North Carolina Counties with 8-Hour Ozone Violations 2005-2007

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.

A map of North Carolina counties with 8 hour ozone violations from 2005 to 2007.

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 2005-2007 Design Value Map, these counties are colored red.

CountyAverage value
Mecklenburg0.093 ppm
Rowan0.090 ppm

Table 2. The following table shows 29 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 2005-2007 Design Value Map, these counties are colored gray and green, with gray signifying counties that would not attain the 2008 8-hour standard.

CountyAverage Value
Alexander0.079 ppm
Avery0.070 ppm
Buncombe0.074 ppm
Caldwell0.076 ppm
Caswell0.077 ppm
Chatham0.074 ppm
Cumberland0.082 ppm
Davie0.083 ppm
Durham0.078 ppm
Edgecombe0.077 ppm
Forsyth0.081 ppm
Franklin0.078 ppm
Graham0.078 ppm
Granville0.081 ppm
Guilford0.082 ppm
Haywood0.079 ppm
Jackson0.077 ppm
Johnston0.076 ppm
Lenoir0.076 ppm
Lincoln0.083 ppm
Martin0.074 ppm
New Hanover0.072 ppm
Person0.077 ppm
Pitt0.077 ppm
Rockingham0.078 ppm
Swain0.066 ppm
Union0.081 ppm
Wake0.081 ppm
Yancey0.078 ppm

Table 3. The following table shows 25 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 2005-2007 Design Value Map, these counties are colored red and gray, with red signifying counties that violated the 1997 8-hour standard and gray signifying counties attaining the 1997 8-hour standard.

CountyAverage Value
Alexander0.079 ppm
Caldwell0.076 ppm
Caswell0.077 ppm
Cumberland0.082 ppm
Davie0.083 ppm
Durham0.078 ppm
Edgecombe0.077 ppm
Forsyth0.081 ppm
Franklin0.078 ppm
Graham0.078 ppm
Granville0.081 ppm
Guilford0.082 ppm
Haywood0.079 ppm
Jackson0.077 ppm
Johnston0.076 ppm
Lenoir0.076 ppm
Lincoln0.083 ppm
Mecklenburg0.093 ppm
Person0.077 ppm
Pitt0.077 ppm
Rockingham0.078 ppm
Rowan0.090 ppm
Union0.081 ppm
Wake0.081 ppm
Yancey0.078 ppm

Table 4. The following table shows 6 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 2005-2007 Design Value Map, these counties are colored green.

CountyAverage Value
Avery0.070 ppm
Buncombe0.074 ppm
Chatham0.074 ppm
Martin0.074 ppm
New Hanover0.072 ppm
Swain0.066 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