Odour and Taste In Water

Odour and taste in water are important aspects of water quality, as they significantly impact its acceptability for drinking and other uses. The presence of unusual or unpleasant odours and tastes in water can be indicative of underlying issues or contaminants, pollutants or impurities. For example, odours can occur in various forms such as natural odours from natural waters such as lakes and rivers, having characteristic odours due to the presence of organic material like algae, decaying leaves and aquatic vegetation, leaving a more earthy or musty odour. Chemical odours such as, chlorine, for example being used in water treatment can produce a chlorine like odour if not properly managed. Sulphur odours which is the presence of hydrogen sulphide gas (H2S) in water which can lead to a “rotten egg” or sulphur like odour, known to occur in groundwater sources with high sulphate levels or in plumbing systems with anaerobic conditions. Industrial and contaminant odours through discharges of contamination events can introduce unusual or chemical odours into water sources, ranging from industrial solvents to petroleum products.

Taste on the other hand also derives from various contaminants, pollutants and impurities for example, chlorine, being commonly used as a disinfectant in water treatment to kill harmful microorganisms, can in some cases be detected as a chlorine taste in drinking water. Metallic tastes from certain metals in water can be present, such as iron or copper, can impact a metallic taste, often associated with corrosion in plumbing systems, fixtures and fittings. Salty tastes from high levels of dissolved salts, such as sodium chloride, leading to a salty taste in water, occurring in areas with brackish groundwater or as a result of seawater intrusion. Earthiness or mustiness tastes occur in waters with high levels of natural organic matter, particularly in surface water sources, giving an earthy or musty taste, often due to the breakdown of organic compounds by microorganisms. Other chemicals, such as solvents or industrial contaminant, can impact specific tastes to water which can be unusual or unpleasant.

Management and remediation of odours and tastes in water can be performed through water treatment plants which use various processes to remove or neutralize odour and taste causing substances, such as activated carbon filtration can be effective in removing organic compounds that cause taste and odours. Proper disinfection with chlorine or other disinfectants, followed by dichlorination if necessary, can be helpful in managing taste and odours in water related to chlorine. Source water protection by protecting water sources from contamination by managing land use and runoff can prevent taste and odour problems associated with organic matter and pollutants. Routine water quality testing and monitoring are essential to detect and address taste and odour issues promptly as water utilities and regulatory agencies conduct such testing to ensure compliance with the current standards and regulations.