Cities across the United States are making recycling a lot simpler for their residents. Put all your paper, glass, metal cans, and plastic bottles into one bin and set it out at the curb, and a truck comes to pick up your mixed recyclables. No need for multiple bins in your garage to sort out glass from cans from paper: Somebody else does the work for you at the other end of the line.
It’s called “single-stream” recycling collection. Not only is it convenient; it makes collecting recyclables cheaper. But there’s a catch, a rather big one: A surprising proportion of your recyclables ends up in the landfill anyway.
In 1987, there were just four single-stream curbside recycling programs in the entire United States. Now, hundreds of communities, from rural outposts to Beverly Hills, have single-stream collection. It’s not hard to understand the appeal single-stream holds for local waste management agencies. The greater convenience makes it more likely that people will participate in your recycling program.
You also save on equipment and labor costs. If you ask the public to separate out paper, glass, and metal, you need trucks with three compartments to haul it away, and your recycling crews do three times the bending and lifting. With just one bin you only need one compartment in your trucks, and they can do the lifting, saving on payroll and workers’ compensation expenses.
“Single-stream collection can work very well if you do it right and scale it properly,” said recycling expert Neil Seldman, executive director of the Institute for Local Self-Reliance, a sustainability think tank.
So what’s the problem? Collecting recyclables is just the beginning. To truly recycle what you set out at the curb, that stuff needs to be made into new products. That means you have to find buyers who want to turn your old bottles, cans, and paper into new stuff.
Once collected, recyclables are taken to a materials recovery facility (MRF), where they’re sorted either by hand or using expensive, high-tech equipment. From there, the materials go to buyers of scrap glass, paper, metal, and plastic. High-quality glass can be turned into new bottles. High-grade office paper can become new office paper. The higher the quality of the recyclables, the better the process works—and the more cash the recycler gets from the sale.
That’s the problem. Single-source collection usually delivers lower-grade material than recyclables from multiple-bin collection programs. That means the material gets “downcycled” into less valuable products, if it isn’t discarded entirely.
For example, clear glass usually brings a much higher price than colored glass, as it can be easily recycled into new clear glass or fiberglass insulation. Sorted brown and green glass can be remade into colored bottles.
But when a single-stream truck dumps its load out onto the concrete floor of a transfer station, many of the jars and bottles in the load will break. That makes it next to impossible to sort the glass, and that means the broken glass can only be used for lower-grade products, such as roadbed fill.
One 2009 study found that about 40 percent of glass collected in single-stream recycling programs was reused for new containers or fiberglass. Another 40 percent went into onetime uses such as roadbed fill, and 20 percent went straight to the landfill.
In other words, of each six-pack of empty bottles put into a single-stream collection bin only about two and a half are reborn as new bottles. By comparison, says the study, programs that require residents to sort their recyclables can sell more than 90 percent of collected glass for use in new containers.
Broken glass ruins other recyclables as well, especially paper. Paper mills won’t use paper that’s obviously contaminated with glass shards, as it ruins their recycled product and can cause serious damage to equipment.
The same goes for plastic. And if single-stream cities find that their income from scrap sales is declining, those losses cut into the money saved on collection. In many cases, that lowers single-stream’s net cost savings to between 1 and 2 percent. Meanwhile, somewhere between 15 and 27 percent of all single-stream collected recyclables end up in a landfill. That undoes the benefit of more people recycling.
Those statistics seem right to Ford Schumann, founder of eastern Maryland’s Infinity Recycling. “It’s really rare for a single-stream operation to sell high-quality glass. Paper markets don’t like single-stream. Actually, no buyers like it.”
Infinity, which provides a variety of recycling collection services to largely rural communities on Maryland’s Eastern Shore, has just launched a “dual-stream” curbside collection service, in which glass, metal, and plastic containers are sorted into one bin, with paper going into the second.
Dual-stream systems reduce glass breakage, leading to better-quality scrap and higher actual recycling rates.
One thing helping maintain the quality of Infinity’s end product is the company’s size.
“We’re small,” said Schumann. “Baltimore County’s MRF handles 1,000 tons of single-stream recyclables a week. We do 1,000 tons a year.”
Call it “artisanal recycling.” That smaller scale is the key to successful recycling, whether or not you use single-stream collection, said Seldman.
Single-stream hasn’t spread in a vacuum. Since the 1990s small local recyclers like Infinity have increasingly found themselves displaced by big companies like Waste Management, which usually replace local MRFs with larger regional facilities. Those mega-MRFs mean dirtier conditions on the sorting line, which means more recyclables end up in landfills.
There’s one other downside to single-stream, regardless of the recycling program’s size: Sorting our recyclables makes us more aware of just what we’re throwing away.
“Dual-stream recycling teaches people,” said Seldman. “It makes them better citizens, in the sense that they help create the most efficient system possible for dealing with our waste.”
That education can result in a passionate devotion to recycling, no matter the inconvenience. “We were all used to dual-stream collection in Washington, D.C.,” said Seldman. “When they switched to single-stream, people were furious.”