Monitoring of groundwater at contaminated sites

Summary

Groundwater monitoring in the vicinity and downstream of polluted sites is important for two reasons: on the one hand, this medium is a preferred route for the transfer of pollutants, and on the other hand, recent European regulatory guidelines will lead to increased monitoring of groundwater as part of achieving the objectives set by the Water Framework Directive (WFD). This report is devoted to groundwater monitoring, in the specific context of monitoring prescribed by Arrêté Préfectoral (AP), when a diagnosis of a polluted site has been carried out and soil and/or groundwater pollution has been detected. The aim of this guide is to highlight the state of the art in terms of monitoring, to present the documents on which the person in charge of setting up and using such a network can rely, the regulations, etc. The first part describes the general practice of groundwater monitoring in France and provides a few reminders. Regulatory aspects, the implications of the WFD and new policy guidelines on polluted sites and soils are also covered. In addition, the ADES database (currently under development) and the hydrogeological contexts are presented. The focus then shifts to polluted sites, with a review of existing French technical documents and the approaches developed in Spain and the UK. Emerging monitoring methods (essentially sampling) are presented and recommendations for setting up a monitoring network are formulated, notably in the form of fact sheets (aide-memoire). Finally, feedback obtained in response to questionnaires sent to various players in the field (consultancies, industry, government departments) is presented.
Use of this work by the MEEDDM