This European Standard specifies performance requirements for the disinfection of effluents from wastewater treatment plants. The primary application is for wastewater treatment plants designed for the treatment of domestic and municipal wastewater for over 50 PT. 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.