If water returns to a tank pit after pumping, what actions must be taken regarding sampling?

The correct answer involves the collection of samples from both the pit water and the soil walls based on the number of tanks present. This is important for a thorough assessment of any potential contamination that may have occurred as a result of the returned water, which could have interacted with petroleum products or other hazardous materials.

In cases where water returns to a tank pit, it serves as an indicator that there may be issues with the containment or that leaks may have occurred. Sampling water provides immediate information about the quality and potential contaminants present in the water itself. Soil samples from the side walls of the pit can reveal whether contaminants have migrated into the surrounding soil, potentially indicating a more extensive issue that needs to be addressed.

Collecting both types of samples ensures a comprehensive evaluation of the situation, as it allows for the identification of contaminants present in both the water and surrounding soils, which is essential for making informed decisions on remediation and safety measures. This approach aligns with best practices in environmental monitoring and regulatory compliance in the management of heating oil tanks.