Utility Locating Blog

How to Find a Leak in a Water Pipe

locate water leak

Our clients often call us asking if we can locate a water leak with our utility locating equipment. While this technology doesn’t give us the exact location of the leak, there are different ways to detect it.

According to the Alliance for Water Efficiency, the typical home loses 2,000 to 20,000 gallons of water per year due to leaks.  Some leaks go undetected for years because the source of the leak is not visible. Such is the case of a leak in a supply pipe that is buried at least 3 feet underground.

When our analyst arrives on your site, he/she will use the utility locating equipment (pictured above) to scan for the water line. On the screen, objects like this line will show up as a hyperbola. From that initial reading, the analyst can follow the path of the line and mark it as he/she goes.

For some clients, this is very useful for inspection. They know exactly where their water line is, so they can excavate and make sure that everything is in good condition. For most clients, they want to know if there is a leak. And if so, where is it exactly?

Our analyst would look for signs of wet or damp soil, this indicates a possible leak and the location of it. When we scan over the leak, the wet soil will typically show up on the screen as a bright reflection. This is an indicator that the equipment has detected a possible water leak.

Do you suspect that you have a water leak? Our GPR analysts are ready to assist you! Contact us for a consultation.

November 10, 2017

FAQ – Concrete Scanning and Utility Locating

There is usually a lot to cover when deciding to utilize concrete scanning or utility locating services. We put together this list to answer your questions and guide you in the right direction for your project.

How long will the service take?

This all depends on your needs, and it varies from project to project. For both concrete scanning and utility locating many variables come into play. Age of concrete, moisture content of the ground, obstructions in the path of utilities, wire mesh and congested rebar, just to name a few. The best way to determine the estimated completion time of the scan or the locate is to contact us. Being prepared with as much information about the area as possible will aide in our estimation time.

You don’t offer your services in my area, can you travel to me?

We can absolutely travel to you. Our analysts frequently travel to where they are needed throughout the United States. Specific pricing for travel time can be discussed with you, give us a call or send us an email.

Can you locate water leaks?

Our utility locating equipment won’t specifically locate a water leak itself. However, we can look for signs that indicate a possible leak. For example, the analyst would look for signs that would be indicative of damp soil. We also trace out water lines so you know exactly where to dig for inspection.

Can you scan while it’s raining?

When using GPR equipment, the collected data from wet surfaces is not accurate.  This means that the results of the service won’t give you the best framework to follow before cutting, coring, drilling, or performing any type of excavation or trenching. Moreover, we can’t get our equipment wet.

Can you scan all concrete?

We scan any concrete slab or structural component as long as it is three months old. It is important to note that our equipment has a scanning depth of 16 inches, or 32 inches if we have access to both sides of the slab or surface.

How soon can I get a report of the findings?

Our analyst will provide a report of the findings after he/she completes the scanning and marking any found objects. This is included in all completed scanning and locating projects.

Do you offer any additional reports?

You can request an additional report, called a formal report, that includes pictures, a summary, and 3D scan. This report, comes at an additional cost and may take up to eight hours to complete. Also, the analyst would complete the report off site and email it to you.


If you have any more questions, or are ready to schedule a scanning or utility locating service, please call us at 844-211-5300 or send us an email at gpr@penhall.com


October 6, 2017

The Use of Utility Locating Services in Hurricane Harvey’s Relief Efforts

Texas utility locating

The Use of Utility Locating Services in Hurricane Harvey’s Relief Efforts

Last week, Penhall Technologies had the opportunity to participate in the efforts for those affected by Hurricane Harvey. We performed our services at the NRG Center in Houston, which hosts the largest emergency shelter in the city.

First of all, the FDNY Incident Management Team called our Houston office for utility locating services. The New York Fire Department hired them to set up a 40’ x 100’ tent. This tent would function as the main location to serve meals to truck drivers delivering supplies for the emergency shelter itself. The NRG stadium expected over 250 truck drivers coming into Houston to deliver these supplies.

Before installing the tent, they decided to scan the proposed location for it. This was about 85,000 square feet. The scan would ensure that the client could install the tent safely, without striking any subsurface hazards. The location for the scanning took place in the parking lot.

Two of our local Houston analysts scanned for all utilities under the asphalt. They used Ground Penetrating Radar with the SIR 4000 antenna and electromagnetic detection technology through the use of the RD 7100 wand. Then, they found and marked out two utility lines. These were a sewer line and a power line.

These lines did not present any issues for the client. The analysts advised to stay a minimum of 3 feet away from the marked utilities. Due to this, the client had plenty of room left to drive the tent’s posts into the ground away from the marked lines.

Harvey utility locating

“Being able to help my community here in Houston is beyond rewarding. Helping with the utility locate at NRG makes me feel as if I’m having a direct effect on the city that I grew up in. The fact that I can give back and aid my fellow Houstonians in a time of adversity is indescribable,” said GPR analyst Jacob Paddock.

The FDNY Incident Management Team was pleased with the locating services. Since then, we have performed another locate for them in Rosharon, Texas before the installation of more tents. Their needs change daily. Therefore, they have been in constant contact with Penhall Technologies.

As a team, we are proud that our services played a role in the relief efforts. In addition, Penhall will continue to assist in any efforts that aid Texas’ recovery. To donate to those affected by Hurricane Harvey, click here.

September 8, 2017

Case Study – Utility Locating Using GPR and Electromagnetic Detection

private utility locator

GPR analyst using the RD-7000 for utility locating

When conducting utility locating services, Penhall Technologies uses two types of technology: Ground penetrating radar (GPR) and electromagnetic detection (EM). Both of these are great resources for locating underground utilities.

GPR locates underground utilities by emitting radar waves into the ground. These waves pass through the substrate and reflect off of objects that vary in dielectric from that of the surrounding earth. Ground penetrating radar works best when you need to locate: buried pipes, cables, underground storage tanks, etc.

On the other hand, electromagnetic induction detects electromagnetic fields. A magnetic field occurs when a current is running through a transmitting line such as an electrical cable or communication line. The EM unit can detect both passive and active signals.

A passive signal is when a utility, such as an electrical line, is currently turned on and is generating an electromagnetic field. An active signal is when a line is not turned on, and a temporary tone is induced into it. This creates a temporary electromagnetic field. The, the EM unit can detect this field.

Recently, our analyst put to use both technologies for a utility locating job. An electrical company contacted us for a project at a medical facility in the city of Seattle, Washington. The electrical company was in charge of rerouting electrical lines through the parking lot of the medical facility.

utility locating

Analyst marking underground utilities

The analyst initiated the scanning and set a dielectric based on the known soil conditions of the area. He conducted GPR first, utilizing the GSSI SIR3000/400MHz antenna combo. The analyst knew that once he completed the locate , the cut and excavation performed by Penhall Company would not go any deeper than three feet. The survey covered not only the requested area, but a much larger area as well to confirm the location of all subsurface hazards.

The analyst marked out several suspected utilities and an area of shallow root systems, despite needing to work around parked vehicles, tight quarters, and raised landscaping beds.

The analyst used electromagnetic detection equipment after the scan. He swept the area with the RD-7000 to ensure maximum accuracy. From this, the analyst located one additional electrical utility. This particular utility was either too small or too deep to see with the GPR equipment. This is why we provide our analysts with both technologies. It makes us the ideal private utility locator.

Penhall Technologies employs multiple technologies for your utility locating needs, making sure that you finish your projects safely and on time.

August 11, 2017

What to Expect – Home Utility Locating

Our analyst performing utility locating services

When you started your home project, you didn’t imagine that you would need our private utility locating services. To ensure that you don’t hit any utility lines, it is important to scan the area first. Damaging utility lines can result in loss of that particular utility. It can also cause injuries for you or the workers hired to do the cutting, trenching, or digging.

For home owners, utility locating can be a first and only experience. This means that it can be hard to know exactly how to proceed. The first step would be to contact 811“call before you dig”, the nationwide public utility locating service. They can locate all public utility lines, from the street to the meter only. If they can’t locate what you need, that’s when we, a private utility locator, come in.

When you call Penhall Technologies or request to quote, it is best to be prepared with essential information regarding the project. This will allow us to provide the best service and accurate pricing. It is important to know the measurements of the area, the type of surface (dirt, asphalt, concrete), and the location (indoors or outdoors). If possible, provide the utilities we may be looking for (water, gas, electrical, sewer) and how many utilities may be running through the area. We will also ask how many locations you need scanned, and what is the private line locating in preparation for.

Example of utility markings at a home


Once the analyst arrives at your home, they will be up to date with the needs and specifications of your project. They will bring two types of equipment to offer you the most accurate reading. A benefit of choosing Penhall Technologies as your private utility locator is that we carry various types of equipment. This is in case one method is not enough to find underground lines. In rare cases, the reading can be inconclusive and show highly congested results.

After the analyst completes the scan, he/she will mark the approximate utility locations with varying colors of spray paint, flags, or both to highlight that location. You can find out what each color means for utility marking in our guide here.

Equipment screen showing utility locating data

Before the analyst marks the utilities, the display screen of the equipment won’t mean much to the common eye. Our expert analysts will be able to identify lines and to differentiate between them based on the data and on physical cues, such as a meter. Now with the analyst’s markings and field report, you can make an informed decision of where to cut, trench, or dig. By deciding to scan first, you will safeguard that your home project is completed safely.

July 21, 2017

We Scan For

  • Pipes and Conduits
  • Post-Tension Cables
  • Utilities and Live Wires
  • Rebar and rebar patterns
  • Voids within the Concrete
  • Structural Integrity of the Concrete