Know before you throw; dual-stream recycling at NU
Everybody knows NU is crazy about recycling. Between RecycleMania, EPA Game Day, and food waste composting, Northwestern is passionate about diverting waste. But how the waste is diverted is a bit more complicated than one might imagine. Recycling at NU works in a system called dual-stream, meaning that there are two separate collections of recyclables, one collection for paper and cardboard and another for cans, glass, and plastic. So your soda can goes in one bin and last quarter’s final paper goes in the other. Some places, like University of Oregon, use a multi-stream system, meaning they separate their recyclables even more, with up to five bins. Many municipalities and universities use a single-stream system, meaning all recyclables go in the same bin on-campus or at home and then get sorted at the recycling plant.
When recycling bins are full, NU custodial and housekeeping staff empty them, taking the contents to designated bins at a collection point. From there a contracted recycling hauler picks up the materials and takes them to a sorting facility or Materials Recovery Facility (MRF).
So why not single-stream? NU has remained dual-stream for two big reasons. The first: Northwestern offices and students use a lot of high-grade copy paper. This bright white paper is the only kind that can be recycled back into high-grade paper. When it is mixed into recycling bins with other materials, like liquids and broken glass, it can’t be made into white paper again. This means it can only be recycled into low-grade, single-use paper products, like tissues or napkins, which end up in a landfill. Northwestern aims to recycle materials at the highest level possible to maximize resource reuse.
The second reason is because dual-stream systems have lower rates of contamination. In fact, according to the Solid and Hazardous Waste Education Center, contamination rates are only between 2 - 3 percent in dual-stream systems, but skyrocket to 15 - 27 percent in single-stream systems. Manager of Sustainability and Resource Management, Julie Cahillane believes, “with single-stream people tend to stop thinking about what they’re throwing into recycling bins and end up including trash.”
However, going single-stream isn’t entirely out of the question. Many Big Ten schools, like Ohio State and University of Michigan, are single stream. NU already recycles 36 percent of the campus waste stream. However, Northwestern is constantly looking for ways to increase the diversion rate, especially at large scale events, including sporting events. Our recycling rate is on par with comparable schools, but we are looking for opportunities to become leaders. If processors and manufacturers can work with single-stream collections and it can be done with less contamination, NU may switch to single stream in the future.
Many cities are single-stream, which makes sense for their needs. Cahillane says the reason this works is because most residential settings don’t use a lot of high-grade paper, like we do at Northwestern, so there isn’t as much of a need to separate it out. Wherever you travel this summer, check local recycling guidelines to find out if your city or workplace is single or multi-stream.