Water quality

​The water quality is high in the Helsinki Metropolitan Area. The household water we produce easily fulfils the quality requirements and recommendations set by the Ministry of Social Affairs and Health in its related decree (1352/2015 and 683/2017). In addition to HSY’s own control samples, the health protection authorities of municipalities monitor the water quality in the supply network in accordance with the control research programme.

We monitor the microbiological, physico-chemical and sensory quality of water provided by the Pitkäkoski and Vanhakaupunki water treatment plants every week day in our laboratory. In addition to this, we supervise the water quality in the water supply network.

The water quality table​ is updated around four times a year.

If you notice any fault in the ​​tap water quality

​The reliability of the water supply network in the Helsinki Metropolitan Area is very good. Sometimes we have to close down parts of the network locally due to, for example, pipe replacements, leakage repairs or network flushing.  We aim to always report these stoppages in advance.

After repair work, deposits or rust may come loose from the pipes, which causes temporal changes to water quality, such as coloured or cloudy water. In such cases, we recommend allowing the water to run until it is colourless and clear again.

If you notice any problems with the water quality, allow all taps to run for about ten minutes and monitor all changes in the water quality.

​If this does not improve the water quality, contact the maintenance services or property manager to check the quality of water coming into the building.

If the whole water supply of the building has the same problem, check out here: Disturbances in water services in our Finnish pages ​​​​»

Use the right dose​​ of detergent

Measure out the detergent based on the instructions for soft water. You do not need to use water softener or softening salts for the washing machines. The household water in the Helsinki Metropolitan Area is soft, which means that its lime content is low. This is why less detergent can be used than with hard water. In the Helsinki Metropolitan Area, the hardness of water ranges from 3.0 to 4.5 dH, depending on the plant.

Read more about detergent dosing and water hardness.