Severn Trent Water’s Minworth sewage treatment works, which serves around 1.75 million of Birmingham’s population, is undergoing a major modernisation project that will improve the quality of the water put back into the River Tame and significantly upgrade the work’s facilities, improving the quality of the 1bl (one billion litre) daily treatment capacity.

The GBP 145 million project is being handled by an alliance comprising Severn Trent Water, North Midland Construction Nomenca and Biwater, with Pick Everard as consultants. Rotork has supplied over 250 Profibus network-enabled IQPro intelligent electric actuators for valve control throughout the new and refurbished plant areas.

Many of the actuators are installed on the new eight-lane inlet works, the new 22 primary settlement tank island and the enlarged activated sludge plant. In all areas Rotork IQPro multi-turn actuators operate penstocks to control the flow through the works, whilst on the activated sludge plant, IQTPro direct drive quarter-turn actuators are also installed on the air flow control valves that regulate the introduction of air into the treatment tanks.

The actuators are linked on fully redundant Profibus field networks to Allen Bradley PLC platforms at intelligent motor control centres throughout the site. These interface with the site’s Rockwell SCADA system, which is accessible at local HMI terminals at key site locations. Feedback from sensors throughout the plant is used to automatically operate the actuators to account for fluctuations in flow, caused, for example, by storm conditions, and to enhance the efficiency of operations.