compulsory mazout tank inspection in Brussels?

Hi! A company informed me of their own initiative that my mazout tank (1160 Auderghem)has to be inspected every 5 years (underground, 3000 litres). This seems to be correct in Flanders, at least.

But on http://www.informazout.be/nl/home/wetgeving_bestaand_en_nieuw_Brussel I found that in Brussels this is not regulated - are you a mazout tank owner in Brussels who can help? Thanks!