Probe into possible contamination of Mansfield and Ashfield's river

The probe follows complaints that ‘raw, untreated sewage’, creating a ‘disgusting froth’, was being dumped into Hermitage Ponds next to King’s Mill Reservoir in Sutton.

The River Maun feeds into the reservoir and then passes north through Mansfield, Edwinstowe and Ollerton.

The complaints were made by Ron Shilton, a 70-year-old project engineer from Kirkby, who regularly enjoys walks from the reservoir, along the Maun into Mansfield.

And he is alarmed that the contaminated water flows through Titchfield Park in Mansfield, where children often play with fishing nets.

Angry Ron said: “It is an ongoing thing at what I call the ‘bottom lake’ at the reservoir.

"You have the fresh water and a series of waterfalls, which are lovely. And then you have this sewage pipe, about four feet wide and two feet high, that pumps a grey soup into the lake.

"When I first saw it two years ago, there was a putrid, horrible stink.”

Ashfield District Council explained that the pipe is an outfall from a sewage treatment works, operated nearby by Severn Trent

A spokesperson said: “The discharge is permitted and it should be treated water, regulated by the Environment Agency.”

However, Ron claims: “You can tell by the colour and smell that the discharge is untreated. I went there the other day and it was disgusting what was coming through.

"The treatment works is automated and unmanned, and it relies on outdated systems to control discharge. This is the result of years of under-investment by Severn Trent.

“The plant is antiquated, and the maintenance and upgrading of its control systems have become secondary.

"If these discharges were treated, you wouldn’t expect them to be grey and smelly, and a frothy mess”.

Severn Trent insisted that untreated sewage was NOT gushing into Hermitage Ponds, but it did admit an inquiry was taking place.

A spokesperson said: “We have been working closely with the Environment Agency following reports of foam discharging from the outfall at Hermitage Ponds, which we believe is down to something like a detergent being illegally released into our sewers that shouldn’t be.

"Our investigations continue with the Environment Agency on this.

"As part of that work, we have been regularly inspecting the outfall, including this week, and confirm that everything is operating as it should. No raw sewage has been spilled.”

A spokesperson for the Environment Agency said: “We take all complaints of pollution very seriously and will not hesitate to take the necessary enforcement action.

"We have not received notification of alleged regular discharges of untreated sewage at Hermitage Ponds.

"Local residents have alerted us to reports of foam in the treated effluent discharge, and our investigations are continuing.

"We urge anyone with concerns to c\all our 24/7 hotline on 0800 807060.”

At the treatment works, sewage goes through several processes to sanitise it and turn it into treated water that is then released into the river via the outfall at Hermitage Ponds. However, the outfall also acts as a storm overflow when needed.

Storm overflows are relief valves, allowing excess stormwater to be released into rivers. They play a vital role in protecting properties from flooding and preventing sewage backing up into streets and homes during heavy rain.

The Severn Trent spokesperson added: “They make sure our sewers aren’t overwhelmed during storms and while they do result in spills into rivers, they are predominantly made up of rain. Their use is permitted and is regulated by the Environment Agency.”

The Environment Agency confirmed that the treatment works at Sutton holds a permit “to discharge treated sewage effluent and settled storm sewage to the River Maun, where it flows through Hermitage Ponds”.

It added: “The permit also allows discharges of emergency sewage and storm sewage to the river where it flows through King’s Mill Reservoir.

"These discharges are monitored by the water company in accordance with the permit.”

Severn Trent and other water companies have come under fire for their over-reliance on storm overflows. And the government has set up a task force to reduce the number of raw-sewage discharges from storm overflows in a bid to cut river pollution.

An investigation by BBC TV’s ‘Panorama’ programme this week revealed that, in 2020, the companies discharged sewage into rivers, via storm overflows, more than 400,000 times and for more than three million hours. The untreated effluent included human waste, wet wipes and condoms.

Severn Trent was responsible for 65,083 storm-overflow discharges, spanning 558,699 hours, according to Environment Agency data.

The Environment Agency said it was “working actively with the water companies to ensure overflows are properly controlled”, and said the harm being done to watercourses and wildlife had to stop.

It has now “announced a commitment to increase the transparency and accessibility of spill data from storm overflows”, which will be published “to hold water companies to account”.

The Rivers Trust said: “The volume of untreated, contaminated wastewater reaching our rivers is shocking. It shows that our current approach to managing stormwater needs a radical overhaul.”

Severn Trent says it “fully understands the concern around storm overflows, and the impact on our rivers” and is “fully committed” to protecting the environment.

It intends to spend £200 million, on top of £355 million already invested, on “reducing the impact of storm overflows on a sewer network that dates back to the Victorian era”. This will mean it can “monitor rivers more closely than ever before”.