According to the American Society of Civil Engineers’ (ASCE) Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data (CI/ASCE 38-02), Subsurface Utility Engineering (SUE) is “a means to better characterize the quality of subsurface utility information and to manage risks associated with construction activities that may affect existing utilities.”

SUE addresses risk management by depicting the source and confidence level related to the existence and location of subsurface utilities. A quality level is assigned to each facility noted on the plans. This risk information is transferred to the contractor with the confidence level for the horizontal and vertical location of the existing underground utilities allowing the contractor to have a clear understanding and, if required, allowing additional subsurface investigation before proceeding with or in advance of the underground construction.

San Dieguito Engineering (SDE) has extensive experience in the use of SUE as a tool to provide a cost-effective, systematic approach to managing risk associated with the research and depiction of existing underground utilities. SDE started a division primarily for SUE, which ultimately became AirX Utility Surveyors, Inc.

SDE and AirX continue to work together to provide all aspects of SUE including utility record research, topographic mapping, surveying, designating, locating, data management, conflict analysis, and 3D modeling for BIM. Utilization of SUE is an integral part of a project as location and identification of existing underground utilities is a critical aspect of the design approach. Unknown or mismarked underground utilities are often responsible for project delays and cost overruns.

On the San Diego International Airport Terminal 2 West expansion project, SDE identified significant cost savings by avoiding construction changes and construction delays due to unknown utilities or mismarked underground utilities.