Lead water service line: how to tell, and what to do
According to the Government of Québec, lead in tap water comes mainly from lead dissolving out of pipes — especially the service lines connecting some homes to the municipal network.
Updated
Where the lead comes from, and which homes are affected
According to the Government of Québec, lead in drinking water comes mainly from lead dissolving out of pipes, especially the service lines connecting some homes to the municipal network. Solder in indoor plumbing can also be a source.
These lead lines were installed in single-family homes and buildings of fewer than eight units, mostly between 1940 and 1955, and even into the 1970s. Since 1980 the National Plumbing Code has prohibited the practice.
On the South Shore, 63% of dwellings in Saint-Lambert, 57% in Saint-Bruno-de-Montarville and 56% in Longueuil predate 1980. A house from that period does not necessarily have a lead line — but that is the housing stock where the question arises.
Recognising a lead pipe
The Government of Québec describes the sign to look for: a soft, grey metal pipe that dents easily and can be nicked with a knife is probably lead.
Your municipality can also tell you whether lead service lines are present on its network.
While you wait for the replacement
In Québec, the maximum lead concentration in drinking water has been 5 µg/L since a regulatory amendment in March 2021. Children under 6 and pregnant women are the most sensitive; the effects of prolonged exposure are mainly neurobehavioural, such as a reduced ability to learn. The government recommends these steps:
- Run the tap for a few minutes after the water turns cold before drinking it, especially if it has sat in the pipes for several hours.
- Use only cold water for cooking, drinks and infant formula.
- Clean the tap aerator regularly.
- Use a pitcher or filter certified to NSF/ANSI No. 53 for lead reduction, and replace cartridges as the manufacturer directs.
- Do not boil water to remove lead: it does not work.
Replacing both sections at once
A service line has two sections: one belongs to the municipality, the other to the owner. Both may be lead, or only one.
When both sections are lead, the Government of Québec recommends replacing them at the same time, so the problem is resolved for good. Check with your municipality before planning the replacement of your section.