All excavations shall be open trench work unless authorized by the Sewer Commissioner. The base of the trench shall be formed to prevent settlement of pipes. Bell holes shall be cut for all pipe to provide ample space for pouring of joints. Backfilling shall be placed in layers and solidly tamped or packed up to two feet above the pipe. Backfilling shall not be done until final inspection by the Sewer Commissioner.
(1998 Code, § 3-209D)