.080 ppm
Rowan 0.088 ppm
Union 0.080 ppm
Wake 0.080 ppm
Yancey 0.077 ppm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 4. The following table shows 9 monitored counties that are attaining the 0.076 ppm standard that was established in 2008. The first column lists the county; the second lists the average value for that county. On the 2006-2008 Design Value Map, these counties are colored green.

County Average Value
Avery 0.068 ppm
Buncombe 0.071 ppm
Caldwell 0.075 ppm
Chatham 0.072 ppm
Johnston 0.075 ppm
Lenoir 0.074 ppm
Martin 0.073 ppm
New Hanover 0.069 ppm
Swain 0.065 ppm

 

 

 

 

 

 

 

 

 

 

 

 

Note:

  • Additional counties may be involved in emission reduction strategies
  • Nonattainment designations may not follow county boundaries
  • Final data validation is not yet complete