California Designated Operator Practice Exam

Which material is NOT suitable for constructing underground storage tanks containing motor vehicle fuel?

1. Fiberglass reinforced plastic

2. Cathodically protected steel

3. Regular steel without protection

4. Steel clad with fiberglass reinforced plastic

The correct answer is: Regular steel without protection

The chosen answer emphasizes the importance of using appropriate materials for constructing underground storage tanks, particularly those containing motor vehicle fuel. Regular steel without protective measures is not suitable because it is highly susceptible to corrosion when in contact with soil and moisture, leading to possible leaks and environmental contamination. The other materials listed have protective qualities or are inherently resistant to corrosion. For example, fiberglass reinforced plastic is non-corrosive and can withstand harsh environmental conditions, making it ideal for use in underground applications. Cathodically protected steel utilizes a sacrificial anode system to prevent corrosion, enhancing the durability of steel tanks buried underground. Steel clad with fiberglass reinforced plastic combines the strength of steel with the non-corrosive properties of fiberglass, providing added protection against deterioration. Thus, regular steel without protection does not meet the necessary criteria for safety and effectiveness in storing motor vehicle fuel, which is why it is identified as the unsuitable choice.