A "geothermal" or "ground source heat pump"
heats and/or cools a building by using a heat-transfer fluid to
exchange heat with the ground or ground water, rather like a giant
refrigerator. Ground source heat pumps are, in principle,
highly desirable; they are much more energy efficient than
conventional HVAC systems, and can moderate peak electrical
However, like all energy sources, ground source heat pumps can
have their drawbacks, including the risk of releasing hazardous
underground gases. Heat pump installers were not being sufficiently
careful about this risk; now they are required to.
In an open loop system, groundwater is pumped from a well or
series of wells and circulated through a heat pump located inside a
building. A heat pump extracts the heat and distributes it
throughout the building. The system then injects the water
back into the aquifer through a well or discharges it to a stream,
river, lake or pond.
In a vertical, closed loop heat pump system, vertical holes are
drilled into the ground and a U-shaped loop of pipe is installed in
each hole. A heat transfer fluid circulates through the system of
pipes connected to the heat pump inside the building. A horizontal
system works much the same way, but the heat transfer fluid
circulates through network of buried pipes in trenches.
Under the new regulation, anyone constructing new or altering,
replacing or extending existing vertical closed loop geothermal
systems that extend more than 5 meters below the ground must obtain
an Environmental Compliance Approval (ECA) from the MOE. As part of
the ECA application, the installer must also submit a work plan
1.is prepared by a licensed engineering practitioner or
2.identifies equipment and procedures to be used to monitor for
the presence and migration of hazardous gas;
3.identifies measures to be taken to prevent or reduce the
likelihood of the migration of hazardous gas, whether through the
hole or otherwise, during construction, alteration, extension or
replacement of the vertical closed loop ground source heat pump,
including detailed requirements for,
ensuring that any space around the underground heat exchanger
is sealed to prevent any movement of hazardous gas between
subsurface formations or between a subsurface formation and the
ground surface, or otherwise managing the gas in a way that removes
any potential hazard, and
decommissioning the heat pump if measures under subclause (i)
are not taken, or are taken but do not remove all potential
4.identifies measures to be taken to prevent an adverse effect
if hazardous gas is encountered;
5.identifies a standard of protection that is at least equal to
what is required in similar circumstances by "Oil, Gas and
Salt Resources of Ontario – Provincial Operating
Standards", version 2.0, dated January 24, 2002 and published
by the Ministry of Natural Resources, as amended from time to time;
6.includes a health and safety plan. O. Reg. 98/12,
s. 3 (3).
Horizontal geothermal systems are not at risk of encountering
natural gas as they are not installed deep enough to encounter
Open loop systems are regulated by the Wells Regulation
(Regulation 903) and the Ontario Water Resources Act. A
sewage works Environmental Compliance Approval is also required for
open loop geothermal systems.
The prohibition against using or operating ground source heat
pumps that use methanol as a heat-transfer fluid (except for those
in operation before June 1, 1998) continues under the new
Ontario's Ministry of the Environment and Climate Change continues to roll out its Climate Change Action Plan with its proposed GHG guide for projects that are subject to the province's Environmental Assessment Act.
The Imperial Oil refinery pled guilty to one offence for discharging a contaminant, coker stabilizer, thermocracked gas, into the natural environment causing an adverse effect and was fined $650,000...
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