Tigard treatment plant turns waste into fertilizer
By Kennedy Smith
Municipal representatives from Oregon cities Eugene, Corvallis and Salem and Washington’s King County headed to Tigard on Thursday to check out a trial experiment at Durham Advanced Wastewater Treatment Facility.
Clean Water Services, which runs the treatment facility, is employing a new technology that removes phosphorus from wastewater and recycles it into environmentally safe commercial fertilizer.
The removal system, developed by Ostara Nutrient Recovery Technologies in Vancouver, B.C., is being used at one other wastewater facility in the United States, in Suffolk, Va.
Typically, wastewater treatment plants remove phosphorus and other pollutants and divert them into a sludge stream of liquids and solids, Phillip Abrary, president of Ostara, said.
Treated solids can be recycled as soil additives, but liquids are reprocessed back through the wastewater system, adding to the cost of the system by clogging pipes with a concrete-like substance called struvite. The new technology removes phosphorus from the liquid, eliminating the presence of struvite.
After the trial, Clean Water Services will consider adding a full-scale reactor, capable of processing all of the sewage that comes through the site, Mark Poling, wastewater department director for Clean Water Services, said Ostara will pay for packaging and shipping the fertilizer, Debra Hadden, a spokeswoman for Ostara, said.
Part of the proceeds from the sale of fertilizer would be given back to the municipality.
The pilot project began in May and will wrap up June 22. Durham Advanced Wastewater Treatment Facility provides treatment for Beaverton, Tigard, Sherwood, Tualatin, Durham and King City.