The Blue Mountains sewage plant costs escalate, more work added

The expansion and upgrade of the Thornbury Wastewater Treatment Plant just got a lot more expensive and complicated.

The Blue Mountains council at its committee of the whole meeting on May 3 received a staff report about the project that outlined significant cost escalations and a new wrinkle that staff had just discovered.

The report asked the committee to approve a 25-per-cent increase to the project’s budget, raising the total to $22.5 million from $18 million. With 60 per cent of the engineering work now complete, staff realized the $18 million budget set in 2020 would not be enough. The increase will be funded from development charges and reserves.

In addition, staff outlined that during the due diligence phase of the project they discovered the plant’s outfall line that returns treated effluent to the Beaver River is too small and will have to be replaced in order for it to handle the plant’s expanded sewage treatment capacity.

“This was a shock for us as a project team,” said Director of Operations Shawn Carey.

Town staff explained that over the years, there are engineering reports about the Thornbury plant dating back to the mid-70s. Somewhere along the line, there was a miscalculation that resulted in the town relying on data that said the outfall line could handle increased capacity from the plant once it was expanded. Once staff and the engineers on the project double-checked the numbers, the problem was discovered.

“There were some things that just didn’t add up,” said Manager of Capital Projects Brent Rolufs. “There were no indications from previous reports that we were going to have a problem.”

The replacement of the undersized outfall pipe is a major project on its own and will require significant regulatory approval from various government agencies. Staff recommended the town begin the work immediately. Staff requested permission to use the services of the engineers on the Thornbury wastewater treatment plant project (IBI Group Professional Services (Canada) Inc.) to design a new outfall line at a cost of $1,600,000 to be funded from Wastewater Development Charges. They estimated the pipe replacement would cost more than $7 million.

“It’s a bit of a mess to clean up,” commented Councillor Rob Sampson, suggesting it might be time for the town to look at alternate sewage treatment technologies rather than continuing on the path of plant upgrades and expansions.

The committee narrowly approved the report and recommendation in a 4-2 vote with councillors Rob Sampson and Andrea Matrosovs opposed. The issue will come to a full council meeting in the future for a decision.