# The Water Supply (Water Quality) Regulations 2016, Schedule 2: Indicator parameters


1 The water should not be aggressive.
2 Where treatment to reduce the level of radionuclides in water intended for human consumption has been taken, monitoring must be carried out to ensure the continued efficacy of the treatment.
3 Remedial action may be taken by the Secretary of State on radiological protection grounds without further consideration and deemed to be justified where radon concentrates exceed 1,000 Bq/1.
4 If tritium concentration exceeds its parametric value, an investigation (which may include analysis) of the presence of artificial radionuclides is required.
5 May be monitored from samples of water leaving treatment works or other supply point, as no significant change during distribution.
(1)
(2)
(3)
(4)
(5)
Item
Parameters
Specification concentration or value (maximum unless otherwise stated) or state
Units of measurement
Point of compliance
1.
Ammonium
0.50
mgNH4/1
Consumers' taps
2.
Chloride1
250
mgC1/
Supply point5
3.
Clostridium
0
Number/100ml
Supply point5
Perfringens
(including spores)
4.
Coliform bacteria
0
Number/100ml
Consumers' taps
5.
Colony counts
No abnormal change
Number/1ml at 22°C
Consumers' taps, service reservoirs and treatment works
6.
Conductivity1
2500
μS/cm at 20°C
Supply point5
7.
Hydrogen ion
9.5 (maximum)
6.5 (minimum)
pH value
Consumers' taps
8.
Indicative dose2
0.10
mSv
Supply point5
(a) gross alpha
0.1
Bq/1
Supply point5
(b) gross beta
1
Bq/1
Supply point5
9.
Radon3
100
Bq/1
Supply point
10.
Sulphate1
250
mgSO4/l
Supply point5
11.
Total organic carbon (TOC)
No abnormal change
mgC/l
Supply point
12.
Tritium (for radioactivity)4
100
Bq/l
Supply point5
13.
Turbidity
1
NTU
Treatment works

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Source: https://www.legislation.gov.uk/uksi/2016/614/schedule/2 (the official version)
Page: https://openlegislation.uk/water-supply-water-quality-regulations-2016/schedule-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.