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ReLoop: What is Single Stream Recycling?

Danielle Peacock

As part of our increasing work in recycling and recovery, Project Associate Danielle Peacock and Senior Manager Anne Bedarf are debuting a new recycling blog series, ReLoop, which will address different recycling topics, questions, and concepts. Danielle kicks the series off with a primer on single stream recycling. If you have a specific recycling topic you would like covered here in the future, let us know!

There are three primary ways to collect household recycling: single stream, source separation, and no separation from trash (or “all in one”). Each of these methods poses unique benefits and trade-offs for recycling. This first installment of ReLoop tackles single stream recycling, which is quickly becoming a national trend.

Single stream recycling requires households to use two separate collection bins for their waste, one for trash and one for recycling. Residents place all of their recyclable materials in one bin, separate from their trash container.1 On collection day, the materials are transported to a Material Recovery Facility, or MRF. The MRF will use a combination of hand sorting, sensors, magnets, and gravity to sort the materials. You can find a great animation of how a MRF works here. After sorting, the materials are baled and sold to market.

Many communities are transitioning to recycling carts that are of equal size to trash bins. This enables and encourages residents to collect more recycling than they could fit into a small tote bin or bag. Communities may even use the same trucks to collect trash and recyclables, minimizing any additional transportation or operating costs. The same truck may pick up your trash one week and recycling the next. Trucks can also be designed with dividers, so that trash goes in one section and recycling in another.

The Good: Putting all recyclable materials into one container makes recycling easier for households. Ease of use, and the prevalence of large bins, allows high collection volume. Participation in recycling is also incentivized when communities reduce trash collection to twice a month and provide increased recycling collection to compensate.

The Bad: While volume is increased, the quality of the materials that are recovered can suffer. When recyclable materials are lower in quality, they fetch a lower price at market and may be used in lower quality products. For example, if a glass jar full of sauce breaks during the recycling process, the sorting equipment may not catch the glass and the sauce will contaminate other materials, like paper. Sorting is also an imperfect science, though the technology continues to evolve.

It is important to place empty and clean materials into your bin, and follow all recycling instructions provided by your community. If you have any questions or comments about single stream recycling, leave us a comment below!



1. The US EPA definition of single stream recycling: “Single stream” collection programs allow participants to put all recyclable materials (e.g., paper, bottles, cans, etc.) into one collection container… These materials are then collected and separated, usually at a central point such as a materials recovery facility (MRF)… For single stream recycling to work, the processing facility must sort the recyclable materials properly and thoroughly to meet market specifications.”

 

5 Responses to ReLoop: What is Single Stream Recycling?

  1. Anne Bedarf says:

    A related anecdote: my mother’s community in PA now has large, rolling carts for recycling. The neighbor told me this weekend that because of them, they are now recycling more, and that it was a good reminder of all of things that can be recycled.

  2. Kate says:

    This blog is a great idea, thank you! I’m curious if you have any information about the rates of material that is discarded resulting from contamination during single-stream vs source separated collection methods? Also, because bales of material collected single-steam are priced lower, are you aware of any waste-to-energy plants that purchase this material for its lower price tag and high BTU?

    • Danielle Peacock says:

      Hi Kate, thanks for your comment!

      Materials discarded as contamination (or “residuals”) vary both between single stream vs. source-separated programs as well as between different communities. The residual rate at your local material recovery facility (MRF) depends on what consumers put in their bins. This makes local education essential. Our local MRF in Charlottesville cites a 5% residual rate. As a starting point, the University of Wisconsin’s Cooperative Extension Program has a great summary on single stream recycling, with some case studies on both cost and residual rates for source separated and single stream recycling. You can find the download “Single Stream Recycling” under the “Publications” tab on the following page, but you could also contact your local facility to find out what their residual rate is. (http://www4.uwm.edu/shwec/programAreas/programInfo.cfm?programId=2)

      Regarding waste to energy, I am personally unaware of any facility that buys bales of single-stream materials. Some states and countries require that recyclables be pre-sorted out of WTE feedstock, and these governments frequently set recycling targets to ensure this effort. The US EPA Solid Waste Management Hierarchy also still places recycling above energy recovery. (http://www.epa.gov/osw/nonhaz/municipal/hierarchy.htm)

      Regards,
      Danielle

  3. Matt Lechel says:

    What’s the actual data? How much does single stream lose through contamination? How much MORE do people recycle because single stream is easier? There seems to be a lot of hype against single stream, but I’m still searching for actual data that proves it’s worse. Can’t consumers be trained to cause less contamination, just as there were trained to separate recycling? We just switched to single stream in my neighborhood and it seems to be going very well. I don’t really see how mixing (washed out) plastic and glass w/ paper causes contamination. Great article, thanks!

    • Danielle Peacock says:

      Hi Matt,

      See my response to Kate above. Unfortunately, as you have probably seen, recycling data can be difficult to compile. Your municipality or local recycling facilities may be able to give you information on residual rates. If you do find more data, I do hope you’ll share!

      Regarding consumers – this is one of the hopes for our How2Recycle Label (www.how2recycle.info). We hope that this new recycling label will teach consumers how to keep the recycling stream clean. I also have to applaud all of the recycling coordinators and educators out there that work very hard to educate consumers.

      Regards,
      Danielle

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