Locals and businesses in the north-east are facing at least three more days of misery, following a burst water main.
Drogheda has remained without a regular water supply after the main - more than four metres below ground - became damaged on Friday morning.
Irish Water has begun a special operation to repair the damage after efforts over the weekend failed.
However, the water utility said it would be Thursday at the earliest by the time the pipe is repaired.
Large queues have been forming at water stations set up to alleviate the crisis, as water tankers have been brought in, some from Northern Ireland, to deal with the demand.
A HSE specialist has warned food businesses may need to "reduce or cease trading" if they cannot guarantee the safety of their food because of the water outage.
Dr Peter Finnegan - based in the Department of Public Health in Navan - said food operators need to assess the risk posed for the duration of the outage.
"It is the responsibility of the food businesses and childcare operators to ensure that food prepared and/or served in their premises does not put the health of the public at risk," Dr Finnegan said.
Businesses in the area have already been hit hard, with some forced to close their doors.
In the Southgate Shopping Centre, on the outskirts of Drogheda, owners of the Relish cafe do not know how long it can remain open, having already closed one of its cafes in another part of town.
"Our coffee machines won't work because they are plumbed directly into the main water supply, so we are having to boil kettles of water we buy from Dunnes Stores to make instant tea and coffee for customers," said manager Estelle Gorman.
"Some customers looking for takeaway coffee have decided to go without as a result, because they can make instant coffee at home.
"We are charging much less for the customers that do take it, because obviously it's just instant and not the coffee they would prefer."
Philip McEvoy in Boyne Valley Seafoods was having similar problems.
The fish shop in Southgate needs a plentiful supply of water for washing and cleaning.
"We are transporting water in from outside, from our homes and places, to keep going. It is very inconvenient," he said.
Families have also been struggling to cope with the crisis.
Kathleen Maguire (73) who has five great-grandchildren, said she has had to trudge home from the shops with bottles of water in her little trolley.
"I got two big bottles of water in Dunnes Stores and brought them home on the bus," she said, speaking at her home in Rathmullen Park.
"I used my wheels to bring them home. I'd been so worried that the water would be gone by the time I got to the shops.
"It's a bad situation. I hate that the laundry is piling up. I like to do washing and I'm very disappointed."
Martin Churchill (52) was operating a water hydrant at Ballsgrove to ensure people could get buckets and containers of water from it.
"Hundreds of people came here to the hydrant. They came from all over the area," he said.
"People have been in good spirits generally but that might be different at the end of this week.
"Of course, the swimming pools are closed so people can't shower there either."
James Guilfoyle (32), of Rathmullen Park, said his house flooded when the water was switched back on temporarily while he was in Dublin with his family.
"You couldn't make it up. The whole town has no water, I get flooded out," said the father-of-three.