Identifying underground utilities – both public and private – is essential for any excavation project. It can mean the difference between a smooth, on-budget job and a costly, potentially dangerous utility strike. That’s why it’s important to understand what’s needed for a successful locate, the types of equipment involved, and whether it’s more practical to rent or purchase your own ground penetrating radar (GPR) and electromagnetic (EM) locating tools, or to bring in professionals to handle the job.

I Called 811. Isn’t That Enough?

In the U.S., 811 One Call services are mandated by law and operate on a state-by-state basis. They’re responsible for marking all public utilities before any digging begins. But here’s the catch: 811 doesn’t cover private utility lines, and it won’t tell you how deep those lines are, only where they are.

That’s a major issue, considering that over 60% of utility lines are privately owned. If you dig without knowing the depth of your electric, gas, water, or telecom lines, you risk serious consequences, from widespread outages and water main breaks to catastrophic gas explosions and injuries.

Can I Locate Utilities Myself? What Tools Are Required?

Yes, you can rent or buy GPR and EM locating equipment. But just because the tools are accessible doesn’t mean the process is simple.

There are two primary technologies used for locating underground utilities:

• Ground Penetrating Radar (GPR): Detects both metallic and non-metallic objects.
• Electromagnetic Locators (EM): Best for metallic pipes, but can locate non-metallic lines with a signal transmitter like a rodder.

Each system has strengths and limitations. For example, a handheld GPR scanner designed for concrete won’t detect a sewer line buried three feet underground. Similarly, an EM locator won’t detect PVC pipes unless a signal is introduced into the line.

What’s the Cost of Renting or Buying GPR Equipment?

Professional-grade GPR systems for utility locating range from $14,000 to $100,000. The price depends on features like:

• Number of frequencies supported
• GPS integration
• User interface and software capabilities
• Cloud connectivity and multi-device access

A typical GPR setup includes a wheeled cart, radar transmitter and receiver, battery, and a digital interface, often a tablet. Lower-end models may offer basic GPS, while high-end units provide advanced mapping and data sharing features.

“The type of ground penetrating radar equipment used is not a differentiator,” says GPRS Field Support Director Jamie Althauser. “Unlike laser scanners, where the equipment can make a great deal of difference, most GPR works the same way.”

Since its rise in the early 2000s, GPR technology has become more user-friendly, with lighter batteries and cloud-based UIs. But the biggest improvements have been in usability and mobility.

“The hardware – ergonomics – the ability to move over terrain is the most important factor,” Althauser adds.

GPR rentals typically cost around $400 per month. This might be sufficient for small, straightforward jobs. But as Althauser points out, the real challenge lies in interpreting the data.

Impulse Radar, for example, is known for its ease of setup. Althauser notes, “You could use it within five minutes, but you wouldn’t know how to interpret the data.”