A uniform slope of at least how many inches per foot is required?

The requirement for a uniform slope in the context of underground storage tanks typically pertains to the need for proper drainage and to prevent the accumulation of liquids, which could lead to contamination or other issues. The minimum slope required is 1/8 inches per foot. This specification ensures that there is sufficient gravitational flow to direct any potential spills or leaks away from the tank and towards adequate drainage points.

Having a slope of at least 1/8 inches per foot is beneficial for maintaining the integrity of the storage system and complying with environmental regulations that aim to protect groundwater and soil from contamination. This standard is established to mitigate risks associated with the failure of storage tanks and to ensure that any accidental release is contained and managed effectively.

While other options present different measurements, they do not meet the minimum requirement established for effective drainage that promotes environmental safety and regulatory compliance.