Engineers are continuing the mammoth task of repairing the leaks that crippled Northern Ireland’s water system.
Regional Development Minister Conor Murphy said an independent probe would examine the causes of the crisis, but insisted that restoring water supplies to homes and businesses was the first priority.
Officials on Friday night said 4,400 homes remained without a water supply but promised to deal with most of the remaining leaks within days.
Arctic weather conditions, followed by a sudden thaw, caused large numbers of burst pipes in buildings and in the mains supply, draining unprecedented amounts of water from the system.
Mr Murphy said: “On behalf of the Executive and this department, I want to apologise to people for the abysmal response there has been to real problems and distress that people have faced over the last week.
“The reality is that the people who have to take us through this issue are the people who are currently based in NIW (Northern Ireland Water). It would be irresponsible to try and change horses mid-stream.
“We have a crisis currently ongoing, we have a lot of people facing very severe hardship and distress.
“The focus and the priority was to deal with that issue and that means that we need to shore up, to encourage, to challenge the people who are tasked with delivering that service to do it properly.”
He said lessons would be learned to ensure there was no repeat of the crisis during the rest of winter. But Mr Murphy said the impending investigation would identify where blame lay for the crisis, adding: “And people will be held accountable.”
NIW’s interim chairman Padraic White emerged from a three-hour board meeting yesterday and promised that communication with the public would be greatly improved. “We expect to see a gradual improvement over the coming days,” he said.