Septic System Regulations — Ontario & Renfrew County

Ontario Building Code Act — Part 8: Sewage Systems

Septic systems in Ontario are regulated under Part 8 of the Ontario Building Code Act. Part 8 sets out the technical requirements for the design, construction, installation, and maintenance of on-site sewage systems serving residential, commercial, and institutional buildings with a design flow of less than 10,000 litres per day. The specific regulation is Ontario Regulation 358/09 (Sewage Systems), which you can read in full at the Ontario e-Laws website.

O. Reg. 358/09 defines five classes of sewage systems. The two most relevant for residential properties in Renfrew County are:

• Class 4: A sewage system that includes a leaching bed — this is a conventional septic system with a septic tank and buried tile field. Class 4 systems are the most common residential septic system in Renfrew County.
• Class 5: A holding tank — a watertight tank that stores sewage until it is pumped out and hauled away. Holding tanks are approved only where site conditions cannot support a Class 4 leaching bed (e.g., shallow bedrock, high water table, or undersized lot).

The Building Code Act also establishes who can design, install, and inspect septic systems. Only licensed installers meeting the Ontario Building Code qualification standards can legally install septic systems in the province.

Required Setback Distances

Ontario Regulation 358/09 specifies minimum setback distances that septic system components must maintain from wells, surface water, and property lines. These setbacks are designed to protect drinking water sources and the environment:

• 15 metres (50 feet): Minimum distance from a septic system (tank and leaching bed) to a drilled well or dug well — this is the most commonly cited setback in Renfrew County property transactions.
• 30 metres (100 feet): Minimum distance from a septic system to any surface water body including lakes, rivers, streams, and ponds. This is especially relevant for waterfront properties on the Ottawa River, Golden Lake, Muskrat Lake, and other Renfrew County water bodies.
• 3 metres (10 feet): Minimum distance from the leaching bed to property lines.
• 5 metres (16 feet): Minimum distance from buildings or structures.

These are the minimum setbacks. Local conditions or additional requirements imposed by the Renfrew County Building Department may require greater distances. For example, a property with a dug well (rather than a drilled well) near a lake may require a 30-metre or greater setback from the well.

Permit Requirements in Renfrew County

All new septic system installations, replacements, and significant alterations require a permit under the Ontario Building Code. In Renfrew County, the Building Department is the approval authority. The process involves:

1. Application submission: The property owner or their authorized contractor submits a permit application with site assessment results (perc test and test pit data), a system design prepared by a qualified designer, and the required fee.
2. Review: The Building Department reviews the application for compliance with O. Reg. 358/09 and any local requirements.
3. Permit issuance: Once approved, the permit is issued and installation can begin.
4. Inspections: Building Department inspectors conduct on-site inspections during installation — typically at the tank placement stage, before backfilling the leaching bed, and at final completion.
5. Approval: After passing all inspections, the system receives a certificate of compliance.

Operating without a permit is a violation of the Building Code Act. Penalties can include orders to cease work, fines, and requirement to remove or replace systems that do not meet Code requirements. Property owners should never proceed with septic work without a valid permit.

Contractor Licensing Requirements

In Ontario, septic system installers must be licensed under the Ontario Building Code Act. A licensed installer has demonstrated knowledge of Part 8 requirements, including system design principles, soil assessment techniques, and proper installation methods. When hiring a contractor in Renfrew County, property owners should:

• Confirm the installer holds a valid Ontario Building Code license for sewage system installation
• Verify the installer is registered with the Renfrew County Building Department (some areas require local registration in addition to provincial licensing)
• Ask whether the installer handles the permit process — most licensed contractors include permit application as part of their service

The Renfrew County Building Department can provide a list of qualified installers who work in the area.

Ontario Water Resources Act (OWRA)

In addition to the Building Code Act, septic systems in Ontario are governed by the Ontario Water Resources Act (R.S.O. 1990, c. O.40). The OWRA prohibits the discharge of any material into the natural environment that may impair water quality. This means a failing septic system that allows untreated sewage to reach groundwater or surface water is an environmental violation under the OWRA. The full act is available on the Ontario e-Laws website.

Under the OWRA, the Ministry of the Environment, Conservation and Parks (MECP) has enforcement authority for environmental violations related to septic system failures. Property owners should be aware that:

• A failing system that causes effluent to surface or contaminate water sources can result in orders from the MECP to repair or replace the system.
• Property owners may be liable for environmental cleanup costs if contamination spreads beyond their property.
• Regular maintenance (including pumping every 3–5 years) is the most effective way to prevent OWRA violations.

Provincial Homeowner Resources

The Ontario government provides educational resources for homeowners with septic systems. The Septic Systems — Homes page on ontario.ca covers basic operation, maintenance tips, and links to the SepticSmart! program. The SepticSmart! booklet explains how septic systems work, what property owners can do to extend system life, and where to find qualified professionals. The Ontario Onsite Wastewater Association (OOWA) also publishes homeowner guides and maintains a directory of member professionals who meet industry standards.

Regulation Summary Table

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