It wreaked havoc across the Fylde coast for more than a month, and cost water bosses millions in compensation.
One year ago today, families and businesses throughout the county were warned to boil all drinking water after a microscopic bug posing a health risk was found in tap supplies.
But, 12 months after traces of cryptosporidium were first discovered, scientists are still unable to reveal how it got there.
An investigation was launched by the Drinking Water Inspectorate (DWI) into the contamination, but has still not reached a conclusion on what caused the major health scare.
Here’s how we reported the crisis one year ago:
While everything is absolutely fine now, we still want to know why it happened.
A DWI spokesman said: “Investigations are ongoing and we will be putting information into the public domain as soon as we are able to.
“It’s a large and complex system and there are a number of lines of inquiry which need to be pursued to their conclusions.”
Bosses at Public Health England said they were also waiting for a report from the DWI, while water firm United Utilities added: “We are still cooperating with the Drinking Water Inspectorate’s ongoing investigation. The findings will be made public once the investigation is complete. The timing is a matter for DWI.”
It was exactly one year ago - on August 6, 2015 - when more than 300,000 homes and businesses were first warned to boil all drinking water to protect against the nasty parasite.
The Fylde coast, Preston, South Ribble and Chorley were affected, and it took 30 days for all supplies to return to normal, leading to compensation payments of between £50 and £60 to all domestic consumers and much more to businesses affected by the alert.
A dead pheasant in an outflow pipe was the most popular theory as to the source.
When the investigation was launched, it centred on the United Utilities water treatment plant at Franklaw near Garstang.
Blackpool MP Paul Maynard said: “I’m sure people would rather forget the stressful 30 days of boiling water this time last year, but it’s worth observing that it’s very strange that a year on the DWI has been unable to announce any cause. I’m sure the DWI will be doing all it can and I look forward to seeing an update report as soon as possible.
“It can’t be that hard to find out what happened and at the moment all we’ve got are rumours.”
Claire Smith, president of Stay Blackpool, said: “At the time the water problem was an inconvenience to everyone, and the larger their property the larger the inconvenience. We haven’t received any more information so we don’t know what happened. We just have to trust that the problem has been solved and that it will not arise again.”
The warning not to drink tap water without boiling it first caused disruption across the county, with some families and organisations struggling to access bottled water.
The Bond Hotel on Bond Street is a popular tourist destination for holidaymakers with disabilities. Owner Karen Atkinson said: “It was incredibly hard work and very stressful at the time because we get a lot of guests with learning disabilities as well as physical disabilities, and some of them didn’t understand that they couldn’t drink the water from the taps.
“While everything is absolutely fine now, we still want to know why it happened.”
Karen Carey, owner of The Winterbourne on Clarendon Road, said: “I’m sure a lot of people would like to know what caused it, especially as they told us they were going to let us know what happened and they haven’t done so.
“It put customers off coming to Blackpool at all because people saw that they couldn’t drink the water. I had a regular guest of mine posting online saying don’t come to Blackpool, you can’t get any water.
“We supplied bottled water to our customers so they could drink and brush their teeth - but obviously we saw a reduction in the number of customers, and we were paying for the bottled water on top of that.
“It affected us badly and we were extremely quiet for a whole month.”
Businesses were not the only victims of the water contamination. Trinity Hospice staff worker Shirley Morgan said the Bispham hospice went into ‘a state of emergency’ when the problems were announced.
She said: “Whenever something like this happens you can imagine the difficulties. The first thing that we did was spring into action and bring in an emergency cover plan that involved getting as much bottled water as possible. Because we had this plan in place we were able to continue looking after our patients.
“We had to introduce a lot of extra precautions to keep patients safe.
“It caused us some headaches but for us it was after the water scare that things really happened. All the schools donated the bottled water they no longer needed to us, which meant we had enough water to cover all our events for the entire year. It just goes to show every cloud has a silver lining.”