UK Drinking Water Regulatory Standards 2018

Regulatory parameters which are monitored in accordance with the Water Supply (Water Quality)(Amendment) Regulations 2018. Some non-regulatory parameters are also included for information only. The table below describes these parameters and standards.

Terms Explained

Parameter: Substance or organism tested for routinely in drinking water.

Directive requirements: These are the standards and specifications set in the EU Drinking Water Directive and were adopted into national legislation.

National requirements: These are national standards and specifications in the regulations which apply only in the England and Wales.

Concentration or value or specification: Maximum or minimum or range allowed in drinking water.

Point of compliance: The point where the legal standards apply, normally this is the consumers tap but it may be at the water works.

µg/l: Micrograms per litre (parts per billion).

mg/l: Milligrams per litre (parts per million).

Microbiological Parameters

Parameters	Concentration or Value maximum)	Units of Measurement	Point of compliance
Enterococci	0	number/100ml	Consumers’ taps
Escherichia coli (E. coli)	0	number/100ml	Consumers’ taps

Table 1: Part I – Directive requirements

Parameters	Concentration or Value maximum)	Units of Measurement	Point of compliance
Coliform bacteria	0	number/100ml	Service reservoirs* and water treatment works
Escherichia coli (E. coli)	0	number/100ml	Service reservoirs and water treatment works

Table 2: Part II – National requirements

Note: *Compliance required as to 95% of samples from each service reservoir

Chemical Parameters

Parameters	Concentration or Value maximum)	Units of Measurement	Point of compliance
Acrylamide	0.10	µg/l	(i)
Antimony	5.0	µgSb/l	Consumers’ taps
Arsenic	10	µgAs/l	Consumers’ taps
Benzene	1.0	µg/l	Consumers’ taps
Benzo(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 (ii)	20	µgNi/l	Consumers’ taps
Nitrate (iii)	50	mgNO3/l	Consumers’ taps
Nitrite (iii)	0.50	mgNO2/l	Consumers’ taps
	0.10		Treatment works
Pesticides (iv)(v)
Aldrin	0.030	µg/l	Consumers’ taps
Dieldrin	0.030	µg/l	Consumers’ taps
Heptachlor	0.030	µg/l	Consumers’ taps
Heptachlor epoxide	0.030	µg/l	Consumers’ taps
other pesticides	0.10	µg/l	Consumers’ taps
Pesticides: Total (vi)	0.50	µg/l	Consumers’ taps
Polycyclic aromatic hydrocarbons (vii)	0.10	µg/l	Consumers’ taps
Selenium	10	µgSe/l	Consumers’ taps
Tetrachloroethene and Trichloroethene (viii)	10	µg/l	Consumers’ taps
Trihalomethanes: Total (ix)	100	µg/l	Consumers’ taps
Vinyl chloride	0.50	µg/l	(i)