
Water's organoleptic properties include odor, taste (aftertaste), turbidity, and color. In this article, we will focus on taste and odor. Although they are primarily aesthetic factors, they can indirectly indicate the presence of certain pollutants in the water. Water's odors and tastes are indicative of the content of certain substances that cause these phenomena, such as dissolved salts, various chemical and organic compounds. It is important to note that these parameters are evaluated on a five-point scale, which is outlined in the table below.
It is worth noting that odors are evaluated for water of any origin; however, this determination is not made for water that is known to be contaminated with harmful impurities.
ASSESSMENT OF WATER ODORS AND TASTES
Scale | Intensity of odors and taste | Brief characteristic of intensity |
| 0 | None | Loss of sense of smell or taste |
| 1 | Very little | Odor or taste that is not detectable, but is determined by an experienced analyst in a laboratory. |
| 2 | Little | Odor or taste that is not noticeable to the consumer, but can be detected if attention is paid to it. |
| 3 | Visible | Odor or taste, easily detectable, gives reason to disapprove of the water. |
| 4 | Strong | Odor or taste that catches attention and makes water unpleasant for drinking |
| 5 | Very strong | The smell or taste is so strong that it makes the water unsuitable for drinking. |
WHY DOES WATER HAVE AN UNPLEASANT SMELL AND HOW TO DEAL WITH IT?
Organoleptic properties of water play a crucial role in determining its quality and suitability for consumption. Among these properties, smell holds particular significance. But why does water sometimes have an unpleasant smell, and how can we address this issue? Understanding the smell of water involves recognizing its various components and the factors that contribute to odour.
When we define taste and odour of water, we often encounter a range of descriptors, from earthy and fishy to chlorine and rotten egg smells. These odours can stem from natural sources, such as organic matter or minerals present in the water, or they may result from treatment processes like chlorination. Regardless of the source, an unpleasant smell in water can be off-putting and indicative of potential contaminants.
When addressing the concern of water odour, it becomes crucial to identify the precise cause of the smell, considering the question of what is the smell of water and whether water does have a smell. Solutions to mitigate odours vary depending on their nature, ranging from straightforward filtration techniques to intricate treatment procedures. By addressing the underlying factors that cause odour, it is possible to ensure that the water not only meets safety standards but also improves the overall drinking experience.
ODOR OF ROTTEN, FISHY OR EARTHY
Most commonly found in water from open reservoirs. Caused by the presence of natural organic compounds in the water. The most well-known of these natural compounds are geosmin and 2-methylisoborneol. These compounds are usually safe for humans, although they can sometimes be caused by the presence of blue-green algae and bacteria in the water. Water is most strongly enriched with these compounds during the flowering period of reservoirs.
Removal: activated carbon filters (adsorption), for drinking - domestic reverse osmosis.
CHLORINE SMELL
Occurs mainly in the central water supply system. Caused by strong chlorination of water at municipal treatment plants.
Removal: activated carbon filters (adsorption), for drinking - home reverse osmosis, triple filters and pitchers.
SMELL OF ROTTEN EGGS
The presence of dissolved hydrogen sulfide (H2S) in the water. Less commonly, the presence of sulfide bacteria that produce hydrogen sulfide. Tap water smells like rotten eggs if it comes directly from a well without further purification.
Removal: Centaur filters (activated carbon - catalytic oxidation and adsorption) or MGS (green sand filter with manganese). Chlorination of water is necessary to remove bacteria.
CHEMICAL AND PHENOLIC ODOR
This type of odor is caused by the entry of wastewater into the water supply system or into the aquifer (in the case of groundwater abstraction).
Removal: activated carbon filter (adsorption).
SALTY TASTE
Caused by elevated levels of salts in the water: NaCl, NaSO4, MgSO4.
Removal: water desalination (deionization or reverse osmosis). For drinking water - home reverse osmosis.
METALLIC TASTE
Indicates an increased content of iron and/or manganese in the water. At very high concentrations, the water from the tap has a smell of an iron.
Removal: complex purification systems with Ecomix, BIRM, MGS, and other iron removal methods.
ALKALINE TASTE
Caused by a high pH level in the water.
Removal: reverse osmosis systems or deionization (H-cation exchange). For drinking - household reverse osmosis.
The table below provides a more detailed classification of odors with an indication of their origin.

