Guidance documents

Information note on Regulation 2 (Interpretation)

For a printable copy of this guidance see: Regulation-2v5-final-3.pdf (

Regulation 2 defines the terms used in the regulations. This information note clarifies some of these terms.

‘The Act’ means the Water Industry Act 1991;

‘accreditation’ means accreditation in accordance with BSEN ISO/IEC 17024 or ISO/IEC17025

‘audit and check monitoring’ were replaced by “Group A and Group B” parameters as part of 2018 amendments of the Regulations

‘consumer’ means a person to whom a private water supply is provided for human consumption;

‘disinfection’ means a process of water treatment to remove, or render harmless to health, every pathogenic micro-organism and pathogenic parasite that could otherwise be present in the water;

E. coli‘ means Escherichia coli, a bacterium indicating evidence of faecal contamination.

‘indicative dose’ or ‘ID’ means the committed effective dose for one year of ingestion resulting from all the radionuclides whose presence has been detected in a supply of water intended for human consumption, of natural and artificial origin, excluding tritium, potassium-40, radon and short-lived radon decay products; Table D of Part 3 of schedule 1.

‘indicator parameter’ means a parameter listed in Table C of Part 2 of Schedule 1;

‘local authority’ means any of the following:

(a) a district council or the council of a county in which there are no district council;
(b) district council;
(c) the council of a county in which there are no district councils.

‘parameter’ means a property, element, organism or substance listed in the first column of the Tables in Schedule 1 as read, where appropriate, with the notes to that Schedule and those Tables;

‘prescribed concentration or value’, in relation to any parameter, means the maximum or minimum concentration or value specified in relation to that parameter in Table A or B in Schedule 1 as measured by reference to the unit of measurement so specified, and as read, where appropriate in the case of Table B, with the notes to that Table;

‘private supply of water’ or ‘private water supply’ means a supply of water other than a supply provided directly by a water undertaker or licensed water supplier, and which is comprised of all physical assets from the point of abstraction to the point of use, including associated pipes, fittings and tanks; and

‘relevant person’ can be any or all of the following:

(a) the owner and the occupier (who may be the same or different persons) of premises (land and any buildings on it), which are supplied with water for domestic or food production purposes by means of a private supply;
(b) the owner and the occupier (who may be the same or different persons) of land on which any part of the supply is situated;
(c) any other person who exercises powers of management or control in relation to that supply.

To note: where more than one relevant person exists, the Water Industry Act 1991 does not advise how costs relating to private water supplies are shared between relevant persons.