Signs the main line is leaking
Underground leaks rarely announce themselves. These are the signs homeowners notice first.
- A water bill that rises with no change in how you use water.
- Soggy or unusually green grass in a strip between the meter and house.
- A damp spot in the yard, driveway or basement wall where the line enters.
- Low water pressure throughout the house.
- The sound of running water when everything is off.
- A meter dial or leak indicator that moves with fixtures closed.
One sign alone does not prove a leak. Together, especially a moving meter and a wet yard, they point to the main line.
Run a meter test
- Turn everything off. Close all faucets, stop the dishwasher and washer, and make sure no one flushes. Turn off the ice maker.
- Find the meter. It is usually in a ground box near the curb or street. Lift the lid carefully and watch for insects.
- Read the leak indicator. Many meters have a small triangle or wheel that spins when any water flows. If it moves with all fixtures off, water is going somewhere.
- Note the reading and wait. Write the numbers, wait 30 minutes to an hour without using water, and read again. A change confirms a leak.
- Close the house valve and retest. If the meter stops once the main valve at the house is shut, the leak is inside the house. If it keeps moving, the leak is in the line between the meter and the house.
Reading the meter results
| Meter result | Likely meaning | Next step |
|---|---|---|
| Stops when house valve is closed | Leak is inside the house | Check toilets, fixtures, water heater, then call for leak detection |
| Keeps moving with house valve closed | Leak is on the line from meter to house | Call a plumber, and the utility to ask about ownership |
| Does not move at all | No steady leak right now | Check for a slow leak by testing overnight |
| Moves slowly | Possible toilet flapper or small leak | Dye test toilets, then retest |
Who handles what in Hazelwood
Missouri American Water supplies water in Hazelwood, as the city's own site notes. For questions about the meter and where the utility's piping ends, call customer service at 866-430-0820, open weekdays from 7 a.m. to 7 p.m. The utility is the right call first if the leak looks to be at or before the meter. A private line on your side is generally the owner's to fix, so ask where the utility's responsibility ends before you hire anyone.
Cold weather makes this more than a theory. The City of Hazelwood lists a frost depth of 30 inches and a winter design temperature of 2 degrees F, and in January 2024 Missouri American Water crews responded to 16 main breaks in one day. Know where your shutoff is before the next freeze, and call 811 before any digging to find the buried line.
Water service lines are commonly polyethylene pipe made to the AWWA C901 standard, and drinking water piping should be certified to NSF/ANSI 61. Knowing the pipe material helps a plumber choose the right locating method and repair.
How a plumber pinpoints the leak
Once the meter test shows a leak on your side, the next job is to find the spot without digging up the whole yard. A plumber uses tools that listen to the pipe or track the water. Each has strengths, and each has limits.
Acoustic listening picks up the hiss of water escaping under pressure. It works well on metal pipe and in quiet conditions, and less well on plastic pipe or on a noisy street. Pressure testing isolates sections of the line to show which one loses pressure. Thermal scanning can help where a hot line runs, but it rarely helps on a deep cold supply line.
We cannot promise a single tool will find every leak. In some cases the plumber narrows the area, then opens the ground at the most likely spot. Our leak detection service combines the tools to keep digging to a minimum.
What affects the price
We do not give dollar figures for leak detection because no reliable national range is available. The cost depends on what the work involves, and we state a clear price before work starts.
A leak you ignore does not stay small. The water bill you pay while it runs is one cost, and soil washout near the foundation is another.
When to call a plumber
Call when the meter moves with the house valve closed, when you see water bubbling in the yard, or when pressure drops with no clear cause. Shut the main valve at the house if water is pooling. If the water is coming from the meter box itself, call the utility.
A line that has leaked in one spot often has other weak sections, especially on older pipe. A water line repair or replacement fixes the section or the whole run. When the leak is inside the walls, burst pipe repair covers the emergency fix, and repiping handles a house whose plumbing keeps failing. We serve homes in Florissant and Bridgeton too.
For a leak that is flooding the property, use the 24/7 line. We offer same-day appointments when available.
Frequently asked questions
Look for a rising bill, a wet yard strip, low pressure and a water meter that moves with every fixture off. Run a meter test to confirm.
Turn off all water use, read the meter, wait 30 to 60 minutes without using water, and read it again. A changed reading means a leak.
The utility handles its own piping up to the meter, and the private line on your side is generally the owner's. Call Missouri American Water at 866-430-0820 to ask where responsibility ends.
Yes. Water escaping underground still passes through the meter, so you pay for it even though you never see it.
Yes. Close the main valve at the house if water is pooling or the leak is large. Then call a plumber.
Frozen ground shifts and pipes contract. Hazelwood's published frost depth is 30 inches, so lines above that depth are exposed. Many leaks show up during thaw, as in the January 2024 cold snap.
Questions about your situation? A licensed plumber is on the line any hour.
Call (855) 575-2890