Sampling and analysis
9.—(1) Subject to regulations 10 and 11, the water authorities shall ensure that waters classified under these Regulations are sampled and samples are analysed, in accordance with paragraphs (2) to (5) below.
(2) Samples shall always be taken at the same sampling point at times when water is being abstracted by the relevant water authority for supply as drinking water and the sampling point chosen by the relevant water authority must be–
(a)at the place where water is abstracted before being sent for purification treatment; and
(b)so situated that samples taken at that point are representative of the quality of the water at that place.
(3) Samples shall be analysed for compliance with the parameters listed in Schedule 1, and where relevant Schedule 2, for the relevant class of waters using methods of measurement which are at least as reliable as those specified in that Part I of Schedule 3 and respect the values shown in that Part for limits of detection, precision and accuracy.
(4) Sampling and analysis shall be carried out at the frequency fixed by the relevant water authority in relation to the sampling point for those waters for each parameter listed in Schedule 1, and where relevant Schedule 2, and, in fixing the frequency,the relevant water authority shall ensure that–
(a)sampling is carried out at regular intervals;
(b)the annual frequency of sampling and analysis for each parameter is not less than that specified in Part II of Schedule 3 for the relevant class of waters; and
(c)sampling is as far as possible spread over the year so as to give a representative picture of the quality of the water.
(5) The containers used for samples, the agents or methods used to preserve part of the sample for the analysis of one or more parameters, the conveyance and storage of the samples and the preparation of samples for analysis must not be such as to bring about any significant change in the results of the analysis.