Recycling Jet Grout Backflow: Waste Mitigation and Cost Benefits-Paper

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The paper evaluates an on-site system for treating jet-grouting backflow, a slurry of grout, water, and excavated soil that must be managed during ground-improvement work. Conventional disposal—often involving vacuum trucks and off-site solidification—can be costly and impractical in congested urban locations.<br /><br />BOS Solutions’ process uses screening, tanks, centrifuges, and flocculant to separate solids from the slurry. The system produces dry, stackable waste for landfill disposal and recovered water that can be reused or discharged when it meets local requirements. Both Toronto and Ottawa projects operated without treatment-related downtime.<br /><br />In Toronto, treatment reduced waste sent for disposal by 35% and lowered estimated costs by 19%, saving approximately C$145,183. In Ottawa, waste volume fell by 47% and costs by 23%, saving approximately C$122,416. Combined savings exceeded C$267,000. The projects also recovered water and reduced the number of hauling trips. The paper estimates that environmental benefits included 240 fewer truckloads, about 14,453 litres of fuel saved, and 38,814 kg less greenhouse-gas emissions.<br /><br />The authors conclude that on-site processing can address the logistical, economic, and environmental disadvantages of conventional spoils disposal. Actual savings depend on project conditions and local disposal costs; the traditional vacuum-truck costs used for comparison were estimates.

Keywords

jet-grouting backflow

on-site slurry treatment

BOS Solutions

ground-improvement work

waste volume reduction

centrifuge separation

flocculant

water reuse

cost savings

greenhouse-gas emissions