News | March 6, 2026

Costain Applies Industrial Cooling Techniques To Critical Water Infrastructure

Innovative approach delivers phase of upgraded wastewater filtration system works ahead of schedule

Costain, the infrastructure solutions company, has applied industrial cooling techniques to upgrade a key wastewater treatment site for United Utilities, delivering a phase of work ahead of schedule.

The innovative work at Crewe Wastewater Treatment Works (WwTW) in Cheshire is being delivered through United Utilities’ Enterprise, which brings together United Utilities, Costain, and six other design and construction partners to deliver a £2.5bn package of major projects.

Costain has applied its industrial cooling expertise, which it has been providing to the energy sector for more than 20 years, at Crewe WwTW to support the refurbishment of two nitrifying trickling filter systems. The works involve the installation of new polypropylene pack media, which has been manufactured and assembled by Costain, to act as filters that use nitrifying bacteria to remove ammonia from the water and convert it into nitrate.

The use of pack media to act as a filter is similar to methods used in industrial cooling, where pack media is installed in cooling towers to provide a large surface area to enable hot water and cool air to interact efficiently, encouraging the process of evaporative cooling.

Costain’s understanding of the conditions at Crewe WwTW and application of the industrial cooling techniques enabled the first phase of the works to be brought forward by 12 months, with phased refurbishments expected to continue throughout the year. Costain is also working with local supply chain partners to recycle the used media, minimising the environmental impact.

"This is the first time that we have applied our industrial cooling techniques to a water company, which has been made possible thanks to our decades-long experience and sophisticated process by which to assemble the pack media." - Mark BlackhamHead of Industrial Cooling at Costain

Mark Blackham continues: "The implementation is enabling us to deliver important upgrades to the wastewater infrastructure which will improve the quality of water in surrounding rivers and benefit local wildlife. We’re looking forward to exploring subsequent opportunities to incorporate the techniques to projects in the water sector.”

"We have an excellent working relationship as a trusted partner to United Utilities. Part of that trust is built on our ability to apply innovative solutions to enable for the safe and efficient treatment of wastewater. By drawing on strong practices and capabilities from our colleagues in the energy sector, we’ve been able to deliver critical upgrades for United Utilities ahead of schedule.” - Richard HelmeProgramme Director at Costain

“We’ve been impressed by the innovative solution Costain has brought to what is a complex project. The upgrades at Crewe will enhance treatment performance and help make the site more resilient for customers as demand grows.” - Tony SlaterEnterprise Director at United Utilities

Tony Slater continues: “Through our Enterprise model, we’re working with delivery partners that have a strong track record of delivering best-in-class water infrastructure solutions, supporting our ambitious plans to transform infrastructure and services across the North West."

The upgrade to Crewe WwTW will support healthier conditions in the nearby River Weaver and, as the area’s population increases, help prepare the site for future demand. The work forms part of United Utilities’ £13bn ‘Big North West Upgrade’, a programme that will deliver new infrastructure, improve water quality, replace ageing water pipes and reduce leakage through to 2030.

Source: Costain Group PLC