Pumps are the largest user of energy in a water and wastewater plant. Effective pump management is vital if energy costs are to be controlled. For many ultrasonic technology is the preferred tool of choice and in this article David Hewitt, product manager at Siemens Automation and Drives, explains how advanced ultrasonic controllers can give the user the power of pump control in order to improve the bottom line. © 2006 Elsevier Ltd. All rights reserved.