Single-Stream Recycling
Single-stream recycling is the collection of all recyclable waste together. For example, this means soda cans, plastic bottles and newspapers can be collected altogether in one bin. Single-stream recycling aims to divert more waste from landfill by making it easier for people to recycle their waste. There’s less decision making required because people don’t need to sort their recyclables. However, single-stream recycling has sparked many discussions and debates over how effective it really is within the recycling industry.
The container on the left collects all recyclables together while the container on the right collects cans & bottles and paper separately.
“What we found [over the years] was that single stream is often reported as having the highest collection volumes … but it´s not just the amount collected. It´s how much actually makes it into a manufactured product at the end of the day. With those higher contamination levels, the costs are higher for the mills and reclaimers, so of course the mills and reclaimers pay less for the output of single‐stream then they do for cleaner materials.”
– quote by Susan Collins, executive director of the Container Recycling Institute (CRI)
Here’s a list of the top advantages and disadvantages of single-stream recycling to help you decide what’s best for your organization.
Advantages
- Increases recycling program participation because it’s a simple system. All recyclables are collected together so people don’t have to spend time deciding which bin to toss their cardboard cup, newspaper or soda can into.
- Easier for custodial staff to collect recycling in one bin at the back-of-house rather than sorting the bags into different front end loaders/dumpsters.
- Opportunity for organizations to reduce their waste hauling costs through contract negotiation and streamlining collections.
- Streamlined waste hauler collection of recycled material. They just pick up the full recyclables bin when ready rather than collecting sorted recycling in different bins on a scheduled pick up.
- Municipalities have seen a significant increase in the volume of recyclable waste being collected in single stream programs. A 2002 study in Minnesota found that 21% more recyclables were collected in single-stream programs.
- The increased volume of recyclable waste being collected diverts more waste from landfill.
- Provides a great opportunity for organizations to increase their diversion rates because the program is simple for people to use and so collects more recyclable waste.
- It’s widely accepted in the recycling industry that collection costs are reduced for municipalities who have single-stream curbside programs. This is due to the decrease in the frequency the collection trucks need to be unloaded and the ability to standardize the fleet.
- A 2007 presentation by the Solid Waste Association of North America (SWANA) stated that collection savings from single stream were $10-20 per ton.
- Municipalities can collect more material with less labour costs; they can reduce the number of employees and improve route efficiency.
Disadvantages
- Recyclables arrive at the Material Recovery Facilities (MRFs) unsorted resulting in increased processing costs because the MRFs have to sort the recyclables before they can sell to the market.
- Mixing recyclable items together reduces the market value due to contamination. The value of paper for example reduces significantly if it’s contaminated by liquids or other items.
- Contamination can also affect the ability of the recycler to produce quality end products. For example if paper is not properly separated into different grades at the MRF and is then delivered to the Mill, the recyclable newsprint could contain some old corrugated cardboard (OCC) which when processed together will result in reduced quality newsprint. This can lead to lost revenue costs for the mills if their newsprint is not good enough quality.
- Contamination can also cause equipment failure for recycling plants and mills which leads to lost productivity and expensive repairs.
- Studies have shown that while single-stream MRFs take in a greater volume of recyclable material compared to dual stream (or source separated recycling), they send a smaller volume out for recycling due to the contamination.
- Unwanted contaminants are sent by the recycler to landfill disposal. This means a plastic bottle that was put in the recycling bin could end up as landfill because it was sorted out as a contaminant at the paper mill.
- On average only 40% of glass from single-stream collection is recycled into glass containers or fibreglass compared to 90% for dual-stream and 98% for bottle-deposit programs. This is because glass gets easily broken in single-stream collection and is then hard to separate at the MRF. Broken glass is usually downcycled into things like sandblasting base or aggregate material and this is less desirable in terms of recycling’s goal for reducing energy conservation and avoiding emissions.
- A large proportion of North America’s recyclables were being shipped to China for sorting and processing into raw materials due to cheaper freight and inexpensive labour.
