This European Standard describes a method for the detection of those serotypes of enterovirus that replicate and form plaques in BGM cells under agar. These will largely be poliovirus and oxsackievirus B serotypes. Most serotypes of echovirus, Coxsackievirus A and animal enteroviruses are unlikely to produce plaques under these conditions. Reoviruses are unlikely to be detectable within the specified seven day incubation period. It is applicable to any type of water and processed water sample although toxic elements may interfere with cell culture. The methods to confirm that the plaques seen contain enterovirus are given. Methods to identify which serotype of enterovirus is found in the plaque are not included as this is not required by the EU Bathing Water Directive. Basic cell culture procedures including the preparation, maintenance and enumeration of BGM cell culture are not described but suggestions are made for media that may be used (see Annex A).