All filling of such excavation, trench or other street opening shall be the responsibility of the permit holder until the permanent paving or other road surface over the street opening is completed. All fills shall be of such quality and composition as may be required by the City and shall at all times be kept even with the existing road surface level. In general, the City shall require 5x limestone to be used for backfill material. (Ord. 2778. Passed 6-16-64.)