From Landfill Airspace to Recoverable Aggregate

As incoming volumes increased, Headlands began looking more closely at what was being placed in its landfill. Much of the soil contained rock, sand and gravel that could potentially be recovered, yet those materials were consuming limited and expensive landfill airspace

“Why are we putting this in the landfill? This makes no sense,” recalled Mike Hofer, Principal of Headlands Environmental.

Headlands initially introduced screeners and later crushers to separate larger aggregate from incoming loads. This reduced the amount of usable material entering the landfill, but it also raised a more important question: If aggregate could be recovered from the soil pile, could the surrounding impacted matrix be treated as well?

The challenge was complicated by the range of material entering the site. Soil from the Lower Mainland and Fraser Valley can include sand, silt, clay, peat, cobble and mixed contamination profiles. Unlike an aggregate operation processing a relatively consistent deposit, Headlands needed a system capable of adapting to changing feed materials from different excavation and infrastructure projects.

Headlands installed Tyrone International’s TrackWash Pro, supplied by Frontline Washing Systems, alongside the Hydro Pro slurry receiving system. The plant was designed from the start to handle both dry excavated soil and wet hydrovac slurry, with separate receiving paths that feed into a shared recovery circuit.

The TrackWash Pro combines the work of four separate machines on a single tracked mobile chassis, allowing Headlands to carry out multiple processing stages within one mobile system.

For dry material, excavated soil is loaded directly into the main processing circuit by excavator. This is the conventional feed path, allowing incoming soil to move straight into the washing process.

Wet material takes a different route. Hydrovac trucks discharge slurry directly into the dedicated Hydro Pro receiving system. This eliminates the need for decant pits or drying beds. Rather than waiting for slurry to settle or stiffen enough to handle, the material can move into processing without a separate drying or pre-treatment stage.

Once the two streams enter the shared recovery circuit, the material moves through several processing stages. Scalping removes oversized material, while a trash screen separates unwanted debris such as wood and plastic. The material then passes through a dual-shaft log washer, where scrubbing helps break down and separate material.

From there, a classifying screen separates the washed material into three aggregate fractions. A sand dewatering screen produces two sand products.