Water quality boost

Southern Water’s £300m environmental improvement scheme includes a new wastewater treatment works (WWTW) and sludge recycling centre, two pumping stations, 11km of sewer tunnel and a 2.5km long sea outfall.

The central control room in Peacehaven is from where duty and standby SCADA systems and four thin client workstations are run. The SCADA / PLC System runs all aspects of the WWTW including wastewater and sludge processing, odour control and HVAC. The SCADA system includes an additional five operator stations mounted on motor control centres dotted around the site, all of which can be used to control the entire system including equipment up to 7km away. The remote sites in other towns have at least one E1000 HMI; these are configured to allow only local control rather that providing access to the whole system.

The core equipment in the works’ control system is Mitsubishi Electric Q-series PLCs and E1000 HMIs. Programmed using the IEC programming standard via the Mitsubishi engineering environment, the PLCs and HMIs interface with Harting connectivity equipment and field devices from at least 10 other manufacturers.

The Mitsubishi PLCs were chosen for their ease of set-up and use, plus their ability to seamlessly integrate with products from other manufacturers. In Peacehaven the main communications network is Profibus, with which the PLCs and HMIs are compatible. (They are also compatible with all the major open networks such as Ethernet, Modbus and CC-Link).

The Mitsubishi Q-series is a single automation platform that brings together modular control features from many different engineering disciplines, including, logic, motion, IT and process control. It is designed to be easy to install and commission and to boost productivity. Southern Water has used the power of the Q-series to combine sequential control with process specific instructions to create a high performance yet simple control system with a high degree of reliability.