What does potholing mean?
Potholing, also known as daylighting, is the preferred method of finding underground utilities and structures. Typically, due to settlement or ground
movement, the location of utilities tends to shift over time. Other methods of utility location, such as charts, maps, and as-built drawings, do not provide an accurate reflection of the position if there is ground movement. Potholing techniques eliminate the risks associated with incorrect utility locations.
Potholing Methods :
There are 3 main potholing techniques used in the construction industry. Choosing which procedure is better suited depends on the scope of works to be carried out, the associated risk, and the project budget.
Hand Digging :
In this method, the excavated material is removed through hand tools, ranging from shovels to digging bars. Hand digging is not suitable for large operations as it is both time and labor-intensive. Small home projects or confined workspaces are instances where hand digging is preferred. An upside to hand digging is the limited cost as expensive equipment is not required.
Backhoes :
This method is now considered a risky potholing method, the use of backhoes was once the most popular potholing technique. Excavation with a backhoe is hazardous as utilities can be damaged during the exposure process. It is always essential that a spotter be present during potholing with a backhoe. The spotter is responsible for communication with the backhoe operator on the observation of any utilities. Backhoes are typically used in greenfield potholing operations, where the risk of interference with existing utilities is reduced.
Vacuum Excavation :
Vacuum excavation is the preferred method of potholing. It is non-destructive, accurate, efficient, safe, and cost-effective. Vacuum excavation is carried out in two ways, either by air excavation or hydro excavation. Depending on the chosen method, water or air is used to break up the soil. Once this is completed, a vacuum gathers the excavated soil.
At Wind River Environmental we are the leading experts in hydro excavation. We recommend using this method as well because of its increased safety to not only your underground utilities but to the contractors as well. It is the preferred method for digging because it is safe, effective, and fast. It is also a less invasive way of exposing your underground utilities as well, allowing for easier and quicker clean up.
Avoiding Damaging Underground Utilities :
Damaging underground utilities can be very expensive. Not only downtime and potential fines or fees from contractors but the unnecessary or extra work that now needs to be done just to get your back where you started. All of this can be easily avoided.
The hydro and air pressure doesn't damage any existing utilities like heavy equipment could. In fact, the hydro excavation process allows us to maneuver around the existing utilities
giving us a clear view of what's there.
The vacuum excavator works in a wide variety of soils and conditions such as clay, rock substrate, and frozen ground. It exposes the pipes and utilities by using a combination of air and water pressure. It then sucks up the slurry debris material utilizing a large, attached hose. Our hydro excavation trucks' tanks store the slurry debris and haul it away for later disposal.
Why not use a digital locator instead of potholing?
While digital locators have become more and more accurate. It's really important to see exactly where the lines are. Contractors are not allowed to just dig in a safe zone, which could be 18 inches to 3 feet from either side. Every state has their own requirements for a safe zone. These requirements still include a non-destructive method to dig it. So, you could dig it by hand or use an hydro excavator.
Is potholing worth it?
YES, hands down! Hitting a gas line or utility pipe with a backhoe, trencher, or a horizontal directional drill could be catastrophic. Think about it, if you hit a water line that feeds into a hospital it could be down for hours or even days. You or your company could be responsible for those damages.
The cost of damages far exceeds the cost of potholing.
For more information on potholing for utilities or to request a service contact us today, and one of our utility contractors would be happy to assist you.
