This document specifies the basic design and construction requirements for wastewater treatment plants for over 50 PT. NOTE 1 Requirements for structures which are not specific for wastewater treatment plants are not within the scope of this document. Other ENs can apply. NOTE 2 Equipment which is not solely used in wastewater treatment plants is subject to the applicable product standards. However, specific requirements for such equipment when used in wastewater treatment plants are included in this part.