What is the minimum number of soil samples required when a tank is removed?

The minimum number of soil samples required during the removal of a heating oil tank is three. This requirement is established to ensure a thorough assessment of the soil quality and potential contamination that may have occurred from leaks or spills associated with the tank.

Collecting three samples allows for a more comprehensive evaluation of the site because it helps to identify the extent and variability of any contamination. The samples should be taken at different locations around the tank—typically, one sample from beneath the tank itself, one from the upgradient side, and one from the downgradient side. This method provides insight into possible contamination flow pathways and can assist in determining the need for further investigation or remediation efforts.

Thus, the requirement for a minimum of three samples ensures that the assessment is adequate to protect human health and the environment and complies with regulatory standards.