The City of Kelowna is trying to figure out what to do with a rapidly growing stockpile of biosolid-based fertilizer.

The fertilizer product — called OgoGrow — is the product of a joint operation with the City of Vernon. It is produced at their facility on the outskirts of Vernon since 2006.

The process takes biosolids — the sludgy end material formed from sewage —  from both cities' wastewater, combines the solids with wood waste and composts the material into a fertilizer that is sold to consumers.

Revenue from sales of the product go back to the operation.

Andrew Reeder, utility planning manager for the City of Kelowna, says they usually produce 29,000 tonnes of OgoGrow a year.

From Sewer To River

Biosolids are combined with wood waste and wood ash to create the OgoGrow fertilizer. (Manuel Balce Ceneta/Associated Press)

However, he says they haven't been able to sell that amount and the city has an excess of 50,000 tonnes in its storage facility.

In the meantime, fertilizer is continually being produced. 

Part of the increase is due to Kelowna's growing population, Reeder says. In February 2016, Stats Canada found the Kelowna Metro area to be the fastest-growing in Canada with a population increase between 2014 and 2015 of 3.1 per cent.

"If the population is growing by two per cent, our growth is also two per cent. It's really a direct link to the number of people we have," he explained.

A product with 'stigma'

Another problem, he says, is the "stigma" around biosolids-based fertilizer. Some critics claim the substance can have pharmaceutical residues, pathogens or heavy metals and pose a risk to human health.

Feeder says consumers shouldn't worry.

"We have a very strict testing regime. The product that we sell to the public is actually been tested very strictly in accordance to federal and provincial guidelines. It's actually a lot safer than other products out there like [animal] manure," he said.

He said the city is looking into different ways it can use the substance including land reclamation projects. The city is also looking into reducing the number of biosolids it creates in the first place by using different treatment processes.

"We're looking at all available possible technical solutions as well as management solutions to see what we can do in terms of the growth that we're seeing in our city and we can do this moving forward," he said.

The cities of Kelowna and Vernon are also launching a survey on possible waste management treatments options. Residents can access the survey online.

Listen to an interview with Andrew Reeder on Daybreak South: