It shall be unlawful for any person to lay or put in place any main pipe or any pipe which is a lateral to any sewer, water or gas pipe, or to any other main, or to lay or place any service pipe or tap running from the main pipe to property line upon any public street or place in the city at a depth less than 18 inches below the official grade of such street or place.
(Code 1957, § 7231)