2.4.1. Characteristics of Groundwater
The geologic formation of Finland is a Precambrian crystalline bedrock, which is covered with thin layers of Quaternary deposits. Precambrian bedrock is solid material which allows only low water movements and small water quantity. There is no karst groundwater because of the lack of calcium minerals in the crystalline bedrock. Groundwater in porous media consists of glacifluvial aquifers (eskers and other gravel and sand formations). The other aquifers consists of small till and silt aquifers.
2.4.2. Structure of the Administrative Organisations Concerning Groundwater Quality
There are 50 groundwater quality sampling sites throughout the country. The Finnish Environment Institute is programme co-ordinator, manager of the database and the reporting centre. Regional Environment Centres carry out maintenance renovation, take samples and are partly responsible for the chemical analyses. The network is a national network which is a part of the Scandinavian Network". The main responsibilities of the institutions involved are to detect changes in groundwater chemistry and infiltration water due to anthropogenic impact, to collect basic data, to provide data for research and scientific purposes and to identify the trends of water quality.
2.4.3. Monitoring of Groundwater Quality
The 50 groundwater sampling sites are representative for the whole area investigated, meaning that the hydrogeological quantity and quality parameters could be calculated from the balances of water and materials. Sampling sites are mostly situated in springs; the others are in tubes and wells. In porous media aquifers there are 20 sampling sites and In other aquifers there are 30 sampling sites. Stations are background stations in nearly natural state, located in areas where the groundwater quality has not been appreciably affected by local environmental disturbances. The stations are situated in different climatic and soil type regions which are hydrogeologically unified groundwater basins or distinct, defined areas within larger basins. The size of areas investigated varies between 0.2 and 3 km².
About 30 determinants are observed 6 times a year in order to identify the groundwater quality. The laboratory of the Finnish Environmental Agency co-operates with the 13 laboratories of the Regional Environment Centres in sampling and analysing. The Finnish Environment Institute is a kind of supervisor for the Regional Environment Centres and gives guidance to them. These public institutions work due to public regulation. Finnish Standard Procedures (SFS-standard) for analytical methods as well as the regulations of the EN 4500-Standards are the basis for the precision and accuracy of the procedures of the laboratories.
The earliest record of the groundwater quality network was taken in 1974. It has an average record length of 20 years. An SAS-database (with ASCII) is used for raw data storage. The hardware used is VAX-VMS. Software tool is SAS. Computerised data have been available since 1975 and are laid down on floppy disks or published in paper form. Parts of the data can be demanded from public organisations like the Finnish Environment Institute which is responsible for the observation report.
2.4.4. Structure of the Administrative Organisations Concerning Groundwater Quantity
The Finnish groundwater monitoring network is a national network which is also part of the Scandinavian Network". The network provides information on changes in the groundwater table of different aquifers and relate observed changes in climatic fluxes. Furthermore it helps to evaluate and predict drought periods. The Finnish Environment Institute is programme co-ordinator, database manager and the centre of reporting. Regional Environment Centres do maintenance renovation.
2.4.5. Monitoring of Groundwater Quantity
The groundwater monitoring consists of 54 groundwater observation stations with 550 observation points throughout the country. These are background stations in nearly natural state, located in areas where the groundwater quality has not been appreciably affected by local environmental disturbances. The stations are situated in different climatic and soil-type regions which are hydrogeologically unified groundwater basins or distinct, defined areas within larger basins. The size of areas investigated varies between 0.2 and 3 km². There are about ten observation tubes and one observation well in every groundwater region.
The sampling sites observe the water level 26 times a year for basic programmes. In addition there is one all-time-recorder for every station. The network has been in operation since 1974 as a whole; the first observations were made in 1968. It has an average record length of 20 years. An INGRES database with FORTRAN programmes is the equipment for data storage and management at the Finnish Environment Institute. SQL is the query language. The groundwater quantity data have been computerised since 1975 and can be made available on floppy disks or on paper sheets. Not all of the data are available, for some information a fee is necessary. The Finnish Environment Institute publishes parts of the groundwater quantity data in yearbooks. The last of these yearbooks was edited in 1992.
For references, please go to http://www.eea.europa.eu/publications/92-9167-032-4/page006.html or scan the QR code.
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