CMDP has secured multiple contracts with Southern Water, valued at £65m ($85.1m), as part of the latter’s Asset Management Period 7 (AMP7) investment programme.  

CMDP is a joint venture (JV) between Costain and MWH Treatment. 

The awarded projects are set to conclude by late 2025. 

They aim to bolster the resilience of the local water supply and upgrade wastewater treatment facilities at Testwood near Southampton and Burham in Kent. 

The integrated CMDP team will collaborate with Southern Water and its engineers to devise cost-effective solutions, as well as optimise asset performance. 

The team will also oversee the delivery of these upgrades through the duration of AMP7.  

The focus will be on renovating, refurbishing, and expanding existing infrastructure to meet the growing demand for clean drinking water and to manage increased wastewater volumes. 

Southern Water water director Tim McMahon said: “With a changing environment and a growing population, it is important that we make strategic investments to upgrade facilities and ensure they are fit-for-purpose for the long term.”   

At Testwood Water Supply Works, CMDP will undertake refurbishments and enhancements to the abstraction points from the River Test, pumping stations, and flow and filtration systems.  

Additionally, the site's rapid gravity filtration facilities will be upgraded, and contact reservoir tanks will be repurposed to improve the site's functionality. 

Meanwhile, Burham Water Supply Works will undergo a refurbishment of the low lift pumping station and granular activated carbon filters, alongside sitewide chemical dosing enhancements.  

Several upgrades will be delivered to fortify the water treatment works, including expanding the usable volume of the lake that supplies the site. 

CMDP JV programme director Chris Hodgson said: “Southern Water is upgrading its infrastructure to ensure it continues providing clean drinking water to its customers while improving resilience for the future.  

“This is important work that will have a transformative impact on the lives of residents and local communities.” 

This month, Costain was also selected as one of seven partners to execute United Utilities’ new water and wastewater infrastructure investment programme.