When is a piping system required to have a secondary containment?

A secondary containment system is crucial in the context of piping systems that transport hazardous materials because it serves as an additional layer of protection against leaks or spills. The purpose of secondary containment is to prevent hazardous materials from escaping into the environment, thereby reducing the risk of contamination and ensuring safety for both human health and the surrounding ecosystem.

When hazardous materials are involved, the potential consequences of a leak are significantly higher due to the risks associated with these substances, such as toxicity, flammability, or environmental harm. Therefore, regulations and best practices typically mandate secondary containment for piping systems designed to transport these types of materials. This requirement helps ensure that any accidental release can be contained and managed appropriately.

While the other options represent situations that can have varying degrees of risk, they do not mandate secondary containment as a standard practice in the same way. Non-hazardous materials, for example, do not typically pose the same level of risk, and not all underground piping systems require secondary containment unless they are used for hazardous materials. Similarly, pressure levels alone (such as exceeding 100 psi) do not inherently dictate the need for secondary containment without considering the nature of the materials being transported.