Lead in Montréal's tap water

Where the lead comes from

The water produced by Montréal's plants contains no lead. It dissolves on the way, in the service line, the pipe linking the street main to the building, laid in lead in many neighbourhoods before 1970. The City screens those lines one by one with a Palintest at the tap, after five minutes of flow then after fifteen minutes of stagnation, and replaces the public portion; the owner must replace the private one.

MTL Stats aggregates the individual results by month: the number of screenings and the share concluding to a lead line, among conclusive tests. Inconclusive tests, when the water is too cold, are left out. Screening mostly happens from May to October.

Reading the lead share

A high share does not mean the whole city's water is contaminated: screenings target first the sectors and buildings most likely to have lead. The multi-year trend follows the progress of the replacement programme.