Private Utility Locating Explained

What is utility locating?

Utility locating is the detection of underground utilities and other subsurface findings through the use of ground penetrating radar and similar tools. Utilities and other findings can be located and marked out in a safe, non-destructive manner.

What type of utilities can be located?

Private utility locating can detect electric, steam, communications, water, gas & oil, sewer & storm, and many other primary and secondary utility services.

When are utility locates required?

Utility locates should be performed before starting any ground-breaking work. While local laws vary as to utility locating requirements, it is safer and wiser to scan before starting work. This can include all types of work ranging from digging a flower bed to performing major excavation work. A utility locate is recommended any time you are digging 16” or deeper.

How long are utility locates good for?

Utility locates are valid as there are accurate marks or plans, and no utilities have been added or removed. Markings can be temporary, done using flags and paint; or a more permanent record can be produced to preserve the utility locating information.

How does surface area impact utility locating?

Utility locating equipment is used to scan a ground surface in order to determine what lies beneath. While surface area can impact the amount of time it takes to perform a scan, greater time impact comes from the number of subsurface findings. A smaller urban area may take longer to scan than an empty plot of land due to the complexity of underground utilities present.

Does the type of utility being located have any impact on the locating process?

Certain materials are easier to locate due to the signal they produce when interacting with GPR equipment. For example, electrical wiring may be easier to detect than non-conductive PVC piping. Certain utilities are buried deeper than others, and may require the use of additional scanning equipment to aid in detection.

Does weather impact utility locating?

Weather conditions do play a role in the accuracy of GPR and other utility locating equipment. Wet conditions make it harder for the equipment to pick up a signal. Performing a utility locate in rainy or snowy conditions may not be possible. An experienced technician will be able to determine if conditions are right for performing a utility locate.

What other factors have an impact on utility locating?

Ground topography & conditions, weather, type of utility being located, and depth of the area are a few of the main factors which should be considered before performing a utility locate. Experienced GPR technicians will be able to determine if conditions are appropriate for utility locating.

What colors are used to mark out utility locations?

Universal colors commonly used for utility location include:

  • Red- Electrical, conduit, lighting
  • Orange- Communication, TV, alarm or signal
  • Yellow- Gas, oil, steam, petroleum
  • Green- Sewer, drain
  • Blue- Potable water
  • Purple- Reclaimed water, irrigation
  • Pink- Temporary marking
  • White- Proposed excavation