The Angling Trust and Action for the River Kennet (ARK) have called for immediate government intervention on sewage pollution.
The groups stress that without this, the ecological health and biodiversity of chalk streams in the Kennet, Lambourn and Pang rivers are at risk of long-term, irreversible damage.
Director of ARK, Charlotte Hitchmough, said she has been left “frustrated” and “shocked” at the current levels of pollution.
A spokesperson from the Department for Environment Food & Rural Affairs (Defra) has said sewage pollution is “unacceptable” which is why they are quadrupling inspections and pursuing criminal prosecution if water companies breach their permits.
“It’s not the way we should be treating our chalk streams and it’s not the way a developed country should be managing their sewer network,” Ms Hitchmough said.
Event duration monitoring has shown the last year has been “particularly bad” she said, with sewage treatment works “discharging untreated sewage continuously for months at a time”.
“We need action and we need action at pace,” she said.
Ms Hitchmough said spills from sewage treatment works are the “tip of the iceberg”, manholes are not monitored and become overwhelmed when sewage systems are full.
“The pressure of the sewage and water in the sewer forces the lid (of the manhole) up and we get untreated sewage pouring directly from the manhole into the river,” she said.
“You can smell it, you can see wet wipes, you can see exactly what the contents are.”
Nitrate and phosphate levels in rivers rise when large sewage spills happen which upsets the balance between algal and plant communities.
Algal growth then begins to stop the photosynthesis of green plants causing them to wither and rot, resulting in a downward spiral of river health.
Ms Hitchmough said “although we’re a long way away” eventually this would lead to “rivers that can’t support life”.
In an urgent appeal to water regulator Ofwat, the Environment Agency, and environment secretary Steve Barclay, the Angling Trust and ARK have raised significant concerns regarding ongoing sewage pollution issues in the Kennet, Lambourn and Pang river catchments, overseen by Thames Water.
Criminal prosecution
A Defra spokesperson said: “Sewage pollution in our waters is unacceptable, which is why we are consulting on banning water bosses’ bonuses when criminal breaches have occurred, as well as quadrupling water company inspections and fast-tracking investments to cut spills.
“100% of overflows are now being monitored and if water companies, including Thames Water, are found to breach their permits action will be taken – up to and including criminal prosecution.”
