I look out for my client's safety/security/timeliness by "overview",. discovering, confirming plant of any size by my protocols. SUE, Subsurface Utility Exploration, codifys competent understanding and common-sense conclusions, always preferable in planning, avoiding C.O.s Like Dig-Safe, Magnetic Field Detection is young..Subcontracting to provide service to utilities has been the pattern, until the last several years. With over 5 years as a field tech I early on made daily use of the method. A vendor to SCRWA and Yankee Gas, I have Amtrak, Metro North Safety, Nuclear rad 1 training, Computerized equip allows for discovery by common-bonds, once an issue. Never use GPR when simple MFD will do. I map what goes into the print. Building interiors a specialty. All work is my own effort