Llyr Gruffydd MS Member of the Senedd for North Wales

An MS has told Welsh Water to “clean up its act” after it was found to have been illegally spilling untreated sewage in North Wales.

Llyr Gruffydd, who represents the region in the Senedd, took aim at the embattled water firm, following its admission that a number of its wastewater treatment plants have been operating in breach of their permits for years.

A report, which was shared with the BBC by mathematician and former University College London Professor Peter Hammond, of the campaign group Windrush Against Sewage Pollution, analysed the performance of 11 sewage treatment works in Wales from 2018 to 2023.

Of these treatment works, Prof Hammond found that 10 had been releasing untreated sewage in breach of their permits.

Four of the sites where these spillages have been happening are in North Wales.

The report found that there were 374 breaches Abererch, while there were 14 breaches in Caernarfon, which resulted in 65 million litres being spilled.

In Llanrwst there 82 breaches which resulted 168 million litres being spilled, while in Ruthin there 106 which accounted for 182 million litres in spillages.

While a plant is permitted to discharge untreated sewage under certain conditions in order to ensure it does not become overwhelmed during heavy rain, it isn’t allowed to release any before it reaches the overflow level stipulated on its permit.

Llyr Gruffydd MS: “Residents across North Wales will understandably be hugely concerned about the news that Welsh Water has been illegally spilling sewage in our waterways for years.

“This isn’t just a few isolated incidents. These spillages have been happening for a number of years.

“It’s clearly time for Welsh Water to clean up its act. While the company has said it is working to resolve these issues we need to make sure that it upholds its legal obligations.

“Natural Resources Wales has a responsibility to firmly enforce the regulations that are in place.

“The recommendations that have been made in the report should be seriously considered.

“There is a strong case for the system being far more transparent, as well as better data collecting and monitoring and these are issues that I have previously championed in the Senedd.”