Expertise and Accuracy Help Avoid Costly Mistakes And Project Delays

When it comes to subsurface imaging, inaccurate information can result in costly conflicts, damage, delays, service disruptions, redesigns, claims and even injuries or lost lives. To avoid these issues, many clients turn to Cardno TBE, a recognized leader in subsurface imaging technologies. Our staff has the expertise required to deliver accurate utility information needed by clients, engineers, contractors and designers to make informed project decisions.

Our staff is highly trained in the following specialties:
  Subsurface Utility Engineering (SUE)
  3-D Underground Imaging
  Utility Coordination
  Utility Design
  Ground Penetrating Radar (GPR)
  Surveying and Mapping
  Global Positioning Systems (GPS)
  Computer-Aided Design and Drafting (CADD)
  Geographic Information Systems (GIS)

Subsurface Utility Engineering (SUE): A Complete Process

Subsurface Utility Engineering (SUE) is an engineering process that has evolved considerably over the past few decades. It has been used primarily by State and local transportation departments, design consultants, and utility companies to locate existing subsurface utilities with a high degree of accuracy and comprehensiveness. The SUE process combines civil engineering, geophysics, and surveying, and utilizes surface geophysics, vacuum excavation, and mapping technologies. When used properly it avoids many conflicts and reduces project delays. Its use has become a routine requirement on highway projects in many states. It is strongly advocated by the Federal Highway Administration (FHWA) and many other governmental transportation agencies.

Evolution of Subsurface Utility Engineering

SUE first came into use in the early 1980s. In the beginning, all of the emphasis was on two technologies -- vacuum excavation and surface geophysics. It soon became obvious that other important aspects of SUE were surveying and data management (i.e., surveying to project control and entering the resulting subsurface utility information into clients’ computer systems or onto project plans).

As time went on, other activities were added, such as sealing deliverables and obtaining professional liability insurance. These activities led to SUE becoming recognized as a professional service rather than a low-bid service.

Perhaps the most significant advancement came in the early 1990s and involved the utility quality levels concept. The use of quality levels allows designers to certify on the plans that a certain level of comprehensiveness and accuracy has been provided.

Thus, during the first two decades of its use, SUE evolved from a technology to a process, from a low-bid activity to a professional engineering service, but another important advancement was yet to come.

ASCE Standard Guidelines

In 2003, the American Society of Civil Engineers (ASCE) published and distributed a document entitled “Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data”. This standard formally defined SUE and set forth standard guidance for collecting and depicting SUE information. This essentially elevated SUE to a new level.

The ASCE standard presents a system of classifying the quality of existing subsurface utility data. Such a classification allows project owners, engineers, and constructors to develop strategies to reduce or allocate risks due to existing subsurface utilities in a defined manner. As a handout or as part of a specification, it assists engineers, owners, and contractors in understanding utility quality level classifications and their allocations of risk. The standard closely follows concepts in place in the SUE profession. Therefore, many states are already in “compliance” with this standard through their use of SUE, or through their inclusion of SUE specifications in their engineering contracts.

The ASCE standard makes it very clear that SUE is a process, not a technology,
and it defines SUE as follows:

Subsurface Utility Engineering (SUE): A branch of engineering practice that involves managing certain risks associated with utility mapping at appropriate quality levels, utility coordination, utility relocation design and coordination, utility condition assessment, communication of utility data to concerned parties, utility relocation cost estimates, implementation of utility accommodation policies, and utility design.

The basic elements that comprise the SUE process are contained in this definition.

SUBSURFACE UTILITY ENGINEERING
A Technology-Driven Process that Results in Increased Safety, Fewer Design Changes, and Lower Costs

SUE Quality Levels
Level A Precise horizontal and vertical location of utilities obtained by the actual exposure (or verification of previously exposed and surveyed utilities) and subsequent measurement of subsurface utilities, usually at a specific point.
Level B Information obtained through the application of appropriate surface geophysical methods to determine the existence and approximate horizontal position of subsurface utilities.
Level C Information obtained by surveying and plotting visible aboveground utility
features and by using professional judgment in correlating this information to
Quality Level D information.
Level D Information derived from existing records or oral recollections.