The Process of Underground Utility Locating: How It’s Done for Safe Digging

A graphic representation of underground utilities

As our cities grow and expand, the need for essential services—such as gas, water, and telecommunications—also increases as buildings, homes, schools, and hospitals require the use of these utilities. Whenever new infrastructure goes up, the complicated work of underground utility locating becomes an essential aspect of construction. Deep beneath the ground we walk on, there is often congestion of utility lines. This makes the work of properly locating them essential for future development.  

So how is it done? 

We take a brief tour into the world of underground utility locating.

Finding Underground Utilities for Safe Digging and Construction

Most people are familiar with “Dial 811 before you dig.” In fact, April is National Safe Digging Month! So why is it important to Dial 811? As many homeowners know, if you’re about to engage in a home project, you don’t want to start poking around and accidentally stick your shovel into a gas line. This could spell bad news for you and get expensive really quickly. The same applies to contractors or construction companies getting ready to begin a project. 

Our cities and towns are often built on layers upon layers of underground constructs and installations. A big part of that is utilities. A professional utility locating service will accurately identify the location of these underground utilities before any digging begins, thus protecting the work. 

A Quick Look Into the Process of Utility Location 

So, how do contractors make sure that they got the right spot? Well, there’s a process involved. It might vary depending on the type of project and surrounding infrastructure. Two main methods exist for utility location. They are active and passive. 

The active location method refers to searching for a specific line through the direct or inductive method. The passive location method involves surveying an area for unknown lines. This process requires the sweeping of the area with the receiver to see what frequencies emerge. 

The utility location process will vary and involve some of the following steps: 

  • First, contractors might review old plans, blueprints, or city documents that might indicate the location of potential utilities. 
  • Depending on the type of work being done, there will be an on-site survey and assessment of all utility vaults and nearby buildings or infrastructure that might indicate the presence of underground utilities. 
  • Contractors might perform an active mode cable and pipe locator survey. This is done with special equipment that uses radio signals. 
  • Then, they search for telecommunications lines using power, radio, and induction model to pick up signals. 
  • They might also conduct a GPR or ground-penetrating radar to search for unknown lines. 
  • Once all possible lines are detected, the location is indicated with paint or flags, as dictated by the AWPA color codes. 

The Equipment Used in Underground Utility Location

The field of utility location is rather specialized and uses special equipment to help facilitate and get the job done. One of the most reliable technologies in the field is the GPR. Ground Penetrating Radar technology is used to scope out and find conductive and non-conductive utilities. 

The equipment has two main working components: a transmitter and a receiver. GPR technology emits radio waves into the ground. When the waves make contact with something, they can reflect off that object and be recorded by the receiver. The signals are then transmitted into an image, which provides a look into what the transmitter is tracking. 

One utility expert described the use of some of this equipment as tuning in and finding your favorite radio station. In the case of the radio, every station has a different signal. These underground utilities similarly emit a unique signal, which the transmitted then picks up. And depending on that signal, what’s beneath the ground can be identified.

Utility lines are constructed of different materials that include aluminum, iron, steel, copper, and more. Multi-frequency systems exist so that the receiver can pick up a variety of frequencies and find different types of lines. 

Why is Utility Location Important for Construction? 

Because of the growing cities and layering of utilities along many routes, utility location is of utmost importance for safe construction. By accurately locating the utilities, it allows the construction to move forward smoothly. The information about the location of these utilities is key for engineers and architects as they move forward with their construction projects. 

Underground utility location serves several purposes: 

  • If utilities are damaged, the construction company is responsible for the damage. An accurate location avoids this scenario. 
  • Utility companies often mark the location of their underground infrastructure, but the markers don’t always guarantee the exact depth, horizontal location, or materials. A professional utility locator also ensures you have the right information to avoid mishaps. 
  • Avoids injury to workers during the excavation or digging process. 
  • Keeps the construction project on track without setbacks, delays, or accidents. 

Want to Learn More About Utility Location?

Are you ready to start digging for a construction project? Before you move forward, consider a professional underground utility locator. With the right equipment and high-level training, we are able to locate, designate areas, and ensure that any digging or construction is done safely and effectively. 

Want to learn more? Contact LB & Sons and talk with a pro today.