What does “tightness testing” of a UST entail?

Tightness testing of a UST (Underground Storage Tank) refers specifically to a procedure designed to assess whether the tank and its piping systems are leak-proof. This testing is critical for environmental protection since leaks can lead to soil and groundwater contamination. During the tightness test, various methods may be used, such as pressure testing, vacuum testing, or using liquid or gas to measure the integrity of the tank and piping over a certain period. Ensuring that USTs are leak-proof helps prevent hazardous materials from escaping into the environment, aligning with regulatory compliance and promoting safety.

The other choices focus on different aspects that do not pertain to tightness testing. Inspecting a tank for structural damage relates to the physical condition of the tank but does not directly assess whether it is leak-proof. Safety drills, while important for emergency preparedness, are unrelated to the integrity of USTs in terms of leaks. Testing for the chemical composition of stored products pertains to quality control of the contents rather than the security of the tank itself.