Welsh Water customers are getting a raw deal, with bills increasing while “disgraceful” pollution continues and executives pocket “scandalous” payments, the Senedd has heard.

Rhys ab Owen expressed concerns about Dŵr Cymru Welsh Water being issued a £1.3m fine for failing to monitor water quality at 300 different sites and committing 800 offences.

“This is on top of the sewage that was discharged last year, over 118,000 times,” he said.

“That is a sewage spill every five minutes – the highest… of any UK water company.”

Mr ab Owen, who sits as an independent, told the Senedd: “Constituents find it very difficult to believe – it sticks in the back of the throat – that executives are paid eye-watering sums, that there are discussions for them to be paid even higher salaries.

“And this at the same time that Dŵr Cymru is increasing household bills by 27 per cent this year, an average of £86 per household.

“Costs for householders are increasing yet scrutiny seems to be decreasing due to lack of funding and investment by the Welsh Government.”

Huw Irranca-Davies said Welsh Water will invest £6bn between 2025 and 2030, including £1.2bn to deliver environmental improvements and tackle nutrient pollution.

The deputy first minister said: “I’ve been consistently clear – both with the water companies and indeed the regulator, Ofwat – that customers in Wales expect to see real, tangible improvements in services… infrastructure and in environmental outcomes.”

He told Senedd members: “The investment… has indeed because it’s frontloaded led to increased bills for consumers, so we need to see that turned into action.

“We need to see the improvement in environmental performance coming through rapidly.

“If the investment is frontloaded, we need to see the benefits come through sooner too and that is right on behalf of the bill payers in Wales.”

He said Welsh Water acknowledged its failings following the court case – committing to reducing the ecological harm from storm overflows by 90 per cent, and 100 per cent by 2032.

Mr Irranca-Davies, whose responsibilities include water, told Senedd members he will shortly be meeting Jane Hanson, who was appointed Welsh Water’s chair in January.

“I can guarantee that this will be one of the matters on the agenda,” he said.

“And I will be seeking assurance on the trajectory of Dŵr Cymru Welsh Water’s turnaround plan.”

Janet Finch-Saunders, the Conservatives’ shadow climate secretary, said: “I just can’t believe that we’re still discussing this. Whilst we’re talking about it, there’s probably dozens of pollution incidents taking place right now.”

She described chief executive Peter Perry receiving total remuneration of £892,000 as scandalous, with a bonus of £91,000 paid in 2024.

Addressing the deputy first minister during topical questions on 21 May, she said: “I do think you need to be far more robust in your meeting with the chair….

“This has to stop and it has to stop immediately because people deserve better.

“This cannot go on for any longer.”