The trend toward more single-stream recycling programs has generated a tremendous amount of interest. Advocates of the sortation and processing procedure note the ability to collect larger amounts of material most cost effectively.
However, opponents feel that as recyclables are commingled together the quality of the collected material significantly declines, resulting in increased outthrows, and lower value of the material.
During the recently concluded Paper Recycling Conference & Exposition, three speakers weighed in on the positives and negatives to this method. Speakers at the panel included a representative from a waste management firm, a representative from a Canadian-based paper company, and a consultant to the solid waste and recycling industry.
Brian Taylor, editor of Recycling Today Magazine, noted that over the past decade, “most communities remained committed to curbside recycling, but public officials also scrutinized the cost of operations much more carefully. On the collections end, cost savings were sought by putting fewer trucks with fewer people on the road, with these trucks ideally running faster routes while collecting more material.”
To deal with the material in a cost effective manner, Taylor continued, “Advocates (of single stream methods) see single-stream processing and mechanical sorting advances as the hope toward the maximum recovery of recyclables. The short-term pain may be blurred paper grades and some rejected shipments, but ultimately MRFs are being equipped to reliably handle a greater percentage of the solid waste stream while shipping out a number of marketable secondary commodities.”
Harvey Gershman, president of the consulting firm Gershman, Brickner, Bratton, ticked off some of the biggest disadvantages to single stream.
One is the residue in the paper, especially glass. “Glass in the single stream is a problem.
“There are higher processing costs. It costs more to unscramble a more scrambled egg. There are more sorting costs.
In a dual stream system glass is more easily sorted. That doesn’t happen in a single stream flow.”
While glass is a big problem, Gershman noted that the amount of glass in the recyclables stream is declining. According to Gershman, glass right now constitutes only around 5 percent of the stream right now. With this in mind, he adds that it may be a better move to remove glass from the materials collected.
As to the growth of single stream MRFs, Gershman noted that there was 1 of these types of MRFs less than 15 years ago. Now, there are around 85 single-stream MRFs, with more expected to be added over the next several years.
Rina McGuire, with Cascades, a large Canadian-based forest products industry, said that the company “didn’t care” whether the material came from a single or multi-stream source.
While the company didn’t come out strongly on either side, she did stress that the quality of the material was essential. Additionally, anyone looking to ship the mill also needs an ample quantity of material.
One of the biggest downsides to single-stream programs is the low quality of the processed material. “If you need more manual sorting it is very costly. There is a higher level of contamination.”
To achieve higher quality, McGuire stressed that the ideal situation is to take in material from a same group of suppliers. At the same time, the need for price stability is a major issue for the material.
Steve Ragiel, vice president of recycling for Waste Management Inc., Houston, cited some of the issues with current recycling programs include high collection costs, high processing costs, very capital intensive, extremely volatile commodity pricing, and extremely tight municipal budgets.
One advantage for single stream collection could be a lower cost material, and an adequate supply of material for mills, Ragiel noted.
He added that, while many opponents to single stream processing cite glass contamination as a big problem, he feels that with the proper sorting, there are some viable end markets for the material.
A key type of equipment to use is an optical sorting system to extract glass.
Backing this opinion, Ragiel said that the company already has more than a dozen single stream recycling facilities, with a number of other facilities scheduled to be reopened with the end of the year.
To view Rina McGuire's presentation Click Here.
To view Steve Ragiel's presentation Click Here.