“When they finished doing that last saw cut and touched it to start peeling the pavement off, the whole section dropped into the ground… landed on a high-pressure gas main… you could have parked a full-size truck in the hole.” – Zander Seaman
Big underground water leaks and the devastating erosion they cause don’t appear out of thin air. When you see sensational news stories about sinkholes swallowing cars or whole houses, there were months, years, and even decades of water loss that either went undetected – or ignored – until it was too late.
We recently reported on several large water main breaks that have caused boil alerts in the Detroit Metro area, an SUV-eating sinkhole in Toledo, Ohio, and the long-term closure of an elementary school in Vermont. You can read more on those events, here.
Before each of these newsworthy events, water was flowing, undetected, from damaged or broken pipes, leaking under concrete slabs and asphalt, and into the surrounding soil, following “the path of least resistance” and eroding thousands of cubic feet of soil, undetected.
As veteran GPRS Leak Detection Project Manager, Zander Seaman put it, “So when that water starts to escape the pipe, it takes the path of least resistance. It’s going to follow the trenching path that the water main was installed in, and then go down a lateral line. More often than not, we find [the leaks] surfacing in storm sewer manholes – old brick structures – or sanitary sewer manholes.”
“A lot of times, we’ll find a leak in a city street, which again has no visible surface signs, and we’ll open a neighboring sanitary manhole and see it coming in through the brick structure itself in multiple locations,” Seaman continued.
Matt Piper, GPRS Market Segment Leader for Environmental Services, calls these subsurface pathways “super-highways,” that can carry water (or any liquified substance like oil and gasoline), underneath the infrastructure of an entire neighborhood or community, wreaking unseen havoc.
Unless you have x-ray vision, it is impossible to see what’s happening in any buried utility, but there is technology available to detect slab leaks, subsurface water main leaks, and even smaller diameter lateral line leaks in pressurized pipes.
Acoustic leak detection and leak correlation, the two types of leak detection practiced by GPRS Leak Detection Services, can detect buried leaks regardless of the type of pipe or location, to find small leaks before they become disasters.
“We find the leaks that don’t surface,” said Seaman. “The ones that don’t create any surface signs, no sinkholes. That’s what municipalities find very beneficial and why we do annual surveys for countless municipalities around the United States.”
“When a water main breaks or when a leak is happening, it’s going to wash out a lot of the surrounding fill material around it, which could potentially undermine high pressure gas mains, communications, or high voltage duct banks, which could eventually cause them to fail, collapse, or break,” said Seaman, pointing out that a gas main break can be the next domino to fall to an unchecked pressurized water leak.
“I found a really big leak down in Westchester County in New York, where we were doing a routine leak survey (also known as a water loss survey).” Seaman explained that the county officials treated the large leak as an emergency and worked with him to close a section of road, “because [I’m going to venture a guess that] there’s a major sinkhole underneath.”
The municipality came out and saw cut an 8x12 foot box in the asphalt to check the pipe.
“When they finished doing that last saw cut and touched it to start peeling the pavement off, the whole section dropped into the ground, landed on a high-pressure gas main, and high voltage – not in a duct bank or in conduit – direct buried lines. Nothing got damaged, but it had been completely undermined. You could have parked a full-size truck in the hole. Very major.”
Seaman is based in the Northeast region but reports being flown in for locates all over the country, including Georgia and Brownsville, Texas. We caught up with him when a Big Three auto manufacturer brought him in to check on a water line leak in a fire pump room. While in the area, he also squeezed in a leak detection locate to train some incoming Project Managers at the University of Toledo’s Glass Bowl Stadium.
“If they call us, there’s a reason… they have high water bills, surfacing water, low pressure, or dirty water… They don’t know how to deal with it in house, so the answer is to find a professional who specializes in leak detection and subsurface infrastructure to come out and do a full system survey, like the 1.5 million square foot manufacturing facility we scanned this week.”
Big business is particularly interested in finding and stopping pressurized water line leaks in their facilities for two reasons: safety and their bottom line. GPRS Leak Detection Services are often called in for institutional inspections after a small problem that’s been swept under the rug grows larger. “They lose water pressure… They can’t pass a fire protection flow test… If they open a hydrant on their property, the rest of the system goes to zero PSI,” offered Seaman.
A fire protection flow test, also known as a water flow or hydrant flow test, can be required by insurers, municipalities, and fire districts to determine the readiness of a water system to manage a fire.
“A fire flow test is the measurement of the normal operating pressure in the water mains under normal distribution-flow conditions (static pressure), the pressure in the water mains when the water is flowing during the test (residual pressure), and the flow pressure at the outlet (pitot pressure.” – University of Tennessee Municipal Advisory Service
If a building or section of water infrastructure fails a flow test, not only could the property in question be at severe fire risk, the failure can cost the building or infrastructure owner to lose water insurance credits for fire suppression.
Loss of water pressure isn’t just a huge problem for businesses and subsurface infrastructure. Often, when building facilities like hospitals and prisons, construction plans include back-up power generation and communications, but no one considers what happens when they can’t access clean water or use the plumbing.
“Take a hospital, for instance,” said Seaman. “They’ve got back-up generators for power, they’ve got back-up communication lines coming in… there’s more than one source. But more often than not, hospitals have one domestic water line and one fire protection water main coming in. So, if there’s a major break on the municipality side of the water system feeding their lines and they have to shut down to repair that section of the water main, then the hospital is out of water for who knows how long, until it can be repaired.”
“Another point of reference is a prison,” he continued. You can’t just pick the prison inmates up and move them to a hotel when they’re out of water. There’s again, generally speaking, one water source – one water main – going into a prison. If there’s a major break, what do they do? They don’t have back-up water. [The municipality] can start trucking it in, but not at the rate these larger customers utilize water.”
Beyond the obvious issues with hundreds or thousands of people in need of plumbing and clean water in facilities like these, the fire hazards and erosion issues also escalate exponentially, as previously reported. When dealing with geographically confined populations like these, the risk to human life also escalates.
So, it makes sense to conduct routine water loss surveys, even when none of the usual symptoms of water loss are evident, to find small leaks before they become huge problems.
Click below for information on how GPRS can conduct water loss surveys for your business, facility, or municipality.