Connecticut Department of Energy & Environmental Protection

Single Stream Recycling FAQ

What is Single Stream Recycling?

Single stream (also known as "fully commingled") recycling refers to a collection system that mixes all recyclable paper fibers and containers together in a bin at the curb and in the collection truck.  In single stream, both the collection and processing systems must be designed to handle this fully commingled mixture of recyclables.

What Are the Advantages Attributed to Single Stream?

Proponents of single stream note these advantages:

  • Easier sorting by residents, than, for example, a dual stream collection system where paper recyclables are kept separate from recyclable containers (e.g. bottles, cans, jars).  This may result in more recyclables placed at the curb and more residents may participate in recycling programs;

  • May reduce collection costs - single compartment trucks should be less expensive to purchase and operate, and collection routes can be serviced more efficiently.

What Are the Potential Advantages when Combined with Other Program Changes?

  • Changing how you collect recyclables, using single compartment vehicles allows for greater fleet flexibility, which could reduce the number of reserve vehicles needed;

  • Changing to a fully-automated collection system may result in fewer worker injuries; and

  • While making changes to your program, adding new materials to the list of acceptable items provides an opportunity to collect more recyclables;

  • Changes to any program are a great opportunity to develop new educational materials and provide outreach to residents. Any education and promotion of a program will ensure greater success and participation.

What Are the Challenges When Switching to Single Stream?

Potential challenges of single stream recycling may include:

  • As with any change in a solid waste collection program, equipment changes, including new carts, different collection vehicles, or upgrading of processing facility, will likely require up-front capital costs;

  • Any changes in your recycling program may require funds to educate residents;

  • Recycling facilities and end users (manufactures using the recycled material) will probably need to update their processes and equipment to assure that recyclables meet market specifications and are actually used to make new products.

  • Increased contamination may be more likely to happen at all levels - at the curb, at the processing facility, and at the end user/manufacturer, potentially resulting in rejection of loads, contamination fees, and reduced commodity prices.

  • Separating high quality fibers from lower quality fibers may result in increased "downcycling" of paper (higher quality paper for low end uses);

  • In order to maintain public confidence, as with any recycling program, haulers, processors, and end-users need to be transparent regarding the actual fate of materials being collected for recycling.

  • Potential for diminished public confidence if more recyclables are destined for landfill disposal due to contamination or become more unmarketable.

What Are the Impacts of Single Stream Collection on Recycling Participation Rates and Program Costs?

With few exceptions, municipalities nation-wide that have implemented single stream collection report not only dramatic increases in amounts of recyclables collected, but an improvement in participation rates. In addition, they state that single stream has resulted in less litter on collection days when covered containers are used. Many of these advantages can be attributed to other collection changes which often accompany the switch to single stream. More and more municipal solid waste managers are looking at single stream as the solution to many municipal solid waste (MSW) issues they face: rising disposal costs, a way to divert materials from solid waste stream, increase recycling participation and the means for adding more recyclables to their programs. The municipality may also benefit from the increased materials collected if they market or get rebates for their recyclables.

However, collecting material for recycling does not guarantee your materials are recycled. In some cases, recycling facilities in CT may not be ‘recycling’ glass collected from municipal recycling programs. Their sorting process may create a substandard product, or they choose to market to local landfills to be used as alternative daily cover (ADC). Connecticut does not recognize ADC as a form of recycling. It’s a beneficial use, but not recycling.

What Is ‘Residue’? 

There are three types of residue commonly associated with the processing of recyclable material:

  • Contaminants are materials that are not recyclable but were set-out for collection together with recyclables;

  • Process Residue is material generated and disposed during the processing of recyclable materials at a recycling facility.  It can include material that was not sorted sufficiently, recyclables badly contaminated during collection and processing, contaminants separated out of the recyclables received, etc.

  • Market Residue is material that is shipped to a manufacturer that cannot use it.  This residue is not disposed by the recycling facility or IPC, but is disposed by the secondary recycling processing facility or a manufacturing facility.  The extent of this residue should be included in quality reports from the manufacturer back to the processor and community program managers.

    (Source: Single Stream Recycling Best Practices Manual, Susan Kinsella and Richard Gertman, February 2007)

The single stream collection process may produce a higher rate of residue. Compaction of the commingled recyclables during collection or transport may break glass and mix glass and plastic with paper; etc. The recycling facility processing that material needs to assure that their processes and equipment are capable of producing high quality material that meets end user (paper mill, manufacturers, etc.) specifications.

Remember that collecting recyclables does not guarantee recycling. Recycling occurs when the material collected actually gets made into a new product.

Mixed broken glass is generally not marketable as a mix for most applications involving melting to produce new glass products, although a few new markets are emerging for this relatively low-value material. However, optical sorting equipment used by some primary recycling facilities and by glass beneficiators (secondary recycling processing facilities) in the Connecticut/Massachusetts region allow mixed broken glass to be separated by color and marketed to make new glass containers as well as to manufacture other products such as fiberglass insulation.  In some cases, low value mixed glass is used as alternate daily cover (ADC) at landfills.  Be aware that Connecticut does not recognize ADC as recycling.  If your glass is being used as alternate daily landfill cover, you are not recycling.

Does the State of Connecticut or the CT Department of Energy and Environmental Protection Support Single Stream Recycling Collection?

The State of Connecticut and DEEP encourage municipalities to develop collection recycling systems that increase participation and which result in increased tonnages of material recycled into new products. When contracting with a recycling facility municipalities should seek information on the residue rate at that facility and information on the quality of material marketed from that facility. EPA provides some guidance  on this issue as does Conservatree Paper (see page 46).

DEEP strongly encourages communities to consider implementing a unit-based pricing structure when any recycling collection program changes are made in an effort to increase recycling recovery efforts in Connecticut.

Is the State of Connecticut or CT Department of Energy and Environmental Protection Mandating Single Stream Recycling Collection?

No. Neither the State of Connecticut nor the CT Department of Energy and Environmental Protection mandate how recycling is collected in a municipality. However, recycling is the law and everyone must recycle the State mandated items. Remember to check your local municipal ordinances which may mandate more materials to be recycled than the State mandates.

Reduce/Reuse/Recycle

Disclaimer: The Connecticut Department of Energy and Environmental Protection (DEEP) maintains the content on this web site to enhance public access to information and facilitate understanding of waste reduction, reuse and recycling. The DEEP is not recommending these resources over any others and recognizes these represent only a partial listing of resources on this subject.

Content Last Updated February 2020