Soil Conductivity Logging

Vironex is able to measure the electrical conductivity (or resistance, as resistance is the inverse of conductivity) of soil. Soil electrical conductivity relates to permeability. Thus, without collecting a sample, we can generate a real-time x/y plot of permeability as a function of depth which in turn yields insights regarding the subsurface transport of contaminants.

Generally, electrical conductivity is inversely proportional to particle size. That is, clays usually have higher conductivity than sands. Another rule of thumb is the smaller the particle size of the soil, the lower the permeability. Thus, electrical conductivity measurements yield important lithological information and identify the locations permeable and non-permeable zones.

 
Two recent examples of how Soil Conductivity Logging has helped our clients optimize site characterization and remediation efforts are as follows:

DNAPL Sampling At Clay Confining Layer - The depth to clay was variable, however with the soil conductivity probe, we were able to precisely find the sand/clay interface in a fraction of the time it would have taken collecting soil cores and without breaching the confining lens. We then advanced our water sampler down the same hole to the exact depths of interest.

Identifying Sandy Gravel Treatment Interval – TCE plume treatment required targeting of a high permeability layer to ensure contact of a chemical oxidant with contaminants and to optimize oxidant costs. With the soil conductivity probe, we were able to isolate this target injection interval in a timely and cost effective manner resulting in overall lower costs for the treatment event.

Pre-Injection		Post Pmag Injection

 

Targeted Injection Into Sandy Gravel Treatment Zone

Advantages of using Soil Conductivity are:

Rapid logging of soil lithology in saturated and/or unsaturated zones.

Eliminates all soil cuttings and waste.

Dramatically reduces the time and cost of site characterization.

Identifies target treatment intervals for in-situ groundwater
   remediation.

 
Soil Conductivity Standard Operating Procedure