S.L. 549.21 Art. 6Regulations may be waived.

(1) For the purposes of regulation 5, surface water shall be assumed to conform to the relevant parameters if samples of this water taken at regular intervals at the same sampling point and used in the abstraction of drinking water show that it complies with the parametric values for the water quality in question, in the case of: - 95% of the samples for parameters conforming to those specified in the "I" columns in Annex II, - 90% of the samples in all other cases, and if in the case of the 5 or 10% of the samples which do not comply:

(a) the water does not deviate from the parametric values in question by more than 50%, except for temperature, pH, dissolved oxygen and microbiological parameters;

(b) there can be no resultant danger to public health;

(c) consecutive water samples taken at statistically suitable intervals do not deviate from the relevant parametric values.

(2) The competent authority shall define the frequency of sampling and the analysis of each parameter, together with the methods of measurement which shall take into account the volume of water abstracted, the extent of the abstraction, the population served, the degree of risk engendered by the quality of the water and seasonal variations in the quality.

(3) Higher values than those referred to in subregulation (2), shall not be taken into consideration in the calculation of the percentages referred to in subregulation (1) when they are the result of floods or natural disasters or abnormal weather conditions: Provided that sampling shall mean, the place at which surface water is abstracted before being sent for purification treatment.