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> Home > Water and soil > Monitoring > Groundwater monitoring GRUMO

 Groundwater monitoring GRUMO

This website gives a presentation of the groundwater monitoring. There are links to reports which are based on results from data collected by the monitoring programme since 1989. The Danish Nature Agency is responsible for the practical execution of the programme, while GEUS serves as a professional database and is responsible for reporting


Lærke Thorling Sørensen 

Senior Adviser
Lærke Thorling Sørensen, CV
Phone: +45 2055 5260

State Geologist, Head of Department
Claus Kjøller, CV
Phone: +45 5172 82602

GRUMO-reports (in Danish)


Grundvandsovervågning 2016

Grundvandsovervågning 2015 

Nyt billede (28) - Kopi.jpg

Grundvandsovervågning 2014​​

Grundvandsovervågning 2013  

Grundvandsovervågning 2012  

Grundvandsovervågning 2011  

Grundvandsovervågning 2010  

Grundvandsovervågning 2009  

Grundvandsovervågning 2008  



Grundvandsovervågning 2004  

Grundvandsovervågning 2003  

Grundvandsovervågning 2002  

Grundvandsovervågning 2001  

Grundvandsovervågning 2000  

Grundvandsovervågning 1999  

Grundvandsovervågning 1999  

The National Groundwater Monitoring Programme, GRUMO, forms part of the national Danish water and nature monitoring programme: NOVANA.

In the current programme period, 2011-2015, the objective and monitoring design have been adapted to the groundwater monitoring requirements of the Water Framework Directive and the Groundwater Directive, and one of several changes is an increased focus on describing the quality of the groundwater that flows into the Danish freshwater bodies and wetlands.

The national monitoring programmes were originally initiated in pursuance of the adoption of the 1987 Water Action Plan and then had two main objectives: Firstly, to measure the impact of the water action plans and the general agriculture regulations relating to the nitrogen and phosphorus burden on the water environment. Secondly, and specifically in relation to groundwater monitoring, the objective was to monitor the development in the quality and quantity of the groundwater resource in general to ensure a good drinking water quality for Denmark's population in the future. Furthermore, the monitoring shall provide knowledge that may enable ongoing adjustment of the waterworks' well monitoring programme.

Monitoring of the groundwater shall ensure continuous accumulation of knowledge about the quality of the groundwater and its suitability for production of drinking water. Finally, the monitoring shall produce knowledge allowing us to assess to which degree the groundwater's quality causes contamination of watercourses and other surface waters, as the groundwater quality has a substantial influence on the water quality in water courses, among others.

The overall objective of the groundwater monitoring initiative is to
  • Produce the knowledge needed about the current status and developments in the quality and quantity of the groundwater and about the causes of any changes observed. This knowledge will be employed to ensure sufficient quantities of the needed quality of water in the future allowing us to cover both society's need for water supply and its need for water in the nature in order to maintain the desired environmental objectives.
  • Overall documentation of the impact of the water action plans and other relevant environmental regulation on the quality and quantity of the groundwater resource - including if the desired environmental objectives are met and if the development is on course.
  • Fulfil Denmark's obligations in pursuance of statutory EU provisions, international conventions and national law.
  • Contribute to strengthening the professional foundation for future international initiatives, national action plans, regional administration and other measures implemented to protect and exploit the groundwater resource, including to contribute to developing various tools and to build a stronger awareness of the link between groundwater and surface water.
  • Continuously disseminate information about the groundwater's quality and quantity, internationally as well as nationally.

Monitoring activities
Under the GRUMO initiative, the groundwater quality is monitored through monitoring of approx. 1,000 monitoring wells. The samples collected are tested for a wide range of substances including nitrate, pesticides, chloride, arsenic, organic pollution components, etc. The sampling frequency is greatest in wells affected by human activity.

In addition to the GRUMO monitoring, the groundwater is also monitored by the waterworks. The quality is monitored in the individual abstraction wells at regular intervals (normally 3-5 years) under the Waterworks' Well Monitoring Programme.

The quantity of the groundwater is monitored several times daily as part of The National Groundwater Level Monitoring Programme. Additionally, the waterworks, anyone abstracting water for irrigation purposes and other persons abstracting water for dedicated purposes shall report the annual abstracted water quantity to the joint public database of JUPITER.


Stationsnet for grundvandsovervågningen i Danmark i 1988-2012

Station net for groundwater monitoring in Denmark, 1988-2012

Since 1989, the status quo of the groundwater monitoring has been presented annually (except for 2006) by GEUS in a report that has been published in electronic form only since 2005.

In the left-hand column of this page, please find links to all reports that are available in electronic form.


Groundwater – nature - surface water
A development initiative has been set in motion that focuses on the interaction between groundwater, ecosystems in dry nature and surface water. In particular, there is a need for an improved method for the description and monitoring of how the conditions of these ecosystems are affected by the chemical composition of the groundwater and changes in the level of the groundwater table, including any periodically flooded areas.
GNOI (Danish acronym for Groundwater, nature and surface water interaction) is an element in the national monitoring programme for the 2011-2015 period, and its objective (according to the programme description) is to maintain and improve the ecological quality of some types of nature that depend on the groundwater quality and quantity, e.g. fens and bogs, through characterisation and monitoring, cf. the requirements of the Water Framework Directive and the Groundwater Directive. Thus, the GNOI shall form the basis for risk assessment and basic analysis, and it shall facilitate the introduction of strategic monitoring programmes in pursuance of the water action plans.

According to the Water Framework Directive, (EC 2000) and the Groundwater Directive (EC, 2006), the groundwater's chemical and quantitative condition shall be monitored both through control monitoring, which is to provide a representative description of the water's condition, and through more targeted operational monitoring initiated on the basis of risk assessment.

Thus, monitoring through characterisation and establishment of time series shall contribute to protecting both drinking water and ecosystems, and form the basis for establishment of threshold values for pollutants from diffuse sources if there is a risk that the impacts obstruct a good ecologic condition of any depending terrestrial ecosystems or the associated lotic ecosystems.

Furthermore, the groundwater's quantitative and qualitative status quo is of pivotal importance when it comes to ensuring a good condition of nature and a high level of preservation worthiness of the groundwater-dependent terrestrial nature types and aquaticlotic ecosystems, cf. the Habitats Directive and a good ecologic and chemical condition in accordance with the Water Framework Directive.

In 2013, the Danish Nature Agency (DNA) decided to launch a basic characterisation that is to characterise the interaction between groundwater, nature and surface water in the Urup Dam on the Danish island of Funen.

  The final GNOI-report (in Danish) is available here (6 MB).

Programme description and organisation of the groundwater monitoring
The Danish Ministry of the Environment is overall responsible for the groundwater monitoring initiative, GRUMO. The local units of the Danish Nature Agency handle the practical implementation of the programme.

The programme description for the groundwater monitoring initiative 2001-2015 appears from NOVANA part 1 and NOVANA part 2. Both in Danish!

GEUS serves as the professional data centre for groundwater and wells, which means that GEUS provides professional consulting on monitoring issues and, among others, prepares and maintains the technical guidelines. GEUS prepares the annual status report, which is available for download from this website.

  • The entire monitoring programme has its own website with the Danish Nature Agency. Please see HERE. (in Danish)
  • The full programme description for the total water and nature monitoring efforts is available at this LINK. (in Danish)


  • The GEUS contact person for groundwater monitoring is Senior Advisor Lærke Thorling, CV, Mail:, Phone: +45 2055 5260
  • The GEUS contact person for groundwater monitoring/pesticides is State Geologist and Head of Department Claus Kjøller, CV, Mail:, Phone: +45 5172 82602

Tecnical guidelines for groundwater monitoring
The objective of technical guidelines is to provide unequivocal instructions for the sampling, analysis, quality assurance and transfer of data. Technical guidelines are mandatory for all programme participants. The target group for the technical guidelines is the persons and institutions that will undertake the establishment, sampling, analysis, quality analysis and data transfer. Furthermore, the guidelines serve as technical documentation detailing the conditions under which groundwater monitoring is performed. The technical guidelines for groundwater sampling and groundwater level measurements are from 2012. The technical guidelines for the establishment of station nets require updating, as the old technical instruction from 2004 remains in use.

Furthermore, technical guidelines are prepared on data handling. The technical guideline on groundwater table data is from 2014, whereas the technical guidelines for chemical water analyses and well data have still to be completed. These will be published online as they are completed. Until further notice, please refer to the JUPITER website.

Techincal Guidelines in English


Techincal Guidelines in Danish

Inter-calibrating of field analyses
To ensure a homogeneous quality of the field work performed, the field analyses were inter-calibrated. All environmental centres participated in the inter-calibration, and the results were disseminated in the below report. The technical instructions will be amended to take into account the results from the inter-calibration at the next revision of the instructions.
Inter-calibrating of the 2007 groundwater sampling NOVANA_final.pdf (500Kb) (in Danish)

The amenability of groundwater monitoring wells for analysis
In 2001-02, a working group consisting of county representatives and GEUS prepared a practical assessment of all groundwater monitoring wells.

Renovation of monitoring wells in the County of Roskilde - age-determination of groundwater using the CFC method before and after.
As a follow-up on the above working report, the County of Roskilde, among others, initiated a more thorough investigation of any monitoring wells that are potentially leaking. The results from the study are available here:

Development in the monitoring of nitrate and the impact of the action plans under the Nitrate Directive.
A report on the monitoring of nitrate in drinking water and surface water in Northern Europe and the means employed to fulfil the requirements of the Nitrate Directive.

The EU Member States are obliged to monitor the content of nitrate in surface water and groundwater and the impact of their action plans/water action plans. The results of the monitoring shall be reported to the EU Commission. The results from an international workshop demonstrated that the countries have different interpretations of how the monitoring needs to be performed as no guidelines are in place to establish how the monitoring shall be implemented, either in the Directive or in any EU guidelines. Another conclusion was that the majority of the countries had increased their monitoring efforts on water quality in the course of the past 10-15 years. This increase is a result of discussions between the member states and the EU Commission to determine how the political regulations were to be established, including e.g. the policy coherence requirements. The member states aim to document the environmental impact of their chosen means by reporting the results of extra monitoring efforts. Another cause explaining that monitoring has been intensified is that the member states who have recently joined the EU have needed to align their monitoring systems to the relevant EU directives.

The Dutch monitoring institute, RIVM, organised this workshop in collaboration with the National Environmental Research Institute, Danish centre on energy (DCE), Aarhus University, and GEUS, both from Denmark, and the Institute for Social-economic Research, LEI, which forms part of the Wageningen University in 2009. Twelve countries from North-Western Europe and Central Europe participated in the second 'MonNO3' workshop. The focus was mainly on exchange of knowledge and facts on monitoring of the impact of the policy adopted in the various countries. An additional focus area was the use of monitoring data for other purposes apart from gaining knowledge about the status quo and trends for water quality, e.g. data that may support the choice between action programmes.


Professional assessment of groundwater wells and measurement wells and monitoring stations as part of the Agricultural Catchment Monitoring
Programme (LOOP) 2010 GEUS, in collaboration with the Danish Nature Agency, Danish Ministry of the Environment, have prepared a GEUS report that presents a professional assessment of groundwater wells and groundwater table measurement wells as part of the Agricultural Catchment Monitoring Programme (LOOP).


Further reading and relevant articles


In Denmark all tap water is groundwater.
For future consumers we monitor the effeciency of the protection measures

Udtagning af vandprøver Sampling of ground water
(Photo: Troels Laier)
Enlarged Photo

Udtagning af vandprøver

Sampling of ground water
(Photo: Troels Laier)
Enlarged photo

Udtagning af vandprøver Sampling of ground water
(Photo: Troels Laier)
Enlarged photo



Det nationale pejlenets 116 punkter Monitoring of ground water table.
From NOVANA-report 2011
Enlarged photo



LOOP 4: Lillebæk, Fyn

LOOP 4: Lillebæk, Fyn. The dens monitoring network in the agricultural catchment monitoring program.
From LOOP-report 2010
Enlarged photo


Overordnet definition af vandtyper

Definition of groundwater chemistry types.
From LOOP-report 2010
Enlarged photo


Urup Dam on Fyn is the first location designated by the Nature Agency where a characterisation of the interaction between groundwater, nature and surface has taken place.
See the report HERE!
(Photo: Bertel Nilsson)


Urup Dam is one of the few Danish habitats the rare yellow wipelip orchid (Liparis loeselii).
(Photo: Bente Fyrstenberg Nedergaard)












Groundwater monitoring GRUMO