Single stream recycling: a mixed bag of pros and cons

Many municipalities collect recycling and trash in the same container because doing so makes life easier for consumers. But the drawbacks may outweigh the benefits in some communities.

Why did municipalities start single stream recycling programs?

Collecting recycling and trash together began in the 1990s and became popular because it made life easier for the consumer. However, drawbacks led some communities to return to their previous recycling collection method.

The three types of recycling collection options for municipalities are:

Single Stream. All recycling and trash are collected together. Workers separate materials later by type at a material recovery facility.

Dual Stream. All recycling is collected together, but trash is kept separate. Workers separate materials later by type.

Multiple Stream. Materials are required to be separated at the recycling collection point. For example, there are separate bins for paper, plastic, metal, trash, etc.

Pros of single stream recycling

Greenhouse gas (GHG) emissions decrease. GHG emissions decrease by 0.901 metric tons of carbon dioxide for each ton of materials processed. Thus, single stream recycling integrates with reducing air emissions, another aspect of environmental planning.¹

More materials can be collected. Labor and monetary savings allow some municipalities to start new recycling collection programs (e.g., green waste).²

The processing system is easier to update. Some municipalities can update their material processing system more easily under single stream, including recycling more types of paper.⁷

Recycling collection costs decrease. Material collection costs are reduced by anywhere from 5% to 40%.^1,2,3,4,6,7

Recycling participation increases. Recycling participation increases anywhere from 10% to 100%.^1,2,3,5,6,7

Workers' compensation costs decrease. Workers' compensation costs decrease because recycling collection becomes more automated and less labor intensive. Thus, single stream recycling integrates environmental planning with employee health and safety.^2,3,5,7

Cons of single stream recycling

Bigger bins in dual stream increase participation more. Offering bigger recycling bins in dual stream programs has been shown to increase recycling participation more than single stream. One study of five collection options recommended dual stream collection on a weekly basis over single stream.^3,4,6

Contamination increases. Mixing recyclables with trash leads to materials being worth less, with anywhere from 2% to 17% of recyclables being contaminated.^2,3,5,6,7

More glass ends up in landfills. In single stream recycling, 40% of glass goes to landfills, versus 10% for dual stream and 2% for multiple stream.³

More paper ends up in landfills. From single stream recycling, 15% of paper cannot be recycled because it contains plastic, glass, or metal residue.⁷

Processing costs are higher. In many cases, the higher costs of processing materials offsets recycling collection cost savings. One study cites this economic drawback as the reason some municipalities switched from single back to dual stream.^3,4,6,7

Processing of materials is poor. Materials do not always separate efficiently. This results in more recyclables going to the landfill.^1,2,4,5,7

Sources:

Should your municipality have a single stream recycling program?

Whether your municipality should have a single stream recycling program or not depends on several factors. Here is a list of questions to ask before making the switch:

Have you recently evaluated your recycling education and outreach to ensure that participants understand your program?

How often do people put materials in the wrong bin and how much time do you spend sorting them?

Do you require residents to drop off any materials themselves, and if so is that location sufficiently staffed to answer questions?

What is your material collection budget and how much money might you save by switching to single stream?

How many materials do you recycle and would single stream increase that amount?

Is your facility capable of processing single stream materials and/or is there a contractor in the area with this capability?

How much money might you lose from material contamination and could this be offset by lower collection costs?

Recycling education and outreach: what makes a successful campaign?

Regular communication can increase both recycling participation and correct material separation. A variety of methods should be used to reach people of different backgrounds. Here are some methods to use for recycling education and outreach campaigns:

Advertise the benefits of following recycling instructions. Make sure that consumers understand the benefits of following recycling separation instructions. Talk about both the environmental benefits (more materials get recycled) and the economic benefits (the municipality makes more money).

Create an effective website. Recycling information websites should be easy to navigate and answer consumers' frequently asked questions (FAQs).

Give brochures or refrigerator magnets to new residents, and annually to current residents. Provide a brochure or refrigerator magnet with current recycling program requirements to new residents, and annually to current residents. While refrigerator magnets cost more, they have greater visibility and are thrown away less often.

Have a presence on social media. Increase your chances of reaching younger residents and their networks by having a presence on social media.

Make effective signage. Recycling program signs should be eye-catching and communicate what is expected of the consumer in as few words as possible.

Use incentives. Encourage correct separation of materials by offering vouchers, charity donations, cash, discounts at local shops, community rewards, and prize drawings. For example, trash collectors could inspect bins on a regular basis and choose a random household that follows the guidelines to win a prize.