Taps are flowing again but the source of high bacteria levels remains a mystery.
The boil water advisory, which started Sept. 2, for most of Vernon and parts of Coldstream has been lifted, but officials are still trying to determine what created the problem at the north Kalamalka Lake intake.
“We’re still not sure what the cause is,” said Al Cotsworth, utilities manager.
It was first believed poor water quality was a result of bacteria attaching itself to calcium carbonate, which creates the blue-green colour of Kalamalka Lake.
However, another possibility is that because there’s no filter on the system, algae and minerals settled in the pipe.
“That can provide a place for bacteria to grow,” said Cotsworth.
“That appears to be what was happening but we’re not 100 per cent sure about that.”
Regional District of North Okanagan staff and consultants are currently reviewing the situation to get a better sense of the potential bacteria source.
Despite the recent boil water alert, RDNO continues to pursue approval from government agencies to defer installation of filtration on the Kal Lake source.
Cotsworth says the main reason for wanting to defer the project is cost — about $8 million for construction and then annual operating expenses.
“Eventually there will be filtration but our main focus is separating irrigation users off Duteau Creek,” he said, adding that the utility and customers can only handle so many financial pressures at once.
An option for reducing the chances of bacteria is to flush the lines of minerals and algae.
Cotsworth is hopeful that another boil water advisory won’t have to be initiated for Kalamalka Lake this year.
“It’s unlikely to return because we generally know what we’re dealing with so we can adjust our activities,” he said.
While the boil water notice is rescinded, some Kalamalka Lake customers should still be cautious.
Residents with immune-compromised systems should boil their water for one minute for drinking, washing produce, making beverages or ice or brushing teeth.
