Air quality in Colchester

Monitoring and managing air quality in Colchester

We are responsible for monitoring and managing air quality in Colchester.

We regularly test the levels of pollution in the air and produce Annual Status Reports of our findings.

Air Quality Annual Status Report 2023 (PDF, 3.39MB)

We also issue environmental permits for certain industrial activities and businesses. 

Environmental permits

Air Quality Management Areas in Colchester

We have 49 air pollution testing sites throughout the city.

Our 49 sites are measured using diffusion tubes, which measure the average monthly level of nitrogen dioxide. At our site on Brook Street, there is a continuous monitoring station which monitors air pollution 24/7.

The legal limit for the air pollutant nitrogen dioxide (NO2), which comes from exhaust fumes, is 40µg/m3 (micrograms per meter cubed). Areas of Colchester that exceed EU guidelines have been declared Air Quality Management Areas (AQMAs).

We have three small areas where the pollution levels are higher than we would like them to be. To ensure we reduce air pollution we have in place an Air Quality Action Plan which states what actions the Council is going to take to improve air quality particularly in our Air Quality Management Areas.

You can see these areas and the roads included on Defra’s interactive map.

Exceedances of the legal EU limit vary throughout Colchester, with many measured sites not exceeding the limit. In 2022 the maximum concentration measured in Colchester was 41.3µg/m3 only marginally above the NO2 annual mean air quality objective of 40µg/m3.

You can find out more about AQMAs by visiting Defra.

Page last reviewed: 22 September 2023