11.—(1) When a local authority monitors a private supply it must take a sample—
(a)if the water is supplied for domestic purposes, from a tap normally used to supply water for human consumption, and which, if there is more than one tap, is representative of the water supplied to the premises;
(b)if the water is used in a food-production undertaking, at the point at which it is used in the undertaking;
(c)if the water is supplied from a tanker, at the point at which it emerges from the tanker;
(d)in any other case at a suitable point.
(2) It must then ensure that the sample is analysed.
(3) Schedule 3 makes further provision for sampling and analysis.