The journey of a can or plastic bottle tossed into Durango's blue plastic recycling bins can be a wild ride, involving fast-moving conveyor belts, massive drops and long road trips.
That's the beauty of the single-stream recycling system: On any given day, a plastic bottle and a tin can that was once smooshed side by side could end up across the country from each other, the aluminum being turned into new cans in the Midwest and the plastic being repurposed in a processing facility in the Northwest.
When the city of Durango ditched curbside sorting in favor of single-stream recycling in February, it joined thousands of other communities across the nation. From 2000 to 2007, the number of Americans with access to curbside recycling who had single stream increased from 11 percent to 50 percent, according to a 2010 article in Resource Recycling.
Many of the biggest players in the waste industry see single stream as the future of recycling and are investing millions in advanced technology to sort paper from cardboard and No. 7 plastics from No. 2s. The single-stream concept has increased participation and collection efficiencies for cities, saved resources and reduced landfill waste.
But the system isn't perfect. Studies show sorting facilities experience contamination and cost increases with the growing diversity of materials, while the markets for the recyclables, especially certain types of plastics, is to some extent new and unstable territory.
In Durango, recycling has met overwhelmingly positive support, said Roy Petersen, director of city operations. From February through June, the city doubled the number of residents participating in the recycling program and has seen the volume of recycling collected increase by 85 percent during the same period in 2012. Trash redirected from Bondad Landfill translates into reductions in greenhouse gas emissions. The additional material diverted from the landfill during the first part of 2013 equates to a reduction of 9,395 metric tons of carbon-dioxide equivalent, equal to the annual emissions of 1,842 passenger vehicles, said Mary Beth Miles, the city's sustainability coordinator.
Keeping it clean, profitable
While single stream has earned green accolades for generally increasing collection volumes and resident participation, the quality of materials tends to take a hit. It's harder to separate the various plastics from one another, and in many places broken glass is impossible to extract from the tangles of paper products.
One nationwide study by the Container Recycling Institute showed that about one quarter of recycled material in single-stream systems is landfilled, though individual rates can range from 5 percent to 30 percent, said Amity Lumper, a principal with Cascadia Consulting Group. According to city statistics, Durango bucks the trend. Only about 1 percent of the materials that come from the city must be diverted to a landfill – because of the efforts of city employees who sort the materials and the city's strict no-glass policy, Miles said.
The Franklin Street Materials Recovery Facility in Denver, where Durango's recycling ends up, sends between 8 percent and 12 percent of its recyclables to the landfill, said Tiffany Moehring, spokeswoman for Waste Management, which owns the facility. Moehring said Waste Management doesn't see a significant difference in contamination rates between single stream and dual stream, the system in which containers and paper are collected separately. The company, like many others, has invested millions in machinery that use gravity, air, magnets and cameras to pull apart various materials to make single-stream sorting more effective, Moehring said.
While the city of Durango has avoided major contamination woes in its switch to single stream, the issue has ballooned to affect suppliers and producers of recycled materials across the world. Last year, a paper mill in eastern Arizona, which felt pressure to process increasingly contaminated loads of paper, closed its doors after the loads mucked up the mill's machinery, and its finances.
Items such as plastic lids, shopping bags and aluminum cans added weight to the incoming loads but were worthless to the mill and clogged the machinery, according to a 2012 article in The Denver Post.
And now China, the United States' No. 1 customer for scrap and trash, has began to turn away shipments of plastics and other materials contaminated with nonrecyclables under its newly launched Operation Green Fence. The initiative has put the brakes on the flow of recyclables out of United States ports, and the effects have ricocheted across the county. At recent conferences, even companies in Colorado that supply recyclable materials – mostly plastics – to producers have seen the effects, said Marjorie Griek, executive director of the Colorado Association for Recycling. As China rejects more materials, the supply builds up in the United States, driving down prices. Cities at the other end of the recycling chain could start to see lower offers for their materials, affecting their ability to fund their programs, Griek said.
The city of Durango is still calculating the costs and savings of single stream, though right now there is no difference between single stream and the city's previous source-separated system, Petersen said.
And while painful, those in the industry said Operation Green Fence was a needed wake-up call that jolted the industry to improve the quality and cleanliness of sorted materials.
“We were basically exporting trash to China, and that's not appropriate,” said Mark Thompson, owner of Phoenix Recycling in Durango.
The end game
One of single stream's benefits, that it collects a much broader range of plastics, poses another challenge to closing the loop of the recycling system. The markets for No. 1 and No. 2 plastics are fairly well-established domestically, but the higher-numbered plastics have fewer established uses. That makes markets for those plastics harder to find and more volatile, said Fay Fisk, with Centennial Recycling, a Colorado company that brokers recyclable materials. Higher-numbered plastics also tend to be sent to overseas producers more often, which comes back to the trickiness of dealing with and depending on foreign markets, Fisk said. The American Chemistry Council's numerical system tries to put dozens of different materials into seven categories, the seventh of which is “other” and can mean anything, Thompson said. Sorting through the multitude can be difficult, he said.
The thing to remember though, is that if companies can reuse the recycled material, they will, Thompson said.
“This is a capitalist system, and people are buying this stuff,” he said. “There is no company that can (economically) buy stuff and then throw things away.”