One of the big misconceptions in the “locating” world is that 811 finds everything. However, any utility beyond the service meter is usually considered to be a private utility, which will require a second call to a firm that locates private utilities. This can range from parking lot lighting to secondary communication lines from building to building.
A couple other big items that are not typically located by 811 are water and sewage. Sometimes the mains are located by the city, but they may be going off maps or assuming it’s manhole to manhole.
One big advantage over 811 that private utility locating companies should always have is ground penetrating radar (GPR).
GPR is a geophysical method that uses radar pulses to image the subsurface. This nondestructive method uses electromagnetic radiation waves and detects the reflected signals from subsurface structures.
GPR is limited on depth, depending on antenna frequency and electrical conductivity of the ground. In clay the conductivity is high, dissipating the waves and making it hard to penetrate decreasing depth, while dry or sandy soils are ideal for wave penetration. Although GPR is a very valuable tool, it should never be the only locating method a private utility locating company uses.
GPR should be considered another tool in the toolbox that assists in helping do a thorough locate. It is highly valuable to use after you have tried all conventional locating equipment in searching for both metallic and nonmetallic pipes, tanks, trenches and voids in the soil.
About Rob
For over 19 years, Rob Harris has led The Underground Detective in providing underground utility locating services to commercial and residential companies in several areas of the U.S.
The Underground Detective began as an effort to help plumbers precisely locate sewer blockages. As technology has grown, the service has adapted and evolved into utility locating, leak detection, vacuum excavation, ground penetrating radar, concrete scanning and utility mapping.
Since Harris took over management of The Underground Detective in 1997, the firm has expanded to a regional service with offices in Knoxville, Tennessee, Philadelphia, Atlanta, Chicago and Toledo, Ohio, along with its original headquarters based in Cincinnati.
Harris has experience in electromagnetic locators, sondes and GPR, including manufactures such as Radiodetection, Subsite, Vivax-Metrotech, Prototek, Goldak, RIDGID and MALA GeoScience.
Included in his multitude of industry specific certifications are OSHA 10 Hr., OSHA 40 Hr. Hazwoper, Smith Defensive Driving certification. Harris also has customer specific certifications, such as BP, Marathon and Shell.
