Irish Water says elevated levels of manganese have led to discolouration of the water in east Cavan.
People living in the area have been sharing photos of brown water coming from their taps in the area over the weekend.
Irish Water says the elevated levels of manganese in the Bailieborough Regional Water Supply Scheme, which also supplies Virginia and Mullagh, followed exceptional rainfall.
It says as a result, work to clean the reservoirs was necessary.
In a statement to Northern Sound News, Irish Water says following reservoir cleaning, the water in Bailieborough is now clear and this has started to filter through to Virginia.
It says reservoirs in Virginia are now being cleaned and this will be completed by tomorrow at the latest.
The utility says that while elevated levels of manganese make the water look muddy or brown, it is still safe to drink.
Irish Water has been called on to provide water tankers for the communities affected by the ongoing issues.
Cathaoirleach of Cavan County Council Shane P O’Reilly has hit out at the lack of communication and information coming from the organisation.
He says many people are concerned with the quality of the water and aren’t drinking it, while others have had laundry stained by it.
Speaking on The Wider View he called for Irish Water to provide tankers:
Statement from Irish Water
Irish Water is committed to providing clean and secure drinking water to customers in the Bailieborough and Virginia areas.
A recent issue with elevated levels of manganese in the Bailieborough Regional Water Supply Scheme which supplies Virginia and Mullagh following exceptional rainfall has led to the necessity for reservoir cleaning in Virginia. This cleaning will flush the water main and clean the water.
While elevated levels of manganese makes the water look muddy or brown, the water is still safe to drink.
Following reservoir cleaning, the water in Bailieborough is now clear and this has started to filter through to Virginia. Reservoirs in Virginia are now being cleaned. This work is ongoing and will be completed by tomorrow at the latest.
Irish Water working in partnership with Cavan County Council would like to thank customers for their patience while this necessary work is ongoing.