The Water Supply (Water Quality) Regulations 2018

Number of samples

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

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

(b) column (2) of Table 2 in Schedule 3 (Group B1 parameters);

(c) column (2) of Table 3 in Schedule 3 (Group B2 parameters);

(d) column (2) of Table 4 in Schedule 3 (Group A1 parameters);

(e) column (2) of Table 5 in Schedule 3 (Group A2 parameters);

(f) column (2) of Table 6 in Schedule 3 (Group A3 parameters); and

(g) column (2) of Table 7 in Schedule 3 (Group A4 parameters).

(2) In respect of any parameter not referred to in paragraph (1), the Welsh Ministers may specify—

(a) the number of samples which a water undertaker must take or cause to be taken from its sampling points in each year; and

(b) its prescribed concentration or value.

(3) Samples required to be taken by this regulation must—

(a) be taken at regular intervals;

(b) in respect of sampling for chemical parameters in the distribution network other than sampling at a consumer’s tap, be taken, and handled in accordance with ISO 5667-5 entitled “Water quality. Sampling. Guidance on treatment of drinking water from treatment works and piped distribution systems.”(1); and

(c) in respect of microbiological parameters in the distribution network and at a consumer’s tap, be taken and handled in accordance with European Standard EN ISO 19458, entitled “Water Quality – Sampling for microbiological analysis”(2), using sampling purpose A in the distribution network and sampling purpose B at a consumer’s tap.

(4) Subject to paragraph (5) the Welsh Ministers may, in respect of any supplies of water by a water undertaker to a water supply zone, treatment works, supply point or a service reservoir, give the water undertaker written notice of any variation of—

(a) the parameters subject to sampling (by the omission or addition of parameters); and

(b) the number of samples which the undertaker must take in the period specified in the notice.

(5) Paragraph (4) does not apply in relation to E.coli.

(6) The Welsh Ministers may give a notice under paragraph (4)—

(a) on the Welsh Ministers’ own motion; or

(b) where paragraph (8) applies, upon application by a water undertaker.

(7) A notice under paragraph (4)—

(a) must specifiy which parameters are subject to variation;

(b) must specify the extent of any variation from the standard number of samples required to be taken under paragraph (1) or from the number of samples required to be taken under paragraph (2);

(c) may require a risk assessment to be undertaken;

(d) may be revoked or varied by the Welsh Ministers.

(8) This paragraph applies where—

(a) a risk assessment complying with this regulation has been undertaken;

(b) the results of the risk assessment described in sub-paragraph (a) are considered, and that risk assessment indicates that no factor can be reasonably anticipated to be likely to cause deterioration of the quality of the water;

(c) in the case where the water undertaker seeks to cease monitoring a particular parameter, the results from samples taken in respect of the parameter collected at regular intervals over a period of at least 3 years are all at less than 30% of the parametric value of the parameter; and

(d) in the case where the water undertaker seeks to reduce the frequency of monitoring in respect of a particular parameter, the results from samples taken in respect of that parameter collected at regular intervals over a period of at least 3 years are all at less than 60% of the parametric value of the parameter.

(9) The Welsh Ministers must by further written notice withdraw a notice under paragraph (4) if the Welsh Ministers believe that any parameter in the water supply to which the notice relates contravenes the prescribed concentration or value or is likely to do so.

(10) A water undertaker given notice under paragraph (4) must institute a monitoring programme which must be kept under annual review.

(11) A risk assessment complies with this regulation where—

(a) it meets the principles of European standard EN 15975-2 entitled “Security of drinking water supply - Guidelines for risk and crisis management - Part 2: Risk management”(3) or of other equivalent standards accepted at international level;

(b) it is subject to a system of quality control which is checked from time to time by a suitably accredited body; and

(c) it takes into account the results of monitoring conducted under the second paragraph of Article 7(1) and Article 8 of Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for Community action in the field of water policy(4).

(12) In this regulation “the standard number” means the number of samples specified in Part 2 or Part 3 of Schedule 3 in respect of a parameter specified in Part 1 of that Schedule.

(1)

This standard was approved by the International Organization for Standardization (ISO) on 15 April 2006. Under reference BS ISO 5667-5:2006 it is published as a UK standard by the British Standards Institution (ISBN 0 580 47140 3).

(2)

This standard was approved by the European Committee for Standardization (CEN) on 1 July 2006. Under reference BS EN ISO 19458:2006, it is published as a UK standard by the British Standards Institution (ISBN 0 5804 49136 6).

(3)

This standard was approved by the European Committee for Standardization (CEN) on 5 July 2013. Under reference BS EN 15975-2:2013, it is published as a UK standard by the British Standards Institution (ISBN 978 0 580 84737 0).

(4)

O.J. No L 327, 22.12.2000, p 1, as last amended by Commission Directive 2014/101/EU (OJ No L 311, 31.10.2014, p 32).