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Sewage dumped into the Sheaf and Porter for thousands of hours in 2020

New data from the Rivers Trust reveals the extent of emergency sewage discharges in Sheffield's small rivers.

The Sheaf and Porter Rivers Trust.

Newly-released data has revealed that untreated sewage was discharged into the Sheaf and Porter rivers for thousands of hours over the course of 2020.

Combined Sewer Overflows (CSOs) are supposed to only be used in emergencies, but an interactive map from the Rivers Trust shows that they're used by water companies routinely in Sheffield.

The state of the Sheaf and the Porter, which both flow into the Don, mirrors that of rivers across the UK – 86% are in a state of poor ecological health.

"The frequency at which CSOs operate is thought to be increasing due to changing weather patterns and the increased areas draining into the network," Ric Bingham of the Sheaf and Porter Rivers Trust told Now Then.

"While investment has been made since privatisation to reduce the number of CSOs and the frequency of their operation, significant further investment and disruption would be required to remove all CSOs – this would require new sewers being laid across the city."

The data shows that one overflow on Hangingwater Road spilled into the Porter 86 times for a total of 142 hours in 2020, slightly upstream from where families play in the river at Endcliffe Park.

At St Mary's Road, another overflow spilled into the Sheaf 163 times in 2020 for a total of 994 hours, a few hundred metres away from where the river joins the Don at Castlegate.

And on Graves Park Beck, which feeds into the Sheaf, one CSO at Fraser Drive spilled 80 times for a total of 1,099 hours in 2020.


A CSO on the Porter.

The Sheaf and Porter Rivers Trust.

The discharges occur when heavy rainfall causes the sewer network, which is supposed to take waste away to be treated, to reach capacity. The overflows then spill over and discharge sewage into rivers and streams.

The overflows are designed for extreme weather events, but The Guardian found that in 2019 sewage was discharged for 1.5m hours in 204,000 separate incidents across the UK.

The government has promised to take action, saying that a new law will create a legal obligation on them and the water companies to reduce raw sewage overflows by September 2022.

Some environmental campaigners believe the problem has been made worse by our system of privately-owned water companies, which they say have not invested enough in infrastructure improvements since they were privatised in 1989.

In Sheffield water privatisation has created a monopoly for Yorkshire Water, which is partly owned by the government of Singapore as an investment.

England is the only country in the world that has privatised its entire water system, and research has found that consumers are paying £2.3bn more per year for water and sewage services than they would if the system was still in public hands.

"Reducing CSO spill duration and frequency would improve the environmental condition of the watercourses as well as reducing the quantities of sewage-derived litter which are visible on the river banks after a storm," said Bingham.

"We therefore call on Yorkshire Water, along with their environmental regulator the Environment Agency and economic regulator Ofwat, to invest more in reducing CSO spills and making Sheffield a cleaner, healthier city."


The Porter flowing into a culvert.

The Sheaf and Porter Rivers Trust.

A spokesperson for Yorkshire Water told Now Then that 55% of their CSOs spill less than 20 times per year, and 94% spill less than 100 times per year.

"We are seeing a combination of factors, from urbanisation to climate change, frequently testing the design and capacity of our network," said the spokesperson.

"At the same time, increased awareness of the operation of storm overflows is driving an important debate on what society sees as acceptable," they continued.

"We will be investing £137 million by 2025 in storm overflow improvements, investigation and increased monitoring."

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