2017-2018 Annual Monitoring Network Plan for North Carolina Air Quality

The North Carolina Division of Air Quality, DAQ, operates a network of air quality monitors across the state. The network, consisting of over 80 monitors at more than 40 sites, measures the concentration of regulated pollutants in the ambient or outdoor air. These pollutants include ozone, lead, fine particles, nitrogen oxides, sulfur dioxide and carbon monoxide. The measured concentrations are compared to the national ambient air quality standards, NAAQS, as set by the United States Environmental Protection Agency, EPA. If violations of these federal standards are detected, the DAQ takes regulatory action to return the ambient air quality to acceptable levels.

Every year the monitoring network is re-evaluated and adjusted to ensure it is providing adequate coverage. In most years these adjustments include starting new monitors, shutting down others, or simply relocating established monitors. The proposed annual network plan is subject to a 30-day public review period prior to being submitted to EPA for approval.

A summary of significant network changes is below:

The North Carolina Network consists of 53 Monitoring Sites.  Forty-two are operated by DAQ, four are operated by Mecklenburg County Air Quality, MCAQ, four are operated by Western North Carolina Regional Air Quality Agency also known as WNC, and three operated by Forsyth County.


The Sulfur Dioxide, SO2, Network

  • New Sites – During 2016 and 2017 four site specific SO2 monitoring stations were added at

    • Duke Roxboro

    • Duke Asheville (WNC)

    • Evergreen Paper, Canton NC

    • CPI Energy, Southport NC

  • Removed Site

    • The DAQ is proposing to end the New Hanover SO2 monitor on Dec.31, 2017, due to reductions in SO2 emissions in the Wilmington Metropolitan Statistical Area, MSA, due to Sutton switching to natural gas, etc.

Particulate Matter, PM2.5 & PM10, Network

  • 2017 added near-road PM2.5 at Triple Oak site in Raleigh – required by EPA

  • 2017 added near road PM2.5 at Remount site in Charlotte operated by MCAQ – required by EPA

  • No significant changes proposed – There is a general move away from gravimetric filters to continuous monitoring.  EPA establishes minimum technical criteria be satisfied before removing gravimetric filters and relying on continuous methods.  Several sites in NC have satisfied and others we are the process of making that demonstration. 

Nitrogen Dioxide, NO2, Network

  • No major changes proposed

Carbon Monoxide, CO, Network

  • 2017 added near-road CO monitor at Triple Oak site in Raleigh – required by EPA

  • 2017 added near road CO at Remount site in Charlotte operated by MCAQ – required by EPA

  • No significant changes proposed

Ozone Network

  • No significant changes in 2016 or proposed for 2017 and 2018


  • Rockwell site in Rowan County - NOy, nitrate and aethalometer, which measures black carbon, were shut down in 2016.  The data was no longer needed and the equipment was old.  The site continues to do ozone monitoring.

Blackstone Site – established in 2013 to obtain background values for hydraulic fracturing study. The data is being reviewed and preliminary indications are that sufficient data has been collected to meet the objectives of the study.  Depending on results of the data review DAQ could request EPA approval to remove the site in late 2017 or early 2018.


2017-2018 Annual Monitoring Network Plan - Volume 1 - By Pollutant

By Division of Air Quality Regional Office: