Utility owners follow the APWA (American Public Works Association) standard to mark the locations of their underground facilities. The following colors are used:
RED – Electric Power Lines, Cables, Conduit and 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 Lines
WHITE – Proposed Excavation
PINK – Temporary Survey Markings