The work will run until late 2025 and will see the CMDP joint venture improve the resilience of the local water supply and upgrade wastewater treatment works at Testwood near Southampton, and Burham in Kent.

Both sites will see major renovation, refurbishment and expansion of existing assets to cope with rising demand for drinking water and increasing volumes of wastewater.

At Testwood Water Supply Works, the joint venture will be refurbishing and making improvements to abstraction points from the River Test, pumping stations and flow and filtration assets.

The work will also include upgrading the rapid gravity filtration facilities and repurposing contact reservoir tanks at the site. 

At Burham Water Supply Works, improvements include a full refurbishment of the low lift pumping station and granular activated carbon filters, and site-wide chemical dosing upgrades. CMDP is also working on a number of upgrades to improve the resilience of the water treatment works, including increasing the usable volume of the lake that feeds the site.   

Alex Vaughan, CEO, Costain, said: “This is important work that will have a transformative impact on the lives of residents and local communities, and builds on Costain’s growing positions with the leading water companies as they continue to improve the quality of our water supply.”