Overview
Groundwater is water located in the saturation zone of the Earth's crust, which moves through soil pores or fractures under the influence of gravity or hydraulic pressure. In other words, if an underground layer of rock or sediment is saturated with water and it is possible to extract groundwater from this layer, then this underground layer of rock or sediment is called an aquifer.
- In Estonia, the volume of groundwater is estimated to be 2000 km³, and it is usable as drinking water and accessible almost everywhere.
Groundwater resources and balance
Groundwater resources refer to the estimated amount of groundwater that can be used while ensuring the preservation of good groundwater status.
Groundwater resources must be assessed in a region if the amount of groundwater extracted from the aquifer exceeds 500 m³ per day. The groundwater commission reviews groundwater resource study reports and submits them to the Minister of Climate for approval. The Environmental Board compiles the groundwater resources balance for Estonia, which includes the established groundwater resources in Estonia, water extraction within these resources, and the volume of groundwater available for use. Additionally, the report presents established groundwater resources, water extraction, and changes in water extraction within counties and groundwater bodies.
Overviews (in Estonian):
Status of groundwater bodies
Estonia has 31 groundwater bodies, whose status is assessed every six years. The most recent assessment of the status of groundwater bodies was conducted in 2020 by the Estonian Geological Survey, resulting in the following summary for Estonia:
- 23 groundwater bodies are in good status: 74%
- 8 groundwater bodies are in poor status: 26%
The sources of pollutants found in groundwater can be very diverse. On one hand, it can be a naturally occurring phenomenon; for example, the deep Cambrian-Vendian Voronka aquifers may mix with saltier water layers, resulting in an increased concentration of chloride ions in the groundwater. On the other hand, the presence of pollutants in groundwater can be caused by human activities: primarily, intensive groundwater extraction, oil shale mining, and agriculture are problematic, leading to pollutant concentrations (such as chloride, sulfates, ammonium, etc.) in groundwater exceeding permissible levels.
More information:
- The objectives for achieving good status of groundwater bodies are detailed in the European Parliament and Council Directive 2000/60/EC.
- Methodology (in Estonian) for assessing the status of groundwater bodies.
- The status of groundwater bodies can be examined in more detail using the map collection below and by reading the status assessment report from 2020 (in Estonian).
Monitoring of groundwater bodies and nitrate-vulnerable zones
Estonia’s national groundwater monitoring is divided into three categories:
1. Quantitative monitoring of groundwater bodies
Approximately 245 monitoring stations, with a monitoring frequency of 12–365 times per year. Measurements are conducted manually or using an automatic water level sensor.
2. Chemical monitoring of groundwater bodies
Approximately 230 monitoring stations, with a monitoring frequency of once per year. Monitoring of hazardous substances rotates according to the monitoring plan.
3. Groundwater monitoring in nitrate-vulnerable zones (NVZs)
- Core NVZ network monitoring: 54 monitoring stations, monitored four times per year.
- Support NVZ network monitoring: 58 monitoring stations, monitored once per year.
- Quarterly reference sampling is conducted from 7 springs and 7 wells outside NVZ areas.
A detailed list of monitoring parameters and criteria is specified for each groundwater body in the Minister of the Environment’s regulations no. 48 and no. 39.
Groundwater monitoring in Estonia is carried out by the Estonian Environmental Research Centre (EKUK), which compiles an annual summary report on groundwater monitoring based on the collected monitoring data. Monitoring data and reports are available in the Estonian environmental monitoring database KESE.
Overviews (in Estonian):
More information
- Borehole registry operations
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Answers to frequently asked questions about wells can be found on the Environmental Agency’s website (in Estonian).
A drilled well may be established by an entrepreneur or person holding the appropriate activity permit. Holders of permits for hydrogeological work.
For borehole registry operations, please contact customer support: @email