Costain wins £150m Thames Water contract to upgrade 15 sewage treatment works

en.Wedoany.com Reported - Dimension News, August 17 – Infrastructure solutions company Costain has been awarded a contract by Thames Water to upgrade strategic treatment assets at 15 sewage treatment works across the Thames Valley region. The contract is valued at approximately £150 million (around $203 million), spanning the AMP8 regulatory period (2025–2030).

The upgrade forms part of Thames Water's "Wastewater Asset Assurance Programme" (WAAP). Thames Water stated this is its largest sewer and sewage treatment works upgrade programme in 150 years, with more than 250 sites set to be upgraded across the Thames Valley region.

Costain's scope of work covers modernisation of inlet works, resilience improvements to storm tanks, and various repairs, modifications, and upgrades to sewage treatment systems. For ease of management, Costain has divided the 15 sites into eastern and western zones, each with a regional senior project manager. Eastern sites include Barkway, Brentwood, Long Reach, Little Hallingbury, North Weald, and Standon; western sites include Aldershot, Burghfield, Esher, Hawley, Lightwater, Marlborough, Northleigh, Waddesdon, and Windsor.

Tim Horton, Capital Delivery Director at Thames Water, said: "We are delivering the largest investment programme in our sewage network in over 150 years to enhance resilience across the region and support a growing population". Matt Bateman, Director of Costain's Water division, said the contract builds on the company's long-standing relationship with Thames Water.

Costain has previously been awarded contracts by Thames Water to upgrade treatment assets at Markyate, Sandhurst, Bricket Wood, and Selborne. The company has also been involved in clay compaction trials for the proposed White Horse Reservoir in Oxfordshire, planned by Thames Water.