Subsurface Utility Engineering

Subsurface Utility Engineering (SUE) is an engineering practice that combines civil engineering, surveying, and geophysics. Evolving considerably over the past few decades, this process utilizes several technologies, including vacuum excavation and surface geophysics, and is routinely used as a requirement for highway projects in many states. However, SUE is not confined to only highways. It can be used with good results on airport, railroad, transit, building construction, military, sanitation, nuclear, and many other public works projects where underground utilities may be encountered.

The U.S. Department of Transportation lists how the proper and successful use of SUE benefits all above-mentioned industries and the impacted utilities in the following ways:

  • Unnecessary utility relocations are avoided. Accurate utility information is available to the highway designers early enough in the development of a project to design around many potential conflicts. This significantly:

    • Reduces costly relocations normally necessitated by highway construction projects.

    • Reduces delays to the project caused by waiting for utility work to be completed so highway construction can begin.

  • Unexpected conflicts with utilities are eliminated. The exact location of virtually all utilities can be determined and accurately shown on the construction plans. As a result:

    • Delays caused by redesign when construction cannot follow the original design due to utility conflicts are reduced.

    • Construction delays caused by cutting, damaging, or discovering unidentified utility lines are reduced.

    • Contractor claims for delays resulting from unexpected encounters with utilities are reduced.

  • Safety is enhanced. When excavation or grading work can be shifted away from existing utilities, there is less possibility of damage to a utility that might result in personal injury, property damage, and releases of product into the environment.

The American Society of Civil Engineers’ (ASCE) defines SUE as a process, not a technology. It defines SUE as a branch of engineering practice that involves managing certain risks associated with: utility mapping at appropriate quality levels, utility coordination, utility relocation design and coordination, utility condition assessment, communication of utility data to concerned parties, utility relocation cost estimates, implementation of utility accommodation policies, and utility design. These activities, combined with traditional records research and site surveys, and utilizing new technologies such as surface geophysical methods and non-destructive vacuum excavation, provide “quality levels” of information.