A 2024 AGC survey found that two thirds of contractor utility strikes involved lines at least two feet from their marked locations, even where 811 had been called. Underground records are the weakest layer in most geospatial datasets, and the consequences are measured in struck lines and change orders rather than in reports.
This session works through the problem from the ground up. It opens on why existing records and paint markings fail so often, and what radar tomography can resolve that a locate ticket cannot. From there, speakers cover how utility locating technology feeds subsurface information into digital mapping workflows, how a contractor captures survey-grade georeferenced point clouds of open trenches using consumer hardware and RTK positioning, and how verified field data is produced, maintained and improved across the full lifecycle of an underground asset. Attendees will leave with practical approaches for capturing what is actually underground and keeping that record trustworthy after the trench closes.
This session will include the following presentations:
Let the Record Show… What’s Actually Underground
Presented by John Lloyd and Rock Eisenheim, PLS, DGT Associates
Most construction projects begin by relying on two sources: existing utility records and the paint markings sprayed on the pavement after an 811 call. The problem is that both are inaccurate more often than the industry likes to admit.
A 2024 AGC survey found that 66% of contractor utility strikes involved lines that were at least two feet from their marked locations, even when 811 had been contacted. The disconnect comes from decades of undocumented infrastructure changes, records lost in digital conversions, and markings that show approximate location while revealing nothing about depth, ownership, or condition.
This session explores how remote sensing replaces that guesswork with verifiable data. Using wide-array ground penetrating radar (GPR) and radar tomography, attendees will see how modern subsurface technology accurately maps buried utilities, reduces uncertainty before excavation begins, and helps teams make safer, more informed decisions in the field.
Closing the Gap Between Surface and Subsurface Mapping
Presented by Pete Mann, Radiodetection
As geospatial technologies continue to advance, organizations are capturing increasingly detailed information about the world above ground. Yet one of the most critical layers of infrastructure remains largely invisible. Underground utilities are essential to nearly every construction, engineering, and asset management project, but accurately documenting their location continues to present challenges.
This presentation explores how utility locating technologies can support digital mapping workflows by helping organizations capture and manage subsurface utility information alongside other geospatial data. By connecting utility locating activities with modern field data collection and GIS processes, utilities, municipalities, engineering firms, and contractors can more effectively document, visualize, and manage underground infrastructure information to support mapping initiatives, damage prevention efforts, and infrastructure planning.
Attendees will learn how utility locating technologies complement broader geospatial workflows by adding the critical subsurface layer that is often missing from digital mapping projects. The session will highlight practical workflow considerations, implementation experiences, and lessons learned from integrating utility locating into modern geospatial data collection practices.
Rapid, Georeferenced Utility Scans with iPhone Lidar and GNSS
Presented by John McKeon and Josh Ng, The Whiting-Turner Contracting Company
Accurate underground utility records remain one of the greatest challenges facing owners and contractors. Traditional documentation methods often leave gaps between what was designed, what was installed, and what ultimately becomes part of the owner’s permanent records.
This presentation explores how our team leveraged Pix4Dcatch, an iPhone Pro, and an Emlid RTK GNSS receiver to rapidly capture highly accurate, georeferenced point clouds of utility trenches and other outdoor construction activities. By combining consumer hardware with survey-grade positioning, we developed a streamlined workflow that produces reliable digital as-built data with minimal equipment, training, or field disruption.
A key success factor was democratizing reality capture across the project team. Rather than relying exclusively on VDC specialists, we trained project superintendents to independently capture field data, allowing documentation to occur at the exact moment utilities were exposed and before they were permanently concealed. This scalable approach significantly increased data collection opportunities while minimizing labor costs.
Attendees will learn how the workflow was implemented across multiple projects on Stanford University’s campus, where our team has worked for over two decades. The session will highlight lessons learned, accuracy considerations, field procedures, and strategies for maintaining consistent geospatial data quality. The discussion will also demonstrate how rapid reality capture contributes to the creation of owner-ready digital twins, providing permanent records of buried utilities and reducing uncertainty for future renovations, maintenance activities, and campus development efforts.
By transforming a smartphone into a practical geospatial capture tool, project teams can improve safety, reduce future excavation risk, and deliver a more complete and reliable digital record of the built environment.
A Lifecycle Approach to Underground Asset Information Management
Presented by Long Zhan, Independent Consultant
Underground infrastructure management depends on the quality of the information used throughout its lifecycle. While GIS, digital twins, and asset management platforms provide powerful tools for organizing and analyzing data, their long-term value is fundamentally influenced by how underground information is produced, verified, maintained, and continuously improved.
This presentation introduces a lifecycle approach to underground asset information management, covering information production, information management, information utilization, and information improvement. Through real-world utility locating examples, it demonstrates how investigation, interpretation, verification, and continuous updating contribute to more trustworthy underground information.
The session discusses why obtaining reliable underground information often requires significantly greater effort than recording it, and how structured information management enables verified field knowledge to remain valuable throughout the life of an infrastructure asset. The presentation also explores how trustworthy underground information supports GIS, digital twins, infrastructure planning, asset management, and long-term risk reduction.
Participants will gain practical perspectives on improving underground information quality and building more reliable digital infrastructure systems for future decision-making.
