This European Standard specifies characteristics and related requirements, assessment methods, the marking and assessment and verification of constancy of performance (AVCP) procedures for packaged and/or site assembled domestic wastewater treatment plants used for populations up to 50 inhabitants. Packaged and/or site assembled domestic wastewater treatment plants in accordance with this European Standard are: - used for the treatment of domestic wastewater including that of guest houses and businesses; - made of concrete, steel, PVC-U, Polyethylene (PE), Polypropylene (PP), Glass Reinforced Polyester (GRP-UP), Polydicyclopentadiene (PDCPD), PVC and/or EPDM; - used buried in the ground; - with or without extension shaft; - made of prefabricated components that are factory or site-assembled by one manufacturer and which are tested as a whole. This European Standard does not cover packaged and/or site assembled domestic wastewater treatment plants where vehicle loads apply to it. The as