Trash Compactor Monitor Saves Money

Duquesne is saving money and reducing greenhouse gas emissions thanks to a simple automatic monitoring system on its four campus trash compactors.

Before the new Compactor Monitoring System (CMS) was installed last August on compactors located at the Public Safety building, Towers, the Union and Brottier Hall, requesting a truck to haul away a trash receptacle and its contents required both regular monitoring and some discernment.

University employees, after dumping a load of refuse, activate a hydraulic ram that compresses the trash, reducing its volume and pushing it farther into the receptacle. Before the CMS system, however, the receptacles were sometimes overfilled and, at other times, hauled away prematurely.

The new CMS hardware, which resides in a small box mounted near each compactor’s controls, consists of little more than a sensor to register the force—increasing as the container fills—required for compacting.

The sensors are doing their job and making a difference, according to Bill Zilcosky, director of building services, grounds and operations for the Department of Facilities Management. During the first five-months after CMS sensors were installed, Waste Management—the University’s refuse hauling vendor—made 25 percent fewer trips to campus than during the same period the previous year, resulting in an estimated $4,400 savings. “The monitoring system is more accurate than the human eye in this situation,” Zilcosky said.

In addition, Waste Management estimates that reducing one haul per month over one year’s time decreases C0₂ emissions by one ton. The company is providing Duquesne’s CMS equipment and their monitoring service at no cost. In the competitive bidding process for the contract to haul the University’s trash, Waste Management was able to underbid their competitors by installing the CMS and making fewer hauls, said Zilcosky.

Fewer campus visits from refuse trucks also lessens traffic and remedies other problems, Zilcosky explained, because removing and replacing the compactors’ receptacles, even when expertly done, ties up the area around the compactor and produces noise for at least a quarter-hour.

Waste Management monitors compactor fullness and stores historical data about usage patterns for each compactor and dispatches trucks to Duquesne as needed. When required, however, University personnel are able to request additional pickups to accommodate special (trash-generating) events, such as when students leave campus at the end of the spring semester.