§ 1.05 ROCK EXCAVATION.
   (A)   Rock excavation, where necessary, shall be kept well in advance of the pipe laying. When rock is encountered, it shall be stripped of earth and the engineer notified, in order that the same may be cross-sectioned, measurements made and recorded. Provide minimum clearance of four inches below and on each side of pipe.
   (B)   Written approval must be obtained from the city before explosives may be used. If explosives are permitted, detailed plans must be submitted outlining all proposed blasting operations, locations, methods and use of mats and other safety measures. The contractor shall provide special hazard insurance covering liability for all blasting operations. The contractor shall use only experienced demolition personnel.
   (C)   The contractor shall remove and dispose of excavated rock not suitable for backfill.
   (D)   Any over excavation below required elevations shall be replaced with specified pipe bedding.