It shall be the duty of a local authority to notify any water undertaker of anything appearing to the authority to suggest—
that any supply by that undertaker , or by a water supply licensee using that undertaker's supply system, of water for domestic or food production purposes to any premises in the area of that authority is, has been or is likely to become unwholesome or (so far as any such premises are concerned) insufficient for domestic purposes;
that the unwholesomeness or insufficiency of any such supply is, was or is likely to be such as to cause a danger to life or health; or
that the duty imposed on that undertaker by virtue of section 68(1)(b) above is being, has been or is likely to be so contravened as to affect any supply of water to premises in that area.
Where a local authority have notified a water undertaker of any such matter as is mentioned in subsection (1) above, it shall be the duty of that authority, if they are not satisfied that all such remedial action as is appropriate will be taken by the undertaker, to inform the Secretary of State about the contents of the notification.
In subsection (1)(a) above, the reference to the water undertaker's supply system shall be construed in accordance with section 17B above.