According to a Spotlight investigation, raw sewage discharges have caused dangerous bacterial levels in Belfast Lough to above permissible limits.
Bacterial levels at certain well-known swimming locations were more than three times higher than allowed for bathing waters, according to expert water sampling.
By discharging untreated sewage into the lough hundreds of times annually, Northern Ireland Water has acknowledged breaking the law.
The Department for Infrastructure’s (DfI) decades-long underfunding of the firm’s sewage network has been cited by the corporation as the primary cause of the spills.
According to the government, John O’Dowd, the minister, recognized the severe financial strains NI Water was experiencing, but he also pointed out that the corporation had previously been given about half of his department’s yearly available budget.