ontario's water well regulations

​​Ontarians deserve access to clean, safe water. This means keeping water free of pollutants and contaminants that could harm the environment and human health.

​Guidelines for well owners; important facts for the real estate community

Over three million Ontarians rely on groundwater for their drinking water. There are hundreds of thousands of water wells across Ontario, providing drinking water to municipalities, industries and private residences.

The Government of Ontario has moved forward over the past ten years on a series of initiatives to preserve water quality, including new legislation, regulations, standards and requirements. Ontario now has the toughest standards and protocols for drinking water in North America.

Wells providing water to small businesses, common spaces and residential communities may qualify as "regulated systems." Private wells are not regulated systems, but there are new rules in place for constructing or decommissioning (abandoning) a well.

Private owners are required by regulation to ensure that nothing gets into water wells that could contaminate the water source.

• Green Facts: Important facts about water well construction (General Interest Publication)
• See Ontario's Wells Regulation (Reg. 903) for more information (Detailed Regulations)

Guidelines for Well Owners

Groundwater is a shared resource that crosses property lines and contamination from one well can put other wells at risk. Owners are responsible for getting well water tested regularly – at least three times per year is recommended, to be confident drinking water is free from bacteria and other contaminants.


What to do:

• Make sure your well is properly constructed and maintained.
• Inspect your well at least once a year to see what repairs may be needed.
• Have a sample of your well water tested at least three times a year.
• Water testing is offered by the Ministry of Health and Long-Term Care.
• Sample bottles are available from public health labs and local health units.
• Get a list of labs that can test your water for chemical contaminants.
• Disinfect all wells prior to use with a concentration of 50 milligrams of chlorine per litre of water standing for at least 12 hours.
• Refer to the disinfection instructions which are part of the current well regulation.
• Get a copy of the Water Well Record that was filed after the well on your property was built, or get a Licensed Well Technician to test and evaluate your well.
• Properly plug and seal unused wells to prevent rapid movement of contaminants down into groundwater.
• Dispose of hazardous materials properly, pump out your septic tank every two years, and plan on replacing your septic system leaching bed every 20-25 years.
• If you need to treat your water, select a treatment system with great care to ensure it will be effective in your particular situation.

What not to do

• Never use untreated surface water for drinking water – untreated surface water is considered unsafe for human consumption!
• Don’t pour water into a well with a low water level – this will undermine the foundation of the well.
• Don’t use a highly vulnerable water supply unless all other attempts to develop an alternative supply have been unsuccessful.

Government Websites

• Ontario Ministry of Environment: www.ene.gov.on.ca
• Ontario Ministry of Health: www.health.gov.on.ca
• Ontario Ministry of Agriculture: www.omafra.gov.on.ca
• Health Canada: www.hc-sc.gc.ca

​It’s a good idea to learn the important facts about water well construction, and the protection of water quality in dug, bored and drilled wells.

Clean water is everybody's business!