Brussels-Capital Region: Monitoring network of the nitrate content in surface waters and groundwater. It was designated in accordance with the prescriptions of the European Directive 91/676/EEC concerning the protection of waters against pollution caused by nitrates from agricultural sources, by the Ministerial Order of 25 May 1999.

Brussels-Capital Region: The nitrate-vulnerable zone is a protected area against the pollution of groundwaters caused by nitrates from agricultural sources. It was designated in accordance with the prescriptions of the European Directive 91/676/EEC, by the Ministerial Order of 25 May 1999.

Brussels-Capital Region: location of the three areas of limitation of aircraft noise defined by the order of the Government of the Brussels-Capital Region of 27 May 1999 on the fight against the noise generated by air traffic. Note : http://geoportal.ibgebim.be/pdf/metadata_doc/19990527_agb_LutteBruit_TraficAerien.pdf