Environmental Red Flags When Buying Land in Ontario: Oil Tanks & Contamination

Generally the new owner. When a property is purchased, any contamination present typically becomes the buyer’s responsibility, and the cleanup costs are usually borne by the new owner rather than the seller. That is exactly why environmental due diligence matters before you close – a problem you identify in advance is a reason to renegotiate, require the seller to remediate, or walk away, while the same problem discovered after closing becomes your bill, which for soil and groundwater remediation can run well into five or six figures. Put an environmental condition in your offer and have your lawyer handle disclosure and liability before you waive conditions.

Look for the tells on a walk-around. Vent or fill pipes sticking out of the ground or a wall and heading downward, copper feeder lines coming out of the foundation, and a sunken patch of lawn or a strip where the grass is dead or unusually green can all point to a buried tank and possible leakage. An old or disconnected oil furnace in the house is another clue. Records are not reliable here, because the TSSA generally did not register private underground fuel tanks before 1990 or fuel-oil tanks before May 2002, so the absence of a record does not mean there is no tank. If you suspect one, get a professional opinion and a Phase 1 assessment before you commit.

A Phase 1 ESA is the standard first step to determine whether a property is likely contaminated, and it involves no digging or sampling. It consists of a records review of past uses of the site and neighbouring properties, a site visit to look for visual evidence such as a buried tank, staining, or buried debris, interviews where useful, and a report with conclusions. If the Phase 1 identifies a real concern, a Phase 2 ESA follows, and that one does involve soil and groundwater sampling to confirm whether contamination is present and how extensive it is. A Phase 1 is worth getting whenever there is any history of fuel, industrial, agricultural, or waste use on or near the lot.

A Phase 1 Environmental Site Assessment commonly costs roughly $3,000 to $5,000, since it is a records-and-site-visit review without any sampling. If it flags a concern and you proceed to a Phase 2, which involves drilling and laboratory testing of soil and groundwater, the cost rises substantially and can range from about $7,000 to $60,000 or more depending on the size of the site and the seriousness of the issues. These are planning ranges that vary by property and consultant. Compared to inheriting a contaminated site, a Phase 1 is inexpensive insurance, and lenders sometimes require one as a condition of financing.

Often yes. Ontario rules require the removal of unused underground storage tanks, and a fuel supplier generally will not fill a tank that is over 25 years old or of unknown age, which can leave a home unable to get heating oil until the tank situation is resolved. Removal must be done by a TSSA-registered fuel-oil contractor – ask for their registration number – and once the tank is out, the surrounding soil must be assessed for contamination and any contamination cleaned up. Removing an empty, intact tank is relatively affordable, but if the tank has leaked, remediating the soil and groundwater is where the cost can climb steeply.

Removing an aboveground tank is relatively inexpensive, often in the range of a few hundred to about $1,500, while removing a typical buried steel tank commonly runs around $2,500 to $5,000 including the required soil assessment. The figure that matters most, though, is what happens if the tank has leaked: remediating contaminated soil and groundwater can run into the tens of thousands or more, depending on how far the contamination has spread. That uncertainty is why a buried tank is risky to inherit, and why you want it identified, removed, and the soil cleared before you take on the property, ideally as a seller obligation negotiated into the deal.

It is strongly worth it whenever there is any sign or history of fuel, industrial, agricultural, or waste activity on or near the lot, or whenever a red flag turns up on your walk-around such as a possible buried tank, an old gas station or junkyard nearby, farm fuel storage, or a suspected dump. For a clean parcel with no history and no visible concerns, you may decide it is not necessary, but the cost of a Phase 1 is small next to the cost of inheriting contamination you did not know about. At minimum, ask the seller for the property’s history in writing, condition the offer on no evidence of contamination, and bring in an environmental professional if anything looks off.