Okotoks is taking a local approach for future expansion of its wastewater treatment.
Senior engineer Jeremy Huet said the town’s wastewater treatment plant is reaching capacity and there are few options but to consider a $21 million expansion of the facility over the next five to 10 years.
“There is a lot of discussion on water in this town,” said Huet. “It’s an important topic, but it’s more than just water procurement. We need a solution for wastewater as well.”
The results of two studies were presented to Town council on May 23. One looked at either building a regional wastewater treatment plant or sending wastewater to Calgary through a pipeline. The second examined upgrades to the current Okotoks plant.
The studies showed it will cost the Town considerably less to upgrade its existing plant.
The Foothills Regional Water Wastewater Collaborative hired consultants to examine building a plant near Aldersyde to service the region. Four options were presented, but they came at a cost close to $500 million, of which Okotoks would have to pay close to half.
“The regional options were cost prohibitive, especially in the absence of grant funding,” said Huet. “It’s just not viable.”
Another option was to construct a pipeline to the Fish Creek wastewater plant in Calgary. He said it would have been a fraction of the cost, coming in just over $200 million. The Town’s share would be between $78 million to $110 million over 25 years.
However, he said the pipeline is a no-go because the City of Calgary is reserving additional capacity at Fish Creek for its own growth.
As a result, the Town is now taking a closer look at expanding its existing treatment facility.
The Town is looking at adding a system that uses membranes with a high rate clarifier to filter water that will treat wastewater to higher standards when river levels are low, while also providing a bypass option during major storms and floods.
“It’s a unique approach… it would protect the river when it’s at its most sensitive point,” said Huet.
He said the Town’s effluent quality is very high, but it would improve with the membrane filtration system, sending even cleaner water into the river.
Biological treatment would also still be used, he said.
“The biological treatment we use involves using microorganisms to break down nutrients like phosphorous and nitrates,” said Huet.
The next step is to receive approval of the proposed upgrade from the Province, he said.
“We will need regulatory approval before we proceed,” said Huet. “Right now we’re engaging Alberta Environment and following up with additional modeling and study to support our method.”
He said much of the estimated $21 million expansion costs could be covered by fees paid by developers.
“This is typically funded through developer levies,” said Huet. “The developers pay a levy per acre to pay for infrastructure upgrades so the cost is recovered through that.”
