This European Standard specifies requirements for control and automation systems on wastewater treatment plants for more than 50 PT. If necessary, the control system should also be designed to cover the control of sewer systems in the receiving area of the wastewater treatment plant. It specifies the necessary information and data which are needed for the design and implementation of such systems as well as the performance requirements with respect to the hard- and software. Differences in wastewater treatment throughout Europe have led to a variety of systems being developed. This standard gives fundamental information about the systems; this standard has not attempted to specify all available systems. Detailed information additional to that contained in this standard can be obtained by referring to the bibliography.