THE loss of water supplies to Greenock’s treatment works at the weekend was one of the biggest challenges faced by Scottish water authorities in decades.
Around 20,000 properties in the area were under the threat of losing their supply on Saturday after ice shut down the intake infrastructure at Loch Thom.
Water operations general manager Kes Juskowiak told Inverclyde Now that the alarm was raised at 6am. He said: “The message came that supply had been lost into the water treatment works [at Overton]. They didn’t know why. A team was sent out to investigate.”
Workers checked the tunnel from Overton to Loch Thom, using access chambers, and discovered the problem was at the ‘tower’ — the structure where the water is taken from the reservoir.
Divers were requested and a specialist six-strong team from a contractor in Edinburgh was dispatched, with their arrival expected around lunch time.
Kes said: “We have seen freezing reservoirs and intakes elsewhere that have required divers this year but mainly in the north and Western Isles where much smaller populations are affected.
“This is the first time we have seen a reservoir as large as this, serving such a large population, freezing.”
It was becoming clear that a large part of Inverclyde could be without water in just a few hours so various Scottish Water emergency response teams with different tasks got to work.
Twenty-nine road tankers from different parts of country brought water into the area and many of them were used to try and maintain supply at Overton.
A customer distribution team was set up to provide bottled water from drive-thru sites at Battery Park and the Waterfront leisure centre in Greenock.
Seventeen vans took water directly to vulnerable customers who couldn’t travel and to care homes. Two tankers were deployed to make sure there was water for Inverclyde Royal Hospital.
A communications team was also operating.
At Loch Thom, the divers worked to unblock an iced-up screen to allow water to get into the tower and also had to clear an inlet pipe. Several cubic metres of ice had to be removed.
David Seales, Scottish Water’s water operations team manager in the west, said: “I’ve been working with Scottish Water for around 25 years now and in all those years I have never seen anything like this happen at an asset of this size.
“Under normal conditions, up to 525 litres of water flows through that intake pipe each second, so it was a phenomenal volume of water to have frozen. It was one of the most challenging situations I’ve ever come up against.”
One of the divers dived in a 40-foot-deep chamber with around 20 feet of water in it to open a valve in the valve chamber and allow water to flow through an alternative intake pipe.
Scottish Water’s alliance partner WGM Engineering deployed booms onto the surface of the reservoir to help minimise the risk of ice forming and making its way to the pipes.
By evening, when some customers were already out of water, the divers had succeeded and the tanks at Overton started filling again.
Once operational, staff closely monitored at the treatment works throughout the night to ensure water quality was not compromised in any way. Divers also remained on stand-by to ensure any issues could be dealt with quickly.
Kes said: “I am very grateful to everyone involved. To man the bottle distribution we sent out a mass text to Scottish Water staff saying we needed help and more than 100 people volunteered. They gave out thousands of water packs.”
He said Scottish Water would now look at any measures to avoid the problem happening again.