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The C448 applies to new and retrofit installations for ground-source pumps.

August 28, 2013  By Muktha Tumkur P.Eng

In support of the Ontario’s provincial government’s long-term plan to
use more renewable energy and eventually close down dirty coal plants

In support of the Ontario’s provincial government’s long-term plan to use more renewable energy and eventually close down dirty coal plants, geothermal systems provide an excellent source of green heating and cooling in a variety of applications, including residential, commercial, agricultural and industrial applications. Geothermal heating and cooling leverages underground temperatures to heat and cool buildings.

As of May 18, 2012, the Ontario’s Ministry of the Environment (MOE) introduced Ontario Regulation 98/12 to improve public safety and protect the environment by strengthening the regulation of vertical closed loop drilling for geothermal energy systems. Regulation 98/12 requires geothermal installers to obtain an Environmental Compliance Approval (ECA) for vertical closed loop geothermal systems. Applicants are required to submit a work plan prepared by a licensed engineering practitioner or a professional geoscientist. The work plan must include measures to prevent an adverse effect if hazardous gas is encountered while constructing, altering, extending or replacing the system.


Very shortly after the regulation was introduced, engineers with the Ontario Geothermal Association (OGA) met with assistant deputy ministers and senior staff members at the Ministry to offer its expertise and assistance and to start the ECA process. Furthermore OGA engineers and their association partners across Canada (with assistance from Golder Associates) prepared and submitted applications to the MOE for an ECA to perform geothermal drilling in Ontario. These applications include mandatory work plans that address the requirements of regulation 98/12 and other instructions that were issued by the MOE.  

The intent of the new regulation and instructions is to develop measures and procedures to protect against the release of hazardous gases such as natural gas and hydrogen sulphide while drilling boreholes and installing the grout and U-loops.

Some of the key requirements of 98/12 and the instructions include:

  • Preparation of a Work Plan by a licensed professional engineer or geoscientist and
  • equipment and procedures for monitoring hazardous gases during geothermal drilling
  • A preliminary site assessment and step-by-step description of all the drilling activities
  • Measures and procedures to be taken to control the release of hazardous gases during drilling and, if required, to kill the borehole (for example, to prevent the release of the gases)
  • Training of drilling crews in the safe management of hazardous gases during drilling
  • Notification to specified individuals if hazardous gas is encountered in a geothermal borehole
  • Preparation of a Mitigation Completion Report by a licensed professional engineer or geoscientist if hazardous gas is encountered in a geothermal borehole.

The Ministry is also requiring installers to notify the landowner, occupant of the building, municipality, fire department and the ministry’s Spills Action Centre if they encounter hazardous natural gas during installation of a closed loop vertical geothermal system.

Geothermal stakeholders and their senior geoscientist advisor met with MOE staff to review their proposed Work Plans. Several concerns were raised by the MOE technical reviewers leading to field tests, observed by MOE personnel that formed the basis for acceptable procedures.  

Procedures acceptable to the MOE have been established and has led to a sample Work Plan template that is available on the OGA website ( for reference by other geothermal drillers in Ontario. Each drilling company is responsible for preparation and submission of their own ECA Application including a Work Plan that is suitable for their equipment and procedures. Each ECA Application is posted for 45 days to allow public comment. 

These procedures have led to guidance and requirements that are now contained within the CSA Group standard, CSA-C448-2013 Design and Installation of Earth Energy Systems, that will now provide more guidance for drillers. The C448 applies to new and retrofit installations and also covers minimum requirements for ground-source heat pumps for residential and commercial buildings. 

The C448 standard is developed and approved by technical subcommittees and a technical committee respectively that represents a multi-stakeholder forum representing the geothermal industry from across Canada. As an accredited standards developer in Canada and the U.S., CSA standards are developed using a consensus based, balanced matrix approach that ensures that concerns from all stakeholders are discussed and vetted. The CSA C448 will be developed as a bi-national standard with the U.S. by 2015 as an ANSI designated standard. CSA Group is a not-for-profit, independent standards developer.    


Muktha Tumkur, P.Eng., is the program manager of renewable energy for the CSA Group. She can be reached at

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