£50m investment at Southport Wastewater Treatment Works gets underway

United Utilities is investing £50 million to upgrade Southport’s Wastewater Treatment Works.

The upgrade will increase stormwater storage at the site and play a key role in enhancing water quality along the Sefton Coast by reducing the number of times that storm overflows operate in heavy rain. The project will be split into two phases, with the first focusing constructing and commissioning a 4,500m³ of stormwater storage to help reduce storm overflows and improve bathing water quality – the equivalent of just under 2.5 Olympic sized swimming pools, or 30,000 bathtubs.

A second phase is expected to complete by summer 2029 and will increase the site’s ability to treat more wastewater during heavy rainfall. The increase allows the return of the existing storm storage earlier which frees up capacity in readiness for the next storm event and replaces the need for further on-site storage.

Locals may notice that early works are already underway, including ecological surveys and site preparation.  

Steven Kenyon, County Business Lead for United Utilities in Merseyside said: “We are committed to continuous improvement to our infrastructure, and upgrades to Southport’s wastewater treatment works is a priority.

“From increasing storage on sites to looking at bespoke solutions such as sustainable drainage and new innovative ways of treating wastewater to even higher standards, we are starting to see the impact our investment is making, and this is helping us make great progress in reducing spills and improving water quality. 

“We continue to review our network and sites across the county to see where we can make further improvements which help reduce the number of times that storm overflows need to operate.” 

The project is being delivered through United Utilities’ new Enterprise delivery model which brings together seven design and construction partners, plus United Utilities, into one integrated team. 

This year, United Utilities announced a landmark agreement with Liverpool City Region and the Mersey Rivers Trust to explore the long-term solutions that will help deliver further water quality improvements around Merseyside.