
1 
These Regulations may be cited as the Surface Waters (Dangerous Substances) (Classification) Regulations 1997 and shall come into force on 26th November 1997.
2 
The classification DS4 and the criteria for that classification set out in Schedule 1 to these Regulations shall apply for classifying inland freshwaters with a view to reducing the pollution of those waters by the dangerous substances listed in that Schedule.
3 
The classification DS5 and the criteria for that classification set out in Schedule 2 to these Regulations shall apply for classifying coastal waters and relevant territorial waters with a view to reducing the pollution of those waters by the dangerous substances listed in that Schedule.
4 
The Environment Agency shall ensure that waters classified under these Regulations are sampled at such sampling points and at such times, and samples are analysed in such manner, as the Agency considers necessary for—
(a) monitoring the effect on those waters of discharges containing the dangerous substances in question; and
(b) determining the extent to which those waters are polluted by those substances and whether the requirements for the relevant classification are satisfied.
5 
Section 83 of the Water Resources Act 1991 (water quality objectives) shall have effect as if—
(a) it imposed a duty on the Secretary of State to exercise his powers under that section to apply the classification DS4 to all inland freshwaters and the classification DS5 to all coastal waters and relevant territorial waters and to specify 1st April 1998 as the relevant date in each case; and
(b) in relation to performance of that duty and the resulting water quality objectives, subsections (3) to (6) of that section (reviews and consultation requirements) were omitted.
Signed by authority of the Secretary of State
Michael Meacher
Minister of State,
Department of the Environment, Transport and the Regions
22nd October 1997Ron Davies
Secretary of State for Wales
24th October 1997
SCHEDULE 1
Regulation 2
1 
Subject to paragraph 2 below, the requirements for the classification DS4 are that—
(a) the annual mean concentration of each substance listed in column (1) of Table 1 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 2 in each sample so taken does not exceed the relevant limit shown in column (2).
2 
Where samples are taken in accordance with regulation 4 above from more than one sampling point in relation to the waters in question, the requirement in paragraph 1(a) above must be satisfied in relation to the samples from each sampling point.

Table 1
(1) (2)
Dangerous substance Limit (in microgrammes per litre) (annual mean)
Arsenic 50
Atrazine and Simazine 2 (for the two substances in total)
Azinphos-methyl 0.01
Dichlorvos 0.001
Endosulphan 0.003
Fenitrothion 0.01
Malathion 0.01
Trifluralin 0.1

Table 2
(1) (2)
Dangerous substance Limit (in microgrammes per litre)
Tributyltin 0.02
Triphenyltin and its derivatives 0.02
SCHEDULE 2
Regulation 3
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).
2 
Where samples are taken in accordance with regulation 4 above from more than one sampling point in relation to the waters in question, the requirement in paragraph 1(a) above must be satisfied in relation to the samples from each sampling point.
3 
In relation to dichlorvos used as a treatment for sea-lice infestation, compliance with the relevant limit in column (2) of Table 4 shall be determined by reference only to samples taken as nearly as maybe after 24 hours have elapsed since it was so used.

TABLE 3
(1) (2)
Dangerous substance Limit (in microgrammes per litre) (annual mean)
Arsenic 25
Atrazine and Simazine 2 (for the two substances in total)
Azinphos-methyl 0.01
Dichlorvos 0.04
Endosulphan 0.003
Fenitrothion 0.01
Malathion 0.02
Trifluralin 0.1

TABLE 4
(1) (2)
Dangerous substance Limit (in microgrammes per litre)
Dichlorvos 0.6
Tributyltin 0.002
Triphenyltin and its derivatives 0.008