Section 6-77-111 - Service lines: installation(a) Depth. Each buried service line must be installed with at least twelve inches of cover in private property and at least eighteen inches of cover in streets and roads. However, where an underground structure prevents installation at those depths, the service line must be able to withstand any anticipated external load.(b) Support and backfill. Each service line must be properly supported on undisturbed or well compacted soil, and material used for backfill must be free of materials that could damage the pipe or its coating.(c) Grading for drainage. Where condensate in the gas might cause interruption in the gas supply to the customer, the service line must be graded so as to drain into the main or into drips at the low points in the service line.(d) Protection against piping strain and external loading. Each service line must be installed so as to minimize anticipated piping strain and external loading.(e) Installation of service lines into buildings. Each underground service line installed below grade through the outer foundation wall of a building must:(1) In the case of a metal service line, be protected against corrosion;(2) In the case of a plastic service line, be protected from shearing action and backfill settlement; and(3) Be sealed at the foundation wall to prevent leakage into the building.(f) Installation of service lines under buildings. Where an underground service line is installed under a building: (1) It must be encased in a gas-tight conduit;(2) The conduit and the service line must, if the service line supplies the building it underlies, extend into a normally usable and accessible part of the building; and(3) The space between the conduit and the service line must be sealed to prevent gas leakage into the building and, if the conduit is sealed at both ends, a vent line from the annular space must extend to a point where gas would not be a hazard, and extend above grade, terminating in a rain and insect resistant fitting.[Eff ] (Auth: HRS § 269-6) (Imp: 49 C.F.R. §192.361, OCT 1, 1990)