A second situation occurs when sulfate in the water changes to hydrogen sulfide in the hot water heater. In this case, a magnesium rod has been installed in the water heater to reduce corrosion of the water heater. As the rod gives up small amounts of magnesium to the water, some hydrogen is released. The hydrogen can then combine with sulfur in the water and form hydrogen sulfide. The offensive odor of hydrogen sulfide generally makes testing unnecessary.
Most people know when hydrogen sulfide is present and seek to correct the problem.
However, in a few cases, the odor may be from sewage pollution. Water with only hydrogen sulfide present does not cause disease. When sewage pollution is a possible source of the sulfur, test your water for coliform bacteria. Collect water samples for the hydrogen sulfide test at the well site. Water testing labs and other pro- fessionals can provide further information on specific steps for testing.