You are hereStoring water for emergencies unsafe, expert says; Bottled, city water deterioriate over time, conference told
Storing water for emergencies unsafe, expert says; Bottled, city water deterioriate over time, conference told
Patrick Dare - The Ottawa Citizen
Storing water for months, or even years, in preparation for an emergency isn't a good idea because its quality deteriorates, says the manager of Ottawa's water system.
Dixon Weir told a seminar this week on drinking water and bottled water that he is "uneasy" with some of the advice the public is being given about preparing for emergencies. His concern is that people will assemble their emergency kits, with tap or bottled water, and store them for many months.
Because the city's tapwater is treated only with limited amounts of chlorine and chloramine, it is not suitable to be stored for long periods.
Meanwhile, the seminar, which was held at the Ottawa Public Library by the Polaris Institute, an organization dedicated to "democratic social change," was told by a university professor that tests have shown bottled water undergoes serious deterioration when it sits for long periods in plastic.
Governments have been urging Canadians in advertising campaigns to get emergency kits together, so they can handle crises, such as the ice storm of January 1998, or the power blackout in the summer of 2003.
But Mr. Weir said people should make sure the container for the water is clean, and replenish the water regularly.
He said the city hasn't done tests to determine the shelf life of its water, but the chemicals added to condition it only have an effect for a limited time.
"The longer you leave it in that bottle, the more opportunity there is for whatever may, or may not be in there, for it to become a concern and potentially contaminate," said Mr. Weir.
The city's water is disinfected so it can travel through the water system, which can take up to 12 days to get to the farthest reaches of the city, such as Manotick, Stittsville and Cumberland. But the city tries to limit the amount of chemicals it uses.
"Our drinking water isn't made with the intent of keeping it preserved forever. Chloramine is a good preservative, but it isn't intended to work ad infinitum," said Mr. Weir.
"We aren't designing that water to have a long shelf life. I would be concerned if people are assuming that they can. When you're pouring water into a bottle, it isn't forever and ever."
Turning to bottled water is not the answer, the Polaris meeting was told.
Water experts said bottled water is a triumph of marketing, but not a good deal financially or health-wise.
Professor William Shotyk, director of the Institute of Environmental Geochemistry at the University of Heidelberg, said recent tests of water quality have found significant levels of antimony, a toxic chemical element, in polyethylene terephthalate (PET) bottles.
The study, involving 132 brands, found increasing levels in bottled water that had been stored for six months at room temperature. Some results reached close to 2,000 parts per trillion, which is the Japanese limit for drinking water.
Mr. Shotyk said the findings raise questions about the purity of bottled water, but the industry is growing fast with limited public scrutiny.
By contrast, public utilities such as Ottawa's water treatment system face heavy scrutiny, including elaborate testing and a growing regimen of regulation.
The irony for Mr. Weir, who runs the water system, is that people are spending more for a single serving of bottled water than they spend for 1,000 litres they get from the city.
Eric Schiller, co-ordinator of a new citizens' group in Ottawa on water, affiliated with the Polaris Institute, said it doesn't make financial sense for people to be consuming all of their water from private sources when the city sells water at 77 cents for 1,000 litres.
But he said one-fifth of people in North America are consuming all of their water from the much more expensive bottled variety, even as questions are being raised about its quality.
In Ontario, Mr. Schiller said the soft drink industry is capitalizing on the freak mishaps of the Walkerton water tragedy -- where a whole town's supply was contaminated by E. coli -- while consumers have developed an ill-founded total confidence in bottled products.
"People will give an arm and a leg for their health. They think, ah, it's safer. It's better. If it's health-oriented, people just dish it out," said Mr. Schiller. "And it's convenience. Good old lazy us, we love this. Carry water around and not have to go and look for a tap."
Fred Michel, a groundwater expert from the Department of Earth Sciences at Carleton University, said city water faces stringent testing for quality that ensures the water is safe. And yet the public remains concerned about the public system's uses of chlorine and chloramine.
The bottled-water industry, however, doesn't do all of the detailed testing of water that would show all the trace amounts of undesirable elements. But the soft drink companies are superb marketers, said Mr. Michel.
"To them, it's just another commodity. They're good at selling. They're good at what they do."
© The Ottawa Citizen 2006