The idyllic image of Montreal's Nuns' Island, long known for its parks and scenery, took a beating Monday when a report revealed the fecal coliform count in the St. Lawrence River around the island is 650 times higher than acceptable levels.

The City of Montreal's environment department report noted that 48 of the more than 8,000 residences on the island dump their raw sewage directly into the river.

A Nuns' Island sewer pipe feeds raw sewage into the St. Lawrence River.
(CBC)

Fecal matter and toilet paper can be seen floating on the surface of the river, the report said.

The island is located in Montreal's borough of Verdun, which has been aware of the problem for several years, said the borough's division chief of public works, Jean Cardin, at a news conference Monday.

Between 2003 and 2005 the borough inspected all the homes on the island, he said.

Inspectors ran food colouring through the pipes and waited to see where it would come out.

That's when they discovered that 48 households were sending their waste directly into the river. But they never made their findings public.

Sam Mazochi, who rents a high-end condo on Terry Fox Drive has discovered to his surprise that his home is one of the offenders.

"That's very disturbing and very sad, that the pipes go into the St. Lawrence. That's very disgusting. So I'm really sorry for that, but I will call the landlord and I will yell at them because it's not right," Mazochi said.

Mazochi's landlord might not even know about the problem, because the city hasn't officially contacted any of the residents.

Cardin said the city is waiting to find out exactly who is at fault before telling residents. He said in some cases plumbers accidentally connected homes to drain pipes that dump waste into the river. In other cases, the municipal pipes were incorrectly installed.

Cardin said the borough is also partly to blame because it should have inspected the homes much sooner.

Cardin says the city might offer subsidies to landlords to fix their pipes. But first they need to determine who's responsible for the mess.

The city doesn't plan to deliver a final report until fall.