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Ammonia Emissions Assessment 

An  Ammonia Emissions Assessment is a report which looks in to the rates of ammonia exposure to sensitive receptors at certain distances from a proposed development, or an existing development. This can be an industrial installation, as waste processing facility but more often than not it is an intensive livestock development.

Do you require an Ammonia Emissions Assessment? Please contact SWEL for a quotation.

chickenAn Ammonia Emissions Assessment is often paired with an Odour Impacts Assessment, in both cases Emission rates are calculated for the proposed development. This can be done using secondary data, which is often the case in planning. Or for an Environmental Permit Application, this may include the collection of real world monitoring data from a pre-existing site. 

This ammonia emssions data is then fed in to emissions modeling software. We use AERMOD, which is a piece of software developed in the USA and is valid alternative to the like of ASDM modelling which is also popular amongst consultants.

The software takes in to account a wide varierty of variable such as the temperatures of air, temperatures of exhaust, turbidity of atmosphere. . . and most importantly wind direction. Typically a 1 year weather data set is used. This gives a idea of ammonia concentrations at nearby receptor locations, which might includes houses, or schools or both.

Image: Piyarat Jun-On [CC BY 4.0], via Wikimedia Commons

Ammonia Emissions Assessment will include benchmarking of current levels of determinants and the developments likely impacts of these levels in relation to current local EQS.

Governmental Guidance on Ammonia

Below guidance is listed on www.gov.uk.

You must submit a risk assessment of the impact of ammonia emissions from your site if either of the following apply:

Factors that could cause an increase of ammonia emissions include:

Do I Always Need a Ammonia Emissions Assessment for an Environmental Permit Application?

No not always, if you are running you your site as an installation, the Emissions for Ammonia may "Screen Out" as part of the H1 Assessment in which case detailed modeling as described above would not be required.

Please contact SWEL for a quotation.


The SCAIL tool (Simple Calculation of Atmospheric Impact Limits) is a suite of screening tools for assessing the impact from agricultural and combustion sources on semi-natural areas like SSSIs and SACs. SCAIL is now available as two models - SCAIL Agriculture and SCAIL Combustion. Both models provide an estimate of the amount of acidity, nitrogen or sulphur deposited on to a habitat or sensitive ecosystem. Output from the models can then be used to assess whether impact limits for the habitat are exceeded or not. The models are useful as an initial screening of sources for IED applications or Appropriate Assessments under the Habitats Directive.

As with our computer modeling SCAIL uses AERMOD to model impacts. With SCAIL the inputs are generalised and pre-determined and although they make a good job for screening out site quickly, they over estimate impacts. Our more complex model can add extra detail, such as variable emission rates that will more accurately reflect you actual activity.

SWEL can undertake this assessment on you behalf, as we have considerable experience. It is not overly difficult to do, but in some cases one must choose inaccurate descriptions (best fit) and some find this a little unnerving.

Example Reports

Ammonia Assessment Cornwall