Ontario Septic Regulations — OBC Part 8 & Renfrew County Permits

The Governing Legislation

Sewage systems in Ontario are regulated under two primary instruments:

Ontario Building Code (OBC) Part 8 — Sewage Systems: Part 8 of the OBC is the primary regulatory framework governing the design, construction, and installation of small sewage systems in Ontario. It defines approval requirements, inspection requirements, and the roles of the approval authority and licensed practitioners.
Ontario Regulation 358/11 — Small Sewage Systems: This regulation, made under the Ontario Building Code Act, defines the technical requirements for different system types — including conventional leaching beds, at-grade systems, raised beds, holding tanks, and tertiary treatment units. It sets out the siting rules, soil criteria, design parameters, and required setback distances.

Together, these instruments establish what systems can be built, where they can be located, who can design and build them, and when inspections are required.

The Renfrew County and District Health Unit — Approval Authority

In Renfrew County, the Renfrew County and District Health Unit (RCDHU) is designated as the approval authority for Part 8 sewage systems. This means RCDHU reviews applications, issues permits, conducts inspections, and provides final approvals for all new septic system installations and major repairs within the county.

A permit from RCDHU is required before any new septic system installation or major repair begins. Proceeding without a permit is a violation of the OBC and can result in orders to remove unpermitted work, fines, and complications during future property transactions. Mortgage lenders and title insurers increasingly verify permit compliance for septic systems on rural properties.

Contact RCDHU early in the process — before engaging contractors. They can advise on the permit application process, required documentation, and typical timelines in your area.

Licensed Practitioners Required

The OBC requires specific licensed practitioners at each stage of the septic process:

Licensed SSSTS (Small Sewage System Treatment Supervisor) — for design: A SSSTS is qualified to conduct the site evaluation, assess soil and water table conditions, select the appropriate system type, and prepare the design drawings submitted to RCDHU with the permit application. The SSSTS is the designer of record for the system. Not all septic contractors hold SSSTS designation — the designer and installer are often different people or companies.
Licensed septic installer — for construction: The physical installation of the system must be conducted by a licensed installer. The installer is responsible for building the system in accordance with the approved design.

Confirm that any contractor you engage holds the appropriate licence for the role they are performing. Ask to see their licence and verify it through the relevant Ontario licensing authority.

Mandatory Inspections

RCDHU inspectors conduct mandatory inspections at critical stages of septic installation:

Excavation inspection: Once the leaching bed area is excavated but before any gravel, pipe, or fill is placed, an inspector must visit the site. This inspection verifies that the actual soil conditions match the designer's assessment and that the excavation dimensions and depth meet the approved design. This is the most critical inspection — do not cover the excavation before it is inspected.
Installation inspection: A second inspection typically occurs after installation is substantially complete but before final backfilling, to confirm the system has been built in accordance with the approved design drawings.

Schedule inspections in advance and allow adequate time — inspection availability varies with seasonal demand, and delays in inspection scheduling can slow your project timeline.

Required Setback Distances

O. Reg. 358/11 establishes minimum setback distances from the sewage system (including both tank and leaching bed) to various features:

15 metres from a drilled well
30 metres from a dug well
30 metres from any water body (lake, river, stream, ditch connected to a water body)
1.8 metres from a property line
1.8 metres from any building foundation

These setbacks apply to all parts of the sewage system, including the tank, distribution box, and the full extent of the leaching bed. On smaller rural lots or waterfront properties, meeting all required setbacks simultaneously can be challenging and may constrain system placement significantly.

Record Keeping

After installation, keep copies of your permit, approved design drawings, and inspection reports in a safe location. These records are valuable for future maintenance planning, property sales, and any permit applications for additions or modifications to your home. RCDHU does maintain permit records, but having your own copies prevents complications if historical records are difficult to locate years later.