A serious incident at the Glenhordial Water Treatment Works led to widespread taste and odour complaints about tap water in the Omagh and Killyclogher areas.

The problems occurred between February 17 and March 7, according to NI Water's latest Annual Water Quality Report. The incident was one of 17 serious events recorded across Northern Ireland during the reporting year.

NI Water stated that the water supplied in the Omagh area met all required physical, chemical and microbiological standards under the regulations. However, a high number of customers reported issues with the mains water supply, which serves thousands of households.

Testing also took place at other locations. In Loughmacrory, near Beragh, there was an exceedance of coliform bacteria, an indicator of microbiological contamination. An investigation could not determine the cause but said it was most likely related to the customer's tap.

NI Water says its accredited laboratories carry out more than 100,000 tests each year to ensure standards are met. The Drinking Water Inspectorate, part of the Department of Agriculture, Environment and Rural Affairs, independently audits those tests and publishes its findings annually.

The report was due to be discussed by councillors this week.