Hydrovac slurry is the mixture of solids, liquids, and entrained air generated during hydro-vacuum excavation operations. This non-destructive excavation technique uses high-pressure water to loosen soils and a powerful vacuum system to extract the resulting slurry. It is widely used for safe and precise digging around existing underground utilities such as electrical cables, gas pipelines, fiber-optic lines, and water networks. The extracted slurry typically contains a high concentration of solids, including soil, sand, silt, clay, gravel, and fragmented rocks. 
In industrial areas or contaminated sites, the hydrovac slurry may also contain hydrocarbons, chemical residues, or other forms of subsurface contamination. Due to its complex and highly variable composition, this slurry is often classified as industrial or controlled waste. As a result, it cannot be discharged directly into municipal drainage systems, open land, or water bodies. Proper handling, transportation, and treatment are required to ensure compliance with environmental regulations and to minimize impacts on local ecosystems and infrastructure.
To process this material effectively, the waste slurry must be transported to a specialized treatment facility where solid–liquid separation can be carried out. Typical treatment methods include the use of coarse separation equipment, vibrating screens, drying screens, decanter centrifuges, and chemical-enhanced dewatering systems. These processes reduce the moisture content of solids, recover reusable water, and minimize the total volume of waste requiring disposal.
GN Solids Control provides a complete equipment package for hydrovac slurry treatment. The system can be configured to handle various slurry characteristics and separation requirements. GN’s solution includes a primary coarse separation shale shaker, double-deck shale shakers for fine screening, large-bowl decanter centrifuges for high-efficiency solids separation, and fully automated dewatering systems for further moisture reduction. Supporting equipment such as mud tanks, agitation systems, and slurry transfer pumps are also integrated to ensure continuous and reliable operation. This comprehensive package enables hydrovac operators and waste management companies to process excavation slurry efficiently, reduce disposal costs, and meet environmental compliance standards.