Finland’s tap water is among the highest quality in the world and is not only completely safe but a pleasure to drink. In Finland tap water has been found to be significantly cleaner than bottled water. A research by the National Institute for Health and Welfare (THL) has shown that bottled water may have up to 100 times more microbes than tap water. Tap water fulfills both Finnish and the European Union requirements and recommendations for the quality of drinking water (Decree of the Ministry of Social Affairs and Health).
Drinking water supply in Tampere is provided by Tampere Water, the municipal enterprise for water services. Most of the raw water is surface water from two lakes (Lake Roine and Lake Näsijärvi) and it is thoroughly treated before distribution. About one third of the tap water is groundwater, which is treated and pumped at multiple groundwater intakes. Groundwater is formed from rainwater by natural filtration through sand and gravel layers of the eskers (ridges) in Tampere and its neighbourhood.
The microbiological quality of all water (both surface water and groundwater) is ensured by disinfection with chlorine or sodium hypochlorite before pumping to the distribution network. Municipal health authorities and Tampere Water monitor water quality frequently.
Tampere Water celebrates its 120th anniversary (1898 – 2018). Tampere Water provides each participant of the European Deaf Futsal Championship with an empty water bottle, which can be filled and refilled straight from the tap instead of bottled water.
https://www.tampere.fi/vesi/inenglish/waterquality.html