City extracts good from the bad. Nutrient recovery site, nation’s first.

Canada’s first commercial nutrient recovery facility at the city’s Wastewater Treatment Plant (WWTP) will not only be good for the environment, it will also benefit Saskatoon taxpayers, says Mayor Don Atchison.

“It makes us the leader in Canada,” said Atchison of the $4.7 million project that uses Ostara Nutrient Recovery Technologies Inc.’s Pearl nutrient recovery process to recover phosphorus and nitrogen from the facility’s waste water stream and transform them into Crystal Green, a slow-release fertilizer.

The technology removes potentially polluting nutrients from the treatment facility’s waste water stream, which will help the city meet nutrient discharge limits and also improve the operational issues caused by the unintentional buildup of struvite scale in plant equipment.

Struvite is a concrete-like mineral deposit that chokes process equipment, increases operating and maintenance costs, and undermines plant reliability.

The formation of struvite is a common challenge in plants like that used by Saskatoon and other cities, said Utility Services general manager Jeff Jorgenson.

“Our priority is to protect the people, property and environment of the community we serve,” Jorgenson said.

“The main benefit is the protection of the plant,” he said. “For years we have been fighting a struvite problem at the Wastewater Treatment Plant … We were spending millions of dollars in repairs.”

The cost savings from fewer dollars spent on plant maintenance and fertilizer sales (about $100,000 annually) will more than offset the cost of the project, Jorgenson said.

“Hopefully we will end up with a surplus from this that will in fact reduce taxes for all of us,” Atchison said.

The Ostara system will recover 75 per cent of the phosphorus and 10 per cent of the nitrogen from the waste water stream before they accumulate in the equipment. “Instead of treating them as waste, or a problem in the pipe, we transform the phosphorous and the nitrogen into a fertilizer that has a high agronomic, environmental and economic value,” said Ostara president and CEO Phillip Abrary.