Managing the tipping floor

As the drop-off point for incoming truckloads of recyclables, the tipping floor at a material recovery facility (MRF) can be an action-packed space.

Depending on the facility, tipping floors can vary in size and contain a diverse array of materials each day—including items that could be considered contamination or hazardous.

According to a panel of waste and recycling industry experts who spoke at the MRF Operations Forum in Chicago in October, there are ways to ensure smooth operation on a MRF’s front end, whether it’s the equipment used to move material or the training and positioning of employees to efficiently run shifts and even aid in fire suppression if the need arises.

During the Best Management Practices for What’s Coming Off the Tipping Floor session, Jim Marcinko, director of recycling operations at Houston-based WM, said traffic is the biggest pressure point when it comes to a tipping floor.

“You want to safely get the truck in and get them out of the facility and, at the same time, when they tip, you’ve got to be able to see the material and address the material,” said Marcinko, who oversees about 50 facilities in the southern U.S. “You look for any gross hazards or things like that before it goes into the pile.”

Shift solutions

With loads of material arriving at a facility at different times, the positioning of staff can differ depending on the shift.

Session moderator Nat Egosi, president of Melville, New York-based RRT Design & Construction, posed the question of what a MRF running two shifts could do when most material is being tipped during the first shift and what pressure there might be to have material available for the second shift.

“You’ll staff differently during the day,” Marcinko said. “Maybe you’ll have somebody who’s focused on loading the system versus somebody who’s focused on managing material and mixing things, where at night you’re just going to be loading the system in from the bulk material. But you’ve got to make sure that it’s all positioned correctly. You don’t want to push [material] to the wrong side of the floor or vice versa.”

Tom Ferretti, senior vice president of operations at Austin, Texas-based Balcones Recycling, used the company’s MRF in Brooklyn, New York, as an example. The facility operates with three shifts, receiving material 24/7, and can have as many as six or seven trucks unloading at a time.

The MRF’s first two shifts focus on moving material once it’s dumped, while the third shift performs maintenance in addition to receiving material.

“We run the two shifts, run down the material, make sure we have enough room and always have a Plan B for a breakdown or if something unexpected happens to ensure we can [continue] to consume,” Ferretti said. “There’s some maintenance [performed] on our third shift, so we run down our tip floors toward the end of the night for fire hazards, dump our bunkers and that’s part of the management of the material coming in.”

Ferretti said the MRF takes steps to keep its employees and equipment safe and ensure a clear operating path.

“We actually make a movable wall with our material,” he said. “As the tip floor grows and shrinks, our loader operators or crane operators are trained to put a 4-foot wall of our inbound material between the equipment and the trucks and people. You can’t have a fixed wall because the floor always swells and contracts. It’s just a safety precaution at the end of the day. We shrink our tonnage, dump our bunkers, protect ourselves from fires and then go on with our maintenance.”

Equipment considerations

The equipment used to load a MRF’s infeed conveyors or drum feeders can vary by facility.

Balcones’ MRFs in the eastern U.S., all located near waterways, use cranes to unload barges, and cranes equipped with grapples also have made a difference on the Brooklyn MRF’s tipping floor.

“The pro of a crane is you can kind of cherry pick your infeed,” Ferretti said, adding that the facility receives a number of plow blades and chains from New York’s Department of Sanitation that could otherwise damage the system.

“We run 65 to 70 tons an hour in our Brooklyn facility, [or] about 1,400 to 1,500 tons a day. And if you have a crane, know your material. Is it 350, 400 tons per cubic yard? You’ve got a 5-yard clamshell [grapple]. We size our equipment to be able to load 30 percent quicker than the consumption of the equipment, so we can catch up. We put a 14-foot bucket on our loader. Our tip floor is only 26,000 square feet, and a crane can pile high.”

Ferretti noted, however, that a crane can be more difficult to procure than a wheel loader in the event of a breakdown, while a loader can move more material than a crane.

Marcinko would choose a crane or material handler with a grapple for his MRFS, though that isn’t necessarily suitable for every location.

“If you have a lot of volume and you can afford to have multiple pieces of equipment out there, that’s great,” he said. “If you have a plant that has 2,000 tons a month and you can afford one loader operator, that’s what you’re going to have. But a crane or excavator can move so much more material efficiently. You can pick through the material.”

For material handler attachments, Ferretti uses clamshell grapples for cherry-picking material in a tidy fashion. Balcones also uses 2-yard orange peel grapples, which he said are preferable for feeding the system, though they don’t “clean the floor” as well as a loader does.

Dealing with contaminants

Whether it arrives loose or in a bag, contamination remains troublesome for MRFs of all sizes.

Todd Hubbard, vice president of recycling at Phoenix-based Leadpoint, said his sorters are trained to simply throw out any bag they can’t see inside. Whether to open bags also can depend on how much time the sorters have.

“If the belt is stacked up and they’ve got to look at a bag versus grabbing a pallet or washing machine or whatever may be coming up there, [I’d say] throw away the bag, go after the big piece and get it off before they have to stop [the system],” Hubbard said.

To help mitigate incoming contamination, WM began deploying camera technology in its trucks two years ago that notifies the company when potentially dangerous contamination is collected, allowing it to correct that disposal behavior. Additionally, WM has camera systems at some of its facilities that can look at individual loads.

“We can take data back to the route managers through the billing systems and say we need to get this information back to the customer,” he said. “We can help our route managers understand it, but we have to eventually get to the customer because the manager didn’t put [the material] in the bin, the customer did.”

Marcinko, Hubbard and Ferretti all perform audits to get a better idea of what’s in their incoming material streams. They then communicate that information to their route managers or the municipalities they work with. However, Ferretti said, it’s unlikely a MRF will be able to completely prevent contamination in incoming loads with this approach.

“You do look for batteries; you look for anything that could be dangerous,” he said. “We prioritize what we’re looking for and then spread it out, take pictures and get them back to the municipality. We’ll put an emphasis on it for a week. If you get a bicycle frame in and they jam something up, let’s work on that.”

The author is associate editor of Recycling Today and can be reached at cvoloschuk@gie.net.