The Advocate General at the European Court of Justice (ECJ), Juliane Kokott, considered that national courts should investigate, at the request of data subjects, whether the choice of location of air quality monitoring stations was in conformity with EU law, in her conclusions delivered on Thursday 28 February (Case C-723/17).
Residents of the Brussels-Capital Region and the ClientEarth environmental organisation are challenging the air quality plan for the Belgian capital drawn up by the regional authorities.
When this dispute was referred to it, the Dutch-speaking court of first instance in Brussels referred the matter to the ECJ for a preliminary ruling in order to shed light on two points. The Belgian court wonders to what extent national courts can control the choice of location of air quality monitoring stations. It also wanted to know whether it was possible to establish an average value on air quality from the results of different stations.
To answer the first question, the Advocate General notes that, under the Ambient Air Quality Directive (2008/50/EC), fixed measuring stations must be set up, particularly where the highest concentrations of certain specific particles are found. While the competent bodies in this field do have discretion as to the choice of locations for such stations, Ms Kokott considers that judicial review must be carried out at national level, at the request of the persons concerned.
And if a court finds that the choice of locations is not in conformity with Union law, it should take the necessary measures to remedy this problem.
On the second question, Ms Kokott considers that compliance with limit values for certain particles should be assessed on the basis of the results provided by fixed measuring stations, without establishing an average value for a set of stations. (Original version in French by Lucas Tripoteau)