Part of Mellieħa Bay was yesterday declared unfit for swimming due to an outflow of sewage into the sea caused by a blockage in a main sewer and a fault at a large block of apartments.

The Environmental Health Directorate said bathing was not recommended between Dawret it-Tunnara and the boathouses at Għajn Żejtuna, close to Santa Marija Estate.

The popular sandy beach of Għadira Bay was not affected by the outflow.

Employees from the Waste Water Unit within the Water Service Corporation started repair works on the main sewer at Marfa Road.

Sources told this newspaper the warning was issued after samples indicated that seawater quality in the areas in question was below the minimum standard.

Residents in Dawret it-Tunnara told the Times of Malta they were completely oblivious to the hazard because there were no visible signs of sewage discharging into the sea. They said that, shortly after 11am, a WSC employee instructed all bathers to get out of the water as a “precautionary measure”. Shortly afterwards, signs were put up warning the public that, due to extraordinary circumstances, bathing in the area was temporarily not recommended.

Though a public official remained on site till the evening to monitor the situation, some could not resist the heat and opted to cool themselves by taking the plunge in spite of the risks involved.

WSC sources blamed an underground seepage of sewage to damaged water culverts by the sea, from where the sewage was then discharged directly into the sea.

The exact nature of the blockage was still unknown at the time of writing. Personnel in special protective equipment were called on site to inspect the main sewer, which was about a storey deep.

The indications were that the fault was either the result of an accumulation of waste or construction debris which, at times, ends up in the sewers as a result of bad workmanship.