What Do the Marks Mean?
The Common Ground Alliance (CGA) maintains a set of Guidelines for Operator Facility Field Delineation to indicate the infrastructural pathways of buried wires and pipelines.
The CGA Best Practices are designed to improve worker safety, protect vital underground infrastructure, and ensure public safety during excavation activities conducted in the vicinity of existing underground facilities.
APWA Uniform Color Code
Facility operators are required to mark all underground utility lines with standard color codes as established by the American Public Works Association (APWA).
WHITE
Area of Proposed Excavation
ORANGE
Communication, CATV, Fiber
RED
Electric
PURPLE
Reclaimed Water, Irrigation
PINK
Temporary Survey Markings
BLUE
Water
YELLOW
Gas, Oil, Steam, Propane
GREEN
Sewer
Common Marking Symbols
Company Identifier
Name, initials, or abbreviation of the facility owner.
Clear/No Conflict
No utilities in the requested area from the identified facility.
Line Markings
Utility identified by initials.
Corridor Markings
Used to mark the width of the corridor when location is known, but number of individual lines is not.
Large Diameter Facility
For large facilities when diameter is known.
Conduit
Width of ducts, whether single or multiple.
Termination Point
Dead end or stub out of a facility line.
Marking Offsets
Indicate facility owner, direction to utility, and distance to facility.