Water line locating in Montreal before replacing a lead service line

Why lead service lines are a Montreal issue

Lead is a very concrete issue in Montreal. According to the 2024 progress report on the City's action plan, about 91,600 lead service lines still need to be replaced, and the deadline for the work has been pushed back to 2040 (1). The buildings most likely to be affected are those with eight units or fewer built before 1970 (2), which covers a large share of the duplexes, triplexes and houses in central neighbourhoods.

The private portion is also targeted. Since 2021, when the City replaces the public portion of a lead service line, it also replaces the private portion if it is lead, at the owner's expense, and the owner can spread the bill over 15 years (3). Many owners therefore prefer to plan the work themselves, and that is where an accurate survey avoids unpleasant surprises.

What we locate on a plex or a house

• The path of the private water service line, from the foundation wall to the exterior shut-off valve
• The estimated depth of the line, useful for planning excavation or pipe pulling
• The other utilities crossing the planned trench (electrical, gas, telecom, drain)
• Multiple service lines side by side, common in buildings where each unit has its own line

What complicates locating in older neighbourhoods

In older areas, yards are narrow, often paved or concreted, and several connections have been modified over successive renovations. Lead is metallic, so it can be traced by electromagnetic locating when an access point is available in the basement. Ground-penetrating radar completes the reading for sections replaced with plastic and for buried obstacles, such as old foundations or mixed fill.

Frequently asked questions

How do I know if my water service line is lead in Montreal? The City publishes an interactive map of water service line screening. For buildings not yet screened, it relies on the year of construction and the number of units (2). A visual check in the basement, near the main shut-off valve, remains the first step.

Why locate the line if the City is doing the work? If you get ahead of the City with your own contractor, the survey shows them where to dig and what to avoid. It reduces the excavated area in the yard and the risk of hitting another utility.