Subsurface Dangers Below

Better know what's below!

Subsurface Dangers Below

Better know what's below!

When penetrating the ground or concrete structures, there are many unknowns that could cause damage to people and equipment. From underground utilities and voids to the reinforcing steel and conduits in concrete, there are a number of potential problems you could encounter from the unknowns.

Subsurface Dangers Below
Unknowns could cause damage to people and equipment. Better know what's below!



Whether you’re working in a big city or a rural area, chances are there’s a utility line closer than you think. There are over 20 million miles of underground utilities in the United States. Out of those 20 million miles, one utility line is damaged every six minutes due to digging. Hitting an underground utility can compromise people’s safety, disconnect them from critical services and delay/add cost to the project just to name a few. A 20-year study conducted by the Common Ground Alliance (CGA) showed that utility hits resulted in $1.7 billion in property damage 1,906 injuries and 402 deaths. Whether you’re digging, coring or directional boring you have the potential to hit unknown’s underground. (Statistical data provided by the Common Ground Alliance CGA). People often think that if they just call 811 they are safe to dig, but that’s not the case. It is the law to call 811 before you dig, but that is just the beginning. 811 only marks out public utilities, leaving private and abandoned lines still to be found.


Voids can be caused by abandon mines, tunnels or naturally formed from erosion. They can also be created when construction projects compromise the structural integrity of underlying rock. Roads, buildings, and other types of construction may cause water to collect in certain areas and wash away the supporting rock layer (especially at low sea levels and after a heavy rainfall). There are a number of reasons you would want to locate a void, from ground support conditions to helping identify the location of a pipe burst. Voids can be particularly dangerous when heavy loads such as cranes or buildings are above them. At a refinery in the United States, voids proved to be costly. As a crane was executing a lift, the outrigger was positioned directly over a void. Without warning the void gave way, causing the outrigger to sink and the crane tipped over. This added unexpected cost, time and injuries to the job which, no one wants.


Concrete Cutting, Coring and Drilling                

Some of the common hazards found  in concrete while cutting, coring or drilling are reinforcing steel, post tension and electrical conduits. One hit can cause damage to equipment, damage to the integrity of the structure or worse yet, injuries to an employee(s).   

Finding the Right Locate Company                

Not knowing what’s underneath the ground or in the concrete can be critical to your project. That’s why finding the right company to do your locates is very important. A bad locate is as bad or worse as not conducting any testing beforehand.

Things you want when choosing the company to conduct a locate for your job site:

  • Good Safety Record: You will want to verify the company’s safety record by checking, TRIR, DART, LTIR, EMR and their OSHA logs. Ask if they’ve had any OSHA violations in the past five years. Also, verify their written program is sufficient and being executed.
  • Safety Training: Verify the company trains and encourages safe work practice by checking their new hire orientation training program, training certificates, ongoing training, is safety a core value? etc.
  • Experience & Training with Their Trade: Having their technician go through a vigorous training program equips them with the experience and knowledge to interpret the data correctly.
  • National Presence: If you can have the same company provide all of your locates, no matter the location, it will make for good relationships and great service. You know what you’re going to get on every job site.
  • Services Provided: Are they just going to provide marks on the surface or can they provide greater detail? Will they do a site walk with you discussing their findings, written reports, CAD drawings etc?
  • Reputation/References: This is very important because you can get a sense of everything above from one conversation. You can tell a lot about a company by the way other people talk about them.

The technology and service is out there to keep your jobsite safe when digging, boring, drilling or coring. GPRS is ready to exceed your expectations!

Let’s all do our part to choose safe work over fast work.

Note: GPRS does not provide geophysical, geological, land surveying or engineering services. If you need such services, please contact an appropriate professional.