Holdenhurst Water Recycling project

Drilling down to achieve quality and sustainable benefits at the Holdenhurst Water Recycling project

Working in partnership with Wessex Water and Evolve Infrastructure on the Holdenhurst water recycling project, we delivered the piling foundations to support the construction of a new 65-metre-long storm tank to increase the storage capacity at the site by over nine million litres.

To reduce waste and improve quality control we calibrated the rig telemetry to ensure consistency between the concrete pumping rates and the piling rig computer during the concreting process for continuous flight auger (CFA) pile installation. This significantly reduced concrete waste during the piling process, as the augers could be extracted at the correct rate for the ground conditions.

In addition, the rig operators carefully monitored the inclination of piles to ensure they were installed within the specified tolerance. The system provided valuable data on rotation rates, torque and depth so that installation could be carefully controlled, reducing non-conformances.

This approach contributed to a ~5% saving of concrete, providing a total saving of 55 tonnes of embodied CO₂ and a reduction of 147m3 in waste.

Our technical teams also optimised the design of the steel despite considerable constructability challenges. The team coordinated operational input from our experienced project managers to ensure the most steel efficient design, considering B type reinforcement against GEWI and Diwidag, whilst ensuring the quality of construction was not compromised. This saved over 20% of steel used to manufacture the piles, equating to 6.5 tonnes of steel.