Horsley WTW Upgrades

A number of new projects that represent a £33 million investment are due to start at Horsley WTW as it is necessary to upgrade the treatment works in guidelines with the DWI, We have selected out partners Mott Macdonald Bentley (MMB) and Ross-Shire Engineering (RSE) to carry out the upgrades. The works consist of three separate contracts • Detailed design and construction of a new contact tank with associated pipework, sampling and dosing arrangements. NWG currently operate the Treated Water Service Reservoir (TWSR) as a combined storage tank and contact tank. This single compartment tank cannot be taken out of service without shutting the whole treatment works off and does not satisfy the DWI requirements for contact time. Thus, the construction of a new independent contact tank is required to satisfy DWI requirements and allow NWG to take the existing and new tanks out of service for regular maintenance without affecting the works output. The contact tank will be constructed at the South West of the works and will run from 2025 until late 2027 – This will be carried out by MMB • Pipework will be renewed on a pumping station (Birney Hill Pumping Station – BHPS) at the south of the works and on completion of the works will be commissioned and put into service allowing us to abandon the old pumping station on site. This work will will run from April/May 2025 and last for around 12 months - This will be carried out by MMB • Construction of new chemical dosing facility which will include the construction of two number new coagulant tanks approximately 5 – 6 m in height to the North of the site adjacent to existing tanks that are larger in height. This is also due to run from April/May 2025 and last for around 12 months. This will be carried out by RSE