Megan Workman

The author is associate editor of Recycling Today magazine.


Sorting out collection systems

Municipal Recycling

Pratt Recycling’s Myles Cohen and Covanta’s Scott Holkeboer take sides on the one-bin approach to recycling.

June 2, 2015


Solid waste management has evolved in the U.S. since it became a social focus in major part because of the first Earth Day in 1970. With the widespread implementation of curbside recycling in the 1990s, our environmental consciousness created a reliable flow of recyclables that industry could rely upon. Recycling has helped shift our collective way of thinking about waste as a treasure.

When recycling first hit the streets, homeowners separated their recyclables into multiple streams, separating newspapers from metal, glass and plastic containers. In the new millennium, however, the trend toward single-stream recycling took hold, where all items, including all grades of clean and dry paper, are commingled into one large bin or wheeled cart. The shift from multistream to single-stream recycling catalyzed even greater levels of participation, helping our nation to reach its current level of recycling about one-third of our waste stream.

However, reaching higher levels of recycling appears stalled. Among the reasons for this lag may be less-than-optimal participation because of the lack of funding for education and the purchase of more single-stream carts coupled with pressure on local budgets.

Keeping in mind that collection costs for waste management can be nearly two-thirds of expenditures, municipalities and private haulers are looking at ways to reduce collection costs by combining all trash and recyclables into a single bin and then, once collected, sorting recyclables, and perhaps organics and a fuel fraction as well, using sophisticated mixed waste processing systems.

As we compare the separate collection of recyclables in a single-stream, two-bin system with processing the combined mixed waste to recover recyclables from a one-bin system, several questions need to be addressed, including end markets and economics.

Meanwhile, communities will need to meet rising citizen demand for more sustainable management of resources. The one-bin, two-bin dialogue is a critical step in finding that right future for us all, and I am grateful to Recycling Today, and my colleagues in the industry, for engaging in that dialogue.

Harvey Gershman is president of solid waste management consulting firm Gershman, Brickner & Bratton Inc. (GBB), Fairfax, Virginia. He can be reached at


In the Q&A that follows, Myles Cohen of Pratt Recycling and Scott Holkeboer of Covanta debate the perceived merits and drawbacks of the single-bin approach to recycling and municipal solid waste collection.

Cohen is president of Atlanta-based Pratt Recycling, the recycling arm of Pratt Industries, the fifth largest box manufacturer in the country. Cohen says the company’s 15 100-percent-recycled paper plants source residential mixed paper and old corrugated containers (OCC) from municipal residential recycling programs as well as from commercial and industrial customers.

Holkeboer is market area vice president for Morristown, New Jersey-based Covanta, a waste, recycling and renewable energy company. By 2016, Covanta plans to open a $45 million advanced materials recovery center (ARC) adjacent to its existing energy-from-waste (EfW) facility in Indianapolis. This mixed waste processing facility, which some people in the industry call a “dirty MRF (material recovery facility),” is expected to recover up to 90 percent of recyclables, including OCC, plastic and metals, while glass and organics may be added in the future, Covanta says.

A lawsuit filed by Graphic Packaging International Inc., RockTenn Converting Co. and Cathy Weinmann against the city of Indianapolis and its Board of Public Works over alleged violations of the city’s Waste Disposal Statute in awarding Covanta the contract to build its ARC in Indianpolis recently was thrown out by Marion County Judge Cynthia Ayers. (See

Recycling Today (RT): What are the benefits and drawbacks of these collection systems?

Scott Holkeboer (SH): One-bin systems with mixed waste processing facilities (MWPFs), like the one planned for Indianapolis with Covanta’s Advanced Recycling Center, can have many benefits for communities that have struggled to increase recycling rates and participation.

First and foremost, MWPFs immediately increase recycling. When operational in 2016, the Covanta ARC will improve recycling fivefold by recovering 80 to 90 percent of recyclable plastic, metal and paper.

Second, MWPFs can deliver this immediate increase in recycling cost effectively. The system planned for Indianapolis requires no capital investment from the city and its taxpayers. In contrast, a citywide curbside program would require tens of millions of dollars in new recycling bins, trucks, labor, fuel and maintenance, in addition to other expenses.

Next, MWPFs can capture high-value metal streams that don’t fall into traditional recycling categories, like metal clothes hangers or pieces of copper from home improvement projects.

A one-bin approach also means that residents no longer have to figure out whether an item is recyclable or not. Recyclables in the waste stream will have the opportunity to be recycled as opposed to curbside [recycling] programs, which require active decision-making from residents.

Some opponents of a one-bin system claim that all materials will be contaminated beyond the point of recycling. Nothing could be further from the truth. Today’s modern MWPFs are nothing like yesterday’s dirty MRF. The Indianapolis facility will incorporate a variety of modern technologies, including optical sorters, advanced screen design, rare earth magnets and advanced eddy current separators for nonferrous metal separation.

With all these benefits, one-bin systems may not be right for every community. They may not make sense for communities with well-established curbside recycling programs—either single stream or source-separated programs.

Myles Cohen (MC): Single stream is extremely different from one bin, and the two should not be confused. Single stream has proven to be successful over many decades and one bin has been a clear failure.

The one-bin system undoubtedly and with solid proof contaminates the recyclable materials. The single-stream system, although there might be some prohibitives and outthrows and things that shouldn’t be in there, they generally are not things like dog poop, kitty litter, liquid from food and grease from kitchen garbage. The typical single-stream system doesn’t have to deal with those putrid materials, and they’re inherent in the one-bin system.

There’s a lot of discussion these days because of the low commodity prices and with the declining amount of newspaper that it’s difficult for single-stream operators to make a profit because the processing cost is sometimes more than the value of the material. That would be exacerbated in the one-bin system because there’s more material to process and that would be doubly [intensified] because it’s going to go to the landfill anyhow, so the drawback with the single-stream system is it’s more expensive, though not as expensive as the one-bin system.

There are still many cities throughout the country that do dual stream, where they separate the paper from plastic, metal and glass, and that’s the optimum, that’s the best economic value for the cities and the recyclers.

There are disadvantages with single stream because of the amount of glass and processing costs recyclers have to deal with.

RT: How do the two processing systems vary from each other?

SH: The newest single-stream processing systems are not very different from state-of-the-art mixed waste systems. Some of the same technology is used in both processes—from magnets and eddy currents to ballistics separation and optical scanners. The main difference is how recyclables are sorted from the incoming material. With a single-stream system, the goal is to remove nonrecyclable material from recyclables, where the opposite is true with a MWPF.

At the Indianapolis facility, we will use a positive sort to remove recyclable materials from the waste stream—as much as 80 to 90 percent of plastics, metals and paper.

MC: They’re hugely different because the one-bin processing center is trying to pull and find uncontaminated materials by sorting through the garbage, and the majority of the materials that are going into the one-bin system are not recyclable. I don’t want to say you’re looking for a needle in the haystack because it’s not quite that bad, but it’s really ‘Where’s Waldo?’ You’re sorting a lot of garbage, so the minority of the material is going to be recyclable.

In single stream or dual stream, you’re going to be recovering over 90 percent of materials; certainly over 85 percent will be recycled. In Version A you have 75 to 85 percent of stuff that’s not going to get recycled, and in the other version you have 85 to 90 percent that is going to get recycled. They’re very, very different in terms of amounts of contamination and the success rates of recycling rates.

RT: How do processors handle concerns related to paper contamination? Are there other materials that pose challenges for either system?

SH: Today’s modern MWPFs are nothing like yesterday’s dirty MRF. For our Indianapolis project, we have incorporated four separate process steps to ensure the highest degree of paper quality: a mechanical screening process, two sequential optical sorting processes and a final QA/QC manual sort. As a result, we are confident we will be able to recover both OCC and mixed paper meeting the quality demands of both domestic and international buyers—the success of our $45 million investment depends on it.

All recycled paper sent to mills from single-stream or mixed waste MRFs have some degree of contamination, and the current specifications of paper buyers and mills account for this. As a result, paper mills have well-established practices and procedures to remove contaminants and assure quality of the paper supply.

MC: There are always materials that cause problems, but the food contamination is a huge issue for paper recovery. Because you can’t unscramble an egg, once it’s contaminated, it’s contaminated.

We, along with our competitors, are making a lot of food-grade packaging. We make a lot of pizza boxes, millions of them, and a lot of them are made from recycled fiber. You don’t want your pizza that you pick up on Friday night to come in a box that was made from newspaper that had been contaminated with food or feces. You just don’t. So we don’t buy that paper from dirty MRFs because we refuse to use that type of material because we have quality requirements and quality demands that are rigorous.

Now, is there other contamination that’s in paper? Yes; but, if we get a load of contaminated paper, we’ll just stop buying from that source. Sometimes it’s a mistake, and it will get fixed, but we will reject that load. That happens from time to time. When we get contamination, it’s usually not grotesque, like food, it’s something like a bowling ball or a metal piece of a lawn mower that someone thought was recyclable, that the MRF missed and that ended up in the bale of paper.

RT: The current national municipal solid waste recycling rate has stagnated at about one-third since the 1990s. In what ways has either system helped to increase this rate?

SH: Specifically, MWPFs can excel in markets that have traditionally struggled with recycling and increase rates immediately. They will not replace well-functioning single-stream and source-separation programs where infrastructure and markets already exist.

They also can be an important tool to serve neighborhoods with high concentrations of multifamily residences, which typically do not recycle at all or struggle to achieve even single-digit recycling levels.

MC: It really hasn’t. I’m not sure single stream will increase the rate, what I will tell you is that dirty MRFs will vastly decrease the rate of recycling. What’s going to increase recycling rates will be to introduce dual stream or single stream in cities that do not currently have a recycling program. There are several [cities] throughout the country that have partial recycling, or they have a third of the city [covered] but not the rest of the city.

Cities should get on board to provide residential recycling for their consumers. There’s a myriad of ways that cities can execute a legitimate recycling program. Dirty MRFs are not the answer, they’re only going to decrease recycling rates.

RT: What role does energy recovery play in one-bin systems? Single stream?

SH: In the case of Indianapolis, we are fortunate to be able to co-locate the ARC adjacent to an existing EfW facility. There are many benefits in pairing the two facilities, including reduced truck traffic, additional metal recycling, continued avoidance of landfills and safe and clean energy that serves much of the downtown area.

Through the expansion of recycling, Covanta’s plan in Indianapolis will save the energy equivalent of 15 million gallons of gasoline, enough to fill nearly 1,800 tanker trucks or the annual energy use of more than 20,000 homes.

It’s important to recognize that 250 million tons of waste are going to landfills in the U.S. each year. Anything we can do to move up the waste hierarchy by increasing recycling, be it through curbside separation, single stream or single bin, and using energy recovery for what remains, will be good for the environment and the economy.

MC: You can recycle a cardboard box anywhere between six and 10 times. As the fibers [of the OCC] keep getting remade into boxes, they get shorter and shorter and weaker and weaker; every box has fibers that are brand new and some that have been recycled six times. When it’s recycled again, one-seventh of that box goes away.

In incineration or waste-to-energy (WTE), you’re only getting the use of that paper one time, and then it goes up in ashes and it’s gone. When you recycle you get to use it over and over and over again. When you burn it, it’s gone. It’s dead. There’s zero advantage for paper [at WTE facilities].

RT: China’s Green Fence forced some recyclers to produce cleaner bales in order to export materials there—how did recyclers of either system respond? How difficult has it been for operators of either system to meet these quality requirements?

SH: We are very confident in the quality of the recyclable material that will result from the Indianapolis project and plan to sell the recovered material to recyclers throughout the Midwest. The recycling markets work. The price paid to a MRF operator, whether single stream or mixed waste, is contingent upon meeting the customer’s quality requirements.

We believe that concerns raised about domestic fiber supply are unfounded. For one, in those markets where MWPFs have developed, they have increased fiber supply in those areas. Second, there is more than enough recovered paper to supply domestic markets. The U.S. is a net exporter of recycled paper, including OCC, old newsprint, mixed paper and high-grade paper.

In fact, we know that some of the very same paper companies that have publically opposed Covanta’s plan to increase recycling in Indianapolis have purchased recycled fiber and, in fact, have paid quality premiums and bonuses to a similar MWPF in Montgomery, Alabama, and never rejected the material for quality reasons. Additionally, this same facility is successfully exporting recyclable material to China.

Meanwhile, Covanta has received tremendous interest from multinational and local recycling companies that are ready to buy the paper, metal and plastics from the ARC.

MC: For the most part, there were a few single-stream operators in the country that maybe did not have the most efficient operations and had a little bit more contamination in their paper, but what Green Fence did was force those people to put more scrutiny on ensuring they were not shipping paper with contamination in it. If you look at the numbers, there’s still a lot of residential mixed paper that’s being shipped from the U.S. to China today, probably still more than two years ago when Green Fence started. It really had no major impact. There are a few players that maybe tried not to spend as much money or time or labor in their processes to remove the materials that shouldn’t be in there, and those people have either gone out of business or they’ve fixed their systems.

The smell alone of the paper that’s processed in one-bin facilities would be something paper mills would need to be worried about because it’s been mixed in with food waste.

Why is one bin different than single stream? You can’t unscramble an egg. Once the food residue is absorbed into the paper, what do you get? You get flies, and odor, insects and maggots. I saw some bales of material that came from a one-bin system, and it was not a pretty sight.

RT: How does one bin/single stream address glass?

SH: We continue to seek outlets for glass, the recovery of which is challenging because there is currently no economically viable outlet, as recently discovered by single-stream recycling programs across the U.S. However, plans for the ARC in Indianapolis allow for the addition of a glass line, and we have pledged to work toward glass recovery in the near future.

MC: Glass is an issue because of the economics of glass these days; it’s a negative value. The industry I think is seriously looking at ways they can successfully do glass but it’s a very, very steep challenge. There are a couple of cities in the country—Harrisburg, Pennsylvania, and Kansas City, Kansas—that have already eliminated glass from their curbside pickup. There are some other cities that are requiring people to go to drop-off centers with it.

What happens with glass is when there are little pieces of shredded paper the glass ends up going with that stream, anything small. Glass is very challenging these days and the industry is trying to work to maintain glass in the single stream, but it’s not easy, and we’re doing it.

Covanta says they are not even going to try to recover glass in Indianapolis. Glass has no value economically, [Covanta] has gone on the record saying that, and the only difference is we’re trying to do it, and we are doing it. We haven’t told communities we won’t accept it, but it’s very challenging economically.

Little bits of shards of glass get into the paper, it’s very hard on your recycling equipment because it’s like rock. It’s very hard on your paper mill, it deteriorates your machinery, and it has no value.

The long-term solution for glass is separate collection, possibly at drop-off centers where consumers would, if they’re passionate about recycling glass, bring it to a drop-off center and separate for clear, green and brown glass. For glass to maintain its value, you can’t mix the cullet. A lot of glass goes to landfill cover, but is that really recycling?

RT: The past decade has experienced a significant increase in packaging generation. Why is one bin/single stream the better way to handle this increased volume of material?

SH: Two-hundred-fifty-million tons of waste are still going into landfills in the United States each year, with a significant portion of that being traditionally recyclable material. We can and must do better. We should be recycling as much material as possible, using traditional programs and new methods like MWPFs for markets that have struggled with recycling or have no systems in place at all. MWPFs are simply a different way to capture recyclables from the waste stream.

MC: The Internet has changed a lot of things. We used to get five times the amount of newspaper versus cardboard in the single-stream system. Now it’s maybe two to three times the amount of newspaper versus cardboard. Five years ago you went into a Borders, you bought a book and you came home with it in a plastic bag. Today, if you buy a book, you are ordering it on Amazon, and it comes delivered to your house in a cardboard box.

The packaging and box business has continued to move along and grow nicely, and a lot of the reason is because there are all of these boxes being shipped to households because more and more people are buying on the Internet. That’s been good for single stream; it’s bad for one bin because those boxes are going to get thrown in with kitchen scraps and food scraps.

RT: Where is the future of residential recycling heading?

SH: In a perfect world, everyone would be passionate about recycling, sort their trash and waste responsibly and actively participate in voluntary recycling programs. But, the reality is very different. The stagnant recycling rates in many communities across the nation should be reason enough for recycling advocates to look for new solutions, new methods and new tools. We believe that by using traditional recycling programs and new methods such as MWPFs, we can see significant increases and recover important resources instead of wasting them in landfills. After decades of struggling to increase recycling, it’s time to try something new.

MC: It continues to increase every year as more and more cities adopt residential recycling. With the current commodity prices where they are, which they’re low, and plastics have been hit hard because of the reduction in the price of oil, it’s hard for single-stream operators to make a profit. But the economy always goes through peaks and valleys, and we’re in a valley right now.

The source of fiber is critical to us to operate 100-percent-recycled paper mills. People like us will always be involved in the business. Independent recyclers who are not making money today have to sell to someone like us who has paper mills; it’s the lifeblood of our business so there will always be a need for recycled plastic, recycled metal and recycled paper, and I think the future of curbside recycling period, whether dual or single stream or drop-off centers will continue to be healthy. However, it is going to have to change due to the fact that there is less newspaper than there used to be, there are less magazines in production, no more telephone books. The future of recycling I think is good for curbside, but it will need to change to accommodate the change in the makeup of the materials; less newspaper, more cardboard and glass will have to be dealt with at some point. If the value of glass continues to stay low, it will be unaffordable to recycle. It has a healthy future, but it has to change.

RT: Some people would say that more recycling education is needed to improve recovery. Does either system have an advantage here?

SH: There will always be a need for public engagement, even with MWPFs. However, instead of focusing on what can and can’t be put in the bin, we can focus on source reduction and reuse, donation programs, e-waste recycling and proper household hazardous waste management.

An MWPF doesn’t eliminate the dialogue on waste; however, it can change it—giving us the opportunity to talk about moving up the waste hierarchy even further.

MC: What are we teaching the next generation about recycling if we tell these kids, ‘Hey, you don’t have to recycle at home anymore; throw all your school paper and junk mail with everything else [into one bin].’ What happens is that the dirty MRF in Indianapolis is only for residential recycling, only for households.

The mother and father go to work, they’ve had a recycle bin next to their desk all of these years, what do they think now? Now if you put it in with your garbage and pizza box and chicken bones, it’s going to the landfill.

What are we teaching our kids about recycling? No one needs to recycle anymore is what we’re telling them. It’s bad. It’s really bad. What are we teaching our kids about recycling if we’re telling them to throw their school papers in the garbage and those paper will never get recycled if it was at the school? It’s going to landfill.

RT: Do you see a scenario where the one-bin approach is preferable to single stream? Do you see a scenario where the single-stream approach is preferable to one bin?

SH: Choosing a recycling solution, whether single stream, one bin or source separation, is unique to each individual community and often comes down to dollars and cents. We believe there is a place for recycling using any and all methods.

MC: Never [is one bin preferred over single stream]. Single stream or dual stream will always be preferable to one bin. Dual stream is the best, and if not dual stream, single stream is OK, and one bin is unacceptable.


Megan Workman is with Recycling Today and can be reached at


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