Single Stream Recycling: Case Studies Prove Major Flaws

Why Do People Advocate Single Stream?

Although advocates swear by its ability to reduce program costs and retrieve more recyclable materials, single stream recycling is being proven as the wrong choice through scores of case studies which champion dual stream as more cost-effective and environmentally sound.

Driven by miscalculated results, advocates estimate that the quantity of commingled materials recycled is higher than that of dual stream (or source separated recycling) but, in reality, the increase in education regarding recycling and the provision of larger recycling containers are two factors that likely have a lot to do with those results. Additionally, a higher quantity of commingled materials usually means more materials that will eventually end up in landfills.

The quality of materials resulting from single stream collections is poor and have many domestic mills and manufacturers struggling to work with the materials. It should be noted, that most of these studies involve residential collections, not large scale office recycling programs, where source separation is still favored.  While there haven’t been any studies on office recycling programs, the recyclables collected in offices have always been cleaner and thus more desirable by the manufacturers who use them.  They rely on these recyclables to make high-quality recycled content products.  If single steam is of questionable benefit for residential recycling, it certainly has no place in the office.

Case Studies Show Undesirable Results

When considering the case of Ann Arbor, Michigan, single stream’s effectiveness seems more than dubious. Upon switching to single stream recycling from a dual-stream system, the city of Ann Arbor was supposedly poised to “double collections and save taxpayers millions.”  According to an article from A2Politico, an online news source from Ann Arbor, it all began in 2008 when the city started losing money and was looking for a way to lower recycling program costs.

Although some citizens rallied to use the funds for police services and park maintenance, the switch was made and between 2008 and 2011 Ann Arbor lost over $700,000. The city noted that with single stream, the end product contamination was up to 15 percent, while with dual stream the end product contamination was only 2 percent. This finding shows just how effective keeping materials separated is when thinking of selling the end materials.

The same month that the city of Ann Arbor switched to single stream, a case study for University of Colorado-Boulder was released which should have dissuaded the single stream advocates of Ann Arbor. The study lasted August through May and concluded that when using single stream, collection costs were not significantly decreased and revenues from selling materials as single stream were significantly less than when marketed as separate grades of paper and containers. The study also concluded that more than $10,000 in revenues were lost as a result of the test.

An extract from the website for AASHE (The Association for the Advancement of Sustainability in Higher Education) gives a more detailed report of the findings from the test at UC-Boulder.

“Keeping paper fibers separate from containers is important for a few reasons:

  •  Papers do not get contaminated with food/beverage residue so they are not down graded and can be used for their “highest and best use”
  •  Preserving more life cycles out of the papers will reduce the need for virgin resources from our earth
  • Broken glass often ends up in the paper fibers within single stream, making it hard or impossible for the mills to recycle without ruining their equipment
  • We generate more revenue for our paper fibers separated from our containers.”

Some additional support against single stream comes in the form of an article, “The Battle for Recycling,” by Daniel Lantz and Clarissa Morawski. This article details case studies conducted in North America and Europe and have gathered evidence in favor of dual stream recycling. Although many cities across North America are converting to single stream, there are many who have steered clear or switched back due to unwanted results.

Municipalities are searching for ways to cut costs but are finding that switching to single stream just isn’t the answer. In 2006, the city of London, Ontario was looking for ways to reduce program costs and collect more recyclable materials. Upon weighing their options, the city found that their current system would be the most effective and switching to single stream would raise costs in order to process the commingled materials.

Similarly, Roseville, Minnesota exhaustively researched the pros and cons of single stream and decided to continue with their existing dual stream program.

Cities like Auburn, Maine have headed down the single stream road and realized their mistake. Auburn switched to single stream with the main goal of increasing the amount of materials retrieved and decreasing the amount going into landfills. Once single stream was in place, the problem of being able to market these commingled and contaminated materials surfaced and the city switched back to dual stream. The chair of Auburn’s solid waste department, Dom Casavant stated, “The problem with a single stream program is that it renders most of the commodities recycled practically worthless.”

Some municipalities are finding ways to steer clear of the single stream system. For example when the citizens of Ottawa, Canada were surveyed about whether they would want to switch to single stream recycling, the residents opted out and chose an alternative. By maintaining their current system and switching pickup to every other week, the city is expected to save tax payers $9 million per year.

Compared to other countries in Europe, the United States seems to be behind in the recycling game. Single stream recycling is mostly non-existent in the European union countries and will not be adopted in the future.

After seeing the results of multiple case studies in many different cities around the U.S. and Canada, it can be concluded that single stream is not the answer. It does not deliver the results originally hoped for and renders most materials recovered worthless, causing higher program costs due to the need to sort the commingled materials. In most cases there may be more materials recovered overall, but not a decline in materials going to landfills. Because single stream collection results in contamination of materials, those materials cannot be sold to mills and manufacturers. Overall, single stream is proven detrimental to the municipalities which adopt it and dual stream is the better choice.

So Why Do Some Places Use Single Stream?

When deciding whether or not to use single stream recycling, municipalities may base their decision on their systems and contracts, their budgets, and whether or not single stream will increase participation and reduce costs. The subject of whether the materials collected actually get recycled is not always a main concern.

Formerly, most of what has been collected through single stream has been exported to China where they were accepting lower quality imports than recycling facilities would in the U.S. However, recently China has become stricter as a result of “Operation Green Fence”. As China becomes more and more strict in what they import, the U.S. will have to find alternatives. China’s “green fence” could change the way we recycle. If we can no longer export our materials we’ll have to find alternatives and looking at our current recycling system may be a good place to start.