This European Standard specifies data which is necessary for the planning, design, bidding, performance guarantees, construction, start-up and compliance testing of a wastewater treatment plant or parts of it. Differences in wastewater treatment throughout Europe have led to a variety of practices being developed. This standard gives fundamental informations 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.