ERH is a common method of remediation for volatile organic compounds in unconsolidated soils, both above and below the water table. In the past eight years, ERH has been used to successfully treat over a dozen contaminated sedimentary bedrock sites. Sedimentary bedrock treatment has recently expanded to greater depths and into difficult, karst limestone environments. With proper design and implementation, the remediation of sedimentary bedrock can be completed as effectively as the remediation of overburden materials.
ERH passes an electrical current through the soil, rock, and groundwater requiring treatment. The principal current path is the thin layer of water immediately adjacent to the soil or rock grains - relatively little current is carried by the water in the soil pores. The electrical current warms the subsurface and then boils a portion of the in situ moisture into steam.
This in situ steam generation occurs in all soil types, regardless of permeability. Sedimentary rocks typically have significant primary porosity and the rock grains generally possess the thin film of water required for electrical conductivity. In summary, in ERH applications, it is not the pore fluid that dominates the electrical conductivity; it is the grain wetting fluid that dominates the electrical conductivity.
The three photos represent examples where TRS completed successful ERH bedrock projects. Full project examples can be accessed by clicking each image.
Contact TRS to obtain a copy of a recently published peer-reviewed technical paper "Electrical resistance heating of volatile organic compounds in Sedimentary rock".