Spatial Moment Analysis for Mass Balance Calculations and Tracking Movement of a Subsurface Hydrocarbon Mound

Leaking underground storage tanks are a proven source of subsurface hydrocarbon contamination. An improbable leak scenario supported by anomalous field data formed the basis of a major lawsuit filed against a tank installer. A simplified hydrocarbon mound migration model, coupled with basic mass balance calculations, showed the field data to be inconsistent with the purported leak scenario, and showed monitoring well tampering to be the source of hydrocarbon contamination. The method described is a simple yet efficient means of developing hydrocarbon mass estimates and mound migration projections. These values can also be valuable in siting injection/extraction locations and developing integrated in situ remediation technologies.