Public water supplies

Northern Ireland Water is the public water supplier in Northern Ireland. The DWI investigates incidences where drinking water quality standards have been breached or compromised and also carries out an annual assessment of Northern Ireland Water.


You can view current and historical reports on the compliance with the drinking water quality standards using the link below:-

Compliance with drinking water quality standards in NI reports

Public water supplies enforcement and prosecution policy

If Northern Ireland Water fails to meet the required standards, the DWI may take enforcement action as detailed in their prosecution policy:-

You can view Undertakings, agreed between NI Water and the Chief Inspector of Drinking Water, following enforcement action taken under Section 31(3)(a) of the Water Sewerage Services (Northern Ireland) Order 2006. Current and historical documents can be viewed using the links below:

Public water supplies legislation

The following legislation implements the requirements set out in the European Drinking Water Directive (98/83/EC):

DWI also has regulatory responsibilities for drinking water quality supplied, via a domestic distribution, to the public in premises such as schools, hospitals and restaurants under:


The contribution of Drinking Water Quality Regulations to the implementation of the Water Framework Directive in Northern Ireland

Drinking Water and Health: a guide for public and environmental health professionals and for those in the water industry in Northern Ireland

Guidance on the Notification of Events

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