Content

Call2Recycle CEO & President, Carl Smith, will be a guest blogger for the month of May on Waste & Recycling News. This is the fifth installment, bookmark this site and check back for new posts each week.

Recent Posts:
Tips for Recyclable Collection and Take-Back Programs at Retailers – May 9, 2012
Product Stewardship Must Be a Shared Responsibility – May 7, 2012
What is product stewardship? – May 3, 2012
Responsible Recycling – May 1, 2012

When to sort the recyclables?

Single-stream recycling collection – combining different types of items such as cans, glass, plastic and paper together – is being credited with impressive volume increases like the 167% jump Westport, Conn., saw over the last nine months. Because it is easier and more convenient for the consumer, single-stream systems maximize the amount collected. With few exceptions, municipalities nationwide that have implemented single-stream collection report not only dramatic increases in amounts of recyclables collected but also in number of participating households. They also cite reduced transportation and labor costs.

However, collecting material for recycling does not guarantee materials are recycled. Recycling occurs when the material collected actually ultimately is transformed into a new product. While the relative cost of single-stream collection is low, the cost benefits fade when system-wide costs are considered. Higher contamination levels in single-stream programs, on average, result in an overall loss rate of 22% to 27% by weight, according to research findings published by the Container Recycling Institute (CRI) in February.

Single-stream collections also tend to include more nonrecyclable material. A study by Eureka Recycling for St. Paul, Minn., found 4.4 percent of materials collected in single-stream were not recyclable, compared to less than 1.9 percent in any other method tested. Mixing materials together means more are contaminated and more sorting is needed.

For example, this additional sorting is especially damaging to glass which once broken, cannot be easily sorted by color. Color-sorted glass from dual-stream curbside programs might bring $25 per ton, according to CRI, while mixed-color glass may only be worth $5 per ton. If the curbside mix is highly contaminated or if there is no glass plant close by, it may be worth nothing at all.

While clean, quality materials, like the glass example, can command a premium price, municipalities do not always have the motivation or experience to consider to the residual value of what they collect. Single-stream systems shift the burden downstream to the material recovery facilities (MRFs) and reprocessing industries that sort the materials and may or may not use them for new products. In a 2006 study for the Minnesota Pollution Control Agency, over 70 percent of the end markets interviewed reported they saw more contamination in the recycled materials they received then than they did in the five years previous. Most of the paper mills and all of the plastics recyclers cited single-stream recycling as a contributing factor to the decline in materials quality.

“With those higher contamination levels, the costs are higher for the mills and reclaimers, so of course the mills and reclaimers pay less for the output of single-stream then they do for cleaner materials,” Susan Collins, executive director of CRI told WRN in April. Increased sorting and processing costs and decreased revenues due to material loss from contamination combine to make single-stream the more expensive collection method.

In another instance, Ms. Collins points out “there is much more work to be done …to research best practices for dual- or multi-stream collection that achieve the best possible cost efficiencies. With better data, we can make better decisions.”

As the Eureka study concludes, there is no single answer or comprehensive solution. The preferable method for each community must take into account not only the costs of collection and processing, but also support for the program in terms of enforcing regulations, educating households, and encouraging participation.