4.10 Marking Multiple Facilities in the Same Trench
Multiple facilities in the same trench are marked individually and with corridor markers.
In general, the number of lines marked on the surface equals the number of lines buried below. In circumstances where the total number of lines buried in the same trench by a single facility owner/operator may not be readily known, a corridor marker is used. The corridor marker indicates the width of the facility. (See Appendix B, “Uniform Color Code and Marking Guidelines.”)20