# The Surface Waters (Dangerous Substances) (Classification) Regulations 1997, Paragraph 1


Subject to paragraphs 2 and 3 below, the requirements for the classification DS5 are that—
(a) the annual mean concentration of each substance listed in column (1) of Table 3 in samples taken from the sampling point for the waters in question in accordance with regulation 4 above does not exceed the relevant limit shown in column (2); and
(b) the concentration of each substance listed in column (1) of Table 4 in each sample so taken does not exceed the relevant limit shown in column (2).

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Source: https://www.legislation.gov.uk/uksi/1997/2560/schedule/2/paragraph/1 (the official version)
Page: https://openlegislation.uk/surface-waters-dangerous-substances-classification-regulations-1997/schedule-2/paragraph-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.