Kier lands £265m Maple Lodge wastewater upgrade role

Kier has secured a key role on Thames Water’s £265m upgrade of Maple Lodge Sewage Treatment Works in Hertfordshire, marking its largest wastewater project to date.

The contractor has signed an £8.7m early contractor involvement agreement to help develop the AMP8 scheme ahead of the main construction phase.

Kier will work with Thames Water and the project design team to finalise the design, manage delivery risks and prepare the programme for construction.

Located at Maple Cross near Rickmansworth, the 24-acre treatment works serves almost 500,000 people across west Hertfordshire.

The upgrade will increase treatment capacity, improve resilience and provide additional storm storage while keeping the site operational throughout construction.

Planned works include upgrades to storm storage, inlet works, screening, primary settlement and biological treatment, alongside new final settlement tanks, tertiary treatment and improvements to electrical, control and monitoring systems.

The appointment builds on Kier’s existing relationship with Thames Water, following previous schemes including the Deephams, £66m Mogden and £45m Faringdon to Blunsdon projects.