Untreated sewage illegally spilled for years, Welsh Water admits
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Dozens of Welsh Water treatment plants have been illegally spilling untreated sewage for years, the company has admitted.
After being presented with analysis by the BBC, the company said between 40 and 50 of its wastewater treatment plants are currently operating in breach of their permits.
The analysis was shared with the BBC by mathematician and former University College London Professor Peter Hammond, from campaign group Windrush Against Sewage Pollution.
After requesting data on 11 Welsh treatment plants, Prof Hammond found that 10 had been releasing untreated sewage in breach of their permits.
A plant is allowed to discharge untreated sewage in order to ensure it does not become overwhelmed during heavy rain.
However, it is not allowed to release any before it reaches the overflow level stipulated on its permit.
We're not proud of this at all. It's a very uncomfortable position to be in - but it's not for the want of trying
The BBC reported that the worst offender is the Cardigan plant in west Wales, which illegally spilled untreated sewage for a cumulative total of 1,146 days from the start of 2018 to the end of May 2023.
“This is the worst sewage works I’ve come across in terms of illegal discharges,” Prof Hammond said.
Steve Wilson, managing director for wastewater services at Welsh Water, told the BBC: “We’re not proud of this at all.
“It’s a very uncomfortable position to be in – but it’s not for the want of trying. We have been trying to fix this.”
Work is scheduled to begin on a new £20 million treatment plant for Cardigan in 2025.
The BBC reported that regulator Natural Resources Wales (NRW) has been aware of the issues at the Cardigan plant for eight years and has issued enforcement notices but no fines.
Huwel Manley, head of operations for south-west Wales at NRW, told the broadcaster: “We have prosecuted Welsh Water on a number of instances for pollution events, just not for low flow spills as is the case here.
“But we are working with trying to set national guidance along with England so that we have a more standardised approach as to how and when we take that prosecution route.”
