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Guidance

Get an air pollution assessment 

A service for air quality consultants and regulators in Northern Ireland to carry out and review air pollution assessments for sensitive ecological sites. 

Applies to Northern Ireland

The service currently only calculates assessments in Northern Ireland. It will be evaluated before a decision is made to roll it out further across the UK.

Use this service to assess how a new development would affect air quality and nutrient nitrogen deposition at sensitive ecological sites.

You can submit the results of the assessment when you apply for:

  • planning permission
  • development consent orders (DCOs)
  • environmental permits
  • inclusion in strategic plans, such as local plans

Using this service

This service is for:

If you are not an air quality consultant, you should consider paying a consultant to check your calculations. You will need to repeat the assessment if there are mistakes.

Start your assessment

Before you start

The service will not save your work. If you cannot complete the assessment in one session, export your input data. You can then import your data back in to complete the assessment.

For all assessments, you’ll need to include:

  • your chosen assessment year (or years)
  • the source location (as grid coordinates)

You will need to provide additional information depending on the type of emission source.

For information on emissions data the service uses, read how the get an air pollution assessment service calculates emissions.

Agriculture emission sources

You will need to include:

  • source height in metres (m)
  • source dimensions (m), as either the diameter or the length and width
  • temperature in degrees Celsius (°C) or density in kilograms per cubic metre (kg/m³)
  • efflux velocity in metres per second (m/s) or volume in cubic metres per second (m³/s)
  • specific heat capacity in Joules per Kelvin per kilogram (J/K/kg)
  • emission rate parameters – for example, either number and type of animals or emission rates of nitrogen oxides (NOx) and ammonia (NH3) in kilograms per year (kg/year)
  • details of how the emission rates vary over time, if the emissions are not continuous throughout a day, week or year

You will also need to select which sector the emissions come from:

  • animal housing – buildings that house animals
  • litter or manure storage – storing slurry or manure
  • farmland – grazing, organic and inorganic fertiliser application, organic processes or animals kept in outdoor yards 
  • greenhouse horticulture
  • other – any sources that do not fit the other categories

Energy, industry and other emission sources

You will need to include:

  • source height (m)
  • source dimensions (m), as either the diameter or the length and width
  • temperature in degrees Celsius (°C) or density (kg/m³)
  • efflux velocity (m/s) or volume (m³/s)
  • specific heat capacity (J/K/kg)
  • emission rates of NOx and NH3 (kg/year)
  • details of how the emission rates vary over time, if the emissions are not continuous throughout a day, week or year

For energy emission sources, you will also need to select one of these sectors:

  • large combustion plant – with a rated thermal input of at least 50 megawatts
  • medium combustion plant – as defined by the Medium Combustion Plant Directive
  • specified generator – as defined by the specified generator regulations
  • other – any sources that do not fit the other categories

For industry emission sources, you will also need to select one of these sectors:

  • waste processing
  • food and beverages
  • chemical industry
  • building materials
  • basic metal
  • metalworking industry
  • other – any sources that do not fit the other categories

Road emission sources

You will need to include:

  • road width and elevation (m)
  • gradient (%)
  • details of any roadside barriers to dispersion (street canyon inputs)
  • traffic flows or NOx and NH3 emission rates (kg/year)
  • details of how the emission rates vary over time, if the emissions are not continuous throughout a day, week or year

Submitting your assessment

After using the service, you will need to:

  1. Export the PDF report from the service.
  2. Present the results in a written report suitable for the type of application you’re making.
  3. Submit the written report and PDF report from the service to the regulatory authority.

For information on presenting the results and submitting your assessment, read:

Regulators: checking an air pollution assessment

When regulatory authorities receive an air pollution assessment that has been created using this service, they may need to check it is accurate.

The application should include:

  • a written report presenting the results of the air pollution assessments
  • the PDF report exported from the service, which includes modelling results

Authorities can upload the PDF report on the first page of the ‘Get an air pollution assessment’ service to view and check that the assessment has been carried out correctly.

Regulators: accessing the in-combination archive 

As a regulator, you should upload air pollution assessments to the in-combination archive as Geography Markup Language (GML) files.

Regulators can use the in-combination archive to: 

  • view or update uploaded applications
  • keep track of any changes made within the in-combination archive to uploaded applications

To use the in-combination archive, you will need to be a regulator and have a GOV.UK One Login. If you do not already have one, you will be able to create one when you first use this service. You will have to wait for approval before you can use the in-combination archive.

Access the ‘Get an air pollution assessment’ service in-combination archive.

Get help with this service

If you need help using this service, contact the air pollution assessment helpdesk.

Email: get.an.air.pollution.assessment@defra.gov.uk 
We aim to reply within 2 working days.

Telephone: 03301 242 162  
Monday to Friday, 8:30am to 4pm (except statutory holidays) 
Find out about call charges 

Updates to this page

Published 12 May 2026

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