Wessex Water fined £500k for sewage leaks that killed thousands of fish

A water company has been fined £500,000 for sewage leaks that killed thousands of fish across Somerset and Wiltshire.

Wessex Water was found to be negligent in failing to promptly report the leaks to the Environment Agency.

Swindon Magistrates’ Court sentenced the company to a total of £500,000 after it pleaded guilty at an earlier hearing to two charges.

The first charge related to the Bowerhill Lodge sewage pumping station at Melksham, in Wiltshire.

The second related to a burst sewer main at the Wick St Lawrence sewage treatment works near Weston-super-Mare, in Somerset.

The company was also ordered to pay costs of £60,000, plus applicable VAT, and a victim surcharge of £170.

More than 2,000 fish killed by pumping station discharge

The two charges at Bowerhill Lodge were for causing stormwater to discharge into the Clackers Brook between March and April 2018, and discharging screened sewage from July to August 2018.

The third charge was for causing untreated sewage effluent to discharge into marsh rhynes, a type of manmade drainage channel, from a rising main leading into the Wick St Lawrence works.

In a case brought by the Environment Agency, the court heard more than 2,100 fish died in the Clackers Brook, a tributary of the River Avon, during the discharge at Bowerhill Lodge.

These included eels, lamprey and bullheads, three species which are threatened and are also listed by the International Union for Conservation of Nature. Investigators found almost all of the fish within a 1km reach had been killed.

The discharge was caused by a mechanical failure and continued for 54.5 hours with sewage flowing through a nature conservation area. The company did not report this to the Environment Agency immediately.

Failures in alarm system meant discharges went unnoticed

The investigation found that failures of the sewage pumping station’s alarm and telemetry system, and a power cable becoming entangled in pump equipment, contributed to the failures.

Further investigation found that there had been other discharges from Bowerhill Lodge Pumping Station earlier that year that Wessex Water had not reported to the Environment Agency.

At Wick St Lawrence, much of the local rhyne was affected by sewage, leading to fish, including spined stickleback and eels, dying after a rising main (a pipe through which sewage is pumped under pressure) burst.

The rising main had already been identified by Wessex Water before the incident, as a critical main that needed to be monitored, but this was not put in place until after the incident.

Wessex Water's rising mains are ageing and vulnerable to bursting

The investigation found that a September 2018 document the company submitted to Ofwat showed the number of rising main bursts had increased markedly in recent years, running at approximately 70-80 per year.

The Environment Agency said that Wessex Water's rising mains are ageing and becoming vulnerable to bursting and the company had predicted it would need to replace them at nine times its current rate to remain stable.

Between 2015 and 2023, six of the 28 serious pollution incidents caused by Wessex Water have arisen from rising mains, accounting for 21% of serious incidents during that period, it said.

District Judge Joanna Dickens said that the company’s failure to report discharges at Bowerhill Lodge "undermines the regulatory regime" though Wessex Water had since taken "considerable and expensive steps" to remedy the situation.

She noted that at Wick St Lawrence, flow pressure monitoring equipment had been installed since the incident and there had been no repetition of any similar incidents.

The judge said that while there was no long-lasting impact to the environment in this case "it was negligent because of the failures at this specific location and the failure to install monitoring equipment at an earlier time".

Ageing system poses a 'risk to people and the environment'

Following the case, the Environment Agency's senior environment officer, Janine Maclean, said: "These cases are further examples of a water company breaking the law and causing serious pollution.

"It was very sad the pollution had such serious impacts - killing fish and other aquatic life.

"Wessex Water’s rising mains are ageing and becoming vulnerable to bursting and are an area of increasing concern to the Environment Agency, presenting risk to people and the environment.

"We recognise the company is increasing its monitoring of rising mains, which is a positive step forward, but monitoring is still reliant on failure, and we would like to see the company significantly increase the level of investment it makes to proactively replace rising mains before they fail.

"We expect all water companies to manage and maintain their sewage pumping stations and rising mains in a responsible and sustainable manner to ensure they do not cause pollution.

"We hope these cases send a clear signal to shareholders and water company board rooms, up and down the country, that investing in resilient sewage systems to prevent pollution, and ensure compliance, must be an essential way of doing business.

"Our dedicated officers are increasing our regulatory inspections of Wessex Water’s sewage pumping stations and we will also be attending more incidents, including those arising from rising mains, with the new resources we are gaining to transform the way we regulate the water industry."

Response from Wessex Water - 'This shouldn't have happened and we're sorry'

A Wessex Water spokesperson said: "These incidents six years ago were caused by a burst sewerage pipe and a mechanical issue that both sadly resulted in fish dying.

"This shouldn't have happened and we're sorry.

"Once the problems were identified, we quickly took action to minimise environmental harm and carried out emergency repairs.

"Since these incidents took place, we have invested in AI technology to detect where potential issues on our network might occur to further protect the environment.

"We’re planning a step change in the maintenance of our sewerage network and, if approved by our regulators, are proposing to spend £300m in this area by 2030."