Northern Ireland Water is facing calls for a full investigation into why it took more than 12 hours for news of a suspect water supply sample to be made public.
Around 220,000 households across counties Antrim and Down were dramatically instructed yesterday to boil all water used for cooking and drinking after coliform bacteria were found in a sample.
While themselves harmless, the coliform micro-organisms found in the sample taken by Northern Ireland Water earlier this week are a possible indicator that other bacteria that cause vomiting and diarrhoea could be present in the water supply, Dr Richard Smithson, consultant in communicable disease control with the Public Health Agency said.
He was among those investigating after a sample indicated problems with supply from the water treatment works at Dunore Point on the shores of Lough Neagh.
While initial test results yesterday indicated that there had been no contamination of the water, Northern Ireland Water had urged householders to boil their water until the results of a final sample test had been completed.
The restrictions were eventually lifted at 8.50pm last night.
Now Northern Ireland Water is facing calls for a full investigation after it was revealed the company took more than 12 hours after the sample was found to warn customers of the problem.
SDLP justice spokesman Alban Maginness MLA has requested an emergency meeting with Northern Ireland Water.
His party colleague, South Antrim MLA Thomas Burns, said yesterday: “We need to find out what has caused this problem, who is responsible and how to prevent an incident like this occurring again. We need prompt answers from NI Water.”
Stormont Environment Committee chairman Patsy McGlone said NI Water stressed that the measures had been precautionary.
Bacteria found in the water supply had initially raised concerns that more dangerous pathogens could have slipped through the net.
As a result, around 220,000 households across counties Antrim and Down were warned to boil water for cooking and drinking after the discovery of the coliform bacteria.
Northern Ireland Water said it had been notified of the sample result on Monday afternoon but the failure was not made public until the following morning.
The company added it had also examined its water treatment processes and had not found any problems.
Dr Smithson said the sample showed coliform bacteria — not E coli — were present in the water supply.
“These bacteria are in themselves harmless but they do show there could have been a failure in the treatment process, so we advise people to boil their water,” he explained as the alert was sounded.
“If there were any harmful bacteria in the water which survived the treatment process they could cause things like diarrhoea and vomiting.”
He said there was no indication that the water had led to any illness and stressed that it was a precautionary measure.
However, Dr Smithson did express concern about the delay in letting people know about the problem.
“That would be a concern for me, if people haven’t been properly notified,” he said. “The fact that so big an area and so many people are affected is worrying too.
“A full scale investigation should be launched into how this happened and to make sure it doesn't recur. The public should have been notified sooner.
“We’ve heard from Northern Ireland Water about how significant the improvements they have made over the last few years are. I’m disappointed that such a problem should arise, particularly over the holiday.”
The anti-water charges We Won’t Pay Campaign attacked the use of Private Finance Initiatives (PFI) as being responsible for deterioration in health and safety and water quality.
Spokesman Gary Mulcahy said: “The privatisation of water treatment facilities via PFI has been directly responsible for cuts in our water service.
“A third of the water service workforce has been laid off, while local water depots have been closed.
“These cuts are part of the drive to cut down on all costs in order to maximise the return for the private companies which have been awarded very lucrative PFI contracts.
“As a matter of public safety, the Minister for Regional Development should immediately take steps to remove these profiteers out of such an important public service.”
Northern Ireland Water interim director of operations David Dangerfield said the company was notified of the problem towards the end of Monday afternoon.
The samples suggested contamination by coliform bacteria, micro-organisms which are found widely in the environment including soil, Mr Dangerfield said.
“We use them as an indicator of a potential problem within the treatment process.
“If we pick up coliforms in a sample like this the first thing we do is check the water treatment process.
“There is nothing wrong with the water treatment process that we can see,” he said.
A number of sewage treatment works discharge waste water into Lough Neagh but Mr Dangerfield said the large Dunore Point water treatment works, which was commissioned within the last 12 months, is more than capable of treating the water to drinking water standards.
“It uses dissolved air flotation to remove material and sediment from the raw water and after the treatment process it is disinfected using chlorine,” he said.
“Modern water treatment plants such as Dunore Point are more than capable of treating water in Lough Neagh and to the very high standards our customers expect.
“In 2008 we had the highest quality of drinking water in Northern Ireland ever and I have no concerns that Dunore Point is inappropriate for treating Lough Neagh's water.”