1. Subject to paragraph 2, the criteria for the classification DS6 are that—
(a)the annual mean concentration of each substance listed in column (1) of Table 8 in samples taken from the sampling point for the waters in question in accordance with regulation 4 does not exceed the relevant concentration specified in column (2) of that Table; and
(b)the concentration of mevinphos in each sample so taken does not exceed 0.02 microgrammes per litre.