Up to 10,000 hidden sewage pipes could be fuelling fivefold increase in fish deaths

15 May 2024, 07:40 | Updated: 15 May 2024, 09:28

Welsh Water Authority Aims To Reduce Sewage Overflow Incidents
Welsh Water Authority Aims To Reduce Sewage Overflow Incidents. Picture: Getty

By Connor Hand and Luke Shannahan

A leading environmental expert has warned that a hidden network of up to 10,000 unmonitored sewage pipes across the country could be driving the UK’s river pollution crisis.

Listen to this article

Loading audio...

Tim Harris, who spent nearly two decades as a scientific advisor at one of the UK’s biggest water companies, United Utilities, and now heads the consultancy TH Environmental, told LBC that water companies have significantly underestimated the number of pipes in operation across the UK.

According to his estimates, the true number could be 50% higher than the 22,000 overflows currently acknowledged by the government.

Mr Harris, who separately provides technical expertise for the charity Rivers Trust, said: “Some water companies might be a bit better than others, but the majority of them still have unknowns out there.

“This is mainly because of the poor record-keeping of the companies that were amalgamated to create the companies that we know now. There are potentially approximately between 20-50% extra outfalls than what [the water companies] are stating and what they are monitoring.”

Read More: Thames Water accused of acting like 'rogue traders' after 136% surge in sewage spills lasting over a day

Read More: Waterborne diseases have soared under Tories, Labour says amid sewage anger

Mr Harris’ comments come as LBC can reveal that there has been a fivefold increase in the number of fish killed where river pollution has potentially been a contributory factor, according to data from the Environment Agency.

Figures obtained through an Environmental Information Request showed that the number of fish killed where water pollution was detected rose to over 216,000 in the financial year 2023/24 - up from 42,070 in 2022/23.

Whilst other factors such as climate change is likely to be having an impact on the number of fish killed, LBC’s data is one of the clearest indications yet of the effect of river pollution on aquatic life.

Jamie Woodward, a professor of physical geography at the university of Manchester, suggested that these figures showed that rivers had “lost their resilience” as a result of pollution:

“There’s been a slow degradation of the river environment because sewage overloads rivers with nutrients, and then bacteria have to break down the organic material and algae produced by those nutrients, taking the oxygen out of the water - and of course the fish population will struggle.”

Data published earlier this year showed that there had been a fifty-four percent increase in the number of sewage spills in 2023, equating to over four million hours’ worth of discharges.Water companies have faced significant criticism for their role in the pollution crisis, with campaigners and MPs pointing to decades of underinvestment since they were passed into private hands.

The industry body, Water UK, has committed to investing £10 billion in improving the UK’s sewage overflow system with the aim of reducing the amount of pollution entering rivers.

But Professor Woodward feels that the proposed investment fails to address the issue:

“Privatisation happened in 1989… Although the water companies have plans to tackle this problem over the next five years, they have basically neglected it for the previous thirty years.

“There’s been enough money in the system to tackle this sewage problem, and bring these hideous spill figures down.”

Water pollution is likely to be an important issue in this year’s general election. A Survation poll conducted last year found that discharges into rivers and seas will affect how more than 56 per cent of people vote.

It is a key issue in particular for the Liberal Democrats, who have put cleaning up the UK’s rivers at the heart of their pitch in a number of key constituencies.

Environment Secretary Steve Barclay on how bosses will face bonus bans for illegal sewage discharges

Responding to LBC’s findings, their leader, Sir Ed Davey, said: “I think it’s a scandal that this is happening. It’s one of the reasons we’re trying to focus attention on it.

“We’ve been talking to local communities [and] environmental campaigners, and they’ve been saying there’s a problem that’s gone unnoticed and that water companies have been getting away with it. It’s across the country.”

A spokesperson for Water UK said in response: “We completely understand the public’s concern about protecting the environment and its biodiversity. Water companies are committed to taking urgent action to restore the health of rivers.

“We have submitted a plan to inject £11 billion into cleaning up our waterways and removing spills, prioritising the use of nature-based solutions such as wetlands, which have proven additional benefits for wildlife, nature and local communities. We’re prioritizing this investment where it matters most.”

Meanwhile, a spokesperson from the Department for Environmental, Food and Rural Affairs said: “We agree the volume of sewage pollution being discharged into our waters is unacceptable, which is why we are consulting on banning water bosses’ bonuses when criminal breaches have occurred, quadrupling company inspections next year, providing more funding to our water regulators, and fast-tracking investment to cut spills”.