# The Surface Waters (Dangerous Substances) (Classification) (Scotland) Regulations 1990, Schedule 1: CRITERIA FOR THE CLASSIFICATION OF INLAND WATERS (DS1)


(1)
(2)
Substance
Concentration in microgrammes per litre (annual mean)
Aldrin, Dieldrin, Endrin and Isodrin
(i) 0.03 for the four substances in total;
(ii) 0.005 for endrin
Cadmium and its compounds
5 (total cadmium: both soluble and insoluble forms)
Carbon tetrachloride
12
Chloroform
12
DDT (all isomers)
0.025
para-para-DDT
0.01
Hexachlorobenzene
0.03
Hexachlorobutadiene
0.1
Hexachlorocyclohexane (all isomers)
0.1
Mercury and its compounds
1 (total mercury: both soluble and insoluble forms)
Pentachlorophenol and its compounds
2

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Source: https://www.legislation.gov.uk/uksi/1990/126/schedule/1 (the official version)
Page: https://openlegislation.uk/surface-waters-dangerous-substances-classification-scotland-regulations-1990/schedule-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.