Apex was engaged to design and construct the Cardrona Valley water treatment plant on a greenfield site to provide drinking water to the new Mt Cardrona Station development and Cardrona Village. The plant was vested to Queenstown Lakes District Council on completion of the works.Raw water is sourced from the Cardrona River and Pringles Creek and treated using a process that includes ultrafiltration using Pentair membranes and gas chlorination. Acid is stored and dosed for pH correction; other chemicals stored and dosed included caustic soda and hypochlorite for membrane cleaning. Residuals are thickened using a lamella clarifier and send to the Cardrona wastewater treatment plant (previously designed and constructed by Apex). The plant was designed to meet all relevant QLDC engineering standards.The overall project included construction of the plant building and site parking, fencing and landscaping. Apex staff are now operating the plant for a two-year period and remote access systems allow remote supervision.