The Hoelscher Ferrer North America (HFNA) consortium has started its operations with the completion of its first Dewatering in Canada. It has been executed in the works of a wastewater pumping station in the town of Orillia, Ontario.
This inaugural project has received the esteemed ‘The Dewatering Consultant Project of the Year‘ distinction in the Award Winners 2023 gala, organized by the renowned global entity, The Dewatering Institute. This prestigious award serves as a strong endorsement of the consortium’s implementation process in Canada, with FERRER® playing a pivotal role as a strategic partner.
Facing water table control challenges that had led a prior company to halt excavation of the WWTP, the contractor JB Enterprises reached out to Hoelscher Ferrer North America for resolution. The previous subcontractor had attempted to lower the water table using an eductor-based system, but its design and capacity proved ineffective.
The construction of the pumping station presented several challenges: its location in an area bathed by the waters of Lake Simcoe; next, the presence of the water table at a depth of just one meter; the depth of the excavation at 12 meters; and the preferential hydraulic connection of the underlying rocky substrate with the lake itself, manifested from a depth of 16 meters.
After a thorough analysis of the previous project’s shortcomings, HFNA‘s technical team devised a solution involving a network of 10 low-capacity deep wells. This innovative approach was rooted in a 3D porous medium numerical flow model, known by the code FEFLOW®.
The execution was completed in a remarkable 45 days, despite facing challenges such as extremely low temperatures, reaching as low as -20°C (-4°F), as well as the unique
characteristics of the soil used, lacking compaction or natural cohesion. These soil properties contributed to the differential settlement of the platform during the installation of the wells.
Dewatering in Canada
The successful completion of HFNA’s Dewatering in Canada plan made it possible to proceed with the construction of the pumping station. All project objectives were met. The determination and confidence that JB Enterprises placed in HFNA played a crucial role in the success of this project.
The previous Wastewater Pumping Station was over 90 years old, and its capacity was insufficient for current needs. This new WWTP, whose works were resumed thanks to the intervention of HFNA, will allow the expansion and improvement of Orillia’s sewage systems.