Thousands of homes and businesses in the Republic of Ireland remain without water five days after a water main burst.
The burst on Friday is affecting 50,000 customers in counties Louth and Meath.
Irish Water has said it could be the weekend before supply returns to normal. It is liaising with Defence Forces to provide alternative supplies.
Northern Ireland Water dispatched tankers on Monday evening to help transport water to those affected.
Speaking to RTÉ, Irish Water managing director Jerry Grant said the complexity of the piping meant it had not been possible to carry out the repairs in the normal timeframe.
In a statement on Monday, the company said it hoped to complete the repair by Thursday.
It added that when the water main is repaired it could take a number of days before full supply is restored.
Water rationing is in place but Our Lady of Lourdes Hospital in Drogheda has been prioritised in order to maintain supply to patients.
Temporary water stations have been set up as shops have been running low on bottled water.
The burst main is located over four metres underground.
It is linked to the Staleen Water Treatment Plant, which supplies drinking water to Drogheda and its surrounding areas.
Irish Water said the burst main was 50 years old and warped.
The mayor of Drogheda, Labour councillor Pio Smith, said Irish Water must plan for future problems.
Speaking to the BBC's Good Morning Ulster, Mr Smith said it was known that the pipes needed to be replaced.
"They had a burst last year as well," he said.
"So even fixing this now on Thursday, I don't necessarily think that it's going to be the end of the problem."
Mr Smith also said he had asked Irish Water to meet with politicians from the affected areas.
"At that meeting we'll be asking questions in relation to what happened, was the contingency plan they had envisaged suitable for what happened and what the future holds."
In order to manage the remaining water, a programme of rationing will continue in the affected areas.
A rolling schedule of supply re-commenced for parts of Drogheda at 09:00 local time on Tuesday.
Thirty-three tankers have now been deployed to replenish temporary water stations.
Irish Water said there are 86 stationary water containers in place across counties Louth and Meath. Eight thousand 5 and 10 litre foldable water containers will be distributed throughout the affected areas.
In a statement, NI Water said it was happy to assist Irish Water.
"Over the last number of years NI Water has worked with other utilities to identify ways in which we could provide mutual support and aid during periods of severe weather or other unforeseen situations," NI Water said.
"This agreement has worked very well in the past and can be a great help to a company when they need it most."
The rationing plan for Tuesday can be found on the Louth County Council website.
Consumers have been asked to bring clean containers and to boil water taken from these stations before use, as a precaution.