Maximizing density in landfill cells increases safety, efficiency, and profits. Because cells have limited square footage and are expensive to build, packing more material into each layer (increasing solid waste compaction) extends the lifespan of the cell while also reducing the risk of air and water penetration or the possibility of contaminant leaks into the surrounding soil. Improving landfill compaction protects nearby land, wildlife, and communities while also minimizing expenses. The secret to increasing landfill cell density lies in the chosen landfill compactor and its PLI (Pounds per Linear Inch) rating.

1. What is PLI?

To calculate PLI, divide the weight of the machine by the total width of all wheels that stay in contact with the ground. PLI is what makes a landfill compactor more fit-for-purpose than something like a bulldozer. Bulldozers typically rest on long, wide tracks that spread the weight of the machine across a larger area, helping them “float” above the surface rather than sinking in or crushing the material below it. Thus, a bulldozer on tracks that weighs the same as a compactor resting on four relatively narrow wheels will result in much less compaction, and its PLI will be significantly less than the PLI of a landfill compactor.

Increasing the weight of the compactor or reducing the width of its wheels will improve PLI. However, if the wheels become too narrow, they are more likely to get stuck or leave a large gap of uncompacted material between them, requiring more passes and reducing productivity. Increasing the weight is a reliable method for increasing PLI and thus for improving landfill airspace.

2. Aljon’s Landfill Compactors Have the Highest Weight Per Class

For machines in the same class with similar wheel designs, landfill compactor weight makes all the difference. Additionally, higher-weight compactors can process more waste each day. Aljon landfill compactors demonstrate that as the weight increases, PLI (and thus compaction efficiency) also increases:

• ADV500: 86,718 lbs to 95,450 lbs; PLI = 450 to 490; processes up to 950 tons per day
• ADV525: 108,000 lbs – 117,602 lbs; PLI = 572 – 598; processes up to 1200 tons per day
• ADV600: 126,160 lbs – 127,500 lbs; PLI = 600 – 613; processes up to 1300 tons per day

In order to make the most of landfill airspace, aim to use the heaviest (and highest PLI) landfill compactor the operation can support. Even if the higher production limits of a larger machine are unnecessary at first, over time, the extra weight will pay for itself by increasing the lifespan of the landfill through higher compaction ratios.