1. Situation
A Phase I Environmental Site Assessment (ESA) performed by a Long Island-based consulting firm at a trucking depot identified records of an abandoned on-site wastewater disposal well (underground injection well or UIW). Additionally, the records revealed that an underground heating oil storage tank was abandoned on the site circa 1958. No records regarding the location or condition of the storage tank were available. Impact Environmental Consulting was contracted to perform geotechnical services to complete a Phase II ESA.

2. Selected Geotechnical Application
The wastewater disposal system structures (underground conduit and outfall well) were located using a GSSI model SIR-2 ground penetrating radar (GPR) unit. Interpretation of the radar images identified the location of the well and confirmed that there were no overflow wells. A Geoprobe model 8ML hydraulic probing unit was subsequently utilized to secure samples from within the well and around the underground storage tank (UST).

3. Outcome
The UIW was found to be contaminated with semivolatile organic compounds (SVOCs). The contaminated soil within the well was appropriately classified as a non-hazardous petroleum contaminated waste and was subsequently mitigated. No heating oil-related contaminants were identified in the subsurface soil samples adjacent to the UST. The tank was subsequently removed from the site without further incident.