What is Sulfur Water?

Hydrogen Sulfide

Sulfur water is hydrogen sulfide that is dissolved in the water.

Foul-smelling or unusual odors from your water should make you question its quality and safety. Some odors indicate the presence of contaminants which may pose a health risk. Other odors, such as those caused by hydrogen sulfide, are more of a nuisance, only affecting the taste of the water.

Sulfur in your water supply is easily recognized by its offensive odor. Hydrogen sulfide gas causes the “rotten-egg” or sulfur water smell. Hydrogen sulfide in water causes no known health effects. However, high concentrations do change the taste of the water.

What are the Effects of Sulfur Water?

Sulfur water corrodes metals such as iron, steel, copper and brass. The corrosion of iron and steel from sulfur forms ferrous sulfide or “black water.” Hydrogen sulfide in water can blacken silverware and discolor copper and brass utensils.

Sulfur water makes cleaning clothes extremely difficult. When using chlorine bleach in sulfur water it will reduce the cleaning power of the detergent being used. The hydrogen sulfide will also corrode exposed metal parts in washing machines, dish washers and other water using appliances.

Iron and manganese, which are often present with hydrogen sulfide, turn the water black and greasy-feeling. If untreated, the water stains laundry, washing machines, sinks and kitchenware. When used in the laundry, chlorine bleach reacts with iron and manganese forming dark rusty or brownish stains on clothes.

Occurrence & Characteristics

Hydrogen Sulfide

Hydrogen sulfide is more commonly found in ground water supplies than in surface water. The reason for this is hydrogen sulfide gas quickly escapes from surface water into the atmosphere.

Wells drilled in shale or sandstone, or near coal or oil fields often have hydrogen sulfide present. The rotten egg smell is not uncommon in Southwest Florida. The Florida Sandstone Aquifer occurs within at least 5 Southwest Florida counties, underlying more than 6500 square kilometers of area.

Hydrogen sulfide may also be produced when sulfate in well water converts to hydrogen sulfide. Certain non-disease-producing bacteria use the oxygen in the sulfate to form hydrogen sulfide.

Hydrogen sulfide causes the distinct, offensive odor of sewage. Occasionally, sewage pollution is the reason for the odor in drinking water. Sewage pollution sulfide, and not a natural source, can occur in some surface water, in poorly constructed wells or in shallow wells close to sewer lines or septic tanks.

Under certain conditions, you may notice hydrogen sulfide when heating water. Heated water releases hydrogen sulfide gas quicker than cold water. 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.

Hydrogen Sulfide Testing

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. Sewage pollution, however, contains disease-producing contaminants. When sewage pollution is a possible source of the sulfur, have your water tested for coliform bacteria.