The tap water of Vancouver residents might be a little cloudy these days owing to debris from the recent storm in water reservoirs, but it's still safe to drink, health officials say.

Dr. Patricia Daly, the chief medical health officer for Vancouver Coastal Health, told CBC news that as of Wednesday morning, the turbidity level at the Seymour reservoir is at 33 NTUs, but no boil-water advisory has been issued yet.

Metro Vancouver's water may be murky, but health officials say it is safe to drink.
(Mike Laanela/CBC)

NTUs are nephelometric turbidity units, an industry-wide measure of water clarity.

During November 2006, about one million Metro Vancouver residents were warned to boil their water for 12 days after a massive storm caused several landslides above the North Shore reservoirs, dumping debris into the water supply.

Daly said that even when the turbidity level hit 100 NTUs last year there were no positive samples of harmful organisms in the water, and that's why no boil-water advisory has been issued this year.

"Having had that experience and many years experience with other episodes where we've seen increased rains, and some turbidity in the water, we feel comfortable not putting a boil-water advisory, even at these turbidity levels," she said.

But Daly advises that people with severely compromised immune systems should always stay away from tap water in general.

In November 2006, several landslides above the Capilano reservoir washed muddy water into the Lower Mainland's water supply.
(CBC)

The Metro Vancouver website advises: "As turbidity increases, statistical studies have indicated there is the potential for an increase in gastrointestinal illness. Those with compromised immune systems due to HIV or who are undertaking chemotherapy or anti-rejection medications should always use drinking water that has been boiled or treated to the same level as boiling.

"In anticipation of increased turbidity, residents may wish to set aside a supply of water in containers," the website also advises.

It's not clear how long it will take for the water to return to normal.

The Lower Mainland's water supply comes from three North Shore mountain reservoirs managed by Metro Vancouver. Officials say a new water treatment plant scheduled to begin operation in late 2009 will solve the problem of cloudy water from the reservoirs.