Managing a municipal solid waste transfer operation involves handling a considerable investment in equipment-scales, software, compactors, perhaps balers, trucks, and more. You want the equipment to function smoothly so that you can keep the waste and recyclables moving. In this article, we take a look at how some transfer operations do business, and point up changes in equipment that could possibly make your life easier.
The city of Dallas, TX, has three solid waste transfer stations, says Gary Middleton, division manager for the city’s transfer operations. Middleton manages all three, and from the transfer stations the waste goes to McCommas Bluff Landfill in the Dallas area. The city runs 21 transfer trucks and trailers to take waste to the landfill.
Each transfer station has three scales that are a combination of Cardinal and Thurman units. The three consist of one inbound scale at each of the stations and one scale in each of two transfer pits per station.
The city uses WasteWorks software from Carolina Software, and it records waste from all city customers. The software stores tare weights for trucks, calculates net weight, and gives different commodities a code. WasteWorks also has different routes that can be inputted, each with a driver’s name.
“Each of the inbound drivers gets a ticket on our inbound scales,” says Middleton. “We have software there called WasteWizard [also from Carolina Software]. The driver inputs route information and a number of informational items along those lines. At the outbound scales, we record that information manually and input that at a separate time into the WasteWorks software.
WasteWizard works at an unattended scale. Cash customers and citizens work with scale attendants. When using WasteWizard, a driver puts in codes for his route and truck number. The software knows his tare weight and calculates the net weight of the waste.
“Sanitation in Dallas has changed radically over the last four or five years,” says Middleton. “We have introduced a single-stream recycling program with a separate operation to pick it up at the curbside. Citizens place recyclables such as newspaper, cardboard, or aluminum cans into a blue recycling bin. The trucks go by and they commingle all of that. Then the trucks either take it directly to our vendor, or they bring it to my transfer operations. From there we transport it to the vendor. The vendor then sorts it, bundles it, sells it, and returns the city’s portion of the proceeds to the city.”
Middleton says his biggest challenge is the maintenance of his trucks and trailers. He runs tractors from Volvo, Peterbilt, and Autocar. In the rear-loader variety, the city still has some International trucks and “maybe even some Sterling trucks, when they still made them.”
The city of Dallas runs five or six maintenance shops distributed throughout the city to take care of the trucks. “We need to have a certain percentage of our trucks up and running to achieve our mission,” says Middleton. “I think we can tear them up quicker than they can fix them sometimes. So keeping them running is a challenge.”
New From Emery Winslow
Emery Winslow Scale Co., Seymour, CT, makes vehicle scale equipment for a broad range of industries, including municipal waste, the aggregate industry, rock quarries, asphalt plants, moving and storage, and more. In addition, Winslow has a broad line of tank scales for the food and chemical processing industries, says Rudi Baisch, vice president of sales and marketing for Winslow.
Recently, Winslow introduced the patented Quick Clean Axle Scale. These scales are primarily for use inside the tunnel areas beneath the tipping floor of a transfer station. “Everybody wants the truck to be on a scale in the pit, but that is probably the harshest environment on the planet,” says Baisch. “The scale is sitting in water with the rodents so it is impossible to clean those pits. We have come up with removable axle scales. They are anywhere from 10 by 10 feet to 10 by 15 feet in dimension.
“You can put two or three of them in the tunnel to weigh the rear tandem axle on one scale and the drive axles on the next scale and optionally you can put another scale up under the steering axles,” says Baisch. “So you can get a weight of all three axle groups while the truck is being loaded. And the big trick here is that each of these scale platforms can be lifted right off of the load cells and out of the pit-in a matter of minutes-with a typical wheel loader which everybody has on site.
“That way you expose the entire pit,” says Baisch. “You can get in there with a high-pressure hose and a shovel and clean it out. The scale drops right back onto the load cell. There is no need to recalibrate the system. You don’t need to call your scale company into to do this work. The people at any transfer facility can do this routinely once a week, once a month, and the whole process takes about half an hour. You never get the problem of these pits filling and getting so packed with garbage that they no longer even function as scales.
Baisch says the Quick Clean Axle Scale was well received at a recent trade show. “Nobody knew that such as scale was now available. It is a huge problem out there, and so our scale was very, very well received.”
For most scales, Baisch says, you need the scale company to come for a service call. He says a crane is needed; you disconnect the scale from the load cells, and with a test truck you have to recalibrate and recertify the whole scale.
“That costs thousands and thousands of dollars,” says Baisch. “With our system, the load cells stay in place. And the deck module lifts right off of the load cells and plops back down on the load cells. We have a couple of customers that do it once a month, and it takes them an hour from beginning to end, including the high-pressure hosedown.
“That is our hot product. Obviously we have full bridge truck scales like everyone has for a tunnel. And we have the in- and outbound truck scales. We have the full line of those. We are in the process of installing a whole set of scales for the city of Phoenix at their transfer station there.”
To cope with the harsh, wet environment in the scale pit of a tunnel, Winslow uses a hydrostatic load cell. Every Emery Winslow scale uses a hydrostatic load cell. Baisch says electronic load cells do not handle the solid waste environment very well.
“The hydrostatic load cell operates on a very thin film of oil, and we transfer a pressure signal over to an instrument enclosure hanging on the wall somewhere,” says Baisch. “And in that box, we do have a transducer, which converts from pressure to electronic signal. The customer still has a digital weight display. He can have remote read-outs; he gets a computer interface; and he gets all kinds of signals, whatever he wants.
“But out under that scale platform there is not a single wire, not a cable, no summing boards, no electronics, no circuitry whatsoever,” says Baisch. “That pit can literally fill with water and the load cells are guaranteed for life against failure from water damage, rodent damage, power surges, and even direct lighting strikes on the scale.
“Anybody’s software can be used. Once our digital weight indicator is set up and functioning, it sends a pressure It sends a digital signal to a computer and so any software package will work with our scale.”
Compaction in Texas
Kenneth Chance is the sanitation superintendent for the city of University Park, TX, a suburb of Dallas with a population of 23,000-plus. Last year the city handled a total of 19,954 tons of solid waste, and that included 4,416 tons of yardwaste and 2,734 tons of recyclables.
The city operates two compactors at its transfer station; one is a Peabody and the other is a Kee-Pak Stationary Compactor from Kee Service Co. Both are 15-cubic-yard compactors. “We have trucks that hold 6 yards, others that hold 16 yards or 30 yards, and we usually put about 54 yards of waste into the back of a trailer,” says Chance.
Only compaction occurs at Chance’s transfer station; there are no scales. Waste is weighed at a landfill or the recycling center. The city runs nine New Way rear-loader trucks and three Heil side-loaders. Two three-quarter-ton pickups are both Dodge vehicles.
Heavy-Duty Cardinal Scales
Cardinal Scale Manufacturing Co., of Webb City, MO, makes heavy industrial truck scales, railroad track scales, heavy capacity hopper scales, floor scales, and more. The company markets a software package that will work with any Cardinal scale, says Ron Ricketts, national sales manager for Cardinal.
The software package is called Win VRS, for Vehicle Recording System. It is PC-based software that tracks material, customers, routes, weights and more. The software will track in-bound and out-bound trucks and produce an invoice that can be used to bill customers. “The software computes that charge and also will track all of your customers, by name, and the material by name, and keep it all straight per customer,” says Ricketts.
Cardinal also makes unattended kiosks that allow a driver to enter a number or swipe an RF badge or a bar code badge. “And then he can conduct his business without an attendant,” says Ricketts.
Cardinal’s wireless communication systems permit connections between scales and personal computers with no need to dig trenches. “It will communicate weight, time and date, the type of waste on a particular vehicle, track the truck number and time, and more,” says Ricketts.
Recycling in Montana
Polson, MT, is a rural community located a little more than an hour’s drive north of Missoula, in the western part of the state. Program manager Mark E. Nelson of the Lake County Solid Waste District operates a transfer station that takes in about 20,000 tons of solid waste annually from Lake County, population 29,000.
Nelson uses WasteWorks, from Carolina Software, to handle accounting work for the trucks that cross his 100-foot Fairbanks scale. “We use tickets if the load is something where we need to collect from somebody,” says Nelson. “If they are cash customers, they pay on the spot. We have a till and the software tracks all of the money for you. If they are on a charge account, then it just creates an account receivable for them. Then once a month we can send a billing statement. The haulers have the ticket as an invoice each time they come through.” Municipal solid waste goes to a landfill in Missoula, MT.
“We have all of the commercial haulers and our own trucks plugged in, so they don’t have to weigh for tare weights,” says Nelson. “If someone comes in and they have household waste, we don’t charge them for that. But if they have a little construction material, we might charge them for that. Typically, they don’t haul much construction material into here.”
For the past year, Nelson says Lake County has been recycling newspapers, magazines, phone books, aluminum cans, plastic bottles, and cardboard. “Recently, we started using the scales with our recycling work,” he says. “Mostly, they are people from businesses that want to know how much they are bringing us. So we weigh them in and out and tell them how much material they recycled.”
Nelson says his transfer station does not always weigh recycled material coming in. “If someone asks, we weigh it for them,” he says. “But we always weigh it when it is going out. We know what the load is going out so that when it gets to the commodity broker or to the mill we know whether they are staying honest or not.”
We asked Nelson how he likes WasteWorks software. “They have been really good, and they have given us good support. If we have a hiccup with it, which we don’t have very many of, we call them and they get back to us right away.”
New From Rice Lake
Rice Lake Weighing Systems, in Rice Lake, WI, manufactures floor scales, bench scales, truck scales, railway track scales, loader scales, end-loader scales, and onboard scales that allow a user to convert a fixed box or flat bed into a scale on top of a motor vehicle.
For the solid waste industry, Rice Lake makes automated ticketing kiosks and onboard scales for refuse trucks. With onboard scales, the indicator can be mounted inside the cab or outside the cab.
New products from Rice Lake include the automated ticketing system-the ATS System being released this year. It interfaces to the company’s PC-based ticketing called On-Trak.
The system allows haulers and transfer stations or landfill operators to keep track of trucks, materials, drivers, and particular jobs and to calculate rates and taxes. It will track the inventory of a particular waste product.
“The nice thing about the automated kiosk is that once a truck is registered and an RFID tag is issued to the driver, they no longer have to get out of the vehicle in order to weigh the vehicle,” says Joe Grell, vice president of strategic development for Rice Lake. “Keeping the drivers inside the truck is safer than allowing them to get out. Automation of the ticketing process also reduces the in-yard time for the vehicle, so it is not on the scale owner’s property quite as long. It allows us to get more vehicles across the scale in a given period of time.”
The automated ticketing system interfaces with Rice Lake’s On-Trak ticketing software, which allows users to export all of the transactions to an ERP system or accounting package.
Rice Lake’s latest generation of automated kiosk is an Ethernet-based product. It allows for a connection back to the PC in the field house via connectional copper, fiber optic or wireless Wi-Fi. The kiosk system can operate on an existing Ethernet network that eliminates wiring altogether to connect the scale house to the kiosk.
Recently, Rice Lake introduced iQube2, which it says is the fastest digital junction box on the market for managing multiple-cell scale systems. The iQube2 can update up to 500 times per second, and it has onboard diagnostics that identify noise, test for linearity and zero reference, and monitor drift.
“The great thing about iQube2 is that the operator can tell if the scale is no longer functioning properly, even though it may appear to be weighing correctly,” says Grell. “Sometimes scales get out of tolerance and iCube2 notifies an operator if that is happening.
“The system can compensate for a failing scale if the operator chooses, but that is not legal for trade,” says Grell. “So in a non-legal-for-trade or noncommercial situation, it will compensate for a bad load cell. In a legal-for-trade situation, it will flag the operator or put a message on the screen advising the operator that the scale is not functioning properly. It can also e-mail a service provider automatically that there is an issue with the scale. The iQube2 can be retrofitted to any load-cell-based scale. So it doesn’t matter if it is a Rice Lake product or not.
Maximizing Fullness of Rolloff Containers
One Plus Corp., of Northbrook, IL, manufactures electronic monitors for commercial compactors used to fill rolloff truck containers. The monitor can e-mail up to four recipients about the status for pickup of the container.
“The container is at the compactor,” says Joan Scott, executive sales manager for One Plus. “Our system evaluates the hydraulic pressure in the compactor. Based on the hydraulic pressure, each monitor is commissioned so that it will automatically e-mail for its own pickup while still allowing the facility to use the compactor.
“In an automatic mode, the monitor will call out on its own for a “˜just-in-time’ pickup,” says Scott. “So if the agreed-upon response time with the hauler and client is 24 hours, the monitor will automatically send e-mails. That allows the facility that uses the compactor and the hauler enough time to arrive to pick up the container. So it maximizes the fullness of the container without inconveniencing the site-and stays within the over-the-road weight limit.
“Each person can has their secure name and password and can view the compactor activity online,” Scott continues. “And they can raise and lower call-out pressure if needed-and justify invoices accordingly-and make sure only full containers are being picked up. Different wastestreams will take up different volumes within a compactor. Corrugated or recyclable materials might only weigh 5 tons when they are picked up, versus regular mixed waste, which can weigh 10 tons. That’s where the sophistication of the system helps out greatly.
“From the hauler side, they can grow their business by 20% without adding another truck or driver, because they are more efficient,” says Scott. “They only pick up full containers, and they use less fuel that way.”
Baling Waste for the Landfill
“We manufacture two-ram balers,” says Brady Bergey, regional sales manager for Excel Manufacturing Co. in St. Charles, MN. “One main ram compacts the solid waste and the second pushes the material out of the bale chamber.
“The theory back in the 1980s was that if you bale your waste you will get more material into the landfill,” says Bergey. “And that rather died out because back then, when technology was not as advanced as it is now, there was quite a bit more labor in handling the bales. But now they have done some studies and found out that if you bale, you can get a higher density of material in the landfill.”
Bergey says his balers are typically designed for material recovery facilities to use in compacting cardboard, plastics, and papers. However, he says, in the past couple of years it’s become popular again to bale, and balers can handle couches, garbage bags full of garbage, even concrete blocks.
And now, a company called Envirobale has come up with a bagging system for solid waste. That has advanced the baling industry, because the bags are cleaner and better than the old wire-tie systems, Bergey says.
“Envirobale is a bag that slides right onto the baler chamber and will fit over your bale like a sock over your foot,” says Bergey. “It slides over the material, you cinch it up, throw it on the truck, take it to the landfill, and stack it nicely there. So you don’t have all of the liquid gushing out of the bale. You are not having pieces fall out. It is a much cleaner system. That has really made a difference in the past couple of years.”
Do you manually lift the bales? No, a forklift does that job. “Envirobale makes three different systems,” says Bergey. One is to lift the bale manually with two people, and there is one that can be loaded with one person and there is a fully automated system. Excel’s balers can be paired up with all three.
“The most common is the one-man system,” says Bergey. “One person pushes some switches to control a jig that is robotically operated. You just load the bag onto this jig and it will put the bag into position for you.
“With a two-man system, they manually take the bag and slide it over the chute of the baler,” says Bergey. “It is pretty simple. It is more labor intensive, but it’s the most economical and the easiest way to do it.” Each bale is 60 inches long by 48 inches wide and 30 inches tall. With the fully automated system, the jig has fingers that grab the bag and put it on the baler.
The advantage is cleanliness, and you don’t have to wait for the baler to throw a wire. Bergey says the wire-tie systems require from five to 12 wires per bale, and that takes time. “Now you can put the bag over the chute, and the material all comes out as one unit,” he says. On average each bale weighs about one ton.
