The Map is Not the Territory
When a utility locator finishes scanning a property, they leave behind a network of colored paint and flags. These marks provide a highly accurate map of where the underground utilities run. However, paint on the ground is still just a representation of what lies beneath.
In the construction industry, you cannot legally or safely drop an excavator bucket directly onto a paint mark. Before heavy machinery can be used, contractors must physically expose and visually verify the exact location and depth of the utility. This crucial process is known as potholing or daylighting.
Understanding the “Tolerance Zone”
In Colorado, utility locating is governed by specific laws to ensure safety. When an 811 locator or a private firm like JLP Tech marks a utility, that mark represents the approximate center of the pipe or cable.
By law, there is a designated Tolerance Zone around that mark. In Colorado, the tolerance zone is typically 18 inches on either side of the exterior edges of the utility.
Within this tolerance zone, the use of mechanized equipment (like backhoes or augers) is strictly prohibited. If you need to dig within this 18-inch safety buffer, you must use non-destructive methods to daylight the line.
How to Safely DayLight a Utility
Potholing is the process of digging a small, precise test hole down to the utility to expose it to daylight. Because mechanical excavators are banned in the tolerance zone, contractors rely on two primary methods:
1. Hand Digging
The traditional method. Workers use blunt-edged shovels and manual labor to carefully dig down to the pipe. While cost-effective for shallow utilities, hand digging is incredibly slow, physically exhausting, and completely impractical in the frozen ground of a Colorado winter.
2. Vacuum Excavation (Hydro or Air Vac)
This is the modern, preferred method for commercial contractors. A vacuum excavation truck uses highly pressurized water (hydro-vac) or compressed air (air-vac) to break up the soil. A massive industrial vacuum hose simultaneously sucks up the debris, cleanly and safely exposing the utility without causing any damage to the pipe or cable casing.
Why Potholing is a Non-Negotiable Step
Skipping the daylighting process and trusting an excavator operator to “feel” the utility is a recipe for disaster. Potholing provides three massive benefits:
- Absolute Depth Verification: Locating equipment provides highly accurate depth estimates, but soil conditions can sometimes cause minor variances. Daylighting gives the contractor the exact, undeniable depth of the utility.
- Identifying the Material: Seeing the utility allows crews to confirm exactly what it is (e.g., verifying if a pipe is a high-pressure steel gas main or a PVC water line) and its exact diameter.
- Liability Protection: If a contractor daylight’s a utility according to state laws and still manages to damage it during subsequent excavation, having documented proof of the pothole drastically reduces their liability.
Partner with JLP Tech for Safe Digging
Safe excavation is a two-step process: identify, then verify.
At JLP Tech, we provide the critical first step. Our expert locators use advanced Ground Penetrating Radar (GPR) and Electromagnetic locators to give your vacuum excavation crews exact targets to hit. By pinpointing the utilities first, we save your daylighting crews from digging expensive, time-consuming “dry holes.”
Plan your next Colorado excavation project the right way. Let JLP Tech mark the target, so you can daylight it with confidence.