California ICC UST Service Technician Practice Exam

Which of the following best defines a tight UST?

1. One that is perfectly sealed

2. One that has no leaks

3. One that is structurally sound

4. One that is fully compliant with regulations

The correct answer is: One that has no leaks

The concept of a tight underground storage tank (UST) revolves primarily around the tank's ability to contain its contents without any leakage. A tight UST is defined as one that has no leaks, meaning it is effectively preventing the escape of petroleum products or hazardous materials into the surrounding environment, which could pose risks to soil and groundwater quality. A UST can be considered "tight" in the context of environmental protection, indicating that it meets the necessary standards to operate without contributing to contamination. This is crucial, as leaks from USTs are not only detrimental to the environment but are also a significant source of liability for operators and owners, often involving regulatory repercussions. While factors like being perfectly sealed, structurally sound, and compliant with regulations are important characteristics of a UST, they do not solely determine the definition of "tight." A tank could be structurally sound and compliant yet still have minor vulnerabilities. Therefore, the defining trait of a "tight" UST focuses specifically on the absence of leaks, ensuring the integrity of the storage system.