What material is commonly used to line underground storage tanks for vapor recovery?

• A. Concrete
• B. Steel
• C. PVC or fiberglass-reinforced plastic
• D. Wood

Answer: (C)

The use of PVC or fiberglass-reinforced plastic to line underground storage tanks for vapor recovery is preferred due to its excellent resistance to a variety of chemicals, including petroleum products. This material offers substantial durability and is less susceptible to corrosion compared to metals, making it suitable for protecting against leakages and environmental contamination. Additionally, fiberglass-reinforced plastic is lightweight, which facilitates easier installation and maintenance.

Concrete, while strong, is porous and may not effectively prevent leaks or vapor permeation over time. Steel, although robust, is prone to rust and corrosion when exposed to water and chemicals, which can compromise the integrity of the tank lining. Wood is not a viable option for underground storage tanks because it can rot and is not resistant to the chemicals stored within. Therefore, the choice of PVC or fiberglass-reinforced plastic ensures a safer and more effective vapor recovery system.