As a historic city, Montreal is home to some of the country’s most picturesque streets and urban architecture. But all that history suggests there may be aging infrastructure behind those pretty facades. So how well does the city’s drinking water compare to other parts of Canada, in other words, how is Montreal’s drinking water quality?
Here’s a look at some of the current issues facing Montreal’s tap supply, from lead piping and water hardness to contamination of the city’s major water source.
A 2019 investigation by Global News into possible drinking water contamination in the province found that levels of lead in some Montreal tap supplies equaled levels found in Flint, Michigan in 2015.
The town of Flint experienced a significant number of serious lead poisonings when the municipality temporarily switched its water source to the Flint River. The slight change in water acidity damaged the town’s aging water infrastructure, causing lead piping to corrode and release the toxic metal into the water supply.
There is no safe level of lead in drinking water, and when consumed in high amounts over long periods of time, the metal can cause a range of health complications, from neurological conditions to infertility. In children, lead poisoning can be particularly serious due to a risk of developmental issues.
This highly alarming finding is due to the fact that Montreal has many thousands of historic lead service pipes carrying drinking water from the mains line to an estimated 300,000 people. The City of Montreal has committed to replacing all lead lines by 2030.
For homes relying on well water, lead is generally less problematic, but there are still other bacterias and contaminants that may be present. Thankfully, several types of filters, such as home water filters for well water, are able to remove most or all bacteria and/or lead from tap water.
When looking for a home filter that’s capable of removing lead, ensure that devices are certified to NSF/ANSI Standard 53 for Drinking Water Treatment Units, the universally recognized standard for reducing harmful contaminants, and specifically mention lead or heavy metals.
It turns out that Montreal may have some of the hardest water in the province, with levels of dissolved minerals reaching around 116 ppm (parts per million) according to McGill University.
While not at the levels of regions like Waterloo, where the use of groundwater aquifers makes the city’s water amongst the hardest in all of Canada, Montreal has moderately hard water for a city that sources the majority of its tap supply from rivers (see below).
Hard water is not considered dangerous and doesn’t count as a contaminant in the traditional sense. Instead, water is defined as hard when it contains high amounts of naturally occurring minerals, particularly calcium and magnesium.
The presence of these substances may subtly change the taste and texture of water and can cause a build-up of scale in appliances like dishwashers and kettles. Those that prefer softer water in their showers and glasses can install a water softener, which replaces hard minerals with salts via a natural mechanism known as ion exchange.
Approximately 90% of all the drinking water across Montreal comes from the St. Laurent River, the second-largest waterway in North America. Like many of the major rivers across the country, researchers are discovering significant levels of pollution in the St. Laurent, caused by industrial, agricultural, and domestic sources.
According to the University of British Columbia, the large size of the St. Laurent drainage basin and the fact that it crosses an international border pose challenges for the management of the river’s health. The many farms and manufacturing plants that border the river contribute to a build-up of chemical contaminants in the soil, which seep into the river’s ecosystem.
Synthetic fertilizers used in agriculture often contain high levels of phosphorus and nitrogen, which cause an overgrowth of aquatic plants like algae and plankton, disrupting the ecosystem of the St. Laurent and other nearby bodies of water such as Lake Saint-Pierre.
Known as eutrophication, this overgrowth of marine plant life results in algal blooms that release toxins into the water and rob the environment of light and oxygen, destabilizing other species. While standard filtration and treatment methods such as chlorination are still adequate to make the river’s water safely drinkable, treatment plants are often required to use higher than average amounts of disinfectant chemicals, which can result in a nasty taste and smell, and an overall drop in the aesthetic quality of tap water for Montreal residents.
The rest of the drinking water in Montreal comes from other well-known bodies of water like the Prairies River and Lake Saint-Louis, all of which are processed by 6 different treatment plants that apply chlorine or ozone disinfection.