The Capital Regional District has issued a boil-water advisory for 71 residential lots near the top of Mount Matheson in East Sooke.
Residents of the Wilderness Mountain Water Service Area are being told to boil their drinking water until further notice.
The service area draws its water from the Wilfred Reservoir and high turbidity in the lake has resulted in elevated cloudiness in treated drinking water, said Matthew McCrank, a senior manager with CRD Integrated Water Services.
“We’ve seen it the last few years, kind of a seasonal effect around this time of year, that the turbidity in that source increases,” he said. “We extract [water] from that lake, filter it and disinfect it and put it out to the community and the treated water remains high even after we’ve done those steps.”
He said that as temperatures warm the biology in the lake increases, which can result in more turbidity.
Island Health describes turbidity as an indirect measure of particulates in the water and says high turbidity can interfere with the disinfection process.
The most recent boil-water advisory for the area was issue in July 2016. The CRD has modified its treatment processes since then and has not had to issue another advisory until now, McCrank said. “This year, the treated-water turbidity has risen to a point that it doesn’t meet the guidelines for Canadian drinking water quality right now.”
McCrank said it’s possible the issues are tied to the warm, dry weather in recent weeks. “We don’t know for sure, but around June and July we do start to see increased activity in the lake and we’ve seen that the last few years.”
The advisory was issued in consultation with Island Health and will be lifted once health officials are satisfied the drinking water poses no health concerns and issue an “all clear” notice.
While the advisory remains in effect, residents can disinfect household tap water by boiling it vigorously for one minute, the district said.
Island Health says boil-water notices are intended to protect people’s health from waterborne infectious agents. “Boiling water for one minute rapidly destroys pathogenic microbes such as, salmonella, cryptosporidium, hepatitis A and norovirus,” the health authority says on its website.
