Managing Landfill Equipment

Heavy equipment is the backbone that supports the landfill industry. But just how big is that backbone? Pretty darn big. Landfills across the US average approximately one (trash machine) for every 250 tons (of daily tonnage) received. Of course there is an economy of scale, but this is the average.

Nor does this include support equipment such as loaders, grinders, tippers, motor graders, water trucks, excavators, etc. Including support equipment, a ballpark estimate puts us at around 10,000 machines at US landfills.

With such a great number of machines at landfills, proper management is vital. It comes down to selecting the right machine for the job, using it efficiently, and tracking its performance to maintain high output with low operating costs. Piece of cake, huh? Let’s see.

Selecting the Right Machine(s)
Landfill machines are selected to perform one or more specific tasks. Multitasking—where a machine is used for various tasks—is generally a good thing, but as a machine becomes more universal, it also becomes less efficient at specifics. Consider for example, the most universal machine in the landfill industry: the track loader.

Historically, small landfills—those that could afford only a single machine—would use track loaders because they do it all—to a degree. They could gather, push, spread, and compact trash. They could also excavate, transport, and place cover soil. They could load trucks, stack rubble, or pull a stuck vehicle out of the mud. They could do it all but none of it particularly well.

Today, many small landfills are very much in the place of having to do it all with one or two multipurpose machines. Managers of those sites often express regret having to use a single machine. This situation most commonly leads us to the question: “Should every landfill have a compactor?” The answer is, “Not necessarily,” and it’s based on simple economics.

There is no question that a compactor will achieve higher density than a crawler (e.g., a dozer or a loader). This will result in added landfill life and cost savings. But are the cost savings sufficient to offset the added cost of having a compactor? Remember: Because a compactor is a specialized machine, a landfill must also have a dozer, loader, or other multipurpose machine. A compactor is almost always an “added” machine, not an alternative “only” machine.
Let’s compare.

Based on this analysis, by using a compactor the landfill could save $83 per day in airspace. And we might assume that every hour spent operating the compactor would equate to a corresponding one-hour savings of dozer time, so the operating costs are a wash. But there is also an owning cost associated with purchasing a compactor. So the final question is, “Would the $83-per-day savings in airspace exceed the cost of purchasing a compactor?”

This is a simplified example, and, of course, every landfill is unique. But machine analysis always comes down to costs versus benefits.

Don’t be misled into thinking that machine compromises apply only between major machine classifications such as dozers versus compactors. It’s true that for a small landfill the multitasking issue may include finding a machine that can push, compact, and cover. But at some point, every landfill must work with some degree of compromise.

A large landfill may have the advantage of specializing to a greater extent by owning many different machines, such as a dozer, a compactor, and a scraper, although at some point there will still be some multitasking. Here’s an example.

At a typical (large) landfill, there are many tasks for which a dozer is best suited. But the ideal size/type of dozer varies depending on the task.

As you can see, there is no single size/type of dozer that is best-suited to every task. Few landfills can afford to own the perfect machine for each task, so they compromise by selecting machines that are the most universal. Here we are again … multitasking.

When selecting a machine for your landfill, take time to evaluate the costs and benefits and plan to accept some degree of compromise. No landfill has the perfect machine for every task. Once you’ve selected the most economical machine(s) for your landfill, take the next step to make sure they are being utilized efficiently. When considering purchase of a machine for a specific purpose, always compare the cost of acquisition with the benefits it will provide.

Are They Working Efficiently?
Working efficiently is not the same thing as keeping busy, though to the casual observer it may appear so. One of the most common examples of this is related to placement of cover soil. Most managers understand and agree on the benefits of minimizing the amount of soil used for cover: save airspace, save soil, reduce machine costs, etc. This is often a clear and stated goal.

But keeping the cover operation lean and mean requires lots of thinking, planning, measuring, calculating … and then more thinking.

Unfortunately, at many landfills, keeping busy is equated to burning fuel and making dust, and there often is little tolerance for all that thinking stuff.

As a result the initial goal to minimize soil use often conflicts with the overriding pressure the operators feel to “keep busy.”

So what’s the answer?

It is to set goals—for example to minimize cover soil use—and then establish benchmarks to track the crew’s performance.

Start by selecting a target depth of cover soil. No, it won’t be 6 inches. Six inches of cover soil is a regulatory minimum that exists only in textbooks and regulatory documents. Because of the irregular surface of trash, much soil is lost into surface voids. As a result, it takes more than 6 inches of soil to provide adequate cover. Based on reviewing numerous landfills across the country, we’ve found the average depth of daily cover soil to be 16 inches.

The least we’ve ever documented was 11 inches and the worst … 42 inches!

When setting benchmarks, including ones for daily soil use, the values must be realistic. Then, understand that due to variations in tonnage, type of waste, etc., the size of each day’s cell will vary—and so, too, will the amount of soil required to cover it.

Here’s a simple way to establish a cover soil budget.

Using Microsoft Excel, create a table like the one shown at the bottom of the page. It’s set up like a multiplication table. You set the target depth of cover soil as one single variable and the average payload of your hauling machine as another. The operators then select the length and width of each day’s cell, find where the two intersect, and presto—they see the number of loads (of soil) allowed for cover. For example, this table is based on a target depth of 11 inches of soil and a scraper payload of 18 cubic yards. If the cell is 80 feet long and 90 feet wide, it will require 13.6 scraper loads to cover it.

Translating your cover soil benchmark into a daily budget allows your crew to work efficiently toward a measurable standard, not one based on fuel and dust. The same concept works for all other repetitive tasks at the landfill. Finally, once you have selected the right machines and they are working efficiently, you’ll want to keep them working that way. This requires some type of feedback system.

One effective method is to generate a manager’s report form. On it you can summarize your crew’s performance compared to the benchmarks you’ve established. By tracking this information on a regular basis, you’ll be able to see what’s working …and what isn’t.

And be sure to pass this information on to your crew. Everyone likes to know how well they’re doing. Benchmarks are a finger on the pulse of your landfill, and a critical part of keeping the operation strong and healthy.