From the responses it seems ...

From the responses it seems that you are using ozone for disinfection of water for sale as mineral water and this process is generating bromates. There was a similar issue a few years ago in London where the local Coca-Cola subsidiary was basically doing the same to treat what I think was London mains water as a 'mineral' water. Heavy levels of ozonation resulted in bromate formation that exceeded the 10 ppb limit. Curiously the same process had been used for years to make the beverage without issue as apparently different standards apply to that.

If it is only a question of disinfection then I would question the selection of the ozone process. Unless there is a need for oxidation of other contaminants I would go for UV for disinfection. If you are stuck with Ozone then the ways to limit the formtion of bromate are to control the ozone dose to the minimum required, to ensure that the contact time is carefully controlled and there is not a section where long contact times can be found. Also pH will affect the kinetics of bromate formation.

It is possible to reduce bromate to bromide by dosing ferrous Fe2+ salts. However this is hardly suited to water intended for drinking.