Figures show there were dozens of raw sewage overflows in Milton Keynes last year

Raw sewage was released into open water in Milton Keynes dozens of times in 2022, figures show.

Figures from the Environment Agency show storm overflows were used 67 times within Milton Keynes' local authority boundaries in 2022, discharging for a total of around 500 hours.

All of these spills were from Anglian Water's network.

Storm overflows normally happen when the sewage system is at risk of being overwhelmed – such as after a heavy rain, or during higher levels of groundwater.

In these cases, water companies may need to release excess water and sewage into rivers and the sea, to prevent water backing up into streets and people's homes.

This has an impact on the quality of natural water sources, with some charities alleging storm overflows are being misused and under-reported.

These figures may not provide a full picture of the amount of water pollution in the area – Milton Keynes may also be impacted by overspills from areas it shares water sources with.

The Rivers Trust said it was particularly concerned by storm overflows being used during hot periods – a risk as England faces a heatwave this week.

Tessa Wardley, director of communications and advocacy at the charity, said: "Discharging untreated sewage in dry weather is bad for both human health and river health – lower river flows mean more concentrated pollutants at a time when more people want to enjoy their rivers."

"These discharges are also the ‘canary in the coalmine’ pointing to greater problems which could cause blockages in the system, groundwater seeping into broken pipes, misconnections, or just poor management choices," she added.

She urged "robust, urgent action" on sewage and river management to help tackle the climate crisis and threats to biodiversity.

Water minister Rebecca Pow said the amount of sewage pumped into rivers is "utterly unacceptable".

A spokesman for Anglian Water said: “We know there is still a great deal to be done to reduce the impacts of spills on our rivers and waterways, and we are investing £200m over five years to address this. The data clearly shows that in 2022 we reduced by over 50% the number of hours of spills compared to 2021.”