If your pool is losing water and no visible leak can be found, the problem is often in the underground plumbing. These leaks cannot be seen and, in most cases, cannot be located without proper diagnostic testing. If you’re unsure how leak detection works or what testing involves, start with our pool leak detection services for a complete overview of the process.
At Atlantic Pool Leak Detection, we specialize in identifying underground plumbing leaks using a combination of pressure testing and advanced acoustic equipment. This process allows us to confirm not only if a pipe is leaking, but also where it is broken..
What is an Underground Pool Plumbing Leak?
An underground pool plumbing leak happens when water escapes from one of the pipes that run beneath the surface, outside of the pool itself. These pipes connect key components like the skimmer, returns, main drain, and cleaner lines, and when something fails, whether it’s a cracked fitting, a joint that has separated, or stress on the pipe from ground movement. Because everything is buried, there are usually no obvious visual signs, which is why these types of leaks often go unnoticed until proper diagnostic testing is performed.
Why Are These Leaks Often Missed?
Underground plumbing leaks are frequently misdiagnosed because they cannot be seen. Many companies rely on visual inspections, dye testing, or pool divers, which can help identify visible leaks but are limited in what they can confirm. While these methods may suggest a problem, they cannot determine whether a plumbing line underground is actually leaking. If the issue is within the plumbing system, it must be pressure tested to be accurately confirmed.
How Underground Plumbing Leaks Are Found
There are two critical steps required to properly identify these leaks:
Pressure Testing
Plumbing lines are tested to determine whether they hold pressure.
- If a line holds pressure, it is not leaking.
- If pressure drops, a leak is confirmed.
This step tells us whether the pipe is leaking. Learn more about this process on our pool pressure testing page.
Pinpointing Underground Leaks
Once a plumbing leak is confirmed, advanced diagnostic methods are used to accurately locate the break underground. This process involves analyzing pressure behavior and detecting subtle indicators within the system to trace the affected line and isolate the failure point.
This process allows us to:
- Trace the issue along the plumbing system
- Isolate the affected section of piping
- Precisely identify the source of the leak
This is how the exact location of the break is determined.
Why Pinpointing Broken Pipes Requires Specialized Experience
Pressure testing can confirm whether a line is leaking, but it does not reveal where the break is located. Accurately pinpointing underground plumbing failures requires the ability to interpret pressure test behavior, apply advanced diagnostic methods beyond basic testing, and understand how plumbing systems behave under leak conditions. This is a highly specialized process that depends on the right equipment, training, and real-world experience, and goes far beyond what most pool service companies are equipped to handle.
Underground Pipe Repair Options: Excavation vs. Pipe Relining
Once an underground plumbing leak has been accurately located, the next step is determining the most appropriate repair method. While traditional excavation remains the most common solution, some underground pool plumbing leaks may also be suitable for pipe relining or epoxy pipe repair, depending on the location of the leak, the condition of the plumbing, and the type of pipe involved.
Traditional Excavation
For many underground plumbing leaks, excavating the affected area is still the most reliable repair method. Because professional leak detection pinpoints the approximate location of the break before digging begins, excavation can often be limited to a much smaller area than if the leak location were unknown.
Accurate leak detection helps reduce unnecessary digging, protects surrounding landscaping and hardscaping, and allows repairs to focus only on the damaged section of pipe.
Pipe Relining & Epoxy Repairs
In some situations, underground plumbing can be repaired without extensive excavation by using pipe relining or epoxy repair methods. These techniques create a new sealed lining inside the existing pipe, helping restore the plumbing while minimizing disruption to the surrounding area.
Pipe relining is not appropriate for every leak. The suitability of this repair depends on several factors, including:
The location of the leak
The condition of the existing plumbing
The type and size of the pipe
Accessibility of the plumbing system
Once the leak has been accurately diagnosed, we can discuss whether pipe relining, epoxy repair, or traditional excavation is the most appropriate solution for your specific pool.
Regardless of the repair method, professional leak detection is always the first step. Before any repair can be recommended, the exact source and location of the underground plumbing leak must be identified.
Real Examples of Underground Plumbing Leaks
These are examples of underground plumbing leaks identified during our leak detection process.
Because these leaks occur below the surface:
- They are not visible from the pool
- They cannot be confirmed with dye testing
- They often go undetected without proper diagnostic testing
Example: Pinpointed the exact location of a broken bottom drain pipe on a commercial pool.
Example: Detected a broken return line and pinpointed the exact spot of the break.
Example: Broken skimmer line – pinpointed break and ready to dig up for repair.
These are the types of leaks that can only be confirmed through pressure testing and then accurately located using specialized diagnostic equipment.
How Pressure Testing Works for Different Pool Plumbing Lines
Pressure testing helps determine whether an individual pool plumbing line is holding pressure or leaking. This is an important distinction in underground pool leak detection because confirming that a line leaks and determining where that line is broken are two separate steps.
Atlantic Pool Leak Detection can isolate and test individual plumbing lines based on the configuration of the pool and the symptoms being investigated.
Skimmer Lines
A skimmer line carries water from the skimmer back toward the pool equipment. If a skimmer line is suspected of leaking, pressure testing can help determine whether the underground plumbing connected to the skimmer is holding pressure.
A leak near the skimmer itself is not necessarily the same as a broken underground skimmer line, which is why testing the plumbing separately can be important.
Return Lines
Return lines carry filtered water back to the swimming pool. Pools may have multiple returns, and a problem with one line does not necessarily mean every return line is compromised.
Individual testing can help isolate a leaking return line before additional underground pool leak detection is performed to locate the break.
Main Drain Lines
Main drain plumbing runs from the deepest portion of the pool toward the equipment system and presents different access considerations than plumbing connected to fittings near the waterline.
When main drain plumbing is suspected, the line can be evaluated as part of the diagnostic process to determine whether it is contributing to the pool’s water loss.
Spa Plumbing
Pools with attached spas may have additional suction, return, jet, or circulation plumbing beneath the pool deck or surrounding property. This makes the overall plumbing system more complex and creates additional potential leak sources.
Testing the relevant spa plumbing independently helps narrow down which part of the system is actually losing pressure rather than assuming the pool and spa share the same problem.
Pressure testing answers an important question: Does this plumbing line leak?
If a line fails, the next step may be pinpointing the location of the underground break. Atlantic Pool Leak Detection uses specialized electronic and acoustic equipment to help determine where a leaking line is broken before repairs are planned.
Can an Underground Pool Leak Be Found Without Digging?
In many cases, the diagnostic portion of underground pool leak detection can be performed without opening the pool deck or randomly excavating the yard.
Pressure testing can first identify which plumbing line is leaking. Specialized electronic and acoustic leak detection equipment can then be used, where conditions allow, to help pinpoint the location of the underground break.
The goal is not to promise that a pool plumbing leak can always be repaired without excavation. Some broken underground pipes still need to be physically accessed for repair. The goal is to gather evidence before anyone starts digging.
Pinpointing the leak first can help limit excavation to the area where testing indicates the break is located rather than opening multiple sections of patio, replacing an entire line unnecessarily, or digging based on guesswork.
Learn more about our non-invasive pool leak detection process and how Atlantic Pool Leak Detection approaches difficult-to-locate water loss.
What Happens After an Underground Pool Leak Is Pinpointed?
Once testing has confirmed a leaking plumbing line and the underground break has been pinpointed, the appropriate repair depends on the location, pipe condition, accessibility, and type of failure.
Some pool pipe leak repairs require targeted excavation to expose and replace the damaged section. Other situations may have repair options that do not require conventional excavation.
The important part is determining what actually failed and where it failed before deciding how to repair it.
If testing also identifies a leak involving an accessible underwater fitting, liner, light, or another submerged component, certain problems may be addressed through underwater pool repairs without draining the entire pool.
Pool Pipe Relining and Epoxy Repair
Traditional underground pool plumbing repair often involves excavating the area above a broken pipe so the damaged section can be accessed. Depending on the type and condition of the plumbing, however, some leaks may be candidates for alternative repair methods such as pipe relining or epoxy-based repair.
These methods are designed to address certain plumbing failures from within the existing line, potentially reducing the amount of excavation required.
Pipe relining is not automatically the right solution for every leaking pool line. The location and nature of the failure, condition of the existing pipe, accessibility, and overall plumbing configuration all matter when determining whether a particular repair method is appropriate.
This is another reason accurate pool pipe leak detection should come before selecting a repair method. First determine which line leaks and where the failure is located. Then determine which repair option makes sense for that particular pipe.
Homeowners searching for pool pipe relining near them should be cautious of choosing a repair method before the underlying plumbing problem has been properly diagnosed.
Do You Receive a Written Pool Leak Detection Report?
Homeowners frequently want documentation showing what was tested and what was found, particularly when the results will be shared with a pool contractor, plumber, insurance company, home buyer, or another party involved in the repair.
If documentation is important for your situation, ask about your specific needs when scheduling so you can confirm what information can be provided following the inspection.
Underground Pool Leak Detection in New Jersey
Atlantic Pool Leak Detection specializes in diagnosing pool plumbing leaks throughout New Jersey. Our process is designed to determine which plumbing line is leaking and, when possible, pinpoint where the underground failure is located before excavation or repair begins.
We work with underground return lines, skimmer plumbing, main drains, spa plumbing, cleaner lines, water-feature plumbing, and other pool-related lines depending on the configuration of the system.
If your pool is losing water and you suspect a buried pipe, start with diagnosis rather than excavation. Visit our New Jersey pool leak detection service area to see the counties and communities we serve.
Why Proper Leak Detection Matters
Without accurate leak detection, homeowners often end up repairing the wrong area, digging unnecessarily, hiring multiple companies, and spending significantly more money than needed. Proper testing and precise leak location ensure the issue is addressed correctly the first time. You can see how this fits into our full non-invasive leak detection process.
Can Pool Divers Locate Underground Plumbing Leaks?
Pool divers play a role in identifying visible leaks, but they cannot test or locate underground plumbing issues. Their work is limited to visible areas and may involve dye testing, but they cannot pressure test plumbing or pinpoint underground pipe breaks. Professional leak detection, on the other hand, confirms leaks through pressure testing and the use of specialized diagnostic equipment to locate issues that cannot be seen. This allows underground problems to be identified accurately. If the leak is underground, it requires proper diagnostic testing, not just visual inspection.
When to Suspect an Underground Plumbing Leak
You may have an underground plumbing leak if you notice ongoing water loss that cannot be explained by evaporation, especially after performing a basic check like a bucket test. Changes in water loss depending on whether the pump is on or off can also point to a plumbing issue. Other common signs include air bubbles coming from return jets, difficulty maintaining pump prime, and wet or soft areas developing near the pool. These symptoms often indicate a problem within the underground plumbing system rather than something visible inside the pool itself.
Frequently Asked Questions
What causes underground pool plumbing leaks?
Underground pool plumbing leaks are typically caused by cracked fittings, separated joints, or pipe damage due to ground movement, age, or pressure. Freeze and thaw cycles in New Jersey can also contribute to pipe failure over time.
How do you find a leak in underground pool pipes?
Underground leaks are found using pressure testing to confirm which line is leaking, followed by specialized diagnostic methods to pinpoint the exact location of the break without unnecessary digging.
Can underground pool leaks fix themselves?
No. Underground leaks will not fix themselves and typically get worse over time. What may start as minor water loss can lead to larger structural or plumbing issues if not properly addressed.
How serious is an underground pool leak?
Underground leaks can lead to continuous water loss, soil erosion, and potential damage to surrounding areas such as patios or decking. Left untreated, they can become more expensive to repair.
Will I see signs of an underground pool leak?
Not always. Many underground leaks show no visible signs. In some cases, you may notice water loss, air in the system, or soft spots in the yard, but proper testing is required to confirm the issue.
Do I need to dig to find an underground pool leak?
No. Proper leak detection identifies the location of the leak before any digging is done. This ensures only the necessary area is opened, avoiding unnecessary disruption.
Can a pool diver find underground plumbing leaks?
No. Pool divers are limited to visible areas inside the pool and cannot test or locate leaks in underground plumbing lines. These types of leaks require pressure testing and specialized diagnostic equipment.
How long does it take to locate an underground pool leak?
The time can vary depending on the complexity of the pool system, but most leak detection processes are completed within a few hours. Additional time may be needed if multiple lines require testing.
What happens after an underground leak is located?
Once the leak is accurately located, the next step is determining the appropriate repair. This typically involves accessing the affected section of pipe and making targeted repairs based on the type of failure.
When should I have my pool checked for an underground leak?
You should consider professional testing if your pool is consistently losing water, especially if the loss cannot be explained by evaporation or basic testing methods.
Call Atlantic Pool Leak Detection
If you suspect your pool has an underground plumbing leak, the first step is getting an accurate diagnosis, not guesswork. Atlantic Pool Leak Detection can identify not just if your pool is leaking, but exactly where the leak is located. Contact us to locate your broken underground pipe or call 732-333-3304.
Learn how we confirm plumbing leaks through pressure testing and accurately diagnose underground pipe failures.
