For the last few decades, Subsurface Utility Engineering (SUE) has elevated the architecture, engineering, and construction (AEC) industries in accuracy and quality by promoting greater knowledge and care of underground assets. In fact, a Penn State University study revealed that every dollar spent investing in the SUE process brings a return of $22.21.
While SUE as a discipline has propelled the industry forward, the terminology – subsurface utility “engineering” – has caused confusion and division among engineers, surveyors, geophysicists, designers, and owners involved in the planning phases of development projects.
When it comes to the underground environment, engineering refers most accurately to the design, relocation, and handling of underground utilities. Those practices are only one part of the equation, however, and using “engineering” as a generalized term diminishes the importance of the first step in any successful project: mapping the above- and below-ground environment.
The leadership team at DGT Associates, an SUE-capable surveying and engineering firm, believes that Subsurface Utility Mapping (SUM) is a more accurate term, and one that better recognizes the importance of what highly trained, professional mapping specialists do to set a strong foundation for projects involving below-ground work.
How SUE Came to Be
SUE as an industry term was born out of an effort in the 1980s to standardize methods of handling the underground environment. Until then, projects were regularly begun with little investment into discovering and planning for what lay under the ground, which led to overbudget projects, delays, and safety issues.
Initially, SUE was dubbed “designating and locating,” which was reflective of the core activity of finding and marking utilities with paint on the ground. Recognizing the need for industry support and more sophisticated methods, engineers ran with the discipline, and renamed it “Subsurface Utility Engineering.”
In 1991, SUE gained an official endorsement from the Federal Highway Administration (FHWA) and a few years later, the famous Purdue study proved its value. This led to the American Society of Civil Engineers (ASCE) National Consensus Standard titled ASCE C-I 38-02, Standard Guidelines for the Collection and Depiction of Existing Subsurface Utility Data. These progressions further solidified SUE’s importance and prominence in the field.
The establishment of SUE as a regulated process was groundbreaking in integrating the underground environment into the initial design stage, moving project development away from a practice of digging without proper understanding of what lay below-ground, thereby creating risk of damage and injury, in the construction phase. The resulting ASCE standards also helped to unify and refine how all parties involved in a project approach the underground environment.
“We appreciate and abide by [ASCE] 38-02,” said DGT Co-founder and Principal Bob Staples, PLS. “But the term SUE, I think it’s kind of deceiving.”
The early professionals did not rush projects through design into construction, despite the urgency of rapidly growing cities. Decision makers of the time thoroughly documented the design and construction details, and the drawings left in today’s archives are a testament to their efforts. In New England, many of the facilities built in the early 20th century or before are still in use today, thanks in large part to accurate as-built documents that facilitate renovation and improvement instead of demolition and reconstruction.
The Surveyor’s Domain
The ASCE Standards list “utility mapping at appropriate quality levels” as the first activity associated with SUE. However, according to standard definitions, that’s a surveyor’s job.
Globally, the International Federation of Surveyors (FIG) specifies that a surveyor’s activities “may occur either on, above or below the surface of the land.”
“We believe our domain is in mapping the existing environment,” said Michael A. Twohig, SUE/SUM Services Manager for DGT Associates. “And we’re more closely aligned with that than someone who says they’re closely involved with engineering.”
The word “engineering” connotes a specific activity that is confined to engineers, yet the first and core activity involved in SUE – mapping – is performed by surveyors. In this regard, SUE is not a new discipline, but rather an extension of an existing one: surveying.
“For us, we go back to a community that has been mapping the real world for over a hundred years versus what somebody came up with in the ’80s to define their own industry standard,” said Twohig.
Utilities and other assets in the underground environment have been discovered and documented by surveyors since the discipline of land surveying began to separate itself form the civil engineering discipline in the 1800s. Surveyors are usually the first on site for a project, and they have been recording what’s beneath our feet and communicating it to their partners – including engineers – since long before SUE was established in the industry lexicon.
“A lot of people believe the clock on this industry started in 1987-88, with the [Federal Highway Administration],” said Twohig. “We believe it’s actually the result of a long legacy of good work done by peers over hundreds of years.
“Some think it’s a revolution, but we think it’s only an evolution.”
Why High-Quality Mapping Matters
Mapping the existing and man-made environment goes back to the definition of a surveyor. DGT takes this charge seriously and is committed to a holistic approach to the mapping process. That means going beyond the acquisition of data to also include coherent, precise presentation of that data.
Recently, DGT met recently with the staff of a northeastern state Department of Transportation (DOT) to discuss to present their approach to utility mapping. One of the DOT engineers brought up recent utility mapping work that had been done by a consulting firm. The end result was a hefty bound report that contained a wealth of information in the form of written text and imagery, but did not contain a single map, making it only partially usable by rest of the professionals on the project.
“If I had five seconds to tell you what we do better, I’d say, ‘We’ll give you a map, drawn to scale, in CAD or GIS format,’” said Clifford.
In addition to mapping for immediate needs on development projects, DGT also produces a Digital Utility Atlas to help campuses and facilities of all kinds shift from clunky paper records to comprehensive digital maps of their underground environments that can be easily updated and used by any party. Pieces like that are instrumental to proper and effective development, and they’re also the kind of deliverable that only a qualified surveying professional can create.
“When we go out there, we use survey equipment and shallow geophysics to locate and map the world, and then we present the information for owners, designers and anyone else that needs it to make informed decisions,” said Twohig.
Everyone Has a Place at the Table
While DGT argues that the terminology of “Subsurface Utility Engineering” is problematic, DGT doesn’t advocate for eliminating it entirely. Instead, the DGT leaders suggest that adopting “Subsurface Utility Mapping” to refer specifically to the work of mapping underground infrastructure can help to better identify all of the different roles that must be played in development.
“The best analogy is that if you were building a house, you’d need a licensed electrician, a licensed plumber, a licensed contractor,” said Twohig. “There are a lot of professionals involved in a project in a building environment, and we believe there’s a lot of professionals involved in SUE. It should not be discriminatory toward engineers, surveyors, or exclusive of any profession.”
This effort requires surveyors, GIS professionals, and others involved in mapping to recognize that they must take ownership of the subsurface work they do. That means pushing for the adoption of SUM work as a precursor to any SUE project.
“Our history is not based on something we adopted in 1980,” Twohig said. “It goes back to the best practices of our profession, which are more than 150 years old. Our justification for the Subsurface Utility Mapping terminology is that we were doing this, and our peers were doing this, for a long time before this industry was recognized as SUE … That’s why we call it SUM.”