Notice of Decision 2025-08-22

An analysis carried out by Jacques Cartier and Champlain Bridges Incorporated (JCCBI) has determined that the project to reconfigure the Bonaventure Expressway into a boulevard is not likely to cause significant adverse environmental effects.

This determination is based on the following factors:

• impacts on the rights of Indigenous Peoples;
• Indigenous knowledge;
• community knowledge;
• comments received from the public;
• technically and economically feasible mitigation measures.

Effective mitigation measures are planned for each potential environmental impact. The project includes measures for protecting the natural environment, fauna, and flora, as well as for controlling nuisances and managing contaminated soil, wastewater, hazardous, and residual materials. Here are a few examples of the most key mitigation measures developed specifically for this project :   

• Worksite Activities: The contractor shall organize worksite activities to reduce the movement of vehicles and machinery, thereby minimizing their environmental impact. For example, the contractor is required to plan work schedules and signage, considering daily rush hours and summer periods, and to minimize the project's overall impact on traffic.  
• Acoustic Environment: When noise emissions of 75 dBA or more are likely to be heard in a sensitive area, the contractor shall, via a noise control program, evaluate the noise that will be emitted and, if necessary, implement the required mitigation measures. The contractor shall also use equipment fitted with noise-reduction devices, such as mufflers and temporary screens.
• Vibrations: The contractor shall take the required measures to reduce vibrations that may be transmitted to neighbouring buildings.
• Excavated Material Management Site: An excavated material management site, including an area for soil segregation, characterization, and temporary storage, will be developed as part of the project to promote soil reuse. Drainage ditches must be developed at the start of the work to collect surface water on the site, as well as a system for on-site runoff water treatment. The contractor shall cover the banks and bottoms of the ditches with a geomembrane. The contractor shall cover with a tarpaulin all excavated soils classified beyond criterion C, and any hazardous materials stored on the excavated material management site, at the end of each workday before they are mandatorily managed off-site. It must also characterize soils from areas likely to contain fragments of invasive alien plant species (IAPS).
• Runoff Water Management: Worksite areas (grading and reprofiling) must be developed to collect and direct all runoff and leachate by gravity toward drainage, mitigation, and treatment structures. The contractor shall treat the collected runoff and leachate that is discharged into the St. Lawrence River by using mitigation or treatment measures set up at the excavated material management site. These measures include the following:
  • ditches with check dams and filtering berms with sediment traps;
  • a sedimentation treatment bassin;
  • water quality monitoring to meet the river discharge objectives estimated based on the Canadian Water Quality Guidelines for the Protection of Aquatic Life.
• Debris Management: Throughout the work in urbanized areas, the contractor shall clean the streets used by vehicles and machinery daily to remove any accumulation of loose materials and other debris. The contractor shall set up a cleaning area for truck tires and excavation equipment. The contractor shall also install temporary silt fences where eroding soil particles are likely to run off outside of the earthwork areas. The objective is to prevent sediment flow from entering the municipal system, ditches, and watercourses and, where applicable, from accumulating on the perimeter of temporary storage or disposal areas near a watercourse and at any other location requested by the engineer. The contractor shall install waterproof protective tarpaulins over stockpiles of unconsolidated materials or excavated residues such as sand and soil, whether temporary or not.
• Groundwater Management: The contractor shall monitor groundwater quality and ensure the integrity of the containment system, the cut-off wall, the groundwater pumping wells, the Free Phase Hydrocarbon (FPH) pumping wells, and the treatment plant.
• Flora Protection: The flora on the shore of the St. Lawrence River must not be removed or damaged. The contractor shall protect all components of the natural shoreline habitat to preserve their ecological value. Avoid using soils from areas where IAPS have been previously identified for backfilling. If soil is being reused from an area where Invasive Alien Plant Species (IAPS) are present, a specific management plan must be developed. This plan must be tailored to each invasive species found, based on how it spreads (its propagation method) and its level of risk.

• Fauna Protection: In general, the contractor shall avoid carrying out work that could lead to the destruction or disturbance of nests during the migratory bird nesting period. If clearing, grubbing, or stripping is necessary during the construction phase, the contractor shall remove vegetation in the work area in the fall or winter to avoid the bird nesting period (April 1 to August 30). If it proves impossible to respect the proposed restriction periods, the contractor shall have the site inspected by a biologist before proceeding with clearing, grubbing, or stripping work to avoid the destruction of migratory bird nests. When reforesting, use plants native to Quebec and diversify the species planted. The contractor shall design the vegetated areas along the Bonaventure Expressway to enhance the habitat for herpetofauna and other wildlife native to the shoreline. Finally, several specific protection measures are also planned for the DeKay's Brownsnake and for turtles. These include implementing a relocation and reintroduction program, as well as monitoring populations during the operational phase to get a better idea of the populations' status and to better measure the project's impact on these populations and their habitat.

Furthermore, as this sector was used as a landfill for industrial and domestic waste for 100 years until 1966, its soil and groundwater are contaminated. Thus, to optimize the environmental management of the sector, JCCBI has developed a risk management strategy based on various environmental response measures that will ensure the health and safety of users and wildlife. This strategy is based on the following elements:

• Containment of contaminated soil - covering with a minimum of 50 cm of clean soil (CCME Parkland criterion) and installing geotextile or permanent infrastructure.
• Biogas capture.
• Installation of a containment, pumping, and treatment system for contaminated groundwater.
• Protection and maintenance of the containment system to ensure it effectively contains and captures free-phase hydrocarbons.
• Soil and bank stabilization.
• Selection of plants with shallow roots and no edible parts.
• Planting pits for deep-rooted trees.
• Worker Protection Program.

The project aligns with the Federal Sustainable Development Strategy, which aims to encourage active transportation and connect Canadians with nature. In addition, rebuilding the Bonaventure Expressway's drainage structures will increase the infrastructure's resilience to climate change.

The project includes implementing a new containment system for contaminated groundwater, which will have a significant positive impact on this component and on surface water quality (the river) during the urban boulevard's operational phase. 

The revegetation and creation of micro-habitats for the DeKay's Brownsnake should allow this species to increase its presence on the site. Furthermore, increasing the canopy index will help reduce heat islands in the summer by cooling the air, decrease air pollution, mitigate weather phenomena such as wind, better manage rainwater, and improve soil quality by stabilizing it and limiting erosion.

Residual and cumulative effects were taken into account in this analysis. By implementing mitigation measures and a comprehensive environmental monitoring program, the project is not expected to cause significant adverse environmental effects. In addition, JCCBI has hired a firm specializing in worksite supervision to continuously monitor the work and ensure compliance with the planned mitigation measures.

Consequently, JCCBI will move forward and allow the project to be carried out, in whole or in part.