A sign warns people not to drink the water from a fountain at the hospital in Walkerton, Ont., May 24, 2000. (Kevin Frayer/Canadian Press)It began on May 12, 2000, with five days of torrential rain. By the time the rain stopped, around 2,300 people — nearly half the residents of the town of Walkerton, Ont. — were suffering from the effects of drinking water contaminated with high levels of E. coli.

Seven people died. Dozens of others continue to deal with the lingering effects of drinking bad water — conditions ranging from high blood pressure to irritable bowel syndrome.

Manure from farmers' fields had washed into the town's main well, contaminating the water supply. Those in charge of making sure the water was safe to drink failed to act on test results that showed the water was dangerous.

E. coli may have put Walkerton on the map, but the disaster's legacy may be a much keener appreciation of just how fragile our water supply can be.

The Ontario government ordered a public inquiry under Justice Dennis O'Connor of the Ontario Supreme Court. Two years later, he released a report that included 121 recommendations.

They focused on:

• Protection of water supplies at the source: for instance, making sure that wells weren't going to be contaminated by agricultural run-off again.
• Allow only accredited labs to test water.
• Set water quality standards so that "a reasonable and informed person would feel safe drinking the water."
• People responsible for ensuring the quality of water at the local level must be properly trained and certified.
• Ontario should create an office of Chief Inspector - Drinking Water Systems.

Ten years later, the province says all recommendations have been acted on.

The town's water tower is seen as a man walks down a road in Walkerton, Ont. May 27, 2000. (Kevin Frayer/Canadian Press)The tainted water affair turned Walkerton resident Bruce Davidson into a clean water activist and he co-founded Concerned Walkerton Citizens. He says the province has come a long way in a decade.

"Back in 2000, we didn't have people who were specifically trained and tasked being drinking water inspectors," Davidson said. "We had generalists. Justice O'Connor said, 'Let's make sure these people who are going out and doing these [water] inspections at least have the training of the people they are inspecting.'"

In 2004, the province established the Walkerton Clean Water Centre, a facility that has trained more than 20,000 people involved in maintaining water supplies. Ontario's Chief Drinking Water Inspector's latest report found that 99.85 per cent of submitted water quality tests meet provincial standards.

"To look at the work that we've done and feel good about it is a great thing," Davidson said. "But I think that we have to realize that the minute we sort of back away from this and say 'That work is done' — to say that the work of source protection is done is kind of like saying, 'What do you mean, I just fed my teenager yesterday.' It's about that ludicrous."

'To say that this is the last threat to our drinking water that we will see would be pretty naïve'—Bruce Davidson

Davidson warns that we may know more about making sure that some bacteria don't get into our water supplies but that doesn't mean we're protected against possible future threats.

"The big fear with H1N1 was that it would mutate into something more pathogenic. Now, thankfully, it didn't seem to go that way, but the E. coli that took life here, was a mutation and we can't pass any laws saying that micro-organisms won't mutate into more pathogenic forms, so to say that this is the last threat to our drinking water that we will see would be pretty naïve. We'll need to build systems that are robust enough to handle eventualities that we may not be able to see right now."

Health Canada estimates that unsafe drinking water kills 90 people a year across the country — and makes another 90,000 sick.

Ecojustice — formerly the Sierra Legal Defense Fund — says the federal government needs to do what jurisdictions like the United States, Australia and the European Union are doing: maintain national standards for drinking water.

In its 2006 report Waterproof 2: Canada's Drinking Water Report Card — the environmental group gave Ontario an A- for drinking water safety. That was the highest of any jurisdiction in Canada. The federal government scored an F, mainly because of its "lack of leadership in providing clean and safe drinking water to all Canadians."

'Some places in Canada have effectively the same regulations that they had pre-Walkerton'—Randy Christensen

Only Nova Scotia, Quebec, Ontario, Manitoba, Alberta and the Yukon require advanced treatment of water supplies. Standards vary across the country. Health Canada has issued drinking water guidelines — but they're not mandatory and are not enforceable.

"We're calling for federal leadership on this issue," Randy Christensen, a staff lawyer with Ecojustice and the author of the 2006 report said. "You have jurisdictions like Ontario which took some positive steps to help alleviate that. If you go to other parts of Canada, not all provinces have followed suit. Some places in Canada have effectively the same regulations that they had pre-Walkerton."

Christensen says even in provinces where action has been taken, there's a growing urban-rural disparity in water quality.

"If you're in a smaller town, you almost certainly … have less protection because your regulatory system isn't as strong. If you have a private well, you're pretty much on your own. You can get a little bit of guidance from [your provincial] ministry."

In Walkerton, Davidson agrees that national standards are the logical next step. Every Canadian, he says, should be confident that the water they drink won't make them sick.

"We have to remember that Walkerton is the cautionary tale that we have to listen to, if we're going to prevent recurrences and if we're going to prosper into the future."