On March 1, approximately 1,000 Portland businesses participating in Metro’s food scraps program made the transition to food-only collection. Three of the largest businesses making the switch were the Oregon Convention Center, Portland’5 Centers for the Arts and the Portland Expo Center, all Metro venues.
Erin Rowland, sustainability coordinator for the Oregon Convention Center, said the transition is an improvement in the region’s collections program.
"Food is the valuable commodity in the system and food-only collection is easier for the public to understand," Rowland said. "Now our customers are not responsible for knowing which plastics are compostable and which papers, etcetera."
The reason for the switch? All those forks and compostable plates and cups weren’t being effectively processed in Oregon’s new anaerobic digestion facility. Food waste that's anaerobically digested is processed in a contained, oxygen-free environment.
The breakdown of the food produces gases that can be converted to electricity. The material remaining after processing can be used as fertilizer or further processed into compost.
JC-Biomethane, the Pacific Northwest’s first biogas plant to accept post-consumer waste is in Junction City, near Eugene, and has been accepting the food waste from Metro’s food scraps programs since it opened in summer 2013. Because the compostable service-ware and other non-food items can’t make it past the initial contaminant removal system, they are screened out and sent to a landfill.
The food waste sent to JC-Biomethane is expected to produce 12,250 megawatt-hours of electricity annually, energy equivalent to what would be needed to power about half the homes in Junction City for a year. The renewable power is sold to Portland General Electric.
In addition to electricity, the digestion process results in a solid that can be is composted to create a soil amendment and a nutrient-rich liquid fertilizer that is given to a local farmer who practices organic and conventional farming. The liquid has already proven to increase the yield of organic wheat, according to Dominic Vacca, JC-Biomethane's CEO.
According to organic waste experts, the benefits of this type of processing are many – especially in an urban area. While traditional open-air composting can result in strong odors when large quantities of food waste are processed, there is not an odor at the anaerobic digestion facility.
"From my perspective, this step - switching to 'food only'" - is a gentle course correction on the continuing pathway of maximizing the value of the region's organic discards," said Meredith Sorensen, principal of Solid Strategies, an organic waste consulting service.
The Metro venues are working on creative strategies to keep the volume of their solid waste streams down and avoid using too many single-use items like plastic forks and paper plates that have to head to a landfill.
The Oregon Convention Center serves catered events on ceramic serviceware, and the concession stands have moved to single-use items. Rowland said the goal is to get away from the single-use items, but a solution may take some creativity.
"Food-only increases the cleanliness of organics collected and forces organizations to think about waste reduction in a different manner," she said. "You have to be more strategic because there aren’t easy solutions, there isn’t a single-use item that can be recycled or composted."
In June, the convention center will pilot a new approach with one convention, Rowland said. "They have rented the whole facility and we are working with them to use china and recyclable plastic. The convention is providing recycling volunteers who will clean the plastics."
Rowland said this is just one of many strategies the OCC is considering.
Portland’5 Centers for the Arts and Portland Expo Center were primarily impacted by the March 1 switch to a food-only effort when it comes to cups from their concession stands.
"We are in the process of selecting the best recyclable or reusable and recyclable cups to use in the future," said Jason Blackwell, the operations director for Portland’5 Centers for the Arts.
Robyn Williams, the centers' executive director, said the switch to food-only is going smoothly – and it’s good for the environment.
"We’re supportive of any sustainability efforts period," Williams said.
Chuck Dills, director of operations at Portland Expo Center said the switch to food-only feels like the right thing to do.
"Ideally, there would be a compostable solution, but we tried that out and it didn’t work, so this makes the most sense to us," he said.
Nearly one month into the switch, Dills said that the transition has gone remarkably well.
"Out of the hundreds of cans of food waste we’ve had at the Expo Center, I’ve had two that were contaminated with some cups and we cleaned those out, so we have a 100 percent success rate so far."