Sulfate Compounds

sulfate compounds are composed of a sulfur ion and four oxygen ions (SO4-2). Most sulfate in groundwater comes from the dissolution of gypsum or other common sulfate-bearing minerals like barite, epsom salt (MgSO47H2O), and gypsum (CaSO42H2O). In addition, some sulfate is added to water by anthropogenic sources such as detergents and detergent precursors, industrial processes, and agricultural practices. Sulfate is also a common constituent of well water and contributes to hardness levels in some groundwater systems.

A variety of sulfate-based chemicals are used in consumer products such as shampoo and soaps. Most of these are synthetic sulfate compounds formed from the reaction of sulfuric acid with other chemicals such as sodium lauryl or sodium laureth sulfate (SLS and SLES). These compounds are considered surfactants – they bind to oil, fat, grease, and dirt and help remove them. They also produce a strong lather that gives them their cleaning properties. Many people are concerned that sulfates are bad for the environment as they require the destruction of tropical rainforests for palm oil and petroleum oils, and they can be toxic to aquatic animals when washed down drains.

Long-term ingestion of drinking waters containing high concentrations of sulfates causes osmotic diarrhea in humans. However, osmotic diarrhea stops once the osmotically active contents of the gastrointestinal tract are excreted from the body. Infants and the elderly consuming formula or powdered nutritional supplements reconstituted in water containing elevated sulfate concentrations may be more sensitive to this effect than adults.