Rotten Egg Odor and Hydrogen Sulfide in Water
A. Source Water
If a rotten egg smell is present it is necessary to first identify the source of the odor. Some wells produce hydrogen sulfide. In such cases the odor of hydrogen sulfide is noticeable when the water is pumped directly from the well. This is source water hydrogen sulfide.
B. Water Heater
In certain instances Hydrogen sulfide is manufactured in the water heater by a reaction with the anode in the water heater. This is a reaction between sulfates in the raw water, the anode installed by the heater manufacturer and certain sulfate digesting bacteria (desulfovibrio desulfuricans). These bacteria are not harmful but they do create a very unpleasant odor under certain circumstances. In some cases the replacement of the factory anode with a bi-metallic anode can solve the problem. In other more severe problems an electronic anode is required. Electronic anodes are more expensive but are the most effective solution.