Drinking Water Quality remains high across Northern Ireland

Date published: 22 September 2022


The Drinking Water Inspectorate (DWI), which is responsible for regulating drinking water quality, has today published its Annual Report for 2021. It states that drinking water quality in Northern Ireland is of a high standard.

Northern Ireland Water Limited (NI Water) is required to undertake a stringent monitoring programme to verify that the tap water it supplies to consumers meets all the stringent quality standards set by the drinking water regulations. During 2021, over 95,000 tests were completed. As outlined in the DWI Report, the overall compliance for the mains water supply in 2021 was 99.88%. The results are based on samples taken from water treatment works, service reservoirs and consumers’ taps.

Welcoming publication of the report, Environment Minister Edwin Poots MLA, said: “I am pleased to welcome the Drinking Water Inspectorate’s annual report on Drinking Water Quality in Northern Ireland. The quality of our drinking water remains high which is vital for Public Health, the hospitality sector, farming and the economy."

COVID-19 continued to have an impact, albeit less significant, on the monitoring of the quality of drinking water supplies across Northern Ireland in 2021. The impact of periods of restricted access to domestic properties resulted in a reduced number of samples being collected for specific parameters that are only monitored at consumers’ taps. This shortfall in regulatory sampling by NI Water was approved by DWI in advance, and hence no enforcement action was taken as it was beyond the company’s control.

The Minister went on to say: “The Drinking Water Inspectorate has an important role to play in providing the Northern Ireland public with independent assurance that their water supply is safe and clean. Through regulatory enforcement, DWI has helped bring about improvements to NI Water’s infrastructure for the benefit of us all."

It is important that NI Water manages risks within the water supply system and this should be supported by an appropriately funded investment programme. The Utility Regulator published its Final Determination on funding for PC21 (the Price Control process from 1 April 2021 to 31 March 2027) in May 2021. NI Water must receive appropriate funding to ensure drinking water quality is maintained in the future.

A small percentage of water is also supplied from private water supplies in Northern Ireland. A number of these supplies serve public buildings, such as hospitals and health care premises, universities, and businesses such as food manufacturers, hotels and restaurants. Extensive monitoring is undertaken of registered private water supplies by the DWI (in conjunction with local councils), with almost 12,000 tests conducted in 2021. The Report published today indicates that the overall compliance figure of 99.19% at private water supplies is slightly lower than that reported for the public water supply. The report provides a breakdown of what these supplies are used for and the issues experienced throughout 2021.

Minister Poots added: “Moving forward, continued improvement in drinking water quality in Northern Ireland remains a priority for the Department. Through its work with NI Water and the owners and users of private water supplies, the Department will continue to encourage the use of innovation and sustainable practices. This will ensure public health protection whilst supporting economic growth.”

Notes to editors: 

  1. The Drinking Water Inspectorate operates as a business unit within the Northern Ireland Environment Agency (NIEA), part of the Department of Agriculture, Environment and Rural Affairs.
  2. The Drinking Water Inspectorate has an independent responsibility to assess and regulate drinking water quality for both public and private water supplies against the regulatory requirements.
  3. NI Water is solely responsible for the supply and distribution of public drinking water.
  4. There were 171 registered private water supplies monitored in Northern Ireland in 2021, with six new sites being registered during that period.
  5. The report is available on the department’s website at: www.daera-ni.gov.uk/articles/duties-drinking-water-inspectorate-dwi
  6. Follow DAERA on Twitter at and Facebook.
  7. All media queries should be directed to the DAERA Press Office: pressoffice.group@daera-ni.gov.uk.
  8. The Executive Information Service operates an out of hours service for media enquiries only between 1800hrs and 0800hrs Monday to Friday and at weekends and public holidays. The duty press officer can be contacted on 028 9037 8110.

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