Beneath the earth’s surface lies a complex network of utility pipes, lines, and cables, crucial to powering and servicing the day-to-day operations of individuals and businesses alike. These systems transport essential resources like water, fiber optic telecommunications, electricity, and natural gas. Since utilities are concealed underground, there’s a high risk of damage during construction. Striking a utility line not only disrupts project progression but can also lead to significant cost overruns, hazardous conditions, and a tarnished reputation. Therefore, it’s vital for project owners and construction managers to partner with licensed professionals to obtain maps and records of utility locations.
A DGT utility survey team member operating a push cart Ground Penetrating Radar (GPR) at an electrical substation.
To ensure the safety and success of projects, Subsurface Utility Engineering (SUE) and Mapping (SUM) can capture detailed, accurate insights into the underground environment with cutting-edge technology such as radar tomography, 3D imaging, and mobile mapping. Along with the popularization of SUE/SUM services, there’s been a recent surge in lower-cost, unlicensed professionals claiming to offer similar mapping services. These organizations lack the training and expertise of established surveying firms, leading to unreliable data and questionable practices. Therefore, it’s critical for project owners to ensure they work with licensed, professional surveying firms to safeguard their investments and project outcomes.
Subsurface utility map crafted by the DGT team, illustrating a complex network of underground networks in an old city street.
Digging Deeper into the Role of Subsurface Insights
SUE/SUM are highly effective underground damage prevention strategies for design and construction teams, providing a comprehensive picture of the underground environment. Before SUE/SUM became mainstream in the 1980s, projects often began with limited consideration of subsurface interference, leading to frequent, costly utility conflicts, construction delays, and public safety hazards. In many cases, contractors were employed to uncover specific underground features, using mechanical excavation to create test pits. While this process was effective in the past, it is very invasive and only uncovers limited subsurface information.
Visual mock-up of an AI-mapping firm’s deliverable, showcasing reduced reliability for underground facility networks.
Innovations in surveying and remote sensing technologies and methodologies have improved surveying accuracy and unlocked new mapping capabilities, setting a global industry standard. As a result, SUE/SUM has promoted greater knowledge and care of underground assets, influencing many state and federal organizations to endorse and recognize SUM as an industry best practice for mitigating utility damage and safeguarding construction workers and the public. A study conducted by the American Society of Civil Engineers (ASCE) revealed that every dollar invested in SUE/SUM generates a remarkable $22.21 return on investment (ROI), highlighting the necessary role these services play in making construction projects safer and more efficient.
Subsurface utility map developed by the DGT team for a drainage system project in Fall River, MA to support replacement of outdated infrastructure.
Why Digital Data Mining isn’t Enough
The accessibility of AI technology has prompted companies to market digital utility maps compiled with AI-generated data scraped from online public records, private records, and satellite imagery. Rather than capturing boots-on-the-ground subsurface intel, these companies often bypass local, professionally licensed surveyors and rely on recycling pre-existing data.
Mobile mapping technology in action in downtown Boston, enabling the DGT team to map underground utilities safely amid busy city streets.
These companies may gain the attention of project owners with promises of a single source of utility data and colorful interactive maps; however, the reality is that the data they provide is often unverified and unreliable. Although these services may appear to provide valuable utility data for low costs, the potential risks associated with inaccurate, outdated, or incomplete data far outweigh the claims of cost and time savings. Failing to work with a professional SUE/SUM team for on-site subsurface investigations can expose project owners to utility damage and legal risks.
Shopping for Accurate Data
Investing in high-quality data is essential to provide your team with the information needed to break ground safely and efficiently. But how can you ensure the data you receive is comprehensive and reliable?
Utilizing cutting-edge remote sensing technologies for subsurface investigations, the DGT team’s digital mapping file reveals existing and abandoned facilities, including buried tram tracks.
The ASCE has established standards for subsurface data: ASCE 38-22 and 75-22 designations. ASCE 38-22 outlines four levels of subsurface data quality (Levels A-D). Level A represents the highest level of detail, while Level D data represents the most simplistic. Quality Level D data is derived solely from existing utility records or verbal recollections; while valuable for planning and initial assessments, this data alone is insufficient to break ground safely. In many cases, these AI-mapping firms only partially capture Quality Level D data. In contrast, Level A-C data involves some form of on-site investigation, boots-on-the-ground, so to speak, with survey-grade locations, offering increased accuracy and quality assurance.
ASCE 75-22 standards aim to ensure accurate records of new, relocated, or daylighted utilities by providing a framework for recording and exchanging utility data. When selecting an SUE/SUM service provider, it’s important to assess ASCE 75-22 verification and identify the quality level of the data you’re purchasing to avoid working with unreliable vendors.
DGT’s utility map transforms intricate web of underground pipes and obstacles into clear, actionable insights to enhance project efficiency and planning accuracy. Project delivery in CAD or GIS.
Project owners should be wary of companies that promote their AI-mapping services as a complete, “one-size-fits-all” solution. A minor residential renovation project requires a vastly different level of subsurface detail compared to a highway reconstruction project. Other warning signs include claims of capturing all utilities digitally, rapid turnaround times, and reliance on AI technology. Additionally, we urge prospective buyers to be cautious of purchasing maps with inaccurate scaling, omitted utility details, and no disclaimers regarding data limitations. While speed and technology can be beneficial, reliable surveyors prioritize accuracy over shortcuts, providing deliverables that uphold the standard of care for professional mapping services. Not only do we hold ourselves to these expectations, but they also reflect the foundational guidelines followed by our peers across the industry.
Leave it to the Pros
At DGT, we provide detailed utility maps that empower our clients to make design and construction decisions with confidence. Although safe digging laws nationwide mandate utility companies to mark utilities with paint or flags, relying on historical utility records alone is not enough to guarantee accurate utility locations. In fact, a 2022 report published by the Common Ground Alliance (CGA) identified inaccurate or incomplete utility markings as the leading cause of utility damage (35.91%). Project owners and managers should source reliable data from licensed professionals to reduce the risk of striking utilities that may be missing or misrepresented in outdated records. Project owners should also request utility mapping services to a clearly defined standard of care, and the existing condition surveys incorporated into construction documents should identify the source of the utility data depicted in the plans and the level of effort, accuracy, and survey practices used for the utility data depiction.
Our team comprises licensed professionals who utilize advanced mapping technology to capture a complete, accurate picture of underground utilities. By offering color-coded 2D and 3D digital maps in CAD, BIM, or GIS formats, we can help ensure your team has the information needed to execute your project safely. We combine innovative technology with decades of demonstrated expertise across the globe to generate mapping results you can depend on.
Explore our SUE/SUM services and experience the value of professional subsurface mapping for yourself: dgtassociates.com/subsurface-utility-engineering-mapping/
As Project Director for Subsurface Mapping at DGT, Michael A. Twohig is an expert in professional utility locating, mapping, and damage prevention, driven by a commitment to advancing safety standards across the industry. Bringing almost 40 years of experience from across the US, Australia, India, and Europe, Mike has worked on projects of varying scales and complexity, focusing his talents on integrating traditional utility locating procedures with land survey best practices.