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).

Advice Letter 02/2020 - Welsh Language Version (PDF 151KB)

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?

26 November 2020

Government and the water industry regulators in England have issued an update to water companies on the Green Economic Recovery : Regulatory assessment process

12 November 2020

Publication of Information Letter 07/2020 - The Water Industry (Suppliers' Information) Direction 2020

4 November 2020

Drinking Water 2020 - Quarter 2 has been published

12 October 2020

DWI is now advertising for a Deputy Chief Inspector. Full details can be found on the Jobs page.

11 September 2020

Publication of Information Letter 06/2020 Assessment of the limitations for chemicals and treatment products intended for the treatment of drinking water (PDF 93KB)

25 August 2020

Drinking Water 2020 - Quarter 1 has been published

28 July 2020

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


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)


Page last modified: 26 November 2020
Page reviewed: 1 December 2020

Drinking Water Inspectorate