Overview

Old oil and gas wells can pose a serious safety risk if they were left unplugged or not properly plugged and decommissioned.

If you are a landowner, you should:

If you find a well:

  • check for signs of leaking
  • confirm if the well has been plugged by checking the Petroleum Well Map
  • find out if the well is eligible for the Abandoned Works Program, whcih could cover the cost of plugging an unsafe well

Check online well maps

Old oil and gas wells are often buried and may not be visible on the surface

If you are not sure if there is a petroleum well on your property, search following online maps to find out if there is a recorded well on or near your property.

Even if no well record exists, there may still be an undocumented well on your property.

If you discover a well on your property that is not shown on these maps, or if you are not sure if what you found is a well, contact the Petroleum Operations Section:

Petroleum Well Map

Use the Petroleum Well Map to find out if there is a record of a well on your property. This map:

  • uses blue dots to show the location of known petroleum wells
  • displays a pop-up window when you click on the blue dot, which shows basic well data based on the Ontario Wells Status Definitions, including whether the well has been plugged
  • lets you download well data into a spreadsheet, which you can use to find your property by county, township, lot and concession instead of using the map

Oil, Gas and Salt Resources Library Petroleum Well Map

Use the Oil, Gas and Salt Resources Library Petroleum Well Map if you know you have an oil or gas well on your property and want to view more detailed records about it. This map:

  • has a free basic search of oil and gas wells that are regulated under the Oil, Gas and Salt Resources Act and located in our ministry database
  • lets you view more information about a well by clicking on the well symbol
  • offers a paid subscription where you can access a more detailed database of well records and reports

If you need help understanding the data about a well, call the Oil, Gas and Salt Resources Act Library at 519-686-2772.

Look for signs of a well

Signs there may be a well on your property include:

  • debris piles
  • old foundations
  • old tanks
  • partially buried pipes
  • stone, brick, wood and clay tiles
  • well casings
A rusty pipe sticking out of the ground.
A rusted pipe laying on the ground and a well casing sticking out of the ground. These are both signs that a well could be present.
A pipe sticking out of the ground with a circular metal cover screwed on the top of the pipe.
A rusty well with debris pile.
A rusty pipe sticking out of the ground.

Pipe or casing material or covers that may conceal a well

Signs of a leaking well

Check your property for any of the following signs of a leaking well.

Fluid

If fluids are escaping from the well, pools of liquid may form that cause soil staining and damage to vegetation.

Sinking ground

If a well is leaking, the ground may dip or sink over or around the well.

Hydrogen sulphide smell

Hydrogen sulphide is a poisonous gas that often has a rotten egg smell. It may be released if a well is leaking.

Soil staining or oily residue that could indicate a well is present.
Areas of black soil staining
Uneven patches of grass that could indicate a well is present.
Depressed or sinking ground
An area of dead vegetation that could indicate a well is present.
Damage to or discoloured vegetation
Dark, oily-looking fluid pooled in shallow channels across a farm field, which may indicate a leaking oil or gas well.
Release of fluids or presence of gas bubbles in pooling water

If you find signs of a well on your property

  1. Report the well to the Spills Action Centre if you suspect the well is leaking.
  2. Apply for the Abandoned Works Program by following the instructions on this page.

Abandoned Works Program

The Abandoned Works Program arranges and pays for the cost of oil and gas well plugging when a well poses a risk to the public or the environment.

In Ontario, oil and gas well operators are responsible for plugging their own wells if the well remains inactive for more than 12 months.

If an active operator of a well cannot be identified, the landowner is responsible for plugging the well.

Landowners can apply for the Abandoned Works Program to have unsafe wells on their property plugged, if the following criteria are met.

Wells that qualify for the program

Any oil or gas well may qualify if both of the following apply:

  • an active operator cannot be identified for the well, other than the landowner
  • you have not used, benefited from, or intentionally tampered with the well

How to apply

If you want to have a well on your property considered for the program, email gasandoilwells@ontario.ca with the following:

  • your contact information
  • well information, including:
    • location
    • licence number
  • a description of wellheads or the well casings visible at the surface, leaking fluids, gas odours, dead vegetation or any other signs that indicate a well may be present
  • photos of the well site (if possible)

After you apply

The ministry will:

  • visit the site to assess the well
  • determine if your well qualifies for the program

If your well qualifies, we will:

  • prioritize your well based on the risk to public safety and potential for environmental damage to determine when it should be plugged. Wells that we rank as immediate or significant hazards are addressed first
  • arrange for a pre-qualified well contractor to plug the well
  • pay for the cost to plug the well

Wells that are prioritized as immediate or significant hazards are plugged first.

How wells are plugged

Wells are plugged with cement by a plugging contractor. In most cases, the plugging contractor may use:

  • a service rig
  • steel tanks to hold fluids during the plugging
  • tanker trucks
  • construction equipment

Existing landowners will need to give the contractor access to the land where the well is situated will need to be granted by the existing landowner. In some cases, this may require the landowner to get consent from adjoining property owners.

Hazards of oil and gas wells

Blowouts

Blowouts occur when natural gas, oil or other fluids unexpectedly escape from a drilling rig, sometimes resulting in fires or spills.

Hydrogen sulphide

Hydrogen sulphide is a toxic gas that smells like rotten eggs at low levels, but is odourless and can be fatal at higher concentrations. It can occur naturally underground and may escape through leaking wells or from surface spills.

Water contamination

Escaping fluids from a well, whether above ground or below, can contaminate fresh water sources and pose risks to human health and the environment.

Well integrity failure

Damage or deterioration of well components can lead to an uncontrolled release of gas or fluids, even at wells that appear inactive or abandoned.

Gas migration and explosion risk

Gas can travel long distances underground through rock fractures or soil. When gas collects in confined spaces like basements, crawl spaces or well pits, it can push out oxygen, which can cause suffocation or reach explosive levels.

Methane

Methane is a colourless, odourless gas that occurs naturally underground and may leak from damaged or aging wells. In confined spaces, it can build up and displace oxygen, causing suffocation or creating an explosion risk.

High pressure and flammability

Fluids from wells can be under high pressure and may be flammable. Only trained and qualified individuals should work on wells and associated pipelines.

Legacy or unknown wells

Older, undocumented or unmapped wells may lack modern construction standards and may contain deteriorated materials, increasing the risk of leaks or gas migration.

Contact

For more information about the Abandoned Works Program, contact:

Petroleum Operations Section
Ministry of Natural Resources
Email: gasandoilwells@ontario.ca            
Telephone: 519-873-4634