Rotork is supplying a water treatment project in an area west of Wrexham, north Wales, UK, aimed at improving the water supply from the Dee Valley Water Plc. A new 4 million litres a day water treatment plant is being built at Pendinas to simultaneously treat the water from three reservoir sources and meet the latest EU requirements for manganese removal. Rotork electric actuators have been installed for the operation of the valves throughout the plant, the majority being butterfly valves fitted with the latest Rotork IQT intelligent quarter-turn actuators. The new plant, which replaces an existing single stage filtration works on the site, is being designed, constructed and commissioned by Biwater Treatment Ltd. The treatment process consists of blending from the three sources, flash mixing and flocculation, pH control with lime, coagulation with aluminium sulphate, dissolved air flotation, first stage rapid gravity filtration, second stage pressure filtration for manganese removal and gas chlorination. Filter backwash water is processed through a washwater recovery plant and the supernatant is returned to the head of works, whilst the sludge is stored for periodic off-site tankering. Rotork actuators control the flow of water throughout the plant. Initially, two IQM modulating actuators regulate the inlet supply to the dissolved air flotation. Each of the four first stage filters is equipped with five lQT actuators to control inlet, outlet and daily backwash and air scour operations. A similar lQT actuated valve configuration operates the three secondary pressure filters.
