With Aecom as its consulting engineer, Kier will upgrade existing tanks and build new ones, replace mechanical and process equipment and upgrade electrical panels.
The project is designed to increase the capacity of preliminary treatment and improve the resilience of the sludge and digester streams at Mogden in preparation for AMP8 works.
Mogden, built in the 1930s, is Thames Water’s third largest treatment works, spanning 55 hectares and serving around 2.1 million people.
Kier Infrastructure managing director Mark Pengelly said: “It is a highly complex and specialised project and the team will be working in a live environment, across multiple locations of the site.
“We will be working with Aecom as design partners and we have selected key Kier and Aecom personnel for their experience and knowledge of STW and complex large-scale civil engineering. They will bring a tried-and-tested approach, having collectively worked together over the past six years, at Deephams STW.”
At the 50-year-old Deephams wastewater treatment works in Edmonton, north London, Kier delivered an upgrade without expanding the site footprint or interrupting the daily flow of sewage.
Kier secured a place on Thames Water’s £2.6bn AMP7 capital programmes framework last year. It has also provided planned and reactive services through the Infrastructure Alliance.