How Greensboro, NC Cut Recycling Contamination Nearly 40 Percent in a Few Years

Greensboro, North Carolina’s waste reduction supervisor Tori Carle Emerson was in for a shock when she saw the telling results of a recent recycling characterization study. The city’s curbside recycling stream was 36.2 percent garbage, despite that Carle Emerson and her team were hitting the pavement, connecting with residents at festivals, schools, and anywhere else they could go to hammer out the message that recycling is important and to explain how it’s done.

They’d gone into neighborhoods inspecting recycling carts; tagged them with handwritten notes to flag contaminants; and sent follow up postcards to reinforce the lessons they were trying to teach.

When she saw the disappointing data, she says, “I had this existential crisis of, “What am I doing in my job?” It seemed no one was listening. So, we had a re-evaluation and reset our process.”

Step one was to map out and target the most problematic communities, which quickly became known as the “Dirty Dozen.”  Each and every cart along those routes was inspected pre-collection, and residents got feedback on what they left at the curb that didn’t belong there. The lion’s share of presentations out in the community focused on these select geographies too.

The program, with education and enforcement as its main levers, continues to evolve as Greensboro pulls more tricks from its hat. The numbers are looking much better; contamination has dropped by nearly 40 percent from 2021 till early 2024. 

How the message is conveyed to residents seems to be making a difference. Carle Emerson is not necessarily of the belief that you can catch more flies with honey; it’s about clearly and firmly communicating expectations. The more direct and specific the feedback the better. 

Residents with minimal contamination get a reminder of acceptable and unacceptable items. An “oops” tag goes out to those who are not doing quite as well. And a pink sticker is affixed to heavily contaminated carts, alerting drivers to not pick them up, and residents are tasked with fixing the issues.

“We are not the recycling police. And we try and bring a human element where we listen, and we acknowledge that we all make mistakes.

“But we do have a four-strike rule. If households are tagged four times in six months we remove their recycling cart.  Mixed garbage and recycling create more problems than we can handle,” Carle Emerson says.

Calls from irate residents are far and few, but when they do roll in, they are embraced as an opportunity to win residents over and bring them to what she calls the “light side of recycling.”

“We take those calls gladly and try and squeeze every bit of information and communication we can into them, so residents feel confident moving forward,” she says.

The teams asks, can I send you a recycling guide? Have you downloaded our app? (with tools from pickup reminders to a waste wizard to search for items to learn if they are recyclable or trash) They point callers to their email address and give out their personal phone lines to call with questions.

“We are trying to have the most amplified message we can on a subject that is not as important as putting food on the table and other things going on in peoples’ lives. They do not think about trash – other than that they want it to disappear. And we are trying to show them what they are doing at the curb is important,” Carle Emerson says.

It’s not an easy undertaking. Greensboro is home to about 300,000 residents, and the waste and recycling team is small – a staff of 3.5. But their job should get easier this summer. That’s when they add automation to their toolbox.

An AI-driven camera will photograph recycling carts as materials are dumped into the hopper. The images are scanned, with contaminants automatically flagged and transferred to postcards that populate with addresses and other data. The postcards will go out to residents pointing out what did not belong in the cart.

A bonus is that the technology generates participation data. Greensboro envisions using that intel to support a campaign to further boost recycling.

The new technology will go for a test drive on three collection trucks in July 2024. It will mean less days spent on manual inspections with one worker driving and another tagging out the window. And it will free up thousands of hours that had been spent processing huge volumes of Excel spreadsheet data to track contamination by household, then generating handmade tags and postcards.

“It’s going to increase our reach substantially. Every household will be inspected. We will know exactly what went into the trucks and will be able to easily follow up with residents,” Carle Emerson says.

The technology, delivered by Prairie Robotics, is able to digitally test various messages in each community and determine which one performs best.

“This has allowed us and our partners to look at the impact of different messaging while the benefit to each new city that joins us is that they get to start by using what we've seen are best practices,” says Sam Dietrich, CEO Prairie Robotics.
Greensboro moves into this technology-driven phase of its work with a lot of good information gleaned from the past few years. A main takeaway lesson in Carle Emerson’s eyes is that tagging works.

She points to a few of the Dirty Dozen routes, some which started with contamination rates as high as 50 percent.

By the second audit year, contamination was down somewhat across the boards. By year three the picture was even better. One route dropped from an improved 41 percent contamination in year two to 16 percent in year three.

Once communities came off the Dirty Dozen list the tagging stopped, yet contamination remained low the next audit year.

“So, we learned we don’t necessarily need to do a deep dive every year into how the route is doing or invest as heavily in ongoing education. That was exciting to see,” Carle Emerson says.

The overarching lesson was, whether it’s done in person or through a combination of human contact and technology, making recycling work hinges on direct, clear  feedback.

“It changes behavior,” Carle Emerson says.

“And that is the holy grail. The holy grail is behavior change.”