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.



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.


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.


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.


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.


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.


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).


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.


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.


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.


Can the smell of water indicate its quality?

Yes, the smell of water can provide valuable information about its quality. While pure water is typically odorless, certain odors can indicate the presence of contaminants or other issues. For example, a rotten egg or sulfur-like smell may indicate the presence of hydrogen sulfide gas, which can occur naturally in groundwater or be produced by certain bacteria. A musty or earthy smell may suggest the presence of algae, molds, or organic matter. It's important to note that some odors may not necessarily indicate a health risk, but they can still be unpleasant. If you notice a strong or persistent odor in your water, it is advisable to have it tested to determine the cause and ensure its safety for consumption.

What does the taste of water indicate?

The taste of water can be indicative of its quality and various factors that may affect it. Generally, water should taste neutral, with no discernible flavor. However, certain tastes can suggest underlying issues. For instance, a metallic taste may indicate the presence of minerals such as iron, copper, or zinc. A salty taste might be a sign of elevated sodium levels or contamination with seawater. Additionally, an earthy or musty taste could suggest the presence of algae or organic matter. While some tastes may be harmless, others can affect the water's palatability or indicate potential health concerns. If you experience an unusual or persistent taste in your water, it is recommended to have it tested to determine the cause and ensure its suitability for consumption.

Is it normal for water to have a chlorine smell?

In certain cases, a chlorine smell in water can be normal and expected. Chlorine is often used as a disinfectant in municipal water treatment processes to kill bacteria and other microorganisms. While chlorine is effective in reducing potential health risks, it can leave a distinct odor. This smell is more noticeable in tap water because the chlorine dissipates when left exposed to air. In most cases, the chlorine smell is not harmful and can be reduced by letting the water sit in an open container or using activated carbon filters. However, if the chlorine smell is excessively strong or persistent, it is advisable to contact your water utility provider for further investigation.

How can I improve the taste and smell of my water?

If you are experiencing unpleasant tastes or smells in your water, there are several steps you can take to improve its quality. First, you can try using an activated carbon filter, which can help remove certain contaminants and reduce odors. These filters are available in various forms, including faucet-mounted filters, pitcher filters, and whole-house filtration systems. Additionally, storing tap water in an open container for a short period can allow volatile compounds, such as chlorine, to dissipate, improving the taste and smell. If the issue persists or you suspect a more significant problem, it is recommended to have your water tested by a certified laboratory to identify any specific contaminants or concerns. Based on the test results, appropriate treatment methods can be determined to ensure safe and pleasant-tasting water.