Lead

In Québec, the concentration of lead in drinking water is generally very low. Lead gets into drinking water mainly as a result of dissolution of lead from pipes, especially connection piping (service line) between some houses and the municipal distribution system.

Lead service lines were installed in single-family homes and buildings with fewer than 8 apartments, especially between 1940 and 1955 and even into the 1970s. This practice was banned by the National Plumbing Code in 1980. Solders in interior plumbing systems in buildings can also be a source of lead in water. However, in 1989, the National Plumbing Code banned the use of solders that contain more than 0.2% lead. Therefore, recent buildings are very unlikely to have a service line or interior plumbing system that contains lead.

On October 23, 2019, the Government of Québec announced its intention to amend the regulations to set the maximum allowable concentration of lead in drinking water at 5 μg/L and to establish a first-flow sampling protocol after 30 minutes stagnation for those in charge of distribution systems. This complies with Health Canada's latest recommendation regarding lead in drinking water.

The people responsible for water distribution systems, including municipalities, must ensure this standard is complied with. When the concentration of lead in water exceeds the value set, the person in charge of the water distribution system or the Regional Public Health Office issues recommendations for the people directly concerned.

Health risks

In general, exposure to lead in drinking water is low and there are few health risks. Children under 6 and pregnant women (for the unborn child) are, however, more sensitive to the effects of lead than adults. The health effects of exposure to lead over several years are mainly neurobehavioural in nature, such as a decrease in learning ability. They depend on the frequency and length of exposure as well as the lead concentration in water. To have a real effect on blood lead levels, exposure must be:

  • regular and sustained over time if the lead concentration in water is low;

    or
  • one-time if the lead concentration in water is high.

Protection and prevention

Measures to lower the concentration of lead in water and reduce exposure in general

  • To flush water that has stagnated in the service line, run the tap for a few minutes once the water is cold (cool in summer) before drinking it, especially if it has been sitting in the pipes for many hours (in the morning and when you get home from work).
  • When preparing food, infant formula and drinks, use only cold tap water. Hot water tends to contain more lead.
  • Remove and clean the aerator (small filter) in the spout of the tap regularly because lead can build up in it.
  • You can also use a water filter pitcher or install a filter on the tap or under the sink. These devices must be certified to NSF/ANSI Standard No. 53 for the reduction of lead. You can buy them at hardware stores and some department stores. Make sure the system remains effective by replacing the filters regularly and following the manufacturer’s maintenance recommendations.

Boiling water will not remove lead because lead does not evaporate. It can even increase the lead concentration in the water.

Check if there is a lead service line in your home

You can check if a portion of the service line between your home and the municipal distribution system is made of lead by examining your water service line. Grey, soft metal pipes that are easily dented or scraped with a knife are probably made of lead.

The service line has two sections; one that belongs to the municipality’s distribution system and one that belongs to the homeowner. Both sections may be made of lead, but it is possible that only the section that belongs to the municipality’s distribution system is made of lead. If so, your municipality should be able to give you information about the presence of this type of service line in its system. If both sections of the service line are made of lead, they should be replaced at the same time in order to solve the problem once and for all.

Connection between the house and the municipal water distribution system

Useful websites

Ministère de l’Environnement et de la Lutte contre les changements climatiques

Direction de santé publique de Montréal