Montreal water lead contamination caused by pipe corrosion

New results from a yearlong investigation allege that some residents in Montreal and other parts of Canada have been exposed to drinking water contaminated with lead in levels that exceed federal guidelines, according to The Associated Press.

The investigation – conducted over a year in 11 Canadian cities by 120 journalists from AP, Global News and the Institute for Investigative Journalism at Concordia University, among others – found that the levels of lead exceed those found in water supplies in Flint, Michigan, a comparison drawn by a city official who confirmed the reporters' findings, according to Global News.

Investigation findings and city response
According to Canada's National Observer, the alleged contamination is believed to have been caused as a result of untreated pipe corrosion occurring over time due to aging lines combined with acidic water while the city has been in the gradual process of replacing lead piping over recent years.

While Mayor Valerie Plante of Montreal has responded that the city's drinking water is safe and that management has been "proactive," she did admit that water that flowed through lead service lines tested at high levels. Since the investigation's findings were sent to Plante, the mayor has called for the expedited replacement of lead-lined piping and the testing of roughly 100,000 homes for the heavy metal.

According to investigation results, one-third of the 12,000 water samples garnered from the 11 cities beginning in 2014 tested higher than Canada's national safety guideline of 5 parts per billion, while 18% of tests exceeded the U.S. limit of 15 ppb, AP reported. Half of the testing carried out in the joint investigation sampled water from lead lines, with the other half focused on non-lead piping. One government official estimated that around half a million lead-lined pipes service numerous water supplies throughout Canada.

Outside of Montreal and the province of Quebec, communities including the port city of Prince Rupert, British Columbia and the town of Oakville, Ontario have also been experiencing lead contamination. Some residents whose properties' water tested with high levels of lead said they were surprised by the results.

olympicstadiumMontreal drinking water lead contamination caused by pipe corrosion

Past corrosion control advice rejected by city
Virginia Tech environmental engineering professor Marc Edwards told Global News that he had been asked in 2006 by Montreal's then-mayor to propose a solution to take action against corrosion and potential lead contamination at the time. Edwards said that his recommendation to treat the city's water with a "non-toxic" substance that prevented corrosion was rejected – something that he alleges "would not have happened in the U.S." under federal law. Edwards estimates that corrosion control measures result in cost savings of "about $10 for every dollar you spend on it."

Unlike the states of the U.S., Canada's provinces set their own water safety and corrosion control rules along similar lines as the federally established guidelines, with the exception of Ontario. For example, British Columbia does not require its municipalities to test their tap water for lead. The 2015 Flint water crisis, by comparison, was found to have been caused by the fact that city officials did not implement corrosion control measures after a water source change had been mandated by federal regulations.

"We did recommend that enhanced corrosion control could probably reduce those lead levels by at least 50-60% beyond what they're currently achieving," Edwards said.

Just over 250 kilometers miles north in the province's capital, Quebec City adds chemicals to its water supplies that create a protective film that lines the inside of piping, much like the Ontario cities of Toronto that requires its water be treated by federal law. Within the same province in the nation's capital, Ottawa, officials employ the use of a "caustic soda" that reduces the city water's acidity level.

While other Canadian metropolitan municipalities have implemented pipe corrosion control measures in their water treatment in past years, Montreal's relative lack of treatment has led experts to suggest that the best way to solve the problem is to replace all of its lead lines. Currently, experts believe that a full-scale replacement would take years due to not only the large amount of lead-lined piping, but also due to the high and relatively unaffordable cost, especially for more rural municipalities with low tax bases.

"Many of these voluntary guidelines need to be changed to be standards, to be requirements," Bruce Lanphear, professor at Simon Fraser University and an expert on lead toxicity, told the National Observer. "Corrosion controls should have been implemented 20 to 30 years ago."