The Technology of Trash

Michael Fickes

Observers often criticize the waste industry for being slow to adopt new technologies. In some ways, the criticism may be deserved. Then again, the industry may have been waiting for technologies better tailored to its needs and budgets. Affordable technologies that target specific needs are arriving on the scene, and waste companies are adopting them.

Today’s in-ground scale systems can resist the effects of water and lightning — longtime problems for transfer stations, landfills and other facilities. At the same time, intelligent scale-house software systems can direct and re-direct drivers when different parts of a facility open and close — a terrific idea for sites that struggle to manage hundreds of trucks arriving and leaving throughout the day.

Then there are new onboard scales that not only sound an alarm when a truck reaches its legal loading limit but can also be set to disable a truck’s lift arms to prevent overloading. That’s a fix for a hardworking driver that keeps coming back with over-the-limit citations. There’s more: Global positioning systems (GPS), route management and communications technologies inside waste truck cabs are making it easier for dispatchers to manage drivers and helping drivers better manage their routes and customers.

Weathering the Environment

Water- and lightning-resistant truck scales appear to be growing in use. Variously called hydraulic and hydrostatic scales by different manufacturers, the devices measure weight with a load cell that compresses a thin film of oil (0.30 of an inch thick) when a load is applied. The pressure pushes tiny volumes of oil through capillary tubes, which deliver the oil to a device that turns the pressure into an electrical signal that is translated into a weight. Because the load cells contain no electronics, lightning strikes and water do not bother them.

Over the past year, Raleigh, N.C.-based Waste Industries installed two sets of hydraulic scales in its Fayetteville, N.C., transfer station. “These kinds of scales are lightning-proof,” says Jerry Johnson, vice president of capital projects for Waste Industries. “When lighting knocks out a conventional load cell, it can cost $6,000 to $10,000 to replace them. As we change our scales out in our branch operations, we’re replacing them with hydraulic scales.”

The new scales include hydrostatic units manufactured by Seymour, Conn.-based Emery Winslow for the pit beneath the tipping floor of the Fayetteville transfer station. Leak and Associates Inc. handled the installation, which included a chain and hook system that enables cleaning of the scale.

“Using the chain and hook, the maintenance crew can pull the scale out of the pit and clean it and maintain it whenever they want,” says John Leak, president of Leak and Associates. “Suppose a certain kind of trash comes in and flows into the pit. You should clean it out right away, and you don’t have time to schedule downtime for a service company to come in and do the work.”

Waste Industries’ Fayetteville transfer station also installed Guardian hydraulic scales made by Webb City, Mo.-based Cardinal Scale Manufacturing Co. in recent months. “We’re using those scales in our outbound lane to scale the trucks out,” says Leroy Hatmaker, operations supervisor.

Intelligent Diversion

Pinellas County Utilities in Pinellas County, Fla., owns an integrated solid waste disposal facility that includes a waste-to-energy (WTE) plant, two landfills that accept putrescible and non-putrescible waste, an area for yard waste and a public drop-off station.

On most days, trucks deliver 90 percent of their trash to the WTE plant, which can burn 3,150 tons per day. On a typical day, the plant takes in about 3,000 tons, while 200 tons might go to the landfills. “A small portion of the waste is sludge or some other material that we can’t use on the WTE side,” says Deb Bush, operations manager for the facility.

However, if the WTE plant goes down or has a problem processing material, the landfills must begin accepting waste intended for the plant. Diverting hundreds of trucks from the WTE plant to one or both of the landfills without disrupting traffic heading to the composing center or the public drop-off station requires a major management effort by the disposal facility’s scale-house staff.

Bush factored traffic diversion into a scale house system upgrade carried out last October. The upgrade enabled the facility to accept credit cards, identify trucks with RFID technology, and associate transactions with video of license tags, drivers and materials. The upgrade, handled by Hunt Valley, Md.-based Paradigm Software, also automates traffic management during diversions.

When a supervisor gives the order to divert traffic by way of a computer, the upgraded software automatically updates the other computers at the facility. Directions related to the diversion will print out on tickets — in a highlighted color — and the computer screens used by drivers moving through the scale house lanes will flash the message, making it hard to miss. The upgraded system can alter the directions given out to each truck depending upon the specifics of the traffic diversion, and the material and size of load a truck is carrying.

The next step will be to integrate the Paradigm system with the facility’s overhead message boards to automatically put up appropriate messages when a traffic diversion is set into motion.

Are You Overloaded?

Time was, drivers estimated the weight of the trash loaded into their truck and headed for the landfill when they thought the truck was more or less fully loaded. Law enforcement in recent years has changed this: No more warnings or winking when a truck is a few pounds over the limit. Drivers who overload their trucks and get caught will return to their yard with a citation for the boss. Drivers who have accidents may find that the authorities will decide to weigh the truck in the process of determining fault.

More and more companies are installing onboard scales so that drivers can be absolutely sure of the weight of their trucks. Legal and liability issues aren’t the only factors driving the trend. Loads that are too heavy are hard on trucks. They raise maintenance costs and shorten the useful life of a vehicle.

Phoenix-based Republic Services Inc. has been pilot testing onboard scales in recent years. This year, it began to roll out the program across the company. “We’re purchasing a significant number of onboard scales with the goal of preventing overloading,” says Mike Davis, Republic’s vice president of operations support.

Republic is buying LoadMaxx onboard scales from Eugene, Ore.-based Air-Weigh. The system provides a small light-emitting diode (LED) readout for the cab’s dashboard so the driver can keep track of the load as it increases throughout the route.

According to Matt Whitfield, maintenance manager with Republic Services of Corvallis, Ore., the Corvallis and Albany divisions of Republic Services, which are neighbors, have been using the scales on about 15 residential and roll-off trucks used by both offices. “Recycling runs light, and there is no need for scales on those trucks,” Whitfield says.

What are the results? “We know we’re running legal now,” says Mike Huycke, the general manager of the Corvallis office. “Before we were guessing. We always want to be legal. Now we are confident that we are.”

A driver might be tempted to ignore a gauge that says a truck has reached its legal limit. What if there are only a couple pick-ups left on the route? Wouldn’t it be a waste of time to go to the landfill and have to come back?

For good drivers that fall into that trap, the scales used by Republic’s Corvallis and Albany offices have a feature that integrates with the electronics governing the lift arms on automated side loaders and front loaders. The scales can disable the lift when a truck’s weight reaches its limit.

It might make your driver mad. But it might also prevent a citation.

Onboard Route Management

GPS systems have been around the waste industry for years. Companies that feel the need to keep a closer eye on drivers have bought systems, and GPS does that job well. But GPS offers other benefits for hauling company managers.

For instance, Santa Clara, Calif.-based Specialty Solid Waste & Recycling found a way to eliminate a substantial amount of overtime pay with a GPS tracking and route monitoring system from San Diego-based Air-Trak.

According to General Manager Jerry Nabhan, the company picks up trash from 29,000 households in Sunnyvale, Calif., under an exclusive contract. The collection trucks deliver the waste to a transfer station where it is compacted into bales and pushed onto Specialty Solid Waste & Recycling transfer trucks that deliver the bales to a landfill.

“It takes 20 minutes to make a bale,” Nabhan says. “If we send the trucks to the transfer station at the same time, they’ll have to wait in line for a long time and some of the drivers will have to log overtime to get finished. By tracking the downtime with the GPS system, we were able to set up a staggered schedule for the drivers going to the transfer station. Those that weren’t on the way to the transfer station were on break.”

Nabhan also is beta testing an RFID system made by Air-Trak. “We recently converted to metered service in Sunnyvale, where you pay one price for a 35-gallon cart and more for a 95-gallon cart,” he says. “RFID chips encoded with the owner’s address are embedded in the carts to help manage this. Now, if a customer paying for 35-gallon service puts out a 95-gallon cart, the route monitoring system sees that the wrong cart is out and records it.”

When Nabhan reviews the day’s work, he calls up an exception report on his computer and can see triangular color-coded error messages overlaying houses along the route map. “Orange triangles mean wrong cart,” he says. “If I hover the cursor over the triangle, the system will tell me the address where the cart belongs. This will help keep billing straight on metered routes.”

Nabhan also is testing the RFID system on his commercial customers. With this system, a reader on the truck captures the information from an RFID chip embedded in a commercial container. When customers call to complain about a missed pickup, the system has the facts. “This system also tells me if a driver picks up a container that isn’t on the route,” Nabhan says. “So this system can do two jobs for us on the commercial side.”

Better Hauling Through Technology

What operations would you like to make more efficient? Where would you like to improve quality or reduce costs in your hauling and disposal business? There may well be a technology that will do exactly what you want it to do.

That was not as true a couple of years ago as it is today. Waste technology has become its own category. It isn’t just the same technology used by another transportation industry. Today, there is advanced technology that is designed specifically for the waste industry, and it can help you get more out of your business.

Michael Fickes is a Westminster, Md.-based contributing writer.

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Sidebar: Learn More About Technology at WasteExpo

The 2011 WasteExpo conference program will include the “Communication, Safety and Tracking Technologies for Improved Collection Operations” session, which will be held from 1:45 p.m. to 3 p.m. on Monday, May 9.

The program also will feature the “Truck Scales and Hydraulic Systems for Increased Productivity” session from 10:15 a.m. to 11:30 a.m. on Wednesday, May 11.

For complete information on the conference program, visit www.WasteExpo.com.