Title; Table of Contents and Exec. Summary

Groundwater Monitoring in Europe Topic report 14/96 by C. Koreimann, J. Grath, G. Winkler, W. Nagy and W.R. Vogel European Topic Centre on Inland Waters October 1996 This report was prepared under the supervision of N. Thyssen, Project Manager, European Environment Agency

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This report provides an overview of the existing groundwater monitoring activities (quality and quantity) in 16 countries in the EEA area. The following topics are included: objectives of monitoring, name of monitoring programme, list of responsible organisations, spatial extent of network, determinands, sampling frequency, analytical methods, data storage and analysis and reporting procedures.

Based on an analysis of ongoing national and regional groundwater monitoring activities strategies are recommended for harmonising groundwater monitoring and establishing a monitoring network that provides comparable data within the European Environment Agency area.

Executive Summary

The aim of this report by the European Topic Centre on Inland Waters is to give an overview of the current groundwater quality and quantity networks and monitoring procedures within the European Environment Agency (EEA) area. The information for this overview was obtained through questionnaires distributed by the EEA’s National Focal Points in 17 of the 18 EEA member countries. (Liechtenstein was not included at this stage). All countries except Belgium and Luxembourg returned the questionnaires. Some countries were also able to include computerised information on monitoring station types in their returns. A detailed inventory of the information obtained has also been created. The following information and topics are included in this overview:

• name of monitoring programmes;

• monitoring objectives (why monitoring is undertaken);

• responsible and collaborating organisations (addresses, contact persons, responsibilities);

• extent of network (geographical coverage, number of regions and sampling sites etc.);

• groundwater regions (area, sampling frequency, etc.) (groundwater quality only);

• monitoring network characteristics;

• observed variables (dimension, frequency, analytical methods, etc.);

• temporal coverage of monitoring;

• data storage and management details;

• data availability (fees, restrictions, reporting organisations, etc.);

• quality control and assurance procedures;

• report of observation (organisation, persons, addresses);

• sampling site details.

From the information obtained it appears that monitoring of groundwater quality has been undertaken in most European countries since the 1970s and ‘80s. France appears to have the oldest network dating back to 1902. In contrast the monitoring of groundwater quantity has a longer tradition in Europe with the oldest networks being in operation since 1845, and most since the beginning of the 20th century.

Groundwater quality monitoring networks have developed as a result of national demands and the (hydro-)geological situation. As a result monitoring objectives vary a lot from country-to-country, though ‘general surveillance’ and ‘the identification of trends in quality’ are widespread goals all over the EEA area. In terms of quantity the respondents gave broadly similar objectives for monitoring activities such as for the collection of basic groundwater data, the management of groundwater resources and water supply, and in support of (hydro-)geological studies investigating, for example, the reasons for temporal and spatial changes in groundwater levels.

All the quality and quantity networks described in the questionnaires are national in extent with the exception of regional networks in the German Länder and France (quantity only). The majority of sampling sites are distributed evenly within the whole groundwater areas and aquifer types (e.g. porous media, karst, artesian and deep groundwater). However many sampling sites for quality are concentrated around drinking water wells. The total number of sampling sites, the total aquifer area and as a consequence the sampling site density varies a lot. These differences are often a result of differences in national objectives as well as differences in the (hydro-) geological situation and land use. Thus in quality networks sample site density ranges from 0.003 sites/km² to 0.57 sites/km², and in quantity networks 0.004 sites/km² to 7.3 sites/km².

Quantity networks comprise various types of observation points such as bored and dug wells, which are mostly used, but also driven wells and spring wells. The quantity variables observed are broadly the same; groundwater level (all countries), then groundwater temperature (nearly all) and also spring level and spring discharge. The frequency of measurement is, however, variable. For example, in the case of groundwater level nearly all countries have some continuous recording. More typically sampling frequency varies from weekly to two times a year. For groundwater temperature it varies from every 15 minutes to 2 times a month.

The number of measured water quality determinands varies from 15 to 106 between the monitoring networks. ‘Basic’ programmes often include between 14 and 51 determinands. The selected determinands appear to be adapted to national circumstances and at present cannot be readily compared at a European level. Not every determinand from a single sample is analysed by a single institution. However, the majority of countries have national standardised sampling and analytical methods as well as standardised regulations for precision and accuracy.

The information held in the inventory will be a very useful tool for further co-operation and development in the fields of water protection in the EEA area. For example, the information will be a key component in the implementation of the proposed groundwater monitoring network for the EEA area (as described in project MW3).

In addition to the report, the collected data from the questionnaires has been incorporated into a relational database. Tables are designed for comparing various aspects of data. Technical details of the database and the organisation of the tables are included in this report. An entity relationship diagram shows the relationships between the different tables. A hard copy of the database tables is also available from the ETC/IW. This report is included in the EEA’s Catalogue of Data Sources (CDS). The CDS is available to all National Focal Points and forms part of the EIONET. The CDS is also scheduled to be made more widely available (for example, to members of the public) through the World Wide Web during 1997.