In 2012, a devastating derecho windstorm wreaked havoc for 700 miles from Ohio to North Carolina, knocking out power for 4 million customers for days and, for some, weeks. It killed 47 people and caused nearly $3 billion in damages. Immediately, interest rose in undergrounding power lines to prevent a repeat of this type of disaster. How can you protect power lines once they’re buried? 

Danger underground

A report from the Energy Networks Association reveals that almost one-third of tradespeople neglect to check for underground cables before beginning their work. In addition to deaths, an average of 70 workers annually suffer life-changing injuries after striking live underground power cables, with nearly half of these incidents occurring on construction sites and public highways and in industrial buildings.

The Texas Department of Insurance reported that the main reasons tradespeople cited for not checking for underground electricity cables were a belief that they would not dig deep enough to hit anything (24%) and a misconception that it was not their responsibility (15%).

In the United States, workers should call the national call-before-you-dig phone number—811—or visit www.call811.com and their state’s 811 center’s website to have underground utilities marked with paint or flags before digging. 

Damage to underground cabling, which includes electric and power utility lines and fiber optic cabling, poses risks to the long-term operation of such cable and can be hazardous to personnel. New research focuses on some facets of the problem, while the Department of Transportation and state-led safety efforts push “digging safety” awareness months and create websites to promote safe digging.

3D images and A.I. reduce risk

Joseph Vantassel, assistant professor of seismic imaging for engineering applications at Virginia Tech, is heading a research project to mitigate such impacts with a $2.5 million grant from the U.S. Department of Energy. His team is developing a method to safely and cost-effectively bury power lines, reducing outages during storms. Their innovative approach uses sensors on drilling equipment to create a 3D view of underground utilities, combined with artificial intelligence (A.I.) predictive modeling to prevent accidental damage to existing infrastructure.

The researchers are collaborating with Virginia Tech Electric Service and experts from various universities, enhancing the efficiency and safety of underground boring processes. Virginia Tech Electric Service supplies electricity to the campus and parts of Blacksburg, Va., and owns a frequently used underground directional boring machine.

Over 90% of the campus power lines are underground. The collaboration involved Vantassel’s team learning about the machine’s functionality, which includes an alarm to prevent hitting vital lines. They also discussed using technology to provide a virtual view of underground obstacles, enhancing operational efficiency.

Better tools for underground cable

A research team at Case Western Reserve University in Cleveland received $2 million in federal funding early in 2024 to develop an underground power line installation tool. Aiming to modernize America’s aging power grid, this innovative “peristaltic conduit” mimics a worm’s movement to navigate through the ground and avoid existing infrastructure obstacles. It features segments that elongate and retract, allowing it to turn in a 5-foot radius.

This method aims to reduce the risks associated with traditional trenchless methods. The DOE’s $34 million federal investment is part of a broader effort to improve grid reliability and resilience against extreme weather by promoting the use of underground power lines.

Not just electric utility lines

Cabling to support broadband operations is also a concern. A report by North Star Policy Action highlights the fact that broadband installation is the leading cause of underground infrastructure damage, accounting for 60% of all directional drilling damage over the past three years.

Even with an average of 1.27 incidents per day, these damages often go unreported unless they involve gas lines. The lack of adequate training and safety standards for broadband installers­—compared to other industries such as gas and electricity—contributes to the problem. Increased federal funding for broadband infrastructure emphasizes the need for improved safety regulations and training standards.

For electrical contractors, the risk of harming infrastructure, operations and personnel because of underground excavation is a very real concern. As research is conducted at Virginia Tech and Case Western, new technologies are being developed and added that can improve the safety profile of underground digging. In addition, working with federal resources such as 811 before excavating offers support and solutions to reduce the risk of excavating while improving overall safety.