Phosphorous is also recovered from the biosolids at a Nutrient Recovery Facility, run in a partnership between EPCOR and the nutrient recovery company Ostara, to produce fertilizer for farm use across Canada.
In addition to the agricultural land application, biosolids are used at surface mining operations undergoing reclamation, such as the Paintearth mine near Forestburg, Alberta. These biosolids help regenerate natural plant life by returning nutrients and organic matter to the land.
And then there is the water, which also goes full circle, whether it comes out of the North Saskatchewan River or the Salt River aquifer. EPCOR’s Jeff Stuck has worked in the Arizona water industry for decades. He has observed the state’s progressive approach to groundwater management for the better part of 30 years. There might be no better example than how reclaimed water is provided to golf courses, for example, so they don’t have to draw water from a river or an aquifer. “It’s part of the whole balancing of limited water resources in Arizona,” says Stuck.
EPCOR provides A+ standard quality effluent in Arizona, which is the highest possible quality rating and indicates the water can be reused for any purpose other than human ingestion. It’s considered safe for body contact, which is why there is no health risk from an accidental spraying in the middle of watering a golf course or a park or a public soccer field. It can also be used for dust control at construction sites. EPCOR is working on another project in the valley’s San Tan area to move treated water to agricultural sites for watering non-edible crops. “It’s all about the aquifer,” says Stuck. “It’s just another way to keep aquifer water in the aquifer and to only draw water for potable purposes. Every other water demand we should be able to fill through alternative means.”
At the Gold Bar plant, back in Edmonton, wastewater is put through a stringent purification process once solids and nutrients have been separated out. Treated water is returned to the North Saskatchewan River. Also worth noting is that EPCOR supplies a portion of the treated water to Suncor for its Edmonton-area operations, which means it does not have to draw water from the North Saskatchewan River. Even before all that happens, however, there are invisible sources of energy and power to be reclaimed. There is the liquid and the solid, but also the gas and the heat. Wastewater is very high in energy, not just because it’s coming from the human body but because it is emanating from controlled climate locations (namely, bathrooms, sinks, showers and drains). Energy is energy and there is no reason not to put it to use. The energy is not yet extracted from the treated water that returns to the river, says Saif Molla. “But when we do it’ll just be another piece in the circular economy puzzle. We are doing a lot but there is still so much potential.”
What is extracted is the biogas produced during the treatment process. “Biogas is a very useful resource,” says Molla. “There’s a significant methane concentration in it, which is natural gas, essentially.” That methane is used to feed boilers that heat the buildings, the boilers and the digesters at Gold Bar, which means some of the energy contained in wastewater, once separated, is turned right around and used to treat and purify the new wastewater coming in.