How much of a tank must be underground for it to be classified as a UST?

For a tank to be classified as an underground storage tank (UST) in Oregon, it must have a minimum of 10% of its volume located below the ground surface. This classification is significant due to the environmental regulations and monitoring requirements that accompany USTs.

The definition is based on ensuring that a substantial portion of the tank is buried, which helps mitigate the risk of leaks and spills that could harm soil and groundwater. Understanding this threshold is crucial for compliance with state and federal regulations governing storage tanks, emphasizing the importance of proper monitoring and maintenance when dealing with USTs.

In summary, the requirement that at least 10% of the tank be underground aligns with safety and environmental protection standards, making it a vital piece of knowledge for anyone involved in the oversight of heating oil tanks or other stored substances.