When single-stream recycling was gaining momentum as a collection method, it promised a number of efficiencies, including lower collection costs, more convenience for residents and higher landfill diversion rates. According to popular consensus, single-stream recycling has delivered on many of its promises. However, the quality of the recyclables recovered in this manner remains a topic of debate among processors and mill consumers.
The downturn in commodity markets experienced in late 2008 and early 2009 caused some critics to question the economics of single-stream recycling, including the Container Recycling Institute (CRI), Culver City, Calif. The CRI published a study in December 2009 that was authored by Clarissa Morawski, principal of CM Consulting, based in Ontario, Canada. The foreword to the study reads, “This new marketplace has in effect tested the single-stream system. Those single-stream haulers and MRFs (material recovery facilities) who have not applied best practices have been riding the wave of rapid economic growth and unprecedented global scrap demand over the past decade.”
Andy Ockenfels, president and CEO of City Carton Recycling, Iowa City, Iowa, a MRF operator, stresses the importance of quality regardless of the market. “While quality is key in a down market, we continue to push to make sure we can ship material in good times and in bad.”
While markets have improved from early 2009, quality remains a concern for many consumers.
PROBLEM MATERIALS |
Glass is one of three “major concerns” Sonoco Recycling sees when processing materials collected via the single-stream method, says Marcy Thompson, division vice president and general manager of the Hartsville, S.C.-based company. “Glass is a specific challenge to collecting and processing recyclables,” she says. “It is cost prohibitive in terms of processing [and] transporting and has very little dollar value in the market, yet it’s 20 percent of [the] single-stream mix. Processing glass is labor intensive, it causes more rapid deterioration of machinery and equipment and it is also difficult to sort. Glass also degrades the quality of other commodities, like fiber, which makes it harder to consume and market.” Plastic bags also can create concerns for single-stream processors, Thompson says. This material can contaminate other recyclables or cause issues with sorting equipment. Matthew Coz, vice president of growth, commodity sales and marketing for Waste Management, Houston, adds that plastic bags and films can wrap around disc screens, causing a reduction in efficiency and eventual downtime to clean screens. “Also, many one-off commodities that sorting systems aren’t designed to recover, but are being recovered, such as rigid plastics, must be sorted by hand,” Coz says are problematic. Thompson also says that scrap metals, such as mufflers, brake pads and other car parts can also create problems for some single-stream MRF operators. |
PLUSES AND MINUSES
FutureMark Paper, an Alsip, Ill.-based manufacturer of coated mechanical printing and writing papers made with up to 100 percent recycled content, takes issue with single-stream fiber. In the October 2010 Paper Recycling Supplement to Recycling Today, company President and CEO Steve Silver says the quality of the paper collected through single-stream programs can sometimes be “terrible.” He adds that after removing the contaminants, “5 to 10 percent of the material we’re paying for isn’t usable” and contributes an additional $8 to $10 per ton in cost on top of what the company is paying its suppliers for material.
According to FutureMark, dealing with out-throws causes the company manufacturing downtime and costs more than $1 million per year in material loss, disposal costs and remediation.
While Silver says he is skeptical about the longevity of the single-stream method, it continues to grow. More than 160 single-stream MRFs operate today. And, according to the American Forest & Paper Association (AF&PA), Washington, D.C., only 29 percent of the population with access to curbside recycling in 2005 was served by a single-stream collection program. That number grew to 50 percent by 2007.
The single-stream collection method benefits haulers in that it allows them to collect more material more efficiently using automated collection, larger bins and often times a single-compartment compaction truck. It also has been shown to increase the volume of recyclables recovered. For instance, Jerry Cifor, CFO of County Waste & Recycling, Clifton Park, N.Y., says the volume of recyclables increased by 24 percent since single-stream recycling was implemented in the company’s service area, while the volume of garbage declined by 24 percent. County Waste is currently processing nearly 10,000 tons per month, Cifor says.
When County Waste, which serves 180,000 residents, moved to single-stream collection, it also expanded the range of recyclables it accepts. Rather than accept only plastics Nos. 1 and 2, County Waste now accepts plastics Nos. 1 through 7 as well as metals beyond aluminum and steel cans, Cifor says.
“We have seen volumes increase by 50 to 300 percent in markets where we have introduced single stream,” says Steve Dunn, region vice president of Houston-based Greenstar Recycling. “Customers respond quickly to the convenience of putting all recyclables into one bin.”
Cifor says the move to single stream has been popular with County Waste customers. “I think our customers love the service, and we’ve picked up customers because of the new service,” he says. “I can’t think of a material negative, other than it cost us a ton of money to [convert to] it.”
County Waste spent roughly $12 million on its new single-stream MRF and also invested $29 million in new collection trucks and containers, Cifor says. The company is expecting a return on investment cycle of five to six years.
The question of who bears the cost burden of turning single-stream material into usable secondary commodities also can be a contentious issue among haulers, processors and consumers.
THE TRUE COST
“There are many advantages to single-stream collection,” says Marcy Thompson, division vice president and general manager, Sonoco Recycling Inc., Hartsville, S.C. “The equipment needed to haul single-stream material is more automated, using less people, meaning haulers can pick up more material in relatively less time.”
She continues, “In contrast, it takes more equipment to process this same material. With the constant improvements being made on the equipment side, processors also have to stay ahead of the curve, looking for the most recent technology and ensuring capital for process and equipment improvements as well as general preventive maintenance.”
In Thompson’s opinion, processors bear most of the financial burden related to single-stream recycling. “They are the ones to right-size equipment and outfit their facilities with the new technology and equipment needed to compete in the marketplace.” Ockenfels says the material stream has changed in conjunction with the growth in single-stream recycling. Namely, City Carton is seeing less ONP (old newspapers) and more mixed paper. “It used to be that ONP was over 50 percent,” he says. “Now it is well below 50 percent.” Office paper, however, has been increasing, he says, as has shredded paper. With the company’s automated sorting system, shredded paper can end up with the rejected items, Ockenfels says, necessitating hand sorting.
Dunn says single-stream processing equipment has evolved since it was first introduced, and that process continues today. “The addition of multiple screens and, especially, the refinement and placement of those screens, along with the inclusion of optical sorters for plastics and paper, have made a significant difference in the ability to sort single-stream materials and allow better quality than earlier systems that relied more heavily on hand sorting or limited screens.”
Matthew Coz, vice president of growth, commodity sales and marketing for Waste Management, Houston, also finds that the inbound quality of recyclables had declined as more materials enter the diversion stream through single-stream collection, though diversion increases by 50 percent on average. “With more and varied materials entering the diversion stream, advances in sorting technologies have not kept pace,” he says. “As a result, we’ve seen some incremental declines in the quality of outbound commodities.”
According to Thompson, “As more material is introduced into recycling programs, the separation becomes even more important, but cost of separation also increases.” She points out that OCC (old corrugated containers) screens were not needed in systems designed just three years ago. “Current technology can be very expensive but it is necessary to remain competitive.”
Jonathan Sloan, president of Canusa-Hershman Recycling, Baltimore, says single-stream recycling necessitates significant investment in processing equipment. “The reality is that to properly and efficiently separate this material into salable commodities, you need a lot of good equipment,” he says. “It is a big capital investment, whether you are processing 15 tons or 50 tons per hour.”
REDUCING RESIDUE
Even with the latest sorting equipment, single-stream MRFs can still experience higher residue rates related to incoming materials.
“The residue depends on the quality of what is put into the recycling bin,” Dunn says. “In Des Moines, for instance, we have worked with our municipal partners to make sure that the local customers are very well educated about what should go into the recycle bin. We launched our single-stream system there earlier in [2010] and the residue rate is very low (3 to 4 percent)—reflecting the strong education component of the program.”
Sonoco’s Thompson says that for the past five years, the company has been operating with a contamination rate of less than 3 percent. “Now that curbside recycling programs are moving toward bigger roll carts (as opposed to smaller bins) and enhanced programs, we have seen that rate increase to about 8 percent or 9 percent and we expect it to continue to rise along with the increased volume.”
Coz says Waste Management has reduced residue rates and operational costs at its single-stream MRFs by focusing on advances in sorting technologies and improving inbound material quality. Educational campaigns have played a critical role in the latter area.
“Research continues to suggest that educational campaigns in support of recycling programs can have an effective impact on the quality of the inbound stream,” Coz says. “Consumers and communities can improve the inbound quality by learning what belongs in the cart or box and what doesn’t. In those instances, our single-stream plants can outperform some of our dual-stream plants.”
Dunn says single-stream MRFs can achieve material quality that rivals dual-stream. He adds, “That said, residue content does usually go up with single stream on a percentage basis, but the overall recovery increases for weight more than make up for the increase in residue. Also, remember that the single-stream system is not ‘creating’ this additional residue in the recycling program. It is really misplaced material that would have been in the garbage stream anyway.”
ISSUES WITH GLASS |
According to the Container Recycling Institute (CRI) study, “Understanding Economic and Environmental Impacts of Single-Stream Collection Systems,” the quality of recyclables recovered through single-stream collection program has been affected. “Glass experiences the greatest loss,” says Susan Collins, executive director of CRI, Culver City, Calif. According to the study, “40 percent of glass from single-stream collection winds up in landfills, while 20 percent is small broken glass (“glass fines”) used for low-end applications. Only 40 percent is recycled into containers and fiberglass.” However, according to the CRI study, an average of 90 percent of mixed glass from dual-stream systems is recycled into containers and fiberglass, while 10 percent is used in low-end applications. “In container-deposit systems, color-sorted material results in 98 percent being recycled and only 2 percent marketed as glass fines,” the report notes. Joe Cattaneo, president of the Glass Packaging Institute, Alexandria, Va., says less glass is available for recycling because of single-stream programs. The relative low value of glass means that it is negatively sorted in most single-stream processing systems, he says. This means that the recovered glass often has to be sold to processors who further separate the material at beneficiation facilities before it can be sold to consumers. Because glass can contaminate other recyclables collected via the single-stream method, it is sometimes removed from these programs, Cattaneo says, and collected at drop-off sites. “People do not in general use drop-off programs as they do curbside programs,” he adds. |
The author is managing editor of Recycling Today and can be contacted at dtoto@gie.net.
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