What is the minimum backfilled cover required for buried piping when physical damage is not a concern?

The minimum backfilled cover required for buried piping, when physical damage is not a concern, is typically set at 18 inches. This standard is based on ensuring the buried piping system is adequately protected and supported by the surrounding soil, which contributes to both maintaining the integrity of the piping and allowing for soil settlement without compromising the system. The 18-inch minimum cover is designed to provide a reasonable balance between protection against natural elements while facilitating maintenance and access if necessary.

Other options representing greater depths, such as 24 inches or 30 inches, while they may provide additional protection, are generally considered unnecessary in situations where physical damage is not a concern, potentially leading to increased construction costs and labor without commensurate benefits. Therefore, the requirement for a minimum of 18 inches aligns with standard industry practices for safety, functionality, and cost-effectiveness.