Sewage discharges into River Tawe and popular beaches remain a concern

Richard Youle, local democracy reporter

Concerns have been raised about sewage discharges into the River Tawe and some popular beaches.

Swansea councillors have been told that discharges of sewage and stormwater into the river and some coastal spots remain an issue.

Hamish Osborn, of environment body Natural Resources Wales (NRW), said “there will have been a significant number of spills” from combined sewer overflows located along the River Tawe all the way into Powys.

Combined sewer overflows discharge wastewater which can contain sewage and other pollutants, as well as rainwater. Without them sewage could back up into homes and businesses during heavy rainfall.

Sewage discharges

Mr Osborn had been asked at a council scrutiny meeting how many times sewage had been discharged into the Tawe and at Langland and Caswell beaches in the last 12 months.

He said he didn’t have the exact figures for the Tawe but they could be collated. He said there were “some high-spilling assets” along the river and Welsh Water was evaluating them and trying to find solutions.

“It’s not a situation we are particularly happy with – the number of spills in the Tawe – but compared to many years ago when we didn’t even know how many were occurring, we have moved on,” said Mr Osborn.

“All the high-spilling assets are being looked at.”

Water quality

Bathing water quality at Swansea beach, whose eastern edge is by the mouth of the Tawe, is usually deemed “good” rather than the “excellent” rating achieved further west at Langland and Caswell.

But the climate change and nature scrutiny panel heard Welsh Water’s pumping station at Langland appeared to be operating in stormwater conditions when it wasn’t supposed to.

Councillors were told its emergency overflow system had discharged 12 times in 2023, including five during the designated bathing water season between May and September. These spills lasted just over 30 minutes each on average.

Mr Osborn said some may have been due to an outfall pipe being blocked or partially blocked, resulting in stormwater backing up into the well of the pumping station.

He said Welsh Water had cleared the outfall, meaning the only time a problem should occur was if the pumps broke down.

Mr Osborn also said stormwater could be getting into the beach-side showers at Langland, which were connected to the foul sewer.

“Work may have to be done to isolate the showers from stormwater run-off,” he said.

Treatment plant

The meeting heard the sewage treatment plant at nearby Caswell was allowed to discharge under certain conditions and there had been three spills in 2023, although one of them could have been triggered by maintenance work.

Generally the situation there, said Mr Osborn, was better than previous years with some sources of incoming surface water being diverted.

Mumbles councillor Will Thomas said he and his ward colleagues have been obtaining data from Welsh Water and pressing the company to act, although he added you’d be looking at “tens of millions of pounds” given the layout of the network in Gower and Swansea.

Cllr Thomas said spill data at Knab Rock pumping station, Mumbles, was “exceptionally high”.

He said he’d been advised Welsh Water was going to fit three new pumps, but he wondered why discharges had been allowed to get so high without intervention from the authorities.

Mr Osborn said the number of spills was “excessive” at Knab Rock and this “obviously needs attention”.

He added, though, that the spills included ones into underground tanks rather than from the tanks into the sea which “confuses the issue somewhat”.

Mr Osborn’s NRW colleague, Sarah Bennett, said it was regulating the matter through a recently modified permit for the Knab Rock pumping station which forced Welsh Water to investigate when a certain number of spills were recorded.

Pressure

Mr Osborne said NRW was putting pressure on Welsh Water to make progress.

“We do regulate this problem – it bothers us, we expect action,” he said.

These issues are not new. At a scrutiny meeting three years ago concerns were raised about large numbers of spills from combined sewer overflows in the Tawe.

One councillor said a combined sewer overflow in Clydach had discharged into the river 154 times in 2020 for a period of 1,166 hours. At the same meeting, Mr Osborn said NRW had “certain issues with” Langland pumping station’s emergency overflow system.

A report before the latest meeting this month said NRW carried out bathing water samples at various beaches and the council did so at non-designated spots at Broughton and Rhossili, Gower.

The report said in general, coastal waters had been “hugely improved by large and sophisticated treatment schemes”.

No-one from Welsh Water was present at the meeting.

A spokesman said afterwards that it has been investigating the pumping stations at Langland and Knab Rock and liaising with NRW with regards to their performance.

“Work has already commenced at both these sites and we update our regulator,” he said.

“For Knab Rock, there is work under way to replace pumps as part of a wider programme, which we believe will improve its flow performance.

“Following network investigations at Langland, we have identified several points of surface water ingress and are investigating ways to remove this.”