Ozone Average Values

Please click here to open the ozone design values map as a PDF.

Table 1. The following table shows the 3-year averages for ozone. The first column lists the county, the second column lists the average value for that county. Where multiple monitors exist in the same county, the value from the monitor recording the highest value has been listed. The current 8-hr ozone standard is 0.070 ppm.

[*] denotes monitors that failed to achieve required data completeness due to weather-related causes.

 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.

^[4] CastNet – (Clean Air Status and Trends Network)- federally operated sites used to evaluate the effectiveness of regional and national control programs for compliance with the NAAQS Ozone

Please click here to open the ozone design values map as a PDF.

Table 1. The following table shows the 3-year averages for ozone. The first column lists the county, the second column lists the average value for that county. Where multiple monitors exist in the same county, the value from the monitor recording the highest value has been listed. The current 8-hr ozone standard is 0.070 ppm.

[*] denotes monitors that failed to achieve required data completeness due to weather-related causes.

 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.

^[4] CastNet – (Clean Air Status and Trends Network)- federally operated sites used to evaluate the effectiveness of regional and national control programs for compliance with the NAAQS Ozone Standard.

Please click here to open the Ozone Values Map as a PDF.

Ozone monitoring sites are located in 31 North Carolina counties and operated by state, local, federal and Tribal Governments.  For Ozone, the United States Environmental Protection Agency (USEPA) defines the Design Value as the 4th highest daily maximum 8-hour average concentration, averaged over a 3-year period.  The current USEPA standard for Ozone is .070 parts per million, or ppm.  Any design value above this level is considered non-attainment of the standard.  There are currently no counties in North Carolina in non-attainment.  The table below lists the current design value for each county in which an ozone monitor is located. The first column lists the county in which the ozone monitor is located, the second column lists the design value calculated for the monitor.  

[*] denotes monitors that failed to achieve required data completeness due to weather related causes.

 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.

^[4] CastNet – (Clean Air Status and Trends Network)- federally operated sites used to evaluate the effectiveness of regional and national control programs for compliance with the NAAQS Ozone Standard.

Please click here to open the Ozone Values Map as a PDF.

Ozone monitoring sites are located in 31 North Carolina counties and operated by state, local, federal and Tribal Governments.  For Ozone, the United States Environmental Protection Agency (USEPA) defines the Design Value as the 4th highest daily maximum 8-hour average concentration, averaged over a 3-year period.  The current USEPA standard for Ozone is .070 parts per million, or ppm.  Any design value above this level is considered non-attainment of the standard.  There are currently no counties in North Carolina in non-attainment.  The table below shows the 4th highest 8- hour average recorded in each county, where a monitor is located, during the last 3-year period.  The first column lists the county, the second column lists the average mean ozone concentration for the period, and the third column lists the 4th highest 8-hour maximum average recorded.  For counties with more than one monitoring site, the value reported is the highest among the inclusive sites. 

 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.

^[4] CastNet – (Clean Air Status and Trends Network)- federally operated sites used to evaluate the effectiveness of regional and national control programs for compliance with the NAAQS Ozone Standard.

Please click here to open the Ozone Values Map as a PDF.

Table 1. The following table shows the 3-year averages for ozone. The first column lists the county, the second column lists the average value for that county. The current 8-hr ozone standard is 0.070 ppm.