Guidelines On Drinking Water Standards UK

Drinking water must be ‘wholesome’ and this is defined in law by standards for a wide range of substances, organisms and properties of water in regulations.

The standards are set to be protective of public health and the definition of wholesome reflects the importance of ensuring that water quality is acceptable to consumers.

There is good agreement worldwide on the science behind the setting of health based standards for drinking water, and this expert evidence is documented by the World Health Organisation in the Guidelines for Drinking Water Quality.

The legal standards in the UK are explained fully in the Water Supply (Water Quality) Regulations 2016.

Below is a brief guide to the regulations and was correct at the time of publication. It is advisable to double check these standards with any amended version of the UK Government regulations above

National Requirements

Parameters Maximum Value units of Measurement point of compliance
Aluminium 200 µgAl/l Consumers’ taps
Colour 20 mg/l Pt/Co Consumers’ taps
Iron 200 µgFe/l Consumers’ taps
Manganese 50 µgMn/l Consumers’ taps
Odour <1 at 25 °C Dilution number Consumers’ taps
Sodium 200 mgNa/l Consumers’ taps
Taste <1 at 25 °C Dilution number Consumers’ taps
Tetrachlormethane 3 µg/l Consumers’ taps
Turbidity 4 NTU Consumers’ taps

CHEMICAL PARAMETERS

Parameters Maximum Value units of Measurement point of compliance
Acrylamide 0.10 µgA/l (i)
Antimony 5.0 µgSb/l Consumers’ taps
Arsenic 10 µgAs/l Consumers’ taps
Benzene 1.0 µg/l Consumers’ taps
Benso(a)pyrene 0.010 µg/l Consumers’ taps
Boron 1.0 mgB/l Consumers’ taps
Bromate 10 µgBrO3/l Consumers’ taps
Cadmium 5.0 µgCd/l Consumers’ taps
Chromium 50 µgCr/l Consumers’ taps
Copper(ii) 2.0 mgCu/l Consumers’ taps
Cyanide 50 µgCN/l Consumers’ taps
1,2 dichloroethane 3.0 µg/l Consumers’ taps
Epichlorohydrin 0.10 µg/l (i)
Fluoride 1.5 mgF/l Consumers’ taps
Lead(ii) 10 µgPb/l Consumers’ taps
Mercury 1.0 µgHg/l Consumers’ taps
Nickel 20 µgNi/l Consumers’ taps
Nitrate 50 mgNO3/l Consumers’ taps
Nitrite 0.50 mgNO2/l Consumers’ taps
  0.10   Treatment works

PESTICIDES

Parameters Maximum Value units of Measurement point of compliance
Aldrin 0.030 µg/l Consumers’ taps
Dieldrin 0.030 µg/l Consumers’ taps
Heptachlor 0.030 µg/l Consumers’ taps
Heptachlorepoxide 0.030 µg/l Consumers’ taps
Other Pesticides 0.10 µg/l Consumers’ taps
Pesticides:Total 0.50 µg/l Consumers’ taps
Polycyclic aromatic hydrocarbons 0.10 µg/l Consumers’ taps
Selenium 10 µg/l Consumers’ taps
Tetrachloroehtane 10 µg/l Consumers’ taps
Trichloroethane 10 µg/l Consumers’ taps
Trihalomethanes 100 µg/l Consumers’ taps
Vinyl chloride 0.50 µg/l Consumers’ taps

MICROBIOLOGICAL PARAMETERS

Parameters Maximum Value units of Measurement point of compliance
Coliform bacteria 0 number/100ml Treatment works
Enterococci 0 number/100ml Consumers’ taps
Escherichia coli (E.coli) 0 number/100ml Treatment works
Escherichia coli (E.coli) 0 number/100ml Consumers’ taps