Successful installation of attenuation tank provides flood protection at LSEP
26th Nov 2025
Kilkern has completed the installation of a 310,000-litre attenuation tank at the Lostock Sustainable Energy Plant Ltd (LSEP), to mark an important step in the delivery of the large-scale civil engineering works required to support the construction of the Energy from Waste (EfW) facility near Northwich in Cheshire.
The stormwater tank is an important component of the site’s rainwater management system and will act as a buffer that regulates the flow of surface water running off the extensive areas of hardstanding. Managing stormwater safely and efficiently is essential to prevent flooding, protect the surrounding environment and maintain compliance with drainage legislation and best practice standards.
Innovative cellular construction
To achieve this, the tank has been built using the ACO Group StormBrixx range of stormwater attenuation and infiltration soakaway crates. This innovative plastic geocellular system has been selected due to its strength, modular format and flexibility, allowing it to be configured to meet the specific constraints of the LSEP site. The crates interlock securely to provide structural stability during installation and long-term use while their lightweight nature supports faster handling and improved on-site productivity.
The design also facilitates easier maintenance access which is an important consideration for long-term site operations.
Kilkern’s civil engineering team managed earthworks, preparation of the tank base, placement of the StormBrixx units, installation of membranes and liners and backfilling to ensure structural integrity and performance. The completed tank will now form a core component of the site’s sustainable drainage system designed to reduce peak runoff rates and support controlled discharge.
Important within the wider programme of works
Patrick Curran, Director at Kilkern, is pleased with the progress made on the attenuation tank and highlighted the importance of the work within the wider programme. He noted that the installation represents another key element being delivered by Kilkern on this high-profile project.
“We are very proud to have played our part in delivering high-quality civil engineering at LSEP,” he said. “This is an exciting flagship development that will make a major contribution to waste management and energy generation in Cheshire. Our team has worked with professionalism and commitment throughout and we look forward to supporting the next stages of delivery on site.”
LSEP is a joint venture between Copenhagen Infrastructure Partners (CIP) and FCC Environment. Once operational, the plant will export up to 69.9MW of electricity to the grid using residual waste as fuel. This waste is the material left after all recyclable content has been removed and would otherwise be sent to landfill. By converting it into energy, the facility will reduce the volume of waste requiring disposal, cut greenhouse gas emissions associated with landfill and provide a reliable source of low carbon electricity.
