Accurately locating buried utilities is essential to any project where invasive activity (drilling, trenching, etc) is planned.  Logic Geophysics uses both traditional locating tools, such as electronic utility locating (EUL) devices, and ground-penetrating radar (GPR). Industry-leading equipment is always used: Sensors & Software GPR, renowned as the industry standard, and Vivax premier electronic locating equipment.
We provide an expanded scope of investigation and enhanced results to promote job site safety for both public and private sites.  Logic Geophysics uses best practices for locating subsurface utilities using GPR data grids, not the "walk and mark" method inexperienced practitioners typically employ.  We offer on-site data processing and a comprehensive range of reporting options to suite your budget and needs.  We can also provide 3D data results compatible with AutoCAD and GIS software as desired.

Things work differently in Alaska - our equipment can locate pipes down to 20 feet below surface!

Applications: GPR can detect metallic and nonmetallic (plastic/HDPE) buried utilities.

Electric
Water
Communication lines
Oil and gas
Sewer and storm
Other primary and secondary utilities
Septic systems
Rebar/PT Cable

Factors in the GPR investigation of utilities

Here are some of the questions we'll ask to help plan your project:
1) The number and type of utilities being located, such as water, power, and others - having an idea of the targets beforehand allows us to plan the optimal survey.
2) The size of the area to be surveyed - the time and cost of the survey depend in part on the area coverage needed. Also, obstructions can increase the time required.
3) The depth of the buried utilities - We use a range of frequencies to provide optimal imaging of targets at different depths. We’ve even found lines 18 feet below surface!
4) The type of soil onsite - Gravels and sands are typically amenable to GPR signal penetration, but clay is not. How well pipes can be detected can also depend on the water content of the soil.
5) Site access - the surface needs to be cleared of obstructions, standing water, snow, and metal objects for us to survey effectively. If site access is difficult and/or remote, the cost of logistics increases. Also, the surface needs to be relatively smooth for use of the wheeled cart.
6) The scope of the project and the desired format of results - a full report costs more than only ground markings.

The importance of gridded data collection: We always collect data in a grid, with parallel and perpendicular transects forming a square or rectangle on the surface.  Collected this way, the GPR data can be processed in depth slices, which provides the most accurate subsurface imaging solution.  Although this methodology is more time consuming and therefore expensive, it's the only reliable way to implement GPR for locating utilities. 

Common Questions about Utility Locates with GPR

Can GPR find plastic pipes?  Yes - our technology and expertise applied to your project can successfully interpret data anomalies characteristic of plastic pipes, depending on site conditions.

Can GPR determine the type of utility?  Determining the type of utility is difficult, but with our GPR expertise and years of experience, our interpretation can yield insights into which utilities are being imaged.

How accurate is GPR at locating utilities? Simply put, GPR is the most accurate method available.  Often we can located objects within an inch of their true location.  Depth accuracy is typically 10%; and we can provide advanced services that can reduce depth uncertainty.

Can we get a permanent record of the results? Yes, of course!  You own the data if you're paying for the project, and we're happy to provide them in whatever format you desire.  Available products include geo-referenced grid/anomaly images, grid coordinates, or real-world coordinates of interpreted results, and 2D or 3D images of the subsurface results.

What qualifications do you have? We are the GPR experts in Alaska!  Logic's geophysicist, Esther Babcock, has a Ph.D. in geophysics and 10 years of project experience throughout Alaska, North America, and the world.  We've cleared hundreds of locations for drilling and excavating operations with a 99.5% success rate.