What is Regulation 31?

Regulation 31 of The Water Supply (Water Quality) Regulations 2016 (as amended)1 implements Article 10 of the Council of the European Union Drinking Water Directive (DWD) in England and Wales for all chemicals and construction products used by water undertakers, from the source of the water, up to the point of delivery to the consumer’s building. It sets out how approvals can be given to such construction products and materials that do not prejudice water quality and consumer safety.

Article 10 of the DWD (PDF 238KB) states that:

Quality assurance of treatment, equipment and materials

Member States shall take all measures necessary to ensure that no substances or materials for new installations used in the preparation or distribution of water intended for human consumption or impurities associated with such substances or materials for new installations remain in water intended for human consumption in concentrations higher than is necessary for the purpose of their use and do not, either directly or indirectly, reduce the protectionof human health provided for in this Directive; the interpretative document and technical specifications pursuant to Article 3 and Article 4 (1) of Council Directive 89/106/EEC of 21 December 1988 on the approximation of laws, regulations and administrative provisions of the Member States relating to construction products (1) shall respect the requirements of this Directive.

The full text of the Water Supply (Water Quality) Regulations is available for England and for Wales.

Guidance on these Regulations is also available.

Details of how to obtain approval for treatment chemicals, construction products and materials for use with drinking water is given in Advice Sheet No 1 (PDF 168KB), together with an explanation of the approval arrangements elsewhere in the United Kingdom.


1 The relevant regulations (for public drinking water suppliers)
The following regulations apply to the approval of substances and products used in the provision of public water supplies within the United Kingdom:

England  - Regulation 31 of The Water Supply (Water Quality) Regulations 2016 (As Amended)(Statutory Instruments 2016 No 614): http://www.legislation.gov.uk/uksi/2016/614/pdfs/uksi_20160614_en.pdf

Wales – Regulation 31 of The Water Supply (Water Quality) Regulations 2018 (Welsh Statutory Instrument 2018 No 647 (W. 121)): http://www.legislation.gov.uk/wsi/2018/647/contents/made

Scotland – Regulation 33 of  The Public Water Supplies (Scotland) Regulations 2014 (Scottish Statutory Instrument No 364): http://www.legislation.gov.uk/ssi/2014/364/contents/made

Northern Ireland – Regulation 33 of The Water Supply (Water Quality) Regulations (Northern Ireland) 2017 (Statutory Rules of Northern Ireland 2017 No.212) - http://www.legislation.gov.uk/nisr/2017/212/contents/made


Page reviewed: 18 July 2018
Page modified:18 July 2018

Drinking Water Inspectorate