Why Does My Water Smell Like Rotten Eggs

Water that is giving off a distinctive smell is most likely contaminated with hydrogen sulfide. Hydrogen sulfide does not usually pose immediate health problems at the levels it is found in domestic drinking supplies. However, it is certainly an inconvenience — especially to one’s nose, as it creates a “rotten egg” smell.

What is Hydrogen Sulfide?

Hydrogen sulfide is a colorless gas that can exist naturally in groundwater. Sulfur-reducing bacteria present in groundwater use sulfur as an energy source to chemically change sulfates to hydrogen sulfide. The bacteria use sulfur from decaying plants and other organic matter in oxygen-deficient environments. They can occur in deep or shallow wells, and reside in plumbing systems.

Hydrogen sulfide crops up in other ways too. The magnesium rod used in water heaters for corrosion control can chemically reduce sulfates to hydrogen sulfide, and sewage pollution can be a source. Hydrogen sulfide also can enter surface water through springs.

Is my well at risk?

Hydrogen sulfide, if present, will vary by well due to the varying geology. It is most common in shales and sandstones. The occurrence of hydrogen sulfide gas has been correlated to groundwater with low pH and groundwater with high levels of iron and/or manganese. It also may be associated with hydrocarbons and peat formations.

To test for hydrogen sulfide, contact a certified drinking water laboratory. Visit http://water.epa.gov/scitech/drinkingwater/labcert/statecertification.cfm for state-specific information on certified drinking water testing labs. The certification officer in your state can provide a list of certified labs in your area.

Hydrogen sulfide escapes (volatizes) from water easily, so samples should be tested on-site or immediately stabilized for laboratory analysis. Laboratory instructions should be followed very carefully.

If you do have a hydrogen sulfide level in your water that is higher than you would like, there are water treatment technologies available to address the problem.

What types of treatment solutions are available to private well owners?

There are various methods. They should be chosen based on the level of hydrogen sulfide, the amount of water being treated, the levels of iron and manganese, and the water pH, among other factors. Methods to reduce or remove hydrogen sulfide include activated carbon filtration, shock chlorination, ion exchange, manganese greensand filtration, oxidation, oxidizing filtration, ozone treatment, and water heater modification.

Please contact us if your well water smell like rotten eggs and we can investigate the exact cause and offer you a solution.