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PM2.5 Average Values

In 2012, the United States Environmental Protection Agency (USEPA) established two complementary primary regulatory standards for PM2.5.  The first is based on a yearly average value and is set at 12 micrograms per cubic meter, µg/m3, based on the average annual weighted mean value, averaged over 3 years.  The second standard is based on daily averages and is set at 35µg/m3 based on the 98th percentile of daily values, averaged over 3 years.  Any site whose 3-year average exceeds either of these values has failed to attain USEPA standards.  The design value is the actual value recorded at a given site used to demonstrate attainment of either of these standards. 

Please click here to open the PM2.5 Daily Standard Design Values map as a PDF.

Please click here to open the PM2.5 Daily Standard Design Values map as a PDF.

At present, all PM 2.5 sites in North Carolina meet the USEPA PM 2.5 standard.  The table below lists the 3-year average values for PM2.5 sites in North Carolina.  The first column lists the county in which the monitor is located.  The second column lists the 3-year annual average weighted mean design value.  The third column lists the 3-year average 98th percentile daily design value.  Where multiple sites exist in one county, only the data from the site reporting the highest value has been reported.  Data which fail to meet the regulatory completeness requirements for a 3-year average have not been included.

County

2016- 2018 Design Value
Average 3-Year Annual
Weighted Mean

2016- 2018 Design Value 
Average 3-Year Daily
98th Percentile

Buncombe [1]    

7.1

22

Catawba [1]   

8.6

20

Cumberland [1]  

8.1

18

Davidson [1]   

8.7

19

Durham [1]    

8.6

18

Forsyth [1]  

7.5

16

Guilford [1]    

7.8

16

Jackson

7.8 28

Johnston [1]  

7.8

15

Mecklenburg [1] 

8.5

18

Mitchell [1]  

7.0

21

Montgomery [1]  

6.3

14

New Hanover [1] 

4.8                              

13

Pitt [1] 

6.6

13

Swain[1]  

8.3 

25

Wake [3,1]   

7.7

15

Purpose of Monitor

[1] SLAMS – (State and Local Monitoring Stations) Network of monitoring stations that monitor ambient air concentrations for pollutants for which standards have been established. The scale of these sites can be either neighborhood or urban.

[2] SPM – (Special Purpose Monitors) SPMs allow the capability of providing monitoring for various reasons such as special studies, modeling verification or compliance status, and other objectives. These monitors are not committed to any one location or for any specified period.

[3] NCORE – (National Core) Community-oriented multi-pollutant monitoring station used to evaluate the regional air quality models used in developing emission strategies and to track trends in air pollution abatement control measures’ impact on improving air quality.

Please click here to open the PM2.5 Daily Standard Design Values map as a PDF.

Please click here to open the PM2.5 Annual Design Values map as a PDF.

At present all PM 2.5 sites in North Carolina meet the USEPA PM 2.5 standard.  The table below lists the 3-year average values for PM2.5 sites in North Carolina.  The first column lists the county in which the monitor is located.  The second column lists the 3-year annual average weighted mean design value.  The third column lists the 3-year average 98th percentile daily design value.  Where multiple sites exist in one county, only the data from the site reporting the highest value has been reported.  Data which fail to meet the regulatory completeness requirements for a 3-year average have not been included.

County

2015- 2017 Design Value
Average 3-Year Annual
Weighted Mean

2015- 2017 Design Value 
Average 3-Year Daily
98th Percentile

Buncombe [1]    

7.4 

23

Catawba [1]   

8.7  

20

Cumberland [1]  

8.3 

17

Davidson [1]   

8.4  

19

Durham [1]    

8.8  

19

Forsyth [1]  

7.6  

16

Guilford [1]    

8.2 

16

Johnston [1]  

7.4 

15

Mecklenburg [1] 

8.7 

18

Mitchell [1]  

7.5  

20

Montgomery [1]  

6.5  

15

New Hanover [1] 

5.7                               

14

Pitt [1] 

6.9  

14

Swain[1]  

8.1 

25

Wake [3]   

8.8 

18

Purpose of Monitor

[1] SLAMS – (State and Local Monitoring Stations) Network of monitoring stations that monitor ambient air concentrations for pollutants for which standards have been established. The scale of these sites can be either neighborhood or urban.

[2] SPM – (Special Purpose Monitors) SPMs allow the capability of providing monitoring for various reasons such as special studies, modeling verification or compliance status, and other objectives. These monitors are not committed to any one location or for any specified period.

[3] NCORE – (National Core) Community-oriented multi-pollutant monitoring station used to evaluate the regional air quality models used in developing emission strategies and to track trends in air pollution abatement control measures’ impact on improving air quality.

2013-2015

2013-2015

Please click here to open the PM2.5 Daily Standard Design Values map as a PDF.

 

Please click here to open the PM2.5 Annual Design Values map as a PDF.

 

Table 1. The following table shows the 3-year averages (2013-2015) for PM2.5. The first column lists the county, the second column lists the annual average, and the third column lists the 98th percentile daily average. The current annual standard is 12 ug/m3 and the current daily standard is 35 ug/m3

County 2013-2015 Annual 3-Year Average

2013-2015 Daily 3-Year Average 

98th Percentile

Alamance 8.1 ug/m3 16 ug/m3
Buncombe 7.7 ug/m3 15 ug/m3
Caswell 8.8 ug/m3 18 ug/m3
Catawba 8.9 ug/m3 18 ug/m3
Cumberland 8.5 ug/m3 16 ug/m3
Davidson 9.2 ug/m3 23 ug/m3
Duplin 7.3 ug/m3 15 ug/m3
Durham 8.3 ug/m3 18 ug/m3
Forsyth 8.5 ug/m3 19 ug/m3
Guilford 8.4 ug/m3 19 ug/m3
Haywood 8.2 ug/m3 18 ug/m3
Jackson 7.3 ug/m3 15 ug/m3
Johnston 7.3 ug/m3 16 ug/m3
Martin 6.9 ug/m3 14 ug/m3
McDowell 8.4 ug/m3 16 ug/m3
Mecklenburg 9.0 ug/m3 18 ug/m3
Montgomery 8.0 ug/m3 15 ug/m3
New Hanover 6.5 ug/m3 14 ug/m3
Pitt 7.3 ug/m3 15 ug/m3
Rowan 8.7 ug/m3 17 ug/m3
Swain 7.6 ug/m3 18 ug/m3
Wake 10.7 ug/m3 22 ug/m3
Watauga 6.7 ug/m3 15 ug/m3
Wayne 8.9 ug/m3 18 ug/m3