The Water Supply (Water Quality) Regulations 2018

Collection and analysis of samples

15.—(1) Every water undertaker or supplementary licensee must secure, so far as reasonably practicable, that when it takes, handles, transports, stores or analyses any sample required to be taken for the purposes of Part 4 or this Part, or causes any such sample to be taken, handled, transported, stored or analysed, it complies with the appropriate requirements.

(2) In this regulation, “the appropriate requirements” means such of the following requirements as are applicable—

(a) the sample is representative of the quality of the water at the time of sampling;

(b) the person taking a sample is subject to a system of quality control to an appropriate standard;

(c) the sample is not contaminated when being taken;

(d) the sample is kept at such a temperature and in such conditions as secure that there is no material alteration of the concentration or value for the measurement or observation of which the sample is intended;

(e) the sample is analysed, whether at the time and place it is taken or as soon as reasonably practicable after it has been taken—

(i) by or under the supervision of a person who is competent to perform that task; and

(ii) with the use of such equipment as is suitable for the purpose;

(f) the collection and transportation of samples, or measurements recorded by continuous monitoring shall be subject to a system of quality control to an appropriate standard checked from time to time by a suitably accredited body.

(3) Every water undertaker or wholesale licensee must secure that a suitably accredited body from time to time checks its compliance with the appropriate requirements.

(4) Additionally, any person involved in seeking to discharge the obligation described in paragraph (1) must ensure that—

(a) the methods of analysis used by that person for the purposes of monitoring and demonstrating compliance with this Part are validated and documented in accordance with European standard EN ISO/IEC 17025 entitled “General requirements for the competence of testing and calibration laboratories”(1) or other equivalent standards accepted at international level; and

(b) that person applies quality management system practices in accordance with European standard EN ISO/IEC 17025 or other equivalent standards accepted at international level.

(5) Every water undertaker or supplementary licensee must maintain such records as are sufficient to enable it to establish, in relation to each sample taken for the purposes of Part 4 or this Part, that such of the appropriate requirements as are applicable to that sample have been satisfied.

(6) Subject to paragraph (7), for the purpose of establishing, within acceptable limits of deviation and detection, whether the sample contains concentrations or values which contravene the prescribed concentrations or values, or exceed the specifications for indicator parameters—

(a) the method of analysis specified in column 2 of Table A1 in Schedule 5 must be used for the parameter specified in relation to that method in column 1;

(b) the method of analysis in respect of the parameters listed in column 1 of Table A3 in Schedule 5 must be capable of measuring concentrations equal to the parametric value with a limit of quantification of 30% or less and an uncertainty of measurement as specified in column 2 of that Table and the result must be expressed—

(i) using at least the same number of significant figures as the parametric value; and

(ii) in the same units laid down in these Regulations; and

(c) the method of analysis used for the odour and taste parameters (items 5 and 7 in Part 2 of Table B in Schedule 1) must be capable, at the time of use, of measuring values equal to the parametric value with a precision or uncertainty of measurement of 1 dilution number at 25°C.

(7) The Welsh Ministers may, on the application of any person, authorise a method of analysis other than that specified in paragraph (6)(a) (“the prescribed method”).

(8) An application for the purposes of paragraph (7) must be made in writing and must be accompanied by—

(a) a description of the method of analysis; and

(b) the results of the tests carried out to demonstrate the reliability of that method and its equivalence to the prescribed method.

(9) The Welsh Ministers must not authorise the use of the method proposed in an application under paragraph (7) unless they are satisfied that the results obtained by the use of that method are at least as reliable as those produced by the use of the prescribed method.

(10) An authorisation under paragraph (7) may be subject to such conditions as the Welsh Ministers consider appropriate.

(11) The Welsh Ministers may at any time, by notice in writing served on the water undertaker or supplementary licensee to which an authorisation under paragraph (7) has been given, revoke the authorisation, but any such notice must be served no later than 3 months before the date on which the revocation is stated to take effect.

(1)

This standard was approved by the European Committee for Standardization (CEN) on 10 November 2017. Under reference BS EN ISO/IEC 17025:2017, it is published as a UK standard by the British Standards Institution (ISBN 0 580 46330 3).