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New report published: Guidance on Decision-making Thresholds for Air Pollution

News Item 2022

Our recently published report – Guidance on Decision-making Thresholds for Air Pollution (JNCC Report No. 696) – outlines decision-making thresholds to help inform assessments of the impacts of air quality on designated nature conservation sites, such as Special Areas of Conservation (SACs), Special Protection Areas (SPAs) and Sites of Special Scientific Interest (SSSIs).

Commissioned by JNCC on behalf of the Inter-agency Air Pollution Group and Defra (Department for Environment, Food and Rural Affairs), the report consists of two documents: a main report which provides guidance; accompanied by a technical report, which describes the evidence used in setting the decision-making criteria.

An assessment of the impacts of air quality on a designated site is required in various decision-making processes, in order to enable an informed decision to be made as to whether a consent, permission or other authorisation should be granted or not.  This might include granting consent for proposals such as the construction of a poultry farm or industrial unit, where there is the potential for air pollution impacts from on-site emissions; or giving permission for residential developments or the building of a school, where there is the potential for impacts from road-traffic emissions.

Decision-making thresholds can be applied to individual projects and proposals to determine whether the risk from air pollution-related impacts from a particular proposal is small enough that no further assessment is necessary, or whether an assessment in combination with other plans and projects is required.  Currently, considerable assessment effort is spent on proposals which fall below the thresholds outlined in the report.  Removing those proposals enables assessment effort to be directed at proposals that require more scrutiny.  The Guidance on Decision-making Thresholds for Air Pollution report therefore empowers decision-makers to have confidence in focussing their efforts on those proposals that require greater scrutiny, without undermining the conservation objectives of designated sites.

The report is intended to be used by anyone involved in the assessment of air pollution impacts on designated sites, including nature conservation body advisers, competent authorities and consultants acting on behalf of project proposers.

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