Any person, persons, firm, corporation or municipality having obtained a permit to drill or push under any street, alley or curbing shall not perform any drilling or pushing operations at a depth less than three feet (3') below the surface of the street, alley or curbing, and shall not drill any hole for the insertion of pipe or other object more than one inch (1") greater in diameter than the pipe or object to be inserted therein. (Ord. 861 §1, 1998)