Pedestrians pass a sign advising of a boil water advisory in White Rock, B.C., on Monday August 23, 2010. Residents of have been told to boil their water after E. Colin bacteria was detected in the city's water supply.DARRYL DYCK
The boil-water advisory in White Rock will continue through the weekend, even as the search continues for the source of E. coli contamination that has left the city of 20,000 without drinkable tap water.
The city has been under a boil-water advisory since Friday after samples of E. coli bacteria found in one of its reservoirs. Epcor, owners and operators of the reservoir, spent this week draining the reservoirs in hopes of discovering what caused the outbreak.
"We have not found anything to indicate the source of the contamination," Epcor's David Rector said Thursday at a press conference in White Rock.
Two of the city's six wells returned positive tests for the E. coli bacteria, which is found in the guts of warm blooded animals. Mr. Rector said if any mammal entered the reservoir it left through an eight-inch pipe while the reservoir was being drained.
He said Epcor had been hoping to find an obvious culprit, such as a mouse or a bird, but has come up empty-handed. "Something did get in there," Mr. Rector said.
White Rock's water is not chlorinated or filtered, and officials said this is the first time the city has experienced E. coli contamination.
The wells, according to Mr. Rector, were completely sealed. He was adamant that this outbreak could have been avoided if chlorination was used.
The city's mayor continues to say that switching to chlorine is a distant solution, but that it would be considered.
The disinfected reservoirs are in the process of being refilled and Fraser Health Authority said they would require three E. coli-free samples taken daily before the boil-water advisory can be lifted.
Dr. Elizabeth Brodken of the Fraser Health Authority said they are watching Peace Arch Hospital closely to see if any patients show symptoms, but so far there have been no cases.
Health Canada has set guidelines for the use of chlorine in water and has issued several publications on the benefits of chlorination. According to one of its reports, "The cancer risk at this level over a lifetime is considered extremely low."
The province's Drinking Water Officer, Barry Boettger, says chlorination is the most practical solution to serve most communities. Although the province has previously considered making chlorination mandatory, Mr. Boettger said, "the [current]requirement is to disinfect surface water, but not necessarily chlorination."
According to Mr. Boettger, a majority of British Columbians are drinking chlorinated water. Although he would not comment on White Rock's decision to abstain, Mr. Boettger said it is often finances that turn some cities against chlorine.
"Switching to chlorine can require purchasing of property, some engineering of environments and capital expenses. It can get very expensive," Mr. Boettger said.