For the first time ever, authorities responsible for tap water in the Greater Vancouver region advise those susceptible to infections to boil their water or buy bottled water, Robert Matas reported today in The Globe and Mail.
The warning is linked to unusually warm weather. Vancouver water was uncharacteristically cloudy yesterday, because of a rapid snowmelt over the past few days.
The risk of becoming sick from drinking the water is extremely small, according to Bob Jones, a quality-control manager. "We're doing it mostly as a precautionary thing," he explained to Matas yesterday.
With a glass of tap water in front of him, George Puil, chairman of the Greater Vancouver Regional District, said he was not unduly concerned. "There's always concern that turbidity [cloudiness] may be hiding some problem," but no one has documented a case of someone becoming sick by drinking Vancouver's water, Puil told Matas, adding that he himself drinks a lot of tap water every day.
Unseasonably warm weather, playing havoc with traditional winter in several provinces, is causing avalanches, mudslides and flooding in British Columbia. Some ski hills on Vancouver's North Shore were temporarily closed this week.
In December, mountains overlooking Vancouver were blanketed with a deeper-than-average snowpack. The warm weather turned snowfall into rain and the snowpack into water. Sudden torrents rushing down the mountains picked up huge amounts of sediment, Jones said.
The region disinfects the water but does not filter it. Yesterday morning, Vancouver's water was more than five times cloudier than usual, Jones said.
Yesterday, Dr. John Blatherwick, the Greater Vancouver Regional District's medical health officer, advised residents particularly susceptible to infection to obtain water from an alternative source or boil it until the cloudiness passes.
He specifically mentioned people with HIV and those whose immune systems are suppressed by cancer treatments or drug therapies associated with organ transplants. The provincial health officer previously advised people with suppressed immune systems to boil their water at all times.
For years, Dr. Blatherwick defended Greater Vancouver's tap water, saying that even when it was cloudy it did not carry bacteria or parasites that could pose a significant health risk.
He abandoned his long-held position after a Health Canada study released 14 months ago found a "statistically significant" relationship between cloudy drinking water and gastroenteritis in people between two and 65 years old. The protocol for issuing warnings was revised to allow the release of more turbidity information.
Dr. Blatherwick said yesterday that the water has been as cloudy at other times without authorities issuing a warning. What has changed is that health officers believe people should have as much information as possible to make their own decisions about issues that may affect their health, he said.