What operational and situational factors affect the size and type of equipment used at a landfill? Money is always the first concern. Available credit and cash flow, along with the current market prices for new and used equipment, will place a ceiling on how large and capable a site’s equipment fleet can be. Within these budgetary constraints, the landfill’s equipment fleet will have to be outfitted and organized according to such external factors as the local climate (especially areas where freezing, inclement weather affects traction and earthmoving) and such internal factors as the type of waste received.
Though this article focuses on municipal solid waste landfills and their equipment needs, it should be remembered that MSW is only one wastestream (and not the largest by any means) that has to be managed. Construction-and-demolition debris, hazardous waste, residual waste, medical waste, industrial waste, mine tailings, sludge, and coal combustion byproducts all require different methods of handling and disposal.
MSW requires efficient spreading and compaction operations that should reduce the volume of the incoming waste by at least 50%. For the most part, modern landfills utilize the area method of waste disposal: Waste is deposited in an area called the workface, which is large enough to allow for efficient compaction and the integrated choreography of incoming waste-hauling trucks and waste-disposal equipment. Old-style disposal methods utilizing pits, trenches, or ramps have been largely abandoned since the widespread adoption, decades ago, of Subtitle D regulations mandating the use of engineered landfills with complex liner-containment and leachate-removal systems.
The deposited and compacted waste will then require cover placed at the end of each workday to prevent the spread of disease vectors, odors, or blowing debris. This cover can be plain soil (usually a layer of 6 inches spread over the current workface) or some alternate material, such as plastic sheathing or spray foam. The type of cover used (or if it is to be reused, as in the case of soil cover being stripped and stockpiled for further use) will determine a significant portion of the landfill’s equipment fleet.
Types of Landfill Equipment
The size of a landfill’s equipment fleet depends on the size of the landfill. Landfills are generally rated as either small (less than 250 tons of waste per day), medium (250 to 500 tons per day) and large (500 or more tons per day). In this age of the 24/7 landfill serving entire regions instead of a few counties, there are even a few landfills that can be called “super size,” taking more than 1,000 tons per day, seven days a week.
Smaller landfills can get by with a minimum equipment fleet consisting of a small-to-medium tractor dozer such as a Cat D6 for spreading MSW (a more rugged D7 would be required at a construction-and-demolition (C&D) landfill, a small steel-drum waste compactor such as a Cat 816F or 826H for C&D landfills (though very small landfills receiving less than 50 tons per day can usually dispense with a compactor), and a small to medium-sized tracked (track loader) front-end loader such as a Cat 953D for placing waste, soil, and aggregate. Given the potential large object size and low overall density of waste, the loader could use a large (more than 2 cubic yards heaped capacity) multipurpose bucket with bolt-on adaptors and long, extended tips.
Medium-size landfills need to upsize to more than one medium-to-heavy dozer, such as the Cat D7, for both MSW and C&D with the optional use of a D7R for C&D, a medium steel drum waste compactor such as the Cat 826H for MSW or 836H for C&D, along with a medium-to-heavy (track loader) front-end loader such as the Cat 963D for MSW or the 973D for C&D. Anytime an 836H is used, it is best to match it with a D8T with it or D7E, though this does depend on waste flow and peak periods.
Large-scale operations require more than two heavy dozers such as the Cat D8T, two or more heavy steel-drum waste compactors such as the Cat 836H, and a large (track loader) front-end loader such as the Cat 963D and 973D. Very large landfills often include a whole host of different equipment for such specialized tasks as recycling, offloading from barges and rail cars, or waste baling.
A landfill’s workface is a harsh environment, often far harsher than typical construction or excavation sites. Equipment, engines, drive trains, undercarriages, wheels, and tractor treads take a beating from ever present dust, debris, and impacts from large sharp objects. So each type of equipment has to be specially modified to protect it from its surroundings.
For dozers to be effective pushing and leveling waste piles, they must have their blades modified to match the material with which they are working. Waste requires a modified semi-universal or universal blade for a dozer to function properly. For example, dozer blades should be equipped with trash racks. These racks consist of welded steel beams connected at right angles with the vertical beam directly welded to the top of the blade. The crossbeams add structural support and allow for the placement of vertical bars or heavy metal screens to provide complete coverage between the crisscrossing beams. This metal lattice effectively doubles the height of the blade without significantly adding to its weight and without obscuring the vision of the compactor operator. This increases the dozer’s capacity, as it can move more waste with each push. Waste is relatively low density, very heterogeneous, and often consists of large objects. This makes waste completely different from typical soils that dozers normally handle. The rack’s screenlike structure also allows it to catch tumbling waste before it can damage the dozer’s radiator or the operator’s cab.
A further modification to a dozer includes the addition of front and rear striker bars attached to the dozer body, greatly improving its performance while operating in waste. These prevent waste from being carried over into and clogging up the dozer’s tractor treads. Additional improvements include rear counterweights that improve balance while operating on steep slopes, heavy-duty crankcase shields, and screens placed to prevent the clogging of radiator and aired inlets by small waste and dust particles. Other factors affect a dozer’s productivity, increasing or decreasing it compared with its baseline performance under idealized conditions (type of material being dozed, wetness or dryness of the material, visibility, weather conditions, increasing downslope and decreasing upslope, working in tandem with other dozers while choreographing its movements with all the other equipment operating on the working face.
Waste handling track loaders require similar upgrades. Protection should be provided by guard packages that protect moving parts (idlers, pivot shafts, drive seals, etc.) from debris. In fact, almost every key engine part needs additional protection. Pre-cleaners that prevent intake port clogging are used to protect carburetors. Radiator protection should allow for quick and easy cleaning to remove accumulated dust and debris particles.
The loader bucket itself has to be a specialized waste bucket for working on a landfill. This is an oversized bucket that takes into account the presence of oversized objects in the waste (as opposed to more homogenous soils managed by traditional loaders). The size of the bucket, however, should not exceed anticipated waste loads. It would be a waste of money, for example, to invest in a bucket that can handle 300 cubic yards per hour when the landfill receives only 100 cubic yards. The oversized buckets also allow for easier working in waste material that can greatly differ in size, shape, and weight, and will clump together. As with other landfill equipment, loader productivity depends on other factors besides bucket sizes: How crowded the workface is, variability of operating slopes, excavation depths, hauling distances, and stationary and moving obstacles.
The king of the working face remains the waste compactor. It is this piece of equipment that directly reduces volume and increases profitability. All other equipment in the landfill’s fleet serve to support compactors and assist them in the job they do. Applied pressure from the weight of the compactor is increased by means of reducing the actual contact area to the tips of add-on cleats. From 20 to 40 tips, set in a staggered pattern that ensures maximum coverage, can be added to the compactor’s smooth drum depending on the size and weight of the compactor.
As with all landfill equipment, these compaction cleats are modified for use on a landfill’s workface and therefore differ somewhat from standard cleats utilized by soil compactors. Short, compared to soil cleats, waste cleats are typically 6 inches to 6.5 inches in length. These cleats are also designed like teeth to chop the waste as well as compact it. Given the extreme wear and tear these cleats are subject to, they are typically designed for easy replacement when worn down. By properly operating and maintaining the waste compactors, waste volumes can be halved and deposited densities doubled.
Along with the big three (dozers, compactors, and loaders), a landfill can be serviced by a mini-fleet of support equipment. This can include road graders, backhoes, water trucks, portable pumps, basic pickup trucks, tool carriers, articulated dump trucks, baling machines, and specialized equipment for placing alternate daily cover (either spray-on shells or roll-out tarps). But most of the main work is performed by the three main pieces of equipment. Though not considered to be physical equipment, the use of GPS tracking and related earthwork productivity software can be key to a landfill’s operational profitability.
Major Suppliers of Landfill Equipment
Caron Compactor Co. designed a replacement cap puller kit consisting of purpose-built pullers along with all the tools necessary to perform the cap replacement. In years past, Caron provided teams of technicians that would travel to a site and perform this cap replacement procedure. Although this program is still available, many customers today have the capability to do this maintenance themselves, thanks to Caron training programs. Caron maintains an in-field support system of service trucks with two-person crews for wheel rebuilding, repair and tip replacement. Caron Field Service helps minimize equipment downtime. The product has been the patented Megamax Pin-On locking teeth, which incorporate a mortise-and-tenon lock design on the cap-to-base assembly. These fit tightly together to enable replacement of the caps, reusing the original bases. The result has been to establish the life of the replacement cap at approximately 10,000-plus hours, then change the caps and run another 10,000 hours. So Caron can provide a limited 10,000-hour wear warranty on its replaceable caps and a 20,000-hour prorated warranty on wheel structures and Pin-On base adapters.
Caterpillar provides one of the industry’s most comprehensive customer service agreements (CSAs). A CSA is any arrangement between the buyer and the Cat dealer that helps lower costs per unit of production. Agreements are tailored to fit business needs and can range from simple preventive maintenance kits to sophisticated total cost performance guarantees. Trained dealer technicians assist by maintaining equipment and driving down operating costs. A CSA is very flexible. There are no preset requirements or specific products and services that have to be bought. In every case and with every piece of equipment, a CSA is an individualized plan. Depending on the customer’s needs, costs can be a flat-rate monthly fee, or some other arrangement based on actual production hours. Agreements may include as few or as many pieces of equipment as the buyer wants. It can cover individual systems, single pieces of equipment, or entire fleets.
In addition to CSAs, Caterpillar offers the Cat Equipment Protection Plan, which can control the costs of unexpected repairs. The plan offers three levels of protection: Powertrain, Powertrain+Hydraulics, and the most comprehensive coverage option, Premier. These plans can be tailored to specific needs by selecting from a wide variety of years/hours combinations. Equipment protection plans safeguard equipment investments in new, used, and rebuilt machines beyond the standard warranty period. Each plan includes all parts and labor to safeguard against failures caused by defects in materials and workmanship. In addition to controlling costs, the plan maximizes productivity by minimizing downtime and extending operating life, improving safety, and allowing for upgrades mandated by new regulations. They are applicable to new and used equipment, certified rebuilt products, hydraulic hammers, telehandlers, and machine-control and guidance technology (AccuGrade Grade Control System, AQUILA Drill and Dragline Systems, CAES, MineStar System components).
In addition to equipment coverage, Caterpillar provides equipment information. It provides technical publications such as operations and maintenance manuals, parts manuals, and service manuals for Cat machines. Operation and maintenance manuals contain operating, maintenance, safety, and service information. Service manuals contain information on how the major operating systems work, testing, adjusting, and troubleshooting guides, as well as disassembly and assembly procedures. Parts manuals have exploded views of all serviced parts on the equipment.
Terra Compactor Wheels provides a no-fault replacement warranty that converts its standard warranty program to a No-Fault Swing Exchange replacement/repair program. Wheels are repaired or replaced as originally purchased. It excludes Terra Rolling Wire Guards and the repair kit pricing of rolling wire guards may be charged at replacement if originally equipped and is repairable. Wheels are exchanged at specified warranty periods of 4.5-inch cleat heights for only the cost of freight/installation and rolling wire guard kit option if originally equipped. A similar warranty based on machine life converts the standard warranty program to a no-fault swing exchange replacement/repair program for standard machine life of 10 years or 25,000 hours (or any specified time requested by customer). However, this includes all wheel body modifications, and rolling wire guards and complete wheel sets are repaired/replaced at specified cleat heights as originally purchased.
Al-jon provides maintenance service with the aim of minimizing downtime. This proactive approach allows Al-jon to meet its ISO uptime goal of 98%. In case of a problem, Al-jon will initiate a plan for correcting the problem within four hours of a service call, with the goal of correcting the issue within 24 to 48 hours, giving Al-jon the best response times in the industry, putting Al-jon equipment back into action as quickly as possible.
Al-jon scrap equipment is designed to utilize available “over the counter” components whenever possible, which gives many of the company’s customers the ability to do repairs on their own. Service centers are strategically placed around the country for solid waste industry customers. Each service center is equipped with factory-trained technicians and parts for immediate repairs. Al-jon’s service department employs trained regional service managers for each region.
Al-jon also provides service-training courses (including both classroom instruction as well as hands-on training) for owners and operators to familiarize them with their equipment. The objective is to provide training on electrical and hydraulic systems, engine diagnostics, and troubleshooting. These courses cover current Al-jon production models, including equipment maintenance and operating procedures.
Service training has enabled customers to recognize potential problems in the field. Service training is facilitated by an in-house trained staff.
HJ Industries provides a complete line of replacement parts (new, used, and rebuilt). These include such mechanical drive parts as differentials, engines, hydraulic pumps, transmissions, torque converters, and the undercarriage. Linkage systems are also provided, such as drive seal guards, drive hubs, and axle guards. Fluid management systems such as hydraulic pumps are also available. Finally, the company’s line of replacement parts includes non-mechanical add-ons and ground engagement parts such as buckets and bucket teeth, compactor tips, and compactor wheels.
The Tarpomatic Automatic Tarping Machine (ATM) is an equipment-mounted unit that unrolls and retrieves alternate daily covers consisting of different types of fabric panels. This system could in itself be considered maintenance for the landfill as a whole, since it greatly extends available disposal airspace. The ATMs come with an extensive service agreement and associated warranties. Support is readily available from the factory and service technicians who will come out to prepare new ATMs with installation of mounting brackets for specific equipment using the ATM and training for equipment operators on proper ATM use, safety, and maintenance.
Airspace Saver, a division of Sassco Supply, manufactures landfill daily cover and environmental tarps in sizes ranging from 25 feet by 25 feet up to 120 feet by 120 feet, using a variety of fabrics from a 6-ounce woven polypropylene up to the heavier-duty 10-ounce, 20-mil-thick woven flame-resistant polyethylene Fabrene material.
A specialty cover used on Tarpomatic’s automatic tarping machines typically lasts customers between 1 to 3 years. Proper compaction, operator awareness, and proper use of the automatic tarping machine are essential for extended tarp life.
Volvo CE’s G-series front-end loaders come with advanced electronic monitoring diagnostics that are designed to prolong machine life, enhance uptime, and maximize productivity. Control electronics (“Contronics”) monitor functions in real time, alerting the operator if problems occur. MATRIS, meanwhile, charts and analyses data on machine handling and operation. VCADS Pro is a system that allows a machine to be fine-tuned to specific applications, further improving performance. Finally, CareTrack uses a transmitter fitted to the machine that allows the current machine data to be viewed via the Internet from anywhere in the world, aiding fast decisions on maintenance and repairs.
Servicing is made easy with the G-series, with daily prestart items quickly checked and scheduled service items conveniently grouped together. The G-series is fitted with a newly designed engine cover that provides better ventilation of the engine compartment. The cover can be electronically opened backwards-giving good access for fast and easy cleaning or servicing duties. Centralized, ground level lubrication banks lower the time spent on scheduled maintenance. And consumables like filters are easy to reach and easy to replace. The G-series comes with a large number of Volvo attachments to suit the application, including high-tip and side-tipping buckets, as well as attachment brackets that make changing tools fast and easy. All features have been designed and approved by Volvo to work in perfect harmony with the machines’ link-arm geometry, breakout, rim-pull, and lifting forces.
GeoShack’s Density Max is a wireless, enhanced GPS that combines Topcon GPS Machine Control Systems hardware with the unique Carlson Landfill Software to maximize landfill density. Density Max allows the user to increase waste density more efficiently by avoiding unnecessary passes with the compactor, controlling waste placement grades and using the CAD-generated surfaces to track in-place density in real time, tracking volume usage and waste placement from remote locations. Like other landfill equipment suppliers, GeoShack provides technical support and total care for its density Max systems. The GeoShack Total Care support package is designed for items such as lasers, autolevels, theodolites, total stations, GPS rover and base stations, robotic total stations, and data collectors. Calibration is provided for lasers, autolevels, theodolites, and total stations along with a free upgrade for the system’s GPS receivers. Customers can purchase the “GeoShack Total Care” annually and continue getting the value-added services, even beyond the manufacturer’s warranty period. Special agreements exist for 3D and 2D machine control, farming applications, and landfill operations.The Human Element
It may seem strange to apply the concept of maintenance to the human operators of landfill equipment. But the days when anyone could keep a job, let alone advance to a higher position, without continuous retraining and re-education are long gone. With each new system improvement and equipment add-on, landfill equipment technology becomes more and more complicated and demanding of skills even as it becomes easier to use and more productive. Experienced operators need continuous upgrades of their skill sets to keep their experience from becoming obsolete. A good supplier of landfill equipment will provide training to upgrade the human operator as it upgrades the equipment. Even the best equipment will be a waste of capital unless the operators are thoroughly trained, and retrained, throughout their careers.