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Drinking Water Testing for Lead

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Since 2007, the Ontario government has been requiring child care centres and schools to flush the plumbing in their facilities and test drinking water for lead.

New amendments to Ontario Regulation 243/07, which took effect July 1, 2017, enhance the safety requirements related to water at our schools by increasing the number of water samples we take. Testing is done for all schools and water fixtures used to providing drinking water to students or for food preparation for children under 18 over a three-year period.


For individual school results or questions about the testing, please contact:
Rebecca Wood
Health & Safety Specialist
T: 905.527.5092, ext. 2689

Ontario Drinking Water Quality Standard

The Ontario drinking water quality standard for lead is 10 micrograms per litre. You may also see this standard written as 10 μg/L or as 0.010 milligrams per litre. This standard is based on a national guideline set by Health Canada.

Drinking Water Fixture Signs

In the coming weeks, any water fixture, such as certain sinks, that are meant to provide water for consumption or for food preparation, will be clearly labelled with a sign illustrating that the water is provided for drinking purposes. Water fountains will not have these signs as their intended purpose is for drinking.

Procedures if Results are Above Provincial Standards

If a child care centre or school gets a drinking water test result that is above the Provincial Standards for lead, the board follows the requirements set out in the regulation to protect our students. Hamilton Public Health may provide additional guidance on corrective actions necessary to ensure the safety of our students.

After corrective action (flushing, removal/replacement of the fixture) and testing shows that the fixture is within Provincial Standards, the board consults with Public Health before allowing the use of the water fixture by our students.

Ontario Regulation 243/07 Questions and Answers

Why does the Ontario government require child care centres and schools to test drinking water for lead?
Young children are more vulnerable to the effects of lead because they absorb ingested lead more easily than adults, which can interfere with the development of their nervous systems. In population studies, exposure to lead has been associated with effects on learning capacity, intellectual development and behaviour.

How will the new rules coming into effect in July 2017 better protect children in child care centres and schools?
Ontario is proactively strengthening its regulation to protect children’s health. Studies1 show that lead levels in drinking water from plumbing can vary substantially between individual taps or fountains. Only by testing each drinking water fixture can child care centres and schools be sure that they are not exposing children to lead through any of the plumbing within their facilities.

What is the drinking water quality standard for lead?
The Ontario drinking water quality standard for lead is 10 micrograms per litre. This standard is based on a national guideline set by Health Canada.

What happens if a child care centre or school finds it has lead in its drinking water above the standard for lead?
If a child care centre or school gets a drinking water test result that is above the standard for lead, the local Medical Officer of Health will assign corrective actions to the facility and it is the facility’s responsibility to ensure those actions are carried out. The Ministry of the Environment and Climate Change will follow up with the facility operator and local Medical Officer of Health if necessary. These local processes have been in place since 2007 and are working well.

How can I find out the lead test results for my child’s child care centre or school?
If you have questions about measures taken by your local child care centre or school to ensure the safety of drinking water, contact your local child care centre, school, or school board.

Why are child care centres and schools required to flush their plumbing?
Flushing has been shown to reduce lead levels in drinking water fixtures. By flushing plumbing and fixtures, water that may have come in contact with lead plumbing is replaced with fresh water. How often a facility has to flush their plumbing and fixtures depends on several factors including the age of the plumbing, previous lead test results or if a device that removes lead, such as a filter, has been installed on a fixture.

How are people exposed to lead?
Lead is a naturally occurring element. Lead has many industrial uses and has been found in water systems since the late 1800s. It is also present in soil, food and indoor dust. Over the past few decades, exposure to lead has significantly decreased due to restrictions in the use of lead in gasoline, paint and solder.

How does lead get into drinking water?
Ontario’s surface and groundwater generally does not contain lead. If lead does occur naturally, the concentrations are typically extremely low and below the drinking water standard for lead. Where there are concentrations of lead in drinking water above the standard, the likely cause is from the lead pipes servicing the premises, lead solder used in the plumbing or fixtures containing high percentages of lead.

Lead pipe service connections have been used to deliver water from distribution pipes since the late 1800s. Older buildings (generally those built before the mid-1950s) are more likely to have lead connections. By 1990, the amount of lead in solder that could be used in drinking water plumbing was substantially reduced.

The amount of lead leaching into drinking water from these components depends largely on the chemical characteristics of the water. In certain circumstances, extended contact between standing water and the components can cause the lead to be released from the pipes. When the tap is turned on, water that has been standing in the pipes may have accumulated lead levels higher than Ontario’s standard for lead.

How can I get the water in my home tested for lead?
If you suspect that you have lead service pipes or lead plumbing in your home, you may wish to have your tap water tested for lead. Some municipalities in Ontario have programs that help residents test their drinking water for lead. Contact your municipality for more information about your water service pipes and what is available in your community.

Alternatively, you can arrange your own drinking water lead test through a licensed laboratory. For more information please visit  Ontario Ministry of the Environment and Climate Change – Drinking Water Information or phone the Public Information Centre at 1-800-565-4923.

Health Information

Updated on Tuesday, June 19, 2018.
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