# The Private Water Supplies (Wales) Regulations 2017, Part 2: Indicator Parameters

Extent: E+W

TABLE C:
Prescribed concentrations, values or states
Parameters
Maximum concentration or value
Units of Measurement
(1)The water should not be aggressive.
(2)Only in the case of surface water or groundwater that has been influenced by surface water.
Ammonium
0.50
mg/l
Chloride
250
mg/l
Clostridium perfringens (including spores)
0
Number/100ml
Coliform bacteria
0
Number/100ml (Number/250ml in the case of water put into bottles or containers)
Colony counts
No abnormal change
Number/ml at 22ºC
Conductivity
2500
µS/cm at 20ºC
Hydrogen ion
9.5 (maximum)
pH value
6.5 (minimum) (in the case of still
water put into bottles or containers the minimum is 4.5)
pH value
Sulphate
250
mg/l
Total organic carbon (TOC)
No abnormal change
mgC/l
Turbidity
1
NTU

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Source: https://www.legislation.gov.uk/wsi/2017/1041/schedule/1/part/2 (the official version)
Page: https://openlegislation.uk/private-water-supplies-wales-regulations-2017/schedule-1/part-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.