The majority of households in Quebec heat their homes with electricity, but around 12% use heating oil.

Heating oil is usually stored in a tank located inside or outside the building. The oil can be dangerous for the environment, so it’s important to keep an eye out for leaks. Tanks that are poorly maintained or too old account for almost 95% of heating oil spills.

Is your home equipped with a heating oil tank? In this article, our residential environmental emergency specialists explain the importance of inspecting and maintaining your oil tank.

The environmental and economic consequences of residential oil spills

Residential oil spills caused by poor tank maintenance often happen very slowly, but the environmental and economic consequences can still be devastating.

A leaking tank can pollute the surrounding soil and even affect nearby wells and bodies of water once the oil seeps far enough into the ground to contaminate the water table. It can then have significant negative effects on the fauna, flora and the human population.

Heating oil spills can also have significant financial repercussions for the homeowner, because the cost of soil analyses and decontamination work can be high. For example, it may be necessary to tear down and rebuild the foundation in order to eliminate all traces of heating oil from a property. Such extensive work will increase the cost of remediation by thousands of dollars. 

If you heat your home with oil, check your insurance coverage to make sure it includes pollution. 

The main causes of residential heating oil spills

There are a variety of factors that can cause a heating oil spill. There are three types of tank failures that commonly lead to oil leaks: manufacturing defects, poor installation and corrosion.

Knowing the common causes of spills can help prevent them

Manufacturing defects

A manufacturing defect in a heating oil tank can lead to a spill if not detected in time. The most common manufacturing defects are a mistake in the chemical composition of the tank’s sheet metal and problems with the welding joints, both of which are difficult to see with the naked eye. Unfortunately, these problems can cause the tank to deteriorate prematurely.

To try to prevent manufacturing defects, oil tank production is subject to various regulations, including CSA standards.

Poor installation

Installing a heating oil tank requires precision and expertise, which is why it must be done by a professional who is a member of the CMMTQ (Corporation of Master Pipe Mechanics of Quebec). 

That being said, even specialists can sometimes make mistakes that lead to a spill. Here are some examples:

  • Using incompatible materials
  • Incomplete assembly, such as a lack of Teflon tape to ensure a good seal between the tank and the vent or gauge
  • An insufficient slope in the tank that prevents water and sediment drainage through the filter. 
  • Placing the tank in a location where water, ice and snow can accumulate



Corrosion, commonly known as rust, can severely damage a tank because it eats through the metal, creating holes. Corrosion can be difficult to detect because it often occurs on the underside of the tank. When a tank is breached at the base, the contents will leak out.

Rust is always a concern, but certain factors increase its likelihood. Humid environments tend to accelerate corrosion. The welding joints between two different kinds of metal are particularly affected by rust. 

Preventing heating oil spills

The consequences of heating oil spills can be catastrophic, so owners and professionals must take particular care with oil tanks and take the steps needed to prevent leaks.

Replace old tanks

Most experts in the field agree that whether they are placed inside or outside, oil tanks should be replaced every 10 years. 

You can check the age of a tank by looking at its label. If there is no label on the tank, it was most likely installed before 1980, meaning that it’s past time to replace it! 

Inspect and maintain oil tanks every year

All heating oil tanks should be inspected and maintained on a yearly basis. Maintenance and inspections are the owner’s responsibility, but should be carried out by a professional. 

There are also warning signs to watch out for at all times:

  • The smell of oil
  • Moisture on the tank
  • Rust on the tank walls
  • Damaged base
  • Bent or twisted pipes

In the event of a heating oil leak, contact EBI Enviro Urgence

The environmental and economic consequences of residential heating oil spills are such that preventive measures must be taken to avoid them. 

If you need to get rid of an old oil tank or heating oil, you can contact our team for environmentally sound disposal. You can also rely on our emergency spill response services in the event of a heating oil spill.