PM2.5 Design Values for 2003-2005 in NC Counties

There are three counties with a 3-year average of the annual mean PM2.5 above the annual standard, and one with a 3-year average of the 98thpercentile above the daily standard that was established in 2007. (It does not exceed the daily standard that was in effect from 1999 through 2006.)

Figure 1 Annual Design Values (Mean) (click for larger image)

Figure 2 Daily Design Values (98th %) (click for larger image)

From 1999 until 2007, the national standard was set at 65 µg/m3. In 2007 the national standard was revised to 35 µg/m3. Catawba County exceeded the 2007 standard (but not the 1999 standard) in 2003-2005. All other counties are attaining the standards.

Table 1. The following table shows 28 counties with a 3-year average of the annual mean PM2.5 for each year and 28 counties with 3-year averages for the 98th percentile of PM2.5 concentrations below the standards established in 2007. The first column lists the county; the second lists the average value for that county (rounded to the specifications of the annual standard); the third lists the average value for that county (rounded to the specifications of the daily standard). In Counties with more than one PM2.5 monitoring site, the value reported is the highest 3-year average among the inclusive sites. Averages for the counties marked with an asterisk are "unofficial estimates", because a sample size requirement (data completeness) was not satisfied.

County Average value Average 98th Percentile
Alamance 14.1 µg/m3 32 µg/m3
Buncombe 12.7 µg/m3 30 µg/m3
Caswell 13.2 µg/m3 30 µg/m3
Catawba (see Table 2) (see Table 2)
Chatham 11.9 µg/m3 26 µg/m3
Cumberland 13.8 µg/m3 31 µg/m3
Davidson (see Table 2) 32 µg/m3
Duplin 11.5 µg/m3 27 µg/m3
Durham 13.6 µg/m3 32 µg/m3
Edgecombe * 12.2 µg/m3  
Forsyth 14.4 µg/m3 32 µg/m3
Gaston 14.3 µg/m3 31 µg/m3
Guilford 13.8 µg/m3 31 µg/m3
Haywood 13.0 µg/m3 27 µg/m3
Jackson 12.0 µg/m3 25 µg/m3
Lenoir 11.3 µg/m3 26 µg/m3
Martin 11.3 µg/m3 24 µg/m3
McDowell 14.1 µg/m3 31 µg/m3
Mecklenburg (see Table 2) 32 µg/m3
Mitchell 12.6 µg/m3 28 µg/m3
Montgomery 12.2 µg/m3 27 µg/m3
New Hanover * 10.0 µg/m3 22 µg/m3
Onslow 11.3 µg/m3 24 µg/m3
Orange 13.2 µg/m3 29 µg/m3
Pitt 11.9 µg/m3 27 µg/m3
Robeson 12.8 µg/m3 30 µg/m3
Rowan * 14.2 µg/m3  
Swain 12.7 µg/m3 27 µg/m3
Wake 13.5 µg/m3 32 µg/m3
Watauga 12.1 µg/m3 31 µg/m3
Wayne 13.2 µg/m3 28 µg/m3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 2. The following table shows 3 counties with a 3-year average of the annual mean PM2.5 for each year above the established standard and one county, Catawba, with a 3-year average of the 98th percentile above the daily standard established in 2007, 35 µg/m3. (Note that during 2003-2005, the level of the daily standard had been set at 65 µg/m3, and Catawba County did not exceed that level. The first column lists the county; the second lists the average value for that county (rounded to the specifications of the annual standard); the third lists the average value for that county (rounded to the specifications of the daily standard).

Note:

  • Additional counties may be involved in emission reduction strategies
  • Nonattainment designations may not follow county boundaries
County Average value Average 98th Percentile
Catawba 15.3 µg/m3 36 µg/m3
Davidson 15.2 µg/m3  
Mecklenberg 15.3 µg/m3