Subsurface Utility Engineering

4Sight is an industry leader in providing high-quality Subsurface Utility Engineering (SUE) services, backed by decades of experience and a team that helped develop the ASCE 38-22 standard. SUE focuses on the accurate mapping, location, and characterization of underground utilities, including water, sewer, gas, electrical, and telecommunications infrastructure.

ASCE Quality Levels

The practice of SUE follows the ASCE 38 Standard, which defines four quality levels to ensure reliable and consistent utility data.

ASCE 38 Quality (QL) Levels for Subsurface Utility Engineering (SUE)

Quality Level D – The essential starting point. Information derived from existing records or verbal recollections

Quality Level C – Information obtained by surveying and plotting visible above ground utility features and by using professional judgement in correlating this information to the Quality Level D information.

Quality Level B – Information obtained through the application of appropriate surface geophysical methods to determine the existence and approximate horizontal position of the utilities.

Quality Level A – Precise horizontal and vertical location of utilities obtained by the actual exposure and subsequent measurement of subsurface utilities.

Each of these levels has a role and helps to support different project decisions. Understanding which level is right for your project requires both expertise and experience, and that's where 4Sight stands apart. We didn't just learn these standards; we helped shape them.

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Deliverables

All SUE deliverables are prepared in accordance with ASCE 38 standards and reviewed and signed by a Professional Engineer. Utility alignments on project drawings are clearly labeled with their respective Quality Levels, accompanied by detailed notes highlighting chamber structures, key field findings, and any conflicts with existing utility records. A comprehensive project report summarizes the investigation scope, equipment used, significant findings, and recommendations, providing clients with actionable insights for informed project planning and risk mitigation.

SUE Investigation Methods

To deliver precise subsurface information, 4Sight employs a variety of advanced investigation techniques tailored to project needs, including:

Aerial Measurements – Capturing surface and utility features from above for context and planning.
Closed-Circuit Television (CCTV) – Inspecting the interior of pipelines and sewer systems.
Electromagnetic Induction – Detecting buried metallic utilities.
Ground-Penetrating Radar (GPR) – Identifying both metallic and non-metallic subsurface utilities.
LiDAR – Creating high-resolution, 3D representations of site conditions.
Vacuum Excavation – Safely exposing underground utilities to verify locations without damaging infrastructure.