(1)It shall be the duty of the Secretary of State to secure that such appointments are made under this Chapter as will ensure that for every area of England and Wales there is at all times both—
(a)a company holding an appointment under this Chapter as water undertaker; and
(b)whether or not the same company in relation to the whole or any part of that area, a company holding an appointment as sewerage undertaker.
(2)Subject to the following provisions of this section—
(a)the Secretary of State; and
(b)with the consent of or in accordance with a general authorisation given by the Secretary of State, the Director,
shall have power, by notice to a company holding an appointment under this Chapter, to terminate the appointment or to vary the area to which it relates.
(3)The appointment of a company to be a water undertaker or sewerage undertaker shall not be terminated or otherwise cease to relate to or to any part of any area except with effect from the coming into force of such appointments and variations replacing that company as a relevant undertaker as secure either-
(a)that another company becomes the water undertaker or, as the case may be, sewerage undertaker for that area or part or for an area that includes that area or part; or
(b)that two or more companies each become the water undertaker or, as the case may be, sewerage undertaker for one of a number of different areas that together constitute or include that area or part.
(4)An appointment or variation replacing a company as a relevant undertaker shall not be made in relation to the whole or any part of the area to which that company’s appointment as water undertaker or, as the case may be, sewerage undertaker relates except where—
(a)that company consents to the appointment or variation;
(b)the appointment or variation relates only to parts of that area none of the premises in which is served by that company; or
(c)the appointment or variation is made in such circumstances as may be set out for the purposes of this paragraph in the conditions of that company’s appointment.