A £6.4 million scheme is underway to extend and upgrade Northumbrian Water’s wastewater treatment works in Kelloe, County Durham.

This WINEP (Water Industry National Environment Programme) scheme will improve the performance of the treatment works and support better water quality in Coxhoe Beck, as well as other watercourses downstream.

Join venture Esh-Stantec has been appointed design and build contractor, with work procured via Northumbrian Water’s Runway 3 Capital Construction Works Framework.

The project will include the installation of an Aquazone chemical dosing delivery system, above ground stainless steel humus settlement tanks, a tertiary treatment plant, and a rising main delivering effluent from the existing biological filters to the new humus tanks. A package plant will be used within the new tertiary treatment plant. This will include a Denora nitrifying submerged aeration filter and a Eliquo Hydrok Mecana pile cloth media filter.

Refurbishment and upgrade works will be carried out to the existing pyramidal flow primary settlement tank, the radial flow primary settlement tank, the existing interstage pumping station, and the final effluent returns pumping station. The current humus settlement tanks and tertiary treatment plant will be decommissioned.

Esh-Stantec is a joint venture formed in 2015 to deliver capital schemes through Northumbrian Water’s Water and Wastewater Infrastructure Framework. The joint venture secured a place on the Runway 3 Framework in 2021 following its success on the Runway 2 Framework.

Work started last October to stabilise the ground via probe drilling and grouting. Since then, underground interconnecting pipework has been installed along with enabling and excavation works to pave the way for the new tertiary treatment plant, humus tanks and rising main.

The project is due for completion in late spring 2024.