Lead in Your Drinking Water

Drinking water is treated and tested to ensure that the level of lead in the treated water is below the Ontario standard of 0.010 milligrams per litre (10 micrograms per litre).  Exposure to small amounts of lead can be harmful, read about the health effects of lead below.

You may have lead in your tap water if your home:

• was built before 1955
• has a lead water service pipe connecting the home to the municipal water supply
• has older household plumbing
• has plumbing fixtures with a higher lead content
• has lead-based plumbing solder

The longer water remains in contact with lead water service pipes, high lead content fixtures and lead-based plumbing solder, the greater the amount of lead that may release into tap water. Learn how to identify if you have lead pipes, and the available loan program to help you replace them.

The City of Hamilton has moved ahead with a Corrosion Control Program which will help protect residents from lead exposure from lead pipes, lead based fixtures and lead solder. The Corrosion Control Program began in November 2018.

How much lead is allowable in drinking water?

The Maximum Allowable Concentration, or MAC, for lead in regulated drinking water systems in Ontario is 0.010 milligrams per litre (10 micrograms per litre). This level is based on average concentrations of lead in water consumed over a long time and long-term effects of lead. Short-term consumption of concentrations above the MAC does not necessarily cause risk to health. Higher susceptibility groups for increased effects from consumption of lead include children six years of age and under, pregnant women and women planning a pregnancy.

When the MAC was set by the province, drinking water was considered to represent 10% of all exposures to lead. The remaining 90% of lead exposure came from air, food, dust and dirt. 

Testing drinking water for lead

If you choose to test your tap water, private labs can test for lead. View a list of labs licensed for testing lead in drinking water or call the Ministry of the Environment at 1-800-565-4923. Call the lab to confirm the price for testing and to get instructions for collecting a water sample.

If you live in an apartment building or private townhouse complex and want lead water testing, you need to contact your superintendent or property management company.

Understanding test results
If you have tested your tap water and need help understanding your test results:

• Call Public Health Services Safe Water Info Line at 905-546-2189
• Check how to interpret drinking water test results

Unsolicited water testing
Water sample bottles delivered to your door requesting that you fill the bottle with tap water to be picked up for testing are not from the City of Hamilton and are not tested by the City of Hamilton lab or the Public Health Ontario lab. We cannot comment on the validity of the test results. 

Lead is a known toxic metal. Exposure to even small amounts of lead can be harmful to human health, especially for babies, young children and pregnant women. Children absorb lead more easily than adults. Pregnant women and women planning a pregnancy can pass lead in their blood to their fetus during pregnancy.