in England and Wales, the Secretary of State, F1a water authority, a county council, . . . F2, a district council, a London borough council, the Common Council of the City of London, the Sub-Treasurer of the Inner Temple and the Under Treasurer of the Middle Temple F3and, for the purposes of sections 91 to 93 of this Act, a sewerage undertaker; and

in Scotland, the Secretary of State, a river purification authority, an islands council or a district council.