The objective of this manual is to disseminate information on automatic and remote operation and instrumentation of pumping stations and distribution and supply systems, including valves, storage tanks, and booster pumps. This third edition of M2 includes basic information on electrical power distribution and updates the automation and instrumentation technology that has changed rapidly since the second edition in 1983. It discusses equipment, terms, and expressions an operator encounters wherever electrical systems, automation, and instrumentation are found in water distribution, treatment, and storage systems.