Let’s talk

• With the project, Hydro-Québec is addressing the demand for power today and tomorrow. The equipment is aging and must be replaced. As a result of demographic growth and economic development in the area, much more electricity is being used now than ever before.
• The project will facilitate development and add some 500 MW of capacity to supply a range of economic and social projects in the area.
• The upgrade is taking place against the broader backdrop of the transmission system development plan for the island of Montréal begun in 2009 to boost Hydro-Québec’s transmission capacity by raising the voltage from 120 kV to 315 kV.
• The project will improve the reliability of the electricity supply and ensure long-term continuity of service for all the region’s residents. If it isn’t carried out, the risk of outages and malfunctions will increase. It will also become difficult to serve new customers and meet demand in this booming area. Hydro-Québec is required to provide electricity to all Québec residents.

• The project has two main components:
  • Rebuilding the overhead transmission line, between Aqueduc substation in LaSalle and Saraguay substation in Saint-Laurent, a distance of 18 km, to raise it from 120 kV to 315 kV
  • Converting three 120-kV transformer substations—Laurent substation (in Saint-Laurent), Hampstead substation (in Côte Saint-Luc) and Rockfield substation (in Lachine)—to 315 kV
• The overhead line will be built on the existing right-of-way. In the upcoming stages, the project team could consider variants on the route with a view to mitigating the impacts of the line, while at the same time taking into account technical, economic, environmental and social feasibility criteria.
• Hydro-Québec is also taking a preliminary look at building a substation in Dorval, along with a supply line connecting it to the rebuilt transmission line.

• Aware of the impacts of such a project on the environment, Hydro-Québec is willing to facilitate initiatives involving greening and sustainable transportation along the power line right-of-way. Hydro-Québec wishes to ensure that the project fits in with the urban development vision of its municipal partners and support their initiatives, such as creating a corridor of biodiversity, connectivity and sustainable mobility along the right-of-way. The feasibility of any such initiatives depends on the specific needs and constraints of the surrounding environment.
• Hydro-Québec and its partners will establish an approach to integrate the project into its environment. This approach may take the form of public information sessions, coordinating committees, working committees or other mechanisms to be determined with municipal entities and community groups.
• A regional monitoring committee made up of various community partners will also be set up and will observe the project’s advancement. Working committees will be struck for specific areas or facilities as part of the project.
• The public is welcome to take part in various information and consultation activities over the next few months. For more information, see the timetable of public participation activities.

• Although the electric and magnetic fields (EMFs) on the transmission line right-of-way existing are very weak, Hydro-Québec has performed an analysis to determine the difference between the EMFs associated with the existing line and those associated with the planned line. We found that EMFs will remain weak, well below the public health authorities’ recommended exposure limits.
• Studies indicate that the electric field generated by the planned 315-kV line will be slightly stronger, but still well below the recommended exposure limit of 4.2 kV/m.* That’s because the electric field is determined by the voltage, which will go from 120 kV up to 315 kV. We should point out that the electric fields do not enter homes, as they are blocked by walls.
• The magnetic field generated by the planned line will be slightly weaker than that the one generated by the existing line. Even at its strongest, the magnetic field will be well below the recommended exposure limit for the public of 200 μT.* This can be explained by two factors: the distance away from the power lines and the current intensity (amperage). The power lines will be higher, and intensity of the magnetic field will weaken with the distance. In the case of this project, the amperage will be lower, and it is amperage (not voltage) that determines the magnetic field.

  *The recommended exposure limits for electric and magnetic fields are those of the International Commission on Non-Ionizing Radiation Protection (ICNIRP), an organization affiliated with the World Health Organization (WHO).

• Evidence from a number of scientific studies carried out over the past 40 years has not demonstrated harmful effects on health from exposure to electric and magnetic fields at voltage levels normally present in the environment, such as those emitted by high-voltage power lines at the edge of their right-of-way.
• Health Canada and the Ministère de la Santé et des Services sociaux du Québec take similar positions on this matter.
  • Health Canada: The Power System and Health – Electric and Magnetic Fields
  • Ministère de la Santé et des Services sociaux du Québec (2014): Position des autorités de santé publique sur la gestion des champs magnétiques émis par les lignes électriques [Public health authorities’ position on electromagnetic fields emitted by power lines] [PDF 2.68 MB – in French only]
• Although the health impacts of EMFs have never been confirmed, Hydro-Québec has made a commitment to be vigilant and prudent with respect to EMFs and their possible health effects.

The literature downloadable using these links will provide additional information:

• Electric and Magnetic Fields
• Brochure: The Power System and Health – Electric and Magnetic Fields [PDF 1.89 MB]
• Video: Electric and Magnetic Fields: Over 40 Years of Scientific Studies
• Video: Electric and magnetic fields: A Québec study

• Power lines, like roads and railways, are an integral part of our modern landscape.
• Experts have found that a number of factors influence property values, including market conditions, the proximity of schools and parks, access to transport, the neighborhood and the quality of buildings. Many of these factors are subjective and mean different things to different people: what is important to one buyer might not necessarily be to another.
• These studies tend to show that, in some extreme cases, when a new electricity transmission corridor is created, the presence of a high-voltage line may play a role in determining the value of properties in urban and rural environments, but any impact observed is minor or barely perceptible and tends to diminish with time.
• Furthermore, the implementation of mitigation measures (such as landscaping) on rights-of-way is a generally well-perceived factor that may help enhance the desirability of the property and therefore its market value.
• Like other public companies in Canada, Hydro-Québec pays compensation only when it obtains a servitude to run a power line or purchases lots needed for a project. In this case, the property rights were acquired from landowners in the 1950s.