All persons to whom permits may be granted to excavate the streets, alleys or public grounds of the city, or any of them, for the purpose of laying pipes, wires or for any kindred purpose, shall, at their own cost and expense, deliver at such place as may be designated by the director of public works for such purpose all such surplus earth, dirt, stone, gravel or other material coming out of such excavation as shall not be necessary for the purpose of refilling the same.
(1964 Code, § 33-26)