Belfast Lough: Vital mussel population threatened by pollution

Drainage in Belfast was originally designed by Victorian engineers as a combined system, with both sewage and storm water flowing through the same pipes.

That was due to the shape of the city, sitting at the bottom of hills at near-sea level.

There are 270 combined storm overflows in the Greater Belfast area, where Mr Brow said there should only be “about 30 to 50”.

Some of those along the shores of Belfast Lough discharge more than 200 times a year.

That means anything that goes into the toilet could end up in the lough.

“Please do not flush anything which is not pee, poo and paper,” said Mr Brow.

“Our toilets should not be used as a bin.

“We should have the systems that are able to keep things in the sewer when they’re flushed, but we don’t.”