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