Lot 5 Works – PRÉSTEP – Rehabilitation program for the Gatineau wastewater treatment plant.

This project aimed to modernize and optimize the wastewater treatment plant to ensure efficient and sustainable treatment of wastewater and sludge, while maintaining plant operations throughout the construction period.
The work carried out included:

Process Mechanical Work:

• Addition and refurbishment of grit removal systems
• Installation of new screening equipment
• Upgrading of the primary sedimentation system
• Replacement of the aeration and blower systems for secondary treatment
• Improvement of sludge-related facilities (pumps, thickener, digesters)
• Modernization of the biogas management system

Civil Work:

• Selective demolition
• Earthwork operations
• Building excavation
• Retaining structure work across three sectors
• Excavation over eight metres deep
• Creation of a pumping and sediment treatment system
• Construction of access routes and exterior surfaces
• Rehabilitation of underground networks (stormwater, sanitary sewer, water distribution)
• Landscaping to restore the site

This modernization project contributes to improving the plant’s environmental performance, optimizing biogas recovery, and ensuring reliable, compliant, and efficient wastewater treatment.

Project Highlights:

• Continuous treatment operations maintained during construction through careful planning and coordination
• Civil work performed year-round, in both summer and winter conditions
• Simultaneous interventions on several critical processes requiring tight management of technical interfaces
• Integration of modern technologies to enhance energy sustainability and reduce environmental impact
• Continuous biogas treatment for energy recovery