The Water Supply (Water Quality) Regulations 2016

Numbers of samples

9.—(1) Subject to paragraph (2), in each year a water undertaker must take or cause to be taken from its sampling points or, to the extent authorised by or under regulation 8, from its supply points, the standard number of samples for analysis as regards residual disinfectant and each parameter listed in—

(a)column 1 of Table 2 in Schedule 3;

(b)column 2 of Table 3 in Schedule 3.

(2) In respect of a parameter subject to check monitoring and where paragraph (3) applies, the number of samples to be taken in the following year for that parameter may be the reduced number.

(3) This paragraph applies where—

(a)a water undertaker is of the opinion that the quality of water supplied to a water supply zone which it supplies is unlikely to deteriorate, and

(b)in each of the two preceding years the results of the samples taken in accordance with these Regulations or the 2000 Regulations show no significant variation and—

(i)if the parameter is colony counts, they have shown no abnormal change;

(ii)if the parameter is hydrogen ion (item 9 in Table 1 of Schedule 3), the water undertaker has established a pH value that is not less than 6.5 and not more than 9.5;

(iii)in any other case, the water undertaker has established a concentration or value for that parameter that is significantly lower than the prescribed concentration or value, or specification.

(4) Samples required to be taken by this regulation must be taken at regular intervals.

(5) In this regulation—

(a)in relation to sampling points, residual disinfectant or a parameter and the supply of water within one of the ranges shown in column 2 of Table 2 in Schedule 3, “the standard number” and the “reduced number” mean the numbers shown in column 4 and column 3 respectively of that Table, as applicable to that substance or parameter by reference to a population within that range;

(b)in relation to supply points, each of the parameters specified as items 7, 8 and 9 to 28 in column 1 of Table 3 in Schedule 3, and the supply of a volume of water within one of the ranges shown in column 3 of that Table, “the standard number” and “the reduced number” mean, subject to sub-paragraph (c), the numbers shown in column 5 and column 4 respectively of that Table, as applicable to that parameter by reference to a volume supplied within that range;

(c)where a particular supply point is in use for only part of a year, “the standard number” and “the reduced number” mean the numbers that bear to the numbers shown in columns 5 and 4 respectively of Table 3 of Schedule 3, in the same proportion as the number of days in that year in which the supply point has been in use bears to 365.