The right retrofit

Casella Waste Systems’ largest material recovery facility (MRF), the Charlestown MRF in Boston, underwent a major retrofit last year. The facility reopened in June 2023 with increased processing capacity and capabilities thanks to equipment and technology supplied by Machinex Industries Inc.

Casella, based in Rutland, Vermont, invested about $20 million into the project, which followed on the heels of more than $30 million in investments the company made in its resource solutions operations over the previous two years.

The site consists of two 65,000-square-foot buildings and originally served as a plywood supply facility in the late 1980s before being converted into a recycling facility in the early ’90s. Absorbed by Casella in 1999 through its acquisition of KTI Inc., the site has undergone multiple retrofits but had not been updated since 2009, when it was converted to a single-stream MRF.

“The goals of the upgrade were to engineer a system that maximized the space, increased capacity, increased efficiency and took advantage of the latest technology available while improving and enhancing the work conditions for our employees,” says Jeff Weld, director of communications at Casella.

Casella’s partnership with Machinex developed after the equipment supplier, headquartered in Plessisville, Quebec, performed several smaller retrofits for the facility.

“We were impressed not only with the equipment and installation but also the follow-up to ensure the projects were operating at maximum efficiency and expectations,” Weld says.

Other than supply chain hiccups attributed to the COVID-19 pandemic, which delayed the project by eight months, Weld says the retrofit was relatively seamless. Casella closed the site for about 20 weeks while the retrofit was underway, diverting material to its MRFs in Auburn, Massachusetts, and Lewiston, Maine—a task Weld says was challenging but, ultimately, successful.

“The [Charlestown] MRF is the fourth-largest MRF in the country,” he says. “Diverting the amount of daily tonnage took a good amount of planning, and ensuring customers didn’t see any operational disruption was important.”

The Charlestown facility processes residential recycling from Massachusetts and parts of New Hampshire, as well as material from Boston-based customers, including universities and hospitals. The site also offers source-separated commercial recycling services accepting fiber, cardboard, mixed paper, plastics, aluminum, tin and glass.

Becoming more efficient

The retrofit aimed to use the MRF’s existing space more efficiently through technological upgrades and changes to the layout.

Annual capacity at the MRF increased from 180,000 tons to 230,000 tons, while hourly capacity increased from 38 tons to 50 tons.

The MRF’s tipping floor capacity increased as well, going from 300 tons to 700 tons. Weld says it’s a benefit that might not be as exciting as other efficiencies gained through the upgrade but is equally important.

“The goals of the upgrade were to engineer a system that maximized the space, increased capacity, increased efficiency and took advantage of the latest technology while improving ... work conditions for our employees.” – Jeff Weld, director of communications, Casella

“Previously, that tip floor was so limited that it created situations where trucks couldn’t easily get in and out, and they had more wait times,” he says. “Now, with more space on the floor … it doesn’t compact and fill up as quickly. It might only seem like 10 minutes added to a driver’s day, but if it gets them out of traffic or home a little earlier than normal, that’s a good thing.”

The upgrade represents a shift away from mechanical sorting technology to artificial intelligence (AI).

Machinex installed nine optical sorters, with six responsible for sorting fiber and three on the container line. Other equipment upgrades include two scalping screens to manage primary fiber tonnage, two ballistic separators, SamurAI robotics technology for quality control (QC), AI reporting software and aspiration points for plastic film removal.

The upgraded facility also features a glass processing system, which can process glass into sizes suitable for the bottle and aggregate markets.

Casella increased the number of balers in the facility from two to three, with new reversible belts that allow for flexibility if one machine is down for maintenance. With one single-ram baler and a pair of two-ram balers, the site now has full redundancy, Weld says.

A comfortable workplace

Improving working conditions for the MRF’s employees was another priority.

The Charlestown MRF previously ran two shifts, requiring the work of part-time laborers in addition to Casella’s full-time employees. The retrofit allowed the facility to transition to a single shift and did not require the reduction of the permanent workforce, some of whom have been employed at the facility for more than two decades.

Fifty employees work at the MRF, and Weld says the retrofit has opened new opportunities for them.

“You’re able to give people more opportunities with a consolidated shift,” he says. “For example, if [an operator] is constantly in the same piece of machinery because they have no choice because they’re working on second shift, now we can rotate them through different pieces of machinery [and] get them more experience in different ways.”

Weld says the retrofit gave Casella a chance to reimagine the site with its employees in mind and address the challenges that come with an older facility, including air flow, heating and cooling.

It’s been more than a year since the facility reopened its doors, and the Charlestown MRF has hit its stride once again. As employees worked through the early challenges of learning the new equipment and processes, Weld says they began to understand how to maximize the benefits of the upgrade.

Although public tours have been limited since reopening, Weld says Casella intends to focus efforts on educating the community about recycling and contamination rates through the reimagined Charlestown MRF. A recycling education room has been built into the facility, and education efforts are the company’s next focus.

“We’re at a place where we have the technology and the infrastructure, now we can really focus on how we get out and educate a bit better,” Weld says. “Next phase: education.”

The author is digital editor of Recycling Today Media Group and can be reached at tkazdin@gie.net.