Lagoon Sludge Removal Project Update – Aeration System Trial - September 25, 2026

The lagoon aeration system is beginning to show some improvement, with dissolved oxygen (DO) levels increasing to approximately 0.60 mg/L over the past two days. While this remains below the trial target of 1.5–2.0 mg/L or greater, staff are encouraged by the recent change.

Additional lab results are also becoming available. The latest results are from samples collected September 15. The raw Biochemical Oxygen Demand (BOD) was 122 mg/L, while the sample collected at the splitter box, after the aeration cell, was 103 mg/L. Design specifications indicate that the splitter box result should be closer to 60 mg/L.

For comparison, samples collected when the aeration system was restarted on September 8 showed a raw BOD of 80 mg/L and a splitter box result of 480 mg/L. The significant increase at the splitter box was expected following the three-month shutdown, as restarting the system stirred up accumulated material in the pond.

These recent results suggest lagoon conditions may be beginning to stabilize as the aeration system continues to operate. Staff will continue to closely monitor dissolved oxygen (DO) levels and laboratory results to assess whether the positive trend continues, with the goal of seeing DO levels increase and BOD levels at the splitter box decrease.

Although the current aeration system is beginning to show positive results, the Municipality is also undertaking proactive background work with its engineering team and aeration provider to identify and evaluate potential future enhancements. This approach ensures that staff are prepared to respond effectively should additional measures be required to support long-term lagoon performance and odour control.

The aeration system trial is expected to run for approximately 14 to 21 days. We are at day 17. 

Updates on the Lagoon Sludge Removal Project will be posted every Tuesday and Friday throughout the aeration trial. Residents can also subscribe to receive project updates directly to their inbox.

Contact the Project Team