Surge in underground leaks across San Ramon Valley possibly linked to earthquake swarm

Stephanie Sierra Image
Thursday, April 16, 2026 8:48PM
Surge of busted pipes in East Bay possibly linked to earthquake swarm

SAN RAMON, Calif. (KGO) -- Weeks after a swarm of earthquakes rattled the San Ramon Valley with little apparent damage, leak specialists are warning of a surge in busted pipes believed to be linked to the quakes, creating underground leaks across the East Bay.

Many viewers initially reported minimal impacts. Now, professionals who track water loss say they are responding to an unusually high volume of calls for hidden leaks beneath homes and businesses.

"Oh my God, there's far too many. I mean, we have cases that have been running for two months, three months. A high-water bill of $2,000!" said Steve Mayer, owner of USA Leak Detector. "Extremely high calls in this area."

Experts say the exact cause is still unclear, but their leading theory is seismic activity.

MORE: Swarm of over 30 earthquakes strike near San Ramon, strongest being 4.2: USGS

A 4.2 earthquake struck near San Ramon Monday morning, following a 3.8 quake and a string of temblors, the U.S. Geological Survey said.

Will Chau recalls waking to his San Ramon home shaking during back-to-back earthquakes in one day last month.

"Boom, boom, boom! There were like five or six different earthquakes, and I swear to God the whole house shook!" Chau said.

At first, Chau noticed no visible damage. But days later, he began seeing signs of water he initially thought came from his sprinkler system.

"I woke up in the morning, and yeah, I thought it was raining from the ground up. I was like, 'Oh wow. Act of God,'" Chau said.

Later, the water kept appearing at different times.

"Then I came home, it's still working... sprinkler... different time of the day... I'm chill with that," he said.

MORE: Prepare NorCal: Disaster Preparedness Resources

When the problem continued, Chau contacted USA Leak Detector.

Mayer said his company is seeing a spike in service calls throughout the East Bay, particularly in Pleasanton, involving both residential and commercial properties.

"We look like the Ghostbusters when we come to properties," Mayer said, referring to the equipment loaded in his truck. "We're talking about at least two to three calls a day."

Many of the affected homes are relatively new, about 15 years old.

Mayer said his technicians typically identify causes such as aging pipes, tree roots or erosion. Recently, however, crews are encountering complete breaks without an obvious explanation.

"Mostly its roots. These days we can't find out why it happened. It's just a complete break. So that's alarming," Mayer said. "We're all suspecting it's the earthquakes."

To help prevent severe water bills, Mayer recommends installing an automatic water shutoff valve, including systems that can be controlled through a mobile app.

"It's an app that you use with your phone so you can set it to where you want to set it," Mayer said. "Once it sees the abnormal use, it'll shut off the water."

Homeowners often miss warning signs.

"Red flags: water company sending notices to the customer and the customer not replying back until they see the heavy water bill," Mayer said.

He says he sees that almost every day.

Another major warning sign is movement at the water meter.

"A meter spinning that dramatic and nobody is using the water. That's the number one indication you need to call your local leak detection company," Mayer said.

USA Leak Detector uses tools including acoustic listening devices that track water up to eight feet underground and thermal imaging that can locate hot-water leaks or moisture buildup within minutes.

In Chau's case, inspectors found his sewer lines had been completely severed, despite being rated for decades of use.

"So, very alarming. This was a complete break of the sewer line. Jackhammer, trenching, it's like having a heart attack!" Chau said.

He is now installing earthquake-resistant piping to reduce future risk.

"I'm a big prep guy, it's better to be safe than sorry," Chau said.

Mayer recommends flexible PEX piping, which can move as the ground shifts. He also advised homeowners to act quickly if they suspect damage, noting insurance companies often allow only a limited window - as short as two weeks in some cases - to file a claim.

The message from experts is clear: even without visible damage after an earthquake, homeowners are urged to watch for warning signs and investigate quickly.

Take a look at more stories and videos by 7 On Your Side.

7OYS's consumer hotline is a free consumer mediation service for those in the San Francisco Bay Area. We assist individuals with consumer-related issues; we cannot assist on cases between businesses, or cases involving family law, criminal matters, landlord/tenant disputes, labor issues, or medical issues. Please review our FAQ here. As a part of our process in assisting you, it is necessary that we contact the company / agency you are writing about. If you do not wish us to contact them, please let us know right away, as it will affect our ability to work on your case. If we are able to assist, we will reach out to you in response.

Now Streaming 24/7 Click Here


Copyright © 2026 KGO-TV. All Rights Reserved.