2.12. Norway

Page Last modified 20 Apr 2016, 02:32 PM

2.12. Norway

2.12.1. Characteristics of Groundwater

In Norway there are two main types of aquifers: bedrock without primary porosity but with secondary passages such as joints and other fractured or Quaternary superficial deposits with primary porosity. Bedrock aquifers: with exception of the upper Permian aeolian sandstone in Brumunddal and some Permian volcanic rocks, all Norwegian bedrock types lack primary porosity and are non permeable on small scale. The presence of groundwater is restricted to joints formed by tectonic fracturing and to a less extent to open fractures and voids formed by dissolution of limestone and vein and void minerals, usually calcite. The abundance of water bearing fractures and the frequency of open joints (fissures) are strongly controlled by rock type (competency), thickness and type and orientation of paleo stress and recent stress. These factors also control the actual fracture pattern and strongly influence topography.

About 80,000 wells have been drilled in bedrock for groundwater supply, and about 4,000 new wells are drilled annually. The wells are mostly used as water supply for single house farm, small concentrations of houses and local waterworks in areas with sparse population. Information on depth and water yield from about 20,000 of the total 80,000 wells drilled in Norwegian bedrock is stored in the hydrogeological Data base for Geological Survey of Norway in Trondheim.

Water quantities usually obtained out of drilled wells in bedrock range from zero to 10,000 l/hour, although the latter figure must be regarded as a very good yield. Most wells have capacities between 300 l/h and 2,000 l/h. The potential of wells drilled in bedrock for household water supply with bigger concentrations is probably somewhat underestimated. With a water consumption of 350 l/person/day only a well that yields about 1 l/s (3,600 l/h) can be sufficient to cover the demand of about 250 people.

Quaternary aquifers: The Quaternary deposits represent a very good aquifer in ice-margin deltas and in glacio-fluvial valley fills. Wells can produce water quantities in the order of ten to a hundred times higher than bedrock wells. Several cities, towns and other rural sites, as well as industrial enterprises use good water from aquifers in Quaternary deposits, The groundwater in fluvial aquifers in the valleys is infiltrated from rivers and is of good quality with groundwater characteristics and stable temperature. The deposits can be regarded as large natural filters. The yield of wells in such aquifers may sometimes give about 100 l/s.

The Norwegian water management terms to these aquifers are regarded as groundwater supplies. Therefore these types of aquifers have not been characterised as bank filtered water.

 
2.12.2. Structure of the Administrative Organisations Concerning Groundwater Quality

In 1977 The Geological Survey of Norway (NGU) and the Norwegian Water Resources and Energy Administration (NVE) initiated a nation wide groundwater monitoring network named „Landsomfattende Grunnvannsnet", LGN) to co-ordinate the groundwater data collection in Norway. This network was extended in 1980 by including four stations within or close to „calibrated" catchments, in order for the Norwegian Institute for Water Research (NIVA) to carry out (in co-operation with NGU) its responsibility for groundwater monitoring within the context of the Norwegian Monitoring Programme for Long-Range Transported Air Pollutants. This programme is a major, collaborative initiative co-ordinated by the state Pollution Control Authority (SFT) to describe and follow trends in precipitation chemistry, soil and water acidification. Within the LGN the NGU is responsible for the monitoring and reporting; apart complies from the four stations where NIVA is responsible. The extent of the monitoring is national. It complies with international and national standards with respects to analyses and international procedures for sampling. The quality of data is hereby assured.


2.12.3. Monitoring of Groundwater Quality

The „Landsomfattende grunnvannsnet, LGN is a national groundwater monitoring network in Norway. Until 1991 NIVA was the responsible organisation for database management and chemical analyses. At present the Geological Survey of Norway (NGU) fulfils these tasks. It co-operates with the Norwegian Water Resources and Energy Administration (NVE) that does the local sampling. The LGN consists of 38 monitoring stations distributed all over the country, groundwater level is measured 2-4 times a month at each station, groundwater temperature is monitored 2-4 times a month at 31 stations and groundwater chemistry is determined 1-2 times a year at 17 stations and monthly at 4 stations. Standardised procedures are used for monitoring, e.g. wells are pumped for sampling. Sampling is taken 15 minutes after the water seems clear. All water determinants are analysed in the laboratories of the NGU using the Norwegian Norm Procedures NS-EN 45001 for precision and accuracy. The earliest record was taken in 1978, the average length of records is 15 years.

Data are stored by NGU in an EXCEL-database using PC with Windows software. Computerised data have been available since 1978. Whether data are passed on free of charge or not, depends on the data amount and degree of processing. The NGU publishes annual reports for consultants, research institutes or environmental organisations.

Another Norwegian groundwater monitoring network is called Norwegian Monitoring Programme for Long-Range Transported Air Pollutants. This programme is a major, collaborative initiative co-ordinated by the State Pollution Control Authority (SFT) to describe and follow trends in precipitation chemistry, soil and water acidification. Within this project NIVA is obliged to take samples, store data on to their database and produce reports. The NGU co-operates with NIVA by measuring water level. The observation points are 4 wells, situated in each groundwater region in porous media. Norwegian standards are used for sampling methodology. The chemical analyses are carried out by one private laboratory. Quality assurance procedures for the laboratory are determined. The laboratory has to use the EN 4500-Standard, data are checked for outliers and ionic balance control is conducted. This network has been in operation since 1980 and the average length of record is 15 years. Data are stored in a „RESA"-database, an application oriented data archive system, developed by „Egil Stoeren Programutvikling". Hardware used is based on a UNIX system running on IBM/PCs. Software tools are C or UNIX. Since 1980 computerised data have been available. The are laid down in floppy disks, paper sheets and reports. NIVA publishes data yearly, the data are for national and local environmental authorities only.

 
2.12.4. Structure of the Administrative Organisations Concerning Groundwater Quantity

In 1977 The Geological Survey of Norway (NGU) and the Norwegian Water Resources and Energy Administration (NVE) initiated a nation wide groundwater monitoring network named „Landsomfattende grunnvannsnet, LGN) to co-ordinate the groundwater data collection in Norway. This network was extended in 1980 by including four stations within or close to „calibrated" catchments, in order for the Norwegian Institute for Water Research (NIVA) to carry out (in co-operation with NGU) its responsibility for groundwater monitoring within the context of the Norwegian Monitoring Programme for Long-Range Transported Air Pollutants. This programme is a major, collaborative initiative co-ordinated by the State Pollution Control Authority (SFT) to describe and follow trends in precipitation chemistry, soil and water acidification. Within the LGN the NGU is responsible for the monitoring and reporting; apart from the four stations where NIVA is responsible. The extent of the monitoring is national. The reason for monitoring is basic data collection for use as reference data and for use in research, trend identification and public information. The Geological Survey of Norway (NGU) and the Norwegian Water Resources and Energy Administration (NVE) are both responsible for the monitoring and reporting. The monitoring does not comply with any international standards. However, internal procedures and database quality assurance routines maintain the demand of quality standard.

 
2.12.5. Monitoring of Groundwater Quantity

The „Landsomfattende Grunnvannsnet", LGN is a national groundwater monitoring network in Norway. The network has the goal to support basic groundwater quantity data for the management of water supply and research. Data collected should improve the knowledge on regional and periodical variations in the quality and quantity of the groundwater and whether these changes may be attributed to geological, topographical and climatic conditions. The programme is co-ordinated by the NGU. The NGU is also the reporting and chemical analysing organisation. It is assisted in its task by the NVE that is responsible for sampling, database management and co-reporting. In porous media 36 sampling sites, mostly driven wells, are distributed. They measure water level and water temperature 2-4 times a month. An internal manual for water level and temperature provide standardised methods of observation for the NVE-observateurs. The earliest record was taken in 1967, the average length of record is 15 years. Groundwater quantity data are stored in a SYBASE-database using SiliconGraphics, IRIX, and MS WINDOWS as operating system running on PCs. Software tools are C, C++, FORTRAN, Usoft Developer and Report Smith. Data are available on floppy disks. Internet, paper sheets and reports. The data are only available via NVE. A handling fee is charged dependent on the data amount and the degree of processing.

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