Regulations and Guidance for public water supplies

The specific requirements for drinking water quality in Northern Ireland are contained within the appropriate drinking water regulations.

Drinking water quality is tested for compliance with the regulatory standards. Tests are carried out for forty different substances or organisms known as parameters. A description of each parameter and its prescribed concentration or value can be found in the European and National Drinking Water Quality Standards tables (.PDF 582Kb).

The Inspectorate from time to time issues Information Letters to NI Water giving advice, technical guidance or requesting information.

Details of chemicals and materials of construction approved for use in the provision of drinking water supplies are available in the list of approved products.

Legislation regarding drinking water can be obtained from the UK Legislation website.

The general principles which will be followed in relation to enforcement and prosecution of NI Water if it fails to meet these standards are set out in the Drinking Water Inspectorate's prosecution policy (.PDF 318Kb).