Call 811 Call 811

For Contractors


Notify your local one-call center by calling 811 or making an online request 2-3 days before work begins. Click here for information about your local one-call center and online service availability.

The one-call center will transmit information to affected utility operators. 



Wait 2-3 days (varies by state; please click here for state law information) for affected utility operators to respond to your request.

On average, between 7-8 utility operators are notified for each request. 


Confirm that all affected utility operators have responded to your request and located accurately. State laws vary on the process for confirmation; please check with your local one-call center for more information.

If you see clear evidence of a utility, such as an above ground marker, manhole cover or utility box, but no marks, please call 811 so that utility can be notified. 


Respect the marks. The marks provided by the affected utility operators are your guide for the duration of your project.

If you are unable to maintain the marks during your project, or the project will continue past your request’s expiration date (varies by state), please call 811 to ask for a re-mark. 


Dig carefully. State laws generally prohibit the use of mechanized equipment within 18-24 inches of a marked utility, which is called the “tolerance zone” (click here for information from your state).

If you must dig near the marks, hand dig or use vacuum excavation to expose the facility. After exposing the facility, avoid using mechanized equipment within the same tolerance zone. 

Watch the 5 Steps to Safer Digging Message

The 5 Steps to Safer Digging video provides the professional excavator or experienced digger with an overview of safe digging practices.

Download the Contractor Process Handout