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.

August 3, 2023

Site excavation work has been progressing well. The Town's contractor has completed the majority of the excavation work required for the new aeration tank, clarifier and Return Activated Sludge / Waste Activated Sludge (RAS/WAS) building. The initial concrete pour for the bases of the new aeration tank, RAS/WAS building and Mixed Liquor Chamber is scheduled for this week. Following that, they plan to begin installation of the underground piping for the new clarifier as well as the formwork and rebar for the new aeration tank.
Staff Report CSOPS.23.017 was presented at a Special Meeting of Council on Friday, April 14. The report requested that the budget for the Thornbury Wastewater Treatment Plant Expansion Phase 1A construction be increased by $4,873,000, to a total budget of $29,000,000 to allow staff to award the construction tender. The request was carried as Council voted to approve the request.

This staff report was brought directly to Council as there is an urgency to keep the project on schedule, and ensure there is adequate capacity at the treatment plant to meet the ongoing needs of the Town.

View Staff Report
On behalf of the IBI Group, a contractor will be completing additional geotechnical work to inform the engineering of the new outfall line for the Thornbury Wastewater Treatment Plant. The geotechnical work will be completed over 1-2 days in the month of April. A track-mounted drilling rig will be used to drill boreholes on Grey Street North and along the unopened Grey Street North road allowance between Bay Street East and the shore of Georgian Bay. Formal notices have been hand delivered to all neighbouring properties.
Site preparation work for the Thornbury Wastewater Treatment Plant Expansion will begin this week. A contractor will be onsite to begin required tree removals. These trees are being removed to accommodate the realignment of the plant entrance and associated site grading. An Arborist Report and a Species at Risk Screening Report were completed for the site, and no concerns were found. A buffer of trees between the Treatment Plant and Highway 26 will be maintained, and the Town intends to plant additional trees on the site to enhance buffers following the completion of construction.
November 30, 2022 - Offshore surveying work

Survey crews will be completing water depth measurement work by boat offshore from Grey Street in Thornbury on Wednesday, November 30, 2022. The work will include surveying the bottom of the lake to aid with the detailed engineering phase of the new Thornbury Wastewater Treatment Plant outfall line.

September 13, 2022 - Upcoming topographical survey work

The IBI Group’s topographical survey crew will be on site Thursday, September 15 and Friday, September 16 from 9:00 a.m. to 4:00 p.m. to survey areas related to the new Wastewater Treatment Plant outfall line that was identified in the May 3, 2022 Staff Report.

View Survey Area

May 3, 2022 - Expansion update and request for budget increase

A Staff Report was presented to Committee of the Whole on Tuesday, May 3 providing an overview of the progress on the Thornbury Wastewater Treatment Plant Expansion Phase 1A.

The report also asked Council to approve an increase of $4,500,000 to the original project budget which was approved in 2019, and to approve the negotiated procurement of engineering services for the design of a new outfall line.

View Staff Report

Map of Project Area

Quarterly Progress Reports

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

Past Progress Reports

Q1 2023	Project Scope: Within expanded scope Project Schedule: On revised schedule Project Budget: Within revised budget
Q4 2022	Project Scope: Within expanded scope Project Schedule: On revised schedule Project Budget: Within revised budget
Q3 2022	Project Scope: Within expanded scope Project Schedule: On revised schedule Project Budget: Within revised budget
Q2 2022	Project Scope: Scope expanded Project Schedule: Schedule revised Project Budget: Budget increased Notes: Project scope, schedule and budget has increased to include the design and construction of a new outfall pipe. View Staff Report
Q1 2022	Project Scope: Within scope Project Schedule: On schedule Project Budget: Within budget