Published on: 1.10.2019
Information produced by Finnish Environment Institute
Where does tap water come from?
Each person in Finland normally consumes slightly over one hundred litres of water a day, while some use up to two hundred litres. Most people get their domestic water from a distribution network, which may obtain the water from many difference sources.
Nine households out of ten have been connected to a municipal water distribution network. Water utilities supply the water for the distribution network by sourcing suitable groundwater or surface water and treating it to ensure that it tastes fresh and is not harmful for health.
Where groundwater is available in sufficient quantities, it is the preferred option as the raw water source. Groundwater often is of such good quality that the only treatment it needs is acidity adjustment, or sometimes its iron or manganese content has to be reduced. Protecting groundwater areas from contamination is vital.
If the volume of groundwater is not sufficient, groundwater reserves can be recharged artificially by infiltrating lake or river water into the soil. Once the water has been purified by being filtered through by the soil, it matches natural groundwater in quality. Nearly 30 water utilities in Finland use artificially recharged groundwater.
Groundwater or artificially recharged groundwater is usually not sufficient to meet the water needs of large cities. In Oulu, for instance, water from the River Oulujoki is used, and the city of Helsinki takes water from Lake Päijänne. Lake or river water needs to be treated more thoroughly than groundwater, but the end result is equally fresh. You will not be able to tell the origin of the water by its taste.
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