What does the term "product tight" refer to in the context of USTs?

In the context of Underground Storage Tanks (USTs), "product tight" refers to the ability of the tank and its components to be impermeable, thus preventing any seepage of the product being stored, such as fuel or hazardous materials. This is essential to preventing environmental contamination, protecting groundwater resources, and ensuring safety.

When a UST is described as "product tight," it indicates that the materials and construction techniques used ensure that no leaks will occur, thereby reducing the risk of spills and leaks that can have serious environmental consequences. This characteristic is fundamental in regulatory compliance, ensuring that installations conform to stringent environmental protection standards.

In contrast, the other options touch on different aspects of UST compliance or operation but do not define "product tightness." The concept does not inherently relate to pressure seals, local regulations, or temperature management, which are separate considerations in the management and regulation of USTs.