What pressure should Underground Storage Tanks (USTs) be tested with air before excavation?

Testing Underground Storage Tanks (USTs) with air pressure before excavation is a critical procedure to ensure safety and integrity. A pressure range of 3-5 PSI is considered effective because it provides a balance that allows for the detection of leaks without risking damage to the tank. This pressure is sufficient to test the strength of the tank structure and assess for any potential failures or weak points that could be exacerbated during excavation activities.

This pressure is also effective for ensuring that any destruction or failure in the tank is identified before any earth-moving activities begin, which can prevent pollution or hazardous incidents. Using a pressure higher than this range might unnecessarily strain the tank, while a lower pressure may not effectively reveal issues that need to be addressed. Thus, the 3-5 PSI range is optimal for performing a thorough and safe assessment of UST integrity prior to excavation.