Barhale, as principal contractor for the Anglian Water @one Alliance, is making strong progress on an important project at Stambourne Wastewater Recycling Centre. The scheme is designed to improve the resilience of the local wastewater network.

The first phase of the project involved the construction of a new pumping station (STM1SP) and rising main at Stambourne WRC, which now transfers flows into the Haverhill WRC catchment. This new infrastructure was successfully constructed and commissioned in December 2024, marking a key milestone in resolving the original compliance challenges.

However, the proposed pump away solution also highlighted potential downstream flooding risks due to hydraulic constraints at Sturmer Watsoe Bridge pumping station. To manage this, the project includes the installation of a new underground storage system, capable of providing 1,290m³ of additional capacity. The storage tank is being constructed using 243m of 2.6m diameter Weholite pipe, installed in sections within a dedicated trench. This system will allow excess stormwater to be held during periods of heavy rainfall before being safely returned to the sewer network once flows subside.

Work on site has already seen the successful completion of a 120m mid-section of the tank, with teams now progressing two 60m end sections. Installation has been challenging due to hard ground conditions, which has required the use of specialist plant and equipment. Temporary works are being delivered by Watson & Hillhouse using a pre-auger attachment to loosen the ground and make piling more efficient. Sheet piles are being installed with a Movax attachment and a 35T excavator, followed by an impact hammer to overcome the difficult ground. In total, 430 steel trench sheets, each 8.5m long, are being driven to provide the safe working environment needed to install the Weholite pipes.

Despite the challenges, the project team is working hard to deliver the scheme safely and efficiently. In line with Barhale’s commitment to sustainability, low-emission plant and a hybrid 35T excavator are being used on site to help reduce carbon impacts. At the same time, regular communication with nearby residents is being maintained.

Once complete, the Stambourne project will play a vital role in strengthening local wastewater infrastructure. By providing much-needed additional storage and reducing the risk of flooding during heavy rainfall, it will help to protect homes, improve resilience and ensure that Anglian Water can continue to deliver reliable services for the local community.