Sampling at treatment works
12.—(1) Subject to paragraph (3), in each year every water undertaker or supplementary licensee must take, or cause to be taken, from the point at which water leaves each treatment works which it uses to supply water to water supply zones, the standard number of samples for analysis—
(a)for determining the concentration of residual disinfectant;
(b)for determining whether, in relation to the colony counts and turbidity parameters, water leaving treatment works meets the specifications for those parameters set out in Schedule 2; and
(c)for testing for compliance with the prescribed concentrations or values in respect of the coliform bacteria, E coli, and nitrite parameters for water leaving treatment works.
(2) Samples required to be taken by this regulation must be taken at regular intervals.
(3) Where a particular treatment works is in use for part only of a year, the minimum number of samples to be taken from that works in that year must bear to the standard number or, as the case may be, the number specified in a current notice given by the Welsh Ministers under regulation 9 which departs from the standard number, the same proportion as the number of days in that year in which the treatment works have been in use bears to 365.
(4) In this regulation, “the standard number” has the same meaning as in regulation 9.