Costain has been selected by Thames Water to deliver around £150m of wastewater treatment upgrades across 15 sites in the Thames Valley region.
The infrastructure company will upgrade strategic treatment assets under Thames Water’s Wastewater Asset Assurance Programme, known as WAAP. The work is designed to improve the resilience of critical wastewater treatment services across the utility’s operating area.
The programme forms part of Thames Water’s wider infrastructure upgrade programme, which includes improvements to sewers and sewage treatment works across London and the Thames Valley. Thames Water has said it plans upgrades at more than 250 sites as part of its long-term investment in wastewater performance, river health and network resilience.
Fifteen wastewater sites included
Costain’s work will include modernising operations at inlet stations, improving the resilience of storm tanks and carrying out repairs, modifications and upgrades to wastewater systems.
The works are expected to be delivered during AMP8, the 2025 to 2030 regulatory investment period for the water sector in England and Wales.
Costain will split the programme into two regions, East and West, with a regional senior project manager appointed for each area.
The Eastern section will include wastewater treatment sites at Barkway, Brentwood, Long Reach, Little Hallingbury, North Weald and Standon. The Western section will include Aldershot, Burghfield, Esher, Horley, Lightwater, Marlborough, Northleach, Waddesdon and Windsor.
Part of wider wastewater investment
Thames Water is undertaking one of the largest investment programmes in its history, with wastewater upgrades intended to improve resilience, support population growth and reduce pressure on ageing infrastructure.
The utility has previously said its wider programme includes investment in stormwater systems, sewage treatment works and sewer upgrades to help reduce pollution and improve river health.
Costain has previously worked with Thames Water on strategic treatment asset upgrades at Markyate and Brickendon, as well as Sandhurst and Selborne. The company has also supported clay compaction trials for the proposed White Horse Reservoir in Oxfordshire.
“We have a long-term, trusted partner relationship with Thames Water and this award is built on our excellent track record of identifying construction efficiencies and delivering best-in-class solutions,” said Matt Bateman, Water Sector Director at Costain.
“We’ll work closely with Thames Water and our supply chain partners to deliver these essential infrastructure upgrades, that will build resilience into the region’s critical wastewater system, efficiently and safely.”
Improving operational performance
Thames Water said the work will help modernise critical wastewater infrastructure and improve operational performance across the region.
“We are delivering the largest programme of investment in our wastewater network in more than 150 years, helping to improve resilience across our region and support a growing population,” said Tim Horton, Capital Delivery Director at Thames Water.
“Costain has a strong track record of safely delivering complex infrastructure projects and will play an important role in upgrading key treatment assets across these 15 sites. Together, we will modernise critical wastewater infrastructure, improve operational performance and help ensure we continue to provide a more reliable service for our customers and the environment.”
The award adds to Costain’s existing water-sector work, including its role on Thames Water frameworks and wider UK water infrastructure programmes.
FAQs
What has Costain been selected to deliver for Thames Water?
Costain has been selected to deliver around £150m of upgrades to wastewater treatment assets across 15 Thames Water sites in the Thames Valley region.
Which Thames Water sites are included in the programme?
The programme includes Barkway, Brentwood, Long Reach, Little Hallingbury, North Weald, Standon, Aldershot, Burghfield, Esher, Horley, Lightwater, Marlborough, Northleach, Waddesdon and Windsor.
What work will be carried out?
The upgrades will include modernising inlet stations, improving storm tank resilience, and carrying out repairs, modifications and upgrades to wastewater systems.
When will the work be completed?
The upgrades are expected to be completed during AMP8, the 2025 to 2030 investment period for the water sector in England and Wales.
Why are the upgrades important?
The works are intended to improve wastewater treatment resilience, support operational performance and help Thames Water respond to population growth and pressure on ageing infrastructure.
