Selling a Rural Home on a Well and Septic in Ontario: What the Seller Is Actually On the Hook For

A buyer will inspect the well and the septic — count on it. But your real legal duties as the seller do not begin at closing. The hardest ones live in Reg 903, and they have been riding with you the entire time you have owned the place.

I am Arthur Zhao. Here is a scene that plays out over and over. A rural listing goes firm, the buyer sends in their inspector, and the report comes back with one line nobody expected: an unregistered, un-sealed old well sitting near the barn. Just like that, a clean deal has a hair in it — and the seller is scrambling to explain something the law had already made their responsibility, years before this buyer ever walked the property.

That is the whole point I want to land. Sellers tend to file well-and-septic duties under “closing-time chores” — test it, disclose it, done. But the duties that actually bite are the quiet ones that have been attached to you the entire time you owned the place. Below I pull apart what is buyer diligence versus seller duty, walk through what each of the two systems demands, and weigh the one call every rural seller has to make: whether to test before you list.

Buyer diligence and seller duty are two different things

Start by separating a confusion that trips up almost every rural seller. A buyer of a rural home is virtually certain to do two things: have the well water tested and have the septic inspected. That is the buyer’s diligence. Whether the buyer looks, and whether you as the seller carry a duty, are two independent lines.

Here is the twist: your hardest duties are not the ones about handing over a test report — Ontario has no law forcing a seller to inspect before listing. They live in two other places: the obligations under Reg 903 that have been riding with you the whole time you owned it, and the case-law duty to disclose a known material latent defect. The buyer’s diligence is, in essence, the moment those first duties get pulled into the open and checked. Confuse “the buyer will look” with “I have a duty,” and you either panic over nothing or miss the thing you actually had to do.

The well: three duties Reg 903 pins on the “well owner”

The well side is governed by R.R.O. 1990, Reg. 903 — the “WELLS” regulation under the Ontario Water Resources Act. It names the duty-holder plainly: the well owner. As long as the well is in your name, these three are live.

1. Keep it maintained. Section 20(1) requires the well owner, after the well’s structural stage is complete, to maintain it at all times in a way sufficient to keep surface water and other foreign material out. Read those three words — “at all times.” This is not a one-time fix; it is a duty that runs the length of your ownership.

2. Keep the casing at a compliant height. Section 20(2) governs how far the casing rises above grade: you may not lower a casing that sits less than 40 cm above the ground, and you may not drop a casing that is 40 cm or higher below that mark. It sounds fussy, but whether surface runoff can pour straight down the casing into the well often comes down to exactly that margin.

3. Abandon any well you no longer use. This is the one rural sellers miss most. Section 21(3) says that if a well is no longer used and is not being kept for future use, the well owner must immediately abandon it — properly, in the regulated way. Plenty of older properties have a well by the barn or the fence line that went idle when the place was connected to a newer source. “Nobody uses it” does not make it disappear; the law wants it sealed and abandoned.

Well vs septic: two regimes, side by side

The septic side: the Building Code, and why “selling” is not the trigger

Your septic system — more precisely an on-site sewage system — does not answer to the water statute. It sits under the Building Code Act, 1992 and the current Building Code (O. Reg. 163/24, which adopts the National Building Code of Canada 2020 and replaced the earlier code regulation). There is a dividing line worth knowing: a system with a design capacity of 10,000 L/day or less that serves its own property — virtually every residential septic setup — falls under the Building Code; once a system runs above 10,000 L/day, it crosses over to the Ontario Water Resources Act (s.53) and the Ministry of the Environment (MECP).

As for mandatory inspections: some parts of Ontario do run a maintenance-inspection program for on-site sewage systems, carried out by a qualified inspector working for the local principal authority — a municipality, a public health unit, or a conservation authority. But whether an inspection is mandatory, and how often, depends on where your property sits and what the local principal authority requires — there is no single province-wide “inspect before you sell” rule, so confirm it with your local municipality, health unit, or conservation authority. The point holds: this inspection runs off location and local programs, not off the act of listing your home.

What does happen, reliably, is that the buyer makes a satisfactory septic inspection a condition of their offer. So the smart seller move is to get ahead of it — pull the system’s location drawing, the last pump-out and inspection dates, and any records — before the sign goes up.

Disclosure: what caveat emptor leaves on your plate

On disclosure, start with the baseline: Ontario runs on caveat emptor, buyer beware. As a rule, the buyer has to find problems through their own reasonable diligence, and you are not required to volunteer patent defects — the ones a buyer would catch on an ordinary inspection.

The important exception: per RECO’s guidance, a seller must disclose a known material latent defect — a hidden problem you already know about that renders the home dangerous or unfit for habitation. On a rural property, that lands squarely on things like a well you know runs dry every August, a septic bed you know is leaching into the water table, or an old well you never registered or sealed.

Running alongside that is a separate, absolute line: you cannot actively conceal or misrepresent. You may stay silent on a patent defect, but you cannot paint over the crack — and once you are asked, or once you choose to speak, you have to tell the truth.

And the SPIS (Seller Property Information Statement)? That is a voluntary OREA form, not a legal requirement. It can help you think through what to disclose, but the moment you complete it, it becomes a written record you are held to — so whether and how to use it is a conversation for your agent and lawyer, not a reflex.

A pre-listing checklist for well-and-septic sellers

Before the sign goes in the ground, walk these four. They cost you a weekend and they take the biggest surprises off the table.

Arthur Zhao

Real Estate Broker · FRI · ABR · SRS · PSA · MCNE · E-PRO · CLHMS & GUILD Elite · REAIS

VP & Branch Manager, Bay Street Group Inc.

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