Domestic and swimming water monitoring

Household water

Mains water

Domestic water must meet the quality requirements and recommendations of the Decree of the Ministry of Social Affairs and Health (1352/2015). The quality requirements and monitoring studies for domestic water in small units are laid down in the Decree of the Ministry of Social Affairs and Health (401/2001).

Water supply companies, water associations and cooperatives are responsible for the quality of the water they supply in their area. The health authority monitors the quality of network water by taking samples in accordance with the monitoring programme. The purpose of the monitoring is to monitor water quality to ensure the distribution of water that is not harmful to health.

A person working in a facility supplying domestic water or similar and performing activities that affect the quality of domestic water must demonstrate their knowledge of domestic water hygiene by completing a so-called competence test. More information about the competence test can be found at the Finnish Social and Health Authority (Valvira).

Well water

Well water is not subject to regular health surveillance. However, it is worth having well water tested every few years, as well structure failures and heavy surface water runoff can impair the well water quality. Residents can also take a well water sample themselves and submit it to an environmental laboratory. For more information about wells, see From the Finnish Environment Institute website.

Swimming water

The municipal health protection authority monitors the water quality of public swimming pools, indoor swimming pools, beaches, spas, and public recreation, rehabilitation, and massage pools.

The Ministry of Social Affairs and Health has issued instructions on the quality and frequency of monitoring of bathing water at the above-mentioned facilities. The number of bathing water samples is mainly determined by the number of visitors. The water quality of public bathing beaches maintained by municipalities is monitored regularly during the bathing season. Samples are taken in June, July and August.

The operator of both swimming pools and public beaches must keep the water quality results visible on the notice board at each swimming area.

Cyanobacteria and their identification

The amount of blue-green algae on the shores and on the water surface can vary considerably depending on weather conditions. The algae situation can even vary daily. In calm weather, algae can accumulate in large quantities on the water surface. Blue-green algae deposits are most common in mid- and late summer when the waters are at their warmest. Swimming in water with blue-green algae is not recommended and it should not be used for cooking, washing dishes, washing clothes or bathing in the sauna.

Minor amounts of blue-green algae appear in the water as small yellowish or greenish pollen-like clumps. In calm weather, blue-green algae form a gauze-like greenish film on the surface of the water. In windy weather, even a large algae deposit can mix with the water, making the entire body of water appear cloudy. Blue-green algae smell earthy, moldy, and musty.

You can try to identify blue-green algae using home remedies. If the algae breaks up into clumps in the water when lifted with a stick, and does not stick to the stick in strands, it is probably blue-green algae. You can also take the water from the algae in a glass and let the water stand for a while. If the algae rises to the surface, it is probably blue-green algae.