For more than 70 years, the heating fuel of choice for Ontario homes was oil.  Fuel oil storage tanks were installed and used in many residential properties as well as properties owned by charities, in particular, churches, synagogues, mosques and other religious organizations, including residences for their spiritual leaders.

With the evolution of home heating technologies, energy efficiency and growing environmental awareness, most homeowners switched over to natural gas. However, not all homeowners had their oil storage tanks removed when they converted to natural gas. In fact, many homeowners may simply have forgotten that they were there. Or homes switched hands over the years and homeowners may not have even be aware of the hazard.

The most commonly used tanks for fuel oil were steel containers that held about 1,000 litres of fuel. The problem with many metal fuel oil tanks is that they rusted from the inside out as a result of condensation accumulation inside the tank over several years. It was difficult to tell if a tank was leaking and underground fuel oil tanks presented a particular concern because of the inability to determine their condition combined with the probability that they would eventually leak (the older the tank, the stronger the likelihood that it would leak).

buried oil tank


Ontario has strict regulations and codes governing the handling and storage of fuel oil that required registration of all existing underground fuel oil tanks with the TSSA (Technical Standards and Safety Authority) and dictated their removal or upgrading according to a phased in four year schedule based on the age of the tank.

Property owners had a legal responsibility to maintain fuel oil storage tanks and to clean up any leaks or spills that may have occurred, whether the fuel oil tanks were situated underground, in a basement or aboveground. Fuel oil leaks and spills caused significant environmental damage and the costs to clean up contaminated soil and groundwater on the property and its surroundings was extensive.

This legal responsibility and potential for legal liability resulted in increased insurance claims made by property owners with underground fuel oil tanks. This caused an increase in homeowners’ insurance concerns, including potential denial of coverage.

The handling and storage of fuel oil is governed under the Technical Standards and Safety Act – Ontario Regulation 213/01 (“Fuel Oil Regulation”), and administered under the Ontario Installation Code for Oil Burning Equipment I (Based on CSA B139, with Ontario Amendments), Edition/2006 (“Ontario Fuel Oil Code”).

The Fuel Oil Regulations and Codes stated that all existing single-wall steel underground tank systems that were 25 years old and more as of October 1, 2001, or of unknown age, and not cathodically protected, were required to be withdrawn from service and removed. All underground fuel tank systems that had not been used for two or more years (and no longer intended to be used), had to be removed, no matter what the age. Furthermore, all underground tanks over 5,000 litres were required to be leak tested annually.

Furthermore, the Regulations stated that fuel oil distributors could not supply fuel oil to an underground tank unless the tank was registered with the TSSA. This requirement has been in effect since May 1, 2002.

Moving forward to today, the TSSA advises potential buyers of property to consider whether there are any underground fuel oil storage tanks on the property before purchasing it, as the new property owner may be responsible for removing any such tanks.


How can I tell if I have a buried oil tank on my property?

The most reliable way to determine if you have an oil tank is to order an inspection from a qualified company. If your home is older than 1970, there is a good chance that there is an oil tank present (or at least there was); don’t rely simply on the date alone.

Do a visual scan of your property. If you see a fill pipe, that could indicate an oil tank. A fill pipe is usually about 2 ¾ inches in diameter and can vary in style. Sometimes the head of the pipe is buried slightly in the ground. The fill pipe would have been the access point to fill the tank with oil.

Another sign that you’ve got an oil tank is the emergency oil burner shut off switch. This switch will say “emergency” switch on its face and have a toggle feature. This would have been used when the tank was being refilled, as well to shut it off in the event of a fire, flood, or earthquake.

If you have vent pipes (heading from the side of the house down into the ground, presumably into the oil tank) or copper feeder lines coming from your foundation, those are flags.  If you notice sunken patches on your lawn, or notice areas where the grass is dead, that could signal the presence of an oil tank as well as indicate potential soil contamination from an oil leak.

In your basement, if you see any cracked or repaired areas of concrete, going from your furnace area towards the foundation or any oil, both of these could indicate that you have (or have had) an oil tank buried beneath your property.

What happens if I have a buried oil tank?

Bottom line, it is smart for homeowners to be proactive in managing the presence of a buried oil tank, regardless if they intend to sell in the near future or years down the road.

As a property owner, you are responsible for maintaining, repairing, upgrading, removing the oil tank, as well as paying for any contamination cleanup. You are also required to use the use the services of a company that is registered with the Technical Standards Safety Authority.  Removing an underground oil tank is risky, highly technical work, and requires specific training and equipment.

If you discover that you have an oil tank buried in your yard:

  • Call for an inspection and/or removal.
  • If the tank is determined to be damaged and unsafe during the inspection, the supply of oil will be halted and the tank removed.
  • The homeowner needs to notify the TSSA when this job has been completed.
  • To determine any potential environmental or other damage, the homeowner is responsible to order an environmental assessment done by a professional engineer, chartered chemist, professional geoscientist or a chartered chemist.
  • If that assessment determines that there has indeed been an oil leak, the homeowner must notify the Spills Action Center at the Ministry of the Environment.

Another issue that the homeowner must be prepared for if an oil leak is found is the ceasing of insurance coverage if it is also determined that the tank is past a certain age. Prepare for the additional costs of filling that hole back up after a tank has been removed.

If it is determined that there has been soil contamination, the homeowner will have to proceed with soil and groundwater remediation.  Once this task is completed, the property owner must supply a report that lays out the tank removal process, how much (if any) oil was removed from the tank and proof that the tank has been removed and disposed of at an appropriate facility and the details of the remediation process.

How much does it cost to remove a buried oil tank?

According to our research, the average cost to remove a buried oil tank is $2500-$3000.  The removal must be conducted by a qualified TSSA registered Petroleum Mechanic 2.  However, if the tank has leaked and contaminated the soil and groundwater, be prepared to spend tens of thousands of dollars to remediate the problem.