Start with the water meter test
The meter is your most honest leak detector. Turn off every fixture, appliance and ice maker in the house, then find the meter and look at the leak indicator. It is often a small triangle or dial that spins when any water moves.
If it moves with everything off, water is going somewhere. Write down the reading, wait an hour without using water, then read it again. A change means a leak between the meter and your fixtures.
The meter test, step by step
Follow this sequence so the result means something.
- Shut off all water use, including the washer, dishwasher and the ice maker.
- Make sure no toilet is running and no one flushes during the test.
- Find the meter, lift its cover if needed, and note the digits and the small leak dial.
- Wait at least an hour, ideally two, without touching any tap.
- Read the meter again. Any change confirms a leak.
- Close the main shutoff valve and read again after the wait. If the dial stops, the leak is inside the house. If it keeps moving, the leak is between the meter and the shutoff.
A moving meter with the main closed points to the service line. See water service line repair for how those leaks are located and fixed.
Toilet leaks and the dye test
A silent toilet leak can waste a lot of water. Drop a few drops of food coloring or a dye tablet into the tank and wait 15 minutes without flushing. If color appears in the bowl, the flapper or fill valve is leaking.
Flappers wear, harden and warp over time, and mineral buildup keeps them from seating. Replacing a flapper is a simple fix. If the dye stays put but the meter still moves, look elsewhere.
Think you have a hidden leak?
Call the 24/7 dispatch line, tell us what the meter and the walls are showing, and we will plan the right test.
Call (973) 488-5410Signs of a leak and where they point
Symptoms help narrow a leak before any tools come out.
| What you notice | Likely source | First check |
|---|---|---|
| Water bill rises with no change in habits | Toilet, supply line or irrigation | Meter test and toilet dye test |
| Musty smell or peeling paint | Slow leak in a wall or under a floor | Moisture meter on the wall, then the room above and below |
| Warm spot on a floor | Hot water line under a slab | Check the heater, and listen near the floor |
| Low water pressure | Leak on the supply or partly closed valve | Compare pressure at several taps and read the meter |
| Water stain on a ceiling | Supply, drain or fixture above | Check the bathroom above, and the tub overflow and seals |
One symptom can have several causes, so combine at least two tests before opening a wall.
Moisture meters, thermal cameras and listening gear
A pin or pinless moisture meter reads the dampness of drywall, wood and tile. A thermal camera shows temperature differences, which can reveal a hot line running through a cold slab or a wet spot cooling the surface. Neither one gives a final answer by itself, since condensation and sun can fool them.
Acoustic gear listens. A ground microphone or a contact listening device picks up the hiss of pressurized water escaping from a pipe. A plumber closes valves, listens along the route and narrows the leak to a few feet before cutting.
Pressure tests and tracer gas
A pressure test isolates a section of pipe, fills it and watches a gauge. If the pressure falls, the section leaks. This works well for supply lines and for finding which leg of a branch is bad.
For hidden leaks that sounds and heat miss, a tracer gas mix of hydrogen and nitrogen can be injected into an isolated line. A sensor at the surface finds where the gas escapes. It is a professional method that avoids tearing up finished floors. Our leak detection work uses these tools to avoid unnecessary demolition.
When a leak is also a safety issue
If water touches electrical panels, outlets or appliances, turn off the power at the breaker only if you can reach it dry, and call a professional. A ceiling that bulges with water can collapse. Shut the main valve and, if possible, drain the pipes by opening low taps.
Slow leaks are less dramatic but cause mold and rot over time, so do not wait for a stain to spread.
Who to call about leaks in Kearny and nearby
In Kearny, the Town of Kearny Water Department runs the system and Veolia handles meter reading and billing. For water main breaks, leaks, broken hydrants and service disruptions, call Veolia at (201) 955-7406. It is staffed weekdays 8 am to 4 pm, with a 24/7 answering service nights, weekends and holidays. Billing and meter questions go to 1-800-242-5695.
In North Arlington, water comes from the Passaic Valley Water Commission, whose customer line is 973-340-4300. In Harrison, the Harrison Water Department is at 973-268-2468. If a leak is between the meter and your house, it is generally the owner's to fix, and a plumber can confirm where it sits.
As a general rule, a meter-based test is the most reliable way to confirm a leak, since the meter measures what the house actually uses. For billing questions the Kearny contact is Veolia at 1-800-242-5695.
Source: Kearny Water Department page, Veolia contact information, PVWC customer line and Harrison 2023 Consumer Confidence Report
What to do once you find the leak
Shut off water to the fixture or the main, take photos of the damage for your records, and dry the area quickly. Fans and open windows help, and wet insulation or drywall often has to be removed to prevent mold.
Call a plumber for repairs that require opening walls or replacing pipe. Homes in North Arlington and Harrison often have older supply piping, and a leak in one spot can signal wear elsewhere. If several leaks appear, discuss repiping rather than patching.
Frequently asked questions
Turn off all water use, note the meter reading and leak dial, wait an hour without using water, then read again. Any change means a leak. Closing the main valve and checking again tells you if it is inside or outside the house.
Add a few drops of food coloring to the tank and wait 15 minutes without flushing. If color shows in the bowl, the flapper or fill valve is leaking. Replacing the flapper is a common fix.
Often yes. Moisture meters, thermal cameras, acoustic listening, pressure tests and tracer gas narrow a leak to a small area. Some jobs still need an access opening, but it is kept as small as possible.
Call Veolia at (201) 955-7406. It is staffed weekdays from 8 am to 4 pm, and the same number goes to a 24/7 answering service at night, on weekends and on holidays.
Not always. Seasonal use, guests, irrigation and a new appliance raise bills. A leak is likely if the meter moves with everything off. For billing and meter questions in Kearny, call 1-800-242-5695.
It can be. Slab leaks erode soil, damage flooring and raise bills. Warm floor spots, a running meter and the sound of water are common signs. Call a plumber promptly to locate it before the damage spreads.
The Passaic Valley Water Commission supplies North Arlington, and its customer line is 973-340-4300. The borough sold its water utility in 2004. Leaks on the house side of the meter are a plumber's job, and (973) 488-5410 reaches us.
Still unsure where the water is going? Call the 24/7 line and a dispatcher will walk through the tests with you.
Call (973) 488-5410