Barrie spends $60M to cut phosphorus levels

By Bob Bruton, Barrie Examiner 

Next year Barrie will begin spending $60 million to cut the level of phosphorus entering Lake Simcoe from the wastewater treatment plant.

Work at the Bradford Street plant could include constructing foundations, concrete tanks, pumps and piping, membranes, mechanical, electrical, instrumentation communications and associated engineering services.

“The project is still on schedule for a construction start in late 2018,” said Graeme King, the city’s environmental senior project engineer. “Currently we are continuing with the pre-design phase.”

Barrie’s sewage plant is currently approved, by Ontario’s Ministry of Environment and Climate Change, for concentration limit discharges of 0.10 milligrams per litre of phosphorus into Kempenfelt Bay and/or Lake Simcoe.

This translates into a loading of 2,774 kilograms a year of phosphorus at the current rated capacity.

The concentration objective is 0.07 mg/l of phosphorus.

“Conventional technology cannot always reliably meet these low requirements,” King said, “and therefore innovative technology has to be implemented, such as the proposed membranes.”

Due to its nutrient value, the phosphorus is mixed with biosolids and then field-applied.

Why is this project, and the cost, necessary?

The 2008 Lake Simcoe Protection Act decreased the amount of phosphorus that can flow into the lake, but Barrie’s sewage plant had already been designed seven years earlier and was being constructed.

The ministry accepted the expected post-construction phosphorus levels at Barrie’s wastewater facility would be .12 mg/l, in accordance with the certificate of approval.

The ministry did note, however, that phosphorus allowance levels might change when the Lake Simcoe Protection Plan was approved.

One of the major focuses of that 2009 plan – developed after the Act to restore the health of Lake Simcoe – was the overabundance of phosphorus.

It enters the lake from storm sewers, septic systems, airborne particles and agricultural runoff, not only from Barrie’s sewage plant.

While some phosphorus is necessary for a healthy lake ecosystem, too much of it increases the growth of plants and algae. Less phosphorus reduces vegetation growth, which results in less oxygen demand when plants decompose.

It’s been reported the dissolved oxygen has been increasing near the bottom of Kempenfelt Bay, King said, allowing the growing coldwater fish to stay closer to the bottom, which protects them from higher-level predators.

The $60-million cost of this program has three funding sources – 35% from wastewater reserves, 32.5% from development charges and 32.5% through debentures, which is how municipalities borrow money. The city is also continuing with efforts to obtain funding from other levels of government.

This project’s construction phase is 2018-2021, and it’s part of Barrie’s capital plan for this period.

King said city staff will be initiating a web page by the end of March 2017, on barrie.ca, to provide project information such as history, background, need, schedule, Class EA requirements, pertinent staff reports and memos.