SEWAGE spills into Dorset waters decreased slightly last year, which has been attributed to drier weather as opposed to action by water companies.

Environment Agency figures, which includes data from all ten water and sewerage companies in England, show a total of 21,878 spills in the area covered by Wessex Water last year.

This is a reduction from 23,524 recorded in 2021.

Devices that monitor sewage spills are now installed in 90.9 per cent of storm overflows in the Wessex area, an improvement on 80.9 per cent previously recorded.

Storm overflows are a safety valve designed to release excess storm water from the sewerage system into rivers or the sea during periods of rainfall to ensure they are not overwhelmed. Water companies should only do this under strictly permitted conditions.

Bournemouth Echo: A Wessex Water recycling centre.A Wessex Water recycling centre. (Image: Wessex Water)

The data shows that in 2022 in Wessex:

  • The average number of spills per storm overflow was 18.5, compared to 22.4 in 2021
  • The total number of monitored spill events was 21,878, compared to 23,524 in 2021;
  • The duration (hours) of monitored spill events in 2022 was 129,957, compared to 151,258 in 2021
  • One per cent of storm overflows spilled more than 100 times, compared to 1.9 per cent in 2021
  • 16 per cent of storm overflows did not spill at all, compared to 11.9 per cent in 2021.

The government has instructed water companies to install monitors on all storm overflows by the end of this year.

Ian Withers, the Environment Agency's Wessex Area environment manager, said: “While the data show a reduction in the number of sewage spills from Wessex Water in 2022, this is due to last year’s below average rainfall.

“Sewage pollution can be devastating to human health, local biodiversity and our environment. We need to see tangible progress from all water companies, including Wessex Water, on reducing spills and acting on monitoring data, and we will continue to hold them to account.”

Bournemouth Echo:

Environment Agency executive director John Leyland added: “The decrease in spills in 2022 is largely down to dry weather, not water company action.”

A Wessex Water spokesperson said: “Storm overflow discharges in the Wessex Water region have significantly reduced, especially near designated bathing waters where they have halved compared to the previous year, and this is down to last year’s dry weather as well as our £3 million a month investment.

“Our work has included separating rainwater from foul water, sealing parts of the sewer network to prevent groundwater overwhelming sewers, installing storm tanks to increase capacity, nature-based solutions such as reed beds to naturally treat storm water before it’s discharged into local watercourses.

“Clearly there’s more to do and we’re committed to continuing to reduce the frequency of discharges, starting with those that operate most frequently or have any environmental impact. We’re also planning to go even further and, if approved by our regulators, will invest more than £9 million per month from 2025.”