What is the minimum backfilled cover required for buried piping?

The minimum backfilled cover required for buried piping is 36 inches. This depth is established to ensure sufficient protection against external impacts and environmental factors that could potentially damage the piping. A cover of this thickness helps to shield the pipes from heavy traffic loads, soil pressure, and natural earth movements.

Additionally, a cover of 36 inches provides adequate insulation to protect the piping from temperature extremes in the ground, as well as reducing the likelihood of freezing in colder climates. This depth also minimizes the risk of infiltration of groundwater or surface water, which can lead to corrosion or other forms of deterioration of the piping material over time.

In contrast, the other options—12 inches, 18 inches, and 24 inches—do not meet the recommended standards for most types of buried piping systems, especially in areas subject to heavy loads or adverse weather conditions.