# The Surface Waters (Classification) (Scotland) Regulations 1990

S.I. 1990/121 · made 23 January 1990

These Regulations prescribe the system of classifying the quality of inland waters (as defined in section 30A(5)(b) of the Control of Pollution Act 1974) according to their suitability for abstraction by water authorities for supply (after treatment) as drinking water.

Made under: Control of Pollution Act 1974 (Section 30B)

PDFs: Printed copy https://openlegislation.uk/surface-waters-classification-scotland-regulations-1990/pdf/uksi_19900121_en.pdf

## Introductory text

WATER SUPPLY, SCOTLAND
Made 23rd January 1990
Laid before Parliament 8th February 1990
Coming into force 1st May 1990
The Secretary of State, in exercise of the powers conferred on him by section 30B of the Control of Pollution Act 1974, hereby makes the following Regulations:

## 1 Citation and commencement

These Regulations may be cited as the Surface Waters (Classification) (Scotland) Regulations 1990 and shall come into force on 1st May 1990.

## 2 Classification of waters

These Regulations, and the system of classification prescribed by these Regulations, apply in relation to inland waters (including any loch or pond which, by virtue of an order made under section 30A(5)(b) of the Control of Pollution Act 1974, is to be treated as a relevant loch or pond).

## 3 Classification of waters

The waters to which these Regulations apply shall be classified DW1, DW2 or DW3, as the case may be, according to the criteria set out in the Schedule to these Regulations, which criteria shall determine their suitability for abstraction by water authorities within the meaning of the Water (Scotland) Act 1980 for supply (after treatment) as drinking water.

## Signature

James Douglas-Hamilton
Parliamentary Under Secretary of State, Scottish Office
St. Andrew’s House,
Edinburgh
23rd January 1990

## Criteria for the classification of waters

The limits set out below are maxima
(1)
(2)
(3)
(4)
(5)
No. in Annex II to 75/440/EEC
Parameters
DW1
DW2
DW3
Note
(1) The value is an upper limit set in relation to the mean annual temperature (high and low).
2
Coloration (after simple filtration)
mg/1 Pt Scale
20
100
200
4
Temperature
°C
25
25
25
7
Nitrates
mg/1 NO3
50
50
50
8(1)
Fluorides
mg/1 F
1.5
10
Dissolved iron
mg/1 Fe
0.3
2
12
Copper
mg/1 Cu
0.05
13
Zinc
mg/1 Zn
3
5
5
19
Arsenic
mg/1 As
0.05
0.05
0.1
20
Cadmium
mg/1 Cd
0.005
0.005
0.005
21
Total chromium
mg/1 Cr
0.05
0.05
0.05
22
Lead
mg/1 Pb
0.05
0.05
0.05
23
Selenium
mg/1 Se
0.01
0.01
0.01
24
Mercury
mg/1 Hg
0.001
0.001
0.001
25
Barium
mg/1 Ba
0.1
1
1
26
Cyanide
mg/1 Cn
0.05
0.05
0.05
27
Sulphates
mg/1 SO4
250
250
250
31
Phenols (phenol index) paranitraniline 4 aminoantipyrine
mg/1 C6H5OH
0.001
0.005
0.1
32
Dissolved or emulsified hydrocarbons (after extraction by petroleum ether)
mg/1
0.05
0.2
1
33
Polycyclic aromatic hydrocarbons
mg/1
0.0002
0.0002
0.001
34
Total pesticides (parathion, BHC, dieldrin)
mg/1
0.001
0.0025
0.005
39
Ammonia
mg/1 NH4
1.5
4

## Explanatory note

(This note is not part of the Regulations)
These Regulations prescribe the system of classifying the quality of inland waters (as defined in section 30A(5)(b) of the Control of Pollution Act 1974) according to their suitability for abstraction by water authorities for supply (after treatment) as drinking water.
The classifications DW1, DW2 and DW3 reflect the mandatory values assigned by Annex II to Council Directive 75/440/EEC, (OJ No.L 194, 25.7.75, p.26) (concerning the quality required of surface water intended for the abstraction of drinking water) to the parameters listed in the Schedule to the Regulations.
The classifications are relevant for the purposes of setting water quality objectives for rivers, lochs and other inland waters under section 30C of the Act and for ascertaining the treatment to which the water is to be subjected before it is supplied for public use, in accordance with Part VI of the Water Supply (Water Quality) (Scotland) Regulations 1990 (S.I. 1990/119).

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Source: https://www.legislation.gov.uk/uksi/1990/121 (the official version)
Page: https://openlegislation.uk/surface-waters-classification-scotland-regulations-1990
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.