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Air infographic​   

Air Quality has improved in Mecklenburg County

At the end of 2015, Mecklenburg County complied with all the current federal, health-based air quality standards.  Find out more about our current compliance status. In 2015, Mecklenburg County had:

276 Green Days, 80 Yellow Days, 9 Orange Days, 0 Red or Purple Days ​Learn more about the color-coded Air Quality Index.

Criteria Air Pollutants

Since the 1960's Mecklenburg County Air Quality ​(MCAQ) has operated a monitoring program to provide high quality data used to determine compliance with federal standards and inform the general public about air quality conditions.  In 2015, MCAQ collected 117,686 measurements with 34 monitors at 6 monitoring stations.


Mecklenburg County exceeded the federal standard for ozone 9 days in 2015.  However, the Mecklenburg County 2015 compliance value demonstrates compliance with the federal health-based standards for ozone.  Learn more about ground-level ozone.

Pollutant Averaging Time

Mecklenburg County

2015 Compliance Value

Federal Standard



8-hour ​68 ppb ​

70 ppb

2015 Standard​

75 ppb

2008 Standard

View historic trend of ozone in Mecklenburg County.



Mecklenburg County continues to demonstrate compliance with the current federal, health-based standards for particulate matter (PM) and other criteria pollutants.  Learn more about these pollutants and associated health impacts.

Pollutant Averaging Time Mecklenburg County 2015 Compliance Value Federal Standard
Particulate Matter
(P​M2.5) ​
24-hour18 µg/m335 µg/m3
Annual9 µg/m312 µg/m3
Particulate Matter (PM10)24-hour51 µg/m3150 µg/m3
Carbon ​Monoxide
(CO) ​
8-hour1.2 ppm9 ppm
1-hour1.5 ppm35 ppm

Sulfur Dioxide


3-hour0.006 ppm0.5 ppm
1-hour7 ppb75 ppb
Nitrogen Dioxide
(NO2) ​
Annual12 ppb53 ppb
1-hour39 ppb100 ppb

Mobile Sources

Nearly 90% of ozone-forming air pollution in Mecklenburg County comes from mobile sources likes cars, trucks, and construction equipment. There are two reliable indicators of on-road mobile source air pollution:​

767,662 registered vehicles in Mecklenburg County in 2015
1. Registered vehicles – The total number of on-road vehicles registered in Mecklenburg County increased from 707,195 vehicles in 2012.
34,916,752 miles driven per day in Mecklenburg County in 2015​2. Vehi​cle Miles Traveled (VMT) – The average number of miles traveled each day by on-road vehicles increased from 33,062,395 miles in 2012.  ​
Charlotte-area commuters are encouraged to choose a cleaner c​ommute (like carpooling, taking transit, walking or biking) to improve local air quality.  On an average day in 2015, 83,565 commuters used Charlotte Area Transit System (CATS) services as an alternative to driving alone.

N​on-road mobile sources, like construction equipment, can emit a significant amount of air pollution.  To reduce non-road mobile source emissions, MCAQ offers their award-winning Grants to Replace Aging Diesel Engines (GRADE) program.  GRADE provides businesses and organizations funding incentives to replace or repower older diesel-powered vehicles and equipment with newer cleaner-operating equipment.  ​ 

Stationary sources are generally larger sources of air pollution that are not mobile.  MCAQ permits 11 major (Title V) sources, 204 minor sources, and 317 gasoline stations (Stage 1).  A major source is one that emits, or has the potential to emit, pollutants over a major source threshold.  A minor source is any source which emits fewer pollutants than the major source threshold.

Permitted stationary sources in Mecklenburg County include concrete plants, fabricated metal product manufacturing, chemical plants, printing operations, autobody repair shops, petroleum bulk storage and dispensing facilities.  The public can access the online Air Pollution Facility Database for information concerning permitted stationary sources.​

MCAQ Activity Levels with Stationary Sources in 2015
Permits Issued117
Permit Applicability Determinations31
Asbestos Inspections173
Citizen Requests for Service29

Of the inspections completed in 2015, 94% of facilities were found to be in​​ compliance.  The three most commonly cited violations at stationary sources are:

  1. Monitoring and Recordkeeping – 11 violations
  2. New Equipment (without a Permit Modification) – 3 violations
  3. Emission Standards – 3 violations​

View the complete list of 2015 Air Quality Indicators presented above.