Welcome to DWI

The Drinking Water Inspectorate (DWI) was formed in 1990 to provide independent reassurance that water supplies in England and Wales are safe and drinking water quality is acceptable to consumers.


2020 - 2025 Vision and Strategic Objectives

DWI’s Vision and Strategic Objectives 2020-2025 launched April 2020.



Coronavirus and Drinking Water
In the UK, drinking water supplies are routinely disinfected as part of the treatment process, and this process removes all harmful pathogens including viruses. The coronavirus CoViD-19 is thought to spread between people who are in close contact with one another, and all evidence from the spread of the virus shows that the drinking water supply is not a route for transmission of the virus.  People should continue to use tap water as normal, including for drinking, hand washing, bathing, cooking, and cleaning teeth. 

The World Health Organisation have issued advice on water, sanitation, hygiene, and waste management, for CoViD-19 (updated 29/07/2020).

Public Supplies

**NEW** Publication of Information Letter 04/2020 Guidance on Drinking Water Supply Operations in Response to Coronavirus (CoViD-19) (PDF 113KB)

Publication of Advice Letter 02/2020 Maintaining drinking water quality when reinstating water supplies after temporary closure due to the CoViD-19 outbreak (PDF 156KB)

Publication of Advice Letter 01/2020 Water suppliers’ responsibilities (PDF 162KB)

Publication of Information Letter 03/2020 Guidance on dealing with concurrent Drinking Water Quality or Sufficiency events during the CoViD-19 Outbreak (PDF 65KB)

Publication of Information Letter 02/2020 Guidance on Drinking Water Quality Legal Instruments during the CoViD-19 Outbreak (PDF 61KB)

Publication of Information Letter 01/2020 - Guidance on Drinking Water Supply Operations in Response to Coronavirus (CoViD-19) (PDF 174KB)


Private Supplies
The Drinking Water Inspectorate has shared advice provided by the World Health Organisation which summarises water, sanitation, hygiene and waste management practices for CoViD-19. This information is provided for the benefit of Local Authorities and operators of private water supplies. WHO advice.(updated 29/07/2020)

There is also updated sampling advice for local authorities


CRU capability restrictions for testing during the CoViD-19 outbreak. (PDF 61KB)


New Government advice for people who work in or run indoor labs and research facilities and similar environments


What's new?

28 July 2020

Publication of Information Letter 05/2020 Chloramination disinfection and associated risks of cyanide formation in treated water (PDF 106KB)

22 July 2020

Government and the water industry regulators in England have issued a joint letter to water companies: Green economic recovery - the water industry's role in building a resilient future

20 July 2020

Drinking Water 2019 - Quarter 4 (PDF 985KB) has been published as part of the Chief Inspector's Report 2019

9 July 2020

The Drinking Water Inspectorate has published its annual reports for public and private water supplies in England and Wales covering 2019.  The reports cover the quality of public drinking water supplies and reports on the progress of local authorities in the regulation of private water supplies. Alongside the reports are published sample results and performance statistics for companies.

29 June 2020

DWI has published Long Term Planning Guidance for water companies on Water Resources and Sufficiency of Supplies (PDF 189KB)

12 May 2020

DWI third party submission to the Competition and Markets Authority case: Ofwat price determinations (PDF 349KB)

03 April 2020

DWI’s Vision and Strategic Objectives 2020-2025 launched.

02 April 2020

The Inspectorate’s Guidance on implementing the requirements of the drinking water quality regulations in England and Wales has been updated following the UK’s exit from the EU.

03 February 2020

DWI updated position paper on Drinking Water Quality in England and Wales as the UK exits from the European Union (PDF 82KB)

01 August 2019

The Drinking Water Inspectorate Risk Management Assessment Scheme has been launched on 01 August 2019. It has been jointly developed by the Inspectorate, Lloyd’s Register and in consultation with water companies. Further details can be found in the Water Safety Plan section of the website.

5 March 2019

Joint letter from UK Regulators on the Suitability of metallic materials for use in contact with drinking water (PDF 159KB)


Page last modified: 11 August 2020
Page reviewed: 11 August 2020

Drinking Water Inspectorate