Curbside recycling material quality is a hot topic around The Recycling Partnership offices and, because you are reading this, it likely is around yours, too.

The Recycling Partnership and the Massachusetts Department of Environmental Protection (MassDEP) recently wrapped up a yearlong project to craft and test a protocol for clamping down on contamination in residential curbside recycling. That work, and the contamination-crushing effort it influenced in Memphis, Tennessee, were referenced in the January 2017 edition of Recycling Today. (See www.RecyclingToday.com/article/rolling-into-success.)

The conversations during the MassDEP project would sound familiar to any recycling program director or material recovery facility (MRF) operator: 1.) contamination levels are too high, 2.) MRF contract requirements aren’t being met, 3.) handling fees or contaminated load rejections are a real possibility and 4.) local governments and/or haulers need to change what residents put in the container and change it fast.

From that work and other experiences around the country, The Recycling Partnership built tools to help communities address inbound curbside recycled material quality and measured the results of applying those tools.

Yet, more is needed. Active industry dialogue is required to address a persistent curbside recycling contamination issue: What is contamination, what are the most problematic contaminants and is weight the best way to measure inbound contamination to improve material quality?

This article is not intended to resolve these questions fully; rather, it endeavors to lay the groundwork for a conversation between community programs and MRFs on how best to move forward to improve quality while offering up a few ideas on how to address these issues on the ground.

What is curbside recycling contamination?

The word “contamination” seems to be used broadly and probably means something different for each sector or even each recycling program manager. Before curbside programs can solve the contamination problem, we have to have a better understanding of which materials actually represent “contamination.”

Contamination is created when the wrong materials are put into the system (e.g., hoses, propane tanks, etc.) or when the right materials are prepared the wrong way (e.g., recyclables in plastic bags, food left in containers, etc.). Acceptable material lists for most programs are relatively basic, including bottles, cans, containers, cardboard and printed paper; thus, literally thousands of items are potentially left for the “no” list, and curbside programs simply cannot list them all for every resident, nor should they.

While it may feel counterintuitive, our experience indicates that if too many unaccepted items are communicated to residents, they will either receive that information as a signal that recycling is hard and confusing, or they will be overloaded with information and tune it all out. The magic number on a no list? Three to five items, which means that the potential options must be culled significantly. And therein lies the question on where to focus attention on cutting contamination: Do we target those items that cause MRFs to shut down, lose time and/or jeopardize worker safety, target unmarketable materials or heavy materials? The answer will help the industry determine the best way to measure contamination; it also may lead to MRF contracts that are structured differently than the standard practice today. Ultimately that will influence how local governments communicate with residents and monitor material quality curbside.

To help drill down and identify what constitutes the three to five top offenders in material contamination, The Recycling Partnership developed a MRF Acceptable Materials Worksheet, available online at http://tools.recyclingpartnership.org/ wp-content/uploads/2015/11/AcceptableMaterialsWorksheet_TRP.pdf. A basic checklist, it facilitates a conversation between the community and the MRF to determine which materials are accepted, which are not accepted (either because they are hazardous to worker safety, can damage equipment and cause costly downtime and/or substantially downgrade the value of other materials or because they are nondetrimental but are not accepted for other reasons), which the MRF does not want listed but will accept if they come through the system and then, finally, which five materials cause the MRF the most problems.

Having used this worksheet with MRFs across the United States, The Recycling Partnership has found five common curbside recycling contamination themes: tanglers (hoses, cords, clothes), film plastic (plastic wrap or bags), bagged things (garbage or recycling), hazardous material (propane tanks, needles/sharps) and a category that can be summed up as “yuck” things that downgrade other materials and clog the system (food, liquids, diapers, etc.). Give or take one or two of those categories that may change because of regional differences or end markets, and they typically constitute the top five categories on a MRF’s no list.

To further distill the composition of contamination found at the curb, during the MassDEP project we conducted recovery rate studies with the consulting group DSM Environmental Services, Windsor, Vermont, which allowed us to peek into curbside carts at the household level. As seen in Figure 1, the contaminants identified were not surprising, but the ratio of materials found was illuminating. The majority of the contamination by weight were recyclables in bags, garbage in bags and all other, which encompassed random items that did not fit in other categories, e.g., joint compound, a bag of dirt, etc.

These findings raise two questions:

Considering that lightweight items like tanglers and plastic bags typically top a MRF’s list of costly issues, how much do the relatively heavier category of unwanted materials actually matter to the MRF’s operations and bottom line?

If weight alone does not adequately capture the presence of the top curbside contaminants, what measurement system should communities and MRFs use instead?

It is not unusual for MRF contracts to allow for penalties when the contamination is more than 10 percent or 20 percent by weight. That is an important and relatively straightforward metric, but it doesn’t account for the havoc that lightweight contaminants can create. After all, one bed sheet or a single cartload of loose plastic bags can lock up disk screens, causing significant downtime daily at a MRF. Such materials, however, only represent 13 percent of contamination by weight (based on the figure “Weight Alone Doesn’t Tell the Story) and yet pose the costliest challenges. “Material quality is an ongoing issue at the MRF, consequently we need ways to measure it that are fair and reflect the challenges that different materials pose,” says Bob Cappadona, vice president at Casella Recycling, headquartered in Rutledge, Vermont. “Bags full of garbage weigh a lot and add to our disposal costs but can be handled in the presort,” he says. “Alternatively, a single hose can bring a MRF to a halt. Plastic bags require the facility to stop so they can be cut out, which is costly and a safety issue.”

Cappadona continues, “Municipal/MRF contracts need a way to adequately measure or act upon the lightweight but highly problematic materials as well as measuring contamination by weight.”

Measurement matters

The question remains: What metric should be used to measure success in reducing contamination? Might two different metrics be needed?

One option is to rework recycling contracts so they focus on the most highly problematic materials (typically tanglers and film/bags) by using per-item penalties, frequency or volume metrics rather than weight-based metrics; thus, crafting contracts around contamination that is blatantly obvious and costly to operations with clear and documentable feedback to the community.

For those communities in the middle of contracts, at least start the conversation and create a feedback loop from the tip floor to the program that monitors and grades loads and isolates problems before it’s too late.

Another option that might cost more on the front end but might result in highly useful information is to do simple curbside studies to determine the composition of contamination and then to develop education and performance metrics around that data.

Once agreed upon metrics are in place, the next step is critical: engaging all stakeholders with a directed effort toward quality improvement and monitoring results. The community program manager, route driver and MRF all have a role to play, and each piece in the material collection/processing puzzle is balanced.

MRF tipping floors are busy and dynamic places, drivers need to get through routes efficiently, community programs must provide good customer service for their residents and no one has a budget to focus on this problem. Nevertheless, if each stakeholder provides a little support and strong communication is present, contamination can be minimized.

Drivers must be empowered to reject egregiously contaminated carts and leave clear communication behind (The training video at www.youtube.com/watch?v=57TV_5SBgYM may help to set local protocols.). MRFs must monitor loads and give quick feedback to the program on a regular basis. And the community must provide clear messaging to residents all year long through signage, direct mail and even quality inspectors tipping cart lids out on the curb.

If a curbside program is finding particular offending materials in carts at high frequencies, a material specific campaign that reinforces again and again that the material is not recyclable should be considered.

“ReCommunity is fully committed to reducing contamination in the recycling stream by providing timely, detailed feedback to our community partners,” says Sean Duffy, president and chief operating officer of the Charlotte, North Carolina-based MRF operator. “In many of our recovery facilities, we have a dedicated material quality inspector who visually inspects individual loads for nonprogram material. This has allowed us to understand the composition of the contamination in greater detail and provide relevant feedback to our customers on the big problem items,” he says.

“We inform our customers of contaminated loads with photos and details the same day of the occurrence,” Duffy continues. “We’ve found immediate communication allows our customers to make effective corrective actions, from driver education to identifying the source along a particular route.

You can’t manage what you can’t measure, so let’s continue the contamination dialogue because it’s worth getting right: Contamination is a costly and dangerous problem that deserves focused attention.

“Additionally, where appropriate, we reject contaminated loads and assess a handling fee,” he says.

The point here is that frequent and timely communication prevents problems from becoming critical before they are addressed, and curbside feedback to residents is required for results.

Where to go from here

You can’t manage what you can’t measure, so let’s continue the contamination dialogue because it’s worth getting right: Contamination is a costly and dangerous problem for MRFs that deserves focused attention.

Communities, haulers and MRFs that are experimenting with new ways to measure, track and manage contamination hopefully will continue to share their results. The Recycling Partnership will further explore this issue with our MRF Working Group, and we will be using the group’s insights to share lessons learned and further develop best-practice-based tools. We also will continue to measure the composition of contamination in the recycling cart with partner cities around the country, further adding to the industry’s understanding of what contamination looks like at the curb and how best to address it through educational and operational interventions.

If we work together, these efforts will lead to better metrics, improved contracts and communications and more, better materials delivered to end markets, which is a hallmark of any strong, high-quality curbside recycling program.

The authors are vice president of technical assistance and strategic partnerships lead, respectively, with The Recycling Partnership, Falls Church, Virginia. They can be reached via email at cmarshall@ recyclingpartnership.org and at kbandhauer@recyclingpartnership.org. More information is available at www.recyclingpartnership.org.