Pohjavesi

Pohjavesi is the Finnish term for groundwater: the freshwater that resides in pores, fractures and voids beneath the Earth’s surface. In Finland it commonly occurs in glacio-fluvial deposits, coarse gravels and sands, or in fractured bedrock. Pohjavesi is often of high quality because it has been naturally filtered as it moves through soil and rock, and it is an important source for drinking water.

Groundwater forms when precipitation infiltrates the ground and recharges aquifers. It moves slowly through the subsurface, with flow paths and residence times varying by geology. Pohjavesi is vulnerable to surface contamination in recharge areas, and its quality can be affected by pollutants such as nitrates from agriculture, pesticides, leaking storage tanks, or improper waste disposal. Protecting recharge zones helps maintain long-term water security.

In Finland, pohjavesi is a key resource for both municipal and private water supplies. It is typically accessed via boreholes or wells and is often treated to meet drinking water standards. Because of its importance and potential vulnerability, groundwater quality is monitored by authorities, and land use planning aims to protect recharge areas.

Protection and management of pohjavesi are governed by national water legislation and environmental regulations. Designated pohjavesialueet (groundwater protection areas) restrict certain activities to limit contamination risk. Ongoing monitoring, risk assessment, and public-information efforts support sustainable use of this essential freshwater resource.