This European Standard specifies the requirements for chemical treatment of wastewater by precipitation/flocculation for removal of phosphorus and suspended solids. The application of polymers is not described in this European Standard. Differences in wastewater treatment throughout Europe have led to a variety of practices being developed. This standard gives fundamental information about the practices; this standard has not attempted to specify all available practices. Detailed information additional to that contained in this standard may be obtained by referring to the bibliography.