According to the Common Ground Alliance, there’s more than 100 billion feet of underground utility lines in the United States. That’s enough electricity wiring, telecommunications cables, sewer pipelines, water pipelines, and natural gas distribution lines to stretch to the moon and back—39 times.

It’s also 100 billion feet of injury risk to utility workers, construction personnel, landscapers, and even private citizens should any of these lines be severed during digging operations.

Knowing the location of these cables and pipelines are located is critical to the safety of your employees as well as those living and working nearby. Just as critical is knowing what to do if any of those lines are severed.

What your employees need to know about underground digging

If an underground electricity line is cut, not only does the power go out but the ground may energize. This creates a risk for electrocution. If a natural gas pipeline is damaged, a gas leak may occur. Depending on the severity of that damage, a fire or a natural gas explosion are both possible.

To help you, your employees, or anyone else digging into the ground, the 811 Call Before You Dig hotline is available. The service is free. By calling in, you reduce the risk of striking an existing utility line to less than one percent. In California, the call to 811 should be made at least two working days (but no more than 14 working days) before digging begins. Each affected utility then sends a worker out to mark the approximate location of utility lines and specify what they are (electrical, cable TV, natural gas, etc.).

What your employees need to do when digging underground

In addition to calling 811, don’t begin work until a job hazard analysis is complete. This is handled by a competent person—which can be you or another employee you assign who is trained and has proper knowledge of the risks of underground utilities.

Stop work immediately if damage occurs to a utility. Notify affected utilities and emergency response as soon as safely possible. If a gas line is struck, evacuate the area in addition to notifying the utility and emergency response. The utility operator is in the best position to identify the hazards associated with the damage and implement the proper action to address those hazards.

If any type of wiring is severed, workers should not take the time to investigate what the wires are. These could be electrical wires, TV cables, or phone lines. Best practices dictate they should presume the lines are electrical, they are live, and that the ground is energized. Workers should then act accordingly to safely exit the area as soon as possible.

  • Anyone inside a vehicle on energized ground should treat the situation the same way as being in a vehicle that has come into contact with power lines. Remain in that vehicle unless it catches fire, and only then attempt to exit the car using a specific method.
  • Anyone on the ground should exit the area right away. Keep the feet together using a shuffling motion where feet are always in contact with the ground.

When safely possible, make the necessary notifications so the lines can be de-energized and repair crews dispatched.

What to cover at your safety meeting about underground digging

One of the safest tools in your toolbox is the telephone. Whether it’s you or a designated employee that makes the 811 calls, discuss with all employees how the process works. Remind them that digging may not begin until after the area is marked.

Other information to cover includes:

  • Where to dig in relation to the utility line markings
  • The procedure to follow in the event an electricity line is cut, including staying in vehicles or how to exit ground that may have been energized
  • Notification of utilities and emergency response if contact is made with existing utilities

With 100 billion feet of underground utility lines crisscrossing our country, it’s impossible to know where it all is. One phone call allows you and your workers to learn in advance where existing lines are in your area. This greatly reduces the risk of damage and injury.

By calling 811, you’re less likely to call 911.

(Rev. 09/2025)