formwork being installed for new aeration tank at thornbury wastewater treatment plant

Thornbury Wastewater Treatment Plant Expansion

On this page:
1. Project Updates
2. Map of Project Area
3. Quarterly Progress Reports

The Thornbury Wastewater Treatment Plant was completed in 1994, with a rated capacity of 3580 m3/day. This project will include the construction/installation of all equipment required for operation of the Extended Aeration treatment system to increase capacity to 5,330 m3/day.

Step 1

  • Civil site prep work

Step 2

  • Addition of one extended aeration tank, including aeration system, required accessories, and alum addition 
  • Addition of one clarifier and associated mechanical system
  • Increase the current Ultraviolet disinfection system to meet 5,330 m3/day
  • Replacement of existing air blowers, including required valves, controls, instrumentation and distribution piping
  • Additional 14,000 m3/day mechanical screen and associated hardware to be added
  • Incorporate energy efficiency throughout the plant
  • Construction of a new outfall pipe to Georgian Bay

Expansion of the plant was approved as part of the 2020 Town Budget. It is anticipated that the detailed design will be completed in Q3 2022. Construction will be completed in two steps to allow for scheduled advancements. The first step is scheduled to be completed in Q3 2022, with the second step beginning immediately afterwards. The project is expected to be completed in Q4 of 2026.

Why Now?

To replace end-of-life equipment and ensure the Thornbury Wastewater Treatment Plant is capable of providing reliable service in line with the forecasted growth of the community.

Project Updates

October 20, 2023

The Town's contractors have been working on building and installing the formwork and rebar for the walls of the new Activated Sludge building and aeration tank. Hydrostatic testing of the piping that will be located beneath the base of slab of the new secondary clarifying tank has also been completed. Work will continue over the coming weeks to prepare for the next round of concrete pours, which will include the walls for the aeration tank and lower walls for the activated sludge building. Upgrades to the existing Secondary Clarifier No.2 are scheduled to start in early November.

Map of Project Area

Map of project area

Quarterly Progress Reports

Q2 2023 Project Scope: Within expanded scope
Project Schedule: On revised schedule
Project Budget: Within revised budget