A 12-foot to 15-foot deep remedial excavation was required at the site to remove and replace contaminated soil and groundwater from a historic railroad fueling facility. The excavation encompassed an area of approximately 0.6 acres and extended adjacent to an active roadway and operating businesses.

Located near the Thea Foss Waterway in an area that was historically mudflats and tidal marshes, the site has since been filled with thick layers of milled wood waste. In addition, the high groundwater at the site would typically requires dewatering to achieve a stable excavation. This would result in a significant volume of contaminated water to treat and movement of adjacent contaminated groundwater into the site.

Frozen soil shoring was selected to provide a stable shoring system that contained the contaminated groundwater and cutoff groundwater inflow from outside the excavation. The system was installed through the woodwaste, around utilities, and near adjacent structures/buildings with no vibration or disturbance to the surrounding properties.

The frozen soil shoring successfully froze the woodwaste that provided a watertight shoring system and virtually eliminated dewatering and treatment requirements. The exposed frozen soil also allowed the contractor to evaluate the face of the excavation and characterize the contamination that remained in the soils underlying the adjacent buildings.