Subsurface Utility Engineering & Mapping Services (SUE/SUM)
Improve safety and efficiency of projects by having more insight into what lies underground.
Subsurface Utility Engineering & Mapping Services (SUE/SUM)
Improve safety and efficiency of projects by having more insight into what lies underground.
A decisive factor in a project’s success depends on accurately knowing the intricacies of your project’s subsurface environment. When combined with underground utility records, subsurface utility mapping delivers the insights your team can rely on.
As a global leader in SUE/SUM services, we help our clients by creating detailed CAD and BIM maps of underground facilities at project sites.

From Marking to Mapping
When it comes to locating underground facilities, DGT goes beyond marking with paint and flags. Subsurface Utility Engineering (SUE) programs provide accurate, detailed mapping services of a variety of underground facilities that save your project time and money.
Subsurface Utility Mapping (SUM) is the new standard in underground work, directly impacting the success of a project by minimizing risk, improving project execution, and minimizing changes and claims.
The Case for SUE/SUM
Safety, Accuracy & Efficiency
There is no room for compromise when it comes to keeping your people safe and your project on time and on budget. SUM is your best defense against the dangers of unknown facilities that may exists beneath your project site. Geographic Information System (GIS) and other methods of gathering SUE data often lack the intricate details necessary to make an underground map that can be used to make major project decisions. While legacy utility plans and GIS data provide valuable information in the preliminary stages of a project planning, precise SUM information provides the 3D data required by design professionals to minimize design conflicts, avoid cost delays due to “surprise discoveries” and mitigate the risk of striking undocumented utilities in the construction phase of a project.
Poor Utility Records Present Risk
In today’s modern environment, some surveying methodologies ignore and oversimplify historical data on existing underground elements. Throughout the past few decades, poor record-keeping principles have only exasperated the challenges project teams face when working in brownfield environments. In addition, abandonment or movement of underground utilities may not have been properly recorded at your project site over the course of time. Because of this, available utility maps may be dated, inaccurate and untrustworthy. Relying on these records alone, without updated subsurface mapping, can present risk to any development project.
Avoid Costly Mistakes
Projects that miss the opportunity to use SUM make themselves vulnerable to a variety of costly mistakes. Missing, incomplete or inaccurate maps of the underground environment have led to costly mistakes on major projects across the United States and the world with effects ranging from small financial burdens to litigation, settlements and tarnished reputations. Projects cannot afford to overlook the opportunity to complete a subsurface utility investigation in the preliminary stages of a project. After all every major project begins with a comprehensive Environmental and Geotechnical Investigation; why not a Subsurface Utility Investigation?
Mitigate Risk with SUM
SUM mitigates this risk by identifying the location of underground utilities and creating color-coded 2D and 3D digital delivery formats to depict and map the underground location of the critical infrastructure that can be delivered in Computer Aided Design (CAD), Building Information Modeling (BIM), or GIS formats. DGT’s SUM data allows for integration by other development, design and construction professionals on a project. With this technology, you can better understand the complexity of your project’s below-ground environment and facilities.
Our Services

DGT Associates is a leader in the development and integration of technologies that advance surveying services. As one of the nation’s earliest adopters of subsurface utility mapping, not just engineering, we know the power of its application to further your goals. Our team offers the proven expertise required to fully understand the complexity of your project’s below-ground environment and infrastructure, working across the United States and internationally.
Remote Sensing Technologies & Mobile Mapping
DGT Associates works with strategic clients using unique remote sensing technologies to map the underground that are ideal in working with both new and old facilities, some of which have been buried for more than 100 years. This includes mobile mapping with simultaneous roadway speed data collection using mobile lidar and Ground Penetrating Radar (GPR).
3D Imaging and Lidar Systems
DGT Associates is one of the leading firms adapting above-ground survey solutions for underground facility mapping. Incorporating best-practices for the above-ground survey services, DGT Associates provides unique solutions for 3D surveys.
2D and 3D Project Delivery Formats
One of the greatest challenges for subsurface utility mapping programs is providing usable, easy-to-read final delivery formats for strategic clients. DGT Associates delivery formats include complex 3D/BIM models and traditional 2D CAD plans.
Public and Private Subsurface Utility Mapping Projects
As one of the early adopters of subsurface utility mapping, DGT has experience on numerous types of projects ranging from higher education, hospitals, private property, air and seaports, manufacturing and transportation projects.
New and Emerging Technologies
In recent years, the use of drones has emerged as a cost-effective method for locating and mapping above and below ground. DGT uses drones on select projects to capture high-resolution surface imagery and drone-mounted infra-red systems to confirm the location of pipes and underground leaks.
Building a Standard of Care
Defining a standard of care when mapping the underground is paramount. DGT has adopted the internationally-recognized American Standard ASCE 38-02 for all SUM projects. By defining a standard of care, DGT can help clients manage and transfer risks associated with underground facilities.
Related Projects
Pepperdine University – Malibu, CA
Pepperdine University tasked DGT with locating and mapping buried facilities to assist the campuses with building a 3D digital map of the underground facilities. Despite being a relatively new campus, Pepperdine University, like many other private facilities, has numerous records for various parts of the campus, but lacked one comprehensive digital file with all details necessary to make informed development decisions.
We were selected by the facility and planning team at Pepperdine university not because of cost or geographic proximity to the campus, but because of our ability to assist the Pepperdine team in transitioning into a digital age. DGT provided 3D utility locating and mapping at the university to begin the compilation of a Master Digital Utility Atlas. The work involved locating and mapping buried infrastructure and defining a sustainable Standard of Care for future generations.
Additional SUE/SUM Projects:
UnionPoint – Weymouth
SITE Re-Development
Harvard Campus Mapping
Higher Education
Logan Airport Modernization
Municipal / Transportation

Successful project teams engage underground stakeholders early on a project with highly reliable SUM information
Over the past three decades; federal, state and institutions have published numerous case studies that support the use of SUM in the early part of project development as a best-practice standard. The return on investment (ROI) and improved project safety associated with SUM implementation is so well received that many Federal and State agencies require SUM be implemented in the early design phase of a project to protect the best interest of the taxpayers and the public. See this APWA 2006 Report on SUE.
Meet the Expert – Michael A. Twohig

Led by Michael A. Twohig, Project Director for Subsurface Mapping and globally recognized SUM expert, the DGT Associates SUM/SUE team understands the complex impact of New England’s centuries of development and has the experience and expertise to meet its unique challenges.
As head of subsurface utility mapping at DGT, Mike brings over 35 years of experience in professional utility locating, mapping, underground damage prevention, and industry safety awareness program to the firm.