Trapped pockets of air in the water network meant Leighton Buzzard and its surrounding areas were left without water for three days, company bosses revealed.
Around 30 members of the public turned up to a meeting at Leighton Buzzard Library Theatre yesterday (Tuesday) where senior representatives from Anglian Water sought to reassure them that last month's water outage would not be repeated.
Company CEO Peter Simpson said he had personally turned up to Leighton Buzzard during the weekend of December 14 and 15 to help with the recovery effort.
A presentation revealed that the initial problem of a stuck valve had been quickly fixed, but air locks had subsequently formed in pipes around the network.
It stated: "Those who remained off water were affected by multiple air locks that proved very challenging to locate and remove.
"They took time to locate and the engineering to remove them was complex.
"Our existing air valves at high points in the network were not able to remove these."
Since then, Anglian Water stated it has completed a "comprehensive and thorough review" of the local network.
New 600mm air valves will be installed at strategic points in the network and around £250,000 will be spent on upgrades.
A woman in the audience said: "I think one of the scariest things about the incident was that while you got the valve fixed quite quickly, that one valve took out the entire area.
"There's a lot of new developments going up in the town, what if this happens again?"
Mr Simpson repeated that the stuck valve was fixed quickly but was challenged by audience members, who argued the valve had caused the air locks.
He then said: "The solutions we've put in place mean that if air does get back into the system, the air valves in different locations will deal with that."
Director of customer and wholesale services Ian Rule said: "Our name is Anglian Water. To provide water is our primary duty and it's our heartfelt apology that over this weekend, we didn't do that.
"We had over 500 people involved directly in the recovery process, including many people from outside our business."
There was wide criticism of the company's own priority service register - which listed 200 customers deemed most at risk - with one person dubbing it "a complete waste of time".
Calls were made for this to be replaced with a new register using up-to-date information from the local authority.
One woman said: "I requested it as I had a three-and-a-half-month-old baby. I rang at about seven or eight in the morning and we didn't get the water until about seven at night."
As a result of the water outage, Anglian Water revealed around 100 customers have since been added to the priority service register. £10,000 was also donated to Leighton Linslade Town Council for a community investment fund.
Mr Rule also told the assembly that Anglian Water's current policy on compensation had been devised with the Consumer Council for Water but it would be looked at again. Last year, just 36 properties across the company's entire patch had been without water for longer than 24 hours.
The impact on business was brought up by Cllr Victoria Harvey, who suggested Anglian Water could include a promotion for the town centre on water bills.
Cllr Harvey said: "This was a Saturday before Christmas at a time when retail sales had been lower than ever before, so it was devastating for local businesses.
"The town was shut up and customers simply went away. I know a lot of business and cafe owners were devastated because they had to close for the whole day and they have been really struggling for compensation."
In response, CEO Peter Simpson and water services director Paul Vallely asked for any affected businesses to speak to their team members present that day.
Members of the public reported varying experiences of Anglian Water's customer services and online media, with some criticisms of the company's communications and lack of local knowledge in the recovery effort.
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