Dumping all your bottles, cans, and paper in one recycling bin is convenient, but those materials may end up in a landfill.
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.
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.
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.