How many samples are required for tank decommissioning?

The requirement for taking two samples during tank decommissioning is based on the guidelines established to ensure adequate assessment of potential contamination in and around the tank site. By obtaining two samples, one can achieve a more reliable representation of the soil or groundwater conditions. This allows for better detection of any contaminants that may have leaked from the tank over time.

The first sample is typically taken from the area immediately surrounding the tank, which helps in identifying any direct impacts caused by the tank’s operation or deterioration. The second sample may be collected from a location at a distance from the tank. This is important because it can indicate whether contaminants have migrated beyond the immediate vicinity of the tank due to factors like soil permeability or groundwater flow.

Thus, having two samples supports a comprehensive understanding of the environmental conditions and potential risks associated with the tank decommissioning process, ensuring that necessary remediation actions can be effectively planned if needed.