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 capacity and processing capabilities thanks to equipment and technology supplied by Plessisville, Quebec-based Machinex Industries Inc.

Casella, based in Rutland, Vermont, invested about $20 million into the project.

“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.

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 1990s. Absorbed by Casella in 1999 through its acquisition of KTI Inc., the site has seen multiple retrofits but has not been updated since 2009, when it was first converted to a single-stream MRF.

Weld says Casella’s partnership with Machinex developed after the equipment supplier 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,” he 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 facility for approximately 20 weeks and diverted material to its MRFs in Auburn, Massachusetts, and Lewiston, Maine, while the retrofit was underway, an aspect Weld says was challenging but, ultimately, successful.

“The Boston 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 our customers did not see any operational disruption was important.”

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

Upgrades

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

Annual capacity increased from 180,000 tons to 230,000 tons, and hourly capacity increased from 38 tons per hour (tph) to 50 tph.

Tip floor capacity increased as well, going from 300 tons to 700 tons, a benefit Weld says may not be as exciting as other efficiencies gained through the upgrade, but is equally as important.

“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 total optical sorters, with six responsible for cleaning fiber and three on the container line. Other equipment upgrades include two scalping screens to manage primary fiber tonnage, two ballistic separators, robotics technology for quality control (QC), AI reporting software and aspiration points for plastic film removal. The facility also features a glass processing system, which can process glass into sizes suitable for 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 two two-ram balers, the site now has full redundancy.

Workforce

Improving working conditions for facility employees was another priority of the upgrade.

The Charlestown MRF previously ran on two shifts, which required the work of part-time laborers. The retrofit allowed the facility to transition to a single shift and did not require a reduction of the already existing permanent employee workforce, some of which 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 the team.

“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 upgrade 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.

The new facility now features enclosed sorting cabins in the occupied QC areas. Weld says these rooms reduce equipment noise, have fresh air heating, ventilation and air conditioning (HVAC) systems to maintain a safe and dust-free environment and have been designed to allow people of different sizes to work comfortably.

It’s been approximately ten months since the facility reopened its doors and the Charlestown MRF is once again hitting its stride. As employees worked through the early challenges of learning new equipment and processes, Weld says those at the facility have begun 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 is 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.”