Municipalities tend to be split on the best way to recycle – single stream or source separation? So, what’s the difference?
The Single Stream AdvantageOn first glance, single stream looks like the most convenient option. The University of Wisconsin (UWM) lists several advantages to the system:
- People are busy and crave convenience, so single stream could possibly lead to more people deciding to recycle. UWM gives the case study of Madison, WI. When the city switched from source separation to single stream in 2005, recycling increased by 25 percent.
- On the trash collector’s end, single stream means reduced costs for cheaper, easier to operate single-compartment trucks.
- The ease in collection leads to less loose waste in the streets.
- Single stream also provides a reason for recycling systems to update their processes, which often results in adding a wider array of materials that can be recycled. The product UWM mentioned was the amount of paper grades collection can handle after updated processes.
- Collectors save money, which could mean 5-25 percent savings on average, resulting in possibly more money back to local governments.
- There’s a concern over glass shards and PET bottles contaminating paper loads and causing issues in paper mills.
- Glass, plastic and aluminum containers can cross-contaminate each other.
- Scrap material quality is much lower under the single stream model, resulting in lost revenue.
- While collection costs are lower, processing and contamination disposing costs jump to about $3 more per ton with single stream. Overall, single stream appears to be more expensive.
- Source separation has a reduction of contamination and increase in materials to be recycled.
- Fuel costs are lower on curbside separation vehicles.
- There are more local jobs for sorters, plus using a real human to sort means they can leave feedback to homeowners about what can be picked up and what can’t.
- Additional compartments in the source separation truck can accommodate for odd items like batteries.
- The total cost for source separation is lower.
- The overall revenue for materials increases with source separation. Paper isn’t contaminated with glass. Metals separated out earlier are more pure (manufacturers find pure aluminum more useful for cans, for instance). Separated, pure glass can be re-melted, rather than sold off as an aggregate.