An Islander filmed the ‘150-square-feet’ ‘chunky’ brown liquid bubbling up in the middle of the bay about 500 metres out to sea from First Tower.
The video has been shared hundreds of times on social media.
However, in a statement a spokeswoman for the Environment Department said there were no issues but added that Environmental Protection officers were investigating.
Effluent from the Bellozanne Treatment Works is pumped into St Aubin’s Bay, about 500 metres from the sea wall, near the First Tower Pumping Station. It is mixed with outflow from streams and other drainage from the Bellozanne Valley.
The spokeswoman said: ‘The sewage treatment works are operating normally. Mixing fresh water with saline always creates some discolouration, and the sewage treatment sometimes produces foam which is fully UV-treated and safe, but which can look unpleasant.
‘Environmental Protection officers are investigating, as they do when they receive all such reports. They are also checking the wider Bellozanne catchment area.’
