In its third such report released Tuesday, the environmental group Ecojustice warns that while some jurisdictions have stepped up water protection efforts in the past five years, most have not done enough.
In 2000, seven people died and 2,500 fell ill in Walkerton, Ont., when the town's poorly monitored drinking water was contaminated with E. coli from farm runoff.
The tragedy prompted most provinces to review and revamp their drinking water laws with mixed results — but that burst of enthusiasm has faded in recent years, according to the report.
"In many places, the health of Canadians is still at risk," the report concludes.
"The lack of recent progress also seems to indicate that the impetus for improved water protection, spurred by events like Walkerton, is on the wane."
The report called "Waterproof 3" finds only Ontario among the provinces worthy of an A grade for its water protection efforts, while Alberta lags with a C-minus.
The federal government gets an F for a record that continues to worsen, the report states.
In particular, the report criticizes Ottawa for a lack of progress on the legislative front, poor water quality for First Nations, and budget cuts it says will hurt Environment Canada's ability to monitor the situation.
"The federal government is failing in almost every aspect of water protection, even though it should be setting rigorous standards," the report says.
In response, Aboriginal Affairs Minister John Duncan told the House of Commons the Conservative government was working with First Nations on water issues.
"We will be reintroducing First Nations water legislation soon to create endorsable standards and guide investments," Duncan said.
For the first time, the report has expanded to include source-water protection efforts — the idea that the best way to provide safe tap water is to ensure the water does not get contaminated in the first place.
The findings are not encouraging.
"Full-fledged source-water protection — a critical first step in achieving safe drinking water systems — has been implemented to some degree in only seven of 13 provinces and territories," the report states.
"(It) is notably lacking in industry-heavy areas where the risk of contamination is high."
According to the report, Prince Edward Island leads when it comes to protecting water sources. Almost everyone getting tap water from systems covered by legally binding source-water protection plans. On the downside, the province does not mandate water treatment.
Alberta has no legislation in place to protect water sources, and its standards for testing and treatment have not changed in five years, the report finds.
The report praises Ontario for implementing "the most ambitious source-water protection program" in the country and having the tough standards for treatment, testing, operator training and public reporting.
Among the territories, Nunavut does not legally protect water sources and its treatment standards are "among the lowest" in Canada. The Northwest Territories gets a nod for an "ambitious" review of its laws.
Canadians living in rural and remote areas are most vulnerable to the "alarming deficiency" when it comes to warnings about contaminated water, the report finds.
B.C. Environment Minister Terry Lake said his province faces geographical challenges providing water to many of its remote and outlying communities. But he said the report indicates British Columbia is making progress.
"In urban areas like Metro Vancouver, the Capital Regional District and cities like Kamloops, Kelowna and Prince George, it's a lot easier to provide water at a very high level of quality than it is in the vast, remote regions of British Columbia. That's where it's a challenge," Lake said.
Overall, the report concludes, the biggest threats have shifted over the past decade from deficiencies in front-line water protection to unprotected source water, climate change and government cuts.
For example, it cites Ontario research that pharmaceuticals are increasingly finding their way into drinking water but testing for them is generally not mandatory and treatment does not always remove them.
Ecojustice — formerly the Sierra Legal Defence Fund — is a national group of lawyers and scientists who work on environmental issues.