That Older Home’s Water Service Line Might Be Lead: How to Check, Test, and How Toronto Helps You Replace It
In homes built before 1975, the service line connecting the street main to your house may contain lead. Canada tightened the drinking-water lead limit by half in 2019 — worth a few minutes to check before you buy
How do I know if an older home has a lead service line, and how serious is lead exposure?
Homes built before 1975 carry higher risk — identify and test the water proactively. According to Health Canada, lead pipe was an acceptable material under the pre-1975 National Plumbing Code of Canada, so it’s more common in older homes and neighbourhoods. On health, Health Canada tightened the maximum acceptable concentration (MAC) for lead in drinking water from 0.01 to 0.005 mg/L in March 2019 (sampled at the tap). There’s no safe level of lead — it’s especially harmful to infants and pregnant people — so it deserves real attention.
Sources: Health Canada / canada.ca (Guidelines for Canadian Drinking Water Quality — Lead; MAC 0.005 mg/L as of March 2019); City of Toronto lead service line replacement program. Reviewed June/July 2026.
Buyers scrutinize the kitchen cabinets, the floors and the roof, but rarely glance at the pipe entering the house on the basement wall — and in pre-1975 homes, that service line may be made of lead. Lead in drinking water is especially unfriendly to infants and pregnant people, and Canada tightened its standard by half in 2019. The good news: lead pipe can be identified, water can be tested, and cities like Toronto run programs to help owners replace it. Here’s how to identify it, how to test, how Toronto replaces it, and how to handle it before you buy.
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Where lead pipe comes from: acceptable before 1975
ℹ️Non-magnetic + scratches silvery = suspected lead. Galvanized steel is magnetic; copper scratches reddish. Use a magnet and a coin for a first pass, but have an inspector or licensed plumber confirm — don’t conclude on your own.
How to identify the service line: scratch, scrape, magnet
⚠️There’s no safe dose of lead — infants and pregnant people are most sensitive. Health Canada tightened the MAC to 0.005 mg/L in 2019. If you have children or a pregnancy and are buying an older home, test the water for lead; clear-looking water tells you nothing.
The most reliable step: test the water for lead
Toronto’s replacement program: the private side too
How to handle it before a sale
Frequently Asked Questions
How old does a home have to be to worry about lead pipe?
According to Health Canada, lead was acceptable under the pre-1975 National Plumbing Code, so pre-1975 homes and older neighbourhoods are the most likely to have a lead service line or lead solder/fittings — those warrant the closest look.
How can I do a first-pass check on the service line?
Look at the section before the water meter in the basement: lead is dull grey and soft, scratches to a shiny silver, and is non-magnetic. Galvanized steel is magnetic; copper scratches reddish. If unsure, have an inspector or plumber confirm.
My water tested high for lead — what do I do short-term?
Use a certified lead-removal filter (NSF/ANSI 53) and run the tap before use as a bridge. That’s mitigation; the real fix is replacing the lead pipe. Cities like Toronto run lead service line replacement programs you can check.
What’s Canada’s drinking-water lead standard?
According to Health Canada, the maximum acceptable concentration (MAC) for lead in drinking water is 0.005 mg/L (sampled at the tap) as of March 2019, down from 0.01 mg/L previously.
Arthur Zhao
Real Estate Broker · FRI · ABR · SRS · PSA · MCNE · E-PRO · CLHMS & GUILD Elite · REAIS
VP & Branch Manager, Bay Street Group Inc.
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