California ICC UST Service Technician Practice Exam

Which of the following is not classified as a UST?

1. 500-gallon waste oil

2. Motor fuel tanks

3. Used oil collection tanks

4. Propane storage tanks

The correct answer is: Used oil collection tanks

The classification of underground storage tanks (USTs) is governed by specific regulations that delineate what constitutes a UST. A UST is generally defined as any tank with at least 10% of its volume underground, used to store regulated substances such as petroleum products or hazardous materials. Used oil collection tanks, while they may hold oil, are often regulated differently compared to USTs. These tanks are typically used for the collection and temporary storage of used oil, which does not fall under the same regulatory oversight as typical USTs that store fuels and hazardous materials. In contrast, the options related to motor fuel tanks and 500-gallon waste oil tanks would qualify as USTs because they are designed to store products covered under UST regulations. Propane storage tanks, depending on their set-up, may not be categorized as USTs either, but they typically fall under different regulations entirely related to liquefied petroleum gases. However, used oil collection tanks are specifically excluded from UST classification because they do not contain regulated substances in the same way that fuel tanks do. This distinction is important for compliance and safety regulations governing the handling, storage, and monitoring of various types of tanks.