Odour in Drinking Water Information:

Properties:

Odour is an organoleptic property, meaning that it can be detected using sense organs. In drinking water, odour can come from a wide variety of sources. Although odour in drinking water does not cause direct harm to human health, it can make water unsatisfactory for consumers.

Sources:

Odour is commonly caused by decaying matter, volatile organic compounds, or bacterial production of hydrogen sulphide gas.1 For example, high concentrations of organic matter and biofilm can build up in raw water sources or distribution systems and contaminate potable water supplies.1 The gas hydrogen sulphide smells like rotten eggs and is formed during bacterial degradation of contaminants under anaerobic conditions during the water treatment process. One of the most significant causes of odour is the presence of volatile organic compounds. Even in low concentrations, these compounds can be detected in drinking water.2

Regulations:

There is no limit for odour in drinking water. Consumer rejection and disapproval of contaminated waters are the main factors taken into consideration when determining the admissibility of a water supply.

Health/Environmental Concerns:

Odour itself does not have any deleterious health effects on humans. However, water that has been contaminated by sewage, wastewater, volatile organic compounds, or bacteria should not be ingested. Odour is therefore an important indicator of water quality that should be closely monitored.

Action:

Quality control tests should be completed regularly; the most efficient way to control odour and promote consumer satisfaction in potable water is through modification of treatment processes.3 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 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.

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

3 Water Quality Standards: Water for Life, 2019. Southern Water Web site. https://www.southernwater.co.uk/help-advice/drinking-water-quality/issues-with-your-waters-colour (accessed Jan 2, 2020).