Provincial septic information for Ontario
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Permits and regulations

OntarioSeptic systems

Ontario regulates most residential septic systems under Part 8 of the current Ontario Building Code. A building permit and inspections are normally handled by the local septic approval authority.

Reviewed June 17, 2026
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Key facts

Before work begins

Main ruleBuilding Code Act and Part 8 of the 2024 Ontario Building Code, O. Reg. 163/24
Approval authorityLocal municipality, health unit or conservation authority, depending on location
General scopeMost onsite sewage systems with a design flow of 10,000 litres per day or less.
  • Confirm which local authority issues the septic building permit.
  • Use qualified and registered designers and installers where the Building Code requires them.
  • Arrange all required inspections before covering or using the system.

General approval path

General approval path

Contact the local municipality, health unit or conservation authority to identify the approval office.
Have the site assessed and the system designed under Part 8.
Submit a building permit application before installation, repair, upgrade or replacement.
Book required inspections and retain the approved plans and inspection records.
Important requirementThe 2024 Ontario Building Code took effect January 1, 2025. Systems above 10,000 litres per day generally move outside Part 8 and may require provincial environmental approval.

This page provides general information. Confirm property-specific requirements with the local and provincial authority before work begins.

Official government sources

Official government sources

Ontario’s Building Codewww.ontario.ca/page/2024-ontario-building-code
Ontario SepticSmart guidewww.ontario.ca/files/2022-10/omafra-septic-smart-understanding-home-wastewater-system-en-2022-10-14.pdf
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