The quality of the data supplied is governed by article 9 relating to quality assurance and assessment of the E-PRTR Regulation and paragraphs 4 of article 2 of the Decree of the Government of the Brussels-Capital Region of 13 November 2008 relating to the obligation of periodic notification of environmental data for certain classified industrial installations.

Each year following the year of notification, the operator receives a letter reminding him of these notification obligations. The form to be used, drawn up in accordance with Article 5 (on notification by operators) point 1 of the Regulation, is sent at the same time as the letter.

The forms sent must be accompanied by any document, calculation or explanation to justify the values declared.

Emissions to air / discharges to water and waste shipments are validated by checking the data and, among other things :

- the calculation method and conversion rules ;

- the measurements used: by comparing the measurement results supplied with measurements carried out by Brussels Environment;

- the list of substances emitted is compared with the list of substances in appendices 4 and 5 of the guidance document for implementation of the European PRTR;

- emission factors are compared with those quoted in the literature,

- annual trends;- a comparison is made with the data available within BE on the basis of other reporting obligations (e.g. the real cost of water treatment, the waste register, etc.),

The European Commission also assesses the data submitted, mainly on the basis of previous and national data.