Oshawa, ON onsite wastewater guide

Septic systems in Oshawa: permits, records, inspections and property checks

Unlike most Durham Region municipalities, Oshawa is expressly excluded from the Durham Region Health Department septic-permit program. The City of Oshawa offers its own online Building Permit Portal with a Sewage System application type for installing, repairing or converting septic to sewer. City documents include a separate Part 8 septic system form and municipal plumbing/septic fee categories. Confirm the actual property system type and the current permit scope first.

First questionSewer or onsite?
Local lensCity of Oshawa Building Services / Part 8
Before buyingRecords + condition
Before workLocation + capacity

First, confirm this property’s wastewater service

Confirm the lot’s actual sewer connection and filing history. A municipal/health process is not proof that a particular septic system is approved.

Local septic / permit route

Use the local authority route below for septic approvals, permits or records. Confirm sewer connection separately with the municipality or utility.

Open local septic / permit page →

Onsite system confirmed

Use the City of Oshawa’s Building Permit Portal and select the sewage-system category for an onsite install, repair or sewer conversion; submit the City septic form and supporting site/design documents. Do not send Oshawa Part 8 applications to the Durham Region Health Department; the Region’s own septic page lists Oshawa as the exception.

City of Oshawa — Building Permits, sewage-system application type ↗

Service unknown

Check utility bills and permit records; ask the local authority to confirm current service before planning an onsite inspection or repair.

How to confirm service →
Provincial rule: In Ontario, most onsite sewage systems with design capacity at or below 10,000 litres per day are regulated under the Building Code Act. Permits are typically issued by the local municipality or, in some areas, a health unit; larger systems may require provincial environmental approval. Open provincial / regional onsite-wastewater authority →
City of Oshawa named Part 8 exception and septic-permit route verified. Confirm the individual property, existing system design, legal permit and service connection before work.

Who approves septic work around Oshawa?

Ontario regulates most residential onsite sewage systems under Part 8 of the Building Code. Systems with a daily design flow of 10,000 litres or less are generally administered by a municipality, health unit or conservation authority; larger systems fall under the environmental approval regime.

Confirm the exact Part 8 authority before applying. New systems, replacements, major repairs, additions or changes that increase design flow can require permit review, site/soil information, design calculations and inspections before covering.

Oshawa local-route status: The strongest verified regulatory anchor for this page is the Ontario provincial/regional onsite-wastewater framework. The municipal website remains useful for sewer-service, zoning, building and property-record questions, but this guide does not label a generic city homepage as a septic permit authority unless the official material clearly says it is.

Official sources for this guide

If sewage is backing up or surfacing, stop using affected fixtures and contact a qualified professional or the responsible authority. Never enter a septic tank.

Where to verify records and approvals

Local municipal source checked 11 October 2026. Individual onsite system approval, service connection and record searches are not verified by this general guide.