Home › White or milky water

Well Water White or Milky? Air Bubbles vs. Something to Test

Updated November 1, 2026 · General information, not medical or plumbing advice

Some links on this page are affiliate links. If you buy through them we may earn a commission at no extra cost to you. How we make money.

Do the glass test

1. Fill a clear glass from the cold tap and set it on the counter.
2. Watch it. Washington's health department says that if the water starts to clear at the bottom of the glass first, the white look is trapped air. It says this is not a health threat and should clear in a few minutes.
3. Compare. USGS says the cloudiness from air typically disappears within seconds, and its advice is to let the water sit in an open container until the bubbles go away.
4. If it does not clear, or something settles to the bottom, see the next section.

Why air bubbles show up

• Pressure. USGS says water in pipes is pressurized and holds more air. When it leaves the tap and the pressure drops, the air comes out as bubbles, like a carbonated soft drink.
• Cold. USGS says it happens most often in cold weather because air dissolves more readily in colder water.
• Your pump. Washington's health department says that if you have your own well, the pumping system may be causing it, and you may need a qualified contractor to work out how to correct it. Our well pump guide and pressure tank guide cover the equipment side.

When it is not just air

• It stays cloudy. TapWaterData says haze that stays is likely sediment, such as silt or fine particles, which it says can stem from a failing well screen, drawing the well down too far, or stirred-up sediment. That is a lighter source than the two above, so treat it as a clue and not a diagnosis.
• It started after heavy rain or flooding. Follow cloudy or brown after rain. Agencies there say to stop drinking the water until the well is disinfected and sampled.
• The taste or smell changed too. The CDC says to test your water if the color, taste or smell changes, and to use a state-certified laboratory. The CDC page does not mention cloudy water by name.
• Only the hot water is cloudy, or you see white scale. The pages we opened do not cover this, so we can't say what it means. A lab test and a hardness result are the next step. See hard well water.

TapWaterData says persistent sediment is worth a turbidity and coliform test rather than ignoring it, and that turbidity can shield bacteria and interfere with disinfection. Ask your local health department which lab to use.

Common questions

Why is my well water white or milky?

USGS says cloudy water, also called white water, is caused by tiny air bubbles and is completely harmless. Washington's health department says milky white or cloudy water is usually caused by tiny air bubbles, and that if you have your own well the pumping system may be causing it.

How can I tell if it is just air?

Fill a clear glass and set it on the counter. Washington's health department says that if the water starts to clear at the bottom of the glass first, the cloudy or white look is trapped air, which is not a health threat and should clear in a few minutes.

Why does it happen more in cold weather?

USGS says air dissolves more readily in colder water, so cold water holds more air. It also says water under pressure holds more air, and when the water leaves the tap and the pressure drops, the air comes out as bubbles, like a carbonated drink.

What if it stays cloudy and does not clear?

Then it is probably not air. TapWaterData says haze that stays comes from suspended particles such as silt or fine sediment, and that persistent sediment is worth a turbidity and coliform test. The CDC says to test your water if the color, taste or smell changes, and to use a state-certified lab.

Do I need a filter?

Not for air. TapWaterData says no treatment is needed if the cloudiness is air. It says a sediment filter sized to the particle load clears most sediment cases, and that if sediment persists or gets worse the well and pump should be inspected. Get a lab result before buying treatment.

Related guides

• Well water cloudy or brown after heavy rain
• Well water testing: what, when and how often
• What's wrong with my well water? (checker)