​This part of the website is meant to ensure that developers and their consultants are familiarised with the air quality requirements, before submitting an application for a development permit.

In air quality we are mostly concerned about the impacts of new developments on traffic flows, so the first item we will ask for is a quantification of the expected increase in traffic flows in annual averaged daily traffic flows or AADT.  It is important that the increases in traffic flows are expressed as AADT, because this will save unnecessary to-ing and fro-ing between ERA and your consultants.  In order to save time we strongly advise you to seek the advice of traffic consultants and ask them to prepare a traffic impact statement for you (TIS).

If the TIS shows that the project is likely to cause an increase of 1000 AADT for passenger cars or 200 AADT for heavy goods vehicles then ERA will ask you for an Air Quality Study (AQS). The terms of reference for the AQS can be downloaded from this link​.

The aim of the AQS is to determine the significance of the impact of the proposed project on air quality.  The contribution of the project to air pollution (due to the increased traffic flows) is expressed in terms of four significance criteria, below:

  • ​Negligible
  • Slight Adverse
  • Moderate Adverse; and
  • Substantial Adverse

​The following tool​​​ should help consultants determine the significance of the impact of the project on air quality.

ERA’s recommendations with respect to the approval of the project depend on the significance of the impact and are reproduced below:

a)     Whenever the impact of the project is determined to be “negligible” no further action will be required from the developer.

b)       If the impact of the project is classified as “substantially adverse” then ERA will not recommend approval unless the project is modified in such a way (including scaling down) that the significance of the impact is measurably lessened to at least “slightly adverse”.  In this case a green travel plan will not be considered as sufficient.

c)      If the impact of the project is “moderate adverse” than the developer will be asked to modify the project. The modifications can include a green travel plan which has to include specific, measurable* and achievable objectives together with their respective implementation time-frames. The developer will be asked to finance at least in part, the implementation of the green travel plan. The implementation of the plan will have to be audited and eventually updated by the developer on a periodic basis. If the green travel plan does not lower the significance of the impact then the developer will we asked to take additional measures.

d)      If the impact of the project is slightly adverse then the developer will be asked to consider alternatives, which will lessen the impact of the project.

*The term measurable in this context means that the green travel plan shall quantify the reduction in the pollutant levels (in µg/m3), over the scenario leading to the classification of the impact as “moderately adverse”.​