Why the service-status question comes first
If a property is connected to a public sewer, most septic design and maintenance guidance is irrelevant to the active wastewater service. If it uses an onsite system, the municipal utility file alone may not tell you the approved onsite design. Some properties also have old, abandoned or partially decommissioned infrastructure. Resolve service status before you interpret an old survey, tank lid or seller statement.
Use records that can identify the exact parcel
Start with the municipality or utility for sewer connection/service information. Check property-tax or utility billing where it distinguishes sewer charges, but do not treat a billing line as the only proof. Then check the onsite approving authority for a permit, filing, registration or approval tied to the lot. If the two records conflict, ask both offices to resolve the current status.
Why the approving authority may not be city hall
Across Canada, onsite authority is split in different ways. BC uses health-authority filings by an Authorized Person. Manitoba administers a provincial registration program. Saskatchewan's public-health system administers private sewage works outside the specific city exceptions identified by the province. New Brunswick uses provincial Technical Inspection Services. Nova Scotia uses its environmental notification/approval framework. Ontario often uses the municipality but can use a health unit or conservation authority as the Part 8 principal authority.
Physical clues are useful—but not decisive
Cleanouts, tank lids, alarms, pump chambers, a visible field or older as-built drawings can help locate infrastructure. They do not establish that the system is active, approved or still serves the building. Conversely, the absence of obvious surface features does not prove a sewer connection. Use physical evidence to ask better record questions.
Why the answer changes renovation planning
Onsite systems can constrain the location and servicing of additions, accessory buildings, pools, driveways or added bedrooms. A public sewer connection can involve separate municipal connection work and fees. In BC, a health officer can in some circumstances order a connection to public sewer under the Sewerage System Regulation. In Québec, municipalities administer the isolated-residence wastewater regulation and also control local servicing. The practical path depends on both the property and jurisdiction.
If you are buying
- obtain written or documentary confirmation of the current wastewater service;
- if onsite, obtain the approval record and as-built/site plan;
- check whether any abandoned tank or former system needs attention;
- match the system record to what is physically present; and
- if future construction matters, verify that plan before removing conditions.
If you are renovating
Give the designer or authority the existing wastewater record and the proposed building/use changes. Do not assume a municipal building permit automatically resolves onsite capacity, or that a septic approval automatically resolves zoning and building rules. They can be parallel approvals.