I’ve been curious about how single stream recycling works, so I did some searching today and found this YT video on the process. It’s pretty interesting how much equipment there is do do the sorting, but I was also struck by the manual labor in the process. Humans manually remove and sort some items that can’t be handled by the machines. I wonder how intensive that job is on the body and mind. In the end, anything that isn’t captured by humans or machines gets set to a landfill or to a trash-to-energy site. I’ve heard that that percentage is large. I wonder how large it is.
I also found this resource from the Container Recycling Institute.
Overall, single-stream costs about $3 more per ton than dual-stream.
I would have expected single-stream to have lower costs because of the efficiency gains. The CRI page linked above has a list of reports on the bottom right. I’d love to read all of them soon, but today I skimmed one: Understanding economic and environmental impacts of single-stream collection systems. Insights:
- Glass is hard to recycle. It has low efficiency in getting into actual recycled glass products.
On average, 40% of glass from single-stream collection winds up in landfills, while 20% is small broken glass (“glass fines”) used for low-end applications. Only 40% is recycled into containers and fiberglass. About one third of the non-recyclable glass is broken glass, too small to separate for recycling, some of which can be used for sandblasting base, aggregate material, or Alternative Daily Cover (ADC). These “down-cycled” uses do not have the same savings in terms of energy conservation and avoided emissions. In contrast, dual-stream systems have an average yield of 90%, and container-deposit systems yield 98% glass available for use in bottlemaking. (Only glass that is sorted by color can be used to make glass containers.)
- Contaminants are thrown away because they can make processing equipment break, which is a huge financial setback.
A study conducted in 2002 by Eureka Recycling (of St. Paul, Minnesota) compared five different collection methods, and found that single-stream collected 21% more material than the baseline method. However, the study did not ultimately recommend a single-stream system, because the lower collection costs were outweighed by higher processing costs and lower material revenues.
I also signed up to be on the waitlist for St. Paul’s Recycling Ambassador program. Hoping that I can actually participate this summer and not have to wait until another year.