Why your well water faucets sputter and spit air, and how to fix it
Sputtering faucets mean air or gas is getting into your water. Common causes are an air-logged pressure tank, a well water level dropping near the pump, and dissolved gas such as methane. Methane can build up and explode in closed spaces, so if you hear gurgling from the well or see milky, bubbly water, test for it.
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Step 1: Notice when it sputters
The timing tells you a lot.
| When it happens | Likely cause |
|---|---|
| After heavy use, like laundry plus showers, then clears up | The water level in the well is dropping near the pump |
| Every time the pump kicks on, with a sudden burst of air | An air-logged pressure tank |
| Steadily, with milky or fizzy water and gurgling from the well | Dissolved gas, possibly methane |
| Only in late summer or during a drought | Low groundwater |
These match the clues the Wisconsin DNR and the Minnesota Department of Health use.
Methane is the cause to rule out first
Methane is a natural gas that can dissolve in groundwater. Minnesota lists the signs: a sputtering or spitting faucet, a gurgling noise from the well, and water that looks bubbly, milky, frothy, or slightly blue.
The danger comes from gas that escapes into the air. Minnesota says methane at 5 to 14% of the air in a closed space can ignite and explode. A spark from a switch in a well house or the flame of a basement water heater can set it off. Methane is lighter than air, so it collects near the ceiling, and enough of it can push out oxygen.
If you suspect methane:
- Keep sparks and flames away from the well and any closed space around it.
- Make sure the well has a vented cap. Minnesota says the vent should go outside, above ground, and away from buildings.
- Ask a lab about a methane test. It needs a special sampling method.
- Test for coliform bacteria and nitrate too. Minnesota says methane is sometimes produced by sewage or other waste.
Penn State Extension suggests routine testing if methane is below about 7 mg/L, a vented well cap above that, and an aeration system above about 28 mg/L. Minnesota says sediment filters, softeners, and carbon filters won't remove methane.
If it sputters after heavy use, the well may be running low
Penn State says a low-yielding well can't keep up during peak use, such as a morning of showers and laundry. When the water drops to the pump intake, the pump pulls air. Wisconsin lists a shallow well and a dropping water table in a drought as clues.
Space out water use and see if the sputtering stops. Penn State's drought fact sheet says groundwater is usually lowest in late summer and early fall.
If it bursts air when the pump starts, check the pressure tank
Wisconsin says an air-logged pressure tank releases a buildup of air suddenly, and asks whether you have one of the large, old-style metal tanks. Wisconsin's fix is to turn off the power, then drain and refill the tank, and only if the tank has air unloaders. A plumber or pump installer can do it.
A pump set deep in the well can release gas bubbles
Wisconsin also notes that water at the bottom of a deep well is under high pressure. Pumping it to the surface lets gas come out as bubbles. A pump installer can raise the pump as high as it will go without losing suction at peak use.
When to call a pro
Call a licensed pump installer if sputtering keeps up, if the pump runs constantly, or if the tank needs servicing. Call a well driller if the water level has dropped for good. Penn State says lowering the pump may help for a while, and deepening the well or drilling a new one is the longer fix.
Questions people ask
Is it safe to drink water from a sputtering faucet?
Wisconsin lists no health concern for air in the lines. Penn State notes there's no drinking water standard for methane. Minnesota says methane isn't known to cause harm when you drink it, though little research has been done, and its warning is about gas building up in closed spaces. Because methane sometimes comes from sewage, Minnesota recommends a coliform bacteria and nitrate test for wells that have it. Minnesota also recommends a bacteria test any time the well is worked on.
Why does my well water spit air only in the morning?
Morning is often peak use. If several people shower and run water at once, a low-yielding well can drop to the pump intake. Penn State suggests spreading use out over the day.
Can a bad pressure tank cause sputtering?
Yes. Wisconsin lists an air-logged pressure tank as a cause of bubbly water and sudden bursts of air.
Where this comes from
- Wisconsin DNR, My Water Appears Bubbly
- Minnesota Department of Health, Methane in Well Water
- Penn State Extension, Common Drinking Water Problems and Solutions
- Penn State Extension, Water Facts 7, Managing Your Well During a Drought
- Penn State Extension, Water Facts 3, Using Low-Yielding Wells
- Minnesota Department of Health, Bacterial Safety of Well Water