
Chlorinated solvent releases at former dry-cleaner sites are often subject to far greater subsurface complexity than traditional monitoring well networks can capture. This was true at a former dry-cleaner site where soil excavation and multiple rounds of bioremediation injections had been implemented. Despite these efforts, PCE concentrations in groundwater remained above regulatory standards — indicating unresolved DNAPL source areas or ineffective treatment.
To clarify the true extent of contamination, Aestus deployed its specialty GeoTrax Survey™ electrical resistivity imaging (ERI) to provide continuous subsurface mapping without additional invasive work. Anomalous zones of interest were targeted for additional sampling and historical and targeted contaminant data were then integrated in 2D and 3D to correlate resistivity variations with geology, DNAPL presence, and biodegradation activity.
This data-calibrated ERI revealed several critical CSM updates:
With these findings, the project team could refine the cleanup strategy, target remediation where it was truly needed, and avoid ineffective sampling or injections. The updated, imaging-supported CSM significantly improved decision-making, reduced uncertainty, and minimized future remediation costs.










