Proposed substation site
Since the beginning of the project, a number of different sites have been considered for the substation. The technical and environmental surveys conducted to date have shown that here is only one location that meets the following key criteria: proximity to Lachute substation and the existing power system, ability to integrate the substation to its host environment, noise levels around the substation, and surface area of the host site.
The site proposed for the new Argenteuil substation is located north of the existing Lachute substation, between Chemin de l’Île-aux-Chats and Avenue d’Argenteuil in Lachute.
Argenteuil substation, which will be similar to Pierre-Le Gardeur substation 315/120‑kV, will cover an area of about eight hectares. It will be designed to accommodate four 450‑MVA transformers, electrical equipment and a control and telecommunications building.
Proposed line routes
The 315/120/25‑kV Argenteuil substation will be supplied by two new double‑circuit lines: one at 315 kV and the other at 120 kV.
The existing 120-kV lines (circuits 1118 and 1121), located north of Highway 50, will also be connected to the future Argenteuil substation.
The new line routes were determined based on the following key criteria:
- Prioritize the use of an existing transmission line right‑of‑way.
- Juxtapose the two new lines and their support structures as much as possible to improve their integration into the landscape.
- Prioritize the shortest line routes to decrease the number of components likely to be impacted.
- Follow lot boundaries whenever possible.
120-kV Double-circuit line
Stretching approximately 7 km, the new 120-kV line will be built along the edge of the right-of-way for the 120-kV single-circuit line erected on wooden H-frames (circuit 1126). Once the new line is commissioned, the old single-circuit line will be dismantled.
315-kV Double‑circuit line
Stretching approximately 5 km, the new 315-kV line will connect the new Argenteuil substation to the existing 315-kV Chénier–Outaouais line (circuits 3121‑3122). It will be juxtaposed to the new 120-kV line, optimizing the use of the existing right‑of‑way.
Right-of-way
The right-of-way for the line routes under study consists of a 30-m long stretch of the right‑of‑way for the existing 120-kV line (circuit 1126), which will be extended on each side to reach a total width of approximately 85 m.
Preliminary technical characteristics of the planned lines
The new 315-kV and 120-kV lines will be supported by steel lattice towers. Reduced‑footprint towers will be prioritized whenever possible on farmland. The height and number of towers will vary according to the terrain and the distance between towers.
