More than fifty Profibus-enabled Rotork IQ and IQT intelligent electric valve actuators have been installed in a major expansion project at the Littleton/Englewood Wastewater Treatment Plant in Colorado, USA. Serving over 300,000 residents in the southern Denver Metropolitan area, the plant is in the final stages to meet population growth and stricter pollution control regulations. Upon completion, the plant’s treatment capacity will increase from 36 to 50 million gallons per day. New Rotork IQ and IQT actuators have been installed throughout the plant processes in areas including: headworks’ grit channel gates; primary clarifier sludge valves; secondary solids contact tank air valves; blower inlet and surge relief valves; centrate inlet, drain and discharge valves; and denitrification filter inlet gates. All the IQ and IQT actuators are connected to a plant-wide Profibus network that also includes process transmitters, flowmeters and analysers as part of an overall plant automation strategy that enables the operators to closely monitor field data. In addition, using data obtained from the IQ and IQT actuators, the control system has been designed to facilitate access to valve operational torque profiles. In addition to the electric actuators, 32 P range pneumatic and 2 EH range electro-hydraulic actuators from Rotork Fluid Systems have also been installed during the Littleton/Englewood expansion project.