Cidon Construction was appointed by repeat client Mott MacDonald Bentley (MMB) to deliver the formwork, reinforcement and concreting (FRC) works for the Horsley Chlorine Contact Tank, continuing a successful working relationship established across previous projects.

Located within Northumbrian Water’s Horsley Treatment Works, the scheme involved the construction of a 65m x 20m buried reinforced concrete tank, providing chlorine contact time as the final treatment stage before water entered the supply network.

The tank comprised two independently operable compartments, with serpentine flow lanes formed using precast baffle walls. Designed for a 50-year service life, the structure was engineered to withstand the site’s highly aggressive soft water conditions.

The scheme formed part of a key investment in Northumbrian Water’s treatment infrastructure, supporting the safe and reliable disinfection of drinking water across the region.

Cidon successfully delivered the technically demanding reinforced concrete works, demonstrating our capability within complex water infrastructure and further strengthening our relationship with MMB and our experience across the water and wastewater sector.

• Full-height in-situ concrete walls cast without horizontal construction joints
• Semi-precast construction incorporating precast baffle walls and roof panels
• Cidon-designed and installed temporary works for the in-situ main tank walls
• Controlled Permeability Formwork (CPF) liners to all in-situ wall faces, eliminating the need for release agents
• C35/45 concrete incorporating 50% GGBS and Xypex waterproofing admixture