Defining Subsurface Utility Engineering
Subsurface Utility Engineering, or SUE as it is commonly called, is a branch of civil engineering practice and is defined by the American Society of Civil Engineers (ASCE) Standard 38-02. SoftDig® is considered a SUE Service Provider in the industry. The term “Subsurface Utility Engineering” was coined by the Federal Highway Administration in 1987 to standardize the practice of utility locating and data collection across the United States in highway projects. Since that time, SUE has evolved into a diverse practice of utility engineering utilizing various and new technologies not only on highway projects but widely used on all types of projects, including industrial sites, large campuses, urban areas, environmental sites, and others. SUE is a recognized professional level of utility locating practice that is supervised by professional engineers. SUE services are frequently specified by engineering firms because of the high standard of data collection and information needed in design projects with impact on existing utilities.
The ASCE Standard 38-02
The ASCE Standard 38-02, titled “Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data” published in 1991 defines a system of classifying the quality of the existing subsurface utility data. “This process allows the project owner, design engineer, subsurface utility engineer, constructor, and utility owner to develop strategies to manage risks caused by existing subsurface utilities in a defined manner” is taken from the abstract of the Standard. The standard defines four quality standards of SUE data collection: Quality Levels A, B, C, and D. SoftDig® normally provides Quality Level A and B services, but can provide Level C as well.
Quality Level D:
SUE Quality Level D is a preliminary utility records research and collection of utility owner records, normally accomplished by obtaining and reviewing available as-builts and utility records of a site. Quality Level D can be completed by the owner in conjunction with his engineer.
Quality Level C:
SUE Quality Level C is information obtained by surveying and plotting visible above-ground utility features and by using professional judgment in correlating this information to Quality Level D information.
Quality Level B:
SUE Quality Level B is information obtained through the application of appropriate surface geophysical methods (such as ground penetrating radar or EMT devices) to determine the existence and approximate horizontal position of subsurface utilities. Quality Level B is does not collect the vertical position of subsurface utilities. Quality Level B service is typically called “designating”.
Quality Level A:
SUE Quality Level A is defined as the precise horizontal and vertical location of utilities obtained by the actual exposure and subsequent measurement of subsurface utilities, usually at a specific point. Minimally intrusive excavation equipment (such as vacuum excavation) is typically used to minimize the potential for utility damage. Quality Level A service is typically called “locating”.