S.L. 549.24 · Quality Of Fresh Waters Supporting (S.L. 549.24)
S.L. 549.24 Art. 11Derogation.
The competent authority may derogate from these regulations:
(a) in the case of certain parameters marked (0) in Annex I, because of exceptional weather or special geographical conditions;
(b) when designated waters undergo natural enrichment in certain substances, so that the values set out in Annex I are not respected.