There can be many causes for dissolved air or gasses in water.

Some of the more common causes for bubbly water on city water systems are:

Cross connections in public water supplies.

Shutdown and restarting of main distribution systems.

Overheating of hot water systems.

Rapid temperature changes in water.

Leaking pump glands or leaks in water supply lines.

Recent plumbing work done on premises.

For one time air-in-water events, the usual remedy is to contact your water utility, and flush the plumbing and fixtures.



Some of the more common causes of gasses and air from private wells and small community water systems are:

Naturally occurring methane gas.

Naturally occurring carbon dioxide.

Overheating of hot water systems.

Hydrogen sulfide gas, from decaying organic matter.

Hydrogen sulfide gas, formed in water heaters by iron or sulfate reducing bacteria.

Hydrogen sulfide gas, formed in cold or hot water iron piping systems.

Zinc reaction in new galvanized piping.

Recent plumbing work done on residence or building.

Bad check valve or foot valve in well, which can cause the pump to lose its prime and suck in air.

Low water level that on occasion allows air to be sucked into pump when well is out of water.


For private systems, solutions vary widely depending on the problem and application. In many cases, venting the water in a holding tank accomplishes the de-gassing, but in some cases, the water must be disinfected, or more extreme de-gassing methods must be employed such as aerators with blower systems.