Costain secures £150m Thames Water wastewater upgrade programme

Costain has secured around £150m of wastewater treatment upgrade work from Thames Water across 15 sites in the South and South East of England.

The programme forms part of Thames Water’s wider investment plan to upgrade more than 250 sewage treatment and sewer sites between 2025 and 2030.

Costain will divide delivery across eastern and western regions, each overseen by a regional senior project manager.

The eastern programme covers sites at Barkway, Brentwood, Long Reach, Little Hallingbury, North Weald and Standon.

The western programme includes Aldershot, Burghfield, Esher, Horley, Lightwater, Marlborough, Northleach, Waddesdon and Windsor.

Works will include the modernisation of inlet stations, improvements to storm tank resilience and wider repairs, modifications and upgrades to wastewater treatment infrastructure.

The award builds on Costain’s existing work with Thames Water, including treatment asset upgrades at Markyate, Brickendon, Sandhurst and Selborne.

Costain has also been carrying out clay compaction trials for Thames Water’s proposed White Horse Reservoir in Oxfordshire.

The £150m programme will support Thames Water’s wider effort to improve the resilience and performance of its wastewater network during the current investment period.