The short version
- Red is electric, yellow is gas and oil, orange is communications
- Blue is drinking water, green is sewer and drain
- Purple is reclaimed water and irrigation
- Pink is temporary survey marks and white outlines proposed digging
Why there is a code
The colors are a standard used across the United States so anyone who sees marks on the ground can tell what kind of line runs below. The standard comes from the American Public Works Association and is followed by locating crews and utility owners.
It lets crews and homeowners recognize hazards at a glance.
The colors
Red marks electric power lines, cables, conduit and lighting cables. Yellow marks gas, oil, steam, petroleum and other flammable material. Orange marks communications, alarm and signal lines, cables and conduit. Blue marks potable water. Purple marks reclaimed water, irrigation and slurry lines. Green marks sewers and drain lines.
Pink marks temporary survey markings, and white marks the proposed excavation area.
Reading the marks
Flags, stakes and spray paint all use the same colors. Lines and arrows show the path of a line, and symbols or letters can note size, material or the owner. Offset marks may sit a few feet to one side of the actual line.
Marks are approximate and need careful interpretation near the line.
What the marks do not tell you
They do not show depth, they do not show private lines and they can fade, wash out or be disturbed. If marks are missing, unclear or contradictory, stop and call 811 again.
When in doubt, pothole to verify before digging.
General information, not engineering, legal or safety advice. Rules and requirements vary by utility, city and county.
