The following guidelines are used to temporarily mark underground facilities to prevent accidental damage or service interruption.

White — Proposed excavation

Pink — Temporary survey markings

Red — Electric power lines, cables, conduit or lighting cables

Yellow — Gas, oil, steam, petroleum or gaseous materials

Orange — Communication, alarm or signal lines, cables or conduit

Blue — Potable water

Purple — Reclaimed water, irrigation and slurry lines

Green — Sewers and drain linesSource: American Public Works Association, Common Ground Alliance