What does a "double-walled" design in Underground Storage Tanks (USTs) provide?

• A. A tank with an inner and outer wall for added safety against leaks
• B. A single wall structure for cost efficiency
• C. A design only used in older models of USTs
• D. Enhanced insulation for temperature control

Answer: (A)

A double-walled design in Underground Storage Tanks (USTs) refers to a construction that features both an inner and an outer wall. This design significantly enhances safety by providing an additional layer of protection against leaks. If the inner wall were to develop a leak, the outer wall acts as a containment barrier, preventing the leaked substance from escaping into the environment. This design is critical for minimizing the risk of soil and groundwater contamination, which can have serious environmental and health implications.

The double-walled construction is a modern standard in tank design, aimed at meeting stricter regulations and improving safety measures. It also facilitates monitoring; some double-walled tanks are equipped with leak detection systems that can indicate any breach between the walls, allowing for timely intervention.

Given that the other options don't accurately depict the function or purpose of a double-walled tank, it's clear why the correct answer focuses on the added safety features provided by this design.