Raw sewage from new homes being flushed into London rivers

An Environment Agency spokesperson said: “Misconnections are a major cause of pollution, especially in urban areas, where the high density of households and associated drainage increases the likelihood of misconnections and therefore the impact on nearby watercourses.

“We encourage anyone who is installing a new toilet, sink, washing machine or dishwasher, to make sure their plumber is connecting them to the wastewater sewer rather than surface water drains.”

Harrow and Ealing councils did not respond to Local Democracy Reporting Service requests for comment.

Barnet Council called the situation “unacceptable” and said it was concerned about the impact on residents, biodiversity, and the local environment.

However, it also criticised the “fragmented legislation” that it said allowed it to happen.

Its spokesperson said: “New property developments are required to submit detailed plans for the proper management of sewage to prevent such pollution.

“However, many adaptations and conversions of existing properties take place without proper consideration and can result in these misconnections.

“We are doing all that we can to raise awareness about this issue, including issuing advice to residents setting out how they can help by checking the water flow connections in their homes.”

Additional reporting by Grant WIlliams, Local Democracy Reporting Service.