Single Stream Recycling

Single stream recycling

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Single stream recycling (also known as “single-sort” or “comingled” recycling)  is a system where all accepted recyclable materials are placed in a single bin, cart or dumpster for collection by the waste management company and sorted in a special facility, rather than being separated into material types by the resident.  Currently in Cocke County we are not using single stream recycling: materials have to be separated by the resident and deposited into separate bins at the convenience center.  Many residents are not willing to invest the effort and simply put all their refuse in the dumpsters headed for the landfill.  Could single stream recycling improve the rate of participation in recycling?  Could the benefits outweigh the disadvantages?  Let’s take a look.

Advantages of Single Stream Recycling [1]

  • Reduced sorting effort by residents may mean more resident participate in recycling and more recyclables are recovered.
  • Reduced collection costs because single-compartment trucks are cheaper to purchase and operate, collection can be automated, and collection routes can be serviced more efficiently.
  • Greater fleet flexibility which allows single compartment vehicles to be used for refuse or recycling, providing greater fleet flexibility and reducing the number of reserve vehicles needed. To avoid confusing customers, a large sign or banner is sometimes used to distinguish when a refuse truck is being used for recycling.
  • Worker injuries may decrease because the switch to single stream is often accompanied by a switch from bins to cart-based collection.
  • Changing to single stream may provide an opportunity to update the collection and processing system and to add new materials to the list of recyclables accepted.
  • This processing means added jobs for the community.

Potential Disadvantages of Single Stream Recycling [1]

  • Initial capital cost for:
    • New carts for city collection
    • Different collection vehicles
    • Upgrading the processing facility
    • Hiring personnel to sort the materials
  • Possible reduced commodity prices due to contamination of paper.
  • Increased “down-cycling” of paper, i.e., use of high quality fibers for low-end uses like boxboard due to presence of contaminants.
  • Potential for diminished public confidence if more recyclables are destined for landfill disposal due to contamination or reduced marketability.

The video below gives a detailed look at how a state-of-the-art, large scale single stream recycling facility works, and what residents need to be aware of to help the facility work efficiently.  As an overview: residents place all recyclable materials into one container either at a collection point like our Convenience Centers or a bin or cart for curb-side collection in cities.  These co-mingled recyclable materials are taken to a sorting facility where personnel and special equipment separate the various types of recyclables and bale them for sale to re-manufacturing buyers.

The biggest issue in sorting is to eliminate contaminants in the finished bales.  To receive top dollar from the buyers, the bales must be found to be free of illicit materials.  High end paper bales, for example, must not contain metal, plastic, or low end papers like pasteboard.  Even shredded paper, although a high end product originally, cannot be handled by these facilities because the shredded paper does not behave like sheets of paper and will end up in the wrong bin or – worse yet – if it has gotten wet will clump up and jam the mechanisms.

Starting up a single stream recycling program can be expensive if state of the art equipment is desired to reduce labor costs.  If the sorting is done primarily by hand, a building, conveyors, bins and a baler as well as storage space are required.  And considerable amounts of labor.

The advantages of co-mingled recycling come mainly from greater participation in recycling programs by residents.  In Cocke County, like most areas, recycling is voluntary: no fines are issued for failure to separate out recyclable materials, therefore many residents don’t wish to invest the effort of separating out the various types of recyclables: paper, cardboard, aluminum, steel, different types of plastic, and depositing each of them in the proper containers. Single stream recycling means residents can place all recyclables in a single container and eliminate most of the sorting and storage hassles.  Increased participation means fewer recyclables ending up in the land fill.  More recyclables being processed means more revenue for the community waste management program and reduced cost for disposal of trash.  Less material going into the land fill means the facility doesn’t fill up as fast, requiring a new location.  And these programs do mean more jobs for the community. Over time, the initial investment is more than paid back through increased revenues and reduced expenses for waste handling.

From an ecological standpoint, maximizing the re-use of recyclable materials not only reduces the amount of non-degradable materials going into the ground, but reduces the need for virgin materials, thus extending the limited natural resources we have.

Of course, for the program to run efficiently, residents need to be conscious of what they toss in the recycling bins.  As the video below mentions paper should be clean, dry and flat; not wadded up, cans should be left whole; not crushed, aluminum foil should be balled not folded… these considerations help the sorting machines work efficiently and reduce problems like jamming.

When residents cooperate with a single stream recycling program, many benefits can be realized by their community.

If your browser won’t play, watch the video on [YouTube]


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