Sulphates

Sarah Jones
Environmental Chemist
Wednesday, 12th June 2019
Share this article
Vials of water in a laboratory for water quality  testing

Sulphates

Sulphates in Drinking Water — Water Library | Acorn Water
Odour Can smell pungent and offensive due to bacterial reduction of sulphate to sulfides
Appearance Depends on source
Taste Pleasant at low concentrations but offensive at high concentrations
Limit 250 mg/L
Sources Industrial activity; mining; water treatment; natural rock and mineral formations
Characteristics Anionic compound that forms a wide variety of compounds; highly water soluble
Health Impacts Acts as a laxative if ingested in high quantities

Table of Contents

Sulphates in Drinking Water Information:

Properties:

Sulphate is an anionic compound with the chemical formula (SO42-) and is commonly found in nature. It is present in a wide variety of rocks and minerals such as gypsum and epsomite. High concentrations of sulphates can cause water to have an unpleasant taste, while low concentrations of calcium and magnesium sulphate are reported by the World Health Organisation to improve the taste of drinking water.1

Sources:

Both natural and anthropogenic sources contribute to elevated sulphate concentrations in drinking water. Sulphates are heavily used in industry for the production of fertilizers, dyes, chemicals, glass, paper, soaps, and biocides. They are also involved in many mining, metal plating, and water treatment processes.1 In particular, aluminium sulphate is widely utilized for coagulation and flocculation in water treatment to remove solid contaminants. Natural sources such as rock formations can also impact the concentration of sulphates present in water supplies.

Regulations:

The concentration of sulphates in drinking water may not exceed 250 milligrams per litre (mg/L).

Health/Environmental Concerns:

If ingested, sulphates can act as laxatives—this effect can be exacerbated by high concentrations of magnesium and sodium.2 Sulphates can also be reduced by certain bacteria that release hydrogen sulphide gas: H2S gas is a particularly unpleasant, pungent-smelling gas that is associated with offensive taste and pipeline corrosion in water supply systems.3

Action:

If high sulphate concentrations are caused by industrial or commercial pollution, the problem may be mitigated at the source. However, sulphate concentrations caused by natural sources or water treatment processes should be treated with desalination methods.1 If you suspect that your drinking water supply is contaminated, contact your Water Service Authority. If drinking water makes you feel ill, contact a doctor right away.

 

 

 

 

1 Guidelines for Drinking Water Quality. Sulfate in Drinking Water; Vol. 2; World Health Organisation: Switzerland, 1996

2 Guide to the Parameters in the European Communities. What’s in your water?; S. I. No. 278 of 2007; National Federation of Group Water Schemes: Ireland.

 3 Interpretation and Standards. Parameters of Water Quality; 1-84096-015-3; Environmental Protection Agency: Ireland, 2001.

Share this article

Sulphates

Sulphates in Drinking Water — Water Library | Acorn Water
Odour Can smell pungent and offensive due to bacterial reduction of sulphate to sulfides
Appearance Depends on source
Taste Pleasant at low concentrations but offensive at high concentrations
Limit 250 mg/L
Sources Industrial activity; mining; water treatment; natural rock and mineral formations
Characteristics Anionic compound that forms a wide variety of compounds; highly water soluble
Health Impacts Acts as a laxative if ingested in high quantities