15.06 What are typical maintenance / inspection requirements for underground piping?

Durng installation, piping should be inspected and pressure tested in accordance with the manufacturers requirements prior to backfilling. Typically a local inspection by building or fire officials is required at this point. Underground piping primary and secondary should also be pressure tested after backfilling is complete and prior to th system being placed into service. This helps protect against the problem of damage during backfilling and surface paving.

California regulations will require an enhanced leak detection test for underground fuel piping. The test, performed by a qualified testing service, includes pressurizing the pipe with a tracer gas, and checking the piping run for leakage.

Underground piping systems are inherently difficult to inspect. However since many problems occur where the piping enters tank sumps and building, these areas should be inspected on a regular basis, at least monthly.

Underground piping system, including secondary containment should be pressure tested at least annually. Many State and local regulations require annual testing.