Progress Continues at Thornbury Wastewater Treatment Plant Expansion

NAC’s work on the Phase 1A Expansion of the Thornbury Wastewater Treatment Plant (WWTP) is moving steadily forward in 2025, with a number of key structural, mechanical, electrical, and commissioning milestones achieved during the first quarter of the year.

Significant progress was made across all major buildings onsite. In the Headworks Building, the mezzanine slab extension was successfully formed and poured, supporting future mechanical and electrical installations. Screening equipment has now been installed, and electrical crews have begun pulling power feeds in preparation for commissioning.

The Administration Building has also seen momentum, particularly in process equipment commissioning. Blower 2 has been tested and tied into the new programmable logic controller (PLC), and Blower 1 followed suit after demolition and replacement of its existing foundation pads.

Heating, ventilation, and air conditioning (HVAC) systems are taking shape across the site. Ductwork and insulation have been completed in the RAS/WAS Building, while installations in the blower room are nearly finished, with only final fans remaining for commissioning.

In the UV Building, structural upgrades continue. Concrete slabs have been poured, upper wall forms are in place, and waterproofing is complete—allowing backfilling operations to begin. Meanwhile, the Return Activated Sludge / Waste Activated Sludge (RAS/WAS) Building is nearing mechanical completion, with the monorail now installed and operational. This will allow for improved maintenance access to the facility’s pumping systems.

Electrical and control systems integration is also well underway. Electrical work in the RAS/WAS Building is complete, and commissioning is actively progressing, with the full building pumping system expected to be online by the end of April.

With these advancements, NAC remains focused on delivering a modernized, higher-capacity treatment facility that supports the Town of Thornbury’s long-term infrastructure needs. The project team continues to drive toward substantial completion in the coming months.