Subsurface Utility Locating and Mark Out

TSPE subsurface utility engineering (SUE) technicians will perform an ASCE Quality Level B (QL-B) subsurface utility investigation to identify, trace, and mark (collectively defined as “designation”) the location of private and public subsurface utilities, sanitary and storm sewers within the project limits.


As part of a QL-B investigation of all utilities, TSPE’s SUE technicians will perform the following:

  • Contact Dig Safely New York to determine the registered utilities serving the project area. Coordinate with registered utilities to request copies of subsurface utility mapping.
  • Document research to obtain copies of available utility mapping, design documents, and as-built mapping to determine the existence of subsurface utilities within the investigation area.
  • Perform a cursory inspection to become familiar with the project site, specifically noting surficial evidence that indicates the presence of subsurface utilities (e.g. manholes, catch basins, trench drains, clean outs, outfalls, valves, meters, poles, vaults, electrical pull boxes, junction boxes, conduits, well casings, tracer wires, utility markers, markings, and pavement cuts).
  • Trace the location of known subsurface utilities constructed of a conductive material (e.g. electric, communications, water, and natural gas) utilizing RF devices.
  • Assess the for and plan the additional investigation within the project area for subsequent geophysical investigations utilizing GPR technology, as needed.


Note: The effectiveness of GPR to designate the existence of a subsurface utility is dependent on the soil and ground water conditions. Soils with significant clay content and high moisture content will attenuate (absorb) the GPR pulse, which significantly reduces signal response and ultimately the ability to identify subsurface utilities and/or structures. GPR profiles may not be collected throughout the entire investigation area; however, GPR technology will be utilized to augment the investigation, as deemed necessary.