The Water Supply (Water Quality) (Amendment) Regulations 2018

Transitional and saving provisions

3.—(1) Despite regulation 2(11) and (15), the following provisions of the 2016 Regulations as in force immediately before 11th July 2018 remain in force in the transitional period with the modifications to those provisions in paragraph (2) and for the purposes set out in paragraph (3)—

(a) regulation 16(5) and (6);

(b) Table A2 in Schedule 5.

(2) The modifications are that—

(a) regulation 16(5) is to be read as if—

(i) “Subject to paragraph (7),” were omitted;

(ii) sub-paragraph (a) were omitted;

(iii) in sub-paragraph (b), for “that Schedule” there were substituted “Schedule 5”;

(b) regulation 16(6) is to be read as if for “limit of detection” to the end there were substituted—

““limit of detection” is to be calculated as—

(a)

three times the standard deviation within a batch of a natural sample containing a low concentration of the parameter; or

(b)

five times the standard deviation within a batch of a blank sample;

“precision” is to be calculated as a measure of random error and may be expressed as the standard deviation (within and between batches) of the spread of results from the mean. A precision measurement of twice the relative standard deviation is acceptable. The term “precision” is further specified in international standard ISO 5725 entitled “Accuracy (trueness and precision) of measurement methods and results”(1), as amended by the technical corrigendum entitled “Accuracy (trueness and precision) of measurement methods and results - Part 1: General Principles and Definitions TECHNICAL CORRIGENDUM 1”(2);

“trueness” is to be calculated as a measure of systematic error which is the difference between the mean value of the large number of repeated measurements and the true value. This term “trueness” is further specified in international standard ISO 5725 entitled “Accuracy (trueness and precision) of measurement methods and results”, as amended by the technical corrigendum entitled “Accuracy (trueness and precision) of measurement methods and results - Part 1: General Principles and Definitions TECHNICAL CORRIGENDUM 1”.”;

(c) in Table A2, the entry in column 4 (limit of detection) which relates to 1,2-dichloroethane is to be read as if for “25” there were substituted “10”.

(3) For the whole of the transitional period or any part of it beginning with 11th July 2018, a water undertaker or wholesale licensee may, in respect of any parameter specified in column 1 of Table A2 in Schedule 5 to the 2016 Regulations, elect to be subject to the saved provisions instead of regulation 16(5)(b) of, and Table A3 in Schedule 5 to, those Regulations as inserted by regulation 2(11) and (15)(c) respectively of these Regulations.

(4) In this regulation—

“saved provisions” means the provisions saved by paragraph (1) as modified by paragraph (2);

“transitional period” means the period beginning with 11th July 2018 and ending with 31st December 2019.

(1)

This standard was published by the International Organization for Standardization (ISO) on 22nd December 1994. Under reference BS ISO 5725-1:1994 to BS ISO 5725-6:1994, it is published as UK standards by the British Standards Institution (ISBN 0 580 24034 7, 0 580 24033 9, 0 580 24029 0, 0 580 24028 2, 978 0 580 63299 0 and 0 580 24024 X).

(2)

ISO 5725-1:1994/Cor 1:1998 published on 2nd May 1998.