Utility Location

SiteScan Detects Underground Obstructions without Costly Excavations through Utility Location Services

Prior to excavating a job site, utility location services should be utilized to prevent unexpected collisions with existing utility lines or buried structures. Our Utility Location equipment allows you to avoid costly and time-consuming issues during trenching, drilling, or digging.

It is always a good idea to contact your local utility companies or Call 811 for preliminary identification of main utility lines before scheduling a comprehensive GPR concrete scan survey.

In addition to public utility location services, SiteScan can locate and identify private utilities that may not be serviced by 811.

 

SiteScan Uses Multiple Technologies to Ensure the Most Accurate Results

We use a combination of methods to positively identify utilities including Electromagnetic Location and Ground Penetrating Radar (GPR).

Electromagnetic Location is often the most common and cost effective method for locating utilities. It is often the first step in a comprehensive investigation. We use a combination of many different tools to electronically locate utilities including:

How Direct Connect Works

The Direct Connect method involves the technician directly connecting a transmitter to the line. A signal is sent down the utility or tracer wire buried with the utility and located with a receiver from above the surface. This is ideal for electrical, communication, and gas lines.

 

 

How Induction Works

Induction involves sending a signal through the surface to the utility when you cannot directly connect to it for various reasons. The utility then transmits this signal which is picked up by a receiver above the surface in the same manner as the Direct Connect method.

 

 

 

How Sonde Works

Sonde locating involves inserting a locatable transmitter into a utility or conduit to be located by a receiver above the surface. Some of the tools we use that have locatable sondes in them are crawler cameras, push cameras, and ram rods. This method is often used for storm drains, waste lines and empty conduit.

 

 

How Ground Penetrating Radar Works

Ground Penetrating Radar works by sending a pulse of energy into a material and recording the strength and the time required for the return of any reflected signal. A series of pulses over a single area make up what is called a scan. Reflections are produced whenever the energy pulse enters into a material with different electrical conduction properties or dielectric permittivity from the material it left. The strength, or amplitude, of the reflection is determined by the contrast in the dielectric constants and conductivities of the two materials.

With GPR, our technicians can quickly identify and mark the location and depth of service utilities – gas, communications, and sewer lines – and other metallic and non-metallic targets including underground storage tanks and PVC pipes.

When utilities are located, our technicians use industry standard colors to mark them directly on the surface. Water based marking paint is used when permitted. When paint is not permitted in cases like finished decorative surfaces or high traffic customer areas, we can use chalk, wax or other marking materials. Flags and whiskers are also used in areas such as grass or dirt when paint markings will not last.

For more information on how GPR and EM work, visit our Resources Page.

APWA-color-codes-for-utilities

Electromagnetic Location of Utilities

Electromagnetic Location is used not just find a utility but to identify the type of utility (e.g., cable, power, water, sewer). Because of this, Electromagnetic locating is the most common and cost effective method for locating utilities and utility lines.

The Electromagnetic Locating method is based on the measurement of the change in mutual impedance between a pair of coils on or above the earth’s surface. Most EM instruments are comprised of two or more sets of coils. These coils are electrically connected and are separated by a fixed distance. The transmitter coil is used to generate an electromagnetic field at a specific frequency. This is known as the primary field. The primary field causes electrical currents to flow in conductive materials in the subsurface. The flow of currents in the subsurface, called eddy currents, generate a secondary magnetic field, which is sensed by the receiver coil. The magnitude of the secondary field sensed by the receiver depends upon the type and distribution of conductive material in the subsurface. Both the induced secondary field, along with the primary field, is detected at the receiver coil.

The magnitude of the secondary field is broken into two orthogonal components. These are the In-phase (real component) and the Quadrature component (imaginary component). Under certain operating conditions, the magnitude of the Quadrature component of the secondary field is linearly proportional to the apparent conductivity. In the absence of a highly conductive material (e.g., metal or metallic targets) in the subsurface, the magnitude of the in-phase component is dependent on the magnetic susceptibility of the subsurface.

Our Electromagnetic Location Equipment

utility-location-other-methods-place-under-our-electromagnetic-location-equipmentWe use the most advanced EM equipment available to ensure you get the best results possible.  The system structure, electronics and coils are designed for maximum structural and thermal stability. These key features minimize signal drift and maintain an accurate zero level and system null across the full bandwidth of the system, whereas signal drift is a common problem with other EM instruments. These older instruments, which do not incorporate the advanced electronics and software control employed in our equipment, produce data with significant problems that cause inaccurate results. You won’t have that issue with SiteScan.  We deliver accurate data every time.

GPR for Utility Locating

GPR is a construction inspection application that allows contractors to detect metallic and non-metallic objects that lie inside a concrete structure or underground. Utility location makes it possible to detect:

  • Rebar
  • Concrete Coring
  • Post-Tension Cables
  • Fiber Optic Cables
  • PVC piping
  • Active and Inactive Utility Lines

With our state-of-the-art technology, the radar in our utility locating services can detect objects up to 12 ft below ground. In addition, all of our technicians can provide real-time data analysis and generate 2D and 3D reports.

Deliverables of a Utility Location Project

By leveraging our SiteScan’s proprietary application that provides unique intelligence and instant report delivery capabilities on every job site, we deliver the reports to you electronically as soon as the scan is completed.

Our technicians collect data for utility location surveys in a grid format, therefore maximizing the area coverage and ensuring the detection of sub-surface objects. After underground objects are located, our technicians use APWA industry standard colors to mark them directly on the surface.  Non-permanent water-based paint is used where permitted.  When paint is not permitted (such as finished decorative surfaces or high traffic customer areas) we use chalk, wax or other materials.

Better Vision, Better Intelligence means that the professional staff here at SiteScan will give you results with unparalleled accuracy and insight. No matter the size or scope of your project, we have the field experience, commitment to quality, and technical resources to overcome any challenge and deliver the information you need.  We have helped on hundreds of projects for a wide variety of clients with our utility location expertise and we are here to help you.