Function: Groundwater production

About 5.4 million m³ of groundwater is generated in Finland every day. Areas of eskers and terminal moraines with sorted coarse-grained soils have the largest high-quality groundwater deposits. 

Soils consisting mainly of small particles such as clay and fine sand are poor in groundwater.  Fine particles impede the water absorption and filtration. These areas are situated most often along the coastline. The water filtration is also minor in peatland areas. Peat absorbs water to a great extent but the groundwater formation is generally minimal. The groundwater in these areas is rich in humic acids and thus the quality is rather low.

Till is the most common soil type in Finland, it covers about half of the total land area. Till is unsorted glacial sediment and usually the sediment layer is relatively thin. The groundwater altitude in these areas fluctuate rapidly depending on precipitation level. The water quality varies a lot as well. During spring and autumn months the groundwater is generally acid and contains humus.

References

Pohjavesialueet. Finnish Environment Institute. [In Finnish]

Ronkainen, N. 2012. Suomen maalajien ominaisuuksia. Suomen ympäristö 2 / 2012. 62 s. [In Finnish]