8.—(1) For those parameters specified as item 6 in column 1 of Table 1, and items 1 to 11 and 14 to 21 in column 1 of Table 3, in Schedule 3, samples may be taken from —
(a)any blending point;
(b)the water leaving any service reservoir which receives water from a treatment works before its supply to any consumer; and
(c)the water leaving any treatment works.
(2) If the Welsh Ministers are satisfied that analysis of those samples will produce data which are unlikely to differ in any material respect from the data that would be produced from analysis within the sampling points, the Welsh Ministers may authorise the use for the purposes of regulation 6 of those samples taken for a water supply zone from a blending point, a service reservoir of that description or a treatment works.
(3) In respect of any water supply zone, the taking of samples from a supply point is not authorised by paragraph (2) where a supplementary licensee introduces water into the water supply zone unless the water quality within the water supply zone remains approximately uniform.
(4) Subject to paragraph (6), the Welsh Ministers may, in relation to any parameter not covered by an authorisation under paragraph (2), on the written application of a water undertaker or on the joint written application of a water undertaker and supplementary licensee, authorise the use for the purposes of regulation 6 of samples taken for a water supply zone otherwise than from a sampling point.
(5) An authorisation under paragraph (4) may extend to all samples in relation to that parameter or to such number or proportion of those samples as is specified in the authorisation.
(6) The Welsh Ministers must not grant an authorisation under paragraph (4) unless they are satisfied that analysis of samples taken from a point other than a sampling point will produce data in respect of the parameter in question which are unlikely to differ in any material respect from the data that would be produced in respect of that parameter from analysis of samples obtained from sampling points.
(7) Subject to paragraph (8), the Welsh Ministers may at any time modify or revoke an authorisation under paragraph (4).
(8) Unless it appears to the Welsh Ministers that the immediate modification or revocation of an authorisation under paragraph (4) is required in the interests of public health, they must not modify or revoke such an authorisation without giving to the water undertaker to which the authorisation relates at least 6 weeks’ notice of their intention to modify or revoke.
(9) A water undertaker must notify the Welsh Ministers as soon as it has reasonable grounds for believing that an analysis of samples taken for a water supply zone from a point other than a sampling point would produce data in respect of the parameter in question which would differ in a material respect from the data produced by an analysis of samples taken from any of the sampling points within that zone.
(10) On being notified under paragraph (9) and without the need for prior notice to the water undertaker, the Welsh Ministers must revoke the authorisation.