Subsurface Utility Engineering (SUE)

Subsurface utility engineering (SUE) is the process of locating underground utilities and is essential to managing certain risks associated with utility mapping for the design of infrastructure projects. SUE can be a valuable cost-saving measure by reducing unexpected conflicts with utilities and avoiding unnecessary delays during construction. Mark Thomas has an in-house SUE team that is dedicated to addressing the ever-increasing demand for SUE and offering all quality levels (QL) with in-house QL -B, -C, and -D, and partnering with subcontractor services for QL-A potholing and traffic control.

QL-A requires the physical location of a utility and provides the most accurate form of data. Data was collected via potholing or vacuum excavation.

QL-B designates underground utilities on the ground surface using markers (i.e. paint or flags) with depth detail using electromagnetic and ground-penetrating radar equipment.

QL-C requires plotting visible utilities, including manholes, valves, fire hydrants, catch basins, and gas risers. Locations are surveyed for accuracy.

QL-D requires gathering historical data including architectural drawings, “as-built” drawings, existing utility records, photographs, survey records, and anecdotal information given by individuals who are familiar with the surveying site.

When engaging professional SUE services, it is important to note the distinctions between an Underground Service Alert (USA) Dig Alert company versus a company that provides all four QL services. Areas serviced by the USA are limited, and schools, universities, apartment complexes, mobile home parks, hospitals, and any other private properties that require permits for digging are excluded from the USA’s coverage. Owners of underground facilities will mark the lines that they own and/or maintain. That usually means up to the meter. Non-pressurized sewer lines, non-pressurized storm drains, or other non-pressurized drain lines do not have to be marked. USA will only locate and mark the underground facility within the delineated area, depths will not be provided. Additionally, USA Dig Alert will not offer services for designing, engineering, or other non-digging purposes, and individuals attempting to engage with USA for these reasons can be charged with hefty fines.

For a more accurate and detailed analysis of the site, including depth detail, we advise clients to engage in professional surveying services that include all quality levels. Also, our clients benefit from an SUE team that has extensive experience working hand-in-hand with our in-house civil designers, giving the SUE team an unmatched understanding of what information designers need to manage underground utility risk. To learn more about SUE and see what we can do to customize a solution for your SUE project, please reach out to us at info@markthomas.com.