Levels of SUE Data: Increasing Utility Location Accuracy

understand what's underneath trademark trinity subsurface
Evan Mowbray

Levels of SUE Data: Increasing Utility Location Accuracy

When it comes to locating utilities underground, there are four main levels of accuracy that come to our attention. It’s important to maintain high accuracy of utility locations in any construction project, whether that’s putting in a fence or replacing an entire infrastructure system. Today we will go over the different levels of subsurface utility data, ranging from quality level D to quality level A data, that help our team at Trinity form the grander picture of the underground utilities in your projects.

An image of a Trinity Subsurface technician putting down utility flags at a residential property near Wilmington, Delaware.

Quality level D data is the lowest level of utility location accuracy. It consists of existing records and accounts made by personnel. This may come from somebody who worked on a project on the site in the past who has a general idea of where utilities could be located, but may be somewhat unreliable being based on memory. Plans may provide some more information in regards to a general overview of utilities, but they may be incomplete for the purposes of your next project. This level of utility knowledge serves as a decent starting point as it provides the understanding of existing utilities, knowledge of previous construction on the work site, and helps prepare the scope for further investigations.

Quality level C data consists of surface features and using them in correlation with the existing records that make up quality level D data. There are a number of different surface features we can use to help understand what’s underneath the surface. Manholes, wells, light poles and electrical boxes can help us in our investigation. This information is incredibly helpful in the early stages of larger projects to determine the overall feasibility of making changes without major disturbance. While searching for this information, it’s not unusual to find that there are utilities that have been omitted from records or incorrectly plotted. This is the jumping off point for further investigations.

An image of Trinity Subsurface technician Bobby Stafford spraying lines to mark subsurface utilities and sewers.

Quality level B data is when we dive deeper into what’s underground without invasive digging methods. Often referred to as designating, this is generally using tools such as ground penetrating radar and electromagnetic detectors to determine the horizontal and vertical locations of utilities within an acceptable tolerance zone, marking everything from electric and communication lines to pipes and conduits. This utility location data is gathered from the surface and plotted through the use of spray paint and flag markers. This is one of the most common methods to determine the locations of utilities.

An image of a Trinity Subsurface technician using a vacuum truck to excavate for utilities.

Quality level A data is the most reliable form of locating utilities. It involves physically exposing the utility to and determining the exact horizontal and vertical location of the utility. Exposing a utility can be a potentially dangerous task if handled incorrectly, as hitting a utility is a possibility if using the incorrect tools. Thankfully, we can utilize the method of vacuum excavation to carefully determine the exact location of utilities, blasting the ground with air or water to remove ground materials from around the utility. Quality level A data brings out more information, such as the material and condition of the excavated utility.

An image of a hydro excavation tool blasting away dirt to locate utilities at a muddy construction site.

Through the use of utility locating, Trinity Subsurface can help gather the utility location data you need to proceed in your next construction project. Give us a call today to find out more about our utility locating services or visit our website for more information.

Back to Blog