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APWA Uniform Color Code for Marking Underground Facilities

Underground facilities shall be marked in accordance with the following designated color code:

White: Pre-marking of the outer limits of the proposed excavation or marking the centerline and width of proposed lineal installations of buried facilities.
Pink: Temporary Survey Markings.
Red: Electric power lines, cables or conduit, and lighting cables.
Yellow: Gas, oil, steam, petroleum, or gaseous materials.
Orange: Communication, alarm or signal lines, cables or conduits, and fiber.
Blue: Potable water.
Purple: Slurry, irrigation and reclaimed water.
Green: Sewers, drainage facilities or other drain lines.

Permanently Marking Underground Facilities

The following recommendations shall be followed when permanently marking underground facilities:

  1. Markers must be clearly visible.
  2. Marker material shall be durable in nature. (Treated Wood, Metallic, UV Resistant Plastics, etc.)
  3. Mark culverts if not readily visible. Mark both ends of all non-visible underground facilities.
  4. Identify type of underground facility if not recognizable from the surface.
  5. It is also recommended that your state's Call Center number appear on the marker if the marker is of sufficient size.

If you have questions regarding the APWA Uniform Color Code, we recommend contacting your state's Utility Notification Center. For contact information, please choose your state above and refer to your state specific phone number.