# The Water Supply (Water Quality) Regulations 2018, Schedule 1: PRESCRIBED CONCENTRATIONS AND VALUES


Table A Microbiological Parameters
1 Compliance required as to 95% of samples from each service reservoir (regulation 4(6)).
Part 1: Directive requirements
Item
Parameters
Concentration or Value (maximum)
Units of Measurement
Point of compliance
1
Enterococci
0
number/100 ml
Consumers' taps
2
E.coli
0
number/100 ml
Consumers' taps
Part 2: National requirements
1
Coliform bacteria
0
number/100 ml
Service reservoirs 1 and water treatment works
2
E. coli
0
number/100 ml
Service reservoirs and water treatment works
Note:
Table B Chemical Parameters
Part 1: National requirements
1 The parametric value refers to the residual monomer concentration in the water as calculated according to specifications of the maximum release from the corresponding polymer in contact with the water. This is controlled by product specification.
2 See also regulation 4(2)(d).
3 See the definition of “pesticides and related products” in regulation 2.
4 The parametric value applies to each individual pesticide.
5 “Pesticides: Total” means the sum of the concentrations of the individual pesticides detected and quantified in the monitoring procedure.
6 The specified compounds are:
benzo(b)fluoranthene
benzo(k)fluoranthene
benzo(ghi)perylene
indeno(1,2,3-cd)pyrene.
The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.
7 The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.
8 The specified compounds are:
chloroform
bromoform
dibromochloromethane
bromodichloromethane.
The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.
Item
Parameters
Concentration or Value (maximum)
Units of Measurement
Point of compliance
1
Acrylamide
0.10
μg/l
1
2
Antimony
5.0
μgSb/l
Consumers' taps
3
Arsenic
10
μgAs/l
Consumers' taps
4
Benzene
1.0
μg/l
Consumers' taps
5
Benzo(a)pyrene
0.010
μg/l
Consumers' taps
6
Boron
1.0
mgB/l
Consumers' taps
7
Bromate
10
μBrO3/l
Consumers' taps
8
Cadmium
5.0
μgCd/l
Consumers' taps
9
Chromium
50
μgCr/l
Consumers' taps
10
Copper
2.0
mgCu/l
Consumers' taps
11
Cyanide
50
μgCN/l
Consumers' taps
12
1, 2 dichloroethane
3.0
μg/l
Consumers' taps
13
Epichlorohydrin
0.10
μg/l
1
14
Fluoride
1.5
mgF/l
Consumers' taps
15
Lead
10
μgPb/l
Consumers' taps
16
Mercury
1.0
μgPb/l
Consumers' taps
17
Nickel
20
μgNi/l
Consumers' taps
18
Nitrate 2
50
mgNO3/l
Consumers' taps
19
Nitrite 2
0.50
mgNO2/l
Consumers' taps
0.10
Treatment Works
20
Pesticides 3,4
Aldrin
0.030
μg/l
Consumers' taps
Dieldrin
Heptachlor
Heptachlor
epoxide
other pesticides
0.10
μg/l
Consumers' taps
21
Pesticides: Total 5
0.50
μg/l
Consumers' taps
22
Polycyclic aromatic hydrocarbons 6
0.10
μg/l
Consumers' taps
23
Selenium
10
μgSe/l
Consumers' taps
24
Tetrachloroethene and Trichloroethene 7
10
μg/l
Consumers' taps
25
Trihalomethanes: Total 8
100
μg/l
Consumers' taps
26
Vinyl chloride
0.50
μg/l
1
Notes:
Part 2: National requirements
Item
Parameters
Concentration or Value (maximum unless otherwise stated)
Units of Measurement
Point of compliance
1
Aluminium
200
μgAl/l
Consumers' taps
2
Colour
20
mg/l Pt/Co
Consumers' taps
3
Iron
200
μgFe/l
Consumers' taps
4
Manganese
50
μgMn/l
Consumers' taps
5
Odour
Acceptable to consumers and no abnormal change
Consumers' taps
6
Sodium
200
mgNa/l
Consumers' taps
7
Taste
Acceptable to consumers and no abnormal change
…
Consumers' taps
8
Tetrachlorome-thane
3
μg/l
Consumers' taps
9
Turbidity
4
NTU
Consumers' taps

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Source: https://www.legislation.gov.uk/wsi/2018/647/schedule/1 (the official version)
Page: https://openlegislation.uk/water-supply-water-quality-regulations-2018/schedule-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.