5.21 Mismarked Facilities

One Call Center Facility Owner Excavator

Practice Statement:

The excavator notifies the facility owner/ operator directly or through the one call center if an underground facility is not found where one has been marked or if an unmarked underground facility is found. Following this notification, the excavator may continue work if the excavation can be performed without damaging the facility, unless specified otherwise in state/provincial law.

Practice Description:

When an excavator finds an unmarked or inaccurately marked facility, excavation stops in the vicinity of the facility and notification takes place. If excavation continues, the excavator plans the excavation to avoid damage and interference with other facilities and protects facilities from damage.


  • Existing state/local laws, including Arizona
  • Existing practice among excavators, including W.F. Wilson & Sons, Inc.


One Call Center One Call Center

Facility Owner Facility Owner

Excavator Excavator

Locator Locator

Project Owner Project Owner

Designer Designer