SC By SCWS Team | February 4, 2026 | 8 min read
Air Bubbles in Well Water
Fill a glass from your well and watch tiny bubbles rise to the surface? You're not alone. Many well owners notice their water looks fizzy or milky with bubbles. Most of the time it's completely harmless dissolved air—but occasionally it signals something that needs attention. Here's how to tell the difference and when to take action.
🧪 The Simple Glass Test
- Fill a clear glass with cold water from your tap
- Set it on the counter and watch for 1-2 minutes
- Bubbles rise from bottom to top and water clears? → Dissolved air (normal)
- Cloudy doesn't clear, or clears from top down? → Something else (investigate)
Why Does Well Water Have Bubbles?
Air and other gases can dissolve into groundwater just like carbon dioxide dissolves into soda. When conditions change—especially when pressure drops at your faucet—those dissolved gases come out of solution as bubbles.
Common Causes of Bubbles
✅ Dissolved Air (Most Common)
Groundwater naturally contains dissolved air. Pressure systems keep it dissolved until released at the faucet. Completely harmless and cosmetic only.
✅ Temperature Changes
Cold water holds more dissolved gas than warm water. As water warms in pipes, gases release. More noticeable in summer or with hot water.
⚠️ Aeration in System
If air is entering through a leak or at the pump, you'll see excessive bubbles plus possible sputtering. Check for system air leaks.
⚠️ Carbon Dioxide
Some aquifers have elevated CO2, making water slightly acidic and fizzy. Can cause corrosion in pipes if levels are high.
🚨 Hydrogen Sulfide
Causes rotten egg smell. Bubbles + odor = H2S. Should be treated to prevent corrosion and eliminate smell.
🚨 Methane (Rare)
Odorless, colorless, flammable. Found near coal, landfills, or gas deposits. Requires testing if suspected. Safety concern.
How to Tell If Bubbles Are Harmless
Dissolved air behaves in a predictable way that's easy to identify:
Signs of Normal Dissolved Air
- Tiny bubbles throughout the water when first drawn
- Water appears milky or cloudy initially
- Bubbles rise to the surface and escape
- Water clears completely from bottom to top
- Clear within 1-2 minutes
- No odor present
- Consistent day after day (not sudden onset)
🔬 Normal Air vs. Problem Bubbles
✅ Normal Dissolved Air
- • Clears from bottom to top
- • Gone within 2 minutes
- • No odor
- • Consistent over time
- • Water is crystal clear after bubbles rise
⚠️ Potential Problem
- • Doesn't clear completely
- • Clears from top down (particles, not air)
- • Has an odor (sulfur, earthy, etc.)
- • Sudden onset or getting worse
- • Accompanied by sputtering
When Bubbles Indicate a Problem
Excessive Air Entering the System
If you're seeing more bubbles than usual, especially combined with sputtering faucets, air is probably entering your system through:
- Pump drawing air (low water level or failing pump)
- Leak in drop pipe or fittings
- Crack at well cap or seal
- Failed check valve allowing water to drain back
See our detailed guide on sputtering well water for troubleshooting these issues.
Hydrogen Sulfide (Rotten Egg Smell)
If your bubbly water also smells like rotten eggs, hydrogen sulfide gas is the culprit. This requires treatment.
Read our complete guide on rotten egg smell in well water.
Methane Gas (Requires Testing)
Methane in well water is uncommon but can occur in certain geological conditions:
🔥 Methane Safety Concerns
- • Methane is odorless and colorless—you can't smell it
- • Flammable when it accumulates in enclosed spaces
- • Can displace oxygen in well pits or enclosed areas
- • Most common near coal deposits, landfills, or oil/gas operations
- • Requires professional testing to confirm
If suspected: Get a dissolved gas test. Levels above 10 mg/L may require venting systems.
Treatment Options for Bubbly Water
When Treatment Isn't Needed
If your water passes the glass test (clears completely, no odor, harmless dissolved air), no treatment is required. It's purely cosmetic. However, if you prefer bubble-free water:
Air Eliminator/Separator
An air eliminator valve installed on the pressure tank automatically vents accumulated air before it reaches your faucets.
- Cost: $100-$300 installed
- Effectiveness: Good for minor air issues
- Maintenance: Periodic inspection/replacement of valve
Aeration Tank System
For significant dissolved gases, an aeration tank exposes water to air, allowing gases to escape before water enters your home.
- Cost: $1,500-$3,500 installed
- Effectiveness: Excellent for dissolved gases including H2S
- Also treats: Iron oxidation, some volatile compounds
Methane Venting System
If testing confirms methane, a specialized venting system safely releases the gas outdoors before it can accumulate.
- Cost: $2,000-$5,000 depending on complexity
- Required if: Methane levels exceed safe thresholds
- Safety: Must be installed by qualified professionals
Bubbles vs. Milky/Cloudy Water
Sometimes people confuse air bubbles with milky or cloudy water that has a different cause:
| Characteristic | Air Bubbles | Other Cloudiness |
|---|---|---|
| How it clears | Bottom to top (bubbles rise) | Top to bottom (particles settle) |
| Time to clear | 1-2 minutes | May take hours or not clear at all |
| Residue left | None | May see sediment at bottom |
| Common cause | Dissolved air/gases | Sediment, bacteria, minerals |
If your water stays cloudy or settles rather than clears, see our guide on milky well water causes.
Frequently Asked Questions
Why are there tiny air bubbles in my well water?
Tiny air bubbles in well water are usually dissolved gases coming out of solution when water pressure drops at your faucet. This is similar to opening a carbonated drink. Common causes include naturally dissolved air in groundwater, temperature changes in pipes, pressure changes in the system, and sometimes gases like methane or hydrogen sulfide. If bubbles appear and then clear, it's typically harmless dissolved air.
Is bubbly well water safe to drink?
Water with dissolved air is perfectly safe to drink—it's just air. However, if the bubbles have an odor (especially rotten egg smell), don't clear within a minute, or are accompanied by other water quality issues, testing is recommended. Methane bubbles (rare) require venting for safety. The simple glass test—fill a glass and watch if bubbles rise and clear from bottom to top—helps distinguish harmless air from potential issues.
How can I tell if bubbles in my well water are a problem?
Concerning signs include: bubbles that don't clear within 1-2 minutes, bubbles with an odor, water that stays cloudy even after bubbles rise, sputtering or spitting from faucets, bubbles that appear suddenly when they never did before, or excessive bubbling. Normal dissolved air will clear completely from bottom to top as bubbles rise and escape.
Can methane cause bubbles in well water?
Yes, methane can dissolve in groundwater and appear as bubbles. Methane is most common in areas with coal deposits, landfills, or oil/gas activity. Unlike regular air, methane is flammable and can accumulate in enclosed spaces. If you suspect methane (bubbles with no odor that continue, located in an area with gas activity), get professional testing. Methane requires proper venting systems for safety.
Do I need to treat air bubbles in my well water?
Most dissolved air doesn't require treatment—it's cosmetic and harmless. However, if bubbles are excessive, accompanied by other issues, or caused by problematic gases, solutions include: aeration tanks that release gases before water enters your home, air release valves on the pressure tank, or specialized methane venting systems. Treatment costs range from $500 for simple air release to $2,000+ for aeration systems.
Concerned About Your Bubbly Water?
If your well water has excessive bubbles, strange odors, or you want to confirm it's safe, Southern California Well Service can test your water and recommend appropriate solutions. We serve San Diego and Riverside Counties with professional water testing and treatment services.
