Utility color codes are used for identifying existing underground utilities in construction areas with the intent of protecting them from damage during excavation.

Public utility systems are often run underground; some by the very nature of their function, others for convenience or aesthetics. Before digging, municipalities often require that the underground systems' locations be denoted and approved. Colored lines and/or flags are used to mark the location and detote the type of underground utility.

The American Public Works Association (APWA) Uniform Color Codes for temporary marking of underground utilities are listed below:

• White – Proposed excavation limits or route
• Red – Electric power lines, cables, conduit, and lighting cables
• Orange – Communication, alarm or signal lines, cables, or conduit
• Yellow – Gas, oil, steam, petroleum, or gaseous material
• Blue – Potable water
• Purple – Reclaimed water, irrigation, and slurry Lines
• Green – Sewers and drain lines
• Pink – Temporary survey markings, unknown/unidentified facilities

External links

• American Public Works Association
• APWA Recommended Marking Guidelines For Underground Utilities (PDF)