Wessex Water has outlined plans to spend £3million a month on reducing the risk of harm from combined sewer overflows (CSOs) including upgrading 42 treatment sites.
Work has already begun to reduce how often overflows operate including investing in artificial intelligence monitoring at bathing sites feeding back near real-time data about water quality.
The investment will total £150 million from a new dedicated funding stream to undertake the work ahead of the next price review period at PR24.
The company’s CSO improvement plan includes adding monitors to every overflow across the region by 2023 and reducing the number of hours they discharge for by 25% by the end of AMP7 in 2025.
“We understand the concerns about storm overflows and agree they should have no place in a 21st century sewerage system,” said Matt Wheeldon, director of asset strategy and compliance at Wessex. “This major investment is the start of decisive action to tackle storm overflows, and our longer-term improvement plan sets out the further progress we will make over the coming years.”
The work is part of the company’s three year plan to the end of AMP7 that forms part of a longer term multiple-AMP investment programme in line with government objectives to eliminate the risk of harm from overflows. Wessex will prioritise work on overflows close to sensitive catchments.
Wheeldon explained the time and resources to address the 1,300 overflows across Wessex’s region will be “significant”. He added: “By committing to spend £3 million every month on overflows, starting with those that discharge most frequently and those that have any environmental impact, we will make a good start.”
A total of 32 new storm tanks will be added to grow capacity during heavy rainfall at wastewater treatment centres and across the network to reduce overflow operation. Work will begin next year on these tanks that will enable more stormwater to be stored and treated.
Capacity will also be increased at 14 treatment sites and work to separate rainwater from wastewater upstream of two overflow points will begin.
The company is targeting nature-based solutions such as reed-beds and wetlands to hold water in rural areas and reduce the flow to overflows.
Overflows play an essential role to stop the risk of flooding in homes within the UK’s sewerage network where surface water and foul water are combined. Heavier rainfall due to climate change, as well as urban spread covering natural drainage areas, misconnected drains, runoff from highways and population growth have contributed to the systems being overloaded.