(1) The Environment Agency shall ensure that waters classified under these Regulations are sampled and samples are analysed in accordance with the following provisions of this Regulation.
(2) Samples in relation to any waters classified under these Regulations shall always be taken at the same sampling point.
(3) The Environment Agency shall fix the exact position of the sampling point, and the depth at which samples are to be taken, having regard in particular to—
(a) the distance of the sampling point to the nearest point where pollutants are discharged; and
(b) local environmental conditions.
(4) Subject to paragraphs (5) and (6) below, sampling for any parameter shall be carried out at least at the minimum frequency specified in the Schedule to these Regulations in relation to that parameter.
(5) Where the Environment Agency’s records show that the quality of any waters classified under these Regulations is appreciably higher for any parameter than the minimum required by these Regulations, the Agency may reduce the sampling frequency for that parameter or, if there is no pollution and no risk of deterioration of its quality, it may dispense with sampling for that parameter altogether.
(6) Where sampling shows that the requirements of regulation 3 above are not being met, the Environment Agency shall establish whether this is the result of chance, a natural phenomenon or pollution and shall adopt appropriate measures.
(7) Samples for any parameter shall be analysed using the reference methods of analysis specified in the Schedule to these Regulations in relation to that parameter or methods which are at least as reliable as the reference methods.