Frequently Asked Questions

What you need to know about Utility Locating

About GPRS

Q: Why should I choose GPRS over a similar company?

A: GPRS is a leader in the field of subsurface scanning. Our focus on private utility locating and concrete scanning has enabled us to become highly specialized within these fields.

One key difference between GPRS and our competitors is the total area we are able to accurately scan within a given timespan. Rigorous training enables our Project Managers to work efficiently and precisely, and to quickly provide you with the information you need.

When you contact GPRS to request a service, we put you in direct contact with a Project Manager local to your area. Their knowledge of the unique conditions that surround your project enables them to ask the right questions to determine if GPRS will be able to serve your project’s needs. Contact us today to experience the GPRS difference yourself.

Q: How quickly can GPRS respond to emergency needs?

A: In most circumstances we can have a Project Manager at your site within 24 hours, and often quicker.

Q: What is the farthest GPRS will travel to reach a site?

A: GPRS provides nationwide Ground Penetrating Radar services with offices in every major city from coast to coast. Simply put, we are willing to do what it takes to serve your project’s needs- including travel.

Q: Is GPRS available to work at night or on weekends?

A: At GPRS we pride ourselves on customer service and our ability to meet your critical scheduling needs. We are able to work nights and weekends in order to help meet your project’s deadlines. Please contact your local GPRS representative for rates and availability.

Q: What type of training do GPRS Project Managers go through?

A: Each of our Project Managers goes through a two- to three-month training process. This includes two weeks at our Training Center, located at our corporate headquarters in Toledo, OH. The GPRS Training Center has a ~1,000 square foot test slab created to simulate nearly 90% of conditions encountered in the field. Trainings are led by our Director of Training and a partner- combined they have over 17 years of hands-on experience. Each trainee is paired with an experienced Project Manager until they have sufficiently demonstrated their technical expertise. This program enables the trainees to grow in knowledge and confidence while simultaneously allowing Project Managers the opportunity for career growth and advancement.

Q: What qualities set GPRS Team Members apart?

A: GPRS strongly believes that the key to our success is our incredible team. When hiring new team members GPRS looks for certain qualities which we feel set us apart from the competition. Our strong sense of integrity, proven competency in our field, and commitment to our customers are just a few of the qualities which make GPRS a cut above the rest.

Q: How does GPRS ensure quality of service?

A: GPRS focuses solely on the fields of utility locating and concrete scanning. All of our team members undergo a rigorous training program in order to ensure they are well prepared to meet your project’s needs. In order to ensure quality and accuracy, GPRS recently developed and began implementing SIM- subsurface investigation methodology. This is a comprehensive specification detailing training methods, equipment usage and means of minimizing error when performing subsurface investigations. This operating procedure was developed using our 18 years of experience and data in the fields of utility locating and concrete scanning.

Q: Does GPRS perform S.U.E. work?

A: Subsurface utility engineering (S.U.E.) is an engineering method of reducing the risk and improving the accuracy of subsurface utility readings. It is broken down into four levels of quality, governed by ASCE Standard 38-02. GPRS is able to provide S.U.E. Quality Level B data, which uses non-destructive surface scanning methods to determine the position of subsurface utilities. GPRS is able to perform S.U.E. work in conjunction with other agencies, but does not currently provide a fully comprehensive in-house S.U.E. service.

Q: What are your rates for different services?

A: Please visit our sales page to request a quote.

Q: Does GPRS purchase used equipment?

A: Yes, we buy used equipment from other GPR companies. Please call our corporate office at (419) 843-9804 and we would be happy to discuss equipment sales.

GPRS uses only the best equipment. All of our units are carefully selected to serve the needs of the job in question. We routinely service and calibrate equipment to ensure the most accurate results for your project.

General Scanning

Q: What is the best time to contact a utility locating service?

A: ALWAYS contact a utility locating service before you dig!!

For many projects, identifying the locations of utilities is crucial during early planning stages in order to assist with placement of various structures, supports, or landscaping features. A private utility locating company such as GPRS is able to help project planning from the pre-planning stages all the way through project close-out.

Proper utility detection also helps to keep workers and those nearby safe by preventing the high risk which comes with striking a buried utility. GPRS has 18 years of experience in locating gas lines, pipelines, communications, electric, water, and sewer lines, as well as void spaces. Contact us today for help locating underground utilities!

Q: What is the difference between GPRS and state-run services such as 811 (Call Before You Dig)?

A: The biggest difference is also the most important one: state-run services are ONLY responsible for locating public utilities. Public utility locating services such as 811 fail to detect private utilities, leaving you without a critical portion of information.

GPRS provides you with a complete and accurate representation of all subsurface utilities, whether public or private.

Q: What is ground penetrating radar (GPR)?

A: Ground penetrating radar is a detection method which uses radio waves to identify buried or hidden elements within a structure or beneath a surface. This non-destructive method uses antennas of varying strengths to transmit a signal into a surface. As the signal encounters different elements within that surface, it is bounced back to a receiver at the surface. This action creates a reading which can be interpreted by experienced GPRS Project Managers in order to determine the location and depth of buried utilities and other subsurface elements.

Q: How is GPR used?

A: GPR is used to identify the depth and location of subsurface elements. GPRS uses this radar for utility locating and concrete scanning applications. Varying antenna strengths are used for different applications, depending on the type of material being scanned and the anticipated depth of the buried elements.

Q: What type of GPR equipment is used?

A: GPRS uses a variety of ground penetrating radar and scanning tools according to a project’s needs. Our most commonly used tools include radar, electromagnetic induction, thermal scanning, and CCTV sewer cameras. Read more about the different types of equipment we use here.

Q: Is GPR affected by the weather or any other factors?

A: GPR is extremely effective at locating subsurface utilities and other elements, however it does have certain limitations. Ground and soil conditions, weather, and type of material being located are just a few of the potential limiting factors. GPRS Project Managers are skilled in determining if GPR is the right choice for you project. In the event that conditions are not suitable for GPR scanning, an alternative recommendation can be made.

Q: Is ground penetrating radar safe to use?

A: Ground penetrating radar (GPR) is a safe, non-invasive tool used in identifying subsurface elements. GPR does not emit any harmful radiation or other byproducts. The scanning process does not create any noise and the area can remain undisturbed during the course of the scan. Contact us with any questions regarding the safety of GPR usage- we would be happy to provide you with additional documentation.

Q: How can I determine if GPR is needed for my project?

A: Contact GPRS by phone or through our website and a local GPRS representative will be in touch with you as soon as possible. Our representatives and local Project Managers are skilled in assessing local conditions and can help you to figure out how GPR services can meet your needs.

Q: What depth can GPR penetrate to?

A: Different types of equipment are used for different scanning needs. For private utility locating needs on grass, asphalt, or concrete the type of antenna used can generally penetrate up to 8', but can vary greatly depending on site conditions.

In certain situations, a larger antenna can be used for greater depth penetration. Please contact your local GPRS representative for more information on selecting the right GPR service for your project.

Q: How accurate are the results of ground penetrating radar?

A: GPR is extremely accurate! While accuracy is reliant upon various external factors such as ground and soil conditions, GPRS standards ensure that we are able to obtain the most precise results possible in each situation. Through past experience we have found that when using a utility locating antenna for scanning, the accuracy is +/- 6” to the center of the object being located and +/- 10% to the actual depth.

The utility locating antenna has a greater depth penetration than other types of antennas used in the field, but GPRS uses a variety of antennas as best suited to the situation in question.

GPRS Project Managers are skilled at assessing local conditions to determine if they will allow for accurate GPR usage. Accuracy results are based on over 50 years of GPR experience.

Q: What size area can be scanned for utilities within one day?

A: The area that GPRS is able to accurately scan within the span of one day varies depending on the project. Vacant lots or open fields can be scanned quickly, due to a low amount of utility congestion. Alternately, a small property in a busy metropolitan area can be more time consuming due to the high utility congestion. The more utilities located within an area the more detail is involved in terms of the scanning process as well as understanding and accurately mapping the site.

Q: Can ground penetrating radar determine the exact size of a subsurface void cavity?

A: GPR equipment can be used to identify the area where a void is occurring and can identify a void’s boundaries. However, the depth from the top of the void to the bottom of the void cannot be accurately measured.

Q: Can GPR be used to locate unmarked grave sites?

A: Yes, ground penetrating radar can be used to determine the location of unmarked graves for site planning purposes. While older grave sites can be harder to locate because of material deterioration, in most cases we can accurately map where these grave sites are found.

Utility Locating

Q: Is GPRS able to distinguish between each type of underground utility which is located?

A: GPRS uses ground penetrating radar and other tools to locate and identify subsurface utilities. In most situations, we are able to locate the utility in question without any problems, although it is not always possible to identify what type of utility it is. When this happens we attempt to trace the utility to a valve, meter, control box, or other type of signifying marker in order to determine the type of utility that has been located. We can also use tools to determine if a line is live and has current running through it. GPRS takes all possible steps in order to successfully locate and identify buried utilities.

Q: Can GPR be used to verify known measurements?

We are able to use GPR to cross-check the measured depth and location of a located utility with existing as-built plans in order to verify the accuracy of plans.

Q: Can you find PVC piping and other non-conductive utilities?

A: GPR scanning is extremely effective at locating all types of subsurface materials including metal, plastic, rubber, optic fiber, cabling, and other non-standard materials. While PVC and other non-conductive materials produce a weaker signal than conductive materials, GPRS Project Managers are skilled at identifying these signals in order to accurately locate buried utilities.

Q: What type of informational output is provided when mapping utilities?

A: Our typical survey output is to flag and paint our findings directly on the surface. This is the most accurate form of mapping when excavation is expected to commence within a few days of service.

GPRS also uses global positioning system (GPS) to collect data points of findings. This data can be used to generate a map, field sketch, Google Earth image, or CAD file to permanently preserve findings for future use. Please contact us to discuss pricing and mapping options that your project may need.