Water leaks can cause severe problems for any home or business. A leaky pipe can lead not only to adverse effects on your water supply but also to flooding and devastating water damage. Therefore, you need to detect a leak early on before it has a chance to worsen.

Unfortunately, pipes aren’t always in plain sight, and with an underground pipe, finding a leak becomes significantly more challenging. So, how do you find a leak in an underground pipe? Such a challenge requires professional knowledge, experience, and equipment.

At Works Plumbing, our experts know the ins and outs of locating and fixing leaks. We’ll tell you everything you need to know about underground pipe leaks, including their causes and consequences, common signs that they exist, and methods of detection. If you believe you have an underground pipe leak, call us right away at 650-414-7261 for professional leak detection and plumbing repair in Pacifica, CA.

Causes of Underground Pipe Leaks

You will find a variety of reasons for an underground pipe to leak. Some common causes of underground pipe leaks include:

Ground Movement

Some natural disasters, such as earthquakes and tremors, cause the ground around the pipes to shift. Ground movement puts tremendous pressure on the pipes, forcing them to shift with the soil. As pipes move out of their original place, they can split and crack, creating leaks.


Chemicals may be present either in the soil or in the water running through the pipes. Over time, these chemicals can corrode the pipes and create holes or cracks where water seeps out. Corrosion is especially prevalent in pipes that consist of metals such as copper or brass.

Tree Roots

Tree roots enter underground pipes through small cracks or holes. As the roots grow, they enlarge the gap where they entered and create significant leaks.

Temperature Drops

When the temperature drops significantly and quickly, it can cause the water inside underground pipes to freeze. The freezing water expands and can burst through the pipes, creating large leaks.

Wear and Tear

As pipes age, they suffer natural wear and tear. The pipes weaken and can become rusty, causing them to give way, crack, or break.

Poor Installation

If an inexperienced pipe installation company lays your underground pipes poorly, they’ll become more susceptible to numerous issues that cause leaks.

How an Underground Pipe Leak Can Affect Your Home or Business

Typically, water leaks relatively slowly from underground pipes. So it may seem that underground pipe leaks are minor issues that don’t require immediate attention. However, failure to address an underground water leak can result in several problems that adversely affect your home or business, including:

  • Flooding
  • Structural water damage
  • Fires
  • Costly pipe repairs and replacement
  • Unusually high water bills 

Common Signs of an Underground Pipe Leak

Because an underground pipe leak can damage your home or business, you need to address it as soon as possible. The sooner you call the experts at Works Plumbing, the quicker we can resolve the leak and reduce the chances of significant issues. 

Since you can’t see underground pipes, it’s crucial to understand how you can diagnose a leak. If one of your pipes does have a leak, it will likely create minor issues within your home or business. Look for the following signs of an underground pipe leak, and call us if you notice any:

Spikes in Your Water Bills

If you have an underground pipe leak, you’ll pay for all the water that exits the pipe without being able to use it. As a result, your water usage and water bills will suddenly spike. If you see a spike in your monthly water bills, you can do a test to determine if an underground water leak has caused the increase.

First, shut off the main water valve to your home or business, locate your water meter, and write down the numbers. Leave the valve off for an hour or so, then come back to the water meter. If the numbers on the water meter reading moved while the water valve was off, then you likely have an underground pipe leak.

Strange, Unpleasant Odors

Underground pipe leaks often result in strange, unpleasant odors in and around homes and businesses. Leaks can create mold or cause underground particles to enter your pipes. This results in strong odors that begin outside your property and can eventually enter through your sinks and drains.

Hissing and Splashing Sounds

Occasionally, you’ll be able to hear a leak in your underground pipe. Decreased water pressure often creates hissing sounds, while water flowing abnormally around the pipe can cause splashing sounds. 

Decreased Water Pressure

Several factors, including underground pipe leaks, can cause the pressure in your water supply to decrease.

Dirty, Contaminated Water

The cracks or holes that cause leaks in underground pipes also create entryways for dirt, grime, and even rust. Such sediments can flow through your pipes and into your water supply, presenting potential health risks.

Wet Spots in Your Yard

Underground pipe leaks that occur in the areas surrounding your home or business can lead to wet spots. Over time, the moist ground may weaken your property’s foundation.

Cracked or Warping Pavement

An excess of water underground can cause the pavement around your home or business to crack and warp. If you see bulges, potholes, or other strange pavement formations, you may have an underground pipe leak.

Finding a Leak in an Underground Pipe

Now that you know what signs to look for, how do you find a leak in an underground pipe? If you notice any of the above signs and suspect you have an underground pipe leak, you’ll need a professional plumbing company to inspect your property’s pipes. At Works Plumbing, we use specialized detection equipment that allows us to find leaks in underground pipes without causing damage to your home or business.

Instead of digging through the earth to reach your pipe, which causes disruption and involves additional expenses, we can detect leaks without physically accessing your underground pipes. Some of the ways we do this include the following:

Thermal Imaging

Using a camera with thermal imaging capabilities, we can detect differences in temperatures at the surface above your pipes. With an underground pipe leak, the surface temperature above the leak should be lower than the surface around it.

Trace Gas Leak Detection

During trace gas leak detection, we pressurize trace gas through your pipes. We then use a gas detector to see if and where the gas escapes to the surface. Wherever the gas does leave the pipes will indicate a leak.

Trace gas detection allows us to pinpoint the location of the leak, as we’ll see the exact spot where the gas exits the pipes. Further, trace gas is non-toxic and will harm neither your property nor the earth around it.

Acoustic Leak Detection

We previously mentioned that leaks often make hissing or splashing sounds as the water escapes or flows around the pipes. Acoustic leak detection involves using sensitive microphones to listen for these sounds and locate the leak.

Leak Noise Correlation

Leak noise correlation involves a relatively more complex method for detecting a leak in an underground pipe. This detection method utilizes electronic devices, and we use it for underground leaks that prove especially difficult to locate.

First, we place two sensors on the pipe, one on either side of the most likely leak location. The sensors record any signs that the pipe emits and transmits them to a radio processing system. The system takes the sounds and uses algorithms to determine the precise location of the underground pipe leak.

Resolving the Underground Pipe Leak

Once you know the location of the leak, you’ll need to determine if the responsibility for the pipe leak belongs to you or the city. Leaks in the vicinity of homes and businesses typically fall under personal ownership, while those on the street section usually belong to the city. The city zoning office can tell you who has the responsibility for repairing the underground pipe leak.

If you are responsible for repairs, your trusted plumbing professionals at Works Plumbing can help. We provide trenchless pipe repair and water line repair and replacement. We’ll safely, efficiently, and effectively fix your pipe leak issues to restore operations in your home or business. 

Call Works Plumbing Today To Schedule Water Leak Detection Service

Underground pipe leaks can be more damaging than you realize. The longer you wait to find and address a leak, the more likely severe issues, such as flooding, structural water damage, and costly expenses, will arise.

Hopefully, we’ve answered the question: how do you find a leak in an underground pipe? We also hope you understand what signs to look for that indicate potential leaks. Works Plumbing has the experience, knowledge, and equipment to find and fix your pipe leak problems.

Don’t let leaks affect your home or business. Call Works Plumbing today at 650-414-7261 to schedule water leak detection.

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