SUE Quality Level

The ASCE 38 quality level system provides a standardized framework for communicating the reliability of underground utility information. Quality Level D is based solely on existing utility records and is the least reliable. Quality Level C adds a survey of visible surface features such as manholes, valve boxes, and pedestals. Quality Level B uses geophysical methods like ground-penetrating radar and electromagnetic locating to approximate the horizontal position of utilities. Quality Level A requires physical exposure of the utility through test holes.

Quality Level A is the only level that provides verified three-dimensional position data (horizontal position, depth, and elevation) along with confirmation of the utility's material, size, and condition. Achieving Quality Level A requires hydrovac potholing or another non-destructive excavation method to physically expose the utility at selected points. The exposed utility is then measured, photographed, and surveyed with precise GPS or total station equipment.

Project owners and engineers specify the required quality level based on the risk profile of the project. High-value infrastructure projects, congested urban corridors, and areas with critical utilities typically require Quality Level A data at key conflict points. The cost of achieving Quality Level A through hydrovac potholing is a fraction of the cost of a utility strike or project delay caused by inaccurate data.