Before the start date of any right-of-way excavation, all persons who have equipment located in the area to be excavated shall mark the horizontal and approximate vertical placement of all said equipment. Any person whose equipment is less than 20 inches below a concrete or asphalt surface shall notify and work closely with the excavation contractor in an effort to establish the exact location of its equipment and the best procedure for excavation. [Ord. 3287 § 1, 1998; Code 1970 § 15.70.150.]