Costain has completed another major milestone on its £20 million update of the Severn Trent Frankley Water Treatment Works.

The new treatment works’ tank structure is now complete, following the final concrete pour to seal up the access doorway on the contact tank where water is held after being dosed with chlorine. Both the tank and the valve chambers, mixing and blending chambers and a new high-level pumping station are now undergoing M&E (mechanical and electrical) commissioning, in preparation for the introduction of the water supply this year.

When up and running the system will further increase the reliability and security of water supplies to Severn Trent’s 1.4 million customers in and around Birmingham.

Jay Standen, Costain Delivery Manager said the concrete build was a major undertaking, commenting:

 “This may look like the straightforward construction of a concrete box but it was in fact 13 conjoined structures of varying size, shape and complexity. It also included over 50 built in covers, numerous penstock openings, weir walls and 37 cast in pipe starters which all needing very exact positioning and construction to ensure the required accuracy.”

The build required more than 7000m3 of concrete and more than 1000 tonnes of steel reinforcement, and involved more than 80 wall pours up to seven metres high and 850mm thick. Pours of up to 400m3 in volume were carried out by one of the largest concrete mobile pumps in the UK.

Jonathan Wagstaff, Severn Trent’s Programme Manager for the project, said the work was a significant milestone in the completion of a major project for Severn Trent Water.