2.—(1) Subject to sub-paragraph (2), in relation to any period of 12 months, shellfish waters shall be treated as complying with the guideline value set out in Table 1 to this Part, if 75 per cent of the samples taken comply with the guideline value.
(2) Non-compliant samples may be ignored for the purposes of sub-paragraph (1) if they are the result of natural cause or force majeure.