About geothermal systems

A ground source heat pump system—or geothermal system—takes heat from the ground in the winter (for heating) and transfers heat back into the ground in the summer (for cooling).

This helps:

  • increase a home or business' energy efficiency
  • reduce the operational costs of heating and cooling systems

The rules

As the geothermal installer or driller, you need to follow certain rules before you construct a new or modify (e.g. alter, replace, extend) an existing vertical closed loop geothermal system.

You must:

  • apply for an Environmental Compliance Approval (ECA), including a work plan if the vertical closed loop geothermal system you plan to install extends more than 5 metres below the ground
  • immediately report hazardous gas, if encountered during construction

If you don't follow the rules, you can be fined and/or charged.

Sales and service provider

If you sell and provide services for geothermal systems but don’t do drilling or installation, then you do not have to apply for an ECA.

An association cannot apply for an ECA on behalf of the drilling industry.

Geothermal system with a well

If you are installing a new, open-loop geothermal system that has a well, you must follow the rules in the Wells Regulation 903, including:

By law, you must have a valid well technician licence in order to construct, maintain, repair or upgrade a well.

You must also get:

Source law

You can find a complete set of provincial rules related to this activity in:

How to apply

To apply for an Environmental Compliance Approval (ECA):

  1. download the Environmental Compliance Approval application for vertical closed loop ground source heat pumps
  2. complete and sign the form
  3. attach the work plan (and any other attachments)
  4. mail the application package (application form, work plan and fee) to:
    Client Services and Permissions Branch
    135 St. Clair Ave West, 1st Floor
    Toronto, Ontario
    M4V 1P5

A single multi-site ECA allows you to install vertical closed loop ground source heat pumps at various locations in the province without having to get an approval for each site.

Processing your application

Review time varies, depending on the quality of your application. If your application is incomplete, or if you provide information that doesn't meet the prescribed standards, the Ministry of the Environment, Conservation and Parks can return it to you without considering it. You'll then have to start the application process from the beginning. Approvals are issued once the public consultation is complete.

Public consultation

All proposals that fall under the Environmental Bill of Rights require you to notify the public of your activity. Your application will be posted on the Environmental Bill of Rights Registry site, for a minimum of 45 days.


Application fee: $1,400

Methods of payment

The fee can be paid by:

  • certified cheque
  • money order
  • Visa or Mastercard

Effective January 16, 2017, the Province of Ontario will no longer accept payments by American Express credit card.

The fee is payable to the "Minister of Finance".

Prepare a work plan

A work plan must be submitted to the Ministry of the Environment, Conservation and Parks as part of the Environmental Compliance Approval application. The purpose of the work plan is to demonstrate that measures will be put in place to protect the environment and public from hazardous gas, if encountered. The government uses the work plan to help review and assess your Environmental Compliance Approval application.

The work plan must be prepared by a:

  • professional geoscientist or
  • licensed engineering practitioner

You are responsible for the cost of hiring the professional.


The work plan must include:

  • a hazardous gas monitoring and detection plan
  • a health and safety plan
  • a drilling plan—drilling methods and types of drilling machines and fluids used
  • measures to prevent or reduce the likelihood of hazardous gas migration when drilling in overburden deposits and Precambrian or sedimentary bedrock
  • drilling methods and equipment to be used if competent sedimentary bedrock is found
  • preparation for a gas mitigation contingency plan, should you encounter a hazardous gas includes a description of:
    • equipment and materials
    • training and qualifications
    • notification contact list

    A gas mitigation contingency plan includes:

    • immediate gas mitigation measures to prevent adverse effects
    • provisions for "killing the hole" or venting, dispersing or flaring the gas
    • notification of the proper authorities
    • procedures for proper installation
    • procedures for proper decommissioning
  • preliminary site preparations—review of available area geological reports/records, etc.
  • mitigation completion report, which includes:
    • measures and safeguards implemented to install or decommission the ground source heat pump system
    • provisions to make the report available to people identified in the notification contact list and the local district or area office of the Ministry of the Environment, Conservation and Parks

Get instructions for completing the work plan

Related requirements

The professional you hire should prepare your work plan in accordance with:

Report hazardous gas

By law, if you detect hazardous gas while constructing, altering, replacing or extending a vertical ground source heat pump, you must immediately notify the:

  • local fire department
  • building occupant(s)
  • landowner(s)
  • Ministry of the Environment, Conservation and Parks’ Spills Action Centre by calling 1-800-268-6060
  • local municipality
  • purchaser of the geothermal system

You must also:

  • manage the gas to remove any potential hazard
  • ensure space around the underground heat transfer tubing is sealed to prevent any movement of hazardous gas between subsurface formations (e.g. natural gas reservoir) and the ground surface or an aquifer

If these measures fail to remove all potential hazards, you must decommission the vertical closed-loop geothermal system.

If you have questions or concerns about an existing geothermal system on your property that was installed prior to the requirements outlined in Ontario Regulation 98/12, and are worried about hazardous gas escaping, you can:

  • contact your installer to inspect your system
  • hire a professional engineer or geoscientist with expertise in geothermal systems to assess your system

If you are concerned about a gas leak, call your local fire department or 911 immediately.